JP6576807B2 - Oil-based ballpoint pen refill and oil-based ballpoint pen using the same - Google Patents

Description

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

  Conventionally, in oil ballpoint pen ink compositions, oil ballpoint pen ink compositions and inks using various dyes such as nigrosine dyes, basic dyes, acid dyes, and dyes processed from them as colorants. There has been proposed a technique for an oil-based ballpoint pen ink composition in which a discharge amount is set.

  As such an ink composition for oil-based ballpoint pens, various colorants are used, and those using a nigrosine dye include those disclosed in JP-A-5-320558, “oil-based black ink”, triallylmethane base. Japanese Patent Application Laid-Open No. 9-165542 “Oil Black Ink”, Japanese Patent Application Laid-Open No. 9-71745 “Oil Black Ink”, and basic dyes are used as the basic dyes. Japanese Patent Application Laid-Open No. 8-134393, “Black Ink Composition for Oil-Based Ballpoint Pens”, etc.

"JP-A-5-320558" "JP-A-9-165542" "Japanese Patent Laid-Open No. 9-71745" "JP-A-8-134393" "Japanese Unexamined Patent Publication No. 2011-153199"

  However, in Patent Document 1, when a nigrosine dye is used as a colorant, the concentration is high, the cost is low, and it is conventionally used, but it is stable with ink components such as organic solvents, resins, and surfactants. It was necessary to take ink stability over time into consideration.

  Further, in Patent Documents 2 and 3, when a salt formation dye of triallylmethane basic dye and azo yellow acid dye is used as a colorant, a part of the salt formation dye collapses and precipitates over time. There was a problem that things were not generated and the writing taste was not sufficient and a dark handwriting could not be obtained.

  In Patent Document 4, a salt-forming dye based on a basic dye as a colorant has good ink aging stability, but newly contains a surfactant and the like in order to improve the writing quality. By doing so, the writing quality can be improved, but there is a problem that the surfactant reacts with the dye and precipitates are generated, which is a concern.

  Moreover, in patent document 5, with the ink for ball-point pens which set the ink discharge amount per 200 m to 32-47 mg (16-23.5 mg in conversion per 100 m), the darkness of a handwriting is not enough by itself, but darker handwriting Was demanded.

  Therefore, in order to improve the writing quality, there is a technology to reduce the ink viscosity, and it is possible to improve the writing quality to some extent, but since 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.

  Furthermore, even in an ink using only a dye as a colorant as in Patent Documents 1 to 5, an improvement in light resistance is demanded and further demanded.

  An object of the present invention is to provide an oil-based ballpoint pen refill which is excellent in ink aging stability, ink sag performance, writing taste and light resistance and is a dark handwriting, and an oil-based ballpoint pen using the same.

In order to solve the above problems, the present invention
“1. An ink composition for oil-based ballpoint pens, in which a ballpoint pen tip holding a ball rotatably is attached to the tip of the ink storage cylinder, and the ink storage cylinder contains a colorant, an organic solvent, and a resin. An oil-based ballpoint pen refill containing an object, wherein the ball surface has an arithmetic average roughness of 0.1 to 15 nm, and the oil-based ballpoint pen ink composition comprises an acid metal-containing dye and an aromatic as a colorant. An oil-based ballpoint pen refill comprising a salt-forming dye with an amine having a ring.
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 and / or a ketone resin.
4). Item 1 or 2, wherein the resin is a polyvinyl butyral resin, and the content of the polyvinyl butyral resin is 50% or more based on the total content of all the resins in the ink composition for oil-based ballpoint pens. The oil-based ballpoint pen refill according to item 2.
5). 5. The oil-based ballpoint pen refill according to any one of items 1 to 4, wherein the acid-containing dye is a copper phthalocyanine acid 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 ink composition further comprises a salt-forming dye of an acid dye and an amine having an aromatic ring (excluding a salt-forming dye of an acid metal-containing dye and an amine having an aromatic ring). The oil-based ballpoint pen refill according to any one of items 1 to 6.
8. The oil-based ballpoint pen refill according to any one of Items 1 to 7, wherein the ink viscosity at a shear rate of 5 sec ^{−1 at} 8.20 ° C. is 5000 mPa · s or less.
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. The oil-based ballpoint pen refill according to item 9 is slidably disposed in a shaft cylinder, and the tip end portion of the ballpoint pen tip can be protruded and retracted from the tip end portion of the shaft cylinder. Ballpoint pen. "

  The present invention was able to provide an oil-based ballpoint pen refill that is excellent in ink aging stability, ink sag performance, writing taste, and light resistance, and is a dark handwriting, and an oil-based ballpoint pen using the same.

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

  A feature of the present invention is that a ballpoint pen tip that rotatably holds a ball is attached to the tip of an ink containing cylinder, and the ink containing cylinder contains a colorant, an organic solvent, and a resin. An oil-based ballpoint pen refill containing an ink composition, wherein the ball surface has an arithmetic mean roughness of 0.1 to 15 nm, and the oil-based ballpoint pen ink composition has an acid metal content as a colorant. It is an oil-based ballpoint pen refill comprising a salt-forming dye of a dye and an amine having an aromatic ring.

  For the colorant used in the present invention, a salt-forming dye of an acid metal-containing dye and an amine having an aromatic ring is used. In order to improve light resistance, it is necessary to use an acidic metal-containing dye containing Cu, Cr, Fe, and Co. In order to stabilize the acidic metal-containing dye in oil-based ink, an aromatic ring is used. A salt-forming dye is obtained by neutralizing with an amine having This is because a strong ionic bonding force acts between the acidic metal-containing dye 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.

  Furthermore, in order to be excellent in ink sag performance and writing quality, it is necessary to include a resin, and as a resin used for an ink composition for an oil-based ballpoint pen, 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 are used. In the present invention, a polyvinyl butyral resin and / or a ketone resin is preferably used in order to have excellent stability in an ink of an acid metal-containing dye and a salt-forming dye of an amine having an aromatic ring.

  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, the polyvinyl butyral resin and the ketone resin are 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 1500 or less is used, it is considered that the ink of the acid metal-containing dye used in the present invention and the salt-forming dye of an amine having an aromatic ring is easily placed. For example, 1-8 nm is preferable, More preferably, it is 2-7 nm. 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, ink aging stability, ink sag performance, writing quality, light resistance are excellent, and in order to obtain a dark handwriting, the arithmetic average roughness of the ball surface is 0.1 to 15 nm. Furthermore, it is important that the oil-based ink composition for ballpoint pens contains a salt-forming dye and a resin of an acid metal-containing dye and an amine having an aromatic ring.

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. For making a darker handwriting, 40 mg or more is preferable. To improve the ink drooping performance and crying, more preferably, 40 mg ~ 60 mg is preferred.
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.

  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. It is preferable to use ceramic balls in consideration of writing taste, ball seat wear, and stability over time. The diameter of the ball is not particularly limited, but is generally about 0.25 mm to 2.0 mm.

  Ballpoint pen tip materials include metal materials such as stainless steel, white, brass (brass), aluminum bronze, and aluminum, and resin materials such as polycarbonate, polyacetal, and ABS. 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.

Among the resins, it is preferable to use a polyvinyl butyral resin in consideration of ink sag performance and excellent writing quality. 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 found that the ink dripping performance and writing quality are improved.
The hydroxyl group content (mol%) of the polyvinyl butyral resin is the content of hydroxyl group (mol%) with respect to the total mol amount of butyral group (mol%), acetyl group (mol%), and hydroxyl group (mol%). Indicates the rate.

  In the present invention, the reason for using polyvinyl butyral resin is that when the tip of the chip is left in the atmosphere, the polyvinyl butyral resin forms a resin film at the tip of the chip and covers the gap between the ball and the tip of the chip. This is because ink drooping can be suppressed. The content of the polyvinyl butyral resin is preferably 50% or more based on the total resin content, and is preferably used as the main resin. This is because when the content of the polyvinyl butyral resin is less than 50% of the total resin content, the formation of the resin film on the tip of the chip 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 the effect of improving the writing quality tends not to be obtained. Considering the tendency to improve ink sag performance and writing quality, the content of the polyvinyl butyral resin is preferably 70% or more with respect to the total resin content, and if considering the tendency, 90% or more. preferable. Furthermore, the acid-containing dye and the salt-forming dye of an amine having an aromatic ring are compatible with the polyvinyl butyral resin, and the content of the polyvinyl butyral resin is large. Even when the content is 90% or more, the ink aging stability is affected. It is preferable because it is difficult.

Moreover, it is preferable that the polyvinyl butyral resin used by this invention shall be the amount of hydroxyl groups 25 mol% or more. This is because the polyvinyl butyral resin having a hydroxyl group content of 25 mol% or more forms a thick resin film at the tip of the tip when the tip of the tip is left in the air, and covers the gap between the ball and the tip of the tip. This is because ink drooping can be suppressed. On the other hand, a polyvinyl butyral resin having a hydroxyl group content of less than 25 mol is not sufficiently soluble in an organic solvent and is not a uniform resin film, so that it is difficult to obtain a sufficient effect of suppressing ink dripping. It is because it is preferable to use this polyvinyl butyral resin. Moreover, the polyvinyl butyral resin having a hydroxyl group content of 30 mol% or more is preferable because the writing quality is easily improved. This is because, during writing, frictional heat is generated by the rotation of the ball, the ink at the tip of the chip is warmed, and the temperature of the ink increases, but the polyvinyl butyral resin is different from other resins, Even if the ink temperature rises, it has the property of making it difficult to lower the ink viscosity, and an ink layer that is always elastic is formed between the ball and the ball seat, making it difficult to make direct contact. It tends to be easy. In particular, oil-based ballpoint pens are effective with oil-based ballpoint pens because writing is often performed with high writing pressure. Further, when a polyvinyl butyral resin having a hydroxyl group content exceeding 40 mol% is used, the amount of moisture absorption tends to increase and the temporal stability with the oil-based ink component tends to be affected. Therefore, a polyvinyl butyral resin having a hydroxyl group content of 40 mol% or less is preferred. Therefore, a polyvinyl butyral resin having a hydroxyl amount of 30 to 40 mol% is preferable, and a hydroxyl group amount of 30 to 36 mol% is more preferable.
The hydroxyl content (mol%) of the polyvinyl butyral resin is the content of hydroxyl groups (mol%) with respect to the total molar amount of butyral groups (mol%), acetyl groups (mol%), and hydroxyl groups (mol%). Indicates the rate.

  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, considering the stability of the acidic metal-containing dye and the salt-forming dye with an amine having an aromatic ring, the average degree of polymerization is preferably 1500 or less, and if considering the writing quality, the average The 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, if 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% by mass is preferable, and when considering more, 7.0 to 25.0% by 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 It is easy to inhibit the effect of the resin, specifically, it inhibits the formation of the resin film on the tip of the chip and makes it difficult to suppress ink sag, and further inhibits the formation of a flexible ink layer, This is because the effect of improving writing quality is difficult to obtain. 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.

Examples of the acidic metal-containing dye used in the present invention include those having a sulfo group (—SO ₃ H), a carboxyl group (—COOH), and the like. acidic metal complex dye having a -SO _{3 H)} is preferable. 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 the acid metal-containing dye include acid metal-containing dyes containing Cu, Cr, Fe, and Co in order to improve light resistance, but have good compatibility with the polyvinyl butyral resin used in the present invention and are stable over time. In view of making the ink good, it is preferable to use an acidic metal-containing dye containing Cu. Furthermore, although there exist phthalocyanine series, azo series, etc., it is preferable to use a copper phthalocyanine series acid dye. Specifically, examples of the copper phthalocyanine-based acid dye include direct blue 86, direct blue 87, direct blue 199, and the like. In consideration of stability with an amine having an aromatic ring and light resistance, direct blue 86 is preferable.

  The amine having an aromatic ring used in the present invention is an amine having an aromatic ring such as a benzene ring, a naphthalene ring or an anthracene ring, and the writing quality can be improved by having the aromatic ring. This is presumed that the aromatic ring has an effect of suppressing metal contact between the ball and the chip body by forming a lubricating film that is easily adsorbed to the metal chip, improving lubricity and improving writing quality. To do. Therefore, in the present invention, by using a salt-forming dye of an acidic metal-containing dye and an amine having an aromatic ring, it becomes possible to improve ink aging stability and writing quality and to improve light resistance. , Mandatory. Therefore, unlike the conventional case, the salt-forming dye can have both the effects of the colorant and the lubricant.

  Examples of amines having an aromatic ring include primary amines, secondary amines, tertiary amines and quaternary amines. However, the acid-containing dyes are sufficiently neutralized to produce more stable salt-forming dyes. In order to make it, it is preferable to use a quaternary amine having an aromatic ring.

  Examples of quaternary amines having an aromatic ring include benzoxonium compounds (Benzoxonium), alkyldimethylbenzylammonium compounds, and alkyldiethylbenzylammonium compounds. Ink aging stability due to compatibility with neutralizing reactivity with acidic metal-containing dyes Considering the writing taste, 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, when the content of the salt-forming dye of the acid metal-containing dye and the amine having an aromatic ring is less than 0.1% by mass with respect to the total amount of the ink composition, desired lubricity and handwriting density can be obtained. If it exceeds 40.0% by mass, the ink aging tends to become unstable, so 0.1 to 40.0% by mass is preferable with respect to the total amount of the ink composition. More preferably, it is 1.0 to 25.0% by mass relative to the total amount of the ink composition, more preferably 5.0 to 20.0% by mass, and considering the stability with polyvinyl butyral, 7.0-15.0 mass% is preferable.

  Further, as the colorant, in addition to the salt-forming dyes of the acid metal-containing dye and the amine having an aromatic ring described above, various dyes and pigments can be used to adjust the color tone, It is easy to obtain ink aging stability of acid metal-containing dye and salt-forming dye of amine having an aromatic ring, and dark fresh handwriting. On the other hand, in order to obtain pigment dispersion stability when using pigment, Since there are problems such as selection of a dispersant and cost problems, it is preferable to use only a dye as the colorant. Furthermore, in consideration of ink aging stability, an acid dye that is a dye of the same system and an amine having an aromatic ring (except for a salt-forming dye of an acid metal-containing dye and an amine having an aromatic ring) should be used. preferable. It is possible to improve ink aging stability and writing quality by using an acid dye and an amine having an aromatic ring, as well as a salt-forming dye of an acid metal-containing dye and an amine having an aromatic ring. It is possible to have both the effect of a colorant and a lubricant, and it is a dye of the same system as a salt-forming dye of an acid metal-containing dye and an amine having an aromatic ring used in the present invention, and is compatible. .

  In addition, an acid dye and an amine having an aromatic ring (excluding a salt-forming dye of an acid metal-containing dye and an amine having an aromatic ring) are used as primary amines, secondary amines, and tertiary amines. In order to sufficiently neutralize the acidic metal-containing dye, it is preferable to use an aromatic quaternary amine in order to produce a more stable salt-forming dye. In addition, examples of aromatic quaternary amines include benzoxonium compounds (Benzoxonium), alkyldimethylbenzylammonium compounds, and alkyldiethylbenzylammonium compounds. Ink aging stability due to compatibility with neutralizing reactivity with acidic metal-containing dyes. Considering the writing taste, a benzoxonium compound (Benzoxonium) is preferable. You may use these individually or in mixture of 2 or more types.

  In addition, acid dyes include triallylmethane acid dyes, azo acid dyes, anthraquinone acid dyes, oxazine acid dyes, and the like. Considering keeping stability, it is preferable to use triallylmethane acid dye or azo acid dye.

  In addition, the content of the acid dye and the amine having an aromatic ring (excluding the salt-forming dye of the acid metal-containing dye and the amine having an aromatic ring) is less than 0.1% by mass with respect to the total amount of the ink composition. In addition, it is difficult to obtain desired lubricity and handwriting density, and when it exceeds 40.0% by mass, the ink aging tends to become unstable, so 0.1 to 40.0% by mass with respect to the total amount of the ink composition. Is preferred. More preferably, it is 1.0 to 25.0 mass%, more preferably 1.0 to 15.0 mass%, based on the total amount of the ink composition, and considering the stability with polyvinyl butyral, 3.0-10.0 mass% is preferable.

Further, as other colorants, general dyes and pigments may be used.
As the dye, oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, and various salt-forming dyes thereof may be employed. Specifically, Bali First Black 1802, Bali First Black 1805, Bali First Black 1807, 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 DYES MVB-3 (above, manufactured by Orient Chemical Industry Co., Ltd.), Eisen Spiron 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, Eisenspire Ron Yellow C-GNH, Eisenspiron Yellow C-2GH, S.R. P. T.A. Blue 111, S.I. P. T.A. Blue GLSH-Special, S. P. T.A. Red 533, S.D. P. T.A. 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.

  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, goxazine, metallic pigment, pearl pigment, fluorescent pigment, phosphorescent pigment and the like. These pigments easily enter the gap between the ball and the ball seat, thereby suppressing metal contact and improving lubricity. Further, in consideration of the gap relationship inside the chip, the average particle diameter is preferably 300 nm or less. More preferably, it is 150 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 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. 3.0-20.0 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 and the phosphate group formed by the polyvinyl butyral are more preferable because the lubricity is easily improved, and further, the lubrication formed by the amine having the aromatic ring. By suppressing the metal contact with the layer, it becomes easy to maintain 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, in consideration of lubricity, the number of carbon atoms contained in the alkyl group is preferably 5 to 18, more preferably, the number of carbon atoms is more preferably 10 to 18, and the acidic metal content Considering the stability of the dye and the salt-forming dye with an amine having an aromatic ring, the above-mentioned 12 to 18 carbon atoms are 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.

  Among these organic solvents, in consideration of ink drooping performance, the use of glycol ether solvent stabilizes the solubility with the polyvinyl butyral resin, thereby obtaining the effect of forming a resin film at the tip of the polyvinyl butyral resin. In particular, when a polyvinyl butyral resin having a hydroxyl group content of 25 mol% or more is used, the effect of forming a resin film is easily obtained, and the alcohol solvent is preferable because it is easily evaporated. It is preferable because the resin film can be easily dried, the resin film can be easily formed, and the ink dripping performance is easily improved. 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-forming dyes of the acidic metal-containing dye and the amine having an aromatic ring are dissolved and stabilized, and stable over a long period of time without being separated from each other. It is preferable because of its property. 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. These organic solvents can be used alone or in combination of two or more.

    Further, the content of the organic solvent is preferably 30.0 to 80.0% 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 5.0 to 50.0% by mass, more preferably 10.0 based on the total amount of the ink composition, considering the dissolution stability with the polyvinyl butyral resin. It is -40.0 mass%. Further, the content of the alcohol solvent is preferably 30.0 to 80.0% by mass, more preferably 40.0 to 70.0%, based on the total organic solvent, considering the drying property at the tip of the chip. % By mass.

  Furthermore, the content of the organic solvent takes into consideration the balance between the polyvinyl butyral resin, the acid-containing dye and the salt-forming dye of the amine having an aromatic ring for a long period of time, and the balance with the ink dripping performance. For example, the ratio of the alcohol solvent content to the glycol ether solvent content is preferably 1: 1 to 1: 5, more preferably 1: 1 to 1: 3.

  Further, as in the present invention, in the oil-based ballpoint pen ink composition comprising a salt-forming dye of an acid metal-containing dye and an amine having an aromatic ring, and a polyvinyl butyral resin, in order to further improve lubricity, fine particles are used. It may be used. This is because the fine particles can improve the lubricity by suppressing the metal contact by entering the fine particles into the gap between the ball and the ball seat in the same manner as the pigment. 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.

Furthermore, 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 can be more 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, fatty acid alkanolamides, anionic surfactants and / or cationic surfactants are used. As a stabilizer, fatty acid as a viscosity modifier, a resin such as ketone resin, terpene resin, alkyd resin, phenoxy resin, polyvinyl acetate, and a pseudoplasticity imparting agent such as fatty acid amide and hydrogenated castor oil In addition, a colorant stabilizer, a plasticizer, a chelating agent, water and the like may be appropriately used. These may be used alone or in combination of two or more.

  Further, when the oil-based ballpoint pen ink composition newly contains an acid metal-containing dye and a salt-forming dye of an amine having an aromatic ring, the ink aging stability can be maintained at the time of production or aging. It is preferable to pay attention also to the pH value because water is contained in the oil-based ink due to moisture absorption due to. In the present invention, a pH value of 3.9 or less is a strongly acidic region, a pH value of 10.1 or more is a strongly alkaline region, and a pH value of 4.0 to 10.0 is an intermediate region between a strongly acidic region and a strongly alkaline region (weak Acid, neutral, weakly alkaline).

  In order to maintain the ink aging stability of the oil-based ballpoint pen ink composition, the pH value is preferably in the neutral range of 4.0 to 10.0. This is because if the pH value is 3.9 or less, the metal ions in the chip body are likely to elute, so metal salt precipitates are likely to occur with the salt-forming dye, and if the pH value is 10.1 or more, This is because the ionic bond of the salt-forming dye tends to be separated, so that there is a tendency that the ink aging stability and the color tone are easily affected, and further the pigment dispersion stability cannot be obtained. Furthermore, considering the ink aging stability, the pH value is preferably 5.0 to 9.0.

  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 pH meter manufactured by Toa DKK Corporation.

The ink viscosity of the oil-based ballpoint pen ink composition 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 5000 mPa · s or less. In particular, in addition to setting the ink viscosity to 5000 mPa · s, it will be described below. When the ink consumption per 100 m is A (mg) and the ball diameter is B (mm), 40 ≦ A / B Since the relationship of ≦ 100 is different from that of the conventional ballpoint pen, the rotational resistance of the ball can be more easily suppressed 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.

  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. If / 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 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-forming dye of an acid metal-containing dye and an amine having an aromatic ring used in the present invention and a polyvinyl butyral resin are used, it has a very strong affinity with a polypropylene ink container, and the ink container is filled with ink. When moving the ink, the ink 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) having an arithmetic mean roughness (Ra) 3 nm of the ball surface at the tip of an ink containing cylinder 2 rotatably held. The ball-point pen tip 4 (the amount of movement of the ball in the vertical axis direction: 12 μm) that presses the ball 3 against the inner wall of the tip end edge by the coil spring 6 is mounted, and the oil-based ballpoint pen of Example 1 is placed in the ink containing cylinder 2. The ink composition 10 (0.4 g) and the grease-like ink follower 5 are directly accommodated to obtain a ballpoint refill 1.

Next, a method for producing a salt-forming dye comprising an acid metal-containing dye and an amine having an aromatic ring will be described.
Formulation Example 1
First, 1000 g of water and 30 g of direct blue 86 (acid metal-containing dye (copper phthalocyanine dye)) were weighed and heated in a beaker, dissolved using a disper stirrer, and then weighed 60 g of a benzoxonium compound. After stirring, filtration was performed using a filter paper, and the residue on the filter paper was dried to obtain a salt-forming dye.

Next, a method for preparing a salt-forming dye of an acid dye and an amine having an aromatic ring will be described.
Formulation Example 2
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 dye.

Next, an Example is shown and this invention is demonstrated.
The oil-based ballpoint pen ink composition of Example 1 is a salt-forming dye as a colorant, an alcohol solvent, a glycol ether solvent, a polyvinyl butyral resin as an organic solvent, a phosphate ester-based surfactant as a lubricant, and a spinnability imparting resin. Polyvinylpyrrolidone was employed, and a predetermined amount thereof was weighed and heated to 60 ° C., and then completely dissolved using a disper stirrer to obtain an ink composition for an oil-based ballpoint pen. 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 = 7.7.
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
Salt-forming dye of Formulation Example 1 12.0% by mass
Salt-forming dye of Formulation Example 2 6.0% by mass
Alcohol solvent (benzyl alcohol) 43.0% by mass
Glycol ether solvent (ethylene glycol monophenyl ether) 27.5% by mass
Polyvinyl butyral resin (ESREC BL-1, hydroxyl group amount: 36 mol%, average degree of polymerization: 300) 10.0% by mass
Lubricant (phosphate ester surfactant) 1.0% by mass
Spinnability imparting resin (polyvinylpyrrolidone) 0.5% by mass

Examples 2-10
As shown in Tables 1 and 2, oil-based ballpoint pen ink compositions of Examples 2 to 10 were obtained in the same procedure as Example 1 except that the components of the ink composition and the chip specifications were changed.
Example 11
As shown in Table 2, the components other than water were changed in the same manner as in Example 1 except that the components of the ink composition and the chip specifications were changed. An ink composition for ballpoint pens was obtained.

Comparative Examples 1-8
As shown in Table 3, the ink compositions for oil-based ballpoint pens of Comparative Examples 1 to 8 were 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. Table 3 shows the measurement and evaluation results.

Test and Evaluation The oil-based ballpoint pen refill 1 prepared in Examples 1 to 11 and Comparative Examples 1 to 8 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.

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 writing defects ... ×

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 ・ ・ ・ ×

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

Light resistance test: A spiral writing test was conducted on JIS P3201 writing paper A under the conditions of a writing angle of 70 ° and a writing load of 150 g at a writing speed of 4.5 m / min, and left for 1 hour, and then xenon fade meter X15F. Using (made by Suga Test Instruments Co., Ltd.), irradiation was performed until the blue scale faded to the third grade, and the handwriting was observed.
Does not fade or slightly fades ... ◎
Fading, but at a level where there is no practical problem ・ ・ ・ ○
Level where fading is conspicuous and causes practical problems ・ ・ ・ ×

Handwriting density: Handwriting written by handwriting was observed.
Thick and clear handwriting
What is a dark handwriting
A handwriting with a darkness that has no practical problem ・ ・ ・ △
Thin handwriting ・ ・ ・ ×

High writing pressure writing test: The wear of the ball seat after the writing test was measured with a running tester with a load of 400 gf, a writing angle of 70 °, and 4 m / min.
Ball seat wear less than 5μm ・ ・ ・ ◎
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 can be written.
Wearing the ball seat is bad and results in poor writing ・ ・ ・ ×

  In Examples 1 to 11, good performance was obtained in all of the ink aging test, writing quality, ink sag performance, light resistance, handwriting density, and high writing pressure writing test.

  In Comparative Examples 1 and 2, since salt-forming dyes of acidic metal-containing dyes and aliphatic amines were used, precipitates were generated and the ink aging stability was poor.

  In Comparative Examples 3, 4, and 5, no salt-forming dye of acid metal-containing dye and basic dye is used, and there is no acid metal-containing dye. Therefore, in the light fastness test, fading is noticeable and is a problem that is practically problematic. And the darkness of the handwriting was also inferior. Further, in Comparative Examples 3 and 4, precipitates were generated and the ink aging stability was poor.

  In Comparative Example 6, since the pigment was used, the ink aging was not stable.

  In Comparative Examples 7 and 8, 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 high writing pressure writing test.

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 to a range of 5000 mPa · s or less, a ballpoint pen tip is used to prevent the ink from dripping. The ball held rotatably at the tip is pressed against the inner wall of the tip edge of the tip directly by a coil spring or through a pressing body, and the ink is applied by giving a gap between the inner wall of the tip tip edge and the ball by the pressing force at the time of writing. It is preferable to provide a valve mechanism for allowing outflow and close a 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 water-based ballpoint pen of a cap type or a knock type filled with the ink composition for oily 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)

A ballpoint pen tip that rotatably holds a ball is attached to the tip of the ink storage cylinder, and an ink composition for an oil-based ballpoint pen containing a colorant, an organic solvent, and a resin is stored in the ink storage cylinder. An oil-based ballpoint pen refill having an arithmetic average roughness of the ball surface of 0.1 to 15 nm, and the oil-based ballpoint pen ink composition has an acidic metal-containing dye and an aromatic ring as a colorant. An oil-based ballpoint pen refill comprising a salt-forming dye with an amine. 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 refill according to claim 1 or 2, wherein the resin is a polyvinyl butyral resin and / or a ketone resin. The resin is a polyvinyl butyral resin, and the content of the polyvinyl butyral resin is 50% or more based on the total content of all resins in the ink composition for oil-based ballpoint pens. 2. An oil-based ballpoint pen refill according to 2. The oil-based ballpoint pen refill according to any one of claims 1 to 4, wherein the acid-containing dye is a copper phthalocyanine acid 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 ink composition further comprises a salt-forming dye of an acid dye and an amine having an aromatic ring (excluding a salt-forming dye of an acid metal-containing dye and an amine having an aromatic ring). The oil-based ballpoint pen refill according to any one of claims 1 to 6. 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 5000 mPa · s or less. 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. The oil-based ballpoint pen refill according to claim 9 is slidably disposed in a shaft cylinder, and a tip end portion of the ballpoint pen tip can be protruded and retracted from the tip end portion of the shaft cylinder. Ballpoint pen

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