JPH06256408A - Method for producing spherical colored particles - Google Patents

Abstract

(57) [Summary] [Purpose] It has a sufficient degree of coloring and color tone, does not elute or migrate colored components, always shows stable light-shielding performance, etc., and has good strength and heat resistance, especially in liquid crystal displays. Provided is a method for industrially advantageously producing spherical colored particles suitable as colored spacer particles. [Structure] The method for producing spherical colored particles is as follows: Solvent Violet 31, Solvent Violet 36, Solvent Green 3, Solvent Green 5, Solvent Yellow 93, Solvent Red 52, Solvent Red 135, Disperse Violet 35 or Disperse. It is composed of dispersing and polymerizing a polymerizable monomer in which at least one kind of oil-soluble dye which is violet 38 is dissolved in an aqueous medium.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing spherical colored particles colored with an oil-soluble dye having a specific color index number.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display (hereinafter referred to as "LC
"D". ), Spacer particles (hereinafter referred to as LC particles) are used to regulate the substrate gap and to keep the thickness of the liquid crystal layer appropriate.
The spacer particles for D are simply referred to as "spacer particles". ) Is used. Generally, such spacer particles have sufficient strength and heat resistance to withstand the pressure and heating conditions in the LCD substrate assembly process, have a narrow particle size distribution that can uniformly maintain the substrate gap, and It is required that the liquid crystal does not elute into the liquid crystal and does not disturb the alignment of the liquid crystal. And more recently,
Particularly, from the viewpoint of improving the image quality by improving the contrast of the color liquid crystal panel, the colored spacer particles (hereinafter, L
The colored spacer particles for CD are simply referred to as "colored spacer particles". ) Is being used,
There is a strong demand for the colored spacer particles to have sufficient light-shielding properties, and the spacer particles, including the colored spacer particles, have excellent adhesiveness, and are used during the production of liquid crystal panels by liquid crystal injection or during the use of liquid crystal panels. To
It is also required that the spacer particles do not move. Conventionally, the colored particles used for the colored spacer particles and the like are (a) a method for dyeing colorless or white polymer particles,
(B) A method in which a monomer containing a colorant is subjected to suspension polymerization or emulsion polymerization to obtain colored particles and then classified, and (C) a method in which a polymer and a colorant are kneaded, and then granulated and classified. ,
(D) It is produced by a method of coating the surface of polymer particles with a pigment or the like. However, among the conventional methods for producing colored particles, in the method (a), not only the dye does not sufficiently penetrate into the inside of the particle, the color tone is thin and the light-shielding property is insufficient, and May dissolve in the liquid crystal and disturb the alignment of the liquid crystal, and in the method (b), a pigment that has no affinity with the component that constitutes the base particle or is poor is often dispersed at a high concentration. Only brittle particles can be obtained, and even when a dye is used as a coloring agent, the polymerization reaction is likely to be hindered or fading during the polymerization. In the method (c), the same coloring as the method (b) is performed. As the particles often become brittle, fractionation of particles having a predetermined particle size and a predetermined particle size distribution mixed with a pigment is low, and further, in the method (d), the pigment on the particle surface is easily peeled or dropped, and Special to improve it There are physical and the like are required of the problem, in the conventional (a) to (d) or the like method, it is difficult to industrially advantageously produce colored particles capable of satisfying various requirements of the ~ like. On the other hand, using a medium containing a water-miscible organic solvent, the monomer, the oil-soluble dye, a dispersion stabilizer and a polymerization initiator are dissolved in the medium to form prepolymer particles by polymerization, By increasing the water concentration in the medium or evaporating the water-miscible organic solvent during the polymerization, the solubility of the monomer and the oil-soluble dye in the medium is reduced, and the monomer and oil are added to the prepolymer particles. It is also known that colored particles having a relatively uniform particle size can be obtained by absorbing a soluble dye and a polymerization initiator to complete the polymerization (see, for example, JP-A-3-140968). However, in this method, the polymerization operation is complicated, and the inhibition of the polymerization reaction and the fading during the polymerization are unavoidable, and the dye retention of the obtained colored particles is not always sufficient.

[0003]

Therefore, the present invention has a sufficient degree of coloring and color tone, does not elute or migrate a coloring component, always shows stable light-shielding performance, etc., and has good strength and heat resistance. In particular, it is an object of the present invention to provide a method for industrially advantageously producing spherical colored particles suitable as colored spacer particles for LCD.

[0004]

In the present invention, the color index numbers are Solvent Violet 31, Solvent Violet 36, Solvent Green 3, Solvent Green 5, Solvent Yellow 93, Solvent Red 52, Solvent Red 135, Disperse Violet 35 or The gist is a method for producing spherical colored particles, characterized in that a polymerizable monomer in which at least one kind of oil-soluble dye which is Disperse Violet 38 is dissolved is dispersed and polymerized in an aqueous medium.

The present invention will be described in detail below. This will clarify the objects, configurations and effects of the present invention. First, the oil-soluble dyes (hereinafter referred to as “specific oil-soluble dyes”) to be dissolved in the polymerizable monomer have color index numbers of solvent violet 31, solvent violet 36, solvent green 3, solvent green 5, solvent yellow 93. , Solvent Red 52, Solvent Red 135, Disperse Violet 35 or Disperse Violet 38. These specific oil-soluble dyes can be used alone or in admixture of two or more.

Here, the color index number is
"Color Index" (ColorIndex th
third edition, 1971; The Soci.
etyof Dyers and Colorists
(UK) and The American Associ
ation of Textile Chemists
And co-colors (US) co-editor)
It is a number assigned to classify industrial dyes / pigments by a display showing a genus name and a color name according to the purpose and a number showing a structure, whereby the dye can be identified.

In the present invention, by using two or more kinds of these specific oil-soluble dyes in an appropriate combination, colored particles having substantially all color tones can be produced. For example, by combining three kinds of solvent violet 36, solvent green 3 and solvent yellow 93, black particles can be obtained,
Such black particles are particularly preferable as the colored spacer particles. Thus, when two or more specific oil-soluble dyes are used in combination, the specific oil-soluble dyes can be mixed in advance and then dissolved in the polymerizable monomer,
It is also possible to dissolve any one or more specific oil-soluble dyes in the polymerizable monomer and then dissolve the remaining specific oil-soluble dyes.

Many oil-soluble dyes other than the specific oil-soluble dyes are known, but for those other than the specific oil-soluble dyes, the inhibition of the polymerization reaction, the fading during the polymerization, or the colored particles after the polymerization are not Elution of dye when contacted with a medium,
Not only does it become unsuitable as general colored particles, but also when used as colored spacer particles, there arises a problem that the alignment of liquid crystals is disturbed and stable light shielding performance cannot be exhibited.

The content of the specific oil-soluble dye in the polymerizable monomer is appropriately selected according to the desired degree of coloring and color tone, but is usually 0.
It is 1 to 20 parts by weight, preferably 1 to 20 parts by weight.

Next, the polymerizable monomer is compatible with the specific oil-soluble dye and is polymerized in an aqueous medium to form spherical polymer particles. Examples of such a polymerizable monomer include vinyl aromatic monomers such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, chlorostyrene, divinylbenzene and diisopropenylstyrene; (meth) acryl. Acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate,
Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, ethylene Glycol di (meta)
Acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, hexaethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate,
Trimethylolpropane tri (meth) acrylate,
Acrylic monomers such as (meth) acrylonitrile; ethyl vinyl ether, n-propyl vinyl ether, n
-Vinyl ether type monomers such as butyl vinyl ether, n-hexyl vinyl ether, cyclohexyl vinyl ether, phenyl vinyl ether; vinyl ester type monomers such as vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate; vinyl chloride, vinylidene chloride , Vinyl bromide, vinylidene bromide and other vinyl halide monomers; (meth) allyl alcohol, methyl (meth) allyl ether, ethyl (meth) allyl ether, 1,4-
Butanediol di (meth) allyl ether, trimethylolpropane tri (meth) allyl ether, acetic acid (meth) allyl, propionic acid (meth) allyl, di (meth)
Examples include allyl monomers such as allyl phthalate and tri (meth) allyl cyanurate. These polymerizable monomers may be used alone or in admixture of two or more.

Preferred polymerizable monomers are styrene, (meth) acrylic acid esters and divinylbenzene,
Divinylbenzene is particularly preferable.

Divinylbenzene is used as a total polymerizable monomer
The colored particles obtained by using ˜100% by weight have particularly excellent dye-retaining property, and even when they are brought into contact with various organic media, the specific oil-soluble dye contained therein is completely eluted or migrated. Since it has no mechanical strength and is not deformed by heat, it can be preferably used as a colored spacer particle.

In the present invention, a solution of a specific oil-soluble dye dissolved in a polymerizable monomer in a predetermined amount (hereinafter referred to as "polymerizable monomer solution") is dispersed in an aqueous medium. The medium consists of water alone or a mixture of water and a small proportion of water-miscible medium. In this case, as the water-miscible medium, for example, alcohols, ketones, ethers, esters, amines and the like can be used. Water is usually used as the aqueous medium, and the water-miscible medium is added if necessary. The dispersion of the polymerizable monomer solution in the aqueous medium can be carried out at once, intermittently or continuously.

When the polymerizable monomer solution is dispersed in the aqueous medium, the amount of the polymerizable monomer solution is usually 0.1 to 30 parts by weight, preferably 1 per 100 parts by weight of the aqueous medium.
~ 20 parts by weight.

When the polymerizable monomer solution is dispersed in the aqueous medium, it is preferable to add a dispersion stabilizer such as an emulsifier and a suspension stabilizer. These dispersion stabilizers can be added to the aqueous medium before the dispersion of the polymerizable monomer solution, or can be added simultaneously with the dispersion of the polymerizable monomer solution.

Examples of the emulsifier include higher fatty acid salts such as sodium oleate, alkylsulfates such as sodium dodecylsulfate, alkylsulfonates such as sodium stearylsulfonate, and alkylarylsulfonates such as sodium dodecylbenzenesulfonate. , Anionic surfactants such as sulfosuccinic acid ester salts such as dioctyl sodium sulfosuccinate; alkyl polyoxyethylene ethers, alkylphenyl polyoxyethylene ethers, polyethylene glycol alkyl ethers, alkylcarbonyloxy polyethylenes, N, N-di (Polyoxyethylene) alkane amides, N, N-di (alkanol) alkane amides, polyethylene glycol fatty acid ester, sorbitan fatty acid ester, fat Nonionic surfactants such as fatty acid polyglyceride, fatty acid polyhydric alcohol esters such as fatty acid sucrose ester, and fatty acid polyhydric alcohol polyoxyethylene ethers; higher alkyl ammonium salts such as dodecyl ammonium chloride, quaternary N such as dodecyl pyridinium chloride -Alkylpyridinium salts,
Quaternary N-alkyl picolinium salts such as dodecyl picolinium chloride, quaternary alkyl ammonium salts such as cetyl trimethyl ammonium bromide, quaternary alkyl imidazolinium salts, quaternary polyoxyethylene alkyl diammonium salts, Cationic surfactants such as quaternary polyoxyethylene alkylammonium salts, quaternary alkoxypropylammonium salts, organic acids or inorganic acid salts of alkylpropylenediamine; alkylamine oxides, alkylglycines, alkylalanines, alkylbetaines , Zwitterionic surfactants such as alkyl imidazolines, and the like. These emulsifiers can be used alone or in admixture of two or more.

Examples of the suspension stabilizer include cellulose derivatives such as hydroxyethyl cellulose and carboxymethyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, sodium polycarboxylic acid, polyacrylic acid or its salt, polyacrylamide and polyethylene oxide. Can be mentioned. These suspension stabilizers can be used alone or in admixture of two or more.

In the present invention, the emulsifier and the suspension stabilizer may be used alone, or the emulsifier and the suspension stabilizer may be used in combination. The amount of these dispersion stabilizers used is usually 10 parts by weight or less, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the polymerizable monomer solution.
Parts by weight.

The polymerization of the polymerizable monomer dispersed in the aqueous medium is usually carried out using a radical polymerization initiator. Examples of such a radical polymerization initiator include lauroyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, cumene hydrido peroxide, p-menthane hydroperoxide, di-t-butyl peroxide, dicumyl peroxide. Oxide, 2,2'-azobisisobutyronitrile, 2,2'-azobisisovaleronitrile and the like, which are soluble in a polymerizable monomer, are polymerized alone or in combination of two or more. It is used by dissolving it in a polar monomer.

The amount of these radical polymerization initiators used is
It is usually 0.1 to 100 parts by weight of the total polymerizable monomer.
It is 10 parts by weight, preferably 0.5 to 5 parts by weight.

As described above, the polymerization conditions in the polymerization using the radical polymerization initiator depend on the kind of the polymerization initiator, the polymerizable monomer, etc., but the polymerization temperature is usually about 0 to 100 ° C. and the polymerization time. However, it is usually about 10 minutes to 48 hours.

The polymerization of the polymerizable monomer dispersed in the aqueous medium can be carried out, for example, by aromatic ketones such as benzophenone and Michler's ketone; acetophenones such as acetophenone and benzoin ether; diketones such as benzyl.
It can also be carried out by irradiation with light in the presence of a photopolymerization initiator or sensitizer such as acyl oxime esters; acyl phosphine oxides. In this case, the radical polymerization initiator may or may not be used.

As described above, spherical colored particles having a uniform particle size can be obtained by dispersing and polymerizing the polymerizable monomer in which the specific oil-soluble dye is dissolved in the aqueous medium.

Further, in the present invention, the polymerizable monomer solution is passed through a filter to be dispersed in an aqueous medium, so that the particle size distribution of droplets is smaller than that in the case of simply mechanically stirring and dispersing. Can be narrowed, so that
The particle size of the obtained spherical colored particles can be represented by a coefficient of variation (= standard deviation of particle size / average particle size × 100) and suppressed to 20% or less.

A method for dispersing droplets in an aqueous medium by passing through a filter in this way has already been disclosed in JP-A-2-9543.
As described in Japanese Patent Publication No. 3, the method of this publication is obtained by dispersing a liquid such as kerosene as a dispersed phase in a liquid as a continuous phase and
I have only prepared emulsions such as / W and W / O / W. On the other hand, the present invention applies such a method to a dispersion of a polymerizable monomer solution containing a specific oil-soluble dye, and then polymerizes to have a uniform particle size distribution, and particularly colored spacer particles. As a result, a very useful spherical colored particle can be obtained, which is a significant effect.

In the present invention, as the filter, a filter capable of dispersing a polymerizable monomer solution in an aqueous medium with a predetermined uniform particle size is used. Examples thereof include woven fabrics of various organic fibers or Non-woven fabric filter: Wire filter of nickel, stainless steel, monel metal, etc .; Sintered metal filter of nickel, stainless steel, etc .; Polymer that pierces resin film of polyester, polycarbonate, etc. with neutrons, charged particle beams, etc. Membrane filters: inorganic filters such as porous ceramics and porous glass can be mentioned, but particularly preferred filters are:
This is a cylindrical porous glass filter developed at the National Miyazaki Prefectural Industrial Research Institute.

The average pore size of the filter is appropriately selected according to the desired particle size of the droplets of the polymerizable monomer solution,
Usually 0.25 to 10 μm, preferably 0.5 to 3 μm
Is. Further, the narrower the pore size distribution of the filter, the more preferable.

The size of the droplets of the polymerizable monomer solution in the aqueous medium depends on the pore size of the filter, the pressure for pushing the polymerizable monomer solution into the aqueous medium, and the flow velocity of the aqueous medium flowing in contact with the surface of the filter. It can be controlled by adjusting the viscosity and the like.

Further, when passing through the filter and dispersing in an aqueous medium, an organic liquid having a high solubility in water, such as methanol, ethanol, or acetone, is dissolved in the polymerizable monomer solution, In the process of dispersing the polymerizable monomer solution, or during the polymerization after dispersion,
It is also possible to adjust the particle size of the spherical colored particles to a smaller size by utilizing the fact that the organic liquid migrates into the aqueous medium. Further, such a method of adjusting the particle size is also effective when the polymerizable monomer solution is dispersed in an aqueous medium without passing through a filter.

FIG. 1 shows an example of a method of polymerizing by dispersing a polymerizable monomer solution through a filter. Here, 1 is a cylindrical porous glass filter, 2 is a holder, 3 is an aqueous medium, 4 is a metering pump, 5 is a polymerizable monomer solution, 6 is a pressure vessel, and 7 is for delivering a polymerizable monomer solution. Of air, 8 is a polymerization vessel.

The polymerizable monomer solution 5 containing the specific oil-soluble dye and the polymerization initiator is placed in the pressure vessel 6 and cooled if necessary to prevent the polymerization. An aqueous medium 3 containing a dispersion stabilizer and the like is quantitatively supplied to the inside of the cylindrical porous glass filter 1 by a quantitative pump 4.
The polymerizable monomer solution 5 is introduced into the holder 2 located outside the cylindrical porous glass filter 1 by pressurizing the gas phase part of the pressure vessel 6 with air 7, and passes through the filter. It becomes fine droplets and is dispersed in the aqueous medium 3 flowing inside the cylindrical porous glass filter 1. The dispersed polymerizable monomer solution 5 is sent to the polymerization container 8 and polymerized to form spherical colored particles.

The coefficient of variation of the particle size of the spherical colored particles thus obtained is usually in the range of 5 to 20%, but it is particularly suitable as the colored spacer particles for keeping the thickness of the liquid crystal phase constant. If necessary, in order to obtain colored particles having a coefficient of variation of 5% or less, a precision sieving machine, a dry classifier (eg, gravity classifier, dry centrifugal classifier, etc.), a wet classifier (eg, hydraulic classifier) Machine, wet mechanical classifier, wet centrifugal classifier, etc.)
And so on.

[0033]

According to the present invention, by dissolving the specific oil-soluble dye in the polymerizable monomer and polymerizing, the inhibition of the polymerization reaction by the dye does not pose a problem and the fading does not occur during the polymerization. Spherical colored particles having a desired particle size can be industrially advantageously produced.

Moreover, the spherical colored particles obtained by the present invention have a sufficient degree of coloring and color tone, and even if they are dispersed in, for example, water or various organic solvents and subjected to ultrasonic waves, the colored components are no longer dissolved. Since it does not migrate and has excellent adhesiveness, the colored particles do not move during the production or use of the liquid crystal panel, and the strength and heat resistance are good. Therefore, particularly when such colored particles are used as colored spacer particles, stable light-shielding performance can be always exhibited. The colored particles obtained by the present invention are also useful as colorants for various rubbers, plastics, paints, light-shielding agents, and the like.

[0035]

EXAMPLES Next, the present invention will be described more specifically by way of examples. However, the present invention does not exceed the gist of the invention.
There is no limitation to these examples. Example 1 Polymerization was carried out by a method using a cylindrical porous glass filter having a length of 125 mm shown in FIG. 1 (average pore size 1.1 μm). A polymerizable monomer solution prepared by dissolving 2 g of solvent violet 36 and 2 g of 2,2′-azobisisobutyronitrile in 100 g of divinylbenzene (purity 81% by weight and containing ethylbenzene 19% by weight) was placed in a pressure vessel. . The vapor phase of the pressure vessel was caused by flowing an aqueous medium consisting of a 0.1% by weight aqueous solution of polyvinyl alcohol (trade name: GH17, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) inside the cylindrical porous filter at 1 liter / hour. 0.6 kg / cm ²
The polymerizable monomer solution was passed through the filter by applying the air pressure of, and dispersed in the aqueous medium for 3 hours. This dispersion was introduced into a polymerization vessel and polymerized under stirring at 90 ° C. for 10 hours to obtain dark purple spherical colored particles. The polymerization conversion rate was 91%. During this polymerization, the polymerization reaction was not hindered, and the dye was not eluted in the aqueous medium. The spherical colored particles obtained had an average particle size of 5.5 μm and a particle size variation coefficient of 11%.
Met. The spherical colored particles were washed with water, further washed with isopropyl alcohol, dried, and then classified with a dry classifier to obtain spherical colored particles 3 having a variation coefficient of 4.5%.
8 g was obtained. The thus-classified spherical colored particles retained their deep purple color even when dispersed in toluene, with the dye no longer eluting. Further, the spherical colored particles after the classification were pressed as colored spacer particles under the conditions of 160 ° C. and 1.0 kg / cm ^{2 in} the LCD substrate assembly process, and the distance between the transparent electrode substrates was kept constant, In addition to being firmly fixed to the upper and lower transparent electrode substrates, the colored particles were stably fixed even when the liquid crystal was injected, and the strength and heat resistance of the colored particles as a whole were excellent.

Example 2 100 g of the same divinylbenzene as used in Example 1
0.3 g of Solvent Yellow 93, 0.7 g of Solvent Green 3 and 1.
0 g and 2,2'-azobisisobutyronitrile to 2 g
Dark black spherical colored particles were obtained in the same manner as in Example 1 except that the polymerizable monomer solution in which g was dissolved was used and a 0.1 wt% aqueous solution of sodium lauryl sulfate was used as the aqueous medium. The polymerization conversion rate was 98%. During this polymerization, the polymerization reaction was not hindered, and the dye was not eluted in the aqueous medium. The obtained spherical colored particles had an average particle size of 5.4 μm and a particle size variation coefficient of 8.6%.
Met. The spherical colored particles were classified in the same manner as in Example 1 to obtain 49 g of spherical colored particles having a particle size variation coefficient of 3.8%.
Got The spherical colored particles after classification maintained a dark black color even when dispersed in toluene, and the dye no longer eluted. Further, the spherical colored particles after the classification were pressed as colored spacer particles under the conditions of 160 ° C. and 1.0 kg / cm ^{2 in} the LCD substrate assembly process, and the distance between the transparent electrode substrates was kept constant, In addition to being firmly fixed to the upper and lower transparent electrode substrates, the colored particles were stably fixed even when the liquid crystal was injected, and the strength and heat resistance of the colored particles as a whole were excellent.

Example 3 A dark black powder was obtained in the same manner as in Example 2 except that a cylindrical porous filter having an average pore size of 0.63 μm was used and the air pressure applied to the pressure vessel was changed to 1.5 kg / cm ² . Spherical colored particles were obtained. The polymerization conversion rate was 96%. During this polymerization, the polymerization reaction was not hindered, and the dye was not eluted in the aqueous medium. The obtained spherical colored particles had an average particle size of 3.4 μm and a particle size variation coefficient of 13%.
Met. The spherical colored particles were classified in the same manner as in Example 1, and 33 g of spherical colored particles having a particle size variation coefficient of 4.8%.
Got The spherical colored particles after classification maintained a dark black color even when dispersed in toluene, and the dye no longer eluted. In addition, the spherical colored particles after the classification were measured with a microcompression tester for the load required to break one particle, and it was 3.8 g, indicating that the colored colored particles have sufficient strength. It became clear. Further, the spherical colored particles after classification are used as colored spacer particles in the LCD substrate assembly process.
When pressed under the conditions of ℃ and 1.0 Kg / cm ² , the distance between the transparent electrode substrates is kept constant, and it firmly adheres to the upper and lower transparent electrode substrates, and the colored particles are stably fixed even when the liquid crystal is injected. In addition, the strength and heat resistance of the colored particles as a whole were excellent.

[0038]

EFFECTS OF THE INVENTION According to the present invention, the inhibition of the polymerization reaction by the dye does not pose any problem, and no fading occurs during the polymerization. Therefore, the spherical colored particles having a desired particle size can be industrially advantageously produced. You can Moreover, the colored particles obtained by the present invention have a sufficient coloring degree and color tone, the colored component does not elute or migrate, and can always exhibit stable light-shielding performance, and also has strength and heat resistance. Good, especially LC
It is useful as a colored spacer particle in D.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the method of the present invention in which polymerization is performed using a cylindrical porous filter.

[Explanation of symbols]

 1 Cylindrical Porous Glass Filter 2 Holder 3 Aqueous Medium 4 Metering Pump 5 Polymerizable Monomer Solution 6 Pressure Vessel 7 Air 8 Polymerization Vessel

Claims (1)

[Claims] 1. An oil-soluble substance having a color index number of solvent violet 31, solvent violet 36, solvent green 3, solvent green 5, solvent yellow 93, solvent red 52, solvent red 135, disperse violet 35 or disperse violet 38. A method for producing spherical colored particles, characterized in that a polymerizable monomer in which at least one dye is dissolved is dispersed in an aqueous medium and polymerized.