JP2024033680A - Ink composition for oily ball point pen, and oily ball point pen using the same - Google Patents

Abstract

To provide an ink composition for an oily ball point pen which improves writing adhesion to a paper surface and slipperiness, does not cause line skipping and writing blurring in handwriting, has good writing property, and improves writing feeling and wear suppression of a ball seat under high writing pressure (writing load of 300 to 500 gf), and an oily ball point pen using the same.SOLUTION: An ink composition for an oily ball point pen contains a coloring agent, a terpene phenol resin, and an alkylene oxide derivative of glycerol.SELECTED DRAWING: None

Description

The present invention relates to an ink composition for an oil-based ballpoint pen and an oil-based ballpoint pen using the same.

When writing with oil-based ballpoint pens, the writing resistance between the ball and the tip body tends to affect the writing quality of the ballpoint pen.In particular, unlike other types of writing instruments, ballpoint pens have a metal tip made of stainless steel or the like at the tip. It has a configuration in which a transfer ball made of a metal such as ultra-steel is held in a ball receiving seat of the metal tip, and a ballpoint pen tip is attached to an ink storage cylinder, but when writing, the rotation of the ball causes line skipping in the handwriting. There were drawbacks such as smudges and uneven dots, poor writing quality, and smudges due to ink remaining at the tip of the tip.

To solve these problems, many ink compositions for oil-based ballpoint pens using various lubricants have been proposed for the purpose of improving lubricity in order to suppress the writing resistance between the ball and the tip body.

Ink compositions for oil-based ballpoint pens using such additives include those using alkyl β-D-glucosides, such as ``Oil-based Ballpoint Pen Ink'' published in JP-A-5-331403 and having an average molecular weight of 200 to 4,000,000. An example using a certain polyethylene glycol is JP-A-7-196971 "Ink composition for oil-based ballpoint pen", an example using N-acyl amino acid, N-acylmethyl tauric acid, N-acylmethylalanine is as follows. JP-A-2007-176995 ``Oil-based ballpoint pen ink'' containing at least a big macadamia nut oil fatty acid decaglyceryl and a polyoxyethylene alkyl ether whose alkyl group has 16 or more carbon atoms and is solid at room temperature, It is disclosed in JP-A No. 2008-88264 "Oil-based ink composition for ballpoint pen" and the like. (Patent Documents 1 to 4)

"Unexamined Japanese Patent Publication No. 5-331403" "Unexamined Japanese Patent Publication No. 7-196971" "Unexamined Japanese Patent Publication No. 2007-176995" "Unexamined Japanese Patent Publication No. 2008-88264"

However, when various additives such as those disclosed in Patent Documents 1 to 4 are used, it is possible to reduce the writing resistance between the ball and the chip body to some extent, but the writing quality is not satisfactory, and the handwriting It was not possible to improve writing quality such as skipped lines and smudges, and there was room for improvement.

The purpose of the present invention is to provide an oil-based material that has good writing properties without skipping or fading in handwriting, and that can improve the writing quality and suppress wear of the ball seat under high writing pressure (writing load of 300 to 500 gf). An object of the present invention is to obtain an ink composition for a ballpoint pen and an oil-based ballpoint pen using the same.

In order to solve the above problems, the present invention provides: 1. An ink composition for an oil-based ballpoint pen, comprising a colorant, a terpene phenol resin, and an alkylene oxide derivative of glycerin.
2. 2. The ink composition for an oil-based ballpoint pen according to item 1, wherein the weight average molecular weight of the terpene phenol resin is 200 or more and 1200 or less.
3. 3. The ink composition for an oil-based ballpoint pen according to item 1 or 2, wherein the alkylene oxide derivative of glycerin has a weight average molecular weight of 300 or more and 5,000 or less.
4. The ink composition for an oil-based ballpoint pen according to any one of Items 1 to 3, wherein the average number of moles of alkylene oxide added to the alkylene oxide derivative of glycerin is 1 or more and 30 or less.
5. The ink composition for an oil-based ballpoint pen contains at least one selected from a phosphate ester surfactant, a silicone surfactant, a surfactant having an acetylene bond, a fluorine surfactant, a fatty acid, and a fatty acid ester. The ink composition for an oil-based ballpoint pen according to any one of Items 1 to 4, characterized in that:
6. 6. The ink composition for an oil-based ballpoint pen according to any one of Items 1 to 5, characterized in that the ink composition for an oil-based ballpoint pen contains a rosin resin.
7. The tip of the ink storage cylinder has a ballpoint pen tip rotatably holding a ball, and the ink composition for an oil-based ballpoint pen according to any one of items 1 to 6 is placed in the ink storage cylinder. An oil-based ballpoint pen characterized by a housing. ”.

The present invention improves the adhesion and slipperiness of handwriting to the paper surface, resulting in no skipped lines or fading in the handwriting, good writing performance, good writing quality, and a ball seat under high writing pressure (writing load of 300 to 500 gf). It was possible to obtain an ink composition for an oil-based ballpoint pen that improves the wear resistance of the ink composition, and an oil-based ballpoint pen using the same.

Embodiments of the present invention will be described in detail below. In addition, in this specification, "parts", "%", "ratio", etc. indicating formulations are based on mass unless otherwise specified, and content is based on the mass of the oil-based ballpoint pen ink composition. is the mass % of the constituent components.

The present invention is characterized in that the ink composition for an oil-based ballpoint pen contains a colorant, a terpene phenol resin, and an alkylene oxide derivative of glycerin.

By containing a terpene phenol resin and an alkylene oxide derivative of glycerin in the ink composition for oil-based ballpoint pens, it improves the adhesion and slipperiness of handwriting to the paper surface, eliminating line skipping and fading, and improves writing performance. It was found that it was possible to improve the writing quality and suppress wear of the ball seat under high writing pressure (writing load of 300 to 500 gf).

(terpene phenolic resin)
The terpene phenol resin used in the present invention is one manufactured by, for example, a method in which terpenes such as α-pinene, β-pinene, limonene, and terpinolene are polymerized in a reaction system in the presence of phenols. can. The phenols include phenol, bisphenol A, and alkylphenols such as cresol, xylenol, pt-butylphenol, p-octylphenol, and p-nonylphenol.

Terpene phenol resin forms a strong handwriting film, which improves the adhesion of handwriting to the paper surface, resulting in good handwriting, with no skipped lines or fading, and good writing performance. Furthermore, the aromatic ring skeleton of terpene phenol resin has a cushioning effect between the ball and the ball seat, improving slipperiness, suppressing the resistance between the ball and the ball seat, and improving the writing quality even under high writing pressure. It is possible to improve the wear control of the ball seat under (writing load of 300 to 500 gf). By using the alkylene oxide derivative of glycerin described below in combination, the interaction works and can further improve the slipperiness, improving the writing feel and suppressing wear on the ball seat under high writing pressure (writing load of 300 to 500 gf). becomes possible.

Regarding the weight average molecular weight of the terpene phenol resin, by forming a stronger handwriting film, it improves the adhesion of handwriting to the paper surface (writability), and the handwriting has no skipping or fading, resulting in good writing performance. The weight average molecular weight is preferably 200 or more and 1200 or less, in order to more easily improve the slipperiness, further improve the dissolution stability in the ink, and make it easier to obtain the effects of the present invention. Considering the adhesion of handwriting to the paper surface, prevention of line skipping and fading in handwriting, and stability of dissolution in ink, it is preferably 300 or more and 1000 or less, and preferably 400 or more and 800 or less. Furthermore, if the weight average molecular weight is too large, the stability over time is likely to be affected, and the viscosity of the ink composition for oil-based ballpoint pens is likely to increase, which tends to affect handwriting due to ink followability, causing line skipping and fading in handwriting. This is because it is easily influenced by
Note that the weight average molecular weight of the terpene phenol resin is measured by the GPC method (gel permeation chromatography).

Regarding the softening point of terpene phenol resin, by maintaining its viscoelasticity, it forms a stronger handwriting film, which improves the adhesion of handwriting to the paper surface (writing quality) and eliminates line skipping and fading in handwriting. The temperature is 70°C or more and 150°C or less, in order to improve writing properties, improve slipperiness, and improve dissolution stability in ink, making it easier to obtain the effects of the present invention. It is preferable. The above-mentioned softening point is preferably 80°C or more and 130°C or less in order to maintain better viscoelasticity, adhesion of handwriting to the paper surface, and prevention of line skipping and fading in handwriting. The temperature is preferably 110°C or higher. Here, the softening point of the resin is a value measured according to JIS K2207.

Regarding terpene phenol resins, the hydroxyl value is generally controlled by the number of phenol moieties. It improves the adhesion of handwriting to the paper surface (writing quality), making the handwriting free of line skipping and fading, making it easier to write, and making it easier to improve slipperiness, and also has good dissolution stability in ink. Considering that the effects of the present invention can be easily obtained, the hydroxyl value of the terpene phenol resin is preferably 200 mgKOH/g or less. Considering more, the above hydroxyl value is preferably 30 mgKOH/g or more and 200 mgKOH/g or less, preferably 50 mgKOH/g or more and 200 mgKOH/g or less, preferably 50 mgKOH/g or more and 200 mgKOH/g or less, and 50 mgKOH/g or more and 100 mgKOH/g. The following are preferred. Note that the hydroxyl value is the number of mg of potassium hydroxide required to neutralize acetic acid bonded to hydroxyl groups when 1 g of resin is acetylated, and is measured based on the potentiometric titration method specified in JIS K 0070. Defined as the value.

When the content of the terpene phenol resin is less than 0.1% by mass based on the total amount of the ink composition for an oil-based ballpoint pen, it is difficult to obtain sufficient effects for adhesion of handwriting to the paper surface and slipperiness. Furthermore, if the resin content exceeds 20% by mass based on the total amount of the ink composition for oil-based ballpoint pens, the solubility in the ink tends to be poor, and the ink viscosity becomes too high, resulting in a decrease in ink consumption, poor writing quality, and poor writing performance. Performance is likely to be affected. Therefore, the content of the resin based on the total amount of the ink composition for oil-based ballpoint pens is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, and 2% by mass or more. It is preferably 10% by mass or less.

(Alkylene oxide derivative of glycerin)
In the present invention, since the alkylene oxide derivative of glycerin easily improves slipperiness, it maintains the lubricity between the writing tip and the surface to be written on (the lubricity between the ball and the tip body), and the writing tip By suppressing the writing resistance of the ball seat under high writing pressure (writing load of 300 to 500gf), it is possible to improve the writing quality and to improve the line skipping and fading in the handwriting. . As in the present invention, when used in combination with terpene phenol resin, the interaction works, improving the adhesion of handwriting to the paper surface and improving the slipperiness, which suppresses wear on the ball seat and improves the writing ability. It is possible to improve the taste, and it is possible to improve the appearance of lines and smudges in handwriting.
Furthermore, since alkylene oxide derivatives of glycerin generally have low volatility, they improve the writing performance of the writing tip even when the writing tip is left in the air, and increase the ink in the ink composition for oil-based ballpoint pens. By suppressing viscosity as much as possible, ink followability can be improved. In particular, terpene phenol resin can be used effectively because it tends to form a strong ink film on the writing tip and tends to affect the writing performance of the writing tip. Furthermore, since the alkylene oxide derivative of glycerin itself exhibits viscosity, it is also possible to reduce the content of terpene phenol resin when adjusting ink viscosity, making it difficult for the ink film to become strong and making the writing tip more viscous. It is preferable to use it together with a terpene phenol resin because it can improve the writing performance.
Examples of alkylene oxide derivatives of glycerin include polyoxyalkylene glyceryl ether, polyoxyalkylene alkyl glucoside, and polyoxypropylene alkyl ether, which can suppress wear on the ball seat by improving slipperiness. Polyoxyalkylene glyceryl ether is preferred from the viewpoint of improving the writing quality and preventing line skipping and fading in the handwriting.

Further, polyoxyalkylene glyceryl ether is obtained by addition polymerizing alkylene oxide to glycerin or polyglycerin, and includes polyoxyalkylene glyceryl ether, polyoxyalkylene diglyceryl ether, polyoxyalkylene triglyceryl ether, and the like.

In addition, when pigments are used as in the present invention, the ink viscosity generally increases over time due to aggregation of the pigments, and ink followability tends to decrease, but polar groups in the structure of the alkylene oxide derivative of glycerin Because it adsorbs to the pigment surface and stably disperses the pigment in the ink, it suppresses the increase in ink viscosity due to pigment aggregation, improving ink followability and producing good handwriting. Therefore, in consideration of pigment dispersion stability and ink followability, it is preferable to use polyoxyalkylene glyceryl ether, and among these, in consideration of pigment dispersion stability and ink followability, it is preferable to use polyoxyalkylene diglyceryl ether.

Moreover, polyoxyalkylene glyceryl ether includes polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, and the like. Among these, polyoxypropylene glyceryl ether has a propylene group, so it has excellent lipophilicity, suppresses moisture absorption of the oil-based ballpoint pen ink composition, and improves stability over time, thereby enhancing the effect of the present invention. Easy to obtain. For this reason, it is preferable to use polyoxypropylene glyceryl ether.

Polyoxyalkylene glyceryl ether improves slipperiness, suppresses wear on the ball seat, improves writing quality, improves line skipping and fading in handwriting, and improves pigment dispersion stability and stability over time. Considering that it is easy to obtain the effects of the present invention by doing so, it is preferable that the average number of added moles of alkylene oxide (average number of added moles of alkylene oxide) is 1 or more and 50 or less; It is preferable that the average number of added moles of alkylene oxide is 1 or more and 30 or less, and in consideration of further improving slipperiness and stability over time, it is preferable that the average number of added moles of alkylene oxide is 1 or more and 20 or less. More preferably, it is 5 or more and 20 or less.

In particular, the average number of moles of propylene oxide added is 1 to 30, considering that by further improving the slipperiness, the wear of the ball seat is suppressed, and the writing quality and handwriting are free from line skipping and fading. It is preferably from 1 to 20, more preferably from 5 to 20, even more preferably from 1 to 12, particularly preferably from 5 to 12. Further, considering that the effects of the present invention can be easily exhibited, the structure of the polyoxyalkylene glyceryl ether is preferably a structure represented by the following formula (1) or (2).

In the formula, m, n, o, p, w, x, y, and z each independently represent the number of alkylene oxides added.
Here, m+n+o+p is the average number of moles of propylene oxide added, and w+x+y+z is the average number of moles of ethylene oxide added.

Among these, the polyoxyalkylene glyceryl ether represented by formula (1) has a large effect of improving stability over time, so the effects of the present invention can be easily obtained, and is therefore preferred.

In addition, the weight average molecular weight of the alkylene oxide derivative of glycerin is preferably 5000 or less. This is because if the weight average molecular weight is too large, the stability over time is likely to be affected, and furthermore, the weight average molecular weight of the alkylene oxide derivative of glycerin is preferably 5000 or less. This is because the viscosity tends to increase, which tends to affect handwriting due to ink followability. Considering stability over time and ink followability, the weight average molecular weight is preferably 3,000 or less, more preferably 1,500 or less, and preferably 1,200 or less. Further, in order to further improve the slipperiness and obtain good handwriting, it is preferable that the number is 900 or less. On the other hand, if the weight average molecular weight is too small, the slipperiness and pigment dispersibility are likely to be affected, so it is preferable that the weight average molecular weight is 300 or more. preferable.
The weight average molecular weight is a value obtained in terms of polystyrene using GPC (gel permeation chromatography).

Furthermore, if the content of the alkylene oxide derivative of glycerin is less than 0.1% by mass based on the total amount of the ink composition for oil-based ballpoint pens, the effects of slipperiness and ink followability may not be obtained, and the content is 40% by mass. If it exceeds this amount, it may affect the stability over time, so it is preferably 0.1% by mass or more and 40% by mass or less, more preferably 3% by mass or more and 30% by mass or less, based on the total amount of the oil-based ballpoint pen ink composition. Furthermore, in consideration of the balance between wear suppression of the ball seat and stability over time, the content is preferably 5% by mass or more and 25% by mass or less, and most preferably 8% by mass or more and 25% by mass or less.

(colorant)
The coloring agent used in the present invention is not particularly limited, and can be appropriately selected and used, such as dyes and pigments. Dyes and pigments may be used in combination.
Dyes include oil-soluble dyes, acidic dyes, basic dyes, metal-containing dyes, and their various salt-forming dyes, such as salt-forming dyes of acidic dyes and basic dyes, organic acid and basic dyes, etc. Examples include salt-forming dyes with acid dyes and organic amines, and salt-forming dyes with acid dyes and organic amines. These dyes may be used alone or in combination of two or more. As the dye, it is preferable to use a salt-forming dye, taking into account its stability over time due to its compatibility with the alkylene oxide derivative of glycerin, and also considering that stability over time can be maintained due to the stability of the salt-forming bond. For example, it is preferable to use a salt-forming dye of a basic dye and an organic acid, a salt-forming dye of a basic dye and an acidic dye, and a salt-forming dye of an acidic dye and an organic amine.

Regarding the dyes, specifically, Varifast Black 1802, Varifast Black 1805, Varifast Black 1807, Varifast Violet 1701, Varifast Violet 1704, Varifast Violet 1705, Varifast Blue 1601, Varifast Blue 1605, Varifast Blue 1613, Varifast Blue 1621, Varifast Blue 1631, Varifast Red 1320, Varifast Red 1355, Varifast Red 1360, Varifast Yellow 1101, Varifast 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, BASE OF BASIC DYES MVB-3 (manufactured by Orient Chemical Industry Co., Ltd.), Eisenspiron Black GMH-Special, Eisenspiron Violet C-RH, Eisenspiron Blue GNH, Eisenspiron Blue 2BNH, Eisenspiron Blue C-RH, Eisenspiron Red C-GH, Eisenspiron Red C-BH, Eisenspiron Yellow C-GNH, Eizenspiron Yellow C-2GH, S. P. T. Blue 111, S. P. T. Blue GLSH-Special, S. P. T. Red 533, S. P. T. Orange 6, S. B. N. Violet 510, S. B. N. Yellow 530, S. R. Examples include C-BH (manufactured by Hodogaya Chemical Industry Co., Ltd.).

Pigments include inorganic, organic, and processed pigments, but specific examples include carbon black, aniline black, ultramarine blue, yellow lead, titanium oxide, iron oxide, phthalocyanine, azo, quinacridone, and diketotin. Examples include pyrrolopyrrole-based, quinophthalone-based, threne-based, triphenylmethane-based, perinone-based, perylene-based, dioxazine-based, metallic pigments, pearl pigments, fluorescent pigments, and phosphorescent pigments.

It is preferable to use pigments as the coloring agent.In the case of ballpoint pens, the pigment particles enter the gap between the ball and the tip body, making it easier to act like a bearing. By suppressing contact and improving slipperiness, it is possible to suppress wear on the ball seat and improve the writing quality, which is likely to have the effect of reducing line skipping and fading in the handwriting. , it is preferable to use pigments. Furthermore, pigments are preferable because they have excellent water resistance and light resistance and can be suitably used for official documents.
In addition, the oil-based ballpoint pen ink composition is preferable because it can withstand high-load writing, so it can be suitably used for copy paper, etc., and it can also be suitably used for official documents.

As for the pigment, the average particle diameter is preferably 1 nm or more and 500 nm or less. More preferably, it is 30 nm or more and 350 nm or less, and still more preferably 50 nm or more and 300 nm or less. By keeping this within the above range, it is possible to suppress wear of the ball seat and improve the writing quality by further improving the slipperiness, which has the effect of making the handwriting less likely to skip lines or fade. It's easy to get caught.
Here, the average particle diameter is determined using a laser diffraction method, specifically, a laser diffraction particle size distribution analyzer (trade name "MicrotracHRA9320-X100", Nikkiso Co., Ltd.) using a standard sample or other measurement method. It can be determined by the particle diameter (D50) when the cumulative volume of the particle size distribution is 50%, which is measured based on the calibrated value.
In addition, since the pigment exhibits the above-mentioned effects in the dispersed state of the pigment in the ink composition for an oil-based ballpoint pen, it is preferable to determine the particle size in the dispersed state.

Furthermore, it is preferable that the content of the pigment is higher than the content of the colorant in the ink composition for an oil-based ballpoint pen. Specifically, by setting the pigment content to 10% by mass or more relative to the colorant content, water resistance, light resistance, and slipperiness can be improved to the required level, but water resistance, light resistance, and From the viewpoint of slipperiness, in order to make handwriting changes less likely to occur, the content is preferably 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass, and 100% by mass or more. It is particularly preferable to express it in mass %.

In general, ink compositions for oil-based ballpoint pens containing pigments tend to have insufficient writing performance and ink followability when the writing tip is dry, but the ink composition for oil-based ballpoint pens according to the present invention By containing oxyalkylene glyceryl ether, even when the content ratio of pigment is high, writing performance and ink followability are maintained well, resulting in good handwriting.

The content of the colorant is preferably 5 to 30% by mass based on the total amount of the ink composition for an oil-based ballpoint pen. This is because if it is less than 5% by mass, it will be difficult to obtain dark handwriting, and if it exceeds 30% by mass, it will tend to affect the stability in the ink. , 7 to 25% by weight, and more preferably 10 to 20% by weight.

(Organic solvent)
In the present invention, it is preferable that an organic solvent is included. Specifically, examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol monophenyl ether, propylene Glycol ether solvents such as glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether, 3-methoxybutanol, 3-methoxy-3-methylbutanol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, butylene glycol , glycol solvents such as ethylene glycol, benzyl alcohol, methanol, ethanol, 1-propanol, 2-propanol, 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, and organic solvents such as ethylene glycol monomethyl ether acetate and other higher alcohols.

Among these organic solvents, aromatic alcohols improve lubricity by having an aromatic ring, and are highly compatible with polyoxyalkylene glyceryl ether, improving solution stability. Preferably, an alcoholic solvent is used.

(surfactant)
The oil-based ballpoint pen ink composition of the present invention preferably contains a surfactant. The oil-based ballpoint pen ink composition contains a surfactant, which improves slipperiness and improves writing performance and writing feel when the tip dries after being left in the air. can be achieved.

The surfactant is preferably at least one selected from phosphate surfactants, silicone surfactants, surfactants having an acetylene bond, fluorine surfactants, fatty acids, and fatty acid esters. .

Among surfactants, phosphate ester surfactants and silicone surfactants are used to improve slipperiness, create better handwriting, and improve writing performance and writing feel. It is preferable. Further, phosphoric acid ester surfactants are preferable because they have the effect of easily improving slipperiness.

Examples of phosphate ester surfactants include phosphate esters and polyoxyethylene alkyl ethers having an alkoxyethyl group (C _n H _2n+1 OCH ₂ CH ₂ O) or an alkoxy group (C _m H _2m+1 O). or phosphoric acid monoester of polyoxyethylene alkyl aryl ether, phosphoric acid diester of polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether, phosphoric acid triester of polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether, alkyl phosphorus Examples include acid esters, alkyl ether phosphates, and derivatives thereof.

Specifically, the phosphate ester surfactants include the phoslex series (manufactured by SC Organic Chemical Co., Ltd.), the JP series (manufactured by Johoku Kagaku Kogyo Co., Ltd.), and the Plasurf series (manufactured by Daiichi Kogyo Co., Ltd.). ), Phosphanol series (manufactured by Toho Chemical Industries, Ltd.), and NIKKOL series (manufactured by Nikko Chemicals Co., Ltd.).

Among phosphoric acid ester surfactants, alkoxyethyl group (C _n H _2n+1 O-C ₂ H ₄ O) or an alkoxy group (C _m H _2m+1 O), phosphoric acid monoester of polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether, polyoxyethylene alkyl ether or polyoxyethylene alkylaryl Preferably it is selected from among the phosphoric diesters of ethers.

Furthermore, among phosphate ester surfactants, alkoxyethyl It is preferable to use a phosphate ester surfactant having a group (C _n H _2n+1 O-C ₂ H ₄ O) or an alkoxy group (C _m H _{2m+1 O} ). It is preferable to use a phosphate ester surfactant having a surfactant of _2m+1 O).

Regarding the phosphate ester surfactant, the carbon chain (n, m) of the terminal alkyl group of the alkoxyethyl group (C _n H _2n+1 O-C ₂ H ₄ O) or alkoxy group (C _m H _2m+1 O) is preferably 1 or more and 20 or less. Furthermore, if the carbon chain (n, m) of the terminal alkyl group of the alkoxyethyl group (C _n H _2n+1 O-C ₂ H ₄ O) or the alkoxy group (C _m H _2m+1 O) has an appropriate length, the In order to easily maintain good slipperiness, the carbon chain (n, m) of the terminal alkyl group is preferably 1 or more and 20 or less; The carbon chain (n, m) is preferably 2 or more and 12 or less, 3 or more and 8 or less, or 3 or more and 6 or less.

Furthermore, by improving the slipperiness of phosphate ester surfactants, it suppresses wear on the ball seat, improves writing feel, improves line skipping and fading in handwriting, and improves writing performance and writing quality. In consideration of improving More preferably, it is 12 or more and 18 or less. This is because if the number of carbon atoms in the alkyl group is too small, slipperiness tends to be insufficient, and if the number of carbon atoms is too large, stability over time tends to be affected.
Phosphate ester surfactant having the above alkoxyethyl group (C _n H _2n+1 O-C ₂ H ₄ O) or alkoxy group (C _m H _2m+1 O) and phosphate ester surfactant having alkyl group It is preferable that the interaction is effective and that the effect of the present invention can be easily obtained because the sliding properties are more likely to be improved by the interaction of using in combination.

In addition, when using a phosphate ester surfactant, the acid value is preferably 160 (mgKOH/g) or less, more preferably 120 (mgKOH/g) or less, and 100 or less. is more preferable because it facilitates the improvement of slipperiness by the phosphate ester surfactant. Furthermore, considering the stability and lubricity in the ink composition for oil-based ballpoint pens, the acid value is preferably 30 (mgKOH/g) or more and 160 (mgKOH/g) or less, and 40 (mgKOH/g) or more and 120 (mgKOH/g) or more. mgKOH/g) or less, and more preferably 40 (mgKOH/g) or more and 100 (mgKOH/g) or less.
A phosphate ester surfactant having the alkoxyethyl group (C _n H _2n+1 O-C ₂ H ₄ O) or an alkoxy group (C _m H _2m+1 O) described above and a phosphate ester interface having a specific acid value. The interaction with the combined use of an activator makes it easier to improve the slipperiness, which makes it easier to obtain the effects of the present invention, which is effective and preferable.
Note that the acid value is expressed in mg of potassium hydroxide required to neutralize the acidic component contained in 1 g of sample.

The content of the surfactant is more preferably 0.1% by mass or more and 5.0% by mass or less based on the total amount of the ink composition for an oil-based ballpoint pen. When it is less than 0.1% by mass, it improves the desired slipperiness, suppresses wear on the ball seat, improves writing quality, improves line skipping and fading in handwriting, and improves writing performance. This is because it tends to be difficult to obtain, and if it exceeds 5.0% by mass, the ink tends to become unstable over time. Taking these into consideration, the content of the surfactant based on the total amount of the ink composition for oil-based ballpoint pens is preferably 0.3% by mass or more and 4.0% by mass or less, and more preferably 0.5% by mass or more and 3% by mass or less. It is preferably .0% by mass or less.

When the ink composition for oil-based ballpoint pens according to the present invention contains a surfactant, the blending ratio (alkylene oxide derivative of glycerin/surfactant) of the surfactant, particularly the alkylene oxide derivative of glycerin as described above, is based on the mass. It is preferably 1 time or more and 30 times or less, more preferably 1 time or more and 25 times or less, more preferably 1 time or more and 20 times or less, more preferably 1 time or more and 15 times or less, and 2 It is more preferably at least 3 times and at most 15 times, more preferably at least 3 times and at most 15 times, and most preferably at least 5 times and at most 15 times. This means that within the above range, it is possible to improve the slipperiness, writing feel, and ink aging in a well-balanced manner.

(organic amine)
The ink composition for an oil-based ballpoint pen according to the present invention preferably contains an organic amine in order to improve the stability of the components contained in the ink composition. Amines containing ethylene oxide such as oxyethylene alkylamine and polyoxyethylene alkylamine, alkylamines such as laurylamine and stearylamine, and dimethylalkylamines such as distearylamine, dimethyllaurylamine, dimethylstearylamine, and dimethyloctylamine, etc. Among them, amines having ethylene oxide and dimethylalkylamines are preferred. In consideration of improving slipperiness and stability over time and making it easier to obtain the effects of the present invention, amines containing ethylene oxide are preferred.

Further, the total amine value of the organic amine is preferably 100 (mgKOH/g) or more and 300 (mgKOH/g) or less, considering stability with the surfactant, pigment, and other components. This is because when it exceeds 300 (mgKOH/g), the reactivity is too strong and it tends to react with the above components, so the stability over time tends to be poor. Furthermore, if the total amine value is less than 100 (mgKOH/g), the stability of the surfactant in the oil-based ballpoint pen ink composition tends to decrease, and the slipperiness tends to decrease. From the viewpoint of stability and slipperiness with the above components, the range is more preferably 150 (mgKOH/g) or more and 300 (mgKOH/g) or less. Further, from the viewpoint of stability, it is preferably 180 (mgKOH/g) or more and 300 (mgKOH/g) or less, and more preferably 230 (mgKOH/g) or more and 270 (mgKOH/g) or less.
In the present invention, the total amine value indicates the total amount of primary, secondary, and tertiary amines, and is expressed in mg of potassium hydroxide equivalent to hydrochloric acid required to neutralize 1 g of sample. .

Regarding the reactivity between organic amines and other components in the ink composition for oil-based ballpoint pens, primary amines are the strongest, followed by secondary amines and tertiary amines, which have the lowest reactivity, so stability over time should be taken into consideration. Therefore, it is preferable to use a secondary amine or a tertiary amine. These may be used alone or in combination of two or more.

In addition, in order to improve the adhesion of handwriting to the paper surface while adjusting the ink viscosity, and to obtain good handwriting without skipping or fading in the handwriting, and to have good writing properties, it is necessary to contain a rosin-based resin. It is preferable. Examples of rosin-based resins include rosin, rosin ester, and hydrogenated rosin ester. It is preferable to use Furthermore, since it is possible to reduce the content of terpene phenol resin, the ink film is less likely to become strong, making it easier to improve the writing performance of the writing tip, so it is preferable to use it in combination with terpene phenol resin. .

Regarding the softening point of rosin resin, considering that it can improve the adhesion of handwriting to the paper surface (writability), there is no skipping or fading of handwriting, and it is easy to make the handwriting good. The temperature is preferably 60°C or higher and 130°C or lower, more preferably 65°C or higher and 115°C or lower. Here, the softening point of the resin is a value measured according to JIS K2207.

If the content of the rosin resin is less than 0.1% by mass based on the total amount of the ink composition for an oil-based ballpoint pen, it is difficult to obtain a sufficient effect to obtain handwriting adhesion (writability) to the paper surface. Furthermore, if the resin content exceeds 20% by mass based on the total amount of the ink composition for oil-based ballpoint pens, the solubility in the ink tends to be poor, and the ink viscosity becomes too high, resulting in a decrease in ink consumption, poor writing quality, and poor writing performance. Performance is likely to be affected. Therefore, the total content of resin based on the total amount of the ink composition for oil-based ballpoint pens is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, and 5% by mass. The content is preferably 12% by mass or less.

(resin)
The ink composition for an oil-based ballpoint pen of the present invention contains other resins other than the terpene phenol resin and the rosin resin in order to improve the adhesion of handwriting to the paper surface and suppress ink leakage at the writing tip. It is preferable. Other resins include polyvinyl butyral resin, ketone resin, amide resin, rosin resin, terpene phenol resin, alkyl phenol resin, polyvinyl butyral resin, styrene-maleic acid resin, ethylene-maleic acid resin, styrene-acrylic resin, acrylic resin, Examples include maleic acid resin, cellulose resin, petroleum resin, coumaron-indene resin, polyethylene oxide, polymethacrylic acid ester, ketone-formaldehyde resin, α- and β-pinene/phenol polycondensation resin. These may be used alone or in combination.

Among these resins, resins that improve the adhesion of handwriting to the paper surface (writability), have good writing performance without skipping or fading, and take into consideration slipperiness and prevention of ink leakage at the writing tip. For example, it is preferably at least one selected from polyvinyl butyral resin and ketone resin. Considering better slipperiness and prevention of ink leakage at the writing tip, polyvinyl butyral resin and ketone resin are more preferable as resins contained in the ink composition for oil-based ballpoint pens, and polyvinyl butyral resin is more preferable. .

In addition, regarding the average degree of polymerization of polyvinyl butyral resin, it improves the adhesion of handwriting to the paper surface (writing quality), making the handwriting free of line skipping and fading, good writing performance, smoothness, and smoothness of the writing tip. Considering ink leakage suppression, the average degree of polymerization is preferably 100 or more and 2,000, and more preferably 100 or more and 1,500 or less, and more preferably 200 or more and 1,000 or less. Here, the average degree of polymerization refers to the number of basic units constituting one molecule of polyvinyl butyral resin, and a value measured based on the method specified in JISK6728 (2001 edition) can be adopted. .

Moreover, it is preferable that the polyvinyl butyral resin has a hydroxyl group content of 25 mol % or more. This is because polyvinyl butyral resins with a hydroxyl group content of less than 25 mol% do not have sufficient solubility in alkylene glycol alkyl ether solvents, making it difficult to obtain the effects of the present invention. Resin is preferable, and furthermore, it is preferable because it easily improves slipperiness and writing feel. Furthermore, if a polyvinyl butyral resin having a hydroxyl group content of more than 40 mol% is used, the amount of moisture absorption tends to increase, which tends to affect the stability over time with the ink components. Therefore, a polyvinyl butyral resin having a hydroxyl group content of 40 mol% or less is preferable. Therefore, a polyvinyl butyral resin having a hydroxyl group content of 30 mol% or more and 40 mol% or less is preferable, and more preferably a hydroxyl group content of 30 mol% or more and 36 mol% or less.
In addition, the amount of hydroxyl groups (mol%) of the polyvinyl butyral resin refers to the content of hydroxyl groups (mol%) with respect to the total mol amount of butyral groups (mol%), acetyl groups (mol%), and hydroxyl groups (mol%). It shows the rate.

If the resin content is less than 3% by mass based on the total amount of the ink composition for oil-based ballpoint pens, it will be difficult to obtain sufficient effects for adhesion of handwriting to the paper surface, slipperiness, and prevention of ink leakage. . Furthermore, if the total resin content exceeds 40% by mass based on the total amount of the ink composition for oil-based ballpoint pens, the solubility in the ink tends to be poor, and the ink viscosity becomes too high, resulting in a decrease in ink consumption and poor writing quality. This tends to affect export performance. Therefore, the total content of resin with respect to the total amount of the ink composition for oil-based ballpoint pens is preferably 3% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 30% by mass or less, and 10% by mass or more and 25% by mass or less. It is preferably less than % by mass.

In addition, the ink composition for an oil-based ballpoint pen of the present invention may appropriately contain a dye, a colorant stabilizer, a plasticizer, a chelating agent, an antifoaming agent, water, a pseudoplasticity imparting agent, and the like. These may be used alone or in combination of two or more.

The ink viscosity of the ink composition for oil-based ballpoint pens of the present invention is not particularly limited, but if the ink viscosity at 20°C and a shear rate of 5 sec ^-1 exceeds 15000 mPa・s, the ball rotation resistance during writing becomes large. The ink viscosity at 20°C and shear rate of 5 sec ^-1 is 15,000 mPa・s or less in order to obtain good handwriting. It is preferable. In order to further improve the writing performance and ink tracking performance and obtain good handwriting, the pressure is preferably 10,000 mPa·s or less, and with more consideration, it is preferably 8,000 mPa·s or less, and furthermore 6,000 mPa·s or less. It is preferable. In addition, if the ink viscosity at ²⁰ °C and shear rate of 5 sec ^-1 is less than 10 mPa・s, the handwriting is likely to be affected by blurring or ink leakage. The ink viscosity is preferably 100 mPa·s or more, more preferably 100 mPa·s or more, and more preferably 5 mPa·s or more.

(Oil-based ballpoint pen)
Further, the ink consumption amount per 100 m of the oil-based ballpoint pen is preferably 20 mg or more and 100 mg or less. This is because within the above range, there will be no dark handwriting, no line skipping or fading, and the writing performance will be good, and the writing quality will be good. mg, preferably from 30 mg to 70 mg.
The ink consumption was measured using five test samples at a writing speed of 4 m/min at 20°C, a writing angle of 70°, and a writing load of 200 g on JIS P3201 writing paper. A written test is conducted, and the average value of the ink consumption per 100 m is defined as the ink consumption per 100 m.

Further, the arithmetic mean roughness (Ra) of the ball surface of the oil-based ballpoint pen tip used in the present invention is preferably 0.1 nm or more and 12 nm or less. This means that enough ink is placed on the ball surface, resulting in good writing quality without skipping or fading in the handwriting, and good writing quality and suppressing wear on the ball seat under high writing pressure (writing load of 300 to 500 gf). In order to achieve this, in consideration of this, the arithmetic mean roughness (Ra) is preferably 1 nm or more and 10 nm or less, more preferably 2 nm or more and 8 nm or less. Note that the surface roughness can be measured using (model name SPI3800N manufactured by Seiko Epson Corporation).

The materials used for the balls are not particularly limited, but include cemented carbide balls whose main component is tungsten carbide, metal balls such as stainless steel, and ceramics such as silicon carbide, silicon nitride, alumina, silica, and zirconia. Balls, ruby balls, etc.

In addition, the ballpoint pen tip is made of metal materials such as stainless steel, nickel silver, brass, aluminum bronze, and aluminum, and resin materials such as polycarbonate, polyacetal, and ABS. Considering the properties, it is preferable that the tip body is made of stainless steel.

Further, it is preferable that the amount of movement of the ball of the ballpoint pen tip used in the present invention in the vertical axis direction is 3 μm or more and 30 μm or less. This is to ensure that the handwriting has no skipped lines or smudges, has good writing performance, has a good writing feel, and suppresses wear on the ball seat under high writing pressure (writing load of 300 to 500 gf). , preferably 10 μm or more and 25 μm or less, and preferably 12 μm or more and 25 μm.

When ink is directly stored in the ink storage cylinder, the rear end of the ink can be filled with an ink backflow preventer.
The ink backflow preventer composition comprises a non-volatile liquid or a hardly volatile liquid.
Specifically, petrolatum, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or cooligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples include polyether-modified silicone oil and fatty acid-modified silicone oil, and one type or two or more types can be used in combination.

It is preferable that the nonvolatile liquid and/or the hardly volatile liquid be thickened to a suitable viscosity by adding a thickener, and the thickener may include silica whose surface has been hydrophobically treated, or silica whose surface has been methylated. Fine particle silica, aluminum silicate, swellable mica, clay thickeners such as hydrophobically treated bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, Examples include dextrin-based compounds such as fatty acid amide, amide-modified polyethylene wax, hydrogenated castor oil, and fatty acid dextrin, and cellulose-based compounds.
Furthermore, the liquid ink backflow preventer and the solid ink backflow preventer may be used together.

Example 1
The ink composition for an oil-based ballpoint pen of Example 1 was prepared by collecting the colorant, organic solvent, alkylene oxide derivative of glycerin, phosphate ester surfactant, organic amine, and resin at 60°C using a disper stirrer. After stirring and dissolving the mixture, the mixture was cooled to room temperature to obtain an oil-based ballpoint pen ink composition.
The specific blending amounts are as follows.

Pigment dispersion (carbon black, average particle diameter 150 nm, containing 20% pigment, containing 20% polyvinyl butyral) 40.0% by mass
Alcohol solvent (benzyl alcohol) 21.0% by mass
Polyoxyalkylene glyceryl ether (formula (1), polyoxypropylene diglyceryl ether) 20.0% by mass
Phosphate ester surfactant (18 carbon atoms in alkyl group, acid value 85 (mgKOH/g)) 2.0% by mass
Organic amine (polyoxyethylene alkylamine) 2.0% by mass
Terpene phenol resin ((weight average molecular weight 550, softening point 100°C, hydroxyl value 60 (mgKOH/g)) 5.0% by mass
Rosin resin (rosin ester (softening point 100-110°C)) 10.0% by mass
Polyvinylpyrrolidone 0.5% by mass

Examples 2-21
As shown in Table 1, ink compositions for oil-based ballpoint pens of Examples 2 to 21 were obtained in the same manner as in Example 1 except that the ink components were changed. The measurement and evaluation results are shown in the table.

Comparative examples 1-2
As shown in the table, ink compositions for oil-based ballpoint pens of Comparative Examples 1 and 2 were obtained in the same manner as in Example 1 except that the ink components were changed. The measurement and evaluation results are shown in the table.

Test and Evaluation The oil-based ballpoint pen ink compositions (0.27 g) prepared in Examples 1 to 21 and Comparative Examples 1 to 2 were placed in an ink storage cylinder (polypropylene), and a ball with a ball diameter of φ0.7 mm was freely rotatable. A held ballpoint pen tip (with a coil spring inside the tip that presses the ball directly against the inner wall of the tip edge, axial movement of the ball: 8 μm, arithmetic mean roughness (Ra) of the ball surface: 5 nm). The installed oil-based ballpoint pen refill was filled with the oil-based ballpoint pen to produce an oil-based ballpoint pen. The following tests and evaluations were conducted using writing paper JIS P3201 as a written test paper.

Writing performance test (line skipping/fading): Handwriting after a 100 m writing test was observed using a running test machine with a load of 200 gf, a writing angle of 70°, and a speed of 4 m/min.
◎・・・There are no skipped lines or smudges in the handwriting.
○...The handwriting has some skipped lines or fading.△...The handwriting has some skipping or fading, but it is at a level that does not pose a practical problem.×...The handwriting has many skipped lines or fading.

Writing taste: A handwritten sensory test was conducted and evaluated.
◎・・・Very smooth
○・・・Smooth
△・・・Smoothness at a level that poses no practical problems
×・・・Heavy item

Wear resistance test (wear test of ball seat): Wear of the ball seat after the written test was measured using a running test machine with a load of 400 gf, a writing angle of 70°, and a running speed of 4 m/min.
◎... Ball seat wear is less than 5 μm ○... Ball seat wear is 5 μm or more and less than 10 μm △... Ball seat wear is 10 μm or more and less than 20 μm, but it is writable ×...The ball seat is badly worn and the writing becomes poor.

Writing performance test: After writing by hand, leave the tip exposed in an environment of 20°C and 65% RH for 24 hours, then write under the following writing conditions in a running test to determine the length of handwriting fading at the beginning of writing. We measured the
<Writing Conditions> Straight writing was performed using a running test machine under the conditions of a writing load of 200 gf, a writing angle of 70°, and a writing speed of 4 m/min for evaluation.
◎...The length of the handwriting smear is less than 5 mm ○...The length of the handwriting smudge is 5 mm or more and less than 10 mm △...The length of the handwriting sludge is 10 mm or more and 20 mm Less than ×...The length of the handwriting smear is 20 mm or more

In Examples 1 to 21, good performance was obtained in the writing performance test (line skipping/fading), writing feel, abrasion resistance test, and writing performance test. Furthermore, although a pigment was used as a colorant, the pigment had good dispersibility and was stable.
Regarding the ink compositions for oil-based ballpoint pens, the ink viscosity of Examples 1, 2, and 3 was measured using a Viscometer RVDV II + Pro CP-52 spindle manufactured by Brookfield Co., Ltd., and it was found that in an environment of 20 ° C. Example 1: Ink viscosity = 3000 mPa·s, Example 9: Ink viscosity = 5000 mPa·s at a shear rate of 5 sec ⁻¹ (rotation speed 2.5 rpm).

In Comparative Example 1, since no terpene phenol resin was used, sufficient effects were not obtained in the writing performance test (line skipping/fading).

In Comparative Example 2, since no alkylene oxide derivative of glycerin was used, sufficient effects were not obtained in the writing performance test (line skipping/fading) and the abrasion resistance test.

In addition, when using a retractable writing instrument (retractable ballpoint pen) such as a knock-type writing instrument or a rotary-feeding writing instrument, the handwriting is likely to be affected by line skipping and fading, so the ink composition for an oil-based ballpoint pen such as the present invention is It is effective to use

In addition, in order to suppress ink leakage and improve writing performance, a ball rotatably held at the tip of a ballpoint pen tip is pressed against the inner wall of the edge of the tip directly by a coil spring or via a pressing body to write. It is preferable to include a valve mechanism that allows ink to flow out by creating a gap between the inner wall of the tip end edge and the ball by the pressing force at the time of use, and closes the minute gap at the tip end when not in use.

In addition, in this example, for convenience, an oil-based ballpoint pen is exemplified in which a refill for an oil-based ballpoint pen containing an ink composition for a writing instrument is directly stored in the barrel, but the writing instrument of the present invention does not have an ink composition in the barrel. The writing instrument may be a ballpoint pen, a marking pen, or a felt-tip pen, which is a direct filling type in which the ink composition for a writing instrument is directly stored in the barrel as a storage cylinder.
Further, in this embodiment, for convenience, a ballpoint pen tip formed by cutting a wire rod is exemplified, but a ballpoint pen tip formed by pressing a pipe material may also be used.

INDUSTRIAL APPLICABILITY The present invention can be used as a writing instrument, and more specifically, it can be widely used as a ballpoint pen as a writing instrument such as a cap type or a retractable type.

Claims (7)

An ink composition for an oil-based ballpoint pen, comprising a colorant, a terpene phenol resin, and an alkylene oxide derivative of glycerin. The ink composition for an oil-based ballpoint pen according to claim 1, wherein the weight average molecular weight of the terpene phenol resin is 200 or more and 1200 or less. The ink composition for an oil-based ballpoint pen according to claim 1 or 2, wherein the alkylene oxide derivative of glycerin has a weight average molecular weight of 300 or more and 5,000 or less. The ink composition for an oil-based ballpoint pen according to claim 1 or 2, wherein the average number of moles of alkylene oxide added to the alkylene oxide derivative of glycerin is 1 or more and 30 or less. The ink composition for an oil-based ballpoint pen contains at least one selected from a phosphate ester surfactant, a silicone surfactant, a surfactant having an acetylene bond, a fluorine surfactant, a fatty acid, and a fatty acid ester. The ink composition for an oil-based ballpoint pen according to claim 1 or 2, characterized in that it comprises: The ink composition for an oil-based ball-point pen according to claim 1 or 2, wherein the ink composition for an oil-based ball-point pen contains a rosin resin. The tip of the ink storage cylinder has a ballpoint pen tip rotatably holding a ball, and the ink composition for an oil-based ballpoint pen according to claim 1 or 2 is stored in the ink storage cylinder. Oil-based ballpoint pen.