JP6010323B2 - Ballpoint pen refill - Google Patents

Description

    The present invention relates to a ballpoint pen refill, and more particularly to a ballpoint pen refill in which a ballpoint pen tip made of a stainless steel material is mounted directly or via a tip holder on the tip of an ink storage cylinder.

  Conventionally, a ballpoint pen refill in which a ballpoint pen tip made of a stainless steel material is mounted directly or via a tip holder on the tip of an ink containing cylinder is well known and disclosed in Japanese Patent Application Laid-Open No. 2001-301378, “Ballpoint Pen Tip” and the like. ing. Stainless steel is a material suitably used as a ballpoint pen tip because of its good wear resistance.

  However, even a ballpoint pen refill using a ballpoint pen tip made of stainless steel has a problem that the tip body is worn by the rotation of the ball by writing. When the tip body is worn, the amount of movement of the ball in the tip in the axial direction, so-called clearance, increases.

  As described above, when the wear of the chip body progresses due to the rotation of the ball by writing and the clearance becomes large, various problems such as ink drooping and the inside of the chip being easily dried cause deterioration of the writing performance.

  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 for the ballpoint pen ink filled into the ball would increase lubricity and reduce the rotational resistance between the ball and the chip body. It is done.

  In addition, various colorants are used in the oil-based ink composition for ballpoint pens, and those using triarylmethane basic dyes and azo yellow acid dye salt-forming dyes are disclosed in JP-A-9-165542. An attempt to make a dark handwriting is considered in the publications “Oil Black Ink” and “Oil Black Ink” of JP-A-9-71745.

"JP 2001-301378 A" "Japanese Patent Laid-Open No. 6-248217" "Japanese Patent Laid-Open No. 9-151354" "JP-A-9-165542" "Japanese Patent Laid-Open No. 9-71745"

  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 tip is not fully satisfactory. It was. Furthermore, by using a surfactant, the surfactant and the dye may react to generate precipitates, which raises a problem of concern.

  In Patent Documents 4 and 5, when a salt-forming dye of triallylmethane-based basic dye and azo-based yellow acidic dye is used as a colorant, part of the salt-forming dye collapses and precipitates over time. There were problems with the generation of things and poor writing.

Further, when an ink having an ink viscosity of 5000 mPa · s at 20 ° C. and a shear rate of 500 sec ⁻¹ is used, there is a problem that not only the above-described sag but also the ink consumption is greatly increased due to abrasion. When the ink consumption increases, new problems such as the scratch resistance of the handwriting deteriorating and soiling the paper surface occur.

  The purpose of the present invention is a ballpoint pen refill that has stable ink aging, good writing quality, maintains lubricity, wears the tip body hard, and has stable ink consumption from the start of writing to the end of ink. Is to provide.

In order to solve the above problems, the present invention
“1. The chip body has a ball holding chamber, an ink flow hole formed in the center of the bottom wall of the ball holding chamber, and a plurality of ink flow grooves extending radially from the ink flow hole, The tip of the tip is crimped inward, and a ball-point pen tip made of stainless steel with a part of the ball protruding from the tip end edge of the tip and rotatably held, either directly on the tip of the ink containing cylinder, or tip holder And using at least a dye and a pigment as a colorant in the ink containing cylinder, the dye is a salt-forming dye of an alkylbenzenesulfonic acid and a basic dye, and the pigment has an average particle size of 300 nm or less This is carbon black, and directly contains ink for oil-based ballpoint pens with an ink viscosity of 10 to 5000 mPa · s at 20 ° C. and a shear rate of 500 sec ⁻¹ . When the ink consumption amount Amg at 0 to 100 m and the ink consumption amount Bmg at 100 m before completion of the ink satisfy 0.8 ≦ A / B ≦ 1.2 , The movement amount of the ball in the axial direction is 3 to 15 μm,
The ball mechanism is provided with a valve mechanism that presses the ball against the inner wall of the tip end edge of the tip directly or via a pressing body with a coil spring, and causes the ink to flow out by providing a gap between the inner wall of the tip end edge and the ball by a pressing force at the time of writing. ballpoint refill to be characterized are.
2. The dye is one or more of a salt-forming dye of alkylbenzene sulfonic acid and xanthene basic dye, alkylbenzene sulfonic acid and triallylmethane basic dye, or alkylbenzene sulfonic acid and azomethine basic dye. 2. The ballpoint pen refill according to item 1 , wherein a salt dye is selected and contained.
3. 3. The ballpoint pen refill according to item 1 or 2 , wherein the alkylbenzene sulfonic acid is dodecyl diphenyl oxide sulfonic acid.
4). 4. The ballpoint pen refill according to any one of items 1 to 3 , wherein the carbon black is basic carbon black.
5. 5. The ballpoint pen refill according to any one of items 1 to 4, wherein the pH of the oil-based ballpoint pen ink composition is 7 to 10. 6. The ballpoint pen refill according to any one of Items 1 to 5, wherein the oil-based ballpoint pen ink composition contains an alcohol-based organic solvent.
7). A ballpoint pen refill in which the ink composition for oil-based ballpoint pens according to any one of Items 1 to 6 is directly stored in the ink storage cylinder, and is formed on a bottom wall of the ball holding chamber. Is provided with a curved contact surface having a curvature different from the curvature of the ball, and the ball is in contact with a contact portion which is a part of the contact surface, A first gap that gradually decreases from the ink circulation hole side is formed from the ink circulation hole side to the contact portion between the ball and the abutment surface, and the abutment from the front end side of the ink circulation groove. The oil-based ballpoint pen refill is characterized in that a second gap that gradually decreases from the front end side of the ink circulation groove to the contact portion is formed.
8). On the surface of the ball, the contact with the contact surface the surface of the ballpoint pen refill according to any of paragraphs 1 to paragraph 7, wherein the lubricating coating layer is provided. "

  The present invention provides a ballpoint pen refill in which the dye and carbon black are stable in ink, the writing quality is good, the tip body is hard to wear, and the ink consumption is stable from the start of writing to the end of ink. We were able to.

1 is a longitudinal sectional view showing a ballpoint pen tip of Example 1. FIG. FIG. 3 is an enlarged vertical sectional view of a principal part, partially omitted, showing the ball-point pen tip of Example 1. It is a figure which shows the ball-point pen refill using the ball-point pen tip of Example 1. FIG.

  The first feature of the present invention is that the chip body has a ball holding chamber, an ink circulation hole formed in the center of the bottom wall of the ball holding chamber, and a plurality of ink circulations extending radially from the ink circulation hole. A ballpoint pen tip made of stainless steel, which has a groove and has a tip of the tip that is caulked inward so that a part of the ball protrudes from the tip tip edge and is rotatably held, is attached to the tip of the ink containing cylinder. Mounted directly or through a chip holder, and at least a dye and a pigment as a colorant are used in the interior of the ink container, the dye is a salt-forming dye of an alkylbenzenesulfonic acid and a basic dye, and the pigment is By using an oil-based ink composition that is carbon black, it is possible to stabilize the ink aging, to improve the writing quality, and to make the chip body difficult to wear.

  The stainless steel material has better wear resistance than copper alloys such as brass, but it is important to improve the lubricity of the ballpoint pen ink and reduce the wear of the tip body. Therefore, in the present invention, it is important to use, as a colorant, a salt-forming dye of alkylbenzenesulfonic acid and a basic dye and carbon black in the oil-based ballpoint pen ink.

  Regarding salt-forming dyes of alkylbenzene sulfonic acid and basic dye used in the present invention, basic dyes such as xanthene, triallylmethane, azomethine, azo, anthraquinone and oxazine are mixed with alkylbenzene sulfonic acid. It is possible to maintain ink aging stability in various environments and for a long period of time in oil-based inks by using a salt reaction dye that has a strong ionic bond between the alkylbenzene sulfonic acid and the basic dye. .

  In addition, the salt-forming dye is not only effective as a colorant, but at the same time, by forming a lubricating film in which the salt-forming dye has a phenylsulfone group or a phenyl group that is easily adsorbed to a metal, a ball and a chip It is presumed that it has the effect of suppressing metal contact between the main bodies, improves lubricity, has good writing quality, and suppresses wear of the ball seat. Therefore, unlike the conventional case, the salt-forming dye can have both the effects of the colorant and the lubricant. Therefore, unlike the conventional case, the salt-forming dye can have both the effects of the colorant and the lubricant. Furthermore, the lubricating film formed by the salt-forming dye of the alkylbenzene sulfonic acid and the basic dye is protected by covering the oxide film on the surface of the stainless steel material, and by suppressing the deterioration of the oxide film, It is estimated that the effect of improving the temporal stability such as corrosion resistance can be obtained.

  However, since the light resistance of the handwriting is weak only by using the salt-forming dye alone, the light resistance can be improved by using carbon black together. In addition, by using carbon black, carbon black particles can enter the gap between the ball and the chip body, thereby suppressing metal contact and improving lubricity. Further, as described above, the lubricating layer is formed by the phenylsulfone group or phenyl group of the salt-forming dye, but the lubrication that further suppresses metal contact by the interaction between the lubricating layer of the salt-forming dye and the carbon black particles. By forming a film, it is possible to improve lubricity and improve writing quality. Therefore, unlike the conventional case, it is possible to have both the effect of the colorant and the lubricant, and it is necessary to use the salt-forming dye and carbon black in combination.

  The second feature of the present invention is that 0.8 ≦ A / B ≦ 1.2 when the ink consumption amount Amg at the time of 0 to 100 m and the ink consumption amount Bmg at 100 m before the end of the ink are set. .

This is because obtaining a stable writing performance from the start of writing to the end of ink is also an important issue for ballpoint pen refills. Ink viscosity oil ballpoint pen ink used in the present invention, 20 ° C., the ink viscosity at a shear rate of 500 sec ^-1 is 10~5000mPa · s and conventional oil-based ballpoint pen ink, 20 ° C., the ink viscosity at a shear rate of 500 sec ^-1 The viscosity is lower than about 10,000 to 20000 mPa · s, and a salt-forming dye of alkylbenzenesulfonic acid and a basic dye and carbon black are used in combination to further improve lubricity and improve writing quality. However, due to the low viscosity, when A / B> 1.2, the scratch resistance is deteriorated and the total writing distance is shortened. When A / B <0.80, writing performance such as handwriting density and writing taste is reduced. Therefore, 0.8 ≦ A / B ≦ 1.2 when the ink consumption Amg at the time of 0 to 100 m and the ink consumption Bmg at 100 m before the end of the ink, from the start of writing to the end of the ink, It is important to maintain the ink consumption within the above-mentioned range, and it is preferable to satisfy 0.9 ≦ A / B ≦ 1.15 considering the effect of writing performance.

  By the way, when the ink consumption Amg at the time of 0 to 100 m and the ink consumption Bmg of 100 m before the end of ink are set to 0.8 ≦ A / B ≦ 1.2, the wear of the chip body is suppressed. Is the most important factor. However, it is not possible to obtain stable writing performance from the start of writing to the end of ink simply by suppressing the wear of the chip body. As described above, the invention of the present application improves the lubricity between the ball and the chip body by using the salt-forming dye of the alkylbenzene sulfonic acid and the basic dye and the carbon black as a colorant. By controlling wear and suppressing deterioration of the oxide film, the ink flow is maintained smoothly from the start of writing to the end of ink in order to improve the stability over time in the chip body, such as the corrosion resistance of ballpoint pen tips. Thus, ink consumption and writing performance can be stabilized.

It should be noted that the ink viscosity of the oil-based ballpoint pen ink of the present invention is that the ink viscosity at 20 ° C. and the shear rate of 500 sec ⁻¹ is less than 10 mPa · s, and the dispersibility of carbon black and the influence of bleeding and ink sag are affected. If the ink viscosity at 20 ° C. and a shear rate of 500 sec ⁻¹ exceeds 5000 mPa · s, the ball rotation resistance at the time of writing tends to increase, affecting the lubricity and tending to increase the writing quality. Therefore, the ink viscosity at 20 ° C. and a shear rate of 500 sec ⁻¹ is preferably 10 to 5000 mPa · s. More preferably, considering the dispersibility and lubricity of carbon black, it is 50 to 4000 mPa · s, and most preferably 100 to 3000 mPa · s.

  Moreover, it is preferable that the movement amount of the ball-point pen tip used in the present invention in the axial direction of the ball is 3 μm to 15 μm. If it is less than 3 μm, the ink consumption tends to be small, which may cause handwriting defects such as handwriting scraping. If it exceeds 15 μm, it becomes difficult to stably supply the ink, and 0.8 ≦ A / B ≦ 1 .2 tends to be difficult to satisfy.

  In addition, among the salt-forming dyes, alkylbenzene sulfonic acid and xanthene basic dye, alkylbenzene sulfonic acid and triallylmethane basic dye, alkylbenzene sulfonic acid and It is preferable to select at least one salt-forming dye from salt-forming dyes with azomethine basic dyes. Further, these salt-forming dyes may be used in combination of two or more kinds of salt-forming dyes, and it is preferable to use two or more kinds of salt-forming dyes in consideration of lubricity. Furthermore, considering more, it is most preferable to use three types of salt-forming dyes in combination.

  Further, if the content of the salt-forming dye of the alkylbenzene sulfonic acid and the basic dye is less than 0.1% by mass with respect to the total amount of the ink composition, it is difficult to obtain desired lubricity, and 40.0% by mass. If it exceeds 1, the ink aging tends to become unstable, so 0.1 to 40.0 mass% is preferable with respect to the total amount of the ink composition. More preferably, it is 3.0-30.0 mass% with respect to the ink composition whole quantity, Most preferably, it is 10.0-30.0 mass%.

In addition, examples of the alkylbenzene sulfonic acid include dodecyl diphenyl oxide sulfonic acid, dodecyl benzene sulfonic acid, etc. In consideration of improving lubricity, dodecyl diphenyl oxide disulfonic acid having a large number of sulfo groups (—SO ₃ H). Is preferred.

  For carbon black, the average particle size is preferably 300 nm or less in consideration of the interstices inside the chip. More preferably, it is 150 nm or less. Here, the average particle diameter is an average particle diameter d50 measured by a particle size distribution meter. The content of carbon black is preferably 0.5 to 15.0 mass% with respect to the total amount of the ink composition. This is because if it is less than 0.5% by mass, the lubricating effect tends to be difficult to obtain, and if it exceeds 15.0% by mass, it tends to aggregate in the ink. 1.0-10.0 mass% is preferable, Most preferably, it is 2.0-7.0 mass%.

Examples of the pigment dispersant include polyvinyl butyral resin, polyacetal resin, polyvinyl alcohol resin, cellulose resin, polyvinyl pyrrolidone, and the like, and one or more of these can be used. As in the present invention, in the case of an oil-based ink composition having an ink viscosity of 5000 mPa · s or less at 20 ° C. and a shear rate of 500 sec ⁻¹ , a polyvinyl butyral resin is preferable, but this is rapidly finely dispersed in an organic solvent. This is because the polyvinyl butyral resin is easily adsorbed on the carbon black, so that the dispersion of the carbon black is easily maintained for a long time. In particular, in consideration of dispersibility with polyvinyl butyral resin, basic carbon black is preferable. Here, the basic carbon black is defined as a basic carbon black having a pH value of 7 or more obtained by dispersing carbon black particles in ion exchange water having a pH of 7 and measuring the pH at 25 ° C. with a pH meter. In consideration of pigment dispersibility, basic carbon black having a pH value of 7 to 10 is most preferable.

  The polybutyral resin is obtained by reacting polyvinyl alcohol (PVA) with butyraldehyde (BA), and the polyvinyl butyral resin preferably has 20 to 40 mol% of hydroxyl groups in the molecule. This is because if it is less than 20 mol%, it tends to be difficult to dissolve in an alcohol-based organic solvent, and if it exceeds 40 mol%, the water resistance tends to be inferior, and more preferably 30-40 mol%. preferable. In consideration of solubility in an organic solvent, the molecular weight is preferably 100,000 or less, and more preferably 30000 or less.

  If the content of the pigment dispersant is less than 0.1% by mass, the pigment dispersibility tends to be inferior, and if it exceeds 20.0% by mass, the solubility in the ink tends to be inferior and the ink viscosity tends to increase. The total amount of the ink composition is preferably 1.0 to 20.0% by mass, and more preferably 3.0 to 10.0% by mass in consideration.

  Further, in the case of newly using the alkylbenzenesulfonic acid and basic dye salt-formation dye and carbon black in the oil-based ballpoint pen ink composition as in the present invention, in order to maintain ink aging stability, Since water is contained in the oil-based ink due to moisture absorption over time, it is preferable to pay attention to the pH value. In the present invention, a pH value of 3.9 or less is a strongly acidic region, a pH value of 10.1 or more is a strongly alkaline region, and a pH value of 4.0 to 10.0 is an intermediate region between a strongly acidic region and a strongly alkaline region (weak Acid, neutral, weakly alkaline).

  The pH of the oil-based ink composition for ballpoint pens of the present invention is preferably 7.0 to 10.0 in consideration of stability over time. In particular, when basic carbon black is used as the carbon black, the pH value is preferably 7.0 to 10.0. This is because when the pH value is 7 or more, the dispersibility of the basic carbon black is improved, and when the pH value is 10.1 or more, the ionic bond of the salt-forming dye is easily separated. This is because stability and color tone tend to be affected. Further, considering the ink aging stability, the pH value is preferably 7.0 to 9.0.

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

  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, 3-methoxy-3-methylbutanol, glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, 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 solvent generally used as ink can be illustrated. Among these, it is preferable to use at least an alcohol solvent in view of dissolution stability of a salt-forming dye of an alkylbenzene sulfonic acid and a basic dye and ink aging stability with carbon black. Furthermore, aromatic alcohol such as benzyl alcohol is most preferably used because it has an effect of improving lubricity. These organic solvents can use 1 type (s) or 2 or more types. The content of the solvent is preferably 10.0 to 70.0% by mass with respect to the total amount of the ink composition in consideration of the solubility of the colorant, handwriting drying property, blurring, and the like. 0.0-65.0 mass% is preferable, Most preferably, it is 45.0-65.0 mass%.

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

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

  Other colorants include the above-mentioned salt-forming dyes of alkylbenzene sulfonic acid and basic dye, carbon black, oil-soluble dyes, acid dyes, basic dyes, metal-containing dyes, etc. Salt-forming dyes, aniline black, ultramarine, yellow lead, titanium oxide, iron oxide, phthalocyanine, quinacridone, DPP, perinone, perylene, gioxazine, metallic pigment, pearl pigment, fluorescent pigment, phosphorescent A pigment such as a pigment may be used. These colorants may be used alone or in combination of two or more.

  In addition, in order to improve lubricity and ink aging stability, as surfactants, phosphate ester surfactants, fluorine surfactants, silicon surfactants, fatty acid alkanolamides, anionic properties Surfactants, cationic surfactants, amphoteric surfactants, anionic surfactants and / or salt formations of cationic surfactants, viscosity modifiers, ketone resins, terpene resins, alkyds Resins such as resins, phenoxy resins, and polyvinyl acetate, and pseudoplasticity imparting agents such as fatty acid amides and hydrogenated castor oil, and colorant stabilizers, plasticizers, chelating agents, water, and the like may be used as appropriate. These may be used alone or in combination of two or more.

  When the oil-based ballpoint pen ink composition of the present invention is used in a ballpoint pen refill, its structure is not particularly limited, but the ink circulation formed in the chip body, in the center of the ball holding chamber and the bottom wall of the ball holding chamber It has a hole and a plurality of ink flow grooves extending radially from the ink flow hole, and by caulking the tip end portion inward, a part of the ball protrudes from the tip end edge and is held freely. An oil-based ballpoint pen in which the ballpoint pen tip is mounted directly on the tip of the ink containing cylinder or via a chip holder, and the salt-forming dye pigment of the alkylbenzenesulfonic acid and the basic dye is used in the ink containing cylinder It can be used as an oil-based ballpoint pen refill that contains the ink composition directly. The structure of the ballpoint pen tip is not particularly limited, but considering the suppression of writing quality and wear of the tip body, the bottom wall of the ball holding chamber has a substantially circular arc with a different curvature from the ball. An ink flow hole is provided between the ball and the contact surface, from the ink flow hole side to the contact portion between the ball and the contact surface. It is preferable to form a first gap that gradually decreases from the side and a second gap that gradually decreases from the ink circulation hole side from the ball holding chamber side to the contact portion between the ball and the contact surface.

  This is because the first gap and the ball holding chamber side gradually decrease from the ink circulation hole side from the ink circulation hole side to the contact portion between the ball and the contact surface between the ball and the contact surface. By forming a second gap that gradually decreases from the ink circulation hole side to the contact portion between the ball and the contact surface, it is easy to make fluid lubrication or mixed lubrication between the ball and the contact surface. This is because it is easy to suppress wear and improve writing quality.

  Further, the relationship between the ball and the contact surface will be described in detail. The lubrication state of the oil-based ballpoint pen ink composition of the present invention by the rotation of the ball is the same as that of the oil-based ballpoint pen ink composition when the ball rotates. It is dragged from the hole into a narrow gap between the ball and the contact surface, and a layer of ink for ballpoint pen is formed between the ball and the contact surface. This ink layer generates pressure and generates a force to float the ball. It is presumed that it is easy to suppress the wear of the bottom wall because a wedge effect is obtained. In particular, in the case of an oil-based ink composition in which a salt-forming dye of an alkylbenzene sulfonic acid and a basic dye and carbon black are used together as in the present invention, the phenyl sulfone group or the phenyl group of the salt-forming dye and carbon black particles It is presumed that it is effective in suppressing the wear of the bottom wall because a wedge effect is easily obtained by the elastic lubricating film layer formed by the action.

  Further, the lubricating state of the oil-based ballpoint pen ink composition from the ink circulation hole due to the rotation of the ball is as described above, and when the ball rotates, the oil-based ballpoint ink composition is moved between the ball and the contact surface. Although drawn into a narrow gap, when writing, the oil-based ballpoint pen ink composition supplied to the contact surface from the ink circulation hole side and the oil-based ballpoint pen ink composition that could not protrude onto the paper surface There is a tendency to return to the contact surface from the chamber. Therefore, by forming the first gap and the second gap, the writing quality and the wear resistance can be easily improved synergistically.

  The shape of the contact surface is preferably a curvature different from the curvature of the ball in order to form the first gap and the second gap between the ball and the contact surface. Moreover, since the wedge effect tends to increase as the distance on the ink circulation hole side becomes smaller, it is preferable to make the gap on the ink circulation hole side smaller. Specifically, when the distance on the ink circulation hole side is longer than 5 μm with the length in the axial direction, the wedge effect is difficult to be obtained, so that it is preferably 5 μm or less, more preferably 0.001 μm to 3 μm, and 0.005 μm. Most preferably, the thickness is 001 μm to 1 μm. In addition, the contact surface is preliminarily arcuate and the first gap is gradually reduced from the ink circulation hole side to the contact portion, so that a high wedge is formed near the contact portion of the ball. Effectively, the force to float the ball is increased, wear of the contact surface can be effectively suppressed, and even if the contact surface is worn, rapid wear can be suppressed and the clearance relationship can be easily maintained. .

Next, a method for producing a salt-forming dye comprising an alkylbenzenesulfonic acid and a basic dye will be described.
Formulation Example 1
First, 1000 g of water and 30 g of basic dye (Basic Red 1) were weighed in a beaker, heated, dissolved using a disper stirrer, 60 g of alkylbenzene sulfonic acid was weighed, stirred and filtered using filter paper The residue on the filter paper was dried to obtain a salt-forming dye.

Next, an Example is shown and this invention is demonstrated.
The ink composition for oil-based ballpoint pens of Example 1 was prepared by dissolving the pigment dispersion resin with an organic solvent and a pigment dispersant at 50 ° C. using a mixing stirrer to prepare Solution A. Carbon black is added to the obtained solution A, and a dispersion base is prepared using three rolls. The remaining components were stirred on this dispersion base at 50 ° C. using a mixing stirrer to obtain an ink composition for oil-based ballpoint pens. Specific blending amounts are as follows. Ink viscosity was measured at a shear rate of 500 sec ⁻¹ in an environment of 20 ° C. using AR-G2 (stainless steel 40 mm 2 ° rotor) manufactured by TA Instruments Inc., and 790 mPa · s. Met. Moreover, when pH value was measured, it was pH = 7.5.

Example 1
Formulation Example 1 Salt-forming dye 7.0% by mass
Formulation Example 2 salt-forming dye 10.0% by mass
Formulation Example 3 salt-forming dye 13.0% by mass
Pigment (basic carbon black) 5.0% by mass
Pigment dispersant (polyvinyl butyral) 2.5% by mass
Organic solvent (benzyl alcohol) 54.1% by mass
Stabilizer (polyoxyethylene alkylamine) 1.0% by mass
Stabilizer (oleic acid) 1.0% by mass
Spinnability imparting material (polyvinylpyrrolidone) 0.4% by mass
Resin (ketone resin) 6.0% by mass

Formulation Examples 2-7
As shown in Table 1, salt-forming dyes of Formulation Examples 2 to 7 were prepared in the same manner as Formulation Example 1 and Formulation Example 2 except that each component was changed, and used in Examples and Comparative Examples.

Examples 2-5
As shown in Table 2, oil-based ballpoint pen ink compositions of Examples 2 to 5 were obtained in the same procedure as Example 1, except that each component was changed.
Example 6
As shown in Table 2, except that each component was changed, each component other than water was carried out in the same procedure as in Example 1, and after cooling at room temperature, water was added and an ink composition for an oil-based ballpoint pen was obtained by disper stirring. It was.

Comparative Examples 1-4
As shown in Table 3, the components were mixed 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 4 were obtained. Table 3 shows the measurement and evaluation results.

Testing and evaluation
The oil-based ballpoint pen ink composition 24 (0.4 g) and the grease-like ink follower 25 produced in Examples 1 to 6 and Comparative Examples 1 to 4 were placed in an ink containing cylinder 22 (polypropylene) with a ball diameter of φ0. An oil-based ballpoint pen was manufactured by filling a ballpoint pen refill 21 equipped with a ballpoint pen tip 1 (stainless steel wire) holding a 7 mm ball 9 rotatably. The following tests and evaluations were performed using a writing paper JIS P3201 as a writing test paper.

  In the present invention, the ballpoint pen tip 1 having the structure shown in FIGS. The ball-point pen tip of FIGS. 1 and 2 is an ink circulation hole 7 in the center of the ball holding chamber 3 of the chip body 2 made of stainless steel wire, and the ink that extends radially from the ink circulation hole 7 and does not reach the tip rear hole 8. A substantially arcuate contact surface 5 having a curvature different from that of the ball 9 is provided on the bottom wall 4 in which the flow groove 6 is formed, and a tungsten carbide ball 9 having a diameter of 0.5 mm is placed on the contact surface 5. By crimping the tip end portion 2a inward, a part of the ball 9 is rotatably held so as to protrude from the tip end edge.

  Such a ball-point pen tip 1 is manufactured as follows. That is, for example, a stainless steel wire having a diameter of 2.3 mm and a hardness of 230 Hv to 280 Hv is cut to a desired length, and the ball holding chamber 3, the ink circulation hole 7, and the ink circulation groove extending radially from the ink circulation hole 7. 6 is produced. Thereafter, hammering is performed from the tip end portion 2a side in a state where the ball 9 is placed on the bottom wall 4 of the ball holding chamber 3, and a curved surface having a larger radius of curvature than the ball 9 is formed by the springback property. The tip end 2a is caulked inward. As a result, a curved contact surface 5 having a curvature different from that of the ball 9 is formed, and the ball 9 is on the peripheral line around the axis on the tip end portion 2a side of the center position of the contact surface 5 in the axial direction. Contact is made at the contact portion 5a. As a result, a first gap S1 and a second gap S2 are formed between the ball 9 and the contact surface 5.

  By forming the first gap S1 and the second gap S2, it is easy to maintain the fluid lubrication or mixed lubrication between the ball 9 and the contact surface 5 (contact portion 5a). For this reason, the wear of the contact surface (contact portion) is suppressed. In the present embodiment, the length H of the opening in the axial direction on the ink circulation hole 7 side of the first gap S1 is 0.9 μm (see FIG. 2).

Testing and evaluation
The oil-based ballpoint pen inks prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were filled in the ballpoint pen refill of Example 1, and the following tests and evaluations were performed using writing paper JIS P3201 as writing test paper.

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

Abrasion resistance test: The wear of the ball seat after the writing test was measured with a running test machine with a load of 200 gf, a writing angle of 70 °, and 4 m / min.
Ball seat wear is less than 2μm and can be written.
Ball seat wear is 2 μm or more and less than 5 μm, and can be written on.
Wear of ball seat is 5 μm or more and less than 10 μm, resulting in poor writing.
Wear of ball seat is 10μm or more, and writing becomes impossible ... ×

Ink consumption test: In an environment of temperature 20 ° C. and humidity 65% RT, a writing test is conducted with a running test machine with a load of 200 gf, a writing angle of 70 °, and 4 m / min, 0 to 100 m (A) and 100 m before the end of writing. The ink consumption (B) was measured.
0.9 ≦ A / B ≦ 1.15 ・ ・ ・ ◎
0.8 ≦ A / B <0.9 or 1.15 ≦ A / B <1.2
A / B <0.80 or A / B> 1.20 ··· ×

Pigment dispersibility test: The pigment dispersibility of the ink composition was observed at an optical microscope (Olympus) magnification of 100 times after 2 months at 50 ° C. and humidity of 80%.
Uniform pigment dispersion ... ◎
A pigment dispersed almost uniformly ・ ・ ・ ○
Pigment agglomeration was observed but there was no practical problem.
Pigment agglomerated ・ ・ ・ ×

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

  In Examples 1 to 6, the ink aging test, writing taste, abrasion resistance test, ink consumption test, and pigment dispersibility test were all good, and the writing performance was good.

  In Comparative Example 1, since a salt-forming dye between dyes was used, pigment stability was not obtained, writing was heavy, and in the wear resistance test, the ball seat was all worn very badly. In addition, in the ink consumption test, the ink consumption decreased, and the handwriting became thinner and blurring occurred.

  In Comparative Example 2, since an acid dye that was not salt-formed was used alone, the pigment dispersion stability was not obtained, the writing quality was inferior, and the wear of the ball seat was all severe in the abrasion resistance test. In addition, in the ink consumption test, the ink consumption decreased, and the handwriting became thinner and blurring occurred.

  In Comparative Example 3, since no pigment was used, the ball seat wear was severe in the abrasion resistance test, the ink consumption increased in the ink consumption test, and writing performance such as scratching was inferior.

  In Comparative Example 4, the ink viscosity was high and the writing quality was poor.

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

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

In order to improve the writing quality as in the present invention, when the ink viscosity at 20 ° C. and the shear rate of 500 sec ⁻¹ is set to a range of 5000 mPa · s or less, a ball-point pen tip is used to prevent the ink from dripping. The ball held rotatably at the tip is pressed against the inner wall of the tip edge of the tip directly by a coil spring or through a pressing body, and the ink is applied by giving a gap between the inner wall of the tip tip edge and the ball by the pressing force at the time of writing. It is preferable to provide a valve mechanism for allowing outflow and close a minute gap at the tip of the tip when not in use.

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

DESCRIPTION OF SYMBOLS 1 Ball-point pen tip 2 Tip body 2a Tip part 2b Seal surface 3 Ball holding chamber 4 Bottom wall 5 Contact surface 5a Contact part 6 Ink flow groove 7 Ink flow hole 8 Rear hole 9 Ball 21 Ball pen refill 22 Ink receiving cylinder 23 Coil Spring 24 Ballpoint pen ink 25 Ink follower S1, S2 Clearance

Claims (8)

The chip body has a ball holding chamber, an ink circulation hole formed in the center of the bottom wall of the ball holding chamber, and a plurality of ink circulation grooves extending radially from the ink circulation hole, The ballpoint pen tip made of stainless steel with a part of the ball protruding from the tip edge of the tip and rotatably held by caulking the inside is directly on the tip of the ink containing cylinder or via a tip holder. A carbon having an average particle diameter of 300 nm or less, and a dye and a pigment as a colorant in combination, and the dye is a salt-forming dye composed of an alkylbenzenesulfonic acid and a basic dye. It is black and directly contains ink for oil-based ballpoint pens having an ink viscosity of 10 to 5000 mPa · s at 20 ° C. and a shear rate of 500 sec ⁻¹ . When the ink consumption amount Amg at 0 to 100 m and the ink consumption amount Bmg at 100 m before the end of ink satisfy 0.8 ≦ A / B ≦ 1.2 , The amount of movement in the axial direction is 3 to 15 μm,
The ball mechanism is provided with a valve mechanism that presses the ball against the inner wall of the tip end edge of the tip directly or via a pressing body with a coil spring, and causes the ink to flow out by providing a gap between the inner wall of the tip end edge and the ball by a pressing force at the time of writing. ballpoint refill to be characterized are. The dye is one or more of a salt-forming dye of alkylbenzene sulfonic acid and xanthene basic dye, alkylbenzene sulfonic acid and triallylmethane basic dye, or alkylbenzene sulfonic acid and azomethine basic dye. The ballpoint pen refill according to claim 1 , wherein a salt dye is selected and contained. 3. The ballpoint pen refill according to claim 1, wherein the alkylbenzene sulfonic acid is dodecyl diphenyl oxide sulfonic acid. The ballpoint pen refill according to any one of claims 1 to 3 , wherein the carbon black is basic carbon black. The ballpoint pen refill according to any one of claims 1 to 4 , wherein the oil-based ink composition for a ballpoint pen has a pH of 7 to 10. The ballpoint pen refill according to any one of claims 1 to 5 , wherein the ink composition for an oil-based ballpoint pen contains an alcohol-based organic solvent. A ballpoint pen refill in which the ink composition for an oil-based ballpoint pen according to any one of claims 1 to 6 is directly stored in the ink storage cylinder, and the bottom wall of the ball holding chamber includes: A curved contact surface having a curvature different from the curvature of the ball is provided, and the ball is in contact with a contact portion which is a part of the contact surface, A first gap gradually decreasing from the ink circulation hole side is formed from the ink circulation hole side to the contact part between the contact surface and the contact part from the tip side of the ink circulation groove. The oil-based ballpoint pen refill is characterized in that a second gap that gradually decreases from the front end side of the ink circulation groove is formed. The ballpoint pen refill according to any one of claims 1 to 7 , wherein a lubricating coating layer is provided on a surface of the ball on the surface of the contact surface.

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