TWI601787B - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Description

Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element.

A liquid crystal display device is known as a display device which is lightweight, thin, and low in power consumption, and has been actively used in large-scale television applications and the like in recent years.

The liquid crystal display element is configured by sandwiching and sealing a liquid crystal layer between a pair of substrates, and aligning liquid crystals of the liquid crystal layer in a predetermined direction between the substrates. In the liquid crystal display device, liquid crystal is applied by applying a voltage to the electrodes provided on the pair of substrates, and the desired image can be displayed by the change in the alignment of the response of the liquid crystal.

In the liquid crystal display device, by providing a liquid crystal alignment film having a liquid crystal alignment ability, the liquid crystal alignment of the liquid crystal layer can be realized by holding one of the liquid crystal layers on the surface of the substrate. In other words, the liquid crystal alignment film is formed on the outermost surface of the pair of substrates which are in contact with the liquid crystal in the liquid crystal display device, and is, for example, a parallel direction with respect to the substrate, and is a constituent member for aligning the liquid crystal between the substrates in a predetermined direction. .

Further, in the liquid crystal alignment film, in addition to the function of aligning the liquid crystal in a predetermined direction, a function of controlling the pretilt angle of the liquid crystal is required to form a pretilt angle between the liquid crystal and the substrate.

On the other hand, the ability of the liquid crystal alignment film to control the alignment of the liquid crystal (hereinafter referred to as the alignment control energy) can be imparted by the alignment treatment of the organic film constituting the liquid crystal alignment film.

Conventionally, a rubbing method has been known as an alignment treatment of a liquid crystal alignment film that imparts alignment control energy. The rubbing method refers to an organic film such as polyvinyl alcohol, polyamide or polyimine on a substrate, and the surface is rubbed in a certain direction by cotton, nylon, polyester, or the like to cause liquid crystal alignment. The method of rubbing direction. Since this rubbing method is simple and can realize a relatively stable liquid crystal alignment state, it is used in the manufacturing process of a conventional liquid crystal display element. In addition, as the organic film used for the liquid crystal alignment film, a polyimide-based organic film excellent in reliability or electrical properties such as heat resistance is selected.

However, the rubbing method of rubbing the surface of the liquid crystal alignment film of the organic film has a problem of generating dust or static electricity. Further, due to the high definition of the liquid crystal display element in recent years, or the unevenness of the active element of the electrode on the substrate or the liquid crystal driving switch, the surface of the liquid crystal alignment film cannot be uniformly rubbed with the cloth, and uniform liquid crystal alignment cannot be achieved. The situation.

Therefore, the optical alignment method is being actively reviewed as another alignment treatment method of the liquid crystal alignment film which does not rub.

The photo-alignment method has various methods for forming an organic film constituting a liquid crystal alignment film by linearly polarizing or collimating light. Anisotropic, and the liquid crystals are aligned according to the anisotropy.

As a main photo-alignment method, a decomposing photo-alignment method is known. For example, a method in which a polyimine film is irradiated with a polarized ultraviolet ray, and an ultraviolet ray absorbs a polarization direction dependence of a molecular structure to cause an anisotropic decomposition, and a liquid crystal is aligned by a polyimine which remains without decomposition (refer to, for example, a patent) Document 1).

Further, a photocrosslinking type or a photoisomerization type photoalignment method is also known. For example, polyethylene cinnamate is used, and polarized ultraviolet rays are irradiated to cause a dimerization reaction (crosslinking reaction) in a double bond portion of two side chains parallel to the polarized light, and the liquid crystal is aligned perpendicular to the polarizing direction. Method of direction (refer to, for example, Non-Patent Document 1).

As described above, in the alignment treatment method of the liquid crystal alignment film by the photo-alignment method, no rubbing is required, and no dust or static electricity is generated. Further, the substrate of the liquid crystal display element having irregularities on the surface can be subjected to alignment treatment, and is an alignment treatment method of a suitable liquid crystal alignment film in an industrial production process.

However, in the photo-alignment method, it is also pointed out that the use of light is a peculiar problem.

In other words, when the organic film on the substrate on which the electrode or the like is formed is irradiated with linearly polarized light or collimated light, it is affected by the reflection of light from the substrate of the lower layer or the like, and there is a disorder in the alignment process. Such disorder of the alignment treatment causes a decrease in the display quality of the obtained liquid crystal display element.

Moreover, after the irradiation of light, there is a case where an unreacted group remains in the liquid crystal alignment film, and a liquid crystal display film is used to manufacture a liquid crystal display. In the case of the element, the unreacted group reacts due to the short-wavelength light in the backlight source or the external light, and there is a problem that the liquid crystal alignment state changes.

For the problem of light reflection in the light alignment method, for example, Patent Document 2 discloses a technique of providing a resin layer of another layer on the lower layer side of the liquid crystal alignment film by the photoalignment method, which is used for the resin layer. Attenuating light from a reflected light such as a substrate or a short-wavelength component in a backlight source.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3893659

[Patent Document 2] Japanese Patent No. 4651677

[Non-patent literature]

[Non-Patent Document 1] M. Shadt et al., Jpn. J. Appl. Phys. 31, 2155 (1992)

However, when a resin layer of another layer is further provided on the lower layer side of the liquid crystal alignment film, the manufacturing steps of the liquid crystal display element are increased as compared with the prior art. That is, compared with the conventional one, the liquid crystal display element using the photo-alignment method The manufacturing method is complicated and has a flaw that leads to a decrease in productivity.

Therefore, in the manufacture of a liquid crystal display element using a photo-alignment method, it is required to provide a liquid crystal display which is not disordered by light due to the same manufacturing method as in the prior art without complicating the manufacturing steps. The technology of components.

The present invention has been made in view of the above-described objects, and an object of the present invention is to provide a liquid crystal alignment agent capable of producing a liquid crystal display element having reduced alignment disorder without requiring a complicated manufacturing method, and providing the liquid crystal alignment agent The obtained liquid crystal alignment film further provides a liquid crystal display element having the liquid crystal alignment film.

The present invention is an invention having the following gist.

A liquid crystal alignment agent characterized by containing a first polymer which reacts with light in a wavelength range of 250 to 380 nm, and at least a compound having a maximum absorption in a wavelength range of 250 to 380 nm and at least a second polymer 1 species.

2. The liquid crystal alignment agent according to the above aspect, wherein the content of at least one of the compound and the second polymer is from 3 to 80% by mass based on the total amount of the first polymer.

3. The liquid crystal alignment agent according to the above 1 or 2, wherein the first polymer is a photoreactive group having a reaction with the light, and the photoreactive group is selected from the group consisting of a cinnabar-based structure and a couma bean. At least one structure of the group formed by the prime structure and the ketone structure.

4. The liquid crystal alignment agent according to the above-mentioned item 3, wherein the photoreactive group is one of the following side chain structures.

(The broken line is shown as a bonding group for the main chain of the polymer. R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (however, the arbitrary hydrogen atom may be substituted by a fluorine atom), or a carbon number 1 to 10 alkoxy groups (however, any of the hydrogen atoms may be substituted by a fluorine atom).

A and B are each independently shown as a single bond or a ring structure represented by the following formula.

T is independently shown as a single bond, an ether, an ester, a guanamine or a ketone linkage. S is a single bond or an alkylene group having 1 to 10 carbon atoms. However, when S and A are both single bonds, the oxygen atoms are not adjacent.

The liquid crystal alignment agent according to any one of the above 1 to 4, wherein the compound and the second polymer have a specific structure. The specific structure is at least one of a phenone structure and a diphenylamine structure.

6. The liquid crystal alignment agent according to the above 5, wherein the specific structure is a structure of the following formula.

(R is shown as an alkyl group having 1 to 5 carbon atoms).

The liquid crystal alignment agent according to any one of the above 1 to 6, wherein the first polymer is selected from the group consisting of polylysine and a polyamidimide obtained by imidating the polyphosphonium amide. At least one polymer of the group formed.

8. The liquid crystal alignment agent according to any one of the above 1 to 7, wherein the second polymer is selected from the group consisting of polylysine and the polyamidite. At least one polymer of the group of polyimine obtained.

A liquid crystal alignment film obtained by applying the liquid crystal alignment agent according to any one of the above 1 to 8, which is obtained by drying and baking.

10. The liquid crystal alignment film according to the above 9, wherein the baking temperature is 50 to 300 °C.

11. The liquid crystal alignment film according to the above 9 or 10, wherein the film thickness after firing is 5 to 300 nm.

A liquid crystal display device comprising the liquid crystal alignment film according to any one of the above items 9-11.

By using the liquid crystal alignment agent of the present invention, a liquid crystal alignment film capable of supplying a liquid crystal display element with reduced alignment disorder and liquid crystal display having the liquid crystal alignment film can be formed without a complicated manufacturing method. The component is used as a portable device for displaying a high-definition image as a display device that is lightweight, thin, and low in power consumption.

Fig. 1 is a graph showing the relationship between the film thickness of an alignment film of a liquid crystal cell and a pretilt angle.

[Best Mode for Carrying Out the Invention]

The present inventors have confirmed that when the light alignment treatment of the liquid crystal alignment film is caused by light reflection from the lower layer such as a glass substrate or an electrode, light interference is caused in the liquid crystal alignment film, and light alignment occurs in the liquid crystal alignment film. The interference of the reflected light of the treatment imparts an alignment control property to the liquid crystal alignment film, and particularly affects the performance of forming the pretilt angle. Specifically, it has been confirmed that the liquid crystal display element has a film thickness dependence of the liquid crystal alignment film with respect to the liquid crystal pretilt angle.

In the film thickness dependence of the liquid crystal alignment film of the liquid crystal pretilt angle, it is known that the unevenness of the pretilt angle is caused even in the surface of the liquid crystal display element and between the plurality of liquid crystal display elements. Display grade The reason for the decrease.

In the light alignment treatment, the light interference that is worried about the liquid crystal alignment film, for example, as disclosed in the above Patent Document 2, in the lower layer of the liquid crystal alignment film, a method of additionally providing a layer for absorbing reflected light between the light reflection layer and the light reflection layer is effect.

However, resetting the layer for absorbing light as described above increases the number of manufacturing steps of the liquid crystal display element and becomes complicated. In other words, it is effective to provide a function of reducing the influence of the light interference on the liquid crystal alignment film itself without providing a new layer for absorbing light and reducing the influence of the reflected light on the liquid crystal alignment film itself.

As a result of further studies, the present inventors have found that, in the liquid crystal alignment film, a material containing attenuating reflected light during photoalignment processing, particularly a layer below the liquid crystal alignment film, forms a layer which attenuates the reflected light. The suppression of optical interference is effective.

Further, it has been found that a layer for suppressing light interference in a liquid crystal alignment film can form a layer for suppressing light interference in a liquid crystal alignment film by utilizing a layer separation phenomenon of a polymer when a liquid crystal alignment film of a polymer is generally formed. . As a result, the present invention has been completed.

That is, in the formation of the liquid crystal alignment film of the polymer, a plurality of kinds of components are used to separate the generated layer, and the liquid crystal alignment film is formed, mainly in the upper layer portion thereof, to form a layer which is suitable for light alignment; in the lower portion thereof Forming a layer that absorbs light as an active ingredient.

The obtained liquid crystal alignment film is mainly subjected to a photoalignment treatment using an upper layer portion, and the liquid crystal alignment can be effectively imparted. On the other hand, in The lower portion of the liquid crystal alignment film, for example, absorbs the reflected light from the substrate or the electrode and attenuates it to suppress the influence of the reflected light on the upper layer. As a result, the liquid crystal alignment film of the present invention can suppress the light interference of the reflected light during the photoalignment treatment, and realize the desired photoalignment treatment, and can reduce the alignment film thickness dependency in the formation of the liquid crystal pretilt angle.

Further, in the case where the liquid crystal alignment film of the present invention is subjected to photo-alignment treatment, even in the case where residual unreacted photoreactive groups remain in the film, it is possible to reduce shortness in the backlight source or external light after the liquid crystal display element is manufactured. The wavelength light, and the reaction of the (unreacted photoreactive group) causes a change in the so-called liquid crystal alignment state.

The liquid crystal alignment film of the present invention is used as a layer separator in the formation of an alignment film as described above. That is, a special method is not applied, and in the same manner as in the related art, a liquid crystal alignment film having a desired structure can be formed by a step of forming a liquid crystal alignment film.

In the liquid crystal alignment film of the present invention, it is not necessary to provide other steps for forming a layer for attenuating the reflected light as disclosed in Patent Document 2, and it is possible to provide a liquid crystal display element having a liquid crystal alignment film by a photoalignment method. The manufacturing method is not complicated.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention comprises: a first polymer which reacts with light in a wavelength range of 250 to 380 nm, and a compound which has a maximum absorption in a wavelength range of 250 to 380 nm and at least a second polymer; 1 species.

By using the first polymer as a component, it is possible to effectively perform optical alignment treatment in the formed liquid crystal alignment film.

Further, by using "a compound having a maximum absorption in a wavelength range of 250 to 380 nm and/or a second polymer" as a component, light from the lower layer side can be formed in the formed liquid crystal alignment film, for example, The reflected light from the substrate or the like is absorbed and attenuated, and in the optical alignment process, the influence of reflected light or the like can be reduced.

The content of the compound having a maximum absorption in the wavelength range of 250 to 380 nm and/or the second polymer contained in the liquid crystal alignment agent of the present invention is preferably set to 3 in combination with the first polymer. ~80% by mass, more preferably 50 to 80% by mass.

[The first polymer reacted with light in the wavelength range of 250 to 380 nm]

The first polymer preferably contains a group having a structure selected from at least one of a group consisting of a cinnamyl structure, a coumarin structure, and a ketone structure, which is wavelength-dependent. The reactive group is in the range of 250 to 380 nm, preferably 280 to 360 nm. Specifically, the photoreactive group of the first polymer preferably contains any one of the following side chain structures.

In the above formula, the dotted line is shown as a bonding group to the main chain of the polymer.

R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (however, the arbitrary hydrogen atom may be substituted by a fluorine atom), or an alkoxy group having 1 to 10 carbon atoms (however, the arbitrary hydrogen atom) Can be replaced by a fluorine atom).

A and B are each independently shown as a single bond or a ring structure represented by the following formula.

T is independently shown as a single bond, an ether, an ester, a guanamine or a ketone linkage. S is a single bond or an alkylene group having 1 to 10 carbon atoms. However, when S and A are both single bonds, the oxygen atoms are not adjacent.

The main chain of the first polymer is preferably selected from the group consisting of hydrocarbons, polyimine, polylysine, acrylate, methacrylate, maleimide, α-methylene-γ-butyrolactone. And at least one of the group formed by the oxime.

The first polymer is particularly preferably a polymer selected from the group consisting of polylysine and a polyimine obtained by imidating the polyamid. Thus, a liquid crystal alignment film which is excellent in heat resistance and electrical properties and high in reliability can be formed.

Polylysine is generally obtained by the reaction of a diamine compound with a tetracarboxylic dianhydride. Hereinafter, suitable diamine compound 1 and tetracarboxylic dianhydride 1 will be described for the formation of a preferred polyamine and polyimine as the first polymer.

[diamine compound 1]

The diamine compound 1 is not limited to one type, and may be used in a plurality of types. It is preferred to use one or more kinds of diamine compounds containing a photoreactive group reactive with light.

The photoreactive group of the diamine compound 1 is preferably a group which reacts with light having a wavelength in the range of 250 to 380 nm. The photoreactive group is exemplified by at least one selected from the group consisting of a cassia thiol structure, a coumarin structure, and a ketone structure.

Specifically, the photoreactive group of the diamine compound preferably contains any one of the following side chain structures.

In the above formula, R is represented by a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (however, the arbitrary hydrogen atom may be substituted by a fluorine atom) or an alkoxy group having 1 to 10 carbon atoms (however, Any hydrogen atom may be replaced by a fluorine atom).

A and B are each independently shown as a single bond or a ring structure represented by the following formula.

T is independently shown as a single bond, an ether, an ester, a guanamine or a ketone linkage. S is a single bond or an alkylene group having 1 to 10 carbon atoms. However, when S and A are both single bonds, the oxygen atoms are not adjacent.

Preferred examples of the diamine compound having a photoreactive group are shown below.

Further, in the C _n H _2n+1 moiety of the diamine compound exemplified in the above formulas, n is an integer of from 1 to 18.

The liquid crystal alignment film of the present invention can be used as a liquid crystal alignment film which is vertically aligned.

As the above-mentioned first polymer to be formed, as described above, at least one selected from the group consisting of polylysine and polyamidene obtained by imidating the polyphosphonium amide is preferably used. a polymer; the polyamic acid is preferably formed from a diamine component comprising a side chain type diamine compound.

The above-mentioned side chain type diamine compound means at least one of an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a hetero ring, and a large cyclic substituent formed by the above in the side chain. Diamine compound.

Specifically, a diamine compound represented by the following formulas [DA-1] to [DA-30] can be exemplified.

(R ₆ is an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group).

(The plurality of S ₅ systems are independently -COO-, -OCO-, -CONH-, -NHCO-, -CH ₂ -, -O-, -CO-, or -NH-, and R ₆ is carbon number 1~ 22 alkyl or fluoroalkyl).

(S ₆ is -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, or -CH ₂ OCO-, and R ₇ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, or a fluorine-containing alkane Base or fluoroalkoxy).

(S ₇ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -, or -CH ₂ -, R ₈ It is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group).

(S ₈ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -, -CH ₂ -, -O- Or -NH-, R ₉ is a fluoro group, a cyano group, a trifluoromethyl group, a nitro group, an azo group, a decyl group, an ethyl group, an ethoxy group, or a hydroxy group).

(R ₁₀ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans-antibody).

The diamine compound of the above formula [DA-1] to [DA-30] may be used in combination with the diamine compound having the above photoreactive group while supplementing the vertical alignment energy. As a more preferable diamine which can be used in combination, in terms of a voltage holding ratio or a residual storage voltage, etc., it is preferably a formula [DA-10] to [DA-30], more preferably a formula [DA-10]. A diamine compound of [DA-16].

The preferred content of the diamine compound is not particularly limited, but is preferably 5 to 50 mol%, more preferably 5 to 30 mol%, based on the diamine component capable of forming the first polymer.

As the above-mentioned first polymer, among the diamine components which are suitable for the formation of a preferred polyphthalic acid and polyimine, in addition to the diamine compound or the side chain type diamine compound having the above photoreactive group, Diamine compounds other than these (sometimes referred to as other diamine compounds) may also be included. The other diamine compound is not particularly limited, and examples thereof include alicyclic diamines, aromatic diamines, aromatic-aliphatic diamines, heterocyclic diamines, and aliphatic diamines. This specific example is as follows.

Examples of the alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, and 4 , 4'-diamino-3,3'-dimethyldicyclohexylamine, isophorone diamine, and the like.

Examples of the aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, and 3 , 5-diaminotoluene, 1,4-diamino-2-methoxybenzene, 2,5-diamino-p-xylene, 1,3-diamino-4-chlorobenzene, 3 , 5-diamino benzoic acid, 1,4-diamino-2,5-dichlorobenzene, 4,4'-diamino-1,2-diphenylethane, 4,4'-di Amino-2,2'-dimethylbibenzyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenyl Methane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 2,2'-diaminopurine, 4,4'-diaminopurine, 4,4'- Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl hydrazine, 3, 3'-Diaminodiphenylphosphonium, 4,4'-diaminobenzophenone, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-amine Phenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 3,5-bis(4-aminophenoxy)benzoic acid, 4,4'-bis(4-amino group Phenoxy)bibenzyl, 2,2-bis[(4-aminophenoxy)methyl]propane, 2,2-bis[4-( 4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy) Phenyl]anthracene, bis[4-(4-aminophenoxy)phenyl]anthracene, 1,1-bis(4-aminophenyl)cyclohexane, α,α'-bis(4-amine Phenyl)-1,4-diisopropylbenzene, 9,9-bis(4-aminophenyl)anthracene, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2 - bis(4-aminophenyl)hexafluoropropane, 4,4'-diaminodiphenylamine, 2,4-diaminodiphenylamine, 1,8-diaminonaphthalene, 1, 5-Diaminonaphthalene, 1,5-diaminoguanidine, 1,3-diaminoguanidine, 1,6-diaminoguanidine, 1,8-diaminoguanidine, 2,7-diamine Base, 1,3-bis(4-aminophenyl)tetramethyldioxane, diphenylamine, 2,2'-dimethylbenzidine, 1,2-bis(4-aminophenyl) Ethane, 1,3-bis(4-aminophenyl)propane, 1,4-bis(4-amino) Phenyl)butane, 1,5-bis(4-aminophenyl)pentane, 1,6-bis(4-aminophenyl)hexane, 1,7-bis(4-aminophenyl) Heptane, 1,8-bis(4-aminophenyl)octane, 1,9-bis(4-aminophenyl)decane, 1,10-bis(4-aminophenyl)anthracene Alkane, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane Alkane, 1,6-bis(4-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy) Octane, 1,9-bis(4-aminophenoxy)decane, 1,10-bis(4-aminophenoxy)decane, bis(4-aminophenyl)propane-1, 3-diester, bis(4-aminophenyl)butane-1,4-dicarboxylate, bis(4-aminophenyl)pentane-1,5-diester, di(4- Aminophenyl)hexane-1,6-diester, bis(4-aminophenyl)heptane-1,7-diester, bis(4-aminophenyl)octane-1, 8-diester, bis(4-aminophenyl)decane-1,9-diester, bis(4-aminophenyl)decane-1,10-diester, 1,3- Bis[4-(4-aminophenoxy)phenoxy]propane, 1,4-bis[4-(4-aminophenoxy)phenoxy]butane, 1,5-bis[4] -(4-Aminophenoxy)phenoxy]pentane, 1,6-bis[4-(4- Phenoxy)phenoxy]hexane, 1,7-bis[4-(4-aminophenoxy)phenoxy]heptane, 1,8-bis[4-(4-aminobenzene) Oxy)phenoxy]octane, 1,9-bis[4-(4-aminophenoxy)phenoxy]decane, 1,10-bis[4-(4-aminophenoxy) Phenoxy]decane and the like.

Examples of the aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, and 4-amino group- N-methylbenzylamine, 3-aminophenethylamine, 4-aminophenethylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylbenzene Ethylamine, 3-(3-aminopropyl)aniline, 4-(3-aminopropyl)aniline, 3-(3-methylaminopropyl)aniline, 4-(3-methylamine Propyl)aniline, 3-(4-aminobutyl)aniline, 4-(4-Aminobutyl)aniline, 3-(4-methylaminobutyl)aniline, 4-(4-methylaminobutyl)aniline, 3-(5-aminopentyl) Aniline, 4-(5-aminopentyl)aniline, 3-(5-methylaminopentyl)aniline, 4-(5-methylaminopentyl)aniline, 2-(6-aminonaphthalene Methylamine, 3-(6-aminonaphthyl)methylamine, 2-(6-aminonaphthyl)ethylamine, 3-(6-aminonaphthyl)ethylamine, and the like.

Examples of the heterocyclic diamines include 2,6-diaminopyridine, 2,4-diaminopyridine, and 2,4-diamino-1,3,5-three. , 2,7-diaminodibenzofuran, 3,6-diaminocarbazole, 2,4-diamino-6-isopropyl-1,3,5-tri , 2,5-bis(4-aminophenyl)-1,3,4- Diazole and the like.

Examples of the aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, and 1,5-diaminopentane. Alkane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminodecane, 1,10-diaminoguanidine Alkane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1,7-diamino-2,5-di Methylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methyl Heptane, 1,12-diaminododecane, 1,18-diaminooctadecane, 1,2-bis(3-aminopropoxy)ethane, and the like.

[tetracarboxylic dianhydride 1]

In order to obtain a polyamic acid which is preferred as the first polymer, it is not particularly limited as long as it is a tetracarboxylic dianhydride which is reactive with the above diamine compound. This specific example is exemplified as follows.

Examples of the tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure include 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2. 3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl- 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 1 , 2,4,5-cyclohexanetetracarboxylic dianhydride, 3,4-dicarboxy-1-cyclohexyl succinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro- 1-naphthalene succinic dianhydride, 1,2,3,4-butane tetracarboxylic dianhydride, bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride, 3 , 3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, cis-3,7-dibutylcyclooctane-1,5- Diene-1,2,5,6-tetracarboxylic dianhydride, tricyclo[4.2.1.0 ^2,5 ]nonane-3,4,7,8-tetracarboxylic acid-3,4:7,8- Di-anhydride, hexacyclohexane [6.6.0.1 ^2,7 .0 ^3,6 .1 ^9,14 .0 ^10,13 ] hexadecane-4,5,11,12-tetracarboxylic acid-4,5:11, 12-dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride.

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, and 2,2',3,3'-linked. Phenyltetracarboxylic dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3, 3',4-benzophenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)ruthenium anhydride, 1,2,5 6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, and the like.

In addition to the above tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure, when an aromatic tetracarboxylic dianhydride is used, since the liquid crystal alignment property is improved and the storage charge of the liquid crystal cell is lowered, it is preferable .

The tetracarboxylic dianhydride may be used in combination of one type or two types or more depending on the characteristics of the liquid crystal alignment property, the voltage holding property, and the stored charge of the liquid crystal alignment film to be formed.

[polyglycine 1]

A preferred polyamine acid as the first polymer can be obtained by a reaction of the above tetracarboxylic dianhydride with a diamine component formed from the above diamine compound.

As a method of obtaining a polyamic acid as the first polymer, a well-known synthesis method can be used. In general, it is a method of reacting a tetracarboxylic dianhydride with a diamine component in an organic solvent.

The reaction of the tetracarboxylic dianhydride with the diamine compound is relatively easy in an organic solvent, and it is advantageous in that no by-products are generated.

The organic solvent used for the reaction of the tetracarboxylic dianhydride and the diamine compound is not particularly limited as long as it is soluble in the produced polylysine. This specific example is as follows.

For example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N- Methyl caprolactam, dimethyl hydrazine, tetramethyl urea, pyridine, dimethyl hydrazine, hexamethylarylene, γ-butyrolactone, isopropanol, methoxymethylpentanol, two Pentene, ethyl amyl ketone, methyl decyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl stilbene, ethyl siroli, acetic acid Bismuth, acetic acid, acesulfame, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, Propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl Ether, dipropylene glycol monoacetate monomethyl Ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl 3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl b Acid ester, butyl butyl ester, butyl ether, diisobutyl ketone, methyl cyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane , diethyl ether, cyclohexanone, ethyl carbonate, ethyl propyl carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, acetone Methyl ester, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3 -methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, ethylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, 3- methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropyl Amidoxime and the like.

These organic solvents may be used singly or in combination. Further, even if the solvent which cannot dissolve the polyamic acid is used, the polylysine which has been produced may be used in the above organic solvent as long as it does not precipitate.

The water in the organic solvent is a cause of hindering the polymerization reaction and further causing hydrolysis of the produced polylysine. Therefore, the organic solvent to be used is preferably dried as much as possible.

When the tetracarboxylic dianhydride and the diamine component are reacted in an organic solvent, any of the following methods may be used: a solution in which a diamine component is dispersed or dissolved in an organic solvent, and a tetracarboxylic dianhydride is added. straight Adding, or dispersing or dissolving in an organic solvent, and then adding the method; conversely, adding a diamine component to a solution in which a tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent; A method of acid dianhydride and a diamine component. Further, when the tetracarboxylic dianhydride or the diamine component is formed of a plurality of types of compounds, the reaction can be carried out in a state of being premixed, or the reaction can be carried out in sequence, or each can be separately produced. The low molecular weight body after the reaction is subjected to a mixing reaction to obtain a high molecular weight body.

The polymerization temperature may be any temperature from -20 to 150 ° C, but preferably from -5 to 100 ° C.

Further, although the reaction can be carried out at any concentration, when the concentration is too low, it becomes difficult to obtain a polymer having a high molecular weight; when the concentration is too high, the viscosity of the reaction liquid becomes too high, and it is difficult to uniformly stir. Therefore, the total concentration of the tetracarboxylic dianhydride and the diamine component in the reaction solution is preferably from 1 to 50% by mass, more preferably from 5 to 30% by mass. The initial stage of the reaction is carried out at a high concentration, and then an organic solvent may be added.

In the above polymerization reaction, the ratio of the total number of moles of the tetracarboxylic dianhydride to the total number of moles of the diamine component is preferably from 0.8 to 1.2, more preferably from 0.9 to 1.1. The same as the general polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the produced poly-proline.

[polyimine 1]

A preferred polyimine as the first polymer can be obtained by dehydration ring closure of the above polyamic acid.

As a preferred polyimine, the dehydration ring closure ratio of the proline group (醯亚 The amination rate is not necessarily required to be 100%, and may be arbitrarily adjusted so as to be 100% or less depending on the use or purpose.

As a method for imidizing polyphosphonium hydrazide, for example, a hydrazine imidization in which a solution of polyproline is directly heated, and a catalyst which is added to a solution of polylysine is imidized. .

The temperature at which the polyaminic acid is thermally imidized in the solution is 100 to 400 ° C, preferably 120 to 250 ° C, to remove the water formed by the ruthenium iodization reaction while excluding the outside of the system. The method is better.

The catalyst oxime imidization of polylysine is carried out by adding a basic catalyst and an acid anhydride to a solution of polyamic acid, and stirring at -20 to 250 ° C, preferably 0 to 180 ° C.

The amount of the alkaline catalyst is 0.5 to 30 moles, preferably 2 to 20 moles, of the prolyl group; the amount of the anhydride is 1 to 50 moles of the amidate group, preferably 3 to 30 moles.

Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine has a moderate alkalinity because of the reaction. should.

Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, when acetic anhydride is used, purification after the completion of the reaction is easy, and therefore it is preferable.

The imidization ratio of the imidization by the catalyst oxime can be controlled by adjusting the amount of the catalyst, the reaction temperature, and the reaction time.

[polyamidate]

The first polymer which is a component of the liquid crystal alignment agent of the present invention may be a polyperurethane or a polyamine in addition to the above polyamic acid or polyimine.

As a method for synthesizing a preferred polyphthalate, for example, a method of reacting a tetracarboxylic acid diester dichloride with the above preferred diamine compound, or a tetracarboxylic acid in the presence of a condensing agent, a base or the like A method of reacting an acid diester with the above preferred diamine compound. By these methods, a polyglycolate of one of the polyimine precursors can be obtained.

Further, a polyglycosyl acid ester can be obtained by esterifying a polyamic acid which has been previously polymerized by a polymer reaction to carboxylic acid in a lysine.

Specifically, the tetracarboxylic acid diester dichloride and the above preferred diamine compound can be used in the presence of a base and an organic solvent at -20 to 150 ° C, preferably 0 to 50 ° C. The reaction is carried out for 30 minutes to 24 hours, preferably 1 to 4 hours.

Base can be used pyridine, triethylamine, 4-dimethylamino Pyridine or the like, but in order to carry out the reaction stably, pyridine is preferred. The amount of the base to be added is preferably from 2 to 4 moles, more preferably from 2.5 to 3.5, from the viewpoint of easy removal, and from the viewpoint of easily obtaining a high molecular weight body, with respect to the tetracarboxylic acid diester dichloride. Double Moore.

When the polycondensation reaction is carried out in the presence of a condensing agent, as the condensing agent, for example, triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylamino group) can be used. Propyl) carbodiimide hydrochloride, N,N'-carbonyldiimidazole, dimethoxy-1,3,5-three Methylformin, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-(benzotriazole- 1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioketo-3-benzo Diphenylzolylphosphonate, 4-(4,6-dimethoxy-1,3,5-tri -2-yl) 4-methoxymorpholine quinone chloride n-hydrate and the like.

Further, in the method using a condensing agent, when a Lewis acid is added as an additive, the reaction can be efficiently carried out. The Lewis acid is preferably a lithium halide such as lithium chloride or lithium bromide. The amount of Lewis acid added is preferably 0.1 to 1.0 moles, more preferably 0.5 to 1.0 moles per mole of the tetracarboxylic acid diester.

As the organic solvent, the organic solvent used in the above polymerization for obtaining a polycarboxylic acid tetracarboxylic dianhydride and a preferred diamine component can be used, but the solubility of the monomer and the obtained polymer is In other words, N-methyl-2-pyrrolidone, γ-butyrolactone or the like is preferably used. These solvents can be used alone or in combination of two or more. Further, in order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, it is preferred to use an organic solvent for the synthesis of the polyphthalate to be dehydrated as much as possible.

In the reaction solution, the total concentration of the tetracarboxylic acid diester dichloride and the diamine component is preferably from 1 to 30% by mass, from the viewpoint that the precipitation of the polymer is less likely to occur and the high molecular weight body is easily obtained. More preferably 5 to 20% by mass.

Further, in order to prevent the incorporation of external air, the reaction is preferably carried out in a nitrogen atmosphere.

[polyamide]

A preferred polyamine as the first polymer may be synthesized in the same manner as the above polyglycolate.

[Recovery of Polymers]

When recovering the produced polylysine and polyimine from a reaction solution such as poly-proline or polyimine, the reaction solution may be placed in a weak solvent to precipitate a polymer. . Examples of the weak solvent used for precipitation include methanol, acetone, hexane, butyl sirolimus, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water, and the like.

After the precipitated polymer is filtered and recovered, it can be dried at normal temperature or under reduced pressure at normal temperature or under reduced pressure. Further, the polymer recovered by precipitation is redissolved in an organic solvent, and when the operation of reprecipitation recovery is repeated for 2 to 10 times, impurities in the polymer can be reduced. In this case, examples of the weak solvent include alcohols, ketones, and hydrocarbons. When three or more types of weak solvents selected from the above are used, the efficiency of purification can be further improved.

When the molecular weight of the obtained coating film, the workability at the time of formation of a coating film, and the uniformity of a coating film are considered as the molecular weight of the poly phthalic acid and / or poly The weight average molecular weight measured by the (Gel Permeation Chromatography) method is preferably from 2,000 to 1,000,000, more preferably from 5,000 to 100,000.

[Compound and second polymer with great absorption in the wavelength range of 250~380nm]

Preferably, the compound and the second polymer have a specific structure which is selected from the group consisting of cassia ketone structure and benzophenone structure for light having a wavelength range of 250 to 380 nm, preferably 280 to 360 nm. And at least one of the groups formed by the diphenylamine structure. In particular, a specific structure having at least one of a benzophenone structure and a diphenylamine structure is more preferable. Further, in the present invention, the term "maximum absorption" means a maximum absorption wavelength in the range of 250 to 380 nm when the monomer used in the polymer of the present invention or the UV-vis spectrum is measured.

As a specific example of the above specific structure, a compound shown below is preferable.

(R is shown as an alkyl group having 1 to 5 carbon atoms).

In particular, as the preferred second polymer, at least one polymer selected from the group consisting of polylysine and polyamidene obtained by imidating the polyamic acid with ruthenium is preferred. . Therefore, a highly reliable liquid crystal alignment film which is excellent in heat resistance or electrical properties can be formed.

Polylysine is generally obtained by a reaction of a diamine compound and a tetracarboxylic dianhydride as described above.

Hereinafter, a diamine compound and a tetracarboxylic dianhydride which can be used in the formation of a preferred polyamic acid and polyimine which are preferred as the second polymer will be described.

[diamine compound 2]

The diamine compound which can be used in the formation of the polyacrylic acid and the polyimine which are preferable as the second polymer is not particularly limited, and examples thereof include alicyclic diamines and aromatic diamines. Aromatic-aliphatic diamines, heterocyclic diamines, aliphatic diamines, and the like. These diamines are selected so as to form a polymer having a maximum absorption in the wavelength range of 250 to 380 nm by a reaction with tetracarboxylic dianhydride as described later, and the combination is selected. Specific examples of the diamine compound which can be used are as follows.

Examples of the alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, and 4, 4'-Diamino-3,3'-dimethyldicyclohexylamine, isophorone diamine, and the like.

Examples of the aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, and 3, 5-diaminotoluene, 1,4-diamino-2-methoxybenzene, 2,5-diamino-p-xylene, 1,3-diamino-4-chlorobenzene, 3, 5-diamino benzoic acid, 1,4-diamino-2,5-dichlorobenzene, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamine -2,2'-dimethylbibenzyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenyl Methane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 2,2'-diaminopurine, 4,4'-diaminopurine, 4,4'-di Aminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl hydrazine, 3,3 '-Diaminodiphenylanthracene, 4,4'-diaminobenzophenone, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminobenzene) Oxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 3,5-bis(4-aminophenoxy)benzoic acid, 4,4'-bis(4-aminophenoxy)bibenzyl, 2,2-bis[(4-aminophenoxy) Methyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane , bis[4-(3-aminophenoxy)phenyl]anthracene, bis[4-(4-aminophenoxy)phenyl]anthracene, 1,1-bis(4-aminophenyl) Cyclohexane, α,α'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 9,9-bis(4-aminophenyl)anthracene, 2,2-dual ( 3-aminophenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-diaminodiphenylamine, 2,4-diaminodiphenyl Amine, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminoguanidine, 1,3-diaminopurine, 1,6-diaminoguanidine, 1 , 8-diaminopurine, 2,7-diaminoguanidine, 1,3-bis(4-aminophenyl)tetramethyldioxane, benzidine, 2,2'-dimethyl linkage Aniline, 1,2-bis(4-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1 , 5-bis(4-aminophenyl)pentane, 1,6-bis(4-aminophenyl)hexane, 1,7-bis(4-aminophenyl)heptane, 1,8 - bis (4-aminobenzene) Octane, 1,9-bis(4-aminophenyl)decane, 1,10-bis(4-aminophenyl)decane, 1,3-bis(4-aminophenoxy) ) propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy) Hexane, 1,7-bis(4-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,9-bis(4-aminophenoxyl) Base) decane, 1,10-bis(4-aminophenoxy)decane, bis(4-aminophenyl)propane-1,3-dicarboxylate, bis(4-aminophenyl) Butane-1,4-dicarboxylate, bis(4-aminophenyl)pentane-1,5-diester, bis(4-aminophenyl)hexane-1,6-dicarboxylate , bis(4-aminophenyl)heptane-1,7-diester, bis(4-aminophenyl)octane-1,8-diester, bis(4-aminophenyl) Decane-1,9-diester, bis(4-aminophenyl)decane-1,10-dicarboxylate , 1,3-bis[4-(4-aminophenoxy)phenoxy]propane, 1,4-bis[4-(4-aminophenoxy)phenoxy]butane, 1, 5-bis[4-(4-aminophenoxy)phenoxy]pentane, 1,6-bis[4-(4-aminophenoxy)phenoxy]hexane, 1,7- Bis[4-(4-aminophenoxy)phenoxy]heptane, 1,8-bis[4-(4-aminophenoxy)phenoxy]octane, 1,9-bis[ 4-(4-Aminophenoxy)phenoxy]nonane, 1,10-bis[4-(4-aminophenoxy)phenoxy]decane, and the like.

Examples of the aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, and 4-amino-N. -methylbenzylamine, 3-aminophenethylamine, 4-aminophenethylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenylethyl Base amine, 3-(3-aminopropyl)aniline, 4-(3-aminopropyl)aniline, 3-(3-methylaminopropyl)aniline, 4-(3-methylamino group Propyl)aniline, 3-(4-aminobutyl)aniline, 4-(4-aminobutyl)aniline, 3-(4-methylaminobutyl)aniline, 4-(4-methyl Aminobutyl)aniline, 3-(5-aminopentyl)aniline, 4-(5-aminopentyl)aniline, 3-(5-methylaminopentyl)aniline, 4-(5- Methylaminopentyl)aniline, 2-(6-aminonaphthyl)methylamine, 3-(6-aminonaphthyl)methylamine, 2-(6-aminonaphthyl)ethylamine , 3-(6-aminonaphthyl)ethylamine, and the like.

As examples of the heterocyclic diamines, for example, 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-three , 2,7-diaminodibenzofuran, 3,6-diaminocarbazole, 2,4-diamino-6-isopropyl-1,3,5-tri , 2,5-bis(4-aminophenyl)-1,3,4- Diazole and the like.

Examples of the aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, and 1,5-diaminopentane. 1,6-Diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-Diaminodecane, 1,10-diaminodecane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-di Methyl hexane, 1,7-diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3 -methylheptane, 1,9-diamino-5-methylheptane, 1,12-diaminododecane, 1,18-diaminooctadecane, 1,2-double (3 -Aminopropoxy)ethane and the like.

Among the above diamine compounds, in particular, 4,4'-diaminodiphenylamine and/or 4,4'-diaminobenzophenone are selected for use in polylysine and polyimine. The formation is better. Therefore, the formed polylysine and polyimine have a high absorption in the wavelength range of 250 to 380 nm.

[tetracarboxylic dianhydride 2]

The tetracarboxylic dianhydride which can be used at the time of formation of the preferable poly phthalic acid and a polyimine of a 2nd polymer is not specifically limited. This combination is selected and used in the form of a polymer having a maximum absorption in the wavelength range of 250 to 380 nm by reaction with the above diamine compound. Specific examples of the tetracarboxylic dianhydride which can be used are exemplified below.

As the tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3 , 4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1 , 2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 1, 2,4,5-cyclohexanetetracarboxylic dianhydride, 3,4-dicarboxy-1-cyclohexyl succinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1 - naphthalene succinic dianhydride, 1,2,3,4-butane tetracarboxylic dianhydride, bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride, 3, 3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, cis-3,7-dibutylcyclooctane-1,5-di Alkene-1,2,5,6-tetracarboxylic dianhydride, tricyclo[4.2.1.0 ^2,5 ]nonane-3,4,7,8-tetracarboxylic acid-3,4:7,8-di Anhydride, Hexacyclo[6.6.0.1 ^2,7 .0 ^3,6 .1 ^9,14 .0 ^10,13 ] Hexadecane-4,5,11,12-tetracarboxylic acid-4,5:11,12 - dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride.

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 2,2',3,3'-biphenyl. Tetracarboxylic dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,3,3 ',4-benzophenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfonic acid dianhydride, 1,2,5 6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, and the like.

In addition to the above tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure, when an aromatic tetracarboxylic dianhydride is used, the liquid crystal alignment property of the liquid crystal alignment film formed by the formed polymer is improved, and It is preferable to reduce the stored charge of the liquid crystal cell.

Among the above tetracarboxylic dianhydrides, polypyridic acid and polyfluorene are used in particular for selecting pyromellitic dianhydride and/or 3,3',4,4'-benzophenone tetracarboxylic dianhydride. The formation of imine is preferred. Therefore, the formed polylysine and polyimine have a high absorption in the wavelength range of 250 to 380 nm.

[Polymidine 2 and Polyimine 2]

A preferred polyglycolic acid as the second polymer can be obtained by a reaction of the above tetracarboxylic dianhydride with a diamine component formed from the above diamine compound.

As the method for obtaining the polyglycolic acid as the second polymer, a conventional synthesis method can be used. For example, it can be obtained by the same method as described above in the method of obtaining a preferred polyamic acid as the first polymer.

Further, as the preferred polyimine of the second polymer, the obtained polyamic acid can be obtained by dehydration ring closure (oxime imidization). Specifically, it can be obtained by the same method as described above in the method of obtaining a preferred polyimine as the first polymer.

In the preferred polyimine as the second polymer, the dehydration ring closure ratio of the guanamine group is not necessarily required to be 100%, and may be 100% or less depending on the use or purpose. Can be adjusted arbitrarily.

When the molecular weight of the obtained coating film, the workability at the time of formation of a coating film, and the uniformity of a coating film are considered as the molecular weight of the poly phthalic acid and / or poly The weight average molecular weight measured by the (Gel Permeation Chromatography) method is preferably from 2,000 to 1,000,000, more preferably from 5,000 to 100,000.

The compound having a maximum absorption in the wavelength range of 250 to 380 nm as another component of the liquid crystal alignment agent of the present invention is preferably a diamine compound and a tetracarboxylic acid which are preferably used in the formation of the second polymer. Diacid anhydride. More specifically, as the diamine compound, for example, 4,4'-Diaminodiphenylamine, 4,4'-diaminobenzophenone or the like. Further, examples of the tetracarboxylic dianhydride include pyromellitic dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride.

[Modulation of Liquid Crystal Aligning Agent]

The liquid crystal alignment agent of the present invention contains, as described above, "a first polymer which reacts with light in a wavelength range of 250 to 380 nm", and a compound which has a maximum absorption in a wavelength range of 250 to 380 nm and a second At least one of the polymers is composed of. The liquid crystal alignment agent is preferably prepared as a coating liquid in a manner suitable for formation of a liquid crystal alignment film.

That is, the liquid crystal alignment agent of the present invention is preferably prepared by dissolving a resin component for forming a resin film in an organic solvent as a solution. Here, the resin component means a resin component including the first polymer and the second polymer described above.

The content of the resin component is preferably from 1 to 20% by mass, more preferably from 3 to 15% by mass, particularly preferably from 3 to 10% by mass, based on the total amount (100% by mass) of the liquid crystal alignment agent.

In the liquid crystal alignment agent, the resin component may be all of the first polymer, or may be the first polymer and the second polymer, but other polymers than those may be mixed. In this case, the content of the other polymer in the resin component is from 0.5 to 15% by mass, preferably from 1 to 10% by mass.

Examples of the other polymer include a polymer obtained by polyacrylamide, polyimine, or the like, which is not reacted in the wavelength range of 250 to 380 nm, and is in the wavelength range of 250 to 380 nm. For not having a pole Big absorber.

The organic solvent used for the liquid crystal alignment agent is not particularly limited as long as it is an organic solvent in which the resin component is soluble. This specific example is exemplified below.

For example: N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone , N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl hydrazine, tetramethylurea, pyridine, dimethyl hydrazine, hexamethylarylene, γ-butyrolactone, 3-methyl Oxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1, 3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl decyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethyl carbonate , propylene carbonate, ethylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone and the like. These can be used alone or in combination.

The liquid crystal alignment agent of the present invention may further contain a component other than the above components such as the first polymer. In this example, for example, when a liquid crystal alignment agent is applied, a solvent or a compound which improves film thickness uniformity or surface smoothness, a compound which improves the adhesion between the liquid crystal alignment film and the substrate, and the like are used.

Specific examples of the solvent (weak solvent) for improving the uniformity of the film thickness or the surface smoothness are as follows.

For example: isopropanol, methoxymethylpentanol, methyl cyproterone, ethyl cyanosine, butyl cyproterone, acesulfame acetate, acesulfame acetate, butyl carbitol , ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol Monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethyl Glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, Dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl Ether, ethyl isobutyl ether, diisobutylene, pentyl acetate, butyl butyl ester, butyl ether, diisobutyl ketone, methyl cyclohexene, propyl ether, dihexyl ether, 1-hexyl Alcohol, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether , pyruvic acid methyl, ethyl pyruvate, 3-methoxypropionic acid methyl, 3-ethoxypropionic acid methyl ethyl, 3-methoxypropionic acid ethyl, 3-ethoxypropionic acid , 3-methoxypropionic acid, 3-methoxypropionic acid propyl 3-methoxypropionic acid butyl, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2 -propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2 -(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, etc. having low surface tension Solvents, etc.

These weak solvents can be used in one type or in a plurality of types.

When a weak solvent is used, the solubility of the solvent contained in the liquid crystal alignment agent as a whole is not significantly lowered, and it is preferably 5 to 80 of the entire solvent. The mass% is more preferably 20 to 60% by mass.

Examples of the compound which improves the uniformity of the film thickness or the surface smoothness include a fluorine-based surfactant, a polyfluorene-based surfactant, and a nonionic surfactant.

Specifically, for example, EFTOP (registered trademark) 301, EF303, EF352 (above, JEMCO Inc., MEGAFAC (registered trademark) F171, F173, R-30 (above, DIC), FLUORAD FC430, FC431 (above is Sumitomo 3M), ASAHI GUARD (registered trademark) AG710 (made by Asahi Glass Co., Ltd.), SURFLON (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (above is AGC SEIMI CHEMICAL System) and so on. The use ratio of the surfactant is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of the resin component contained in the liquid crystal alignment agent.

Specific examples of the compound which improves the adhesion between the liquid crystal alignment film and the substrate include, for example, a functional decane-containing compound or an epoxy group-containing compound described below.

For example: 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, 2-aminopropyltriethoxydecane, N -(2-Aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxydecane, 3-ureido Propyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxycarbonyl-3-aminopropyl Triethoxy decane, N-triethoxydecyl propyl triethylene triamine, N-trimethoxydecylpropyltriethylenetriamine, 10-trimethoxydecyl-1,4,7-triazinane, 10-triethoxydecyl-1,4,7-triazole Decane, 9-trimethoxydecyl-3,6-diazadecyl acetate, 9-triethoxydecyl-3,6-diazadecyl acetate, N-benzyl-3 -Aminopropyltrimethoxydecane, N-benzyl-3-aminopropyltriethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane, N-phenyl-3- Aminopropyltriethoxydecane, N-bis(exooxyethyl)-3-aminopropyltrimethoxydecane, N-bis(extended oxy)-3-aminopropyltriethoxylate Pyridin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexyl Glycol, N,N,N',N',-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N ,N,N',N',-four shrinkage Glyceryl-4,4'-diamino-diphenylmethane and the like.

In addition to the improvement of the adhesion between the substrate and the liquid crystal alignment film, the liquid crystal alignment agent may contain the following phenolic plastic additive for the purpose of preventing deterioration of electrical characteristics due to the backlight when the liquid crystal display element is formed. The specific phenolic plastic additive is as follows, but is not limited to this structure.

When the compound having a good adhesion to the substrate is used, the compound is used in an amount of preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the resin component contained in the liquid crystal alignment agent. When the amount used is less than 0.1 part by mass, the effect of improving the adhesion cannot be expected; when it is more than 30 parts by mass, the alignment of the liquid crystal is deteriorated.

In addition to the above-mentioned components, the liquid crystal alignment agent of the present invention may be added to the electrical properties such as the dielectric constant or the conductivity of the liquid crystal alignment film as long as the effect of the present invention is not impaired. An electric or conductive substance, more preferably, a crosslinkable compound may be added for the purpose of increasing the hardness or density of the film at the time of the liquid crystal alignment film.

<Liquid alignment film and liquid crystal display element>

The liquid crystal alignment agent of the present invention is the same as the liquid crystal alignment agent conventionally used for forming a liquid crystal alignment film made of polyimine, and can be coated and fired on a substrate without using other methods. The liquid crystal alignment film of the present invention is formed. Further, by applying light alignment treatment by light irradiation, alignment control energy can be imparted, and it can be used for the production of a liquid crystal display element.

When a liquid crystal alignment agent is applied to form a liquid crystal alignment film, as a substrate to be used, when the liquid crystal display element to be produced is a transmissive type It is preferable to use a substrate having high transparency. In this case, it is not particularly limited, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. Further, in order to drive the liquid crystal in the liquid crystal display device, it is preferable to use a substrate in which a transparent electrode such as an ITO (Indium Tin Oxide) electrode is formed, in terms of simplification of the manufacturing process. Further, in the case of a reflective liquid crystal display device, only one side substrate may be an opaque material such as a germanium wafer, and the electrode may be formed of a material that reflects light such as aluminum.

In the formation of the liquid crystal alignment film of the present invention, the method of applying the liquid crystal alignment agent is not particularly limited. As a coating method of a liquid crystal alignment agent, there are generally screen printing, lithography, quick-drying printing, inkjet, and the like in the industry. As another coating method, there are a method using an immersion, a roll coater, a slit coater, a spin coater, etc., and these can be used for the purpose.

The liquid crystal alignment agent is applied to the substrate and fired, and is heated at 50 to 300 ° C, preferably 80 to 250 ° C, 1 to 200 minutes, preferably 10 to 100 minutes by a heating means such as a hot plate. For example, the solvent of the organic solvent can be evaporated to form a coating film.

When the thickness of the coating film formed after firing is too thick, it is disadvantageous in terms of power consumption when used for a liquid crystal display element, and when the thickness is too thin, the reliability of the liquid crystal display element is lowered. Therefore, the thickness of the coating film after firing is preferably 5 to 300 nm, more preferably 10 to 100 nm.

When the liquid crystal is aligned horizontally or obliquely, the coated film after baking is treated by irradiating polarized ultraviolet rays. That is, the light alignment process is performed by light irradiation.

Further, the liquid crystal alignment film of the present invention can impart alignment control energy even by rubbing treatment, and in particular, can form a pretilt angle.

In the liquid crystal display device of the present invention, a liquid crystal cell is produced by a known method by the liquid crystal alignment agent of the present invention, after obtaining a "substrate with a liquid crystal alignment film" on which a liquid crystal alignment film is formed. And it becomes a liquid crystal display element. For example, a liquid crystal display element in a vertical alignment (VA) mode can be provided.

For example, in the case of the liquid crystal cell fabrication, a method may be exemplified: preparing a pair of substrates on which the liquid crystal alignment film of the present invention is formed, and dispersing a spacer on a liquid crystal alignment film of a single substrate, and using a liquid crystal alignment film. A method in which the surface is formed on the inner side, and the substrate is bonded to the other substrate, and the liquid crystal is injected under reduced pressure to perform sealing; or the liquid crystal is dropped on the liquid crystal alignment film surface on which the spacer is dispersed, and the substrate is pasted and sealed. Method, etc. The diameter of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm. The spacer diameter determines the distance between one of the liquid crystal layers and the substrate, that is, determines the thickness of the liquid crystal layer.

As described above, the liquid crystal display element produced by using the liquid crystal alignment treatment agent of the present invention is excellent in reliability, and is suitable for use in a large-screen, high-definition liquid crystal television or the like.

[Examples]

The following examples are intended to describe the invention in more detail, but the invention should not be limited or construed.

Abbreviations and structures of the main compounds used in the examples and comparative examples, As described below.

(tetracarboxylic dianhydride)

CBDA: 1,2,3,4-cyclobutane tetracarboxylic dianhydride

PMDA: pyromellitic anhydride

BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride

(diamine)

m-PDA: m-phenylenediamine

PCH: 1,3-diamino-4-[4-(4-heptylcyclohexyl)phenoxy]benzene

DAM-1: (E)-2,4-diaminophenethyl 3-(4-(4-heptylcyclohexyl)phenyl)acrylate

DAM-2: N1-(4-aminophenyl)benzene-1,4-diamine

DAM-3: N1-(4-aminophenyl)-N1-methylbenzene-1,4-diamine

DAM-4: 4,4'-diaminobenzophenone

DAM-5: 4,4'-oxydiphenylamine

DAM-6: 3,5-diamino benzoic acid

DAM-7: 2,4-diaminophenethyl cinnamate

(Organic solvents)

NMP: N-methyl-2-pyrrolidone

BCS: Butyl cypress

[Molecular weight determination]

The molecular weight of the polyimine of the synthesis example is a room temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by SENSHU Scientific Co., Ltd., and a pipe column (KD-803, KD-805) manufactured by Shodex Co., Ltd., as follows. The way to do the measurement.

Column temperature: 50 ° C

Dissolution: N,N'-dimethylformamide (as an additive with lithium bromide-hydrate (LiBr.H2O) of 30 mmol/L (liter), phosphoric acid. Anhydrous crystal (o-phosphoric acid) of 30 mmol/L, tetrahydrofuran (THF) is 10ml/L)

Flow rate: 1.0ml/min

Standard sample for the production of calibration lines: TSK standard polyethylene oxide (molecular weight: about 9,000,000, 150,000, 100,000, and 30,000) manufactured by TOSOH Co., Ltd., and polyethylene glycol (molecular weight of about 12,000, 4000, and manufactured by Polymer Laboratories). 1000).

<Synthesis Example 1>

CBDA (2.499 g, 12.74 mmol) and DAM-1 (6.015 g, 13.0 mmol) were mixed in NMP (48.24 g), and the reaction was allowed to stand at room temperature for 20 hours to obtain a polyamine acid solution. NMP (42.57 g) and BC (42.57 g) were added to the polyamic acid solution and diluted to 6% by mass, and a polyphthalic acid solution (A1) was obtained by stirring at room temperature for 5 hours. The polyamino acid contained had a number average molecular weight of 9000 and a weight average molecular weight of 28,000. In addition, the obtained polyaminic acid solution (A1) can be used not only as a liquid crystal alignment agent but also as a liquid crystal alignment agent (A1).

<Synthesis Example 2>

BODA (1.626 g, 6.24 mmol) and DAM-1 (6.015 g, 13.0 mmol) were mixed in NMP (37.68 g), and reacted at 80 ° C for 5 hours, then CBDA (1.224 g, 6.24 mmol) was added. NMP (12.56 g) was reacted at 40 ° C for 10 hours to obtain a polyaminic acid solution. After adding NMP to the polyamic acid solution (58.0 g) and diluting to 6 mass%, acetic anhydride (3.91 g) and pyridine (2.02 g) were added as a ruthenium catalyzed catalyst, and the reaction was carried out at 50 ° C for 3 hours. . This reaction solution was poured into methanol (530 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 100 ° C to obtain a polyimine powder (B). The polyimine had a hydrazine imidation ratio of 50%, a number average molecular weight of 11,000, and a weight average molecular weight of 31,000.

NMP (29.3 g) was added to the obtained polyimine powder (B) (6.0 g), and the mixture was stirred at 70 ° C for 5 hours to be dissolved. will NMP (34.7 g) and BC (30.0 g) were added to this solution, and the polyimine solution (B1) was obtained by stirring. In addition, the obtained polyaminic acid solution (B1) can be used not only as a liquid crystal alignment agent but also as a liquid crystal alignment agent, and can be used as a liquid crystal alignment agent (B1).

<Synthesis Example 3>

CBDA (2.447 g, 12.48 mmol) and DAM-2 (2.59 g, 13.0 mmol) were mixed in NMP (28.55 g), and the reaction was allowed to stand at room temperature for 20 hours to obtain a polyaminic acid solution. NMP (25.19 g) and BC (25.19 g) were added to the polyamic acid solution and diluted to 6% by mass, and stirred at room temperature for 5 hours to obtain a polyaminic acid solution (C1). The polyamino acid contained had a number average molecular weight of 8,700 and a weight average molecular weight of 18,000.

Next, the polyaminic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and the polyamic acid solution (C1) (8.0 g) were mixed at room temperature for 3 hours to prepare a vertical alignment. Liquid crystal alignment agent (C2) of liquid crystal alignment film.

Further, the polyimine solution (B1) (2.0 g) obtained in Synthesis Example 2 and the polyamic acid solution (C1) (8.0 g) were mixed at room temperature for 3 hours to prepare a vertical alignment property. Liquid crystal alignment agent (C3) of liquid crystal alignment film.

<Synthesis Example 4>

CBDA (2.447 g, 12.48 mmol), and DAM-3 (2.773 g, 13.0 mmol) were mixed in NMP (29.58 g), and the reaction was allowed to proceed at room temperature. After a few hours, a polyaminic acid solution was obtained. NMP (26.1 g) and BC (26.1 g) were added to the polyamic acid solution and diluted to 6% by mass, and a polyphthalic acid solution (D1) was obtained by stirring at room temperature for 5 hours. The polyamino acid contained had a number average molecular weight of 9,100 and a weight average molecular weight of 19,000.

Next, the polyaminic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and the polyamic acid solution (D1) (8.0 g) were mixed at room temperature for 3 hours to prepare a vertical alignment property. Liquid crystal alignment agent (D2) of liquid crystal alignment film.

<Synthesis Example 5>

CBDA (2.447 g, 12.48 mmol) and DAM-4 (2.759 g, 13.0 mmol) were mixed in NMP (29.5 g), and the reaction was allowed to stand at room temperature for 20 hours to obtain a polyamine acid solution. NMP (26.0 g) and BC (26.0 g) were added to the polyamic acid solution and diluted to 6% by mass, and a polyphthalic acid solution (E1) was obtained by stirring at room temperature for 5 hours. The polyamic acid contained had a number average molecular weight of 10,500 and a weight average molecular weight of 26,000.

Next, the polyaminic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and the polyamic acid solution (E1) (8.0 g) were mixed at room temperature for 3 hours to prepare a vertical alignment. Liquid crystal alignment agent (E2) of liquid crystal alignment film.

<Synthesis Example 6>

CBDA (2.498 g, 12.74 mmol), and DAM-7 (3.670 g, 13.0 mmol) were mixed in NMP (34.96 g) and allowed to react at room temperature 20 After a few hours, a polyaminic acid solution was obtained. NMP (30.84 g) and BC (30.84 g) were added to the polyamic acid solution and diluted to 6% by mass, and a polyaminic acid solution (F1) was obtained by stirring at room temperature for 5 hours. The polyamino acid contained had a number average molecular weight of 10,800 and a weight average molecular weight of 23,000.

Next, the liquid crystal alignment agent (A1) (2.0 g) obtained in Synthesis Example 1 and a polyamic acid solution (F1) (8.0 g) were mixed at room temperature for 3 hours to prepare a vertical alignment liquid crystal alignment film. Liquid crystal alignment agent (F2).

<Synthesis Example 7>

BODA (2.439 g, 9.75 mmol), DAM-2 (1.295 g, 6.5 mmol), m-PDA (0.422 g, 3.9 mmol), and PCH (0.990 g, 2.6 mmol) were mixed in NMP (16.1 g). After reacting at 80 ° C for 5 hours, CBDA (0.535 g, 2.7 mmol) and NMP (8.05 g) were added, and the reaction was carried out at 40 ° C for 10 hours to obtain a proline solution. After NMP was added to the polyamic acid solution (36.0 g) and diluted to 6 mass%, acetic anhydride (6.31 g) as a ruthenium amide catalyst and pyridine (1.95 g) were added to carry out the reaction at 100 ° C. hour. This reaction solution was poured into methanol (350 ml), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 100 ° C to obtain a polyimine powder (G). The polyimine had a hydrazine imidation ratio of 76%, a number average molecular weight of 14,000, and a weight average molecular weight of 46,000.

NMP (14.6 g) was added to the obtained polyimine powder (G) (3.0 g), and the mixture was stirred at 70 ° C for 5 hours and dissolved. will NMP (17.4 g) and BC (15.0 g) were added to this solution, and a polyimine solution (G1) was obtained by stirring.

Next, the polyaminic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and the polyimine solution (G1) (8.0 g) were mixed at room temperature for 3 hours to prepare a vertical alignment property. Liquid crystal alignment agent (G2) of liquid crystal alignment film.

<Comparative Synthesis Example 1>

CBDA (2.447 g, 12.48 mmol) and DAM-5 (2.603 g, 13.0 mmol) were mixed in NMP (28.62 g), and the reaction was allowed to stand at room temperature for 20 hours to obtain a polyamine acid solution. NMP (22.38 g) and BC (22.38 g) were added to the polyamic acid solution and diluted to 6% by mass, and stirred at room temperature for 5 hours to obtain a polyaminic acid solution (H1). The polyamino acid contained had a number average molecular weight of 11,000 and a weight average molecular weight of 29,000.

Next, the polyaminic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and a poly-proline solution (H1) (8.0 g) were mixed at room temperature for 3 hours to prepare a vertical alignment liquid crystal. Liquid crystal alignment agent (H2) of the alignment film.

<Comparative Synthesis Example 2>

CBDA (2.498 g, 12.74 mmol) and DAM-6 (1.978 g, 13.0 mmol) were mixed in NMP (25.37 g), and the reaction was allowed to stand at room temperature for 20 hours to obtain a polyaminic acid solution. NMP (22.38g) and BC (22.38g) were added to the polyamic acid solution and diluted to 6% by mass, and borrowed The polyamine acid solution (I1) was obtained by stirring at room temperature for 5 hours. The polyamino acid contained had a number average molecular weight of 11,000 and a weight average molecular weight of 28,000.

Next, the polyaminic acid solution (A1) (2.0 g) obtained in Synthesis Example 1 and the polyamic acid solution (I1) (8.0 g) were mixed at room temperature for 3 hours to prepare a vertical alignment property. Liquid crystal alignment agent (I2) of liquid crystal alignment film.

<Example 1>

Using the liquid crystal alignment agent (C2) obtained in Synthesis Example 3, a liquid crystal cell was produced by the procedure shown below.

[Production of liquid crystal cell]

The liquid crystal alignment agent (C2) obtained in Synthesis Example 3 was spin-coated on a glass substrate to be a transparent electrode forming surface on which a transparent electrode made of an ITO film was attached, and dried on a hot plate at 80 ° C for 90 seconds. The film was fired in a hot air circulating oven at 200 ° C for 30 minutes to form a liquid crystal alignment film having a film thickness of 50 nm.

For this substrate, linear polarized UV (ultraviolet light) of 313 nm having an irradiation intensity of 11.0 mW/cm was irradiated at 20 mJ. The direction of the incident light is inclined by 40° with respect to the normal direction of the substrate. The linearly polarized UV is adjusted by passing a 313 nm band-pass filter through the ultraviolet light of the high-pressure mercury lamp through a 313 nm band-pass filter.

Preparing two sheets of the substrate manufactured according to the above manufacturing method, After the 6 μm bead spacer was spread on the liquid crystal alignment film of one of the substrates, the sealant was printed thereon. Next, the liquid crystal alignment faces of the two substrates were opposed to each other, and the projection directions of the optical axes of the linearly polarized UVs of the respective substrates were pressed in antiparallel, and the sealant was applied at 150 ° C for 105 minutes. Chemical company, XN-1500T) heat hardening. Negative liquid crystal (manufactured by Merck Co., Ltd., MLC-6608) having a negative dielectric anisotropy was injected into the empty unit cell thus produced by a vacuum injection method to prepare a vertically aligned liquid crystal cell.

According to the same production method, five kinds of vertical alignment type liquid crystal cells of the same structure were produced except that the film thicknesses of the liquid crystal alignment films were different from 70 nm, 100 nm, 120 nm, 150 nm, and 200 nm, respectively, and were used for the following evaluation.

[Evaluation of pretilt angle]

The liquid crystal pretilt angle was measured using each of the produced liquid crystal cells. The pretilt angle was measured by using the "Axo Scan" manufactured by Axo Metrix Co., Ltd. by the Mueller matrix method. The measurement results are shown in Table 1.

<Example 2>

Six types of liquid crystal cells were produced in the same manner as in Example 1 except that the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (C3), and the pretilt angle was measured for each liquid crystal cell.

<Example 3>

Six types of liquid crystal cells were produced in the same manner as in Example 1 except that the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (D2), and the pretilt angle was measured for each liquid crystal cell.

<Example 4>

Six types of liquid crystal cells were produced in the same manner as in Example 1 except that the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (E2), and the pretilt angle was measured for each liquid crystal cell.

<Example 5>

Six types of liquid crystal cells were produced in the same manner as in Example 1 except that the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (F2), and the pretilt angle was measured for each liquid crystal cell.

<Example 6>

Six types of liquid crystal cells were produced in the same manner as in Example 1 except that the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (G2), and the pretilt angle was measured for each liquid crystal cell.

<Comparative Example 1>

Six types were produced in the same manner as in Example 1 except that the polyamic acid solution (A1) was used as the liquid crystal alignment agent (A1) and the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (A1). The liquid crystal cell is subjected to measurement of the pretilt angle for each liquid crystal cell.

<Comparative Example 2>

Six types of liquid crystals were produced in the same manner as in Example 1 except that the polyimine solution (B1) was used as the liquid crystal alignment agent (B1) and the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (B1). The unit cell, and the pretilt angle was measured for each liquid crystal cell.

<Comparative Example 3>

Six types of liquid crystal cells were produced in the same manner as in Example 1 except that the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (H2), and the pretilt angle was measured for each liquid crystal cell.

<Comparative Example 4>

Six types of liquid crystal cells were produced in the same manner as in Example 1 except that the liquid crystal alignment agent (C2) was changed to the liquid crystal alignment agent (I2), and the pretilt angle was measured for each liquid crystal cell.

The measurement results of the pretilt angles of the liquid crystal cells of Examples 1 to 6 are shown in Table 1. Further, the measurement results of the pretilt angles of the liquid crystal cells of Comparative Examples 1 to 4 are shown in Table 2.

In Tables 1 and 2, the amount of change in the pretilt angle due to the film thickness of the liquid crystal alignment film is described for each of Examples 1 to 6 and Comparative Examples 1 to 4. (degree)).

△ In each of Examples 1 to 6 and Comparative Examples 1 to 4, the pretilt angles of the liquid crystal cells having different film thicknesses of the liquid crystal alignment films were compared, and the maximum pretilt angle and the minimum pretilt angle were obtained. The difference is taken as the value to be evaluated.

Fig. 1 is a graph showing the relationship between the film thickness of the alignment film of the liquid crystal cell and the pretilt angle.

Fig. 1 shows the results of comparison between Example 6 and Comparative Example 4, which shows a phenomenon in which the pretilt angle of the liquid crystal fluctuates by changing the film thickness of the liquid crystal alignment film of the liquid crystal cell.

As shown in Table 2 and Comparative Example 4 of FIG. 1, the vertical alignment liquid crystal alignment film corresponding to the prior art photo-alignment treatment is known, and the liquid crystal pretilt angle of the liquid crystal cell is exhibited due to the change in the film thickness. big change. This means that at the interface between the liquid crystal alignment film and the substrate, UV (ultraviolet light) during light alignment treatment is reflected and dried on the surface of the liquid crystal alignment film. Involved.

Further, as shown in the graphs of Example 6 in Table 1 and FIG. 1, since the liquid crystal alignment film is mixed (blended) with a material which absorbs in the ultraviolet field, it is known that the liquid crystal alignment film can be suppressed. The change in the pretilt angle caused by the film thickness. This reason is because the material existing in the mixture absorbs the reflected light, so that light interference on the surface of the alignment film can be suppressed.

<Example 7>

Next, in Examples 1 to 6 and Comparative Examples 1 to 4, a liquid crystal cell having a pretilt angle and a film thickness of a liquid crystal alignment film of 100 nm was used, and the liquid crystal cell was placed on a backlight for a liquid crystal panel. The light from the backlight was irradiated for aging for 300 hours. Thereafter, the pretilt angle was measured for each liquid crystal cell in the same manner as described above, and the change (Δθ) of the pretilt angle before and after aging was evaluated. The evaluation results are shown in Table 3.

In addition, in Table 3, the pretilt angle of the liquid crystal cell before aging is referred to as "pretilt angle 1", and the pretilt angle after aging is referred to as "pretilt angle 2".

As can be seen from the evaluation results of Table 3, in Comparative Examples 1 to 4, the pretilt angle showed a large change to a higher value before aging due to the influence of the backlight source. This is understood to mean that an unreacted photoreactive group which does not react with the polarized UV at the time of the alignment treatment gradually generates a photoreaction due to the backlight source, and as a result, the anisotropy of the surface of the liquid crystal alignment film gradually decreases. Therefore.

On the other hand, it was confirmed that the change of the pretilt angle due to the backlight source was suppressed by using the liquid crystal cell in which the liquid crystal alignment agents of the materials 1 to 6 in the ultraviolet field were absorbed. This is understood to mean that the liquid crystal alignment agent is a material which absorbs in the ultraviolet field and absorbs ultraviolet light generated from the backlight, and as a result, exhibits an "unreacted photoreactive group" which imparts an alignment control energy. It is not easy to produce a reaction effect.

[Industry Utilization]

A liquid crystal display element having a photoalignment-processable liquid crystal alignment film formed by using the liquid crystal alignment agent of the present invention can be suitably used as a large-sized liquid crystal TV because it can be used for high-productivity manufacturing and has excellent display characteristics. Or a display element for a portable data terminal such as a smart phone that displays a high-definition image.

The specification, the scope of the patent, the drawings and the abstract of the Japanese Patent Application No. 2012-182104, filed on Aug. 21, 2012, the entire disclosure of which is hereby incorporated by reference.

Claims (9)

A liquid crystal alignment agent characterized by comprising: a first polymer which reacts with light in a wavelength range of 250 to 380 nm, and at least 1 of a compound having a maximum absorption in a wavelength range of 250 to 380 nm and a second polymer; The first polymer is a photoreactive group having a reaction with the light, and the photoreactive group is at least one selected from the group consisting of a cinnamyl structure, a coumarin structure, and a ketone structure. The first polymer is at least one polymer selected from the group consisting of polylysine and polyamidene obtained by imidating the polyphosphonium, the second polymer It is at least one polymer selected from the group consisting of polyamic acid and polyamidene obtained by imidating the polyphosphonium amide, and contains the second polymer. The liquid crystal alignment agent of claim 1, wherein the content of at least one of the compound and the second polymer is from 3 to 80% by mass based on the total amount of the first polymer. The liquid crystal alignment agent of claim 1, wherein the photoreactive group is one of the following side chain structures, (The dotted line is shown as a bonding group for the main chain of the polymer, and R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (however, the arbitrary hydrogen atom may be substituted by a fluorine atom), or a carbon number 1 to 10 alkoxy groups (however, any of the hydrogen atoms may be substituted by a fluorine atom), and A and B are each independently shown as a single bond or a ring structure represented by the following formula. T is independently shown as a single bond, an ether, an ester, a guanamine or a ketone bond, and S is a single bond or an alkylene group having 1 to 10 carbon atoms; however, when S and A are the same single bond, the oxygen atom is not Is adjacent). The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the compound and the second polymer have a specific structure having at least one of a phenone structure and a diphenylamine structure. The liquid crystal alignment agent of claim 4, wherein the specific structure is a structure of the following formula, (R is shown as an alkyl group having 1 to 5 carbon atoms). A liquid crystal alignment film which is obtained by applying the liquid crystal alignment agent according to any one of claims 1 to 5, and drying and baking. The liquid crystal alignment film of claim 6, wherein the baking temperature is 50 to 300 °C. The liquid crystal alignment film of claim 6 or 7, wherein the film thickness after firing is 5 to 300 nm. A liquid crystal display element characterized by having the liquid crystal alignment film according to any one of claims 6 to 8.