JP5436202B2 - Oil-based ballpoint pen refill - Google Patents

Description

  The present invention relates to a ballpoint pen refill, and more particularly to a ballpoint pen refill comprising a ballpoint pen tip having a coil spring disposed at the rear end of a ball.

  A coil spring is disposed at the rear end of the ball, and the ball is brought into intimate contact with the inner wall surface of the tip of the tip by the pressing force of the coil spring, and a gap is formed between the ball and the inner wall of the tip of the tip by writing pressure during writing. A ballpoint pen tip equipped with a valve mechanism for forming a ballpoint is well known and disclosed in Japanese Unexamined Patent Publication No. 2000-158869 “Ballpoint Pen Tip” and the like.

  Such a ballpoint pen tip equipped with a valve mechanism is intended to bring the ball into intimate contact with the inner wall surface of the tip of the tip, but the pressing force on the ball gives the pressing force to the center of the ball, It becomes easy to bring the ball into close contact with the inner wall surface of the tip of the chip without tilting the ball.

  By the way, in the ballpoint pen refill comprising a ballpoint pen tip having a coil spring disposed at the rear end of the ball, there is a problem that not only the ball seat but also the tip of the rod shaft portion of the coil spring is worn by the rotation of the ball by writing. there were.

  When the tip of the rod shaft portion of the coil spring is worn, there is a problem that affects the writing performance, for example, the pressing force of the ball is reduced or the wear powder causes a writing failure.

  In order to suppress such abrasion, as disclosed in JP-A-6-248217, “Ink Composition for Ballpoint Pen”, JP-A-9-151354, “Ink Composition for Oil-Based Ballpoint Pen”, etc. The use of various surfactants such as fluorine-based surfactants and silicon-based surfactants in the ink for ballpoint pens filled in the ball will increase lubricity and reduce the rotational resistance between the ball and coil spring. It is done.

"JP 2000-158869 A" "Japanese Patent Laid-Open No. 6-248217" "Japanese Patent Laid-Open No. 9-151354"

  However, when various surfactants such as Patent Documents 2 and 3 are used, the writing quality can be improved to some extent, but the effect of suppressing the wear of the ball seat and the coil spring is sufficiently satisfactory. There wasn't.

  An object of the present invention is to provide a ballpoint pen refill that has good writing quality, maintains lubricity, and is less likely to wear a ball seat and a coil spring.

In order to solve the above problems, the present invention
"1. A part of the ball protrudes from the tip end of the tip of the ink containing cylinder and is rotatably held, and pressed forward by the rod shaft portion of the coil spring. A ballpoint pen tip comprising a valve mechanism is mounted directly or via a tip holder, and an oil- based ballpoint pen refill is formed by directly filling an oil-based ballpoint pen ink in an ink containing cylinder, wherein the coil spring is An oily ballpoint pen refill comprising a bare wire of stainless steel wire and containing an acidic compound having an aromatic ring and a quaternary ammonium salt with a quaternary amine in the oily ballpoint pen ink.
2. The oil-based ballpoint pen refill according to item 1, wherein the oil-based ballpoint pen ink contains an organic amine having ethylene oxide.
3. Item 3. The oil-based ballpoint pen refill according to Item 1 or 2, wherein the acidic compound having an aromatic ring has a molecular weight of 200 or more.
4). Content of the acidic compound which has the said aromatic ring is 0.1-20.0 mass%, The ball-point pen refill of any one of Claim 1 thru | or 3 characterized by the above-mentioned.
5. Item 5. The oil-based ballpoint pen refill according to any one of Items 1 to 4 , wherein the acidic compound is alkylbenzene sulfonic acid.
6). Oily ballpoint refill according to any of paragraphs 1 to paragraph 5, wherein the pH of the oil-based ballpoint pen ink is 4 to 10.
7). The oily 20 ° C. ballpoint pen ink, the ink viscosity at a shear rate of 500 sec ^-1 is oily ballpoint refill according to any of paragraphs 1 to paragraph 6, characterized in that a 10~5000mPa · s. Is.

  The present invention can provide a ballpoint pen refill that has good writing quality, maintains lubricity, and is less likely to wear the ball seat and the coil spring.

It is a longitudinal cross-sectional view of the ball-point pen refill in this invention. FIG. 2 is an enlarged cross-sectional view of a main part, partly omitted in FIG. 1.

  A feature of the present invention is that, in a ballpoint pen refill comprising a ballpoint pen tip having a coil spring disposed at the rear end of the ball, a bare wire of stainless steel wire is used as the coil spring, and an aromatic ring is added to the ballpoint pen ink. It is to contain an acidic compound.

  In consideration of suppression of wear, it is preferable to use a surface-treated wire as the coil spring. However, new problems such as the corrosion resistance of the surface-treated material and the relationship with the ballpoint pen ink occur. Therefore, it is most preferable to use a bare wire of stainless steel wire as the coil spring. The stainless steel wire is not particularly limited, such as SUS304, and may be any bare wire that has not been subjected to surface treatment when it is placed in the ballpoint pen tip.

  However, since the wear resistance of the bare stainless steel wire is lowered, it is important to improve the lubricity of the ballpoint pen ink and reduce the wear. Therefore, in the present invention, the ballpoint pen ink contains an acidic compound having an aromatic ring.

This is presumed to suppress wear of the straight rod portion of the coil spring contacting the ball by forming a lubricating film that is easily adsorbed to the metal. Since a bare stainless steel wire is used for the coil spring, it is important to use an acidic compound as the compound having an aromatic ring. This is because the acidic compound has an effect of protecting the oxide film formed on the surface of the stainless steel material, and can improve stability over time such as corrosion resistance of the ballpoint pen tip.

  Thus, by improving the lubricity between the ball, the chip body, and the coil spring, not only the wear is suppressed, but also a smooth writing feeling can be obtained, and the effect of improving the writing quality can be achieved.

  The acidic compound having an aromatic ring used in the present invention is an acidic compound having an aromatic ring such as a benzene ring, a naphthalene ring or an anthracene ring. In addition, the acidic compound having an aromatic ring is most preferably one having a molecular weight of 200 or more because it has a larger number of aromatic rings such as a benzene ring because the lubricity is more easily improved.

Specific examples of the acidic compound having an aromatic ring include alkylbenzene sulfonic acid, naphthalene sulfonic acid, and naphthalene sulfonic acid.
-Formaldehyde condensate, alkyl diphenyl ether disulfonic acid, polyoxyethylene alkyl phenyl ether phosphoric acid and the like. Further, if the compound having an aromatic ring contains a functional group having a sulfur atom (S, SO, SO ₂ , SO _3, etc.), a strong lubricating layer is formed between the ball and the ball seat, so that the lubricity is improved. In view of this, alkylbenzene (RC ₆ H ₄ —SO ₃ ^— , R; alkyl group) is particularly preferable, and examples include dodecylbenzenesulfonic acid and dodecyldiphenyloxidesulfonic acid.

  Further, if the content of the acidic compound having an aromatic ring is less than 0.1% by mass relative to the total amount of the ink composition, the desired lubricity may not be obtained, and if it exceeds 20.0% by mass. Since the ink aging may become unstable, 0.1 to 20.0% by mass is preferable with respect to the total amount of the ink composition. More preferably, it is 0.5-10.0 mass% with respect to the ink composition whole quantity, Most preferably, it is 2.0-8.0 mass%.

  Some of these acidic compounds having an aromatic ring have water-soluble properties and are difficult to dissolve in oil-based ballpoint pen inks, leaving concerns over the ink aging stability. Therefore, it is preferable to use a salt-formation product obtained by neutralizing an acidic compound having an aromatic ring with a basic compound. The salt formation obtained in this way has a strong ionic bond strength and significantly improves long-term ink aging stability.

  Examples of basic compounds include primary amines, secondary amines, tertiary amines, and quaternary amines, but a more stable salt product obtained by sufficiently neutralizing an acidic compound has a 4 It is a quaternary ammonium salt.

  A quaternary amine having an aromatic ring includes a benzoxonium compound (Benzoxonium), an alkyldimethylbenzylammonium compound, a tetradecyldimethylbenzylammonium compound, a hexadecyldimethylbenzylammonium compound, an octadecyldimethylbenzylammonium compound, an octadecyldimethylbenzylammonium compound, Examples of the cocoalkyldimethylbenzyl and ammonium compounds include dodecyl diethylbenzylammonium compounds, and benzoxonium compounds (Benzoxonium) are most preferable in consideration of writing quality and stability over time. You may use these individually or in mixture of 2 or more types.

Further, when an organic amine having ethylene oxide (CH ₂ CH ₂ O) is used in combination with the salt structure, a lubricating effect is more easily obtained. Therefore, it is preferable to use oxyethylene alkylamine or polyoxyethylene alkylamine having ethylene oxide (CH ₂ CH ₂ O) as the organic amine. You may use these individually or in mixture of 2 or more types.

  By the way, in order to contain the acidic compound which has an aromatic ring in the ink for ball-point pens, and to maintain ink aging stability and the corrosion resistance of a coil spring, pH 4.0-10.0 are preferable and it is set to pH 5.0-9.0. Most preferred. If the pH value is 3.9 or less, the metal ions in the chip body are likely to elute, so that metal salt precipitates are likely to be generated. If the pH value is 10.1 or more, a good color tone of the colorant, Since dissolution or dispersion stability can no longer be obtained, by setting the pH value in the neutral range of 4.0 to 10.0, the ink aging stability is improved and the corrosion resistance of the coil spring is affected. Can be reduced.

  Furthermore, in consideration of the stability of the salt-forming body, when the pH value is 3.9 or less in a strongly acidic region and the pH value is 10.1 or more in a strong alkali region, the ionic bond of the salt-forming body is easily separated. For this reason, an intermediate region (weakly acidic, neutral, weakly alkaline) having a pH of 4.0 to 10.0 is most preferable because the stability over time is good. Furthermore, when considering the stability over time, the pH value is preferably 5.0 to 9.0.

  In the present invention, when the pH value is less than 4.0, a strongly acidic region, when the pH value exceeds 10.0, a strongly alkaline region, pH 4.0 or more, less than 6.0 is a weakly acidic region, 6.0 or more, 8.0 or less is defined as a neutral region, and more than 8.0 is defined as 10.0 or less as a weak alkaline region.

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

  If the content of the acidic compound having an aromatic ring is less than 0.1% by mass relative to the total amount of the ink composition, the desired lubricity may not be obtained. If it exceeds 20.0% by mass, Is likely to be unstable, so 0.1 to 20.0% by mass is preferable with respect to the total amount of the ink composition. More preferably, it is 0.5-10.0 mass% with respect to the ink composition whole quantity, Most preferably, it is 2.0-8.0 mass%.

The ink viscosity of the ink composition for the ballpoint pen of the present invention is not particularly limited. However, when the ink viscosity at 20 ° C. and a shear rate of 500 sec ⁻¹ is less than 10 mPa · s, bleeding and ink sag are caused in the handwriting. Since the influence is likely to occur, and when the ink viscosity at 20 ° C. and the shear rate of 500 sec ⁻¹ exceeds 5000 mPa · s, the ball rotation resistance at the time of writing tends to increase and the writing taste tends to be heavy. Therefore, the ink viscosity at 20 ° C. and a shear rate of 500 sec ⁻¹ is preferably 10 to 5000 mPa · s. More preferably, it is 50-3,000 mPa * s, Most preferably, it is 100-1500 mPa * s which has the remarkable effect which suppresses abrasion of a ball seat and a coil spring.

  As for the colorant used in the present invention, there are dyes and pigments. As for the dyes, there are oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, direct dyes, and various salt-forming dyes. It can be adopted. Examples of the pigment include inorganic, organic and processed pigments. These dyes and pigments can be used in combination of two or more. In particular, it is preferable to use a dye for the pigment because there is a possibility that the writing quality is deteriorated due to rotation inhibition between the ball and the chip body.

For oil-based dyes, specifically, Bali First Black 1802, Black 1805, Black 1701, Blue 1601, Blue 1621, Red 1320, Red 1360, Yellow 1101, Yellow 1151, Nigrosine Base EXBP, Nigrosine Base EX, BASE OF BASIC DYES ROB-B, RO6G-B, VPB-B, VB-B, MVB-3, Eisenspiron Black GMH-Special, Violet C-RH, Blue GNH, Blue C-RH, Red C-GH, Red C-BH, Yellow C-GNH, Yellow C-2GH, S. P. T. T. et al. Blue 111, Blue GLSH-special, Red 533, Orange 6, S. B. N. Violet 510, S.I. B. N. Yellow 510, Yellow 530, S.I. R. C-BH etc. are mentioned.
Specific examples of water-based dyes include Direct Black 17, 19, 22, 154, 195, Acid Black 1, 2, 24, Direct Yellow 4, 26, Direct Red 1, 23, 31, Direct Blue 1, 41, 71, 119, Direct Orange 6, etc., Acid Black 1, 2, 24, 26, Acid Orange 56, Acid Yellow 3, 17, 42, 61 Acid Red 8, 9, 9, 51, Acid Blue 1, 7, 62, 90, Acid Green 3, 9, 16, Acid Violet 15, 17, C.I. I. Basic erotic-1, 2 and 21, C.I. I. Basic Orange 2, 14 and C.I. I. Basic Red 1, 2 and 9, C.I. I. Basic Violet 1, 3, 10, and C.I. I. Basic Bull-3, 7 and 26, Basic Green 4, C.I. I. Basic Brown 12, C.I. I. Examples include Basic Black 2, Methyl Violet, Victoria Blue FB, Malachite Green, and Rhodamine series.

  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 quinophthalone Selenium, triphenylmethane, perinone, perylene, goxazine, metallic pigment, pearl pigment, fluorescent pigment, phosphorescent pigment, and the like. These dyes and pigments may be used alone or in combination of two or more. As for content of a coloring agent, 1.0-50.0 mass% is preferable with respect to the ink composition whole quantity.

  Examples of the 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-propano , Isopropanol, isobutanol, t-butanol, propargyl alcohol, allyl alcohol, 3-methyl-1-butyn-3-ol, alcohols such as ethylene glycol monomethyl ether acetate and other higher alcohols, phenyl cellosolve, etc. The solvent generally used as ink for ball-point pens, such as cellosolve, can be illustrated, and these can be used 1 type or 2 or more types. The content of the organic solvent is preferably 5.0 to 50.0% by mass with respect to the total amount of the ink composition in consideration of solubility of the colorant, handwriting drying property, blurring, and the like.

  In addition, in order to improve the aging stability and lubricity of the colorant, as the organic amine and surfactant, phosphate ester surfactant, fluorine surfactant, silicon surfactant, acetylene Surfactant, fatty acid, etc. as pigment dispersant, polyvinyl butyral resin, polyvinyl alcohol resin, acrylic resin, etc., viscosity modifier, ketone resin, terpene resin, alkyd resin, phenoxy resin, polyvinyl acetate, polyvinyl pyrrolidone, etc. Resin, fatty acid amide, hydrogenated castor oil, cross-linked acrylic acid polymer, xanthan gum and other pseudoplasticity imparting agents, colorant stabilizer, plasticizer, chelating agent, water, rust inhibitor, antibacterial agent, etc. May be used as appropriate. These may be used alone or in combination of two or more.

  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 according to the first embodiment shown in FIGS. 1 and 2 is provided with a ballpoint pen tip 4 in which a ball 3 having a ball diameter of φ0.7 mm is rotatably held at the tip of an ink containing cylinder 2 and also contains ink. The ballpoint pen refill 1 is obtained by directly accommodating the ink 11 for the ballpoint pen and the ink follower 12 in the ink blend 1 in the cylinder 2. Further, in the ball-point pen tip 4, a coil spring 10 that always presses the ball 3 against the inner wall of the tip end edge 5a is disposed at the rear end of the ball. The coil spring used a bare wire of SUS304, and the ball pressing force was 10 g.

  The ballpoint pen tip 4 has an ink circulation hole 7 and a radially extending ink circulation groove 8 in the ball holding chamber 6, and a ball seat 9 having substantially the same shape as a writing ball provided on the bottom wall of the ball holding chamber 6. By placing the ball 3 and caulking the tip end edge 5a of the tip end portion 5 inward, a part of the ball 3 is rotatably held so as to protrude from the tip end edge 5a.

Ink for ballpoint pens, dyes, organic solvents, benzyl alcohol, ethylene glycol monophenyl ether, salt-forms of acidic compounds (alkylbenzenesulfonic acid) having an aromatic ring and basic compounds (benzoxonium compounds) (Salt Formation Formulation 1), oleic acid as the organic acid, polyvinylpyrrolidone (PVP K-90: manufactured by IPS Japan Co., Ltd.), and ketone resin (Hilac 110H: manufactured by Hitachi Chemical Co., Ltd.) as the resin Was weighed in a predetermined amount and heated to 60 ° C., and then completely dissolved using a disper stirrer to obtain an oil-based ballpoint pen ink. Specific blending amounts are as follows. AR-G2 manufactured by TA Instruments Inc. (stainless steel)
The ink viscosity was measured at a shear rate of 500 sec ⁻¹ in an environment of 20 ° C. using a 40 mm 2 ° rotor) and found to be 180 mPa · s. The ink consumption per 100 m was 46 mg / 100 m.

Ink formulation 1
Dye (Spiron Black-GMH-S) 15.0% by mass
Dye (Barry First Violet 1701) 15.0% by mass
Organic solvent (benzyl alcohol) 60.7 mass%
Salt-formed body (prepared in Formulation Example 1) 5.0% by mass
Organic acid (oleic acid) 1.0% by mass
Resin (Polyvinylpyrrolidone) 0.3% by mass
Resin (ketone resin) 2.0% by mass

Salt formation example 1
First, 100 g of water and 30 g of alkylbenzene sulfonate were weighed and heated in a beaker and dissolved using a disper stirrer. Then, 19.5 g of a benzoxonium compound was weighed, stirred, and filtered using a filter paper. To obtain a salt structure (molecular weight: 600 to 700).

Formulation Examples 2-5
As shown in Table 1, salt-making bodies of Formulation Examples 2 to 5 were prepared in the same manner as Formulation Example 1, except that each component was changed.

Examples 2-5
As shown in Table 2, oil-based ballpoint pen ink compositions of Examples 2 to 4 were obtained in the same procedure as Example 1 except that each component was changed.

  As shown in Table 2, the water-based ballpoint pen ink composition of Example 5 was changed to each component. First, water, a water-soluble organic solvent, a lubricant, a pH adjuster, a humectant, a fungicide, and a rust inhibitor A water-based base ink is prepared by heating and stirring the agent with a magnetic hot stirrer.

Then, while heating the base ink prepared above, the shear thinning agent was added and mixed and stirred thoroughly using a homogenizer stirrer until uniform, and then filtered using filter paper. 5 aqueous ballpoint pen ink compositions were obtained.

Comparative Examples 1-4
As shown in Table 3, blending was performed in the same procedure as in Example 1 except that each component was changed, and ink compositions for oil-based ballpoint pens of Comparative Examples 1 to 3 were obtained. Table 3 shows the measurement and evaluation results. As shown in Table 3, the water-based ballpoint pen ink composition of Comparative Example 4 was mixed in the same procedure as in Example 5 by changing each component, and the water-based ballpoint pen ink composition of Comparative Example 4 was obtained. It was.

Test and Evaluation Ink blends 1 to 5 and Examples 1 to 5 and Comparative Examples 1 to 4 were filled with the ballpoint pen refill of Example 1 and the following using writing paper JIS P3201 as writing test paper. Were tested and evaluated.
Test and Evaluation The oil-based ballpoint pen ink composition, the water-based ballpoint pen ink composition, and the grease-like ink follower prepared in Examples 1 to 5 and Comparative Examples 1 to 4 were filled in a ballpoint refill, An aqueous ballpoint pen was made. The following tests and evaluations were performed using a writing paper JIS P3201 as a writing test paper. In addition, since the chip specifications differ between the oil-based ballpoint pen and the water-based ballpoint pen, the test items of the wear resistance test were separately performed for the oil-based ballpoint pen and the water-based ballpoint pen.

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

Abrasion resistance test 1 (for oil-based ballpoint pen): The wear of the ball seat after the writing test was measured with a running test machine having a load of 200 gf, a writing angle of 70 °, and 4 m / min.
Ball seat wear less than 10μm ・ ・ ・ ◎
The wear of the ball seat is 10 μm to 20 μm, but writing is possible.
Wearing the ball seat is bad and results in poor writing ・ ・ ・ ×
Abrasion resistance test 1 (for water-based ballpoint pen): Wear of the ball seat after the writing test was measured with a running test machine with a load of 100 gf, a writing angle of 70 °, and 4 m / min.
Ball seat wear is less than 10μm and can be written.
Wear of the ball seat is 10 to 40 μm and can be written.
The ball seat wear exceeds 40 μm, and writing becomes impossible.

Abrasion resistance test 2: (For oil-based ballpoint pen) The wear of the coil spring after the writing test was observed with a microscope using a traveling tester with a load of 200 gf, a writing angle of 70 °, and 4 m / min.
Coil spring wear less than 0.1mm
Coil spring wear of 0.3 mm to 0.5 mm
Coil spring wear exceeds 0.5 mm ・ ・ ・ ×
Abrasion resistance test 2: (for water-based ballpoint pen) The wear of the coil spring after the writing test was observed with a microscope using a traveling tester with a load of 100 gf, a writing angle of 70 °, and 4 m / min.
Coil spring wear less than 0.1mm
Coil spring wear of 0.3 mm to 0.5 mm
Coil spring wear exceeds 0.5 mm ・ ・ ・ ×

  In Examples 1 to 5, good performance was obtained in both writing quality and wear resistance test.

  In Comparative Examples 1 to 4, since a compound having no aromatic ring was used, the writing was heavy, and in the abrasion resistance test, all the ball seats were severely worn, and writing was poor or impossible to write.

   In addition, the ball-point pen refill of this invention can be used as an oil-based ball-point pen refill or a water-based ball-point refill.

  For ink consumption, a spiral writing test was conducted using five test samples at a writing speed of 4 m / min on a writing paper JIS P3201 writing paper at a writing angle of 70 ° and a writing load of 200 g. When the average value of ink consumption per 100 m is defined as ink consumption per 100 m, the ink consumption per 100 m is less than 30 mg when used as an oil-based ballpoint pen refill. Therefore, it is difficult to obtain a dark handwriting, and if it exceeds 70 mg, the ink consumption is excessive, and the handwriting drying property may be adversely affected. Therefore, the ink consumption is preferably 30 to 70 mg / 100 m, and more preferably 40 to 60 mg / 100 m. In addition, when used as a water-based ballpoint pen refill, the ink consumption per 100 m is less than 50 mg, so that the ink consumption is small. Therefore, there is a possibility that bleeding may occur in the handwriting and affect the handwriting dryness. Therefore, it is preferable that the ink consumption is 50 to 300 mg / 100 m. More preferably, it is 80-250 mg / 100m.

  The ballpoint pen refill of the present invention can be widely used as a ballpoint pen, such as a cap type and a knock type, which have good writing quality and can suppress wear of the ball seat.

DESCRIPTION OF SYMBOLS 1 Ball-point refill 2 Ink accommodating cylinder 3 Ball 4 Ball-point pen tip 5 Tip front-end | tip part 5a Tip front-end edge 6 Ball holding chamber 7 Ink distribution hole 8 Radial groove 9 Ball seat 10 Coil spring

Claims (7)

A part of the ball protrudes from the tip end of the tip of the ink containing cylinder and is held rotatably, pressed forward by the bar shaft portion of the coil spring, and a valve is formed on the inner wall of the ball and tip tip. A ballpoint pen tip comprising a mechanism is mounted directly or via a tip holder, and an oil- based ballpoint pen refill in which ink for ballpoint pen is directly packed in an ink containing cylinder, wherein the coil spring is made of stainless steel An oil-based ballpoint pen refill comprising an acidic compound having an aromatic ring and a quaternary ammonium salt with a quaternary amine in the oil-based ballpoint pen ink. The oil-based ballpoint pen refill according to claim 1, wherein the oil-based ballpoint pen ink contains an organic amine having ethylene oxide. 3. The oil-based ballpoint pen refill according to claim 1, wherein the acidic compound having an aromatic ring has a molecular weight of 200 or more. Content of the acidic compound which has the said aromatic ring is 0.1-20.0 mass%, The ball-point pen refill of any one of Claim 1 thru | or 3 characterized by the above-mentioned. The oil-based ballpoint pen refill according to any one of claims 1 to 4 , wherein the acidic compound is an alkylbenzenesulfonic acid. Oily ballpoint refill according to any one of claims 1 to 5 pH of the oil-based ballpoint pen ink is characterized in that 4 to 10. The oily 20 ° C. ballpoint pen ink, the ink viscosity at a shear rate of 500 sec ^-1 is oily ballpoint refill according to any one of claims 1 to 6, characterized in that a 10~5000mPa · s.

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