JP2009108120A - Ink composition for oily ballpoint pen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition for oily ballpoint pen which keeps lubricating property even under high writing pressure (writing load of 500 gf), suppresses wear of a ball seat and has good stability of the ink with time. <P>SOLUTION: The ink composition for oily ballpoint pen contains at least a colorant, an organic solvent, a resin, polyethylene glycol and a surfactant, wherein the composition contains a specified polyethylene glycol as the above polyethylene glycol. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

    The present invention relates to an ink composition for oil-based ballpoint pens, and more particularly to an ink composition for oil-based ballpoint pens in which a polyethylene glycol having a specific average molecular weight and a surfactant are used in combination in the ink composition.

  Many oil-based ballpoint pen ink compositions that use various additives have been proposed in the past for the purpose of obtaining a smooth handwriting feel and smooth light writing with excellent lubrication performance. Has been.

As such an oil-based ballpoint pen ink composition, those using polyethylene glycol include those disclosed in JP-A-7-196971, “oil-based ballpoint ink composition”, and those using a fluorine-based surfactant. Japanese Laid-Open Patent Application No. 9-151354 discloses an “oil-based ink composition for ballpoint pens”.
"Japanese Patent Laid-Open No. 7-196971" "Japanese Patent Laid-Open No. 9-151354"

  However, as described in Patent Document 1, polyethylene glycol alone has a problem of poor lubricity and a heavy writing quality as compared with a surfactant. Further, by containing polyethylene glycol, if the writing load is about 100 gf, wear of the ball seat can be suppressed, but under high writing pressure, for example, at a writing load of 500 gf, it is possible to suppress wear of the ball seat. It was difficult.

  Further, in Patent Document 2, although a fluorine-based surfactant is used, the lubricity is poor under high writing pressure, and wear of the ball seat cannot be suppressed, which causes a problem of writing failure.

  An object of the present invention is to provide an ink composition for a ballpoint pen that maintains lubricity even under high writing pressure (writing load 500 gf), suppresses wear of a ball seat, and has good ink aging stability.

In order to solve the above problems, the present invention
“1. An oil-based ballpoint pen ink composition containing at least a colorant, an organic solvent, a resin, polyethylene glycol, and a surfactant, wherein the polyethylene glycol has an average molecular weight of 800 or more. Ink composition.
2. The surfactant is a phosphate ester surfactant, and the content of the phosphate ester surfactant is 0.1 to 5.0% by mass with respect to the total mass of the ink composition. An ink composition for oil-based ballpoint pens as described in item 1.
3. The ink composition for oil-based ballpoint pens according to item 2, wherein the phosphate ester-based surfactant contains at least an alcohol phosphate-based surfactant.
4). The ink composition for oil-based ballpoint pens according to item 3, wherein the phosphate ester-based surfactant contains at least a lauryl alcohol-based, tridecyl alcohol-based, or short-chain alcohol-based surfactant. object.
5). Item 5. The ink composition for oil-based ballpoint pens according to any one of Items 1 to 4, wherein the polyethylene glycol has a hydroxyl value in the range of 30 to 120.
6). 6. The oil-based ink composition for ballpoint pens according to any one of items 1 to 5, wherein the resin contains at least polyvinylpyrrolidone.
7. The ink composition for oil-based ballpoint pens according to any one of items 1 to 6, wherein the ink viscosity at 20 ° C. and a shear rate of 6.8 sec ⁻¹ is 100 to 5000 mPa · s. . Is.

  The present invention contains at least a colorant, an organic solvent, a resin, polyethylene glycol having an average molecular weight of 800 or more, and a surfactant, so that lubricity is maintained even under high writing pressure (writing load 500 gf), and wear of the ball seat is reduced. An ink composition for oil-based ballpoint pens that is suppressed and has good ink aging stability could be provided.

  A feature of the present invention is that, in an oil-based ballpoint pen ink composition, polyethylene glycol having an average molecular weight of 800 or more and a surfactant are used in combination.

The polyethylene glycol used in the present invention is a polymer compound having a structure in which ethylene glycol is polymerized, and is represented by a general formula of HO (CH ₂ CH ₂ O) _n H, and is contained in an oil-based ink to form a thick film. Form. Since this thick film is considered as one of the elastic elements, the elastic force can be improved by the thick film. Therefore, wear of the ball seat can be suppressed by suppressing metal contact between the ball and the ball seat by the thick film formed in the oil-based ink.

  Moreover, since the average molecular weight of polyethylene glycol is less than 800, the average molecular weight is low, and the straight chain of polyethylene glycol is shortened, which is sufficient to suppress metal contact between the ball and the ball seat. A film cannot be obtained. Particularly under high writing pressure (writing load of 500 gf), since the wear of the ball seat is generally remarkable, polyethylene glycol having an average molecular weight of 800 or more is indispensable. Moreover, since there exists a tendency for solubility to be a little inferior when the average molecular weight of polyethyleneglycol exceeds 25000, the range of average molecular weight 800-25000 is more preferable, Most preferably, it is average molecular weight 800-9000. Specifically, examples of the polyethylene glycol having an average molecular weight of 800 to 25000 include PEG1000, PEG1540, PEG2000, PEG4000, PEG6000, PEG10000, PEG20000 (Daiichi Kogyo Seiyaku Co., Ltd.), and the like. Polyethylene glycols in the range are PEG1000, PEG1540, PEG2000, PEG4000, PEG6000, etc.

  Furthermore, polyethylene glycol has the effect of dissolving and stabilizing the water in the ink when it is contained in the oil-based ink. Conventionally, oil-based inks are likely to deteriorate with time due to water absorption over time, so polyethylene glycol can be used more effectively in the present invention. In particular, a hydroxyl value of 30 or more is more preferable because water solubility is excellent. In addition, the greater the hydroxyl value, the better the water absorption effect. However, if the hydroxyl value exceeds 120, water is absorbed more than necessary, and the ink aging tends to become unstable. It is more preferable that the value is 120 or less. Therefore, considering the ink aging stability, the hydroxyl value of polyethylene glycol is preferably in the range of 30 to 120, and most preferably in the range of 70 to 120. In particular, in order to adjust the ink viscosity of an oil-based ballpoint pen, an oil-based ink containing water can be used more suitably. Specific examples of the polyethylene glycol having a hydroxyl value in the range of 70 to 120 include PEG1000 and PEG1540 (Daiichi Kogyo Seiyaku Co., Ltd.). The hydroxyl value was calculated by the pyridine phthalic anhydride method.

  If the content of polyethylene glycol is less than 0.1% by mass with respect to the total amount of the ink composition, it is difficult to obtain the effect of suppressing metal contact between the ball and the chip body, and there is a possibility that writing failure may occur. If it exceeds 0.0 mass%, the stability of the colorant may be deteriorated. Therefore, the content is preferably 0.1 to 15.0 mass% with respect to the total amount of the ink composition. Furthermore, in order to obtain better ink aging stability, 3.0 to 10.0% by mass is most preferable with respect to the total amount of the ink composition.

  By the way, polyethylene glycol having an average molecular weight of 800 or more has an effect of suppressing metal contact between the ball and the chip body. On the other hand, polyethylene glycol alone cannot provide sufficient lubricity, so the writing quality is inferior. Under rolling (writing load 500 gf), it was difficult to suppress wear.

    As a result of diligent research, the present inventors have obtained a lubricity that was not obtained with polyethylene glycol alone by using a surfactant together, resulting in good writing quality and high writing pressure (writing load 500 gf). It has been found that wear is also suppressed.

    Examples of the surfactant used in the present invention include surfactants such as phosphate ester surfactants, silicon surfactants, fluorine surfactants, and acetylene glycol surfactants. These surfactants are used to improve the writing quality because the lubricity between the ball and the chip body can be improved and a smooth writing feel can be obtained. Among them, those having a phosphate group have an adsorptive power to metals, and are therefore adsorbed to balls, chip bodies, etc., and are therefore more lubricious than other types of surfactants. Since it is more effective under high writing pressure (writing load 500 gf), it is more preferable to use a phosphate ester surfactant.

［式中、Ｒはアルキル又はアルキルアリル基を、nはエチレンオキサイド付加モル数を、Ｒ’はＨまたはＲＯ（ＣＨ_２ＣＨ_２Ｏ）_ｎ基を示す。］ Phosphate ester surfactants include polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphate monoester, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphate diester, phosphate triester, Alternatively, there are derivatives thereof, but these phosphate surfactants may be used alone or in combination of two or more. Among these, in consideration of ink aging stability, it is preferable to use a polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether phosphoric acid monoester or phosphoric acid diester represented by the general formula (Chemical Formula 1). .

[Wherein, R represents an alkyl or alkylallyl group, n represents the number of moles of ethylene oxide added, and R ′ represents H or RO (CH ₂ CH ₂ O) _n group. ]

Examples of the phosphoric acid ester-based surfactant such as (Chemical Formula 1) include styrenated phenol-based, nonylphenol-based, lauryl alcohol-based, tridecyl alcohol-based, octylphenol-based, and short-chain alcohol-based surfactants. Further, among this, styrenated phenol, nonylphenol type, phenyl skeleton of octylphenol system such as _{(C 6 H 5 -, C} 6 H 4 -, C 6 H 3 - , etc.) phosphoric acid ester-based surfactant having a can, Since the phenyl skeleton forms a steric structure, it has the effect of causing steric hindrance compared to other systems. The lubricity is somewhat inferior and the improvement in writing taste is small. Surfactants are preferred, and lauryl alcohol, tridecyl alcohol, and short chain alcohol are most preferred.

  Specific examples of such phosphate ester surfactants include Prisurf A208B (lauryl alcohol), A219B (lauryl alcohol), and the like from the Prisurf series (Daiichi Kogyo Seiyaku Co., Ltd.). A213B (lauryl alcohol type), A210B (lauryl alcohol type), A215C (tridecyl alcohol type), A212C (tridecyl alcohol type), A208F (short chain alcohol type), and the like. The short chain alcohol is an alcohol having 1 to 4 carbon atoms. These surfactants may be used alone or in combination of two or more.

  Further, if the content of the phosphate ester-based surfactant is less than 0.1% by mass relative to the total amount of the ink composition, the desired lubricity may not be obtained in the ink, and 5.0% by mass If it exceeds 1, the ink aging may become unstable, so 0.1 to 5.0% by mass is preferable with respect to the total amount of the ink composition. Most preferably, it is 0.5 to 3.0 mass% with respect to the total amount of the ink composition.

As described above, by using polyethylene glycol having an average molecular weight of 800 or more and a surfactant in combination, lubricity is maintained even under high writing pressure (writing load 500 gf), wear of the ball seat is suppressed, and good ink aging is achieved. Stability is obtained. In particular, a low-viscosity oil-based ink having an ink viscosity of 5000 mPa · s or less at 20 ° C. and a shear rate of 6.8 sec ⁻¹ is more effective because a load is easily applied to the ball seat.

  As for the resin used in the present invention, phenol resin, maleic resin, amide resin, xylene resin, rosin resin and hydrogenated compounds thereof, urea resin, ketone resin, terpene resin, alkyd resin, xylene resin, phenoxy resin, polyvinyl butyral Resin, polyvinyl acetate, polyvinylpyrrolidone, polyethylene oxide, cross-linked acrylic acid polymer and the like. You may use these individually or in mixture of 2 or more types. If the resin content is less than 0.1% by mass relative to the total amount of the ink composition, it is difficult to obtain the desired ink viscosity, and if it exceeds 30.0% by mass, the writing performance may be inferior. Therefore, 0.1 to 30.0 mass% is preferable.

  Among them, polyvinylpyrrolidone has an average molecular weight of 100,000 or more, and the average molecular weight is very large, so the straight chain is long, so it is possible to cover the ball and the ball seat with a polyvinylpyrrolidone film. A thick film that is one of the elastic elements is formed. By using together with the polyethylene glycol, a thicker film is formed, so that more elastic force is generated, and it is considered that the effect of suppressing metal contact between the ball and the ball seat is likely to be obtained. Polyvinylpyrrolidone also has the effect of imparting spinnability to the ink composition and preventing crying. Therefore, it is more preferable to use at least polyvinylpyrrolidone as the resin.

  Specific examples of the polyvinyl pyrrolidone used in the present invention include trade names manufactured by ISP Japan Co., Ltd .; PVP K-15, PVP K-30, PVP K-90, PVP K-120, and the like. You may use these individually or in mixture of 2 or more types.

The ink viscosity of the oil-based ink composition of the present invention is not particularly limited, but when the ink viscosity at 20 ° C. and a shear rate of 6.8 sec ⁻¹ is less than 100 mPa · s, the ink viscosity is too low. , The effect of suppressing metal contact between the ball and the ball seat by the polyethylene glycol tends to be low, and when the ink viscosity at 20 ° C. and a shear rate of 6.8 sec ⁻¹ exceeds 5,000 mPa · s, Ball rotation resistance at the time of writing tends to increase, and writing tends to be heavy. Therefore, the ink viscosity at 20 ° C. and a shear rate of 6.8 sec ⁻¹ is preferably 100 to 5,000 mPa · s. More preferably, 500 to 3,000 mPa · s is preferable.

    As for the colorant used in the present invention, there are dyes and pigments. As for the dyes, oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, and various salt-forming dyes can be used. is there.

  Regarding the dye, specifically, Bali First Black 1802, Bali First Black 1805, Bali First Black 1807, Bali First Violet 1701, Bali First Blue 1601, Bali First Blue 1605, Bali First Blue 1621, Bali First Red 1320, Bali First Red 1355, Bali First Red 1360, Bali First Yellow 1101, Bali First Yellow 1151, Nigrosine Base EXBP, Nigrosine Base EX, BASE OF BASIC DYES ROB-B, BASE OF BASIC DYES RO6G-B, BASE OF BASIC DYES VPB-B, BASE OF BASIC DYES VB-B, BASEOF BASIC D ES MVB-3 (above, manufactured by Orient Chemical Co., Ltd.), Eisenspiron Black GMH-Special, Eisenspiron Violet C-RH, Eisenspiron Blue GNH, Eisenspiron Blue 2BNH, Eisenspiron Blue C-RH, Eisen Spiron Red C-GH, Eisen Spiron Red C-BH, Eisen Spiro Yellow C-GNH, Eisen Spiro 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.

  Examples of pigments include inorganic, organic, and processed pigments. Specifically, carbon black, aniline black, ultramarine, yellow lead, titanium oxide, iron oxide, phthalocyanine, azo, quinacridone, and quinophthalone Selenium, triphenylmethane, perinone, perylene, goxazine, metallic pigment, pearl pigment, fluorescent pigment, phosphorescent pigment, and the like. These dyes and pigments may be used alone or in combination of two or more. As for content of a coloring agent, 1.0-50.0 mass% is preferable with respect to the ink composition whole quantity.

  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 ethers such as methoxybutanol and 3-methoxy-3-methylbutanol, glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, butylene glycol and ethylene glycol, benzyl alcohol, methanol, ethanol, 1 -Propanol, 2-propa Alcohol, isopropanol, isobutanol, t-butanol, propargyl alcohol, allyl alcohol, 3-methyl-1-butyn-3-ol, alcohols such as ethylene glycol monomethyl ether acetate and other higher alcohols, phenyl cellosolve, etc. Organic solvents generally used as oil-based ballpoint pen inks such as cellosolves can be exemplified, and one or more of these can be used. The content of the organic solvent is preferably 5.0 to 50.0% by mass with respect to the total amount of the ink composition in consideration of solubility of the colorant, handwriting drying property, blurring, and the like.

  In addition, oleic acid, stearic acid, ricinoleic acid, lauric acid, etc. are used as organic acids for the purpose of neutralizing the oil-based ink composition in order to improve the aging stability and lubricity of the colorant. Alkylamine, polyoxyethylenealkylamine, oxyethylenealkylamine, alkanolamine or the like may be used as the amine, water, organic acid amide or the like may be used as the viscosity modifier, and a dye stabilizer, plasticizer, or the like may be used. These may be used alone or in combination of two or more.

Next, an Example is shown and this invention is demonstrated.
The ink composition for oil-based ballpoint pens of Example 1 contains, as a colorant, a dye (Spiron Black-GMH-S: manufactured by Hodogaya Chemical Co., Ltd., Barry First Violet 1701: manufactured by Orient Chemical Industry Co., Ltd.), an organic solvent As benzyl alcohol, ethylene glycol monophenyl ether, phosphate ester surfactant as a lubricant (Pricesurf A210B: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), organic acid as oleic acid, amine as organic amine, resin as polyvinylpyrrolidone (PVP K-90: manufactured by IPS Japan Co., Ltd.), ketone resin (Hilac 110H: manufactured by Hitachi Chemical Co., Ltd.), polyethylene glycol (PEG 1540: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Dispense after weighing and heating to 60 ° C. Completely dissolved using a stirrer to obtain an oil-based ballpoint pen ink composition. Specific blending amounts are as follows. The ink viscosity was measured at a shear rate of 6.8 sec ⁻¹ (rotation speed: 20 rpm) in a 20 ° C. environment using a Brookfield DV-II viscometer (No. 27 rotor), and at 1800 mPa · s. there were.

Example 1
Dye (Spiron Black-GMH-S) 20.0% by mass
Dye (Barry First Violet 1701) 18.0% by mass
Organic solvent (benzyl alcohol) 20.5% by mass
Organic solvent (ethylene glycol monophenyl ether) 30.0% by mass
Lubricant (phosphate-based surfactant) 2.0% by mass
Organic acid (oleic acid) 2.0% by mass
Amine (organic amine) 2.0% by mass
Polyethylene glycol (PEG 1540) 3.0% by mass
Resin (Polyvinylpyrrolidone) 0.5% by mass
Resin (ketone resin) 2.0% by mass

Examples 2-11
As shown in Tables 1 and 2, oil-based ballpoint pen ink compositions of Examples 2 to 11 were obtained in the same procedure as Example 1 except that the components were changed to the formulations shown in Tables 1 and 2. Tables 1 and 2 show the measurement and evaluation results.

Comparative Examples 1-6
The ink was blended as shown in Table 3, and blended in the same procedure as in Example 1 to obtain oil ballpoint pen ink compositions of Comparative Examples 1-6. Table 3 shows the measurement and evaluation results.

Test and Evaluation A ballpoint pen tip in which the ink composition for oil-based ballpoint pens produced in Examples 1 to 11 and Comparative Examples 1 to 6 is held in an ink containing cylinder (polypropylene) with a ball diameter of φ0.7 mm rotatably ( The following test and evaluation were carried out using a copy paper (PPC paper) as a writing test paper.

High writing pressure writing test: The wear of the ball seat after the writing test was measured with a running tester with a load of 500 gf, a writing angle of 70 °, and 4 m / min.
Ball seat wear less than 10μm ・ ・ ・ ◎
Ball seat wear is 10 μm or more and less than 20 μm, but can be written.
Wearing the ball seat is bad and results in poor writing ・ ・ ・ ×

Written taste: A hand-written sensory test was performed and evaluated.
Smooth and good ・ ・ ・ ◎
Somewhat inferior ・ ・ ・ ○
Heavy and inferior ・ ・ ・ ×

Ink aging test: After standing at room temperature for 6 months, the ink state in the ink container of the refill was observed with a microscope.
No precipitate is present ... ◎
Precipitates exist, but there are no practical problems
Precipitates are generated and the practicality is poor.

  In Examples 1 to 11, good performance was obtained in both the high writing pressure writing test, writing quality, and ink aging test.

  Since Comparative Examples 1 and 2 did not contain polyethylene glycol, Comparative Examples 3 and 4 contained polyethylene glycol having an average molecular weight of less than 800. Therefore, in the high writing pressure writing test, the wear of the ball seat was severe, and the writing was poor. It has become.

In Comparative Examples 5 and 6, since no surfactant was contained, the writing taste was heavy and inferior, and the handwriting was severely damaged.

  The present invention relates to an ink composition for oil-based ballpoint pens. More specifically, the present invention relates to an ink composition for oil-based ballpoint pens containing at least a colorant, an organic solvent, a resin, polyethylene glycol, and a surfactant, and has an average molecular weight of the polyethylene glycol. By using an oil-based ballpoint pen ink composition characterized by having a viscosity of 800 or more, it retains lubricity even under high writing pressure (writing load 500 gf), suppresses wear of the ball seat, and is stable over time with ink. Can provide an oil-based ink composition for ballpoint pens. Therefore, it can be widely used as a ballpoint pen, such as a cap type and a knock type.

Claims (7)

An oil-based ballpoint pen ink composition comprising at least a colorant, an organic solvent, a resin, polyethylene glycol, and a surfactant, wherein the polyethylene glycol has an average molecular weight of 800 or more. object. The surfactant is a phosphate ester surfactant, and the content of the phosphate ester surfactant is 0.1 to 5.0% by mass with respect to the total mass of the ink composition. 2. The ink composition for oil-based ballpoint pens according to claim 1. The oil-based ballpoint pen ink composition according to claim 2, wherein the phosphate ester-based surfactant contains at least an alcohol phosphate-based surfactant. The ink composition for oil-based ballpoint pens according to claim 3, wherein the phosphate ester-based surfactant includes at least a lauryl alcohol-based, tridecyl alcohol-based, and short-chain alcohol-based phosphate ester surfactant. object. 5. The ink composition for oil-based ballpoint pens according to claim 1, wherein the polyethylene glycol has a hydroxyl value in the range of 30 to 120. 6. The ink composition for oil-based ballpoint pens according to any one of claims 1 to 5, wherein the resin contains at least polyvinylpyrrolidone. The ink composition for oil-based ballpoint pens according to any one of claims 1 to 6, wherein the ink viscosity at 20 ° C and a shear rate of 6.8 sec ^-1 is 100 to 5000 mPa · s.