JP2016113545A - Oily ink composition for writing instruments and writing instrument prepared therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oily ink composition for writing instruments that inhibits metal salt deposits from occurring by a reaction with an ink component and a writing instrument prepared therewith.SOLUTION: An oily ink composition for writing instruments comprises at least a colorant, an organic solvent, and Kojic acid.SELECTED DRAWING: None

Description

  The present invention relates to an oil-based ink composition for a writing instrument and a writing instrument using the same, and more specifically, relates to an oil-based ink composition for a writing instrument that suppresses metal salt precipitates generated by reaction with an ink component and a writing instrument using the same. Is.

    Conventionally, in oil-based ink compositions for writing instruments, oil-based ink compositions for writing instruments containing colorants, organic solvents, resins, and the like have been proposed.

Examples of such oil-based ink compositions for writing instruments include JP-A-6-212111 “Oil composition for oil-based ballpoint pens”, JP-A-8-41408 “Ink composition for oil-based ballpoint pens and oil-based ballpoint pens”, JP-A-8-134393. “Oil ink for ballpoint pen” is disclosed.
"JP-A-6-212111" "JP-A-8-41408" "Japanese Patent Laid-Open No. 2006-8974"

  However, when a writing instrument is used using the oil-based ballpoint pen ink composition of Patent Documents 1 and 2, a ballpoint pen tip body or ink using a metal such as stainless steel, brass, or white material as a tip material or ink containing cylinder. Metal ions such as manganese ions, chromium ions, copper ions, zinc ions and nickel ions elute from the container, reacting with the ink components to generate metal salts, and had the problem of causing poor writing. .

  Furthermore, as in Patent Document 3, there are many techniques for improving lubricity using a surfactant such as N-acylamino acid and N-acylmethyltaurine. Even in this case, a metal ballpoint pen is used in the ink. It is easy to react with the metal ions eluted from the chip body or the ink container, and the problem of generating a metal salt is likely to occur.

  As in Patent Documents 1 to 3, depending on the selection of ink components such as colorants, organic solvents, surfactants, resins, etc., there is compatibility with the metal ballpoint pen tip body and ink container, and it reacts in ink. It is very important to deal with deposits such as metal salts.

  The objective of this invention is providing the oil-based ink composition for writing instruments which suppressed the metal salt precipitate which reacts with an ink component and generate | occur | produces.

In order to solve the above problems, the present invention provides "1. An oil-based ink composition for writing instruments, comprising at least a colorant, an organic solvent, and kojic acid.
2. The oil-based ink composition for writing instruments according to item 1, wherein the content of the kojic acid is 0.1 to 5.0% by mass.
3. The pH value of the oil-based ink composition for writing instruments is 5 to 12, The oil-based ink composition for writing instruments according to item 1 or 2.
4). The oil-based ink composition for a writing instrument according to any one of claims 1 to 3, wherein the oil-based ink composition for a writing instrument contains a surfactant.
5. The oil-based ink composition for writing instruments according to any one of claims 1 to 4, wherein the oil-based ink composition for writing instruments contains water.
6). A writing instrument comprising the oil-based ink composition for a writing instrument according to any one of items 1 to 5 directly packed in an ink containing cylinder.
7). A ballpoint pen tip holding a ball rotatably is attached to the tip of the ink containing cylinder directly or via a chip holder, and the ink containing cylinder is set forth in any one of items 1 to 6. An oil-based ballpoint pen in which an oil-based ballpoint pen refill containing the oil-based ink composition for a writing instrument is disposed in a shaft tube, wherein the ballpoint pen tip is made of a stainless material. "

  The present invention was able to provide an oil-based ink composition for writing instruments in which metal salt precipitates generated by reacting with the ink component were suppressed, and an oil-based ink composition using the same.

  A feature of the present invention is that it comprises at least a colorant, an organic solvent, and kojic acid.

Kojic acid is formally called 5-hydroxy-2- (hydroxymethyl) -4-pyrone, and is a compound obtained from fermentation metabolites of fungi such as Aspergillus genus and Gluconobacter genus. 1).

  As for kojic acid used in the present invention, the ball pen tip body of the writing instrument member, the ink containing cylinder, etc., when using metals such as stainless steel, brass, and whitewood, the ball pen tip body, ink Before metal ions such as manganese ions, chromium ions, copper ions, zinc ions, nickel ions elute from the container and react with the ink components to generate metal salts, adjacent to kojic acid = O and -OH Kojic acid can form a metal complex with a metal ion at an appropriate molar ratio to suppress metal salt precipitates.

  Moreover, as for content of kojic acid, 0.1-5.0 mass% is more preferable with respect to the ink composition whole quantity. This is because if it is less than 0.1% by mass, the desired metal salt suppression effect tends to be difficult to obtain, and if it exceeds 5.0% by mass, the ink aging tends to become unstable, Considering the tendency, 0.5 to 3.0% by mass is preferable, and more considering 1.0 to 2.0% by mass is most preferable.

The pH value of the oil-based ink composition for writing instruments is preferably 5-12. This is because when it pH value is less than 5, -OH is O of the kojic acid ^- a difficult becomes, by = O and -OH of kojic acid, in order to easily create a stable metal complex is less effective, pH value If the value exceeds 12, the colorant is easily separated, and the ink aging stability and the color tone are likely to be affected. Furthermore, if it is considered that a more stable metal complex can be easily produced and metal salt precipitates are further suppressed, the pH value is preferably 7.0 to 10.0.

  The pH value in the present invention is determined by collecting oil-based ink in a container, adding ion-exchanged water, heating with stirring, allowing to cool after heating, and evaporating in the method for measuring an oil-based ink composition for writing instruments. After replenishing the water content, it is filtered using filter paper. The value measured at 20 degreeC using the IM-40S type | mold pH meter by the Toa DK company is shown using the upper layer of the filtered filtrate.

  Also, when using phosphate ester surfactants, fatty acids, etc. as surfactants to improve lubricity and ink aging stability, phosphate groups, fatty acid groups, etc. are liberated in the ink. Thus, it is effective and preferable to use kojic acid as in the present invention because it easily reacts with the metal ball pen tip body and the metal of the ink containing cylinder and easily generates a metal salt. In particular, it is effective when using phosphate ester surfactants and fatty acids.

    In addition, if water is included in order to contain water in the ink due to moisture absorption during production or over time, to lower the ink viscosity, or to improve the writing quality, it contains water. In order to suppress the growth of bacteria that are concerned, it is effective and preferable to use kojic acid having an antibacterial effect.

  The water content is preferably 0.1 to 20.0% by mass with respect to the total amount of the ink composition. If the amount is less than this range, the desired lubricating effect may not be obtained, and if the range is exceeded, the ink aging may become unstable. In consideration of making the ink aging better, it is preferably 1.5 to 8.0% by mass, and most preferably 4.0 to 7.0% by mass. The method of adding water is not particularly limited. However, even if water is added as it is to an ink in which components other than water are appropriately mixed, the components used in the ink composition for oil-based ballpoint pens such as a colorant and a resin are used. The moisture may be absorbed or absorbed in advance.

  The colorant used in the present invention includes dyes and pigments. The types of dyes include oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, direct dyes, and various salt-forming dyes. There are salt-forming dyes of acid dyes and basic dyes, salt-forming dyes of organic acids and basic dyes, salt-forming dyes of acid dyes and organic amines, etc. It is effective and preferable to use kojic acid as in the present invention, since it may react with metal ions eluted from the ball-point pen tip body or ink containing cylinder produced to generate a metal salt.

  Regarding the dye, specifically, Bali First Black 1802, Bali First Black 1805, Bali First Black 1807, Bali First Violet 1701, Bali First Violet 1704, Bali First Violet 1705, Bali First Blue 1601, Bali First Blue 1605, Bali First Blue 1613, Bali First Blue 1621, Bali First Blue 1631, Bali First Red 1320, Bali First Red 1360, Bali First Red 1380, Bali First Yellow 1101, Bali First Yellow 1151, (above, manufactured by Orient Chemical Co., Ltd.) , Eisenspiron Black GMH-Special, Eisenspiron Violet C-RH, Eisen Pilon Blue GNH, Eisenspiron Blue 2BNH, Eisenspiron Blue C-RH, Eisenspiron Red C-GH, Eisenspiron Red C-PH, Eisenspiron Red C-BH, Eisenspiron Yellow C-GNH, Eisenspir Ron Yellow C-2GH, S. P. T.A. Blue 111, S.I. P. T.A. Blue GLSH-special P. T.A. Red 533, S.D. P. T.A. Orange 6, S. B. N. Violet 510, S.I. B. N. Yellow 510, S.I. B. N. Yellow 530, S.I. R. C-BH (above, manufactured by Hodogaya Chemical Co., Ltd.) and the like.

  As for content of a coloring agent, 5.0-40.0 mass% is preferable with respect to the ink composition whole quantity. If the amount is less than 5.0% by mass, dark handwriting tends to be difficult to obtain. If the amount exceeds 40.0% by mass, the solubility in ink tends to be affected. Considering it, 7.0 to 25.0 mass% is preferable, and further considering it is 10.0 to 20.0 mass%.

  Examples of the organic solvent used in the present invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol monophenyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether, 3 -Glycol ether solvents such as methoxybutanol and 3-methoxy-3-methylbutanol, glycol solvents such as diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, butylene glycol and ethylene glycol, benzyl alcohol, methanol, ethanol , 1-propanol, 2- For oil-based ballpoint pens such as lopanol, isopropanol, isobutanol, t-butanol, propargyl alcohol, allyl alcohol, 3-methyl-1-butyn-3-ol, alcohol solvents such as ethylene glycol monomethyl ether acetate and other higher alcohols The organic solvent generally used as ink can be illustrated.

  Further, the content of the organic solvent is preferably 10.0 to 70.0% by mass with respect to the total amount of the ink composition in consideration of improving solubility, handwriting drying property, bleeding, etc. If it does, 30.0-65.0 mass% is preferable, Most preferably, it is 45.0-65.0 mass%.

  Furthermore, it is preferable to use an organic amine in the oil-based ink composition for writing instruments of the present invention. This is to make it easier to form a complex of kojic acid and metal ions by making the pH value easier to be in the range of 5 to 12. For organic amines, oxyethylene alkylamines, polyoxyethylene alkylamines, etc., alkylamines such as laurylamine, stearylamine, distearylamine, dimethyllaurylamine, dimethylstearylamine, dimethyloctylamine, monoethanolamine, Examples include alkanolamines such as diethanolamine, triethanolamine, and dimethylethanolamine. Among these organic amines, primary amines are highly reactive, so that colorant separation and color tone are likely to be affected. Therefore, secondary amines and / or tertiary amines are preferably used. In particular, among secondary amines and / or tertiary amines, oxyethylene alkylamines and polyoxyethylene alkylamines are preferred in view of controlling ink aging stability and pH value to 5-12. You may use these individually or in mixture of 2 or more types.

  The content of the organic amine is preferably 0.1 to 10.0% by mass with respect to the total amount of the ink composition, more preferably, taking into account ink aging stability, neutralization with a surfactant, and pH value. 0.5 to 5.0 mass%.

  Specific examples of organic amines include oxyethylene alkylamines and polyoxyethylene alkylamines such as Nimine L-201 (secondary amine), L-202 (tertiary amine), and L-207 (tertiary amine). ), S-202 (tertiary amine), S-204 (tertiary amine), S-210 (tertiary amine), DT-208 (tertiary amine) (manufactured by NOF Corporation) Etc. Examples of the alkylamine include Farmin 80 (primary amine), Farmin D86 (all secondary amines), Farmin DM2098 (tertiary amine), Farmin DM8680 (tertiary amine) (Kao Corporation), and the like. You may use these individually or in mixture of 2 or more types.

  In addition, the ink composition according to the present invention includes, as other additives, (i) a viscosity modifier / dispersant such as fatty acid amide, hydrogenated castor oil, etc., in order to improve lubricity and ink aging stability. Resin such as pseudoplasticity imparting agent, butyral resin, ketone resin, polyvinylpyrrolidone, (ii) colorant stabilizer, (iii) plasticizer, (iv) chelating agent, or (v) water as co-solvent You may use suitably. These may be used alone or in combination of two or more.

  In addition, the materials such as the ballpoint pen tip body and the ink containing cylinder include metal materials such as stainless steel, white, brass (brass), aluminum bronze, aluminum, and resin materials such as polycarbonate, polyacetal, and ABS. In the case of writing instruments using a ballpoint pen tip body made of stainless steel, an ink container, etc., manganese ions such as manganese and chromium contained in the stainless steel and chromium ions react with the ink components to produce metal salts. Therefore, it is effective and preferable to use kojic acid as in the present invention.

Further, the ball-point pen tip ball is not particularly limited, but a cemented carbide ball mainly composed of tungsten carbide uses cobalt, nickel, or the like as its binder. The kojic acid is less likely to corrode the ball of the ball-point pen tip than the chelating agent such as aminocarboxylic acid against metals such as cobalt and nickel, so that it is difficult to cause the ball rotation resistance due to corrosion, and good writing quality. Is easily obtained and can be suitably used for cemented carbide balls.
The diameter of the ball is not particularly limited, but is generally about 0.2 mm to 2.0 mm.

    The oil-based ink composition for a writing instrument of Example 1 includes a dye as a colorant, an alcohol solvent as an organic solvent, a glycol ether solvent, a ketone resin as a viscosity modifier, a phosphate ester surfactant and a fatty acid as a surfactant, Kojic acid, oxyethylene alkylamine as organic amine, and polyvinylpyrrolidone resin as spinnability-imparting resin are weighed, weighed a predetermined amount, heated to 60 ° C, and completely dissolved using a disper stirrer. An oil-based ink composition for writing instruments was obtained. Specific blending amounts are as follows. Moreover, when pH of Example 1 was measured at 20 degreeC using the IM-40S type | mold pH meter, it was pH = 7.2.

Example 1
Colorant (salt-forming dye of organic acid and basic dye) 20.0% by mass
Alcohol solvent (benzyl alcohol) 31.8% by mass
Glycol ether solvent (ethylene glycol monophenyl ether) 21.9% by mass
Viscosity modifier (ketone resin) 18.0% by mass
Surfactant (phosphate-based surfactant) 1.0% by mass
Surfactant (fatty acid) 3.0% by mass
Kojic acid 2.0% by mass
Organic amine (oxyethylene alkylamine) 2.0% by mass
Spinnability imparting resin (polyvinylpyrrolidone resin) 0.3% by mass

Examples 2-6
As shown in Table 1, oil-based ink compositions for writing instruments of Examples 2 to 6 were obtained in the same procedure as Example 1 except that each component was changed. The measurement and evaluation results are shown in the table.

Comparative Examples 1-5
As shown in Table 2, oil-based ink compositions for writing instruments of Comparative Examples 1 to 5 were obtained in the same procedure as Example 1 except that each component was changed. The measurement and evaluation results are shown in the table.

Test and Evaluation Stainless steel in which the oil-based ink composition for writing instruments prepared in Examples 1 to 6 and Comparative Examples 1 to 5 is held by a ball (φ0.7 mm) rotatably at the tip of an ink containing cylinder (made of polypropylene). The ballpoint pen tip of the material is mounted, and the ink for oil-based ballpoint pen of Example 1 (0.2 g) is directly accommodated in the ink-holding cylinder, so that the ballpoint refill is an oil-based ballpoint pen manufactured by Pilot Corporation (trade name: An oil-based ballpoint pen was prepared by placing it on a (super grip), and the following tests and evaluations were performed.

Metal salt precipitate test in the chip: The ink in the chip main body was observed with a microscope at an optical microscope (Olympus) magnification of 100 times after 60 weeks, 80% humidity and 2 weeks.
Good without metal salt precipitates ... ◎
Slightly generated metal salt precipitates ... ○
Metal salt precipitates are generated, but there are no practical problems.
Metal salt precipitates are generated, causing blurring or writing defects.

  In Examples 1 to 6, good performance was obtained in the metal salt precipitate test in the chip.

  In Comparative Examples 1 to 3, since kojic acid was not used, metal salt precipitates were generated, causing dullness and poor writing.

  In Comparative Examples 4 and 5, aminocarboxylic acid was used, but metal salt precipitates were generated, resulting in blurring and poor writing. Furthermore, when the ball surface was observed with a microscope, corrosion was observed.

  The present invention is not limited to the ballpoint pens of the examples, and can be suitably used for fountain pens, markers, sign pens, plate pens, and the like. Can be widely used as a writing instrument.

  When a coil spring that presses a ball made of stainless steel is disposed in the ballpoint pen tip body, a metal salt is generated by reacting with the ink component, as in the case of the metal ballpoint pen tip body and the ink containing cylinder. Since there is a possibility, the effect of this invention is remarkable.

Claims (7)

An oil-based ink composition for writing instruments, comprising at least a colorant, an organic solvent, and kojic acid. The oil-based ink composition for a writing instrument according to claim 1, wherein the content of the kojic acid is 0.1 to 5.0% by mass. 3. The oil-based ink composition for writing instruments according to claim 1, wherein the oil-based ink composition for writing instruments has a pH value of 5 to 12. 4. The oil-based ink composition for a writing instrument according to any one of claims 1 to 3, wherein the oil-based ink composition for a writing instrument contains a surfactant. The oil-based ink composition for writing instruments according to any one of claims 1 to 4, wherein the oil-based ink composition for writing instruments contains water. A writing instrument, wherein the oil-based ink composition for a writing instrument according to any one of claims 1 to 5 is directly packed in an ink containing cylinder. The writing instrument according to any one of claims 1 to 6, wherein a ballpoint pen tip holding a ball rotatably is attached to a front end portion of the ink storage cylinder directly or via a chip holder, and the ink storage cylinder is provided with the writing instrument according to any one of claims 1 to 6. An oil-based ballpoint pen comprising an oil-based ballpoint pen refill containing an oil-based ink composition disposed in a shaft tube, wherein the ballpoint pen tip is made of a stainless material.