JPH09194842A - Spacer for liquid crystal and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a spacer for a liquid crystal, which can control the abnormal orientation of the liquid crystal around a spacer and can prevent the passage of light when lighting a liquid crystal panel by introducing a graft polymer chain having a long-chain alkyl group into the surfaces of polymer particles. SOLUTION: This spacer for a liquid crystal comprises polymer particles having a graft polymer chain with a long-chain alkyl group introduced into the surfaces. It is produced by subjecting the polymer particle surface having a functional group with radical chain transfer capability and/or an active group capable of initiating radical polymerization introduced therein to graft polymerization with one or more polymerizable vinyl monomers having a long-chain alkyl group, or a mixture of one or more of these monomers and one or more other polymerizable vinyl monomers copolymerizable therewith.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal spacer and a method for manufacturing the liquid crystal spacer.

[0002]

2. Description of the Related Art In a liquid crystal panel, an inorganic or organic liquid crystal spacer is used to maintain a gap between the panels. However, in the liquid crystal panel, the alignment of the liquid crystal molecules becomes irregular at the interface between the liquid crystal and the spacer (abnormal alignment), and the display quality is significantly deteriorated. When the above-mentioned abnormal orientation occurs, a region called a domain is generated around the spacer. This domain causes light leakage during the operation of the liquid crystal panel and reduces the contrast of the liquid crystal panel. It is well known that the domain disappears when liquid crystal molecules are vertically aligned at the interface between the liquid crystal and the spacer. In order to promote vertical alignment on the spacer surface, a liquid crystal spacer in which a long-chain alkyl group is present on the surface of crosslinked polymer fine particles is provided (JP-A-4-27).
917). The liquid crystal spacer is produced by impregnating crosslinked polymer fine particles with a polymerizable vinyl monomer having a long-chain alkyl group and a polymerization initiator, and then performing polymerization. However, in the conventional method, the domain was not completely eliminated because the introduction of the alkyl group into the spacer surface was not sufficient.

[0003]

In the above-mentioned prior art, since the crosslinked polymer fine particles are impregnated with the polymerizable vinyl monomer having a long-chain alkyl group and the polymerization initiator, the crosslinked polymer fine particles and the polymerizable vinyl monomer are used. The degree of impregnation varies depending on the type of the polymer or the polymerization initiator, and the degree of impregnation varies depending on the impregnation conditions such as the impregnation temperature and the impregnation pressure. It was difficult to do. Further, when the crosslinked polymer fine particles are impregnated with the polymerizable vinyl monomer or the polymerization initiator, the polymerizable vinyl monomer or the polymerization initiator is diluted by the crosslinked polymer fine particles, so that the polymerization efficiency decreases. There is also a problem to say.

[0004]

As a means for solving the above-mentioned conventional problems, the present invention provides a spacer for a liquid crystal comprising polymer particles having a graft polymer chain having a long chain alkyl group introduced on the surface thereof. The spacer for liquid crystal has a functional group capable of radical chain transfer on the surface and / or
Or one or more polymerizable vinyl monomers having a long-chain alkyl group on the surface of the polymer particles introduced with an active group having a radical polymerization initiation ability, or a polymerizable vinyl monomer having a long-chain alkyl group Graft polymer chain having a long-chain alkyl group by graft-polymerizing a mixture of one or more and one or more polymerizable vinyl monomers copolymerizable with the polymerizable vinyl monomer. Manufactured by introducing. Desirable functional groups capable of radical chain transfer are, for example, mercapto groups and / or polymerizable vinyl groups, and desirable active groups having radical polymerization initiation ability are, for example, peroxide groups and / or azo groups. .

[Polymer Particles Having a Predetermined Functional Group on the Surface] A polymer particle having a functional group capable of radical chain transfer and / or an active group having a radical polymerization initiation ability is introduced on the surface used in the spacer for liquid crystal of the present invention. To produce coalesced particles, first, polymer particles having a functional group on the surface for introducing the functional group are produced. What is desirable as a method for producing polymer particles having a predetermined functional group on the surface is to polymerize the monomer in a solvent in which the monomer dissolves and the polymer based on the monomer does not dissolve, A precipitation polymerization method for precipitating coalesced particles, or a polymer particle obtained by the above precipitation polymerization method is swollen with a monomer, and the monomer is further polymerized by a radical contained in the polymer particle, and It is a seed polymerization method for obtaining a secondary polymer particle, and when the polymer particle is produced by the above production method, a polymerizable vinyl monomer having a predetermined functional group on the surface or a polymerizable vinyl monomer having a predetermined functional group A mixed monomer of the polymer and another polymerizable vinyl monomer copolymerizable with the polymerizable vinyl monomer is used.

The predetermined functional groups introduced in the above method include hydroxyl group, carboxyl group, epoxy group, hydrolyzable silyl group, silanol group, isocyanate group, amino group, amide group, sulfone group, mercapto group and the like. There is a functional group or a functional group that produces the above functional group by means of hydrolysis, condensation, ring opening, or the like. As the polymerizable vinyl monomer having the functional group, for example, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate,
2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, allyl alcohol, hydroxyl group-containing monomers such as polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, atropic acid, Α, β-Unsaturated carboxylic acids such as citraconic acid, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxyethyl succinic acid, 2-methacryloyl Carboxyl group-containing monomers such as oxyethyl phthalic acid and 2-methacryloyloxyethyl hexahydrophthalic acid, and epoxy groups such as glycidyl acrylate, glycidyl methacrylate and glycidyl allyl ether Monomers, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxypropylmethyldimethoxysilane , Γ-methacryloxypropylbis (trimethoxy) methylsilane, 11-methacryloxyundecamethylenetrimethoxysilane, vinyltriethoxysilane, 4-vinyltetramethylenetrimethoxysilane, 8-vinyloctamethylenetrimethoxysilane, 3-
Trimethoxysilylpropyl vinyl ether, vinyltriacetoxysilane, p-trimethoxysilylstyrene,
p-triethoxysilylstyrene, p-trimethoxysilyl
-α-methylstyrene, p-triethoxysilyl-α-methylstyrene, γ-acryloxypropyltrimethoxysilane, vinyltrimethoxysilane, N-β (N-vinylbenzylaminoethyl-γ-aminopropyl) trimethoxysilane Hydrochloride, hydrolyzable silyl group-containing monomer such as vinyltrichlorosilane, acryloyl isocyanate, methacryloyl isocyanate, acrylic isocyanate, isocyanate such as m-isopropenyl-α, α-dimethylbenzyl isocyanate Group-containing monomers, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminopropyl methacrylate, amino group-containing monomers such as dimethylaminopropyl acrylate, acrylamide, methacrylamide, diacetone acrylamide, Amide group-containing monomers such as N-vinylformamide and N-vinylacetamide, P-
Sulfonate styrene, 2- (acryloylamino) -2-methylpropane sulfonic acid, etc., sulfone group-containing monomer, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, mercaptopropylmethyltrimethoxysilane, etc. There is a quantity etc.

Other polymerizable vinyl monomers copolymerizable with the above-mentioned polymerizable vinyl monomer having a functional group include, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n- Butyl acrylate, iso-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate,
Aliphatic or cyclic acrylates and / or methacrylates such as n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, stearyl methacrylate, lauryl methacrylate , Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether and iso-butyl vinyl ether, styrenes such as styrene and α-methyl styrene,
Nitrile-based monomers such as acrylonitrile and methacrylonitrile, fatty acid vinyl such as vinyl acetate and vinyl propionate, halogen-containing monomers such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride, ethylene, propylene, isoprene And the like, dienes such as chloroprene and butadiene, and water-soluble monomers such as vinylpyrrolidone, vinylpyridine and vinylcarbazole. The above examples do not limit the invention. The above monomers are used alone or in combination of two or more.

In the above precipitation polymerization and seed polymerization, divinylbenzene, diallyl phthalate, tetraallyloxyethane, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane are used as a part of the monomers. Method using polyvalent vinyl compound such as trimethacrylate and / or γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxy Silane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxypropylbis (trimethoxy) methylsilane, 11-methacryloxyundecamethylenetrimetho Xysilane, vinyltriethoxysilane, 4-vinyltetramethylenetrimethoxysilane, 8-vinyloctamethylenetrimethoxysilane, 3-
Trimethoxysilylpropyl vinyl ether, vinyltriacetoxysilane, p-trimethoxysilylstyrene,
p-triethoxysilylstyrene, p-trimethoxysilyl
-α-methylstyrene, p-triethoxysilyl-α-methylstyrene, γ-acryloxypropyltrimethoxysilane, vinyltrimethoxysilane, N-β (N-vinylbenzylaminoethyl-γ-aminopropyl) trimethoxysilane -Crosslinked polymer particles obtained by a method in which a vinyl monomer having a hydrolyzable silyl group such as a hydrochloride is used and then, after polymerization, is crosslinked by a siloxane bond by hydrolysis, are preferable. The crosslinked polymer particles have good solvent resistance and heat resistance. In the above precipitation polymerization method, a cellulose derivative such as hydroxyethyl cellulose, hydroxypropyl cellulose, or cellulose acetate butyrate may be used as a dispersant in order to prevent the precipitated polymer particles from being associated with each other. In the precipitation polymerization and the seed polymerization, particles having a true spherical shape and a uniform particle size distribution suitable as a spacer for liquid crystals can be obtained, and particularly in the seed polymerization, a true spherical particle having a large particle diameter can be obtained.

[Polymer Particles Having Radical Chain Transfer Functional Group Introduced on Surface] Polymer particles having a radical chain transfer functional group introduced on the surface can be produced by a predetermined method on the surface produced by the above method. Radical chain by reacting a polymer particle having a functional group of 1 with a compound having a functional group capable of reacting with the predetermined functional group and a functional group capable of radical chain transfer such as a polymerizable vinyl group or a mercapto group. Introduce a transferable functional group.

[Polymer Particles Introducing Active Group Having Radical Polymerization Initiation Ability on Surface] To produce polymer particles introducing an active group having radical polymerization initiation ability on the surface, the surface produced by the above method is used. Having radical polymerization initiation ability by reacting a polymer particle having a predetermined functional group with an initiator such as a peroxide, a perhydride, or an azo compound having a functional group capable of reacting with the predetermined functional group. A polymer particle having an active group introduced or a functional group capable of radical chain transfer introduced on the surface is used, and a peroxide group is originated from the functional group capable of radical chain transfer on the surface of the polymer particle. Using a polymerization initiator of a polymerizable vinyl monomer having, for example, or a mixture of the polymerizable vinyl monomer and another polymerizable vinyl monomer copolymerizable with the polymerizable vinyl monomer By graft polymerization Te,
An active group having a radical polymerization initiation ability is introduced on the surface of the polymer particles.

[Formation of Graft Polymer Chain Having Long-Chain Alkyl Group] Polymer particles having a functional group capable of radical chain transfer and / or an active group having radical polymerization initiation ability introduced on the surface produced as described above. To the polymerizable vinyl monomer having a long chain alkyl group, or another polymerizable vinyl monomer copolymerizable with the polymerizable vinyl monomer having the long chain alkyl group and the polymerizable vinyl monomer By graft-polymerizing the mixture with and without a polymerization initiator, a graft polymer chain having a long-chain alkyl group is introduced on the surface of the polymer particles. The polymerizable vinyl monomer having a long-chain alkyl group has 6 carbon atoms.
Those having the above long-chain alkyl group are preferable, and those having the long-chain alkyl group having 12 or more carbon atoms are particularly preferable. Examples of the polymerizable vinyl monomer having such a long-chain alkyl group include 2-ethylhexyl acrylate,
Stearyl acrylate, lauryl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, isobornyl acrylate, octyl acrylate, isooctyl acrylate, nonylphenoxyethyl acrylate, nonylphenol 10EO acrylate, lauryl polyoxyethylene acrylate, octylphenol polyoxyethylene acrylate, Stearylphenol polyoxyethylene acrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, isobornyl methacrylate, octyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, cetyl methacrylate, behenyl methacrylate, isodecyl methacrylate Acrylate, tridecyl methacrylate, cyclohexyl methacrylate, polyethylene glycol polytetramethylene glycol monomethacrylate, lauryl polyoxyethylene methacrylate, polyoxyethylene allyl glycidyl nonyl phenyl ether. Further, as the other polymerizable vinyl monomer copolymerizable with the polymerizable vinyl monomer having a long-chain alkyl group, the same polymerizable vinyl monomer as used in the production of polymer particles may be used. used.

When polymer particles having a functional group capable of radical chain transfer on the surface are used, the terminal of the functional group is terminated by addition of a polymerization initiator or irradiation of high energy rays such as ultraviolet rays and electron beams. A radical is generated, and a polymerizable vinyl monomer having a long-chain alkyl group originating from the radical, or a polymerizable vinyl monomer having a long-chain alkyl group and the polymerizable vinyl monomer can be copolymerized Graft-polymerize a mixture with the polymerizable vinyl monomer. When the polymer particles introduced with an active group having the radical polymerization initiation ability are used, the active group is decomposed by heating or irradiation with a high energy ray to generate a radical, and the long chain starts from the radical. Grafting a polymerizable vinyl monomer having an alkyl group or a mixture of a polymerizable vinyl monomer having a long-chain alkyl group and another polymerizable vinyl monomer copolymerizable with the polymerizable vinyl monomer Polymerize.

In the present invention, a polymerizable vinyl monomer having a predetermined functional group is added to a polymer particle having a functional group capable of radical chain transfer and / or an active group having a radical polymerization initiation ability introduced on the surface thereof, or A mixture of the polymerizable vinyl monomer having the predetermined functional group and another polymerizable vinyl monomer copolymerizable with the polymerizable vinyl monomer, or a polymerizable vinyl monomer having a predetermined functional group Or a polymerizable vinyl monomer having a long-chain alkyl group, or a polymerizable vinyl monomer having a predetermined functional group and another polymerizable vinyl monomer copolymerizable with the polymerizable vinyl monomer. Primary graft polymerization of a mixture with a polymerizable vinyl monomer having a long-chain alkyl group to a mixture with a monomer, and a predetermined functional group of the primary graft polymer chain with a functional group capable of reacting with the functional group. Radical chain transfer A functional group capable of radical chain transfer is introduced by reacting a compound having a functional group capable of reacting with the compound, or an initiator such as a peroxide, a perhydride or an azo compound capable of reacting with the functional group is reacted. By introducing an active group capable of initiating a radical polymerization, the polymerizable vinyl monomer having a long-chain alkyl group in the graft polymer chain, or the polymerizable vinyl monomer having a long-chain alkyl group A secondary graft polymer chain having a long-chain alkyl group on the surface of the polymer particle by secondary graft polymerization of a mixture of a vinyl monomer and another polymerizable vinyl monomer copolymerizable, or a tertiary polymer A graft polymer chain may be introduced.

The thus-produced spacer for liquid crystal of the present invention has a graft polymer chain having a long-chain alkyl group introduced on the surface. The long-chain alkyl group concentration of the polymer chain can be directly and easily adjusted by the concentration of the polymerizable vinyl monomer having a long-chain alkyl group used when introducing the graft polymer chain. Further, the polymerizable vinyl monomer and the polymerization initiator are not diluted, and thus high graft polymerization efficiency can be obtained. Since the graft polymer chain having the long-chain alkyl group and the polymer particle are covalently bonded, the layer of the graft polymer chain having the graft polymer chain having the long-chain alkyl group and the polymer particle are They are integral and the layer of the graft polymer chain does not separate from the polymer particles. When the thickness of the layer of the graft polymer chain having a long chain alkyl group is 0.01 μm or more, the polymer particles are aligned with the polymer particles due to the melting effect of the graft polymer chain or the reaction with the functional group residue on the alignment substrate. It also has adhesion to the substrate. When polymer particles having a graft polymer chain having a long-chain alkyl group on the surface thereof are used as a spacer for a liquid crystal panel, liquid crystal molecules are prepared for the long-chain alkyl group of the graft polymer chain on the surface of the polymer particles. Because they are regularly arranged vertically. Disordered alignment of liquid crystal molecules near the liquid crystal spacer is suppressed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

[Example 1] (Polymer particles A having -SiOH on the surface)
Production of 30 g of hydroxypropyl cellulose having a molecular weight of 1.0 × 10 ⁵ was dissolved in 250 g of ethyl alcohol and charged into a reactor, and further 8 g of styrene monomer, 4 g of γ-methacryloxypropyltrimethoxysilane 4 and 2,2′- Charge 0.1 g of azobisisobutyronitrile to the reactor,
Precipitation polymerization was performed for 10 hours under a nitrogen stream to obtain polymer particles having an average particle diameter of 5.8 μm and a standard deviation of 1.5%. After the polymer particles are separated and washed, they are treated with an acid or an alkali to crosslink Si—O—Si siloxane bonds inside the polymer particles, and silanol groups (Si—OH) are present on the surface of the polymer particles. Particle A was produced.

[Example 2] (Production of polymer particles B having -OH groups on the surface) 2 g of n-butyl peroxide was mixed with sodium lauryl sulfate (0.2 g).
The emulsion was finely dispersed in 20 g of water in which 15 g was dissolved so that the oil droplet diameter was 0.5 μm or less. The above polymerization initiator dispersion was put into 40 g of an aqueous dispersion of polystyrene particles (particle diameter 1.2 μm) of 5% by weight, and the oil droplets of the polymerization initiator were polystyrene by slowly stirring at 30 ° C. for 12 hours. The particles were absorbed into a seed particle dispersion liquid.
Next, a mixed monomer of 45 g of styrene, 15 g of 2-hydroxypropyl methacrylate, and 10 g of divinylbenzene was dissolved in 2.85 g of sodium lauryl sulfate to prepare water 3.
The mixture was finely dispersed in 50 g, and the seed particle dispersion was added to and mixed with the mixed monomer dispersion to allow the seed particles to absorb the mixed monomer. Then, 100 g of a 10% by weight aqueous solution of polyvinyl alcohol was added to the above dispersion, and the temperature was raised to 80 ° C. to polymerize the mixed monomer absorbed by the seed particles. Six hours after the temperature was raised, the mixed monomer disappeared, and -O was formed on the surface having an average particle size of 7 μm and a standard deviation of 4.5%.
Polymer particles B having H groups and having a uniform spherical shape were obtained.

[Example 3] (Production of polymer particles C having -COOH groups on the surface) Hydroxypropyl cellulose 50 having a molecular weight of 4 x 10 ^5.
g was dissolved in 300 g of methyl alcohol and charged into a reactor, and further 10 g of styrene, 5 g of divinylbenzene, 2 g of methacrylic acid, and 2,2'-azobisisobutyronitrile were added.
2 g of the polymer was charged into the reactor and subjected to precipitation polymerization at 60 ° C. for 8 hours in a nitrogen stream to obtain uniform spherical polymer particles having an average particle size of 6.25 μm and a standard deviation of 3% having —COOH groups on the surface. C was obtained.

[Example 4] (Production of polymer particles D having an epoxy group on the surface) 200 g of ethyl propionate was charged into a reactor, and 85.7 g of glycidyl methacrylate, 9.7 g of 2-hydroxyethyl methacrylate and ethylene glycol were further charged. 4.6 g of dimethacrylate and 0.15 g of azobis (2,4-dimethylvaleronitrile) were charged into the reactor, and the temperature was 50 ° C., and 1
By performing precipitation polymerization for 6 hours in a nitrogen stream, spherical polymer particles D having an epoxy group on the surface and having an average particle diameter of 4.9 μm and a standard deviation of 5.0% were obtained.

[Example 5] (Production of polymer particles E, F, G having a chain-transferable polymerizable vinyl group on the surface of polymer particles) Silanol groups on the surfaces produced by Examples 1 to 3 and 5, 20 g of methyl ethyl ketone and 3 g of methacryloyl isocyanate are collectively charged to 1 g of each of polymer particles A, B, and C having active hydrogen such as a hydroxyl group and a carboxyl group, and the chain-transferable polymerizable vinyl is allowed to react at room temperature for 30 minutes. Group-containing polymer particles E, F, G
was gotten.

[Example 6] (Production of polymer particles H having a chain-transferable polymerizable vinyl group on the surface of polymer particles) To 10 g of polymer particles D having an epoxy group on the surface produced by Example 4, Cyclohexanone 100g,
Polymer particles 5 having a polymerizable vinyl group capable of chain transfer on the surface were obtained by charging 5 g of methacrylic acid and 0.5 g of hydroquinone into a reactor and reacting under reflux for 4 hours.

[Example 7] (Production of polymer particles I having azo groups on the surface of polymer particles) 50 g of dimethylformamide was added to 10 g of polymer particles D having an epoxy group on the surface produced by Example 4.
Polymer particles I having an azo group on the surface were obtained by reacting g of 2,2-azobis-2- (2-imidazoline) propane with 10 g at 50 ° C. for 5 hours.

Example 8 (Production of Polymer Particle J Having Azo Group on Polymer Particle Surface) For 10 g of polymer particle B having a hydroxyl group on the surface produced in Example 2 and 50 g of dimethylformamide,
4,4-azobis-4-cyanovaleric acid chloride 10
g, and 10 g of triethylamine were added dropwise to obtain polymer particles J having an azo group on the surface.

Example 9 (Polymer particles K having a graft polymer chain containing a peroxide on the surface of the polymer particles,
Production of L and M) To 10 g of each of the polymer particles E, F and G having a polymerizable vinyl group on the surface produced according to Example 5, 200 g of methyl ethyl ketone and a 70 wt% toluene solution of t-butylperoxyallyl carbonate. 50 g, methyl methacrylate 80 g, benzoyl peroxide 0.1 g
Are charged all at once and heated to 70 to 90 ° C under a nitrogen stream,
When the graft polymerization reaction was carried out for a period of time to remove the free polymer, polymer particles K, L and M having a graft polymer chain containing peroxide on the surface were obtained.

[Example 10] (Introduction of a graft polymer chain containing a long-chain alkyl group on the surface of polymer particles) Polymer particles E, F having polymerizable vinyl groups on the surface produced by Examples 5 and 6. For each 10g of G and H,
Methyl ethyl ketone 200g, methyl methacrylate 5
0 g, N-lauryl methacrylate 50 g, and benzoyl peroxide 0.5 g were charged all at once, the temperature was raised to the polymerization initiator cleavage temperature, and the graft polymerization reaction was carried out for 2 hours under a nitrogen stream to obtain a graft polymer chain having a long chain alkyl group. Spacer samples E-1, F-1, introduced on the surface of polymer particles,
G-1 and H-1 were obtained.

[Example 11] (Introduction of graft polymer chain containing long-chain alkyl group on the surface of polymer particle) Polymer particles I and J having azo group on the surface produced in Examples 7 and 8 respectively. Toluene 200 for 10 g
g, methyl methacrylate 20 g, 2-hydroxybutyl methacrylate 20 g, stearyl methacrylate 6
Spacer sample I-1, in which 0 g was charged all at once, the temperature was raised to the cleavage temperature of the polymerization initiator, and the graft polymerization reaction was carried out for 3 hours under a nitrogen stream to introduce a graft polymer chain having a long chain alkyl group onto the surface of polymer particles. J-1 was obtained.

Example 12 (Introduction of Graft Polymer Chain Containing Long Chain Alkyl Group on Polymer Particle Surface) Polymer particle K having a graft polymer chain containing a peroxide group on the surface produced in Example 9 , L, and M of 10 g each, xylene 200 g, methyl methacrylate 20 g, octyl methacrylate 30 g, and lauryl polyoxyethylene methacrylate 50 g were charged all at once, the temperature was raised to the polymerization initiator cleavage temperature, and the graft polymerization reaction was performed under a nitrogen stream for 3 hours. Spacer sample K in which a graft polymer chain having a long-chain alkyl group is introduced on the surface of polymer particles
-1, L-1, and M-1 were obtained.

[Example 13] (Production of polymer particles having a grafted primary side chain) Graft polymer particles having a graft polymer chain having a long-chain alkyl group produced in Example 11 on the surface of the polymer particles To 10 g of each of the spacer samples I-1 and J-1 on the surface, 30 g of xylene and 2 g of isocyanate ethyl methacrylate were charged all at once, and a graft polymerization reaction was carried out at 80 ° C. for 2 hours to give a vinyl group on the side chain of the graft polymer. Introduce. 200 g of methyl cellosolve and 5 parts of methyl methacrylate were respectively added to 10 g of polymer particles having a graft polymer chain having a vinyl group introduced on the side chain on the surface.
0 g, 2-hydroxypropyl methacrylate 50 g,
When 0.5 g of benzoyl peroxide was charged all at once, the temperature was raised to the cleavage temperature of the polymerization initiator, and the graft polymerization reaction was carried out for 1.5 hours in a nitrogen stream. A secondary graft polymer chain is formed having a long chain alkyl group as the side chain of the coalesced chain. Spacer sample I produced in this way
-2 and J-2 are easily dispersed in alcohol.

Comparative Example 1 10 g of the polymer particle surface A having silanol groups on the surface prepared in Example 1 was dispersed in 30 g of a 2 wt% toluene solution of octadecyltrimethoxysilane and heated at 50 ° C. for 1 hour. After that, it was filtered and washed, and heated in a dryer at 130 ° C. for 1 hour to obtain a comparative spacer sample N which is a polymer particle having a long chain alkyl group on the surface.

Comparative Example 2 10 g of commercially available silica particles having no surface treatment were dispersed in 30 g of a 2% by weight toluene solution of octadecyltrimethoxysilane, and the mixture was heated to 50 ° C.
After heating for 1 hour at 80 ° C., the mixture was filtered, washed, and heated in a dryer at 130 ° C. for 1 hour to obtain a comparative spacer sample O which is silica particles having a long-chain alkyl group on the surface.

[Evaluation] The above spacer samples E-1 and F-
1, G-1, H-1, I-1, J-1, K-1, L-
1, M-1, I-2, J-2, N, O were used to prepare a liquid crystal display panel, and the abnormal alignment around the liquid crystal spacer during lighting was observed and evaluated. The results are shown in Table 1. (Liquid Crystal Panel Making Method) A substrate (90 × 100) on which an ITO / polyimide alignment film was formed and rubbed
mm, made by EHC) spray gun with 150
Sprayed so as to 180 pieces / mm ^2, 150 ℃, 30
Heat treatment for minutes was performed. After that, a sealant is printed on the peripheral portion of the substrate and the substrates are bonded together by a conventional method.
A STN liquid crystal panel was prepared by injecting it into the No. 3 (S078W) cell. (Evaluation Method) A direct current voltage (DC) of 50 V for 1 second was applied to the liquid crystal panel produced by the above method, and changes in alignment abnormality (light leakage state) around the liquid crystal spacers were evaluated before and after the application. The light leakage evaluation criteria are shown by 1 to 6 and are as follows. 1: Not generated 2: Partially generated 3: 1/3 generated around particles 4: Half or more generated around particles 5: Generated from all around particles 6: Large generation

[Table 1] * Mother particles are polymer particles without graft polymer chains introduced on the surface.

From the evaluation results shown in Table 1 above, the spacer sample composed of polymer particles having a graft polymer chain having a long-chain alkyl group on the surface was compared with mother particles to which the graft polymer chain was not introduced. The light leakage prevention performance around the particles is remarkably improved. On the other hand, the comparative spacer samples N and O in which the long-chain alkyl group having only the coupling agent treatment was introduced on the surface of the particles showed some improvement, and the graft polymer chain having the long-chain alkyl group improved the light leakage. Does not reach.

[0032]

INDUSTRIAL APPLICABILITY In the present invention, since the liquid crystal molecules can be vertically aligned on the spacer surface by the graft polymer chain having a long-chain alkyl group introduced on the spacer surface, the abnormal alignment of the liquid crystal around the spacer for liquid crystal can be achieved. To prevent light leakage when the liquid crystal panel is turned on. As a result, the contrast of the liquid crystal panel is improved and the display quality can be improved.

Front page continuation (72) Inventor Katsumi Hara 8-3, Ninomachi, Mizuho-ku, Nagoya, Aichi Natco Paint Co., Ltd. (72) Inventor, Hitomi Koseki, 8-3, Ninomachi, Mizuho-ku, Aichi No. Natoko Paint Co., Ltd. Research Institute (72) Inventor Yoshihiko Yamakado 8-3 Ninomachi, Mizuho-ku, Nagoya-shi, Aichi Natco Paint Co. Research Institute (72) Inventor Hironori Hata Nino, Mizuho-ku, Nagoya-shi, Aichi Prefecture 8-3 Machi Natoko Paint Co., Ltd. Research Institute

Claims (3)

[Claims] 1. A spacer for a liquid crystal, comprising polymer particles having a graft polymer chain having a long-chain alkyl group introduced on the surface thereof. 2. One or two kinds of polymerizable vinyl monomers having a long-chain alkyl group on the surface of a polymer particle in which a functional group capable of radical chain transfer and / or an active group having radical polymerization initiation ability is introduced on the surface. Or a mixture of one or more polymerizable vinyl monomers having a long-chain alkyl group and one or more polymerizable vinyl monomers copolymerizable with the polymerizable vinyl monomer A method for producing a spacer for liquid crystal, comprising introducing a graft polymer chain having a long-chain alkyl group by graft-polymerizing 3. The functional group capable of radical chain transfer is a mercapto group and / or a polymerizable vinyl group, and the active group capable of initiating radical polymerization is a peroxide group and / or an azo group. Method for manufacturing the described spacer for liquid crystal