JP7196847B2 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element for manufacturing a liquid crystal display element having excellent burn-in property.

Liquid crystal display elements are known as lightweight, thin, and low power consumption display devices, and have made remarkable progress in recent years, such as being used for large-sized televisions. A liquid crystal display element is configured, for example, by sandwiching a liquid crystal layer between a pair of transparent substrates provided with electrodes. In the liquid crystal display element, an organic film made of an organic material is used as a liquid crystal alignment film so that the liquid crystal is in a desired alignment state between the substrates.

That is, the liquid crystal alignment film is a constituent member of the liquid crystal display element, is formed on the surfaces of the substrates that sandwich the liquid crystal and is in contact with the liquid crystal, and plays the role of orienting the liquid crystal in a certain direction between the substrates. In addition to the role of aligning the liquid crystal in a certain direction, such as a direction parallel to the substrate, the liquid crystal alignment film is sometimes required to play the role of controlling the pretilt angle of the liquid crystal. The ability to control the alignment of the liquid crystal in such a liquid crystal alignment film (hereinafter referred to as alignment controllability) is imparted by subjecting the organic film constituting the liquid crystal alignment film to alignment treatment.

A rubbing method is conventionally known as an alignment treatment method for a liquid crystal alignment film for imparting alignment controllability.
However, the rubbing method of rubbing the surface of the liquid crystal alignment film made of polyimide or the like sometimes causes problems such as generation of dust and static electricity. In addition, the surface of the liquid crystal alignment film cannot be evenly rubbed with a cloth due to the recent increase in definition of the liquid crystal display element and the unevenness caused by the electrodes on the corresponding substrate and the switching active element for driving the liquid crystal. In some cases, alignment of the liquid crystal could not be achieved.

Therefore, a photo-alignment method has been actively studied as another alignment treatment method for a liquid crystal alignment film that does not involve rubbing. There are various photo-alignment methods, but anisotropy is formed in the organic film constituting the liquid crystal alignment film by linearly polarized light or collimated light, and the liquid crystal is aligned according to the anisotropy.

As a main photo-alignment method, a decomposition-type photo-alignment method is known. For example, a polyimide film is irradiated with polarized ultraviolet rays to cause anisotropic decomposition using the polarization direction dependence of ultraviolet absorption in the molecular structure. Then, the polyimide left without being decomposed is used to orient the liquid crystal (see Patent Document 1, for example).

Also known are photocrosslinking and photoisomerization photoalignment methods. For example, polyvinyl cinnamate is used and irradiated with polarized ultraviolet rays to cause a dimerization reaction (crosslinking reaction) at the double bond portions of the two side chains parallel to the polarized light. Then, the liquid crystal is oriented in a direction orthogonal to the polarization direction (see Non-Patent Document 1, for example). In addition, when a side-chain type polymer having azobenzene in the side chain is used, it is irradiated with polarized ultraviolet rays to cause an isomerization reaction in the azobenzene portion of the side chain parallel to the polarized light, causing the liquid crystal to liquefy in the direction perpendicular to the polarization direction. Orient (see, for example, Non-Patent Document 2).

Moreover, as a photo-alignment film for improving the afterimage property by AC driving, a method of using a polyamic acid produced using a diamine containing a cyclobutane ring and an imide group is known (for example, Patent Documents 2, 3 and 4). see).

As in the above examples, the alignment treatment method for the liquid crystal alignment film by the photo-alignment method does not require rubbing, and there is no concern about the generation of dust or static electricity. Further, the alignment treatment can be applied even to the substrate of the liquid crystal display element having unevenness on the surface, and the alignment treatment method of the liquid crystal alignment film is suitable for the industrial production process.

On the other hand, although the horizontal electric field type liquid crystal cell has excellent viewing angle characteristics, the electrode portion formed in the substrate is small, so if the voltage holding ratio of the liquid crystal alignment film is weak, a sufficient voltage cannot be applied to the liquid crystal. Display contrast decreases. In addition, static electricity is likely to accumulate in the liquid crystal cell, and electric charge is accumulated in the liquid crystal cell even when an asymmetrical voltage is applied during driving. It affects the display as burn-in and significantly degrades the display quality of the liquid crystal element. In such a state, if the current is supplied again, the liquid crystal molecules are not well controlled at the initial stage, causing flicker or the like. In particular, in the horizontal electric field method, since the distance between the pixel electrode and the common electrode is shorter than in the vertical electric field method, a strong electric field acts on the alignment film and the liquid crystal layer, and this problem tends to become noticeable. there were.

Japanese Patent No. 3893659 Korean Patent Application Publication No. 10-2016-0042614 Korean Patent Application Publication No. 10-2017-0127966 Korean Patent Application Publication No. 10-2018-0020722

M. Shadt et al., Jpn. J. Appl. Phys. 31, 2155 (1992). K. Ichimura et al., Chem. Rev. 100, 1847 (2000).

As described above, the photo-alignment method does not require the rubbing process itself as compared with the rubbing method that has been industrially used as an alignment treatment method for liquid crystal display elements, and therefore has a great advantage. In contrast to the rubbing method in which the alignment controllability is substantially constant, the photo-alignment method can control the alignment controllability by changing the irradiation amount of polarized light. However, in the photo-alignment method, when attempting to achieve alignment controllability to the same extent as in the rubbing method, a large amount of polarized light irradiation is required, and stable liquid crystal alignment cannot be achieved in some cases. .

For example, in the decomposition-type photo-alignment method described in Patent Document 1 described above, it is necessary to irradiate a polyimide film with ultraviolet light from a high-pressure mercury lamp with an output of 500 W for 60 minutes. Become. Also, in the case of the dimerization type or photoisomerization type photo-alignment method, a large amount of ultraviolet irradiation of several J (joules) to several tens of J may be required. Furthermore, in the case of the photo-crosslinking type or photo-isomerization type photo-alignment method, the heat stability and light stability of the alignment of the liquid crystal are inferior, so when it is used as a liquid crystal display device, problems such as poor alignment and display burn-in occur. was there. In particular, in horizontal electric field driving type liquid crystal display elements, since liquid crystal molecules are switched in-plane, misalignment of the liquid crystal tends to occur after the liquid crystal is driven.

Therefore, in the photo-alignment method, it is required to realize highly efficient alignment treatment and stable liquid crystal alignment. There is a need for alignment agents.

In addition, as a countermeasure against display burn-in caused by residual DC, when a liquid crystal alignment film is formed, a component other than polyamic acid or polyimide, which is imparted with the ability to control the alignment of liquid crystals by irradiating polarized ultraviolet rays, is added to increase the volume resistivity. Techniques have been used to add low polyamic acid to the alignment agent. However, when a liquid crystal aligning agent in which two kinds of polyamic acids or polyimides are mixed is stored at 23° C., the liquid crystal alignment stability may decrease with the lapse of storage time. Accordingly, there is a demand for a liquid crystal alignment film and a liquid crystal alignment agent that do not reduce liquid crystal alignment stability while eliminating display burn-in caused by residual DC.

The present invention provides a substrate having a liquid crystal alignment film for a lateral electric field drive type liquid crystal display element, which is imparted with highly efficient alignment control ability and excellent in image sticking characteristics due to liquid crystal alignment misalignment and residual DC, and a lateral electric field having the substrate. An object of the present invention is to provide a drive type liquid crystal display device.

As a result of intensive studies to solve the above problems, the present inventors have found a polyamic acid obtained from a specific aromatic tetracarboxylic dianhydride and a diamine, or an imidized polymer of a polyamic acid, and an aliphatic tetracarboxylic acid By using a polyamic acid obtained from a carboxylic acid dianhydride and a diamine having a specific structure, or an imidized polymer of a polyamic acid, highly efficient alignment controllability is imparted, and image sticking characteristics due to liquid crystal alignment misalignment and residual DC. The inventors have found that a liquid crystal alignment film having an excellent property can be obtained, and completed the present invention.

Thus, the present invention is based on the above findings and has the following gist.
1. (Aa) from a polyamic acid obtained using a tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride represented by the following formula (1) and a diamine component and an imidized polymer of the polyamic acid at least one selected polymer,
(Ab) Polyamic acid obtained using a tetracarboxylic dianhydride component containing an aliphatic tetracarboxylic dianhydride and a diamine component containing a diamine represented by the following formula (2), and the polyamic acid at least one polymer selected from imidized polymers,
and an organic solvent, and the weight ratio of (Aa) and (Ab) is (Aa):(Ab) = 55:45 to 90:10, preferably 60:40 to 90 :10, more preferably 60:40 to 85:15.

In formula (1), i is 0 or 1, X is a single bond, ether bond, carbonyl, ester bond, phenylene, linear alkylene having 1 to 20 carbon atoms, branched alkylene having 2 to 20 carbon atoms, a group consisting of a cyclic alkylene having 3 to 12 carbon atoms, a sulfonyl bond, an amide bond, or a combination thereof, wherein the alkylene having 1 to 20 carbon atoms is interrupted by a bond selected from an ester bond and an ether bond; and the carbon atoms of phenylene and alkylene may be substituted with one or more identical or different substituents selected from halogen atoms, cyano groups, alkyl groups, haloalkyl groups, alkoxy groups and haloalkoxy groups. .

2. 10 to 100 mol % of the tetracarboxylic dianhydride component (Aa) is the tetracarboxylic dianhydride of formula (1).
3. 3. The liquid crystal aligning agent according to 1 or 2, wherein 10 to 100 mol % of the tetracarboxylic dianhydride component (Ab) is an aliphatic tetracarboxylic dianhydride.
4. 4. The liquid crystal aligning agent according to any one of 1 to 3, wherein 10 to 100 mol % of the diamine component (Ab) is the diamine of formula (2).

5. 1 to 4, wherein the tetracarboxylic dianhydride represented by the formula (1) is at least one selected from pyromellitic dianhydride and 3,3′,4,4′-biphenyltetracarboxylic dianhydride The liquid crystal aligning agent according to any one of.
6. 6. The liquid crystal aligning agent according to any one of 1 to 5, wherein the aliphatic tetracarboxylic dianhydride is cyclobutanetetracarboxylic dianhydride or 1,3-dimethylcyclobutanetetracarboxylic dianhydride.

7. [I] A step of applying the composition according to any one of the above 1 to 6 onto a substrate having a conductive film for lateral electric field driving to form a coating film;
[II] The step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] The step of heating the coating film obtained in [II];
A method for producing a substrate having a liquid crystal alignment film, which obtains a liquid crystal alignment film for a lateral electric field drive type liquid crystal display element to which alignment control ability is imparted by having the above.
8. 8. A substrate having a liquid crystal alignment film for a lateral electric field drive type liquid crystal display element manufactured by the method as described in 7 above.
9. 9. A lateral electric field driven liquid crystal display device comprising the substrate according to 8 above.

10. A step of preparing the substrate (first substrate) according to 8 above;
[I'] A step of applying the composition according to any one of claims 1 to 6 on a second substrate to form a coating film;
[II'] The step of irradiating the coating film obtained in [I'] with polarized ultraviolet rays;
[III'] A step of heating the coating film obtained in [II']; obtaining a liquid crystal alignment film imparted with alignment control ability; obtaining a second substrate having the liquid crystal alignment film; and [IV] obtaining a liquid crystal display element by arranging the first and second substrates so that the liquid crystal alignment films of the first and second substrates face each other through the liquid crystal; A method for manufacturing a liquid crystal display device, for obtaining a lateral electric field driven liquid crystal display device.
11. 11. A lateral electric field driven liquid crystal display device manufactured by the method described in 10 above.

The liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention can align the liquid crystal with a small amount of polarized ultraviolet irradiation, and even if the liquid crystal alignment agent is stored at 23 ° C., the liquid crystal alignment stability of the liquid crystal alignment film is deteriorated. It is possible to speed up the relaxation of the residual DC accumulated by the DC voltage without causing the voltage to drop.

The liquid crystal aligning agent of the present invention includes (Aa) a polyamic acid obtained using a tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride represented by the following formula (1) and a diamine component; At least one polymer selected from imidized polymers of polyamic acids, (Ab) a tetracarboxylic dianhydride component containing an aliphatic tetracarboxylic dianhydride and a diamine represented by the following formula (2) At least one polymer selected from polyamic acid obtained using a diamine component containing and an imidized polymer of the polyamic acid, and an organic solvent, (Aa) and (Ab) The weight ratio is (Aa):(Ab) = 55:45 to 90:10, preferably 60:40 to 90:10, more preferably 60:40 to 85:15. do.

In formula (1), i is 0 or 1, X is a single bond, ether bond, carbonyl, ester bond, phenylene, linear alkylene having 1 to 20 carbon atoms, branched alkylene having 2 to 20 carbon atoms, a group consisting of a cyclic alkylene having 3 to 12 carbon atoms, a sulfonyl bond, an amide bond, or a combination thereof, wherein the alkylene having 1 to 20 carbon atoms is interrupted by a bond selected from an ester bond and an ether bond; and the carbon atoms of phenylene and alkylene may be substituted with one or more identical or different substituents selected from halogen atoms, cyano groups, alkyl groups, haloalkyl groups, alkoxy groups and haloalkoxy groups. .
Each component will be described in detail below.

<(Aa) component>
The (Aa) component used in the liquid crystal aligning agent of the present invention is obtained using a tetracarboxylic dianhydride component containing the tetracarboxylic dianhydride represented by the above formula (1) and a diamine component. It is at least one polymer selected from polyamic acids and imidized polymers of the polyamic acids.

<Tetracarboxylic dianhydride component>
Examples of the tetracarboxylic dianhydride represented by formula (1) include, but are not limited to, the following compounds. In the formula below, q represents an integer of 1 to 20.

Among the tetracarboxylic dianhydrides represented by the formula (1), the above formulas (1-1), (1-2), (1-3), ( 1-4), (1-5) and (1-7) are preferred, and from the viewpoint of stable supply, the above formulas (1-1) and (1-5) are particularly preferred.

In the component (Aa), if the amount of the tetracarboxylic dianhydride represented by the formula (1) in the total tetracarboxylic dianhydride component is too small, the effects of the present invention cannot be obtained. Therefore, the amount of the tetracarboxylic dianhydride represented by the formula (1) is 30 to 100 mol% with respect to 1 mol of the total tetracarboxylic dianhydride used in the production of the component (Aa). It is preferably 50 to 100 mol %, still more preferably 70 to 100 mol %.

Each of the tetracarboxylic dianhydrides represented by formula (1) may be used alone or in combination. In that case, the tetracarboxylic dianhydride represented by formula (1) It is preferable to use the above preferred amount as a total.

<Diamine component>
A diamine represented by the following formula (5) is used as the diamine component used in the production of the component (Aa) of the present invention.

W2 in Formula (5) is a ^divalent organic group, the structure of which is not particularly limited, and two or more types may be mixed. Specific examples thereof include structures represented by the following formulas [W ² -1] to [W ² -152]. R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group.

Among them, from the viewpoint of alleviating the residual DC accumulated by the DC voltage, W2-7, W2-8, W2-20, W2-21, W2-23, W2-24, W2-26, W2-40, W2-41 , W2-49, W2-51, W2-65, W2-67, W2-68, W2-69, W2-70, W2-71, W2-142, W2-144, W2-148, W2-151 are preferred , W2-65, W2-67, W2-68, W2-69, W2-70, W2-71, W2-142, W2-144, W2-148 and W2-151 are more preferred.

<(Ab) component>
The (Ab) component used in the liquid crystal aligning agent of the present invention is a tetracarboxylic dianhydride component containing an aliphatic tetracarboxylic dianhydride and a diamine component containing a diamine represented by the above formula (2). and at least one polymer selected from polyamic acids obtained using and imidized polymers of the polyamic acids.

Specific aliphatic tetracarboxylic dianhydrides used in the present invention include tetracarboxylic dianhydrides represented by the following formula (3). In the formula, X ₁ is any one of the following (X-1) to (X-28).

In formula (X-1), R ₃ to R ₆ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group, more preferably a hydrogen atom or a methyl group.

Among the above _, (X _{- 1} ) is most preferable from the viewpoint of photo _{- orientation} . A structure in which R ₆ is a hydrogen atom is preferred, and a structure in which R ₃ to R ₆ are hydrogen atoms is particularly preferred.

In the component (Ab), if the amount of the aliphatic dianhydride in the total tetracarboxylic dianhydride component is too small, the effects of the present invention cannot be obtained. Therefore, the amount of the aliphatic tetracarboxylic dianhydride is preferably 50 to 100 mol%, more preferably 60 to 100 mol %, more preferably 80 to 100 mol %.

The ratio of the diamine represented by the formula (2) in the polyamic acid and the imidized polymer of the polyamic acid, which is the component (Ab) of the present invention, is 1 mol of the total diamine used in the production of the component (Ab). , preferably 10 to 100 mol%, more preferably 30 to 100 mol%, still more preferably 50 to 100 mol%.

The polyamic acid and the imidized polymer of the polyamic acid, which are the components (Ab) contained in the liquid crystal aligning agent of the present invention, are represented by the above formula (5) in addition to the diamine represented by the above formula (2). You may use the diamine which is carried out.

In the polyamic acid and the imidized polymer of the polyamic acid which are the component (Ab) contained in the liquid crystal aligning agent of the present invention, when the ratio of the diamine represented by the formula (5) increases, the effect of the present invention is exhibited. Not preferred as it can be damaged. Therefore, the ratio of the diamine represented by formula (5) is preferably 0 to 90 mol%, more preferably 0 to 70 mol%, and still more preferably 0 to 50 mol%, relative to 1 mol of the total diamine. .

<Method for producing polyamic acid>
Polyamic acid, which is a polyimide precursor used in the present invention, can be synthesized by the method shown below.
Specifically, a tetracarboxylic dianhydride and a diamine are reacted in the presence of an organic solvent at −20 to 150° C., preferably 0 to 70° C., for 30 minutes to 24 hours, preferably 1 to 12 hours. can be synthesized by
The organic solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone, etc., in view of the solubility of the monomer and polymer. may be used.
The concentration of the polymer is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoints that precipitation of the polymer hardly occurs and that a high molecular weight product is easily obtained.
The polyamic acid obtained as described above can be collected by precipitating a polymer by injecting the reaction solution into a poor solvent while stirring well. Further, a purified polyamic acid powder can be obtained by performing precipitation several times, washing with a poor solvent, and drying at room temperature or by heating. The poor solvent is not particularly limited, but includes water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, toluene and the like, preferably water, methanol, ethanol and 2-propanol.

<Method for producing polyimide>
The polyimide used in the present invention can be produced by imidating the polyamic acid.
When producing a polyimide from a polyamic acid, chemical imidization by adding a catalyst to the solution of the polyamic acid obtained by the reaction of the diamine component and the tetracarboxylic dianhydride is convenient. Chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature and the molecular weight of the polymer is less likely to decrease during the imidization process.
Chemical imidization can be carried out by stirring a polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. As the organic solvent, the solvent used in the polymerization reaction described above can be used. Basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Among them, pyridine is preferable because it has an appropriate basicity for advancing the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, acetic anhydride is preferred because it facilitates purification after the reaction is completed.
The imidization reaction temperature is -20 to 140°C, preferably 0 to 100°C, and the reaction time is 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 times the moles of the polyamic acid groups, preferably 2 to 20 times the moles, and the amount of the acid anhydride is 1 to 50 times the moles of the polyamic acid groups, preferably 3 to 30 times the moles. Mole. The imidization rate of the resulting polymer can be controlled by adjusting the catalyst amount, temperature and reaction time.
Since the added catalyst and the like remain in the solution after the imidization reaction of the polyamic acid, the obtained imidized polymer is recovered by the means described below, redissolved in an organic solvent, and the present invention It is preferable to set it as the liquid crystal aligning agent of this.

The polyimide solution obtained as described above is poured into a poor solvent while stirring well to precipitate a polymer. Precipitation is carried out several times, washed with a poor solvent, and dried at room temperature or by heating to obtain a purified polymer powder.
The poor solvent is not particularly limited, but includes methanol, 2-propanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene and the like, and methanol, ethanol, 2-propanol, Acetone and the like are preferred.

The weight ratio of component (Aa) and component (Ab) thus produced is (Aa):(Ab)=55:45 to 90:10, preferably 60:40. The effect of the invention is exhibited when the ratio is up to 90:10, more preferably 60:40 to 85:15. That is, within the above range, the residual DC accumulated by the direct current is quickly relieved and the liquid crystal alignment stability is excellent, so that the burn-in property is excellent.

The polyimide precursor used in the present invention is obtained from a reaction between a diamine component and a tetracarboxylic acid derivative, and examples thereof include polyamic acids and polyamic acid esters.

<Polyimide Precursor - Production of Polyamic Acid>
The method for producing the polyamic acid described in the sections for the components (Aa) and (Ab) is followed.

<Polyimide Precursor - Production of Polyamic Acid Ester>
A polyamic acid ester, which is a polyimide precursor used in the present invention, can be produced by the following production methods (1), (2), or (3).

(1) Production from polyamic acid A polyamic acid ester can be produced by esterifying the polyamic acid produced as described above. Specifically, a polyamic acid and an esterifying agent are reacted in the presence of an organic solvent at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 hours, preferably 1 to 4 hours. can be manufactured.
As the esterifying agent, those that can be easily removed by purification are preferable, and include N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, N,N-dimethylformamide dipropyl acetal, and N,N-dimethylformamide. Dineopentyl butyl acetal, N,N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p -tolyltriazene, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride and the like. The amount of the esterifying agent to be added is preferably 2 to 6 molar equivalents per 1 mol of repeating units of the polyamic acid.

Examples of organic solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide or 1,3-dimethyl- Imidazolidinones are mentioned. Further, when the polyimide precursor has a high solvent solubility, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or Formula [D-1] to Formula [D-3] described later. A solvent represented by can be used.
These solvents may be used alone or in combination. Furthermore, even a solvent that does not dissolve the polyimide precursor may be mixed with the solvent and used as long as the generated polyimide precursor does not precipitate. Moreover, water in the solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyimide precursor, so it is preferable to use a dehydrated and dried solvent.
The solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone in view of the solubility of the polymer, and these may be used singly or in combination of two or more. good. The concentration at the time of production is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoints that precipitation of the polymer is less likely to occur and a high molecular weight product can be easily obtained.

(2) Production by reaction of tetracarboxylic acid diester dichloride and diamine Polyamic acid ester can be produced from tetracarboxylic acid diester dichloride and diamine.
Specifically, a tetracarboxylic acid diester dichloride and a diamine are mixed in the presence of a base and an organic solvent at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 hours, preferably 1 to 4 hours. It can be produced by reacting.
Pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used as the base, but pyridine is preferred because the reaction proceeds moderately. The amount of the base to be added is preferably 2 to 4 times the molar amount of the tetracarboxylic acid diester dichloride because it is an amount that can be easily removed and a high molecular weight product can be easily obtained.
The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone in terms of solubility of the monomer and polymer, and these may be used singly or in combination of two or more. The polymer concentration during production is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoints that precipitation of the polymer is less likely to occur and a high molecular weight product can be easily obtained. Moreover, in order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, the solvent used in the production of the polyamic acid ester is preferably dehydrated as much as possible, and is preferably kept in a nitrogen atmosphere to prevent contamination with outside air.

(3) Production from tetracarboxylic acid diester and diamine Polyamic acid ester can be produced by polycondensation of tetracarboxylic acid diester and diamine.
Specifically, a tetracarboxylic acid diester and a diamine are mixed in the presence of a condensing agent, a base, and an organic solvent at 0° C. to 150° C., preferably 0° C. to 100° C., for 30 minutes to 24 hours, preferably 3 to 15 hours. It can be produced by time reaction.
The condensing agent includes triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N'-carbonyldiimidazole, dimethoxy-1,3,5-triazide Nylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium Tetrafluoroborate, O-(benzotriazol-1-yl)-N,N , N′,N′-tetramethyluronium hexafluorophosphate, diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate and the like can be used. The amount of the condensing agent to be added is preferably 2 to 3 times the molar amount of the tetracarboxylic acid diester.

Tertiary amines such as pyridine and triethylamine can be used as the base. The amount of the base to be added is preferably 2 to 4 times the molar amount of the diamine component because it is an amount that can be easily removed and a high molecular weight product can be easily obtained.
Moreover, in the above reaction, the reaction proceeds efficiently by adding a Lewis acid as an additive. Preferred Lewis acids are lithium halides such as lithium chloride and lithium bromide. The amount of the Lewis acid to be added is preferably 0 to 1.0 times the molar amount of the diamine component.
Among the above three methods for producing a polyamic acid ester, the above method (1) or (2) is particularly preferable because a high-molecular-weight polyamic acid ester can be obtained.
The solution of the polyamic acid ester obtained as described above is poured into a poor solvent while stirring well to precipitate the polymer. Precipitation is carried out several times, washed with a poor solvent, and dried at room temperature or by heating to obtain a purified polyamic acid ester powder. Poor solvents include, but are not limited to, water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

<Liquid crystal aligning agent>
The liquid crystal aligning agent used in the present invention has the form of a solution in which a polymer component is dissolved in an organic solvent. The weight average molecular weight of the polymer is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, still more preferably 10,000 to 100,000. Also, the number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, still more preferably 5,000 to 50,000.
The concentration of the polymer of the liquid crystal aligning agent used in the present invention can be appropriately changed by setting the thickness of the coating film to be formed. % or more, and preferably 10% by mass or less from the viewpoint of storage stability of the solution. A particularly preferred polymer concentration is 2 to 8% by weight.

The organic solvent contained in the liquid crystal aligning agent used in the present invention is not particularly limited as long as it uniformly dissolves the polymer component. Specific examples include N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethylsulfoxide, dimethylsulfone, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide and the like. These may be used singly or in combination of two or more. Moreover, even a solvent that cannot uniformly dissolve the polymer component by itself may be mixed with the above organic solvent as long as the polymer is not precipitated.

In addition, the organic solvent contained in the liquid crystal aligning agent is a mixed solvent in which a solvent that improves the coating properties and the surface smoothness of the coating film when applying the liquid crystal aligning agent in addition to the above solvents is used. is common, and such a mixed solvent is suitably used also in the liquid crystal aligning agent of this invention. Specific examples of the organic solvent used in combination are listed below, but are not limited to these examples.
For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol , 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 2,6- dimethyl-4-heptanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2, 3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diisopropyl ether, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene Glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2- Pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 4,6-dimethyl-2-heptanone, 3-ethoxybutylacetate, 1-methylpentylacetate tart, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2-(methoxymethoxy)ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-(hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoethyl ether Propylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate , diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, acetic acid Ethyl, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate , 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, lactic acid methyl ester, lactic acid ethyl ester, lactic acid n-propyl ester, lactic acid n-butyl ester, lactic acid isoamyl ester , and solvents represented by the following formulas [D-1] to [D-3].

In formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, in formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and formula [D-3] Among them, D3 represents an alkyl group having 1 to ⁴ carbon atoms.

Preferred combinations of solvents include N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, and N-ethyl-2-pyrrolidone. and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2, 6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone, γ-butyrolactone, dipropylene glycol dimethyl ether, and the like. The kind and content of such a solvent are appropriately selected according to the liquid crystal aligning agent coating device, coating conditions, coating environment, and the like.

Moreover, in order to raise the mechanical strength of a film|membrane, you may add the following additives to the liquid crystal aligning agent of this invention.

These additives are preferably 0.1 to 30 parts by weight per 100 parts by weight of the polymer component contained in the liquid crystal aligning agent. If the amount is less than 0.1 parts by mass, no effect can be expected, and if the amount exceeds 30 parts by mass, the orientation of the liquid crystal is lowered.
In addition to the above, the liquid crystal aligning agent of the present invention includes a polymer other than a polymer, and a liquid crystal alignment film for the purpose of changing electrical properties such as dielectric constant and conductivity, as long as the effects of the present invention are not impaired. A dielectric or conductive substance, a silane coupling agent for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate, a cross-linking compound for the purpose of increasing the hardness and denseness of the film when it is made into a liquid crystal alignment film, and even a coating An imidization accelerator or the like may be added for the purpose of efficiently advancing the imidization of the polyamic acid when the film is baked.

<Liquid crystal alignment film> and <Method for manufacturing liquid crystal alignment film>
The liquid crystal aligning film of the present invention is a film obtained by applying the liquid crystal aligning agent to a substrate, drying, and baking. The substrate to which the liquid crystal aligning agent of the present invention is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a silicon nitride substrate, an acrylic substrate, a plastic substrate such as a polycarbonate substrate, or the like can be used. From the viewpoint of process simplification, it is preferable to use a substrate on which an ITO electrode or the like for is formed. In the case of a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side.

Examples of the method for applying the liquid crystal aligning agent of the present invention include a spin coating method, a printing method, an inkjet method, and the like. Any temperature and time can be selected for the drying and baking steps after applying the liquid crystal aligning agent of the present invention. In general, it is dried at 50° C. to 120° C. for 1 minute to 10 minutes in order to sufficiently remove the contained organic solvent, and then calcined at 150° C. to 300° C. for 5 minutes to 120 minutes. The thickness of the coating film after baking is not particularly limited, but it is 5 to 300 nm, preferably 10 to 200 nm, because if it is too thin, the reliability of the liquid crystal display element may deteriorate.

A rubbing method, an optical alignment treatment method, etc. are mentioned as a method of aligning the obtained liquid crystal aligning film.
The rubbing process can be performed using an existing rubbing apparatus. The material of the rubbing cloth in this case includes cotton, nylon, rayon, and the like. As the conditions for the rubbing treatment, a rotation speed of 300 to 2000 rpm, a feed rate of 5 to 100 mm/s, and a pressing amount of 0.1 to 1.0 mm are generally used. After that, the residue generated by the rubbing is removed by ultrasonic cleaning using pure water, alcohol, or the like.

As a specific example of the photo-alignment treatment method, the coating film surface is irradiated with radiation polarized in a certain direction, and in some cases, further heat-treated at a temperature of 150 to 250 ° C. to impart liquid crystal alignment ability. mentioned. As radiation, ultraviolet rays and visible rays having a wavelength of 100 nm to 800 nm can be used. Among these, ultraviolet rays having a wavelength of 100 nm to 400 nm are preferred, and those having a wavelength of 200 nm to 400 nm are particularly preferred. In order to improve liquid crystal orientation, radiation may be applied while heating the coated film substrate at 50 to 250°C. The radiation dose is preferably 1 to 10,000 mJ/cm ² , particularly preferably 100 to 5,000 mJ/cm ² . The liquid crystal alignment film produced as described above can stably orient liquid crystal molecules in a certain direction.
A higher extinction ratio of polarized ultraviolet rays is preferable because higher anisotropy can be imparted. Specifically, the extinction ratio of linearly polarized ultraviolet light is preferably 10:1 or more, more preferably 20:1 or more.

The film irradiated with polarized radiation may then be contact-treated with a solvent containing at least one selected from water and organic solvents.
The solvent used for the contact treatment is not particularly limited as long as it dissolves the decomposition products produced by light irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, 3- methyl methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate; Two or more of these solvents may be used in combination.

At least one selected from the group consisting of water, 2-propanol, 1-methoxy-2-propanol and ethyl lactate is more preferable from the viewpoint of versatility and safety. Particularly preferred are water, 2-propanol, and mixed solvents of water and 2-propanol.
In the present invention, the contact treatment between the film irradiated with polarized radiation and the solution containing the organic solvent is a treatment such as immersion treatment or spray treatment, which preferably allows sufficient contact between the film and the liquid. done. Among them, a method of immersing the film in a solution containing an organic solvent for preferably 10 seconds to 1 hour, more preferably 1 to 30 minutes, is preferred. The contact treatment may be carried out at room temperature or with heating, preferably at 10 to 80°C, more preferably at 20 to 50°C. In addition, means for enhancing contact, such as ultrasonic waves, can be applied as necessary.
After the above contact treatment, either or both rinsing with a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone, and methyl ethyl ketone, or drying for the purpose of removing the organic solvent in the solution used. may be performed.

Furthermore, the film that has been subjected to contact treatment with a solvent as described above may be heated at 150° C. or higher for the purpose of drying the solvent and reorienting the molecular chains in the film.
The heating temperature is preferably 150 to 300°C. A higher temperature promotes the reorientation of the molecular chains, but if the temperature is too high, the molecular chains may be decomposed. Therefore, the heating temperature is more preferably 180 to 250°C, particularly preferably 200 to 230°C.
If the heating time is too short, the effect of reorientation of the molecular chains may not be obtained, and if it is too long, the molecular chains may be decomposed, so 10 seconds to 30 minutes is preferable, and 1 minute. ~10 minutes is more preferred.

The method for producing a substrate having a liquid crystal alignment film of the present invention preferably includes the following steps [I] to [IV].
[I] (Aa) Polyamic acid obtained using a tetracarboxylic dianhydride component containing the tetracarboxylic dianhydride represented by formula (1) and a diamine component, and imidization polymerization of the polyamic acid At least one type of polymer selected from coalescence, (Ab) using a tetracarboxylic dianhydride component containing an aliphatic tetracarboxylic dianhydride and a diamine component containing a diamine represented by formula (2) A liquid crystal aligning agent containing at least one polymer selected from the polyamic acid obtained by and the imidized polymer of the polyamic acid and an organic solvent is coated on a substrate having a conductive film for lateral electric field driving. forming a coating film;
[II] The step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] The step of heating the coating film obtained in [II];
have
Through the above steps, a liquid crystal alignment film for a lateral electric field drive type liquid crystal display device having an alignment control ability can be obtained, and a substrate having the liquid crystal alignment film can be obtained.

Also, by preparing a second substrate in addition to the obtained substrate (first substrate), a lateral electric field driven liquid crystal display element can be obtained.
For the second substrate, a substrate not having a conductive film for driving a horizontal electric field is used instead of a substrate having a conductive film for driving a horizontal electric field. Since a substrate that does not have a conductive film is used, steps [I′] to [III′] may be abbreviated in the present application for the sake of convenience. 2 substrates can be obtained.

A method for manufacturing a lateral electric field driving liquid crystal display element includes:
[IV] A step of arranging the first and second substrates obtained above so that the liquid crystal alignment films of the first and second substrates face each other through the liquid crystal to obtain a liquid crystal display element;
have Thus, a lateral electric field driven liquid crystal display element can be obtained.

Each step of [I] to [III] and [IV] of the production method of the present invention will be described below.
<Step [I]>
In step [I], a coating film is formed by coating a polymer composition containing a photosensitive main polymer and an organic solvent on a substrate having a conductive film for lateral electric field driving.

<Substrate>
Although the substrate is not particularly limited, it is preferable to use a highly transparent substrate when the liquid crystal display element to be manufactured is of a transmissive type. In that case, there is no particular limitation, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used.
In consideration of application to a reflective liquid crystal display device, an opaque substrate such as a silicon wafer can also be used.

<Conductive film for lateral electric field driving>
The substrate has a conductive film for lateral electric field driving.
Examples of the conductive film include, but are not limited to, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and the like when the liquid crystal display device is of a transmissive type.
Further, in the case of a reflective liquid crystal display element, the conductive film may be, but is not limited to, a material such as aluminum that reflects light.
A conventionally known technique can be used as a method for forming the conductive film on the substrate.

The method of applying the polymer composition described above onto a substrate having a conductive film for lateral electric field driving is not particularly limited.
Industrially, screen printing, offset printing, flexographic printing, ink jet method, or the like is generally used as the coating method. Other coating methods include a dip method, a roll coater method, a slit coater method, a spinner method (rotational coating method), a spray method, and the like, and these may be used depending on the purpose.

After coating the polymer composition on the substrate having a conductive film for lateral electric field driving, it is heated to 50 to 300° C., preferably 50 to 50° C. by heating means such as a hot plate, thermal circulation oven or IR (infrared) oven. The coating film can be obtained by evaporating the solvent at 180°C. The drying temperature at this time is preferably lower than that in the step [III] from the viewpoint of liquid crystal alignment stability.
The thickness of the coating film is preferably 5 nm to 300 nm, more preferably 10 nm to 150 nm, because if it is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease. is.
It is also possible to provide a step of cooling the substrate having the coating film formed thereon to room temperature after the step [I] and before the subsequent step [II].

<Step [II]>
In step [II], the coating film obtained in step [I] is irradiated with polarized ultraviolet rays. When the film surface of the coating film is irradiated with polarized ultraviolet rays, the substrate is irradiated with the polarized ultraviolet rays from a certain direction through a polarizing plate. Ultraviolet rays having a wavelength of 100 nm to 400 nm can be used as the ultraviolet rays. Preferably, the optimum wavelength is selected through a filter or the like depending on the type of coating film to be used. Then, for example, ultraviolet light with a wavelength in the range of 240 nm to 400 nm can be selected and used so as to selectively induce a photodecomposition reaction. As ultraviolet rays, for example, light emitted from a high-pressure mercury lamp or a metal halide lamp can be used.

The dose of polarized UV radiation depends on the coating used. The irradiation amount is the maximum value of ΔA (hereinafter also referred to as ΔAmax), which is the difference between the ultraviolet absorbance in the direction parallel to the polarization direction of the polarized ultraviolet light and the ultraviolet light absorbance in the direction perpendicular to the polarization direction of the polarized ultraviolet light. It is preferably in the range of 1% to 70%, more preferably in the range of 1% to 50% of the amount of.

<Step [III]>
In step [III], the coating film irradiated with the polarized ultraviolet rays in step [II] is heated. Heating can impart alignment control ability to the coating film.
For heating, a heating means such as a hot plate, thermal circulation oven or IR (infrared) oven can be used. The heating temperature can be determined in consideration of the temperature at which the coating film to be used exhibits good liquid crystal alignment stability and electrical properties.

The heating temperature is preferably within a temperature range in which the main chain type polymer exhibits good liquid crystal alignment stability. If the heating temperature is too low, the thermal anisotropic amplification effect and thermal imidization tend to be insufficient. They tend to disappear, in which case self-assembly can make it difficult to reorient in one direction.

The thickness of the coating film formed after heating is preferably 5 nm to 300 nm, more preferably 50 nm to 150 nm, for the same reason as described in step [I].
With the steps described above, the production method of the present invention can introduce anisotropy into the coating film with high efficiency. And a substrate with a liquid crystal alignment film can be manufactured with high efficiency.

<Step [IV]>
In step [IV], the substrate (first substrate) having a liquid crystal alignment film on a conductive film for driving a horizontal electric field obtained in step [III] and steps [I′] to [III′] in the same manner as described above. ] and the substrate with a liquid crystal alignment film having no conductive film (second substrate) are arranged opposite to each other so that both liquid crystal alignment films face each other through the liquid crystal, and the liquid crystal is formed by a known method. This is a step of manufacturing a cell and manufacturing a lateral electric field driving liquid crystal display element.
In steps [I'] to [III'], the substrate having no lateral electric field driving conductive film is used instead of the substrate having the lateral electric field driving conductive film in step [I]. It can be carried out in the same manner as steps [I] to [III]. The difference between steps [I] to [III] and steps [I'] to [III'] is only the presence or absence of the above-described conductive film, so the description of steps [I'] to [III'] is omitted. do.

<Liquid crystal display element>
In the liquid crystal display element of the present invention, after obtaining a substrate with a liquid crystal aligning film from the liquid crystal aligning agent of the present invention by the method for producing a liquid crystal aligning film, a liquid crystal cell is produced by a known method, and the liquid crystal is used. It is used as a display element.
As an example of the method of manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described. A liquid crystal display element having an active matrix structure in which a switching element such as a TFT (Thin Film Transistor) is provided in each pixel portion forming an image display may be used.
First, transparent glass substrates are prepared, a common electrode is provided on one substrate, and a segment electrode is provided on the other substrate. These electrodes can be ITO electrodes, for example, and are patterned so as to display a desired image. Next, an insulating film is provided on each substrate so as to cover the common electrodes and the segment electrodes. The insulating film can be, for example, a film made of SiO ₂ —TiO ₂ formed by a sol-gel method.

Next, the liquid crystal alignment film of the present invention is formed on each substrate by the method described above.
One substrate is overlaid on the other substrate so that the alignment film surfaces face each other, and the periphery is bonded with a sealing material. A spacer is usually mixed in the sealing material in order to control the gap between the substrates. Moreover, it is preferable to disperse spacers for controlling the gap between the substrates even in the in-plane portions where the sealing material is not provided. A part of the sealing material is provided with an opening through which the liquid crystal can be filled from the outside.
Next, a liquid crystal material is injected into the space surrounded by the two substrates and the sealing material through the opening provided in the sealing material. This opening is then sealed with an adhesive. For injection, a vacuum injection method may be used, or a method utilizing capillary action in the atmosphere may be used. Next, a polarizing plate is installed. Specifically, a pair of polarizing plates are attached to the surfaces of the two substrates opposite to the liquid crystal layer. The liquid crystal display device of the present invention is obtained through the above steps.

In the present invention, as the sealing agent, for example, a resin that has a reactive group such as an epoxy group, an acryloyl group, a methacryloyl group, a hydroxyl group, an allyl group, and an acetyl group and is cured by ultraviolet irradiation or heating is used. In particular, it is preferred to use a curable resin system having both epoxy and (meth)acryloyl reactive groups.
The sealant of the present invention may contain an inorganic filler for the purpose of improving adhesion and moisture resistance. The inorganic filler that can be used is not particularly limited, but specific examples include spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, Calcium sulfate, mica, talc, clay, alumina, magnesium oxide, zirconium oxide, aluminum hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos, etc. preferably spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate , aluminum silicate. Two or more kinds of the above inorganic fillers may be mixed and used.

As described above, the substrate for a lateral electric field-driven liquid crystal display device manufactured using the polymer of the present invention or the lateral electric field-driven liquid crystal display device having the substrate can produce excellent liquid crystal with a small amount of polarized ultraviolet irradiation. Since it exhibits alignment stability and residual DC relaxation properties, it can be suitably used for large-screen, high-definition liquid crystal televisions and the like. In addition, the liquid crystal alignment film manufactured by the method of the present invention has excellent reliability and can be used for a variable phase shifter using liquid crystal, and this variable phase shifter can change the resonance frequency, for example. It can be suitably used for antennas and the like.

EXAMPLES The present invention will be specifically described below with reference to examples, etc., but the present invention is not limited to these examples. Abbreviations of compounds and solvents are as follows.
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve DA-1: Compound DA-2 represented by the following structural formula (DA-1): Compound DA-3 represented by the following structural formula (DA-2): Compound DA-4 represented by the following structural formula (DA-3): Compound DA-5 represented by the following structural formula (DA-4): Compound DA-6 represented by the following structural formula (DA-5) : compound DA-7 represented by the following structural formula (DA-6): compound CA-1 represented by the following structural formula (DA-7): compound CA- represented by the following structural formula (CA-1) 2: Compound CA-3 represented by the following structural formula (CA-2): Compound CA-4 represented by the following structural formula (CA-3): Compound represented by the following structural formula (CA-4)

<Measurement of viscosity>
In the synthesis examples, the viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), a sample amount of 1.1 mL, a cone rotor TE-1 (1 ° 34', R24), and a temperature of 25. Measured in °C.

<Synthesis Example 1>
2.18 g (5.40 mmol) of DA-1 and 3.43 g (12.6 mmol) of DA-2 were weighed into a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and 55.8 g of NMP was added. , and dispersed by stirring while sending nitrogen. While stirring this diamine solution under water cooling, 3.25 g (16.6 mmol) of CA-1 was added, further 23.9 g of NMP was added, and the mixture was stirred at 23° C. for 5 hours under a nitrogen atmosphere to give a polyamic acid-polyimide copolymer. A polymer solution was obtained. The viscosity of this polyamic acid-polyimide copolymer solution at a temperature of 25° C. was 178 mPa·s.
30.2 g of this polyamic acid-polyimide copolymer solution was placed in a 100 mL Erlenmeyer flask equipped with a stir bar, 16.8 g of NMP and 20.1 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours. , to obtain a liquid crystal aligning agent (A-1).

<Synthesis Example 2>
5.10 g (12.6 mmol) of DA-1 and 1.32 g (5.40 mmol) of DA-3 were weighed into a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and 61.8 g of NMP was added. , and dispersed by stirring while sending nitrogen. While stirring this diamine solution under water cooling, 2.19 g (11.2 mmol) of CA-1 and 1.21 g (5.40 mmol) of CA-2 were added, further 26.5 g of NMP was added, and The mixture was stirred at 40° C. for 6 hours to obtain a polyamic acid-polyimide copolymer solution. The viscosity of this polyamic acid-polyimide copolymer solution at a temperature of 25° C. was 193 mPa·s.
31.3 g of this polyamic acid-polyimide copolymer solution was placed in a 100 mL Erlenmeyer flask equipped with a stir bar, 17.4 g of NMP and 20.9 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours. , to obtain a liquid crystal aligning agent (A-2).

<Synthesis Example 3>
2.79 g (14.0 mmol) of DA-4 and 1.47 g (6.00 mmol) of DA-3 were weighed into a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and 50.5 g of NMP was added. , was dissolved by stirring under nitrogen. While stirring this diamine solution under water cooling, 5.59 g (19.0 mmol) of CA-3 was added, 21.7 g of NMP was added, and the mixture was stirred at 50°C for 20 hours under a nitrogen atmosphere to form a polyamic acid solution. Obtained. The viscosity of this polyamic acid solution at a temperature of 25° C. was 480 mPa·s.
29.0 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask equipped with a stirrer, 25.1 g of NMP and 23.2 g of BCS were added, stirred with a magnetic stirrer for 2 hours, and the liquid crystal aligning agent ( A-3) was obtained.

<Synthesis Example 4>
In a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, 3.19 g (16.0 mmol) of DA-4 and 0.433 g (4.00 mmol) of DA-5 were weighed, and 47.3 g of NMP was added. , was dissolved by stirring under nitrogen. While stirring this diamine solution under water cooling, 5.59 g (19.0 mmol) of CA-3 was added, 20.3 g of NMP was further added, and the mixture was stirred at 50°C for 20 hours under a nitrogen atmosphere to form a polyamic acid solution. Obtained. The viscosity of this polyamic acid solution at a temperature of 25° C. was 455 mPa·s.
30.7 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask equipped with a stirrer, 26.6 g of NMP and 24.6 g of BCS were added, stirred with a magnetic stirrer for 2 hours, and the liquid crystal aligning agent ( A-4) was obtained.

<Synthesis Example 5>
In a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, 3.19 g (16.0 mmol) of DA-4 and 0.433 g (4.00 mmol) of DA-6 were weighed, and 47.3 g of NMP was added. , was dissolved by stirring under nitrogen. While stirring this diamine solution under water cooling, 5.59 g (19.0 mmol) of CA-3 was added, 20.3 g of NMP was further added, and the mixture was stirred at 50°C for 20 hours under a nitrogen atmosphere to form a polyamic acid solution. Obtained. The viscosity of this polyamic acid solution at a temperature of 25° C. was 418 mPa·s.
30.1 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask equipped with a stirrer, 26.1 g of NMP and 24.1 g of BCS were added, stirred with a magnetic stirrer for 2 hours, and the liquid crystal aligning agent ( A-5) was obtained.

<Synthesis Example 6>
In a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, 3.19 g (16.0 mmol) of DA-4 and 0.977 g (4.00 mmol) of DA-3 were weighed, and 41.0 g of NMP was added. , was dissolved by stirring under nitrogen. While stirring this diamine solution under water cooling, 1.65 g (8.40 mmol) of CA-1 was added, and after stirring for 4 hours at 23° C. under a nitrogen atmosphere, 2.18 g (10.0 mmol) of CA-4 was added. Further, 17.6 g of NMP was added and stirred at 50° C. for 18 hours under a nitrogen atmosphere to obtain a solution of polyamic acid. The viscosity of this polyamic acid solution at a temperature of 25° C. was 246 mPa·s.
29.7 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask equipped with a stirrer, 25.7 g of NMP and 23.8 g of BCS were added, stirred with a magnetic stirrer for 2 hours, and the liquid crystal aligning agent ( A-6) was obtained.

<Synthesis Example 7>
3.97 g (20.0 mmol) of DA-7 was weighed into a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 49.1 g of NMP was added, and the mixture was dissolved by stirring while supplying nitrogen. While stirring this diamine solution under water cooling, 5.59 g (19.0 mmol) of CA-3 was added, 21.0 g of NMP was further added, and the mixture was stirred at 50°C for 20 hours under a nitrogen atmosphere to form a polyamic acid solution. Obtained. The viscosity of this polyamic acid solution at a temperature of 25° C. was 376 mPa·s.
30.4 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask equipped with a stirrer, 26.4 g of NMP and 24.3 g of BCS were added, stirred with a magnetic stirrer for 2 hours, and the liquid crystal aligning agent ( A-7) was obtained.

<Synthesis Example 8>
8.07 g of the liquid crystal aligning agent (A-1) obtained in Synthesis Example 1 and 12.1 g of the liquid crystal aligning agent (A-3) obtained in Synthesis Example 3 were weighed into a 50 mL Erlenmeyer flask containing a stirring bar. It was taken out and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-8).

<Synthesis Example 9>
8.12 g of the liquid crystal aligning agent (A-1) obtained in Synthesis Example 1 and 12.2 g of the liquid crystal aligning agent (A-4) obtained in Synthesis Example 4 were weighed into a 50 mL Erlenmeyer flask containing a stirring bar. It was taken out and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-9).

<Synthesis Example 10>
8.21 g of the liquid crystal aligning agent (A-1) obtained in Synthesis Example 1 and 12.3 g of the liquid crystal aligning agent (A-5) obtained in Synthesis Example 5 were weighed into a 50 mL Erlenmeyer flask containing a stirring bar. It was taken out and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-10).

<Synthesis Example 11>
6.02 g of the liquid crystal aligning agent (A-2) obtained in Synthesis Example 2 and 14.0 g of the liquid crystal aligning agent (A-6) obtained in Synthesis Example 6 were weighed into a 50 mL Erlenmeyer flask containing a stirrer. It was taken out and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-11).

<Synthesis Example 12>
6.11 g of the liquid crystal aligning agent (A-2) obtained in Synthesis Example 2 and 14.3 g of the liquid crystal aligning agent (A-7) obtained in Synthesis Example 7 were weighed into a 50 mL Erlenmeyer flask containing a stirring bar. It was taken out and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-12).

<Synthesis Example 13>
4.24 g of the liquid crystal aligning agent (A-1) obtained in Synthesis Example 1 and 16.96 g of the liquid crystal aligning agent (A-3) obtained in Synthesis Example 3 were weighed into a 50 mL Erlenmeyer flask containing a stirrer. It was taken out and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-13).

<Comparative Synthesis Example 1>
2.18 g (5.40 mmol) of DA-1 and 3.43 g (12.6 mmol) of DA-2 were weighed into a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and 58.1 g of NMP was added. , and dispersed by stirring while sending nitrogen. While stirring this diamine solution under water cooling, 3.61 g (16.6 mmol) of CA-4 was added, further 24.9 g of NMP was added, and the mixture was stirred at 50° C. for 18 hours under a nitrogen atmosphere to form a polyamic acid-polyimide copolymer. A polymer solution was obtained. The viscosity of this polyamic acid-polyimide copolymer solution at a temperature of 25° C. was 269 mPa·s.
30.6 g of this polyamic acid-polyimide copolymer solution was placed in a 100 mL Erlenmeyer flask equipped with a stir bar, 17.0 g of NMP and 20.4 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours. , to obtain a liquid crystal aligning agent (B-1).

<Comparative Synthesis Example 2>
3.97 g (20.0 mmol) of DA-7 was weighed into a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, 39.5 g of NMP was added, and dissolved by stirring while sending nitrogen. While stirring this diamine solution under water cooling, 3.73 g (19.0 mmol) of CA-1 was added, further 16.9 g of NMP was added, and the mixture was stirred at 23° C. for 4 hours under a nitrogen atmosphere to form a polyamic acid solution. Obtained. The viscosity of this polyamic acid solution at a temperature of 25° C. was 265 mPa·s.
29.9 g of this polyamic acid solution was placed in a 100 mL Erlenmeyer flask equipped with a stirrer, 25.9 g of NMP and 23.9 g of BCS were added, stirred with a magnetic stirrer for 2 hours, and the liquid crystal aligning agent ( B-2) was obtained.

<Comparative Synthesis Example 3>
8.14 g of the liquid crystal aligning agent (B-1) obtained in Comparative Synthesis Example 1 and 12.2 g of the liquid crystal aligning agent (A-3) obtained in Synthesis Example 3 were placed in a 50 mL Erlenmeyer flask containing a stirring bar. It was weighed and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (B-3).

<Comparative Synthesis Example 4>
6.07 g of the liquid crystal aligning agent (A-2) obtained in Synthesis Example 2 and 14.2 g of the liquid crystal aligning agent (B-2) obtained in Comparative Synthesis Example 2 were placed in a 50 mL Erlenmeyer flask containing a stirring bar. It was weighed and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (B-4).

<Comparative Synthesis Example 5>
10.1 g of the liquid crystal aligning agent (A-2) obtained in Synthesis Example 2 and 10.1 g of the liquid crystal aligning agent (A-7) obtained in Synthesis Example 7 were weighed into a 50 mL Erlenmeyer flask containing a stirrer. It was taken out and stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (B-5).

<Preparation of liquid crystal cell for evaluating relaxation characteristics of liquid crystal alignment stability and residual DC>
A method of manufacturing a liquid crystal cell for evaluating the stability of liquid crystal alignment and relaxation properties of residual DC will be described below.
A liquid crystal cell having the configuration of an FFS liquid crystal display element was produced. First, a substrate with electrodes was prepared. The substrate is a glass substrate with a size of 30 mm×35 mm and a thickness of 0.7 mm. An IZO electrode constituting a counter electrode was formed as a first layer on the entire surface of the substrate. A SiN (silicon nitride) film formed by a CVD method was formed as a second layer on the counter electrode of the first layer. The SiN film of the second layer has a film thickness of 500 nm and functions as an interlayer insulating film. On the SiN film of the second layer, a comb-shaped pixel electrode formed by patterning an IZO film was arranged as a third layer to form two pixels, a first pixel and a second pixel. . The size of each pixel is 10 mm long and about 5 mm wide. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the action of the SiN film of the second layer.

The pixel electrode of the third layer is composed of a plurality of comb-like electrode elements arranged in a dogleg shape with a bent central portion, similar to the figure described in Japanese Patent Application Laid-Open No. 2014-77845. shape. The width of each electrode element in the lateral direction is 3 μm, and the interval between electrode elements is 6 μm. Since the pixel electrode forming each pixel is configured by arranging a plurality of V-shaped electrode elements with bent central portions, the shape of each pixel is not rectangular but bent at the central portion like the electrode elements. , Bold, with a shape resembling a Chinese character. Each pixel is vertically divided by the curved portion in the center, and has a first region above the curved portion and a second region below the curved portion.
Comparing the first region and the second region of each pixel, the formation direction of the electrode elements of the pixel electrodes constituting them is different. That is, when the direction of a line segment obtained by projecting the plane of polarization of polarized ultraviolet rays (to be described later) onto the substrate is used as a reference, in the first region of the pixel, the electrode elements of the pixel electrode are formed so as to form an angle of +10° (clockwise). However, in the second region of the pixel, the electrode elements of the pixel electrode were formed to form an angle of −10° (clockwise). That is, in the first region and the second region of each pixel, the direction of the rotational movement (in-plane switching) of the liquid crystal induced by the voltage application between the pixel electrode and the counter electrode within the substrate plane is They are arranged in opposite directions.

Next, the liquid crystal aligning agents obtained in Synthesis Examples 8 to 12 and Comparative Synthesis Examples 3 and 4 were filtered through a 1.0 μm filter, and then applied to the prepared substrate with electrodes by spin coating. . It was then dried on a hot plate set at 70°C for 90 seconds. Then, using an exposure apparatus APL-L050121S1S-APW01 manufactured by Ushio Inc., the substrate was irradiated with linearly polarized ultraviolet light from a vertical direction through a wavelength selection filter and a polarizing plate. At this time, the direction of the plane of polarization was set so that the direction of the line segment obtained by projecting the plane of polarization of the polarized ultraviolet rays onto the substrate was inclined by 10° with respect to the third-layer IZO comb-teeth electrode. Next, baking was performed for 30 minutes in an IR (infrared) oven set at 230° C. to obtain a substrate with a polyimide liquid crystal alignment film having a film thickness of 100 nm subjected to alignment treatment. Further, a substrate with a polyimide liquid crystal alignment film was obtained by subjecting a glass substrate having columnar spacers having a height of 4 μm and having an ITO electrode formed on the back surface as a counter substrate to alignment treatment in the same manner as described above. These two substrates with a liquid crystal alignment film were used as one set, and a sealant was printed on one of the substrates with the liquid crystal injection port left. The substrates were pasted together and pressure-bonded so that the direction of the line segment projected onto the substrate was parallel. After that, the sealant was cured to produce an empty cell with a cell gap of 4 μm. Liquid crystal MLC-7026-100 (negative liquid crystal manufactured by Merck) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain an FFS liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120° C. for 30 minutes and allowed to stand overnight at 23° C., and then used for evaluation of liquid crystal alignment stability and relaxation properties of residual DC.

<Evaluation of liquid crystal alignment stability>
Using the above liquid crystal cell, an AC voltage of 14 VPP was applied at a frequency of 30 Hz for 96 hours in a constant temperature environment of 60°C. After that, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited and left at 23° C. overnight.
After standing, the liquid crystal cell was placed between two polarizing plates arranged so that the polarizing axes were perpendicular to each other, and the backlight was turned on with no voltage applied so that the brightness of the transmitted light was minimized. The arrangement angle of the liquid crystal cell was adjusted. Then, the rotation angle when the liquid crystal cell was rotated from the angle at which the second region of the first pixel was the darkest to the angle at which the first region was the darkest was calculated as the angle Δ. Similarly, for the second pixel, the second region and the first region were compared to calculate a similar angle Δ. Then, the average value of the angle Δ values of the first pixel and the second pixel was calculated as the angle Δ of the liquid crystal cell. When the angle Δ of the liquid crystal cell was less than 0.4°, it was defined as "good", and when the angle Δ was 0.4° or more, it was evaluated as "poor".
In addition, the value of the angle Δ when using the liquid crystal aligning agent stored at −20 ° C. for 8 days is Δ[1], and the value of the angle Δ when using the liquid crystal aligning agent stored at 23 ° C. for 8 days is Δ [ 2], and the degree of deterioration of the angle Δ due to storage at 23°C was calculated by the following formula.

Degree of deterioration of angle Δ due to storage at 23°C = Δ[2] ÷ Δ[1] × 100

When this value was less than 150, it was defined as "good", and when it was 150 or more, it was defined as "poor".

<Evaluation of relaxation properties of residual DC>
The liquid crystal cell is placed between two polarizing plates arranged so that the polarization axes are orthogonal, and the pixel electrode and the counter electrode are shorted to the same potential. The backlight was illuminated, and the angle of the liquid crystal cell was adjusted so that the brightness of the light transmitted through the LED backlight measured on the two polarizing plates was minimized.
Next, while applying a rectangular wave with a frequency of 30 Hz to this liquid crystal cell, the VT characteristic (voltage-transmittance characteristic) was measured at a temperature of 23° C., and an AC voltage at which the relative transmittance was 23% was applied. Calculated. Since this AC voltage corresponds to a region where luminance varies greatly with respect to voltage, it is convenient to evaluate residual DC via luminance.

Next, at a temperature of 23° C., an AC voltage with a relative transmittance of 23% and a rectangular wave with a frequency of 30 Hz were applied for 5 minutes, and then a DC voltage of +1.0 V was superimposed and driven for 30 minutes. After that, the DC voltage was turned off, and only the AC voltage with the relative transmittance of 23% and the rectangular wave with the frequency of 30 Hz was applied for 30 minutes.
The faster the relaxation of the accumulated charge, the faster the charge accumulation in the liquid crystal cell when the DC voltage is superimposed. Therefore, evaluation was made based on the degree to which the relative transmittance decreased after 30 minutes. That is, when the relative transmittance decreased to less than 29% after 30 minutes of DC voltage superimposition, it was defined as "good", and when the relative transmittance was 29% or more, it was evaluated as "poor".

<Example 1>
Using two types of the liquid crystal aligning agent (A-8) obtained in Synthesis Example 8, one stored at −20° C. for 8 days and the other stored at 23° C. for 8 days, a liquid crystal cell was produced as described above. did. Irradiation with polarized ultraviolet rays was performed using a high-pressure mercury lamp through a wavelength selection filter: 240LCF and a 254 nm type polarizing plate. The irradiation amount of polarized ultraviolet rays was measured using an illuminometer UVD-S254SB manufactured by Ushio Inc., and the irradiation amounts were 200, 300, 400, 600, 900, 1500, and 2000 mJ/ ^cm2 at a wavelength of 254 nm. Seven liquid crystal cells with different amounts of polarized ultraviolet irradiation were produced by changing the procedure.
As a result of evaluating the liquid crystal alignment stability of these liquid crystal cells, the polarized ultraviolet irradiation dose at which the angle Δ was the best was 300 mJ/cm ² , the angle Δ[1] was 0.18°, and the angle Δ[2] was The degree of deterioration of the angle Δ after storage at 0.19° and 23°C was 106, which was good.
In addition, the relaxation property of residual DC with the same amount of polarized ultraviolet irradiation, which was previously evaluated before the evaluation of the liquid crystal orientation stability, was good, with a relative transmittance of 26.1% after 30 minutes of DC voltage superimposition. rice field.

<Examples 2 to 6>
The liquid crystal alignment stability and residual DC relaxation properties were evaluated in the same manner as in Example 1, except that the liquid crystal alignment agents obtained in Synthesis Examples 9 to 13 were used.

<Comparative Examples 1 to 3>
Liquid crystal alignment stability and residual DC relaxation properties were evaluated in the same manner as in Example 1, except that the liquid crystal alignment agents obtained in Comparative Synthesis Examples 3 to 5 were used.

Regarding the liquid crystal aligning agents used in Examples 1 to 6 and Comparative Examples 1 to 3, the liquid crystal aligning agent containing the polymer represented by (Aa) and the liquid crystal containing the polymer represented by (Ab) Table 1 shows the weight % of each in the alignment agent and the liquid crystal alignment agent containing the polymers represented by (Aa) and (Ab).
In Table 2, when using the liquid crystal aligning agents obtained in Examples 1 to 6 and Comparative Examples 1 to 3, the amount of polarized ultraviolet irradiation at which the angle Δ was the best, the results of evaluation of liquid crystal alignment stability, residual DC shows the results of the evaluation of the relaxation properties of

As shown in Table 1, in Examples 1 to 6, the angle Δ, which is the difference in alignment azimuth angle before and after AC driving, was less than 0.4°, which was good, and the liquid crystal aligning agent was stored at 23°C for 8 days. The degree of deterioration of the angle Δ at the time is less than 150 and is good, and the angle Δ becomes the best with a small amount of polarized ultraviolet irradiation of 300 mJ/cm ² . It is good when it is less than 29.0%, and all of them have good afterimage characteristics, so that the display quality of the liquid crystal display device is excellent. On the other hand, in Comparative Examples 1 to 3, all of the angle Δ, the degree of deterioration of the angle Δ after storage at 23° C., the amount of polarized ultraviolet irradiation, and the relative transmittance after 30 minutes of DC voltage superimposition were not satisfactory.
As described above, it was confirmed that the liquid crystal display device manufactured by the method of the present invention exhibits excellent afterimage characteristics.

A substrate for a lateral electric field-driven liquid crystal display device manufactured using the polymer of the present invention or a lateral electric field-driven liquid crystal display device having the substrate has excellent liquid crystal alignment stability and residual DC even with a small amount of polarized ultraviolet irradiation. , the productivity and afterimage properties are excellent. Therefore, it can be suitably used for large-screen, high-definition liquid crystal televisions and the like.

Claims (13)

(Aa) the following formula (1) (in formula (1), i is 0 or 1, X is a single bond, an ether bond, a carbonyl, an ester bond, phenylene, or a linear alkylene having 1 to 20 carbon atoms; , a branched alkylene having 2 to 20 carbon atoms, a cyclic alkylene having 3 to 12 carbon atoms, a sulfonyl, an amide bond, or a group consisting of a combination thereof, wherein the alkylene having 1 to 20 carbon atoms is an ester optionally interrupted by bonds selected from bonds and ether bonds, and the carbon atoms of phenylene and alkylene are one or more identical or selected from halogen atoms, cyano groups, alkyl groups, haloalkyl groups, alkoxy groups and haloalkoxy groups; (which may be substituted with different substituents). at least one polymer selected from polymers,
(Ab) Polyamic acid obtained using a tetracarboxylic dianhydride component containing an aliphatic tetracarboxylic dianhydride and a diamine component containing a diamine represented by the following formula (2), and the polyamic acid At least one polymer selected from imidized polymers, and an organic solvent, wherein the weight ratio of (Aa) and (Ab) is (Aa):(Ab) = 60 : 40 to 80:20 ,
The diamine component of (Ab) is the following formula (5) other than the diamine represented by the formula (2) (W ² in the formula (5) is a divalent organic group and the following formula [ W ^2-19 ], [W ^2-23 ] to [W ^2-26 ], [W ^2-39 ] , [W 2-59 ] to [W 2-64] ^{, [} W ^2-67 ] , [W ^2-84 ], [W 2-86], [W 2-90], [W ^2-94 ] , ^{[ W 2-95} ] ^, [W 2-98], [W 2-100] ^, [W ² -113] to [W ² -115], [W ² -121] to [W ² -125], [ W ² -129] , [W ² -137] to [W ² -139 ], [W ² - 141] and [W ² -143], wherein R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. .)
A liquid crystal aligning agent having a diamine having a structure represented by .

10 to 100 mol % of the tetracarboxylic dianhydride component (Aa) is the tetracarboxylic dianhydride represented by the formula (1). Liquid crystal aligning agent. 3. The liquid crystal aligning agent according to claim 1, wherein 10 to 100 mol % of the tetracarboxylic dianhydride component (Ab) is an aliphatic tetracarboxylic dianhydride. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein 80 to 100 mol% of the tetracarboxylic dianhydride component (Ab) is an aliphatic tetracarboxylic dianhydride. 5. The liquid crystal aligning agent according to any one of claims 1 to 4, wherein 10 to 100 mol% of the diamine component (Ab) is the diamine of formula (2). The structures of the diamines other than the diamine represented by the formula (2) are [W ² -60], [W ² -121] (provided that n=4 only), [W ² -129], [W ² -137] to [ W ² -139 ] (however, in [W ² -137] to [W ² -139] , only when n = 2 or n = 4) and [W ² -143 ] The liquid crystal aligning agent according to any one of claims 1 to 5, which is a structure represented by any one selected from the group consisting of 1. The tetracarboxylic dianhydride represented by the formula (1) is at least one selected from pyromellitic dianhydride and 3,3′,4,4′-biphenyltetracarboxylic dianhydride. 7. The liquid crystal aligning agent according to any one of 6. The liquid crystal aligning agent according to any one of claims 1 to 7, wherein the aliphatic tetracarboxylic dianhydride is cyclobutanetetracarboxylic dianhydride or 1,3-dimethylcyclobutanetetracarboxylic dianhydride. [I] A step of applying the liquid crystal aligning agent according to any one of claims 1 to 8 onto a substrate having a conductive film for lateral electric field driving to form a coating film;
[II] The step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] The step of heating the coating film obtained in [II];
A method for producing a substrate having a liquid crystal alignment film, which obtains a liquid crystal alignment film for a lateral electric field drive type liquid crystal display element to which alignment control ability is imparted by having the above. A liquid crystal alignment film for a lateral electric field drive type liquid crystal display element formed from the liquid crystal alignment agent according to any one of claims 1 to 8. A substrate having the liquid crystal alignment film for a lateral electric field driven liquid crystal display element according to claim 10 . A lateral electric field driven liquid crystal display device comprising the substrate according to claim 11 . preparing a substrate (first substrate) according to claim 11 ;
[I'] A step of applying the liquid crystal aligning agent according to any one of claims 1 to 8 on a second substrate to form a coating film;
[II'] The step of irradiating the coating film obtained in [I'] with polarized ultraviolet rays; and [III'] The step of heating the coating film obtained in [II'];
A step of obtaining a second substrate having the liquid crystal alignment film, which obtains a liquid crystal alignment film imparted with alignment control ability by having disposing the first and second substrates so that the films face each other to obtain a liquid crystal display element;
A method for manufacturing a liquid crystal display element, obtaining a lateral electric field driven liquid crystal display element by having