JP2015033782A - 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 oil-based ball point pen refill and an oil-based ball point pen using the same capable of obtaining deep handwriting, and excellent in ink dripping resistance and in feeling of writing.SOLUTION: In an oil-based ball point pen refill, a ball point pen tip rotatably holding a ball is attached on a tip of an ink storing tube directly or through a tip holder, and an ink composition for the oil-based ball point pen composed at least of a color agent, an organic solvent and a resin is stored in the ink storing tube. Arithmetic average roughness of a surface of the ball is 0.1-15 nm, the color agent is composed only of a dye, the resin contains at least a polyvinyl butyral resin, the content of the polyvinyl butyral resin is 50% or more based on the total resin content in the ink composition for the oil-based ball point pen, and an ink viscosity is 10000-50000 mPa s at 20°C and 5 secof shear rate.

Description

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

  Conventionally, in order to obtain a dark handwriting in an oil-based ballpoint pen ink composition, Japanese Patent Application Laid-Open No. 7-188601 “Oil-based ballpoint ink composition”, Japanese Patent Application Laid-Open No. 8-157765 “oil-based ballpoint ink composition”, etc. Ink compositions for oil-based ballpoint pens using various dyes such as dyes have been proposed.

Japanese Patent Application Laid-Open No. 6-313144 discloses an “oil-based ballpoint pen” which has an ink viscosity of 100 mPa · S or less at a shear rate of 400 s ⁻¹ and 1000 mPa · S or more at a shear rate of 5 s ^{−1 to} improve the writing quality. Is disclosed.

"Japanese Patent Laid-Open No. 7-188601" "JP-A-8-157765" "JP-A-6-313144"

  However, in Patent Documents 1 and 2, when a nigrosine dye is used as a colorant, it is possible to darken the handwriting to some extent, but it is not sufficient, so it is necessary to increase the content of the nigrosine dye. In some cases, the viscosity of the ink was high, the writing quality was poor, and there was a problem of dye solubility in organic solvents.

  Further, when the ink viscosity is lowered, there are problems of ink leakage (ink dripping) from the gap between the ball and the tip of the chip, and the ball seat is easily worn. In view of these problems, it is also possible to add a shear thinning agent that increases the ink viscosity at rest and lowers the ink viscosity at the time of writing, as in Patent Document 3, to impart shear thinning to the ink. However, new problems such as ink followability and compatibility between the shear thinning agent and other ink components occur.

  In addition, as a method of dealing with the structure by the chip, the ink is dripped by constantly pressing the ball against the inner wall surface of the tip of the chip with a coil spring or the like in the chip body and closing the minute gap between the ball and the tip of the chip. Although it can be suppressed, there are also problems that the manufacturing cost increases, the rotation of the ball tends to be inferior, and the writing quality tends to be affected.

  An object of the present invention is to provide an oil-based ballpoint pen refill with a dark handwriting, good ink sag performance and excellent writing quality, and an oil-based ballpoint pen using the same.

In order to solve the above problems, the present invention
“1. A ballpoint pen tip holding a ball rotatably is attached to the tip of the ink containing cylinder directly or via a chip holder, and the oil containing substance composed of at least a colorant, an organic solvent, and a resin in the ink containing cylinder. An oil-based ballpoint pen refill containing a ballpoint pen ink composition, wherein the ball surface has an arithmetic average roughness of 0.1 to 15 nm, the colorant is composed only of a dye, and the resin is at least polyvinyl butyral The content of the polyvinyl butyral resin is 50% or more based on the total resin content in the oil-based ballpoint ink composition, and the ink viscosity at 20 ° C. and a shear rate of 5 sec ⁻¹ is An oil-based ballpoint pen refill characterized by being 10,000 to 50,000 mPa · s.
2. 2. The oil-based ballpoint refill according to claim 1, wherein the amount of movement of the ball in the axial direction is 5 to 20 μm, and the amount of ink consumed per 100 m of the oil-based ballpoint refill is 30 to 80 mg.

3. The average degree of polymerization of the polyvinyl butyral resin is 800 to 2500, and the oil-based ballpoint pen refill according to item 1 or 2.
4). 4. The oil-based ballpoint pen refill according to any one of items 1 to 3, wherein the oil-based ballpoint pen ink composition contains a phosphate ester surfactant.
5. The oil-based ballpoint pen according to any one of claims 1 to 4, wherein the oil-based ballpoint pen refill is disposed in a shaft cylinder.
6). The oil-based ballpoint pen refill is a retractable oil-based ballpoint pen that is slidably disposed in a shaft cylinder, and the tip end portion of the ballpoint pen tip can be protruded from the tip end portion of the shaft cylinder. Or the oil-based ball-point pen of any one of Claim 5 thru | or 5. "

  The present invention was able to provide an oil-based ballpoint pen refill with a dark handwriting, good ink sag performance, and excellent writing quality, 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. FIG. 2 is an enlarged vertical cross-sectional view of a main part, partly omitted in FIG. 1.

The first feature of the present invention is that a ballpoint pen tip holding a ball rotatably is mounted at the tip of the ink storage cylinder directly or via a chip holder,
An oil-based ballpoint pen refill containing an oily ballpoint pen ink composition comprising at least a colorant, an organic solvent, and a resin, wherein the ball surface has an arithmetic average roughness of 0.1 to 15 nm, and the colorant is a dye. The resin contains at least a polyvinyl butyral resin, and the content of the polyvinyl butyral resin is 50% or more with respect to the total resin content in the ink composition, and a shear rate of 20 ° C. The ink viscosity at 5 sec ⁻¹ is 10,000 to 50,000 mPa · s.

  As described above, in order to obtain a dark handwriting, it is conceivable to increase the dye concentration and to eject a large amount of ink on the paper surface. However, increasing the dye concentration tends to lower the stability over time, and simply reduces the ink consumption. If it increases, there is a problem that the ink dripping performance tends to be inferior and crying is likely to occur. In view of these problems, the present invention solves the above-mentioned problems by using a specific resin.

  Only the dye is used for the colorant used in the present invention. As the dye, oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, direct dyes, and various salt-forming dyes thereof can be used. This is because among the colorants, it is easy to obtain a dark and fresh handwriting when using a dye. On the other hand, when using a pigment, in order to obtain pigment dispersion stability, problems such as selection of a pigment dispersant and cost Because there is a problem, only the dye is used.

  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. As mentioned above, the present invention is characterized by containing at least a polyvinyl butyral resin. Polyvinyl butyral 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. In the ink composition for oil-based ballpoint pens, the dye described above is used. It has been found that a dark handwriting can be obtained by using only the colorant and the polyvinyl butyral resin as the main resin, thereby improving the writing quality.

  It is considered that the ink composition for an oil-based ballpoint pen contains a polyvinyl butyral resin as a main resin, so that the ink is easily placed on the surface of the ball, so that the writing quality is good and a dark handwriting can be obtained. More specifically, the synergistic effect of setting the ink viscosity to 10,000 to 50,000 mPa · s makes it easy for the ink to aggregate on the ball surface, to be easily placed on the ball surface, and to hold the ink on the ball surface. It is presumed that an ink layer is formed between the ball and the ball seat, the writing quality is improved, and the handwriting is not easily broken when transferred to the paper surface, so that a dark handwriting is obtained.

  Moreover, it is important to contain polyvinyl butyral resin as the main resin (50% or more of the total resin content). This is because the content of polyvinyl butyral resin is less than 50% of the total resin content. The other resin inhibits the formation of the resin film at the tip of the chip, prevents ink drooping, and inhibits the formation of an elastic resin film, resulting in improved writing quality. This is because it disappears. Considering the tendency to improve ink drooping performance and writing quality, the content of polyvinyl butyral resin is preferably 70% or more with respect to the total resin content, and further considering that tendency, it is 90% or more. preferable.

The ink viscosity of the oil-based ballpoint pen ink composition of the present invention is such that when the ink viscosity at 20 ° C. and a shear rate of 5 sec ⁻¹ is less than 10,000 mPa · s, it is difficult to suppress ink sag, and 20 ° C., shear rate. When the ink viscosity at 5 sec ⁻¹ exceeds 50000 mPa · s, the writing quality is lowered and it tends to be difficult to obtain a dark handwriting. In addition, since the present invention uses polyvinyl butyral resin as the main resin, as described above, it is easy to form an ink layer between the ball and the chip body, particularly the ball and the ball seat, and it is possible to improve the writing quality. In consideration of ink sag suppression and writing quality, the ink viscosity is more preferably 15000 to 30000 mPa · s, and most preferably 20000 to 30000 mPa · s.

  By the way, a polyvinyl butyral resin is used as in the present invention, the content of the polyvinyl butyral resin is 50% or more based on the total resin content in the ink composition, and the ink viscosity is 10,000 to 50,000 mPa · s. Since this has the effect of significantly improving the ink dripping performance, the ball is always pressed against the inner wall surface of the tip of the tip with a coil spring or the like in the tip body, and the ball and tip of the tip are By closing the minute gap, it is not necessary to have a structure that suppresses ink sag, and the effect of suppressing ink sag is obtained, so there is no need to provide a coil spring or the like in the chip body, which reduces the number of parts. It can be suitably used for connection, in / out type and / or low-priced products.

  The arithmetic average roughness (Ra) of the ball surface used in the present invention is 0.1 to 15 nm. This is because when the arithmetic average roughness (Ra) is less than 0.1 nm, it is difficult to obtain sufficient ink on the ball surface even when using the polyvinyl butyral described above, it is difficult to obtain a dark handwriting at the time of writing, Scratch is likely to occur. In particular, when the average degree of polymerization of the polyvinyl butyral resin is 1200 to 2000 and the average degree of polymerization is high, the cohesive force of the ink tends to increase, so that the arithmetic average roughness (Ra) is 1-15 nm on the ball surface. It is more preferable because the ink is easily placed thereon. On the other hand, it is preferable that the arithmetic average roughness (Ra) is large because it is easier to retain ink on the ball surface. However, if the arithmetic average roughness (Ra) exceeds 15 nm, the rotational resistance between the ball and the ball seat increases. This is because the taste tends to be inferior, and the writing performance such as blurring, line skipping, and line unevenness tends to be affected. Considering that more, 3 to 13 nm is preferable, and 5 to 10 nm is more preferable. In addition, the measurement of arithmetic surface roughness can be calculated | required by (model name SPI3800N by Seiko Epson Corporation).

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, 10.0% by mass or more is preferable, and if it exceeds 30.0% by mass, the ink viscosity tends to be too high and affects the writing quality. 0% by mass is preferable, and 12.0 to 25.0% by mass is most preferable in consideration of the above.

Moreover, in order to obtain a dark handwriting, it is preferable to discharge many on a paper surface, and when the ink consumption per 100 m is less than 30 mg, it is difficult to obtain a dark handwriting. Moreover, since it is difficult to suppress ink dripping when it exceeds 80 mg, it shall be 30 mg-80 mg. More preferably, it is 45 to 70 mg. This is because 45 mg or more is preferable for making darker handwriting, and 70 mg or less is preferable in consideration of suppressing ink drooping 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 ball | bowl axial direction in the ball-point pen tip used for this invention shall be 5 micrometers-20 micrometers. This is because if it is less than 5 μm, it is difficult to transfer the ink held on the ball to the paper surface, and it becomes difficult to darken the handwriting, and if it exceeds 20 μm, ink dripping tends to occur. Considering that more, 7 to 16 μm is preferable.

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 amount: 33 ± 3 mol%),
Average polymerization degree: 2400), BM-1 (hydroxyl group amount: 34 mol%, average polymerization degree: 650), BM-2 (hydroxyl group quantity: 31 mol%, average polymerization degree: 800), BM-5 (hydroxyl group quantity) : 34 mol%, average degree of polymerization: 850), BL-1 (hydroxyl group amount: 36 mol%, average degree of polymerization: 300), BL-1H (hydroxyl group amount: 30 mol%), BL-2 (hydroxyl group amount: 36 mol) %, Average polymerization degree: 450), BL-2H (hydroxyl group amount: 29 mol%), BL-10 (hydroxyl group amount: 28 mol%), etc., trade names of Kuraray Co., Ltd .; Mobital B20H (hydroxyl group amount: 26-31 mol%, average polymerization degree: 250-500), 30T (hydroxyl group amount: 33-38 mol%, average polymerization degree: 400-650), 30H (hydroxyl group amount: 26-31 mol%, average polymerization degree: 00-650), 30HH (hydroxyl group amount: 30-34 mol%, average degree of polymerization: 400-650), 45H (hydroxyl group amount: 26-31 mol%, average degree of polymerization: 600-850), 60T (hydroxyl group amount) : 34-38 mol%, average polymerization degree: 750-1000), 60H (hydroxyl group amount: 26-31 mol%, average polymerization degree: 750-1000), 75H (hydroxyl group quantity: 26-31 mol%, average polymerization degree: 1500-1750) and the like. You may use these individually or in mixture of 2 or more types.

Moreover, it is preferable that polyvinyl butyral resin 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 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.

  The average degree of polymerization of the polyvinyl butyral resin is preferably 800 to 2000. This is preferable because the average degree of polymerization is 800 or more because the ink is easily placed on the paper surface, and it is easy to maintain a three-dimensional handwriting and easily obtain a dark handwriting when transferred to paper. In this case, the average degree of polymerization is preferably 2000 or less. Therefore, the average degree of polymerization is preferably 800 to 2000, and when the average degree of polymerization is 1200 or more, the ink dripping performance tends to be improved, and thus the average degree of polymerization is most preferably 1200 to 2000. 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. .

  Resins other than the polyvinyl butyral resin may be appropriately used as an ink viscosity modifier or a spinnability imparting agent. In particular, it is preferable to contain a polyvinyl pyrrolidone resin, since the incorporation of the polyvinyl pyrrolidone resin increases the binding property of the ink and suppresses the generation of excess ink at the tip of the chip. If the content of the polyvinyl pyrrolidone resin is less than 0.01% by mass relative to the total amount of the ink composition, it tends to be difficult to suppress the generation of excess ink, and if it exceeds 3.0% by mass, it dissolves in the ink. Since there exists a tendency for property to be inferior, 0.01-3.0 mass% is preferable with respect to the ink composition whole quantity. If the above reason is considered, 0.1 to 2.0 mass% is preferable. Specific examples include trade names of IP Japan Co., Ltd .; PVP K-15, PVP K-30, PVP K-90, PVP K-120, and the like. You may use these individually or in mixture of 2 or more types.

  The types of dyes include salt-forming dyes of basic dyes and acid dyes, salt-forming dyes of basic dyes and organic acids, and salt-forming dyes of acid dyes and organic amines. It is preferable to use a salt-forming dye of a basic dye and an acid dye that gives a dark handwriting. In particular, the ink consumption per 100 m is 30 to 80 mg, which is higher than the conventional one. It is preferable to use a salt dye because a darker handwriting can be easily obtained. In addition, when other types of dyes are used, it is most preferable to use only a salt-forming dye of a basic dye and an acid dye, since the ink aging stability and writing quality are easily affected. In addition, regarding salt-forming dyes of basic dyes and acidic dyes, basic dyes include basic dyes such as xanthene skeleton, triallylmethane skeleton, azomethine skeleton, azo skeleton, anthraquinone skeleton, and oxazine skeleton. Include acid dyes such as triallylmethane skeleton, azo skeleton, anthraquinone skeleton, and oxazine skeleton, and can be obtained by salting these basic dyes or acid dyes.

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

  The content of the colorant is preferably 5.0 to 30.0% by mass with respect to the total amount of the ink composition. If the amount is less than 5.0% by mass, a dark handwriting tends to be difficult to obtain. If the amount exceeds 30.0% by mass, the solubility in ink tends to be affected. Considering it, 7.0 to 25.0 mass% is preferable, and further considering it is 10.0 to 20.0 mass%.

  Examples of the organic solvent used in the present invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol monophenyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether, 3 -Glycol ethers such as methoxybutanol and 3-methoxy-3-methylbutanol, glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, butylene glycol and ethylene glycol, benzyl alcohol, methanol, ethanol 1-propanol, 2-pro For oil-based ballpoint pens such as alcohols such as diol, isopropanol, isobutanol, t-butanol, propargyl alcohol, allyl alcohol, 3-methyl-1-butyn-3-ol, 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, when a glycol ether solvent is used, the solubility of the polyvinyl butyral resin is stabilized, so that the effect of forming a resin film at the tip of the polyvinyl butyral resin is improved. The alcohol solvent is preferable because it is easily obtained, and the alcohol solvent is preferable because it easily volatilizes, is easy to dry at the tip of the chip, easily forms a resin film, and easily improves ink dripping performance. Therefore, in the present invention, it is preferable to use a glycol ether solvent and an alcohol solvent in combination. In particular, in view of improving lubricity, it is preferable to have an aromatic ring. 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 10.0 to 70.0% by mass with respect to the total amount of the ink composition in consideration of improving solubility, handwriting drying property, bleeding, and the like. Further, the content of the glycol ether solvent is preferably 10.0 to 50.0% by mass, more preferably 10.0 to 30% with respect to the total organic solvent in consideration of the dissolution stability with the polyvinyl butyral resin. 0.0% by mass. Further, the content of the alcohol solvent is preferably 30.0 to 90.0% by mass, more preferably 50.0 to 90.0%, based on the total organic solvent, considering the drying property at the tip of the chip. % By mass.

  In order to improve the writing quality, it is preferable to use a surfactant, particularly 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, as described above, the lubricity is easily improved by the ink layer and the phosphate group formed of the polyvinyl butyral resin as described above.

  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, 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, it is preferable that carbon number contained in an alkyl group is 5-15, and it is more preferable that it is 10-15. 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 film formed and may improve the writing performance. Therefore, unlike the cap-type writing tools, the pen tip is always exposed to the outside in the in-and-out writing tools such as the knock-type writing tools and the rotary pay-out writing tools, so it is easy to affect the writing performance. It is more preferable to use a 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: 160-185), 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) Etc. It is. These surfactants may be used alone or in combination of two or more.

Furthermore, it is preferable to use an organic amine in the oil-based ballpoint pen ink of the present invention for the purpose of neutralizing a phosphate ester surfactant or the like. Examples of the organic amine include oxyethylene alkylamine, polyoxyethylenealkylamine, and the like, and alkylamines such as laurylamine, stearylamine, distearylamine, dimethyllaurylamine, dimethylstearylamine, and dimethyloctylamine. Among them, when an organic amine having ethylene oxide (CH ₂ CH ₂ O) is used, it is easy to obtain a lubricating effect. Therefore, oxyethylene alkyl amine and polyoxyethylene alkyl amine having ethylene oxide (CH ₂ CH ₂ O) Is preferably used.

  Regarding the reactivity between the organic amine and the other components in the ink, the primary amine is the strongest, and then the reactivity with the secondary amine and the tertiary amine is small. It is preferable to use a tertiary amine and / or a tertiary amine. You may use these individually or in mixture of 2 or more types.

  Specific examples of the oxyethylene alkylamine and polyoxyethylene alkylamine include Nimine L-201 (total amine value: 232 to 246, secondary amine), L-202 (total amine value: 192 to 212, 3). Secondary amine), L-207 (total amine number: 107 to 119, tertiary amine), S-202 (total amine value: 152 to 166, tertiary amine), S-204 (total amine value: 120). -134, tertiary amine), S-210 (total amine value: 75-85, tertiary amine), DT-208 (total amine value: 146-180, tertiary amine) (Nippon Yushi Co., Ltd.) Manufactured) and the like. Specific examples of the alkylamine include Farmin 80 (total amine number: 204-210, primary amine), Farmin D86 (total amine number: 110-119, secondary amine), Farmin DM2098 (total amine number: 254). -265, tertiary amine), Farmin DM 8680 (total amine number: 186-197, tertiary amine) (Kao Corporation) and the like. You may use these individually or in mixture of 2 or more types. The content of the oxyethylene alkylamine and the polyoxyethylene alkylamine is preferably 0.1 to 10.0% by mass, more preferably 0, based on the total amount of the ink composition in consideration of lubricity and stability over time. It is 5-5.0 mass%.

  Further, when the total amine value of the organic amine is X and the acid value of the phosphate ester surfactant is Y, it is preferable that 0.1 ≦ Y / X ≦ 2.0. This is because if Y / X> 2.0 or Y / X <0.10, it is easy to promote precipitation over time due to the influence of ions of the ball material made of metal or the chip body, and it depends on the precipitate. This is because it tends to cause poor writing. In consideration of the above reasons, 0.1 ≦ Y / X ≦ 1.0 is preferable, and 0.3 ≦ Y / X ≦ 0.8 is most preferable in consideration of further consideration.

  In addition, in the ink composition according to the present invention, as other additives, in order to improve lubricity and ink aging stability, (i) surfactants such as fluorine surfactants, silicone surfactants, (Ii) Viscosity adjustment of fatty acid alkanolamide, anionic surfactant, cationic surfactant, amphoteric surfactant, and salt-form of anionic surfactant and / or cationic surfactant Agents such as fatty acid amides, pseudoplasticizers such as hydrogenated castor oil, (iii) colorant stabilizers, (iv) plasticizers, (v) chelating agents, or (vi) water as a co-solvent. You may use suitably. These may be used alone or in combination of two or more.

  The material of the ball used in the present invention is not particularly limited, but may be, for example, a simple substance of various metals, an alloy, or ceramics. Specifically, a single metal such as steel, copper, aluminum or nickel may be used, or an alloy such as white or stainless steel may be used. Further, carbides such as metals, oxides, nitrides, borides, or suicides can be used. As the carbide, a carbide such as titanium, vanadium, chromium, tantalum, niobium, molybdenum, boron, zircon, tungsten, or silicon can be used. As the oxide, an oxide such as aluminum, chromium, magnesium, silicon, beryllium, thorium, titanium, calcium, or zircon can be used. A nitride such as titanium, boron, silicon, silicon, or aluminum can be used as the nitride. As the boride, borides such as zircon, chromium or titanium can be used. As the hatching, a hatching such as molybdenum, titanium, or chromium can be used, and it is preferable to make a ceramic ball in consideration of writing taste, ball seat wear, and stability over time. The diameter of the ball body is not particularly limited, but is generally about 0.25 mm to 2.0 mm.

  Further, the material of the chip body used in the present invention is not particularly limited, but may be, for example, a simple substance or an alloy of various metals, ceramics, resin, or the like. Specifically, a single metal such as steel, copper, aluminum or nickel may be used, or an alloy such as white or stainless steel may be used. In consideration of workability such as writing quality and cutting, it is preferable to use a stainless steel chip body in consideration of wear and stability over time of the chip body and ball seat made of white and white.

  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
1 and 2, the ball pen refill 1 of Example 1 has a ball 3 (φ0.7 mm) having an arithmetic mean roughness (Ra) 6 nm of the ball surface on the surface of the ink containing cylinder 2 rotatably. The ballpoint pen tip 4 is mounted, and the oil-based ballpoint pen ink 10 (0.2 g) of Example 1 is directly stored in the ink storage cylinder 2 to obtain the ballpoint refill 1.

  Specifically, the ball-point pen tip 4 is formed by cutting a stainless steel wire having a diameter of 2.3 mm and a hardness of 230 Hv to 280 Hv to a desired length, and radiating from the ball holding chamber 6, the ink circulation hole 7, and the ink circulation hole 7. After forming the ink flow groove 8 extending in the direction of the ball, a substantially circular arc-shaped ball seat 9 is formed on the bottom wall of the ball holding chamber 6. Thereafter, the ball 3 of silicon nitride material is placed on the ball seat 9 and the tip end portion 5 is caulked inward.

  Further, the ball protrusion H from which the ball 3 protrudes from the tip end in a state where the ball 3 is placed on the ball seat 9 is 30.0% of the ball diameter, the caulking angle α is 70 degrees, and the vertical clearance of the ball 3 Is 15 μm, the inner diameter of the ball holding chamber is 104.0% of the ball diameter, and the diameter of the ball seat 9 is 86.0% of the ball diameter.

The ink composition for oil-based ballpoint pens of Example 1 is a dye as a colorant, benzyl alcohol as an organic solvent, ethylene glycol monophenyl ether, polyvinyl butyral resin, a phosphate ester surfactant as a lubricant, and oxyethylene alkyl as an organic amine. Polyvinylpyrrolidone was employed as an amine and spinnability imparting agent, and a predetermined amount 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. Ink viscosity of Example 1 was measured using a viscometer RVDVII + Pro CP-52 spindle manufactured by Brookfield Co., Ltd. in an environment of 20 ° C. and a shear rate of 5 sec ⁻¹ (rotation speed: 2.5 rpm). As a result, the ink viscosity was 23000 mPa · s. Further, the ink consumption per 100 m was 45 mg / 100 m.

Example 1 (Ink formulation)
Colorant (dye, salt-forming dye of basic dye and acid dye) 18.0% by mass
Organic solvent (benzyl alcohol) 54.0% by mass
16.5% by mass of organic solvent (ethylene glycol monophenyl ether)
Polyvinyl butyral resin (ESREC BH-3, hydroxyl group amount: 34 mol%, average degree of polymerization: 1700) 9.0% by mass
Lubricant (phosphate ester surfactant) 1.0% by mass
Organic amine (oxyethylene alkylamine) 1.0% by mass
Spinning agent (polyvinylpyrrolidone resin) 0.5% by mass

Examples 2-11
As shown in Table 1, the oil-based ballpoint pen inks of Examples 2 to 11 were used in the same procedure as Example 1 except that the ink formulations of Examples 2 to 11 and the arithmetic average roughness (Ra) of the ball surface were changed. A composition and an oil-based ballpoint pen refill were obtained. Tables 1 and 2 show the measurement and evaluation results.

Comparative Examples 1-8
As shown in Table 3, for the oil-based ballpoint pens of Comparative Examples 1-8, the same procedure as in Example 1 was applied except that the ink composition of Comparative Examples 1-8 and the arithmetic average roughness (Ra) of the ball surface were changed. An ink composition and an oil-based ballpoint pen refill were obtained. Table 3 shows the measurement and evaluation results.

Test and Evaluation The oil-based ballpoint pen refills produced in Examples 1 to 11 and Comparative Examples 1 to 8 were placed in an oil-based ballpoint pen (trade name: Supergrip) manufactured by Pilot Corporation to produce and write an oil-based ballpoint pen. The following tests and evaluations were performed using writing paper JIS P3201 as a test paper.

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 ・ ・ ・ ×

Ink sag test: The sample was left for 7 days in an environment of 30 ° C. and 85% RH with the pen tip downward, and ink leakage from the tip of the tip was confirmed.
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 ・ ・ ・ ◎
What is smooth ・ ・ ・ ○
Smoothness of a level that is not a problem for practical use ・ ・ ・ △
Heavy thing

Written performance test: After writing on paper, the written handwriting was observed.
There is no problem in practical use because the handwriting has blurring, line skipping, blurring, line irregularities, etc.
Scratches, line skipping, blurring, line irregularities, etc. in the handwriting, poor practicality ・ ・ ・ ×

  In Examples 1 to 11, good performance was obtained in both handwriting density, writing taste, ink sag test, and writing performance test.

  In Comparative Examples 1 and 2, since the polyvinyl butyral resin was not used, the writing was heavy and the ink sag was not good.

  In Comparative Example 3, since the ink viscosity was 60000 mPa · s, the writing quality was heavy, the handwriting was not dark, and severe blurring and line unevenness occurred in the handwriting.

  In Comparative Example 4, since the ink viscosity was 5000 mPa · s, the ink dripping was bad.

  In Comparative Examples 5, 6, and 8, since the polyvinyl butyral resin was less than 50%, the ink dripping was poor and the writing quality was heavy.

  In Comparative Example 7, the arithmetic average roughness (Ra) of the surface of the ball was 22 nm, the writing quality was heavy, and severe blurring and line unevenness occurred in the handwriting.

  In Examples 1 to 11, a ball having a ball diameter of φ0.7 mm was used, but when the test and evaluation of Examples 1 to 11 were performed by changing the ball diameter to a ball of φ1.0 mm, the darkness of the handwriting was increased. In addition, good performance was obtained in both writing taste, ink sag test, and writing performance test.

  In addition, in the case of using a retractable oil-type ballpoint pen such as a knock-type oil-type ballpoint pen or a rotary feed-out type oil-based ballpoint pen, the ink drooping performance is one of the most important performances. It is effective to use an oil-based ballpoint pen refill that can improve the ink drooping performance by covering the gap between the ball and the tip of the chip.

  Further, in this embodiment, for the sake of convenience, an oil ballpoint pen containing an oil ballpoint pen refill that directly contains an ink composition for an oil ballpoint pen is illustrated in the shaft tube, but the oil ballpoint pen of the present invention includes a shaft tube. A direct-packing type oil-based ballpoint pen may be used in which an ink-containing tube is used and the ink composition for an oil-based ballpoint pen is directly stored in the shaft tube. Further, in this embodiment, for the sake of convenience, a ballpoint pen tip formed by cutting a wire rod is illustrated, but a ballpoint pen tip formed by pressing a pipe member may be used.

  In this embodiment, the caulking angle of the ball-point pen tip is set to 70 degrees. However, if the caulking angle is too large, the paper contact angle tends to decrease, and therefore the angle is 90 degrees or less, preferably 80 degrees or less. preferable. If the caulking angle is 50 degrees or less, the space for storing ink between the ball 9 and the tip edge of the chip tends to be small, and it is difficult for ink to return, and it is difficult to suppress ink scooping, so the caulking angle is 50 degrees. It is preferable that the angle be -90 degrees.

  Further, the inside diameter of the ball exit and the ball holding chamber is not particularly limited, but in order to obtain the ink consumption per 100 m (30 to 80 mg), the ball exit is 10.0 to the ball diameter. 30.0%, the inner diameter of the ball holding chamber is preferably 105.0 to 120.0% of the ball diameter, and the ball seat diameter is preferably 70 to 95% of the ball diameter.

  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 Tip end part 6 Ball holding chamber 7 Ink distribution hole 8 Ink distribution groove 9 Ball seat 10 Oil-based ball-point pen ink H Ball out α Caulking angle

Claims (6)

An oil-based ballpoint pen ink comprising at least a colorant, an organic solvent, and a resin in which a ballpoint pen tip that rotatably holds a ball is attached to the tip of the ink storage tube directly or via a chip holder. An oil-based ballpoint pen refill containing the composition, wherein the arithmetic mean roughness of the surface of the ball is 0.1 to 15 nm, the colorant comprises only a dye, and the resin contains at least a polyvinyl butyral resin. And content of the said polyvinyl butyral resin shall be 50% or more with respect to content of all the resin in the said ink composition for oil-based ball-point pens, and the ink viscosity in 20 degreeC and the shear rate of 5 sec- ¹ is 10000-50000mPa. -An oil-based ballpoint pen refill characterized by being s. 2. The oil-based ballpoint pen refill according to claim 1, wherein an amount of movement of the ball in the axial direction is 5 to 20 μm and an ink consumption amount per 100 m of the oily ballpoint pen refill is 30 to 80 mg. 3. The oil-based ballpoint pen refill according to claim 1, wherein an average degree of polymerization of the polyvinyl butyral resin is 800 to 2500. 4. The oil-based ballpoint pen refill according to any one of claims 1 to 3, wherein the oil-based ballpoint pen ink composition contains a phosphate ester-based surfactant. The oil-based ballpoint pen according to any one of claims 1 to 4, wherein the oil-based ballpoint pen refill is disposed in a shaft cylinder. The oil-based ballpoint pen refill is a retractable oil-based ballpoint pen that 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. The oil-based ballpoint pen of any one of thru | or 5.

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