JP6691356B2 - Oil-based ballpoint pen refill and oil-based ballpoint pen using the refill - Google Patents

Description

The present invention relates to an ink composition for an oil-based ballpoint pen, and more specifically to an ink composition for an oil-based ballpoint pen which has good lubricity and handwriting even under high pressure writing.

  2. Description of the Related Art Conventionally, a ballpoint pen is different from other types of writing instruments, and has a tip made of a metal tip made of stainless steel or the like, and a transfer ball made of metal such as super steel held in a ball receiving seat of the metal tip. Although the tip was attached to the ink containing cylinder, the ball was worn during writing due to the rotation of the ball, causing line jumps and scratches on the handwriting. Further, recently, when writing on a copy sheet, writing pressure is higher than usual (writing with high writing pressure), so that it is necessary to improve lubricity and improve writing performance with high writing pressure.

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

  As an oil-based ink composition for an oil-based ballpoint pen using such a lubricant, a composition using an alkyl β-D-glucoside is disclosed in JP-A-5-331403, "Oil-based ballpoint pen ink", having an average molecular weight of 200 to 4,000,000. As one using a certain polyethylene glycol, JP-A No. 7-196971 "Ink composition for oil-based ballpoint pen", one using N-acyl amino acid, N-acyl methyl tauric acid, N-acyl methyl alanine, It is disclosed in Japanese Patent Application Laid-Open No. 2007-176995, "Ink for oil-based ballpoint pens" and the like.

"JP-A-5-331403" "Japanese Patent Application Laid-Open No. 7-196971" "Japanese Patent Laid-Open No. 2007-176995"

  However, when various lubricants such as those of Patent Documents 1 to 3 were used, the lubricity could be improved to some extent and abrasion of the ball seat could be suppressed, but when writing with a higher writing pressure than usual (high With writing pressure writing), the lubricity was not satisfactory, and lines were skipped in the handwriting, and scratches and the like occurred, which was not sufficient.

  An object of the present invention is to provide an ink composition for oil-based ballpoint pens, which maintains lubricity even with high pressure writing (500 g) and has good handwriting.

  In the present invention, an oil-based ink composition for a ballpoint pen comprises a colorant, an organic solvent, a branched chain fatty acid and / or a branched chain aliphatic alcohol, and the branched chain fatty acid and / or aliphatic alcohol. It has 14 to 22 carbon atoms, and is an ink composition for oil-based ballpoint pens.

  A ballpoint pen according to the present invention is characterized by containing the above oil-based ink composition for a ballpoint pen.

  The present invention provides an oil-based ink composition for an oil-based ballpoint pen, which retains the lubricity of the ball even at high writing pressure writing (500 g), suppresses the abrasion of the ball seat, has no line scatter on the handwriting, and is free from scratches and having good handwriting. I was able to.

  The first feature of the present invention is to provide an oil-based ink composition for an oil-based ball-point pen, which contains a branched chain fatty acid having 14 to 22 carbon atoms and / or an aliphatic alcohol, and an ink composition for an oil-based ball-point pen. This is the oil-based ballpoint pen used.

  The branched chain fatty acid having 14 to 22 carbon atoms and / or the branched chain aliphatic alcohol can be dissolved and stabilized in the oil-based ink within the above numerical range to form an adsorption film. Therefore, not only the lubricity of normal writing (100-200g) but also the lubricity of high writing pressure (500g) is improved, the lubricity of the ball is maintained, the abrasion of the ball seat is suppressed, and the line jumps to the handwriting. It is possible to obtain good handwriting without blurring.

  Specific examples of the branched-chain fatty acid having 14 to 22 carbon atoms and / or the branched-chain aliphatic alcohol include isoarachidic acid, isopalmitic acid, isostearic acid, isomyristic acid, and isoaralkyl alcohol. , Isopalmityl alcohol, isostearyl alcohol, isomyristyl alcohol and the like. Specific examples thereof include FINEOXOCOL 1600, 180, 180N, 180T, 2000, isopalmitic acid, isostearic acid, isostearic acid N, isostearic acid T, and isoarachidic acid (manufactured by Nissan Chemical Industries, Ltd.). .

  Among the branched chain fatty acids having 14 to 22 carbon atoms and / or the branched chain aliphatic alcohols, those having 16 to 20 carbon atoms are preferably used. If the branched chain has 16 or more carbon atoms, the branched chain fatty acid adsorbed on the metal surface of the ball or the body of the ballpoint pen tip and / or the alkyl chain of the branched chain aliphatic alcohol is bulky. By having a high structure, since the area covering the metal surface increases, the metal contact is relaxed, the lubricity is easily improved, and the lubricity in high-writing pressure writing (500 g) is easily improved. Further, when the carbon chain has a branched chain and has more than 20 carbon atoms, the molecules are likely to be sterically repulsed due to the structure which is too bulky, and the adsorption to the metal surface is hindered, and the lubricity is likely to be impaired. Furthermore, considering more lubricity, 1 out of isoarachidic acid (20 carbon atoms), isopalmitic acid (16 carbon atoms), isoaralkyl alcohol (20 carbon atoms), and isopalmityl alcohol (16 carbon atoms). It is preferable to select one or more species. In particular, the fatty acids having the branched chain, such as isoarachidic acid (20 carbon atoms) and isopalmitic acid (16 carbon atoms), have a well-balanced and bulky structure that easily improves lubricity. By having it, the lubricity in writing with a high writing pressure (500 g) is likely to be improved, which is preferable, and from further consideration, isoarachidic acid (having 20 carbon atoms) is most preferable.

  Further, among the branched-chain fatty acids having 14 to 22 carbon atoms and / or the branched-chain aliphatic alcohols, the writing performance at the time of dry-up can be improved. To improve the writing performance during dry-up, the above-mentioned isoarachidic acid (20 carbon atoms), isopalmitic acid (16 carbon atoms), isoarachiyl alcohol (20 carbon atoms), isopalmityl alcohol (16 carbon atoms) is used. ) Is included, and having an isoarachidyl group or an isopalmityl group has the effect of softening the ink film formed at the tip of the ballpoint pen tip, and can improve the writing performance during dry-up. Of these, isoarachidic acid (having 20 carbon atoms) and isoaralkyl alcohol (having 20 carbon atoms) having an isoarachidyl group are preferably used, considering the writing performance at the time of dry-up, by making the ink coating softer. Considering this, isoarachidic acid (having 20 carbon atoms) is preferable. In particular, in retractable writing instruments such as knock-type writing instruments and rotary feeding type writing instruments, unlike the cap-type writing instruments, the ballpoint pen tip is always exposed to the outside, so it is easy to affect the writing performance during dry-up, preferable.

  Further, when the content of the branched chain fatty acid having 14 to 22 carbon atoms and / or the branched chain aliphatic alcohol is less than 0.1% by mass based on the total amount of the ink composition, a high writing pressure is obtained. There is a possibility that the lubricating effect in writing (500 g) and the writing effect at the time of dry-up may not be obtained, and if it exceeds 10.0% by mass, the ink stability over time may be affected. 0.1 to 10.0% by mass is preferable, and considering the lubricity in writing with higher writing pressure (500 g), 0.5 to 10.0% by mass is preferable, and further ink stability over time should be taken into consideration. For example, 1.0 to 5.0 mass% is the most preferable.

  An aromatic alcohol solvent is preferably used as the organic solvent used in the present invention. This is because the fatty acid having a branched chain having 14 to 22 carbon atoms and / or the aliphatic alcohol having a branched chain is stably dissolved, ink stability over time is easily obtained, and the aromatic ring is further contained. Therefore, lubricity is easily improved, which is preferable.

  In addition, it is preferable to use a glycol ether solvent other than the aromatic alcohol solvent because it easily absorbs moisture, softens the formed film, and improves the writing performance during dry-up. Therefore, in the present invention, it is preferable to use the glycol ether solvent and the aromatic alcohol solvent in combination. In particular, in consideration of improving lubricity, it is preferable to use an aromatic glycol ether solvent and an aromatic alcohol solvent in combination, because it is preferable to have an aromatic ring.

  Specific examples of the aromatic alcohol solvent as the organic solvent used in the present invention include benzyl alcohol, phenylethyl alcohol, methylphenylcarbinol, and phthalyl alcohol. Further, specific examples of the glycol ether solvent 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, and diethylene glycol dimethyl ether. , 3-methoxybutanol, 3-methoxy-3-methylbutanol, and the like. 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 mass% with respect to the total amount of the ink composition in consideration of improving the solubility, the handwriting drying property, the bleeding and the like. Further, the content of the glycol ether solvent is preferably 10.0 to 50.0% by mass, and more preferably 10.0 to 30.0% by mass with respect to the total organic solvent in consideration of the drying property at the tip of the chip. %.

  The colorant used in the present invention is not particularly limited, such as dyes and pigments, and can be appropriately selected and used. The dyes include oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, and various salt-forming dyes thereof, such as salt-forming dyes of acid dyes and basic dyes, organic acids and basic dyes. Examples thereof include salt-forming dyes with and salt-forming dyes with acid dyes and organic amines. These dyes may be used alone or in combination of two or more.

  Examples of the pigment include inorganic, organic and processed pigments. Specifically, carbon black, aniline black, ultramarine blue, yellow lead, titanium oxide, iron oxide, phthalocyanine-based, azo-based, quinacridone-based, DPP-based Examples include quinophthalone-based, slene-based, triphenylmethane-based, perinone-based, perylene-based, gioxazine-based, metallic pigments, pearl pigments, fluorescent pigments, and phosphorescent pigments. Considering lubricity, it is preferable to contain a pigment. This is because when pigment is used, the pigment particles get into the gap between the ball and the chip body, making it easier to work like a bearing, and suppressing metal contact to improve lubricity and wear of the ball seat. This is because it is easy to obtain the effect of suppressing In particular, in consideration of improvement of lubricity, it is preferable to use carbon black. Further, the average particle size is preferably 300 nm or less in consideration of the gap relationship inside the ballpoint pen tip. More preferably, it is 150 nm or less. Here, the average particle size is a volume-based cumulative 50% average particle size (D50). The average particle diameter can be measured by, for example, a laser diffraction method or a Microtrac particle size distribution measuring device (manufactured by Nikkiso Co., Ltd.). These pigments may be used alone or in combination of two or more.

  In the present invention, a resin may be used as the viscosity modifier, specifically, polyvinyl butyral resin, polyacetal resin, polyvinyl alcohol resin, cellulose resin, polyvinylpyrrolidone resin, ketone resin, terpene resin, alkyd resin, phenoxy resin, Examples thereof include polyvinyl acetate resin. Among them, the ketone resin has good compatibility with the branched chain fatty acid having 14 to 22 carbon atoms and / or the branched chain aliphatic alcohol, and has the characteristics of the present invention such as lubricity and dry-up property. This is preferable because it is easy to improve the lubricity in writing with a high writing pressure (500 g) without inhibiting the writing performance, and it is easy to suppress the abrasion of the ball seat.

  Further, the ketone resin preferably has a hydroxyl value of 250 (mgKOH / g) or more, which is more than 250 (mgKOH / g) because it is easily dissolved in an alcohol solvent or a glycol solvent. Considering solubility, the hydroxyl value of the ketone resin is preferably 300 (mgKOH / g) or more.

  If the content of the resin is less than 3.0 mass% with respect to the total amount of the ink composition, the ink dripping performance tends to be poor, and if it exceeds 40.0 mass%, the lubricity, the writing performance during dry-up, the ink Among them, the solubility is likely to be poor, so 3.0 to 40.0 mass% is preferable with respect to the total amount of the ink composition. Further, considering the lubricity, the writing performance, and the ink dripping 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 lubricity tends to be affected. , 5.0-30.0 mass% is preferable.

  In the present invention, it is preferable to include a phosphate ester surfactant. This is because, in the phosphate ester type surfactant, the phosphate group easily acts on the ball of the ballpoint pen tip or the metal surface of the tip body, forms a lubricating film, and more easily suppresses wear of the ball seat of the ballpoint pen tip. This is because. Particularly, in the present invention, not only the adsorption film formed by the branched chain fatty acid having 14 to 22 carbon atoms and / or the branched chain aliphatic alcohol, but also formed by the phosphate ester-based surfactant. By both actions of the lubricating film, the lubricity in writing with high writing pressure (500 g) is easily improved, and abrasion of the ball seat is easily suppressed, which is preferable.

  Examples of the phosphoric acid ester-based surfactants include polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether phosphoric acid monoester, polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether phosphoric acid diester, and polyoxyethylene alkyl ether. Or, a phosphoric acid triester, an alkyl phosphoric acid ester, an alkyl ether phosphoric acid ester of polyoxyethylene alkylaryl ether, a derivative thereof or the like can be mentioned. System, lauryl alcohol system, tridecyl alcohol system, octylphenol system and the like. You may use these phosphate ester type surfactants individually or in mixture of 2 or more types. Among them, in consideration of lubricity, the number of carbon atoms contained in the alkyl group is preferably 8 to 18, and further in consideration of ink stability over time, the number of carbon atoms is more preferably 10 to 18. Most preferably, the carbon number is 12 to 18 because it is easy to suppress abrasion of the ball seat in high pressure writing (500 g). If the number of carbon atoms in the alkyl group is excessively low, the lubricity tends to be insufficient, and if the number of carbon atoms is excessively high, the ink stability over time tends to be affected.

Furthermore, the phosphoric acid ester-based surfactant tends to soften the ink film formed at the tip of the ballpoint pen tip, which may improve the writing performance during dry-up. Especially, in retractable writing instruments such as knock-type writing instruments and rotary feeding type writing instruments, unlike the cap-type writing instruments, the ballpoint pen tip is always exposed to the outside, so the writing performance during dry-up is likely to be affected. It is more preferable to use a phosphate ester type surfactant.
Therefore, in order to suppress the abrasion of the ball seat in high pressure writing (500 g) and further improve the writing performance during dry-up, the fatty acid having a branched chain having 14 to 22 carbon atoms and / or a branched chain is used. It is preferable to use a chain-containing aliphatic alcohol in combination with a phosphate ester-based surfactant because it is more effective.

  Further, the content of the phosphoric acid ester-based surfactant is more preferably 0.1 to 5.0 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 tends to become unstable over time. Considering this tendency, 0.3 to 3.0% by mass is preferable with respect to the total amount of the ink composition, and more consideration, 0.5 to 3.0% by mass is most preferable.

  Specific examples of the phosphoric acid ester-based surfactant include PLYSURF A217E (alkyl group: C14) and A219B (alkyl group: C12) from PLYSURF series (Daiichi Kogyo Seiyaku Co., Ltd.). ), A215C (alkyl group: C12), A208B (alkyl group: C12), A208N (alkyl group: mixture of C12 and C13), phosphanol series (Toho Chemical Industry Co., Ltd.) Manufactured), phosphanol RB410 (alkyl group: carbon number 18), RS-610 (alkyl group: carbon number 12 to 15), RS-710 (alkyl group: carbon number 13) and the like. . You may use these surfactants individually or in mixture of 2 or more types.

The ink viscosity of the ink composition for an oil-based ballpoint pen of the present invention is not particularly limited, but when the ink viscosity at 20 ° C. and a shear rate of 500 sec ⁻¹ is less than 10 mPa · s, bleeding or ink dripping on the handwriting occurs. Since the effect is likely to occur, and when the ink viscosity at 20 ° C. and a shear rate of 500 sec ⁻¹ exceeds 30,000 mPa · s, the ball rotation resistance during writing becomes large, and the lubricity is likely to be affected. Therefore, the ink viscosity at 20 ° C. and a shear rate of 500 sec ⁻¹ is preferably 10 to 30000 mPa · s. Considering the improvement of lubricity, 10 to 20000 mPa · s is preferable, and 500 to 15000 mPa · s is most preferable.

  Furthermore, it is preferable to use an organic amine in the ink composition for an oil-based ballpoint pen of the present invention for the purpose of neutralizing the branched chain fatty acid and / or the branched chain aliphatic alcohol, the surfactant and the like. Examples of the organic amine include oxyethylene alkylamine, polyoxyethylene alkylamine and the like, and alkylamines such as laurylamine, stearylamine, distearylamine, dimethyllaurylamine, dimethylstearylamine and dimethyloctylamine. You may use these individually or in mixture of 2 or more types.

  Regarding the organic amine used in the present invention, the total amine value of the organic amine is preferably in the range of 70 to 300 (mgKOH / g). When it exceeds 300 (mgKOH / g), the reactivity is so strong that it easily reacts with other components in the ink, and the ink stability over time tends to be poor. If the total amine value is less than 70 (mgKOH / g), the neutralization with respect to the surfactant becomes insufficient, and the ink stability over time tends to be affected, and further, the metal surface of the ball, chip body, etc. Adhesion to water is likely to be poor, and it is difficult to obtain the desired lubrication performance. More preferably, the range of 100 to 300 (mgKOH / g) is preferable in consideration of the above ink stability over time and lubricity, and more preferably 150 to 270 (mgKOH / g). The total amine value indicates the total amount of primary, secondary, and tertiary amines, and is expressed in mg of potassium hydroxide equivalent to hydrochloric acid required to neutralize 1 g of the sample.

  Specific examples of oxyethylene alkylamines and polyoxyethylene alkylamines include Nymeen L-201 (total amine value: 232-246, secondary amine) and L-202 (total amine value: 192-212, 3). Secondary amine), the same L-207 (total amine value: 107 to 119, tertiary amine), the same S-202 (total amine value: 152 to 166, tertiary amine), the same S-204 (total amine value: 120) To 134, tertiary amine), S-210 (total amine value: 75 to 85, tertiary amine), DT-208 (total amine value: 146 to 180, tertiary amine) (NOF Corporation) Manufactured) and the like. Specific examples of the alkylamine include Farmin 80 (total amine value: 204 to 210, primary amine), Farmin D86 (total amine value: 110 to 119, secondary amine), Farmin DM2098 (total amine value: 254). ˜265, tertiary amine), Pharmin DM8680 (total amine value: 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 organic amine is preferably 0.1 to 10.0% by mass, and more preferably 0.5 to 5.0% by mass with respect to the total amount of the ink composition in consideration of lubricity and stability over time. Is.

  In addition, in addition, in order to improve lubricity and ink stability over time, as a surfactant, a fluorine-based surfactant, a silicone-based surfactant, a fatty acid alkanolamide, an anionic surfactant, a cationic interface. An active agent, an amphoteric surfactant, a salt-forming substance of an anionic surfactant and / or a cationic surfactant, a viscosity modifier, a fatty acid amide, a pseudoplasticizer such as hydrogenated castor oil, As the spinnability imparting agent, polyvinylpyrrolidone, a colorant stabilizer, a plasticizer, a chelating agent, water or the like may be appropriately used. These may be used alone or in combination of two or more.

  Examples of the material of the ball-pen tip include metal materials such as stainless steel, nickel silver, brass (brass), aluminum bronze, and aluminum, and resin materials such as polycarbonate, polyacetal, and ABS. In consideration of the characteristics, a nickel-white chip body is preferable, and in consideration of wear of the ball seat and stability over time, a stainless steel chip body is preferable.

  The material used for the balls is not particularly limited, but is a cemented carbide ball containing tungsten carbide as a main component, a metal ball such as stainless steel, or a ceramic such as silicon carbide, silicon nitride, alumina, silica, or zirconia. Examples include balls and ruby balls. The diameter of the ball is not particularly limited, but is generally about 0.25 mm to 2.0 mm.

The arithmetic mean roughness (Ra) of the ball surface used in the present invention is preferably 0.1 to 15 nm. This is because if the arithmetic average roughness (Ra) is less than 0.1 nm, it is difficult to deposit the ink on the surface of the ball, the handwriting is easily skipped, and scratches easily occur, and the arithmetic average roughness (Ra) exceeds 15 nm. Since the surface of the ball is too rough and the rotation resistance between the ball and the ball seat is large, the lubricity is liable to be affected. Therefore, when further considered, the thickness is preferably 3 to 13 nm, more preferably 3 to 10 nm. Is.
The surface roughness can be measured by (model name SPI3800N manufactured by Seiko Epson Corporation).

Example 1
The ink composition for an oil-based ballpoint pen of Example 1 contains a dye as a colorant, benzyl alcohol, ethylene glycol monophenyl ether as an organic solvent, isoarachidic acid as a branched chain fatty acid, and a phosphate ester-based surfactant as an lubricant, an organic compound. Oxyethylenealkylamine as the amine, ketone resin and fatty acid amide as the viscosity modifier, polyvinylpyrrolidone as the spinnability imparting agent were weighed in a predetermined amount and heated to 60 ° C., and then a Disper stirrer was used. It was completely dissolved to obtain an oil-based ink composition for a ballpoint pen. The specific compounding amount is as follows. In addition, when the ink viscosity was measured at a shear rate of 500 sec ⁻¹ under an environment of 20 ° C. using AR-G2 manufactured by TA Instruments Co., Ltd. (40 mm 2 ° rotor made of stainless steel), it was 15000 mPa · s. there were.

Coloring agent (salt forming dye) 20.0% by mass
Organic solvent (benzyl alcohol) 19.0 mass%
Organic solvent (ethylene glycol monophenyl ether) 28.5% by mass
Branched fatty acid (isoarachidic acid) 3.0% by mass
Lubricant (phosphate ester type surfactant) 1.0% by mass
Organic amine (oxyethylene alkylamine) 2.0% by mass
Viscosity modifier (ketone resin) 24.0% by mass
Viscosity modifier (fatty acid amide) 2.0% by mass
Spinnability imparting agent (polyvinylpyrrolidone resin) 0.5% by mass

Examples 2-9
As shown in the table, the ink compositions for oil-based ballpoint pens of Examples 2 to 9 were obtained in the same procedure as in Example 1 except that each component was changed.

Comparative Examples 1-6
As shown in the table, the ink compositions for oil-based ballpoint pens of Comparative Examples 1 to 6 were obtained by blending in the same procedure as in Example 1 except that each component was changed.

Testing and evaluation
The ink compositions (0.29 g) for the oil-based ballpoint pens prepared in Examples 1 to 9 and Comparative Examples 1 to 6 were placed in an ink container (polypropylene), and the ball surface had an arithmetic mean roughness (Ra) of 8 nm. An oil-based ballpoint pen was manufactured by filling a ballpoint pen refill equipped with a ballpoint pen tip (stainless steel wire) that rotatably holds a φ1.0 mm ball. The following tests and evaluations were performed using a writing paper JIS P3201 as a writing test paper.

High writing pressure writing test: Wear of the ball seat after the writing test was measured with a running tester with a load of 500 gf, a writing angle of 70 °, and 4 m / min, and the handwriting was observed.
The ball seat wear is less than 5 μm and the handwriting is good.
The ball seat wear is 5 μm or more and less than 10 μm, and the handwriting is good.
Ball seat wear is 10 μm or more and less than 20 μm, but there is line skipping or blurring in the handwriting, but there is no practical problem.
The ball seat is badly worn, and the line strokes and scratches on the handwriting are severe.

Dry-up performance test: After writing by handwriting, leave the tip of the tip for 24 hours in an environment of 20 ° C and 65% RH, and then write under the following writing conditions in a running test to evaluate the blurring of handwriting in writing. did.
<Writing conditions> Under the conditions of a writing load of 200 gf, a writing angle of 70 °, and a writing speed of 4 m / min, straight line writing was performed with a running tester, and the handwriting blur length was measured and evaluated.
Handwriting blur less than 5 mm ・ ・ ・ ◎
Handwriting blur 5 mm or more and less than 10 mm ・ ・ ・ ○
Handwriting blur 10 mm or more and less than 20 mm ... △
Handwriting Scratches 20 mm or more ・ ・ ・ ×

  In Examples 1 to 9, good performance was obtained in both the high writing pressure writing test and the dry-up performance test.

Example 1 (isoarachidic acid), Example 4 (isopalmitic acid), Example 6 (isostearic acid), Example 7 (isoaralkyl alcohol), Example 8 (isopalmityl alcohol), Example 9 (iso The length of handwriting blur in the dry-up performance test of stearyl alcohol) was as follows.
<Test results>
Example 1 (isoarachidic acid): 1.4 mm, Example 4 (isopalmitic acid): 4.8 mm, Example 6 (isostearic acid): 7.8 mm, Example 7 (isoaralkyl alcohol): 1.6 mm , Example 8 (isopalmityl alcohol): 3.2 mm, Example 9 (isostearyl alcohol): 8.8 mm.
From the above results, it was found that having an isoarachidyl group or an isopalmityl group is advantageous in terms of dry-up performance, and particularly having an isoarachidyl group is most effective.

  In Comparative Examples 1 to 6, since the fatty acid having a branched chain and / or the aliphatic alcohol having a branched chain was not contained, the ball seat was badly worn in the high writing pressure writing test, and the line stroke and scraping were bad in the handwriting. The dry-up performance test was also inferior.

When the ink viscosity at 20 ° C. and a shear rate of 500 sec ⁻¹ is set in the range of 500 to 15000 mPa · s in order to improve the lubricity as in the present invention, it is possible to prevent the ink from dripping or dry up. To improve the writing performance, the ball rotatably held at the tip of the ballpoint pen tip is pressed against the inner wall of the tip edge by a coil spring directly or through a pressing body, and the tip edge is pressed by the pressing force during writing. It is preferable to provide a valve mechanism for giving a gap to the inner wall and the ball to allow the ink to flow out, and to close the minute gap at the tip of the chip when not in use.

  INDUSTRIAL APPLICABILITY The present invention can be used as an oil-based ballpoint pen, and more specifically, can be widely used as a cap-type, knock-type water-based ballpoint pen filled with the oil-based ballpoint pen ink composition.

Claims (7)

An oil-based ballpoint pen refill in which a ballpoint pen tip rotatably holding a ball is attached to the tip of an ink container, and the ink composition for the oil-based ballpoint pen is housed in the ink container. The ink composition for use comprises a colorant, an organic solvent, a branched chain fatty acid and / or a branched chain aliphatic alcohol, a ketone resin, a phosphate ester surfactant, and an organic amine. The carbon number of the fatty acid and / or aliphatic alcohol which it has is 16-20, the hydroxyl value of the said ketone resin is 250 (mgKOH / g) or more, and the carbon contained in the alkyl group of the said phosphate ester type surfactant. The number is 12 to 18, the total amine value of the organic amine is 100 to 300 (mgKOH / g), and the arithmetic average roughness of the ball surface is (Ra) is 3 to 13 nm, and is an oil-based ballpoint pen refill. Oily ballpoint refill of claim 1, wherein the oil-based ballpoint pen ink composition, characterized in that it comprises a pigment. Fatty acids and / or aliphatic alcohols having a branched chain, claim, characterized in that isoarachic acid, isopalmitic acid, are those selected Lee SOARER kill alcohols, one or more of the iso-palmityl alcohol 1 Alternatively, the oil-based ballpoint pen refill according to item 2. The oil-based ballpoint pen refill according to any one of claims 1 to 3 , wherein the organic solvent is an aromatic alcohol or glycol ether solvent. The oil-based ballpoint pen refill according to any one of claims 1 to 4, wherein the branched-chain fatty acid and / or fatty alcohol is isoarachidic acid and / or isopalmitic acid. An oil-based ballpoint pen comprising the oil-based ballpoint pen refill according to any one of claims 1 to 5 disposed in a barrel. An oil-based ballpoint pen refill according to any one of claims 1 to 5 is slidably disposed in a barrel, and a tip end portion of the ballpoint pen tip is capable of projecting and retracting from the barrel end portion. An oil-based ballpoint pen characterized by being an oil-based ballpoint pen.