JP2003295198A - Spacer dispersion liquid for manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spacer dispersion liquid for manufacturing a liquid crystal display device, with which spacers can be stably disposed on a substrate by an ink jet system and can be disposed accurately on a non-display part of the substrate for the liquid crystal display device, and the liquid crystal display device wherein excellent display quality is developed without light leakage and the like caused by the spacers, can be obtained. <P>SOLUTION: The spacer dispersion liquid for manufacturing the liquid crystal display device wherein spacers are disposed in optional positions on the substrate by the ink jet system, is characterized in that spacer particles which constitute the spacer dispersion liquid are formed by bonding a vinyl thermoplastic resin formed by radically polymerizing vinyl monomers having a hydrophilic functional group and/or a 3-22C alkyl group onto the surface of inorganic fine particles or organic fine particles by graft polymerization and dispersed in a mono particle shape in an medium consisting of water and/or a hydrophilic organic solvent and having 25 to 45 mN/m surface tension at 20°C. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer dispersion liquid for manufacturing a liquid crystal display device in which spacers are arranged at arbitrary positions on a substrate by an inkjet method.

[0002]

2. Description of the Related Art Liquid crystal display devices are now widely used in personal computers, portable electronic devices and the like. FIG. 1 is a sectional view showing an example of a liquid crystal display device. As shown in FIG. 1, a liquid crystal display device is generally provided with a transparent electrode 3, an alignment film 8, a color filter 4, a black matrix 5 and the like inside.
Two transparent substrates 1 having a polarizing plate 2 arranged on the outside are opposed to each other with a sealing material 9 arranged around them, and a liquid crystal 6 is enclosed in the formed void. There is. In this liquid crystal display device, two transparent substrates 1
Regulates the space between the liquid crystal layer and the appropriate liquid crystal layer thickness (cell gap)
The spacer 7 is used for maintaining the above.

In the conventional method of manufacturing a liquid crystal display device, spacers are randomly and evenly dispersed on a substrate on which pixel electrodes are formed, so that the spacers are also arranged on the pixel electrodes, that is, in the display portion of the liquid crystal display device. I will end up. The spacer is generally formed of synthetic resin, glass, or the like. When the spacer is arranged on the pixel electrode, a phenomenon that polarization is disturbed to lose the polarization property, so-called depolarization phenomenon occurs, and the spacer portion is The problem of light leakage occurs.
Also, because the alignment of the liquid crystal on the spacer surface is disturbed,
There is a problem that light leakage occurs and the contrast and color tone are deteriorated to deteriorate the display quality. Further, in the TFT liquid crystal display device, the TFT element is arranged on the substrate, but if the spacer is arranged on this TFT element, the TFT element is seriously damaged when pressure is applied to the substrate. Problems occur.

In order to suppress the problems associated with the random and uniform distribution of the spacers, it is considered to dispose the spacers only under the light shielding layer. As a method of disposing the spacer only at a specific position in this manner, for example, in Japanese Patent Laid-Open No. 4-198919, the spacer corresponds to the opening after the opening of the mask having the opening is aligned with the position to be arranged. There is disclosed a color liquid crystal panel which is arranged only in the position where the light is turned on.
Japanese Unexamined Patent Publication 7 discloses a method of manufacturing a liquid crystal display device in which a spacer is electrostatically adsorbed on a photoreceptor and then transferred to a transparent substrate.

However, the methods disclosed in both of the above publications have a problem that the alignment film on the substrate is damaged and the display quality is deteriorated because the mask and the photoconductor are directly in contact with the substrate. is there.

Further, in Japanese Patent Laid-Open No. 10-339878, a liquid crystal display in which a spacer is arranged at a specific position by electrostatic repulsive force by applying a voltage to pixel electrodes on a substrate to disperse the charged spacers A method of manufacturing a device is disclosed.

However, in the method disclosed in the above publication, it is impossible to arrange the spacers completely at arbitrary positions because the electrodes are required to follow the pattern to be arranged, and the applicable liquid crystal display device can be used. There is a problem that the type of is restricted.

On the other hand, in Japanese Unexamined Patent Publication No. 57-58124, a spacer is used in a liquid crystal display element in which a spacer and a liquid crystal are interposed in a gap between translucent electrode substrates having transparent electrodes adhered and formed on opposite surfaces. Disclosed is a method of manufacturing a liquid crystal display device in which spacers are arranged on an electrode substrate by using an inkjet printing apparatus, that is, spacers are arranged by an inkjet printing method. This method does not directly contact the substrate itself unlike the above method, and
It can be said that this is an effective method because the spacers can be arranged in arbitrary patterns in arbitrary patterns.

The light-shielding film on which the spacers are to be arranged is called a black matrix and has a width of about 10 to 30 μm.
m. In order to selectively dispose the spacers in such a narrow region, a very high ejection accuracy of the inkjet device is required. Among inkjet devices,
In a piezo-type inkjet apparatus that is preferably used for ejecting a dispersion liquid of particles such as spacers, the surface tension of the ejected liquid greatly affects the ejection accuracy. Generally, the surface tension of the discharge liquid is preferably 25 to 55 mN / m, and therefore the spacer dispersion liquid is also preferably adjusted to this surface tension.

However, the conventional spacer has generally been applied by a wet spraying method in which it is dispersed in a medium such as lower alcohol, chlorofluorocarbon, water or the like and sprayed in a spray form from a nozzle. Since the tension is a low surface tension of 30 mN / m or less, it is difficult to disperse such a spacer in a medium having a relatively high surface tension for inkjet.

Further, in Japanese Patent Laid-Open No. 2000-347191, a pair of electrode substrates opposed to each other with a liquid crystal material interposed therebetween and the electrode substrates are selectively dispersed by an ink jet method between the electrode substrates. Disclosed is a liquid crystal display device including a spacer that holds a space, wherein the spacer includes solid fine particles and a binder resin, and a manufacturing method thereof. This method is a method in which a binder resin made of a hydrophobic acrylic monomer or styrene is adsorbed on the surface of the spacer to cover it.

However, it is necessary to have a very high degree of mono-particle property in order to stably discharge by the ink jet system and to accurately align the gap in the cell of the liquid crystal display device. Even if the surface is coated, the surface tension required for inkjet ink is 25 to 55 m.
There is a problem that it is difficult to completely disperse the spacers in the medium of N / m in the form of single particles. Further, since the hydrophobic surface coating layer has a weak affinity to the alignment film formed on the substrate, its adhesiveness is not sufficient, and the arranged spacer moves inside the liquid crystal cell due to a shock, etc. There is a problem that it is easy to damage.

Further, it is necessary to prevent light leakage due to the abnormal alignment of the liquid crystal around the spacers protruding on the pixel, but the introduction of a hydrophobic functional group known to effectively control the abnormal alignment of the liquid crystal is introduced. Is in the direction opposite to that in which the spacer is dispersed in the form of a single particle in a medium for inkjet ink. Furthermore, it is difficult to completely immobilize the binder resin on the surface of the solid fine particles by the coating method mainly based on the adsorption action, and a part of the binder resin is eluted into the ink during the storage as an inkjet ink and is discharged onto the substrate. At this time, there is a problem that the alignment film is covered or is dissolved in the liquid crystal in the liquid crystal cell to cause a poor display quality of the liquid crystal display device.

As described above, since it is a spacer dispersion liquid for ink-jet ink, the properties required for the surface layer of the spacers are intricately entangled with each other, and it is possible to satisfy all the requirements while maintaining excellent dispersibility. The current situation is that it is difficult.

[0015]

SUMMARY OF THE INVENTION In view of the above-mentioned problems and the present situation, an object of the present invention is to stably dispose spacers on a substrate by an ink jet method and accurately dispose them on a non-display portion of a liquid crystal display substrate. It is possible to provide a spacer dispersion liquid for manufacturing a liquid crystal display device, which is capable of obtaining a liquid crystal display device exhibiting excellent display quality without light leakage due to the spacer.

[0016]

A spacer dispersion liquid for manufacturing a liquid crystal display device according to the present invention is used for manufacturing a liquid crystal display device in which spacers are arranged at arbitrary positions on a substrate by an ink jet method. A spacer dispersion liquid, wherein the spacer constituting the spacer dispersion liquid is a vinyl-based monomer having a hydrophilic functional group and / or an alkyl group having 3 to 22 carbon atoms on the surface of the inorganic fine particles or the organic fine particles. A vinyl-based thermoplastic resin obtained by radical polymerization is bonded by graft polymerization, and is composed of water and / or a hydrophilic organic solvent, and has a surface tension at 20 ° C. of 2
It is characterized in that it is dispersed in the form of single particles in a medium of 5 to 45 mN / m.

Further, the spacer dispersion liquid for manufacturing a liquid crystal display device according to the invention of claim 2 constitutes the vinyl-type thermoplastic resin in the spacer dispersion liquid for manufacturing a liquid crystal display device according to claim 1. The vinyl-based monomer is 30 to 80% by weight of the vinyl-based monomer having a hydrophilic functional group and the vinyl-based monomer 20 to 20 is an alkyl group having 3 to 22 carbon atoms.
It is characterized by containing 60% by weight.

Furthermore, the spacer dispersion liquid for producing a liquid crystal display device according to the invention of claim 3 is the same as the spacer dispersion liquid for producing a liquid crystal display device according to claim 1 or 2, wherein a hydrophilic functional group is added. Is at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfonyl group, a phosphonyl group, an amino group, an amide group, an ether group, a thiol group and a thioether group.

The spacer constituting the spacer dispersion liquid for producing a liquid crystal display device of the present invention (hereinafter, simply referred to as "spacer dispersion liquid") has a hydrophilic functional group and a hydrophilic functional group on the surface of the inorganic fine particles or the organic fine particles. And / or a vinyl-based thermoplastic resin obtained by radical polymerization of a vinyl-based monomer having an alkyl group having 3 to 22 carbon atoms, which is bonded by graft polymerization.

The above-mentioned inorganic fine particles are not particularly limited, and examples thereof include silica fine particles. These inorganic fine particles may be used alone or in combination of two or more kinds.

The organic fine particles are not particularly limited, and examples thereof include organic polymer fine particles. These organic fine particles may be used alone or in combination of two or more kinds. The inorganic fine particles and the organic fine particles may be used alone or in combination.

In the present invention, among the above-mentioned inorganic fine particles and organic fine particles, the inorganic fine particles and the organic fine particles have an appropriate hardness that does not damage the alignment film formed on the substrate of the liquid crystal display device, and the thickness due to thermal expansion or thermal contraction. The organic polymer-based fine particles are preferably used because they have the advantages that they can easily follow changes in the above condition and that the movement of the spacer inside the cell is relatively small.

The composition of the monomer for obtaining the above organic polymer is not particularly limited, but it is possible to obtain an organic polymer having an appropriate strength and the like. A mixed monomer composed of a functional monomer is preferable. The content of the polyfunctional monomer in the mixed monomer is not particularly limited, but is preferably 30% by weight or less. When the content of the polyfunctional monomer in the mixed monomer exceeds 30% by weight, the strength and hardness of the obtained organic polymer may be too high.

The monofunctional monomer is not particularly limited, but examples thereof include styrene derivatives such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, chloromethylstyrene; vinyl chloride. ;
Vinyl esters such as 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) Examples thereof include (meth) acrylic acid esters such as acrylate. These monofunctional monomers may be used alone or in combination of two or more kinds. In addition, for example, "(meth) acrylic" referred to herein means "acrylic" or "methacrylic".

The polyfunctional monomer is not particularly limited, but for example, divinylbenzene; diallyl phthalate; triallyl isocyanurate; 1,
6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) ) Acrylate, dipentaerythritol hexa (meth) acrylate, polytetramethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate and other (meth) acrylic acid esters Polyethylene such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate Rikoruji (meth) acrylate; polypropylene glycol di (meth) acrylates such as propylene glycol di (meth) acrylate;
2,2-bis [4- (methacryloxyethoxy) phenyl] propane di (meth) acrylate, 2,2-hydrogenated bis [4- (acryloxypolyethoxy) phenyl] propane di (meth) acrylate, 2,2-bis 2,2-Bis [4-] such as [4- (acryloxyethoxypolypropoxy) phenyl] propane di (meth) acrylate
Examples thereof include (acryloxypolyalkoxy) phenyl] propane di (meth) acrylates, and isomers or derivatives thereof. These polyfunctional monomers may be used alone or in combination of two or more kinds.

The method for polymerizing the above monomers, preferably a mixed monomer comprising a monofunctional monomer and a polyfunctional monomer, to produce organic polymer fine particles is not particularly limited. However, for example, a suspension polymerization method, a seed polymerization method, a dispersion polymerization method and the like can be mentioned, and any manufacturing method may be adopted.

The suspension polymerization method has a relatively wide particle size distribution,
Since polydispersed particles can be obtained, it is suitable for the purpose of producing fine particles having various kinds of particle diameters. However, when particles produced by the suspension polymerization method are used as spacers, it is preferable to perform classification operation to select and use particles having a desired particle size or particle size distribution. Further, the seed polymerization method and the dispersion polymerization method are suitable for the purpose of producing a large amount of fine particles having a specific particle diameter, because monodisperse particles can be obtained without requiring a classification operation.

In the above polymerization, a medium and a polymerization initiator are used.

The medium may be appropriately selected according to the type of monomer used and the monomer composition, and is not particularly limited. For example, water; methanol, ethanol, propanol and the like. Alcohols; cellosolves such as methyl cellosolve and ethyl cellosolve; ketones such as acetone, methyl ethyl ketone, methyl butyl ketone, 2-butanone; acetic acid esters such as ethyl acetate and butyl acetate; acetonitrile, N, N-dimethylformamide, dimethyl Hydrocarbons such as sulfoxide may, for example, be mentioned. These media may be used alone or in combination of two or more kinds.

The above-mentioned polymerization initiator is not particularly limited, but for example, benzoyl peroxide, lauroyl peroxide, benzoyl orthochloroperoxide, benzoyl orthomethoxyperoxide, 3,5,5-trimethylhexahexa Noyl peroxide, t-butylperoxy-2
-Organic peroxides such as ethylhexanoate and di-t-butyl peroxide; azobisisobutyronitrile,
Azobiscyclohexacarbonitrile, azobis (2,
Examples thereof include azo compounds such as 4-dimethylvaleronitrile). These polymerization initiators may be used alone or in combination of two or more kinds.

The amount of the above-mentioned polymerization initiator to be used is not particularly limited, but with respect to 100 parts by weight of the monomer,
The amount of the polymerization initiator is preferably 0.1 to 10 parts by weight.
The amount of the polymerization initiator used was 0.
If it is less than 1 part by weight, the polymerization reaction may not proceed sufficiently, and conversely, if it exceeds 10 parts by weight with respect to 100 parts by weight of the monomer, the molecular weight of the obtained organic polymer may be too low. is there.

In suspension polymerization, a poor solvent for a monomer is used as a medium, and a monomer composition comprising a monomer and a polymerization initiator is used so that a desired particle size or particle size distribution is obtained. It is a method of dispersing and polymerizing. As a medium (poor solvent) in suspension polymerization, usually, a dispersion stabilizer added to water is used. The dispersion stabilizer is not particularly limited, for example, polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, polyacrylic acid, polyacrylamide, water-soluble polymers such as polyethylene oxide, and nonionic Examples thereof include surfactants such as surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. These dispersion stabilizers may be used alone or in combination of two or more kinds.

The conditions for suspension polymerization may be appropriately determined according to the type of monomer used and the composition of the monomer, and are not particularly limited, but the polymerization temperature is usually 50 to 80 ° C.
It is preferable that the polymerization time is 3 to 24 hours.

The seed polymerization method is a polymerization method in which monodisperse seed particles produced by a soap-free polymerization method or an emulsion polymerization method are further absorbed with a monomer to expand them to a target particle diameter. The monomer used for preparing the seed particles is not particularly limited, but in order to suppress phase separation during seed polymerization, a monomer similar to the monomer used during seed polymerization is used. Among them, styrene and derivatives thereof are more preferably used because they have good monodispersibility in particle distribution.

Since the particle size distribution of the seed particles is also reflected in the particle size distribution after seed polymerization, it is preferably as monodisperse as possible, and the Cv value is preferably 5% or less. Since the phase separation from the seed particles is likely to occur during the seed polymerization, the monomer to be absorbed by the seed particles during the seed polymerization is a monomer that is as similar as possible to the monomer used for preparing the seed particles. It is preferable. For example, when the seed particles are made of a styrene resin, the monomer to be absorbed by the seed particles is preferably an aromatic divinyl monomer, and when the seed particles are made of an acrylic resin, a monomer which is absorbed by the seed particles is preferably used. The monomer is preferably an acrylic multi-vinyl monomer.

In the seed polymerization, the amount of the above-mentioned monomer added to the seed particles is not particularly limited, but it is preferably 20 to 100 parts by weight of the monomer per 1 part by weight of the seed particles. . If the amount of the monomer added is less than 20 parts by weight relative to 1 part by weight of the seed particles, the strength of the obtained organic polymer fine particles may be insufficient, and conversely, the seed particles 1
If the amount of the monomer added is more than 100 parts by weight, the particles may coalesce during the seed polymerization, and the particle distribution of the resulting organic polymer fine particles may spread to an undesired extent. .

In the above seed polymerization, a dispersion stabilizer may be used if necessary. The dispersion stabilizer is not particularly limited, for example, polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, polyacrylic acid, polyacrylamide, water-soluble polymers such as polyethylene oxide, and nonionic Examples thereof include surfactants such as surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. These dispersion stabilizers may be used alone or in combination of two or more kinds.

The dispersion polymerization method is carried out by using a poor solvent as a medium in which a monomer dissolves but a polymer formed does not dissolve, and a polymer dispersion stabilizer is added to the polymerization system to produce a polymer. It is a method of precipitating the polymer in the form of particles.

Generally, when a monomer containing a crosslinkable monomer is polymerized by a dispersion polymerization method, particles are likely to aggregate,
Although it is difficult to stably obtain monodisperse crosslinked fine particles, it is possible to stably polymerize a monomer containing a crosslinkable monomer by selecting the polymerization conditions.

The content of the crosslinkable monomer in the monomer containing the above-mentioned crosslinkable monomer is not particularly limited, but aggregation of particles during dispersion polymerization and strength of the obtained crosslinked fine particles are obtained. Considering the above, it is preferably 50% by weight or more. When the content of the crosslinkable monomer in the monomer containing the crosslinkable monomer is less than 50% by weight, the surface of the fine particles generated during the polymerization becomes soft in the medium, so that the particles may collide with each other. Cohesion may occur, and the particle-based distribution of the obtained crosslinked fine particles may spread to an undesired degree or may become an aggregate. Further, even if the monodispersity is maintained, the crosslink density becomes low, and the strength required as a spacer may not be sufficiently obtained.

The above-mentioned inorganic fine particles or organic fine particles (hereinafter, "inorganic fine particles or organic fine particles" are simply referred to as "fine particles") may be colored in order to improve the contrast of the display element. good.

The method of coloring the above-mentioned fine particles is not particularly limited, but for example, a coloring treatment method with a coloring agent such as carbon black, disperse dye, acid dye, basic dye, metal oxide, or the like A method of forming a film of an organic substance on the surface and decomposing or carbonizing the film of the organic substance at a high temperature for coloring, and the like can be mentioned, and any method may be adopted. When the material forming the fine particles is colored, the fine particles may be used as they are without being subjected to a coloring treatment.

Since the spacer constituting the spacer dispersion liquid of the present invention is used as the spacer (gap material) of the display element, the above-mentioned fine particles constituting the spacer or the finally obtained spacer has a certain strength. It is preferable that

When the compression elastic modulus (10% K value) when the diameter of the fine particles or the spacer is displaced by 10% is taken as an index showing the compressive strength of the fine particles or the spacer, the spacer of the display element is particularly limited. Although it is not a thing, the compression elastic modulus (10% K value) of fine particles or spacers is 200.
It is preferably 0 to 15000 MPa.

The compression modulus (1
If the 0% K value) is less than 2000 MPa, the spacer may be deformed due to the press pressure during assembling the display element, and it may be difficult to form an appropriate gap. 10% K value) is 1500
When it exceeds 0 MPa, when the spacer is incorporated in the display element, the alignment film on the substrate may be damaged and display abnormality may occur.

The compression elastic modulus (10% K value) means
In order to accurately grasp the hardness of the flexible fine particles or the spacer, it means a value measured by the following method. [Measurement Method of Compressive Elastic Modulus (10% K Value)] For example, as described in Japanese Patent Publication No. 6-503180, a fine compression tester (model “PCT-200”,
(Made by Shimadzu Corporation), diameter 50μ made of diamond
compress the fine particles or spacers with the smooth end face of the cylinder of m,
The compression load when the diameter of the fine particles or the spacer is displaced by 10% is obtained.

The spacer constituting the spacer dispersion liquid of the present invention is obtained by radically polymerizing a vinyl monomer having a hydrophilic functional group and / or an alkyl group having 3 to 22 carbon atoms on the surface of the above-mentioned fine particles. A vinyl-based thermoplastic resin is bonded by graft polymerization.

The hydrophilic functional group is not particularly limited, but for example, a hydroxyl group, a carboxyl group,
Examples thereof include a sulfonyl group, a phosphonyl group, an amino group, an amide group, an ether group, a thiol group, and a thioether group. Among them, a hydroxyl group, a carboxyl group, and an ether group are preferably used because they have little interaction with liquid crystals. . These hydrophilic functional groups may be used alone or in combination of two or more kinds.

The vinyl-based monomer having the hydrophilic functional group is not particularly limited, but for example, 2
-Hydroxyethyl (meth) acrylate, 1,4-hydroxybutyl (meth) acrylate, (poly) caprolactone-modified hydroxyethyl (meth) acrylate,
Vinyl-based monomers having a hydroxyl group such as allyl alcohol and glycerin monoallyl ether; acrylic acid such as (meth) acrylic acid, α-ethylacrylic acid and crotonic acid, and their α-alkyl or β-alkyl derivatives; Unsaturated dicarboxylic acids such as acids, maleic acid, citraconic acid and itaconic acid; vinylic monomers having a carboxyl group such as mono-2- (meth) acryloyloxyethyl ester derivatives of the above unsaturated dicarboxylic acids;
Vinyl monomers having a sulfonyl group such as t-butyl acrylamide sulfonic acid, styrene sulfonic acid and 2-acrylamido-2-methylpropane sulfonic acid; phosphonyl groups such as vinyl phosphate and 2- (meth) acryloyloxyethyl phosphate. Vinyl-based monomers having; vinyl-based monomers having amino groups such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; terminal alkyl ethers of (poly) ethylene glycol (meth) acrylate, (poly) propylene glycol (meth) acrylate Vinyl monomers having an ether group such as terminal alkyl ether of tetrahydrofurfuryl (meth) acrylate; (poly) ethylene glycol (meth) acrylate, (poly) propylene glycol ( Vinyl monomers having a hydroxyl group and ether group such as data) acrylate; (meth) acrylamide, methylol (meth) acrylamide, vinyl monomers having a amide group such as vinyl pyrrolidone. These vinyl-based monomers having a hydrophilic functional group may be used alone or in combination of two or more kinds.

The alkyl group having 3 to 22 carbon atoms is not particularly limited, but for example, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group. Group, n-pentyl group, n-hexyl group,
Cyclohexyl group, 2-ethylhexyl group, n-heptyl group, n-octyl group, n-nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, nonadecyl group, eicodecyl group,
Examples thereof include a henicosyl group, a docosyl group, and an isobornyl group. These C3-C22 alkyl groups may be used alone or in combination of two or more.

The vinyl monomer having an alkyl group having 3 to 22 carbon atoms is not particularly limited, but, for example, (meth) acrylic acid and the above 3 to 22 carbon atoms are included.
An ester compound consisting of the above alkyl group; an ester compound consisting of vinyl alcohol and the above C3 to C22 alkyl group; and a vinyl ether compound consisting of a vinyl group and the above C3 to C22 alkyl group. These vinyl monomers having an alkyl group having 3 to 22 carbon atoms may be used alone or in combination of two or more kinds. The vinyl-based monomer having a hydrophilic functional group and the vinyl-based monomer having an alkyl group having 3 to 22 carbon atoms may be used alone or in combination.

In the present invention, although not particularly limited, the vinyl-based monomer constituting the vinyl-based thermoplastic resin is the vinyl-based monomer 30 having the hydrophilic functional group.
-80 wt% and 20-60 wt% of the vinyl monomer having an alkyl group having 3 to 22 carbon atoms is preferably contained.

When the content of the vinyl-based monomer having a hydrophilic functional group in the vinyl-based monomer is less than 30% by weight, the resulting spacer is dispersed in the dispersion medium in the form of sufficiently monoparticles. It becomes difficult to do so, aggregated particles are likely to be generated, stable ejection with an inkjet device may be difficult, or the cell gap may not be accurately formed. When the content of the vinyl-based monomer having a hydrophilic functional group exceeds 80% by weight, when a cell of a liquid crystal display device is formed, abnormal alignment of liquid crystal is likely to occur on the surface of the spacer protruding in the display pixel. Therefore, the display quality may be deteriorated.

Further, the number of carbon atoms in the vinyl monomer is 3 to
The content of vinyl monomer having 22 alkyl groups is 2
When it is less than 0% by weight, when a cell of a liquid crystal display device is formed, abnormal alignment of liquid crystal is likely to occur on the surface of the spacer protruding in the display pixel, which may lead to deterioration in display quality. When the content of the vinyl-based monomer having an alkyl group having 3 to 22 carbon atoms in the vinyl-based monomer exceeds 60% by weight, the dispersion stability of the resulting spacer in the medium may decrease. is there.

A vinyl-based thermoplastic resin obtained by radical-polymerizing a vinyl-based monomer having the hydrophilic functional group and / or an alkyl group having 3 to 22 carbon atoms is bonded to the surface of the fine particles by graft polymerization. When a vinyl-based thermoplastic resin layer having a plurality of different compositions is laminated for the purpose of increasing the thickness of the surface-coating layer when forming a surface-coating layer of vinyl-based thermoplastic resin, the hydrophilic functional group described above is used. The preferred vinyl-based monomer containing 30 to 80% by weight of the vinyl-based monomer having 20 to 60% by weight of the vinyl-based monomer having an alkyl group having 3 to 22 carbon atoms is a surface coating. It suffices to consider only the vinyl-based thermoplastic resin that is the outermost layer of the layer. This is because functions such as dispersibility in a spacer dispersion liquid or a medium used for an inkjet ink and suppression of abnormal liquid crystal alignment are exhibited depending on the state near the surface of the spacer.

In the present invention, the vinyl-based thermoplastic resin is graft-polymerized on the surface of the fine particles to chemically bond and fix them to form a surface coating layer made of the vinyl-based thermoplastic resin on the surface of the fine particles. The surface coating layer formed by such a method is preferable because it hardly causes problems such as peeling or elution of the surface coating layer in the inkjet ink or the cell of the liquid crystal display device. Among them, for example, as described in JP-A No. 11-223821, a fine particle having a reducing group on the surface is reacted with an oxidizing agent to generate a radical on the surface of the fine particle, and by graft polymerization using the radical as a starting point. The method of forming a surface coating layer made of a vinyl-based thermoplastic resin on the surface of the fine particles is preferable because it can form a surface coating layer having a high density and a sufficient thickness.

The above-mentioned spacer constituting the spacer dispersion liquid of the present invention comprises water and / or a hydrophilic organic solvent.
It is dispersed in the form of single particles in a medium having a surface tension of 25 to 45 mN / m at 0 ° C.

Generally, an ink jet device tends to be able to eject stably when the medium is water or a hydrophilic organic solvent, and when the medium is a strongly hydrophobic organic solvent,
There are problems such that the member forming the head is attacked by the medium, and a part of the adhesive agent for bonding the member is eluted into the medium. Therefore, the medium of the spacer dispersion liquid or the inkjet ink is preferably water or a hydrophilic organic solvent.

The water is not particularly limited, but examples thereof include ion-exchanged water, pure water, ground water, tap water, and industrial water. These waters may be used alone or in combination of two or more kinds.

The hydrophilic organic solvent is not particularly limited, but for example, ethanol, n-propanol, 2-propanol, 1-butanol, 2-butanol, 1-methoxy-2-propanol, furfuryl. Monoalcohols such as alcohol and tetrahydrofurfuryl alcohol; ethylene glycol multimers such as ethylene glycol, diethylene glycol, triethylene glycol and tetraethylene glycol; propylene glycol such as propylene glycol, dipropylene glycol, tripropylene glycol and tetrapropylene glycol. Polymers of ethylene glycol and propylene glycol, such as monomethyl ether, monoethyl ether, monoisopropyl ether,
Lower monoalkyl ethers such as monopropyl ether and monobutyl ether; ethylene glycol multimers and propylene glycol multimers dimethyl ether,
Lower dialkyl ethers such as diethyl ether, diisopropyl ether and dipropyl ether; alkyl esters such as monoacetate and diacetate of ethylene glycol multimers and propylene glycol multimers; 1,3-propanediol, 1,2- Butanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 3-hexene-2,5-diol, 1,5-pentanediol,
Diols such as 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 1,6-hexanediol and neopentyl glycol; ether derivatives of diols; acetates of diols Derivatives: glycerin, 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,2,5
-Polyhydric alcohols such as pentanetriol, trimethylolpropane, trimethylolethane and pentaerythritol; ether derivatives of polyhydric alcohols; acetate derivatives of polyhydric alcohols, etc., dimethyl sulfoxide, thiodiglycol, N-methyl- 2-pyrrolidone, N-vinyl-2-pyrrolidone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidine, sulfolane, formamide, N, N-dimethylformamide,
N, N-diethylformamide, N-methylformamide, acetamide, N-methylacetamide, α-terpineol, ethylene carbonate, propylene carbonate, bis-β-hydroxyethyl sulfone, bis-
β-hydroxyethylurea, N, N-diethylethanolamine, abietinol, diacetone alcohol,
Urea etc. are mentioned. These hydrophilic organic solvents may be used alone or in combination of two or more kinds. Further, water and the hydrophilic organic solvent may be used alone or in combination.

In the present invention, the surface tension at 20 ° C. of the medium composed of water and / or the hydrophilic organic solvent is 2
It is necessary to be 5 to 45 mN / m. If the surface tension of the medium at 20 ° C. deviates from the range of 25 to 45 mN / m, the resulting spacer dispersion liquid or inkjet ink will have insufficient ejection performance and ejection accuracy.

The medium used in the present invention has a boiling point of 10
It is preferable that the hydrophilic organic solvent having a temperature of less than 0 ° C. be contained, and more preferable that the hydrophilic organic solvent having a boiling point of 70 ° C. or more and less than 100 ° C. be contained. The boiling point referred to in the present invention means the boiling point under the condition of 1 atm.

The hydrophilic organic solvent having a boiling point of less than 100 ° C. is not particularly limited, but examples thereof include lower monoalcohols such as ethanol, n-propanol and 2-propanol, and acetone. These hydrophilic organic solvents having a boiling point of less than 100 ° C. may be used alone or in combination of two or more kinds.

The hydrophilic organic solvent having a boiling point of less than 100 ° C. is volatilized at a relatively low temperature when the spacer dispersion liquid or the inkjet ink is discharged onto the substrate and then dried. In the spacer dispersion liquid of the present invention, when the medium comes into contact with the alignment film at a high temperature, the alignment film is contaminated and the display quality of the liquid crystal display device is impaired. Therefore, it is preferable to use a hydrophilic organic solvent having a boiling point of less than 100 ° C. However, the boiling point is 10
If the hydrophilic organic solvent below 0 ° C. easily volatilizes at room temperature, agglomerated particles are likely to be generated during the production or storage of the spacer dispersion liquid or the inkjet ink, or the spacer dispersion liquid or the inkjet ink near the nozzle of the inkjet device may be generated. A hydrophilic organic solvent, which easily volatilizes at room temperature, is not preferable, because it tends to dry and impairs the inkjet dischargeability.

The hydrophilic organic solvent having a boiling point of less than 100 ° C. is not particularly limited, but the surface tension at 20 ° C. is preferably 25 mN / m or less.
Generally, an inkjet device has a surface tension of 3 at 20 ° C. of a spacer dispersion liquid or an inkjet ink to be ejected.
Good ejection accuracy is exhibited in the case of 0 to 50 mN / m.
On the other hand, the higher the surface tension of the spacer dispersion liquid or the droplets of the inkjet ink discharged onto the substrate, the more suitable it is to move the spacer in the drying process.

2 of hydrophilic organic solvents having a boiling point of less than 100 ° C.
When the surface tension at 0 ° C. is 25 mN / m or less, the spacer dispersion liquid or the inkjet ink has a relatively low surface tension at the time of ejection, and thus it becomes possible to obtain good ejection accuracy, and thus it is possible to obtain good ejection accuracy on the substrate. After being discharged, the spacer dispersion liquid or the inkjet ink is volatilized before the other medium components, and the surface tension of the spacer dispersion liquid or the inkjet ink is increased, so that the spacer is easily moved during the drying process.

The content of the hydrophilic organic solvent having a boiling point of less than 100 ° C. in the medium used in the present invention is 20% of that of the medium.
There is no particular limitation as long as the surface tension at 0 ° C. does not deviate from the range of 25 to 45 mN / m, and the amount is preferably 10 to 80% by weight.

When the content of the hydrophilic organic solvent having a boiling point of less than 100 ° C. in the medium is less than 10% by weight, the above effects due to the inclusion of the hydrophilic organic solvent having a boiling point of less than 100 ° C. can be sufficiently obtained. On the contrary, if the content of the hydrophilic organic solvent having a boiling point of less than 100 ° C. in the medium exceeds 80% by weight, the spacer dispersion liquid or the inkjet ink tends to be dried during the production or storage, and the aggregation may occur. Particles may be generated, or the spacer dispersion liquid or the inkjet ink near the nozzle of the inkjet device may be excessively dried, which may impair the ejection property or the ejection accuracy.

The medium used in the present invention preferably contains a hydrophilic organic solvent having a boiling point of 150 ° C. or higher, more preferably a hydrophilic organic solvent having a boiling point of 150 to 200 ° C. It is that.

The hydrophilic organic solvent having a boiling point of 150 ° C. or higher is not particularly limited, but examples thereof include lower alcohol ethers such as ethylene glycol, ethylene glycol monomethyl ether and ethylene glycol dimethyl ether. These hydrophilic organic solvents having a boiling point of 150 ° C. or higher may be used alone or in combination of two or more.

The hydrophilic organic solvent having a boiling point of 150 ° C. or higher suppresses the generation of aggregated particles by drying during the production or storage of the spacer dispersion liquid or the ink-jet ink, or
It is possible to prevent the spacer dispersion liquid and the inkjet ink from being excessively dried in the vicinity of the nozzle of the inkjet device and impairing the ejection property and the ejection accuracy.

The hydrophilic organic solvent having a boiling point of 150 ° C. or higher is not particularly limited, but the surface tension at 20 ° C. is preferably 30 mN / m or higher.
When the surface tension of the hydrophilic organic solvent having a boiling point of 150 ° C. or higher at 20 ° C. is 30 mN / m or more, after the hydrophilic organic solvent having a lower boiling point is volatilized from the spacer dispersion liquid or the inkjet ink discharged onto the substrate. Since the surface tension of the spacer dispersion liquid or the inkjet ink is kept high, the spacer can be easily moved during the drying process.

The content of the hydrophilic organic solvent having a boiling point of 150 ° C. or higher in the medium used in the present invention is 20% of that of the medium.
There is no particular limitation as long as the surface tension at 0 ° C. does not deviate from the range of 25 to 45 mN / m, and the amount is preferably 10 to 80% by weight.

When the content of the hydrophilic organic solvent having a boiling point of 150 ° C. or higher in the medium is less than 10% by weight, the above effects due to the inclusion of the hydrophilic organic solvent having a boiling point of 150 ° C. or higher can be sufficiently obtained. On the contrary, when the content of the hydrophilic organic solvent having a boiling point of 150 ° C. or higher in the medium exceeds 80% by weight, the drying time of the spacer dispersion liquid or the inkjet ink is remarkably lengthened and the productivity is lowered. Alternatively, the alignment film may be contaminated and the display quality of the liquid crystal display device may be impaired.

The solid content concentration of the spacer in the spacer dispersion liquid of the present invention is not particularly limited, but is preferably 0.05 to 5% by weight, more preferably 0.1 to 2%. % By weight.

When the solid content concentration of the spacer in the spacer dispersion liquid is less than 0.05% by weight, the discharged spacer dispersion liquid or ink jet ink droplets may not contain an effective amount of spacers. On the contrary, when the solid content concentration of the spacer in the spacer dispersion liquid exceeds 5% by weight, the nozzle of the inkjet device is likely to be clogged, or the content of the spacer in the discharged spacer dispersion liquid or the droplets of the inkjet ink is large. Excessiveness may make it difficult to move the spacer during the drying process.

In the spacer dispersion liquid of the present invention, the spacers are dispersed in the medium in the form of single particles. If the spacers are not dispersed in the medium in the form of single particles and are in an agglomerated state, the ejection property and the ejection accuracy are reduced, and the nozzles of the inkjet device are clogged.

The spacer dispersion liquid of the present invention contains, for example, a tackifier, a viscosity adjusting agent, a pH adjusting agent, a surfactant, and a defoaming agent, if necessary, within a range not hindering the achievement of the object of the present invention. One kind or two or more kinds of various additives such as an agent, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber and a colorant may be added.

The above-mentioned spacer dispersion liquid of the present invention or the method for ejecting the ink-jet ink comprising the spacer dispersion liquid onto the substrate is not particularly limited, and for example, it may be carried out as follows.

The ink jet device used for ejection is not particularly limited, but for example, a piezo system in which the liquid is ejected from the nozzle by vibration of the piezo element, the liquid is expelled by rapid heating, and the liquid is ejected from the nozzle. Examples of the method include a thermal method of discharging from a nozzle, a bubble jet (registered trademark) method of discharging a liquid from a nozzle by rapid heating of a heating element, and any method may be adopted.

The nozzle diameter of the above ink jet device is
Although not particularly limited, it is preferably 20 to 100 μm. When the nozzle aperture of the inkjet device is less than 20 μm, when a spacer having a particle size of 2 to 10 μm is ejected, the difference between the particle size and the particle size is too small, and the ejection accuracy is reduced, or nozzle clogging occurs and ejection is impossible. In some cases, the nozzle diameter of the inkjet device is 1
If it exceeds 00 μm, the diameter of the ejected droplets becomes large and the diameter of the droplets ejected on the substrate also becomes large, so that the spacer placement accuracy may become rough.

The diameter of the droplet discharged from the nozzle is not particularly limited, but is preferably 10 to 80 μm. The method for controlling the diameter of the liquid droplets ejected from the nozzle within the above preferable range is not particularly limited, but for example, a method for optimizing the nozzle diameter or an electric signal for controlling the inkjet device is optimized. And the like, and any method may be adopted. Especially when using a piezo system inkjet device,
It is preferable to adopt the latter method.

The diameter of the droplets discharged onto the substrate is not particularly limited, but is preferably 30 to 150 μm. The diameter of the droplet discharged onto the substrate is 30 μm
In order to keep the number below, it is necessary to make the nozzle diameter very small, which may increase the possibility of nozzle clogging by spacers or increase the accuracy of nozzle processing. If the diameter of the ejected droplets exceeds 150 μm, the spacer placement accuracy may become poor.

The substrate to which the spacer dispersion liquid or the ink jet ink of the present invention is ejected is not particularly limited, and for example, it is generally used as a panel substrate of a liquid crystal display device such as a glass plate or a resin plate. You can use the one that you have.

In the present invention, it is preferable to eject the spacer dispersion liquid or the inkjet ink on the surface of one of the two substrates constituting the liquid display device. A resin thin film called an alignment film for controlling the alignment of liquid crystal molecules is usually formed on the surface of the substrate on which the spacer dispersion liquid or the inkjet ink is ejected. A polyamide resin thin film is usually used as an alignment film used in a liquid crystal display device, and its surface is rubbed to control the alignment of liquid crystals. Therefore, the medium of the spacer dispersion liquid or the inkjet ink must not have the contamination property of the alignment film that penetrates into the alignment film or dissolves the alignment film.

The arrangement of the spacers on the substrate is not particularly limited, and it may be a random arrangement or a pattern arrangement in which the spacers are patterned and arranged at specific positions. In order to suppress deterioration of display quality such as light leakage, it is preferable to dispose the panel in a non-display portion of the panel.

The non-display portion is a light-shielding layer called a black matrix formed around the pixel,
For example, in the TFT liquid crystal display device, there is a portion where the TFT element is located, but it is preferable that the spacer is arranged under the black matrix so as not to destroy the TFT element. The width of the black matrix is usually 10 to 30 μm.

The number of spacers arranged (particle density) is not particularly limited, but is usually 5 in a 1 mm square area.
It is preferably 0 to 300. The spacers may be arranged in any part under the black matrix in any pattern as long as the above preferable particle density is satisfied.

The method for drying the medium in the spacer dispersion liquid or the ink jet ink droplets discharged onto the substrate is not particularly limited, and for example, it may be performed as follows.

In the above drying, after the spacer dispersion liquid or the inkjet ink ejected onto the substrate from the nozzle of the ink jet device is dried, the spacer dispersion liquid or the inkjet ink liquid immediately after the spacer is ejected onto the substrate. It is preferable to dry so as to exist in a circle having a diameter smaller than that of the droplet.

As described above, in order to gather near the center of the spacer dispersion liquid or ink jet ink droplets immediately after the spacer is discharged in the drying process, the boiling point of the medium,
It is important to set the drying temperature, the drying time, the surface tension of the medium, the contact angle of the medium with respect to the alignment film, the concentration of the spacers and the like to appropriate conditions, but the drying conditions are particularly important.

That is, it is preferable to dry with a certain time width so that the medium does not run out while the spacer moves on the substrate. Therefore, the drying condition in which the medium dries rapidly is not preferable. Further, if the medium is in contact with the alignment film at a high temperature for a long time, the alignment film may be contaminated and the display quality of the liquid crystal display device may be deteriorated. Further, even under the condition that the substrate surface temperature is relatively low, the productivity of the liquid crystal display device is lowered if the drying time is remarkably lengthened.

In consideration of such constraints, the substrate surface temperature at the time when the spacer dispersion liquid or the inkjet ink is ejected onto the substrate is not particularly limited, but the spacer dispersion liquid or the inkjet ink medium is used. The temperature is preferably 20 ° C. or more lower than the boiling point of the lowest boiling medium component contained therein.

If the substrate surface temperature is lower than the boiling point of the medium component having the lowest boiling point by less than 20 ° C., the medium component having the lowest boiling point is rapidly volatilized, and the spacer cannot move in the drying process, or the lowest temperature. Due to the rapid boiling of the medium component of the boiling point, the spacer moves around the substrate with the droplets,
The placement accuracy of the spacer may be significantly reduced.

In the drying method in which the spacer dispersion liquid or the inkjet ink is discharged onto the substrate and then the medium is volatilized while the substrate surface temperature is gradually raised, the spacer dispersion liquid or the inkjet ink is discharged onto the substrate. The substrate surface temperature at that time is not particularly limited, but is a temperature lower than the boiling point of the lowest boiling point medium component contained in the medium of the spacer dispersion liquid or the inkjet ink by 20 ° C. or more, and drying. It is preferable that the substrate surface temperature is 90 ° C. or lower until completion, and more preferably 70 ° C. or lower.

If the substrate surface temperature is lower than the boiling point of the medium component having the lowest boiling point by less than 20 ° C., the medium component having the lowest boiling point is volatilized rapidly, and the spacer cannot move in the drying process, or the lowest temperature. Due to the rapid boiling of the medium component of the boiling point, the spacer moves around the substrate with the droplets,
The placement accuracy of the spacer may be significantly reduced. or,
If the substrate surface temperature exceeds 90 ° C. until the drying is completed, the alignment film may be contaminated and the display quality of the liquid crystal display device may be impaired. Incidentally, the completion of the drying mentioned here means a time point when the spacer dispersion liquid or the droplets of the inkjet ink discharged onto the substrate disappears.

The substrate on which the spacers are arranged by the above-described method is thermocompression bonded to the opposing substrate through the peripheral sealing material, and the gap between the formed substrates is filled with the liquid crystal, whereby the liquid crystal display device is formed. It

[0098]

In the spacer dispersion liquid of the present invention, the spacer constituting the spacer dispersion liquid radically polymerizes a vinyl monomer having a hydrophilic functional group and / or an alkyl group having 3 to 22 carbon atoms on the surface of fine particles. Since the resulting vinyl-based thermoplastic resin is bonded by graft polymerization, water and / or
Alternatively, the spacers are completely dispersed in the form of single particles and stably in a medium composed of a hydrophilic organic solvent and having a surface tension of 25 to 45 mN / m at 20 ° C., which is a condition under which stable ejection can be performed by an inkjet device. be able to.

Therefore, the spacer dispersion liquid of the present invention and the ink-jet ink comprising the spacer dispersion liquid are excellent in dischargeability and can maintain the cell gap of the liquid crystal display device accurately, so that a liquid crystal display exhibiting uniform display quality can be obtained. The device can be obtained.

By using a vinyl monomer having an alkyl group having 3 to 22 carbon atoms as a monomer constituting the above vinyl thermoplastic resin, a spacer is formed in a pixel in a cell of a liquid crystal display device. Even when it protrudes, abnormal alignment of liquid crystal on the surface of the spacer hardly occurs, and a liquid crystal display device exhibiting excellent display quality can be obtained.

[0101]

BEST MODE FOR CARRYING OUT THE INVENTION The following examples are given to illustrate the present invention in more detail, but the present invention is not limited to these examples.

(1) Preparation of Spacer Seed Particles In a separable flask, 15 parts by weight of divinylbenzene, 5 parts by weight of isooctyl acrylate and 1.3 parts by weight of benzoyl peroxide as a polymerization initiator were charged and uniformly mixed with stirring. did. Next, 20 parts by weight of a 3% by weight aqueous solution of polyvinyl alcohol (trade name "Kuraray Poval GL-03", manufactured by Kuraray Co., Ltd.) and sodium dodecyl sulfate 0.5.
After adding 1 part by weight and uniformly stirring and mixing, 140 parts by weight of ion-exchanged water was added. Then, under an atmosphere of nitrogen gas, while stirring this aqueous solution, a polymerization reaction was carried out at 80 ° C. for 15 hours to obtain fine particles. After the obtained fine particles were sufficiently washed with hot water and acetone, a classification operation was performed to vaporize acetone to produce spacer seed particles. The obtained spacer seed particles have an average particle diameter of 5 μm and a CV value of 3.0%.
Met.

(2) Preparation of spacers 5 parts by weight of the spacer seed particles obtained above were added to 20 parts by weight of dimethyl sulfoxide and 10 parts of hydroxymethacrylate.
The mixture was added to a mixed monomer consisting of 1 part by weight, 8 parts by weight of isobutyl methacrylate and 2 parts by weight of methacrylic acid, dispersed by a sonicator, and then uniformly stirred and mixed. Next, the reaction system was replaced with nitrogen gas, and stirring was continued at 30 ° C. for 2 hours. Then, 10 parts by weight of a 0.1 mol / L cerium ammonium nitrate aqueous solution prepared with a 1N aqueous nitric acid solution was added to the reaction system, and a polymerization reaction was carried out for 5 hours.
The reaction solution was taken out, and the particles and the reaction solution were separated by filtration using a 3 μm membrane filter. The obtained particles were thoroughly washed with ethanol and acetone, and then dried under reduced pressure with a vacuum dryer to prepare spacers (A) in which the vinyl-type thermoplastic resin was graft-polymerized on the surfaces of the spacer seed particles.

In the same manner as above except that the composition of the mixed monomer was changed to that shown in Table 1, spacer (B) to spacer (D) in which the vinyl type thermoplastic resin was graft-polymerized on the surface of the spacer seed particles. ) Was produced.

Further, hydroxyethyl methacrylate 10
Parts by weight, isobutyl methacrylate 8 parts by weight and methacrylic acid 2 parts by weight as a mixed monomer were radical solution polymerized in ethyl acetate, and then ethyl acetate was removed by vacuum drying to obtain a solid resin, which was then pulverized into a resin powder. Got the body Then, using 5 parts by weight of the spacer seed particles obtained in (1) and 2 parts by weight of the resin powder obtained above, JP-A-2000-3
In the same manner as in Example 1 described in Japanese Patent No. 47191, a spacer (E) having a coating layer formed on the surface of spacer seed particles was produced by a high-speed air current impact method.

(3) Preparation of medium 60 parts by weight of ethylene glycol, 20 parts by weight of isopropyl alcohol and 20 parts by weight of ion-exchanged water were uniformly stirred and mixed to prepare a medium (a). 2 of the obtained medium a
The surface tension at 0 ° C. was 35 mN / m.

Medium (b) to medium (d) were prepared in the same manner as described above except that the composition of the medium was as shown in Table 2. Table 2 shows the surface tensions of the obtained media (b) to (d) at 20 ° C.

Example 1 0.5 part by weight of the spacer (A) was slowly added to 100 parts by weight of the medium (a) and uniformly stirred and mixed by a sonicator to prepare a spacer dispersion liquid.

(Examples 2 to 5) and (Comparative Examples 1 to 1)
Comparative Example 3) A spacer dispersion liquid was prepared in the same manner as in Example 1 except that the combination of the spacer and the medium was the combination shown in Table 3.

The performances (dispersibility, spacer disposition, liquid crystal display cell display quality, liquid crystal purity) of the spacer dispersions obtained in Examples 1 to 5 and Comparative Examples 1 to 3 are as follows. It was evaluated by the method. The results are shown in Table 3.

Dispersible spacer The dispersion liquid was filtered through a stainless mesh having a mesh size of 10 μm, and the dispersibility was evaluated according to the following criteria. [Judgment Criteria] ◎ The stainless steel mesh had almost no clogging, and the spacer dispersion liquid passed through smoothly. ◯ The spacer dispersion liquid passed through the stainless mesh, but some clogging was observed in the stainless mesh after filtration. Further, the spacers that had settled with time could be easily redispersed by shaking the container. B: The stainless steel mesh was often clogged, and the spacer dispersion liquid did not pass through the space, but it was possible to filter it over time. Also, the spacers that settled out with time did not redisperse even when the container was shaken. ×: The stainless steel mesh was extremely clogged, and the spacer dispersion liquid did not pass at all.

Arrangement of Spacer Spacer dispersion liquid was mixed with stainless steel mesh (opening 10 μm).
m) was filtered to remove aggregates, and then the mixture was discharged onto a substrate using an inkjet device equipped with a piezo type head having a diameter of 30 μm. The above-mentioned substrate has IT on the surface.
A polyimide intermediate (trade name "LP
-64 ", manufactured by Toray Industries, Inc.) was uniformly applied, dried at 150 ° C., baked at 280 ° C. for 90 minutes and cured to form an alignment film. In the color filter glass substrate, a black matrix having a width of 20 μm is formed between the pixels of the color filter, and spacers are arranged on the black matrix at an interval of 150 μm by an inkjet device. Also, the spacers were arranged so that the spray density was 100 pieces / mm ² . At the time of disposing the spacers, a substrate at room temperature is placed on the stage, and the discharged substrate is quickly replaced by 90
It was transferred to a hot plate heated to ℃ and dried. After visually confirming that the medium was completely dried, the medium was further left at the same temperature for 30 minutes. After disposing the spacer on the substrate by the above method, the disposition condition was observed with a microscope, and disposition property of the spacer was evaluated according to the following criteria. [Judgment Criteria] ∘ The lines in which the spacers were arranged were straight at equal intervals, no spacers were missing, and the spacer dispersion liquid was stably discharged straight from each nozzle. ∙ The lines with spacers were straight at approximately equal intervals, but some spacer omission was observed. △ ・ ・ ・ The spacing of the lines with spacers is not uniform,
It wasn't ejected straight. X: Almost no spacer was discharged onto the substrate.

The color filter glass substrate on which the spacers are arranged in the same manner as the display quality of the liquid crystal display cell and the counter substrate are provided with the peripheral sealing material (the product name of the main agent is “SE4500”, the product name of the curing agent is “T”, and the HAVEN is HAVEN).
(Chemikacal Co., Ltd.) was printed by a screen printing method and bonded, and then the peripheral sealing material was cured by heating at 160 ° C. for 90 minutes to form an empty cell having a cell gap of 5 μm. Next, a liquid crystal (trade name "S-811", manufactured by Merck & Co., Inc.) containing a predetermined amount of a chiral agent was filled in the empty cell, and the injection port was sealed with a sealing agent, and then 120 ° C.
And heat-treated for 30 minutes to prepare a liquid crystal display cell. Next, a voltage of 4.2 V was applied and the image of the liquid crystal display cell magnified with a microscope was visually observed, and the display quality of the liquid crystal display cell was evaluated according to the following criteria. [Judgment Criteria] ∙ The light leakage around the spacers protruding in the display area was very small, and the image quality was good. △ ・ ・ ・ Light leakage was observed around the spacer protruding in the display area. X: The spacers protruding in the display area were shining so clearly that the contrast of the display image was lowered and the image quality was poor.

Liquid crystal purity Spacer 0.1 g was replaced with liquid crystal (trade name "ZLI-4720-
000 ", manufactured by Merck & Co., Inc.) and allowed to stand at 80 ° C. for 200 hours, then the liquid crystal was recovered and the purity of the liquid crystal was measured by gas chromatography.

[0115]

[Table 1]

[0116]

[Table 2]

[0117]

[Table 3]

As is clear from Tables 1 to 3, the spacer dispersions of Examples 1 to 5 according to the present invention have dispersibility,
Good or excellent performance was exhibited in all of the disposition property of the spacer, the display quality of the liquid crystal display cell, and the purity of the liquid crystal.

On the other hand, the spacer dispersion of Comparative Example 1 in which the surface tension of the medium at 20 ° C. exceeded 45 mN / m and the spacer of Comparative Example 2 in which the surface tension of the medium at 20 ° C. was less than 25 mN / m. In each of the dispersions, the disposition property of the spacer on the substrate was poor, so that the display quality of the liquid crystal display cell could not be evaluated. In addition, the spacer dispersion liquid of Comparative Example 3 using the spacer produced by the impact method in a high-speed air stream instead of the graft polymerization was inferior in liquid crystal purity.

[0120]

As described above, in the spacer dispersion liquid of the present invention, the spacers can be stably arranged on the substrate by the ink jet method and can be accurately arranged on the non-display portion of the liquid crystal display device substrate. In addition, since it is possible to obtain a liquid crystal display device exhibiting excellent display quality without light leakage due to the spacers, it is preferably used for manufacturing a liquid crystal display device.

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[Procedure amendment]

[Submission date] May 14, 2002 (2002.5.1)
4)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a liquid crystal display device.

[Explanation of symbols] 1 transparent substrate 2 Polarizer 3 transparent electrodes 4 color filters 5 Black matrix 6 liquid crystal 7 Spacer 8 Alignment film 9 Seal material

Claims (3)

[Claims] 1. A spacer dispersion liquid for manufacturing a liquid crystal display device in which spacers are arranged at arbitrary positions on a substrate by an inkjet method, wherein the spacers constituting the spacer dispersion liquid are inorganic fine particles or organic fine particles. A vinyl-based thermoplastic resin obtained by radical polymerization of a vinyl-based monomer having a hydrophilic functional group and / or an alkyl group having 3 to 22 carbon atoms is bonded to the surface of the fine particles by graft polymerization, and water is used. And / or hydrophilic organic solvent,
A spacer dispersion liquid for producing a liquid crystal display device, which is dispersed in a medium having a surface tension at 25 ° C. of 25 to 45 mN / m in the form of single particles. 2. The vinyl-based monomer constituting the vinyl-based thermoplastic resin is a vinyl-based monomer 30 having a hydrophilic functional group.
2. The spacer dispersion liquid for producing a liquid crystal display device according to claim 1, wherein the spacer dispersion liquid comprises 20 to 60% by weight and 20 to 60% by weight of a vinyl-based monomer having an alkyl group having 3 to 22 carbon atoms. . 3. The hydrophilic functional group is at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfonyl group, a phosphonyl group, an amino group, an amide group, an ether group, a thiol group and a thioether group. The spacer dispersion liquid for manufacturing a liquid crystal display device according to claim 1, wherein the spacer dispersion liquid is present.