JP5637019B2 - Liquid crystal alignment agent - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent. More specifically, the present invention relates to a liquid crystal aligning agent suitably used for forming a liquid crystal alignment film used for a horizontal electric field type liquid crystal display element or a retardation film by a photo-alignment method.

In the liquid crystal display element, a liquid crystal alignment film is provided on the substrate surface in order to align liquid crystal molecules in a predetermined direction with respect to the substrate surface. This liquid crystal alignment film is usually formed by a method (rubbing method) in which the surface of the organic film formed on the substrate surface is rubbed in one direction with a cloth material such as rayon. The same applies to a horizontal electric field type liquid crystal display element. However, if the liquid crystal alignment film is formed by rubbing treatment, dust and static electricity are likely to be generated during the rubbing process, so that dust adheres to the alignment film surface and causes display defects. In the case of a substrate having a (Thin Film Transistor) element, there is also a problem that a circuit breakdown of the TFT element occurs due to the generated static electricity and causes a reduction in product yield. Therefore, as another means of aligning the liquid crystal in the liquid crystal cell, a photo-alignment method has been proposed in which a liquid-sensitive organic thin film formed on the substrate surface is irradiated with polarized or non-polarized radiation to impart liquid crystal alignment ability. (See Patent Documents 1 to 4). This photo-alignment method can form uniform liquid crystal alignment without generating dust or static electricity during the process. Furthermore, by using a suitable photomask during irradiation, liquid crystal alignment ability can be given only to an arbitrary region on the organic thin film, or irradiation with different irradiation directions or polarization axes is performed multiple times. It is also possible to form a plurality of regions having different liquid crystal alignment directions on a single organic thin film by combining the method of performing the method or the method of using such a method with the method using a photomask.
However, even if the liquid crystal alignment film formed by the photo-alignment method has a desired pretilt angle expression at the beginning of formation, the alignment state at the beginning of formation changes over time due to long-time voltage application. It has been pointed out that there is a need for improvement.

By the way, as a liquid crystal display element, in addition to a liquid crystal display element having a conventionally known TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, VA (Vertical Alignment) type, or the like, an IPS (Inside) -Known as a horizontal electric field type liquid crystal display element in which an electrode is formed only on one side of a pair of opposed substrates, such as a plane switching (FF) type or an FFS (Fringe Field Switching) type, and an electric field is generated parallel to the substrate. (Patent Documents 5 to 7 and Non-Patent Document 1). This horizontal electric field type liquid crystal display element has wider viewing angle characteristics than the conventional vertical electric field type liquid crystal display element in which electrodes are formed on both substrates to generate an electric field in a direction perpendicular to the substrate, and also has a high viewing angle characteristic. It is known that high quality display is possible. Since the horizontal electric field type liquid crystal display element responds to the electric field only in the direction in which the liquid crystal molecules are parallel to the substrate, the change in the refractive index in the major axis direction of the liquid crystal molecules is not a problem. There is little change in the contrast and the contrast of the displayed color, so that high-quality display is possible regardless of the viewing angle. In order to obtain such an advantageous effect, since it is advantageous that the incident angle dependency of incident polarized light is small, in the horizontal electric field type liquid crystal display element, in the initial alignment characteristics when no electric field is applied. A low pretilt angle is desired.
In such a horizontal electric field type liquid crystal display element, it is desirable to use the photo-alignment method in order to avoid the drawbacks of the rubbing method described above when imparting liquid crystal alignment properties to the liquid crystal alignment film. However, the liquid crystal aligning agent applicable to said photo-alignment method will contain an aromatic structure in a large ratio in order to provide photosensitivity to the polymer contained therein. However, when a liquid crystal alignment film containing an aromatic structure in a large proportion is used, the pretilt angle inevitably increases, and the advantageous effects as described above in the lateral electric field type display element are diminished.
Further, in a horizontal electric field type liquid crystal display element using a photo-alignment method, afterimages and image sticking may be problems, and improvements are desired. In particular, the difference in luminance generated on the screen due to the change in the orientation state over time is recognized as burn-in by the observer, and improvement thereof is urgent.
As described above, in a horizontal electric field type liquid crystal display element, the above-described advantageous effects can be sufficiently exhibited by the photo-alignment method, and a liquid crystal alignment film exhibiting improved afterimage characteristics and image sticking characteristics is formed. However, a liquid crystal aligning agent capable of achieving the above has not been known, and it is strongly desired to provide such a liquid crystal aligning agent.

In the liquid crystal display element, a retardation film is further used for the purpose of eliminating the color shift of display and the dependency of viewing angle (see Patent Documents 9 and 10).
Such a retardation film is manufactured by a method using a plastic film stretching process, a method of curing a polymerizable liquid crystal on a substrate, or the like. Among these, the retardation film manufactured by the latter method can have more complicated optical characteristics, and is extremely useful in a liquid crystal display device. In the method for curing the polymerizable liquid crystal, it is necessary to cure the polymerizable liquid crystal molecules in a state in which the polymerizable liquid crystal molecules are aligned in a predetermined direction with respect to the substrate surface. Generally, a method of forming a layer and curing the layer is generally used. When the liquid crystal alignment film is provided with the liquid crystal alignment ability, there is a problem similar to the above. Therefore, application of the photo-alignment method is also being studied in this field.
By the way, in recent years, a technique for expressing 3D (three-dimensional) video has been flourishing, and displays that can view 3D video for home use have been spreading. As a 3D video display method, for example, Patent Document 17 is arranged so that right-eye images and left-eye images form images with different polarization states, and the right eye and the left eye see only the respective polarization state images. A method using polarizing glasses including a polarizing plate has been proposed (see Patent Document 11). A stereoscopic image obtained by this method has no flicker, and an observer can appreciate the stereoscopic image by wearing light and inexpensive polarized glasses.

As a technique for forming an image in which the polarization state of the right-eye image and the left-eye image is different with a single display device, which is assumed as a 3D video display device for home use, the polarization axes are orthogonal to each other between adjacent pixels. There is known a system in which a mosaic-shaped polarizing layer is closely attached to the front surface of one display device and a viewer can observe a stereoscopic image by wearing polarized glasses.
As this polarizing layer, the use of a patterned retardation film patterned on the order of micrometers can be considered. As a method for producing such a patterned retardation film, for example, Patent Document 12 discloses a method of irradiating a photosensitive polymer layer with polarized light. However, the thermal stability of the photosensitive polymer layer by this technique is not sufficient, and there is a disadvantage that the contrast at the boundary between adjacent regions having different polarization states is insufficient.
As described above, in the field of retardation films, there is a strong desire to provide a material that maintains a stable polarization state and is excellent in contrast at the boundary between adjacent regions having different polarization states.

JP 2003-307736 A JP 2004-163646 A JP 2002-250924 A JP 2004-83810 A U.S. Pat. No. 5,928,733 JP 56-91277 A JP 2008-46184 A JP-A 63-291922 JP-A-4-229828 JP-A-4-258923 Japanese Patent No. 3461680 JP 2005-49865 A JP 2010-97188 A

“Liq. Cryst.”, Vol. 22, p379 (1996) "UV curable liquid crystal and its application", Liquid Crystal, Vol. 3, No. 1, 1999, pp34-42

The present invention has been made in view of the above circumstances, and the object thereof is when applied to a TN-type, STN-type, or horizontal electric field type liquid crystal display element, particularly when applied to a horizontal electric field type liquid crystal display element. Another object of the present invention is to provide a liquid crystal aligning agent capable of forming a liquid crystal alignment film capable of achieving both wide viewing angle characteristics, high-quality display and good image sticking characteristics by a photo-alignment method.
Another object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal aligning film for producing a retardation film in which the polarization state is stably maintained and the boundary contrast between adjacent regions having different polarization states is excellent. It is in.
Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are:
Following formula (1)

(In the formula (1), R is an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a halogen atom or a cyano group, a is an integer of 0 to 4, and “*” is a bond. Represents that.)
Is achieved a structure represented by the by the liquid crystal aligning agent containing a polymer having a main chain.

The liquid crystal aligning agent of the present invention is a photo-alignment liquid crystal alignment film that enables both wide viewing angle characteristics and high-quality display, and good image sticking characteristics, particularly when used in a horizontal electric field type liquid crystal display element. It can be formed by the method.
Accordingly, a horizontal electric field type liquid crystal display element comprising a liquid crystal alignment film formed from such a liquid crystal aligning agent has both a wide viewing angle characteristic and a high-quality display and a good image sticking characteristic. As a liquid crystal display element, for example, a liquid crystal display element used in a display device such as a watch, a portable game, a word processor, a notebook computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile phone, various monitors, a liquid crystal television, etc. Can be applied.
The liquid crystal aligning agent of the present invention can further provide a liquid crystal aligning film for a retardation film that maintains a stable polarization state and is excellent in contrast at the boundary between adjacent regions having different polarization states. The retardation film manufactured using the liquid crystal aligning film formed from the liquid crystal aligning agent of this invention is suitable as a retardation film used for the display apparatus for 3D image display.

It is explanatory drawing which shows the pattern of the electrically conductive film in the board | substrate which has a comb-tooth-shaped electrically conductive film used in the Example and the comparative example.

The liquid crystal aligning agent of this invention contains the polymer (henceforth a "specific polymer") which has a structure (henceforth "structure (1)") represented by the said Formula (1) in a principal chain . To do.
<Specific polymer>
R in the formula (1) is preferably an alkyl group having 1 to 4 carbon atoms or a halogen atom, and more preferably a methyl group or a fluorine atom. a is preferably 0 to 2, and more preferably 0 or 1.
In addition to the structure (1) as described above, the specific polymer in the present invention includes a methylene group or an alkylene group having 2 to 12 carbon atoms (provided that the alkylene group is a methylene group other than the end of the alkylene group and ( One or more of di) alkylmethylene groups are oxygen atoms, ester bonds, divalent alicyclic groups having 5 to 10 carbon atoms, arylene groups having 6 to 24 carbon atoms, dialkylsilylene groups, or 2 silicon atoms. It is preferable to further have a structure (hereinafter referred to as “structure (2)”) consisting of 10 to 10 dialkylsiloxyxylene groups. When the specific polymer further has such a structure, appropriate flexibility is imparted to the liquid crystal alignment film formed from the liquid crystal aligning agent containing the specific polymer, and as a result, excellent liquid crystal alignment properties are exhibited. This is preferable.
Examples of the divalent alicyclic group having 5 to 10 carbon atoms include a 1,4-cyclohexylene group;
Examples of the arylene group having 6 to 24 carbon atoms include a 1,3-phenylene group and a 1,4-phenylene group;
Examples of the dialkylsiloxyxylene group having 2 to 10 silicon atoms include the following formula:

(In the above formula, b is an integer of 1 to 8, c is an integer of 1 to 9, and "*" indicates a bond.)
And the like can be mentioned respectively.
Specific examples of the structure (2) include, for example, 1,2-ethylene group, 1,4-butylene group, 1,6-hexylene group, 1,8-octylene group, 1,10-decylene group, 1, 12-dodecylene group and the following formula

(In the above formula, “*” indicates a bond.)
The structure which consists of group represented by each of these can be mentioned.
As the structure (2) in the present invention, an alkylene group having 2 to 12 carbon atoms (provided that this alkylene group has at least one of a methylene group and a (di) alkylmethylene group located at a position other than the terminal of the alkylene group). , An oxygen atom, an ester bond, and a divalent alicyclic group having 5 to 10 carbon atoms may be substituted).
The content of the structure (1) in the specific polymer is preferably 5 × 10 ⁻⁴ to 4 × 10 ⁻³ mol / g, and preferably 1 × 10 ^{−3 to} 3.5 × 10 ⁻³ mol / g. It is more preferable that it is 1.5 × 10 ^{−3 to} 3 × 10 ⁻³ mol / g.
The content ratio of the structure (2) in the specific polymer is preferably 6 × 10 ⁻³ mol / g or less, more preferably 1 × 10 ^{−3 to} 6 × 10 ⁻³ mol / g, further it is preferably 1.5 × ^{10 -3} ~4 × ¹⁰ -3 mol / g.
The structure (1) in the specific polymer is located in the main chain of the polymer.
Structure (2) in the specific polymer, the main chain of the polymer, can be located in one or more locations selected from the side chains and ends, to be located in the main chain of the polymer, forming This is preferable in that the pretilt angle of the liquid crystal alignment film can be reduced.

As the main skeleton of the specific polymer in the present invention, for example, polyorganosiloxane, polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polysiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, Examples include poly (meth) acrylate, a reaction product of a polyfunctional carboxylic acid and a polyfunctional epoxy compound, and among these, a reaction product of a polyfunctional carboxylic acid and a polyfunctional epoxy compound is preferable.
The reaction product of the polyfunctional carboxylic acid and the polyfunctional epoxy compound as the specific polymer in the present invention may be produced by any method as long as it has the structure (1). It is a reaction product of a polyfunctional epoxy compound containing a diepoxy compound and a polyfunctional carboxylic acid containing a dicarboxylic acid having the structure (1). It is preferable from the viewpoint of being easy.
Hereafter, the manufacturing method of the preferable specific polymer in this invention is explained in full detail.

[Polyfunctional epoxy compound]
The polyfunctional epoxy compound used for producing the preferred specific polymer in the present invention includes a diepoxy compound. The diepoxy compound is a compound having two epoxy groups, and may be a compound in which the two epoxy groups are bonded, and further has the structure (2) as described above in addition to the two epoxy groups. It may be a compound. Diepoxy compound In addition to the two epoxy groups, the compound further having the structure (2) as described above is preferable because the obtained specific polymer has the structure (2) in addition to the structure (1).
Specific examples of such diepoxy compounds include compounds represented by the following formula (DE-1) as compounds in which two epoxy groups are bonded;
Examples of the compound having the above structure (2) in addition to the two epoxy groups include compounds represented by the following formulas (DE-2) to (DE-11).

A diepoxy compound may be used individually by 1 type, and 2 or more types may be mixed and used for it.
As the polyfunctional epoxy compound in the present invention, other polyfunctional epoxy compounds can be used in addition to the diepoxy compound as described above. Other polyfunctional epoxy compounds that can be used here are preferably compounds having three or more epoxy groups, more preferably compounds having three or four epoxy groups, for example trimethylolpropane tri Glycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl -4,4'-diaminodiphenylmethane and the like can be mentioned as preferred, and one or more selected from these can be used.
The use ratio of the diepoxy compound in the polyfunctional epoxy compound is preferably more than 0.5 mol, more preferably more than 0.5 mol and not more than 0.999 mol with respect to 1 mol of the polyfunctional epoxy compound in total. More preferably, it is more than 0.8 mol and not more than 0.998 mol, particularly preferably more than 0.9 mol and not more than 0.995 mol. By setting it as such a use ratio, the light-resistant heat resistance of the electrical property of the liquid crystal aligning film formed can be improved more without impairing the effect of this invention.

[Polyfunctional carboxylic acid]
The polyfunctional carboxylic acid used for producing a preferred specific polymer in the present invention is a compound having at least one of the above structure (1) and two carboxyl groups (dicarboxylic acid having the above structure (1)). , Hereinafter also simply referred to as “dicarboxylic acid”).
Examples of such dicarboxylic acids include the following formulas (DC-1) to (DC-4).

And the like, and the like.
Only one kind of dicarboxylic acid may be used alone, or two or more kinds thereof may be mixed and used.
As polyfunctional carboxylic acid in this invention, other polyfunctional carboxylic acid can be used with the above dicarboxylic acid. The other polyfunctional carboxylic acid that can be used here is a polyfunctional carboxylic acid not having the structure (1), preferably a compound having three or more carboxyl groups, and more preferably three. Or it is a compound which has four carboxyl groups.
Examples of such other polyfunctional carboxylic acids include trimellitic acid, pyromellitic acid, 1,3,5-tris (4-carboxyphenyl) benzene, 1,2,4-cyclohexanetricarboxylic acid, 4,5-cyclohexanetetracarboxylic acid and the like can be mentioned as preferred ones, and one or more selected from these can be used.
The use ratio of the dicarboxylic acid in the polyfunctional carboxylic acid is preferably more than 0.5 mol, more preferably more than 0.5 mol and not more than 0.999 mol with respect to 1 mol in total of the polyfunctional epoxy compound. More preferably, it is more than 0.8 mol and not more than 0.998 mol, particularly preferably more than 0.9 mol and not more than 0.995 mol. By setting it as such a use rate, the light-resistant heat resistance of an electrical property can be improved more without impairing the effect of this invention.

[Method for producing specific polymer]
A preferred specific polymer in the present invention can be obtained by reacting the polyfunctional epoxy compound as described above with a polyfunctional carboxylic acid, preferably in an appropriate organic solvent.
The use ratio of the polyfunctional epoxy compound and polyfunctional carboxylic acid in the production of the specific polymer should be 0.8 to 1.2 mol as the usage amount of the polyfunctional carboxylic acid with respect to 1 mol of the polyfunctional epoxy compound. Is preferable, and it is more preferable to set it as 0.9-1.1 mol.
Examples of the organic solvent that can be used in the reaction of the polyfunctional epoxy compound with the polyfunctional carboxylic acid include aliphatic hydrocarbons, phenolic solvents, ethers, esters, ketones, aprotic polar solvents, and the like. Among these, it is preferable to use a phenolic solvent or an aprotic polar solvent from the viewpoint of solubility of raw materials and products. Specific examples of the preferred organic solvent include m-cresol, xylenol, phenol, halogenated phenol and the like as the phenolic solvent;
Examples of aprotic polar solvents include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N, N-dimethylimidazolidinone, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexa Examples thereof include methylphosphotriamide and the like.
The organic solvent has a solid content concentration (a ratio in which the weight of components other than the organic solvent in the reaction solution occupies the total weight of the solution) is preferably 5% by weight or more, more preferably 10 to 50% by weight. Used in proportions.

Reaction of a polyfunctional epoxy compound and polyfunctional carboxylic acid can be performed in presence of a catalyst as needed. As such a catalyst, in addition to an organic base, a compound known as a so-called curing accelerator that accelerates the reaction between an epoxy compound and an acid anhydride can be used.
Examples of the organic base include primary and secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine, and pyrrole;
Tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, diazabicycloundecene;
A quaternary organic amine such as tetramethylammonium hydroxide can be used. Among these organic bases, tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine and 4-dimethylaminopyridine; quaternary organic amines such as tetramethylammonium hydroxide preferable.
Examples of the curing accelerator include tertiary amines such as benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, cyclohexyldimethylamine, and triethanolamine;

2-methylimidazole, 2-n-heptylimidazole, 2-n-undecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenyl Imidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1- (2-cyanoethyl) -2-methylimidazole, 1- (2-cyanoethyl) -2-n-undecylimidazole, 1- ( 2-cyanoethyl) -2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-di (Hydroxymethyl) imidazole, 1- (2-cyanoethyl) -2-fur Nyl-4,5-di [(2′-cyanoethoxy) methyl] imidazole, 1- (2-cyanoethyl) -2-n-undecylimidazolium trimellitate, 1- (2-cyanoethyl) -2-phenyl Imidazolium trimellitate, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')] ethyl-s -Triazine, 2,4-diamino-6- (2'-n-undecylimidazolyl) ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1 ' )] Ethyl-s-triazine, isocyanuric acid adduct of 2-methylimidazole, isocyanuric acid adduct of 2-phenylimidazole, 2,4-diamino-6- [2'-methyl] An imidazole compound such as an isocyanuric acid adduct of loumidazolyl- (1 ′)] ethyl-s-triazine;
Organophosphorus compounds such as diphenylphosphine, triphenylphosphine, triphenyl phosphite;

Benzyltriphenylphosphonium chloride, tetra-n-butylphosphonium bromide, methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide , Ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium acetate, tetra-n-butylphosphonium o, o-diethylphosphorodithionate, tetra-n-butylphosphonium benzotriazolate, tetra -N-butylphosphonium tetrafluoroborate, tetra-n-butylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate Such bets quaternary phosphonium salts;
Diazabicycloalkenes such as 1,8-diazabicyclo [5.4.0] undecene-7 and organic acid salts thereof;
Organometallic compounds such as zinc octylate, tin octylate, aluminum acetylacetone complex;
Quaternary ammonium salts such as tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, tetra-n-butylammonium chloride;
Boron compounds such as boron trifluoride and triphenyl borate;
Metal halides such as zinc chloride and stannic chloride;
Examples include latent curing accelerators such as high melting point dispersion type latent curing accelerators, microcapsule type latent curing accelerators, and thermal cationic polymerization type latent curing accelerators. Examples of the high melting point dispersion type latent curing accelerator include amine addition type accelerators such as dicyandiamide and an adduct of an amine and an epoxy resin;
Examples of the microcapsule-type latent curing accelerator include accelerators in which the surface of a curing accelerator such as the imidazole compound, organic phosphorus compound, and quaternary phosphonium salt is coated with a polymer;
Examples of the thermal cationic polymerization type latent curing accelerator include Lewis acid salts and Bronsted acid salts.

It is preferable that the usage-amount of the said catalyst shall be 30 weight part or less with respect to 100 weight part in total of a polyfunctional epoxy compound and polyfunctional carboxylic acid.
The reaction between the polyfunctional epoxy compound and the polyfunctional carboxylic acid is preferably performed at a temperature of 25 to 200 ° C, more preferably 40 to 180 ° C, preferably 10 minutes to 48 hours, more preferably 1 to 24 hours.
The terminal of the specific polymer in the present invention may be a carboxyl group, an epoxy group, or an epoxy group opened by hydrolysis or the like. In the present invention, the specific polymer can be used for the preparation of the aligning agent as it is without modifying the terminal. However, at the time of or after the production of the specific polymer of the present invention, a monocarboxylic acid such as benzoic acid or a monoepoxy compound such as benzyl glycidyl ether is added and reacted to form a specific polymer having a terminal modified. May be used for the preparation of the alignment agent.

<Other ingredients>
The liquid crystal aligning agent of the present invention contains the specific polymer as described above as an essential component, but may contain other components as long as the effects of the present invention are not diminished. Examples of such other components include a polymer having no structure (1) (hereinafter referred to as “other polymer”), a compound having at least one epoxy group in the molecule (however, it corresponds to a specific polymer). (Hereinafter referred to as “epoxy compound”), functional silane compounds, and the like.
[Other polymers]
Said other polymer can be used in order to improve the solution characteristic of the liquid crystal aligning agent of this invention, and the electrical property of the liquid crystal aligning film obtained. Such other polymers are polymers having no structure (1), such as polyamic acid, polyimide, polyorganosiloxane, polyamic acid ester, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene). -Phenylmaleimide) derivative, poly (meth) acrylate and the like are preferably selected, and one or more of these can be used.
As another polymer in the present invention, it is preferable to use at least one polymer selected from the group consisting of polyamic acid and polyimide.

{Polyamic acid}
The polyamic acid can be obtained by reacting tetracarboxylic dianhydride and diamine.
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention include an aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, an aromatic tetracarboxylic dianhydride, and the like. Can be mentioned. Specific examples of these include aliphatic tetracarboxylic dianhydrides such as butane tetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 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- No 1,2-dicarboxylic acid 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2 : 4,6: 8-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone and the like;
As aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride can be mentioned, respectively,
Tetracarboxylic dianhydrides described in Patent Document 13 (Japanese Patent Laid-Open No. 2010-97188) can be used.

Among these, the tetracarboxylic dianhydride used for synthesizing the polyamic acid preferably includes an alicyclic tetracarboxylic dianhydride, and 2,3,5-tricarboxycyclopentyl. It is preferable that it contains at least one selected from the group consisting of acetic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, in particular 2,3,5-tricarboxycyclopentyl acetic acid dianhydride It is preferable that a thing is included.
The tetracarboxylic dianhydride used to synthesize the polyamic acid comprises 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride. It is preferable that at least one selected from the group contains 50 mol% or more, more preferably 80 mol% or more, more preferably 2,3,5-tricarboxyl, based on the total tetracarboxylic dianhydride. Most preferably, it is composed of at least one selected from the group consisting of cyclopentylacetic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

Examples of the diamine used for synthesizing the polyamic acid include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Specific examples thereof include aliphatic diamines such as 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;
Examples of aromatic diamines include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 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-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylene Riden) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diamino Pyrimidine, 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 3,5-diaminobenzoic acid, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4- Diaminobenzene, 3,5-diaminobenzoate cholestanyl, 3,5-diaminobenzoate cholestenyl, 3,5-diaminobenzoate lanostannyl, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis ( 4-Aminophenoxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5- Aminobenzoate, 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 and the following formula (D-1)

(In the formula (D-1), ^{X I} is an alkyl group having 1 to 3 carbon ^atoms, * ^-O-, * -COO- or ^* -OCO- (where bond marked with "*" is diaminophenyl group And m is 0 or 1, n is an integer of 0 to 2, and p is an integer of 1 to 20.)
A compound represented by:
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, respectively.
Diamines described in Patent Document 13 (Japanese Patent Laid-Open No. 2010-97188) can be used.
The ^{X I} in the above formula (D-1) an alkyl group having 1 to 3 carbon ^atoms, * -O- or ^* -COO- (provided that a bond marked with "*" is bonded to the diamino phenyl group.) In Preferably there is. Specific examples of the group C _p H _{2p + 1} — include, for example, methyl group, 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, n-nonadecyl group, n -An eicosyl group etc. can be mentioned. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to the other groups.
Specific examples of the compound represented by the formula (D-1) include, for example, dodecanoxy-2,4-diaminobenzene, tetradecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2, 4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, tetradecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, Octadecanoxy-2,5-diaminobenzene, the following formulas (D-1-1) to (D-1-3)

And the like, and the like.
In the above formula (D-1), it is preferable that m and n are not 0 at the same time.
These diamines can be used alone or in combination of two or more.
The proportion of tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis reaction is 0.2 eq. Of tetracarboxylic dianhydride acid anhydride group with respect to 1 equivalent of amino group contained in the diamine compound. The ratio which becomes -2 equivalent is preferable, More preferably, it is the ratio which becomes 0.3-1.2 equivalent.

The polyamic acid synthesis reaction is preferably performed in an organic solvent, preferably at a temperature of −20 to 150 ° C., more preferably at a temperature of 0 to 100 ° C., preferably 0.5 to 24 hours, more preferably 2 to 10 Done for hours. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N, Aprotic polar solvents such as N-dimethylimidazolidinone, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide;
Mention may be made of phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount (a) of the organic solvent used is such that the total amount (b) of tetracarboxylic dianhydride and diamine compound is preferably 0.1 to 50% by weight, more preferably 5 to 5%, based on the total amount (a + b) of the reaction solution. The amount is 30% by weight.
As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent.
When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction.
The polyamic acid is isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling off the organic solvent in the reaction solution under reduced pressure using an evaporator. Etc. The polyamic acid is dissolved again in an organic solvent and then precipitated in a poor solvent, or the polyamic acid is dissolved again in an organic solvent and the solution is washed and then distilled off under reduced pressure with an evaporator once or several times. The polyamic acid can be purified by a method that is repeated.

{Polyimide}
The polyimide can be synthesized by dehydrating and ring-closing the imamic acid structure of the polyamic acid obtained as described above to imidize. At this time, all of the amic acid structure may be dehydrated and closed to completely imidize, or only a part of the amic acid structure may be dehydrated and closed to form a partially imidized product in which the amic acid structure and the imide structure coexist. Also good. The imidation ratio of the polyimide used in the present invention is preferably 40% or more, and more preferably 50 to 95%.
The polyamic acid is dehydrated and closed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to this solution, and heating as necessary. It can be done by a method.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. If the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and if the reaction temperature exceeds 200 ° C., the molecular weight of the resulting polyimide may decrease. The reaction time in the method of heating the polyamic acid is preferably 0.5 to 48 hours, more preferably 2 to 20 hours.
On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of a polyamic acid structural unit. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used in the dehydration ring-closing 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 to 180 ° C., more preferably 10 to 150 ° C., and the reaction time is preferably 0.5 to 20 hours, more preferably 1 to 8 hours.

  The polyimide obtained in the above method (i) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained polyimide. On the other hand, in the above method (ii), a reaction solution containing polyimide is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. It may be used for the preparation of a liquid crystal aligning agent or may be used for the preparation of a liquid crystal aligning agent after purifying the isolated polyimide. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. The isolation and purification of the polyimide can be performed by performing the same operation as described above as the isolation and purification method of the polyamic acid.

{Use ratio of other polymers}
When the liquid crystal aligning agent of the present invention contains another polymer together with the above-mentioned specific polymer, the use ratio of the other polymer is the sum of the polymers (of the specific polymer and the other polymer). 99% by weight or less, more preferably 95% by weight or less, still more preferably 80% by weight or less, particularly 50% by weight or less. Preferably there is. By using such a use ratio, without impairing the effect of the present invention, it is possible to further improve the electrical properties of the liquid crystal alignment film to be formed, and further contribute to the cost reduction of the liquid crystal alignment agent, preferable.

[Epoxy compound]
The said epoxy compound can be contained in the liquid crystal aligning agent of this invention from a viewpoint of improving the adhesiveness with respect to the substrate surface of the liquid crystal aligning film formed.
Examples of such epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′— Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-dia Bruno diphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, etc., it may be mentioned as being preferred.
When the liquid crystal aligning agent of this invention contains an epoxy compound, as the content rate, it is preferably 40 parts by weight or less, more preferably 30 parts by weight or less, with respect to 100 parts by weight of the total polymer. is there.

[Functional silane compounds]
The said functional silane compound can be used in order to improve the adhesiveness with the board | substrate of the liquid crystal aligning film obtained. Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl) -3. -Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltri Methoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7 Triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl- 3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene ) -3-Aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane And patents Document 8 such as those described in (JP 63-291922 JP), reaction products of a silane compound having a tetracarboxylic acid dianhydride and amino group can be used.
When the liquid crystal aligning agent of the present invention contains a functional silane compound, the content is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, with respect to 100 parts by weight of the total polymer. is there.

<Liquid crystal aligning agent>
As described above, the liquid crystal aligning agent of the present invention contains a specific polymer as an essential component, and additionally contains other components as necessary. Preferably, each component is dissolved in an organic solvent. Prepared as a solution composition.
As the organic solvent that can be used for preparing the liquid crystal aligning agent of the present invention, a solvent that dissolves the specific polymer and other components optionally used and does not react with these is preferable. Examples of such organic solvents include N-methyl-2-pyrrolidone, 縺 | butyrolactone, 縺 | butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene Glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, 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 dimethyl ether, diethylene glycol Diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. One or more selected from these can be preferably used.
The preferable solvent used for the preparation of the liquid crystal aligning agent of the present invention is obtained by combining one or more of the above organic solvents, and is contained in the liquid crystal aligning agent at the following preferable solid content concentration. Each component does not precipitate, and the surface tension of the liquid crystal aligning agent is in the range of 25 to 40 mN / m.
When the substrate to which the liquid crystal aligning agent of the present invention is applied is highly soluble in the organic solvent (for example, when a flexible substrate such as triacetyl cellulose (TAC) is used), the organic solvent, or Instead of the organic solvent, other organic solvents that do not dissolve the substrate or hardly dissolve the substrate can be used. Examples of such other organic solvents include cyclohexane, cyclopentanone, cyclohexanone, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, isobutyl alcohol, n-butyl alcohol, methyl proxitol, ethyl acetate, propyl acetate, isopropyl acetate. Butyl acetate, sec-butyl acetate, tert-butyl acetate, isobutyl acetate, propylene glycol monomethyl ether acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, propylene glycol monomethyl ether, ethyl cellosolve, 2,3-pentanedione, 1,2-dimethoxyethane, 1,1-diethoxyethane, 1,2-diethoxyethane, etc., and one selected from these It can be used on. The use ratio of the organic solvent to the other organic solvent can be appropriately set in consideration of the solubility of each component contained in the liquid crystal aligning agent of the present invention and the solubility of the substrate to be used.

The solid content concentration of the liquid crystal aligning agent of the present invention, that is, the ratio of the weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent is selected in consideration of viscosity, volatility, Preferably it is the range of 1-10 weight%. The liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film that becomes a liquid crystal aligning film. When the solid content concentration is less than 1% by weight, the film thickness of this coating film becomes too small. In some cases, it is difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film due to excessive film thickness, and the viscosity of the liquid crystal aligning agent increases, resulting in insufficient coating characteristics. There is a case. The particularly preferable range of the solid content concentration varies depending on the method employed when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 6% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 0 ° C. to 200 ° C., more preferably 0 ° C. to 40 ° C.

<Method for forming liquid crystal alignment film>
The liquid crystal aligning agent of this invention can be used conveniently in order to form a liquid crystal aligning film by the photo-alignment method. The liquid crystal aligning agent of the present invention is applied to a TN type, STN type or lateral electric field type liquid crystal display element, particularly when applied to a horizontal electric field type liquid crystal display element; or when applied to the production of a retardation film. The effect of the present invention is exhibited to the maximum, which is preferable.
To form a liquid crystal alignment film using the liquid crystal aligning agent of the present invention,
(A) applying a liquid crystal aligning agent of the present invention on a substrate to form a polymer coating film; and (b) applying a radiation to the polymer coating film to form a liquid crystal alignment film. It can depend on the way you go. Hereinafter, the steps (a) and (b) will be described.

(A) Step of applying a liquid crystal aligning agent of the present invention on a substrate to form a polymer coating film Here, when applying the liquid crystal aligning agent of the present invention to a TN type or STN type liquid crystal display element, A pair of two substrates on which a patterned transparent conductive film is provided is applied to the transparent conductive film forming surface of the two substrates to form a coating film. When the liquid crystal aligning agent of the present invention is applied to a horizontal electric field type liquid crystal display element, a substrate having an electrode in which a transparent conductive film or a metal film is patterned in a comb shape on one side, and no electrode are provided. The counter substrate is paired, and the liquid crystal aligning agent of the present invention is applied to the surface on which the comb-like electrode is formed and one surface of the counter substrate to form a coating film.
In the above two cases, as the substrate, for example, a glass such as float glass or soda glass, a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, or polycarbonate can be used. As the transparent conductive film, for example, an ITO film made of In ₂ O ₃ —SnO _{2 or} a NESA (registered trademark) film made of SnO ₂ can be used. As the metal film, for example, a film made of a metal such as chromium can be used. For patterning the transparent conductive film and the metal film, for example, a method of forming a pattern by a photo-etching method or a sputtering method after forming a transparent conductive film without a pattern, or a mask having a desired pattern when forming the transparent conductive film The method using can be used.
On the other hand, when using the liquid crystal aligning agent of this invention in order to manufacture the liquid crystal aligning film of retardation film, the liquid crystal aligning agent of this invention is apply | coated on one transparent substrate, and a coating film is formed. Examples of transparent substrates used in this case include glass substrates such as float glass and soda glass, triacetyl cellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polyamide, polyimide, polymethyl methacrylate, and polycarbonate. And so on. Among these, TAC is a material generally used as a protective layer of a polarizing film that bears an important function in a liquid crystal display element.

In any of the above cases, a functional silane compound is previously formed on the substrate and the electrode in order to further improve the adhesion between the substrate or the conductive film or the electrode and the coating film when the liquid crystal aligning agent is applied onto the substrate. Alternatively, titanate or the like may be applied.
The liquid crystal aligning agent can be applied onto the substrate by an appropriate application method such as an offset printing method, a spin coating method, a roll coater method, or an ink jet printing method, and then the application surface is preheated (prebaked). And then baking (post-baking) to form a coating film. The pre-bake conditions are, for example, 0.1 to 5 minutes at 40 to 120 ° C., and the post-bake conditions are preferably 120 to 300 ° C., more preferably 150 to 250 ° C., preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the coating film after post-baking is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(B) The process of irradiating the polymer coating film with radiation The liquid crystal alignment ability is obtained by irradiating the coating film formed in the process (a) with linearly polarized light, partially polarized radiation or non-polarized radiation. Is granted. Here, as the radiation, for example, ultraviolet rays including visible light having a wavelength of 150 to 800 nm and visible light can be used, but ultraviolet rays including light having a wavelength of more than 300 nm and not more than 400 nm are preferable. Here, in order to prevent the deterioration of the coating film due to the effect of cutting the polymer molecular chain due to irradiation with high-energy short-wave ultraviolet light, irradiation is performed through a UV cut filter that cuts ultraviolet light with a wavelength of 300 nm or less. Is preferred. When the irradiated radiation is linearly polarized or partially polarized, the irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized radiation, the direction of irradiation needs to be an oblique direction.
As a light source to be used, for example, 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, or the like can be used. The ultraviolet rays in the preferable wavelength region can be obtained by means of using the light source in combination with, for example, a filter or a diffraction grating.
The radiation dose is preferably 100 to 50,000 J / m ² , more preferably 300 to 20,000 J / m ² .

Here, when the liquid crystal alignment film is applied to the production of a retardation film, it is convenient to form a plurality of regions having different alignment states in the plane of the liquid crystal alignment film. Thus, the produced retardation film has a plurality of regions having different polarization states, and can be suitable as a retardation film for 3D video display, for example.
In order to form such a liquid crystal alignment film having a plurality of regions having different alignment states, for example, the following method can be exemplified. When forming the liquid crystal alignment film by irradiating the coating film with radiation, if the radiation to be irradiated is linearly polarized or partially polarized, the direction in which the polarization direction of the irradiation radiation is projected onto the coating surface varies from region to region. Can depend on how to do;
On the other hand, when the radiation to be irradiated is non-polarized light, the irradiation direction can be changed for each region. In any of the above cases, as the degree of changing the direction, the angle difference between the adjacent regions is preferably 70 to 110 °, more preferably 85 to 95 °, and 90 °. Is most preferred. Such irradiation for changing the polarization direction or the irradiation direction for each region of the coating film is, for example, after performing a first irradiation with radiation having the first polarization direction or irradiation direction while shielding a part of the coating film, In this case, it is possible to use a method in which the second irradiation with the radiation having the second polarization direction or the irradiation direction is performed only on the region which is shielded by the first irradiation after shielding the exposure part in the first irradiation. The light shielding can be performed by a mask having a desired opening pattern, for example.
When the retardation film produced by the method of the present invention is applied to a retardation film for 3D video display, two types of regions having different alignment states are distributed in the form of stripes on the liquid crystal alignment film surface. It is convenient to do.
A liquid crystal alignment film can be formed as described above. This liquid crystal alignment film can be applied to the production of a liquid crystal display element or a retardation film. Hereinafter, a manufacturing method for the liquid crystal display element and a manufacturing method for the retardation film will be described in order.

<Method for manufacturing liquid crystal display element>
The liquid crystal display element formed using the liquid crystal aligning agent of this invention can be manufactured as follows, for example.
First, a pair of substrates on which a liquid crystal alignment film is formed is prepared as in steps (a) and (b) above, and a liquid crystal cell having a configuration in which liquid crystals are sandwiched between the pair of substrates is manufactured. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
The first method is a conventionally known method. First, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole.
The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped on the liquid crystal alignment film surface. The other substrate is bonded so as to face each other, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, whereby a liquid crystal cell can be manufactured.
In any case, it is desirable to remove the flow alignment at the time of filling the liquid crystal by heating the liquid crystal cell to a temperature at which the liquid crystal used has an isotropic phase and then gradually cooling it to room temperature.
And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell. Here, in the two substrates on which the liquid crystal alignment film is formed, a desired liquid crystal display element can be obtained by appropriately adjusting the angle formed by the polarization direction of the irradiated linearly polarized radiation and the angle between each substrate and the polarizing plate. Can be obtained.

As the sealing agent, for example, an aluminum oxide sphere as a spacer and an epoxy resin containing a curing agent can be used.
As the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal, or the like can be used. Those having positive dielectric anisotropy forming a nematic liquid crystal are preferred, such as biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, Bicyclooctane liquid crystals, cubane liquid crystals, and the like are used. In addition, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate;
Chiral agents such as those sold under the trade names “C-15” and “CB-15” (Merck)
A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be further added and used.
The polarizing plate used outside the liquid crystal cell is composed of a polarizing film called “H film” in which polyvinyl alcohol is stretched and oriented while absorbing iodine and sandwiched between cellulose acetate protective films, or the H film itself. A polarizing plate etc. can be mentioned.

<Method for producing retardation film>
The retardation film of the present invention can be produced, for example, as follows.
First, a single substrate on which a liquid crystal alignment film is formed as in steps (a) and (b) above is prepared, and (c) a polymerizable liquid crystal is applied onto the liquid crystal alignment film and polymerized. Through a process comprising a step of forming a coating film of the polymerizable liquid crystal, and (d) curing the coating film of the polymerizable liquid crystal by performing one or more treatments selected from the group consisting of heating and radiation irradiation, A retardation film can be obtained. Hereinafter, steps (c) and (d) will be described.

(C) Step of forming polymerizable liquid crystal coating film by applying polymerizable liquid crystal on polymer coating film after irradiation with radiation In this step, at least part of the formed liquid crystal alignment film surface is polymerizable. Apply liquid crystal. The polymerizable liquid crystal used here is not particularly limited as long as it is a liquid crystal compound that can be polymerized by heating or irradiation. For example, a nematic liquid crystal compound as described in Non-Patent Document 2 (“UV curable liquid crystal and its application”, liquid crystal, Vol. 3, No. 1, 1999, pp 34 to 42) can be used.
Only 1 type may be used for a polymeric liquid crystal, and 2 or more types may be mixed and used for it. In addition to the polymerizable liquid crystal, it is selected from a photopolymerization initiator, a thermal polymerization initiator, a non-polymerizable liquid crystal (eg, twisted nematic alignment liquid crystal, cholesteric liquid crystal, discotic liquid crystal, etc.), a chiral agent, a solvent, and the like. One or more kinds may be used in combination.
As a method for applying the polymerizable liquid crystal, for example, an appropriate method such as a roll coater method, a spinner method, a printing method, or an ink jet method can be employed.
As a film thickness of the coating film of the polymerizable liquid crystal, a film thickness capable of obtaining desired optical characteristics can be appropriately selected. For example, when manufacturing a half-wave plate for visible light having a wavelength of 540 nm, the film thickness is selected such that the retardation of the formed retardation film is 240 to 300 nm. Is selected to be 120 to 150 nm. The optimum film thickness for obtaining the target retardation varies depending on the optical characteristics of the polymerizable liquid crystal used. For example, when a polymerizable liquid crystal (RMS03-013C) manufactured by Merck is used, a film thickness for producing a quarter-wave plate is suitably in the range of 0.6 to 1.5 μm. The appropriate film thickness of the polymerizable liquid crystal coating film can be easily determined by a few preliminary experiments by those skilled in the art.

(D) Step of curing one or more treatments selected from the group consisting of heating and radiation irradiation to cure the coating film of the polymerizable liquid crystal The heating condition in the case of curing the polymerizable liquid crystal by heating is the polymerization used Depends on the polymerizability of the crystalline liquid crystal. For example, when using a polymerizable liquid crystal, RMS03-013C, manufactured by Merck, it is preferable that the heating temperature is in the range of 40 to 80 ° C. and the heating time is 20 seconds to 10 minutes.
In the case where the polymerizable liquid crystal is cured by radiation irradiation, examples of the radiation used include non-polarized ultraviolet rays. The irradiation dose of radiation, preferably to 1,000 J / ^{m 2} or more 100,000J / ^m less than ^2, and more preferably a 10,000~50,000J / ^{m 2.}
A retardation film can be produced as described above.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
The weight average molecular weight (Mw) in the following polymer synthesis examples is a polystyrene conversion value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
The “inert atmosphere” in the following synthesis examples is a nitrogen atmosphere.
In addition, in the following synthesis examples, the synthesis | combination of each compound was repeated as needed by the following synthesis scale, and the required amount in the synthesis examples of subsequent polymers was ensured.
<Synthesis of dicarboxylic acid>
In the following synthesis examples DC-1 to DC-4, compounds represented by the above formulas (DC-1) to (DC-4) as dicarboxylic acids having the structure (1) (hereinafter referred to as “compounds”, respectively). DC-1) "," Compound (DC-2) "," Compound (DC-3) "and" Compound (DC-1) ") were synthesized.

Synthesis example DC-1
(1) Synthesis of 4-acryloyloxybenzoic acid 13.8 g (100 mmol) of 4-hydroxybenzoic acid, 8 g (200 mmol) of sodium hydroxide and 400 mL of pure water were charged into a 1 L three-necked flask equipped with a dropping funnel and cooled in an ice bath. did. A methylene chloride solution 120 mL solution containing 10.86 g (120 mmol) of acrylic acid chloride was added dropwise from the dropping funnel over 1.5 hours. After completion of the dropwise addition, the mixture was stirred for 2 hours in an ice bath, and then the temperature of the reaction mixture was returned to room temperature, followed by further stirring for 3 hours for reaction. The reaction mixture was then bathed again, and 1N hydrochloric acid was added dropwise until the liquidity of the reaction mixture became acidic. The precipitated solid was collected using a suction funnel and recrystallized from ethanol to obtain 16 g of 4-acryloyloxybenzoic acid.
(2) Synthesis of Compound (DC-1) This synthesis was performed under an inert atmosphere.
4-acryloyloxybenzoic acid 5g obtained above, 5.3 g of 4-bromobenzoic acid, 60 mg of palladium acetate, 0.32 g of tris (o-tolyl) phosphine, 11 g of triethylamine and 40 mL of dimethylacetamide were mixed in a 200 mL flask. The reaction was carried out at 6 ° C. with stirring for 6 hours. After returning the temperature of the reaction mixture to room temperature, 200 mL of 1N hydrochloric acid was added. The precipitated solid was collected by filtration and recrystallized from ethanol to obtain 6 g of Compound (DC-1).

Synthesis example DC-2
(1) Synthesis of bis (4-acryloyloxyphenyl) methane A 200 mL three-necked flask equipped with a dropping funnel was charged with 10 g of 4-hydroxydiphenylmethane, 11 g of triethylamine and 60 mL of tetrahydrofuran to obtain a solution. After this solution was ice-cooled, 50 mL of a tetrahydrofuran solution containing 10 g of acrylic acid chloride was dropped from the dropping funnel. After completion of the dropwise addition, the reaction was further continued with stirring in an ice bath for 3 hours, and then the reaction mixture was separated and washed with a mixed solvent consisting of ethyl acetate and water. The organic layer was collected and dried over magnesium sulfate, and then the organic solvent was distilled off to obtain 15 g of bis (4-acryloyloxyphenyl) methane.
(2) Synthesis of Compound (DC-2) This synthesis was performed under an inert atmosphere.
A 300 mL flask containing 8 g of the bis (4-acryloyloxyphenyl) methane obtained above, 10.5 g of 4-bromobenzoic acid, 120 mg of palladium acetate, 0.63 g of tris (o-tolyl) phosphine, 21 g of triethylamine and 90 mL of dimethylacetamide. The reaction was carried out with stirring at 140 ° C. for 6 hours. The temperature of the reaction mixture was returned to room temperature, and 500 mL of 1N hydrochloric acid was added. The precipitated solid was collected by filtration and recrystallized from ethanol to obtain 4 g of Compound (DC-2).

Synthesis example DC-3
(1) Synthesis of 1,4-diacryloyloxybenzene A 300 mL three-necked flask equipped with a dropping funnel was charged with 10 g of hydroquinone, 20 g of triethylamine and 100 mL of tetrahydrofuran to obtain a solution. This solution was ice-cooled, and 90 mL of a tetrahydrofuran solution containing 19 g of acrylic acid chloride was added dropwise thereto. The reaction was further continued for 3 hours under stirring in an ice bath, and the resulting reaction mixture was subjected to liquid separation washing with a mixed solvent consisting of ethyl acetate and water. The organic layer was collected and dried over magnesium sulfate, and then the organic solvent was distilled off to obtain 16 g of 1,4-diacryloyloxybenzene.
(2) Synthesis of Compound (DC-3) This synthesis was performed under an inert atmosphere.
8 g of 1,4-diacryloyloxybenzene obtained above, 15 g of 4-bromobenzoic acid, 165 mg of palladium acetate, 0.9 g of tris (o-tolyl) phosphine, 30 g of triethylamine and 130 mL of dimethylacetamide were mixed in a 500 mL flask. The reaction was conducted at 140 ° C. with stirring for 6 hours. After completion of the reaction, the temperature of the reaction mixture was returned to room temperature, and 700 mL of 1N hydrochloric acid was added. The precipitated solid was collected by filtration and recrystallized from ethanol to obtain 8 g of Compound (DC-3).

Synthesis example DC-4
Compound (DC-4) 3 was prepared in the same manner as in Synthesis Example DC-2 except that 11.4 g of 2-fluoro-4-bromobenzoic acid was used instead of 4-bromobenzoic acid in Synthesis Example DC-2. .5 g was obtained.

<Synthesis of specific polymer>
Synthesis example SP-1
In a 50 mL flask, 3 g (0.01 mol) of the compound (DC-1) obtained in Synthesis Example DC-1 as a polyfunctional carboxylic acid, and Compound 0 represented by the above formula (DE-1) as a polyfunctional epoxy compound .83 g (0.01 mol) and 10 g of N-methyl-2-pyrrolidone as a solvent were added, and this was stirred for 6 hours at 140 ° C. to carry out the reaction, whereby the polymer (SP-1) as a specific polymer was obtained. A solution containing was obtained. The polymer (SP-1) contained in this solution had a weight average molecular weight (Mw) of 4,200.

Synthesis Examples SP-2 to SP-20 and Synthesis Example rp-1
In the synthesis example SP-1, the polyfunctional carboxylic acid and the polyfunctional epoxy compound were used in the same manner as in the synthesis example SP-1, except that the types listed in Table 1 were used in the amounts shown in Table 1, respectively. A solution containing each of the polymers (SP-2) to (SP-20) as the specific polymer and the polymer (rp-1) as the other polymer was obtained.
In Synthesis Examples SP-9 and SP-19, two types of compounds are used as a polyfunctional epoxy compound, and in Synthesis Example SP-20, two types of compounds are used as a polyfunctional carboxylic acid. did. Synthesis example rp-1 is a comparative synthesis example.
The molecular weight of the polymer contained in each solution is shown in Table 1.
Abbreviations of the polyfunctional carboxylic acid and the polyfunctional epoxy compound in Table 1 have the following meanings, respectively.
[Polyfunctional carboxylic acid]
DC-1: Compound (DC-1) obtained in Synthesis Example DC-1 above
DC-2: Compound obtained in Synthesis Example DC-2 (DC-2)
DC-3: Compound obtained in Synthesis Example DC-3 (DC-3)
DC-4: Compound obtained in Synthesis Example DC-4 (DC-4)
tc-1: pyromellitic acid α: compound represented by the following formula (α)

[Polyfunctional epoxy compound]
DE-1: Compound represented by the above formula (DE-1) DE-2: Compound represented by the above formula (DE-2) DE-3: Compound represented by the above formula (DE-3) DE- 4: Compound represented by the above formula (DE-4) DE-5: Compound represented by the above formula (DE-5) DE-6: Compound represented by the above formula (DE-6) DE-7: Compound represented by the above formula (DE-7) DE-8: Compound represented by the above formula (DE-8) te-1: N, N, N ′, N′-tetraglycidyl-m-xylenediamine

<Synthesis of other polymers>
[Synthesis of polyamic acid]
Synthesis example PA-1
200 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 210 g (1, .2) of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine. 0 mol) was dissolved in 3,670 g of N-methyl-2-pyrrolidone and reacted at 40 ° C. for 3 hours to obtain a solution containing 10% by weight of polyamic acid (PA-1). The solution viscosity of this solution was 160 mPa · s.

Synthesis example PA-2
2,3,5-tricarboxycyclopentylacetic acid dianhydride (22.4 g, 0.1 mol) and cyclohexanebis (methylamine) (14.23 g, 0.1 mol) were mixed with N-methyl-2-pyrrolidone (329.3 g). And a reaction was carried out at 60 ° C. for 6 hours to obtain a solution containing polyamic acid (PA-2).
The solution containing this polyamic acid (PA-2) was subjected to synthesis of the following polyimide (PI-1) in an amount corresponding to 17.5 g in terms of polyamic acid, and the remaining portion was liquid crystal It used for preparation of the orientation agent.

[Synthesis of polyimide]
Synthesis example PI-1
An amount corresponding to 17.5 g in terms of the polyamic acid in the polyamic acid (PA-2) obtained in the above synthesis example PA-2 was converted into 232.5 g of N-methyl-2-pyrrolidone, A solution containing polyimide (PI-1) was obtained by adding 3.8 g of pyridine and 4.9 g of acetic anhydride and performing dehydration conversion with stirring at 120 ° C. for 4 hours to perform imidization. The imidation ratio of the polyimide (PI-1) contained in this solution was 60%.

Example 1
<Preparation of liquid crystal aligning agent>
N-methyl-2-pyrrolidone and butyl cellosolve are added to a solution containing the polymer (SP-1) obtained in Synthesis Example SP-1 as a specific polymer, and the solvent composition is N-methyl-2-pyrrolidone: butyl cellosolve. = 50: 50 (weight ratio) and a solid content concentration of 3.0% by weight. A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore diameter of 1 μm.

<Evaluation of liquid crystal alignment>
(1) Manufacture of liquid crystal display element On the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film, the liquid crystal aligning agent prepared above is applied using a spinner, and prebaked on a hot plate at 80 ° C. for 1 minute. Then, the film was heated (post-baked) at 200 ° C. for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen to form a coating film having a thickness of 0.1 μm. Next, polarized ultraviolet light 10,000 J / m ² containing a 313 nm emission line using a Hg-Xe lamp and a Grand Taylor prism on the surface of the coating film and cutting an emission line of 300 nm or less using a UV cut filter is applied to the substrate. The liquid crystal alignment film was irradiated from the vertical direction. The same operation was repeated to produce a pair (two) of substrates having a liquid crystal alignment film.
An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm is applied to the outer periphery of the surface having one liquid crystal alignment film of the above substrates by screen printing, and the liquid crystal alignment film surfaces of a pair of substrates are made to face each other. The adhesive was pressure-bonded so that the projection direction of the ultraviolet optical axis of each substrate onto the substrate surface was antiparallel, and the adhesive was thermally cured at 150 ° C. for 1 hour. Next, the liquid crystal injection port was filled with a liquid crystal “MLC-7028” manufactured by Merck Co., Ltd., and the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, this was heated to 150 ° C. and then gradually cooled to room temperature. Next, the polarizing plates are bonded to both the outer surfaces of the substrate so that the polarization directions thereof are orthogonal to each other and form an angle of 45 ° with the projection direction of the optical axis of the liquid crystal alignment film onto the substrate surface. A liquid crystal display device was manufactured.
(2) Evaluation of liquid crystal alignment The liquid crystal display element manufactured above was observed with an optical microscope for the presence or absence of abnormal domains, and the liquid crystal alignment was evaluated as “good” when no abnormal domains were observed. The liquid crystal alignment of the display element was “good”.

<Evaluation of seizure characteristics>
(1) Manufacture of a transverse electric field type liquid crystal display element In the manufacture of (1) liquid crystal display element of the above <Evaluation of liquid crystal orientation>, a glass substrate having two lines of comb-like conductive film patterns made of chromium as a glass substrate In addition to the above, the liquid crystal aligning agent was applied to the conductive film of the substrate having the comb-like conductive film and one surface of the other substrate, respectively. Evaluation> In the same manner as in the manufacture of (1) liquid crystal display element, a horizontal electric field type liquid crystal display element was manufactured.
A schematic diagram showing the configuration of the electrode pattern on the glass substrate is shown in FIG.
The two conductive film patterns of the horizontal electric field mode liquid crystal display element manufactured above are hereinafter referred to as “electrode A” and “electrode B”, respectively.
(2) Evaluation of burn-in characteristics The horizontal electric field type liquid crystal display device manufactured as described above is placed in an environment of 25 ° C. and 1 atm. A composite voltage of 5V was applied for 2 hours. Immediately thereafter, an AC voltage of 4 V was applied to both electrode A and electrode B. The time from when the voltage of 4V AC was started to be applied to both electrodes until the difference in light transmittance between the electrodes A and B could not be visually confirmed was measured. When this time is less than 20 seconds, the image sticking property is “excellent”, when it is 20 seconds or more and less than 60 seconds, the image sticking property is “excellent”, and when it is 60 seconds or more and less than 100 seconds, the image sticking property is “good”, 100 The burn-in characteristic was “good” when it was longer than 150 seconds and less than 150 seconds, and the burn-in characteristic “bad” when it was longer than 150 seconds was evaluated as “good”. It was.

Examples 2-18, 26 and 27 and Comparative Example 1
In Example 1 above, a liquid crystal aligning agent was prepared in the same manner as in Example 1 except that solutions containing the types and amounts of polymers listed in Table 2 were used as polymers, and a liquid crystal display device was produced. And evaluated. The evaluation results are shown in Table 2.
In Comparative Example 1, another polymer was used instead of the specific polymer.

Example 19
In this example, the specific polymer and another polymer were mixed and used.
The solution containing the polyamic acid (PA-1) obtained in Synthesis Example PA-1 was taken in an amount corresponding to 80 parts by weight in terms of the polyamic acid (PA-1) contained therein. 20 parts by weight of the specific polymer (SP-10) obtained in Synthesis Example SP-10 was added, N-methyl-2-pyrrolidone and butyl cellosolve were added, and the solvent composition was N-methyl-2-pyrrolidone: butyl cellosolve = The solution was 50:50 (weight ratio) and the solid content concentration was 3.0% by weight. A liquid crystal aligning agent was prepared by filtering this solution through a filter having a pore diameter of 1 μm.
Furthermore, a liquid crystal display element was manufactured and evaluated using this liquid crystal aligning agent. The evaluation results are shown in Table 2.

Examples 20-25
A liquid crystal aligning agent was prepared in the same manner as in Example 19 except that solutions containing the types and amounts of polymers listed in Table 2 were used as the specific polymer and the other polymer, respectively. And evaluated.
Each of the specific polymer and the other polymer was used for the preparation of the liquid crystal aligning agent as a solution containing the types of polymers shown in Table 2. The amounts listed in Table 2 for specific polymers and other polymers are the amounts of polymer contained in the polymer solution used.
In Examples 21 and 25, two other polymers were used.
The evaluation results are shown in Table 2.

Example 28
<Manufacture of retardation film 1>
The liquid crystal aligning agent prepared in Example 2 was applied on one surface of a transparent glass substrate using a spinner, pre-baked for 1 minute on a hot plate at 80 ° C., and then at 200 ° C. in an oven in which the inside of the chamber was replaced with nitrogen. Post-baking was performed for 1 hour to form a coating film having a thickness of 0.1 μm. Polarized ultraviolet rays 10,000 J / m ² including a bright line having a wavelength of 313 nm using a Hg-Xe lamp and a Grand Taylor prism on the surface of the coating film and cutting a bright line having a wavelength of 300 nm or less using a UV cut filter are applied to the substrate. The liquid crystal alignment film for retardation film was manufactured by irradiating from the perpendicular direction.
Next, a polymerizable liquid crystal (Merck, RMS03-013C, used after being filtered through a filter having a pore diameter of 0.2 μm) was applied to the surface on which the liquid crystal alignment film produced above was formed using a spinner. Bake on a hot plate at 60 ° C. for 1 minute, and further irradiate non-polarized ultraviolet rays 30,000 J / m ² including a bright line with a wavelength of 365 nm from a direction perpendicular to the surface of the polymerizable liquid crystal coated surface using a Hg-Xe lamp. Then, a retardation film was produced by curing the polymerizable liquid crystal.

<Evaluation of retardation film>
When the retardation film produced above was observed with a polarizing microscope, no abnormal domain was observed.
Moreover, the retardation film produced above was sandwiched between two polarizing plates arranged in crossed Nicols, and observed using transmitted light (visible light) from the direction opposite to the observation side. Here, the polarization direction of the polarized ultraviolet rays irradiated when forming the liquid crystal alignment film of the retardation film on the retardation film is parallel to the polarization direction of one of the polarization plates, and the other polarization direction. When sandwiched at a right angle, the entire surface was observed dark,
When the polarization direction of the polarized ultraviolet rays irradiated when forming the liquid crystal alignment film of the retardation film is sandwiched so as to form an angle of 45 ° with the polarization direction of the two polarizing plates, the entire surface is observed brightly. The retardation film has been shown to have birefringence.

Example 29
<Production of retardation film having different polarization direction for each region>
The liquid crystal aligning agent prepared in Example 2 was applied on one surface of a transparent glass substrate using a spinner, pre-baked for 1 minute on a hot plate at 80 ° C., and then at 200 ° C. in an oven in which the inside of the chamber was replaced with nitrogen. Post-baking was performed for 1 hour to form a coating film having a thickness of 0.1 μm.
In the state where half of the surface of the coating film was shielded from light, the first polarized ultraviolet light (including a bright line having a wavelength of 313 nm using a Hg-Xe lamp and a Grand Taylor prism was used, and a bright line having a wavelength of 300 nm or less was cut using a UV cut filter. Polarized ultraviolet rays 10,000 J / m ² ) were irradiated from a direction perpendicular to the substrate, and the first ultraviolet rays were irradiated. Next, the exposed portion in the first ultraviolet irradiation is shielded from light, and the second polarized ultraviolet light (Hg-Xe lamp) whose polarization direction is rotated by 90 ° with respect to the unexposed portion is polarized ultraviolet light in the first ultraviolet irradiation. And a polarized ultraviolet ray (10,000 J / m ² ) including a bright line having a wavelength of 313 nm using a Grand Taylor prism and a bright line having a wavelength of 300 nm or less cut using a UV cut filter from a direction perpendicular to the substrate. 2 was irradiated to produce a liquid crystal alignment film for retardation film.
Next, a polymerizable liquid crystal (Merck, RMS03-013C, used after being filtered through a filter having a pore diameter of 0.2 μm) was applied to the surface on which the liquid crystal alignment film produced above was formed using a spinner. Bake on a hot plate at 60 ° C. for 1 minute, and further irradiate non-polarized ultraviolet rays 30,000 J / m ² including a bright line with a wavelength of 365 nm from a direction perpendicular to the surface of the polymerizable liquid crystal coated surface using a Hg-Xe lamp. Then, by curing the polymerizable liquid crystal, a retardation film having a different polarization direction for each region was produced.

<Evaluation of retardation film>
When the retardation film produced above was observed with a polarizing microscope, no abnormal domain was observed.
Moreover, the retardation film produced above was sandwiched between the polarizing plate 1 and the polarizing plate 2 arranged in crossed Nicols, and observed using transmitted light (visible light) from the opposite direction to the observation side. Here, the polarization direction of the first polarized ultraviolet rays irradiated on the retardation film when forming the liquid crystal alignment film of the retardation film is parallel to the polarization direction of the polarizing plate 1 and perpendicular to the polarization direction of the polarizing plate 2. (At this time, the polarization direction of the second polarized ultraviolet light is perpendicular to the polarization direction of the polarizing plate 1 and parallel to the polarization direction of the polarizing plate 2). Whereas
When the polarization directions of the first and second polarized ultraviolet rays irradiated when forming the liquid crystal alignment film of the retardation film are sandwiched so as to form an angle of 45 ° with the polarization directions of the two polarizing plates, respectively. Shows that the entire surface was brightly observed regardless of the region where the polarization direction of the irradiation radiation was different, indicating that the retardation film had birefringence.

Further, the retardation film produced in this example and the retardation film produced in Example 28 were overlapped and observed using transmitted light (visible light) from the direction opposite to the observation side. Here, the polarization direction of the polarized ultraviolet rays irradiated when forming the liquid crystal alignment film of the retardation film of Example 28 is irradiated when forming the liquid crystal alignment film of the retardation film of this example (Example 29). In the case where the first polarized ultraviolet light is overlapped so as to be parallel to the polarization direction, the exposed portion of the first ultraviolet irradiation is observed to be bright and the exposed portion of the second ultraviolet irradiation is observed to be dark.
Polarization direction of polarized ultraviolet light irradiated when forming the liquid crystal alignment film of the retardation film of Example 28 is polarized light of the first polarized ultraviolet light irradiated when forming the liquid crystal alignment film of the retardation film of this example. When they were stacked so as to be perpendicular to the direction, the exposed portion exposed to the first ultraviolet irradiation was dark and the exposed portion exposed to the second ultraviolet irradiation was observed brightly. In any of the above cases, the boundary between the bright region and the dark region is partitioned with a clear edge.
From this, it was confirmed that the retardation film of a present Example has a different polarization direction for every area | region.

Claims (11)

Following formula (1)

(In the formula (1), R is an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a halogen atom or a cyano group, a is an integer of 0 to 4, and “*” is a bond. Represents that.)
Characterized in that it contains a polymer having a structure represented by the the main chain liquid crystal alignment agent. The polymer, a polyfunctional epoxy compound comprising a diepoxy compound, a reaction product of a polyfunctional carboxylic acid, comprising the dicarboxylic acid having the above structure, the liquid crystal aligning agent of claim 1. It characterized in that it is formed from a liquid crystal aligning agent according to claim 1 or 2, a liquid crystal alignment film. A liquid crystal display element comprising the liquid crystal alignment film according to claim 3 . The liquid crystal display element of Claim 4 which is a horizontal electric field system. A method for forming a retardation film, comprising at least the following steps (a) to (d):
(A) A step of applying a liquid crystal aligning agent according to claim 1 or 2 on a substrate to form a polymer coating film,
(B) a step of irradiating the coating film of the polymer with radiation to form a liquid crystal alignment film;
(C) applying a polymerizable liquid crystal on the liquid crystal alignment film to form a coating film of the polymerizable liquid crystal, and (d) performing one or more treatments selected from the group consisting of heating and radiation irradiation. A step of curing the coating film of the polymerizable liquid crystal. A retardation film formed by the method according to claim 6 . A liquid crystal display device comprising the retardation film according to claim 7 . The liquid crystal display element according to claim 8 , which is used for 3D video display. Under following formula (1)

(In the formula (1), R is an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a halogen atom or a cyano group, a is an integer of 0 to 4, and “*” is a bond. Represents that.)
It characterized by having a structure represented by the the main chain, a polymer. The polyfunctional epoxy compound containing a diepoxy compound and the polyfunctional carboxylic acid containing the dicarboxylic acid which has a structure represented by the said Formula (1) are made to react, The polymer of Claim 10 characterized by the above-mentioned. Production method.

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