Oily red pigment dispersion liquid for writing implement ink and oily red pigment for writing implement ink

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an oil-based red pigment dispersion liquid for writing tool ink and an oil-based red pigment writing tool ink, and more particularly to an oil-based red pigment dispersion liquid for ballpoint pen ink and an oil-based red pigment ballpoint pen ink.

【0002】

[Conventional technology]

Ballpoint pens are widely used as writing instruments because they have a very smooth writing feel. The pen tip of a ballpoint pen is composed of a ball, a receiving seat for supporting the ball, an ink guide hole for guiding ink from an ink storage tube to the ball, and the like. When writing with a ballpoint pen, ink first adheres to the ball inside the chip, and the ink is transferred to the paper at any time by rotating the ball.

【0003】

Due to the writing mechanism peculiar to such a ballpoint pen, in the ballpoint pen tip, it is required that the ink smoothly moves to the space between the ball and the receiving seat. If the smooth movement of the ink is hindered in this space, the adhesion of the ink to the ball becomes inhomogeneous or intermittent, so that the smooth writing taste of the ballpoint pen is impaired, and writing defects such as blurring may occur.

【0004】

The oil-based ballpoint pen ink is generally a viscous composition containing an organic solvent, a colorant, a lubricant, a viscosity modifier, a fixing agent, and the like, and many types are known. For example, Japanese Patent Application Laid-Open No. 11-116879 describes an oil-based red ballpoint pen ink containing benzyl alcohol or ethylene glycol as an organic solvent, an oil-soluble red dye as a colorant, and a surfactant, a fatty acid, a ketone resin, etc. as an additive. Has been done.

【0005】

As a colorant for ballpoint pen ink, a colorant of the type that dissolves in an organic solvent, that is, a dye has been conventionally used. This is because when a colorant that does not dissolve in an organic solvent, such as a pigment, is used, the viscosity of the ink changes when the pigment coagulates and precipitates, which hinders the smooth flow of the ink in the space between the ball and the receiving seat. This is because it is considered that there is a high possibility that it will be done. Further, when the pigment particles become coarse, the writing quality deteriorates or writing becomes impossible due to the phenomenon of ball wear due to collision with the ball.

【0006】

That is, in the pigment ink, since the colorant is not dissolved in the solvent but dispersed, there is an essential problem that the colorant is more likely to coagulate and settle than the dye ink in which the colorant is dissolved in the solvent. There is. As a result, pigment inks have lower storage stability than dye inks, and pigments tend to aggregate and settle over time and thicken, so they are used as ballpoint pen inks that require the ink to flow smoothly over a long period of time. Has been considered unsuitable for.

【0007】

However, in recent years, pigments have begun to attract attention instead of dyes in order to give handwriting resistance to light and water, and pigment inks using pigments as colorants are also desired for oil-based ballpoint pens.

【0008】

Japanese Unexamined Patent Publication No. 11-21494 describes a red metallic ink for ballpoint pens containing a red pigment "CI Pigment Red 17" as a colorant. However, this red pigment is an azo pigment. Although the azo pigment is a pigment, it has poor fastness to alcohol, and when alcohol is used as a solvent, it partially dissolves in the azo pigment.

【0009】

As a result, since the azo pigment has poor color development and turns yellow when inked, there is a problem that a clear red handwriting cannot be obtained immediately after writing before the light resistance of the handwriting becomes a problem. That is, this pigment ink has an unfavorable hue as a normal ballpoint pen ink that does not contain a metallic pigment.

【0010】

When a pigment is used as an ink colorant, it is necessary to disperse and stabilize it in an organic solvent in advance using a disperser in the presence of various resins, polymer dispersants or surfactants. However, these have problems such as sedimentation and aggregation of the pigment over time or thickening of the viscosity of the pigment ink, and it is an important point in the formulation design to impart excellent stability over time. ing.

【0011】

[Problems to be Solved by the Invention]

The present invention has been used to solve the above-mentioned problems, and an object of the present invention is to select a pigment that exhibits good color development and dispersion stability in an alcohol-based organic solvent, and to use the pigment over time. It is an object of the present invention to provide a red pigment dispersion liquid in which pigment particles do not aggregate or settle. In addition, by using the pigment dispersion liquid, we provide an oil-based red pigment writing instrument ink that has good writing performance without thinning or fading of handwriting, and has excellent stability over time without thickening of the ink or aggregation of pigments. To do.

【0012】

[Means for solving problems]

The present invention is an oil-based red pigment dispersion for writing instrument ink, which comprises an alcohol-based organic solvent, a pigment dispersion resin dissolved in the organic solvent, and a red pigment which is diketopyrrolopyrrole dispersed in the organic solvent. Is provided, thereby achieving the above objectives.

【0013】

The oil-based red pigment dispersion liquid for writing tool ink of the present invention is a step of providing a mixture containing an alcohol-based organic solvent, a pigment dispersion resin, and a red pigment which is diketopyrrolopyrrole; It is preferable to produce by a method including a step of dispersing the mixture; and a step of dispersing the mixture using a fine dispersion mill medium;

【0014】

In order to achieve stability over time of the red pigment dispersion of the present invention, the blending ratio of the red pigment and the resin (red pigment / resin) is 0.5 to 5, preferably 1 to 3, and more preferably 1 to. It is 2. When the blending ratio of the red pigment and the resin is less than 0.5, there is at least a surplus resin other than the pigment surface coated, and that portion becomes a core and is combined with the pigment coated resin to form a red pigment dispersion liquid. Is thickened, and sufficiently stable dispersion cannot be obtained. On the contrary, if it exceeds 5, the resin that covers the pigment surface is insufficient, so that the red pigment is sufficiently stable because it approaches from the part not covered with the resin by the van der Waals force and eventually aggregates. No dispersion can be obtained.

【0015】

BEST MODE FOR CARRYING OUT THE INVENTION

The first embodiment of the present invention is an oil-based red pigment dispersion liquid for writing instrument ink containing an organic solvent, a pigment dispersion resin dissolved in the organic solvent, and a red pigment dispersed in the organic solvent.

【0016】

The oil-based red pigment dispersion for writing instrument ink is basically a high-concentration composition of the pigment component of the oil-based red pigment writing instrument ink. Generally, an oil-based red pigment writing instrument ink is prepared by adding an appropriate diluting solvent or additive to an oil-based red pigment dispersion for writing instrument ink by a known method. That is, when the oil-based red pigment writing instrument ink is used as the final product, the oil-based red pigment dispersion liquid for writing instrument ink is an intermediate composition used for preparing the oil-based red pigment writing instrument ink.

【0017】

Generally, an oil-based red pigment dispersion liquid for writing instrument ink has a solid content of about 15 to 50% by weight, and this is adjusted to a solid content of 20 to 50% by weight to obtain an oil-based red pigment writing instrument ink.

【0018】

As the organic solvent, a general organic solvent such as that used in writing instrument ink can be used. The preferred organic solvent is an alcohol-based organic solvent usually used in ballpoint pen inks. A high boiling point solvent having a boiling point of 150 ° C. or higher at normal pressure is particularly preferable.

【0019】

The alcohol solvent of the present invention includes (monohydric) alcohols, polyhydric alcohols (glycols) and derivatives thereof. Examples thereof include alcohols such as benzyl alcohol, 1-octanol, 2-octanol, α-methylbenzyl alcohol, and further, ethylene glycol, diethylene glycol, propylene glycol, hexylene glycol, benzyl glycol, ethylene glycol monophenyl ether (phenyl). Glycol), dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monophenyl ether, diethylene glycol monophenyl ether, propylene glycol monophenyl ether, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, Examples thereof include glycols such as tripropylene glycol monoethyl ether, propylene glycol methyl ether acetate and propylene glycol diacetate, and derivatives thereof. Further, the above-mentioned organic solvent may be used alone or in combination of two or more. The amount used is preferably 50 to 85% by weight based on the total amount of the red pigment dispersion liquid.

【0020】

As the red pigment, a red pigment used in known writing instruments can be used. It is preferable to use a diketopyrrolopyrrole pigment. This is because they exhibit excellent color development, fastness, and dispersibility in alcohol-based organic solvents. Further, the hue of the diketopyrrolopyrrole pigment is suitable for writing instruments.

【0021】

The preferred diketopyrrolopyrrole as the red pigment used in the present invention is of the formula. [0022]

[Chemical 1]

<img file="JP2001192596A_D0001.tif" />【0023】

[In the formula, R¹And R²Is a phenyl group or a naphthyl group which may independently have a substituent which does not impart water solubility, and is R.³And R⁴Is a hydrogen atom or a substituent that does not impart water solubility independently. ] Is a compound having the structure shown in.

【0024】

As the above diketopyrrolopyrrole pigment, R¹And R²Is a phenyl group selected from the group consisting of an unsubstituted phenyl group, a chlorophenyl group, a bromphenyl group and a cyanophenyl group, and R³And R⁴A red pigment represented by the general formula [I] where is a hydrogen atom is particularly preferable.

【0025】

In addition to diketopyrrolopyrrole pigments, red pigments include, for example, azo pigments such as naphthol AS and β-naphthol, but azo pigments have azo groups in their molecular structures and are therefore solvent resistant. In terms of sex, it has a weak side. Moreover, when the organic solvent used is a polarly strong solvent as described above, the azo pigment dissolves in the solvent, causing poor color development and discoloration.

【0026】

Examples of diketopyrrolopyrrole that can be used as a red pigment in the present invention include "CIPIGMENT Red 254", "CIPIGMENT Red 255", and "CIPIGMENT Red 272". Diketopyrrolopyrrole pigments having a primary particle size of 100 to 250 nm are preferable.

【0027】

More specifically, the product names "CROMOPHTAL DPP Coral Red C", "CROMOPHTAL DPP Flame Red FP", "CROMOPHTAL DPP Red BP", "CROMOPHTAL DPP Red BOC", "IRGAZIN DPP SCARLET" manufactured by Ciba Specialty Chemicals Co., Ltd. EK, "IRGAZIN DPP Red BTR", "IRGAZIN Red 2031", "IRGAZIN DPP Red BO", "IRGAZIN DPP Red BL" and the like.

【0028】

As the pigment-dispersed resin, a resin commonly used in ordinary oil-based writing instrument inks can be used. For example, polyvinyl butyral resin, rosin-modified maleic acid resin, ketone resin, maleic acid resin, ester gum, xylene resin, alkyd resin, phenol resin, terpenphenol resin, polyvinylpyrrolidone and the like are used. Preferred examples include polyvinyl butyral resin, rosin-modified maleic acid resin, ketone resin, phenol-modified xylene resin, and terpene phenol resin. These resins may be used alone or in combination of two or more.

【0029】

Considering the long-term storage stability of the pigment dispersion liquid, the softening point of the pigment dispersion resin is 80 to 150 ° C, preferably 100 to 135 ° C, and more preferably 105 to 130 ° C. By using the pigment dispersion resin in the range of 5 to 30% by weight, preferably 10 to 20% by weight, based on the total amount of the dispersion liquid, the pigment dispersibility is improved and the good viscosity is adjusted.

【0030】

Specifically, the polyvinyl butyral resin is manufactured by Sekisui Chemical Co., Ltd. under the trade names BL-1, BL-2, BL-S, BX-10, BX-L, BM-1, BM-2, BM-S, BX-1, BH-3, etc .; or product names # 2000-L, # 3000-1, # 3000-2, # 3000-4, # 4000-1, # 4000-2, etc. manufactured by Denki Kagaku Kogyo Co., Ltd. Be done.

【0031】

Specific examples of the phenol-modified xylene resin include trade names HP-70, HP-100, HP-120, HP-150, HP-210, and GHP-160 manufactured by Mitsubishi Gas Chemical Company.

【0032】

Specific examples of the ketone resin include the trade names Hirac 111 and Hirac 222 manufactured by Hitachi Chemical Industries, Ltd., and the trade name K-90 manufactured by Arakawa Chemical Co., Ltd.

【0033】

Specific examples of the terpene phenol resin include YS Polystar T80, YS Polystar T100, YS Polystar T115, YS Polystar T130, YS Polystar T145, YS Polystar S145, Mighty Ace G125, and Mighty Ace G150 manufactured by Yasuhara Chemical Co., Ltd. Be done.

【0034】

Specifically, the rosin-modified maleic acid resin is manufactured by Hitachi Chemical Polymer Co., Ltd. under the trade names of Tesspole 1101, Tesspole 1103, Tesspole 1104, Tesspole 1105, Tesspole 1150, Tesspole 1151, Tesspole 1152, Tesspole 1155, Tesspole 1158, Tesspole 1161 and the like. Can be mentioned.

【0035】

Further, one or more kinds of dispersants and rheology control agents (including thickeners) may be used in combination for the purpose of further improving the dispersion stability of the red pigment dispersion liquid under various conditions. The amount of these additions is not limited as long as it does not deteriorate the physical properties of the pigment dispersion liquid, but is preferably 0 to 20% by weight, more preferably 0 to 10% by weight, based on the entire pigment dispersion liquid.

【0036】

Specific examples of the dispersant include Abyssia brand names Solsparse 12000, Solspers 20000, Solspers 24000, Solspers 27000, Solspers 28000, etc .; Dispersive 2001, etc .; Product names manufactured by Kyoeisha Chemical Co., Ltd. Floren G-700, Floren DOPA-17, Floren DOPA-17HF, Floren DOPA-33, etc. can be mentioned.

【0037】

Anionic surfactants such as fatty acid salts, aromatic sulfonates, higher alcohol sulfates, fatty acid sulfates, alkylallyl sulfonates; decaglycerin fatty acid esters, hexaglycerin fatty acid esters, polyoxyethylene alkyl ethers. Using nonionic surfactants such as sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene polyalkyl ether, polyoxyethylene alkyl phenyl ether, etc. Is also good.

【0038】

The rheology control agent may be in the form of scales, rods (needle), lumps (spheres), or liquid, and can be used regardless of whether it is inorganic or organic. Specific examples thereof include inorganic bentnite, smectite, silica, calcium carbonate, organic urea compound, amide compound, urethane compound, vegetable oil, polyethylene, acrylic compound and the like. Although it depends on the amount added, the inorganic compound may adversely affect the wear of the ball and the receiving seat and the writing performance, so an organic compound is preferable if possible.

【0039】

As the dispersion method of the present invention, a known dispersion method can be used, but it is desirable to obtain a two-step dispersion step of first coarsely dispersing and then finely dispersing. Diketopyrrolopyrrole pigments used as red pigments belong to condensed polycyclic pigments and are considerably hard on the skeleton. Therefore, the order of dispersion is to first coarsely disperse the pigments under conditions requiring a large amount of energy, and then coarsely disperse the pigments. Dispersion is performed under the condition that the pigment is finely dispersed.

【0040】

As the disperser used in the present invention, a disperser such as a ball mill, an attritor, a hoologette mixer, an impeller mill, a colloidal mill, a sand mill [for example, a bead mill, a sand glider, a super mill, an agitator mill, a dyno mill (trade name)] is used. , Can be mixed or dispersed. At this time, a mill medium can be used. The material of the mill medium is not particularly limited, and for example, beads made of glass, stainless steel, zircon, or zirconia can be used. The mill medium is preferably filled in an amount of 60 to 95% by volume, particularly 75 to 85% by volume, based on the capacity of the mill.

【0041】

A more preferable dispersion method is to first perform pigment dispersion including a step of coarsely dispersing the pigment to an average particle size of 500 nm or less and a step of finely dispersing the coarsely dispersed pigment dispersion liquid to an average particle size of 400 nm or less. The coarse dispersion step and the fine dispersion step are performed by changing the dispersion conditions. For example, coarse dispersion uses a disperser or mill medium for coarse dispersion, and fine dispersion uses a disperser or mill medium for fine dispersion.

【0042】

Preferred dispersers for performing the coarse dispersion step are bead mills and various sand mills, and the mill medium is preferably zirconia beads having a diameter of 3 mm or 4 mm. Further, another preferable condition for performing the coarse dispersion step is to set the filling rate of the mill medium to 75 to 80%.

【0043】

Preferred dispersers for performing the fine dispersion step are bead mills and various sand mills, and the mill medium is preferably zirconia beads having a diameter of 2 mm. Further, another preferable condition for carrying out the fine dispersion step is to set the filling rate of the mill medium to 80 to 85%.

【0044】

In the above two-step dispersion step, for example, in the first-step coarse dispersion, the beads are dispersed with a bead diameter of, for example, 3 mm, and then as the second-step dispersion, the beads are replaced with 2 mm beads for dispersion. If it is not easy to replace the beads, use a crusher with different conditions, such as putting 3 mm beads in the first stage crusher and 2 mm beads in the second stage crusher. It may be connected and dispersed. If this second step of dispersion is not performed, coarse particles may remain in the dispersion liquid, causing ball wear in writing with a ballpoint pen and impairing smooth writing performance.

【0045】

In the pigment dispersion liquid obtained by the above dispersion method, it is desirable that the average particle size of the red pigment is 400 nm or less. More preferably, the average particle size of the red pigment is 50 to 350 nm, and even more preferably 100 to 300 nm. If the average particle size is larger than 400 nm, the pigment particles will settle, which will result in poor ink ejection from the tip of the ballpoint pen. Further, when diketopyrrolopyrrole is used as a red pigment, it is practically difficult to make the average particle size of the red pigment 100 nm or less.

【0046】

As for the particle size distribution of the pigment dispersion liquid obtained by the above dispersion method, it is desirable that the content of particles of the red pigment having a particle size of 1 μm or more is 10% by weight or less. Due to the design of the ballpoint pen, the gap where the ballpoint pen ink is ejected from the tip is only a few μm, and especially if there are more than 10% by weight of coarse particles of 1 μm or more, the coarse particles overlap and move between the ball and the tip. When passing through, the ball wears and the writing feeling is impaired. Therefore, it is important to suppress coarse particles of 1 μm or more to 10% by weight or less by performing the dispersion in the second step of the above dispersion method.

【0047】

The oil-based red pigment dispersion liquid for writing instrument ink of the present invention is less likely to cause thickening or coagulation and sedimentation of pigments, and in order to provide a writing instrument ink (for example, ballpoint pen ink) that requires the property that the ink flows smoothly for a long period of time. Shows sufficient stability over time. For example, the oil-based red pigment dispersion for writing instruments of the present invention hardly thickens even when stored at normal pressure of 50 ° C. for 1 month. Specifically, the thickening rate in that case is almost 20% or less, and the thickening rate does not exceed 30%.

【0048】

A second form of the present invention is an oil-based red pigment writing instrument ink containing an organic solvent, a pigment-dispersed resin dissolved in the organic solvent, and a red pigment dispersed in the organic solvent. As described above, this oil-based red pigment writing instrument ink can be prepared by a known method by adding an appropriate organic solvent, resin, additive, etc. to the oil-based red pigment dispersion liquid for writing instrument ink of the present invention.

【0049】

The amount of the red pigment in the oil-based red pigment writing instrument ink of the present invention may be an amount suitable for the desired hue and density, but if the amount added is too large, the writing line may be blurred or the ink may be used as a ballpoint pen ink. Problems such as inability to draw lines due to the lack of ink, so-called inability to write, and conversely, in the case of a small amount, problems such as inferior coloring of the handwriting occur. The amount of the pigment is preferably 5 to 30% by weight, preferably 7 to 15% by weight, based on the total pigment ink composition. In addition, known dyes, inorganic pigments or organic pigments can be added as long as they have the desired purpose and effect.

【0050】

The preferable composition of the oil-based red pigment writing tool ink of the present invention contains at least an organic solvent, a pigment dispersion resin dissolved in an organic solvent, and a colorant, and the red pigment is a diketopyrrolopyrrole pigment, and the diketopyrrolopyrrole-based pigment thereof. The blending ratio of the pigment and the resin (diketopyrrolopyrrole pigment / resin) is in the range of 0.5 to 5, preferably 1 to 3, and the softening point of the resin dissolved in the organic solvent is 80 to 150 ° C. It is preferably 100 to 135 ° C, and further 105 to 130 ° C. In order to further improve the pigment dispersion stability, it is preferable to use one or two or more resins selected from polyvinyl butyral resin, phenol-modified xylene resin, ketone resin, and terpenephenol resin as the pigment dispersion resin.

【0051】

The organic solvent added for dilution or viscosity adjustment is preferably an organic solvent added to the above pigment dispersion, and the total organic solvent is preferably 40 to 90% by weight, more preferably 50 to 80% by weight, based on the total pigment ink. More preferred.

【0052】

A resin can be added for the purpose of improving the fixability of handwriting, adjusting the viscosity, and stabilizing the dispersion of pigments. For example, ketone resin, xylene resin, polyethylene oxide, rosin derivative, terpene resin, kumaron-inden resin, polyvinyl butyral resin, terpene phenol resin, phenol-modified xylene resin, polyvinylpyrrolidone, acrylic resin, styrene-acrylic resin, A resin or oligomer for general pigment dispersion such as styrene-maleic acid resin, rosin-modified maleic acid resin, rosin-modified fumaric acid resin, and terpene-maleic acid resin can be shown.

【0053】

Various conventionally known methods for producing writing instrument ink can be applied to the adjustment of the oil-based red pigment writing instrument ink of the present invention. That is, a writing instrument ink composition can be obtained by dispersing the pigment dispersion liquid together with other components by a dispersion mixer. As the dispersion mixing, a disperser such as a sand mill, a ball mill, a homomixer, a bead mill, or a high-speed disperser can be used for mixing or dispersion.

【0054】

In addition to the above components, the oil-based red pigment writing instrument ink of the present invention has various components such as antioxidants, ultraviolet absorbers, lubricants, preservatives, fungicides, rust preventives, dispersants, and rheology control agents. Additives may be appropriately selected and used as needed.

【0055】

Dispersants used to improve writability and stabilize the dispersion of pigments include Abyssia's trade name Sols Pace 12000, Solspures 20000, Solsperse 27000, Solsperse 24000, Solsperse 28000, etc .; Series, Dispersive 180 series, Dispersive 2000, Dispersive 2001, etc .; Product names manufactured by Kyoeisha Chemical Co., Ltd. Floren G-700, Floren DOPA-17, Floren DOPA-17HF, Floren DOPA-33, etc. can be mentioned.

【0056】

In addition, anionic surfactants such as fatty acid salts, aromatic sulfonates, higher alcohol sulfates, fatty acid sulfates, alkylallyl sulfonates; decaglycerin fatty acid ester, hexaglycerin fatty acid ester, polyoxyethylene alkyl ether. Nonionic surfactants such as sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene polyalkyl ether, polyoxyethylene alkyl phenyl ether, etc. may also be used. You can.

【0057】

Examples of the above-mentioned lubricant include castor oil, a polyoxyethylene adduct of castor oil, polyoxyethylene alkylamine, molybdenum disulfide and the like.

【0058】

Examples of the above thickeners include organic bentonites such as Benton SD-2 and Benton 27 manufactured by NL Chemicals, TIXOGEL VZ and TIXOGELEZ manufactured by Nissan Gardler Catalyst, and EX-0101 traded by SUD Chemicals. Silica-based thickeners; Silica-based thickeners such as Aerosil 380, Aerosil COK84, Mizusawa Chemicals, Mizusakasil P-801, etc.; VA-500, Tarren VA-800, trade names ASA T-1, ASA T-51, ASA T-350F manufactured by Ito Oil Co., Ltd., and other fatty acid polyamides can be mentioned.

【0059】

[Effect of the invention]

The red pigment dispersion liquid of the present invention has a good hue and is excellent in various fastnesses such as weather resistance and solvent resistance by using diketopyrrolopyrrole as a colorant. In addition, because of its excellent stability over time, the pigment particles do not aggregate over time to form coarse particles or settle in the pigment dispersion.

【0060】

The writing instrument ink using the red pigment dispersion liquid of the present invention has excellent lubricity, has the effect of reducing wear of the ball-point pen when used as a ballpoint pen ink, has excellent durability, and has excellent writing feeling, and also has pigment dispersion. It has good properties over time and is excellent in stability over time. If the pigment hardens in the ink storage tube, or if the writing tip is left facing upward, the ink's followability will be poor, causing blurring, or writing taste due to ball wear. Does not cause writing defects such as worsening.

【0061】

[Example]

Next, the present invention will be specifically described with reference to examples, but of course, the present invention is not limited to these. In the following description, "part by weight" is abbreviated as "part".

【0062】

In Examples 1 to 10 and Comparative Examples 1 to 3, the oil-based red pigment dispersion liquid for ballpoint pen ink of the present invention and a method for producing the same will be described.

【0063】

Example 1 In a mixed solvent of 972 g of phenyl glycol and 324 g of benzyl alcohol, 144 g of polyvinyl butyral resin (trade name: Eslek BM-1, Sekisui Chemical Co., Ltd., softening point: 110 to 120 ° C) is added and stirred for about 2 hours. Dissolved while. Then, 360 g of diketopyrrolopyrrole (trade name: IRGAZIN DPP RedBO, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0064】

Measurement of average particle size and particle size distribution The particle size of the pigment particles in the dispersion obtained in Example 1 was measured using a laser light scattering particle size distribution measuring device (trade name: LPA3000 / 3100, manufactured by Otsuka Electronics Co., Ltd.), and the results are shown in the table. Shown in 1.

【0065】

Measurement of viscosity change rate (viscosity thickening rate) The viscosity of the dispersion obtained in Example 1 was measured with a rotary viscometer (EHD type) at 25 ° C. (This is the initial value.) Furthermore, this dispersion is placed in an oven kept warm at 50 ° C for 1 month, and then the same measurement is performed. The results are shown in Table 1.

【0066】

[Number 1]

Viscosity change rate = (value after 1 month-initial value) ÷ (initial value) [0067]

Confirmation of dispersibility The dispersion obtained in Example 1 was used. After diluting 2-fold with a mixed solvent of phenyl glycol and benzyl alcohol, a small amount was spotted on the preparation. This was covered with a cover glass and allowed to stand at room temperature for 1 day, and then pigment aggregates were confirmed with an optical microscope.

【0068】

Example 2 In a mixed solvent of 918 g of phenyl glycol and 306 g of benzyl alcohol, 216 g of polyvinyl butyral resin (trade name: Eslek BL-1, softening point: 100 to 110 ° C) manufactured by Sekisui Chemical Co., Ltd. is added and stirred for about 2 hours. Dissolved while. Then, 360 g of diketopyrrolopyrrole (trade name: CROMOPHTAL DPPFlame Red FP, manufactured by Ciba Specialty Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 4 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0069】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0070】

Example 3 In a mixed solvent of 972 g of phenyl glycol and 324 g of benzyl alcohol, 144 g of phenol-modified xylene resin (trade name: HP-100, softening point: 105 to 125 ° C, manufactured by Mitsubishi Gas Chemical Company, Inc.) was added and stirred for about 2 hours. Dissolved while. Then, 360 g of diketopyrrolopyrrole (trade name: IRGAZIN Red 2031, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0071】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0072】

Example 4 In a mixed solvent of 972 g of phenyl glycol and 324 g of benzyl alcohol, 144 g of ketone resin (trade name: Hirac 222, softening point: 100 to 120 ° C) manufactured by Hitachi Kasei Kogyo Co., Ltd. was added and dissolved with stirring for about 2 hours. did. Then, 360 g of diketopyrrolopyrrole (trade name: IRGAZIN Red 2031, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. After that, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0073】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0074】

Example 5 144 g of terpene phenol resin (trade name: YS Polystar T115, softening point: 110 to 120 ° C) manufactured by Yasuhara Chemical Co., Ltd. was added to a mixed solvent of 972 g of phenyl glycol and 324 g of benzyl alcohol and dissolved with stirring for about 2 hours. .. Then, 360 g of diketopyrrolopyrrole (trade name: IRGAZIN Red2031, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0075】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0076】

Example 6 In a mixed solvent of 900 g of phenyl glycol and 288 g of benzyl alcohol, 252 g of polyvinyl butyral resin (trade name: Eslek BL-1, softening point: 100 to 110 ° C) manufactured by Sekisui Chemical Co., Ltd. is added and stirred for about 2 hours. Dissolved while. Then, 360 g of diketopyrrolopyrrole (trade name: CROMOPHTAL DPPFlame Red FP, manufactured by Ciba Specialty Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0077】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0078】

Example 7 180 g of polyvinyl butyral resin (trade name: Eslek BM-1, softening point: 110 to 120 ° C) manufactured by Sekisui Chemical Co., Ltd. is put in a mixed solvent of 950 g of phenyl glycol and 310 g of benzyl alcohol and stirred for about 2 hours. Dissolved while. Then, 360 g of diketopyrrolopyrrole (trade name: IRGAZIN Red BO, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0079】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0080】

Example 8 In a mixed solvent of 972 g of phenyl glycol and 324 g of benzyl alcohol, 144 g of polyvinylpyrrolidone resin (trade name: K-30, softening point manufactured by ISP Japan: 100 to 110 ° C) was added and stirred for about 2 hours. Dissolved. Then, 360 g of diketopyrrolopyrrole (trade name: IRGAZIN Red 2031, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0081】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0082】

Example 9 In a mixed solvent of 900 g of phenyl glycol and 288 g of benzyl alcohol, 252 g of polyvinyl butyral resin (trade name: Eslek BL-1, softening point: 100 to 110 ° C) manufactured by Sekisui Chemical Co., Ltd. is added and stirred for about 2 hours. Dissolved while. Then, 360 g of diketopyrrolopyrrole (trade name: CROMOPHTAL DPPFlame Red FP, manufactured by Ciba Specialty Chemicals) was added and stirred for about 2 hours. Then, the mixture was dispersed for about 2 hours in a horizontal disperser filled with 3 mm beads to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0083】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0084】

Example 10 180 g of polyvinyl butyral resin (trade name: Eslek BM-1, softening point: 110 to 120 ° C) manufactured by Sekisui Chemical Co., Ltd. is put in a mixed solvent of 950 g of phenyl glycol and 310 g of benzyl alcohol and stirred for about 2 hours. Dissolved while. Then, 360 g of diketopyrrolopyrrole (trade name: IRGAZIN Red BO, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, dispersion was carried out for about 2 hours in a horizontal disperser filled with 2 mm beads to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had good color tone and fluidity.

【0085】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0086】

Comparative example 1 60 g of polyvinyl butyral resin (trade name: Eslek BM-1, softening point: 110 to 120 ° C) manufactured by Sekisui Chemical Co., Ltd. is put in a mixed solvent of 1000 g of phenyl glycol and 380 g of benzyl alcohol and stirred for about 2 hours. Dissolved while. Then, 360 g of diketopyrrolopyrrole (trade name: IRGAZIN DPP RedBO, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had poor fluidity and eventually thickened.

【0087】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0088】

Comparative example 2 Put 750 g of polyvinyl butyral resin (trade name: Eslek BL-1, softening point: 100 to 110 ° C) manufactured by Sekisui Chemical Co., Ltd. in a mixed solvent of 500 g of phenyl glycol and 190 g of benzyl alcohol, and heat at 40 ° C. It was dissolved with stirring for about 4 hours. Then, 360 g of diketopyrrolopyrrole (trade name: CROMOPHTAL DPP Flame Red FP, manufactured by Ciba Speciality Chemicals) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 4 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. Liquidity was poor both during and after dispersion.

【0089】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the particle size of 1 μm or more, and the rate of change in viscosity.

【0090】

Comparative example 3 In a mixed solvent of 972 g of phenyl glycol and 324 g of benzyl alcohol, 144 g of polyvinyl butyral resin (trade name: Eslek BM-1, Sekisui Chemical Co., Ltd., softening point: 110 to 120 ° C) is added and stirred for about 2 hours. Dissolved while. Then, 360 g of monoazo red pigment (trade name: Briliant Carmine7009, manufactured by Sanyo Pigment Co., Ltd.) was added and stirred for about 2 hours. Then, it was dispersed for about 1 hour in a horizontal disperser filled with 3 mm beads. Then, the beads were replaced with 2 mm beads and dispersed for about 40 minutes to prepare an oil-based red pigment dispersion for ballpoint pen ink. The obtained dispersion had no problem in both color tone and fluidity, but the color tone changed over time. (It's getting a little yellowish.

【0091】

Table 1 shows the measurement results of the average particle size of the above oil-based red pigment dispersion for ballpoint pen ink, the content of particles of 1 μm or more, and the rate of change in viscosity (viscosity).

【0092】

[table 1]

<img file="JP2001192596A_D0002.tif" />【0093】

In Examples 11 to 17 and Comparative Examples 4 to 6, the oil-based red pigment ballpoint pen ink using the oil-based red pigment dispersion liquid for ballpoint pen ink of the present invention will be described.

【0094】

Example 11 50 parts of red pigment dispersion obtained in Example 1, 25 parts of phenyl glycol, 10 parts of benzyl alcohol, 5 parts of rosin-modified phenol resin (softening point: 110 to 115 ° C), ketone resin (softening point: 100 to 120) ° C) An oil-based red pigment ball pen ink was prepared by dispersing and mixing 5 parts, 1 part of polyvinylpyrrolidone, and 4 parts of oleic acid.

【0095】

The ink obtained above was filled in a ballpoint pen composed of a cemented carbide ball having a diameter of 0.7 mm, a stainless steel tip, and a storage tube to obtain an oil-based ballpoint pen. Writing with the ballpoint pen showed smooth and good writing performance. Then, after leaving it in a constant temperature bath at 50 ° C with the writing tip facing up for 1 month, leave it at room temperature for 1 day, write straight with a writing angle of 70 ° and a load of 100 g, and the cassoulet length at that time. Was measured, and the results are shown in Table 3.

【0096】

The oil-based ballpoint pen obtained above is written with a writing tester in accordance with JIS S6039 under the conditions of a load of 100 g, a writing angle of 70 °, and a writing speed of 4 m / min. The writing feeling was tested by handwriting, and the results are shown in Table 3.

【0097】

Examples 12 ~ 17 In Examples 12 to 17, the red pigment dispersion obtained in Example 1 of Example 11 was replaced with the red pigment dispersion shown in Table 3, and other than that, an oil-based red pigment ballpoint pen ink was prepared in the same manner as in Example 11. did. Each of the obtained inks showed a good color tone as in Example 11, the viscosity of the ink was stable without agglutination and precipitation of the pigment, and good writability was shown in the initial stage and with time.

【0098】

Comparative Examples 4 ~ 6 In Comparative Examples 4 to 6, the red pigment dispersion obtained in Example 1 of Example 11 was replaced with the red pigment dispersion shown in Table 3, and other than that, an oil-based red pigment ballpoint pen ink was prepared in the same manner as in Example 11. did.

【0099】

In Comparative Examples 7 and 8, the oil-based red ballpoint pen ink of the prior art will be described.

【0100】

Comparative example 7 Salt-forming dye obtained from 20 g of CIBASIC RED 1 dye and 5 g of CIACID YELLOW 23 dye, phenyl glycol 45 g, benzyl alcohol 15 g, rosin-modified phenol resin (softening point: 110 to 115 ° C) 5 g, ketone resin (softening point) : 100 ~ 120 ° C) 5 g, polyvinylpyrrolidone 1 g, and oleic acid 4 g were mixed by stirring to prepare an oil-based red ballpoint pen ink. The obtained red ink was slightly yellowish.

【0101】

Comparative Example 8 Polyvinyl butyral resin (softening point: 100 to 110 ° C) 180 g, rosin-modified phenol resin (softening point: 110 to 115 ° C) 150 g, ketone resin (softening point: softening point) in a mixed solvent with 720 g of phenyl glycol and 460 g of benzyl alcohol. : 100 ~ 120 ° C) 150 g was added and dissolved with stirring for about 2 hours. Then, 300 g of CIPIGMENT RED 17 (SANYO RED BS, manufactured by Sanyo Dye Co., Ltd.) was added, and the mixture was stirred for about 2 hours. Then, dispersion was carried out for about 30 minutes with a horizontal disperser filled with 2 mm beads to prepare a red pigment dispersion liquid. Then, 750 g of phenyl glycol, 300 g of benzyl alcohol, 30 g of polyvinylpyrrolidone, and 120 g of oleic acid were further diluted to prepare an oil-based red pigment ballpoint pen ink. The obtained red ink showed discoloration over time. (It has become yellowish) [0102]

Table 2 shows the measurement results of the average particle size of the red pigment dispersions of Comparative Examples 7 and 8, the content of particles of 1 μm or more, and the rate of change in viscosity (viscosity).

【0103】

[Table 2]

<img file="JP2001192596A_D0003.tif" />【0104】

Examples 18 to 19 describe the oil-based red pigment ballpoint pen ink of the present invention.

【0105】

Example 18 In a mixed solvent of 660 g of phenyl glycol and 420 g of benzyl alcohol, 120 g of polyvinyl butyral resin (trade name: Eslek BM-1, Sekisui Chemical Co., Ltd. softening point: 110 to 120 ° C), rosin-modified phenol resin (softening point:) 150 g of 110 to 115 ° C), 150 g of ketone resin (softening point: 100 to 120 ° C), 120 g of oleic acid, and 30 g of polyvinyl butyralidone were added and dissolved with stirring for about 2 hours. Then, 300 g of diketopyrrolopyrrole (IRGAZIN DPPRed BO, manufactured by Ciba Speciality Chemicals) was added, and the mixture was stirred for about 2 hours. Then, the ink was dispersed in a horizontal disperser filled with 2 mm beads for about 30 minutes, and then diluted with 750 g of phenyl glycol and 300 g of benzyl alcohol to prepare an oil-based red pigment ballpoint pen ink. The obtained ink had good color tone and fluidity.

【0106】

Example 19 In a mixed solvent of 700 g of phenyl glycol and 460 g of benzyl alcohol, 200 g of phenol-modified xylene resin (trade name: HP-100, manufactured by Mitsubishi Gas Chemicals, Inc., softening point: 105 to 125 ° C), rosin-modified phenol resin (softening point:: 150 g of 110 to 115 ° C), 150 g of ketone resin (softening point: 100 to 120 ° C), 120 g of oleic acid, and 30 g of polyvinylpyrrolidone were added and dissolved with stirring for about 2 hours. Then, 300 g of diketopyrrolopyrrole (IRGAZIN DPP Red BO, manufactured by Ciba Speciality Chemicals) was added, and the mixture was stirred for about 2 hours. Then, the ink was dispersed in a horizontal disperser filled with 2 mm beads for about 30 minutes, and then diluted with 750 g of phenyl glycol and 300 g of benzyl alcohol to prepare an oil-based red pigment ballpoint pen ink. The obtained ink had good color tone and fluidity.

【0107】

The ink obtained above was filled in a ballpoint pen composed of a cemented carbide ball having a diameter of 0.7 mm, a stainless steel tip, and a storage tube to obtain an oil-based ballpoint pen. Writing with the ballpoint pen showed smooth and good writing performance. Then, after leaving it in a constant temperature bath at 50 ° C with the writing tip facing up for 1 month, leave it at room temperature for 1 day, write straight with a writing angle of 70 ° and a load of 100 g, and the cassoulet length at that time. Was measured, and the results are shown in Table 3.

【0108】

The oil-based ballpoint pen obtained above is written with a writing tester in accordance with JIS S6039 under the conditions of a load of 100 g, a writing angle of 70 °, and a writing speed of 4 m / min. The writing feeling was tested by handwriting, and the results are shown in Table 3.

【0109】

[Table 3]

<img file="JP2001192596A_D0004.tif" />