JP3259923B2 - Oil-based ink composition for ballpoint pens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-based ink composition for a ballpoint pen. More specifically, the present invention relates to an oil-based ink composition for a ball-point pen, which exhibits excellent lubricity, suppresses abrasion between the ball seat and the ball at the tip of the ball-point pen and smoothes out the ink.

[0002]

2. Description of the Related Art Conventionally, oil-based ink compositions for ball-point pens include oleic acid and the like in order to smoothly rotate a ball into an ink composition containing an oil-soluble dye or pigment, an oil-soluble resin and a solvent. Contains higher fatty acids. However, since oleic acid has the property of corroding copper and copper alloys, it has the disadvantage of significantly shortening the life of ballpoint pens when the balls and ball seats used in ballpoint pens are made from them. I have.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to overcome the disadvantages of conventional oil-based ballpoint pens, have excellent lubricity, and do not corrode copper or copper alloy unlike conventional oleic acid. Therefore, it is an object of the present invention to obtain an oil-based ink composition for ball-point pens which has little writing blur, does not cause discoloration due to rust, and has good dispersibility and stable aging with a pigment ink.

[0004]

The present inventors have made intensive studies to solve these drawbacks, and as a result, have found that an ink composition containing an oil-soluble dye or pigment, an oil-soluble resin, an organic solvent, and the like can be used. The problem has been solved by providing an oil-based ink composition for ballpoint pens, which comprises 4,4'-diaminodicyclohexylmethane.

Hereinafter, the present invention will be described in detail. 4,
4'-Diaminodicyclohexylmethane is added as a lubricant, and the amount used is 0.1 to the total amount of the ink composition.
-20% by weight can be used, preferably 0.5-10% by weight. If the amount used is small, a sufficient lubricating effect cannot be obtained, and if the amount used is large, the stability over time deteriorates.

[0006] The oil-soluble dye contained in the oil-based ink composition for ball-point pens of the present invention may be any of those used in ordinary oil-based ball-point inks.
05 (manufactured by Orient Chemical Industries, registered trademark), Varifast Violet # 1701 (manufactured by Orient Chemical Industries, registered trademark), oil-soluble dyes such as Spiron Orange GRH, Spiron Red BEH, Sudan Blue II base, auramine, rhodamine, methyl Violet, malachite green, crystal violet, can be arbitrarily selected from the free base of basic dyes such as Victoria Blue BOH, etc., each may be used alone,
Two or more kinds may be combined.

As the pigment, various known pigments can be used.
Specific examples include organic pigments such as azo pigments, condensed polyazo pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, perinones, perylene pigments, and the like. Examples thereof include inorganic pigments such as titanium, iron oxide and carbon black, and fluorescent pigments. These may be used alone or in combination of two or more. The amount of these colorants used is 0.1 to 50% by weight based on the total ink composition.
And preferably 1 to 30% by weight. If the amount is small, the handwriting becomes thin, and if the amount is large, the viscosity of the ink composition becomes high and the writing quality becomes poor.

As the dispersant, those generally used as pigment dispersants such as resins and surfactants can be used, and the use amount thereof is preferably 1 to 30% by weight based on the total amount of the ink.

[0009] The resin may be one used for ordinary oil-based ballpoint pen inks. Specific examples thereof include ketone resins, xylene resins, phenol resins, coumarone indene resins, polyvinylpyrrolidone, and polyvinyl butyral. Two or more kinds may be combined.
The amount of these resins used is preferably in the range of 1 to 30% by weight based on the total amount of the ink.

The organic solvent may be any of those used in ordinary oil-based ballpoint pen inks, such as benzyl alcohol, phenoxyethanol, N-methyl-2-pyrrolidone, isophorone, glycols, glycol ethers and glycol ether acetates. These can be used alone or in combination of two or more. These organic solvents are preferably in the range of 20 to 70% by weight based on the total amount of the ink.

In addition, if necessary, a rust inhibitor, a surfactant,
Extreme pressure additives and the like can be appropriately selected and used. Benzotriazole and the like can be used as a rust preventive. As the surfactant, sorbitan fatty acid ester, silicon-based surfactant, fluorine-based surfactant and the like can be used.
As the extreme pressure additive, tricrisyl phosphate or the like can be used.

[0012]

The reason why the water-based ink composition for a ball-point pen of the present invention is effective in preventing the wear of the ball receiving portion is not clear, but is presumed as follows. That is, 4,4 '
-It is considered that diaminodicyclohexylmethane is adsorbed on the surface of the ball or the ball receiving seat, forms a thin film, and improves the lubricity of ball rotation.

[0013]

Next, the present invention will be described in more detail by way of examples. In the following, “parts” means “% by weight”. Example 1 Varifast Black # 1805 (manufactured by Orient Chemical) 15.0 parts Varifast Yellow AUM (manufactured by Orient Chemical) 5.0 parts Spiron Violet CRH (manufactured by Hodogaya Chemical) 10.0 parts Benzyl alcohol 15.0 parts Propylene glycol monophenyl ether 35.0 parts Hirac # 110 (Hitachi Chemicals, ketone resin) 10.0 parts 4,4'-diaminodicyclohexylmethane 10.0 parts Each of the above components is heated to 60 to 70 ° C. After heating and dissolving with stirring for 4 hours, the mixture was filtered under pressure at 70 ° C. to obtain a black ink. Example 2 Cyanine Blue BNRS (manufactured by Toyo Ink Co., Ltd.) 25.0 parts Spiron Violet CRH (manufactured by Hodogaya Chemical) 10.0 parts Benzyl alcohol 5.0 parts Tripropylene glycol monomethyl ether 30.0 parts Hirac # 110 ( 10.0 parts of 4,4'-diaminodicyclohexylmethane 20.0 parts of the above components were heated to 60 to 70 ° C, stirred and dissolved for 4 hours, and then filtered under pressure at 70 ° C. A blue ink was obtained.

Example 3 Carbon black MA-100 (manufactured by Mitsubishi Kasei) 20.0 parts ESREC BL-1 (polyvinyl butyral resin, manufactured by Sekisui Chemical) 15.0 parts Benzyl alcohol 15.0 parts Tripropylene glycol monomethyl ether 49. 3 parts PVPK-90 (polyvinylpyrrolidone resin, BASF resin) 0.2 parts 4,4'-diaminodicyclohexylmethane 0.5 parts Among the above components, carbon black, polyvinyl butyral resin and tripropylene glycol monomethyl ether are mixed in a sand mill. After dispersing for 1 hour, the remaining components were mixed, dissolved by stirring, and filtered under pressure at 70 ° C. to obtain a black ink. Example 4 Cyanine Blue # 4933 (manufactured by Dainichi Seika) 20.0 parts ESREC BL-1 (polyvinyl butyral resin, manufactured by Sekisui Chemical) 20.0 parts Propylene glycol monophenyl ether 10.0 parts Dipropylene glycol monomethyl ether 39. 8 parts PVPK-90 (polyvinylpyrrolidone resin, BASF resin) 0.2 parts 4,4′-diaminodicyclohexylmethane 10.0 parts Among the above components, copper phthalocyanine blue, polyvinyl butyral resin and dipropylene glycol monomethyl ether are sand-milled. After dispersing for 1 hour, the remaining components were mixed, dissolved by stirring, and filtered under pressure at 70 ° C. to obtain a black ink.

Comparative Example 1 A black ink was obtained in the same manner as in Example 1, except that 4,4'-diaminodicyclohexylmethane in the ink component was replaced with the same amount of oleic acid. Comparative Example 2 A blue ink was obtained in the same manner as in Example 2, except that 4,4′-diaminodicyclohexylmethane in the ink component was replaced with the same amount of oleic acid. Comparative Example 3 A black ink was obtained in the same manner as in Example 3, except that 4,4′-diaminodicyclohexylmethane in the ink component was replaced with the same amount of oleic acid. Comparative Example 4 A blue ink was obtained in the same manner as in Example 4, except that 4,4′-diaminodicyclohexylmethane in the ink component was replaced with the same amount of oleic acid.

[0016]

The oil-based ink compositions for ballpoint pens obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were mounted on one end of a polypropylene tube with a carbide ball having a diameter of 0.7 mm and a ballpoint pen socket made of nickel silver. The effect was confirmed with a so-called free ink type writing instrument obtained by press-fitting a pen body and removing bubbles in the ink by centrifugation using a spiral writing tester. The conditions of the testing machine at that time were a writing angle of 70 degrees, a load of 200 g, and a speed of 4 m / min.
201 writing paper A, and under the above conditions, the ball sinking after writing 500 m was measured using a tool microscope. In addition, a handwriting sensory test was conducted and the sample was
After standing for 2 weeks in a thermo-hygrostat at 70 ° C. and 70%, the degree of rust inside the ballpoint pen tip was visually inspected. After removing the cap of another sample and leaving it in a constant temperature and humidity bath at 25 ° C. and 65% for one day, the writing angle was 70 ° and the load was 200 g. Table 1 shows the results.

[Table 1] Evaluation criterion for writing feeling Squeaky ─── There is resistance and I can't write smoothly. As described above, the oil-based ink composition for a ballpoint pen in the present invention has excellent lubricity, has an effect of reducing wear of the ball seat, has excellent durability and excellent writing feeling, and has a conventional oleic acid and the like. As described above, since the copper or copper alloy does not corrode, there is little writing blur, no discoloration due to rust, etc., and a pigment ink can provide an oil-based ink composition for ballpoint pens having excellent dispersibility and excellent stability over time.

Claims (1)

(57) [Claims] 1. An oil-based ink composition for ballpoint pens comprising an oil-soluble dye or pigment, an oil-soluble resin and an organic solvent,
An oil-based ink composition for a ballpoint pen, comprising 4,4'-diaminodicyclohexylmethane.