KR102313135B1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Abstract

(Project) It is excellent in the printability by the inkjet coating method, and is providing the liquid crystal aligning agent which provides the liquid crystal aligning film excellent in electrical properties.
(Solution means) A liquid crystal aligning agent containing at least 1 sort(s) of polymer (A) selected from the group which consists of polyamic acid obtained by making tetracarboxylic dianhydride and diamine react, a polyimide, and polyamic acid ester, and a solvent, the said The liquid crystal aligning agent in which a solvent contains at least 1 sort(s) chosen from the group which consists of diethylene glycol propyl methyl ether and diethylene glycol butyl methyl ether is provided.

Description

A liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element {LIQUID CRYSTAL ALIGNING AGENT, LIQUID CRYSTAL ALIGNMENT FILM AND LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element. In more detail, it is related with the liquid crystal display element excellent in the liquid crystal aligning agent which provides a liquid crystal aligning film with favorable applicability|paintability especially in the inkjet coating method, and an electrical property.

Currently, as a liquid crystal display element, a liquid crystal aligning film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate on which a transparent conductive film such as ITO (indium oxide-tin oxide) is formed to obtain a substrate for a liquid crystal display element, the 2 The sheets are arranged to face each other, and a layer of nematic liquid crystal having positive dielectric anisotropy is formed in the gap between the substrates to form a cell of a sandwich structure, and the long axis of the liquid crystal molecules moves from one substrate to the other. A TN type liquid crystal display element having a so-called TN (Twisted Nematic) type liquid crystal cell that is continuously twisted toward a substrate by 90° is known. Moreover, the STN (Super Twisted Nematic) type liquid crystal display element with high contrast and little visual dependence compared with a TN type liquid crystal display element has been developed. This STN type liquid crystal display device uses a liquid crystal obtained by blending a chiral agent, which is an optically active material, with a nematic liquid crystal, and the long axis of liquid crystal molecules is continuously twisted over 180° or more between substrates. It uses the double refraction effect.

In addition, in recent years, two electrodes for driving liquid crystal are disposed in a comb-tooth shape on one of a pair of substrates, and an electric field parallel to the surface of the substrate is generated to control liquid crystal molecules. is being proposed This element is generally called an in-plane switching type (IPS type), and it is known that the viewing angle is excellent and wide. In particular, when an IPS-type device is used in combination with an optical compensation film, viewing angle characteristics can be further improved, and a wide viewing angle comparable to a cathode-ray tube can be obtained without gradation inversion or color tone change.

In addition to these, a vertically aligned liquid crystal display device called a multi-domain vertical alignment (MVA) method or a patterned vertical alignment (PVA) method in which liquid crystal molecules having negative dielectric anisotropy are vertically aligned on a substrate are proposed (see Patent Document 1 and Non-Patent Document 1). These vertical alignment system liquid crystal display elements are excellent in a viewing angle, contrast, etc., and it is excellent also in the point of a manufacturing process, such as not having to perform a rubbing process in formation of a liquid crystal aligning film.

In recent years, the spread of liquid crystal televisions is progressing, and a large line called the so-called "seventh generation" is operating. In addition, the construction of a larger "8th generation" line is also planned. Advantages of using a large line to increase the size of the substrate are that, since a plurality of panels are taken from one substrate, the process time can be reduced and the cost can be reduced, and it is possible to cope with the increase in the size of the liquid crystal display element itself. points can be mentioned. On the other hand, as a disadvantage of enlargement of a board|substrate, the point that it is difficult to ensure the uniformity of the printing of a liquid crystal aligning agent over a large area is mentioned. When film-forming over a large area is performed by the offset printing machine widely employ|adopted especially conventionally, the point which the problem of the electrical property of the liquid crystal aligning film resulting from the printing defect of a liquid crystal aligning agent may arise is mentioned.

In order to solve said problem, examination using the inkjet coating method for formation of a liquid crystal aligning film is made|formed. As an advantage of the inkjet coating method, since the liquid crystal aligning agent used in printing is substantially the same as the liquid amount apply|coated in reality, the point which can expect the usage-amount reduction of a liquid crystal aligning agent is mentioned. In addition, since the printing plate is not used, it is possible to reduce the time, effort and cost required for maintenance such as replacement or cleaning thereof becoming unnecessary, and the point of having flexibility to cope with various panel sizes.

Japanese Laid-Open Patent Publication No. 11-258605

「Liquid crystal」, Vol.3 (No.2), p117 (1999)

The large-sized board|substrate manufactured with a large-scale line WHEREIN: In order to manufacture a liquid crystal display element with a high yield, the inkjet coating method WHEREIN: The liquid crystal aligning agent excellent in printability is calculated|required more than ever. Moreover, the request|requirement for display quality improvement in recent years is becoming more strict. For example, with respect to an electrical characteristic, the liquid crystal aligning film which has the characteristic more than before is calculated|required.

This invention is made|formed based on said circumstances, and one of the objects is excellent in the printability by the inkjet coating method especially, and is providing the liquid crystal aligning agent which provides the liquid crystal aligning film excellent in electrical properties.

Further objects and advantages of the present invention will become apparent from the following description.

The above object and advantage of the present invention are first, as a liquid crystal aligning agent containing at least one polymer (A) selected from the group consisting of polyamic acid, polyimide and polyamic acid ester, and a solvent, It is achieved with the liquid crystal aligning agent characterized by containing at least 1 sort(s) chosen from the group which consists of diethylene glycol propyl methyl ether and diethylene glycol butyl methyl ether.

The said object and advantage of this invention are achieved by the liquid crystal display element provided with the liquid crystal aligning film obtained from said liquid crystal aligning agent secondly.

The liquid crystal aligning agent of this invention can improve the product yield in the manufacturing process by a large-scale line at the point excellent in applicability|paintability at the time of especially using for the inkjet coating method. Moreover, the liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention is excellent in an electrical property, and is suitable for applying to a liquid crystal display element.

(Form for implementing the invention)

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The liquid crystal aligning agent of this invention contains the at least 1 sort(s) of polymer (A) chosen from the group which consists of polyamic acid, a polyimide, and polyamic acid ester as a polymer component, The said polymer (A) is disperse|distributed to a solvent, or It is prepared as a liquid composition formed by dissolving.

«Polymer (A)»

<Polyamic acid>

The polyamic acid in this invention can be obtained by making tetracarboxylic dianhydride and diamine react.

(tetracarboxylic acid dianhydride)

As tetracarboxylic dianhydride used for the synthesis|combination of polyamic acid, aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, etc. are mentioned, for example. As specific examples thereof,

Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride;

As the alicyclic tetracarboxylic dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a,4, 5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4 ,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 3- Oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3 -furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-2 anhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-2anhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3 ,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride, etc.;

As aromatic tetracarboxylic dianhydride, For example, pyromellitic dianhydride etc.;

In addition to those mentioned respectively, the tetracarboxylic dianhydride of Unexamined-Japanese-Patent No. 2010-97188 can be used. In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

As tetracarboxylic dianhydride used for a synthesis|combination, it is preferable to contain alicyclic tetracarboxylic dianhydride from viewpoints, such as transparency and solubility to a solvent. Also, among the alicyclic tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5- Dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5- (tetrahydro -2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane- It is preferable to contain at least 1 sort(s) selected from the group which consists of 2:4,6:8-2 anhydride and 1,2,3,4- cyclobutanetetracarboxylic dianhydride, 2,3,5-tri Carboxycyclopentylacetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-2anhydride and 1,2,3,4-cyclobutanetetracarbon It is especially preferable to include at least 1 sort(s) selected from the group which consists of an acid dianhydride.

As the tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-2 When at least 1 sort(s) selected from the group which consists of anhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride are included, content of the sum total of these compounds is tetracarboxylic acid used for the synthesis|combination of polyamic acid. It is preferable that it is 10 mol% or more with respect to the whole quantity of a dianhydride, and it is more preferable that it is 20-100 mol%.

(diamine)

As diamine used for the synthesis|combination of polyamic acid, an aliphatic diamine, alicyclic diamine, aromatic diamine, diaminoorganosiloxane etc. are mentioned, for example. Specific examples of these diamines include, as aliphatic diamines, metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;

Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), 1,3-bis(aminomethyl)cyclohexane;

As the aromatic diamine, for example, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,2'-dimethyl -4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,7-diaminofluorene, 4,4'-diamino Diphenyl ether, 1,3-bis(4-aminophenoxy)propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl)fluorene , 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'- (p-phenylenediiso Propylidene) bisaniline, 4,4'-(m-phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy) Biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl- 3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)-benzidine, N,N'-Bis(4-aminophenyl)-N,N'-dimethylbenzidine, 1,4-bis-(4-aminophenyl)-piperazine, 1-(4-aminophenyl)-2,3- Dihydro-1,3,3-trimethyl-1H-inden-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine , 3,5-diaminobenzoic acid, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyl Oxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid cholestanyl, 3,5-diaminobenzoic acid cholestenyl, 3,5-dia Lanostanyl minobenzoate, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzoyloxy)cyclo Hexyl-3,5-diaminobenzoate, 4-(4'-trifluoromethylbenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl )phenyl)-4 -Butylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4- Heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, 2,4-diamino-N,N-diallylaniline, 4 -Aminobenzylamine, 3-aminobenzylamine and the formula (D-1):

(In formula (D-1), X ^I and X ^II are each independently a single bond, -O-, *-COO-, *-OCO-, or *-NH-CO- (provided that "*" the attached bond is bonded to a diaminophenyl group), R ^I and R ^II are each independently an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2; c is an integer from 1 to 20, n is 0 or 1, m is 0 or 1;

However, a and b do not simultaneously become 0, and when X ^I is *-NH-CO-, n is 0)

compounds represented by ;

As the diaminoorganosiloxane, for example, 1,3-bis(3-aminopropyl)-tetramethyldisiloxane etc. are mentioned, respectively, and the diamine of Unexamined-Japanese-Patent No. 2010-97188 is used. can In addition, these diamines can be used individually by 1 type or in combination of 2 or more types.

^{As a divalent group represented by "-X I} -(R ^I -X ^II ) _n -" in the formula (D-1), a C1-C3 alkanediyl group, *-O-, *-COO- , *-OC ₂ H ₄ -O- or *-NH-CO- (however, the bond attached to "*" bonds to a diaminophenyl group).

As a specific example of the group "-C _c H _{2c +1} ", for example, a methyl group, an ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group , n-nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group Real group, n-nonadecyl group, n-eicosyl group, etc. are mentioned. It is preferable that two amino groups in a diaminophenyl group exist at the 2,4-position or 3,5-position with respect to another group.

Specific examples of the compound represented by the formula (D-1) include compounds represented by each of the following formulas (D-1-1) to (D-1-4).

In addition, as diamine, 1 type of these compounds can be used individually or in combination of 2 or more type.

The diamine used when synthesizing the polyamic acid in the present invention preferably contains 30 mol% or more of aromatic diamine with respect to all diamines, more preferably 50 mol% or more, and contains 80 mol% or more It is particularly preferred.

When setting it as the liquid crystal aligning agent for liquid crystal display elements of TN type, STN type, or vertical alignment type, in order to provide favorable liquid-crystal orientation, what has a pretilt component may be used as diamine. As the diamine having such a pretilt component, as the pretilt component, an alkyl group having 4 to 20 carbon atoms, a fluoroalkyl group having 4 to 20 carbon atoms, an alkoxy group having 4 to 20 carbon atoms, a group having a steroid skeleton having 17 to 51 carbon atoms, and diamines having at least one selected from the group consisting of a group in which a plurality of rings are bonded directly or via a linking group. Specifically, for example, dodecaneoxy-2,4-diaminobenzene, tetradecanoxy-2,4-diaminobenzene, pentadecaneoxy-2,4-diaminobenzene, hexadecaneoxy-2,4 -diaminobenzene, octadecanoxy-2,4-diaminobenzene, dodecaneoxy-2,5-diaminobenzene, tetradecaneoxy-2,5-diaminobenzene, pentadecaneoxy-2,5-dia Minobenzene, hexadecaneoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-dia Minobenzene, cholestenyloxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid cholestanyl, 3,5-diaminobenzoic acid cholestenyl, 3,5-diaminobenzoic acid lanostanyl, 3 ,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-dia Minobenzoate, 4-(4'-trifluoromethylbenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butyl Cyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclo hexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, diamine represented by the said formula (D-1), etc. are mentioned. In addition, the diamine which has a pretilt component can be used individually by 1 type or in combination of 2 or more type.

It is preferable that the total amount contains 5 mol% or more with respect to all the diamines, and, as for the diamine which has a pretilt component, it is more preferable to contain 10 mol% or more.

When liquid-crystal orientation is provided with respect to the coating film produced using the liquid crystal aligning agent of this invention by the photo-alignment method, a part or all of the polymer (A) used for preparation of the liquid crystal aligning agent of this invention is a photo-alignment structure It is preferable to use a polymer having Here, the photo-alignment structure is a concept including both the photo-alignment group and the decomposition type photo-alignment unit. Specific examples of the photo-alignment structure include structures derived from various compounds exhibiting photo-alignment properties by photoisomerization, photodimerization, photolysis, etc., for example, azobenzene containing azobenzene or a derivative thereof as a basic skeleton. A group, a group having a cinnamic acid structure containing cinnamic acid or a derivative thereof as a basic skeleton, a chalcone-containing group containing a chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton; and a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a polyimide-containing structure containing a polyimide or a derivative thereof as a basic skeleton, and the like.

(Molecular weight modifier)

At the time of synthesizing polyamic acid, it is good also as synthesizing a terminal-modified polymer using an appropriate molecular weight modifier together with tetracarboxylic dianhydride and diamine as described above. By setting it as such a terminal modification type polymer, the applicability|paintability (printability) of a liquid crystal aligning agent can further be improved, without impairing the effect of this invention.

As a molecular weight modifier, an acid monhydride, a monoamine compound, a monoisocyanate compound, etc. are mentioned, for example. Specific examples of these are acid monoanhydrides, such as maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, and n-hexadecylsuccinic anhydride. My back;

As the monoamine compound, for example, aniline, cyclohexylamine, n-butylamine or the like;

As a monoisocyanate compound, phenyl isocyanate, naphthyl isocyanate, etc. are mentioned, respectively, for example.

It is preferable to set it as 20 weight part or less with respect to a total of 100 weight part of tetracarboxylic dianhydride and diamine to be used, and, as for the usage ratio of a molecular weight modifier, it is more preferable to set it as 10 weight part or less.

<Synthesis of polyamic acid>

The ratio of using tetracarboxylic dianhydride and diamine to be used in the synthesis reaction of polyamic acid is preferably such that the acid anhydride group of tetracarboxylic dianhydride is 0.2 to 2 equivalents with respect to 1 equivalent of the amino group of the diamine, 0.3 to The ratio used as 1.2 equivalent is more preferable.

The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. -20 degreeC - 150 degreeC are preferable and, as for the reaction temperature at this time, 0-100 degreeC is more preferable. Moreover, 0.1 to 24 hours are preferable and, as for reaction time, 0.5 to 12 hours are more preferable.

Here, examples of the organic solvent include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons.

Specific examples of these organic solvents include aprotic polar solvents, for example, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone. , N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphotriamide and the like;

As the phenolic solvent, for example, phenol, m-cresol, xylenol, halogenated phenol and the like;

Examples of the alcohol include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether;

As the ketone, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like;

As the ester, for example, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methylmethoxypropionate, ethylethoxypropionate, diethyl oxalate, diethyl malonate, isoamylpropionate , isoamyl isobutyrate and the like;

As the ether, for example, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol propyl methyl ether, diethylene glycol butyl methyl ether, tetrahydrofuran, diisopentyl ether, etc.;

As the halogenated hydrocarbon, for example, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene and the like;

As the hydrocarbon, for example, hexane, heptane, octane, benzene, toluene, xylene and the like;

each can be heard.

Among these organic solvents, at least one selected from the group consisting of aprotic polar solvents and phenolic solvents (hereinafter, organic solvent X), or at least one selected from organic solvent X, alcohols, ketones, esters, It is preferable to use a mixture with at least one selected from the group consisting of ethers, halogenated hydrocarbons and hydrocarbons (hereinafter, organic solvent Y). In the latter case, the proportion of the organic solvent Y used is preferably 50% by weight or less, more preferably 40% by weight or less, and still more preferably 30% by weight with respect to the total amount of the organic solvent X and the organic solvent Y. is below.

The amount of the organic solvent used (a) is preferably such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50 wt% with respect to the total amount (a+b) of the reaction solution.

As described above, a reaction solution obtained by dissolving polyamic acid is obtained. After this reaction solution may be used for preparation of a liquid crystal aligning agent as it is, after isolating the polyamic acid contained in a reaction solution, you may provide for preparation of a liquid crystal aligning agent, or after refining the isolated polyamic acid, preparation of a liquid crystal aligning agent may be provided to When polyamic acid is subjected to dehydration ring closure to obtain a polyimide, the reaction solution may be directly subjected to dehydration ring closure reaction, or polyamic acid contained in the reaction solution may be isolated and then subjected to dehydration ring closure reaction, or isolated polyamic acid After purification, it may be subjected to a dehydration ring closure reaction. Isolation and purification of polyamic acid can be performed according to a known method.

<Polyimide>

The polyimide contained in the liquid crystal aligning agent of this invention can be obtained by carrying out dehydration ring-closure of the polyamic acid synthesize|combined as mentioned above, and imidating it.

The polyimide may be a complete imidized product in which all of the amic acid structures of the polyamic acid precursor thereof are cyclized by dehydration, or a partial imidized product in which only a part of the amic acid structure is cyclized by dehydration and coexistence of the amic acid structure and the imide ring structure. is good too It is preferable that the imidation ratio of the polyimide in this invention is 30 % or more, It is more preferable that it is 40 to 99 %, It is more preferable that it is 50 to 99 %. This imidation ratio shows the ratio which the number of imide ring structures occupies with respect to the sum of the number of the male acid structures of a polyimide, and the number of imide ring structures in percentage. Here, an isoimide ring may be sufficient as a part of an imide ring.

The dehydration ring closure of the polyamic acid is preferably performed by heating the polyamic acid or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution and heating as necessary. . Among these, the latter method is preferable.

In the method of adding a dehydrating agent and a dehydration ring closure catalyst to the polyamic acid solution, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent to be used is preferably 0.01 to 20 moles with respect to 1 mole of the amic acid structure of the polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. It is preferable that the usage-amount of a dehydration ring-closure catalyst shall be 0.01-10 mol with respect to 1 mol of the dehydrating agent used. Examples of the organic solvent used for the dehydration ring closure reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0-180°C, more preferably 10-150°C. Reaction time becomes like this. Preferably it is 1.0 to 120 hours, More preferably, it is 2.0 to 30 hours.

In this way, the reaction solution containing a polyimide is obtained. After this reaction solution may be used for preparation of a liquid crystal aligning agent as it is, after removing a dehydrating agent and a dehydration ring closure catalyst from a reaction solution, it may provide for preparation of a liquid crystal aligning agent, and after isolating a polyimide, it uses for preparation of a liquid crystal aligning agent Or you may use for preparation of a liquid crystal aligning agent, after refine|purifying the isolated polyimide. These purification operations can be performed according to a known method.

<Polyamic acid ester>

The polyamic acid ester contained in the liquid crystal aligning agent of this invention is synthesize|combined by, for example, [I] making the polyamic acid obtained by the said synthesis reaction react with a hydroxyl-containing compound, a halide, an epoxy-group-containing compound, etc., [ II] A method of reacting a tetracarboxylic acid diester with diamine, and [III] A method of reacting a tetracarboxylic acid diester dihalide with diamine.

Here, as a hydroxyl-containing compound used by method [I], For example, Alcohol, such as methanol, ethanol, and a propanol;

Phenols, such as a phenol and cresol, etc. are mentioned. Examples of the halide include methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane, and the like, and an epoxy group-containing compound As an example, propylene oxide etc. are mentioned. The tetracarboxylic acid diester used in method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the synthesis of the polyamic acid using the alcohols described above. Further, the tetracarboxylic acid diester dihalide used in method [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with a suitable chlorinating agent such as thionyl chloride. As the diamine used in Methods [II] and [III], the diamine etc. exemplified in the synthesis of the polyamic acid can be used. In addition, the polyamic acid ester may have only a dark acid ester structure, and the partial esterification product in which a dark acid structure and a dark acid ester structure coexist may be sufficient as it.

After the reaction solution containing polyamic acid ester may be used for preparation of a liquid crystal aligning agent as it is, and after removing a dehydrating agent and a dehydration ring closure catalyst from a reaction solution, you may provide for preparation of a liquid crystal aligning agent, after isolating polyamic acid ester, liquid crystal You may use for preparation of an aligning agent, or after refine|purifying the isolated polyamic acid ester, you may use for preparation of a liquid crystal aligning agent. These purification operations can be performed according to a known method.

<Solution viscosity, reduced viscosity and weight average molecular weight>

The polyamic acid, polyimide, and polyamic acid ester obtained as described above preferably have a solution viscosity of 10 to 800 mPa·s, and a solution viscosity of 15 to 500 mPa·s when this is a solution having a concentration of 10% by weight. It is more preferable to have In addition, the solution viscosity (mPa*s) of the said polymer is 10 weight by weight of the concentration prepared using the positive solvent (for example, gamma -butyrolactone, N-methyl-2-pyrrolidone, etc.) of the said polymer. It is the value measured at 25 degreeC with respect to the polymer solution of % using the E-type rotational viscometer.

Although the reduced viscosity is not particularly limited as long as it is a range capable of forming a uniform coating film, it is preferably 0.05 to 3.0 dl/g, more preferably 0.1 to 2.5 dl/g, and 0.3 to 1.5 dl/g. more preferably.

It is preferable that the weight average molecular weights of polystyrene conversion measured by gel permeation chromatography (GPC) about the polyamic acid, a polyimide, and polyamic acid ester made to contain in the liquid crystal aligning agent of this invention are 500-100,000, 1,000- It is more preferable that it is 50,000.

≪Solvent≫

The liquid crystal aligning agent of this invention contains at least 1 sort(s) (henceforth a specific solvent (B)) chosen from the group which consists of diethylene glycol propyl methyl ether and diethylene glycol butyl methyl ether as a solvent component. By containing such a specific solvent (B) in a liquid crystal aligning agent, it becomes the thing excellent in the printability in especially the inkjet coating method.

With respect to the specific solvent (B), as diethylene glycol propyl methyl ether, the propyl group may be either linear or branched, and specifically, diethylene glycol n-propyl methyl ether and diethylene glycol isopropyl methyl ether. can be heard Preferably, it is diethylene glycol isopropyl methyl ether. Further, as the diethylene glycol butyl methyl ether, the butyl group portion may be either linear or branched, and specifically, diethylene glycol n-butyl methyl ether, diethylene glycol isobutyl methyl ether, diethylene glycol sec -Butyl methyl ether, etc. are mentioned. Preferably, it is diethylene glycol n-butylmethyl ether. In addition, a specific solvent (B) can be used individually by 1 type or in combination of 2 or more type.

(Other solvents)

It is preferable that the liquid crystal aligning agent of this invention contains other solvents other than the said specific solvent (B) as a solvent component. As said other solvent, the solvent (henceforth a "1st solvent") which can melt|dissolve the polymer (A) contained in the liquid crystal aligning agent of this invention, the said specific solvent as a poor solvent of the said polymer (A) and organic solvents other than (B).

The first solvent may be a good solvent for the polymer (A), and preferred specific examples thereof include, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and N-pentyl-2. -pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, N,N,2-trimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, γ-butyrolactone, N,N -Dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, tetramethylurea, hexamethylphosphotriamide , m-cresol, and the like. In addition, a 1st solvent can use said thing individually by 1 type or in mixture of 2 or more types.

Further, as the poor solvent of the polymer (A), the organic solvent other than the specific solvent (B) is, for example, methyl 2-hydroxyisobutyrate, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxyprop. Cypionate, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), Ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether (DPM) , diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, ethylene carbonate, propylene carbonate, diacetone alcohol, diethylene glycol diethyl ether, diisopentyl ether, propylene glycol diacetate, and the like. The said organic solvent can be used individually by 1 type or in mixture of 2 or more types of said thing. In addition, below, as a poor solvent of the said polymer (A), the group which consists of organic solvents other than the said specific solvent (B), and the said specific solvent (B) is also called "2nd solvent."

From a viewpoint of suppressing precipitation of a polymer (A), the content rate (When using 2 or more types, the total amount) of a specific solvent (B) improves the printability by the inkjet coating method to a liquid crystal aligning agent It is preferable to set it as 90 weight% or less with respect to the total amount of the solvent contained. More preferably, it is 85 weight% or less, More preferably, it is 80 weight% or less, Especially preferably, it is 75 weight% or less. In addition, although the lower limit in particular of the said content rate is not restrict|limited, It is preferable to set it as 1 weight% or more.

To [ the content rate of the said 1st solvent / the whole quantity of the solvent contained in a liquid crystal aligning agent from a viewpoint of suppressing precipitation of a polymer (A) ], Preferably it is 5 weight% or more, More preferably, it is 10 weight%. or more, and more preferably 20 wt% or more. In addition, about the upper limit of the content rate of the said 1st solvent, from a viewpoint of acquiring the effect by addition of the said specific solvent (B) suitably with respect to the whole quantity of the solvent contained in a liquid crystal aligning agent, Preferably it is 95 weight % or less, more preferably 90 weight% or less, and still more preferably 85 weight% or less.

To [ the content rate of organic solvents other than the said specific solvent (B) ] in the said 2nd solvent with respect to the whole quantity of the solvent contained in a liquid crystal aligning agent, Preferably it is 80 weight% or less, More preferably, it is 70 weight% It is less than, More preferably, it is 50 weight% or less, Especially preferably, it is 30 weight% or less.

The ratio of the first solvent and the second solvent is preferably 0.03 times (by weight) or more, the amount of the second solvent used relative to the amount of the first solvent used from the viewpoint of improving the applicability to the substrate, It is more preferable to set it as 0.05 times (weight) or more. Moreover, from a viewpoint of suppressing precipitation of a polymer, it is preferable to set it as 2.5 times (weight) or less, and it is more preferable to set it as 2.0 times (weight) or less.

≪Other ingredients≫

Although the liquid crystal aligning agent of this invention contains the above polymer (A) and a solvent, it may contain other components as needed. Examples of such other components include other polymers other than the above polymer (A), compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy group-containing compounds”), functional silane compounds, and the like. have.

[Other polymers]

The above other polymers can be used for improving solution properties and electrical properties. Examples of such other polymers include polyester, polyamide, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-phenylmaleimide) derivative, poly(meth)acrylate, etc. . Among these, it is preferable that it is at least 1 sort(s) of polymer chosen from the group which consists of polyester, polysiloxane, and poly(meth)acrylate, and it is more preferable that it is polysiloxane.

Moreover, you may use the polymer which has a photo-alignment structure as said other polymer. It is preferable to set it as the polymer which has a photo-alignment group specifically, and it is more preferable to set it as the polymer into which the group which has a cinnamic acid structure as a photo-alignment group was introduce|transduced. Among these, polysiloxane having a cinnamic acid structure can be preferably used from the viewpoint of easy introduction of the photo-alignment group to the polymer.

In addition, the polymer which has a photo-alignment group can be synthesize|combined by a conventionally well-known method. For example, polysiloxane having a photo-alignment group is prepared by reacting polysiloxane having an epoxy group and carbonic acid having a photo-alignment group in an organic solvent such as ether, ester, or ketone in the presence of a catalyst such as a quaternary ammonium salt. can be synthesized.

In detail, polysiloxane can be obtained by hydrolyzing and condensing a hydrolysable silane compound, for example. As a silane compound used for the synthesis|combination of polysiloxane, For example, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-aminopropyl Trimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(meth)acryl oxypropyl trimethoxysilane, vinyl trimethoxysilane, etc. are mentioned, One type of these can be used individually or in combination of 2 or more types.

The hydrolysis/condensation reaction can be carried out by reacting one or two or more of the above silane compounds with water, preferably in the presence of a suitable catalyst and organic solvent. In the hydrolysis/condensation reaction, the proportion of water used is preferably 0.5 to 100 moles, more preferably 1 to 30 moles, with respect to 1 mole of the silane compound (total amount).

Examples of the catalyst used in the hydrolysis/condensation reaction include an acid, an alkali metal compound, an organic base, a titanium compound, and a zirconium compound. The amount of the catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, etc., and should be set appropriately, for example, with respect to the total amount of the silane compound, preferably 0.01 to 3 moles, more preferably 0.05 to it is 1 fold

Examples of the organic solvent used in the hydrolysis/condensation reaction include hydrocarbons, ketones, esters, ethers, and alcohols. Among these, it is preferable to use a water-insoluble or poorly water-soluble organic solvent. The proportion of the organic solvent used is preferably 10 to 10,000 parts by weight, and more preferably 50 to 1,000 parts by weight with respect to 100 parts by weight in total of the silane compound used for the reaction.

It is preferable to carry out the said hydrolysis and condensation reaction by heating with an oil bath etc., for example. In the case of a hydrolysis/condensation reaction, it is preferable to make heating temperature into 130 degrees C or less, and it is more preferable to set it as 40-100 degreeC. It is preferable to set it as 0.5 to 12 hours, and, as for heating time, it is more preferable to set it as 1 to 8 hours. During heating, the liquid mixture may be stirred or may be placed under reflux. In addition, after completion of the reaction, it is preferable to wash the organic solvent layer separated from the reaction solution with water. In this washing|cleaning, it is preferable at the point which washing|cleaning operation becomes easy by washing|cleaning using the water (for example, about 0.2 weight% of ammonium nitrate aqueous solution etc.) containing a small amount of salt. Washing is performed until the water layer after washing becomes neutral, after that, the organic solvent layer is dried with a desiccant such as anhydrous calcium sulfate or molecular sieve if necessary, and then the solvent is removed to obtain polysiloxane. In addition, polysiloxane having a reactive group can be obtained by reacting the obtained polysiloxane with a reactive compound (eg, carboxylic acid having a photo-alignment group).

It is preferable that the weight average molecular weight (Mw) of polystyrene conversion measured by GPC exists in the range of 100-50,000, and, as for polysiloxane made into the liquid crystal aligning agent of this invention, it is more preferable to exist in the range of 200-10,000. When the weight average molecular weight of polysiloxane exists in the said range, when manufacturing a liquid crystal aligning film, it will be easy to handle, and the obtained liquid crystal aligning film will have sufficient material strength and a characteristic.

When adding said other polymer to a liquid crystal aligning agent, it is preferable to set it as 50 weight part or less with respect to 100 weight part of all the polymers in a liquid crystal aligning agent, and, as for the compounding ratio, it is more preferable to set it as 0.1-40 weight part, It is more preferable to set it as 0.1-30 weight part.

About the polymer component contained in the liquid crystal aligning agent of this invention, the following aspect is mentioned as a preferable aspect.

(I) An aspect containing only the polymer (A) as a polymer component.

(II) The aspect in which the polymer (A) and another polymer are contained as a polymer component, and the other polymer is polysiloxane.

Among these, the aspect of said (II) is preferable at a point with favorable electrical characteristics.

When containing polysiloxane in a liquid crystal aligning agent, it is preferable that the compounding ratio sets it as 0.5-90 weight part with respect to a total of 100 weight part of a polymer (A) from a viewpoint of fully acquiring the improvement effect of printability and an electrical property, , It is more preferable to set it as 1-85 weight part, and it is still more preferable to set it as 3-80 weight part.

[Epoxy group-containing compound]

An epoxy group containing compound can be used in order to improve the adhesiveness with the board|substrate surface in a liquid crystal aligning film. Here, as the epoxy group-containing compound, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, Dil ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol di Glycidyl ether, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N, N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidylbenzylamine, N,N-diglycidylaminomethylcyclohexane, N,N- Diglycidylcyclohexylamine etc. are mentioned.

When adding these epoxy-group containing compounds to a liquid crystal aligning agent, 40 weight part or less is preferable with respect to a total of 100 weight part of the polymer contained in the liquid crystal aligning agent, and, as for the compounding ratio, 0.1-30 weight part is more preferable.

[Functional Silane Compound]

The said functional silane compound can be used for the purpose of the printability improvement of a liquid crystal aligning agent. Examples of such a functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2 -Aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxy Silane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-tri Methoxysilyl-3,6-diazanonylacetate, 9-trimethoxysilyl-3,6-diazanonanoic acid methyl, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyl Trimethoxysilane, glycidoxymethyl trimethoxysilane, 2-glycidoxyethyl trimethoxysilane, 3-glycidoxy propyl trimethoxysilane, etc. are mentioned.

When adding these functional silane compounds to a liquid crystal aligning agent, 2 weight part or less is preferable with respect to a total of 100 weight part of a polymer, and, as for the compounding ratio, 0.02-0.2 weight part is more preferable.

Although the solid content concentration (the ratio which the total weight of components other than the solvent of a liquid crystal aligning agent occupies to the total weight of a liquid crystal aligning agent) in the liquid crystal aligning agent of this invention considers a viscosity, volatility, etc., it is selected suitably, Preferably is in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of this invention is apply|coated to the board|substrate surface so that it may mention later, Preferably, when heated, the coating film used as the coating film which is a liquid crystal aligning film or a liquid crystal aligning film is formed. At this time, when solid content concentration is less than 1 weight%, the film thickness of a coating film becomes too small and it is difficult to obtain a favorable liquid crystal aligning film. On the other hand, when solid content concentration exceeds 10 weight%, the film thickness of a coating film becomes excessive and it is hard to obtain a favorable liquid crystal aligning film, and the viscosity of a liquid crystal aligning agent increases and it becomes inferior to an application|coating characteristic.

The range of especially preferable solid content concentration changes with the method used when apply|coating a liquid crystal aligning agent to a board|substrate. For example, in the case of spin coating, a solid content concentration of 1.5 to 4.5 wt% is particularly preferable. In the case of the offset printing method, it is especially preferable to make the solid content concentration into the range of 3 to 9 weight%, and to make the solution viscosity into the range of 12 to 50 mPa·s accordingly. In the case of the inkjet printing method, it is particularly preferable to set the solid content concentration to be in the range of 1 to 8% by weight, and thereby the solution viscosity to be in the range of 3 to 20 mPa·s. The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

<Liquid crystal alignment film and liquid crystal display element>

The liquid crystal aligning film of this invention is formed with the liquid crystal aligning agent prepared as mentioned above. Moreover, the liquid crystal display element of this invention is equipped with the liquid crystal aligning film formed using the liquid crystal aligning agent of this invention. The drive mode to which the liquid crystal display element of this invention is applied is not specifically limited, It can apply to various drive modes, such as a TN type, STN type, IPS type, FFS type, VA type, and MVA type. Below, while demonstrating the manufacturing method of the liquid crystal display element of this invention, the manufacturing method of the liquid crystal aligning film of this invention is demonstrated in the description.

The liquid crystal display element of this invention can be manufactured by the process of the following (1)-(3), for example. In the step (1), the substrate used differs depending on the desired driving mode. Steps (2) and (3) are common to each drive mode.

[Step (1): Formation of a coating film]

First, a coating film is formed on a board|substrate by apply|coating the liquid crystal aligning agent of this invention on a board|substrate, and heating an application surface then.

(1-1) In the case of manufacturing a TN type, STN type, or VA type liquid crystal display element, two substrates on which a patterned transparent conductive film is formed are set as a pair, and the The liquid crystal aligning agent of the present invention is preferably applied by an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method, respectively. The liquid crystal aligning agent of this invention has the advantage which can exhibit especially favorable applicability|paintability (printability), when the inkjet printing method is employ|adopted as an application|coating method.

Here, as a board|substrate, For example, glass, such as float glass and soda glass;

A transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly(alicyclic olefin) can be used. As a transparent conductive film formed on one surface of the substrate, an NESA film (registered trademark of PPG Corporation in the United States) made of _{tin oxide (SnO 2 ), an ITO film made of indium oxide-tin oxide (In 2} O ₃ -SnO ₂ ), etc. are used. can To obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a method of using a mask having a desired pattern when forming the transparent conductive film, etc. have. At the time of application|coating of a liquid crystal aligning agent, in order to make the adhesiveness of a board|substrate surface and a transparent conductive film and a coating film more favorable, a functional silane compound, a functional titanium compound, etc. are added to the surface which should form a coating film among the board|substrate surface. You may perform the pre-processing which apply|coats in advance.

After application|coating of a liquid crystal aligning agent, for purposes, such as liquid flow prevention of the apply|coated aligning agent, Preferably, preliminary heating (pre-baking) is performed. Prebaking temperature becomes like this. Preferably it is 30-200 degreeC, More preferably, it is 40-150 degreeC, Especially preferably, it is 40-100 degreeC. Prebaking time becomes like this. Preferably it is 0.25 to 10 minutes, More preferably, it is 0.5 to 5 minutes. After that, the solvent is completely removed and, if necessary, a calcination (post-baking) step is performed for the purpose of thermal imidization of the amic acid structure present in the polymer. This baking (post-baking) temperature becomes like this. Preferably it is 80-300 degreeC, More preferably, it is 120-250 degreeC. Post-baking time becomes like this. Preferably it is 5 to 200 minutes, More preferably, it is 10 to 100 minutes. Thus, the film thickness of the film|membrane formed becomes like this. Preferably it is 0.001-1 micrometer, More preferably, it is 0.005-0.5 micrometer.

(1-2) When manufacturing an IPS type or FFS type liquid crystal display element, the electrode formation surface of the board|substrate on which the electrode which consists of the transparent conductive film or metal film patterned in the comb-tooth shape is formed, and the electrode which is not formed opposing A coating film is formed by apply|coating the liquid crystal aligning agent of this invention to one surface of a board|substrate, respectively, and heating each application surface then. At this time, the material of the substrate and the transparent conductive film used, the coating method, the heating conditions after application, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate and the preferable film thickness of the coating film to be formed are the same as in (1-1) above. As the metal film, for example, a film made of a metal such as chromium can be used.

In either case of said (1-1) and (1-2), after apply|coating a liquid crystal aligning agent on a board|substrate, the coating film used as an orientation film is formed by removing an organic solvent. At this time, when the polymer contained in the liquid crystal aligning agent of the present invention is a polyamic acid, a polyamic acid ester, or an imidized polymer having an imide ring structure and a amic acid structure, a dehydration ring closure reaction is performed by further heating after the formation of the coating film. It may advance and it is good also as a more imidized coating film.

[Step (2): Orientation ability imparting treatment]

When manufacturing the liquid crystal display element of TN type, STN type, IPS type, or FFS type, the process which provides liquid-crystal orientation ability to the coating film formed in the said process (1-1) is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. As the treatment for imparting liquid crystal alignment ability, a rubbing treatment in which the coating film is rubbed in a certain direction with a roll wound with a cloth made of, for example, nylon, rayon, cotton, or the like fiber, photo-alignment treatment in which the coating film is irradiated with polarized or non-polarized radiation and the like. On the other hand, when manufacturing a VA-type liquid crystal display element, although the coating film formed in the said process (1-1) can be used as a liquid crystal aligning film as it is, you may perform an orientation ability provision process with respect to the said coating film.

In the photo-alignment treatment, as the radiation to be irradiated to the coating film, for example, ultraviolet rays and visible rays containing light having a wavelength of 150 to 800 nm can be used. When the radiation is polarized light, linearly polarized light or partially polarized light may be sufficient. In the case where the radiation to be used is linearly polarized light or partially polarized light, irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination thereof. When irradiating a non-polarized radiation, the direction of irradiation is made into an oblique direction.

As a light source to be used, a low pressure mercury lamp, a high pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser etc. can be used, for example. Ultraviolet rays in a preferable wavelength range can be obtained by means of using a light source in combination with, for example, a filter, a diffraction grating, or the like. The radiation dose is preferably 100 to 50,000 J/m 2 , more preferably 300 to 20,000 J/m 2 . In addition, light irradiation to the coating film may be performed while heating the coating film in order to increase the reactivity. The temperature at the time of heating is 30-250 degreeC normally, Preferably it is 40-200 degreeC, More preferably, it is 50-150 degreeC.

In addition, with respect to the liquid crystal aligning film after the rubbing treatment, by irradiating an ultraviolet ray to a part of the liquid crystal aligning film, a process to change the pretilt angle of a part of the liquid crystal aligning film, or after forming a resist film on a part of the liquid crystal aligning film surface, After performing a rubbing process in the direction different from the previous rubbing process, you may perform the process which removes a resist film, so that a liquid crystal aligning film may have different liquid-crystal orientation ability for every area|region. In this case, it is possible to improve the viewing characteristic of the liquid crystal display element obtained. The liquid crystal aligning film suitable for a VA-type liquid crystal display element can be used suitably also for the liquid crystal display element of PSA(Polymer Sustained Alignment) type.

[Step (3): Construction of liquid crystal cell]

A liquid crystal cell is manufactured by preparing two board|substrates with a liquid crystal aligning film as mentioned above, and arrange|positioning a liquid crystal between the board|substrates of 2 sheets opposingly arranged. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.

The first method is a method known conventionally. First, two substrates are arranged to face each other through a gap (cell gap) so that each liquid crystal aligning film is opposed to each other, and the periphery of the two substrates is bonded using a sealing agent, and the substrate surface and partitioned by the sealing agent A liquid crystal cell can be manufactured by sealing an injection port after injecting and filling a liquid crystal in a cell gap. The second method is a method called an ODF (One Drop Fill) method. After apply|coating an ultraviolet-ray curable sealing compound to the predetermined place on one board|substrate among two board|substrates in which the liquid crystal aligning film was formed, for example, and further dripping a liquid crystal to predetermined several places on the liquid crystal aligning film surface, liquid crystal A liquid crystal cell can be manufactured by bonding the other board|substrate so that an alignment film may oppose, spreading a liquid crystal on the whole surface of a board|substrate, then irradiating ultraviolet light to the whole surface of a board|substrate and hardening a sealing compound. In any case, the liquid crystal cell produced as described above is heated to a temperature at which the used liquid crystal takes an isotropic phase, and then gradually cooled to room temperature to remove the flow orientation at the time of liquid crystal filling. desirable.

As a sealing agent, the epoxy resin etc. containing the aluminum oxide sphere as a hardening|curing agent and a spacer can be used, for example.

Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal, and among them, a nematic liquid crystal is preferable, for example, a Cipher base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, and an ester liquid crystal , terphenyl-based liquid crystal, biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, bicyclooctane-based liquid crystal, cuban-based liquid crystal, and the like can be used. Moreover, to these liquid crystals, For example, cholesteric liquid crystals, such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate;

Chiral agents marketed as "C-15" and "CB-15" (manufactured by Merck Corporation);

A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate to the outer surface of a liquid crystal cell. Examples of the polarizing plate bonded to the outer surface of the liquid crystal cell include a polarizing plate in which a polarizing film called “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched by a cellulose acetate protective film, or a polarizing plate composed of the H film itself. have. In addition, when rubbing process is performed with respect to a coating film, two board|substrates are opposingly arrange|positioned so that the rubbing direction in each coating film may become mutually predetermined angle, for example, orthogonal or antiparallel.

The liquid crystal display element of this invention can be effectively applied to various apparatuses, For example, a desk calculator, a wrist watch, a desk clock, a mobile phone, a counting board, a word processor, a personal computer, a liquid crystal television, a portable game. , car navigation systems, camcorders, PDAs, digital cameras, smartphones, and display devices such as various monitors.

[Example]

Hereinafter, the present invention will be described in more detail by way of Examples, but the present invention is not limited to these Examples.

[Weight Average Molecular Weight of Polymer]

A weight average molecular weight (Mw) is a polystyrene conversion value measured by the gel permeation chromatography in the following conditions.

Column: TSKgelGRCXLⅡ, manufactured by Tosoh Corporation

Solvent: tetrahydrofuran

Temperature: 40℃

Pressure: 68kgf/cm2

[Solution Viscosity of Polymer Solution]

The solution viscosity [mPa·s] of the polymer solution was measured at 25°C using an E-type rotational viscometer with respect to a solution prepared at a polymer concentration of 10% by weight using a predetermined solvent.

In addition, the required amounts of the raw material compound and the polymer used in the following examples were ensured by repeating the synthesis|combination of the raw material compound and polymer on the synthesis scale shown in the following synthesis example as needed.

[Synthesis of polyamic acid]

[Synthesis Example 1]

112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro- 157 g (0.50 mol) of 2,5-dioxo-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, and 95 g (0.88 mol) of p-phenylenediamine as a diamine compound , 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl 32 g (0.10 mol), 3,6-bis (4-aminobenzoyloxy) cholestane 6.4 g (0.010 mol) and 4.0 g (0.015 mol) of octadecaneoxy-2,5-diaminobenzene was dissolved in 960 g of N-methyl-2-pyrrolidone, and reacted at 60°C for 9 hours. A small amount of the obtained polyamic acid solution (PA-1) was aliquoted, and N-methyl-2-pyrrolidone was added thereto to obtain a solution having a concentration of 10% by weight, and the solution viscosity was 58 mPa·s.

[Synthesis of polyorganosiloxane having an epoxy group]

[Synthesis Example 2]

In a reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux cooling tube, 100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECETS), 500 g of methylisobutylketone and 10.0 g of triethylamine was added and mixed at room temperature. Next, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and then reacted at 80°C for 6 hours while mixing under reflux. After completion of the reaction, the organic layer was taken out, washed with 0.2 wt% ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to make polyorganosiloxane having an epoxy group viscous. It was obtained as a transparent liquid.

[Synthesis of photo-oriented polyorganosiloxane]

[Synthesis Example 3]

In a 100 mL three-neck flask, 9.3 g of polyorganosiloxane having an epoxy group obtained in Synthesis Example 2 above, 26 g of methyl isobutyl ketone, 3 g of the following cinnamic acid derivative (K-1) and a trade name “UCAT 18X” (San Apro Co., Ltd.) ) 0.10 g of the quaternary amine salt of manufacture) was put, and it stirred at 80 degreeC for 12 hours. After completion of the reaction, re-precipitation is performed with methanol, the precipitate is dissolved in ethyl acetate to obtain a solution, the solution is washed with water 3 times, the solvent is distilled off, and the photo-alignment polyorganosiloxane compound (S-1) was obtained as a white powder (6.3 g). The weight average molecular weight (Mw) of the photo-alignment polyorganosiloxane compound (S-1) was 3,500.

[Synthesis Example 4]

(Synthesis of compound (K-2))

To a 100 mL eggplant-type flask equipped with a reflux tube and a nitrogen introduction tube, 4.63 g of compound (A-1), 50 mL of thionyl chloride, and 0.05 mL of N,N-dimethylformamide were added, and the mixture was refluxed for 1 hour. After completion of the reaction, the mixture was dried to dryness by concentration under reduced pressure, and then 75 mL of tetrahydrofuran was added (set as (A-2) liquid). On the other hand, to a 100 mL three-necked flask equipped with a thermometer and a nitrogen inlet tube, 2.62 g of 4-hydroxycinnamic acid, 4.41 g of potassium carbonate, 38 mL of water, 19 mL of tetrahydrofuran and 0.15 g of tetrabutylammonium bromide were added to bring the temperature to 5° C. or less. was ice cold Then, after the (A-2) liquid prepared previously was dripped over 30 minutes, it returned to room temperature and stirred for 4 hours. After completion of the reaction, 100 mL of ethyl acetate and 200 mL of 1N hydrochloric acid were added and washed, followed by separation and washing three times with 100 mL of water. Then, the organic layer was dried over magnesium sulfate, filtered, concentrated under reduced pressure, and the precipitated white crystals were filtered and dried to obtain 1.8 g of compound (K-2).

[Synthesis Example 5]

(Synthesis of compound (K-3))

5.09 g of lithium chloride and 1.64 g of zinc chloride were put into the 300 mL three necked flask which put the stirring bar, and nitrogen substitution was carried out. After adding 120 mL of ethylene magnesium chloride-tetrahydrofuran 1 mol/L solution thereto and stirring at room temperature for 1 hour, it cooled to 0 degreeC, 12.6 g of cyclooctanone was dripped there, and it was made to react at room temperature for 15 hours. (referred to as (A-5) liquid). Then, saturated ammonium chloride aqueous solution was dripped at (A-5) liquid, 300 mL of ethyl acetate was added, ice bathing. The organic layer was separated and washed three times with 300 mL of water, and then the organic layer was dried with magnesium sulfate. Then, 11.7 g of compound (A-3) was obtained by concentrating by the rotary evaporator, distilling off a solvent, and distilling a residue.

10.9 g of compound (A-3) was put into the 300 mL three necked flask which put the stirring bar, and it ice-baked at 0 degreeC. 134 mL of n-butyllithium-hexane 1.6 mol/L solution was added dropwise thereto, and after stirring at 0° C. for 20 minutes, a solution in which 13.9 g of methyl 4-(chlorocarbonyl)benzoate was dissolved in 30 mL of tetrahydrofuran was added dropwise. , and stirred at 0°C for 2 hours. 5 mL of water was dripped there, and 200 mL of ethyl acetate was added. The organic layer was separated and washed three times with 300 mL of water, and then the organic layer was dried with magnesium sulfate. Then, 13.4g of compound (A-4) was obtained by concentration with a rotary evaporator.

To a 100 mL three-neck flask equipped with a stirrer, 9.55 g of compound (A-4), 30 g of methanol, 10 g of water, and 2.52 g of lithium hydroxide monohydrate were added, and after stirring at room temperature for 1 hour, 50 mL of ethyl acetate was added to the reaction solution. added The organic layer was separated and washed once with 10 mL of diluted hydrochloric acid and three times with 50 mL of water, and then the organic layer was dried with magnesium sulfate. Then, it concentrated with the rotary evaporator, and concentrated slowly until the internal content became 20 g, and the white solid which precipitated on the way was collect|recovered by filtration. 5.5 g of compound (K-3) was obtained by vacuum-drying this white solid.

[Synthesis Example 6]

In a 100 mL three-neck flask, 9.3 g of polyorganosiloxane having an epoxy group obtained in Synthesis Example 2, 26 g of methylisobutyl ketone, 5.8 g of compound (K-2) obtained in Synthesis Example 4, and a trade name “UCAT 18X” ( 0.10 g of a quaternary amine salt manufactured by San Apro Co., Ltd.) was put, and the mixture was stirred at 80°C for 12 hours. After completion of the reaction, re-precipitation is performed with methanol, the precipitate is dissolved in ethyl acetate to obtain a solution, the solution is washed with water 3 times, and the solvent is distilled off to distill off the photo-alignment polyorganosiloxane compound (S-2) was obtained as a white powder (9.1 g). The weight average molecular weight (Mw) of the photo-alignment polyorganosiloxane compound (S-2) was 3,600.

[Synthesis Example 7]

In a 100 mL three-necked flask, 9.3 g of polyorganosiloxane having an epoxy group obtained in Synthesis Example 2, 26 g of methylisobutyl ketone, 5.8 g of Compound (K-2) obtained in Synthesis Example 4, 5.8 g of Synthesis Example 5 1.8 g of compound (K-3) and 0.10 g of a brand name "UCAT 18X" (a quaternary amine salt manufactured by San Apro Co., Ltd.) were put, and it stirred at 80 degreeC for 12 hours. After completion of the reaction, reprecipitation is performed with methanol, the precipitate is dissolved in ethyl acetate to obtain a solution, and the solution is washed with water three times, and then the solvent is distilled off to distill off the photo-alignment polyorganosiloxane compound (S-3) was obtained as a white powder (6.3 g). The weight average molecular weight (Mw) of the photo-alignment polyorganosiloxane compound (S-3) was 3,500.

[Example 1]

To the polyamic acid solution (PA-1) obtained in Synthesis Example 1, 8 parts by weight of the photo-alignment polyorganosiloxane compound (S-1) obtained in Synthesis Example 3 based on 100 parts by weight of polyamic acid was added, and further N -Methyl-2-pyrrolidone and diethylene glycol isopropyl methyl ether were added, and the solvent composition was N-methyl-2-pyrrolidone: diethylene glycol isopropyl methyl ether = 30: 70 (weight ratio), solid content concentration It was set as the 3.0% solution. After filtering this with a filter with a pore diameter of 0.2 micrometer, it used for the following evaluation.

<Evaluation of inkjet applicability>

As a board|substrate which apply|coats a liquid crystal aligning agent, the glass substrate with a transparent electrode which consists of ITO is heated for 1 minute on a 200 degreeC hotplate, then ultraviolet-ray/ozone cleaning is performed, and immediately after making the contact angle of the water of the transparent electrode surface 10 degrees or less. used the one of

The liquid crystal aligning agent (the thing after filtration) prepared above was apply|coated on the transparent electrode surface of the said glass substrate with a transparent electrode using the inkjet coating machine (Shibaura Mechatronics Co., Ltd. product). The application conditions at this time were 2,500 times/(nozzle-minute), and the discharge amount was 250 mg/10 second, and 2 reciprocating (total 4 times) application|coating was made into it. After leaving still for 1 minute after application|coating, the coating film with an average film thickness of 0.1 micrometer was formed by heating. About the obtained coating film, it visually observed under irradiation of the interference-sign measuring lamp (sodium lamp), and evaluated the nonuniformity and the lump. The heating temperature is set to 50°C, 60°C, and 80°C, and the case where both unevenness and agglomeration are not seen at any temperature is defined as inkjet applicability "good A (double-circle)", and unevenness and/or agglomeration at one heating temperature “Good B (○)” when this was observed, “Possible (Δ)” when unevenness and/or agglomeration was observed at two heating temperatures, and “Bad (×)” when unevenness and/or agglomeration was observed at all heating temperatures. )" was made. The inkjet applicability|paintability of the liquid crystal aligning agent of this Example was "good|favorableness B (circle)."

<Production of liquid crystal cell>

The liquid crystal cell for evaluating the liquid-crystal orientation and voltage retention was manufactured as follows. In addition, manufacture of a liquid crystal cell WHEREIN: Although application|coating of a liquid crystal aligning agent was performed by the spin coating method, this is for enabling comparison with the comparative example of the later which is inferior to inkjet applicability|paintability.

The liquid crystal aligning agent (those after filtration) prepared above is applied by spin coating on the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film, prebaked on a hot plate at 80° C. for 1 minute, and then 200 By post-baking on a hotplate at °C for 10 minutes, a coating film having an average film thickness of 0.1 µm was formed. The same operation was repeated to manufacture a pair (two sheets) of the board|substrate which has a coating film on the transparent conductive film. Then, with respect to the substrate surface on the side having the coating film, using an Hg-Xe lamp and a Glan Taylor prism, polarized ultraviolet rays 1,000 J/m 2 are irradiated from the vertical direction of the substrate surface, and a liquid crystal aligning film having a film thickness of 0.1 µm A pair of substrates were obtained.

After applying an epoxy resin adhesive containing an aluminum oxide sphere having a diameter of 5.5 µm to each outer edge having a liquid crystal aligning film of the pair of substrates, bonding and pressing so that the liquid crystal aligning film surfaces face each other, the adhesive was cured . Next, a liquid crystal cell was manufactured by filling a nematic liquid crystal (Merck company make, MLC-6601) between a pair of board|substrates from a liquid crystal injection port, and sealing a liquid crystal injection port with an acrylic photocuring adhesive agent.

<Evaluation of voltage retention rate>

About the liquid crystal cell obtained above, after applying the voltage of 5V with the application time of 60 microseconds, and the span of 167 milliseconds, the voltage retention rate 167 milliseconds after application cancellation|release was measured. As the measuring device, a VHR-1 manufactured by Toyo Technica Corporation was used. When this value was 95% or more, the voltage retention ratio "Good A (double-circle)" was defined, when it was less than 95% and 93% or more, the voltage retention ratio "Good B (○)", and when it was less than 93%, the voltage retention ratio "possible" As a result of evaluating the case of ((triangle|delta))" and evaluation impossibility as voltage retention rate "bad (x)", the voltage retention ratio of the liquid crystal cell of this Example was "good A (double-circle)".

[Examples 2 to 11 and Comparative Examples 1 to 4, Comparative Example 6]

In the said Example 1, various evaluation was performed while carrying out similarly to Example 1 and preparing the liquid crystal aligning agent except having used the thing of the kind and quantity shown in following Table 1 for a polymer and a solvent, respectively. The evaluation results are shown in Table 1 below.

[Example 12 and Comparative Example 5]

Example 1, except that in Example 1, the polymers and solvents in the types and amounts shown in Table 1 were used, respectively, and in the production of the liquid crystal cell, rubbing treatment was performed instead of the photo-alignment treatment. Various evaluations were performed while carrying out similarly to and preparing a liquid crystal aligning agent. The rubbing treatment was performed using a rubbing machine having a roll wound with nylon cloth, at a rotation speed of 1,000 rpm, a moving speed of the stage of 25 mm/sec, and a bushy foot press-in length of 0.4 mm. The evaluation results are shown in Table 1 below.

In Table 1, the abbreviations of compounds have the following meanings, respectively.

IPDM: diethylene glycol isopropyl methyl ether

BDM: diethylene glycol n-butyl methyl ether

NMP: N-methyl-2-pyrrolidone

BC: Butyl Cellosolve

DPM: dipropylene glycol monomethyl ether

DEDG: diethylene glycol diethyl ether

As shown in Table 1, in all of Examples 1-12, the printability and voltage retention by the inkjet coating method were evaluation of "good A (double-circle)" or "good B (circle)". On the other hand, in the comparative example, at least one of the printability by the inkjet coating method and the voltage retention rate was inferior to that of an Example.

Claims (4)

As a liquid crystal aligning agent containing at least 1 sort(s) of polymer (A) selected from the group which consists of polyamic acid, a polyimide, and polyamic acid ester, and a solvent,
The solvent contains diethylene glycol propyl methyl ether or both diethylene glycol propyl methyl ether and diethylene glycol butyl methyl ether;
Furthermore, polysiloxane which has a photo-alignment group is contained, The liquid crystal aligning agent characterized by the above-mentioned. delete The liquid crystal aligning film formed using the liquid crystal aligning agent of Claim 1. A liquid crystal display element provided with the liquid crystal aligning film of Claim 3.