JP7463157B2 - Thermochromic writing implements - Google Patents

Description

The present invention relates to a thermochromic writing instrument. More specifically, the present invention relates to a thermochromic writing instrument that contains a writing instrument ink that contains a reversible thermochromic microencapsulated pigment that encapsulates a reversible thermochromic composition that is black when colored and changes color to colorless when decolorized.

Conventionally, a thermochromic writing instrument containing a thermochromic ink composition (ink) containing a microencapsulated pigment encapsulating a reversible thermochromic composition has been known. Since handwriting formed using this writing instrument can be erased by heating, this writing instrument is widely used for a variety of purposes.
Generally, it is preferable that a writing instrument has a high writing density in order to improve the visibility of the writing, but in a thermochromic ink composition containing a microcapsule pigment, the reversible thermochromic composition, which is a coloring material, is encapsulated in a microcapsule, so that it tends to be difficult to obtain a high writing density compared to other writing instruments in which the coloring material is not encapsulated in a microcapsule. Therefore, studies have been conducted to improve the density of the writing formed by a thermochromic writing instrument (for example, see Patent Document 1).
Patent Document 1 discloses an ink composition for a writing instrument containing a microencapsulated pigment characterized by containing at least a specific leuco dye, a color developer, and a discoloration temperature regulator. The ink composition described above is capable of forming handwriting with excellent color development by using the specific leuco dye, but there is room for improvement in the handwriting density.
In order to improve the density of the handwriting, it is possible to increase the blending ratio of the microcapsule pigment in the ink or to increase the ink consumption of the writing instrument, but if the blending ratio of the microcapsule pigment or the ink consumption of the writing instrument is too high, the density of the handwriting increases, but the remaining color of the handwriting in the erased state tends to be easily visible, which impairs the practical use of the thermochromic writing instrument. Also, since a large amount of the microcapsule pigment accumulates on the paper surface, more heat is required to completely erase the handwriting, which increases the number of times it is rubbed, and this can easily cause strain on the hands.

JP 2014-5422 A

The present invention aims to provide a thermochromic writing instrument that has excellent writing density, in which the remaining color of the writing is difficult to see when it is in an erased state, provides good contrast between the colored and erased states of the writing, and allows writing to be easily erased or discolored.

The thermochromic writing instrument according to the present invention comprises:
(a) a fluoran derivative represented by formula (I) as an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that reversibly induces an electron donating/accepting reaction between the components (a) and (b) in a specific temperature range. A reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition therein.
A thermochromic writing instrument containing a writing instrument ink comprising a vehicle,
The reversible thermochromic microencapsulated pigment is blended in the range of 5 to 40% by mass in the total amount of the ink for the writing instrument, and the ink consumption of the thermochromic writing instrument when 50 m is written on writing paper A conforming to old JIS P3201 at 20°C is 60 to 280 mg, and the value C obtained by dividing the density value of the handwriting in a colored state by the density value of the handwriting in a decolorized state is 20 or more.
[Wherein,
n1 is 0, 1 or 2;
n2 is 0 or 1;
X's each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, or a group having 6 to 12 carbon atoms and represented by formula (i):
(Wherein,
ni is 0 or 1;
Ri is a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms.
and
provided that, when n2 is 0, one of the two X's is a group represented by formula (i), and the other is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, and the total number of carbon atoms of the two X's is 10 to 22, and when X's is a hydrogen atom, the number of carbon atoms represented by X's is 0;
When n2 is 1, both of X's are not hydrogen atoms,
Y's are each independently a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 3 carbon atoms, and Z's are each independently a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 3 carbon atoms.

The thermochromic writing instrument of the present invention can produce writing with excellent writing density, with little visible residual color in the erased state, and with excellent contrast between the colored state and the erased state, without increasing the blending ratio of the microcapsule pigment in the ink or the ink consumption of the writing instrument too much, and because the amount of accumulation of the microcapsule pigment in the writing on the writing surface is appropriately adjusted, the writing can be easily erased or discolored.

1 is a graph illustrating hysteresis characteristics in a color density-temperature curve of a heat-discolorable, reversible thermochromic composition. 1 is a graph illustrating the hysteresis characteristic in a color density-temperature curve of a heat-discolorable, reversible thermochromic composition having color memory properties. 1 is a graph illustrating the hysteresis characteristic in a color density-temperature curve of a reversible thermochromic composition that develops color upon heating.

The reversible thermochromic composition of the present invention includes a reversible thermochromic composition of a heat-discolorable type (discolored by heating and colored by cooling) that contains at least three essential components: (i) an electron-donating color-forming organic compound, (ii) an electron-accepting compound, and (iii) a reaction medium that determines the temperature at which the color-forming reaction of components (i) and (ii) occurs.
The reversible thermochromic composition may be a reversible thermochromic composition of the heat-discoloring type (discolored by heating and colored by cooling) having a relatively small hysteresis width (ΔH) (ΔH=1 to 7° C.), which is described in JP-B-51-44706, JP-B-51-44707, JP-B-1-29398, etc. and which changes color around a certain temperature (discoloration point), exhibits a discolored state in a temperature range above the high-temperature discoloration point, and a colored state in a temperature range below the low-temperature discoloration point, and of the two states, only one specific state exists in the room temperature range, and the other state is maintained while the heat or cold required to express that state is applied, but returns to the state exhibited in the room temperature range when the application of heat or cold is removed (see FIG. 1). (See FIG. 1.)

In addition, a reversible thermochromic composition of a heat-discoloring type (discolored by heating and colored by cooling) that exhibits a large hysteresis width (ΔH=8 to 70° C.) as described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, JP-A-2005-1369, etc., in which the shape of a curve plotting the change in color density due to temperature change follows a path that is significantly different when the temperature is increased from the lower side of the color change temperature range and when the temperature is decreased from the higher side of the color change temperature range, and in which the colored state in a temperature range below the complete color development temperature _t1 or the decolored state in a high temperature range above the complete decolorization temperature _t4 has color memory in a specific temperature range [a temperature range between the color development start temperature _t2 and the decolorization start temperature _t3 (a substantially two-phase retention temperature range)] can also be used. (See Figure 2).

Each of components (a), (b) and (c) will be specifically described below.
Component (A), that is, the electron-donating organic color-forming compound, is a component that determines the color and is a compound that develops color by donating electrons to component (B), which is a color developer.

The fluoran derivative used in the present invention is represented by the formula (I).
[Wherein,
n1 is 0, 1 or 2;
n2 is 0 or 1;
X's each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, or a group having 6 to 12 carbon atoms and represented by formula (i):
(Wherein,
ni is 0 or 1;
R ⁱ is a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms.
and
provided that when n2 is 0, one of the two X's is a group represented by formula (i) (preferably, ni is 0 or 1, and R ⁱ is a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms), the other is a hydrogen atom, or a linear or branched alkyl group having 1 to 10 carbon atoms, and the total carbon number of the two X's is 10 to 22, and when X's is a hydrogen atom, the carbon number represented by X is 0,
When n2 is 1, both of X are not hydrogen atoms, and preferably both of X are not hydrogen atoms;
Each Y is independently a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 3 carbon atoms, and each Z is a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 3 carbon atoms.

The fluoran derivative represented by formula (I) is preferably represented by formula (Ia) or formula (Ib) described below.

The fluoran derivative represented by formula (Ia) will now be described.
{wherein
n a is 0, 1 or 2;
^Xa each independently represents a linear or branched alkyl group having 1 to 8 carbon atoms, or a group having 6 to 12 carbon atoms and represented by formula (ia):
[Wherein,
nia is 0 or 1;
R ^ia is a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxyl group, a linear or branched alkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms), or a linear or branched alkoxy group having 1 to 5 carbon atoms (preferably 1 to 3 carbon atoms).
and
Y ^a is each independently a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z ^a is a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 3 carbon atoms.

The reversible thermochromic composition used in the present invention, which uses the fluoran derivative represented by formula (Ia), has a large difference in density between the colored state and the decolored state, i.e., has excellent contrast between the colored state and the decolored state. Furthermore, even if the temperature is repeatedly changed, the reversible thermochromic composition is unlikely to lose its reversible thermochromic function of being in a decolored state at temperatures above the high-temperature discoloration point (complete decolorization temperature) and in a colored state at temperatures below the low-temperature discoloration point (complete color development temperature), and the density of the colored state and the decolored state is unlikely to change even if it is used repeatedly.

With respect to ^Xa ,
Examples of the linear or branched alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group.
^Xa is preferably a linear or branched alkyl group having 2 to 6 carbon atoms, such as an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, or an n-hexyl group, since this tends to exhibit a high density in the color-developed state.

With respect to R ^ia in the group represented by formula (ia),
Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, and an n-hexyl group.
Examples of linear or branched alkoxy groups having 1 to 5 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, isopentoxy, and neopentoxy groups.
As R ^ia , a linear or branched alkyl group having 1 to 4 carbon atoms is preferred because it has excellent solubility.

With regard to Y ^a ,
Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.
With regard to Y ^a , in order to obtain an excellent contrast between the colored state and the colorless state, it is preferable that n a is 0 (i.e., unsubstituted), or n a is 1 and Y ^a is a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and it is more preferable that n a is 0 or n a is 1 and Y ^a is a halogen atom.

With respect to Z ^a ,
Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.
Examples of the linear or branched alkoxy group having 1 to 3 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group.
Z ^a is preferably a halogen atom, and more preferably a chlorine atom, since this tends to exhibit high density in the color-developed state.
The substitution position of Z ^a is not particularly limited, but the para position is preferred because it facilitates the development of a high color density.

In formula (Ia), X ^a is each independently a linear or branched alkyl group having 1 to 8 carbon atoms, or a group represented by formula (ia) having 6 to 12 carbon atoms, na is 0, 1, or 2, Y ^a is each independently a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z ^a is a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 3 carbon atoms. The reversible thermochromic composition of the present invention to which the fluoran derivative of the present invention is applied tends to exhibit a high concentration in the colored state, and tends to have a low residual color in the decolored state. Furthermore, when X ^a are mutually different functional groups, the reversible thermochromic composition tends to have a low residual color in the decolored state, which is preferable.
As for the fluoran derivatives represented by formula (Ia) in which ^Xa are different functional groups, it is preferred that one of ^Xa in formula (Ia) is a linear or branched alkyl group having 1 to 8 carbon atoms and the other is a group represented by formula (ia), it is more preferred that one of ^Xa is a linear or branched alkyl group having 1 to 8 carbon atoms and the other is a group represented by formula (ia) and is unsubstituted (nia is 0) or R ^ia is a linear or branched alkyl group having 1 to 4 carbon atoms, it is even more preferred that one of ^Xa is a linear or branched alkyl group having 2 to 6 carbon atoms and the other is a group represented by formula (ia) and R ^ia is a linear or branched alkyl group having 1 to 4 carbon atoms.
By using a fluoran derivative having the above structure, it becomes easier to obtain a reversibly thermochromic composition having excellent contrast between the colored state and the decolorized state and high practicality.

As the fluoran derivative represented by formula (Ia), a reversible thermochromic composition having an excellent contrast between the colored state and the decolorized state can be easily obtained, and therefore a fluoran derivative in which X ^a is each independently a linear or branched alkyl group having 1 to 8 carbon atoms, or a group represented by formula (ia), na is 0, 1 or 2, Y ^a is each independently a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z ^a is a halogen atom is preferred.
Further, in order to provide an excellent contrast between the colored state and the decolorized state and to easily reduce residual color in the decolorized state, a fluoran derivative in which, in formula (Ia), X ^a are each independently a linear or branched alkyl group having 1 to 8 carbon atoms, or a group represented by formula (ia), and X ^a are different functional groups from one another, na is 0, 1 or 2, Y ^a are each independently a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z a are a halogen atom is more preferable, and a fluoran derivative in which, in formula (Ia), one of X ^a is a linear or branched alkyl group having 1 to 8 carbon atoms, and the other is a group represented by formula (ia), na is 0, 1 or 2, Y a are each independently a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z ^a are a halogen atom is even more preferable, and a fluoran derivative in which, in formula (Ia), X a is a linear or branched alkyl group having 1 to 8 carbon atoms, and the other is a group represented by formula (ia), na is 0, 1 or 2, Y ^a are each independently a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z ^a are a halogen atom is even more preferable, Fluoran derivatives in which one of ^Xa is a linear or branched alkyl group having 1 to 8 carbon atoms and the other is a group represented by formula (ia) and is unsubstituted (nia is 0), or R ^ia is a linear or branched alkyl group having 1 to 4 carbon atoms, na is 0, 1 or 2, Y ^a are each independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z ^a are halogen atoms are even more preferred, and fluoran derivatives in which one of ^Xa is a linear or branched alkyl group having 2 to 6 carbon atoms and the other is a group represented by formula (ia), R ^ia is a linear or branched alkyl group having 1 to 4 carbon atoms, na is 0, 1 or 2, Y ^a are each independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z ^a are halogen atoms are particularly preferred.

The fluoran derivatives represented by formula (Ia) applicable to the present invention include, for example,
2-(4-fluoroanilino)-3-methyl-6-(N,N-diethylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N,N-di-n-butylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N,N-di-n-hexylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N,N-di-n-octylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N,N-diphenylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-n-butyl-N-ethylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-ethyl-N-n-hexylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-ethyl-N-n-octylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-ethyl-N-phenylamino)fluoran,
2-(3-fluoroanilino)-3-methyl-6-[N-(2-chlorophenyl)-N-ethylamino]fluoran,
2-(4-fluoroanilino)-3-methyl-6-[N-(4-bromophenyl)-N-ethylamino]fluoran,
2-(4-fluoroanilino)-3-methyl-6-[N-ethyl-N-(2-methoxyphenyl)amino]fluoran,
2-(2-fluoroanilino)-3-methyl-6-[N-ethyl-N-(4-ethoxyphenyl)amino]fluoran,
2-(3-fluoroanilino)-3-methyl-6-[N-ethyl-N-(4-isopropoxyphenylamino)]fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-ethyl-N-p-tolylamino)fluoran,
2-(3-fluoroanilino)-3-methyl-6-[N-ethyl-N-(4-ethylphenyl)amino]fluoran,
2-(4-fluoroanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-ethylamino]fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-n-butyl-N-n-heptylamino)fluoran,
2-(2-fluoroanilino)-3-methyl-6-(N-n-butyl-N-phenylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-[N-(2-bromophenyl)-N-n-butylamino]fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-n-butyl-N-p-tolylamino)fluoran,
2-(3-fluoroanilino)-3-methyl-6-(N-ethyl-N-n-hexylphenylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-n-hexyl-N-n-octylphenylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-phenyl-N-n-hexylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-n-hexyl-N-p-tolylamino)fluoran,
2-(2-fluoroanilino)-3-methyl-6-(N-tert-butyl-N-n-hexylphenylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-[N-(4-ethylphenyl)-N-n-octylamino]fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-n-octyl-N-n-propylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-n-heptyl-N-n-octylamino)fluoran,
2-(4-fluoroanilino)-3-methyl-6-(N-n-octyl-N-p-tolylamino)fluoran,
2-(3-fluoroanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-n-octylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-dimethylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-diethylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-n-propylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-diisopropylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-n-butylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-diisobutylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-sec-butylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-tert-butylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-n-pentylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-diisopentylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-dineopentylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-n-hexylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-n-heptylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-n-octylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-diphenylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-[N,N-di-(2-chlorophenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N,N-di-(4-bromophenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N,N-di-(2-methoxyphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N,N-di-(3-ethoxyphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N,N-di-(4-n-propoxyphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N,N-di-(4-isopropoxyphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-(N,N-di-p-tolylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-[N,N-di-(4-n-butylphenyl)amino]fluoran,
2-(3-chloroanilino)-3-methyl-6-(N-n-hexyl-N-methylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-n-butyl-N-ethylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-tert-butyl-N-ethyl-amino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-ethyl-N-n-hexylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-ethyl-N-n-octylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-ethyl-N-phenylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-chlorophenyl)-N-ethylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-bromophenyl)-N-ethylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-ethyl-N-(4-nitrophenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-ethyl-N-(4-methoxyphenyl)amino]fluoran,
2-(2-chloroanilino)-3-methyl-6-[N-(4-ethoxyphenyl)-N-ethylamino]fluoran,
2-(3-chloroanilino)-3-methyl-6-[N-ethyl-N-(4-n-propoxyphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-ethyl-N-(4-isopropoxyphenyl)amino]fluoran,
2-(2-chloroanilino)-3-methyl-6-(N-ethyl-N-p-tolylamino)fluoran,
2-(3-chloroanilino)-3-methyl-6-(N-ethyl-N-p-tolylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-ethyl-N-p-tolylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-ethyl-N-(4-ethylphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-ethyl-N-(4-n-propylphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-ethyl-N-(4-isopropylphenyl)amino]fluoran,
2-(3-chloroanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-ethylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-ethylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-ethyl-N-(4-isobutylphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-sec-butylphenyl)-N-ethylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-tert-butylphenyl)-N-ethylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-n-octyl-N-n-propylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-n-butyl-N-n-heptylamino)fluoran,
2-(2-chloroanilino)-3-methyl-6-(N-n-butyl-N-phenylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(2-bromophenyl)-N-n-butylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-n-butyl-N-(4-cyanophenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-n-butyl-N-p-tolylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-tert-butyl-N-n-pentylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-tert-butyl-N-n-hexylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-tert-butyl-N-heptylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-tert-butyl-N-n-octylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-chlorophenyl)-N-tert-butylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-tert-butyl-N-(4-carboxyphenyl)amino]fluoran,
2-(2-chloroanilino)-3-methyl-6-[N-tert-butyl-N-(2-n-propoxyphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-tert-butyl-N-p-tolylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-tert-butyl-N-(4-tert-butylphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-n-hexylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-n-hexyl-N-(4-n-octylphenyl)amino]fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-phenyl-N-n-hexylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-n-hexyl-N-p-tolylamino)fluoran,
2-(2-chloroanilino)-3-methyl-6-[N-(4-tert-butylphenyl)-N-n-hexylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-n-heptyl-N-n-octylamino)fluoran,
2-(2-chloroanilino)-3-methyl-6-[N-(3-bromophenyl)-N-n-octylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-hydroxyphenyl)-N-n-octylamino]fluoran,
2-(4-chloroanilino)-3-methyl-6-(N-n-octyl-N-p-tolylamino)fluoran,
2-(4-chloroanilino)-3-methyl-6-[N-(4-ethylphenyl)-N-n-octylamino]fluoran,
2-(3-chloroanilino)-3-methyl-6-[N-(4-n-butoxyphenyl)-N-n-octylamino]fluoran,
2-(4-methylanilino)-3-methyl-6-(N,N-diethylamino)fluoran,
2-(4-methylanilino)-3-methyl-6-(N,N-di-n-butylamino)fluoran,
2-(4-methylanilino)-3-methyl-6-(N,N-di-n-hexylamino)fluoran,
2-(4-methylanilino)-3-methyl-6-(N,N-di-n-octylamino)fluoran,
2-(4-methylanilino)-3-methyl-6-(N,N-diphenylamino)fluoran,
2-(4-methylanilino)-3-methyl-6-(N-n-butyl-N-ethylamino)fluoran,
2-(4-methylanilino)-3-methyl-6-(N-ethyl-N-n-hexylamino)fluoran,
2-(4-methylanilino)-3-methyl-6-(N-ethyl-N-n-octylamino)fluoran,
2-(4-methylanilino)-3-methyl-6-[N-ethyl-N-(4-ethylphenyl)amino]fluoran,
2-(4-methylanilino)-3-methyl-6-[N-(4-chlorophenyl)-N-ethylamino]fluoran,
2-(4-methylanilino)-3-methyl-6-[N-(4-bromophenyl)-N-ethylamino]fluoran,
2-(4-methylanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-ethylamino]fluoran,
2-(4-n-butylanilino)-3-methyl-6-(N,N-diethylamino)fluoran,
2-(4-n-butylanilino)-3-methyl-6-(N,N-di-n-butylamino)fluoran,
2-(4-n-butylanilino)-3-methyl-6-(N-n-butyl-N-ethylamino)fluoran,
2-(4-n-butylanilino)-3-methyl-6-(N-ethyl-N-n-hexylamino)fluoran,
2-(4-n-butylanilino)-3-methyl-6-(N-ethyl-N-n-octylamino)fluoran,
2-(4-n-butylanilino)-3-methyl-6-[N-ethyl-N-(4-ethylphenyl)amino]fluoran,
2-(4-n-butylanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-ethylamino]fluoran,
2-(4-methoxyanilino)-3-methyl-6-(N,N-diethylamino)fluoran,
2-(4-ethoxyanilino)-3-methyl-6-(N,N-di-n-butylamino)fluoran,
2-(4-ethoxyanilino)-3-methyl-6-(N-n-butyl-N-ethylamino)fluoran,
2-(4-ethoxyanilino)-3-methyl-6-(N-ethyl-N-n-hexylamino)fluoran,
2-(4-ethoxyanilino)-3-methyl-6-(N-ethyl-N-n-octylamino)fluoran,
2-(4-ethoxyanilino)-3-methyl-6-[N-ethyl-N-(4-ethylphenyl)amino]fluoran,
2-(4-ethoxyanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-ethylamino]fluoran,
6-methyl-2'-(4'-chloroanilino)-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-n-octylamino]fluoran,
7-methyl-2'-(4'-chloroanilino)-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-ethylamino]fluoran,
6-chloro-2'-(4'-chloroanilino)-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-ethylamino]fluoran,
7-chloro-2'-(4'-chloroanilino)-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-n-octylamino]fluoran,
6-ethoxy-2'-(4'-chloroanilino)-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-n-octylamino]fluoran,
7-ethoxy-2'-(4'-chloroanilino)-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-n-octylamino]fluoran,
6,7-dichloro-2'-(4'-chloroanilino)-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-n-octylamino]fluoran,
Examples include 6,7-dimethyl-2'-(4'-chloroanilino)-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-n-octylamino]fluoran.

The fluoran derivative represented by formula (Ib) will now be described.
(Wherein,
nb is 0, 1 or 2;
X ^b1 is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms;
X ^b2 is a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms;
However, the total number of carbon atoms of X ^b1 and X ^b2 is 4 to 16, and when X ^b1 or X ^b2 is a hydrogen atom, the number of carbon atoms represented by X ^b1 or X ^b2 is 0, and each Y ^b is independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.

The bright reversible thermochromic composition used in the present invention, which uses the fluoran derivative represented by formula (Ib), has a large difference in density between the colored state and the decolored state, i.e., has excellent contrast between the colored state and the decolored state. Furthermore, even if the temperature is repeatedly changed, the reversible thermochromic composition is unlikely to lose its reversible thermochromic function of being in a decolored state at temperatures above the high-temperature discoloration point (complete decolorization temperature) and in a colored state at temperatures below the low-temperature discoloration point (complete discoloration temperature), and the density of the colored state and the decolored state is unlikely to change even if it is used repeatedly.

With regard to X ^b1 ,
Examples of the linear or branched alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, and an n-decyl group.
X ^b1 is preferably a linear or branched alkyl group having 2 to 8 carbon atoms, such as an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, or an n-octyl group, since this tends to exhibit a high density in a color-developed state.

With regard to X ^b2 ,
Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, and an n-hexyl group.
Examples of linear or branched alkoxy groups having 1 to 5 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, isopentoxy, and neopentoxy groups.
X ^b2 is preferably a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, or an n-hexyl group, since this tends to exhibit a high density in a color-developed state.

With respect to ^Yb ,
Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.
With regard to ^Yb , in order to obtain an excellent contrast between the colored state and the colorless state, it is preferable that nb is 0 (i.e., unsubstituted), or that nb is 1 and ^Yb is a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and it is more preferable that nb is 0 or that nb is 1 and ^Yb is a halogen atom.

As the fluoran derivative represented by formula (Ib), since it becomes easy to obtain a reversible thermochromic composition having excellent contrast between the colored state and the decolorized state, X ^b1 is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, X ^b2 is a linear or branched alkyl group having 1 to 6 carbon atoms, the total number of carbon atoms of X ^b1 and X ^b2 is 4 to 16, nb is 0, 1 or 2, and Y ^b is each independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. Fluoran derivatives are preferred, and since the residual color in the decolorized state is likely to be low in the fluoran derivative of the above structure, the total number of carbon atoms of X ^b1 and X ^b2 is preferably 4 to 12, more preferably 5 to 11.
Further, a fluoran derivative in which X ^b1 is a linear or branched alkyl group having 1 to 10 carbon atoms, X ^b2 is a linear or branched alkyl group having 1 to 6 carbon atoms, the total carbon number of X ^b1 and X ^b2 is 4 to 16, nb is 0, 1 or 2, and Y ^b is each independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms is more preferable, and in the fluoran derivative of the above structure, the total carbon number of X ^b1 and X ^b2 is preferably 4 to 12, and more preferably 5 to 11.
Further, fluoran derivatives in which X ^b1 is a linear or branched alkyl group having 2 to 8 carbon atoms, X ^b2 is a linear or branched alkyl group having 1 to 4 carbon atoms, the total number of carbon atoms of X ^b1 and X ^b2 is 4 to 12, nb is 0, 1 or 2, and Y ^b is each independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms are more preferred, and in the fluoran derivatives of the above structure, the total number of carbon atoms of X ^b1 and X ^b2 is preferably 5 to 11, and more preferably 6 to 9.

As the fluoran derivative applicable to the present invention, a fluoran derivative represented by formula (Ib) in which X ^b1 is a linear or branched alkyl group having 2 to 8 carbon atoms, X ^b2 is a linear or branched alkyl group having 1 to 4 carbon atoms, the total carbon number of X ^b1 and X ^b2 is 6 to 9, nb is 0, 1 or 2, and Y ^b are each independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms is most preferably used.

The fluoran derivative represented by formula (Ib) applicable to the present invention includes, for example,
2-anilino-3-methyl-6-(N-n-butyl-N-phenylamino)fluoran,
2-anilino-3-methyl-6-(N-phenyl-N-n-hexylamino)fluoran,
2-anilino-3-methyl-6-(N-phenyl-N-n-octylamino)fluoran,
2-anilino-3-methyl-6-(N-n-decyl-N-phenylamino)fluoran,
2-anilino-3-methyl-6-(N-n-butyl-N-p-tolylamino)fluoran,
2-anilino-3-methyl-6-(N-n-hexyl-N-p-tolylamino)fluoran,
2-anilino-3-methyl-6-(N-n-octyl-N-p-tolylamino)fluoran,
2-anilino-3-methyl-6-(N-n-decyl-N-p-tolylamino)fluoran,
2-anilino-3-methyl-6-[N-ethyl-N-(4-ethylphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-(4-ethylphenyl)-N-n-butylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-ethylphenyl)-N-n-hexylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-ethylphenyl)-N-n-octylamino]fluoran,
2-anilino-3-methyl-6-[N-n-decyl-N-(4-ethylphenyl)amino]fluoran,
2-anilino-3-methyl-6-(4-n-butylphenylamino)fluoran,
2-anilino-3-methyl-6-(4-tert-butylphenylamino)fluoran,
2-anilino-3-methyl-6-[N-(4-n-butylphenyl)-N-ethylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-tert-butylphenyl)-N-ethylamino]fluoran,
2-anilino-3-methyl-6-[N-n-butyl-N-(4-n-butylphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-n-butyl-N-(4-tert-butylphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-(4-n-butylphenyl)-N-n-hexylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-tert-butylphenyl)-N-n-hexylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-n-butylphenyl)-N-n-octylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-tert-butylphenyl)-N-n-octylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-n-butylphenyl)-N-n-decylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-tert-butylphenyl)-N-n-decylamino]fluoran,
2-anilino-3-methyl-6-(4-n-hexylphenylamino)fluoran,
2-anilino-3-methyl-6-[N-ethyl-N-(4-n-hexylphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-n-butyl-N-(4-n-hexylphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-n-hexyl-N-(4-n-hexylphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-(4-n-hexylphenyl)-N-n-octylamino]fluoran,
2-anilino-3-methyl-6-[N-n-decyl-N-(4-n-hexylphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-n-butyl-N-(4-methoxyphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-n-hexyl-N-(4-methoxyphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-(4-methoxyphenyl)-N-octylamino]fluoran,
2-anilino-3-methyl-6-[N-n-decyl-N-(4-methoxyphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-ethyl-N-(4-ethoxyphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-n-butyl-N-(4-ethoxyphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-(4-ethoxyphenyl)-N-n-hexylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-ethoxyphenyl)-N-octylamino]fluoran,
2-anilino-3-methyl-6-[N-n-decyl-N-(4-ethoxyphenyl)amino]fluoran,
2-anilino-3-methyl-6-[N-ethyl-N-(4-isopropoxyphenyl)amino]fluoran,
2-anilino-3-methyl-6-(4-n-butoxyphenylamino)fluoran,
2-anilino-3-methyl-6-[N-(4-n-butoxyphenyl)-N-ethylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-n-butoxyphenyl)-N-n-butylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-n-butoxyphenyl)-N-n-hexylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-n-butoxyphenyl)-N-n-octylamino]fluoran,
2-anilino-3-methyl-6-[N-(4-n-butoxyphenyl)-N-n-decylamino]fluoran,
6-methyl-2'-anilino-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-ethylamino]fluoran,
7-methyl-2'-anilino-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-ethylamino]fluoran,
6-n-butyl-2'-anilino-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-ethylamino]fluoran,
7-n-butyl-2'-anilino-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-ethylamino]fluoran,
6-chloro-2'-anilino-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-ethylamino]fluoran,
7-chloro-2'-anilino-3'-methyl-6'-[N-(4'-n-butylphenyl)-N-ethylamino]fluoran,
6-methyl-2'-anilino-3'-methyl-6'-[N-n-butyl-N-(4'-n-hexylphenyl)amino]fluoran,
7-methyl-2'-anilino-3'-methyl-6'-[N-n-butyl-N-(4'-n-hexylphenyl)amino]fluoran,
6,7-dichloro-2'-anilino-3'-methyl-6'-[N-(4'-ethylphenyl)-N-n-octylamino]fluoran,
Examples include 6,7-dimethyl-2'-anilino-3'-methyl-6'-[N-(4'-ethylphenyl)-Nn-octylamino]fluoran.

Component (b), that is, an electron accepting compound, is a compound that accepts electrons from component (a) and functions as a developer for component (a).
Examples of the electron-accepting compound include compounds selected from a group of compounds having an active proton, a group of pseudo-acidic compounds (a group of compounds that are not acids but act as an acid in the reversible thermochromic composition to cause the component (A) to develop color), and a group of compounds having an electron vacancy, etc. Among the above-mentioned component (B), a compound selected from a group of compounds having an active proton is preferred.

Examples of compounds having an active proton include compounds having a phenolic hydroxyl group and derivatives thereof, carboxylic acids and derivatives thereof, acidic phosphate esters and derivatives thereof, azole compounds and derivatives thereof, 1,2,3-triazole and derivatives thereof, cyclic carbosulfimides, halohydrins having 2 to 5 carbon atoms, sulfonic acids and derivatives thereof, inorganic acids, etc. As carboxylic acids and derivatives thereof, aromatic carboxylic acids and derivatives thereof, or aliphatic carboxylic acids and derivatives thereof having 2 to 5 carbon atoms are preferred.

Examples of pseudo-acidic compounds include metal salts of compounds having a phenolic hydroxyl group, metal salts of carboxylic acids, metal salts of acidic phosphates, metal salts of sulfonic acids, aromatic carboxylic acid anhydrides, aliphatic carboxylic acid anhydrides, mixed anhydrides of aromatic carboxylic acids and sulfonic acids, cycloolefin dicarboxylic acid anhydrides, urea and its derivatives, thiourea and its derivatives, guanidine and its derivatives, halogenated alcohols, etc.

Compounds that have electron vacancies include borates, borate esters, inorganic salts, etc.

Among the above-mentioned (b) components, compounds having a phenolic hydroxyl group are preferred because they can more effectively express the thermochromic properties.

Compounds having a phenolic hydroxyl group include a wide range of compounds, from monophenol compounds to polyphenol compounds, and further include bisphenol compounds, trisphenol compounds, phenol-aldehyde condensation resins, etc. Compounds having a phenolic hydroxyl group preferably have at least two benzene rings. Compounds having a phenolic hydroxyl group may also have substituents such as alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, carboxyl groups and their esters or amide groups, halogen atoms, etc.

Examples of metals contained in metal salts of compounds having phenolic hydroxyl groups include sodium, potassium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum.

Examples of compounds of component (b) are given below.
Examples of the compound having one phenolic hydroxyl group include
Phenol,
o-cresol,
m-cresol,
p-cresol,
4-ethylphenol,
4-n-propylphenol,
4-n-butylphenol,
2-tert-butylphenol,
3-tert-butylphenol,
4-tert-butylphenol,
4-n-pentylphenol,
4-tert-pentylphenol,
4-n-octylphenol,
4-tert-octylphenol,
4-n-nonylphenol,
4-n-dodecylphenol,
3-n-pentadecylphenol,
4-n-stearylphenol,
1-(4-hydroxyphenyl)decan-1-one,
4-chlorophenol,
4-bromophenol,
4-trifluoromethylphenol,
4-methylthiophenol,
4-nitrophenol,
2-phenylphenol,
4-phenylphenol,
2-benzylphenol,
2-benzyl-4-chlorophenol,
4-cumylphenol,
4-hydroxybenzophenone,
4-chloro-4'-hydroxybenzophenone,
4-fluoro-4'-hydroxybenzophenone,
4-cyclohexylphenol,
2-hydroxybenzyl alcohol,
3-hydroxybenzyl alcohol,
4-hydroxybenzyl alcohol,
4-(2-hydroxyethyl)phenol,
3-methoxyphenol,
4-ethoxyphenol,
4-n-propoxyphenol,
4-n-butoxyphenol,
4-n-heptyloxyphenol,
4-(2-methoxyethyl)phenol,
α-naphthol,
β-naphthol,
2,3-dimethylphenol,
2,4-dimethylphenol,
2,6-dimethylphenol,
2,6-di-tert-butylphenol,
2,4-dichlorophenol,
2,4-difluorophenol,
Thymol,
3-methyl-4-methylthiophenol,
2-tert-butyl-5-methylphenol,
2,6-bis(hydroxymethyl)-4-methylphenol,
2,3,5-trimethylphenol,
2,6-bis(hydroxymethyl)-4-tert-octylphenol,
6-hydroxy-1,3-benzoxathiol-2-one,
2,4-bis(phenylsulfonyl)phenol,
2,4-bis(phenylsulfonyl)-5-methylphenol,
2,4-bis(4-methylphenylsulfonyl)phenol,
2-phenylphenol, 4-phenylphenol,
2,6-diphenylphenol,
3-benzylbiphenyl-2-ol,
3,5-dibenzylbiphenyl-4-ol,
4-cyano-4'-hydroxybiphenyl,
1-hydroxybenzotriazole,
1-hydroxy-5-methylbenzotriazole,
1-hydroxy-5-chlorobenzotriazole,
1-hydroxy-5-methoxybenzotriazole,
1-hydroxy-4-benzoylaminobenzotriazole,
1-hydroxy-4,5,6,7-tetrachlorobenzotriazole,
1,4-hydroxybenzotriazole,
1-hydroxy-5-nitrobenzotriazole,
1-hydroxy-5-phenylbenzotriazole,
1-hydroxy-5-benzylbenzotriazole,
1-hydroxy-5-ethylbenzotriazole,
1-hydroxy-5-n-octylbenzotriazole,
1-hydroxy-5-n-butylbenzotriazole,
n-Butyl 4-hydroxybenzoate,
n-Octyl 4-hydroxybenzoate,
2-heptadecafluorooctylethane 4-hydroxybenzoate,
benzyl 4-hydroxybenzoate,
4-hydroxybenzoic acid benzyl ester,
4-hydroxybenzoic acid-o-methylbenzyl
4-hydroxybenzoic acid-m-methylbenzyl
p-methylbenzyl 4-hydroxybenzoate,
p-ethylbenzyl 4-hydroxybenzoate,
p-propylbenzyl 4-hydroxybenzoate,
p-tert-butylbenzyl 4-hydroxybenzoate,
phenylethyl 4-hydroxybenzoate,
4-hydroxybenzoic acid-o-methylphenylethyl ester,
4-hydroxybenzoic acid-m-methylphenylethyl ester,
p-methylphenylethyl 4-hydroxybenzoate,
p-ethylphenylethyl 4-hydroxybenzoate,
p-propylphenylethyl 4-hydroxybenzoate,
An example thereof is p-tert-butylphenylethyl 4-hydroxybenzoate.

Examples of compounds having two phenolic hydroxyl groups include
Resorcinol,
2-methylresorcinol,
4-n-hexylresorcinol,
4-n-octylresorcinol,
4-tert-octylresorcinol,
4-benzoylresorcinol,
4-nitroresorcinol,
β-Methyl resorcylate,
β-benzyl resorcylate,
2-chloro-4-pentanoylresorcinol,
6-chloro-4-pentanoylresorcinol,
2-chloro-4-hexanoylresorcinol,
6-chloro-4-hexanoylresorcinol,
2-chloro-4-propanoylresorcinol,
6-chloro-4-propanoylresorcinol,
2,6-dichloro-4-propanoylresorcinol,
6-fluoro-4-propanoylresorcinol,
2-chloro-4-phenylacetylresorcinol,
6-chloro-4-phenylacetylresorcinol,
2-chloro-4-β-phenylpropanoylresorcinol,
6-chloro-4-β-phenylpropanoylresorcinol,
2-chloro-4-phenoxyacetylresorcinol,
6-chloro-4-phenoxyacetylresorcinol,
4-benzoyl-2-chlororesorcinol,
6-chloro-4-m-methylbenzoylresorcinol,
4-[1',3',4',9'a-tetrahydro-6'-hydroxyspiro(cyclohexane-1,9'-[9H]-xanthene)-4'a-[2H]-yl]-1,3-benzenediol,
Hydroquinone,
Methylhydroquinone,
Trimethylhydroquinone,
Catechol,
4-tert-butylcatechol,
1,6-dihydroxynaphthalene,
2,7-dihydroxynaphthalene,
1,5-dihydroxynaphthalene,
2,6-dihydroxynaphthalene,
2,4-dihydroxybenzophenone,
4,4'-dihydroxybenzophenone,
2,4-dihydroxy-2'-methylbenzophenone,
2,4-dihydroxy-3'-methylbenzophenone,
2,4-dihydroxy-4'-methylbenzophenone,
2,4-dihydroxy-4'-ethylbenzophenone,
2,4-dihydroxy-4'-n-propylbenzophenone,
2,4-dihydroxy-4'-isopropylbenzophenone,
2,4-dihydroxy-4'-n-butylbenzophenone,
2,4-dihydroxy-4'-isobutylbenzophenone,
2,4-dihydroxy-4'-tert-butylbenzophenone,
2,4-dihydroxy-4'-n-pentylbenzophenone,
2,4-dihydroxy-4'-n-hexylbenzophenone,
2,4-dihydroxy-4'-n-heptylbenzophenone,
2,4-dihydroxy-4'-n-octylbenzophenone,
2,4-dihydroxy-4'-n-decylbenzophenone,
2,4-dihydroxy-2',3'-dimethylbenzophenone,
2,4-dihydroxy-2',4'-dimethylbenzophenone,
2,4-dihydroxy-2',5'-dimethylbenzophenone,
2,4-dihydroxy-2',6'-dimethylbenzophenone,
2,4-dihydroxy-3',4'-dimethylbenzophenone,
2,4-dihydroxy-3',5'-dimethylbenzophenone,
2,4-dihydroxy-2',4',6'-trimethylbenzophenone,
2,4-dihydroxy-2'-methoxybenzophenone,
2,4-dihydroxy-3'-methoxybenzophenone,
2,4-dihydroxy-4'-methoxybenzophenone,
2,4-dihydroxy-2'-ethoxybenzophenone,
2,4-dihydroxy-4'-ethoxybenzophenone,
2,4-dihydroxy-4'-n-propoxybenzophenone,
2,4-dihydroxy-4'-isopropoxybenzophenone,
2,4-dihydroxy-4'-n-butoxybenzophenone,
2,4-dihydroxy-4'-isobutoxybenzophenone,
2,4-dihydroxy-4'-n-pentyloxybenzophenone,
2,4-dihydroxy-4'-n-hexyloxybenzophenone,
2,4-dihydroxy-4'-n-heptyloxybenzophenone,
2,4-dihydroxy-4'-n-octyloxybenzophenone,
2,4-dihydroxy-4'-n-nonyloxybenzophenone,
2,4-dihydroxy-2',3'-dimethoxybenzophenone,
2,4-dihydroxy-2',4'-dimethoxybenzophenone,
2,4-dihydroxy-2',5'-dimethoxybenzophenone,
2,4-dihydroxy-2',6'-dimethoxybenzophenone,
2,4-dihydroxy-3',4'-dimethoxybenzophenone,
2,4-dihydroxy-3',5'-dimethoxybenzophenone,
2,4-dihydroxy-3',4'-diethoxybenzophenone,
2,4-dihydroxy-2',3',4'-trimethoxybenzophenone,
2,4-dihydroxy-2',3',6'-trimethoxybenzophenone,
2,4-dihydroxy-3',4',5'-trimethoxybenzophenone,
Examples include 2,4-dihydroxy-3',4',5'-triethoxybenzophenone.

Further, examples of the bisphenol compound include
1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)propane,
1,1-bis(4-hydroxyphenyl)n-butane,
1,1-bis(4-hydroxyphenyl) n-pentane,
1,1-bis(4-hydroxyphenyl)n-hexane,
1,1-bis(4-hydroxyphenyl) n-heptane,
1,1-bis(4-hydroxyphenyl) n-octane,
1,1-bis(4-hydroxyphenyl)-n-nonane,
1,1-bis(4-hydroxyphenyl) n-decane,
1,1-bis(4-hydroxy-3-methylphenyl)decane,
1,1-bis(4-hydroxyphenyl)-n-dodecane,
1,1-bis(4-hydroxyphenyl)-2-methylpropane,
1,1-bis(4-hydroxyphenyl)-3-methylbutane,
1,1-bis(4-hydroxyphenyl)-3-methylpentane,
1,1-bis(4-hydroxyphenyl)-2,3-dimethylpentane,
1,1-bis(4-hydroxyphenyl)-2-ethylbutane,
1,1-bis(4-hydroxyphenyl)-2-ethylhexane,
1,1-bis(4-hydroxyphenyl)-3,7-dimethyloctane,
1,1-bis(4-hydroxyphenyl)cyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxy-3-methyl)cyclohexane,
Diphenolic acid,
1-phenyl-1,1-bis(4-hydroxyphenyl)methane,
2,2-bis(4-hydroxyphenyl)propane,
2,2-bis(4-hydroxyphenyl)n-butane,
2,2-bis(4-hydroxyphenyl)n-pentane,
2,2-bis(4-hydroxyphenyl)n-hexane,
2,2-bis(4-hydroxyphenyl) n-heptane,
2,2-bis(4-hydroxyphenyl) n-octane,
2,2-bis(4-hydroxyphenyl)n-nonane,
2,2-bis(4-hydroxyphenyl)n-decane,
2,2-bis(4-hydroxyphenyl)-n-dodecane,
2,2-bis(4-hydroxyphenyl)-6,10,14-trimethylpentadecane,
1-phenyl-1,1-bis(4-hydroxyphenyl)ethane,
2,2-bis(4-hydroxyphenyl)methylpropionate,
2,2-bis(4-hydroxyphenyl)butyl propionate,
2,2-bis(4-hydroxy-3-methylphenyl)methyl propionate,
2,2-bis(4-hydroxyphenyl)ethyl propionate,
2,2-bis(4-hydroxyphenyl)-4-methylpentane,
2,2-bis(4-hydroxyphenyl)-4-methylhexane,
2,2-bis(4-hydroxyphenyl)hexafluoropropane,
2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)hexafluoropropane,
2,2-bis(4-hydroxy-3-methylphenyl)propane,
2,2-bis(4-hydroxy-3-methylphenyl)butane,
2,2-bis(4-hydroxy-3-isopropylphenyl)propane,
2,2-bis(3-sec-butylphenyl-4-hydroxy)propane,
2,2-bis(4-hydroxy-3-phenylphenyl)propane,
2,2-bis(3-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(3-fluoro-4-hydroxyphenyl)propane,
2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)propane,
9,9-bis(4-hydroxy-3-methylphenyl)fluorene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
3,3-bis(4-hydroxyphenyl)oxindole,
3,3-bis(4-hydroxy-3-methylphenyl)oxindole,
bis(2-hydroxyphenyl)methane,
bis(2-hydroxy-5-methylphenyl)methane,
Bis(2-hydroxy-3-hydroxymethyl-5-methyl)methane,
4,4'-[1,4-phenylenebis(1-methylethylidene)]bis(2-methylphenol),
1,1-bis(4-hydroxy-3-phenylphenyl)cyclohexane,
3,3-ethyleneoxydiphenol,
1,4-bis(4-hydroxybenzoate)-3-methylbenzene,
4,4″-dihydroxy-3″-methyl-p-terphenyl,
4,4″-dihydroxy-3″-isopropyl-p-terphenyl,
2,2-dimethyl-1,3-bis(4-hydroxybenzoyloxy)propane,
2,2'-biphenol,
4,4'"-dihydroxy-p-quaterphenyl,
4,4-dihydroxydiphenyl ether,
bis(4-hydroxyphenylthioethyl)ether bis(4-hydroxyphenyl)sulfone,
4-benzyloxy-4'-hydroxydiphenyl sulfone,
4-(4-methylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(4-ethylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(4-n-propylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(4-isopropylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(4-n-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(4-isobutylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(4-sec-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(4-tert-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(3-methylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(3-ethylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(3-n-propylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(3-isopropylbenzyloxy)-4'-dihydroxyphenyl sulfone,
4-(3-n-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(3-isobutylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(3-sec-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(3-tert-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-methylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-ethylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-n-propylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-isopropylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-n-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-isobutylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-sec-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-tert-butylbenzyloxy)-4'-hydroxydiphenyl sulfone,
2,4'-dihydroxydiphenyl sulfone,
3,4'-dihydroxydiphenyl sulfone,
4-hydroxydiphenyl sulfone,
4-methyl-4'-hydroxyphenyl sulfone,
4-ethyl-4'-hydroxydiphenyl sulfone,
4-n-propyl-4'-hydroxydiphenyl sulfone,
4-isopropyl-4'-hydroxydiphenyl sulfone,
4-chloro-4'-hydroxydiphenyl sulfone,
4-fluoro-4'-hydroxydiphenyl sulfone,
4-chloro-2-methyl-4'-hydroxydiphenyl sulfone,
4-methoxy-4'-hydroxydiphenyl sulfone,
4-ethoxy-4'-hydroxydiphenyl sulfone,
4-n-propoxy-4'-hydroxydiphenyl sulfone,
4-isopropoxy-4'-hydroxydiphenyl sulfone,
4-n-butoxy-4'-hydroxydiphenyl sulfone,
4-isobutoxy-4'-hydroxydiphenyl sulfone,
4-sec-butoxy-4'-hydroxydiphenyl sulfone,
4-tert-butoxy-4'-hydroxydiphenyl sulfone,
4-n-pentyloxy-4'-hydroxydiphenyl sulfone,
4-isopentyloxy-4'-hydroxydiphenyl sulfone,
4-(1-propenyloxy)-4'-hydroxydiphenyl sulfone,
4-(2-propenyloxy)-4'-hydroxydiphenyl sulfone,
4-benzyloxy-4'-hydroxydiphenyl sulfone,
4-(β-phenoxyethoxy)-4'-hydroxydiphenyl sulfone,
4-(β-phenoxypropoxyl)-4'-hydroxydiphenyl sulfone,
bis(2-allyl-4-hydroxydiphenyl)sulfone,
bis[4-hydroxy-3-(2-propenyl)phenyl]sulfone,
bis(3,5-dibromo-4-hydroxyphenyl)sulfone,
bis(3,5-dichloro-4-hydroxyphenyl)sulfone,
bis(3-phenyl-4-hydroxyphenyl)sulfone,
bis(4-hydroxy-3-n-propylphenyl)sulfone,
bis(4-hydroxy-3-methylphenyl)sulfone,
3,4-dihydroxydiphenyl sulfone,
3',4'-dihydroxy-4-methyldiphenyl sulfone,
3,4,4'-trihydroxydiphenyl sulfone,
bis(3,4-dihydroxyphenyl)sulfone,
2,3,4-trihydroxydiphenyl sulfone,
4-isopropoxy-4'-hydroxydiphenyl sulfone,
4-n-propoxy-4'-hydroxydiphenyl sulfone,
4-allyloxy-4'-hydroxydiphenyl sulfone,
4-benzyloxy-4'-hydroxydiphenyl sulfone,
4-(2-propenyloxy)-4'-hydroxydiphenyl sulfone,
3-benzyl-4-benzyloxy-4'-hydroxydiphenyl sulfone,
3-phenethyl-4-phenethyloxy-4'-hydroxydiphenyl sulfone,
3-methylbenzyl-4-methylbenzyloxy-4'-hydroxydiphenyl sulfone,
4-benzyloxy-3'-benzyl-4'-hydroxydiphenyl sulfone,
4-phenethyloxy-3'-phenethyl-4'-hydroxydiphenyl sulfone,
4-methylbenzyloxy-3'-methylbenzyl-4'-hydroxydiphenyl sulfone,
α,α'-bis{4-(p-hydroxyphenylsulfone)phenoxy}-p-xylene,
4,4'-{oxybis(ethylene oxide-p-phenylene sulfonyl)}diphenol,
Bis(4-hydroxyphenyl)sulfide, bis(4-hydroxy-3-methylphenyl)sulfide,
Bis(3,5-dimethyl-4-hydroxyphenyl)sulfide,
bis(3-ethyl-4-hydroxyphenyl)sulfide,
Bis(3,5-diethyl-4-hydroxyphenyl)sulfide,
Bis(4-hydroxy-3-n-propylphenyl)sulfide,
Bis(3,5-di-n-propyl-4-hydroxyphenyl)sulfide,
Bis(3-tert-butyl-4-hydroxyphenyl)sulfide,
Bis(3,5-di-tert-butyl-4-hydroxyphenyl)sulfide,
Bis(4-hydroxy-3-n-pentylphenyl)sulfide,
Bis(3-n-hexyl-4-hydroxyphenyl)sulfide,
Bis(3-n-heptyl-4-hydroxyphenyl)sulfide,
Bis(5-tert-octyl-2-hydroxyphenyl)sulfide,
Bis(2-hydroxy-3-tert-octylphenyl)sulfide,
Bis(2-hydroxy-5-n-octyl-phenyl)sulfide,
bis(5-chloro-2-hydroxyphenyl)sulfide,
Bis(3-cyclohexyl-4-hydroxyphenyl)sulfide,
bis(4-hydroxyphenylthioethoxy)methane,
1,5-(4-hydroxyphenylthio)-3-oxypentane,
Examples include 1,8-bis(4-hydroxyphenylthio)-3,6-dioxaoctane.

Examples of compounds having three phenolic hydroxyl groups include pyrogallol, phloroglucinol, phloroglucinol carboxylic acid, gallic acid, octyl gallate, and dodecyl gallate.

Further examples of trisphenol compounds include:
4,4',4"-Methylidynetrisphenol,
4,4',4"-Methylidynetris(2-methylphenol),
4,4'-[(2-hydroxyphenyl)methylene]bis(2,3,5-trimethylphenol),
4,4'-[(4-hydroxyphenyl)methylene]bis(2-methylphenol),
4,4'-[(4-hydroxyphenyl)methylene]bis(2,6-dimethylphenol),
4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bisphenol,
4,4'-[(4-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
4,4',4"-ethylidynetrisphenol,
4,4',4"-ethylidynetris(2-methylphenol),
4,4'-[(2-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenol,
2,4-bis[(2-hydroxy-5-methylphenyl)methyl]-6-cyclohexylphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}methylidene]bisphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}propylidene]bisphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}butylidene]bisphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}pentylidene]bisphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}hexylidene]bisphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}heptylidene]bisphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}isobutylidene]bisphenol,
4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}neopentylidene]bisphenol,
2,2'-[1-{4-[1-(2-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol,
3,3'-[1-{4-[1-(3-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol,
4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-fluorophenol),
4,4'-[1-{4-[1-(3-chloro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-chlorophenol),
4,4'-[1-{4-[1-(3-bromo-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-bromophenol),
4,4'-[1-{4-[1-(4-hydroxy-3-methylphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-methylphenol),
4,4'-[1-{4-[1-(3-ethyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-ethylphenol),
4,4'-[1-{4-[1-(3-tert-butyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-tert-butylphenol),
4,4'-[1-{4-[1-(4-hydroxy-3-trifluoromethylphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-trifluoromethylphenol),
1,1-bis(4-hydroxyphenyl)-4-(4-hydroxy-α-ethyl)benzylcyclohexane,
4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bisphenol,
4,4'-[(3-hydroxyphenyl)methylene]bis(2,6-dimethylphenol),
2,2'-[(4-hydroxyphenyl)methylene]bis(3,5-dimethylphenol),
4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2,6-dimethylphenol),
2,2'-[(2-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
4,4'-[(3-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol),
4,4'-[(4-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol),
4,4'-[(3-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
4,4'-[(4-hydroxyphenyl-3-methoxy)methylene]bis(2-cyclohexyl-5-methylphenol),
1,1-bis(4-hydroxyphenyl)-4-hydroxyphenylcyclohexane,
4,4'-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-phenyl)propylidene]bis(2-cyclohexyl-5-methylphenol),
4,4'-[(2-hydroxyphenyl)methylene]bis(2-methylphenol),
2,4',4"-Methylidynetrisphenol,
4,4'-[(2-hydroxyphenyl)methylene]bis(3-methylphenol),
4,4'-[4-(4-hydroxyphenyl)-sec-butylidene]bis(4-hydroxyphenol),
2,2'-[(3-hydroxyphenyl)methylene]bis(3,5-dimethylphenol),
4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2,5-dimethylphenol),
4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2,6-dimethylphenol),
2,2'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(3,5-dimethylphenol),
2,2'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(3,5-dimethylphenol),
2,2'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(3,5-dimethylphenol),
4,4'-[(2-hydroxyphenyl)methylene]bis(2-isopropylphenol),
4,4'-[(3-hydroxyphenyl)methylene]bis(2-isopropylphenol),
4,4'-[(4-hydroxyphenyl)methylene]bis(2-isopropylphenol),
2,2'-[(3-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
2,2'-[(4-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
2,2'-[(4-3-ethoxy-4-hydroxyphenyl)methylene]bis(3,5-dimethylphenol),
1,1-bis(4-hydroxy-3-methylphenyl)-4-(4-hydroxyphenyl)cyclohexane,
4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2-isopropylphenol),
4,4'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(2-isopropylphenol),
4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2-isopropylphenol),
2,2'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol),
2,2'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol),
2,2'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol),
4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-isopropylphenol),
2,2'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol),
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)cyclohexane,
4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2-tert-butyl-5-methylphenol),
4,4'-[(2-hydroxyphenyl)methylene]bis(2-cyclohexylphenol),
4,4'-[(3-hydroxyphenyl)methylene]bis(2-cyclohexylphenol),
4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-tert-butyl-6-methylphenol),
4,4'-[(3-methoxy-2-hydroxyphenyl)methylene]bis(2-cyclohexylphenol),
4,4'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(2-cyclohexylphenol),
4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-tert-butylphenol),
4,4'-[1-{4-[1-(3,5-dimethyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2,6-dimethylphenol),
4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
4,4'-[(3-cyclohexyl-4-hydroxyphenyl)ethylidene]bis(2-cyclohexylphenol),
4,4'-[(5-cyclohexyl-4-hydroxy-2-methoxyphenyl)ethylidene]bis(2-cyclohexyl-5-methylphenol),
4,4'-[1-{4-[1-(3-cyclohexyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-cyclohexylphenol),
4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol,
4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-methylphenol),
4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2,6-dimethylphenol),
2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-methylphenol,
2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-methylphenol,
2,6-bis[(4-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(4-hydroxyphenyl)methyl]-4-ethylphenol,
2,4-bis[(4-hydroxy-3-methylphenyl)methyl]-6-methylphenol,
2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-methylphenol,
2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-ethylphenol,
2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-ethylphenol,
2,6-bis[(3,5-dimethyl-2-hydroxyphenyl)methyl]-4-methylphenol,
2,6-bis[(2,4-dimethyl-6-hydroxyphenyl)methyl]-4-methylphenol,
2,4-bis[(4-hydroxyphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-3,4-dimethylphenol,
2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol,
2,6-bis[(4-hydroxy-2,3,6-trimethylphenyl)methyl]-4-methylphenol,
2,4-bis[(4-hydroxy-3-methylphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-cyclohexylphenol,
2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-cyclohexylphenol,
2,6-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-4-ethylphenol,
2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol,
4,4',4"-Methylidynetris(2,6-dimethylphenol),
α-(4-hydroxy-3-methylphenyl)-α,α'-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α'-(4-hydroxy-3-methylphenyl)-α,α-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α,α-bis(4-hydroxy-3-methylphenyl)-α'-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α,α'-bis(4-hydroxy-3-methylphenyl)-α-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
1,1-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)-1-methylpropyl]cyclohexane,
2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol,
1,1'-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1,1'-bis(4-hydroxy-3-methylphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1,1'-bis(3,5-dimethyl-4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1-(4-hydroxyphenyl)-1-[4,4-bis(4-hydroxyphenyl)cyclohexyl]-4-isopropylcyclohexane,
4,4'-[3-(2,5-dimethyl-4-hydroxyphenyl)butylene]bis(2,5-dimethylphenol),
1,3,5-tri(4-hydroxy-3-phenylphenyl)adamantane,
1,3,5-tri(3-cyclohexyl-4-hydroxyphenyl)adamantane,
2,4-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-cyclohexylphenol,
2,4-bis[(3-cyclohexyl-4-hydroxyphenyl)methyl]-6-methylphenol,
2,4-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-fluorophenol,
2,6-bis[(3-fluoro-4-hydroxyphenyl)methyl]-4-fluorophenol,
2,4-bis[(3-fluoro-4-hydroxyphenyl)methyl]-6-methylphenol,
4,4'-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-biphenylpropylidene]bis(5-cyclohexyl-2-methylphenol),
4,4'-[3-(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropylidene]bis(2,5-dimethylphenol),
2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-methylphenol, 1,1,2-tris(4-hydroxyphenyl)ethane,
1,1,3-tris(4-hydroxyphenyl)propane, 1,1,4-tris(4-hydroxyphenyl)butane,
1,2,2-tris(4-hydroxyphenyl)propane, 1,2,2-tris(4-hydroxyphenyl)butane,
1,2,2-tris(4-hydroxyphenyl)pentane, 1,2,2-tris(4-hydroxyphenyl)hexane,
1,2,2-tris(4-hydroxyphenyl)heptane, 1,2,2-tris(4-hydroxyphenyl)octane,
1,2,2-tris(4-hydroxyphenyl)-3-methylbutane 1,2,2-tris(4-hydroxyphenyl)-3,3-dimethylbutane,
1,2,2-tris(4-hydroxyphenyl)-4,4-dimethylpentane, 1,3,3-tris(4-hydroxyphenyl)butane,
1,3,3-tris(4-hydroxyphenyl)pentane, 1,3,3-tris(4-hydroxyphenyl)hexane,
1,3,3-tris(4-hydroxyphenyl)heptane, 1,3,3-tris(4-hydroxyphenyl)octane,
1,3,3-tris(4-hydroxyphenyl)nonane, 1,4,4-tris(4-hydroxyphenyl)pentane,
1,4,4-tris(4-hydroxyphenyl)hexane, 1,4,4-tris(4-hydroxyphenyl)heptane,
1,4,4-tris(4-hydroxyphenyl)octane, 1,4,4-tris(4-hydroxyphenyl)nonane,
1,4,4-tris(4-hydroxyphenyl)decane, 1,2,2-tris(2-hydroxyphenyl)propane,
1,1,2-tris(3-hydroxyphenyl)propane,
1-(4-hydroxyphenyl)-2,2-bis(2-hydroxyphenyl)propane,
1,2,2-tris(3-fluoro-4-hydroxyphenyl)propane,
1,2,2-tris(3-chloro-4-hydroxyphenyl)propane,
1,2,2-tris(3-bromo-4-hydroxyphenyl)propane,
2,2-bis(3-ethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(3-tert-butyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(2-hydroxy-3-biphenylyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(3-trifluoromethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2-(3-methyl-4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)propane,
1-(3-methyl-4-hydroxyphenyl)-2,2-bis(4-hydroxyphenyl)propane,
3-(3-methyl-4-hydroxyphenyl)-1,3-bis(4-hydroxyphenyl)butane,
1-(3-methyl-4-hydroxyphenyl)-3,3-bis(4-hydroxyphenyl)butane,
4-(3-methyl-4-hydroxyphenyl)-1,4-bis(4-hydroxyphenyl)pentane,
1-(3-methyl-4-hydroxyphenyl)-4,4-bis(4-hydroxyphenyl)pentane,
1,2-bis(3-methyl-4-hydroxyphenyl)-2-(4-hydroxyphenyl)propane,
3,3-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)butane,
1,3-bis(3-methyl-4-hydroxyphenyl)-3-(4-hydroxyphenyl)butane,
4,4-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)pentane,
1,4-bis(3-methyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)pentane,
1,1,2-tris(3-methyl-4-hydroxyphenyl)ethane,
1,2,2-tris(3-methyl-4-hydroxyphenyl)propane,
1,1,3-tris(3-methyl-4-hydroxyphenyl)propane,
1,3,3-tris(3-methyl-4-hydroxyphenyl)butane,
1,1,4-tris(3-methyl-4-hydroxyphenyl)butane,
1,4,4-tris(3-methyl-4-hydroxyphenyl)pentane,
4,4'-[4-(4-hydroxyphenyl)-sec-butylidene]bis(2-methylphenol)
Examples include:

Examples of compounds having four or more phenolic hydroxyl groups include
Bis[2-hydroxy-3-(2-hydroxy-5-methylbenzyl)-5-methylphenyl]methane,
4,6-bis[(4-hydroxyphenyl)methyl]-1,3-benzenediol,
4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2,6-dimethylphenol),
4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol),
4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-methylphenol),
4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2,3,6-trimethylphenol),
1,1,2,2-tetrakis(4-hydroxyphenyl)ethane,
1,1,2,2-tetrakis(4-hydroxy-3-methylphenyl)ethane,
1,1,2,2-tetrakis(3,5-dimethyl-4-hydroxyphenyl)ethane,
α,α',4α",α'"-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,4-dimethylbenzene,
2,2'-bis[4,4-bis(4-hydroxy-3-methylphenyl)cyclohexyl]propane,
2,2'-[(3,4-dihydroxyphenyl)methylene]bis(3,5-dimethylphenol),
3,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]catechol,
4,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-1,3-benzenediol,
2,2'-[(3,4-dihydroxyphenyl)methylene]bis(3,5,6-trimethylphenol),
4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexylphenol),
bis[3-(2-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(3-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
Bis[3-(2-hydroxybenzyl)-3-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
Bis[3-(3-hydroxy-2-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
Bis[3-(4-hydroxy-3-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
Bis[3-(3-hydroxy-4-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
Bis[3-(2-hydroxy-3-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
α,α',α",α'"-tetrakis(4-hydroxyphenyl)-1,4-dimethylbenzene,
Bis[3-(3,6-dimethyl-2-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
[3-(3,6-dimethyl-2-hydroxybenzyl)-2-hydroxy-5-methylphenyl],
[3-(2,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
Bis[3-(2,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
Bis[3-(3,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
Bis[3-(2-hydroxy-3,4,6-trimethylbenzyl)-2-hydroxy-5-methylphenyl]methane,
Bis[2-hydroxy-3-(4-hydroxy-2,3,5-trimethylbenzyl)-5-methylphenyl]methane,
4,4',4",4'"-tetrakis(4-hydroxyphenyl)-1,1'-bicyclohexyl,
2,2'-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane,
4,4',4",4'"-tetrakis(4-hydroxy-3-methylphenyl)-1,1'-bicyclohexyl,
Bis[3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)-4-hydroxy-5-methylphenyl]methane,
4,4',4",4'"-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,1'-bicyclohexyl,
1,1-bis[3-(2-hydroxy-5-methylbenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[3-(3,5-dimethyl-4-hydroxybenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
4,6-bis[α-methyl-(4-hydroxyphenyl)benzyl-1,3-benzenediol,
2,2-bis[3-(4-hydroxy-3-methylbenzyl)-4-hydroxy-5-methylphenyl]propane,
2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)benzyl]-4-[α-methyl-(3,5-dimethyl-4-hydroxyphenyl)benzyl]phenol,
4,4',4",4'"-tetrakis(4-hydroxy-3-isopropylphenyl)-1,1'-bicyclohexyl,
4,4'-bis[(3,4-dihydroxyphenyl)methylene]bis(2-isopropylphenol),
2,4,6-tris(4-hydroxybenzyl)-1,3-benzenediol,
4,6-bis(3,5-dimethyl-4-hydroxybenzyl)pyrogallol,
3,3'-[(2-hydroxyphenyl)methylene]bis(5-methylcatechol),
2,6-bis(2,4-dihydroxybenzyl)-4-ethylphenol,
2,4-bis(2,4-dihydroxybenzyl)-6-cyclohexylphenol,
2,6-bis(5-tert-butyl-2,3-dihydroxybenzyl)-4-methylphenol,
2,4,6-tris(3,5-dimethyl-4-hydroxybenzyl)resorcinol,
2,4,6-tris(3,5-dimethyl-2-hydroxybenzyl)resorcinol,
2,6-bis(2,4-dihydroxybenzyl)-3,4-dimethylphenol,
2,6-bis[3-(2-hydroxy-5-methylbenzyl)-2,5-dimethyl-4-hydroxybenzyl]-3,4-dimethylphenol,
4,6-bis(α-methyl-4-hydroxybenzyl)pyrogallol,
4,4'-[1-{4-[1-(3,5-bis(4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxybenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-3-methylbenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3,5-dimethyl-4-hydroxybenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,6-trimethylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2,3,6-trimethylbenzyl)phenol],
Bis[5-(2,4-dihydroxybenzyl)-4-hydroxy-3-methylphenyl]methane, bis[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane,
Bis[3-(2,4-dihydroxy-3-methylbenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane,
Bis[5-(4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane,
1,1-bis[5-(4-hydroxybenzoyl)-2,3,4-trihydroxyphenyl]ethane,
3,3',5,5'-tetrakis(4-hydroxybenzyl)-4,4'-dihydroxybiphenyl,
3,3',5,5'-tetrakis(4-hydroxy-3-methylbenzyl)-4,4'-dihydroxybiphenyl,
3,3',5,5'-tetrakis(2-hydroxy-5-methylbenzyl)-4,4'-dihydroxybiphenyl,
3,3',5,5'-tetrakis(3,5-dimethyl-4-hydroxybenzyl)-4,4'-dihydroxybiphenyl,
Bis[3-(α,α-bis(4-hydroxy-3-methylphenyl)methyl-4-hydroxyphenyl]methane,
Bis[3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane,
4,4',4"-ethylidynetris{[2-(2-hydroxy-5-methyl)benzyl]-6-methylphenol},
2,2-bis[3,5-bis(2-hydroxy-5-methylphenylmethyl)phenyl]propane,
Bis[3-(α,α-bis(2,5-dimethyl-4-hydroxyphenyl)methyl-4-hydroxyphenyl]methane,
Bis[5-(3,5-dimethyl-4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane,
Bis[3-(2,3,4-trihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane,
1,1-bis[3-(2,3,4-trihydroxybenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,8,15,22-tetranonyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane,
4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2-methylbenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(2-hydroxy-5-methylbenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3-ethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-ethyl-4-hydroxybenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3,5-dimethyl-2-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3,5-dimethyl-2-hydroxyphenyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-3-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-3-isopropylphenyl)phenol],
Bis[3-(α,α-bis(3,5-dimethyl-4-hydroxyphenyl)methyl-4-hydroxyphenyl]methane,
Bis[3-(α,α-bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)methyl-4-hydroxyphenyl]methane,
4,4'-[4-hydroxy-3,5-bis(2-hydroxybenzyl)methylene]bis[2,6-bis(2-hydroxybenzyl)]phenol,
4,4'-[4-hydroxy-3,5-bis(4-hydroxybenzyl)methylene]bis[2,6-bis(4-hydroxybenzyl)]phenol,
4,4',4"-ethylidynetris[2,6-bis(2-hydroxybenzyl)phenol],
4,4',4"-ethylidynetris[2,6-bis(4-hydroxybenzyl)phenol],
2,2-bis[3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl]propane,
1,8,15,22-tetraethyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane,
α,α',α",α'"-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,4-dimethylbenzene,
4,4'-[1-{4-[1-(3,5-bis(2-hydroxy-5-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(2-hydroxy-5-isopropylphenyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,5-trimethylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2,3,5-trimethylphenyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3-sec-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-sec-butyl-4-hydroxyphenyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3-tert-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-tert-butyl-4-hydroxyphenyl)phenol],
2,6-bis{[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxy]benzyl}-4-methylphenol,
1,1-bis[5-(2,4-dihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[5-(2,3,4-trihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane,
Examples include 2,2-bis[4,4',4'',4''-tetrakis(3,5-dihydroxymethyl-4-hydroxyphenyl)cyclohexyl]propane.

Examples of carboxylic acids and their derivatives include:
3,5-di(α-methylbenzyl)salicylic acid,
4-(2-p-methoxyphenyloxyethoxy)salicylic acid,
4-hydroxyphenylbenzoic acid,
4-chlorobenzoic acid,
4-[2-(p-methoxyphenoxy)ethyloxy]salicylic acid,
4-[3-(p-tolylsulfonyl)propyloxy]salicylic acid,
5-[p-(2-p-methoxyphenoxyethoxy)cumyl]salicylic acid,
4-octyloxycarbonylaminosalicylic acid,
3,5-distyrenated salicylic acid,
N-(p-toluenesulfonyl)-glycine,
N-(p-toluenesulfonyl)-alanine,
N-(p-toluenesulfonyl)-β-alanine,
N-phenylaminocarbonyl-glycine,
N-phenylaminocarbonyl-valine,
N-(m-tolylaminocarbonyl)-phenylalanine,
N-(m-tolylaminocarbonyl)-cysteine-S-benzyl,
N-(m-tolylaminocarbonyl)-methionine,
N-(m-tolylaminocarbonyl)-tyrosine,
N-(p-tolylaminocarbonyl)-phenylalanine,
N-(p-tolylaminocarbonyl)-cysteine-S-benzyl,
N-(p-tolylaminocarbonyl)-methionine,
N-(p-tolylaminocarbonyl)-methionine,
N-(phenylaminocarbonyl)-methionine,
N-(p-tolylaminocarbonyl)-tyrosine,
2-O-(phenylaminocarbonyl)-mandelic acid,
2-O-(p-tolylaminocarbonyl)-mandelic acid,
2-O-(m-tolylaminocarbonyl)-mandelic acid,
2-O-(o-tolylaminocarbonyl)-mandelic acid,
2-O-(1-naphthylaminocarbonyl)-mandelic acid,
2-O-(3-isopropenyl-α,α-dimethylbenzylaminocarbonyl)-mandelic acid,
2-O-(benzylaminocarbonyl)-mandelic acid,
2-O-(phenethylaminocarbonyl)-mandelic acid,
2-O-(phenylaminocarbonyl)-lactic acid,
2-O-(p-tolylaminocarbonyl)-lactic acid,
2-O-(m-tolylaminocarbonyl)-lactic acid,
2-O-(o-tolylaminocarbonyl)-lactic acid,
2-O-(1-naphthylaminocarbonyl)-lactic acid,
2-O-(3-isopropenyl-α,α-dimethylbenzylaminocarbonyl)-lactic acid,
2-O-(benzylaminocarbonyl)-lactic acid,
An example is 2-O-(phenethylaminocarbonyl)-lactic acid.

Examples of acidic phosphate ester compounds include methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, isodecyl acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, monobutyl phosphate, dibutyl phosphate, monoisodecyl phosphate, bis(2-ethylhexyl)phosphate, etc.

As the component (b), a compound having a phenolic hydroxyl group is preferable because it can more effectively express the thermal discoloration property, but it may also be a compound selected from aromatic carboxylic acids, aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and their metal salts, or 1,2,3-triazole and its derivatives.

The above-mentioned electron-accepting compound can be applied not only to the reversible thermochromic composition of the present invention in which a fluoran derivative having a specific structure is used as an electron-donating color-forming organic compound, but also to a reversible thermochromic composition in which a conventionally known electron-donating color-forming organic compound such as a phthalide compound, a fluoran compound, a styrinquinoline compound, a diazarhodamine lactone compound, a pyridine compound, a quinazoline compound, or a bisquinazoline compound is used.
Examples of the phthalide compound include a diphenylmethane phthalide compound, a phenylindolyl phthalide compound, an indolyl phthalide compound, a diphenylmethane azaphthalide compound, a phenylindolyl azaphthalide compound, and derivatives thereof.
Among the above phthalide compounds, phenylindolyl azaphthalide compounds and derivatives thereof are preferred.
In addition, the fluoran compound may include an aminofluoran compound, an alkoxyfluoran compound, and derivatives thereof.

Examples of conventionally known electron donating organic color formers include:
3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide,
3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide,
3,3-bis(1-n-butyl-2-methylindol-3-yl)phthalide,
3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide,
3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-(2-n-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-[2-ethoxy-4-(N-ethylanilino)phenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-(2-acetamido-4-diethylaminophenyl)-3-(1-propylindol-3-yl)-4-azaphthalide,
3,6-bis(diphenylamino)fluoran,
3,6-dimethoxyfluoran,
3,6-di-n-butoxyfluoran,
2-methyl-6-(N-ethyl-N-p-tolylamino)fluoran,
3-chloro-6-cyclohexylaminofluoran,
2-methyl-6-cyclohexylaminofluoran,
2-(2-chloroamino)-6-dibutylaminofluoran,
2-(2-chloroanilino)-6-di-n-butylaminofluoran,
2-(3-trifluoromethylanilino)-6-diethylaminofluoran,
2-(3-trifluoromethylanilino)-6-dipentylaminofluoran,
2-dibenzylamino-6-diethylaminofluoran,
2-N-methylanilino-6-(N-ethyl-N-p-tolylamino)fluoran,
1,3-dimethyl-6-diethylaminofluoran,
2-chloro-3-methyl-6-diethylaminofluoran,
2-anilino-3-methyl-6-diethylaminofluoran,
2-anilino-3-methoxy-6-diethylaminofluoran,
2-anilino-3-methyl-6-di-n-butylaminofluoran,
2-anilino-3-methoxy-6-di-n-butylaminofluoran,
2-xylidino-3-methyl-6-diethylaminofluoran,
2-anilino-3-methyl-6-(N-ethyl-N-p-tolylamino)fluoran,
1,2-Benz-6-diethylaminofluoran,
1,2-Benz-6-(N-ethyl-N-isobutylamino)fluoran,
1,2-Benz-6-(N-ethyl-N-isoamylamino)fluoran,
2-(3-methoxy-4-dodecoxystyryl)quinoline,
2-diethylamino-8-diethylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1'(3'H)isobenzofuran]-3'-one,
2-di-n-butylamino-8-di-n-butylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one,
2-di-n-butylamino-8-diethylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1'(3'H)isobenzofuran]-3'-one,
2-di-n-butylamino-8-(N-ethyl-N-i-amylamino)-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1'(3'H)isobenzofuran]-3'-one,
2-di-n-butylamino-8-di-n-pentylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1'(3'H)isobenzofuran]-3'-one,
4,5,6,7-tetrachloro-3-(4-dimethylamino-2-methoxyphenyl)-3-(1-butyl-2-methyl-1H-indol-3-yl)-1(3H)-isobenzofuranone,
4,5,6,7-tetrachloro-3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methyl-1H-indol-3-yl)-1(3H)-isobenzofuranone,
4,5,6,7-tetrachloro-3-(4-diethylamino-2-ethoxyphenyl)-3-(1-n-pentyl-2-methyl-1H-indol-3-yl)-1(3H)-isobenzofuranone,
4,5,6,7-tetrachloro-3-(4-diethylamino-2-methylphenyl)-3-(1-ethyl-2-methyl-1H-indol-3-yl)-1(3H)-isobenzofuranone,
3',6'-bis[phenyl(2-methylphenyl)amino]-spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one,
3',6'-bis[phenyl(3-methylphenyl)amino]-spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one,
3',6'-bis[phenyl(3-ethylphenyl)amino]-spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one,
2,6-bis(2'-ethyloxyphenyl)-4-(4'-dimethylaminophenyl)pyridine,
2,6-bis(2',4'-diethyloxyphenyl)-4-(4'-dimethylaminophenyl)pyridine,
2-(4'-dimethylaminophenyl)-4-methoxyquinazoline,
4,4'-Ethylenedioxy-bis[2-(4-diethylaminophenyl)quinazoline]
Examples include:
In addition, the fluorans may be compounds having a substituent on the phenyl group forming the xanthene ring, or may be compounds having a substituent on the phenyl group forming the xanthene ring and also having a substituent (e.g., an alkyl group such as a methyl group, or a halogen atom such as a chlorine atom) on the phenyl group forming the lactone ring, which exhibit a blue or black color.

The component (c) of the reaction medium that reversibly induces an electron donor-acceptor reaction between the components (a) and (b) in a specific temperature range will now be described.
Examples of the component (c) include alcohols, esters, ketones, ethers, and acid amides.
When the reversible thermochromic composition of the present invention is applied to microencapsulation and secondary processing, compounds having 10 or more carbon atoms are preferably used in order to stably retain the composition in the capsule, since low molecular weight compounds will evaporate out of the capsule when subjected to high heat treatment.

As alcohols, aliphatic monohydric saturated alcohols having 10 or more carbon atoms are effective, such as decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, heptadecyl alcohol, octadecyl alcohol, eicosyl alcohol, and docosyl alcohol.

As esters, esters having 10 or more carbon atoms are effective, and examples thereof include esters obtained from any combination of a monovalent carboxylic acid having an aliphatic, alicyclic or aromatic ring and a monovalent alcohol having an aliphatic, alicyclic or aromatic ring, esters obtained from any combination of a polyvalent carboxylic acid having an aliphatic, alicyclic or aromatic ring and a monovalent alcohol having an aliphatic, alicyclic or aromatic ring, esters obtained from any combination of a monovalent carboxylic acid having an aliphatic, alicyclic or aromatic ring and a monovalent alcohol having an aliphatic, alicyclic or aromatic ring, and any combination of a monovalent carboxylic acid having an aliphatic, alicyclic or aromatic ring and a polyvalent alcohol having an aliphatic, alicyclic or aromatic ring. Examples of the esters include esters obtained by combining ethyl caprylate, octyl caprylate, stearyl caprylate, myristyl caprate, docosyl caprate, 2-ethylhexyl laurate, n-decyl laurate, 3-methylbutyl myristate, cetyl myristate, isopropyl palmitate, neopentyl palmitate, nonyl palmitate, cyclohexyl palmitate, n-butyl stearate, 2-methylbutyl stearate, 3,5,5-trimethylhexyl stearate, and stearic acid. n-Undecyl stearate, pentadecyl stearate, stearyl stearate, cyclohexylmethyl stearate, isopropyl behenate, hexyl behenate, lauryl behenate, behenyl behenate, cetyl benzoate, stearyl 4-tert-butylbenzoate, dimyristyl phthalate, distearyl phthalate, dimyristyl oxalate, dicetyl oxalate, dicetyl malonate, dilauryl succinate, dilauryl glutarate, diundecyl adipate, dilauryl azelate, di-(n-nonyl) sebacate, 1 Examples include 18-octadecylmethylenedicarboxylate dineopentyl, ethylene glycol dimyristate, propylene glycol dilaurate, propylene glycol distearate, hexylene glycol dipalmitate, 1,5-pentanediol distearate, 1,2,6-hexanetriol trimyristate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanedimethanol dimyristate, xylene glycol dicaprinate, and xylene glycol distearate.

Also effective are esters of saturated fatty acids and branched aliphatic alcohols, esters of unsaturated fatty acids or branched or substituted saturated fatty acids and branched aliphatic alcohols or aliphatic alcohols having 16 or more carbon atoms, and ester compounds selected from cetyl butyrate, stearyl butyrate, and behenyl butyrate.
Examples of the ester compounds include 2-ethylhexyl butyrate, 2-ethylhexyl behenate, 2-ethylhexyl myristate, 2-ethylhexyl caprate, 3,5,5-trimethylhexyl laurate, 3,5,5-trimethylhexyl palmitate, 3,5,5-trimethylhexyl stearate, 2-methylbutyl caproate, 2-methylbutyl caprylate, 2-methylbutyl caprate, 1-ethylpropyl palmitate, 1-ethylpropyl stearate, 1-ethylpropyl behenate, laurate, 3,5,5-trimethylhexyl ester ... 1-Ethylhexyl phosphate, 1-ethylhexyl myristate, 1-ethylhexyl palmitate, 2-methylpentyl caproate, 2-methylpentyl caprylate, 2-methylpentyl caprate, 2-methylpentyl laurate, 2-methylbutyl stearate, 2-methylbutyl stearate, 3-methylbutyl stearate, 1-methylheptyl stearate, 2-methylbutyl behenate, 3-methylbutyl behenate, 1-methylheptyl stearate, 1-methylheptyl behenate, 1-ethylcaproate 1-ethylpentyl palmitate, 1-methylpropyl stearate, 1-methyloctyl stearate, 1-methylhexyl stearate, 1,1-dimethylpropyl laurate, 1-methylpentyl caprate, 2-methylhexyl palmitate, 2-methylhexyl stearate, 2-methylhexyl behenate, 3,7-dimethyloctyl laurate, 3,7-dimethyloctyl myristate, 3,7-dimethyloctyl palmitate, 3,7-dimethyloctyl stearate, 3,7-dimethyloctyl behenate Examples of such esters include 3,7-dimethyloctyl ester, stearyl oleate, behenyl oleate, stearyl linoleate, behenyl linoleate, 3,7-dimethyloctyl erucate, stearyl erucate, isostearyl erucate, cetyl isostearate, stearyl isostearate, 2-methylpentyl 12-hydroxystearate, 2-ethylhexyl 18-bromostearate, isostearyl 2-ketomyristate, 2-ethylhexyl 2-fluoromyristate, cetyl butyrate, stearyl butyrate, and behenyl butyrate.

Furthermore, in order to change color while exhibiting a large hysteresis characteristic in the color density-temperature curve and to impart color memory depending on temperature change, examples of carboxylate compounds that exhibit a ΔT value (melting point-cloud point) of 5°C or more and less than 50°C as described in JP-B-4-17154 include carboxylate compounds containing a substituted aromatic ring in the molecule, esters of carboxylic acids containing unsubstituted aromatic rings and aliphatic alcohols having 10 or more carbon atoms, carboxylate compounds containing a cyclohexyl group in the molecule, esters of fatty acids having 6 or more carbon atoms and unsubstituted aromatic alcohols or phenols, esters of fatty acids having 8 or more carbon atoms and branched aliphatic alcohols, esters of dicarboxylic acids and aromatic alcohols or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, dimyristin, distearin, etc.

Also effective are fatty acid ester compounds obtained from an aliphatic monohydric alcohol having an odd number of carbon atoms of 9 or more and an aliphatic carboxylic acid having an even number of carbon atoms, and fatty acid ester compounds having a total of 17 to 23 carbon atoms obtained from n-pentyl alcohol or n-heptyl alcohol and an aliphatic carboxylic acid having an even number of carbon atoms of 10 to 16.
Examples of the fatty acid ester compound include n-pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caprylate, n-undecyl caprylate, n-tridecyl caprylate, n-pentadecyl caprylate, n-heptyl caprate, n-nonyl caprate, n-undecyl caprate, n-tridecyl caprate, n-pentadecyl caprate, n-pentyl laurate, n-heptyl laurate, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, n-heptyl myristate, Examples thereof include n-butyl, n-nonyl myristate, n-undecyl myristate, n-tridecyl myristate, n-pentadecyl myristate, n-pentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-undecyl palmitate, n-tridecyl palmitate, n-pentadecyl palmitate, n-nonyl stearate, n-undecyl stearate, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eicosanoate, n-undelsyl eicosanoate, n-tridecyl eicosanoate, n-pentadecyl eicosanoate, n-nonyl behenate, n-undecyl behenate, n-tridecyl behenate, and n-pentadecyl behenate.

As the ketones, aliphatic ketones having a total carbon number of 10 or more are effective, and examples thereof include 2-decanone, 3-decanone, 4-decanone, 2-undecanone, 3-undecanone, 4-undecanone, 5-undecanone, 2-dodecanone, 3-dodecanone, 4-dodecanone, 5-dodecanone, 2-tridecanone, 3-tridecanone, 2-tetradecanone, 2-pentadecanone, 8-pentadecanone, 2-hexadecanone, 3-hexadecanone, 9-heptadecanone, 2-pentadecanone, 2-octadecanone, 2-nonadecanone, 10-nonadecanone, 2-eicosanone, 11-eicosanone, 2-heneicosanone, 2-docosanone, laurone, and stearone.
Further, aryl alkyl ketones having a total carbon number of 12 to 24, for example, n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecanophenone, 4-n-dodecaacetophenone, n-tridecanophenone, 4-n-undecanoacetophenone, n-laurophenone, 4-n-decanoacetophenone, n-undecanophenone, 4-n-nonylacetophenone, n-decanophenone, 4-n-octylacetophenone, n ... Examples of acetophenone include 4-n-heptylacetophenone, n-octanophenone, 4-n-hexylacetophenone, 4-n-cyclohexylacetophenone, 4-tert-butylpropiophenone, n-heptaphenone, 4-n-pentylacetophenone, cyclohexyl phenyl ketone, benzyl-n-butyl ketone, 4-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone, 1-acetonaphthone, 2-acetonaphthone, and cyclopentyl phenyl ketone.

As ethers, aliphatic ethers having a total of 10 or more carbon atoms are effective, and examples thereof include dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether, diundecyl ether, didodecyl ether, ditridecyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decanediol dimethyl ether, undecanediol dimethyl ether, dodecanediol dimethyl ether, tridecanediol dimethyl ether, decanediol diethyl ether, undecanediol diethyl ether, etc.

Examples of acid amides include acetamide, propionic acid amide, butyric acid amide, caproic acid amide, caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, erucic acid amide, benzamide, caproic acid anilide, caprylic acid anilide, capric acid anilide, lauric acid anilide, myristic acid anilide, palmitic acid anilide, stearic acid anilide, behenic acid anilide, oleic acid anilide, erucic acid anilide, caproic acid N-methylamide, caprylic ... acid N-methylamide, lauric acid N-methylamide, myristic acid N-methylamide, palmitic acid N-methylamide, stearic acid N-methylamide, behenic acid N-methylamide, oleic acid N-methylamide, erucic acid N-methylamide, lauric acid N-ethylamide, myristic acid N-ethylamide, palmitic acid N-ethylamide, stearic acid N-ethylamide, oleic acid N-ethylamide, lauric acid N-butylamide, myristic acid N-butylamide, palmitic acid N-butylamide, stearic acid N-butylamide, oleic acid N-butylamide, lauric acid N-octylamide amide, myristic acid N-octylamide, palmitic acid N-octylamide, stearic acid N-octylamide, oleic acid N-octylamide, lauric acid N-dodecylamide, myristic acid N-dodecylamide, palmitic acid N-dodecylamide, stearic acid N-dodecylamide, oleic acid N-dodecylamide, dilauric acid amide, dimyristic acid amide, dipalmitic acid amide, distearic acid amide, dioleic acid amide, trilauric acid amide, trimyristic acid amide, tripalmitic acid amide, tristearic acid amide, trioleic acid amide, succinic acid amide, adipic acid Examples include succinic acid N-methylamide, adipic acid N-methylamide, glutaric acid N-methylamide, malonic acid N-methylamide, azelaic acid N-methylamide, succinic acid N-ethylamide, adipic acid N-ethylamide, glutaric acid N-ethylamide, malonic acid N-ethylamide, azelaic acid N-ethylamide, succinic acid N-butylamide, adipic acid N-butylamide, glutaric acid N-butylamide, malonic acid N-butylamide, adipic acid N-octylamide, and adipic acid N-dodecylamide.

Furthermore, the component (iii) may be a compound represented by the following formula (1).
_[ In the formula, _R1 represents a hydrogen atom or a methyl group, m represents an integer of 0 to 2, one of _X1 and _X2 is -( _CH2 ) _nOCOR2 or -( _CH2 ) _nCOOR2 , _and the other represents a hydrogen atom, n represents an integer of 0 to 2, _R2 represents an alkyl group or an alkenyl group having 4 or more carbon atoms, _Y1 and _Y2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, and r and p each independently represent an integer of 1 to 3.]
Of the compounds represented by formula (1), when R ₁ is a hydrogen atom, a reversible thermochromic composition having a wider hysteresis width can be obtained, which is preferable, and further, when R ₁ is a hydrogen atom and m is 0, it is more preferable.
Among the compounds represented by formula (1), a compound represented by the following formula (2) is more preferred.
(In the formula, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, and more preferably an alkyl group having 12 to 22 carbon atoms.)
Examples of the compound represented by formula (2) include 4-benzyloxyphenylethyl octanoate, 4-benzyloxyphenylethyl nonanoate, 4-benzyloxyphenylethyl decanoate, 4-benzyloxyphenylethyl undecanoate, 4-benzyloxyphenylethyl dodecanoate, 4-benzyloxyphenylethyl tridecanoate, 4-benzyloxyphenylethyl tetradecanoate, 4-benzyloxyphenylethyl pentadecanoate, 4-benzyloxyphenylethyl hexadecanoate, 4-benzyloxyphenylethyl heptadecanoate, and 4-benzyloxyphenylethyl octadecanoate.

Furthermore, the component (iii) may be a compound represented by the following formula (3).
(In the formula, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, m and n each independently represent an integer from 1 to 3, and X and Y each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom.)
Examples of the compound represented by formula (3) include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, 1,1-diphenylmethyl dodecanoate, 1,1-diphenylmethyl tridecanoate, 1,1-diphenylmethyl tetradecanoate, 1,1-diphenylmethyl pentadecanoate, 1,1-diphenylmethyl hexadecanoate, 1,1-diphenylmethyl heptadecanoate, and 1,1-diphenylmethyl octadecanoate.

Furthermore, the component (iii) may be a compound represented by the following formula (4).
(In the formula, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, m represents an integer of 1 to 3, and n represents an integer of 1 to 20.)
Examples of the compound represented by formula (4) include a diester of malonic acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, a diester of succinic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of succinic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, a diester of glutaric acid and 2-(4-benzyloxyphenyl)ethanol, a diester of glutaric acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, a diester of adipic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of pimelic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of suberic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of suberic acid and 2-[4-(3-methyl Examples of the diester include a diester of suberic acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, a diester of suberic acid and 2-[4-(2,4-dichlorobenzyloxy)phenyl]ethanol, a diester of azelaic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of sebacic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of 1,10-decanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of 1,18-octadecanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, and a diester of 1,18-octadecanedicarboxylic acid and 2-[4-(2-methylbenzyloxy)phenyl]ethanol.

Furthermore, the component (iii) may be a compound represented by the following formula (5).
(In the formula, R represents an alkyl group or alkenyl group having 1 to 21 carbon atoms, and n represents an integer of 1 to 3.)
Examples of the compound represented by formula (5) include a diester of 1,3-bis(2-hydroxyethoxy)benzene and capric acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and undecanoic acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and lauric acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and myristic acid, a diester of 1,4-bis(hydroxymethoxy)benzene and butyric acid, a diester of 1,4-bis(hydroxymethoxy)benzene and isovaleric acid, and a diester of 1,4-bis(2-hydroxyethoxy)benzene and acetic acid. Examples of such esters include diesters of 1,4-bis(2-hydroxyethoxy)benzene and propionic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and valeric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and caproic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and caprylic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and capric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and lauric acid, and diesters of 1,4-bis(2-hydroxyethoxy)benzene and myristic acid.

Furthermore, the component (iii) may be a compound represented by the following formula (6).
(In the formula, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, m represents an integer of 1 to 3, and n represents an integer of 1 to 20.)
Examples of the compound represented by formula (6) include a diester of succinic acid and 2-phenoxyethanol, a diester of suberic acid and 2-phenoxyethanol, a diester of sebacic acid and 2-phenoxyethanol, a diester of 1,10-decanedicarboxylic acid and 2-phenoxyethanol, and a diester of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol.

Furthermore, the component (iii) may be a compound represented by the following formula (7).
(In the formula, R represents any one of an alkyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, a cycloalkyl group, and an alkenyl group having 4 to 22 carbon atoms; X represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom; and n represents 0 or 1.)
Examples of the compound represented by formula (7) include decyl 4-phenylbenzoate, lauryl 4-phenylbenzoate, myristyl 4-phenylbenzoate, cyclohexylethyl 4-phenylbenzoate, octyl 4-biphenylacetate, nonyl 4-biphenylacetate, decyl 4-biphenylacetate, lauryl 4-biphenylacetate, myristyl 4-biphenylacetate, tridecyl 4-biphenylacetate, pentadecyl 4-biphenylacetate, cetyl 4-biphenylacetate, cyclopentyl 4-biphenylacetate, cyclohexylmethyl 4-biphenylacetate, hexyl 4-biphenylacetate, and cyclohexylmethyl 4-biphenylacetate.

Furthermore, the component (iii) may be a compound represented by the following formula (8).
(In the formula, R represents an alkyl group having 3 to 18 carbon atoms or an aliphatic acyl group having 3 to 18 carbon atoms; X represents any one of a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, and a halogen atom; Y represents a hydrogen atom or a methyl group; and Z represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, and a halogen atom.)
Examples of the compound represented by formula (8) include phenoxyethyl 4-butoxybenzoate, phenoxyethyl 4-pentyloxybenzoate, phenoxyethyl 4-tetradecyloxybenzoate, esters of phenoxyethyl 4-hydroxybenzoate and dodecanoic acid, and dodecyl ether of phenoxyethyl vanillate.

Furthermore, the component (iii) may be a compound represented by the following formula (9).
(In the formula, R represents any one of an alkyl group having 4 to 22 carbon atoms, an alkenyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, and a cycloalkyl group; X represents any one of a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom; Y represents any one of a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom; and n represents 0 or 1.)
Examples of the compound represented by formula (9) include benzoate ester of octyl 4-hydroxybenzoate, benzoate ester of decyl 4-hydroxybenzoate, 4-methoxybenzoate ester of heptyl 4-hydroxybenzoate, 2-methoxybenzoate ester of dodecyl 4-hydroxybenzoate, and benzoate ester of cyclohexylmethyl 4-hydroxybenzoate.

Furthermore, the component (iii) may be a compound represented by the following formula (10).
(In the formula, R represents any one of an alkyl group having 3 to 18 carbon atoms, a cycloalkylalkyl group having 6 to 11 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, and an alkenyl group having 3 to 18 carbon atoms; X represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and a halogen atom; and Y represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, and a halogen atom.)
Examples of the compound represented by formula (10) include phenoxyethyl ether of nonyl 4-hydroxybenzoate, phenoxyethyl ether of decyl 4-hydroxybenzoate, phenoxyethyl ether of undecyl 4-hydroxybenzoate, and phenoxyethyl ether of dodecyl vanillate.

Furthermore, the component (iii) may be a compound represented by the following formula (11).
(In the formula, R represents a cycloalkyl group having 3 to 8 carbon atoms or a cycloalkylalkyl group having 4 to 9 carbon atoms, and n represents an integer of 1 to 3.)
Examples of the compound represented by formula (11) include a diester of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanecarboxylic acid, a diester of 1,4-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid, and a diester of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid.

Furthermore, the component (iii) may be a compound represented by the following formula (12).
(In the formula, R is any one of an alkyl group having 3 to 17 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and a cycloalkylalkyl group having 5 to 8 carbon atoms; X is any one of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a methoxy group, an ethoxy group, and a halogen atom; and n is an integer of 1 to 3.)
Examples of the compound represented by formula (12) include a diester of 4-phenylphenol ethylene glycol ether and cyclohexane carboxylic acid, a diester of 4-phenylphenol diethylene glycol ether and lauric acid, a diester of 4-phenylphenol triethylene glycol ether and cyclohexane carboxylic acid, a diester of 4-phenylphenol ethylene glycol ether and octanoic acid, a diester of 4-phenylphenol ethylene glycol ether and nonanoic acid, a diester of 4-phenylphenol ethylene glycol ether and decanoic acid, and a diester of 4-phenylphenol ethylene glycol ether and myristic acid.

It is also possible to use a reversible thermochromic composition of the heat-coloring type (which develops color when heated and loses color when cooled) that uses gallic acid esters (JP Patent Publication 51-44706, JP Patent Publication 2003-253149) as an electron-accepting compound, and a reversible thermochromic microcapsule pigment that encapsulates the composition (see Figure 3).

The reversible thermochromic composition of the present invention is a compatible solution containing the above components (A), (B), and (C) as essential components. The ratio of each component depends on the concentration, discoloration temperature, discoloration form, and type of each component, but the component ratio that generally provides the desired properties is 1 part of component (A) to 0.1 to 100, preferably 0.1 to 50, and more preferably 0.5 to 20, of component (B), and 5 to 200, preferably 5 to 100, and more preferably 10 to 100, of component (C) (all the above ratios are in parts by mass).

Furthermore, the reversible thermochromic composition may contain various light stabilizers, if necessary.
The light stabilizer is contained to prevent photodegradation of the reversible thermochromic composition consisting of components (A), (B), and (C), and is blended in a ratio of 0.3 to 24% by mass, preferably 0.3 to 16% by mass, per 1% by mass of component (A). Among the light stabilizers, the ultraviolet absorber effectively blocks ultraviolet rays contained in sunlight and the like, and prevents photodegradation caused by the excited state due to the photoreaction of component (A). Furthermore, the antioxidant, singlet oxygen quencher, superoxide anion quencher, ozone quencher, etc. suppress oxidation reactions caused by light.
The light stabilizers may be used alone or in combination of two or more kinds.

Examples of ultraviolet absorbing agents among light stabilizers include:
2,4-hydroxybenzophenone,
2-hydroxy-4-methoxybenzophenone,
2,2'-dihydroxy-4,4'-dimethoxybenzophenone,
2,2',4,4'-tetrahydroxybenzophenone,
2-hydroxy-4-methoxybenzophenone-5-sulfonic acid,
2-hydroxy-4-octyloxybenzophenone,
Bis-(5-benzoyl-4-hydroxy-2-methoxyphenyl)-methane,
2-(3',5'-di-tert-amyl-2'-hydroxyphenyl)benzophenone,
4-dodecyloxy-2-hydroxybenzophenone,
2-hydroxy-4-octadecyloxybenzophenone,
2,2'-dihydroxy-4-methoxybenzophenone,
4-benzyloxy-2-hydroxybenzophenone,
Benzophenone-based ultraviolet absorbers such as 2-(3',5'-di-tert-amyl-2'-hydroxyphenyl)benzophenone,
Phenyl salicylate,
4-tert-butylphenyl salicylate,
4-octylphenyl salicylate,
2,4-di-tert-butylphenyl-4-hydroxybenzoate,
1-hydroxybenzoate,
3-tert-butyl-1-hydroxybenzoate,
1-hydroxy-3-tert-octyl benzoate,
Salicylic acid-based ultraviolet absorbers such as resorcinol monobenzoate,
2-ethyl-2-cyano-3,3'-diphenylacrylate,
2-ethylhexyl-2-cyano-3,3'-diphenylacrylate,
Cyanoacrylate ultraviolet absorbers such as 2-ethylhexyl-2-cyano-3-phenylcinnate,
2-(5-tert-butyl-2-hydroxyphenyl)benzotriazole,
2-(2-hydroxy-5-methylphenyl)benzotriazole,
2-[3,5-bis(a,a-dimethylbenzyl)-2-hydroxyphenyl]-2H-benzotriazole,
2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole,
2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole,
2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole,
2-(3,5-di-tert-amyl-2-hydroxyphenyl)benzotriazole,
β-[3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl]propionic acid-polyethylene glycol 300 ester,
2-(3-dodecyl-2-hydroxy-5-methylphenyl)benzotriazole,
Bis{β-[3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl]}propionic acid-polyethylene glycol 300 ester,
2-(3-tert-butyl-2-hydroxyphenyl-5-propyloctylate)-5-chlorobenzotriazole,
2-[2-hydroxyphenyl-3,5-di-(1,1'-dimethylbenzyl)phenyl]-2H-benzotriazole,
2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole,
2-(3-tert-butyl-5-octyloxycarbonylethyl-2-hydroxyphenyl)benzotriazole,
2-(2-hydroxy-5-tetraoctylphenyl)benzotriazole,
2-(2-hydroxy-4-octoxyphenyl)benzotriazole,
2-[2'-hydroxy-3'-(3",4",5",6"-tetrahydrophthalimidomethyl)-5'-methylphenyl]benzotriazole,
benzotriazole-based ultraviolet absorbers such as 2-(5-tert-butyl-2-hydroxyphenyl)benzotriazole;
Ethanediamide-N-(2-ethoxyphenyl)-N'-(4-isododecylphenyl),
oxalic acid anilide ultraviolet absorbers such as 2,2,4,4-tetramethyl-20-(β-lauryl-oxycarbonyl)-ethyl-7-oxa-3,20-diazodispiro(5,1,11,2)heneicoic acid-21-one;
2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-(2-hydroxy-4-pentoxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine,
2,4-diphenyl-6-[2-hydroxy-4-(2-butoxyethoxy)phenyl]-1,3,5-triazine,
2,4-di-p-trail-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine,
2,4-di-p-trail-6-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine,
2,4-di-p-trail-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine,
2,4-di-p-trail-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine,
2,4-di-p-trail-6-(2-hydroxy-4-pentoxyphenyl)-1,3,5-triazine,
2,4-di-p-trail-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,
2,4-di-p-trail-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine,
2,4-di-p-trail-6-[2-hydroxy-4-(2-hexyloxyethoxy)phenyl]-1,3,5-triazine,
2-{4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,
2-{4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,
2-[4-{[2-hydroxy-3-(2'-ethyl)hexyl]oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,
2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-[2,4-bis(butyloxyphenyl)]-1,3,5-triazine,
Examples include triazine-based ultraviolet absorbers such as 2-{2-hydroxy-4-[(1-octyloxycarbonylethoxy)phenyl]}-4,6-bis(4-phenylphenyl)-1,3,5-triazine.

Examples of antioxidants (antiaging agents) include:
Dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate,
poly{[6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2-4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]}hexamethylene,
2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentapetyl-4-piperidyl),
N,N'-bis(3-aminopropyl)ethylenediamine-2,4-bis[N-butyl-N-(1,2,2,6,6-pentapetyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine condensate,
Bis(1,2,2,6,6-pentamethyl-4-piperidylsebacic acid),
4-benzoyloxy-2,2,6,6-tetramethylpiperidine,
bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate,
hindered amine antioxidants such as 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4,5]decane-2,4-dione,
2,6-di-tert-butyl-4-methylphenol,
2-tert-butyl-4-methoxyphenol,
2,6-di-tert-butyl-4-ethylphenol,
octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,
2,2-methylenebis(4-methyl-6-tert-butylphenol),
4,4-thiobis(2-methyl-6-tert-butylphenol),
2,2-thiobis(4-methyl-6-tert-butylphenol),
4,4-butylidenebis(3-methyl-6-tert-butylphenol),
3,9-bis{1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl},
2,4,8,10-tetraoxaspiro[5,5]undecane,
1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,
1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,
Tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane,
2,2-ethylenebis(4,6-di-tert-butylphenol),
Bis[3,3-bis-(4'-hydroxy-3'-tert-butylphenyl)butyric acid]glycol ester,
1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6-[1H,3H,5H]-trione,
Tocopherol,
1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate,
Pentaerythritol tetrakis(3-lauryl thiopropionate),
Triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate],
1,6-hexadiol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],
2,2-thioethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],
N,N'-hexamethylenebis(3,5-tert-butyl-4-hydroxy-hydrocinnamamide),
Tris-(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,
2,2,4-trimethyl-1,2-hydroquinone,
Styryl phenol,
2,5-di-tert-butylhydroquinone,
phenolic antioxidants such as bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate;
Dilauryl-3,3'-thiodipropionate,
Dimyristyl-3,3'-thiodipropionate,
Distearyl-3,3'-thiodipropionate,
Sulfur-based antioxidants such as stearyl thiopropylamide,
Tris(2,4-di-tert-butylphenyl)phosphite,
Bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite,
3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester,
triphenyl phosphite,
diphenyl isodecyl phosphite,
phenyl isodecyl phosphite,
4,4'-butylidene-bis(3-methyl-6-tert-butylphenylditridecyl)phosphite,
Octadecyl phosphite,
Tris(nonylphenyl)phosphite,
Diisodecyl pentaerythritol diphosphite,
9,10-dihydroxy-9-oxa-10-phosphaphenanthrene,
10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydroxy-9-oxa-10-phosphaphenanthrene-10-oxide,
10-decyloxy-9,10-dihydroxy-9-oxa-10-phosphaphenanthrene,
cyclic neopentanetetraylbis(2,4-di-tert-butylphenyl)phosphite,
cyclic neopentanetetraylbis(2,6-di-tert-butyl-4-methylphenyl)phosphite,
2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite,
2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine,
Examples include phosphoric acid-based antioxidants such as octylated diphenylamine.

Examples of singlet oxygen quenchers include carotenes, dyes, amines, phenols, nickel complexes, and sulfides, such as 1,4-diazabicyclo[2,2,2]octane (DABCO), β-carotene, 1,3-cyclohexadiene, 2-diethylaminomethylfuran, 2-phenylaminomethylfuran, 9-diethylaminomethylanthracene, 5-diethylaminomethyl-6-phenyl-3,4-dihydroxypyran, nickel dimethyldithiocarbamate, nickel 3,5-di-tert-butyl-4-hydroxybenzyl-O-ethylphosphonate, and nickel 3,5-di-tert -butyl-4-hydroxybenzyl-O-butylphosphonate, nickel [2,2'-thiobis (4-tert-octylphenolate)] n-butylamine, nickel [2,2'-thiobis (4-tert-octylphenolate)] 2-ethylhexylamine, nickel bis [2,2'-thiobis (4-tert-octylphenolate)], nickel bis [2,2'-sulfone bis (4-octylphenolate)], nickel bis (2-hydroxy-5-methoxyphenyl-N-n-butylaldimine), nickel bis (dithiobenzyl), nickel bis (dithiobiacetyl), etc. can be mentioned as examples.

Examples of superoxide anion quenchers include complexes of superoxide dismutase with cobalt and nickel.

Examples of ozone quenchers include 4,4'-thiobis(6-tert-butyl-m-cresol), 2,4,6-tri-tert-butylphenol, 1,4-diazabicyclo[2,2,2]octane, N-phenyl-β-naphthylamine, α-tocopherol, 4,4'-methylene-bis(2,6-di-tert-butylphenol), P,P'-diaminodiphenylmethane, 2,2'-methylene-bis(6-tert-butyl-p-cresol), N,N'-diphenyl-p-phenylenediamine, N,N'-diphenylethylenediamine, and N-isopropyl-N'-phenyl-p-phenylenediamine.

The reversible thermochromic composition of the present invention is effective when used as is, but it can also be encapsulated in microcapsules to form a reversible thermochromic microencapsulated pigment (hereinafter sometimes referred to as a "microencapsulated pigment" or "pigment"), or dispersed in a thermoplastic resin or a thermosetting resin to form reversible thermochromic resin particles (hereinafter sometimes referred to as "resin particles").
The reversible thermochromic composition is preferably encapsulated in a microcapsule to form a reversible thermochromic microcapsule pigment, because the encapsulation in a microcapsule makes it possible to form a chemically and physically stable pigment, and the reversible thermochromic composition can be kept in the same composition under various conditions of use, and can exhibit the same effects.
Microencapsulation may be appropriately selected according to the application from the conventionally known isocyanate-based interfacial polymerization method, melamine-formaldehyde-based in situ polymerization method, liquid curing coating method, phase separation method from an aqueous solution, phase separation method from an organic solvent, melt dispersion cooling method, air suspension coating method, spray drying method, etc. Furthermore, a secondary resin film may be further provided on the surface of the microcapsules according to the purpose to impart durability or modify the surface properties for practical use.
The reversible thermochromic microcapsule pigment preferably has a mass ratio of inclusions to wall film of 7:1 to 1:1, and by having the mass ratio of inclusions to wall film within the above range, a decrease in color density and clarity during color development is prevented. More preferably, the mass ratio of inclusions to wall film is 6:1 to 1:1.

The average particle size of the reversible thermochromic microencapsulated pigment or resin particles is preferably in the range of 0.01 to 50 μm, more preferably 0.1 to 30 μm, and even more preferably 0.5 to 20 μm. If the average particle size of the microencapsulated pigment or resin particles exceeds 50 μm, the dispersion stability and processing suitability are lacking when blended into ink, paint, or resin. On the other hand, if the average particle size of the microencapsulated pigment or resin particles is less than 0.01 μm, it becomes difficult to exhibit high-concentration color development.
The average particle diameter was measured by determining the particle region using an image analysis type particle size distribution measurement software (manufactured by Mountec Corporation, product name: MacView), calculating the projected area equivalent circle diameter (Heywood diameter) from the area of the particle region, and measuring the average particle diameter of particles equivalent to a sphere of equal volume using this value.
When the particle size of all or most of the particles exceeds 0.2 μm, it is also possible to measure the average particle size of particles equivalent to an equal volume sphere by the Coulter method using a particle size distribution measuring device (product name: Multisizer 4e, manufactured by Beckman Coulter, Inc.).
Furthermore, the volumetric particle size and average particle size may be measured using a laser diffraction/scattering type particle size distribution measuring device (manufactured by HORIBA, Ltd., product name: LA-300) that has been calibrated based on values measured using the above software or a measuring device using the Coulter method.

A reversible thermochromic composition, a reversible thermochromic colorant such as a reversible thermochromic composition, a reversible thermochromic microcapsule pigment or a resin particle, etc. can be dispersed in a vehicle containing water and/or an organic solvent and, if necessary, various additives to form an ink composition (hereinafter, sometimes referred to as "ink"), which can be used as a reversible thermochromic liquid composition such as ink for writing instruments such as marking pens, ballpoint pens, fountain pens and brush pens.
The thermochromic writing implement (hereinafter sometimes referred to as "writing implement") according to the present invention contains ink for writing implements which contains a reversible thermochromic microencapsulated pigment and a vehicle.

The reversible thermochromic liquid composition may contain various additives.
Examples of the additives include resins, crosslinking agents, curing agents, drying agents, plasticizers, viscosity modifiers, dispersants, ultraviolet absorbers, antioxidants, light stabilizers, anti-settling agents, smoothing agents, gelling agents, defoaming agents, matting agents, penetrating agents, pH adjusters, foaming agents, coupling agents, moisturizing agents, antifungal agents, preservatives, and rust inhibitors.

Examples of the vehicle for the writing instrument used in the ink for the writing instrument include an oil-based vehicle containing an organic solvent, or an aqueous vehicle containing water and, if necessary, an organic solvent. Preferably, the vehicle for the writing instrument used in the present invention is an aqueous vehicle.
Examples of organic solvents include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, and N-methyl-2-pyrrolidone.

Examples of inks for writing instruments include shear-thinning inks that contain a shear-thinning agent in the vehicle, and cohesive inks that contain a polymeric coagulant in the vehicle and suspend microencapsulated pigments in a loosely coagulated state.

An ink containing a shear thinning agent in the vehicle (shear thinning ink) can suppress aggregation and sedimentation of the microencapsulated pigment and can also suppress bleeding of handwriting, making it possible to form good handwriting.
Furthermore, when a shear-thinning ink is contained in a ballpoint pen-shaped writing instrument, it is possible to prevent ink leakage from the gap between the ball and the tip when the writing instrument is not in use, and to prevent ink backflow when the writing tip is left facing upward (upright state).

Examples of shear-thinning agents include xanthan gum, welan gum, succinoglycan (average molecular weight: about 1 to 8 million), which is an organic acid-modified heteropolysaccharide whose constituent monosaccharides are glucose and galactose, alka gum, guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alginic acid alkyl esters, polymers with a molecular weight of 100,000 to 150,000 that are mainly composed of alkyl esters of methacrylic acid, glucomannan, thickening polysaccharides with gelling ability extracted from seaweed such as agar and carrageenan, benzylidene sorbitol and benzylidene xylitol or derivatives thereof, cross-linked acrylic acid polymers, inorganic substances, etc. Examples include fine particles, polyglycerin fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyethylene glycol fatty acid esters, polyoxyethylene castor oil, polyoxyethylene lanolin, lanonine alcohol, beeswax derivatives, polyoxyethylene alkyl ethers, polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid amides, and other nonionic surfactants with an HLB value of 8 to 12, salts of dialkyl or dialkenyl sulfosuccinic acid, mixtures of N-alkyl-2-pyrrolidone and anionic surfactants, and mixtures of polyvinyl alcohol and acrylic resins.

In inks that contain a polymeric flocculant in the vehicle (flocculant inks), the microencapsulated pigment forms loose aggregates via the polymeric flocculant, preventing the microencapsulated pigments from coming into contact with each other and flocculating, improving the dispersibility of the pigment.

Examples of the polymer flocculant include polyvinylpyrrolidone, polyethylene oxide, and water-soluble polysaccharides.
Examples of water-soluble polysaccharides include tragacanth gum, guar gum, pullulan, cyclodextrin, water-soluble cellulose derivatives, and the like.
Furthermore, examples of water-soluble cellulose derivatives include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose, and hydroxypropyl methyl cellulose.
Among the above polymer flocculants, hydroxyethyl cellulose is preferred because of its excellent dispersibility.

Specific examples of polymer flocculants include those manufactured by Sumitomo Seika Chemicals Co., Ltd. under the product names HEC A grade, S grade, and CF grade; those manufactured by Daicel Phi-Chem Co., Ltd. under the product names HEC Daicel SP type, SE type, and EE type; those manufactured by Dow Chemical Japan Co., Ltd. under the product names CELLOSIZE WP type, QP type, and EP type; and those manufactured by Sansho Co., Ltd. under the product name SANHEC.
The polymer flocculant is preferably blended in an amount of 0.1 to 1 mass %, more preferably 0.3 to 0.5 mass %, based on the total amount of the ink. By being in the above range, the microencapsulated pigment forms loose aggregates, and the effect of improving the dispersibility of the pigment can be fully exerted.

Furthermore, the dispersibility of the microencapsulated pigment can be improved by blending a dispersant into the ink.
In addition, a polymer flocculant and a dispersant can be used in combination. When the two are used in combination, the dispersibility of the microencapsulated pigment can be improved, and the dispersibility of the loose aggregates of the microencapsulated pigment formed via the polymer flocculant can be further improved.

Examples of dispersants include synthetic resins such as polyvinylpyrrolidone, polyvinyl butyral, polyvinyl ether, styrene-maleic acid copolymers, ketone resins, hydroxyethyl cellulose and derivatives thereof, and styrene-acrylic acid copolymers, acrylic polymers, PO·EO adducts, and polyester amine oligomers.
Among the above dispersants, acrylic polymer dispersants are preferred because they have excellent dispersibility for the microencapsulated pigment, acrylic polymer dispersants having a carboxyl group are more preferred, and acrylic polymer dispersants having a comb structure and a carboxyl group on the side chain are even more preferred.
A particularly preferred dispersant is an acrylic polymer dispersant having a comb structure and multiple carboxyl groups on the side chains, and a specific example is Solsperse 43000, a product manufactured by Lubrizol Japan Co., Ltd.
The dispersant is preferably blended in an amount of 0.01 to 2% by mass, more preferably 0.1 to 1.5% by mass, based on the total amount of the ink. If the blending ratio of the dispersant exceeds 2% by mass, the microencapsulated pigment is likely to settle or float when subjected to external vibration, etc. On the other hand, if the blending ratio of the dispersant is less than 0.01% by mass, the effect of improving dispersibility is unlikely to be achieved.

In addition, by using a comb-shaped acrylic polymer dispersant having a carboxyl group on the side chain and an organic nitrogen-sulfur compound together with a polymer flocculant, the dispersibility of the loose aggregates of the microencapsulated pigment formed via the polymer flocculant can be improved.
The organic nitrogen sulfur compound further improves the dispersibility of the loose aggregates of the microencapsulated pigment, which are dispersed by the acrylic polymer dispersant with a comb-shaped structure having carboxyl groups on the side chains. Therefore, when the ink is placed in a writing instrument and used in practice, settling of the microencapsulated pigment due to vibration can be further suppressed.

Examples of the organic nitrogen-sulfur compound include compounds selected from thiazole-based compounds, isothiazole-based compounds, benzothiazole-based compounds, and benzisothiazole-based compounds. For example, one or more compounds selected from 2-(4-thiazoyl)-benzimidazole (TBZ), 2-(thiocyanatomethylthio)-1,3-benzothiazole (TCMTB), 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and the like can be exemplified.
Among the above organic nitrogen-sulfur compounds, one or more compounds selected from 2-(4-thiazoyl)-benzimidazole (TBZ), 2-methyl-4-isothiazolin-3-one, and 5-chloro-2-methyl-4-isothiazolin-3-one are preferred.
Specific examples of organic nitrogen-sulfur compounds include those manufactured by Permachem Asia Co., Ltd., product names: Topside 88, 133, 170, 220, 288, 300, 400, 500, 600, 700Z, 800, and 950; and those manufactured by Hokko Sangyo Co., Ltd., product names: Hoxstar HP, Hoxstar E50A, Hoxside P200, 6500, 7400, Hoxside MC, 369, and Hoxside R-150.
The mass ratio of the acrylic polymer dispersant having a comb structure and having a carboxyl group in the side chain to the organic nitrogen sulfur compound is preferably 1:1 to 1:10, and more preferably 1:1 to 1:5. When the ratio is within the above range, it is possible to fully exhibit the effect of dispersing the mild aggregates of the microencapsulated pigment and suppressing sedimentation of the microencapsulated pigment due to vibration.

In addition, by blending a water-soluble resin into the ink, it is possible to impart adhesion and viscosity to the handwriting on the paper surface, and it is also possible to further improve the function of increasing the dispersibility of the microencapsulated pigment in the ink, which contains an acrylic polymer dispersant with a comb-shaped structure and carboxyl groups on the side chains, and an organic nitrogen-sulfur compound.

Examples of the water-soluble resin include alkyd resins, acrylic resins, styrene-maleic acid copolymers, cellulose derivatives, polyvinylpyrrolidone, polyvinyl alcohol, and dextrin.
Of the above water-soluble resins, polyvinyl alcohol is preferred, and partially saponified polyvinyl alcohol with a saponification degree of 70 to 89 mol % is more preferred because the ink is highly soluble even in the acidic range.
The water-soluble resin is preferably blended in an amount of 0.3 to 3.0% by mass, more preferably 0.5 to 1.5% by mass, based on the total amount of the ink.

Furthermore, by blending a specific gravity adjuster into the ink, when the viscosity of the vehicle is low, it is possible to prevent the microencapsulated pigment from settling or floating in the ink and becoming localized when the ink is subjected to external stimuli such as vibration.

The specific gravity of the microencapsulated pigment depends on the particle size of the microencapsulated pigment, the components and their contents encapsulated in the microcapsules, the components and film thickness of the capsule wall membrane, the colored state of the microencapsulated pigment, and the temperature, but the specific gravity is preferably in the range of 1.05 to 1.20, more preferably 1.10 to 1.20, and even more preferably 1.12 to 1.15 when the microencapsulated pigment is in a completely colored state and water is used as the reference substance in an environment of 20° C. Furthermore, microencapsulated pigments having a large hysteresis width (ΔH) often use a component (c) having two or more aromatic rings in the molecule, and have a large specific gravity as described above, but such pigments, in an ink containing a specific gravity adjuster, are prevented from settling or floating in the ink when subjected to external influences such as vibration during transportation, even if the viscosity of the vehicle is low.
The specific gravity of the microcapsulated pigment can be measured by the following method.

(Method for measuring specific gravity of microencapsulated pigment)
1. 30 ml of an aqueous glycerin solution and 1 g of a microcapsule pigment in a fully colored state are placed in a screw cap bottle and mixed to obtain a microcapsule pigment dispersion.
2. 30 ml of the microcapsule pigment dispersion is adjusted to 20° C. and centrifuged at 1000 rpm for 30 seconds. A cooling tabletop centrifuge (manufactured by Kokusan Co., Ltd., product name: H103N) can be used as the centrifuge.
3. Observe the microcapsule pigment dispersion.
If most of the microencapsulated pigment has settled to the bottom of the beaker, repeat steps 1 and 2 using an aqueous solution with a higher glycerin concentration than the aqueous glycerin solution used at this time, and observe the state of the dispersion.
If it is confirmed that most of the microencapsulated pigment is floating on the liquid surface, repeat steps 1 and 2 using an aqueous solution with a lower glycerin concentration than the aqueous glycerin solution used at this time, and observe the state of the dispersion.
The above series of operations is repeated until it is visually confirmed that most of the microencapsulated pigment is not floating on the liquid surface or settling, but that the glycerin aqueous solution is uniformly colored except for the liquid surface and the bottom of the screw tube bottle. The specific gravity of the glycerin aqueous solution when this state is observed is measured and is regarded as the specific gravity of the microencapsulated pigment. The specific gravity of the glycerin aqueous solution can be measured by the hydrometer method described in JIS K0061, Section 7.1, using an aqueous solution adjusted to 20°C.

The settling and floating stability of the pigment is at its highest when the difference in specific gravity between the vehicle and the pigment is minimal, and the specific gravity adjuster mentioned above brings the specific gravity of the vehicle closer to that of the microencapsulated pigment. The specific gravity of the vehicle depends on the specific gravity of the water-soluble substance dissolved in the vehicle and the amount added, so adding and dissolving a larger specific gravity adjuster in the vehicle can increase the specific gravity of the vehicle.

Specific gravity adjusters include those that dissolve in the vehicle and adjust the specific gravity of the vehicle to be closer to that of the microcapsule pigment, such as oxygen acids and salts of Group 6 elements with atomic weights in the range of 90 to 185.

The above-mentioned oxygen acids and salts thereof are selected from the group consisting of oxygen acids of transition metal elements and salts thereof, and the oxygen acid ions thereof are said to form tetrahedrons or octahedrons in which oxygen atoms are usually coordinated to metal atoms or the like in a 4- or 6-position.
The tetrahedral or octahedral units may be a single unit, or may be a polyacid having a structure in which the tetrahedral or octahedral units are bonded via edges or vertices, and may be a polyacid salt, which is a salt thereof. A polyacid is a polyacid formed by condensation of oxyacids of metal elements, and a polyacid formed of only one type of metal and in which all the condensed anions are of the same type is called an isopolyacid, and a polyacid formed by condensation of two or more types of anions is called a heteropolyacid. The respective salts are called isopolyacid salts and heteropolyacid salts. The above polyacids include isopolyacids, heteropolyacids, etc., and the above polyacid salts include isopolyacids, heteropolyacids, etc.

The specific gravity adjuster may include a single oxyacid and its salt, an isopolyacid and its salt, a heteropolyacid and its salt, and the like.
Examples of the single oxyacid include molybdic acid and tungstic acid, and examples of the salt of the single oxyacid include sodium molybdate, potassium molybdate, ammonium molybdate, sodium tungstate, potassium tungstate, ammonium tungstate, lithium tungstate, and magnesium tungstate.
Examples of isopolyacids include metamolybdic acid, paramolybdic acid, metatungstic acid, paratungstic acid, isotungstic acid, and the like. Further, examples of isopolyacid salts include sodium metamolybdate, potassium metamolybdate, ammonium metamolybdate, sodium paramolybdate, potassium paramolybdate, ammonium paramolybdate, sodium metatungstate, potassium metatungstate, ammonium metatungstate, barium metatungstate, sodium paratungstate, sodium isotungstate, and the like.
Examples of heteropolyacids include molybdophosphoric acid, molybdosilicic acid, tungstophosphoric acid, and tungstosilicic acid, and examples of heteropolyacid salts include sodium molybdophosphate, sodium molybdosilicate, sodium tungstophosphate, and sodium tungstosilicate.
The above oxygen acids and salts thereof may be used alone or in combination of two or more kinds.

Among the above-mentioned specific gravity adjusters, metatungstic acid, paratungstic acid, sodium metatungstate, potassium metatungstate, ammonium metatungstate, barium metatungstate, sodium paratungstate, sodium isotungstate, tungstophosphoric acid, tungstosilicic acid, sodium tungstophosphate, and sodium tungstosilicate are preferred, and sodium isotungstate, sodium metatungstate, and sodium paratungstate are more preferred.
The above-mentioned sodium isotungstate, sodium metatungstate, and sodium paratungstate are not only highly safe but also have a high specific gravity themselves, so that it is easy to adjust the high specific gravity liquid according to the amount added, and are therefore preferable.

The specific gravity adjuster is preferably blended in an amount of 2 to 20% by mass, more preferably 5 to 15% by mass, based on the total amount of the ink. If the blending ratio of the specific gravity adjuster exceeds 20% by mass, the microcapsule pigment tends to aggregate. On the other hand, if the blending ratio of the specific gravity adjuster is less than 2% by mass, the effect of adjusting the specific gravity of the vehicle becomes poor.
The mass ratio of the microencapsulated pigment to the specific gravity adjusting agent is preferably 0.05 to 4.0, more preferably 0.075 to 2.0, and even more preferably 0.1 to 1.5.

When the vehicle for the writing instrument is an aqueous vehicle, the vehicle contains at least water, and the amount of water is preferably 30 to 80% by weight, more preferably 40 to 70% by weight, based on the total amount of the ink.

Furthermore, by blending a water-soluble organic solvent into the ink, evaporation of water from the ink is suppressed, fluctuations in the specific gravity of the vehicle are prevented, and good dispersion stability of the microencapsulated pigment is maintained, while the structure of the polymer flocculant or the loose aggregates formed by the polymer flocculant and the dispersant can be stabilized.
Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thioethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, and N-methyl-2-pyrrolidone.
When the hysteresis width (ΔH) of the microencapsulated pigment to be incorporated in the ink is large, the specific gravity of the microencapsulated pigment is greater than 1. Since using a water-soluble organic solvent having a specific gravity greater than that of water makes it easier to adjust the specific gravity of the vehicle, it is preferable to use glycerin or the like having a specific gravity of more than 1.1 as the water-soluble organic solvent.

The water-soluble organic solvent is preferably blended in an amount of 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass, based on the total amount of ink. If the blending ratio of the water-soluble organic solvent exceeds 40% by mass, the dissolution stability of the specific gravity adjuster is likely to decrease. On the other hand, if the blending ratio of the water-soluble organic solvent is less than 1% by mass, the effect of suppressing water evaporation becomes poor.

When the writing ink is used in a ballpoint pen, it is preferable to add a lubricant such as a higher fatty acid such as oleic acid, a nonionic surfactant with a long-chain alkyl group, polyether-modified silicone oil, a thiophosphite triester such as thiophosphite tri(alkoxycarbonylmethyl ester) or thiophosphite tri(alkoxycarbonylethyl ester), a phosphate monoester of polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether, a phosphate diester of polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether, or a metal salt, ammonium salt, amine salt, or alkanolamine salt thereof to the ink to prevent wear of the ball seat.

In addition, various additives such as a pH adjuster, a rust inhibitor, a preservative, or an antifungal agent may be added as necessary.
Examples of the pH adjuster include inorganic salts such as sodium carbonate, sodium phosphate, and sodium acetate, and organic basic compounds such as water-soluble amine compounds.
Examples of the rust inhibitor include benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, and saponin.
Examples of the preservative or antifungal agent include carbolic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, and 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine.
Other additives include urea, nonionic surfactants, reduced or non-reduced starch hydrolysates, oligosaccharides such as trehalose, wetting agents such as sucrose, cyclodextrin, glucose, dextrin, sorbitol, mannitol, and sodium pyrophosphate, antifoaming agents, dispersants, fluorine-based surfactants that improve the penetration of ink, and nonionic surfactants.

The ink contains a reversible thermochromic microencapsulated pigment in an amount of preferably 5 to 40% by weight, more preferably 10 to 40% by weight, and even more preferably 10 to 30% by weight, based on the total weight of the ink. By containing the microencapsulated pigment in the above range, the desired color density can be obtained and a decrease in ink outflow can be prevented.

The ink composition according to the present invention can be produced by any conventionally known method. Specifically, the ink composition can be produced by blending the required amounts of the above-mentioned components and mixing them with various stirrers such as a propeller stirrer, homodisper, or homomixer, or various dispersing machines such as a bead mill.

When the ink for a writing instrument according to the present invention is used in a ballpoint pen, the viscosity thereof is preferably in the range of ¹ to 2000 mPa·s, more preferably 3 to 1500 mPa·s, and even more preferably 500 to 1000 mPa·s, since the ink can suppress sedimentation or aggregation of the microcapsule pigment when measured under conditions of a rotation speed of 3.84 sec ^-1 in an environment of 20°C. Furthermore, the viscosity is preferably in the range of 1 to 200 mPa·s, more preferably 10 to 100 mPa·s, and even more preferably 20 to 50 mPa·s, since the ink can improve the ink dischargeability from the pen tip of the ballpoint pen when measured under conditions of a rotation speed of 384 sec-1 in an environment of 20°C.
By having the viscosity within the above range, it is possible to maintain the dispersion stability of the microencapsulated pigment and the free flowability of the ink within the mechanism of the ballpoint pen at a high level.
The viscosity can be measured using a digital viscometer (Brookfield, product name: DV-II, cone-type rotor (CPE-42)) by placing the ink in an environment of 20°C and at a shear rate of 3.84 sec ^-1 (1 rpm) or 384 sec ^-1 (100 rpm).

When the writing instrument ink according to the present invention is used in a ballpoint pen, the surface tension is preferably in the range of 20 to 50 mN/m, more preferably 25 to 45 mN/m, in an environment of 20° C. By having a surface tension in the above range, it is easy to suppress bleeding of written lines and strike-through onto the paper surface, and the wettability of the ink to the paper surface can be improved.
The surface tension can be measured by a surface tension meter (manufactured by Kyowa Interface Science Co., Ltd., product name: DY-300) by placing the ink in an environment of 20° C. and using a platinum plate according to the vertical plate method.

When the writing instrument ink according to the present invention is used in a ballpoint pen, the pH is preferably in the range of 3 to 10, more preferably 4 to 9. When the pH is in the above range, aggregation or precipitation of the microencapsulated pigment contained in the ink in a low temperature range can be suppressed.
The pH can be measured by placing the ink in an environment of 20° C. using a pH meter (manufactured by DKK-TOA Corporation, product name: IM-40S type).

When the ink for a writing instrument according to the present invention is used in a marking pen, the viscosity is preferably in the range of 3 to 25 mPa·s, more preferably 4 to 20 mPa·s, and even more preferably 5 to 15 mPa·s when measured under conditions of a rotation speed of 6 rpm in an environment of 20° C. Furthermore, when measured under conditions of a rotation speed of 12 rpm, the viscosity is preferably in the range of 2 to 20 mPa·s, more preferably 3 to 15 mPa·s, and even more preferably 4 to 15 mPa·s. When measured under conditions of a rotation speed of 30 rpm, the viscosity is preferably in the range of 1 to 20 mPa·s, more preferably 2 to 15 mPa·s, and even more preferably 3 to 10 mPa·s. By having the viscosity in the above range, the fluidity of the ink and the dispersion stability of the microcapsule pigment can be improved.
The viscosity can be measured by placing the ink in an environment of 20° C. using a BL type rotational viscometer (manufactured by Toki Sangyo Co., Ltd., product name: TVB-M type viscometer, B type rotor).

When the writing instrument ink according to the present invention is used in a marking pen, the surface tension is preferably in the range of 25 to 50 mN/m, more preferably 25 to 45 mN, and even more preferably 35 to 45 mN/m in an environment of 20° C. By having a surface tension within the above range, it is easy to suppress bleeding of writing lines and strike-through onto the paper surface, and the wettability of the ink to the paper surface can be improved.
The surface tension can be measured by a surface tension meter (manufactured by Kyowa Interface Science Co., Ltd., product name: DY-300) by placing the ink in an environment of 20° C. and using a glass plate according to the vertical plate method.

When the writing ink according to the present invention is used in a marking pen, its pH is preferably in the range of 3 to 8, more preferably 4 to 7, and even more preferably 5 to 6. By having the pH in the above range, aggregation or precipitation of the microencapsulated pigment contained in the ink in a low temperature range can be suppressed.
The pH can be measured by placing the ink in an environment of 20° C. using a pH meter (manufactured by DKK-TOA Corporation, product name: IM-40S type).

A writing instrument containing the writing instrument ink of the present invention preferably contains 5 to 40% by mass of reversible thermochromic microencapsulated pigment in the total amount of the writing instrument ink, and consumes 60 to 280 mg of ink when writing 50 m on writing paper A conforming to old JIS P3201 at 20°C, and the value C obtained by dividing the density value of the handwriting in a colored state by the density value of the handwriting in a decolorized state is 20 or more.

If the blending ratio of microcapsule pigment exceeds 40% by mass, the ink flowability is likely to decrease, and the amount of microcapsule pigment accumulated on the paper surface becomes excessive, requiring more heat to erase or discolor the colored handwriting, which can be a strain on the hands when rubbing the handwriting to erase or discolor it. On the other hand, if the blending ratio of microcapsule pigment is less than 5% by mass, it becomes difficult to obtain the desired color density.

In addition, the amount of ink consumed by the writing instrument when writing 50 m, i.e., the "amount of ink consumed by the writing instrument per unit length", is calculated by the difference (W1-W2) between the mass of the writing instrument before writing (W1) and the mass of the writing instrument after writing a certain distance (W2).
If the ink consumption of the writing implement exceeds 280 mg when writing 50 m, the amount of microencapsulated pigment deposited on the paper surface becomes excessive, and more heat is required to erase or discolor the colored handwriting, which tends to cause strain on the hands when rubbing the handwriting to erase or discolor it, and also tends to cause writing defects such as bleeding. On the other hand, if the ink consumption is less than 60 mg, the writing density of the writing implement tends to be low, and also tends to cause writing defects such as smearing.

The "ink consumption per unit length" of the writing implement according to the present invention can be measured by writing on writing paper A conforming to old JIS P3201 under the following conditions in an environment of 20°C using an automatic writing tester conforming to JIS S6054 or JIS S6037.
Writing speed: 4m/min
Writing angle: 70°
Writing load: 100gf
In addition, for marking pens equipped with a chisel-shaped resin-finished pen body, the measurement is performed by bringing the broad surface of the pen body into close contact with the paper surface and maintaining the writing angle at 70°.

Moreover, a value C obtained by dividing the density value of the handwriting in a colored state by the density value of the handwriting in a decolored state is obtained by measuring the K value of the handwriting in each state using a fluorescent spectrodensitometer.
In general, it is preferable for a writing instrument to have a high writing density in order to improve the visibility of the handwriting. Furthermore, in a writing instrument containing ink for a writing instrument that contains a reversible thermochromic microencapsulated pigment, it is practical if the remaining color of the handwriting (color residue) after erasing by heat such as rubbing is difficult to see.
C represents the degree of density of the colored handwriting relative to the decolored handwriting, that is, the contrast between the colored and decolored states, and the value of C increases as the density value of the decolored handwriting decreases.
When C is 20 or more, the density of the handwriting in the colored state is high and the density of the handwriting in the erased state is low, and the contrast between the colored state and the erased state is good, so that the color of the handwriting is good in the colored state and the remaining color in the erased state after the handwriting is erased is difficult to see, and a writing instrument that satisfies practicality can be obtained. On the other hand, a writing instrument with C of less than 20 has a high density of the handwriting in the erased state, poor contrast between the colored state and the erased state, and the remaining color of the handwriting after erasing is easily visible, which is likely to impair the practicality of the writing instrument.
The density value (K value) of the handwriting can be measured using a fluorescent spectrodensitometer (manufactured by Konica Minolta, Inc., product name: FD-7 type).

Next, a writing instrument such as a ballpoint pen or a marking pen that contains the above-mentioned writing instrument ink will be described.
When filling a ballpoint pen, the structure and shape of the ballpoint pen itself are not particularly limited, and an example is a ballpoint pen having an ink reservoir tube filled with shear-thinning ink inside a barrel, the ink reservoir tube communicating with a ballpoint pen tip having a ball attached to the tip, and further having a liquid plug to prevent backflow in close contact with the end face of the ink.
Examples of ballpoint pen tips include tips in which the ball is held in a ball-holding portion formed by deforming the area near the tip of a metal pipe by pressing inward from the outer surface, tips in which the ball is held in a ball-holding portion formed by cutting a metal material with a drill or the like, tips in which a resin ball receiving seat is provided inside a metal or plastic tip, and tips in which the ball held in the tip is urged forward by a spring body.
The material of the ballpoint pen tip and ball is not particularly limited, and examples thereof include cemented carbide (super hard), stainless steel, ruby, ceramic, resin, rubber, and the like.
The diameter of the ball is preferably about 0.3 to 2.0 mm, more preferably about 0.3 to 1.5 mm, and even more preferably about 0.3 to 1.0 mm.
Generally, a ballpoint pen with a small diameter ball consumes less ink and tends to have a low writing density, and a ballpoint pen containing a writing instrument ink containing a reversible thermochromic microcapsule pigment tends to have a low writing density. Furthermore, since the amount of ink on the ball surface is small, the ball surface dries (dries up), which tends to cause writing defects such as smudges. In particular, when the blending ratio of the microcapsule pigment in the ink is increased to increase the solid content of the ink in order to improve the writing density, the dry-up resistance tends to decrease. However, when the writing instrument ink of the present invention is used in a ballpoint pen with a ball having a diameter of 0.3 to 0.5 mm, the writing density can be increased without increasing the solid content of the pigment, and the writing density can be improved without impairing the dry-up resistance, and the writing instrument can have an excellent contrast between the colored state and the decolored state.
In general, ballpoint pens with large diameters consume a large amount of ink and tend to produce high handwriting density, and ballpoint pens containing writing instrument inks containing reversible thermochromic microcapsule pigments can produce high handwriting density, but tend to leave a visible residual color when the handwriting is erased. However, when the writing instrument ink of the present invention is used in a ballpoint pen equipped with a ball having a diameter of 0.5 to 1.0 mm, it is possible to make the residual color in the erased state of the handwriting less visible, resulting in a writing instrument with excellent contrast between the colored state and the erased state.

The ink reservoir tube may be a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon, or a tubular body made of metal.
The ink reservoir may be connected to the tip directly or through a connecting member.
In addition, the ink holding tube may be in the form of a refill, with the refill housed in a barrel made of resin, metal, etc., or the barrel itself with a tip attached to the end may serve as the ink container, with ink being filled directly into the barrel.

Furthermore, when ink is stored in a retractable ballpoint pen, the structure and shape of the retractable ballpoint pen are not particularly limited, and any structure can be used as long as the writing tip provided on the ballpoint pen refill is stored within the barrel while being exposed to the outside air, and the writing tip protrudes from the barrel opening upon activation of the retractable mechanism.
Examples of the retraction mechanism include: (1) a side-slide type retraction mechanism in which an operating part (clip) movable in the front-rear direction protrudes radially outward from the rear side wall of the barrel, and the operating part is slid forward to cause the writing tip to appear and disappear from the front end opening of the barrel; (2) a rear-end knock type retraction mechanism in which an operating part provided at the rear end of the barrel is pressed forward to cause the writing tip to appear and disappear from the front end opening of the barrel; (3) a side-knock type retraction mechanism in which an operating part protruding from the outer surface of the side wall of the barrel is pressed radially inward to cause the writing tip to appear and disappear from the front end opening of the barrel; and (4) a rotating type retraction mechanism in which an operating part at the rear of the barrel is rotated to cause the writing tip to appear and disappear from the front end opening of the barrel.
The retractable ballpoint pen may be a composite type retractable ballpoint pen that contains a plurality of ballpoint pen refills in a barrel and causes the writing tip of one of the ballpoint pen refills to protrude and retract from the front end opening of the barrel by operating a retractable mechanism.

The rear end of the ink filled in the ink reservoir is filled with an ink backflow preventer.
The ink backflow preventive composition comprises a non-volatile liquid or a hardly-volatile liquid, examples of which include petrolatum, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or cooligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, polyether-modified silicone oil, fatty acid-modified silicone oil, and the like.
The ink backflow preventive composition may be used alone or in combination of two or more kinds.

It is preferable to thicken the non-volatile liquid and/or the low-volatility liquid to a suitable viscosity by adding a thickener.
Examples of thickeners include clay-based thickeners such as silica whose surface has been hydrophobically treated, fine particle silica whose surface has been methylated, aluminum silicate, swellable mica, and bentonite and montmorillonite that have been hydrophobically treated; fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, and zinc stearate; tribenzylidene sorbitol, fatty acid amides, amide-modified polyethylene wax, hydrogenated castor oil, dextrin-based compounds such as fatty acid dextrins, and cellulose-based compounds.
Furthermore, the above-mentioned liquid ink backflow preventive composition and a solid ink backflow preventive composition may be used in combination.

A ballpoint pen containing the ink for a writing instrument according to the present invention has a high writing density in the colored state, a low writing density in the decolorized state, and a good contrast between the colored state and the decolorized state, and the writing in the colored state can be erased or discolored more easily. Therefore, it is preferable that the total amount of the ink for a writing instrument contains 10 to 35 mass% of a reversible thermochromic microencapsulated pigment, the ink consumption when writing 50 m on writing paper A conforming to the old JIS P3201 is 70 to 210 mg, and the value C obtained by dividing the density value of the writing in the colored state by the density value of the writing in the decolorized state is 20 or more. Furthermore, since the density of the writing in the decolorized state is lower and the contrast between the colored state and the decolorized state is even better, it is more preferable that the reversible thermochromic microcapsule pigment is blended in the range of 10 to 35 mass% in the total amount of the writing instrument ink, the ink consumption when 50 m is written on writing paper A conforming to old JIS P3201 is 80 to 190 mg, and the value C obtained by dividing the density value of the writing in the colored state by the density value of the writing in the decolorized state is 25 or more, and it is even more preferable that the reversible thermochromic microcapsule pigment is blended in the range of 10 to 35 mass% in the total amount of the writing instrument ink, the ink consumption when 50 m is written on writing paper A conforming to old JIS P3201 is 90 to 170 mg, and the value C obtained by dividing the density value of the writing in the colored state by the density value of the writing in the decolorized state is 25 or more.

When filling a marking pen, the structure and shape of the marking pen itself are not particularly limited, and examples include a marking pen in which an ink occlusion body made of a fiber bundle is built into the barrel, and a marking pen tip made of a fiber processed body with capillary gaps is attached to the barrel directly or via an intermediate member, and the ink occlusion body and tip are connected to the ink occlusion body, and the ink is impregnated with cohesive ink, and a marking pen in which the tip and an ink reservoir are arranged via a valve that opens when the tip is pressed, and the ink is directly contained in the ink reservoir.

Examples of marking pen tips include conventional porous materials with interconnected pores, such as resin-processed fibers, fused heat-melting fibers, and felt, with a porosity selected from the range of approximately 30 to 70%, and one end of the tip is processed into a bullet-like, rectangular, chisel-like, or other shape suited to the purpose for which it is used.

The ink occlusion body is made by bundling crimped fibers in the longitudinal direction, and is placed inside a plastic cylinder or a covering such as a film, with the porosity adjusted to a range of approximately 40 to 90%.

The valve body can be of the conventional general-purpose pumping type, but it is preferable to use one with a spring pressure that can be pressed and released by the pressure of the pen.

A marking pen containing the ink for a writing instrument according to the present invention has a high writing density in the colored state, a low writing density in the erased state, and a good contrast between the colored state and the erased state, and the writing in the colored state can be erased or discolored more easily. Therefore, it is preferable that the reversible thermochromic microencapsulated pigment is blended in the total amount of the ink for a writing instrument in the range of 10 to 30 mass%, the ink consumption when writing 50 m on writing paper A conforming to the old JIS P3201 is 100 to 260 mg, and the value C obtained by dividing the density value of the writing in the colored state by the density value of the writing in the erased state is 20 or more. Furthermore, since the density of the writing in the decolorized state is lower and the contrast between the colored state and the decolorized state is even better, it is more preferable that the reversible thermochromic microcapsule pigment is blended in the range of 10 to 30 mass% in the total amount of the ink for the writing instrument, the ink consumption when writing 50 m on writing paper A conforming to the old JIS P3201 is 120 to 250 mg, and the value C obtained by dividing the density value of the writing in the colored state by the density value of the writing in the decolorized state is 21.5 or more.

Furthermore, the shapes of the above-mentioned ballpoint pens and marking pens are not limited to those described above, but may be composite writing instruments (double-headed, tip-operating, etc.) equipped with tips of different shapes or nibs that dispense ink of different colors.

The handwriting obtained by writing on a surface to be written on using a writing instrument containing the above-mentioned ink for writing instruments can be discolored by rubbing with a finger or by using a heating or cooling tool.
Examples of the heating tool include an electrically-heated color-changing tool equipped with a resistance heating element such as a PTC element, a heat-changing tool filled with a medium such as hot water, a heat-changing tool using steam or laser light, application of a hair dryer, etc. A friction member is preferably used because it can change color by a simple method.
Examples of cooling devices include electrochemically-induced color-changing devices using a Peltier element, color-changing devices filled with a refrigerant such as cold water or ice chips, cooling agents, refrigerators, freezers, and the like.

The friction member is preferably an elastic body such as an elastomer or plastic foam, which has a high elastic feel and can generate appropriate friction and heat during rubbing.
Although a general eraser for erasing pencil marks may be used to rub the marks, the rub produces eraser dust during the rub, and therefore the above-mentioned friction member, which produces almost no eraser dust, is preferably used.
Examples of the material for the friction member include silicone resin, SEBS resin (styrene-ethylene-butadiene-styrene block copolymer), and polyester resin.

A writing instrument set can also be obtained by combining a writing instrument with a friction member (friction body) of any shape that is separate from the writing instrument, and by providing the above-mentioned friction member on the writing instrument, the writing instrument can be made to have excellent portability.
In the case of a writing instrument with a cap, the location where the friction member is provided is not particularly limited, and for example, the cap itself may be formed from a friction member, the barrel itself may be formed from a friction member, if a clip is provided, the clip itself may be formed from a friction member, or the friction member may be provided at the tip (top) of the cap or the rear end of the barrel (the part where the writing tip is not provided).
In the case of a retractable writing instrument, the location where the friction member is provided is not particularly limited, and for example, the barrel itself may be formed from a friction member, or if a clip is provided, the clip itself may be formed from a friction member, or the friction member may be provided near the opening of the barrel, at the rear end of the barrel (the portion where the writing tip is not provided), or at the knock portion.

The following are examples. Note that parts in the examples indicate parts by weight.

Preparation of reversible thermochromic microcapsule pigment A (a) 2-(4-chloroanilino)-3-methyl-6-(N-n-hexyl-N-p-tolylamino)fluoran 6 parts, (b) 1,1-bis(4-hydroxyphenyl)-2-ethylhexane 6 parts, 2,2-bis(4-hydroxyphenyl)hexafluoropropane 10 parts, (c) 4-benzyloxyphenylethyl caprate 50 parts, a reversible thermochromic composition was added to a mixed solution of aromatic isocyanate prepolymer 35 parts and cosolvent 40 parts as a wall film material, and then emulsified and dispersed in an 8% polyvinyl alcohol aqueous solution. After stirring while heating, 2.5 parts of water-soluble aliphatic modified amine was added, and stirring was continued to prepare a microcapsule dispersion. From the microcapsule dispersion, a reversible thermochromic microcapsule pigment A with an average particle size of 1.9 μm was obtained by centrifugation.
The reversible thermochromic microencapsulated pigment A had a complete color-developing temperature _t1 of -18°C and a complete decolorizing temperature _t4 of 64°C, and reversibly changed from black to colorless due to temperature change.

Preparation of reversible thermochromic microcapsule pigment B (a) 6 parts of 2-(4-chloroanilino)-3-methyl-6-[N-(4-n-butylphenyl)-N-ethylamino]fluoran as component (b), 6 parts of 1,1-bis(4-hydroxyphenyl)-2-ethylhexane as component (c), 10 parts of 2,2-bis(4-hydroxyphenyl)hexafluoropropane as component (d), and 50 parts of 4-benzyloxyphenylethyl caprate as component (e), were added to a mixed solution of 35 parts of aromatic isocyanate prepolymer as a wall film material and 40 parts of cosolvent, and then emulsified and dispersed in an 8% polyvinyl alcohol aqueous solution. After stirring while heating, 2.5 parts of water-soluble aliphatic modified amine were added, and stirring was continued to prepare a microcapsule dispersion. From the microcapsule dispersion, a reversible thermochromic microcapsule pigment B with an average particle size of 2.1 μm was obtained by centrifugation.
The reversible thermochromic microencapsulated pigment B had a complete color-developing temperature _t1 of -18°C and a complete decolorizing temperature _t4 of 63°C, and reversibly changed from black to colorless due to temperature change.

Preparation of reversible thermochromic microcapsule pigment C (a) 2-anilino-3-methyl-6-(N-n-hexyl-N-p-tolylamino)fluoran 6 parts, (b) 1,1-bis(4-hydroxyphenyl)-2-ethylhexane 6 parts, 2,2-bis(4-hydroxyphenyl)hexafluoropropane 10 parts, (c) 4-benzyloxyphenylethyl caprate 50 parts, a reversible thermochromic composition consisting of a wall film material of aromatic isocyanate prepolymer 35 parts and a cosolvent 40 parts mixed solution, emulsified and dispersed in an 8% polyvinyl alcohol aqueous solution, continued stirring while heating, then added water-soluble aliphatic modified amine 2.5 parts, further continued stirring to prepare a microcapsule dispersion. From the microcapsule dispersion, a reversible thermochromic microcapsule pigment C with an average particle size of 2.0 μm was obtained by centrifugation.
The reversible thermochromic microencapsulated pigment C had a complete color-developing temperature _t1 of -18°C and a complete decolorizing temperature _t4 of 64°C, and reversibly changed from black to colorless due to temperature change.

Preparation of reversible thermochromic microcapsule pigment D (a) 2-anilino-3-methyl-6-(N-n-octyl-N-p-tolylamino)fluoran 6 parts, (b) 1,1-bis(4-hydroxyphenyl)-2-ethylhexane 6 parts, 2,2-bis(4-hydroxyphenyl)hexafluoropropane 10 parts, (c) 4-benzyloxyphenylethyl caprate 50 parts, a reversible thermochromic composition was added to a mixed solution of aromatic isocyanate prepolymer 35 parts and cosolvent 40 parts as a wall film material, and then emulsified and dispersed in an 8% polyvinyl alcohol aqueous solution. After stirring while heating, 2.5 parts of water-soluble aliphatic modified amine was added, and stirring was continued to prepare a microcapsule dispersion. From the microcapsule dispersion, a reversible thermochromic microcapsule pigment D with an average particle size of 1.9 μm was obtained by centrifugation.
The reversible thermochromic microencapsulated pigment D had a complete color-developing temperature _t1 of -18°C and a complete decolorizing temperature _t4 of 64°C, and reversibly changed from black to colorless due to temperature change.

Preparation of reversible thermochromic microcapsule pigment E (a) 2-anilino-3-methyl-6-(N-ethyl-N-p-tolylamino)fluoran 6 parts, (b) 1,1-bis(4-hydroxyphenyl)-2-ethylhexane 6 parts, 2,2-bis(4-hydroxyphenyl)hexafluoropropane 10 parts, (c) 4-benzyloxyphenylethyl caprate 50 parts, a reversible thermochromic composition was added to a mixed solution of aromatic isocyanate prepolymer 35 parts and cosolvent 40 parts as a wall film material, and then emulsified and dispersed in an 8% polyvinyl alcohol aqueous solution. After stirring while heating, 2.5 parts of water-soluble aliphatic modified amine was added, and stirring was continued to prepare a microcapsule dispersion. From the microcapsule dispersion, a reversible thermochromic microcapsule pigment E with an average particle size of 2.0 μm was obtained by centrifugation.
The reversible thermochromic microencapsulated pigment E had a complete color-developing temperature _t1 of -17°C and a complete decolorizing temperature _t4 of 64°C, and reversibly changed from black to colorless due to temperature change.

Example 1
Preparation of Water-Based Ink for Writing Instruments 25 parts of reversible thermochromic microencapsulated pigment A (previously cooled to −18° C. or lower to develop a black color), 0.3 parts of a shear thinning agent (xanthan gum), 10 parts of urea, 10 parts of glycerin, 0.5 parts of a nonionic penetrability agent (manufactured by San Nopco Ltd., product name: Nopco SW-WET-366), 0.1 parts of a modified silicone antifoaming agent (manufactured by San Nopco Ltd., product name: Nopco 8034), 0.5 parts of a phosphate ester surfactant (manufactured by Dai-ichi Kogyo Seiyaku Kogyo Co., Ltd., product name: Plysurf AL), 0.5 parts of a pH adjuster (triethanolamine), 0.2 parts of a fungicide (manufactured by Lonza Japan Ltd., product name: Proxel XL-2), and 52.9 parts of water were mixed to prepare a water-based ink for writing instruments.

Manufacture of ballpoint pen The above-mentioned water-based ink was sucked and filled into an ink reservoir made of a polypropylene pipe, and then connected to a ballpoint pen tip having a 0.3 mm diameter carbide ball at its tip via a resin holder. Next, a viscoelastic ink backflow prevention body (liquid plug) mainly composed of polybutene was filled from the rear end of the ink reservoir, and a tail plug was fitted to the rear of the pipe, and degassing was performed by centrifugation to obtain a ballpoint pen refill.
Next, the above refill was incorporated into a barrel to prepare a ballpoint pen (retractable ballpoint pen).
The ballpoint pen has a tip attached to a ballpoint pen refill, which is stored in the barrel in a state exposed to the outside air, and the tip protrudes from the front end opening of the barrel by operating a clip-shaped mechanism (slide mechanism) attached to the rear side wall of the barrel. The rear end of the barrel is made of SEBS resin as a friction member.

Tables 1 to 5 below show the compositions of the water-based inks and the diameters of the ballpoint pen balls of Examples 1 to 20 and Comparative Examples 1 to 10.
The water-based inks of Examples 2 to 20 and Comparative Examples 1 to 10 were prepared by changing the types and amounts of the materials used in Example 1 as shown in Tables 1 to 5. The ballpoint pens were also prepared by changing the diameter of the ball used in Example 1 as shown in Tables 1 to 5.

The contents of the materials in Tables 1 to 5 will be explained according to the note numbers.
(1) Shear thinning agent (xanthan gum)
(2) Nonionic penetrating agent [manufactured by San Nopco Ltd., product name: Nopco SW-WET-366]
(3) Modified silicone defoamer [manufactured by San Nopco Ltd., product name: Nopco 8034]
(4) Phosphate ester surfactant [manufactured by Daiichi Kogyo Seiyaku Kogyo Co., Ltd., product name: Plysurf AL]
(5) pH adjuster (triethanolamine)
(6) Mildewproofing agent [manufactured by Lonza Japan Co., Ltd., product name: Proxel XL-2]

Example 21
Preparation of Water-Based Ink for Writing Instruments 23 parts of reversible thermochromic microencapsulated pigment A (previously cooled to -18°C or lower to develop a black color), 0.5 parts of a polymer flocculant (hydroxyethyl cellulose) [manufactured by Dow Chemical Japan Co., Ltd., product name: CELLOSIZE WP-09], 0.2 parts of an acrylic polymer dispersant [manufactured by Nippon Lubrizol Co., Ltd., product name: Solsperse 43000], 1 part of an organic nitrogen sulfur compound (a mixture of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one) [manufactured by Hokko Chemical Industry Co., Ltd., product name: Hokuside R-150], 0.5 parts of polyvinyl alcohol, 25 parts of glycerin, 0.02 parts of an antifoaming agent, and 49.78 parts of water were mixed to prepare a water-based ink for writing instruments.

The above-mentioned water-based ink was impregnated into an ink occlusion body made of polyester sliver covered with a synthetic resin film, and housed in a barrel made of polypropylene resin. A resin-processed pen body (bullet-shaped) made of polyester fiber was connected to the tip of the barrel via a resin holder, and a cap was attached to prepare a marking pen. The top of the cap was fitted with SEBS resin as a friction member.

Example 22
Preparation of Water-Based Ink for Writing Instruments 20 parts of reversible thermochromic microencapsulated pigment A (previously cooled to -18°C or lower to develop a black color) and 10 parts of polymer flocculant (hydroxyethyl cellulose) [manufactured by Dow Chemical Japan, product name: CELLOSIZE] were mixed. A water-based ink for writing instruments was prepared by mixing 0.4 parts of an acrylic polymer dispersant (manufactured by Lubrizol Japan, product name: Solsperse 43000), 0.2 parts of preservative A (2-pyridinethiol 1-oxide sodium) (manufactured by Lonza Japan, product name: Sodium Omadine), 0.2 parts of preservative B (3-iodo-2-propynyl N-butylcarbamate) (manufactured by Lonza Japan, product name: Glycasil 2000), 18 parts of glycerin, 0.2 parts of an antifoaming agent, 0.05 parts of a pH adjuster (10% diluted phosphoric acid solution), and 53.55 parts of water, and then adding and mixing 7 parts of a specific gravity adjuster (sodium polytungstate) (manufactured by SOMETU, product name: SPT-1).

The above-mentioned water-based ink was impregnated into an ink occlusion body made of polyester sliver covered with a synthetic resin film, and housed in a barrel made of polypropylene resin. A resin-processed pen body (bullet type) made of polyester fiber was attached to the tip of the barrel via a resin holder, and a cap was attached to prepare a marking pen. The rear end of the barrel was fitted with SEBS resin as a friction member.

Example 23
Preparation of Water-Based Ink for Writing Instruments 25 parts of reversible thermochromic microencapsulated pigment A (previously cooled to -18°C or lower to develop a black color), 0.5 parts of a polymer flocculant (hydroxyethyl cellulose) [manufactured by Dow Chemical Japan Co., Ltd., product name: CELLOSIZE WP-09], 0.2 parts of an acrylic polymer dispersant [manufactured by Nippon Lubrizol Co., Ltd., product name: Solsperse 43000], 1 part of an organic nitrogen sulfur compound (a mixture of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one) [manufactured by Hokko Chemical Industry Co., Ltd., product name: Hokuside R-150], 0.5 parts of polyvinyl alcohol, 25 parts of glycerin, 0.02 parts of an antifoaming agent, and 47.78 parts of water were mixed to prepare a water-based ink for writing instruments.

The above-mentioned water-based ink was impregnated into an ink occlusion body made of polyester sliver covered with a synthetic resin film, and housed in a barrel made of polypropylene resin. A resin-processed pen body (chisel type) made of polyester fiber was connected to the tip of the barrel via a resin holder, and a cap was attached to prepare a marking pen. The rear end of the barrel was fitted with SEBS resin as a friction member.

Tables 6 to 10 below show the composition of each of the water-based inks of Examples 21 to 40 and Comparative Examples 11 to 23, and the shape of the resin-finished pen body of the marking pen.
The water-based inks of Examples 24 to 40 and Comparative Examples 11 to 23 were prepared by changing the types and amounts of the materials used in Examples 21 to 23 as shown in Tables 6 to 10. Marking pens were also prepared by changing the shape of the resin-processed pen body used in Examples 21 to 23 as shown in Tables 6 to 10.

The contents of the materials in Tables 6 to 10 are explained according to the note numbers.
(1) Polymer flocculant (hydroxyethyl cellulose)
[Product name: CELLOSIZE WP-09, manufactured by Dow Chemical Japan Co., Ltd.]
(2) Acrylic polymer dispersant [manufactured by Lubrizol Japan, product name: Solsperse 43000]
(3) Organic nitrogen sulfur compounds (mixture of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one)
[Hokuko Chemical Industry Co., Ltd., product name: Hokuside R-150]
(4) Preservative A (sodium 2-pyridinethiol 1-oxide)
[Manufactured by Lonza Japan Co., Ltd., product name: Sodium Omagine]
(5) Preservative B (3-iodo-2-propynyl N-butylcarbamate)
[Manufactured by Lonza Japan Co., Ltd., product name: Graicasil 2000]
(6) Specific gravity adjuster (sodium polytungstate)
(Manufactured by SOMETU, product name: SPT-1)

Preparation of an erasing tool SEBS resin (SEBS copolymer elastomer) [manufactured by Aron Chemical Industries, Ltd., product name: AR-885C] was melt-kneaded at 150°C and molded into a dome shape so that the tip (scraping part) had a curvature radius R of 2.5 mm, to obtain a friction member. The Shore A hardness of the friction member measured with a durometer [manufactured by Techclock, Ltd., product name: GS-719G] in accordance with the measurement method described in JIS K6253 was 83.
Next, the above-mentioned friction member was attached to the rear end of a ballpoint pen barrel having a structure in which a ballpoint pen tip (writing tip) provided on a ballpoint pen refill protrudes from the front end opening of the barrel by operating a clip-shaped retractable mechanism (slide mechanism) provided on the rear side wall of the barrel, thereby producing an eraser.

Measurement of ink consumption After measuring the mass (W1) of the writing implements (ballpoint pens or marking pens) prepared in Examples 1 to 40 and Comparative Examples 1 to 23, the writing implements were set in an automatic writing tester conforming to JIS S6054 or JIS S6037, and a writing test was performed in which 50 m was written on writing paper A conforming to old JIS P3201 under the following conditions at room temperature (20° C.), and the mass (W2) of the writing implement after 50 m was measured. Next, the ink consumption of the writing implement (the ink consumption of the writing implement when writing 50 m) was calculated from the difference (W1-W2) between the mass (W1) of the writing implement before writing and the mass (W2) of the writing implement after writing 50 m.
Writing speed: 4m/min
Writing angle: 70°
Writing load: 100gf
In the case of a marking pen equipped with a chisel-type resin-processed pen body, the wide surface of the pen body was brought into close contact with the paper surface to maintain a writing angle of 70°. In addition, the writing test was performed by continuously writing a 3 cm diameter circle in a spiral shape for 50 m on the writing paper when the writing instrument was a ballpoint pen or a marking pen equipped with a bullet-type resin-processed pen body, and by continuously writing a straight line for 50 m on the writing paper when the writing instrument was a marking pen equipped with a chisel-type resin-processed pen body.

Evaluation of handwriting in colored and decolored states Among the writing implements produced in Examples 1 to 40 and Comparative Examples 1 to 23, for the ballpoint pens or the marking pens equipped with bullet-shaped resin-processed pen bodies, 12 elliptical circles with a major axis of about 15 mm and a minor axis of about 8 mm were handwritten in a spiral pattern in a direction parallel to the short side of an A4-size test paper (portrait) in a room temperature (20° C.) environment, so that the circles were in contact with each other.
In addition, for the marking pens equipped with chisel-type resin-processed pen bodies among the writing implements produced in Examples 1 to 40 and Comparative Examples 1 to 23, a straight line of 15 cm was handwritten on an A4-size test paper (portrait) in a room temperature (20°C) environment in a direction parallel to the short side of the paper with the wide surface of the pen body in close contact with the paper. The resulting handwriting was visually confirmed, and the colored handwriting was evaluated according to the following criteria. Note that writing paper A conforming to the old JIS P3201 was used as the test paper.
A: The color density of the handwriting was high, and good coloring was obtained.
B: The color density of the handwriting was slightly low, but was at a level that did not cause any practical problems.
C: The color density of the handwriting was low, and good coloring was not obtained.
Next, each of the colored handwritings obtained on the test paper was rubbed and erased with the above-mentioned eraser, and the erased areas were visually inspected and the erased handwritings were evaluated according to the following criteria.
A: The density of the decolorized handwriting was low, and no residual color was visible in the decolorized state.
B: The density of the erased handwriting was somewhat high, and slight residual color was visible in the erased state, but was at a level that did not cause any practical problems.
C: The density of the decolorized handwriting was high, and residual color was visible in the decolorized state.

Preparation of samples for concentration measurement and for evaluation of handwriting erasability Among the writing implements prepared in Examples 1 to 40 and Comparative Examples 1 to 23, ballpoint pens or marking pens equipped with a bullet-shaped resin-processed pen body were set in a record-type line-drawing machine (manufactured by DC Corporation, product name: PL-1000) and samples were prepared by drawing a 10 m circle on writing paper A conforming to old JIS P3201 under the following conditions at room temperature (20°C).
Writing speed: 4m/min
Writing angle: 70°
Writing load: 100gf
Furthermore, among the writing implements produced in Examples 1 to 40 and Comparative Examples 1 to 23, the marking pens equipped with a chisel-shaped resin-processed pen body were set in an automatic writing tester conforming to JIS S6037 so that the wide surface of the pen body was in close contact with the paper surface, and a straight line of 10 cm was written on writing paper A conforming to the old JIS P3201 under the following conditions at room temperature (20° C.) to produce samples.
Writing speed: 4m/min
Writing angle: 70°
Writing load: 100gf

Measurement of handwriting density The drawn line portions of the samples prepared above were set in the measurement portion of a fluorescence spectrodensitometer (manufactured by Konica Minolta, Inc., product name: FD-7 type), and the density value in the colored state was measured from the K value of the fluorescence spectrodensitometer. Next, the drawn line portions of each sample were rubbed and erased with the above-mentioned eraser, and the erased portions were set in the measurement portion of the above-mentioned fluorescence spectrodensitometer, and the density value in the decolorized state was measured from the K value of the fluorescence spectrodensitometer.
Furthermore, C was calculated by dividing the measured density value in the colored state by the density value in the decolored state.

Evaluation of handwriting erasability The above-mentioned eraser was pressed against the drawn line portion of each sample prepared above at an angle of 70° to the paper surface, and rubbed by moving it back and forth over the paper surface five times at a speed of 10 m/min and a load of 500 gf. The degree of erasure of the drawn line portion after rubbing was visually confirmed, and the handwriting erasability was evaluated according to the following criteria.
A: The drawn lines at the rubbed areas were completely erased.
B: Most of the drawn lines in the rubbed areas were erased, and there was no problem in practical use.
C: There were many places where the drawn lines were not erased even after rubbing.

The following Tables 11 to 20 show the ink consumption of the writing implement when writing 50 m of each of the water-based inks of Examples 1 to 40 and Comparative Examples 1 to 23, the handwriting evaluation of the colored and decolored states, the results of the concentration measurement, the C value obtained from the concentration measurement, and the results of the handwriting erasability.

_t1 Complete coloring temperature _t2 Coloring start temperature _t3 Discoloration start temperature _t4 Complete discoloration temperature _T1 Complete discoloration temperature _T2 Discoloration start temperature _T3 Coloring start temperature _T4 Complete coloring temperature ΔH Hysteresis width

Claims (11)

(a) a fluoran derivative represented by formula (I) as an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that reversibly induces an electron donating/accepting reaction between the components (a) and (b) in a specific temperature range. A reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition therein.
A thermochromic writing instrument containing a writing instrument ink that changes color from colored to colorless, comprising:
The reversible thermochromic microencapsulated pigment is blended in the range of 5 to 40% by mass in the total amount of the ink for the writing instrument, and the thermochromic writing instrument consumes 60 to 280 mg of ink when writing 50 m on writing paper A conforming to old JIS P3201 at 20°C, and the value C obtained by dividing the density value of the handwriting in a colored state by the density value of the handwriting in a decolorized state is 20 or more.
[Wherein,
n1 is 0, 1 or 2;
n2 is 0 or 1;
X's each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, or a group having 6 to 12 carbon atoms and represented by formula (i):
(Wherein,
ni is 0 or 1;
R ⁱ is a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms.
and
provided that, when n2 is 0, one of the two X's is a group represented by formula (i), and the other is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, and the total number of carbon atoms of the two X's is 10 to 22, and when X's is a hydrogen atom, the number of carbon atoms represented by X's is 0;
When n2 is 1, both of X's are not hydrogen atoms,
Each Y is independently a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 3 carbon atoms; and
When n2 is 1, Z is a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 3 carbon atoms, with the proviso that the substitution position of Z is the para position . 2. The thermochromic writing instrument of claim 1, wherein the fluoran derivative is represented by formula (Ia):
[Wherein,
n a is 0, 1 or 2;
^Xa each independently represents a linear or branched alkyl group having 1 to 8 carbon atoms, or a group having 6 to 12 carbon atoms and represented by formula (ia):
(Wherein,
nia is 0 or 1;
R ^ia is a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms.
and
Each Y ^a is independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and Z ^a is a halogen atom, with the proviso that Z ^a is substituted at the para position . 2. The thermochromic writing instrument of claim 1, wherein the fluoran derivative is represented by formula (Ib):
(Wherein,
nb is 0, 1 or 2;
X ^b1 is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms;
X ^b2 is a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms;
provided that the total number of carbon atoms in X ^b1 and X ^b2 is 5 to 11 , and when X ^b1 or X ^b2 is a hydrogen atom, the number of carbon atoms represented by X ^b1 or X ^b2 is 0, and each Y ^b is independently a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. The thermochromic writing instrument according to any one of claims 1 to 3, wherein the vehicle is an aqueous vehicle. The thermochromic writing instrument according to any one of claims 1 to 4, wherein the thermochromic writing instrument is a ballpoint pen. The thermochromic writing instrument according to claim 5, in which the reversible thermochromic microencapsulated pigment is blended in the range of 10 to 35% by mass in the total amount of the ink for the writing instrument, the ink consumption of the writing instrument when writing 50 m on writing paper A conforming to old JIS P3201 at 20°C is 70 to 210 mg, and the value C obtained by dividing the density value of the writing in a colored state by the density value of the writing in a decolorized state is 20 or more. The thermochromic writing instrument according to claim 5 or 6, wherein the ball at the writing tip of the ballpoint pen has a diameter of 0.3 to 0.5 mm. The thermochromic writing instrument according to claim 5 or 6, wherein the ball at the writing tip of the ballpoint pen has a diameter of 0.5 to 1.0 mm. The thermochromic writing instrument according to any one of claims 1 to 4, wherein the thermochromic writing instrument is a marking pen. The thermochromic writing instrument according to claim 9, in which the reversible thermochromic microencapsulated pigment is blended in the range of 10 to 30% by mass in the total amount of the ink for the writing instrument, the ink consumption of the writing instrument when writing 50 m on writing paper A conforming to old JIS P3201 at 20°C is 100 to 260 mg, and the value C obtained by dividing the density value of the writing in a colored state by the density value of the writing in a decolorized state is 20 or more. The thermochromic writing instrument according to any one of claims 1 to 10, which is provided with a friction member that discolors handwriting made with the thermochromic writing instrument due to frictional heat.