JP2009193006A - Spacer particle dispersion liquid, and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spacer particle dispersion liquid, continuously stably disposing spacer particles on a substrate by an ink jet device, and obtaining a liquid crystal display device having excellent display quality, and to provide a liquid crystal display device. <P>SOLUTION: The spacer particle dispersion liquid for disposing spacer particles at optional positions on the substrate using an ink jet device contains spacer particles and a solvent, wherein the spacer particles have AB type or ABA type block copolymer containing a positive charging block and a negative charging block on the surface of the base material fine particle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a spacer particle dispersion that can continuously and stably dispose spacer particles on a substrate by an ink jet device, and to obtain a liquid crystal display device having excellent display quality, and a liquid crystal display device. .

Liquid crystal display devices are currently widely used in personal computers, portable electronic devices, and the like. The liquid crystal display device generally has a structure in which liquid crystal is sandwiched between two substrates on which a color filter, a black matrix, a linear transparent electrode, an alignment film, and the like are formed. Here, it is the spacer particles that regulate the distance between the two substrates and maintain the proper thickness of the liquid crystal layer.

In the conventional method of manufacturing a liquid crystal display device, spacer particles can be arranged by a wet spraying method in which spacer particles are sprayed on a substrate using a solvent such as isopropanol, or by applying air pressure without using a solvent. A dry spraying method or the like in which spacer particles are sprayed on a substrate by use has been used.
However, in such a method, spacer particles are randomly and uniformly distributed on the substrate on which the pixel electrode is formed. Therefore, the spacer particles are arranged on the pixel electrode, that is, on the display unit (pixel region) of the liquid crystal display device. It was easy.
Since general spacer particles are made of synthetic resin, glass, or the like, when the spacer particles are arranged on the pixel electrode, a phenomenon in which the polarization is disturbed and the polarization property is lost, so-called depolarization phenomenon occurs. There was a problem that the part leaked light. Further, the alignment of the liquid crystal on the surface of the spacer particles may cause a problem that light is lost and the contrast and color tone are lowered to deteriorate the display quality.
Furthermore, in the TFT liquid crystal display device, the TFT element is disposed on the substrate. However, when spacer particles are disposed on the TFT element, the element may be damaged if pressure is applied to the substrate. .

In order to solve the problems associated with random dispersion of spacer particles, various attempts have been made to arrange the spacer particles in the non-pixel region.
As a method of arranging spacer particles only in a non-pixel region, that is, a specific position, for example, in Patent Document 1, after aligning an opening of a mask with a portion where spacer particles are arranged, the spacer particles are dispersed through the mask. The method is shown. For example, Patent Document 2 discloses a method in which spacer particles are electrostatically adsorbed to a photoconductor and then transferred to a transparent substrate. Furthermore, Patent Document 3 discloses a method for manufacturing a liquid crystal display device in which spacer particles are arranged at specific positions by electrostatic repulsion by applying a voltage to pixel electrodes on a substrate and dispersing charged spacer particles. It is shown.

However, in the methods described in Patent Documents 1 and 2, since the mask and the photoconductor are brought into direct contact with the substrate surface, the alignment film formed on the substrate surface may be damaged, and the image quality of the liquid crystal display device is deteriorated. There was something to do. On the other hand, in the method described in Patent Document 3, it is necessary to configure the electrodes according to the arrangement pattern of the spacer particles, and thus it is difficult to arrange the spacer particles at an arbitrary position.

On the other hand, Patent Document 4 discloses a method of arranging spacer particles on a substrate using an ink jet apparatus. This method is effective because spacer particles can be arranged in a specific pattern at a specific position without damaging the alignment film formed on the surface of the substrate because the mask or photoconductor is not directly contacted on the substrate. It can be said that it is a simple method.

In the method of disposing spacer particles on a substrate using an ink jet device, a spacer particle dispersion liquid containing spacer particles and a dispersion solvent for dispersing the spacer particles is filled into the ink jet device, and the spacer particle dispersion liquid is discharged from a nozzle. Droplets are discharged toward the substrate. However, when the spacer particle dispersion liquid is actually discharged using an ink jet apparatus, there is a problem that a discharge failure of the spacer particles occurs.

As a means for solving the ejection failure of spacer particles, for example, a method is known in which surface treatment is performed on the spacer particles (self-dispersing treatment), thereby imparting dispersibility to the dispersion solvent and improving the ejection properties. Yes.
However, when a spacer particle dispersion liquid containing spacer particles subjected to such a self-dispersion treatment is to be ejected by an ink jet apparatus, the ejection stability often decreases during ejection, or spacers are contained in the ejected droplets. There was a problem that particles may not be included.
Japanese Patent Laid-Open No. 4-198919 JP-A-6-258647 JP-A-10-339878 JP-A-57-58124

In view of the above-described situation, the present invention provides a spacer particle dispersion that can continuously and stably dispose spacer particles on a substrate by an ink jet device, and that can provide a liquid crystal display device excellent in display quality. An object of the present invention is to provide a liquid crystal display device.

The present invention is a spacer particle dispersion for disposing spacer particles at an arbitrary position on a substrate using an ink jet apparatus, and contains spacer particles and a solvent. A spacer particle dispersion having an AB type or ABA type block copolymer containing a positively charged block and a negatively charged block on the surface.
The present invention is described in detail below.

The inventors of the present invention have a spacer particle dispersion liquid containing spacer particles subjected to self-dispersion treatment, the discharge stability is reduced during discharge, or the reason why the spacer particles are not included in the discharged droplets. It was found that the SUS filter installed in the flow path of the ink jet apparatus is clogged. As a self-dispersing treatment, it is common to introduce a hydrophilic group such as a carboxyl group on the surface of the spacer particles so as to be negatively charged and to impart dispersibility by the electrostatic repulsive force. On the other hand, SUS filters are usually positively charged. Therefore, it is considered that clogging of the filter is likely to occur because the negatively charged spacer particles adhere to the positively charged SUS filter and cannot be removed.
By the way, for example, in a spacer particle dispersion using a mixed solvent of a plurality of solvents such as a ternary system of isopropanol, water and ethylene glycol as a medium, for example, as shown in FIG. The solvent composition changes before the spacer particles are placed on the substrate. This change in solvent composition increases hydrophobicity or hydrophilicity, but spacer particles that have been subjected to conventional self-dispersion treatment cannot cope with changes in the solvent composition, resulting in a decrease in dispersibility. It has also been clarified that spacer particles may be arranged in places other than the place to be arranged.
Therefore, as a result of intensive studies, the present inventors have used spacer particles having a block copolymer containing a positively charged block and a negatively charged block on the surface, thereby changing the solvent composition as shown in FIG. Since the conformation of the graft chains on the surface of the spacer particles changes, it is possible to obtain a spacer particle dispersion excellent in the dispersibility of the spacer particles until the spacer particles are arranged on the substrate after being ejected from the ink jet apparatus. The headline and the present invention have been completed.

The spacer particle dispersion of the present invention contains spacer particles and a solvent, and the spacer particles contain AB-type or ABA-type block copolymers containing a positively charged block and a negatively charged block on the surface of the substrate fine particles. Have

The substrate fine particles may be inorganic particles such as silica particles or organic particles made of an organic polymer as long as the block copolymer is present on the surface. In particular, it has an appropriate hardness that does not damage the alignment film formed on the substrate of the liquid crystal display device, can easily follow a change in thickness due to thermal expansion and contraction, and the movement of the spacer particles inside the cell. Organic particles are preferred because they are relatively few.

Although it does not specifically limit as said organic type particle | grains, Since the intensity | strength etc. can be adjusted to a suitable range, the copolymer of a monofunctional monomer and a polyfunctional monomer is suitable.
The monofunctional monomer is not particularly limited. For example, styrene derivatives such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, and chloromethylstyrene; vinyl chloride; vinyl such as vinyl acetate and vinyl propionate. Esters; unsaturated nitriles such as acrylonitrile; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, ethylene glycol Examples include (meth) acrylate derivatives such as (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, and cyclohexyl (meth) acrylate. These monofunctional monomers may be used independently and 2 or more types may be used together.

Examples of the polyfunctional monomer include divinylbenzene, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolpropanetetra (meta ) Acrylate, diallyl phthalate and its isomer, triallyl isocyanurate and its derivative, trimethylolpropane tri (meth) acrylate and its derivative, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, polyethylene glycol di (meth) acrylate such as ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, etc. Ripropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 2,2-bis [4- (methacrylic) 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane di (meth) acrylate such as loxyethoxy) phenyl] propanedi (meth) acrylate, 2,2-hydrogenated bis [4- (acryloxypolyethoxy) Phenyl] propane di (meth) acrylate, 2,2-bis [4- (acryloxyethoxypolypropoxy) phenyl] propane di (meth) acrylate, and the like. These polyfunctional monomers may be used independently and 2 or more types may be used together.

The monofunctional monomer or polyfunctional monomer may have a hydrophilic group. The hydrophilic group is not particularly limited, and examples thereof include 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 monomer having a hydrophilic group is not particularly limited. For example, 2-hydroxyethyl (meth) acrylate, 1,4-hydroxybutyl (meth) acrylate, (poly) caprolactone-modified hydroxyethyl (meth) acrylate, allyl Monomers having a hydroxyl group such as alcohol and glyceryl monoallyl ether; acrylic acids such as (meth) acrylic acid, α-ethylacrylic acid and crotonic acid, and α- or β-alkyl derivatives thereof; fumaric acid and maleic acid Unsaturated dicarboxylic acids such as acid, citraconic acid and itaconic acid; monomers having a carboxyl group such as mono 2- (meth) acryloyloxyethyl ester derivatives of these unsaturated dicarboxylic acids; t-butylacrylamide sulfonic acid, styrene sulfone Acid, 2-acrylamido-2-methylpropane Monomers having a sulfonyl group such as sulfonic acid; Monomers having a phosphonyl group such as vinyl phosphate and 2- (meth) acryloyloxyethyl phosphate; Amines having an acryloyl group such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate A compound having an amino group such as; a monomer having both a hydroxyl group and an ether group such as (poly) ethylene glycol (meth) acrylate and (poly) propylene glycol (meth) acrylate; (poly) ethylene glycol (meth) acrylate Monomers having ether groups such as terminal alkyl ethers of (poly) propylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, etc .; (meth) acrylamide, methylol Meth) acrylamide, monomers having a amide group such as vinyl pyrrolidone.

The method for producing the organic particles is not particularly limited, and examples thereof include various polymerization methods such as a suspension polymerization method, a seed polymerization method, and a dispersion polymerization method.
In the suspension polymerization method, since the particle size distribution of the obtained particles is relatively wide and polydisperse particles are obtained, when used as spacer particles, classification operation is performed to obtain a desired particle size or particle size distribution. It is suitably used when obtaining various types of particles. On the other hand, seed polymerization and dispersion polymerization are suitable for producing a large amount of particles having a specific particle diameter because monodispersed particles can be obtained without going through a classification step.

The polymerization initiator used in the suspension polymerization method, seed polymerization method, dispersion polymerization method and the like is not particularly limited. For example, benzoyl peroxide, lauroyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, 3, Organic peroxides such as 5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethylhexanoate, di-t-butyl peroxide, azobisisobutyronitrile, azobiscyclohexacarbonitrile And azo compounds such as azobis (2,4-dimethylvaleronitrile).

Further, as the substrate fine particles, micropearl (manufactured by Sekisui Chemical Co., Ltd.) or the like is also preferably used.

The block copolymer is an AB type or an ABA type containing a positively charged block and a negatively charged block.
Here, the AB type block copolymer is a copolymer in which a polymer chain of a polymerizable monomer represented by A and a polymer chain represented by B are chained as a block as shown in (1) below. The ABA block copolymer is a copolymer as shown in (2) below. In the present invention, either the positive charging block or the negative charging block may correspond to A and B.
AAA ... AAABBBB ... BBB (1)
AA ... AAABB ... BBAA ... AA (2)
Further, the block _copolymer, A n _{B m-type (n, m = 50~2000),} A n B m A o type (n, m, o = 100~2000 ) polymerization degree of AB block as May be different, or the degree of polymerization may be different between the front and back A blocks.

As shown in FIG. 1, for example, when the solvent of the spacer particle dispersion of the present invention is a mixed solvent of isopropanol, water and ethylene glycol, first, when the spacer particle dispersion is discharged from the ink jet apparatus, the isopropanol Water and ethylene glycol are present and are in a hydrophobic state (FIG. 1 (1)). As time elapses, isopropanol volatilizes first and becomes hydrophilic (FIG. 1 (2)). Furthermore, when time passes, water will volatilize and it will be in a weak hydrophilic state (FIG. 1 (3)).
For example, for the spacer particles, when the block copolymer is AB type as shown in FIG. 2 and the positively charged block is bonded to the base particles, the solvent composition is as shown in FIG. The spacer particles form a salt having a positively charged block on the surface (FIG. 2 (1)). When the solvent composition is as shown in FIG. 1 (2), the dielectric constant of the solvent increases, so that the spacer particles are separated from the salt, and a negatively charged block is present on the surface (FIG. 2 (2)). When the solvent composition is as shown in FIG. 1 (3), the dielectric constant of the solvent decreases, and the spacer particles again form a salt with a positively charged block on the surface (FIG. 2 (3)).
Here, the liquid contact portion of the ink jet apparatus is usually made of SUS and is positively charged, and the substrate is usually made of polyimide and is negatively charged. Therefore, when the spacer particles are in the state shown in FIG. 2 (1), the spacer particles do not adhere to the wetted part made of SUS (because the positively charged block on the surface of the spacer particles and the wetted part of the positive charge are repelled). ). When the spacer particles are in the state shown in FIG. 2 (2), even if the droplets shrink due to volatilization of the isopropanol in the spacer particle dispersion, the spacer particles do not adhere to the substrate, and the spacer particles match the shrinkage of the droplets. Are gathered and dispersed in the spacer particle dispersion (because the negatively charged block on the surface of the spacer particles and the negatively charged substrate are repelled). In the state shown in FIG. 2C, the spacer particles are arranged on the substrate (because the positively charged particles on the surface of the spacer particles and the negatively charged substrate attract each other).

Examples of the monomer that forms the positively charged block include (meth) acrylic acid having an amino group, and specific examples include the following.
Examples of (meth) acrylic acid having a primary amino group include, for example, 2-aminocinnamic acid, ethyl 4-aminobenzene acrylate, ethyl α-aminobenzene acrylate, 2-amino-2-methyl-1-propanol, Examples include 3-phenylacrylic acid, 2-aminoethanol / acrylic acid, and the like.
Examples of (meth) acrylic acid having a secondary amino group include, for example, 3-diethylamino-2-hydroxypropyl methacrylate, 3-dimethylamino-2-hydroxypropyl methacrylate, Nt-butylaminoethyl acrylate, α- (Acetylamino) cinnamic acid, 1- (tert-butylamino) ethyl acrylate, 2-anilinoethyl methacrylate, 3-[(5-methyl-2-pyridinyl) amino] acrylic acid, 2- (methylamino) acrylate ) Ethyl, 3- (methylaminocarbonyl) acrylic acid, 2- (ethoxycarbonylaminomethyl) ethyl acrylate, 2-[[(isopropyloxy) carbonyl] amino] ethyl acrylate, 2- (cyclohexylamino) ethyl acrylate , 2-[(tert-butylamino) methyl] Ethyl acrylic acid, and the like.
Examples of the (meth) acrylic acid having a tertiary amino group include 2- (diethylamino) ethyl (meth) acrylate, 2- (dimethylamino) ethyl (meth) acrylate, 2-cyano-3- [4- (Diethylamino) phenyl] ethyl acrylate, E) -2-cyano-3- [N-ethyl-N- (1,3-benzodioxol-5-yl) amino] ethyl acrylate, 1- (dimethylamino Methyl) -2- (dimethylamino) ethyl methacrylic acid, 2-diethylaminoethyl 3,3-diphenylacrylate, 3- (dimethylamino) propyl acrylate, 2- (diisopropylamino) ethyl methacrylate, 2-cyano-3 -[5- (dimethylamino) -2-furyl] methyl acrylate, 2- (diethylaminomethyl) acrylic acid,-[2-sia 2- (dimethylamino) ethyl] ethyl acrylate, 4- (phenylallylamino) methyl methacrylate, 4- [allyl (tert-butyl) amino] methyl methacrylate, 2- (dimethylaminomethyl) acrylic acid, acrylic 2- [N-ethyl (2-hydroxyethyl) amino] ethyl acid, 3- (diethylamino) -2-hydroxypropyl acrylate, 3- (diethylamino) propyl acrylate, 2- (diethylamino) -1-methyl acrylate Ethyl, 2- (dibutylamino) ethyl acrylate, 3- (dibutylamino) propyl acrylate, 2- (dibutylamino) propyl acrylate, 3- (dimethylamino) phenyl acrylate, 2- (dimethylamino) acrylate 2-methylpropyl, 2- (butylethyl acrylate) ) Ethyl, 2 - [(diethylamino) methyl] ethyl acrylate, 4- (dimethylamino) phenyl, 2 - [(dimethylamino) methyl] ethyl acrylate, and the like.
Of these, a tertiary amine is preferred as the monomer forming the positively charged block. Primary and secondary amines are poor in long-term stability due to their high reactivity. Furthermore, among tertiary amines, the substituents R ¹ and R ² represented by the following general formula (1) preferably have 1 to 10 carbon atoms. When the number of carbon atoms exceeds 10, steric hindrance is so great that it may not be possible to cause a conformational change. More preferably, it has 5 or less carbon atoms.

Examples of the monomer that forms the negatively charged block include those having a carboxyl group, a sulfonyl group, and a phosphonyl group. Specific examples include (meth) acrylic acid, α-ethylacrylic acid, crotonic acid, and the like. Acrylic acids and their α-alkyl derivatives or β-alkyl derivatives; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid; mono 2- (meth) acryloyloxyethyl esters of the above unsaturated dicarboxylic acids Vinyl monomers having a carboxyl group such as derivatives; monomers having a sulfonyl group such as t-butylacrylamidesulfonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid; vinylphosphate, 2- ( Such as (meth) acryloyloxyethyl phosphate Monomeric vinyl monomer having a Sufoniru group.
The monomer for forming the negatively charged block is preferably a carboxyl group. The sulfonyl group and phosphonyl group are inferior in display performance.

In the above block copolymer, the degree of polymerization of each block is not particularly limited, but a preferred lower limit is 50 and a preferred upper limit is 2000. Outside this range, the spacer particles may not be able to undergo a conformational change with respect to a change in solvent composition. The preferred lower limit is 100 and the preferred upper limit is 1000.

In the block copolymer, the above-described conformational change is likely to occur, and therefore, the chain of the positively charged block is preferably longer than the chain of the negatively charged block as a whole. That is, it is preferable that the polymerization degree of the positively charged block is larger than that of the negatively charged block.

The block copolymer preferably has a nonionic block having a degree of polymerization of 10 to 1000 between the positively charged block and the negatively charged block. As described above, the solvent composition of the spacer particle dispersion discharged onto the substrate by the ink jet apparatus changes due to volatilization or the like with time, but by having the nonionic block, the graft chain on the surface of the spacer particles Conformational changes are likely to occur.

The monomer for forming the nonionic block is not particularly limited. For example, 2-hydroxyethyl (meth) acrylate, 1,4-hydroxybutyl (meth) acrylate, (poly) caprolactone-modified hydroxyethyl (meth) acrylate, Vinyl monomers having a hydroxyl group such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, allyl alcohol, glycerin monoallyl ether; ether groups such as polyethylene glycol methyl ether methacrylate and polypropylene glycol methyl ether methacrylate Examples thereof include vinyl monomers.

The method for forming the block copolymer on the surface of the substrate fine particles is not particularly limited. For example, the surface of the substrate fine particles is chloromethylated and treated with N, N-diethyldithiocarbamic acid. Examples thereof include a method in which the vinyl monomer is photoreacted with the obtained N, N-diethyldithiocarbamate photoiniferter-immobilized substrate fine particles.
Further, if the block copolymer is AB type or ABA type, any block of a positively charged block, a negatively charged block, or a nonionic block may be directly bonded to the surface of the base material fine particle. Since it is easy to take the conformation change as described above, it is preferable that a negatively charged block is bonded to the surface of the base particle.

The spacer particles are preferably adjusted so that the zeta potential in a 0.1 M NaCl solution is positively charged. When the zeta potential is positively charged, the spacer particles are not attached to the ink jet apparatus made of SUS.

Although it does not specifically limit as solid content concentration of the spacer particle | grains in the spacer particle | grain dispersion liquid of this invention, A preferable minimum is 0.01 weight% and a preferable upper limit is 10 weight%. If it is less than 0.01% by weight, there is a high probability that the ejected droplets do not contain spacer particles. If it exceeds 10% by weight, the nozzles of the ink jet apparatus may be easily blocked, and landing The number of spacer particles contained in the dispersed droplets becomes too large, and the spacer particles are less likely to move during the drying process. A more preferred lower limit is 0.1% by weight, and a more preferred upper limit is 3% by weight.

Moreover, it is preferable that the spacer particle | grain dispersion liquid of this invention is disperse | distributing the spacer particle | grains to single particle form. If aggregates of spacer particles are present in the spacer particle dispersion of the present invention, not only the discharge accuracy is lowered, but in some cases, the nozzles of the ink jet apparatus may be clogged.

The spacer particle dispersion liquid of the present invention is an adhesive component for imparting adhesiveness, improves the dispersion of spacer particles, and controls physical properties such as surface tension and viscosity within the range that does not impair the effects of the present invention. Various surfactants, viscosity modifiers and the like may be added for the purpose of improving the discharge accuracy and improving the mobility of the spacer particles.

The spacer particle dispersion of the present invention contains a solvent.
Although it does not specifically limit as said solvent, It is preferable that they are various solvents which are liquid at the temperature discharged from the nozzle of an inkjet apparatus. Of these, a water-soluble or hydrophilic solvent is preferable. When a highly hydrophobic solvent is used as the solvent of the spacer particle dispersion liquid of the present invention, the solvent may invade the member constituting the nozzle, or a part of the adhesive bonding the member may be dissolved in the solvent. is there.

The spacer particle dispersion of the present invention preferably contains a solvent having a boiling point of 150 ° C. or higher, and more preferably contains a solvent having a boiling point of 150 ° C. or higher and a surface tension of 30 mN / m or higher. When a solvent having a boiling point of 150 ° C. or higher and a surface tension of 30 mN / m or higher is included, the receding contact angle (θr) described later can be increased.
In addition, when a solvent having a boiling point of 150 ° C. or higher and a surface tension of 30 mN / m or higher is included, the droplet diameter when the spacer particle dispersion is discharged and landed on the substrate is reduced, so that the droplet spreads. Is unlikely to occur. Furthermore, the spacer particles can easily move toward the landing center of the droplet. Therefore, the spacer particles can be arranged on the substrate with high accuracy.

The solvent having a boiling point of 150 ° C. or higher is not particularly limited, but ethylene glycol, propylene glycol, 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, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexane It is preferably at least one selected from the group consisting of diol, 1,6-hexanediol, and neopentyl glycol. Of these, ethylene glycol and propylene glycol are preferable, and ethylene glycol is most preferable.

When the spacer particle dispersion of the present invention is dried, the solvent having a low boiling point volatilizes first. When the solvent having a low boiling point volatilizes first, the ratio of the solvent having a boiling point of 150 ° C. or higher and a surface tension of 30 mN / m or higher in the remaining spacer particle dispersion increases. When the ratio of the solvent having a boiling point of 150 ° C. or more and a surface tension of 30 mN / m or more increases, the surface tension of the remaining spacer particle dispersion becomes higher and the spacer particles easily move toward the landing point center. .

In order to adjust the surface tension of the spacer particle dispersion of the present invention, specifically, not to make it too high (for example, 50 mN / m or less), the solvent of the spacer particle dispersion has a boiling point of less than 150 ° C. It is more preferable that the solvent further be included. More preferably, it contains a solvent having a boiling point of 70 ° C. or higher and lower than 100 ° C.
Specifically, the solvent contains water, a solvent having a boiling point of less than 150 ° C., and a solvent having a boiling point of 150 ° C. or more, the water content is 0 to 60% by weight, and the boiling point is 150 ° C. It is preferable that the content of the solvent having less than 2 to 50% by weight and the content of the solvent having the boiling point of 150 ° C. or higher is 30 to 96% by weight.

Although it does not specifically limit as said solvent whose boiling point is less than 150 degreeC, It is at least 1 sort (s) selected from the group which consists of ethanol, n-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol. It is preferable. Of these, 2-propanol is most preferable.

The solvent having a boiling point of less than 150 ° C. volatilizes at a relatively low temperature when the spacer particle dispersion of the present invention is discharged onto the substrate and then dried. In particular, in the spacer particle dispersion of the present invention, when the solvent contacts the alignment film at a high temperature, the alignment film is contaminated and the display quality of the liquid crystal display device is impaired, so that the drying temperature cannot be increased too much. Therefore, it is preferable to use a solvent having a boiling point of less than 150 ° C. However, if the solvent having a boiling point of less than 150 ° C. is likely to be volatilized at room temperature, aggregated particles are likely to be generated during the production or storage of the spacer particle dispersion of the present invention, or the spacer particle dispersion near the nozzles of the inkjet device. Since it becomes easy to dry and ink jet discharge property is impaired, the solvent which volatilizes easily at room temperature is not preferable.

If the temperature at which the spacer particle dispersion liquid of the present invention discharged onto the substrate is dried is high, the alignment film may be damaged and the display image quality of the liquid crystal display device may deteriorate, but the boiling point is less than 150 ° C. By using a solvent, the drying temperature can be lowered and damage to the alignment film can be prevented.

The solvent having a boiling point of less than 150 ° C. preferably has a surface tension at 20 ° C. of less than 28 mN / m, more preferably 25 mN / m or less. When the surface tension of the solvent is 28 mN / m or more, the surface tension of the spacer particle dispersion of the present invention is increased, and the discharge performance may be deteriorated depending on the surface tension of the liquid contact portion of the nozzle of the ink jet apparatus.

When the spacer particle dispersion liquid of the present invention contains a solvent having a boiling point of less than 150 ° C. and a surface tension of less than 28 mN / m, it becomes easy to introduce the spacer particle dispersion liquid into an ink jet apparatus described later. Will improve.

The spacer particle dispersion of the present invention may contain a solvent X having a boiling point of 200 ° C. or higher and a surface tension at 20 ° C. of 42 mN / m or higher as a medium. In the present specification, “boiling point” refers to the boiling point under 1 atm. When the solvent X is contained, the receding contact angle (θr) can be further increased with various substrates.

The solvent X is not particularly limited as long as it has the boiling point and surface tension described above. For example, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6- Examples include hexanediol, diethylene glycol, triethylene glycol, glycerin, 2-pyrrolidone, nitrobenzene and the like. Among them, 1,3-propanediol, 1,4-butanediol and glycerin are preferably used because the spacer particles can be effectively gathered in a short time during drying. Since the spacer particles can be collected more effectively in a short time during drying, glycerin is more preferably used. As the solvent X, the above-described solvents may be used alone, or two or more kinds may be used in combination.

The content of the solvent X is not particularly limited, but a preferable range is 0.1 to 50% by weight in the solvent, a more preferable range is 1 to 30% by weight, and a further preferable range is 1 to 10% by weight. .

When the spacer particle dispersion is dried, the solvent having a low boiling point volatilizes first. Since the solvent having a low boiling point volatilizes first, the ratio of the solvent X in the remaining spacer particle dispersion increases. When the ratio of the solvent X is increased, the surface tension of the remaining spacer particle dispersion is further increased, and the spacer particles are easily moved toward the landing point center.

Examples of solvents that can be used other than the solvents described above include the following. Examples of water-soluble or hydrophilic solvents include water, ethanol, n-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-hexanol, 1-methoxy-2-propanol, and furfuryl. Monoalcohols such as alcohol and tetrahydrofurfuryl alcohol, multimers of ethylene glycol such as ethylene glycol, diethylene glycol, triethylene glycol and tetraethylene glycol; propylene glycol such as propylene glycol, dipropylene glycol, tripropylene glycol and tetrapropylene glycol Multimers of glycols (monoethylene ether, monoethyl ether, monoisopropyl ether, monopropyl ether of glycols (referring to the above-mentioned ethylene glycol and propylene glycol)) Lower monoalkyl ethers such as butyl and monobutyl ether; lower dialkyl ethers such as dimethyl ether, diethyl ether, diisopropyl ether and dipropyl ether of glycols; alkyl esters such as monoacetate and diacetate of glycols, 1,3 -Propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 3-hexene-2,5-diol, 1,5- Diols such as pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 1,6-hexanediol, neopentylglycol, ether derivatives of diols, diols Class of acetate derivatives, glycerin, 1, , 4-butanetriol, 1,2,6-hexanetriol, 1,2,5-pentanetriol, trimethylolpropane, trimethylolethane, pentaerythritol, and other polyhydric alcohols or ether derivatives thereof, acetate derivatives, methyl acetate Esters such as ethyl acetate, 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-hydroxyethylsulfone, bis- β-hydroxyethylurea, N, N-diethylethanolamine, abietinol, diacetone alcohol, urea and the like can be mentioned.

The spacer particle dispersion of the present invention improves the dispersion of spacer particles within the range that does not impair the object of the present invention, improves the discharge accuracy by controlling physical properties such as surface tension and viscosity, Various surfactants, viscosity modifiers and the like may be contained for the purpose of improving mobility.

The spacer particle dispersion of the present invention preferably has a lower pH limit of 7. If it is less than 7, the effect of inhibiting spacer particle adhesion to the SUS filter becomes insufficient, and the filter may be clogged. A more preferred lower limit is 8.

The spacer particle dispersion of the present invention has a small content of non-volatile components excluding spacer particles, specifically, the content ratio of non-volatile components having a particle size smaller than 1 μm is based on the entire spacer particle dispersion of the present invention. And less than 0.001% by weight. If it exceeds 0.001% by weight, the liquid crystal and the alignment film are contaminated, and the display quality such as contrast of the liquid crystal display device may be inferior.
The non-volatile components include, for example, dust in the atmosphere, impurities contained in the solvent used to disperse the spacer particles, pulverized spacer particles, ionic compounds such as metal ions, and the like. It shall contain solids and non-spherical fine particles that do not have shape retention in the particle dispersion.

As a method for reducing the non-volatile components in the spacer particle dispersion of the present invention, for example, first, the spacer particle dispersion of the present invention is filtered with a filter having a filtration diameter larger than the particle diameter of the spacer particles to remove large dust. Then, after the spacer particle dispersion of the present invention is centrifuged to precipitate the spacer particles, the supernatant is discarded, and the filtered spacer particles are filtered through a filter having a filtration diameter of 1 μm to add spacer particles. A method in which the spacer particles are filtered with a filter having a filtration diameter smaller than the particle diameter of the spacer particles, and the filtered spacer particles are dispersed in a solvent filtered with a filter having a filtration diameter of 1 μm; Examples thereof include a method using an ion-adsorbing solid such as a salt. These methods may be repeated.

In the spacer particle dispersion of the present invention, the difference between the specific gravity of the spacer particles and the specific gravity of the liquid portion excluding the spacer particles is preferably 0.5 or less. If it exceeds 0.5, the spacer particles may settle during storage of the spacer particle dispersion of the present invention, and the number of spacer particles in the discharged spacer particle dispersion of the present invention may become uneven.

In the spacer particle dispersion of the present invention, the difference between the solubility parameter value of the surface of the spacer particle and the solubility parameter value of the liquid part excluding the spacer particle is preferably 5.0 or less. If it exceeds 5.0, the dispersibility of the spacer particles in the spacer particle dispersion of the present invention may be inferior, and the number of spacer particles in the discharged spacer particle dispersion of the present invention may be uneven.

The spacer particle dispersion of the present invention preferably has a surface tension of 25 to 50 mN / m. If the surface tension is outside this range, it may be difficult to stably discharge with an inkjet apparatus.
The spacer particle dispersion preferably has a value obtained by subtracting the value of the surface tension of the substrate from the value of the surface tension of the spacer particle dispersion from −2 to 40 mN / m. If it is less than −2 mN / m, the landing diameter of the spacer particle dispersion of the present invention may be very large when it is landed on the substrate. If it exceeds 40 mN / m, the landed spacer particle dispersion May move easily, and the spacer particles may not be arranged accurately.
In the present specification, the surface tension is a value measured by a Wilhelmy method using a platinum plate.

In the spacer particle dispersion of the present invention, for example, it is preferable to mix the above-described low boiling point low surface tension solvent and high boiling point high surface tension solvent so as to satisfy the above-mentioned requirements for surface tension. By selecting such a combination, the surface tension increases as the landed droplets of the spacer particle dispersion liquid of the present invention dry, so that the force that reduces the diameter of the droplets as the droplets dry is obtained. It can limit the range in which the final spacer particles are placed.

The spacer particle dispersion of the present invention preferably has a receding contact angle (θr) with respect to the substrate of 5 ° or more. If the receding contact angle is 5 degrees or more, when the droplet of the spacer particle dispersion liquid of the present invention that has landed on the substrate is dried, it shrinks toward the center and at least one droplet is contained in the droplet. It is possible for the spacer particles to gather near the center of the droplet. If it is less than 5 degrees, the droplet dries around the center (landing center) where the droplet landed on the substrate, the droplet diameter decreases, and the spacer particles hardly gather at the center.
In this specification, the receding contact angle means that a droplet of the spacer particle dispersion liquid of the present invention placed on the substrate is first placed on the substrate in the process from being placed on the substrate until drying. This is the contact angle indicated when starting to become smaller than the actual landing diameter (when the droplet starts to shrink), or the contact angle indicated when 80 to 95% by weight of the volatile components of the droplet are volatilized.

The receding contact angle tends to be smaller than the so-called contact angle (the initial contact angle when a droplet is placed on a substrate, which is usually called the contact angle in most cases). This is because the initial contact angle is the contact angle of the droplet on the substrate surface not in contact with the solvent constituting the spacer particle dispersion of the present invention, while the receding contact angle is that of the present invention. This is considered to be due to the contact angle of the droplet with respect to the substrate on the substrate surface after contacting the solvent constituting the spacer particle dispersion. That is, when the receding contact angle is significantly lower than the initial contact angle, it indicates that the alignment film is damaged by those solvents, and it is preferable to use these solvents against alignment film contamination. It is thought that it shows that there is not.

In the spacer particle dispersion of the present invention, the preferable lower limit of the initial contact angle θ between the spacer particle dispersion and the substrate surface is 10 degrees, and the preferable upper limit is 110 degrees. When the angle is less than 10 degrees, the spacer particle dispersion liquid droplets of the present invention discharged onto the substrate may be in a state of being wet spread on the substrate, and the arrangement interval of the spacer particles may not be narrowed. The liquid droplets easily move around on the substrate with a slight vibration, and as a result, the placement accuracy may deteriorate, or the adhesion between the spacer particles and the substrate may deteriorate.

The spacer particle dispersion according to the present invention has a preferable lower limit of 0.5 mPa · s and a preferable upper limit of the viscosity at the head temperature at the time of discharging measured with an E-type viscometer or a B-type viscometer at least when discharging from an inkjet apparatus. 15 mPa · s. If the pressure is less than 0.5 mPa · s, it may be difficult to control the discharge amount when discharging from the ink jet apparatus, and if it exceeds 15 mPa · s, the ink jet apparatus may not be able to discharge. A more preferred lower limit is 5 mPa · s, and a more preferred upper limit is 10 mPa · s.
When discharging the spacer particle dispersion liquid of the present invention, the head temperature of the ink jet apparatus is cooled by a Peltier element, a refrigerant, or the like, or heated by a heater, etc. The temperature may be adjusted between -5 ° C and 50 ° C.

The spacer particle dispersion of the present invention preferably has an alignment film solvent solubility of the spacer particles of less than 5%. If it exceeds 5%, the alignment film may be damaged or liquid crystal contamination may occur.
The alignment film solvent solubility can be measured, for example, by the following method. That is, the spacer particle dispersion of the present invention corresponding to 100 mg in solid content is dried at 90 ° C. for 5 hours and 150 ° C. for 5 hours in a vacuum, and then baked at 220 ° C. for 1 hour. After measuring the weight (Wa) of the cured product, it was placed in 10 g of N-methyl 2-pyrrolidone and allowed to stand for 5 hours while shaking, the solid content was filtered off, dried at 150 ° C. for 5 hours in vacuo and dried to dryness. Measure the weight (Wb). The alignment film solvent solubility can be determined by the following formula.
Alignment film solvent solubility = (Wa−Wb) / Wa

The spacer particle dispersion liquid of the present invention is a method in which droplets of the spacer particle dispersion liquid are ejected using an ink jet device to land on a predetermined position on the substrate, and then dried to dry the spacer particles on the substrate. Can be placed in position.
That is, a method of manufacturing a liquid crystal display device having a pixel region and a non-pixel region, wherein the spacer particle dispersion of the present invention is applied to the non-pixel region of the first substrate or the second substrate using an inkjet device. Arranging at a specific position, drying the spacer particle dispersion, and superimposing the first substrate and the second substrate so as to face each other with the liquid crystal and the spacer particles interposed therebetween. A method for manufacturing a liquid crystal display device is also one aspect of the present invention.

It does not specifically limit as a board | substrate provided with the manufacturing method of the liquid crystal display device of this invention, What is normally used as a panel substrate of a liquid crystal display device, such as glass and resin, can be used. Of the pair of substrates, a substrate in which a color filter is provided in a pixel region can be used as one substrate. In this case, the pixel region is defined by a black matrix such as a resin in which a metal such as chrome or carbon black that hardly transmits light is dispersed. This black matrix constitutes a non-pixel region.

In the manufacturing method of the liquid crystal display device of the present invention, since the spacer particle dispersion of the present invention described above is used, the SUS filter of the ink jet device is not clogged, and the spacer particles are arranged continuously and stably. And a liquid crystal display measure with excellent display quality can be manufactured.
A liquid crystal display device produced by the method for producing a liquid crystal display device of the present invention is also one aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the spacer particle dispersion liquid which can arrange | position the spacer particle | grain on the board | substrate by an inkjet apparatus stably continuously, and can obtain the liquid crystal display device excellent in display quality, and liquid crystal display An apparatus can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
(Production of spacer particles)
10 parts by weight of substrate fine particles (trade name “Micropearl”, manufactured by Sekisui Chemical Co., Ltd.) are dispersed in 100 parts by weight of anhydrous dimethylformamide (DMF), 2 parts by weight of anhydrous chloroacetic acid are added, and the mixture is stirred for 12 hours in a nitrogen atmosphere. . After washing with DMF, a chloromethylated substrate fine particle DMF dispersion was obtained.
To this, 2 parts by weight of sodium N, N-diethyldithiocarbamate (SDC) was added and stirred for 12 hours under light shielding. 5 parts by weight of 2-hydroxyethyl methacrylate was added to the obtained N, N-diethyldithiocarbamate-based photoiniferter-immobilized substrate fine particle DMF dispersion and stirred for 60 minutes while irradiating with ultraviolet rays. Subsequently, 5 parts by weight of methacrylic acid was added, and further irradiated with ultraviolet rays for 30 minutes.
Then, 5 parts by weight of 2-hydroxyethyl methacrylate was added and irradiated with ultraviolet rays for 30 minutes, and 5 parts by weight of dimethylaminoethyl methacrylate was added and irradiated with ultraviolet rays for 30 minutes.
By subjecting this to ultrasonic cleaning with DMF, spacer particles having a block copolymer containing a positively charged block and a negatively charged block on the surface of the substrate fine particles were obtained.
The obtained spacer particles were AB block copolymers having a negatively charged block with a degree of polymerization of 1000 and a positively charged block with a degree of polymerization of 1000.
Each degree of polymerization was converted based on the measured molecular weight. The molecular weight of the block copolymer having a positively charged block and a negatively charged block on the surface of the substrate fine particles was determined using a silver deposition / time-of-flight secondary ion mass (TOF-SIMS) method.
During the reaction, sampling was performed every 10 minutes. The spacer particles were washed with DMF. Subsequently, it was washed with acetone, and dried spacer particles obtained by vacuum drying were obtained.
The dry spacer particles were attached to a metal plate, silver was deposited on the surface, and the deposited surface was subjected to TOF-SIMS analysis. The molecular weight of the block copolymer was obtained by integrating the obtained molecular weights.

(Preparation of spacer particle dispersion)
From the obtained spacer particles, a required amount to obtain a predetermined particle concentration (1.5% by weight) is slowly added to a mixed solvent of 75% by weight of ethylene glycol, 15% by weight of isopropanol, and 10% by weight of water, and a sonicator Was dispersed by thorough stirring while being used. Thereafter, the mixture was filtered through a stainless steel mesh having an opening of 20 μm to remove aggregates, thereby obtaining a spacer particle dispersion.

(Comparative Example 1)
10 parts by weight of substrate fine particles (trade name “Micropearl”, manufactured by Sekisui Chemical Co., Ltd.) are dispersed in 100 parts by weight of anhydrous dimethylformamide (DMF), 2 parts by weight of anhydrous chloroacetic acid are added, and the mixture is stirred for 12 hours in a nitrogen atmosphere. . After washing with DMF, a chloromethylated substrate fine particle DMF dispersion was obtained.
To this, 2 parts by weight of sodium N, N-diethyldithiocarbamate (SDC) was added and stirred for 12 hours under light shielding. 5 parts by weight of dimethylaminoethyl methacrylate was added to the obtained N, N-diethyldithiocarbamate photoiniferter-immobilized substrate fine particle DMF dispersion and stirred for 60 minutes while irradiating with ultraviolet rays.
By subjecting this to ultrasonic cleaning with DMF, spacer particles having a block copolymer containing a positively charged block on the surface of the substrate fine particles were obtained.
Thereafter, a spacer particle dispersion was prepared in the same manner as in Example 1.

(Production of liquid crystal display device)
(1) Preparation of color filter model substrate A black matrix (width 25 μm, vertical interval 150 μm, horizontal interval 75 μm, thickness 0.2 μm) made of metallic chromium was provided on a glass substrate by a conventional method. Color filter pixels (thickness 1.5 μm) composed of three colors of red, green, and blue were formed on and between the black matrix so that the surface was flat. An overcoat layer having a substantially constant thickness and an ITO transparent electrode were provided thereon. Furthermore, water repellent treatment was performed with a CF ₄ / N ₂ mixed gas using a “normal pressure plasma surface treatment apparatus” manufactured by Sekisui Chemical Co., Ltd. to prepare a color filter model substrate.
The surface tension of the obtained color filter model substrate was 27.4 mN / m.

(2) Preparation of counter TFT array model substrate A black matrix (width 25 μm, vertical interval 600 μm, horizontal interval 200 μm, thickness 0.2 μm) made of metallic chromium was provided on a glass substrate by a conventional method. Color filter pixels (thickness 1.5 μm) composed of three colors of red, green, and blue were formed on and between the black matrix so that the surface was flat. Next, a step made of copper (width 8 μm, height difference 5 nm) was provided on the glass substrate at a position opposite to the black matrix by a conventionally known method. An ITO transparent electrode having a substantially constant thickness was provided thereon.
Next, a polyimide resin solution (manufactured by Nissan Chemical Industries, Ltd., Sun Ever SE1211) was uniformly applied thereon by a spin coating method. After application, the film was dried at 80 ° C. and then baked and cured at 210 ° C. for 1 hour to form an alignment film having a substantially constant thickness to prepare a TFT array model substrate.
The surface tension of the formed alignment film was 30.2 mN / m.

(3) Preparation of inkjet apparatus An inkjet apparatus equipped with a piezo-type head having a diameter of 50 μm was prepared. The liquid contact part of the ink chamber of this head was made of a glass ceramic material. The nozzle surface was subjected to fluorine-based water repellent finish.

(4) Arrangement of spacer particles Using the obtained liquid crystal spacer particle dispersion, spacer particles were arranged on a color filter model substrate by an ink jet apparatus by the following method. In addition, when arrange | positioning spacer particle | grains, arrangement | positioning was started, after throwing away 0.5 mL of initial liquid crystal spacer particle dispersion liquid discharged from the nozzle of an inkjet apparatus.
First, the substrate was placed on a stage heated to 45 ° C. with a heater. On this substrate, using the above-described ink jet device, aiming at a position corresponding to the black matrix, droplets of liquid crystal spacer particle dispersion liquid at every 110 μm interval on every other vertical line. Were discharged at a pitch of 110 μm × 150 μm in width, arranged, and dried. The distance between the nozzle tip and the substrate during ejection was 0.5 mm, and ejection was performed by the double pulse method.
After discharging, the droplets were dried at 90 ° C. to evaporate the solvent, and then baked at 220 ° C. for 1 hour to cure the adhesive component.

Thereafter, a polyimide resin solution (Nissan Chemical Co., Ltd., Sun Ever SE1211) was uniformly applied by spin coating on the color filter model substrate on which the spacer particles were arranged. After coating, the film was dried at 80 ° C. and then baked and cured at 210 ° C. for 1 hour to form an alignment film having a substantially constant thickness.

(5) Completed liquid crystal display device A color filter model substrate on which spacer particles are arranged and a TFT array model substrate as a counter substrate were bonded together using a peripheral sealant. After bonding, the sealing agent is heated at 150 ° C. for 1 hour to be cured to produce an empty cell in which the cell gap is equal to the particle diameter of the spacer particles, and then filled with liquid crystal by a vacuum method. A liquid crystal display device was manufactured by sealing the inlet.

<Evaluation>
The spacer particle dispersions obtained in Example 1 and Comparative Example 1 were evaluated as follows. The results are shown in Table 1 below.

(Evaluation of dispersibility of liquid crystal spacer particle dispersion)
The liquid crystal spacer particle dispersion is diluted to 0.1 wt% with a mixed solvent having the same composition constituting it. This was dropped on a slide glass, immediately covered with a cover glass, and the dispersion state of the spacer particles was observed over 5 visual fields with a transmission microscope at a magnification of 400 times, and the degree of dispersibility was determined according to the following criteria.
Similarly, about 1 g of the liquid crystal spacer particle dispersion diluted to 0.05 wt% is concentrated to about 50% by drying under reduced pressure at 45 ° C. using a vacuum dryer. The concentrated liquid crystal spacer particle dispersion is irradiated with ultrasonic waves for about 1 minute, and after standing for about 1 minute, the dispersion state of the spacer particles is observed in the same manner, and the degree of dispersibility is determined according to the following criteria. . In addition, it was set as the dispersibility with respect to the solvent which remains to the last in the drying process by the dispersibility of this concentrated spacer particle dispersion.
○: Spacer agglomerates with two or more agglomerates within one field of view on average and no more than four agglomerates △: Spacer agglomerates with two or more agglomerates within the field of view on average 1 to 10 and no more than 4 agglomerates × 1 Spacer agglomerates with 2 or more agglomerates in the field of view more than 10 on average, or more than 4 agglomerates

(Check for clogged filter)
1 kg of the spacer particle dispersion was taken in a container that can be sealed, and SUS filter (270/2000 mesh, 10 μm openings) having a diameter of 10 mm was circulated at a flow rate of 150 mL / hour using a pump through a tube installed in the middle. Circulation was continued for 3 hours, and the degree of clogging of the filter was confirmed. The degree of filter clogging was determined according to the following criteria.
A: After 3 hours, there is no solid matter on the filter, and the circulation of the spacer particle dispersion does not stop.
◯: Solid matter that can be visually recognized is present on the filter after 3 hours, but the circulation of the spacer particle dispersion does not stop.
Δ: Circulation of the spacer particle dispersion is stopped between 1 hour and less than 3 hours.
X: The circulation of the spacer particle dispersion stops in less than 1 hour.

(State of spacer particles when drying droplets)
The droplets formed by discharging the spacer particle dispersion onto the surface of the color filter model substrate described above were dried, the state of the spacer particles accompanying the weight reduction was observed, and the determination was made according to the following criteria.
○: Almost all spacer particles gathered together.
Δ: Some spacer particles gathered together.
X: Many spacer particles were dispersed.

(Spacer particle placement accuracy)
The arrangement state of the spacer particles after the droplets were dried was determined according to the following criteria.
A: Most of the spacer particles were in the region corresponding to the non-pixel region.
(Triangle | delta): Some spacer particles protruded from the area | region corresponding to a non-pixel area | region.
X: Many spacer particles protruded from the region corresponding to the non-pixel region.

(Evaluation of display quality)
The display image quality of the liquid crystal display device was observed and judged according to the following criteria.
A: Almost no spacer particles were observed in the display area, and no light omission was caused by the spacer particles. Moreover, there was no unevenness (straight unevenness) due to a band-like gap defect due to the presence of a row in which no spacers were arranged.
Δ: Although there is no unevenness (straight irregularity) due to a band-like gap defect due to a row in which spacers are not arranged, slight spacer particles are observed in the display region, and light leakage due to the spacer particles is slight. .
X: There was unevenness (straight irregularity) due to a band-like gap defect due to the presence of a row where no spacers were arranged, and spacer particles were observed in the display area, and light leakage due to the spacer particles was observed.

ADVANTAGE OF THE INVENTION According to this invention, the spacer particle dispersion liquid which can arrange | position the spacer particle | grain on the board | substrate by an inkjet apparatus stably continuously, and can obtain the liquid crystal display device excellent in display quality, and liquid crystal display An apparatus can be provided.

It is the figure which showed an example of the change of the solvent composition of the spacer particle dispersion liquid of this invention. It is the figure which represented typically the conformation change of the block copolymer of the surface of spacer particle | grains.

Explanation of symbols

1 Spacer Particle Dispersion 2 Substrate 3 Spacer Particle 4 Positive Charge Block 5 Negative Charge Block

Claims (7)

A spacer particle dispersion for disposing spacer particles at an arbitrary position on a substrate using an inkjet device,
Spacer particles containing a solvent and a spacer particle, wherein the spacer particles have an AB-type or ABA-type block copolymer containing a positively charged block and a negatively charged block on the surface of the substrate fine particles. Dispersion. The spacer particle dispersion according to claim 1, further comprising a nonionic block between the positively charged block and the negatively charged block. The spacer dispersion liquid according to claim 1 or 2, wherein the positively charged block and the negatively charged block each have a polymerization degree of 50 to 2000. The solvent contains water, a solvent having a boiling point of less than 150 ° C., and a solvent having a boiling point of 150 ° C. or more, and the content of the water is 0 to 60% by weight, and the content of the solvent having a boiling point of less than 150 ° C. 4. The spacer particle dispersion according to claim 1, wherein the content of the solvent having a boiling point of 150 ° C. or higher is 30 to 96% by weight. The solvent having a boiling point of less than 150 ° C is at least one selected from the group consisting of lower monoalcohols such as ethanol, n-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, acetone, and the like. The spacer particle dispersion according to claim 4, wherein Solvents having a boiling point of 150 ° C. or higher are ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 3-methyl-1,5. -Pentanediol, 3-hexene-2,5-diol, 1,5-pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 1,6- The spacer particle dispersion according to claim 4, wherein the spacer particle dispersion is at least one selected from the group consisting of hexanediol and neopentyl glycol. A liquid crystal display device comprising the spacer particle dispersion according to claim 1, 2, 3, 4, 5 or 6.

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