JP3304502B2 - Method for producing colored particles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing colored particles particularly useful as colored spacer particles for a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display (hereinafter referred to as "LCD")
That. In (2), spacer particles (hereinafter, spacer particles for LCD are simply referred to as “spacer particles”) are used in order to regulate the gap between the substrates and keep the thickness of the liquid crystal layer at an appropriate level. Generally, such spacer particles should have sufficient strength and heat resistance to withstand the pressure and heating conditions in the LCD substrate assembly process, and have a narrow particle size distribution capable of uniformly holding the substrate gap.
It is required that the compound does not elute into the liquid crystal component and does not disturb the orientation of the liquid crystal. More recently, colored spacer particles (hereinafter, referred to as “colored spacer particles” are referred to simply as “colored spacer particles”) from the viewpoint of improving the image quality by improving the contrast of a color liquid crystal panel and the like. However, the colored spacer particles are strongly required to have a sufficient light-shielding property, and the spacer particles, including the colored spacer particles, are excellent in adhesiveness. It is also required that the spacer particles do not move during use of the inside or the liquid crystal panel. Conventionally, colored particles used for colored spacer particles and the like,
(A) a method of dyeing uncolored polymer particles, (b) a method of subjecting a monomer containing a colorant to suspension polymerization or emulsion polymerization to obtain colored particles, and then classifying the particles. It is produced by a method of kneading a colorant, granulating and classifying, and (d) a method of coating the surface of polymer particles with a pigment. However, among the conventional methods for producing colored particles,
In the method (a), in general, the dye does not sufficiently penetrate into the interior of the particles, and the color tone is light and the light-shielding property is insufficient. There is also known a method of dyeing an epoxy group-containing copolymer with a dye having reactivity with the epoxy group (see, for example, JP-A-4-103633). Since the production process of the colored particles is multi-stage, there is a problem in productivity, and since the dyed area is limited to the copolymer surface, it cannot be said that sufficient light-shielding properties can be achieved. In this case, there is no affinity for the components that make up the base particles, or poor pigments are dispersed at a high concentration, so that often only brittle particles are obtained. Is disturbed or fades during polymerization Easier, in the method (c),
As in the method (b), the colored particles often become brittle, and the fraction of particles having a predetermined particle size and a predetermined particle size distribution containing the pigment is low, and in the method (d), the particle surface There are problems such as the pigment being easily peeled off and falling off, and a special treatment is required in order to improve it. In the conventional methods (a) to (d), the methods described above
It is difficult to industrially produce colored particles that can satisfy various requirements such as the above.

[0003]

Accordingly, the present invention has a sufficient degree of coloring and color tone, has no elution or migration of coloring components, always shows stable light shielding performance, and has good strength and heat resistance. Accordingly, it is an object of the present invention to provide a method for industrially advantageously producing colored particles suitable as colored spacer particles.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a polymerizable monomer containing a hydroxyl group-containing monomer and / or a polymerizable monomer in which a hydroxyl group-containing polymer is dissolved (hereinafter referred to as "monomers of these monomers"). A polymerizable monomer solution) is dispersed in an aqueous medium in which a reactive dye is dissolved and polymerized.

Hereinafter, the present invention will be described in detail. This will clarify the objects, configurations and effects of the present invention. First, as the hydroxyl group-containing monomer used in the present invention, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, Hydroxyalkyl (meth) acrylates such as glycerin mono (meth) acrylate or di (meth) acrylate and trimethylolpropane mono (meth) acrylate or di (meth) acrylate; diethylene glycol mono (meth) acrylate, tetraethylene glycol mono Polyethylene glycol mono (meth) acrylates such as (meth) acrylate and hexaethylene glycol mono (meth) acrylate; unsaturated alcohols such as (meth) allyl alcohol; Hydroxyl-containing vinyl aromatic compounds such as phenol, vinyl cresol and vinyl naphthol; and hydroxyl-containing vinyl ethers such as ethylene glycol monovinyl ether, diethylene glycol monovinyl ether, 1,4-butanediol monovinyl ether, trimethylolpropane monovinyl ether or divinyl ether. Can be mentioned. These hydroxyl group-containing monomers can be used alone or in combination of two or more.

Examples of the hydroxyl group-containing polymer soluble in the polymerizable monomer include (co) polymers of the above-mentioned hydroxyl group-containing monomer, cellulose derivatives such as hydroxyethylcellulose and ethylcellulose; methyl starch, Starch derivatives such as ethyl starch; polyvinyl alcohol derivatives such as partially saponified polyvinyl acetate and partially acetalized polyvinyl alcohol; and branched polyalkylene glycols such as branched polyethylene glycol and branched polypropylene glycol. These hydroxyl group-containing polymers can be used alone or in combination of two or more.

In the present invention, the polymerizable monomer has 1 to 100 parts by weight of a hydroxyl-containing monomer and / or a hydroxyl-containing polymer dissolved therein per 100 parts by weight in total.
The amount of the hydroxyl group-containing monomer used is 100 parts by weight or less, preferably 2 to 50 parts by weight, more preferably 4 to 50 parts by weight, based on 100 parts by weight of the total polymerizable monomer. The amount of the polymer used is 20 parts by weight or less, preferably 1 to 100 parts by weight, per 100 parts by weight of the total polymerizable monomer.
10 parts by weight.

Further, as the polymerizable monomer other than the hydroxyl group-containing monomer, for example, styrene, α-methylstyrene,
Vinyl aromatic monomers such as vinyl toluene, α-chlorostyrene, chlorostyrene, divinylbenzene and diisopropenylbenzene; (meth) acrylic 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 (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, hexaethylene glycol di (meth) acrylate, Propylene glycol di (meth) acrylate, 1,4-butanediol di (meth)
Acrylic monomers such as acrylate, trimethylolpropane tri (meth) acrylate and (meth) acrylonitrile; ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, n-hexyl vinyl ether, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether; Vinyl ether monomers such as ethylene glycol divinyl ether, diethylene glycol divinyl ether, 1,4-butanediol divinyl ether, trimethylolpropane trivinyl ether, phenyl vinyl ether and naphthol vinyl ether; vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate And vinyl ester monomers such as vinyl chloride, vinylidene chloride, vinyl bromide and vinylidene bromide. (Meth) allyl alcohol, methyl (meth) allyl ether, ethyl (meth) allyl ether, 1,4-butanediol di (meth) allyl ether, trimethylolpropane tri (meth) allyl ether, Examples include allyl monomers such as (meth) allyl acetate, (meth) allyl propionate, di (meth) allyl phthalate, and tri (meth) allyl cyanurate. These polymerizable monomers are used alone or in combination of two or more to dissolve the hydroxyl group-containing monomer and / or the hydroxyl group-containing polymer.

Among these polymerizable monomers other than the hydroxyl group-containing monomer, styrene, (meth) acrylates, and divinylbenzene are preferable, and divinylbenzene is particularly preferable.

[0010] Divinylbenzene is used as the total polymerizable monomer.
By using 0 to 100% by weight, it is possible to obtain a particularly preferable colored spacer particle because the mechanical strength is high and the material is not deformed by heat. The more preferable content of divinylbenzene in the whole polymerizable monomer is 50 to 100% by weight, particularly preferably 70 to 100% by weight.

Next, the reactive dye used in the present invention is a water-soluble dye capable of forming a covalent bond with the polymerizable monomer in the presence of an alkali. Depending on the bonding mode, the reaction can be classified into a substitution substitution reaction type and a conjugate addition reaction type. Examples of the commutative substitution reaction type dyes include those comprising a reactive group base such as triazine, pyrimidine and quinoxaline and a leaving group such as chlorine.These commutative substitution reaction type dyes include the leaving group. And a hydroxyl group-containing monomer and / or a hydrogen atom of a hydroxyl group in the hydroxyl group-containing polymer react with each other, and the reaction product is released,
Instead, the reactive group base binds to the hydroxyl-containing monomer and / or the hydroxyl-containing polymer. Conjugate addition reaction type dyes include azo-based, anthraquinone-based, phthalocyanine-based and other base molecules and dichlorotriazinyl, chlorotriazinyl, vinyl sulfone, trihalopyrimidine, dichloroquinoxaline, α-bromoacrylamide, etc. In these conjugate addition reaction type dyes, the unsaturated bond of the active group is cleaved, and the dye is bonded to the parent molecule through an ether bond.

Examples of such reactive dyes include Reactive Red 1, 2, 3, 4, 8, 17, 22, 3
3, 41; reactive yellow 1, 2, 3, 4, 5,
14, 15, 17, 170; Reactive Orange 1,
2, 4, 7, 14, 16, 59, 60, 109, 11
1: reactive violet 1, 2, 3, 25, 4
0; reactive blue 1, 2, 17, 20, 108,
147, 204, 210, 224 and the like.

The amount of the reactive dye to be used is selected according to the type of the dye, the desired degree of coloring, etc., and is usually 0.1 to 200 parts by weight per 100 parts by weight of the polymerizable monomer solution. Parts, preferably 1 to 100 parts by weight.

In the present invention, the polymerizable monomer solution is
The reactive dye is dispersed in an aqueous medium in which the reactive dye is dissolved. The aqueous medium is composed of water alone or a mixture of water and a small proportion of a water-miscible medium. In this case, as the water-miscible medium, for example, alcohols, ketones, ethers, esters, amines and the like can be used. The dispersion of the polymerizable monomer solution in the aqueous medium can be performed at once, intermittently or continuously.

The amount of the polymerizable monomer solution dispersed in the aqueous medium is usually 0.1 to 50 parts by weight, preferably 0 to 50 parts by weight, per 100 parts by weight of the aqueous medium. 0.1 to 30 parts by weight.

When dispersing the polymerizable monomer solution 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 polymerizable monomer solution is dispersed, 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, alkyl sulfates such as sodium dodecyl sulfate, alkyl sulfonates such as sodium stearyl sulfonate, and alkyl aryl sulfonates such as sodium dodecyl benzene sulfonate. Surfactants such as sulfosuccinate esters such as dioctyl sodium sulfosuccinate; alkyl polyoxyethylene ethers, alkylphenyl polyoxyethylene ethers, polyethylene glycol alkyl ethers, alkyl carbonyloxy polyethylenes, N, N-di (Polyoxyethylene) alkaneamides, N, N-di (alkanol) alkaneamides, polyethylene glycol fatty acid esters, sorbitan fatty acid esters, fats Nonionic surfactants such as fatty acid polyhydric alcohol esters such as acid monoglyceride and fatty acid sucrose ester; fatty acid polyhydric alcohol polyoxyethylene ethers; higher alkyl ammonium salts such as dodecyl ammonium chloride; and 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 cetyltrimethylammonium bromide, quaternary alkyl imidazolinium salts, quaternary polyoxyethylene alkyl diammonium salts, Cationic surfactants such as quaternary polyoxyethylene alkyl ammonium salts, quaternary alkoxypropyl ammonium salts, and organic or inorganic acid salts of alkyl propylene diamine; alkyl amine oxides, alkyl glycines, alkyl alanines, alkyl betaines And zwitterionic surfactants such as alkyl imidazolines. These emulsifiers can be used alone or in combination of two or more.

Examples of the suspension stabilizer include polyvinylpyrrolidone, sodium polycarboxylate, polyacrylic acid or a salt thereof, polyacrylamide, polyethylene oxide and the like. These suspension stabilizers can be used alone or in combination of two or more.

In the present invention, each of the emulsifier and the suspension stabilizer can be used alone, or an emulsifier and a suspension stabilizer can be used in combination. The amount of the dispersion stabilizer to be used is generally 0.001 to 20 parts by weight, preferably 0.1 to 100 parts by weight, per 100 parts by weight of the polymerizable monomer solution.
01 to 10 parts by weight.

The polymerization of the polymerizable monomer dispersed in the aqueous medium is usually performed using a radical polymerization initiator. Examples of such a radical polymerization initiator include lauroyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, cumene hydrodropoxide,
Applicable to polymerizable monomers such as p-menthane hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,2'-azobisisobutyronitrile, and 2,2'-azobisvaleronitrile. Soluble, alone or 2
A mixture of more than one species is used.

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

The polymerization conditions using such a radical polymerization initiator vary depending on the type of polymerization initiator, polymerizable monomer, etc., but the polymerization temperature is usually about 0 to 100 ° C., and the polymerization time is , Usually about 10 minutes to 48 hours.

The polymerization of a polymerizable monomer dispersed in an aqueous medium is carried out by, for example, 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 irradiating light in the presence of a photopolymerization initiator such as an acyl oxime ester or an acyl phosphine oxide or a sensitizer. In this case, the radical polymerization initiator may or may not be used.

During the polymerization of the polymerizable monomer dispersed in the aqueous medium, the reaction system is kept alkaline. PH during polymerization
Increases the chemical bonding of the reactive dye to the (co) polymer molecule. However, if the pH is too high, the reaction between the reactive dye and the aqueous medium is accelerated. Therefore, it is necessary to appropriately adjust the pH according to the type of the reactive dye to be used.

As described above, the polymerizable monomer solution is
By dispersing and polymerizing the reactive dye in an aqueous medium in which the reactive dye is dissolved, spherical colored particles can be obtained, and during the polymerization, and even after the polymerization, the reactive dye is
It is absorbed inside the (co) polymer particle or adsorbed on the (co) polymer particle surface and chemically bonded to the polymer molecules constituting the (co) polymer.

Further, in the present invention, the polymerizable monomer solution is passed through a filter and dispersed in an aqueous medium in which a reactive dye is dissolved, so that the polymerizable monomer solution is merely mechanically stirred and dispersed. The particle size distribution of the droplets can be narrowed as compared with that, and as a result, the particle size of the obtained colored particles is represented by a coefficient of variation (= standard deviation of particle size / average particle size × 100) and is not more than 20%. It can be suppressed.

The method of dispersing droplets in an aqueous medium by passing through a filter as described above has already been disclosed in JP-A-2-9543.
As described in Japanese Patent Application Publication No. 3 (1993) -313, the method disclosed in the publication discloses dispersing a liquid such as kerosene as a dispersed phase in a liquid as a continuous phase,
/ W, W / O / W, etc. On the other hand, the present invention has a uniform particle size distribution by applying such a method to a dispersion of a polymerizable monomer solution in an aqueous medium in which a reactive dye is dissolved, and then polymerizing. In particular, a particularly advantageous effect is obtained in that spherical colored particles extremely useful as colored spacer particles can be obtained.

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 a woven or nonwoven filter of various organic fibers; Wire filters of nickel, stainless steel, monel metal, etc .; sintered metal filters of nickel, stainless steel, etc .; polymer membrane filters, which are made by irradiating neutrons, charged particle beams, etc. to resin films of polyester, polycarbonate, etc .; Porous ceramic,
Inorganic filters such as porous glass can be mentioned, and a particularly preferred filter is a cylindrical porous glass filter developed at the National Industrial Research Institute of Miyazaki Prefecture.

The average pore size of the filter is appropriately selected depending on the desired particle size of the droplets of the polymerizable monomer solution, and is usually 0.5 to 10 μm, preferably 0.5 to 3 μm. The narrower the pore size distribution of the filter, the better.

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

Further, when the polymerizable monomer solution is dispersed in an aqueous medium by passing through a filter, an organic liquid having high solubility in water, for example, methanol, ethanol,
By dissolving acetone or the like in the polymerizable monomer, when the polymerizable monomer solution is dispersed or during polymerization after the dispersion, the organic liquid is transferred to the aqueous medium. It is also possible to adjust the particle size of the spherical colored particles to a smaller one. Such a method for 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 a polymerizable monomer solution by dispersing the 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 a polymerizable monomer solution delivery. Is a polymerization vessel.

Now, the polymerizable monomer solution 5 is supplied to the pressure vessel 6
And cooled as needed to prevent polymerization. An aqueous medium 3 containing a dispersion stabilizer and the like is supplied to a metering pump 4
Is supplied to the inside of the cylindrical porous glass filter 1. The polymerizable monomer solution 5 is introduced into the holder 2 located outside the cylindrical porous glass filter 1 by pressurizing the gas phase 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 dispersion of the polymerizable monomer solution 5 is sent to the polymerization vessel 8 and polymerized to form spherical colored particles having a uniform particle size.

The colored particles thus obtained have an average particle diameter of usually about 2 to 20 μm and a coefficient of variation of the particle diameter.
Usually, it is 20% or less, but it is a precision sieve, a dry classifier (eg, a gravity classifier, a dry centrifugal classifier, etc.), a wet classifier (eg, a hydraulic classifier, a wet mechanical classifier, a wet centrifugal classifier, etc.)
By performing classification using such a method, colored particles having a variation coefficient of 5% or less, which are particularly suitable as colored spacer particles for keeping the thickness of the liquid crystal phase constant, can be obtained.

[0035]

According to the present invention, the polymerizable monomer solution is dispersed and polymerized in an aqueous medium in which a reactive dye is dissolved, so that the inhibition of the polymerization reaction is not a problem and the color is faded during the polymerization. Therefore, colored particles can be industrially advantageously produced.

Moreover, despite the use of the reactive dye dissolved in an aqueous medium, most of the dye is chemically bonded inside or on the surface of the (co) polymer particles, so that the resulting coloring Even when the particles come into contact with water or various organic media, the dye does not migrate or elute.

Further, the polymerizable monomer solution is passed through a filter and dispersed in an aqueous medium in which a reactive dye is dissolved,
By polymerization, colored particles having a uniform particle size can be efficiently produced.

Further, the colored particles obtained according to the present invention have a sufficient degree of coloring and color tone, and have good strength and heat resistance. Therefore, particularly when such colored particles are used as colored spacer particles, stable light-shielding performance can always be exhibited. Further, the colored particles produced according to the present invention are also useful as a coloring agent for various rubbers, plastics, paints and the like, a light-shielding agent and the like.

[0039]

Next, the present invention will be described more specifically with reference to examples. However, unless the present invention exceeds the gist,
The present invention is not limited to these embodiments. Example 1 Polymerization was carried out using a cylindrical porous glass filter (average pore diameter: 1.1 μm) having a length of 125 mm and an inner diameter of 10 mm shown in FIG. A polymerizable monomer solution obtained by dissolving 2 g of hydroxyethyl methacrylate and 2 g of 2,2′-azobisisobutyronitrile in 100 g of divinylbenzene (purity 81% by weight, containing 19% by weight of ethylbenzene) was placed in a pressure vessel. 5 Sulfatoethyl sulfone reactive dye (trade name Remazol Black B, manufactured by Mitsubishi Kasei Hoechst)
The aqueous medium consisting of a 0.1% by weight aqueous solution of sodium dodecyl sulfate containing 0.1% by weight is adjusted to pH 9 with sodium hydroxide, and while flowing at 1 liter / hour inside the cylindrical porous filter, the gas phase of the pressure vessel is The polymerizable monomer solution was passed through the filter by applying an air pressure of 0.6 kg / cm ² to the mixture, and dispersed in the aqueous medium over 3 hours. This dispersion is introduced into a polymerization vessel and stirred for 90 minutes.
Polymerization was performed at 10 ° C. for 10 hours to obtain dark black colored particles. The polymerization conversion in this polymerization was 91%. The obtained colored particles had an average particle size of 5.8 μm and a variation coefficient of the particle size of 12%. The colored particles are washed with water, further washed with isopropyl alcohol, dried, and then classified by a dry classifier to obtain a colored particle 35 having a variation coefficient of 4.3% in particle diameter.
g was obtained. The colored particles after classification, even when dispersed in toluene, no longer eluted the dye and maintained a deep black color. Further, when the colored particles after this classification were used as colored spacer particles and pressed under the conditions of 160 ° C. and 1.0 kg / cm ^{2 in} the LCD substrate assembly process, the distance between the transparent electrode substrates was kept constant, and The colored particles were 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
In the same manner as in Example 1 except that a polymerizable monomer solution in which 1 g of ethylcellulose and 2 g of 2,2′-azobisvaleronitrile were dissolved was used, and a 0.1% by weight aqueous solution of sodium lauryl sulfate was used as an aqueous medium. Thus, dark black colored particles were obtained. The polymerization conversion rate in this polymerization was 95%. The obtained colored particles have an average particle size of 6.1 μm,
The coefficient of variation of the particle size was 7.9%. This colored particles,
Classification was performed in the same manner as in Example 1, and the coefficient of variation of the particle size was 3.5%.
51 g of colored particles were obtained. Even if the colored particles after classification are dispersed in toluene, the dye is no longer eluted,
It had a dark black color. Further, when the colored particles after this classification were used as colored spacer particles and pressed under the conditions of 160 ° C. and 1.0 kg / cm ^{2 in} the LCD substrate assembly process, the distance between the transparent electrode substrates was kept constant, and While 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 also excellent.

Example 3 The procedure of Example ² was repeated except that a cylindrical porous glass filter having an average pore diameter of 0.63 μm was used and the air pressure applied to the pressure vessel was changed to 1.5 kg / cm ^2. Colored particles were obtained. The polymerization conversion in this polymerization was 93%. The obtained colored particles had an average particle size of 3.5 μm and a variation coefficient of the particle size of 10%. The colored particles were classified in the same manner as in Example 1 to obtain a colored particle 3 having a variation coefficient of 4.6%.
6 g were obtained. The colored particles after classification did not elute the dye anymore even when dispersed in toluene, and maintained a deep black color. In addition, with respect to the colored particles after classification, the load required to break one particle measured using a micro compression tester was 3.1 g, and it was revealed that the particles had sufficient strength as colored spacer particles. . Further, the colored particles after the classification are used as colored spacer particles in an LCD substrate assembly process at 160 ° C. and 1.0 kg / cm ^2.
When the pressure was applied under the above conditions, the distance between the transparent electrode substrates was kept constant, and the transparent particles were firmly fixed to the upper and lower transparent electrode substrates, and the colored particles were stably fixed even when the liquid crystal was injected.

Example 4 Example 2 was repeated except that a monochlorotriazine dye (Procion Black BG, manufactured by ICI) was used as a reactive dye at 6% by weight based on an aqueous medium and polymerization was carried out at neutral pH. Similarly, dark black colored particles were obtained. The polymerization conversion in this polymerization was 92%. The obtained colored particles have an average particle size of 6.5 μm and a variation coefficient of the particle size of 8.6.
%Met. The colored particles were classified in the same manner as in Example 1 to obtain 46 g of a colored particle having a variation coefficient of 3.9%. The colored particles after classification did not elute the dye anymore even when dispersed in toluene, and maintained a deep black color. In addition, with respect to the colored particles after classification, the load required to break one particle measured using a micro compression tester was 3.5 g, and it was revealed that the particles had sufficient strength as colored spacer particles. . Furthermore, the colored particles after this classification are
As a colored spacer particle, when pressed at 160 ° C. and 1.0 kg / cm ^{2 in} the LCD substrate assembly process, the distance between the transparent electrode substrates is kept constant, and it is firmly fixed to the upper and lower transparent electrode substrates. The colored particles were stably fixed even when the liquid crystal was injected.

[0043]

According to the present invention, the inhibition of the polymerization reaction by the dye present at the time of polymerization is not a problem at all, and there is no fading during the polymerization. In particular, the polymerizable monomer solution is passed through a filter and dispersed in an aqueous medium to be polymerized, whereby colored particles having a uniform particle size can be efficiently produced. it can. Moreover, the colored particles obtained according to the present invention have a sufficient degree of coloring and color tone, do not dissolve or migrate the coloring component, and have good strength and heat resistance. Therefore, particularly when such colored particles are used as colored spacer particles, stable light-shielding performance can always be exhibited.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION 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

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Yasuda 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-4-7301 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 2/44

Claims (1)

(57) [Claims] 1. A polymerizable monomer containing a hydroxyl group-containing monomer,
A method for producing colored particles, comprising dispersing and polymerizing a polymerizable monomer in which a hydroxyl group-containing polymer is dissolved in an aqueous medium in which a reactive dye is dissolved.