JP3341065B2 - Ink composition for marking pen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for a marking pen, and more particularly to a marking pen whose cap is removed and which can be immediately marked even after being left for a long time with the pen tip exposed to the atmosphere. The present invention relates to an ink composition for a marking pen having excellent performance (hereinafter referred to as cap-off resistance).

[0002]

2. Description of the Related Art An ink composition containing a polyglycerin ester as an additive for imparting cap-off resistance is disclosed in JP-B-62-34352 and JP-B-1-53707. And Japanese Patent Publication No. 3-49947) and an ink composition to which a sucrose ester is added (Japanese Patent Publication No. 1-49391).

[0003]

The above ink compositions for marking pens according to the prior art require the addition of a considerable amount of the above additives in order to obtain practical cap-off resistance, whereby the object of the ink is reduced. It is inevitable that the adhesion to the object is reduced, and the application has been limited to the application to a marking pen for a writing board which does not require the adhesion.

[0004]

The ink composition for a marking pen of the present invention is a composition containing a colorant, a resin, an organic solvent for dissolving the resin, and an additive for imparting cap-off resistance. The coloring agent is an organic solvent-soluble dye (C.I.
I. Solvent dyes), organic pigments, carbon black, titanium white, and the like are used, and as the pigment, an easily dispersible processed pigment which has been previously surface-treated with a resin is preferably used. These colorants are used in the range of 1 to 25% by weight in the ink composition.

As the resin, rosin derivatives such as rosin, ester gum, rosin-modified maleic resin, ketone resin,
Soluble phenolic resin, cellulose derivative, styrene
Maleic acid copolymer, vinyl acetate, vinyl butyral,
Resins commonly used in organic solvent-based marking pens, such as vinyl resins such as vinylpyrrolidone, phenol-modified xylene resins, xylene resins, terpene resins, acrylic resins, aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, and alkyd resins Is used in the range of 1 to 30% by weight in the ink composition.

[0006] melting point indicate to Es in the additive in the range of 25 ° C. to 65 ° C. for imparting resistance to cap off properties to the ink
Teryl compounds , specifically, oleyl behenate (melting point: 38 to 40 ° C.), behenyl oleate (melting point: 32 to 4 ° C.)
2 ° C), behenyl isostearate (melting point 32-43)
C), behenyl laurate (melting point 48-50 ° C), stearyl stearate (melting point 58-61 ° C), coconut oil fatty acid stearyl alcohol ester (melting point 38-48).
C.), dimyristyl adipate (mp. 45-48.degree. C.) and butanediol dilaurate (mp. 44-45.degree. C. ) . An ester compound having a melting point lower than the melting point range (for example, isostearyl isostearate having a melting point of 0 ° C. or lower) or an ester compound having a higher melting point [for example, behenyl behenate (melting point 68 to 71 ° C.), behenyl montanate (melting point 68-71 ° C.) does not exhibit the function of imparting cap-off resistance to the ink. The ester compound having the above melting point range is used in the ink composition in the range of 0.05 to 0.5% by weight, preferably in the range of 0.1 to 0.4% by weight. The cap-off resistance is sufficiently exhibited by the addition in the above range, and the addition of a larger amount rather deteriorates the cap-off resistance or the ink stability.

As the solvent, those which dissolve the resin from organic solvents commonly used for ink for marking pens are selected and applied. Specifically, lower aliphatic alcohols such as ethanol and isopropanol, glycol ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether, lower fatty acid esters such as butyl acetate and ethyl propionate, and aliphatic hydrocarbons such as hexane and heptane And xylene, etc., which are used as the main solvent. Further, an ester-based high-boiling solvent selected from propylene glycol monoethyl ether acetate, ethyl ethoxypropionate, benzyl propionate, and the like shows a suitable solubility for the ester compound and facilitates dissolution of the ester compound during ink preparation. Since the ester compound is present in a stable dissolved state in the ink, it may be used in combination with the main solvent. The total solvent is used in the range of 45 to 98% by weight in the ink composition.

The ink composition of the present invention is prepared by mixing or dissolving a resin and an additive in a solvent and dissolving or dispersing a colorant in a vehicle obtained by dissolving the colorant.

[0009]

[Work] When a marking pen filled with the ink composition of the present invention is left in a state where the cap is detached, as the solvent of the ink on the pen tip surface evaporates, additives in the ink precipitate and the pen tip surface is removed. Cover and form a very thin film.
This coating is impermeable to solvent vapors, but is easily destroyed by very light abrasion. Therefore, when the film is formed on the pen tip surface, the solvent in the ink present in the pen tip remains without substantially volatilizing, and during the subsequent marking, the pen tip and the object are rubbed. As a result, the film is easily broken, and the ink immediately flows out of the pen tip. Since the additive exerts the above-mentioned action with a small amount, it does not adversely affect the adhesion of the marked ink to the object.

[0010]

EXAMPLES Example inks and comparative inks having the compositions shown in Table 1 were prepared according to the above-mentioned formulations.

[0011]

[Table 1]

The contents of the raw materials are shown below according to the note numbers in the table. (1) Pigment dispersion composed of 10% carbon black, 10% resin and the remainder being a mixed solvent of ethanol and isopropanol (Micropigmo AMBK, trade name of Orient Chemical Co., Ltd.) (2) Balifast Red 1308 (Orient Chemical (3) Synthetic Resin SK (trade name of Huls) (4) Behenyl laurate, melting point 48-50 ° C (5) Oleyl behenate, melting point 38-40 ° C (6) Behenyl oleate, melting point 32 -42 ° C (7) Behenyl isostearate Melting point 32-43 ° C (8) Butanediol dilaurate Melting point 44-45 ° C (9) Hexaglycerin distearate (10) Hexaglycerin sesquistearate (11) Decaglycerin pentastearate ( 12) Isostearyl isostearate Melting point 0 ° C or less (13) behenyl montanate mp 77 to 80 ° C. (14) Propylene glycol monomethyl ether (15) Propylene glycol monoethyl ether acetate

A predetermined amount of the sample ink is filled in a marking pen provided with a pen tip made of a fiber bundle resin processed body and an ink occluding body made of a fiber bundle covered in a tube shape.
A sample marking pen was obtained and subjected to the following tests. The handwriting written on the polyester film with each sample pen,
Apply a force of about 1Kgw with the thumb around which the gauze is wound
It was rubbed several times, and the adhesion of the ink was evaluated from the degree of peeling of the handwriting. Evaluation ：: No change ×: Peeled Next, the sample pen with the cap removed was placed at 25 ° C. and 60% RH.
After standing for 2 hours in a constant temperature and humidity room adjusted to the conditions described in (1) above, writing was performed on a sheet of paper with a sample pen, and it was examined whether or not writing was possible immediately. Evaluation ：: Writable immediately ×: Not writable Table 2 shows the test results.

[0014]

[Table 2]

[0015]

When the ink composition of the present invention is left in a marking pen with the cap removed, the effect of suppressing the evaporation of the solvent in the ink at the pen tip is exerted and marking can be performed immediately even after a long time. It is. Then, there is no decrease in the adhesion of the ink to the target object, which is exhibited by the marking pen ink having this kind of cap-off resistance.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-294372 (JP, A) JP-A-62-25184 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (3)

(57) [Claims] 1. An ink composition comprising a colorant, a resin, an organic solvent for dissolving the resin, and an additive,
The additive Lau showing a melting point in the range of 2 5 ° C. to 65 ° C.
Behenyl phosphate, oleyl behenate, behe oleate
Nil, behenyl isostearate, stearic stearate
Ril, coconut oil fatty acid stearyl alcohol ester,
Dimyristyl dipinate, butanediol dilaurate
An ink composition for a marking pen, which is an ester compound selected from the group consisting of 0.05 to 0.5% by weight of the ink composition. 2. The ink composition according to claim 1, wherein the amount of said ester compound is an ink composition.
2. The composition according to claim 1, wherein the content is in the range of 0.1 to 0.4% by weight.
Ink composition for marking pens. 3. The method according to claim 1, wherein a part of the solvent is propylene glycol.
Coal monoethyl ether acetate, ethyl ethoxy
E selected from propionate and benzyl propionate
3. The mark according to claim 1, which is a stele-based high-boiling solvent.
Ink composition for pen.