TWI458758B - Liquid crystal alignment agent for inkjet coating, liquid crystal alignment film and liquid crystal display element - Google Patents

Description

Liquid crystal alignment agent for inkjet coating, liquid crystal alignment film, and liquid crystal display element

The present invention relates to a liquid crystal alignment agent which mainly comprises a polyoxyalkylene obtained by polycondensing an alkoxydecane and which can be formed into a uniform film by inkjet coating, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and the like A liquid crystal display element of a liquid crystal alignment film.

The liquid crystal display element is generally known in a configuration in which two substrates on which a liquid crystal alignment film is provided on a transparent electrode are opposed to each other, and a liquid crystal substance is filled in the gap.

Recently, as a light source for a liquid crystal projector for commercial use and a home theater (referred to as a third thin type television and a rear projection type television), a metal halide lamp having a strong irradiation intensity has been used. Therefore, as a characteristic of the liquid crystal alignment film, not only high heat resistance but also high light resistance is required.

The liquid crystal alignment film material generally used is mainly composed of polyphthalic acid or polyimine, but an inorganic liquid crystal alignment film is also proposed. For example, a liquid crystal alignment film is formed by vapor deposition (for example, refer to Patent Document 1).

Further, as a coating type inorganic liquid crystal alignment film, an alignment agent composition containing a reaction product of tetraalkoxy decane, trialkoxy decane, alcohol, and oxalic acid has been proposed, and an electrode substrate for a liquid crystal display element has been reported. A liquid crystal alignment film having excellent vertical alignment, heat resistance, and uniformity is formed thereon (for example, refer to Patent Document 2).

Further, a liquid crystal alignment agent composition containing a reaction product of a tetraalkoxynonane, a trialkoxysilane and water, and a glycol ether solvent has been proposed, and it has been reported that it can prevent display defects and remain after being driven for a long time. A liquid crystal alignment film which is excellent in characteristics, does not reduce the ability of liquid crystal alignment, and has a small decrease in voltage retention ratio of light and heat (for example, refer to Patent Document 3).

In general, as a film formation method of a liquid crystal alignment film, a spin coating method, a dip coating method, a soft relief printing, or the like is exemplified, but in practice, flexographic printing is often used. However, in the flexographic printing, it is necessary to replace the printing plate corresponding to the size of the substrate for forming the liquid crystal alignment film, and in order to stabilize the film forming step, there is a problem that film formation must be temporarily formed.

Therefore, an inkjet coating method which is a new coating method which does not use a printing plate has been attracting attention. In the inkjet coating method, a droplet is dropped on a substrate, and a film is formed by expanding the wetness of the liquid. The printing process is not used, and a free printing pattern can be set, so that the manufacturing steps of the liquid crystal display element can be simplified. Further, there is no need to temporarily form a film and there is an advantage that the coating liquid is less wasted. Therefore, it is expected that the cost of the liquid crystal panel is lowered and the production efficiency is improved.

In these cases, it is desired that the inorganic liquid crystal alignment film has excellent heat resistance and light resistance, and it is desirable to introduce a process for forming a liquid crystal alignment film by inkjet coating, and it is required to have an inorganic liquid crystal alignment corresponding to the requirements. Agent.

Prior technical literature

Patent literature

Patent Document 1: JP-A-2003-50397

Patent Document 2: Japanese Patent Publication No. 09-281502

Patent Document 3: JP-A-2005-250244

An object of the present invention is to provide a liquid crystal alignment agent which can be formed by an inkjet coating method, and a liquid crystal alignment film which provides in-plane uniformity of a film by inkjet coating and excellent edge straightness of a film end portion. .

That is, the present invention has the following main points.

(1) A liquid crystal alignment agent for inkjet coating, which comprises a polyoxyalkylene (A) having a side chain composed of a hydrocarbon group having 8 to 30 carbon atoms substituted or unsubstituted by a fluorine atom, and carbon a diol solvent (B) having 2 to 7 and a solvent (C): a solvent (C): a compound selected from at least one selected from the group consisting of formula (T1), formula (T2), and formula (T3) One or more solvents selected from the group consisting of a ketone having 3 to 6 carbon atoms and an alkanol having 5 to 12 carbon atoms:

[wherein, X ₁ , X ₃ and X _{5 are} each independently an alkyl group having 1 to 4 carbon atoms, and X ₂ and X _{6 are} each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X ₄ is a carbon number of 1 An alkyl group of ~4, P is an alkyl group having 1 to 3 carbon atoms, and m, n, j, and k are each independently an integer of 1 to 3, and h is an integer of 2 or 3.

(2) The liquid crystal alignment agent for inkjet coating according to the above (1), wherein the solvent (C) is selected from the group consisting of a compound of the formula (T1), the formula (T2) or the formula (T3), and a carbon number of 3 to 6. One or more solvents selected from the group consisting of ketones and alkanols having 5 to 12 carbon atoms.

(3) The liquid crystal alignment agent for inkjet coating according to the above (1) or (2), wherein the polyoxyalkylene (A) is an alkoxy group containing an alkoxydecane represented by the formula (1). a polyoxane obtained by polycondensation of decane,

R ¹ Si(OR ² ) ₃ (1)

(R ¹ represents a hydrocarbon group having 8 to 30 carbon atoms which may be substituted by a fluorine atom, and R ² represents a hydrocarbon group having 1 to 5 carbon atoms).

(4) The liquid crystal alignment agent for inkjet coating according to the above (3), wherein the polyoxyalkylene (A) is an alkoxysilane represented by the formula (1) and represented by the following formula (2) a polyoxyalkylene obtained by polycondensation of an alkoxydecane of an alkoxydecane,

(R ³ ) _n Si(OR ⁴ ) _4-n (2)

(R ³ represents a hydrogen atom or a hydrocarbon group having a carbon number of 1 to 7, R ⁴ represents a hydrocarbon group having 1 to 5 carbon atoms of, n represents an integer of 0 to 3).

(5) The liquid crystal alignment agent for inkjet coating according to the above (3) or (4), wherein the polyoxyalkylene (A) is an alkoxysilane represented by the formula (1) and the following formula ( 3) a polyoxyalkylene obtained by polycondensation of an alkoxydecane represented by an alkoxydecane,

Si(OR ⁴ ) ₄ (3)

(R ⁴ represents a hydrocarbon group having 1 to 5 carbon atoms).

The liquid crystal alignment agent for inkjet coating according to any one of the above aspects, wherein the diol solvent (B) is selected from the group consisting of ethylene glycol, diethylene glycol, and dipropylene glycol. 2-methyl-2,4-pentanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1 , 4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,3-pentanediol, 2,4 - pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,3-hexyl Glycol, 2,4-hexanediol, 2,5-hexanediol, 3,4-hexanediol, 1,2-heptanediol, 2,3-heptanediol, 3,4-heptanediol , 1,3-heptanediol, 2,4-heptanediol, 3,5-heptanediol, 1,4-heptanediol, 2,5-heptanediol, 1,5-heptanediol, 2 One or more solvents selected from the group consisting of 6-heptanediol, 1,6-heptanediol, and 1,7-heptanediol.

(7) The liquid crystal alignment agent for inkjet coating according to any one of the above (1), wherein X ₂ in the formula (T1) is a hydrogen atom.

The liquid crystal alignment agent for inkjet coating according to any one of the above aspects (1), wherein the ruthenium atom of the polyaluminoxane (A) is converted to a value of SiO ₂ . The total amount is 100 parts by mass, the diol solvent (B) is 20 to 18,000 parts by mass, and the solvent (C) is 20 to 18,000 parts by mass.

(9) The liquid crystal alignment agent for inkjet coating according to any one of the above (1), wherein the ruthenium atom of the polysiloxane (A) is converted to a value of SiO ₂ . The total amount is 100 parts by mass, the diol solvent (B) is 120 to 17,000 parts by mass, and the solvent (C) is 120 to 17,000 parts by mass.

(10) The liquid crystal alignment agent for inkjet coating according to any one of the above (1), wherein the liquid crystal alignment agent has a viscosity of 1.8 to 18 mPa·s.

The liquid crystal alignment agent for inkjet coating according to any one of the above-mentioned (1), wherein the liquid crystal alignment agent has a surface tension of 20 to 40 mN/m.

(12) A liquid crystal alignment film which is characterized in that the liquid crystal alignment agent for inkjet coating according to any one of the above (1) to (11) is applied onto a substrate and fired. And the winner.

(13) A method of forming a liquid crystal alignment film, which is characterized in that the liquid crystal alignment agent for inkjet coating according to any one of the above (1) to (11) is applied onto a substrate, and Those who have been burned.

(14) A liquid crystal display element comprising the liquid crystal alignment film according to (12) above.

The liquid crystal alignment agent of the present invention can form a liquid crystal alignment film excellent in the in-plane uniformity of the film and the edge straightness of the film end portion by inkjet coating.

The invention is described in detail below.

<polyoxane A>

The polyoxyalkylene (A) used in the present invention has a side chain (hereinafter also referred to as a specific organic group) composed of a hydrocarbon group having 8 to 30 carbon atoms, preferably 8 to 22 carbon atoms which are substituted or unsubstituted with a fluorine atom.

Although the specific organic group described above has an effect of aligning the liquid crystal in one direction, it is not particularly limited as long as it has such an effect. Examples of such examples include an alkyl group, a fluoroalkyl group, an alkenyl group, a phenethyl group, a fluorophenylalkyl group, a styrylalkyl group, a naphthyl group and the like. Among these, an alkyl group is preferred because it is relatively easy to obtain.

The polyoxyalkylene (A) used in the present invention may also have a plurality of specific organic groups.

The polyoxyalkylene (A) used in the present invention may have a specific organic group as long as it does not impair the effects of the present invention for the purpose of improving the adhesion between the substrate and the adhesion to the liquid crystal molecules. Different side chains (hereinafter also referred to as second organic groups).

The second organic group is an organic group having a carbon number of preferably from 1 to 7, more preferably from 1 to 5. The second organic group may also have an aliphatic hydrocarbon; a ring structure such as an aliphatic ring, an aromatic ring or a heterocyclic ring; an unsaturated bond; a hetero atom such as an oxygen atom, a nitrogen atom or a sulfur atom; and a branched structure. The second organic group is a vinyl group or a hydrocarbon group having 1 to 7 carbon atoms, and any hydrogen atom of the hydrocarbon group may also be a glycidoxy group, a mercapto group, a methacryloxy group, an acryloxy group, an isocyanate group, an amine group or The ureido group is substituted and may also have a hetero atom. The polyoxyalkylene (A) used in the present invention may have one or a plurality of second organic groups.

The polyoxyalkylene (A) used in the above invention is not particularly limited, but is generally obtained by polycondensation of an alkoxydecane.

In other words, the alkyl alkane is polycondensed by using an alkoxydecane represented by the following formula (1) as an essential component to obtain a polyoxyalkylene (A).

R ¹ Si(OR ² ) ₃ (1)

In the formula (1), R ¹ is a specific organic group, and R ² is a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms.

Examples of R ¹ as described above are the same as a specific organic group, wherein R ¹ is an alkyl of alkoxy silane-cheaper to easily obtain a commercial product therefore preferred. Further, the hydrocarbon group of R ² is preferably a carbon number of 1 to 4.

Specific examples of the alkoxydecane represented by the above formula (1) are exemplified, but are not limited thereto.

For example, octyltrimethoxydecane, octyltriethoxydecane, decyltrimethoxydecane, decyltriethoxydecane, dodecyltrimethoxydecane, dodecyltriethoxydecane, Cetyltrimethoxydecane, cetyltriethoxydecane, heptadecyltrimethoxynonane, heptadecyltriethoxydecane,octadecyltrimethoxydecane,octadecane Triethoxy decane, nonadecyltrimethoxynonane, nonadecyltriethoxydecane, undecyltriethoxydecane, undecyltrimethoxydecane, 21-twenty-two Carbonalkenyl triethoxydecane, tridecafluorooctyltrimethoxydecane, tridecafluorooctyltriethoxydecane, heptadecafluorodecyltrimethoxydecane, heptadecafluorodecyltriethoxydecane , isooctyltriethoxydecane, phenethyltriethoxydecane, pentafluorophenylpropyltrimethoxydecane, m-vinylphenylethyltrimethoxydecane, p-vinylphenyl Trimethoxy decane, (1-naphthyl) triethoxy decane, (1-naphthyl) trimethoxy decane, allyloxy undecyl triethoxy decane, benzo醯oxypropyltrimethoxydecane, 3-(4-methoxyphenoxy)propyltrimethoxydecane, 1-[(2-triethoxydecyl)ethyl]cyclohexane-3 , 4-epoxide, 2-(diphenylphosphinyl)ethyltriethoxydecane, diethoxymethyloctadecyldecane, dimethoxymethyloctadecyldecane, two Ethoxydodecylmethylnonane, dimethoxydodecylmethyldecane, diethoxymethylmethyldecane, dimethoxydecylmethyldecane, diethoxyoctyl Base decane, dimethoxyoctylmethyl decane, ethoxy dimethyl octadecyl decane, methoxy dimethyl octadecyl decane, and the like.

Among them, preferred are octyltrimethoxydecane, octyltriethoxydecane, decyltrimethoxydecane,decyltriethoxydecane,dodecyltrimethoxydecane,dodecyltriethyl Oxydecane, cetyltrimethoxydecane, cetyltriethoxydecane, heptadecyltrimethoxydecane, heptadecyltriethoxydecane,octadecyltrimethoxydecane , octadecyltriethoxydecane, nonadecyltrimethoxynonane, nonadecyltriethoxydecane, undecyltriethoxydecane, or undecyltrimethoxydecane, Diethoxymethyloctadecane, diethoxydodecylmethylnonane.

In the present invention, a plurality of alkoxydecanes represented by the formula (1) may be used in combination.

The use ratio of the alkoxydecane represented by the formula (1) is less than 0.1 mol% in all the alkoxydecanes used to obtain the polyoxyalkylene (A), since good liquid crystal alignment is sometimes not obtained. Therefore, it is preferably 0.1 mol% or more. More preferably 0.5% or more. When the amount is more than 30 mol%, the formed liquid crystal alignment film may not be sufficiently cured, and therefore it is preferably 30 mol% or less. More preferably 22% or less. It is better to be 15% or less.

In the present invention, the polyoxyalkylene (A) is preferably obtained by polycondensation of an alkoxydecane represented by the formula (1) and an alkoxydecane represented by the following formula (2). Oxane.

(R ³ ) _n Si(OR ⁴ ) _4-n (2)

In the formula (2), R ³ is a hydrogen atom, a halogen atom, a vinyl group or a hydrocarbon group having 1 to 7 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 7 carbon atoms. Any hydrogen atom of the above hydrocarbon group may be substituted with a glycidoxy group, a mercapto group, a methacryloxy group, an acryloxy group, an isocyanate group, an amine group or a urea group, and may have a hetero atom. R ⁴ is a hydrocarbon number of 1 to 5, preferably 1 to 4, more preferably 1 to 3, and n is 0 to 3, preferably an integer of 0 to 2.

Further, when R ³ of the formula (2) is a vinyl group or a hydrocarbon group, it is represented by the above-mentioned second organic group. Therefore, in this case, the example of R ^{3 is} the same as that described for the second organic group.

As the alkoxydecane represented by the formula (2), there are exemplified by methyltrimethoxydecane, methyltriethoxydecane, methyltripropoxydecane, ethyltrimethoxydecane, and ethyltriethoxylate. Base decane, propyl trimethoxy decane, propyl triethoxy decane, butyl trimethoxy decane, butyl triethoxy decane, pentyl trimethoxy decane, pentyl triethoxy decane, hexyl trimethyl Oxydecane, hexyltriethoxydecane, 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, N-2(aminoethyl)3-aminopropyltri Ethoxy decane, N-2 (aminoethyl) 3-aminopropyltrimethoxydecane, 3-(2-aminoethylaminopropyl)trimethoxynonane, 3-(2-amine Ethylethylaminopropyl)triethoxydecane, 2-aminoethylaminomethyltrimethoxydecane, 2-(2-aminoethylthioethyl)triethoxydecane, 3- Mercaptopropyltriethoxydecane, mercaptomethyltrimethoxydecane, 3-ureidopropyltriethoxydecane, vinyltriethoxydecane, vinyltrimethoxydecane,allyltriethoxy Baseline, 3-methylpropenyloxypropyl three Oxydecane, 3-methylpropenyloxypropyltriethoxydecane, 3-propenyloxypropyltrimethoxydecane, 3-propenyloxypropyltriethoxydecane, 3-isocyanate Propyltriethoxydecane, trifluoropropyltrimethoxydecane, chloropropyltriethoxydecane, bromopropene triethoxydecane, 3-mercaptopropyltrimethoxydecane, and the like.

Specific examples of the alkoxydecane in the case where R ³ is a hydrogen atom in the alkoxydecane represented by the formula (2), and examples thereof include trimethoxydecane, triethoxydecane, tripropoxydecane, and tributoxy Base decane and the like.

In the alkoxydecane represented by the formula (2), the alkoxydecane in which n is 0 represents a tetraalkoxydecane of the formula (3).

Si(OR ⁴ ) ₄ (3)

In the formula (3), R ^{4 is} as described above.

The tetraalkoxydecane represented by the formula (3) is preferred because it is easily condensed with the alkoxydecane represented by the formula (1) to obtain a polyoxyalkylene (A).

Specific examples of the tetraalkoxydecane represented by the formula (3) include tetramethoxynonane, tetraethoxydecane, tetrapropoxydecane, tetrabutoxydecane, and the like.

When the alkoxy decane represented by the above formula (2) or formula (3) is used, one type may be used, or a plurality of types may be used as appropriate.

And when used in the alkoxydecane represented by the above formula (2) or formula (3), in order to obtain all of the alkoxydecanes of the polyoxyalkylene (A), the alkane represented by the formula (2) or the formula (3) The total amount of oxydecane used is preferably from 70 to 99.7 mol%. More preferably 78~99.7 mol%. Further, the alkoxy decane represented by the formula (2) or the formula (3) is from 85 to 99.7 mol%.

The polyoxyalkylene (A) used in the present invention is obtained by condensing an alkoxydecane containing an alkoxysilane represented by the above formula (1) as an essential component in an organic solvent. In this case, an alkoxydecane containing an alkoxydecane represented by the formula (1), the formula (2) and the formula (3) is preferred. Usually, polyoxyalkylene (A) is obtained by polycondensing these alkoxydecanes as a solution which is uniformly dissolved in an organic solvent.

The method for condensing the polyoxyalkylene (A) used in the present invention is not particularly limited, and for example, a method of hydrolyzing and condensing an alkoxydecane in an alcohol or a glycol solvent is exemplified. At this time, the hydrolysis and condensation reaction may be either partial hydrolysis or complete hydrolysis. In the case of complete hydrolysis, it is theoretically possible to add water of 0.5 times moles of all alkoxy groups in the alkoxy decane, and water is usually added in excess of 0.5 times mole.

In the present invention, the amount of water used in the above reaction may be appropriately selected depending on the desired ratio, but usually, it is preferably 0.5 to 2.5 times moles of all alkoxy groups in the alkoxydecane.

Further, in order to promote hydrolysis and condensation reaction, an acid such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, oxalic acid, maleic acid or fumaric acid, ammonia, methylamine, ethylamine, ethanolamine or triethylamine is used. A catalyst such as a base or a metal salt such as hydrochloric acid, sulfuric acid or nitric acid. Further, in general, hydrolysis and condensation reaction can be promoted by heating a solution in which alkoxysilane is dissolved. In this case, the heating temperature and the heating time may be appropriately selected depending on, for example, heating and stirring at 50 ° C for 24 hours, heating under reflux for 1 hour, and the like.

Further, as another method, for example, a method in which a mixture of alkoxysilane, a solvent, and oxalic acid is heated and polycondensed is exemplified. Specifically, a method in which oxalic acid is added to an alcohol as an alcohol solution of oxalic acid in advance and then mixed with an alkoxy decane in a heated state of the solution is used. In this case, the amount of oxalic acid used is preferably 1 to 2 moles for all alkoxy groups of the alkoxydecane. The heating in this method can be carried out at a liquid temperature of 50 to 180 ° C, preferably in such a manner as not to cause evaporation or volatilization of the liquid, for example, in a vessel equipped with a reflux tube under reflux for several tens of minutes to several tens of hours.

When a polyoxyalkylene (A) is obtained, when a plurality of alkoxydecanes are used, the alkoxydecane may be previously mixed as a mixture, or a plurality of alkoxydecane may be sequentially mixed.

The solvent (hereinafter also referred to as a polymerization solvent) used in the polycondensation of the alkoxydecane is not particularly limited as long as it can dissolve the alkoxysilane. Further, even when the alkoxydecane is not dissolved, it may be dissolved at the same time as the polycondensation reaction of the alkoxydecane proceeds. In general, since alcohol is formed by polycondensation of alkoxysilane, an alcohol, a glycol, a glycol ether, or an organic solvent having good compatibility with an alcohol is used.

Specific examples of the polymerization solvent include methanol, ethanol, propanol, butanol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 2-methyl-2,4-pentanediol, and ethylene. Alcohol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, two Glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether , propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N - dimethyl acetamide, γ-butyrolactone, dimethyl hydrazine, tetramethyl urea, hexamethylphosphoric acid triamide, m-cresol or the like.

In the present invention, a plurality of the above polymerization solvents may also be used.

The solution obtained by the above-mentioned methods is usually 20% by mass or less, preferably 15% by mass in terms of the concentration of SiO ₂ (hereinafter referred to as SiO ₂ conversion) in terms of the ruthenium atom of all the alkoxy decane charged as a raw material. %the following. By selecting an arbitrary concentration within the concentration range, gel formation can be suppressed, and a homogeneous solution can be obtained.

<Soluble of polyoxyalkylene (A)>

In the present invention, the solution obtained by the above method may be directly used as a solution of polyoxyalkylene (A), and the solution obtained by the above method may be concentrated as needed, and the solvent may be added to be diluted or substituted into other solvents to serve as a polyfluorene. a solution of oxane (A).

At this time, the solvent to be used (hereinafter also referred to as an additive solvent) may be the same solvent as that used for the polycondensation, or may be a different solvent. The solvent is not particularly limited as long as it can uniformly dissolve the polyoxyalkylene (A), and one type can be used arbitrarily.

Specific examples of such added solvents include alcohols such as methanol, ethanol, propanol, butanol, and diacetone; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; a glycol such as alcohol, diethylene glycol, propylene glycol or 2-methyl-2,4-pentanediol; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol Dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, a glycol ether such as diethylene glycol dipropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether or propylene glycol monobutyl ether; esters of methyl acetate, ethyl acetate, ethyl lactate, etc.; -methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, dimethyl hydrazine, tetramethylurea, six Methylphosphorus triamide, m-cresol and the like.

In the present invention, a solution of the polyoxane (A) obtained as described above may be used singly or in combination of plural kinds.

<diol solvent (B)>

The diol solvent (B) used in the present invention is a diol compound having 2 to 7, preferably 2 to 5 carbon atoms, and specific examples thereof include ethylene glycol, diethylene glycol, dipropylene glycol, and 2-methyl group. -2,4-pentanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butyl Glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,3-pentanediol, 2,4-pentanediol 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2 , 4-hexanediol, 2,5-hexanediol, 3,4-hexanediol, 1,2-heptanediol, 2,3-heptanediol, 3,4-heptanediol, 1,3 - heptanediol, 2,4-heptanediol, 3,5-heptanediol, 1,4-heptanediol, 2,5-heptanediol, 1,5-heptanediol, etc., 2,6- Heptanediol, 1,6-heptanediol, 1,7-heptanediol, and the like.

The diol solvent (B) may also be used in combination. Among them, ethylene glycol, diethylene glycol, dipropylene glycol, 2-methyl-2,4-pentanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1, 5-pentanediol, 2,3-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5- Hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 3,4-hexanediol or a mixed solvent of these.

These diol compounds (B) can also be used as a solvent since they are usually liquid. Therefore, it may be used as a polymerization solvent or an additive solvent in the case of polycondensation of the polyoxyalkylene (A), or may be added after synthesizing the polyoxyalkylene (A) in another solvent.

The content of the diol compound (B) used in the present invention is 100 parts by mass based on the total amount of SiO _{2 in terms} of the ruthenium atom of the polysiloxane (A) in the liquid crystal alignment agent, and the diol solvent ( B) is 20 to 18,000 parts by mass, preferably 120 to 17,000 parts by mass, more preferably 150 to 16,000 parts by mass. When it is less than 20 parts by mass, there is a case where good coatability cannot be obtained.

The diol compound (B) used in the present invention has an effect of suppressing liquid expansion especially at the time of coating, and a liquid crystal alignment film which is particularly excellent in edge straightness can be obtained.

<Solvent (C)>

The solvent (C) used in the present invention is at least one compound selected from the group consisting of the following formula (T1), formula (T2), and formula (T3), a ketone having 3 to 6 carbon atoms, and a carbon number of 5 to 12; One or more solvents selected from the group consisting of alkanols.

In the formula, X ₁ , X ₃ and X _{5 are} each independently an alkyl group having 1 to 4 carbon atoms, and X ₂ and X _{6 are} each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X ₄ is a carbon number of 1~ 4 is an alkyl group, P is an alkyl group having 1 to 3 carbon atoms, and m, n, j, and k are each independently an integer of 1 to 3, and h is an integer of 2 or 3.

The solvent (C) used in the present invention is preferably selected from the group consisting of a compound of the above formula (T1), formula (T2) or formula (T3), a ketone having 3 to 6 carbon atoms and an alkanol having 5 to 12 carbon atoms. More than one solvent selected by the group.

The solvent (C) used in the present invention may be, for example, a compound represented by the above formula (T1) or a solvent of a ketone having 3 to 6 carbon atoms, or a compound represented by the formula (T1) and represented by the formula (T2). The mixed solvent of the compound may be a mixed solvent of the compound represented by the formula (T1) and the compound represented by the formula (T3), and further may be a compound represented by the formula (T1) and an alkane having 5 to 12 carbon atoms. A mixed solvent of alcohol.

Further, X ₂ and X ₆ in the above formula (T1) and formula (T3) are preferably a hydrogen atom.

Specific examples of the compound represented by the formula (T1) include 1-methoxy-2-propanol (propylene glycol monomethyl ether), 1-ethoxy-2-propanol (propylene glycol monoethyl ether), and 1-propyl. Oxy-2-propanol (propylene glycol monopropyl ether), 1-butoxy-2-propanol (propylene glycol monobutyl ether), 1,2-dimethoxypropane (propylene glycol dimethyl ether), 1, 2 - Diethoxypropane (propylene glycol diethyl ether), 1,2-dipropoxypropane (propylene glycol dipropyl ether), 1,2-dibutoxypropane (propylene glycol dibutyl ether), and the like. Among them, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-propoxy-2-propanol or 1-butoxy-2-propanol is preferred.

Specific examples of the compound represented by the formula (T2) include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, and ethylene glycol dibutyl ether. Among them, ethylene glycol dimethyl ether or ethylene glycol dibutyl ether is preferred.

Specific examples of the compound represented by the formula (T3) include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, and diethylene glycol II. Methyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether and the like. Among them, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether or diethylene glycol dibutyl ether is preferred. .

Specific examples of the ketone having 3 to 6 carbon atoms of the solvent (C) include methyl ethyl ketone and methyl isobutyl ketone.

Specific examples of the alkanol having 5 to 12 carbon atoms of the solvent (C) include hexanol, heptanol, octanol, decyl alcohol, decyl alcohol, undecyl alcohol, and dodecanol. Among them, preferred are hexanol, heptanol, octanol, nonanol or decyl alcohol.

The solvent (C) used in the present invention may also be used as a polymerization solvent or an added solvent in the polycondensation of the polyoxyalkylene (A), or may be synthesized in another solvent. A) added later.

The content of the solvent (C) is 100 parts by mass based on the total amount of SiO _{2 in terms} of the atomic atom of the polyoxyalkylene (A), and the solvent (C) is 20 to 18,000 parts by mass, preferably 120%. 17,000 parts by mass, more preferably 150 to 16,000 parts by mass. When it is less than 20 parts by mass, there is a case where good coatability cannot be obtained.

These solvents (C) have an effect of suppressing the expansion of the liquid at the time of coating, and a liquid crystal alignment film which is particularly excellent in in-plane uniformity can be obtained.

<Other solvents>

In the present invention, a solvent other than the diol compound (B) and the solvent (C) may be used insofar as the effects of the present invention are not impaired. Specific examples of the other solvent are alcohols such as methanol, ethanol, propanol, butanol, and diacetone alcohol; acetone, ethyl carbitol, butyl carbitol, methyl acetate, ethyl acetate, ethyl lactate, and the like. Esters; N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, dimethyl hydrazine, four Methyl urea, hexamethylphosphoric acid trisamine, m-cresol, and the like.

<Other ingredients>

In the present invention, other components than the polysiloxane (A), the diol compound (B), and the solvent (C), such as inorganic fine particles and metal alkoxide, may be contained within a range not impairing the effects of the present invention. (metalloxanes) oligomers, metal alkoxy polymers, leveling agents, surfactants and other components.

The inorganic fine particles are preferably fine particles such as cerium oxide fine particles, alumina fine particles, titanium oxide fine particles, and magnesium fluoride fine particles, and are preferably colloidal solutions of the inorganic fine particles. The colloidal solution may be one in which inorganic fine particles are dispersed in a dispersion medium, or may be a commercially available colloidal solution.

In the present invention, by containing inorganic fine particles, it is possible to impart a surface shape or other function to the formed hardened film. The inorganic fine particles preferably have an average particle diameter of 0.001 to 0.2 μm, more preferably 0.001 to 0.1 μm. When the average particle diameter of the inorganic fine particles exceeds 0.2 μm, the transparency of the cured film formed using the prepared coating liquid may be lowered.

As the dispersion medium of the inorganic fine particles, water and an organic solvent can be exemplified. As the colloidal solution, it is preferred to adjust the pH or pKa to 1 to 10 from the viewpoint of the stability of the coating liquid for forming a film. Better for 2~7.

The organic solvent used in the dispersion medium of the colloidal solution may, for example, be methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, butanediol, pentanediol, 2-methyl-2,4-pentanediol. Alcohols such as diethylene glycol, dipropylene glycol, and ethylene glycol monopropyl ether; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene and xylene; Amidoxime such as carbamide, dimethylacetamide or N-methylpyrrolidone; esters of ethyl acetate, butyl acetate, γ-butyrolactone, etc.; tetrahydrofuran, 1,4-two An ether such as an oxane. Among them, alcohols or ketones are preferred. These organic solvents may be used singly or in combination of two or more kinds as a dispersion medium.

The metal alkoxy oligo or metal alkoxy polymer is a single or composite oxide precursor of ruthenium, titanium, zirconium, aluminum, ruthenium, osmium, iridium, tin, indium, zinc or the like. The metal alkoxy oligomer or the metal alkoxy polymer may be a commercially available product, or may be obtained by a general method such as hydrolysis from a monomer such as a metal alkoxide, a nitrate, a hydrochloride or a carboxylate. By.

In the present invention, by containing a metal alkoxy oligomer or a metal alkoxy polymer, the refractive index of the cured film can be increased to impart photosensitivity. When a metal alkoxy oligomer or a metal alkoxy polymer is used, it may be used simultaneously with the synthesis of the polyoxyalkylene (A), or may be added later to the polyoxyalkylene (A).

Specific examples of the metal alkoxy oligo or metal alkoxy polymer of the commercially available product include methyl decanoate 51 manufactured by COLCOAT Co., Ltd., methyl decanoate 53A, ethyl decanoate 40, and ethyl decanoate 48. a oxyalkylene oligomer or a siloxane polymer such as EMS-485 or SS-101; a titanyl oxide oligomer such as a n-butylene oxide tetramer manufactured by Kanto Chemical Co., Ltd.; These may be used alone or in combination of two or more.

Further, the leveling agent and the surfactant can be used by a known one, and in particular, a commercially available product is preferable because it is easily obtained.

Further, the method of mixing the above other components in the polyoxane (A) may be carried out simultaneously with the solution of the polyoxyalkylene (A) and the diol compound (B), or may be mixed after the mixing. There is no particular limitation.

<Modulation of liquid crystal alignment agent>

The method of preparing the liquid crystal alignment agent of the present invention is not particularly limited. The polysiloxane (A), the diol compound (B), the solvent (C), and other components may be uniformly mixed.

Usually, since the polyoxyalkylene (A) is polycondensed in a solvent, a solution state is obtained.

Therefore, the method of directly using the polymerization solution of the polyoxane (A) described above is a simple method. When the polymerization solvent of the polyoxyalkylene (A) is the diol compound (B) or the solvent (C), the diol compound (B) or the solvent (C) may not be added subsequently. Further, when the solution of the polyoxyalkylene (A) does not contain the diol compound (B) or the solvent (C), the diol compound (B) or the solvent (C) may be added and used in the preparation of the liquid crystal alignment agent.

When the liquid crystal alignment agent is blended, the concentration of SiO ₂ in the liquid crystal alignment agent is preferably from 0.5 to 15% by mass, more preferably from 1 to 6% by mass. When the SiO ₂ conversion concentration range is obtained, it is easy to obtain a desired film thickness by one application, and a sufficient solution storage life can be easily obtained.

In addition, at this time, at least one solvent selected from the group consisting of a polymerization solvent of polysiloxane (A), an additive solvent, and a diol compound (B) can be used as the solvent for adjusting the concentration in terms of SiO ₂ .

The viscosity of the liquid crystal alignment agent in the present invention is 1.8 to 18 mPa‧s measured by an E-type viscosity meter (for example, a viscometer TV-20 manufactured by Toki Sangyo Co., Ltd.), or the surface tension is in a hanging drop method (for example, a synergistic interface). It is preferable that the AUTO DISPENCER AD-3) manufactured by Science Co., Ltd. is 20 to 40 mN/m, and it is easy to form a good coating film by inkjet coating. More preferably, it is a liquid crystal alignment agent having the aforementioned viscosity and the aforementioned surface tension.

According to the present invention, by using the liquid crystal alignment agent, inkjet coating can form a liquid crystal alignment film having excellent in-plane uniformity of the liquid crystal alignment film and edge straightness of the film end portion.

<Liquid crystal alignment film and method of forming the same>

Examples of the coating method of the liquid crystal alignment agent for forming the liquid crystal alignment film include a spin coating method, a printing method, an inkjet coating method, a spray method, a roll coating method, and the like, but it is expected to further improve the productivity of the spray. The ink coating method is attracting attention.

The inkjet coating method is a method in which fine droplets are dropped on a substrate to form a film by liquid wetting.

The liquid crystal alignment agent of the present invention has good coatability, and can be stably applied when an inkjet coating method is used, and a liquid crystal alignment film can be obtained by the coating method. Moreover, after baking, it can be baked, and it can become a cured film.

In order to form a film more uniformly by the inkjet coating method, it is necessary to stably eject the liquid from the nozzle of the inkjet. One of the important reasons for making a liquid stable spray is related to the viscosity of the liquid. The liquid viscosity of the liquid crystal alignment agent varies depending on the inkjet coating device used, but it is preferably measured by an E-type viscometer (for example, a viscometer TV-20 manufactured by Toki Sangyo Co., Ltd.). The range of 18 mPa ‧ (measurement temperature 25 ° C). More preferably 3~15mPa‧s.

Further, the liquid surface tension, which is one of the important causes of the liquid crystal expansion of the drop, also has a large influence. The liquid surface tension of the liquid crystal alignment agent varies depending on the type of the material to be used, but is preferably 20 to 40 mN/m as measured by a hanging drop method (for example, AUTO DISPENCER AD-3 manufactured by Kyowa Interface Science Co., Ltd.). 25 ° C) range.

The liquid crystal alignment agent of the present invention preferably has a viscosity of 1.8 to 18 mPa ‧ (measuring temperature of 25 ° C) and a surface tension of 20 to 40 mN/m (measurement temperature of 25 ° C).

The drying step after the application of the liquid crystal alignment agent of the present invention is not necessarily required, but the time from the application to the time before the firing is not constant for each substrate, or is not immediately baked after coating, preferably. Contains a drying step. In the drying, the solvent may be removed to such an extent that the shape of the coating film is not deformed depending on the substrate transport or the like, and the drying method is not particularly limited. For example, it is dried on a hot plate at a temperature of 40 to 150 ° C, preferably 60 to 100 ° C for 0.5 to 30 minutes, preferably for 1 to 5 minutes.

The coating film formed by coating the liquid crystal alignment agent by the above method can be fired to form a cured film. In this case, the firing temperature may be carried out at a temperature of from 100 to 350 ° C, preferably from 140 to 300 ° C, more preferably from 150 to 230 ° C, and still more preferably from 160 to 220 ° C.

The polyoxyalkylene (A) in the liquid crystal alignment film is subjected to polycondensation in the firing step. However, in the present invention, it is not necessary to completely condense condensation within the range which does not impair the effects of the present invention. However, it is preferred to be fired at a high temperature higher than the heat treatment temperature of the sealant hardening or the like which is required in the production process of the liquid crystal cell by 10 ° C or higher.

The thickness of the cured film can be selected as needed. When the thickness of the cured film is 5 nm or more, it is preferable to obtain the reliability of the liquid crystal display element. More preferably 10 nm or more. Moreover, when it is 300 nm or less, it is preferable that the power consumption of the liquid crystal display element does not become extremely large. More preferably 150 nm or less.

Such a cured film can be directly used as a liquid crystal alignment film. However, the cured film is rubbed, irradiated with polarized light or light of a specific wavelength, and subjected to treatment with an ion beam or the like, and may be a liquid crystal alignment film.

Since the liquid crystal alignment film of the present invention formed by the above method exhibits high water repellency, good liquid crystal vertical alignment property can be obtained.

<Liquid crystal display element>

The liquid crystal display element of the present invention can be obtained by forming a liquid crystal alignment film on a substrate by the above method, and then forming a liquid crystal cell by a known method. For example, an example of the formation of a liquid crystal cell is generally a method in which a substrate of a liquid crystal alignment film is formed, a spacer is held, a sealant is fixed, a liquid crystal is injected, and the package is filled. At this time, the size of the spacer used is 1 to 30 μm, but preferably 2 to 10 μm. The method of injecting the liquid crystal is not particularly limited, and a vacuum method in which the liquid crystal cell to be produced is depressurized, and a liquid crystal is injected into the liquid crystal, or a dropping method in which the liquid crystal is dropped and then encapsulated is exemplified.

The substrate used for the liquid crystal display element is not particularly limited as long as it is a substrate having high transparency, but a substrate for forming a transparent electrode for driving liquid crystal is usually formed on the substrate.

As a specific example, there may be exemplified a glass plate; polycarbonate, poly(meth) acrylate, polyether oxime, polyacrylate, polyurethane, polyfluorene, polyether, polyether ketone, top three Forming on a plastic board such as pentene, polyolefin, polyethylene terephthalate, (meth)acrylonitrile, triacetyl cellulose, diethyl cellulose, acetate butyrate cellulose, etc. The substrate of the transparent electrode.

Further, regarding a high-performance element such as a TFT type liquid crystal display element, an element such as a transistor is formed between an electrode for driving a liquid crystal and a substrate. In the case of a transmissive liquid crystal display device, generally, the above-described substrate is used. However, in the reflective liquid crystal display device, an opaque substrate such as a germanium wafer may be used only for a single-sided substrate. At this time, a material such as aluminum which can reflect light can also be used for the electrode formed on the substrate.

Example

The following is more specifically illustrated by the examples of the invention, but should not be construed as being limited thereto.

Abbreviations of the compounds used in this example are as follows.

TEOS: tetraethoxy decane

C18: octadecyltriethoxydecane

UPS: 3-ureidopropyltriethoxydecane

HG: 2-methyl-2,4-pentanediol

BCS: 2-butoxyethanol

PB: 1-butoxy-2-propanol

1,3-BDO: 1,3-butanediol

MIBK: methyl isobutyl ketone

DEDE: Diethylene glycol diethyl ether

EDM: ethylene glycol dimethyl ether

C8OH: 1-octanol

<Synthesis Example 1>

To a 1 liter (L) four-necked reaction flask equipped with a thermometer and a reflux tube, 30.2 g of HG, 39.6 g of TEOS, and 4.2 g of C18 were placed, and a solution of the alkoxydecane monomer was stirred and stirred. In the solution, an oxalic acid solution obtained by mixing HG 15.1 g, water 10.8 g, and 0.2 g of oxalic acid as a catalyst was added dropwise thereto at room temperature for 30 minutes, and the mixture was stirred at room temperature for 30 minutes after the dropwise addition. Thereafter, the mixture was heated under reflux for 1 hour, and allowed to cool to obtain a polyoxane solution (K1) having a solid content concentration of 12% by mass in terms of SiO ₂ .

<Synthesis Example 2>

To a 1 L four-necked reaction flask equipped with a thermometer and a reflux tube, 30.2 g of BCS, 39.6 g of TEOS, and 4.2 g of C18 were placed, and a solution of the alkoxydecane monomer was stirred and stirred. In the solution, an oxalic acid solution obtained by mixing BCS 15.1 g, water 10.8 g, and 0.2 g of oxalic acid as a catalyst was added dropwise thereto at room temperature for 30 minutes, and the mixture was stirred at room temperature for 30 minutes after the completion of the dropwise addition. Thereafter, the mixture was heated under reflux for 1 hour, and allowed to cool to obtain a polyoxane solution (K2) having a solid content concentration of 12% by mass in terms of SiO ₂ .

<Synthesis Example 3>

To a 1 L four-necked reaction flask equipped with a thermometer and a reflux tube, 22.6 g of HG, 7.5 g of BCS, 39.6 g of TEOS, and 4.2 g of C18 were placed, and a solution of the alkoxydecane monomer was stirred and stirred. In this solution, an oxalic acid solution obtained by mixing HG 11.3 g, BCS 3.8 g, water 10.8 g, and 0.2 g of oxalic acid as a catalyst was added dropwise at room temperature for 30 minutes, and the mixture was added at room temperature after completion of the dropwise addition. Stir for 30 minutes. Thereafter, the mixture was heated under reflux for 1 hour, and allowed to cool to obtain a polyoxane solution (K3) having a solid content concentration of 12% by mass in terms of SiO ₂ .

<Synthesis Example 4>

To a 1 L four-necked reaction flask equipped with a thermometer and a reflux tube, HG 29.9 g, TEOS 39.2 g, and C18 4.2 g were placed, and a solution of the alkoxydecane monomer was stirred and stirred. In the solution, an oxalic acid solution obtained by mixing HG 14.9 g, water 10.8 g, and 0.2 g of oxalic acid as a catalyst was added dropwise thereto at room temperature for 30 minutes, and the mixture was stirred at room temperature for 30 minutes after the dropwise addition. Thereafter, after heating under reflux for 30 minutes, a mixed solution of a UPS 92% by mass methanol solution of 0.57 g and HG 0.32 g was added, and further, after superheating under reflux for 30 minutes, the mixture was allowed to cool to obtain a solid content concentration of 12 by mass in terms of SiO _{2 .} % polyoxane solution (K4).

The alkoxydecane and solvent used in each of the synthesis examples are summarized in Table 1.

<Examples 1 to 5, Comparative Example 1>

50 g of the polyaluminoxane solution (K1) obtained in Synthesis Example 1 was mixed with each solvent so as to have a solvent composition shown in Table 2, and a liquid crystal alignment agent having a solid content concentration of 3% by mass in terms of SiO ₂ (KL1~) was obtained. KL5, KM1).

<Example 6>

50 g of the polyaluminoxane solution (K4) obtained in Synthesis Example 4 was mixed with each solvent so as to have a solvent composition shown in Table 2, and a liquid crystal alignment agent (KL6) having a solid content concentration of 3% by mass in terms of SiO ₂ was obtained. .

<Comparative Example 2>

50 g of the polyaluminoxane solution (K2) obtained in Synthesis Example 2 and 150 g of BCS were mixed and stirred to obtain a liquid crystal alignment agent (KM2) having a solid content concentration of 3% by mass in terms of SiO ₂ .

<Comparative Example 3>

50 g of the polyaluminoxane solution (K2) obtained in Synthesis Example 3 was mixed with HG 34.8 g and BCS 115.2 g, and stirred to adjust the solvent composition so that the mass ratio became HG:BCS=30:70, and SiO ₂ conversion solid was obtained. A liquid crystal alignment agent (KM3) having a component concentration of 3% by mass.

Table 2 shows the liquid crystal alignment agents of Examples 1 to 6 and Comparative Examples 1 to 3, and the contents thereof are summarized in Table 2.

The solution viscosity and surface tension of the liquid crystal alignment agents obtained in Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 3. The solution viscosity and surface tension of the liquid crystal alignment agent were measured by the following methods.

[solution viscosity]

The measurement was carried out at a temperature of 25 ° C using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TV-20).

[Surface Tension]

The measurement was carried out using AUTO DISPENCER AD-3 manufactured by Kyowa Interface Chemical Co., Ltd.

[Inkjet coating]

The liquid crystal alignment agent was applied onto the substrate by using the following inkjet apparatus and coating conditions, followed by drying to prepare a liquid crystal alignment film.

Device name: Micro-pattern coating device HIS200-1H (manufactured by Hitachi PLANT TECHNOLOGY)

Coated substrate: 100×100mm ITO substrate

Coating area: 30×40mm

Coating conditions: decomposition energy 25 μm, phase speed 50 mm/sec, frequency 1000 Hz, pulse width 9.6 μsec, droplet amount 42 pl, pitch width 70.5 μm, pitch length 125 μm, applied voltage 14V to 19V (adjusted to a film thickness of 100 nm) ), nozzle gap 0.5 mm, homogenization time 30 seconds, drying temperature 60 ° C, drying time 2 minutes (heating plate).

[Coating property evaluation]

The liquid crystal alignment film obtained above was visually observed and observed under a microscope to confirm the coatability. The results are shown in Table 4.

Whether or not film formation is possible: ○ for the film without defects and XX for the film without defects.

In-plane uniformity: ○ in the film surface uniformity, and × in the case of grapefruit skin markings or linear markings.

Edge straightness: those who are very straightforward are recorded as ○, and those who lack straightness are recorded as ×.

As is clear from Table 4, in Comparative Example 1, film formation was impossible, and in Examples 1 to 6, the in-plane uniformity and edge straightness of the liquid crystal alignment film were good as compared with Comparative Examples 2 and 3, and the coating property was improved.

[Production of liquid crystal cell]

Two glass substrates with transparent electrodes formed on the liquid crystal alignment film were prepared, and a spacer having a particle diameter of 6 μm was spread on the liquid crystal alignment film surface of one substrate, and then epoxy resin was coated on the outer edge portion of the substrate by screen printing. After the subsequent treatment, the liquid crystal alignment film is bonded to the opposite side to be pressed together, and then hardened to form an empty liquid crystal cell. In this empty liquid crystal cell, MLC-6608 (trade name) manufactured by Merck Co., Ltd. was injected by a vacuum injection method, and then a liquid crystal cell (element) was produced by encapsulating an injection hole with a UV curable resin.

In the examples, the coating film was formed by the method described in the above [Inkjet Coating], dried on a hot plate at a temperature of 80 ° C for 5 minutes, and then fired in a hot air circulating type clean oven at a temperature of 200 ° C. A liquid crystal alignment film having a film thickness of 80 nm obtained in 60 minutes. Further, in the comparative example, a liquid crystal alignment film having a film thickness of 80 nm obtained by the same method as that of the Example except that the spin coating method was used instead of the inkjet coating was used.

[Liquid alignment]

The liquid crystal cell produced by the above method for producing [liquid crystal cell] was observed under a polarizing microscope to confirm the alignment state of the liquid crystal. When the liquid crystal cell showed no defect and the uniform alignment state was recorded as ○, when one of the liquid crystal cells was found to be defective and when it was not vertically aligned, it was marked as ×. The results are shown in Table 5.

[Contact angle]

On the liquid crystal alignment film, 3 μl of pure water was dropped, and the contact angle was measured using an automatic contact angle meter (manufactured by Kyowa Interface Chemical Co., Ltd., CA-Z type). The results are shown in Table 5.

In the examples, the coating film was formed by the method described in the above [Inkjet Coating], dried on a hot plate at a temperature of 80 ° C for 5 minutes, and then fired in a hot air circulating type clean oven at a temperature of 200 ° C. A liquid crystal alignment film having a film thickness of 80 nm obtained in 60 minutes. Further, in the reference example, a liquid crystal alignment film having a film thickness of 80 nm obtained by the same method as that of the Example except that the spin coating method was used instead of the inkjet coating was used.

As is clear from Table 5, the liquid crystal alignment film obtained by the inkjet coating method also showed the same vertical alignment property as the liquid crystal alignment film obtained by other coating methods.

[Industry possible use]

The liquid crystal alignment film obtained by the liquid crystal alignment agent for inkjet coating of the present invention is excellent in the in-plane uniformity of the film and the edge straightness of the film end portion, so that the liquid crystal display element using the same can be preferably used as a high reliability. Liquid crystal display device.

The entire disclosure of the specification, the patent application, and the abstract of the Japanese Patent Application No. 2008-334176, filed on Dec.

Claims (7)

A liquid crystal alignment agent for inkjet coating, which comprises the following polyoxyalkylene oxide (A), a diol solvent (B) described below, and a solvent (C) described below, with respect to a polyoxyalkylene oxide (A) 100 parts by mass of the total amount of ruthenium atoms converted to SiO ₂ , 120 to 17,000 parts by mass of the diol solvent (B), and 120 to 17,000 parts by mass of the solvent (C); A): Any one of the following polyoxyalkylenes, which is obtained by polycondensation of an alkoxydecane having an alkoxydecane represented by the formula (1), R ¹ Si(OR ² ) ₃ ( 1) (R ¹ represents a hydrocarbon group having 8 to 30 carbon atoms which may be substituted by a fluorine atom, R ² represents a hydrocarbon group having 1 to 5 carbon atoms), or contains an alkoxydecane represented by the formula (1) and the following formula ( 2) A polyoxyalkylene obtained by polycondensation of an alkoxydecane represented by an alkoxydecane, (R ³ ) _n Si(OR ⁴ ) _4-n (2) (R ³ represents a hydrogen atom or a carbon number of 1~ 7 a hydrocarbon group, R ⁴ represents a hydrocarbon group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, or an alkoxydecane represented by the formula (1) and an alkoxydecane represented by the following formula (3) the alkoxy silane-obtained by polycondensation of alkyl poly silicon _{^{oxide, Si (OR 4) 4 (}} 3) (R 4 represents a hydrocarbon group having 1 to 5 carbon atoms of); two Solvent (B): 2-methyl-2,4-pentanediol; solvent (C): a compound selected from the group consisting of formula (T1), formula (T2) or formula (T3), ketone having 3 to 6 carbons and More than one solvent consisting of a group of 5 to 12 carbon atoms: [wherein, X ₁ , X ₃ and X _{5 are} each independently an alkyl group having 1 to 4 carbon atoms, and X ₂ and X _{6 are} each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X ₄ is a carbon number of 1 An alkyl group of ~4, P is an alkyl group having 1 to 3 carbon atoms, and m, n, j, and k are each independently an integer of 1 to 3, and h is an integer of 2 or 3. The liquid crystal alignment agent for inkjet coating according to the first aspect of the invention, wherein X ₂ in the above formula (T1) is a hydrogen atom. 1. The liquid crystal alignment agent for inkjet coating according to claim 1 or 2, wherein the liquid crystal alignment agent has a viscosity of 1.8 to 18 mPa. s. The liquid crystal alignment agent for inkjet coating according to the first or second aspect of the invention, wherein the liquid crystal alignment agent has a surface tension of 20 to 40 mN/m. A liquid crystal alignment film which is characterized by using an ink jet apparatus and coating a liquid crystal alignment agent for inkjet coating according to any one of claims 1 to 4. It is placed on a substrate and fired. A method for forming a liquid crystal alignment film, which is characterized in that the liquid crystal alignment agent for inkjet coating according to any one of claims 1 to 4 is applied onto a substrate by an inkjet device, and is obtained by firing. By. A liquid crystal display element characterized by having a liquid crystal alignment film of claim 5 of the patent application.