JPH10324706A - Production of spacer for liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject spacer having both of an abnormal orientation- preventive property and mechanical strength by dispersing seed particles into a reaction medium, dissolving a free-radical-polymerizable monomer for polymerization thereof and forming the polymer layers on the surfaces of the seed particles. SOLUTION: This spacer is obtained by dispersing seed particles [polymer fine particles, etc., resulted by polymerizing a polymerizable monomer such as styrene derivatives, vinyl esters, unsaturated nitriles, (meth)acrylic ester derivatives and conjugated dienes, and a crosslinkable monomer such as divinylbenzene] into a reaction medium (allowing a free radical-polymerizable monomer but not its resultant polymer to dissolve therein), dissolving the radical-polymerizable monomer [preferably, an alkyl (meth)acrylate, etc., shown by the formula (R<1> is H, a methyl; R<2> is a 6 to 30C alkyl)] and polymerizing it in the presence of a free radical polymerization initiator, thus forming the polymer layers onto the surfaces of the seeds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method for manufacturing a spacer for a liquid crystal display element having both properties such as dispersibility and adhesion to a substrate and mechanical strength required for the spacer.

[0002]

2. Description of the Related Art As shown in FIG. 1, a conventional twisted nematic (TN) mode liquid crystal display device using spacers comprises a pair of substrates 8, 10, and a pair of substrates 8, 10;
And the substrates 8, 1
In order to keep the gap between the pair of substrates 8 and 10 constant, the sealing member 1 filled around the substrate 0 and the polarizing films 12 and 13 coated on the surfaces of the substrates 8 and 10 are used as constituent materials. In addition, a spacer 9 is arranged between the substrates 8 and 10.

On the substrates 8 and 10, a pattern of transparent electrodes 3 and 6 made of an ITO film or the like is formed on one surface of transparent substrates 2 and 5 made of glass.
5 can be obtained by coating the surface of the substrate 5 with alignment control films 4 and 7 made of a polyimide film or the like. The alignment control films 4 and 7 are subjected to an alignment control process by rubbing.

As a material for the spacer 9, generally,
Organic and inorganic materials are used. Examples of the spacer made of an inorganic material include those containing aluminum oxide, silicon dioxide, and the like (Japanese Patent Application Laid-Open No. 63-73225, Japanese Patent Application Laid-Open No.
No. 599974). However, a conventional spacer made of an inorganic material has a high hardness and damages an alignment film, and a change in thickness due to thermal expansion and shrinkage is difficult to follow a substrate, thereby causing gap unevenness.

Further, the spacer made of an organic material has an appropriate hardness that does not damage the alignment film, easily follows a change in thickness due to thermal expansion or thermal contraction, and has a small spacer movement in the cell. It has properties and mainly uses polystyrene-based or benzoguanamine-based polymers (Japanese Patent Application Laid-Open Nos. 60-220288 and 1-293316).
No.). Further, for the purpose of preventing agglomeration of particles, a method of polymerizing by absorbing a fluorine-containing monomer into a seed polymer has been studied (JP-A-4-69645).

However, the liquid crystal display device manufactured using such a spacer has a problem that abnormal alignment of liquid crystal occurs around the spacer immediately after the cell is manufactured (hereinafter, referred to as an “initial state”) and after a high voltage is applied. was there. Especially,
In a liquid crystal display device using a super twisted nematic (STN) liquid crystal, the tendency is remarkable, and there is a problem that a uniform image cannot be maintained. This abnormal alignment is because liquid crystal molecules are aligned around the spacer, and the magnitude of the abnormal alignment is estimated to depend on the degree of alignment of the liquid crystal molecules.

Various methods for solving such an abnormal orientation have been studied. For example, Japanese Patent Application Laid-Open No. 6-67182
Japanese Patent Application Laid-Open Publication No. H11-139,086 discloses a method of changing the dielectric constant of a spacer. JP-A-6-118421 discloses a method of changing the surface composition of a spacer.

However, if the composition of the polymer is largely changed in order to prevent abnormal alignment, the particles become fragile particles not having the necessary strength for the spacer, and are broken when the liquid crystal display element is assembled. I do.

In recent years, spacers have been required to have various functions from the viewpoints of display quality of liquid crystal display elements, processes for manufacturing display elements, and the like. For example, as the range of use of the liquid crystal display element spreads from a room to a vehicle such as a car or a train, movement of the spacer due to vibration becomes a problem, and a spacer having strong adhesiveness is required. I have. In addition, from the viewpoint of the manufacturing process, solvent dispersibility and the like that can be sprayed on the substrate without aggregation even when a hydrophilic organic medium is used has become an important performance.

Such individual performance can be achieved by changing the composition used for the spacer. By the way, since the spacer is used as a member for maintaining the gap between the glass substrates of the liquid crystal display element, it is needless to say that in addition to these performances, a certain mechanical strength is required. However, when the composition is made to emphasize the performance such as abnormal orientation prevention and adhesiveness, the obtained spacer is likely to be particles having low mechanical strength, and conversely, emphasizing strength is effective for abnormal orientation prevention and adhesion. When the components are reduced, there is a problem that the intended performance is not exhibited.

In order to solve this problem, a core-shell in which a component having performance such as abnormal orientation prevention is formed on the surface of the core particle by imparting mechanical strength as a cell gap holding member to the inner core particle. Methods for exerting various properties by using particles are also being studied. For example, JP-A-7-33
No. 3622 discloses a method using a reactive polymerization dispersant to form a nonionic hydrophilic unit on the surface. JP-A-4-96902 discloses that
A method of introducing a hydrophilic monomer during suspension polymerization is disclosed. However, in these methods, the components for forming the surface layer are limited to those having a hydrophilic property, and it is difficult to control the thickness and amount of the layer. There are also problems such as the inability to uniformly modify the entire surface and the necessity of complicated multi-step operations for forming a shell layer.

Japanese Patent Application Laid-Open No. 7-301810 discloses a method in which active sites are provided on the surface of particles, and a graft chain is extended from the active sites to form a surface layer.
However, in this method, it is necessary to carry out a reaction for bonding a reaction site such as a polymerization initiator and a double bond to the particle surface, and then repeat a reaction for extending a graft chain, and the operation is complicated. There is a problem that coalescence of particles occurs.

By the way, the size of the liquid crystal display element is increasing year by year, and it is a technical point of a liquid crystal display element maker how to efficiently manufacture a large panel. In the current manufacturing process of a liquid crystal display panel, there are two methods of spraying liquid crystal spacers on a glass substrate: a wet spraying method in which spacers are dispersed in an organic medium and then spraying, and a dry spraying method in which spacers are sprayed as they are. There are streets, but for the production of large panels,
The wet spraying method is efficient, and the spacer used in this method needs to have good dispersibility in the spraying liquid. In particular, recently, due to environmental considerations, the spray liquid has changed from a fluorine-based organic medium to water or a hydrophilic organic medium.
Even in such a hydrophilic medium, a good dispersion performance is required for the spacer.

[0014]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a method of manufacturing a spacer for a liquid crystal display element having both the property of preventing abnormal alignment and the mechanical strength required for the spacer. An object of the present invention is to provide a method for manufacturing a spacer for a liquid crystal display element, which also has characteristics such as dispersibility and adhesion to a liquid crystal display element.

[0015]

According to the present invention, the seed particles are dispersed in a reaction medium, a radical polymerizable monomer is further dissolved, and the resultant is polymerized in the presence of a radical polymerization initiator. A method for producing a spacer for a liquid crystal display element, wherein a layer of a polymer comprising the radical polymerizable monomer is formed on the surface of seed particles, wherein the reaction medium dissolves the radical polymerizable monomer. This is a method for producing a spacer for a liquid crystal display element which does not dissolve the produced polymer. Hereinafter, the present invention will be described in detail.

In the present invention, the radically polymerizable monomer starts polymerization in the reaction medium or on the dispersed seed particles, and the polymer chains cannot be dissolved in the reaction medium as they grow, Precipitates on the surface of the seed particles. In particular, when the radical polymerizable monomer is easily compatible with the seed particles, the polymerization proceeds more efficiently on the seed particle surface layer.

Since the seed particles used in the present invention function as core particles of the obtained spacer for a liquid crystal display element, various properties such as a particle size, a particle size distribution, and a mechanical strength are required. The seed particles preferably have a particle size of 1 to 10 μm.
Further, the particle size distribution of the seed particles is preferably 10% or less as a Cv value obtained by dividing the standard deviation by the average particle size.

The seed particles are preferably selected so that the resulting spacer has a mechanical strength of 250 to 1000 at a 10% K value. If the 10% K value is less than 250, the strength of the particles is not sufficient, so that the spacer may be broken when assembling the liquid crystal display element and an appropriate gap may not be obtained. When incorporated, the alignment film on the substrate may be damaged and display abnormalities may occur.

Here, the above-mentioned 10% K value is defined as Table 6
In accordance with Japanese Patent No. 503180, the obtained fine particles were compressed at a compressive strength of 0.27 g / sec on a smooth end surface of a diamond-made cylinder having a diameter of 50 μm using a micro compression tester (PCT-200, manufactured by Shimadzu Corporation). Compressed with a maximum test load of 10 g and determined by the following formula (I). K = (3 / √2) · ^FS -3 / 2 · R- ^{1 / 2} (I) In the formula, F represents a load value (kg) at 10% compressive deformation of the fine particles, and S represents fine particles. Represents the compressive displacement (mm) at 10% compressive deformation of R, and R is the radius (m
m).

Examples of the seed particles include polymer fine particles obtained by polymerizing a polymerizable monomer and a crosslinkable monomer. The polymerizable monomer is not particularly limited,
For example, styrene derivatives such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, and chloromethylstyrene; vinyl esters such as vinyl chloride, vinyl acetate and vinyl propionate; unsaturated nitriles such as acrylonitrile; Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, ethylene glycol (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, cyclohexyl (meth) acrylate, glycidyl (meth) acrylate And conjugated dienes such as butadiene and isoprene.
These may be used alone or in combination of two or more.

The crosslinking monomer is not particularly restricted but includes, for example, divinylbenzene, polyethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Examples include trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolpropanetetra (meth) acrylate, diallyl phthalate and its isomers, triallyl isocyanurate and its derivatives, and the like. These may be used alone or in combination of two or more.

In the present invention, the crosslinkable monomer preferably accounts for 30% by weight or more of all monomers from the viewpoint of improving the strength of the obtained spacer for a liquid crystal display device.

As the above seed particles, in addition to the above, particles are prepared from particles having a reactive point in the side chain of a radical polymerizable monomer such as γ-methacryloxypropyltrimethoxysilane, and the side chain portion is crosslinked. What gave sufficient mechanical strength by reaction may be used.

The seed particles are not limited to polymer fine particles comprising the polymerizable monomer, but may be benzoguanamine,
Polymer fine particles such as nylon; inorganic fine particles such as silica may be used.

In the present invention, colored fine particles are preferably used as the seed particles in order to improve the contrast of a liquid crystal display device. Examples of the colored fine particles include, for example, those in which the seed particles are treated with a pigment such as carbon black, a disperse dye, an acid dye, a dye such as a basic dye, a metal oxide, or the like; Examples include a film formed and colored by being decomposed or carbonized at a high temperature. If the material forming the fine particles has a color itself, it may be used without coloring.

As a method for producing the colored fine particles, for example, a composition obtained by dispersing a pigment in the polymerizable monomer is subjected to suspension polymerization in an aqueous medium in the presence of a polymerization initiator. Method and the like.

The above-mentioned pigments are not particularly restricted but include, for example, inorganic coloring pigments such as carbon black, graphite, iron black, chrome green, cobalt green and chromium oxide; brilliant carmine BS, lake carmine FB, brilliant fast scarlet, lake red. 4R, permanent red R, fast red FGR, toluidine malon, bisazo yellow, fast yellow G, bisazo orange, vulcan orange, pyrazolone red and other azo organic coloring pigments or condensed azo organic coloring pigments; phthalocyanine blue, first sky Phthalocyanine organic coloring pigments such as blue and phthalocyanine green; dye lake organic coloring pigments such as yellow lake, rose lake, violet lake, blue lake and green lake; quinophthalone organic coloring Pigments, and the like. These may be used alone or in combination of two or more.

The amount of the pigment is preferably from 1 to 180 parts by weight based on 100 parts by weight of the polymerizable monomer serving as the seed particles. If it is less than 1 part by weight, it becomes difficult to color deeply,
When the amount exceeds 180 parts by weight, the mechanical strength of the obtained polymer fine particles may decrease. More preferably, 3 to 16
0 parts by weight.

For uniformly dispersing the pigment in the polymerizable monomer, for example, a ball mill, a bead mill, a sand mill, an attritor, a sand grinder, a nanomizer, or the like can be used.

When the pigment is dispersed in the polymerizable monomer, a dispersant may be added to improve the dispersibility of the pigment. The dispersant is not particularly limited and includes, for example, water-soluble polymers such as polyvinyl alcohol, starch, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, and sodium polymethacrylate; barium sulfate, calcium sulfate, aluminum sulfate, calcium carbonate, calcium phosphate, Examples include talc, clay, diatomaceous earth, and metal oxide powder. The amount of the dispersant added is preferably 0.01 to 20 parts by weight based on 100 parts by weight of the polymerizable monomer.

In the present invention, the radical polymerizable monomer used for forming the polymer layer on the surface of the seed particles is not particularly limited, and may exhibit the desired performance to be imparted to the spacer. Any monomer that can be used,
For example, when it is desired to impart hydrophilicity, a monomer having a hydroxyl group such as hydroxyethyl (meth) acrylate; a monomer having a polyethylene glycol component such as methoxypolyethylene glycol (meth) acrylate can be used. In order to impart hydrophobicity, alkyl (meth) acrylates such as butyl (meth) acrylate; fluorine-containing (meth) acrylates such as trifluoroethyl (meth) acrylate and pentafluoropropyl (meth) acrylate; styrene, p -Styrene derivatives such as chlorostyrene can be used. In addition, glycidyl (meth) acrylate, (meth) acrylic acid, (meth) acrylamide, or the like can be used to provide a reaction site. These may be used alone,
Two or more kinds may be used in combination.

In the present invention, the radical polymerizable monomer may be a linear or branched compound having 6 to 30 carbon atoms represented by the following general formula (1) in order to impart the property of preventing abnormal alignment. It is preferably an alkyl (meth) acrylate having an alkyl group in a form.

[0033]

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In the formula, R ¹ represents a hydrogen atom or a methyl group. R ² represents a linear or branched alkyl group having 6 to 30 carbon atoms.

When the alkyl group of the alkyl (meth) acrylate has less than 6 carbon atoms, even if a polymer layer is formed on the surface of the seed particles, the performance of preventing abnormal orientation may not be sufficient. If it exceeds, the solvent to be dissolved may be limited and impractical. In addition, a polymerizable monomer having 30 or more carbon atoms is hardly available and its unit price is high. is there. More preferably, 8 to
22.

The alkyl (meth) acrylate preferably has 6 to 30 carbon atoms in the alkyl chain.
For example, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate,
Examples thereof include lauryl (meth) acrylate, cetyl (meth) acrylate, and stearyl (meth) acrylate. These may be used alone or in combination of two or more.

In forming the polymer layer, the alkyl (meth) acrylate may be used in combination with another copolymerizable monomer. However, the compounding amount of the alkyl (meth) acrylate is preferably 50% by weight or more of all monomers. When the content is less than 50% by weight, a sufficient function as an abnormal orientation preventing layer may not be achieved.

When the above alkyl (meth) acrylate is used as the radical polymerizable monomer, the use of the compound represented by the following general formula (2) improves the dispersibility and adhesion to the substrate. Is preferred.

[0039]

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In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a methyl group or a (meth) acryl group.
m represents an integer of 4 to 40.

The compound represented by the general formula (2) is a monofunctional or bifunctional compound having an ethylene glycol component in a side chain.
It is a functional (meth) acrylate, and the number of repeating ethylene glycol portions is preferably 4 to 40.
If the number of repetitions is less than 4, the dispersibility during wet spraying may not be sufficiently improved. If the number is more than 40, the solubility of the produced polymer in an aqueous medium is greatly increased, and the uniform polymerization of the polymer into the seed particles is achieved. It becomes difficult to form a layer. It is difficult to obtain a polymerizable monomer having a large number of repetitions, and its unit price is high, which is disadvantageous in terms of cost. More preferably, 8 to 3
0. The compounds represented by the general formula (2) may be used alone or in combination of two or more.

When the compound represented by the general formula (2) is used as the other monomer, the charge of the alkyl (meth) acrylate with the compound represented by the general formula (2) may be reduced. Is preferably 80:20 to 20:80. When the amount of the alkyl (meth) acrylate is less than 20% by weight, the formed polymer layer may not function as an abnormal orientation preventing layer, which is not preferable. If the amount of the compound represented by the general formula (2) is less than 20% by weight, the dispersibility of the spacer in the aqueous dispersion medium may not be improved, which is not preferable.

When the alkyl (meth) acrylate represented by the above general formula (1) and the compound represented by the above general formula (2) are used in combination, further, other monomers copolymerizable with these monomers are used. A dimer may be used.

In the present invention, it is preferable to use a fluorine monomer represented by the following general formula (3) as the radical polymerizable monomer.

[0045]

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In the formula, R ⁵ represents a hydrogen atom or a methyl group. R ⁶ represents a fluorine-containing functional group.

The fluoromonomer is not particularly restricted but includes, for example, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, pentafluoropropyl (meth) acrylate, octafluoroamyl (meth) acrylate, Heptadecafluorodecyl (meth) acrylate, perfluorobutylethyl (meth) acrylate, 2- (N-ethylperfluorooctasulfoamido) ethyl (meth) acrylate, 3-perfluorobutyl-2-hydroxypropyl (meth) acrylate , 3-perfluorooctyl-2
-Hydroxypropyl (meth) acrylate, 3- (perfluoro-3-methylbutyl) -2-hydroxypropyl (meth) acrylate, 3- (perfluoro-5-
Methylhexyl) -2-hydroxypropyl (meth) acrylate, 3- (perfluoro-7-methyloctyl) -2-hydroxypropyl (meth) acrylate,
3- (perfluoro-8-methyldecyl) -2-hydroxypropyl (meth) acrylate, 2- (N-ethylperfluorooctasulfoamido) ethyl acrylate, 2- (N-ethylperfluorooctasulfoamido) ethyl methacrylate, etc. (Meth) acrylic acid ester derivatives. These may be used alone or in combination of two or more.

In forming the polymer layer, the fluorine-based monomer may be used in combination with another copolymerizable monomer. However, it is preferable that the compounding amount of the fluorine-based monomer is 10% by weight or more of all the monomers. 10% by weight
If the amount is less than the above range, the layer may not function sufficiently as an abnormal alignment preventing layer.

When the above-mentioned fluorine-based monomer is used as the above-mentioned radically polymerizable monomer, the use of the compound represented by the following general formula (4) improves the dispersibility and adhesion to the substrate. preferable.

[0050]

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In the formula, R ⁷ represents a hydrogen atom or a methyl group. R ⁸ represents a methyl group or a (meth) acryl group.
n represents an integer of 1 to 50. The compound represented by the general formula (4) is a monofunctional or bifunctional (meth) acrylate having an ethylene glycol component in a side chain,
The number of repeating ethylene glycol moieties is preferably 1 to 50. If the number of repetitions exceeds 50, the solubility of the produced polymer in an aqueous medium is greatly increased, and it becomes difficult to form a uniform polymer layer on the seed particles, which is disadvantageous in cost. The compounds represented by the general formula (4) may be used alone or in combination of two or more.

The compounding amount of the compound represented by the general formula (4) is preferably at least 10% by weight based on the total monomers. If the content is less than 10% by weight, the dispersion and adhesion may not be sufficiently improved.

When the fluorine-based monomer represented by the general formula (3) and the compound represented by the general formula (4) are used in combination, other monomers copolymerizable with these monomers are further used. A dimer may be used.

In the present invention, it is preferable to use an acrylic silane compound represented by the following general formula (5) as the radical polymerizable monomer.

[0055]

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In the formula, R ⁹ represents a hydrogen atom or a methyl group. R ¹⁰ represents a methoxy group, an ethoxy group, a methyl group or a trimethylsilyl group.

The acrylic silane compound is not particularly restricted but includes, for example, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane. Ethoxysilane, (3-acryloxypropyl) tris (trimethylsiloxane) silane, (3-acryloxypropyl) methylbis (trimethylsiloxy) silane and the like can be mentioned. These may be used alone or in combination of two or more.

In forming the polymer layer, the acrylic silane compound may be used in combination with another copolymerizable monomer. However, it is preferable that the acrylic silane compound accounts for 50% by weight or more of all monomers. When the content is less than 50% by weight, a sufficient function as an abnormal orientation preventing layer may not be achieved.

In the present invention, it is excellent in preventing abnormal orientation,
Although it is possible to obtain a liquid crystal display element spacer having the mechanical strength necessary for the spacer,
In order to obtain a spacer for a liquid crystal display element which also has excellent properties such as dispersibility, a radical polymerizable monomer used for forming a polymer layer on the surface may be selected.

In the present invention, a crosslinkable monomer may be added to the radical polymerizable monomer in forming the polymer layer. Examples of the crosslinkable monomer include those used in the polymerization of the seed particles.

The reaction medium used in the present invention dissolves the above-mentioned radical polymerizable monomer but does not dissolve the resulting polymer, and is selected depending on the type of the radical polymerizable monomer used. But, for example, alcohols such as methanol, ethanol and propanol; cellosolves such as methyl cellosolve and ethyl cellosolve; ketones such as acetone, methyl ethyl ketone and methyl butyl ketone;
Hydrocarbons such as hexane, heptane, octane and the like can be mentioned. Further, they can be used as a mixed solvent of these, a mixed solvent with another organic solvent compatible with these, or a mixed solvent with water, but are not particularly limited.

The radical polymerization initiator used in the present invention is not particularly restricted but includes, for example, benzoyl peroxide, lauroyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl Peroxide, t-butylperoxy-
Organic peroxides such as 2-ethylhexanoate and di-t-butyl peroxide; azobisisobutyronitrile;
Azobiscyclohexacarbonitrile, azobis (2,
Azo compounds such as 4-dimethylvaleronitrile). The amount of the radical polymerization initiator used is usually
0.1 to 100 parts by weight of the radical polymerizable monomer
10 parts by weight are preferred.

In the present invention, the seed particles are dispersed in the reaction medium, and the radically polymerizable monomer is dissolved to initiate polymerization. The charged amount of the seed particles is
What is necessary is just to make the said seed particle into the said reaction medium the quantity which becomes 0.1-100 weight%. The amount of the radical polymerizable monomer used is determined by the type of the monomer used and the thickness of the surface layer to be formed.
By adding about 100 parts by weight, a polymer layer can be uniformly formed on the surface of the seed particles.

The radical polymerizable monomer and the radical polymerization initiator may be initially charged in their entirety, or may be partially charged and then supplied stepwise or continuously later. In the polymerization, the reaction system may be replaced with an inert gas such as nitrogen in order to prevent the polymerization from being inhibited by oxygen.

In the above polymerization, a dispersion stabilizer may be used, if necessary. The dispersion stabilizer is not particularly limited as long as it is a polymer soluble in the reaction medium, and examples thereof include polyvinyl alcohol, polyvinyl pyrrolidone, methyl cellulose, ethyl cellulose, polyacrylic acid, polyacrylamide, and polyethylene oxide. Further, a nonionic surfactant or an ionic surfactant is appropriately used.

The spacer for a liquid crystal display element obtained by the present invention is, for example, as shown in FIG. 1, two glass substrates on which an alignment film and a transparent electrode are arranged, facing each other via the spacer for a liquid crystal display element. It is suitably used for a liquid crystal display device in which liquid crystal is sealed between the glass substrates.

In the present invention, a core-shell type liquid crystal display element spacer can be easily obtained without being affected by the hydrophilicity or hydrophobicity of the radical polymerizable monomer forming the surface layer. The spacer for a liquid crystal display element obtained by the present invention has a surface layer provided with an anti-abnormal orientation property, and has good mechanical strength. In addition, by using a monofunctional or bifunctional (meth) acrylate having an ethylene glycol component in a side chain in the obtained spacer for a liquid crystal display element, the performance of dispersing and adhering to a substrate is also simplified. Can be given.

[0068]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Preparation of Seed Particles A mixture of 100 parts by weight of divinylbenzene (hereinafter referred to as "DVB") and 2 parts by weight of benzoyl peroxide was added to 800 parts by weight of a 3% aqueous solution of polyvinyl alcohol and stirred with a homogenizer. Then, the particle size was adjusted. Thereafter, the mixed solution was transferred to a reaction vessel, and the temperature was raised to 80 ° C. under a nitrogen stream with stirring to carry out a reaction for 15 hours. After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed. The obtained fine particles had an average particle size of 6.0 μm.
m, Cv value = 5, and the following operation was performed using these fine particles as seed particles.

Preparation of Spacer for Liquid Crystal Display Element 250 parts by weight of ethanol were put into a separable flask.
One part by weight of polyvinylpyrrolidone was added and completely dissolved. Further, 4 parts by weight of the seed particles obtained by the above operation was added and sufficiently dispersed by stirring. 2 parts by weight of lauryl methacrylate (hereinafter referred to as "LMA") and 80 parts by weight of ion-exchanged water were added thereto, and the mixture was stirred uniformly. Nitrogen gas was introduced into the system, and stirring was continued at room temperature for 24 hours. Next, 0.023 parts by weight of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was dissolved in 30 parts by weight of ethanol and added to the system, and then the system was heated to 60 ° C. The polymerization was continued for 24 hours while stirring. After the completion of the polymerization, the reaction solution was taken out, and the fine particles and the reaction solution were separated by filtration with a 3 μm membrane filter. The fine particles were sufficiently washed with ethanol, and dried under reduced pressure with a vacuum drier.

To confirm the surface layer, use TOF-SIMS
(Time-of-flight secondary ion mass spectrometer manufactured by Charles Evans) As a result, a mass peak specific to a methacryl group was observed at minus 85, and minus 1
In 83, a mass peak unique to LMA was observed. No plus 115 peak derived from DVB was observed. Thus, it was determined that an LMA layer was formed on the surface layer of the fine particles.

Evaluation of Liquid Crystal Display Element Using a spacer synthesized by the above method, a substrate size of 50
(Mm) × 50 (mm), S with a cell gap of 6.0 μm
After producing a TN type liquid crystal display element, cell evaluation was performed as follows. First, a voltage of AC 3 V is applied to the liquid crystal display element, and the cell display characteristics in the initial state are observed with a polarizing microscope. Then, a voltage of 400 Hz and 50 V is applied to the liquid crystal display element for 5 seconds, and then a voltage of 3 V is applied. Then, the cell display characteristics under a voltage applied state were observed with a polarizing microscope, and when light leakage occurred around the spacer after the voltage application, it was evaluated that abnormal alignment occurred. The results are shown in Table 1.

Evaluation of Mechanical Strength Using a micro-compression tester (PCT-200, manufactured by Shimadzu Corporation), the obtained fine particles were converted to a diamond-made 50 μm diameter.
The cylinder was compressed with a maximum test load of 10 g at a compressive strength of 0.27 g / sec on the smooth end face of the m-shaped cylinder, and the K value was measured from the above formula (I). The results are shown in Table 1.

Example 2 The following operation was performed using the fine particles obtained in Example 1 as seed particles. Preparation of Liquid Crystal Display Element Spacer Put 150 parts by weight of ethanol into a separable flask,
One part by weight of polyvinylpyrrolidone was added and completely dissolved. Further, 4 parts by weight of the seed particles obtained in Example 1 were added,
The mixture was sufficiently dispersed by stirring. 2 parts by weight of butyl methacrylate (hereinafter, referred to as "BMA") and 150 parts by weight of ion-exchanged water were added thereto, and the mixture was stirred uniformly. Nitrogen gas was introduced into the system, and stirring was continued at room temperature for 24 hours. Next, V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator
After dissolving 0.023 parts by weight in 30 parts by weight of ethanol, the solution was added to the system, and then the system was heated to 60 ° C. The polymerization was continued for 24 hours while stirring. After the completion of the polymerization, the reaction solution was taken out, and the fine particles and the reaction solution were separated by filtration with a 3 μm membrane filter. The fine particles were sufficiently washed with ethanol, and dried under reduced pressure with a vacuum drier.

TOF-SIMS using the obtained fine particles
As a result, a mass peak specific to a methacryl group was observed at minus 85. Plus 11 from DVB
5 peaks were not observed. From this, it was determined that a BMA layer was formed on the surface of the fine particles. Also,
Evaluation of the liquid crystal display element and evaluation of the mechanical strength were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 60 parts by weight of tetramethylol methane triacrylate
20 parts by weight of DVB and 20 parts by weight of acrylonitrile were uniformly mixed, 12 parts by weight of carbon black was added, and the carbon black was uniformly dispersed over 48 hours using a bead mill. 2 parts by weight of benzoyl peroxide were uniformly mixed with the monomer mixture, and further added to 850 parts by weight of a 3% aqueous solution of polyvinyl alcohol. After finely stirring and adjusting the particle size, transfer the mixture to a reaction vessel,
The temperature was raised to 80 ° C. under a nitrogen stream, and the reaction was carried out for 15 hours. After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed. The obtained fine particles had an average particle size of 6.0 μm and a Cv value of 5. Using these fine particles as seed particles, the same operation as in Example 1 for producing a spacer for a liquid crystal display element was performed. To confirm the surface layer, use TOF-S
As a result of analysis by IMS, a mass peak specific to a methacryl group was observed at minus 85, and LM was found at minus 183.
A unique mass peak was observed. No plus 115 peak derived from DVB was observed. Thus, it was determined that an LMA layer was formed on the surface layer of the fine particles. The evaluation of the liquid crystal display element and the evaluation of the mechanical strength were performed in the same manner as in Example 1. The results are shown in Table 1.

Example 4 As a polymerizable monomer when producing a spacer for a liquid crystal display element,
The same operation as in Example 1 was performed except that stearyl methacrylate was used instead of LMA. Using the obtained fine particles, evaluation of a liquid crystal display element and evaluation of mechanical strength were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 5 As a polymerizable monomer when producing a spacer for a liquid crystal display element,
The same operation as in Example 1 was performed except that 2-ethylhexyl methacrylate was used instead of LMA. Using the obtained fine particles, evaluation of a liquid crystal display element and evaluation of mechanical strength were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 6 60 parts by weight of tetramethylol methane triacrylate
20 parts by weight of DVB and 20 parts by weight of acrylonitrile were uniformly mixed, 12 parts by weight of carbon black was added thereto, and the carbon black was uniformly dispersed over 48 hours using a bead mill. 2 parts by weight of benzoyl peroxide were uniformly mixed with the monomer mixture, and further added to 850 parts by weight of a 3% aqueous solution of polyvinyl alcohol. After well-stirring and particle size adjustment, the temperature was raised to 80 ° C. under a nitrogen stream, and the reaction was carried out for 15 hours. After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed. The obtained fine particles had an average particle size of 6.0 μm and a Cv value of
It was 5. Using these fine particles as seed particles, the same procedure as in Example 4 was performed to fabricate a spacer for a liquid crystal display element. Using the obtained fine particles, evaluation of a liquid crystal display element and evaluation of mechanical strength were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 7 The same operation as in Example 4 was carried out except that silica fine particles having an average particle diameter of 6.0 μm (Hypressica, manufactured by Ube Nitto Kasei Co., Ltd.) were used as seed particles. Using the obtained fine particles, evaluation of a liquid crystal display element and evaluation of mechanical strength were performed in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 Surfactant Hitenol N-08 (Daiichi Kogyo Seiyaku Co., Ltd.)
800 parts by weight of 3% aqueous solution, 80 parts by weight of LMA, DVB
A mixed solution of 20 parts by weight and 2 parts by weight of benzoyl peroxide was added, and the mixture was stirred with a homogenizer to adjust the particle size. Thereafter, the mixed solution was transferred to a reaction vessel, and the temperature was raised to 80 ° C. under a nitrogen stream with stirring to carry out a reaction for 15 hours.
After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed. The obtained fine particles have an average particle size =
6.0 μm, Cv value = 5. As a result of analysis by TOF-SIMS to confirm the surface layer, the result was minus 8
5, a methacryl group-specific mass peak was observed, and a minus 183 LMA-specific mass peak was observed. In addition, a plus 115 peak derived from DVB was also observed.
From this, it was determined that both LMA and DVB appeared in the surface layer of the fine particles. The evaluation of the liquid crystal display element and the evaluation of the mechanical strength were performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 In 800 parts by weight of a 3% aqueous solution of polyvinyl alcohol, 40 parts by weight of styrene, 60 parts by weight of DVB, and 2,2-azobisisobutyronitrile (hereinafter referred to as “AIBN”) 1
A part by weight of the mixture was added, and the mixture was stirred with a homogenizer to adjust the particle size. Thereafter, the mixed solution was transferred to a reaction vessel, and the temperature was raised to 80 ° C. under a nitrogen stream while stirring.
A time reaction was performed. The polymerization rate at this time was determined by a gravimetric method, and was about 30%. 1 part by weight of AIBN, 50 parts by weight of polyethylene glycol monomethacrylate (average number of moles of ethylene glycol added = n = 9) were added to this polymerization system,
An emulsion obtained by treating a mixture of 1.5 parts by weight of sodium lauryl sulfate and 200 parts by weight of ion-exchanged water with a homogenizer is added, and the mixture is stirred under a nitrogen stream under a nitrogen stream.
Polymerization was further performed at 12 ° C. for 12 hours. After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed. The obtained fine particles had an average particle size of 6.0 μm and a Cv value of 5. TOF-SIM using the obtained fine particles
As a result of the analysis at S, a mass peak specific to a methacryl group was observed at minus 85, and a mass peak specific to ethylene glycol was observed at plus 45. Thus, it was determined that a polyethylene glycol monomethacrylate layer was formed on the surface of the fine particles. Evaluation of the liquid crystal display element and evaluation of the mechanical strength were performed in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 3 The same operation as in Comparative Example 2 was performed except that the polyethylene glycol monomethacrylate added during the polymerization was changed to LMA. To confirm the surface layer, use TOF-SIMS
As a result of analysis by
5. No minus 183 mass peak specific to LMA was observed. From this, it was determined that the LMA layer was not formed on the surface. Evaluation of the liquid crystal display element and evaluation of the mechanical strength were performed in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 4 30 parts by weight of hydroxypropyl cellulose, styrene 8
Parts by weight, 4 parts by weight of γ-methacryloxypropyltrimethoxysilane and 0.1 part by weight of AIBN
It was dissolved in 0 parts by weight, transferred to a reactor, and polymerized at 65 ° C. for 10 hours under a nitrogen stream. The obtained fine particles had an average particle size of 5.8 μm and a Cv value of 4. After the fine particles are washed, they are treated with an acid, and a silanol group (Si
-OH). 20 parts by weight of toluene and 30 parts by weight of mercaptopropyltrimethoxysilane are collectively charged with 10 parts by weight of the fine particles obtained by the above treatment, and reacted at 80 ° C. for 6 hours to form a mercapto group (SH) on the surface of the fine particles. Was formed.

Further, 20 parts by weight of methyl ethyl ketone and 3 g of a 30% toluene solution of methacryloyl isocyanate were charged into 10 parts by weight of the fine particles at a time, and reacted at 120 ° C. for 2 hours to introduce a vinyl group on the surface of the fine particles.
Further, methyl ethyl ketone 2 was added to 1 part by weight of the fine particles.
0 parts by weight, 5 parts by weight of a 70% toluene solution of t-butyl peroxyallyl carbonate, 15 parts by weight of LMA and A
0.2 parts by weight of IBN are charged all at once, and the temperature is 80 ° C. under a nitrogen stream.
And heated for 4 hours. As a result of analysis by TOF-SIMS to confirm the surface layer, the result was minus 8
5, a methacryl group-specific mass peak was observed, and a minus 183 LMA-specific mass peak was observed. From this, it was determined that LMA appeared on the surface layer of the fine particles. Evaluation of the liquid crystal display element and evaluation of the mechanical strength were performed in the same manner as in Example 1, and the results are shown in Table 1. In this production method, the reaction operation is many, the operation is complicated, and aggregation of fine particles occurs during the reaction process.

Comparative Example 5 Using the seed particles obtained in Example 1 as they were, an evaluation of a liquid crystal display element and an evaluation of mechanical strength were performed. The results are shown in Table 1.

[0087]

[Table 1]

As is clear from the above results, according to the present invention, it was possible to produce spacers for liquid crystal display elements having various surface layers while maintaining high mechanical strength. On the other hand, as in Comparative Example 1, if a large amount of a composition (LMA in Comparative Example 1) desired to be exposed to the surface in one-stage polymerization is charged, the composition can be exposed to the surface, but the mechanical strength is maintained. It was difficult. As in Comparative Examples 2 and 3, when a composition desired to be a surface layer is added by emulsification during the polymerization, a monomer having high hydrophilicity as in Comparative Example 2 is possible, but as in Comparative Example 3, Difficult with highly hydrophobic monomers. As in Comparative Example 4, it is possible to form a surface layer by a graft reaction by introducing a reaction site on the surface, but the operation is complicated, and problems such as a decrease in yield and aggregation of fine particles occur. did. In the case of the seed particles not covered with the abnormal orientation preventing layer as in Comparative Example 5, abnormal orientation occurred.

Example 8 250 parts by weight of ethanol was placed in a separable flask.
One part by weight of polyvinylpyrrolidone was added and completely dissolved. Further, 4 parts by weight of the seed particles obtained in Example 1 was added,
The mixture was sufficiently dispersed by stirring. Here, 1.4 parts by weight of stearyl methacrylate (hereinafter, referred to as “SMA”) and 0.6 parts by weight of light ester 9EG (manufactured by Kyoeisha Chemical Co., Ltd., ethylene glycol dimethacrylate, average ethylene glycol addition mole number n = 9) and 80 parts by weight of ion-exchanged water was added and uniformly stirred and mixed. Nitrogen gas was introduced into the system, and stirring was continued at room temperature for 24 hours. Next, 0.023 parts by weight of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was dissolved in 30 parts by weight of ethanol, and then added to the system.
Thereafter, the temperature of the system was raised to 60 ° C. While stirring
The polymerization was continued for 24 hours. After completion of the polymerization, the reaction solution was taken out, and the particles and the reaction solution were separated by filtration with a 3 μm membrane filter. The particles were sufficiently washed with ethanol, and dried under reduced pressure with a vacuum dryer. Using the particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and wet sprayability and adhesion were evaluated as described below. The results are shown in Table 2.

Evaluation of wet spraying property 1 g of the synthesized spacer was dispersed in 50 g of a spraying solution of water: isopropyl alcohol (hereinafter referred to as “IPA”) = 5: 5, and a 15 cm square glass plate was spread using a spacer wet spraying machine. Sprayed. The evaluation was performed on 36
The positions were observed with a magnifying glass, the number of aggregates of eight or more spacers was counted, and Xa as an index of wet sprayability was determined by the following equation. Xa = A / 36 In the formula, A represents the number of aggregated eight or more spacers.

Evaluation of Adhesion A spacer was sprayed on a glass substrate provided with a polyimide alignment film, and after a heat treatment at 95 ° C. × 1 hour, air blow (3 kg /
(cm ² × 5 sec) before and after the number of spacers was compared and evaluated as a residual ratio.

Example 9 Instead of light ester 9EG, light ester 1 was used as a polymerizable monomer when producing a spacer for a liquid crystal display element.
The same operation as in Example 8 was performed except that 30 MA (manufactured by Kyoeisha Chemical Co., Ltd., methoxyethylene glycol methacrylate, average number of moles of ethylene glycol added n = 9) was used. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and wet sprayability and adhesion were evaluated in the same manner as in Example 8. The results are shown in Table 2.

Example 10 As a polymerizable monomer at the time of producing a spacer for a liquid crystal display element, SMA was 1.5 parts by weight, and light ester 9EG was used.
Light ester 130MA1.
The same operation as in Example 8 was performed except that 5 parts by weight was used. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and wet sprayability and adhesion were evaluated in the same manner as in Example 8. The results are shown in Table 2.

Example 11 041MA (manufactured by Kyoeisha Chemical Co., Ltd., methoxyethylene glycol methacrylate, average number of moles of ethylene glycol added n = 30) was used instead of light ester 9EG as a polymerizable monomer when producing a spacer for a liquid crystal display element. The same operation as in Example 8 was performed except that was used. Using the obtained particles, a liquid crystal display device was evaluated in the same manner as in Example 1, and wet sprayability and adhesion were evaluated in the same manner as in Example 8. The results are shown in Table 2.

Example 12 The same operation as in Example 8 was performed except that LMA was used instead of SMA as the polymerizable monomer at the time of producing the spacer for the liquid crystal display element. Using the obtained particles, a liquid crystal display device was evaluated in the same manner as in Example 1, and wet sprayability and adhesion were evaluated in the same manner as in Example 8. The results are shown in Table 2.

Example 13 250 parts by weight of ethanol was placed in a separable flask,
One part by weight of polyvinylpyrrolidone was added and completely dissolved. Further, 4 parts by weight of the seed particles obtained in Example 5 was added,
The mixture was sufficiently dispersed by stirring. Here, 1 part by weight of SMA,
LMA 0.6 parts by weight, light ester 130 MA 0.4
Parts by weight and 80 parts by weight of ion-exchanged water were added and stirred uniformly. Nitrogen gas was introduced into the system, and stirring was continued at room temperature for 24 hours. Next, 0.023 parts by weight of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was dissolved in 30 parts by weight of ethanol and added to the system, and then the system was heated to 60 ° C. The polymerization was continued for 24 hours while stirring.
After completion of the polymerization, the reaction solution was taken out, and the particles and the reaction solution were separated by filtration with a 3 μm membrane filter. The particles were sufficiently washed with ethanol, and dried under reduced pressure with a vacuum dryer. Using these particles, a liquid crystal display device was evaluated in the same manner as in Example 1, and wet sprayability and adhesion were evaluated in the same manner as in Example 8. The results are shown in Table 2.

Comparative Example 6 Surfactant Hitenol N-08 (Daiichi Kogyo Seiyaku)
Stearyl methacrylate 5 in 800 parts by weight of 3% aqueous solution
0 parts by weight, 20 parts by weight of light ester 130MA, DV
A mixture of 30 parts by weight of B and 2 parts by weight of benzoyl peroxide was added, and the mixture was stirred with a homogenizer to adjust the particle size.
Thereafter, the temperature was raised to 80 ° C. under a nitrogen stream with stirring, and the reaction was carried out for 15 hours. After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed.
The obtained particles had an average particle size of 6.0 μm and a Cv value of 5. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and wet sprayability and adhesion were evaluated in the same manner as in Example 8. The results are shown in Table 2.

[0098]

[Table 2]

Example 14 A separable flask was charged with 150 parts by weight of ethanol.
One part by weight of polyvinylpyrrolidone was added and completely dissolved. Further, 4 parts by weight of the seed particles obtained in Example 1 was added,
The mixture was sufficiently dispersed by stirring. Here, 2 parts by weight of pentafluoropropyl methacrylate (hereinafter, referred to as “FPMA”) and 180 parts by weight of ion-exchanged water were added and uniformly stirred. Nitrogen gas was introduced into the system, and stirring was continued at room temperature for 24 hours. Next, as a polymerization initiator, 1.023 parts by weight of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved in 30 parts by weight of ethanol, and then added to the system.
Temperature. The polymerization was continued for 24 hours while stirring. After completion of the polymerization, the reaction solution was taken out, and the particles and the reaction solution were separated by filtration with a 3 μm membrane filter. The particles were sufficiently washed with ethanol, and dried under reduced pressure with a vacuum dryer. Using these particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. The results are shown in Table 3.

Example 15 As a polymerizable monomer when producing a spacer for a liquid crystal display element,
Instead of FPMA, 2- (N-ethyl perfluorooctasulfoamido) ethyl acrylate (FX manufactured by 3M, FX
The same operation as in Example 14 was performed except that -13) was used. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. The results are shown in Table 3.

Example 16 As a polymerizable monomer when producing a spacer for a liquid crystal display element,
The same operation as in Example 14 was performed, except that FPMA was 0.2 parts by weight and 1.8 parts by weight of butyl methacrylate was further used. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. The results are shown in Table 3.

Example 17 Using the seed particles obtained in Example 5, the same operation as in Example 14 for producing a spacer for a liquid crystal display element was performed. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. The results are shown in Table 3.

Example 18 The same operation as in Example 14 was carried out except that 6.0 μm silica particles (Hypressica, manufactured by Ube Nitto Kasei Co., Ltd.) were used as seed particles. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. The results are shown in Table 3.

Comparative Example 7 Surfactant Hitenol N-08 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
A mixture of 70 parts by weight of pentafluoropropyl methacrylate, 30 parts by weight of DVB and 2 parts by weight of benzoyl peroxide was added to 800 parts by weight of a 3% aqueous solution, and the mixture was stirred with a homogenizer to adjust the particle size. Thereafter, the temperature was raised to 80 ° C. under a nitrogen stream with stirring, and the reaction was carried out for 15 hours. After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed. The obtained particles had an average particle size of 6.0 μm and a Cv value of 5. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. The results are shown in Table 3.

[0105]

[Table 3]

Example 19 150 parts by weight of ethanol was placed in a separable flask.
One part by weight of polyvinylpyrrolidone was added and completely dissolved. Further, 4 parts by weight of the seed particles obtained in Example 1 was added,
The mixture was sufficiently dispersed by stirring. Here, 1.2 parts by weight of FPMA (manufactured by Daikin Chemicals Co., Ltd., M-1210), 0.8 parts by weight of light ester 130MA, and 18 parts of ion-exchanged water
0 parts by weight was added, and the mixture was stirred uniformly. Nitrogen gas was introduced into the system, and stirring was continued at room temperature for 24 hours. Next, V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) 0.023 as a polymerization initiator
Parts by weight were dissolved in 30 parts by weight of ethanol and added to the system, and then the system was heated to 60 ° C. The polymerization was continued for 24 hours while stirring. After completion of the polymerization, the reaction solution was taken out, and the particles and the reaction solution were separated by filtration with a 3 μm membrane filter. Wash the particles thoroughly with ethanol,
Vacuum drying was performed with a vacuum dryer. Using these particles,
The evaluation of the liquid crystal display device and the evaluation of the mechanical strength were performed in the same manner as in Example 1, and the evaluation of the wet sprayability and the evaluation of the adhesion were performed in the same manner as in Example 8. The results are shown in Table 4.

Example 20 As a polymerizable monomer at the time of producing a spacer for a liquid crystal display element,
Instead of FPMA, 2- (N-ethyl perfluorooctasulfoamido) ethyl acrylate (FX manufactured by 3M, FX
The same operation as in Example 19 was performed except that -13) was used. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and evaluation of wet sprayability and evaluation of adhesion were performed in the same manner as in Example 8. The results are shown in Table 4.

Example 21 As a polymerizable monomer at the time of producing a spacer for a liquid crystal display element,
FPMA is 1.0 part by weight, light ester 130M
Instead of 0.8 parts by weight of A, light ester 9EG0.6
The same operation as in Example 19 was performed, except that 0.4 parts by weight of n-butyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester NB) was used. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and evaluation of wet sprayability and evaluation of adhesion were performed in the same manner as in Example 8. The results are shown in Table 4.

Example 22 The same operation as in Example 19 was performed using the seed particles obtained in Example 5. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and evaluation of wet sprayability and evaluation of adhesion were performed in the same manner as in Example 8. The results are shown in Table 4.

Example 23 The same operation as in Example 19 was performed except that 6.0 μm silica particles (Hypressica, manufactured by Ube Nitto Kasei Co., Ltd.) were used as seed particles. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and evaluation of wet sprayability and evaluation of adhesion were performed in the same manner as in Example 8. The results are shown in Table 4.

Comparative Example 8 Surfactant Hitenol N-08 (Daiichi Kogyo Seiyaku)
800 parts by weight of a 3% aqueous solution, 50 parts by weight of pentafluoropropyl methacrylate, 130MA20 light ester
A mixed solution of 30 parts by weight of DVB, 30 parts by weight of DVB and 2 parts by weight of benzoyl peroxide was added, and the mixture was stirred with a homogenizer to adjust the particle size. Then, with stirring, under a nitrogen stream, 80
C. and the reaction was carried out for 15 hours. After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed. The obtained particles had an average particle size of 6.0 μm, Cv
Value = 5. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1, and wet sprayability and adhesion were evaluated in the same manner as in Example 8. The results are shown in Table 4.

[0112]

[Table 4]

Example 24 250 parts by weight of ethanol was placed in a separable flask.
One part by weight of polyvinylpyrrolidone was added and completely dissolved. Further, 4 parts by weight of the seed particles obtained in Example 1 was added,
The mixture was sufficiently dispersed by stirring. 2 parts by weight of (3-acryloxypropyl) tris (trimethylsiloxane) silane and 80 parts by weight of ion-exchanged water were added thereto, and the mixture was stirred uniformly. Nitrogen gas was introduced into the system, and stirring was continued at room temperature for 24 hours. Next, 0.023 parts by weight of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was dissolved in 30 parts by weight of ethanol, and then added to the system.
Temperature. The polymerization was continued for 24 hours while stirring. After completion of the polymerization, the reaction solution was taken out, and the particles and the reaction solution were separated by filtration with a 3 μm membrane filter. The particles were sufficiently washed with ethanol, and dried under reduced pressure with a vacuum dryer. Using these particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. Table 5 shows the results.

Example 25 As a polymerizable monomer for producing a spacer for a liquid crystal display element,
The same operation as in Example 24 was performed except that (3-acryloxypropyl) methylbis (trimethylsiloxy) silane was used instead of (3-acryloxypropyl) tris (trimethylsiloxane) silane. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. Table 5 shows the results.

Example 26 The same operation as in Example 24 was performed using the seed particles obtained in Example 5. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. Table 5 shows the results.

Example 27 The same operation as in Example 24 was performed, except that 6.0 μm silica particles (Hypressica, manufactured by Ube Nitto Kasei Co., Ltd.) were used as seed particles. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. Table 5 shows the results.

Comparative Example 9 Surfactant Hitenol N-08 (Daiichi Kogyo Seiyaku)
A mixture of 80 parts by weight of (3-acryloxypropyl) tris (trimethylsiloxane) silane, 20 parts by weight of DVB, and 2 parts by weight of benzoyl peroxide was added to 800 parts by weight of a 3% aqueous solution, and the particle size was adjusted by stirring with a homogenizer. went. Thereafter, the temperature was raised to 80 ° C. under a nitrogen stream with stirring, and the reaction was carried out for 15 hours. After the obtained fine particles were washed with hot ion-exchanged water and methanol, a classification operation was performed. The obtained particles had an average particle size of 6.0 μm and a Cv value of 5
Met. Using the obtained particles, evaluation of a liquid crystal display device and evaluation of mechanical strength were performed in the same manner as in Example 1. Table 5 shows the results.

[0118]

[Table 5]

[0119]

The method for manufacturing a spacer for a liquid crystal display element according to the present invention is as described above, so that a spacer for a liquid crystal display element having both the property of preventing abnormal alignment and the mechanical strength basically required of the spacer is obtained. be able to. In recent years,
Even in the case of spraying using a commonly used hydrophilic solvent in the production of a large-sized liquid crystal display panel with increasing demand, by selecting a polymerizable monomer, the performance such as adhesion and spraying properties can be improved. The provided liquid crystal display element spacer can be obtained. Thus, by using this spacer, an abnormal alignment phenomenon of the liquid crystal does not occur, and a good liquid crystal display element with uniform image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seal member 2 Transparent substrate 3 Transparent electrode 4 Alignment control film 5 Transparent substrate 6 Transparent electrode 7 Alignment control film 8 Substrate 9 Spacer 10 Substrate 11 Nematic liquid crystal 12 Polarizing film 13 Polarizing film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 20/28 C08F 20/28 G02F 1/1339 500 G02F 1/1339 500

Claims (7)

[Claims] 1. A method for dispersing seed particles in a reaction medium and further dissolving a radical polymerizable monomer, followed by polymerization in the presence of a radical polymerization initiator, whereby the radicals are formed on the surface of the seed particles. A method for producing a liquid crystal display element spacer for forming a polymer layer comprising a polymerizable monomer,
The method for producing a spacer for a liquid crystal display element, wherein the reaction medium dissolves the radical polymerizable monomer but does not dissolve the polymer produced. 2. The method according to claim 1, wherein the radically polymerizable monomer is a compound represented by the following general formula (1). Embedded image (In the formula, R ¹ represents a hydrogen atom or a methyl group.
² represents a linear or branched alkyl group having 6 to 30 carbon atoms. ) 3. The method for producing a spacer for a liquid crystal display element according to claim 2, wherein a compound represented by the following general formula (2) is further used as the radical polymerizable monomer. Embedded image (Wherein, R ³ represents a hydrogen atom or a methyl group.
⁴ represents a methyl group or a (meth) acryl group. m is
Represents an integer of 4 to 40. ) 4. The method for producing a spacer for a liquid crystal display device according to claim 1, wherein the radical polymerizable monomer is a compound represented by the following general formula (3). Embedded image (Wherein, R ⁵ represents a hydrogen atom or a methyl group.
⁶ represents a fluorine-containing functional group. ) 5. The method for producing a spacer for a liquid crystal display device according to claim 4, wherein a compound represented by the following general formula (4) is further used as the radical polymerizable monomer. Embedded image (Wherein, R ⁷ represents a hydrogen atom or a methyl group.
⁸ represents a methyl group or a (meth) acryl group. n is
Represents an integer of 1 to 50. ) 6. The method for producing a spacer for a liquid crystal display device according to claim 1, wherein the radical polymerizable monomer is a compound represented by the following general formula (5). Embedded image (In the formula, R ⁹ represents a hydrogen atom or a methyl group.
¹⁰ represents a methoxy group, an ethoxy group, a methyl group or a trimethylsilyl group. ) 7. The method according to claim 1, wherein the seed particles are colored with a pigment or a dye.
7. The method for producing a spacer for a liquid crystal display element according to 5 or 6.