JPS645553B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to recording materials, and is applied to pressure-sensitive recording, heat-sensitive recording, etc., which develop color by reacting with colorless or light-colored compounds. Recordings using coloring compositions that have been conventionally used for these recordings have some dissatisfaction with coloring speed, coloring density, fastness, especially light fastness, moisture resistance, water resistance, solvent resistance, etc. was. According to the present invention, in order to solve these drawbacks, a color-forming composition system consisting of a conventional electron donor and an electron acceptor is combined with a β-diketone derivative having 6 or more carbon atoms and a metal. A coloring composition is provided that is characterized in that it contains a metal chelate compound that is easy to dissolve in an organic solvent as a coloring aid. The electron donors used in the present invention are conventionally known ones, such as triphenylmethane phthalide series, fluoran series, phenothiazine series, indolylphthalide series, lyuco auramine series, spiropyran series, and triphenylmethane phthalide series. It means colorless dyes such as enylmethane-based, triazene-based, naphtolactam-based, benzopyran-based, azomethine-based, and hydroxyphthalane-based dyes. Electron acceptors are inorganic and organic color developers that exhibit color reactions with them, such as clays,
Zeolite, bentonite, colloidal silica,
It means artificial silicates, phenols and their derivatives, aldehyde initial condensates of salicylic acid and its derivatives, and the like. The organic solvent easily soluble metal chelate compound composed of a β-diketone derivative and a metal used in the present invention is
The compound acts as a coloring aid in the coloring composition described above, and is the following compound. As is well known, diketone is a general term for compounds having two ketonic carbonyl groups, and those directly adjacent to the carbonyl groups are α-diketones, 1, 2, and 3.
Those with intervening carbon chains are called β, γ, and δ diketones, respectively. The diketone used in the present invention is β-diketone, and has the formula As in, formula (a) (keto form), formula (b) (enol form)
It exists as an equilibrium mixture of tautomers. The simplest derivative of β-diketone is one in which R ₁ and R ₂ are -CH ₃ and R ₃ is -H in formula (a), that is, the formula

It is acetylacetone (2,4-pentanedione) of the formula. When R ₁ and R ₂ in formula (a) are -H or -OH, they are called ketoaldehydes or keto acids, which are not diketones and therefore do not fall within the scope of the present invention. That is, in the case of the present invention, R ₁ and R ₂ represent -C as described later, and R ₃ represents -H or -C. As shown in formula (c) above, such a β-diketone coordinates to the metal as an anion with an enol structure by reacting with a metal ion, forming a 6-membered chelate ring, and forming a 4-coordinated divalent metal ion or a 6-coordinated divalent metal ion. It coordinates with the trivalent metal ion to form a coordination-saturated, uncharged complex.
Although such uncharged complexes contain metal ions, they are easily soluble in organic solvents and have a low melting temperature. formula Acetylacetone chelate of Zn() is easily soluble in organic solvents. However, the expression The acetylacetone chelate of Co() is an uncharged complex, but the central metal ion is not completely covered by hydrophobic ligands, making it soluble in water and sparingly soluble in organic solvents. In the case of the present invention, unlike an ionic reaction in an aqueous solution, the coloring reaction is an electron acceptance reaction in an organic solvent, so such a compound does not function as a coloring aid in the present invention. Therefore,
An essential condition for the coloring aid of the metal chelate compound in the present invention is that it is easily soluble in an organic solvent. However, this indicates the state of the metal chelate compound existing in the coloring composition system before the coloring reaction, and the structure is such that it remains easily soluble in organic solvents after the coloring reaction. is not limited. The β-diketone derivatives in the present invention include (1) those having an aliphatic side chain, (2) those containing an alicyclic structure, (3) those having an aromatic side chain, (4) those containing a heterocycle, (5) those containing halogen elements, and (6) triketones, tetraketones, and higher polyketones containing β-diketone structures. Specific names of compounds belonging to this classification are as follows. (1) 2,4-hexanedione, 2,4-heptanedione, 2,4-octanedione, 2,4-nonanedione, 6-methyl-2,4-octanedione, 2,4-decanedione, 3-methyl -2,4-nonanedione, 2,4-undecanedione, 3-ethyl-4,6-nonanedione, 2,4-dodecanedione, 3-ethyl-8-methyl-4,6-nonanedione, 2,4-tride candione, 3-ethyl-4,6-undecanedione, 2,4-tetradecanedione, 2,4-pentadecanedione, 2,4-hexadecanedione, 2,4-heptadecanedione, 2,4-octadecanedione, 2,4-nonadecanedione, 2,4-eicosandione, 7,9-eicosandione, 9,11-docosandione, 13-dodecyl-12,14-pentacosandione, 19-hexadecyl-18,20-heptatricone Sangeon et al. (2) 1-cyclopropyl-1,3-butanedione, 2-acetylcyclohexanone, 2-butyrylcyclohexanone, 2-caproylcyclohexanone, 2-benzoylcyclohexanone, 2-(2-benzylpropionyl)cyclohexanone, etc. (3) 1-phenyl-1,3-butanedione, 1-phenyl-1,3pentanedione, 1-phenyl-1,3hexanedione, 1-phenyl-2,4-heptanedione, 2-phenyl-2, 4-heptanedione, 1-phenyl-5-methyl-1,3hexanedione, 1-phenyl-3,5-decanedione, 1-phenyl-4-ethyl-1,3-octanedione, 1,3-diphenyl- 1,3-propanedione, 1-phenyl-2-heptyl-1,3-butanedione, 3,6-diphenyl-2,4-hexanedione, 1-phenyl-2,4-tridecanedione, 1-phenyl- 3,5-tetradecanedione, etc. (4) 1-(2-furyl)-1,3-butanedione, 1-(2-pyridyl)1,3-butanedione, 1-(2-furyl)-5-methyl-1,3-hexanedione, 1 -(2-furyl)-1,3-decanedione, 1-(2-thienyl)-1,3-decanedione, etc. (5) 1-chloro-1,1-difluoro-2,4-
heptanedione, 1,1,1,2,2-pentafluoro-3,
5-heptanedione, 1-chloro-1,1-difluoro-6-methyl-2,4-heptanedione, 2-(1,1,2,2,2-pentafluoropropionyl)cyclopentanone, 1-chloro -1,1-difluoro-2,4-
Decanedione, 1,1,1,2,2-pentafluoro-3,
5-decanedione, 1,1,1,2,2-pentafluoro-3,
5-undecanedione etc. (6) 2,4,6-heptanetrione, 2,4,6-octantrione, 3,5-dimethyl-2,4,6-heptantrione, 1-phenyl-1,3,5-hexantrione, 1 -(4-chlorophenyl)-1,3,5-hexantrone, 1-phenyl-1,3,5-decanetrione, 1-phenyl-5-(3-pyridyl)-1,
3,5-pentanethrone, 1,4-diphenyl-1,3,5-hexantrone, 2,4,5,7-octantetrone, 3,5,6,8-decantetrone, 2,4,10, 12-tridecantetrone, bis(acetoacetyl)ferrocene, 1,8-diphenyl-1,3,6,8-octantetrone, 1,11-diphenyl-1,3,5,7,9,
11-undecanehexaone, 1,15-diphenyl-1,3,5,11,13,
15-pentadecanehexaone, 9,11,19,21-neucosantetron, 4,4'-bis(benzoylacetyl)biphenyl, etc. The β-diketone derivatives listed above become metal chelate compounds and are easily soluble in organic solvents. It has a low melting point and high thermal stability. Metal chelate compounds having hydrophilic groups in their side chains are not easily soluble in organic solvents, and metal chelate compounds with less than 5 carbon atoms have slightly inferior thermal stability and photostability. Not limited. The metals used to form metal chelate compounds with β-diketone derivatives are mainly divalent to tetravalent metals, such as Be(), Mg(), Al(), Ti(), V
(), Cr(), Mn(), Fe()(), Co(
)
Metals such as ( ), Ni ( ), Cu ( ), Zn ( ), Zr ( ), etc. are used. However, among these metal chelate compounds, those having a structure that provides easy solubility in organic solvents as described above are used in the present invention. Further, B() does not belong to metals, but forms a chelate compound with β-diketone that is easily soluble in organic solvents and is useful as an auxiliary agent in the present invention, so it is included in the present invention. Ag() is also a monovalent metal, but
They are likewise encompassed by the present invention. Among these metals, Mg, Al, and Zn are particularly preferred because they form light-colored to colorless chelate compounds. When a metal chelate compound produced from a β-diketone derivative and a metal as described above is blended into a color-forming composition system consisting of an electron donor and an electron acceptor, the coloring speed, coloring density, etc. , light resistance, moisture resistance, water resistance, solvent resistance, etc. are significantly improved. Although its mechanism of action is not clear, metal chelate compounds with β-diketones are easily soluble in organic solvents.
Because it melts at a relatively low temperature and has high thermal stability, the metal ion at the center of the metal chelate molecule in the color-forming composition system acts as an electron acceptor between the color-forming electron donor and electron acceptor. It is presumed that the rate of color development becomes faster and the density of color development becomes higher due to the promotion of color development. Further, the increase in the fastness of the recording is considered to be due to the fact that the colored component after coloration, that is, after completion of the electron-accepting reaction, leaves a stable resonance structure as a result. The metal chelate compound of the present invention does not develop color upon contact with electron-donating colorless dyes, so it can be coexisted within the colorless dye capsule, and can be used as color developers such as phenol and salicylic acid. They can coexist. Therefore, in capsules, gravure, flexo ink,
Letterpress, offset ink, hot melt ink,
It is blended together with colorless dyes or color developers in water-based paints. Further, although the metal chelate compound of the present invention is usually blended alone, several types may be used in combination to ensure the effect. The method used for thermal recording paper will be described in Examples. Next, an example will be given and explained. Parts are by weight. Example 1 5 parts of crystal violet lactone are dissolved in 92.5 parts of diallylethane (SAS-296, Nisseki Chemical). While keeping the temperature at 95℃, 2.5 chelates consisting of 2 moles of 2,4-dodecanedione and 1 mole of Zn.
and dissolve. At that time, crystal violet lactone does not turn purple-blue. The obtained solution was made into a gelatin capsule liquid by a conventional method, and 10 parts of polyvinyl alcohol (Denka size A-50, Denki Kagaku) was added thereto to make a coating liquid.
An amount of 4 g/m ² was applied with an air knife to a 40 g/m ² high-quality paper. On the opposite side of this coated paper, the following was letterpress printed, with a coating weight of 2 g/m ² . 138 parts of salicylic acid, 150 parts of p-tert-butylphenol, 162 parts of 37% formaldehyde aqueous solution and 100 parts of 2N hydrochloric acid were kept at 100°C for 10 hours, and the resulting condensate was washed with water, dried and pulverized. Add 4 parts of guanidine carbonate to 15 parts of this condensate powder, mix in a kneader, add 24 parts of linseed oil and stir, further add 1 part of stearic acid and knead, transfer to a roll mill, and mix with 56 parts of aluminum hydroxide. The mixture was mixed well and finally 0.2 parts of manganese naphthenate was added to create a uniform ink-like consistency. Comparative Example 1 5 parts of crystal violet lactone was dissolved in 95 parts of diallylethane (SAS-296, Nisseki Chemical), and 2,4-dodecanedione was dissolved as in Example 1.
A gelatin capsule liquid was made without adding Zn chelate. A double-sided coated paper was obtained in the same manner as in Example 1 except for this. Example 2 10 parts of salicylic acid, p-tert-butylphenol, formaldehyde condensate powder obtained in Example 1,
An aqueous dispersion (solid content concentration 25%) in a ratio of 2 moles of 2-benzoylcyclohexanone, 5 parts of a chelate composed of 1 mole of Zn, and 3 parts of hydroxyethyl cellulose is prepared using a ball mill and is designated as Solution A. Separately, an aqueous dispersion (solid content concentration 25%) containing 7 parts of crystal violet lactone and 1.4 parts of hydroxyethyl cellulose was prepared using a ball mill and used as liquid B. Next, liquids A and B are mixed and stirred gently, and polyethylene latex (50% concentration) is added to the liquid (polyethylene content is 5% based on the total solid content of the mixture of A and B) to form a coating liquid. do. This coating solution was coated with ^an air knife in an amount of 4 g/m ² on high-quality paper. Comparative Example 2 A coated paper was obtained in exactly the same manner as in Example 2 except that 5 parts of the Zn chelate with 2-benzoylcyclohexanone was removed from Solution A. Test Example The results of the performance comparison test of the coated papers obtained in the above Examples and Comparative Examples are shown in Table 1.

[Table] In Table 1, the measurement conditions and evaluation criteria are as follows. Measurement conditions (A): Capsule surface and developer surface facing each other, 200Kg/cm ²
After 2 minutes of color development under pressure, it was measured using a Macbeth densitometer (the larger the number, the higher the concentration). (B): Measured using a Macbeth densitometer 2 hours after color development (the larger the number, the higher the concentration). (C): The color-developing area was exposed to water vapor at 100°C for 10 seconds and the disappearance concentration was observed. (D): The colored part was immersed in distilled water at 20°C for 24 hours and the concentration lost was observed. (E): The coloring area was irradiated with ultraviolet rays for 6 hours, and the lost density was observed using a fade-o-meter. (F): Ligroin was dropped onto the colored area and the concentration disappeared after 20 seconds was observed. (G): Measured using a Macbeth densitometer immediately after heating at 130°C for 0.5 seconds (the larger the number, the higher the concentration). Evaluation criteria: 〇...No change, △...Slightly disappeared, ×...Significantly disappeared Example 3 4 parts of a chelate consisting of 3 moles of 1,3-diphenyl-1,3-propanedione and 1 mole of Al were added to Example 1. When mixed with a color developer finished in the form of ink, and coated on paper as in Example 1, and overprinted with the crystal violet lactone capsule coated paper of Comparative Example 1, initial color density, color density,
Good results were obtained in terms of moisture resistance, water resistance, porosity resistance, and solvent resistance. Example 4 1-(2-pyridyl)-1,3-butanedione 2
5 parts of a chelate consisting of mol and 1 mol of Zn,
A thermosensitive recording paper obtained in the same manner as in Example 2 except for using the 2-benzoylcyclohexanone chelate of Example 2 developed color upon heating at a lower temperature than in the case of the same example, and the fastness of the coloring component increased. Example 5 Chelate compound consisting of 2 moles of 3,5-dimethyl-2,4,6-heptanetrione and 1 mole of Mg
Pressure-sensitive recording paper obtained in the same manner as in Example 1 by replacing 2.5 parts with the 2,4-dodecanedione chelate used in Example 1 had almost the same results in color development and fastness as in Example 1. Obtained.

Claims (1)

[Claims] 1. A color-forming composition system consisting of an electron donor and an electron acceptor contains, as a color-forming aid, a metal chelate compound which is easily soluble in an organic solvent and is composed of a β-diketone derivative having 6 or more carbon atoms and a metal. A coloring composition characterized by: