JP2007009091A - Ink composition for ball point pen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition which is used for ball point pens rotatably holding balls in ball holders and extruding the ink composition with the rotation of the balls, respectively, as writing members, and is not leaked from the ink-extruding portions, even when the ball point pens are left for long times in downward postures. <P>SOLUTION: The ink composition for the ball point pens contains at least a particle below-mentioned, a colorant, a solvent and a resin soluble in the solvent. The above particle has a plate-like part and a spherical, mass-like or rod-like part that is erected and projected from this plate-like part or has a shape in which a plurality of plate-like parts are jointed with the mutual surfaces not laid on top of another. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a so-called ballpoint pen ink composition that holds a ball rotatably as a writing member in a ball holder and discharges the ink composition as the ball rotates, and is left facing for a long time. In particular, the present invention relates to an ink composition for a ballpoint pen that causes less leakage of the ink composition from the ink discharge portion and that causes little ink composition writing.

  Conventionally, when a ballpoint pen is not used, the ink composition leaks from the ink discharge port at the tip of the ballpoint pen tip, and may occur as a waste of the ink composition at the time of writing. In addition, in the case of a ballpoint pen that supports the discharge of the ink composition when writing by the pressure of compressed gas or the like, it is not only one that compresses and encloses the gas so as to constantly increase the pressure in the sealed structure, but if necessary Even if the gas is compressed and introduced by a pumping mechanism, etc., the ink composition leaks from the ink discharge port due to the accumulated pressure, such as when the increased pressure is not completely consumed by writing. The drawbacks were easy to occur.

Various attempts have been made to solve such drawbacks. For example, the invention described in JP-A-2002-003772 (Patent Document 1) discloses an oil-based ink composition for ballpoint pens using 1 to 5% of polyvinylpyrrolidone having an average molecular weight of 250,000 or more. It is said that it has improved the drop of the stickers. Further, in the invention described in JP-A-10-195365 (Patent Document 2), an oil-based ink composition for ballpoint pens using silica having a primary average particle diameter of 7 to 40 nm and a specific surface area of 50 to 380 m ² / g is disclosed. It is said that the leakage of the ink composition is improved when the ink discharge port is left facing for a long time.
JP 2002-003772 A Japanese Patent Laid-Open No. 10-195365

Even in the invention described in each of the above patent documents, when left for a long time with the ink discharge port of the ballpoint pen facing down, the ink composition leaks and drops off, and it cannot be said that it is still sufficient. There wasn't. In particular, a ballpoint pen that supports the discharge of the ink composition when writing by the pressure of a compressed gas or the like has been insufficient.
Even if the present invention is left for a long time with the ink discharge port of the ballpoint pen facing downward, it can be used for a ballpoint pen that supports the discharge of the ink composition when writing by the pressure of compressed gas or the like. It aims at obtaining the ink composition for ball-point pens which a composition does not leak.

  That is, the present invention has a plate-like portion and a spherical, block-like, or rod-like portion that stands up and protrudes from the plate-like portion, or a shape in which a plurality of plate-like portions are joined without overlapping each other. The gist of the ink composition for ballpoint pens includes at least particles having a colorant, a colorant, a solvent, and a resin soluble in the solvent.

The ball-point pen ink composition of the present invention has a plate-like portion and a spherical, block-like, or rod-like portion that stands up and protrudes from the plate-like portion, or a plurality of plate-like portions are surfaces. Particles having a shape bonded without overlapping each other are accumulated in a narrow gap in the ball-point pen tip by combining a plurality of particles due to steric hindrance due to the protruding portion. It is presumed that the deposit of the particles suppresses the flow of the ink composition, so that the leakage of the ink composition can be suppressed.
In writing, a force directed toward the ink discharge port is applied to the deposited particles by the rotation of the ball, and the accumulated deposits of the deposited particles are easily destroyed and the ink composition is ejected smoothly.

A shape having a plate-like portion used in the present invention and a spherical, lump-like, or rod-like portion that stands up and protrudes from this plate-like portion, or a plurality of plate-like portions combined without overlapping each other It is considered that the particles having, due to steric hindrance due to the protruding portion, are combined into a plurality of particles and deposited in a narrow gap in the ballpoint pen tip to prevent ink leakage.
In order to obtain particles having the above shape, a composite of a plurality of particles having different shapes may be used. For example, a shape in which a plurality of plate-like particles and a plurality of spherical particles are combined in combination at random. Particles. In order for the composite to have protrusions that cause steric hindrance, the maximum diameter of the plate-like particles constituting the composite is preferably 6 times or more the thickness. In addition to the plate-like particles, the composite may contain particles of any shape such as a sphere (lump) shape, a rod (needle) shape, an irregular (no) shape, and the like.
Amount of particles having a plate-like portion and a spherical, lump-like, or rod-like portion protruding upright from the plate-like portion, or having a shape in which a plurality of plate-like portions are combined without overlapping each other Is preferably 0.1% by weight or more and 10% by weight or less based on the total amount of the ink composition for ballpoint pens. If the amount used is less than 0.1% by weight, the flow resistance against the ink composition is weak, and the ink composition for ballpoint pens may leak. If the amount used is more than 10% by weight, the ink composition for ballpoint pens will be discharged. There is a risk of getting worse.
An average particle of particles having a plate-like portion and a spherical, lump-like, or rod-like portion standing up and protruding from the plate-like portion, or having a shape in which a plurality of plate-like portions are bonded without overlapping each other The diameter is preferably 1 μm or more in order to obtain an appropriate flow resistance. Moreover, since there exists a possibility of becoming a cause of clogging when an average particle diameter is too long, 10 micrometers or less are preferable.
A commercial product of a particle having a plate-like portion and a spherical, lump-like, or rod-like portion standing up and protruding from the plate-like portion, or having a shape in which a plurality of plate-like portions are bonded together without overlapping each other. As a specific example, as a composite of plate-shaped kaolinite particles and spherical quartz particles, Siritin V85 (average particle size 3 μm), Siritin V88 (average particle size 3 μm), Siritin N82 (average particle size 2. 3 μm), Siritin N85 (average particle size 2.3 μm), Siritin Z86 (average particle size 1.8 μm), Siritin Z89 (average particle size 1.8 μm), Siricolloid P82 (average particle size 1.6 μm), Siricolloid P87 ( (Average particle size 1.6 μm), surface-treated actidyl EM (average particle size 1.8 μm), actidyl MM (average particle size 1.8 μm) (above, Hoffman Minerals, Germany), etc. That.
In the present invention, there is a plate-like portion and a spherical, lump-like, or rod-like portion that stands up and protrudes from this plate-like portion, or a shape in which a plurality of plate-like portions are joined without overlapping each other. The average particle size of the particles having a particle diameter corresponding to 50% of the cumulative distribution curve of the number of particles, measured by spectral light wave diffraction of Fraunhofer line using a laser measuring device of Malvern, The diameter is equal to the number of particles.

  The ball-point pen using the ink composition for the ball-point pen of the present invention may have a generally used ball-point pen tip, and the ball holder for holding the ball includes stainless steel, brass, bronze, white and white, etc. A material obtained by cutting and rolling the metal can be used, and a ball as a writing member can be a sintered body of tungsten carbide, silicon carbide, zirconia, or the like. The combination of the above-described ball holder and ball is appropriate. FIG. 1 shows a longitudinal sectional view of an essential part of an example of a ballpoint pen tip. A ball holder 2 that partially holds and holds a ball 1 as a writing member from the tip, and the ball holder 2 has a through hole 3 as a path for the ink composition. The through-hole 3 includes a ball holding chamber 3a for holding the ball 1, a center hole 3b formed as a central portion of the inward projecting portion 4 for regulating the backward movement of the ball 1, and a rear hole 3c connected to the ink tank. And is in communication with the radial groove 5 that opens in the ball receiving seat surface 4a on the ball holding chamber 3a side of the inward projecting portion 4. When the ball 1 is most retracted and is in contact with the inward protruding portion 4, the portion from the vicinity of the maximum diameter portion of the ball 1 to the opening of the ball holder 2 Assuming that the ink composition is located along the center line of No. 2, the gap is the narrowest part of the path of the ink composition. For example, when the ball diameter is 0.7 mm, the gap is approximately 2.0 μm or less. ing. Among them, the narrowest gap portion is in the vicinity of the maximum diameter portion of the ball 1 (the portion surrounded by a circle as the I portion in the figure), which is a gap that is almost zero, and when the ball diameter is 0.7 mm, The gap in the part is about 5.0 μm, which is somewhat larger than this.

As the coloring material, dyes and / or pigments can be used without any particular limitation.
In the case of using an oil-soluble dye as a coloring material, a conventionally known oil-soluble dye can be used, and specific examples include rhodamine B base (CI. 45170B, manufactured by Taoka Dye Manufacturing Co., Ltd.), Soldan Red 3R ( CI 21260, manufactured by Chugai Kasei Co., Ltd.), methyl violet 2B base (C.I. 42535B, manufactured by National Aniline Div.), Victoria Blue F4R (C.I. 42563B), nigrosine base LK ( CI. 50415) (manufactured by BASF, Germany), Bali First Yellow # 3104 (C.I. 13900A), Bali First Yellow # 3105 (C.I. 18690A), Orient Spirit Black AB (C.I. I.50415), Bali First Black # 3804 (C.I.121) 5), Bali First Yellow # 1109, Bali First Orange # 2210, Bali First Red # 1320, Bali First Blue # 1605, Bali First Violet # 1701 (above, manufactured by Orient Chemical Industry Co., Ltd.), Spiron Black GMH Special, Spiron Yellow C-2GH, Spiro Yellow C-GNH, Spiro Red C-GH, Spiro Red C-BH, Spiro Blue C-RH, Spiro Violet C-RH, S. P. T.A. Orange 6, S. P. T.A. Examples include Blue 111 (manufactured by Hodogaya Chemical Co., Ltd.). Furthermore, C.I. I. Basic Blue 1, 7, 7, 8, C.I. I. Basic violet 1, 3 and C.I. I. Basic dyes such as Basic Red 1 and C.I. I. A salt-forming dye with an acid dye selected from Acid Yellow 23 and 36 can also be used. The oil-soluble dyes exemplified above can be used alone or in combination of two or more, and the amount used is preferably 6% by weight or more and 45% by weight or less based on the total amount of the ink composition.

  Moreover, when using a pigment as a coloring material, a conventionally well-known pigment can be used for a pigment, and as an organic pigment, C.I. I. PIGMENT RED2, 3, 5, 8, 17, 17, 31, 31, 38, 41, 48: 1, 48: 2, 48: 3, 49, 50, 53: 1, 57: 1, 58: 2, 60, 63: 1, 63: 2, 64: 1, 88, 112, 122, 123, 144, 146 149, 166, 168, 170, 170, 176, 177, 178, 179, 180, 185, 190, 194, 202, 206, 207, 208, the same 209, 211, 213, 216, 245, 254, 255, 264, 270, 272, C.I. I. PIGMENT ORANGE 5, 10, 13, 16, 36, 40, 43, 61, 64, 71, 73, C.I. I. PIGMENT VIOLET 19, 23, 31, 33, 36, 37, 38, 50, C.I. I. PIGMENT BLUE 2, 9, 15, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 5, 15: 6, 16, 16, 17, 22, 25, 28, 29, 36, 60, 66, 68, 76, C.I. I. PIGMENT BROWN 23, 25, 26, C.I. I. PIGMENT YELLOW 1, 3, 12, 13, 24, 83, 93, 94, 95, 97, 99, 108, 109, 110, 117, 120, the same 128, 139, 147, 151, 153, 166, 167, 173, C.I. I. PIGMENT GREEN 7, 10, 36, C.I. I. And organic pigments such as PIGMENT BLACK 7. These organic pigments can be used singly or in combination of two or more, and the amount used can be from 1% by weight to 45% by weight with respect to the total amount of the ink composition, thereby obtaining a sufficient handwriting concentration. Therefore, it is preferably 6% by weight or more and 40% by weight or less. If the amount used is small, the handwriting becomes thin, and if the amount is large, the followability of the ink composition from the ballpoint pen may be deteriorated, resulting in blurring or the ink composition being unable to be ejected.

Inorganic pigments include carbon black such as black iron oxide, furnace black, channel black, thermal black, acetylene black, yellow iron oxide, red iron oxide, ultramarine, bitumen, cobalt blue, titanium yellow, turquoise, molybdate. Examples thereof include inorganic pigments such as orange and titanium oxide.
These inorganic pigments can be used singly or in combination of two or more, and the amount used can be from 1% by weight to 50% by weight, preferably 10% by weight, based on the total amount of the ink composition. % To 40% by weight.
As other pigments, fluorescent pigments, pearl pigments, phosphorescent pigments, metal pigments, composite metal pigments, metal oxide pigments and the like may be used. For example, examples of the fluorescent pigment include FZ-5000 series (manufactured by Sinloihi Co., Ltd.). Examples of the pearl pigment include Pearl Glaze MRY-100 and ME-100 (manufactured by Nippon Koken Chemical Co., Ltd.). GSS (Nemoto Special Chemical Co., Ltd.) etc. are mentioned as a luminous pigment. In addition, as a metal pigment, it is used for the purpose of producing a glittering feeling different from the color of the handwriting. Aluminum powder, bronze powder, zinc powder and the like are specific examples of commercially available aluminum powders such as Super Fine No. . 22000, ibid. 18000, Fine No. 900, ibid. 800 (above, manufactured by Daiwa Metal Powder Industry Co., Ltd.).
These pigments can be used singly or in combination of two or more, and the amount used can be from 1% by weight to 45% by weight, preferably 10% by weight, based on the total amount of the ink composition. The content is 40% by weight or less.

In order to increase the dispersion efficiency of the pigment, a material obtained by finely dispersing the pigment in the polymer compound in advance may be used. In particular, when such a pigment is used, it can be easily dispersed in production and can be used as a useful means in production. For example, Microlith Yellow 3G-K, Yellow 4G-K, Yellow 3R-K, Scarlet RK, DPP Red BK, Magenta 5B-K, Violet BK, Blue A3R-K, Blue 4G-K, Green G-K, Black C-K, White RK (above, pigment finely dispersed in vinyl chloride / vinyl acetate copolymer resin, Ciba Specialty Chemicals ( IK Yellow, IK Red, IK Blue, IK Green, IK Black (pigment finely dispersed in vinyl chloride / vinyl acetate resin, manufactured by Fuji Dye Co., Ltd.), Microlith Yellow 2G-T, Yellow 3R-T, Brown 5R-T, Scarlet RT, Red BR-T, Bl ue GS-T, Green GT, Black CT (pigment finely dispersed in rosin ester resin, manufactured by Ciba Specialty Chemicals Co., Ltd.), Microlith Yellow 4G-A, Yellow MX-A Yellow 2R-A, Brown 5R-A, Scarlet RA, Red 2C-A, Red 3R-A, Magenta 2B-A, Violet B-A, Blue 4G-A, Green GA, Black CA, White RA (pigment finely dispersed in ethyl cellulose resin, manufactured by Ciba Specialty Chemicals), L1 / S Yellow NIF, L1 / 8 Red F3RK-70 , L1 / 8 violet RN50, L1 / 8 orange 501, L1 / 8 brown 5R, L1 / 8 Black MA100, NC790 White (pigment finely dispersed in nitrocellulose resin, manufactured by Taihei Chemical Products Co., Ltd.), Renol Yellow GG-HW, Yellow HR-HW, Orange RL-HW, Red FGR- HW, Red HF2B-HW, Red F5RK-HW, Carmine FBB-HW, Violet RL-HW, Blue B2G-HW, Green GG-HW, Brown HFR-HW, Black R-HW, White T-HW (pigment finely dispersed in polyvinyl butyral resin, manufactured by Clariant Japan Co., Ltd.), Fuji AS Black 810, AS Red 575, AS Blue 650, AS Green 737, AS White 165 (Pigment finely dispersed in polyvinyl butyral resin Ltd.) and the like.
In addition, the said dye, an organic pigment, an inorganic pigment, etc. can also be mixed and used.

  When the ink composition for a ballpoint pen of the present invention is an oil-based ink composition using an organic solvent, a cellulose-based polymer compound and / or a polyvinyl butyral resin is used so that the ballpoint pen is used in a high humidity environment. Ink composition that maintains stability over time and is less susceptible to influence in higher humidity environments by using ethyl cellulose, nitrocellulose, cellulose acetate, cellulose acetate butyrate and cellulose acetate propionate among cellulose compounds Can be a thing. In addition, it is considered that the particles of the present invention and the cellulose-based and polyvinyl butyral resins are well-suited and have a function of stabilizing the dispersed particles.

In addition, as a method for producing an ink composition for ballpoint pens, the cellulose polymer compound and / or polyvinyl butyral resin in which a pigment is finely dispersed in advance are pulverized to form particles, and the particles are converted into the cellulose polymer compound. And / or the pigment is finely and uniformly dispersed by blending into the organic solvent in which the polyvinyl butyral resin is soluble or the above-mentioned cellulose polymer compound and / or the composition containing the organic solvent in which the polyvinyl butyral resin is soluble. Therefore, an ink composition that is more stable over time can be obtained than those dispersed from ordinary raw pigments. The ink composition for a ballpoint pen can be obtained by dissolving and dispersing the above components using a lab mixer, a bead mill, a three roll, or the like.
The plate-like portion used in the present invention has a spherical or block-like or rod-like portion that stands up and protrudes from this plate-like portion, or a shape in which a plurality of plate-like portions are joined without overlapping each other. The particles having the above-mentioned cellulose-based polymer compound and / or mixed with a resin solution dissolved in a solvent of polyvinyl butyral resin, dispersed by a ball mill, bead mill, three rolls, etc. are mixed at the time of pigment dispersion and dispersed. , Particle dispersion efficiency increases.

  In the case of using an organic solvent, it is preferable to use a cellulosic compound because it forms a tough interface against moisture in a state dissolved in the organic solvent. Among cellulose compounds, ethyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, and nitrocellulose have particularly good effects. For example, commercially available products such as etose 4, 7, 10, 20, 45, 50, 70, 100 (ethyl cellulose, manufactured by Dow Chemical Japan Co., Ltd.), cellulose acetate CA -320S, CA-394-60S, CA-398-3, CA-398-6, CA-398-10, CA-398-30 (above, cellulose acetate, manufactured by Eastman Chemical Co., Ltd.) Cellulose acetate butyrate CAB-171-15, CAB321-0.1, CAB-381-0.1, CAB-381-2, CAB-500-5, CAB-551-0.01 ( Cellulose acetate butyrate, manufactured by Eastman Chemical Co.), cellulose acetate propionate CAP-482-0.5, CAP-482 20, the CAP-504-0.2 (or, cellulose acetate propionate, Eastman Chemical Co., Ltd.). Even in the case of cellulose compounds, methyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, and ethyl hydroxyethyl cellulose are soluble in water, but are used in combination with a polymer compound that is soluble in an organic solvent and not soluble in water. For the purpose described above, for example, a leakage preventing agent, it is possible to use it within a range that does not adversely affect the function and effect of the present invention.

  The polyvinyl butyral resin has a function of creating a tough interface with respect to moisture in a state dissolved in an organic solvent and improving the dispersibility of the pigment, like the cellulose compound. For example, Denkabutyral # 2000L, # 3000-1, # 3000-2, # 3000-3, # 3000-4, # 3000-K, # 4000-1, # 4000- 2, # 5000-A, # 6000-C (above, manufactured by Denki Kagaku Kogyo Co., Ltd.), ESREC BL-1, BL-2, BL-3, BL-S, BX-L, BM-1, BL-2, BM-5, BM-S, BH-3, BX-1, BX-2, BX-5, BX-55, BH-S (and above) And Sekisui Chemical Co., Ltd.). The amount used may be 0.5 wt% or more and 15 wt% or less, preferably 5 wt% or more and 10 wt% or less, with respect to the total amount of the ink composition for ballpoint pens.

  In addition to the above polymer compounds as resins, resins usually used as fixing agents and dispersants for ink compositions for ballpoint pens, such as ketone resins, sulfoamide resins, acrylic resins, maleic resins, styrene and maleic esters Copolymer, copolymer of styrene and acrylic acid or ester thereof, ester gum, xylene resin, urea resin, polyamide resin, alkyd resin, phenol resin, alkylphenol resin, terpene phenol resin, rosin resin and hydrogenated compounds thereof , Polyvinyl acetal, polyvinyl alkyl ether, polyvinyl pyrrolidone, polyethylene oxide and the like can be used in combination. These resins may be used alone or in combination of two or more, and the blending amount is in the range of 0.1 wt% to 30 wt% with respect to the total amount of the ink composition for ballpoint pens. It is. These resins have the effect of adjusting the viscosity of the ink composition for ballpoint pens and improving the adhesion and water resistance.

  As the solvent used in the present invention, water or a conventionally known organic solvent can be used. The organic solvent preferably has a boiling point of 150 ° C. or higher, and a conventionally known ballpoint pen solvent can be used as the solvent. For example, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monophenyl ether Benzyl glycol, propylene glycol normal butyl ether, propylene glycol monophenyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol normal propyl ether, dipropylene glycol monophenyl Ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monobutyl ether, tripropylene glycol monophenyl ether, and other glycol ether solvents, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol Glycol solvents such as glycerin and polyethylene glycol, ester solvents such as 2-ethylhexyl acetate, isobutyl isobutyrate, ethyl lactate and butyl lactate, benzyl alcohol, β-phenylethyl alcohol, α-methylbenzyl alcohol, Alcohol solvents such as lauryl alcohol, tridecyl alcohol, isododecyl alcohol, isotridodecyl alcohol, etc. There can be used. Among the above solvents, a glycol ether solvent is preferably a cellulose resin having good solubility and is effective in stability over time. These may be used alone or in admixture of two or more. The blending amount may be 20% by weight or more and 90% by weight or less, preferably 35% by weight or more and 75% by weight based on the total amount of the ink composition for ballpoint pens. % Or less.

  As an example of solubilization of these organic solvents and polymer compounds, as an example, polymer compounds such as ethyl cellulose, nitrocellulose, cellulose acetate butyrate, ketone resin, polyvinyl butyral, benzyl alcohol, etc. Examples include alcohol solvents and combinations with glycol ether solvents such as ethylene glycol monobenzyl ether, ethylene glycol monophenyl ether, tripropylene glycol monomethyl ether, and tripropylene glycol monobutyl ether.

  Other anti-corrosion agents such as hydrogenated castor oil, fatty acid amide wax, bentonite, synthetic fine silica, etc., organic phosphate esters, dicyclohexylamine oleate, aliphatic polycarboxylic acid esters, etc. Agent, antifoaming agent such as polysiloxane, polymethylalkylsiloxane, lubricant such as lauroyl sarcosine, oleoyl sarcosine, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, alkyl ether sorbitan fatty acid ester, polyglycerin fatty acid Auxiliary agents commonly used in ink compositions for ballpoint pens such as surfactants such as esters, ultraviolet absorbers, dispersants, anti-scratch agents, and leak-proofing agents may be included.

The ink composition for a ballpoint pen of the present invention can be obtained by dispersing and mixing the above components using a dispersing machine such as a dyno mill, a ball mill, a roll mill, an attritor, a sand grinder, a turbo mixer, a laboratory mixer, a homomixer or the like.
In addition, all the viscosity measurements were obtained by measuring at a shear rate of 1 s ⁻¹ in a measurement environment of 25 ° C. using a STRESS rheometer manufactured by Bohlin.

(Silytin V-88 dispersion)
Siritin V-88 (composite of plate-like kaolinite particles and spherical quartz particles, average particle size of 3 μm, manufactured by Hoffman Mineral, Germany) 8 parts by weight Ethylene glycol monophenyl ether 64 parts by weight Ethylene glycol mono of Etcell 7 28% by weight of phenylglycol 10% by weight solution (ethyl cellulose, manufactured by Dow Chemical Japan Co., Ltd.) The above composition was stirred and mixed with a lab mixer, and then dispersed with three rolls to obtain a siritin V-88 dispersion. Obtained.

(Silytin N-85 dispersion)
Siritin N-85 (composite of plate-like kaolinite particles and spherical quartz particles, average particle size 2.3 μm, manufactured by Hoffmann Minerals, Germany) 8 parts by weight ethylene glycol monophenyl ether 64 parts by weight Denkabutyral 2000 L Ethylene glycol monophenyl glycol 10% by weight solution (polyvinyl butyral resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 28 parts by weight The above composition was stirred and mixed with a laboratory mixer, then dispersed with three rolls, and silitin N- An 85 dispersion was obtained.

(Silytin Z-89 dispersion)
Siritin Z-89 (composite of plate-like kaolinite particles and spherical quartz particles, average particle size 1.8 μm, manufactured by Hofmann Mineral Germany) 8 parts by weight ethylene glycol monophenyl ether 64 parts by weight Denkabutyral 2000 L Ethylene glycol monophenyl glycol 10% by weight solution (polyvinyl butyral resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 28 parts by weight The above composition was stirred and mixed with a laboratory mixer, then dispersed with three rolls, and silitin Z- An 89 dispersion was obtained.

(Silicolloid P-87 dispersion)
Siricolloid P-87 (composite of plate-like kaolinite particles and spherical quartz particles, average particle size 1.6 μm, manufactured by Hoffmann Minerals, Germany) 8 parts by weight Ethylene glycol monophenyl ether 64 parts by weight Denkabutyral 2000 L Ethylene glycol monophenyl glycol 10 wt% solution (polyvinyl butyral resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 28 parts by weight The above blend was stirred and mixed with a laboratory mixer, and then dispersed with three rolls to obtain a colloid colloid P-87. A dispersion was obtained.

(Lubicol K-90 dispersion)
Rubiscol K-90 (polyvinylpyrrolidone, average molecular weight 360,000, manufactured by BASF)
10% by weight
90% by weight of ethylene glycol monophenyl ether
The above blend was stirred and dissolved with a lab mixer to obtain a rubiscol K-90 dispersion.

(Aerosil # 200 dispersion)
Aerosil # 200 (silica powder, primary average particle size 12 nm, manufactured by Nippon Aerosil Co., Ltd.)
8 parts by weight ethylene glycol monophenyl ether 64 parts by weight Denkabutyral 2000 L ethylene glycol monophenyl glycol 10% by weight solution (polyvinyl butyral resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 28 parts by weight The above composition was stirred and mixed with a laboratory mixer. Thereafter, dispersion treatment was performed with three rolls to obtain Aerosil # 200 dispersion.

(Satinton No4 dispersion)
Satinton No. 4 (Kaolinite, plate shape, particle size 2-5 μm, manufactured by Engelhard)
8 parts by weight ethylene glycol monophenyl ether 64 parts by weight Denkabutyral 2000 L ethylene glycol monophenyl glycol 10% by weight solution (polyvinyl butyral resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 28 parts by weight The above composition was stirred and mixed with a laboratory mixer. Thereafter, dispersion treatment was performed with three rolls to obtain a satinton No. 4 dispersion.

(Diacle clay dispersion)
Diamond clay (natural silica, amorphous, particle size 2 to 5 μm, manufactured by Hayashi Kasei Co., Ltd.) 8 parts by weight ethylene glycol monophenyl ether 64 parts by weight Denkabutyral 2000 L ethylene glycol monophenyl glycol 10% by weight solution (polyvinyl butyral) Resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 28 parts by weight The above composition was stirred and mixed with a laboratory mixer, and then dispersed with three rolls to obtain a diamond clay dispersion.

(Mixed dispersion of satin No. 4 and diamond clay)
Satinton No. 4 (Kaolinite, plate shape, particle size 2-5 μm, manufactured by Engelhard)
4 parts by weight diamond clay (natural silica, amorphous, particle size 2-5 μm, Hayashi Kasei Co., Ltd.) 4 parts by weight ethylene glycol monophenyl ether 64 parts by weight Denkabutyral 2000 L ethylene glycol monophenyl glycol 10% by weight solution (Polyvinyl butyral resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 28 parts by weight The above composition was stirred and mixed with a laboratory mixer, and then dispersed with three rolls to obtain a mixed dispersion of Satinton No. 4 and diamond clay.

Example 1
Microlith BLACK C-A (processed pigment finely dispersed in ethyl cellulose, C.I.
PIGMENT BLACK7 and ethyl cellulose have a weight ratio of 6: 4, manufactured by Ciba Specialty Chemicals Co., Ltd.) 25 parts by weight Hilac 110H (ketone resin, manufactured by Hitachi Chemical Co., Ltd.) 3 parts by weight Siritin V-88 dispersion ( 5 parts by weight oleic acid 2 parts by weight ethylene glycol monophenyl ether 60 parts by weight benzyl alcohol 5 parts by weight The components except for the microlith BLACK C-A in each of the above components were heated and stirred to confirm complete dissolution. At that time, Microlith BLACK C-A was gradually added and dispersed at a high speed for 1 hour with a lab mixer to obtain an ink composition for a black oil-based ballpoint pen with a viscosity of 27600 mPa · s (25 ° C.).

(Example 2)
Renol Black R-HW (processed pigment finely dispersed in polyvinyl butyral resin, carbon black 40% by weight, polyvinyl butyral resin 60% by weight, manufactured by Clariant Japan) 25 parts by weight Hilac 111 (ketone resin, Hitachi Chemical Co., Ltd.) Co., Ltd.) 3 parts by weight Silytin N-85 dispersion (as described above) 5 parts by weight oleic acid 2 parts by weight ethylene glycol monophenyl ether 60 parts by weight benzyl alcohol 5 parts by weight Ingredients except for Renol black R-HW Was heated and stirred, and when complete dissolution was confirmed, Renol Black R-HW was gradually added, dispersed at high speed for 1 hour with a laboratory mixer, and a black oil-based ballpoint pen ink composition with a viscosity of 37100 mPa · s (25 ° C). I got a thing.

(Example 3)
Renol Red FGR-HW (Processed pigment finely dispersed in polyvinyl butyral resin, Pi
gment Red 112 50% by weight, polyvinyl butyral resin 50% by weight, manufactured by Clariant Japan Co., Ltd. 9 parts by weight Spiron Orange # 6 (oil-soluble dye, manufactured by Hodogaya Chemical Co., Ltd.) 15 parts by weight Spiron Red C-GH (oil-soluble) Dye, manufactured by Hodogaya Chemical Co., Ltd.) 12 parts by weight Spiron Red C-BH (oil-soluble dye, manufactured by Hodogaya Chemical Co., Ltd.) 0.6 parts by weight Spiron Yellow C-2GH (oil-soluble dye, Hodogaya Chemical Co., Ltd.) 3 parts by weight Hilac 110H (ketone resin, manufactured by Hitachi Chemical Co., Ltd.) 12 parts by weight Siritin N-85 dispersion (described above) 6 parts by weight Ethylene glycol monophenyl ether 38 parts by weight benzyl alcohol 4.4 parts by weight Renol Red FGR-HW and Spiron Orange # 6, Spiron Red C-GH, Spiron Red C After stirring and dissolving the above components except for BH and Spiron Yellow C-2GH with a lab mixer, Renol Red FGR-HW is gradually added, dispersed at high speed for 1 hour with a lab mixer, and the remaining components are blended. Using a lab mixer, the ink composition for a red oil ballpoint pen having a viscosity of 20500 mPa · s (25 ° C.) was obtained by high-speed dispersion for 1 hour.

Example 4
Renol Black R-HW (processed pigment finely dispersed in polyvinyl butyral resin, carbon black 40% by weight, polyvinyl butyral resin 60% by weight, manufactured by Clariant Japan Co., Ltd.) 25 parts by weight Nigrosine EX (dye, Orient Chemical Co., Ltd.) 8 parts by weight Rubiscol K-90 (described above) 0.3 parts by weight Hilac 111 (ketone resin, manufactured by Hitachi Chemical Co., Ltd.) 16 parts by weight Siritin Z-89 dispersion (described above) 5 parts by weight oleic acid 2 parts by weight ethylene glycol monobenzyl ether 33 parts by weight benzyl alcohol 10.7 parts by weight Renol black R-HW and components other than nigrosine EX in each of the above components were heated and stirred, and when complete dissolution was confirmed, Renol Gradually add black R-HW, disperse at 80 ° C for 1 hour at high speed, Shin EX was added, 1 hour fast dispersion to give a black oil-based ink composition for a ballpoint pen of the viscosity 69300mPa · s (25 ℃).

(Example 5)
Renol Blue B2G-HW (processed pigment finely dispersed in polyvinyl butyral resin, phthalocyanine blue 50% by weight, polyvinyl butyral resin 50% by weight, manufactured by Clariant Japan) 17 parts by weight Spiron Blue BPNH (dye, Hodogaya Chemical Co., Ltd.) 5 parts by weight Spiron Blue C-RH (dye, manufactured by Hodogaya Chemical Co., Ltd.) 3 parts by weight Spiron Violet C-RH (dye, manufactured by Hodogaya Chemical Co., Ltd.) 2 parts by weight Resin SK (ketone resin, Huls) 7 parts by weight Siritin Z-89 dispersion (previously described) 4 parts by weight ethylene glycol monophenyl ether 46 parts by weight ethylene glycol monohexyl ether 16 parts by weight Renol blue B2G-HW, spiron blue BPNH and spirone blue in the above components C-RH and spirone violet The components except C-RH were heated and stirred, and when complete dissolution was confirmed, Renol Blue B2G-HW was gradually added, dispersed at 80 ° C. for 1 hour at high speed, and then the remaining components were further added. The mixture was dispersed at high speed for 1 hour with a mixer to obtain an ink composition for a blue oil-based ballpoint pen having a viscosity of 56,500 mPa · s (25 ° C.).

(Example 6)
Renol Black R-HW (processed pigment finely dispersed in polyvinyl butyral resin, carbon black 40% by weight, polyvinyl butyral resin 60% by weight, manufactured by Clariant Japan) 25 parts by weight Hilac 111 (ketone resin, Hitachi Chemical Co., Ltd.) 3 parts by weight Siricolloid P-87 dispersion (previously described) 5 parts by weight oleic acid 2 parts by weight ethylene glycol monophenyl ether 60 parts by weight benzyl alcohol 5 parts by weight Ingredients excluding Renol Black R-HW Was heated and stirred, and when complete dissolution was confirmed, Renol Black R-HW was gradually added, dispersed at high speed for 1 hour with a laboratory mixer, and a black oil-based ballpoint pen ink having a viscosity of 37100 mPa · s (25 ° C). A composition was obtained.

(Example 7)
Irgadine RED 2030 (pigment, CI Pigment Red 254, manufactured by Ciba Specialty Chemicals) 20 parts by weight Disperbyk-160 (polymer pigment dispersant, manufactured by Big Chemie Japan)
2 parts by weight Etcelle 7 (ethyl cellulose, manufactured by Dow Chemical Japan Co., Ltd.) 8 parts by weight T-20SF (hydrogenated castor oil compound, manufactured by Ito Oil Co., Ltd.) 0.1 part by weight Siritin N-85 dispersion (described above) ) 7 parts by weight Propylene glycol monophenyl ether 48 parts by weight Tripropylene glycol monomethyl ether 14.9 parts by weight The components except for Irgazine RED2030 in each of the above components were heated and stirred, and Irgazine RED2030 was added, and dispersed with a bead mill. An ink composition for a red oil ballpoint pen was obtained at 6600 mPa · s (25 ° C.).

(Example 8)
Microlith BLACK C-A (processed pigment finely dispersed in ethyl cellulose, C.I.
PIGMENT BLACK7 and ethylcellulose have a weight ratio of 6: 4, manufactured by Ciba Specialty Chemicals Co., Ltd.) 20 parts by weight Rubiscol K-90 (polyvinylpyrrolidone, manufactured by BASF) 0.3 parts by weight Hilac 110H (ketone resin, Hitachi Chemical Co., Ltd.) 13 parts by weight Siritin V-88 dispersion (as described above) 8 parts by weight oleic acid 2 parts by weight ethylene glycol monophenyl ether 43 parts by weight ethylene glycol monobenzyl ether 13.7 parts by weight Ingredients except for Microlith BLACK C-A were heated and stirred. When complete dissolution was confirmed, Microlith BLACK C-A was gradually added and dispersed at a high speed for 1 hour with a lab mixer, with a viscosity of 5900 mPa · s (25 degreeC) black oil-based ball-point pen ink composition was obtained.

(Comparative Example 1)
Renol Black R-HW (processed pigment finely dispersed in polyvinyl butyral resin, carbon black 40% by weight, polyvinyl butyral resin 60% by weight, manufactured by Clariant Japan) 25 parts by weight Hilac 111 (ketone resin, Hitachi Chemical Co., Ltd.) 3 parts by weight Rubiscol K-90 dispersion (previously described) 10 parts by weight oleic acid 2 parts by weight ethylene glycol monophenyl ether 53.6 parts by weight benzyl alcohol 5 parts by weight Denkabutyral 2000 L ethylene glycol monophenyl glycol 10 Weight% solution (polyvinyl butyral resin, manufactured by Denki Kagaku Kogyo Co., Ltd.) 1.4 parts by weight The components excluding Renol Black R-HW in each of the above components were heated and stirred, and when dissolution was confirmed completely, Gradually add Renol Black R-HW, 1 hour fast dispersion in Bomikisa to give a black oil-based ink composition for a ballpoint pen of the viscosity 38400mPa · s (25 ℃).

(Comparative Example 2)
In Example 2, the viscosity was 37300 mPa · s (25 ° C.) except that Aerosil # 200 dispersion (described above) was added instead of Siritin N-85 dispersion (described above). An oil-based ink composition for black ballpoint pens was obtained.

(Comparative Example 3)
In Example 2, the same procedure as in Example 2 was used except that the Satinton No. 4 dispersion (described above) was used instead of the Siritin N-85 in the Siritin N-85 dispersion (described above), and the viscosity was 37100 mPa An oil-based ink composition for black ballpoint pens of s (25 ° C.) was obtained.

(Comparative Example 4)
In Example 2, it was the same as in Example 2 except that instead of silytin N-85 in the silytin N-85 dispersion (previously described), only the removed clay clay dispersion (previously described) was added. Thus, an oil-based ink composition for black ballpoint pens having a viscosity of 37100 mPa · s (25 ° C.) was obtained.

(Comparative Example 5)
In Example 2, instead of the siritin N-85 in the siritin N-85 dispersion (described above), the same amount of the mixed dispersion of satin No. 4 and diamond clay (described above) was added. In the same manner as in No. 2, an oil-based ink composition for black ballpoint pens having a viscosity of 37100 mPa · s (25 ° C.) was obtained.

As described above, the ink compositions for ballpoint pens obtained in Examples 1 to 8 and Comparative Examples 1 to 5 are commercially available oil-based ballpoint pens (BP107, manufactured by Pentel Co., Ltd., and the pen tip is mainly composed of a stainless tip and tungsten carbide. The test sample was filled with 0.3 g of a writing instrument similar to that of a cemented carbide ball.
However, in the case of writing, a pressure machine was attached to the rear end of the refill of the above sample, and the device was devised and modified so that writing was possible with a differential pressure of 50 kPa with respect to atmospheric pressure.
As a test item, an ink leakage test was performed. The results are shown in Table 1.
In addition, the viscosity measurement of the ink composition for ball-point pens of an Example and a comparative example was all measured and calculated | required by shear rate 1s- ¹ in the measurement environment of 25 degreeC using the STRESS rheometer by Bohlin.

Ink leakage test The above samples filled with the ink compositions for ballpoint pens of Examples 1 to 8 and Comparative Examples 1 to 5 were equipped with a pressure machine at the rear end of the refill, and the pressure difference was increased to 50 kPa with respect to atmospheric pressure. Left in the room indoors. After removing the cap and making a test writing to confirm that there is no blur, wipe off any ink composition for the ballpoint pen that has adhered to the surface of the ballpoint pen tip, and without exposing the cap, expose the exposed ball to anyone else. In a state where the ball is not touched, the ball is left facing for 12 hours at room temperature, and then the ball-point pen tip of each sample is visually observed to check the leakage state of the ink composition for the ball-point pen. In order to evaluate the amount of the ballpoint pen ink composition leaked, the leaked ballpoint pen ink composition adhering to the surface of the ballpoint pen tip was rubbed on the center of the micro slide glass S-7224 (manufactured by Matsunami Glass Industry Co., Ltd.). Gently place the same glass on it in the same direction and leave it for 2 minutes. A place where the length of a straight line that can be drawn on a ball-point pen ink composition spreading in a circular shape by its own weight is maximized, and a place where the length of a straight line that can be drawn in a direction perpendicular to the straight line is maximized are measured. And the value which multiplied each length was substituted for the amount of the ink composition for ball-point pens which leaked.

The principal part sectional view showing a ball-point pen tip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ball 2 Ball holder 3 Through-hole 3a Ball holding room 3b Middle hole 3c Rear hole 4 Inward protrusion part 4a Ball receiving seat surface 5 Radial groove

Claims (3)

Colored with a plate-like portion and particles having a spherical or lump-like or rod-like portion protruding from the plate-like portion, or a plurality of plate-like portions combined without overlapping surfaces A ballpoint pen ink composition comprising at least a material, a solvent, and a resin soluble in the solvent. Particles having a shape in which the plate-like portion and the spherical or lump-like or rod-like portion protruding from the plate-like portion are protruded, or a plurality of plate-like portions are combined without overlapping each other. The ink composition for a ballpoint pen according to claim 1, which is a composite of a plurality of particles having different shapes. The ink composition for a ballpoint pen according to claim 2, wherein the composite is a composite of kaolinite and quartz particles.

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