JP2017109347A - Oil-based ball point pen refill and oil-based ball point pen using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition for oil-based ball point pen which has good writing quality, suppresses abrasion of a ball seat, and has good ink temporal stability and ink dripping performance, and to provide an oil-based ball point refill using the same.SOLUTION: In an oil-based ball point pen refill which has a ball point pen chip that rotatably holds a ball on a tip of an ink storage cylinder and stores an ink composition for oil-based ball point pen, arithmetic average roughness of the ball surface is 0.1-15 nm, the ink composition for oil-based ball point pen contains a colorant, an organic solvent, a resin and a salt formation body, the salt formation body is a salt formation body of an acidic compound and amine having an aromatic ring, and a content of the salt formation body is 0.01-2.0 mass% with respect to the total amount of the ink composition.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, unlike other types of writing instruments, a ballpoint pen is composed of a metal tip made of stainless steel or the like at the tip and a transfer ball made of metal such as super steel held in a ball receiving seat of the metal tip. Although it has a configuration in which the chip is mounted on the ink storage cylinder, there is a problem that wear of the ball seat occurs due to rotation of the ball during writing, lines are scattered on the handwriting, blurring, etc., and writing quality is deteriorated.

  In order to solve these problems, a large number of oil-based ballpoint pen ink compositions using various lubricants have been proposed for the purpose of improving the lubricity between the ball of the ballpoint pen tip and the ball seat.

  As the ink composition for oil-based ballpoint pens using such a lubricant, as the one using alkyl β-D-glucoside, JP-A-5-331403 “Oil-based ballpoint pen ink” has an average molecular weight of 200 to 4000000. As what uses a certain polyethylene glycol, as what uses Unexamined-Japanese-Patent No. 7-196971 "Ink composition for oil-based ball-point pens", N-acylamino acid, N-acylmethyltauric acid, N-acylmethylalanine, Japanese Patent Application Laid-Open No. 2007-17695 “Oil-based ballpoint pen ink” and the like.

"Japanese Patent Laid-Open No. 5-331403" "Japanese Patent Laid-Open No. 7-196971" "JP 2007-17695 A" "JP-A-9-165542" "Japanese Patent Laid-Open No. 9-71745"

  However, when various lubricants such as Patent Documents 1 to 3 are used, the wear of the ball seat can be suppressed while improving the writing quality to some extent, but the lubricity is not satisfactory and there is room for improvement. was there. Furthermore, when a new lubricant is used, precipitates and the like may be generated depending on the compatibility with components such as a colorant and a resin in the ink. Therefore, it is necessary to consider the ink aging stability.

  In Patent Documents 4 and 5, when a salt-forming dye of triallylmethane-based basic dye and azo-based yellow acidic dye is used as a colorant, part of the salt-forming dye collapses and precipitates over time. Not only was the product generated, but the lubricity was not sufficient, and the writing quality was poor, leaving room for improvement. In the case of using a new dye, since a precipitate or the like may be generated depending on the compatibility with the components in the ink, the selection of the dye is very important.

  In addition, there is a technology to reduce the ink viscosity to improve the writing quality, and it is possible to improve the writing quality to some extent, but because the ink viscosity is low, ink leakage (ink dripping) from the gap between the ball and the tip of the tip In order to improve both writing quality and ink leakage (ink dripping) performance, there was a point to be improved.

  An object of the present invention is to provide an oil-based ballpoint pen ink composition that has good writing quality, suppresses wear of a ball seat, and has good ink aging stability and ink drooping performance.

In order to solve the above problems, the present invention
“1. An oil-based ballpoint pen refill having a ballpoint pen tip that rotatably holds a ball at the tip of an ink-holding cylinder, and containing an ink composition for an oil-based ballpoint pen in the ink-holding cylinder, The arithmetic average roughness of the surface is 0.1 to 15 nm, and the ink composition for oil-based ballpoint pens includes a colorant, an organic solvent, a resin, and a salt-forming body, and the salt-forming body contains an acidic compound and a fragrance. An oil-based ballpoint pen refill which is a salt-formation product with an amine having a ring, and the content of the salt-formation product is 0.01 to 2.0% by mass relative to the total amount of the ink composition.
2. 2. The oil-based ballpoint pen refill according to claim 1, wherein an amount of movement of the ball in a vertical axis direction is 5 to 20 μm.
3. 3. The oil-based ballpoint pen refill according to item 1 or 2, wherein the resin is a polyvinyl butyral resin.
4). 4. The oil-based ballpoint pen refill according to any one of claims 1 to 3, wherein the content of the polyvinyl butyral resin is 70% or more with respect to the total resin content of the ink composition.
5). Item 5. The oil-based ballpoint pen refill according to any one of Items 1 to 4, wherein the acidic compound is an acidic dye.
6). 6. The oil-based ballpoint pen refill according to any one of items 1 to 5, wherein the amine having an aromatic ring is a quaternary amine.
7). The oil-based ballpoint pen refill according to any one of Items 1 to 6, further comprising a pigment in the oil-based ballpoint pen ink composition.
8). 8. The oil-based ballpoint refill according to any one of items 1 to 7, wherein the ink viscosity at 20 ° C. and a shear rate of 5 sec ⁻¹ is 10 to 5000 mPa · s.
9. An oil-based ballpoint pen comprising the oil-based ballpoint pen refill according to any one of items 1 to 8 disposed in a shaft tube.
10. An oil-in type oil-based ballpoint pen, wherein the oil-based ballpoint pen refill according to item 8 is disposed in a shaft tube so that the oil-based ballpoint pen refill can protrude from the tip of the shaft tube. "

  The present invention improves the lubricity, suppresses writing taste and wear of the ball seat, has excellent ink aging stability for a long period of time, has excellent ink sag performance, and is an oil-based ballpoint pen refill that is a dark handwriting. It was possible to provide an oil-based ballpoint pen using

It is a longitudinal cross-sectional view of the ball-point pen refill in this invention.

  A feature of the present invention is an oil-based ballpoint pen refill that has a ballpoint pen tip that rotatably holds a ball at the tip of an ink-containing cylinder, and that contains an ink composition for an oil-based ballpoint pen in the ink-containing cylinder. The ball surface has an arithmetic average roughness of 0.1 to 15 nm, the oil-based ballpoint pen ink composition comprises a colorant, an organic solvent, a resin, and a salt-forming body, and the salt-forming body is acidic. It is a salt-form of a compound and an amine having an aromatic ring, and the content is 0.01 to 2.0% by mass with respect to the total amount of the ink composition. .

   It is important to select a salt formation product of an acidic compound and an amine having an aromatic ring for the salt formation product used in the present invention. An amine having an aromatic ring is an amine having an aromatic ring such as a benzene ring, a naphthalene ring, or an anthracene ring. By having an aromatic ring, the lubricity is improved, and the writing taste and wear suppression of the ball seat are improved. It becomes possible. This is because the aromatic ring forms a lubricating film that is easily adsorbed to the metal chip, and has the effect of suppressing metal contact between the ball and the chip body, improving lubricity and improving the writing quality and wear of the ball seat. Presumed to have good suppression. Further, in order to stabilize the amine having an aromatic ring in oil-based ink, it is neutralized with an acidic compound to obtain a salt-form. This is because a strong ionic bonding force acts between the acidic compound and the amine having an aromatic ring, and it can be assumed that the ink aging stability can be maintained for a long time in the oil-based ink. Therefore, in the present invention, by using a salt-form of an acidic compound and an amine having an aromatic ring, it is possible to improve writing taste and ball seat wear suppression and to have excellent ink aging stability. And

  Here, not only the salt formation product of an acidic compound and an amine having an aromatic ring, but also the content of the salt formation product of the acidic compound and an amine having an aromatic ring is based on the total amount of the ink composition. , 0.01 to 2.0% by mass is essential. This is because if the content of the salt-forming body is within the above range, the reason is not clear, but the lubricity is particularly improved, and the effect of suppressing the wear of the ball seat, which has not been obtained conventionally, is particularly obtained. If considering the effect of suppressing the wear of the ball seat, 0.01 to 1.0% by mass is preferable with respect to the total amount of the ink composition, and if more considered, 0.05 to 0.5% with respect to the total amount of the ink composition. % By mass is preferable, and most preferably 0.05 to 0.3% by mass with respect to the total amount of the ink composition.

  Furthermore, a certain degree of lubricity can be improved by including 0.01-2.0 mass% of salt formation body of an acidic compound and the amine which has an aromatic ring with respect to the ink composition whole quantity. However, in order to further improve the lubricity, improve the writing feel and wear suppression of the ball seat, and improve the ink dripping performance, it is necessary to include a resin.

  Moreover, it is preferable to set it as 0.1-15 nm about the arithmetic mean roughness (Ra) of the ball | bowl surface of the ball-point pen tip used by this invention. This is because when the arithmetic average roughness (Ra) is less than 0.1 nm, it is difficult to place ink sufficiently on the surface of the ball, and it is difficult to obtain a dark handwriting at the time of writing. When the roughness (Ra) exceeds 15 nm, the ball surface is too rough, and the rotational resistance between the ball and the ball seat is large, so the writing quality tends to be inferior, and the writing performance such as blurring, line skipping, and line unevenness in the handwriting. It is because it becomes easy to have an influence on. In particular, when a polyvinyl butyral resin described later is used, it is more preferable because the ink is easily placed on the ball surface having the arithmetic average roughness (Ra) of 0.1 to 10 nm. In particular, when the polyvinyl butyral resin having an average degree of polymerization of 200 to 2000 is used, it is easy to place ink on the salt compound of the acidic compound used in the present invention and an amine having an aromatic ring. 1 to 8 nm is preferable, and 2 to 7 nm is more preferable. In addition, the measurement of surface roughness can be calculated | required by (model name SPI3800N by Seiko Epson Corporation).

  As described above, as in the present invention, writing quality is good, the wear of the ball seat is suppressed, the ink aging stability and ink sag performance are excellent, and the arithmetic average roughness of the surface of the ball is used to make a dark handwriting. It is important that the oil-based ballpoint pen ink composition further comprises a salt-forming body of an acidic compound and an amine having an aromatic ring, and a resin.

In the present invention, as means for obtaining a darker handwriting, it is preferable to eject a large amount of ink onto the paper surface during writing. Specifically, the ink consumption of the oil-based ballpoint pen refill is preferably 30 mg or more, because if the ink consumption per 100 m is less than 30 mg, it is difficult to obtain dark handwriting and good writing quality, the ink consumption per 100 m is preferable. If the consumption exceeds 70 mg, ink dripping is likely to occur from the gap between the ball and the tip of the chip, and crying is likely to occur, so 70 mg or less is preferable. Therefore, the ink consumption per 100 m of the oil-based ballpoint pen refill is preferably 30 to 70 mg, 40 mg or more is preferable for making darker handwriting, and 40 to 60 mg is preferable for improving ink dripping performance and crying. .
The ink consumption was measured using 5 test samples at a writing speed of 4 m / min under the conditions of 20 ° C., writing paper JIS P3201 writing paper, a writing angle of 70 ° and a writing load of 200 g. A writing test is performed, and the average value of the ink consumption per 100 m is defined as the ink consumption per 100 m.

  Moreover, it is preferable that the moving amount | distance of the vertical axis | shaft direction of the ball | bowl of the ball-point pen tip used for this invention shall be 5-20 micrometers. If the thickness is less than 5 μm, the ink consumption per 100 m decreases, the ink consumption is difficult to set to 30 mg or more, and it becomes difficult to obtain a dark handwriting. If the thickness exceeds 20 μm, the ink consumption increases. This is because it is difficult to set the ink consumption to 70 mg or less, and the ink drooping performance is likely to be affected. In consideration of this, it is preferably 7 to 17 μm, and more preferably 10 to 16 μm. It is preferable.

  In order to make the handwriting darker, not only the ink consumption is set, but also the relationship with the ball diameter is important. When the ink consumption per 100 m of the oil-based ballpoint pen refill is A (mg) and the ball diameter is B (mm), the relationship is 40 ≦ A / B ≦ 100, It tends to be a darker handwriting. As for the relationship of 40 ≦ A / B ≦ 100, if 40> A / B, the ink consumption is not sufficient with respect to the ball diameter, and it is difficult to obtain a dark handwriting and good writing taste. When / B> 100, ink dripping or crying occurs from the gap between the ball and the tip of the tip, which tends to affect handwriting dryness. Considering darker handwriting and ink sag, it is preferable to satisfy the relationship of 50 ≦ A / B ≦ 80. Specifically, when the ball diameter is B (mm) = 0.7 (mm), the ink consumption A (mg) per 100 m is set to A = 30 to 70 (mg). A relationship of 40 ≦ A / B ≦ 100 can be established.

  The material used for the ball is not particularly limited, but a cemented carbide ball mainly composed of tungsten carbide, a metal ball such as stainless steel, a ceramic such as silicon carbide, silicon nitride, alumina, silica, zirconia, etc. Ball, ruby ball and the like. In consideration of writing taste, ball seat wear, and stability over time, a ceramic ball is preferable. The diameter of the ball is not particularly limited, but is generally about 0.25 mm to 2.0 mm.

  Examples of the material for the ballpoint pen tip include stainless steel, white metal, brass (brass), aluminum bronze, aluminum and other resin materials, polycarbonate, polyacetal, ABS and other resin materials. In consideration of the properties, a white chip body is preferable, and in consideration of ball seat wear and stability over time, a stainless steel chip body is preferable.

  Examples of the resin used in the oil-based ballpoint pen ink composition include polyvinyl butyral resin, polyacetal resin, polyvinyl alcohol resin, cellulose resin, polyvinyl pyrrolidone resin, ketone resin, terpene resin, alkyd resin, phenoxy resin, and polyvinyl acetate resin. However, in the present invention, in order to be excellent in ink sag performance, writing taste, and ball seat wear suppression, as well as excellent ink aging stability with acid dyes and salt-forming dyes with amines having an aromatic ring, It is preferable to use a polyvinyl butyral resin. This is because polyvinyl butyral resin forms a resin film at the tip of the tip and covers the gap between the tip of the ball and the tip, thereby suppressing ink drooping. In addition, the ink is always elastic between the ball and the ball seat. Forming a layer and making it difficult to make direct contact, so that it is easier to improve writing taste and ball seat wear suppression by a synergistic effect with the lubricating film that is easily adsorbed to the metal tip formed by the salt-forming dye. This is because it becomes possible.

  Furthermore, the content of the polyvinyl butyral resin is set to 70% or more with respect to the total resin content in the oil-based ballpoint pen composition, and is used as the main resin. This is because when the content of the polyvinyl butyral resin is less than 70% of the total resin content, the formation of the resin film on the tip of the tip is inhibited by other resins, and the ink sag cannot be suppressed, and the elasticity is further increased. This is because the formation of a certain ink layer is hindered, and it becomes difficult to obtain the effect of improving the writing quality and wear of the ball seat. Considering the tendency to improve ink sag performance, writing taste and ball seat wear, the content of polyvinyl butyral resin is preferably 80% or more based on the total resin content. 90% or more is preferable. Furthermore, the compatibility between the salt-form of an acidic compound and an amine having an aromatic ring and the polyvinyl butyral resin is good, and the content of the polyvinyl butyral resin is large. Even if it is 90% or more, the ink aging stability is hardly affected. ,preferable.

The polyvinyl butyral resin is obtained by reacting polyvinyl alcohol (PVA) with butyraldehyde (BA), and has a structure having a butyral group, an acetyl group, and a hydroxyl group. Although there is a technique suitably used as the dispersant, the present invention has been found to improve the ink drooping performance, writing quality and ball seat wear.

  Further, regarding the average degree of polymerization of the polyvinyl butyral resin, when the average degree of polymerization is 200 or more, the ink drooping performance is improved and the cohesive force of the ink can be increased, so that the ink can easily be placed on the ball surface. When ink remains in the ink, the ink tends to enter between the ball and the ball seat, so that the ball is less likely to come into direct contact with the ball seat, which tends to improve the writing quality. On the other hand, when the average degree of polymerization exceeds 2000, the ink viscosity tends to be too high and the writing quality tends to be affected. Therefore, the average degree of polymerization is preferably 200 to 2000. Furthermore, in consideration of the stability of the acidic compound, in particular, a salt formation product of an acidic dye and an amine having an aromatic ring, the average degree of polymerization is preferably 1500 or less, and if considering the writing quality, The average degree of polymerization is preferably 1000 or less. Therefore, the average degree of polymerization is preferably 200 to 1500, and more preferably the average degree of polymerization is most preferably 200 to 1000. Here, the average degree of polymerization means the number of basic units constituting one molecule of the polyvinyl butyral resin, and a value measured based on the method defined in JIS K6728 (2001 version) can be adopted. .

  As for the polyvinyl butyral resin, specifically, trade names manufactured by Sekisui Chemical Co., Ltd .; ESREC BH-3 (hydroxyl group amount: 34 mol%, average degree of polymerization: 1700), BH-6 (hydroxyl group amount: 30 mol%). , Average polymerization degree: 1300), BX-1 (hydroxyl group amount: 33 ± 3 mol%, average polymerization degree: 1700), BX-5 (hydroxyl group quantity: 33 ± 3 mol%, average polymerization degree: 2400), BM -1 (hydroxyl group amount: 34 mol%, average degree of polymerization: 650), BM-2 (hydroxyl group amount: 31 mol%, average degree of polymerization: 800), BM-5 (hydroxyl group amount: 34 mol%, average degree of polymerization: 850) ), BL-1 (hydroxyl group amount: 36 mol%, average polymerization degree: 300), BL-1H (hydroxyl group amount: 30 mol%), BL-2 (hydroxyl group amount: 36 mol%, average polymerization degree: 450), Same B L-2H (hydroxyl content: 29 mol%), BL-10 (hydroxyl content: 28 mol%), etc., trade name of Kuraray Co., Ltd .; Mobital B20H (hydroxyl content: 26-31 mol%, average degree of polymerization: 250) -500), 30T (hydroxyl group amount: 33-38 mol%, average polymerization degree: 400-650), 30H (hydroxyl group amount: 26-31 mol%, average polymerization degree: 400-650), 30HH (hydroxyl group amount: 30-34 mol%, average polymerization degree: 400-650), 45H (hydroxyl group amount: 26-31 mol%, average polymerization degree: 600-850), 60T (hydroxyl group amount: 34-38 mol%, average polymerization degree: 750) -1000), 60H (hydroxyl group amount: 26-31 mol%, average degree of polymerization: 750-1000), 75H (hydroxyl group amount: 26-31 mol%, average degree of polymerization: 1). 00-1750), and the like. You may use these individually or in mixture of 2 or more types.

  If the content of the polyvinyl butyral resin is less than 3.0% by mass relative to the total amount of the ink composition, the amount of resin film formation may be insufficient, and the ink drooping performance tends to be inferior, and exceeds 40.0% by mass. Since the solubility in the ink tends to be inferior, 3.0 to 40.0% by mass is preferable with respect to the total amount of the ink composition. Furthermore, considering the ink drooping performance, 5.0% by mass or more is preferable, and if it exceeds 30.0% by mass, the ink viscosity tends to be too high and the writing quality tends to be affected. 0.0 mass% is preferable, and in consideration of 7.0 to 25.0 mass% is most preferable.

  As the resin other than the polyvinyl butyral resin, an ink viscosity adjusting resin or a spinnability imparting resin may be appropriately used. In particular, it is preferable to contain a spinnability-imparting resin, because by adding a spinnability-imparting resin, the binding property of the ink is improved and the occurrence of excess ink (crying mottling) at the tip of the chip is easily suppressed. As the spinnability-imparting resin, polyvinyl pyrrolidone is preferable, and specifically, trade names of IP Japan Co., Ltd .; PVP K-15, PVP K-30, PVP K-90, PVP K-120, etc. Is mentioned. You may use these individually or in mixture of 2 or more types.

  The content of the spinnability imparting resin used in the present invention is preferably 0.1 to 20.0% with respect to the total resin content in the oil-based ballpoint pen composition. This is because when the content of the spinnability imparting resin is less than 0.1% of the total resin content, there is a tendency that it is difficult to suppress the generation of excess ink (crying blur), and when it exceeds 20%, polyvinyl butyral The effect of the resin tends to be hindered, specifically, the formation of the resin film on the tip of the chip is hindered, making it difficult to suppress the ink sag and further hindering the formation of a flexible ink layer. This is because it is easy to make it difficult to improve the writing quality. Considering the tendency to suppress excess ink, the content of the spinnability imparting resin is preferably 1.0 to 20.0% with respect to the total resin content, and ink drooping performance and writing quality are improved. Considering the tendency, 1.0 to 10.0% is preferable, and further considering the tendency, 2.0 to 7.0% is preferable.

The acidic compounds used in the present invention include those containing a functional group having a sulfur atom (S, SO, SO ₂ , SO ₃ etc.) and those having a carboxyl group (—COOH), etc. In view of the improvement in properties, an acidic compound containing a functional group having a sulfur atom (S, SO, SO ₂ , SO ₃ etc.) is preferred. This is considered to be because when a functional group having a sulfur atom (S, SO, SO ₂ , SO _3, etc.) is used, it is easy to form a strong lubricating layer between the ball and the ball seat, so that the lubricity is easily improved. This is because a synergistic lubricating effect can be obtained by using together with an amine having an aromatic ring. Among these, in consideration of lubricity, an acidic compound having a sulfo group (—SO ₃ H) is preferable.

Examples of the acidic compound used in the present invention include acidic dyes and surfactants such as dialkylsulfosuccinic acid, alkylbenzenesulfonic acid, naphthalenesulfonic acid, naphthalenesulfonic acid-formaldehyde condensate, and fatty acid. If used, it is possible to have both the effect of a colorant and a lubricant. Therefore, it is preferable to form a salt-form of an acid dye and an amine having an aromatic ring. Base
It is preferable to use an acid dye having (—SO ₃ H). This is because if a sulfo group (—SO ₃ H) is included, it is easy to form a strong lubricating layer between the ball and the ball seat, and therefore it is considered that the lubricity is likely to be improved. This is because a synergistic lubricating effect is also obtained.

  Examples of acid dyes include triallylmethane acid dyes, azo acid dyes, anthraquinone acid dyes, and oxazine acid dyes. In view of maintaining stability, it is preferable to use an azo acid dye.

  Specific examples of the acid dye include C.I. I. Acid Black 1, 2, 7, 16, 17, 24, 26, 28, 31, 41, 48, 52, 58, 60, 63, 94, 107, 109, 112, 118, 119, 121, 122, 131, 155, 156, C.I. I. Acid Yellow 1, 3, 4, 7, 11, 12, 13, 14, 17, 18, 19, 23, 25, 29, 34, 36, 38, 40, 41, 42, 44, 49, 53, 55, 59, 61, 71, 72, 76, 78, 79, 99, 111, 114, 116, 122, 135, 142, 161, 172, C.I. I. Acid Orange 7, 8, 10, 19, 20, 24, 28, 33, 41, 45, 51, 56, 64, C.I. I. Acid Red 1, 4, 6, 8, 13, 14, 15, 18, 19, 21, 26, 27, 30, 32, 34, 35, 37, 40, 42, 51, 52, 54, 57, 80, 82, 83, 85, 87, 88, 89, 92, 94, 97, 106, 108, 110, 111, 114, 115, 119, 129, 131, 133, 134, 135, 143, 144, 152, 154, 155, 172, 176, 180, 184, 186, 187, 249, 254, 256, 289, 317, 318, C.I. I. Acid Violet 7, 11, 15, 17, 34, 35, 41, 43, 49, 51, 75, C.I. I. Acid Blue 1, 7, 9, 15, 22, 23, 25, 27, 29, 40, 41, 43, 45, 49, 51, 53, 55, 56, 59, 62, 78, 80, 81, 83, 90, 92, 93, 102, 104, 111, 113, 117, 120, 124, 126, 138, 145, 167, 171, 175, 183, 229, 234, 236, 249, C.I. I. Acid Green 3, 9, 12, 16, 19, 20, 25, 27, 41, 44, C.I. I. Acid brown 4, 14 etc. are mentioned. Triallylmethane acid dyes, C.I. I. Acid Violet 17, C.I. I. Acid Blue 90, C.I. I. Acid Blue 9 and azo acid dyes include C.I. I. Acid Yellow 36, C.I. I. Acid Yellow 42, C.I. I. Acid Red 97 and the like. Among them, C.I. I. Acid Yellow 36, C.I. I. Acid Yellow 42 is preferable. I. Acid yellow 42 is most preferred.

  Examples of amines having an aromatic ring include primary amines, secondary amines, tertiary amines, and quaternary amines. Acid compounds, particularly acidic dyes, can be sufficiently neutralized to produce a more stable salt. In order to prepare a body, it is preferable to use a quaternary amine having an aromatic ring.

  Examples of the quaternary amine having an aromatic ring include benzoxonium compounds, alkyldimethylbenzylammonium compounds, alkyldiethylbenzylammonium compounds, etc., and ink aging due to the compatibility of neutralizing reactivity with acidic compounds, particularly acidic dyes. Considering stability and writing quality, a benzoxonium compound (Benzoxonium) is preferable. Specifically, as benzoxonium compounds (Benzoxonium), benzylbistetradecylammonium compounds (Benzylbis (2-hydroxypropyl) tetradecylammonium), benzyldodecylbisammonium compounds (Benzyldodecylbis (2-hydroxypropyl) ammonium), benzyldecylbisammonium compounds (Benzyldecylbis (2-hydroxypropyl) ammonium) and the like, and examples of the alkyldimethylbenzylammonium compound include a tetradecyldimethylbenzylammonium compound, a hexadecyldimethylbenzylammonium compound, an octadecyldimethylbenzylammonium compound, and a palm alkyldimethylbenzylammonium compound. Examples of the alkyldiethylbenzylammonium compound include dodecyldiethylbenzylammonium compound. You may use these individually or in mixture of 2 or more types.

   Further, as the colorant, general dyes and pigments may be used. However, when the salt-forming body and the resin are included as in the present invention, it is preferable to include a pigment. This is because it contains pigment, and pigment particles enter the gap between the ball and the chip body, which acts like a bearing and suppresses metal contact, thereby improving lubricity. Because there is. Therefore, unlike the prior art, the pigment can have the effects of a colorant and a lubricant. In the present invention, when a polyvinyl butyral resin is used as the resin, a metal chip formed of the salt-forming body as described above by using the salt-forming body, the polyvinyl butyral resin, and the pigment in combination. The interaction between the lubricating film that is easily adsorbed on the surface, the elastic ink layer formed by the polyvinyl butyral resin, and the action of the pigment as a bearing improves the writing taste and ball seat wear suppression. It is because it becomes possible to make it easy. Furthermore, by using a pigment in combination, it is possible to obtain a dark handwriting that is difficult to obtain with only the salt-forming dye, and at the same time, it is possible to improve light resistance.

  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 DPP Quinophthalone, selenium, triphenylmethane, perinone, perylene, dioxazine, metallic pigment, pearl pigment, fluorescent pigment, phosphorescent pigment, and the like. These pigments tend to suppress metal contact and improve lubricity by entering the gaps in the chip body. In particular, it is preferable to use an organic pigment in consideration of improvement in stability with time and lubricity due to compatibility between the salt-form and the polyvinyl butyral resin, and in consideration of lubricity, diketopyrrolopyrrole. Based pigments are preferred. Further, in consideration of the gap relationship inside the chip, the average particle diameter is preferably 300 nm or less. More preferably, it is 200 nm or less. Here, the average particle diameter is an average particle diameter D50 measured by a particle size distribution meter. These pigments may be used alone or in combination of two or more.

  The content of the pigment is preferably 0.01 to 20% by mass with respect to the total amount of the ink composition in consideration of the effect as a colorant. However, in order to improve the lubricity as in the present invention, the ink is used. 0.01-8.0 mass% is preferable with respect to the composition whole quantity. If it is less than 0.01% by mass, the lubricity is not sufficient, and it tends to be difficult to improve the writing taste and the suppression of wear of the ball seat. This is because it is too much and the lubricity is easily affected. In addition, when a salt compound of an acidic compound, particularly an acidic dye and an amine having an aromatic ring, and a pigment are used in combination, there is an effect of making it easier to particularly improve the wear suppression of the ball seat by each interaction. In consideration of this, 0.01 to 1.2% by mass is preferable with respect to the total amount of the ink composition, and more preferably 0.05 to 0.5% by mass with respect to the total amount of the ink composition, Most preferably, 0.05-0.3 mass% is preferable with respect to the ink composition whole quantity.

  As other colorants, oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, and various salt-forming dyes thereof may be used as the dye. Among them, it is preferable to further include a salt-forming dye of a basic dye and an organic acid in consideration of stability over time and lubricity due to the compatibility between the acidic compound and the salt-forming body of an amine having an aromatic ring. In view of this, it is preferable to comprise a salt-forming dye of a basic dye and an alkylbenzene sulfonic acid. 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. T. Blue 111, S.I. P. T. T. Blue GLSH-Special, S. P. T. T. Red 533, S.D. P. T. T. Orange 6, S. B. N. Violet 510, S.I. B. N. Yellow 530, S.I. R. C-BH (above, manufactured by Hodogaya Chemical Co., Ltd.) and the like.

  The content of other colorants is preferably 1.0 to 30.0 mass% with respect to the total amount of the ink composition. This is because if the amount is less than 1.0% by mass, a dark handwriting tends to be difficult to obtain, and if it exceeds 30.0% by mass, the ink tends to aggregate in the ink. 3.0-15.0 mass% is most preferable.

  Furthermore, in order to maintain lubricity even under high writing pressure (writing load 400 gf) and suppress wear of the ball seat, it is preferable to use a phosphate ester-based surfactant. This is because, in the phosphate ester-based surfactant, the phosphate group is easily adsorbed on the metal surface, the lubricity between the ball and the chip body is maintained, and the writing quality is easily improved. In particular, in the present invention, as described above, the ink layer formed by the polyvinyl butyral and the phosphoric acid group are preferable because the lubricity is easily improved, and further, the acidic compound and the amine having an aromatic ring are more preferable. By suppressing the metal contact with the lubricating film formed by the salt-forming body, it becomes easy to maintain the lubricity even under high writing pressure (writing load 400 gf).

  Phosphate ester surfactants include polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphate monoester, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphate diester, polyoxyethylene alkyl ether Or phosphoric acid triesters, alkyl phosphoric acid esters, alkyl ether phosphoric acid esters or derivatives thereof of polyoxyethylene alkylaryl ethers, and the alkyl group of the phosphoric acid ester type surfactant includes styrenated phenol type, nonylphenol type Type, lauryl alcohol type, tridecyl alcohol type, octylphenol type and the like. These phosphate ester surfactants may be used alone or in combination of two or more. Among these, considering lubricity, the number of carbon atoms contained in the alkyl group is preferably 5-18, and further considering that the number of carbons is more preferably 10-18, the acidic compound and In consideration of the stability with a salt-forming body with an amine having an aromatic ring, the carbon number of 12 to 18 is preferable. When the number of carbon atoms in the alkyl group is excessively small, lubricity tends to be insufficient, and when the number of carbon atoms is excessively large, the ink aging stability tends to be affected.

  Furthermore, phosphate ester surfactants tend to soften the formed film, and may improve the writing performance during dry-up. The polyvinyl butyral resin used in the present invention tends to be inferior in the writing performance at the time of dry-up due to the formed film, and when a phosphate ester surfactant is used, the formed film is softened and the writing is easily improved. Therefore, among them, the number of carbon atoms contained in the alkyl group is preferably 12-18, and if further considered, the number of carbon atoms is more preferably 12-15. In particular, in the in / out type writing tools such as knock type writing tools and rotary feeding type writing tools, since the pen tip is always exposed to the outside unlike the cap type writing tools, it tends to affect the writing performance at the time of dry-up, It is more preferable to use a phosphate ester surfactant.

  Further, the content of the phosphate ester-based surfactant is more preferably 0.1 to 5.0% by mass with respect to the total amount of the ink composition. This is because if it is less than 0.1% by mass, the desired lubricity tends to be difficult to obtain, and if it exceeds 5.0% by mass, the ink aging tends to become unstable, and this tendency Is considered to be 0.3 to 3.0% by mass relative to the total amount of the ink composition, and 0.5 to 3.0% by mass is most preferable considering more.

Specific examples of the phosphate ester surfactant include Prisurf A217E (alkyl group: 14 carbon atoms, acid value: 45 to 58), A219B from the Prisurf series (Daiichi Kogyo Seiyaku Co., Ltd.). (Alkyl group: carbon number 12, acid value: 44 to 58), A215C (alkyl group: carbon number 12, acid value: 80 to 95), A208B (alkyl group: carbon number 12, acid value: 135 to 155) ), A208N (alkyl group: mixture of 12 and 13 carbon atoms, acid value: 160 to 185), phosphanol series (manufactured by Toho Chemical Co., Ltd.), phosphanol RB410 (alkyl group: carbon) No. 18, acid value: 80 to 90), RS-610 (alkyl group: carbon number 13, acid value: 75 to 90), RS-710 (alkyl group: carbon number 13, acid value: 55 to 75) And the like. These surfactants may be used alone or in combination of two or more.
In addition, about an acid value, it shall represent with the mg number of potassium hydroxide required in order to neutralize the acidic component contained in 1g of samples.

  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. These organic solvents can be used alone or in combination of two or more.

  Among these organic solvents, it is easy to put ink on the ball, which works favorably in handwriting scraping and hollowing out, improves writing performance, and further considers wear suppression of the ball seat, and glycol ether solvent can be used. preferable. In particular, it is possible to make it easier to suppress the wear of the ball seat by dissolving and stabilizing the glycol ether solvent, the salt compound of the acidic compound and the amine having an aromatic ring, and the polyvinyl butyral resin. In particular, it is preferable when a polyvinyl butyral resin having a hydroxyl amount of 30 mol% or more is used. Also, an alcohol solvent is preferable because it easily volatilizes, easily dries at the tip of the chip, easily forms a resin film, and easily improves ink drooping performance. Therefore, in the present invention, it is preferable to use at least a glycol ether solvent and an alcohol solvent in combination. Furthermore, by using an aromatic alcohol solvent, the polyvinyl butyral resin and the salt-formed body of the acidic compound and an amine having an aromatic ring are dissolved and stabilized, and the ink aging stability can be maintained for a long time without being separated from each other. Since it is obtained, it is preferable. Furthermore, in view of improving lubricity, it is preferable to have an aromatic ring, and therefore it is preferable to use an aromatic glycol ether solvent and an aromatic alcohol solvent in combination.

  Further, the content of the organic solvent is preferably 3.0 to 70.0% by mass with respect to the total amount of the ink composition in consideration of improving solubility, handwriting drying property, bleeding, and the like. In addition, the content of the glycol ether solvent is preferably 3.0 to 20.0% by mass, more preferably 5.0%, based on the total amount of the ink composition, in view of the dissolution stability with the polyvinyl butyral resin. ˜12.0 mass%. Further, the content of the alcohol solvent is preferably 40.0 to 85.0% by mass, more preferably 50.0 to 75% with respect to the total amount of the ink composition in consideration of the drying property at the tip of the chip. 0.0% by mass.

  Furthermore, the content of the organic solvent is such that the polyvinyl butyral resin and the salt compound of the acidic compound and amine having an aromatic ring can be dissolved and stabilized for a long period of time, ink drooping performance, writing performance, ball seat wear In consideration of the balance with suppression, the ratio of the alcohol solvent content to the glycol ether solvent content is preferably 1: 5 to 1:30, more preferably 1: 7 to 1:25. is there.

  Further, as in the present invention, in the oil composition for an oil-based ballpoint pen comprising an acid compound and an amine having an aromatic ring and a polyvinyl butyral resin, fine particles are used in order to further improve the lubricity. Also good. This is because the fine particles can enter the gap between the ball and the ball seat, thereby suppressing metal contact and improving lubricity. Specific examples of the fine particles include resin fine particles such as acrylic, silicone, and polyethylene, alumina fine particles, and silica fine particles. Among these, spherical silica fine particles are preferable. The fine particles are preferably fine particles having an average particle diameter of 5 to 100 nm in consideration of lubricity, and the average particle diameter is a median diameter, and can be determined by a centrifugal sedimentation method, a laser diffraction method, a BET method, or the like.

Further, when the oil-based ballpoint pen ink of the present invention is further used in combination with an organic amine having ethylene oxide (CH ₂ CH ₂ O) in addition to an amine having an aromatic ring, a lubricating effect is easily obtained. Therefore, it is preferable to use oxyethylene alkylamine and polyoxyethylene alkylamine having ethylene oxide (CH ₂ CH ₂ O). You may use these individually or in mixture of 2 or more types.

Specific examples of oxyethylene alkylamines and polyoxyethylene alkylamines include Nimine L-201, L-202, L-207, S-202, S-204, S-210, and T ₂ -206, the S-210, the DT-203, the DT-208, the L-207, the T ₂ -206, the DT-208 (NOF Co., Ltd.). The content of the oxyethylene alkylamine and polyoxyethylene alkylamine is preferably 0.1 to 10.0% by mass, more preferably 1%, based on the total amount of the ink composition, considering lubricity and stability over time. 0.0 to 5.0% by mass.

In addition, in order to improve lubricity, as surfactants, fluorine surfactants, silicone surfactants, and viscosity modifiers such as ketone resins, terpene resins, alkyd resins, phenoxy resins, polyacetic acids A resin such as vinyl or a pseudoplasticity imparting agent such as hydrogenated castor oil, or a colorant stabilizer, a plasticizer, a chelating agent, water, or the like may be used as appropriate. These may be used alone or in combination of two or more.

  Further, when the ink composition for oil-based ballpoint pens newly contains a salt-form of an acidic compound and an amine having an aromatic ring, and a polyvinyl butyral resin, in order to maintain ink aging stability, It is preferable to pay attention to the pH value because water is contained in the oil-based ink due to moisture absorption over time or the like.

  In order to maintain the ink aging stability and lubricity of the oil-based ballpoint pen ink composition of the present invention, the pH value is preferably 3.0 to 10.0. This is because if the pH value is less than 3.0, metal ions in the chip body are likely to elute, so that metal salt precipitates are likely to occur with the salt-forming body, and if the pH value exceeds 10.0, This is because the ionic bond of the salt-forming body tends to be separated, which tends to affect the ink aging stability, lubricity, and color tone, and pigment dispersion stability cannot be obtained. Further, considering the ink aging stability, the pH value is preferably 3.0 to 9.0, and more preferably, the pH value is preferably 3.5 to 8.0.

  The pH value in the present invention is a method for measuring an ink composition for oil-based ballpoint pens, in which oil-based ink is collected in a container, ion-exchanged water is added, heated with stirring, allowed to cool after heating, After replenishing the amount of water evaporated, filter using filter paper. Using the upper layer of the filtered filtrate, pH measurement shows a value measured at 20 ° C. using an IM-40S type pH meter manufactured by Toa DKK Corporation.

The ink viscosity of the ink composition for oil-based ballpoint pens of the present invention is not particularly limited, but the ink viscosity at 20 ° C. and a shear rate of 5 sec ⁻¹ is preferably 10 to 5000 mPa · s. In particular, in addition to setting the ink viscosity to 10 to 5000 mPa · s, when the ink consumption per 100 m is A (mg) and the ball diameter is B (mm), the relationship of 40 ≦ A / B ≦ 100 As described above, by making the relationship different from that of the conventional ballpoint pen, it is easy to suppress the rotational resistance of the ball more synergistically, so that the lubricity is improved and the writing quality is easily improved. In addition, when the ink viscosity at 20 ° C. and a shear rate of 5 sec ⁻¹ is less than 500 mPa · s, it is difficult to suppress ink sag, and thus the ink viscosity is preferably 500 to 5000 mPa · s. In consideration of further improving writing quality and suppression of ink sag, the ink viscosity is more preferably 1000 to 4000 mPa · s, and further more preferably 1500 to 3500 mPa · s.

  The ink container used in the present invention is limited in materials that can be employed from the viewpoint of chemical resistance, moisture permeability, air permeability, and the like. In that respect, it is preferable to conventionally use polypropylene as a material. However, when a salt-form of an acid dye and an amine having an aromatic ring and a polyvinyl butyral resin are used, it has a very strong affinity with the polypropylene ink container, and the ink moves when the ink moves inside the ink container. Tends to adhere to the inner wall, making it difficult to determine the remaining amount of ink. Therefore, when polypropylene is used as the ink containing cylinder, it is preferable to treat the inner wall of the ink containing cylinder with silicone. This is because the silicone is applied to the inner wall of the ink storage cylinder so that the polypropylene, which is the storage cylinder material, does not come into direct contact with the ink, but maintains the relationship in which silicone is interposed in the middle, and is stored when the ink moves. It is possible to prevent adhesion to the inner wall of the cylinder.

  Examples of the silicone material include dimethyl silicone, methyl phenyl silicone, methyl hydrogen silicone, alkyl aralkyl silicone, polyether silicone, and high fatty acid ester fatty acid silicone. Among them, adhesion prevention is excellent and non-reactive. In view of the stability of the oil-based ink component, alkylaralkyl silicone is preferable. The most effective application method is to apply uniformly to the inner wall at the time of extrusion.

  Next, embodiments of the ballpoint pen of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

Example 1
The ballpoint pen refill 1 of Example 1 shown in FIG. 1 has a ball 3 (φ0.7 mm) with an arithmetic mean roughness (Ra) 3 nm of the ball surface rotatably held at the tip of the ink containing cylinder 2. The ballpoint pen tip 4 (the amount of movement of the ball in the vertical axis direction: 12 μm) is pressed against the inner wall of the tip end edge of the tip 3 by the coil spring 6, and the ink composition for oil-based ballpoint pen of Example 1 is placed in the ink containing cylinder 2. 10 (0.4 g) and the grease-like ink follower 5 are directly accommodated to obtain the ballpoint pen refill 1.

Next, a method for producing a salt structure will be described.
Formulation Example 1
First, 1000 g of water and 30 g of Acid Yellow 42 (azo acid dye (with sulfo group)) were weighed and heated in a beaker, dissolved using a disper stirrer, and then a benzoxonium compound (having an aromatic ring) 60 g of amine) was weighed, stirred, and filtered using filter paper, and the residue on the filter paper was dried to obtain a salt-forming body (salt-forming dye).

Formulation Examples 2-3
As shown in Table 1, salt-formation bodies (salt-formation dyes) of Formulation Examples 2 and 3 were prepared in the same manner as Formulation Example 1 except that each component was changed, and used in Examples and Comparative Examples.

Next, an Example is shown and this invention is demonstrated.
The oil-based ballpoint pen ink composition of Example 1 is a salt-formation body (salt-formation dye) of Formulation Examples 1 and 2 as a colorant, a pigment dispersion, an alcohol solvent as an organic solvent, a glycol ether solvent, a polyvinyl butyral resin as a resin, A phosphate ester surfactant is used as the lubricant, and polyvinylpyrrolidone is used as the spinnability-imparting resin. A predetermined amount is weighed and heated to 60 ° C., and then completely dissolved using a disper stirrer to make an oil-based ballpoint pen. An ink composition was obtained. Specific blending amounts are as follows.
The ink viscosity was measured at a shear rate of 5 sec ⁻¹ in an environment of 20 ° C. using AR-G2 (stainless steel 40 mm 2 ° rotor) manufactured by TA Instruments Inc., and found to be 2000 mPa · s. Met.
Moreover, when pH value was measured, it was pH = 4.0.
In addition, the ink consumption (A) per 100 m of Example 1 was 45 mg / 100 m and A / B = 64 when a spiral writing test was performed with a ballpoint refill with a ball diameter (B) of 0.7 mm. .
The ink consumption (A) per 100 m in Example 2 was 38 mg / 100 m and A / B = 76 when a spiral writing test was conducted with a ballpoint refill with a ball diameter (B) of 0.5 mm. .

Example 1
Formulation Example 1 salt-form body 0.2% by mass
Salt formation body of formulation example 2 5.0 mass%
Pigment dispersion (pigment content 20%) 0.5% by mass
Alcohol solvent (benzyl alcohol) 71.8% by mass
Glycol ether solvent (ethylene glycol monophenyl ether) 5.0% by mass
Polyvinyl butyral resin (ESREC BL-1, hydroxyl group content: 36 mol%, average degree of polymerization: 300) 15.0 mass%
Lubricant (phosphate-based surfactant) 2.0% by mass
Spinnability imparting resin (polyvinylpyrrolidone) 0.5% by mass

Examples 2-12
As shown in Tables 2 and 3, oil-based ballpoint pen ink compositions of Examples 2 to 12 were obtained in the same procedure as in Example 1 except that each component of the ink composition and the chip specifications were changed.

Comparative Examples 1-10
As shown in Tables 4 and 5, the ink composition for oil-based ballpoint pens of Comparative Examples 1 to 10 was obtained by blending in the same procedure as in Example 1 except that each component of the ink composition and the chip specifications were changed. It was.

Test and Evaluation The oil-based ballpoint pen refill 1 prepared in Examples 1 to 12 and Comparative Examples 1 to 10 was disposed in an oil-based ballpoint pen (trade name: Acro Ball) manufactured by Pilot Corporation, and an oil-based ballpoint pen was manufactured. The following tests and evaluations were performed using a writing paper JIS P3201 as a writing test paper.

Written taste: A hand-written sensory test was performed and evaluated.
Very smooth ・ ・ ・ ◎
Smooth thing ○○
Somewhat heavy ・ ・ ・ △
Heavy thing

Abrasion resistance test: The wear of the ball seat after the writing test was measured with a running test machine with a load of 200 gf, a writing angle of 70 °, and 4 m / min.
Ball seat wear less than 2μm ・ ・ ・ ◎◎
Ball seat wear less than 5μm ・ ・ ・ ◎
Ball seat wear is 5 μm or more and less than 10 μm.
Wear of ball seat 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 ・ ・ ・ ×

Ink aging test: The ink in the chip body was observed with a microscope.
Good without deposits ... ◎
Slightly generated precipitates ... ○
Precipitates are generated, but there are no practical problems.
Precipitates are generated, causing scumming or poor writing ・ ・ ・ ×

Ink sag test: The ink was left for 7 days under an environment of 30 ° C. and 85% RH for 7 days to confirm ink leakage from the tip of the tip.
There are no ink droplets at the tip of the tip.
Ink droplets at the tip of the tip are within 1/4 of the taper.
Ink droplets at the tip of the tip are 1/4 or more and 1/2 of the taper part ... △
Ink drop on tip of tip is more than 1/2 of taper part ・ ・ ・ ×

  In Examples 1 to 12, good performance was obtained in terms of writing quality, abrasion resistance test, ink aging test, and ink drooping performance. Furthermore, when the handwriting in a writing taste test and an abrasion resistance test was confirmed, the density of the handwriting was also favorable.

  In Comparative Examples 1-3 and 6, since a salt-form of an acidic compound and an amine having an aromatic ring is not used, the lubricity is poor, the writing quality is inferior, the wear of the ball seat is bad, and the writing is poor. There was something to end up with.

  In Comparative Examples 4 and 5, the content of the salt-forming body of the acidic compound and the amine having an aromatic ring is too large, the lubricity is poor, the writing quality is poor, the wear of the ball seat is bad, and the writing is poor. There was something to end up with.

  In Comparative Examples 7 and 8, since a salt-formation product of an acid dye and an aliphatic amine and a salt-formation product of an acid dye and a basic dye were used, precipitates were generated and the ink stability over time was poor.

  In Comparative Examples 9 and 10, since balls having an arithmetic average roughness (Ra) of 22 nm and 17 nm on the ball surface were used, the writing quality was inferior, and the wear of the ball seat was also inferior in the wear resistance test.

  Furthermore, a ballpoint pen using a ball with a ball diameter of 0.5 mm or less has a small contact area between the ball and the ball seat, and it tends to affect the writing quality and wear of the ball seat due to an increased load on the unit area. The effect of the present invention is remarkable.

In order to improve the writing quality as in the present invention, when the ink viscosity at 20 ° C. and a shear rate of 5 sec ⁻¹ is set in the range of 10 to 5000 mPa · s, a ballpoint pen is used to prevent the ink from dripping. The ball held rotatably at the tip of the tip is pressed against the inner wall of the tip end of the tip directly by a coil spring or via a pressing body, and the ink is applied to the inner wall of the tip end of the tip and the ball by the pressing force at the time of writing. It is preferable to provide a valve mechanism for allowing the chip to flow out, and to close the minute gap at the tip of the tip when not in use.

  In the present invention, by providing a lubricating coating layer on the surface of the ball and / or the surface of the contact surface, a synergistic effect between the lubricating coating layer and the fluid lubrication or mixed lubrication by the ink layer described above causes the ball and the inner wall of the chip. This is preferable because the contact resistance can be remarkably reduced and the wear resistance and writing feeling of the contact surface can be remarkably improved.

  The lubricating coating layer used in the present invention includes diamond-like carbon (DLC), tungsten disulfide (WS2), molybdenum disulfide (MoS2), graphite, fluorine-containing polymers such as tetrafluoroethylene (PTFE), silicone, and the like. Conventionally known solid lubricants such as resins can be used as appropriate. The method for coating the lubricating coating layer is not particularly limited, and examples thereof include vacuum deposition, ion deposition, physical vapor deposition, chemical vapor deposition, and vacuum arc deposition. There may be. In particular, among the above-described lubricants, diamond-like carbon (DLC) is most preferably used in consideration of wear resistance and lubricity.

  The present invention can be used as an oil-based ballpoint pen. More specifically, the present invention can be widely used as a cap-type or knock-type oil-based ballpoint pen filled with the ink composition for oil-based ballpoint pens.

DESCRIPTION OF SYMBOLS 1 Ball-point pen refill 2 Ink storage cylinder 3 Ball 4 Ball-point pen tip 5 Ink follower 6 Coil spring 10 Oil-based ink for ball-point pens

Claims (10)

An oil-based ballpoint pen refill having a ballpoint pen tip that rotatably holds a ball at the tip of the ink-holding cylinder, and containing an ink composition for an oil-based ballpoint pen in the ink-holding cylinder, wherein the ball surface arithmetic The average roughness is 0.1 to 15 nm, and the oil-based ballpoint pen ink composition comprises a colorant, an organic solvent, a resin, and a salt-form, and the salt-form has an acidic compound and an aromatic ring. An oil-based ballpoint refill which is a salt-form with an amine and the content of the salt-form is 0.01 to 2.0% by mass relative to the total amount of the ink composition. 2. The oil-based ballpoint pen refill according to claim 1, wherein an amount of movement of the ball in a vertical axis direction is 5 to 20 μm. The oil-based ballpoint pen refill according to claim 1 or 2, wherein the resin is a polyvinyl butyral resin. 4. The oil-based ballpoint pen refill according to claim 1, wherein the content of the polyvinyl butyral resin is 70% or more based on the total resin content of the ink composition. 5. The oil-based ballpoint pen refill according to any one of claims 1 to 4, wherein the acidic compound is an acidic dye. The oil-based ballpoint pen refill according to any one of claims 1 to 5, wherein the amine having an aromatic ring is a quaternary amine. The oil-based ballpoint pen refill according to any one of claims 1 to 6, further comprising a pigment in the oil-based ballpoint pen ink composition. 8. The oil-based ballpoint pen refill according to claim ^1, wherein the ink viscosity at 20 ° C. and a shear rate of 5 sec ⁻¹ is 10 to 5000 mPa · s. 9. An oil-based ballpoint pen comprising the oil-based ballpoint pen refill according to any one of claims 1 to 8 disposed in a shaft tube. An oil-in-ball type oil-based ballpoint pen comprising:

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