TWI816648B - Manufacturing method of liquid crystal display element, substrate for liquid crystal display element, and liquid crystal display element assembly - Google Patents

Abstract

The subject of the present invention is to provide a manufacturing method of a liquid crystal display element, a substrate for a liquid crystal display element and a liquid crystal display element assembly used in the manufacturing method. The manufacturing method of the liquid crystal display element can more easily manufacture a liquid crystal display element having an alignment state in A liquid crystal display element with different liquid crystal layers on both sides. The solution of the present invention is to form a liquid crystal alignment film using a liquid crystal alignment agent of the same composition containing a polymer having a free radical generation structure that generates free radicals upon irradiation of light on each of a pair of substrate surfaces. Alignment film forming step; applying light irradiation to at least one of the pair of substrates so that the light irradiation amounts of the liquid crystal alignment films of the two liquid crystal alignment films become different states; and then, on the pair of substrates, A liquid crystal layer forming step of forming a liquid crystal layer containing a liquid crystal compound is performed between the substrates.

Description

Manufacturing method of liquid crystal display element, substrate for liquid crystal display element, and liquid crystal display element assembly

The present invention relates to a method for manufacturing a liquid crystal display element, a substrate for a liquid crystal display element, and an assembly of a liquid crystal display element. In particular, the present invention relates to a vertically aligned liquid crystal display element produced by irradiating ultraviolet rays with a voltage applied to the liquid crystal molecules. Manufacturing method, substrate for liquid crystal display element, and liquid crystal display element assembly.

In a liquid crystal display element in which liquid crystal molecules aligned perpendicularly to a substrate respond to an electric field (also called a vertical alignment (VA) method), the manufacturing process includes a step of irradiating ultraviolet rays to the liquid crystal molecules while applying a voltage.

In such a vertical alignment type liquid crystal display element, it is known to add a photopolymerizable compound to a liquid crystal composition in advance, and to use a vertical alignment film such as a polyimide type film to irradiate the liquid crystal cell with ultraviolet rays while applying a voltage. This technology for accelerating the response speed of liquid crystal (PSA (Polymer Sustained Alignment) type element, see Patent Document 1 and Non-Patent Document 1, for example).

In such a PSA type device, the tilt direction of the liquid crystal molecules in response to the electric field is usually controlled by protrusions provided on the substrate or slits provided on the display electrodes, but by adding light to the liquid crystal composition The polymerizable compound irradiates the liquid crystal cell with ultraviolet light while applying a voltage, and forms a polymer structure that memorizes the tilt direction of the liquid crystal molecules on the liquid crystal alignment film. Therefore, it is different from controlling the tilt direction of the liquid crystal molecules with only protrusions or slits. Comparing methods, it is said that the response speed of liquid crystal display elements will become faster.

In recent years, as the quality of liquid crystal display elements has improved, it is hoped to further speed up the response speed of liquid crystal to voltage application or further improve reliability. Therefore, it is necessary to irradiate the liquid crystal with long-wavelength ultraviolet rays that do not cause decomposition of components in the liquid crystal, so that the polymerizable compound reacts efficiently and exhibits the ability to fix the alignment. Furthermore, it is also necessary that unreacted polymeric compounds do not remain after ultraviolet irradiation, thereby not adversely affecting the reliability of the liquid crystal display element.

Therefore, a liquid crystal alignment agent is proposed, which introduces a specific structure that generates free radicals due to ultraviolet irradiation into the polymer constituting the liquid crystal alignment agent. Through the use of this liquid crystal alignment agent, the liquid crystal and/or the liquid crystal can be aligned during use. In a liquid crystal display element obtained by a step of reacting a polymerizable compound in a film, by increasing the reactivity of the polymerizable compound, the response speed of the liquid crystal display element can be improved (see Patent Document 2).

On the other hand, a method for manufacturing a liquid crystal display element is proposed, which uses a first alignment liquid containing a first alignment agent to form a first alignment film on a first substrate, and uses a second alignment liquid containing a second alignment agent on a second substrate. Two alignment liquids are used to form a second alignment film. The liquid crystal layer is sandwiched between these substrates and light is irradiated while applying an electric field, so that the liquid crystal molecules adjacent to the first alignment film exhibit the first pretilt angle. , causing the liquid crystal molecules adjacent to the second alignment film to exhibit the second pretilt angle (see Patent Document 3). Prior art documents Patent documents

Patent document 1: Japanese Patent Application Publication No. 2003-307720 Patent document 2: WO2015/033921 Patent document 3: Korean Publication No. 10-2016-0002599 Non-patent document

Non-patent document 1: K. Hanaoka, SID 04 DIGEST, P.1200-1202

Problems to be solved by inventions

However, in the method of Patent Document 3, two types of liquid crystal alignment agents must be used. Due to the increase in the number of steps or the increase in production lines, there is a problem that a large investment in equipment is required.

An object of the present invention is to provide a method for manufacturing a liquid crystal display element that does not involve the above-mentioned problems and can more easily manufacture a liquid crystal display element having a liquid crystal layer with different alignment states on both sides, and a liquid crystal display element using this manufacturing method. Substrate and liquid crystal display element assembly. means of solving problems

The inventors of the present invention conducted diligent examinations and found out that by using a liquid crystal alignment agent containing a polymer having a free radical generating structure that generates free radicals upon irradiation of light, at least one side of the liquid crystal layer can be aligned in advance before the liquid crystal layer is provided. The liquid crystal alignment film is irradiated with light to inactivate at least a part of the radical generating structure of the radical generating structure of one liquid crystal alignment film, or the light irradiation is performed in such a manner that the amounts of light irradiation for the two are different, so that the two The free radical generating abilities of the two sides are different, thereby forming a liquid crystal layer with different alignment states on both sides of the liquid crystal layer, thereby completing the present invention.

That is, the present invention has the following gist. A method for manufacturing a liquid crystal display element, characterized by comprising: forming a liquid crystal alignment agent of the same composition containing a polymer having a free radical generation structure that generates free radicals upon irradiation of light on each of a pair of substrate surfaces. a liquid crystal alignment film forming step of the liquid crystal alignment film; a light irradiation step of applying light to at least one of the pair of substrates so that the light irradiation amounts of the two liquid crystal alignment films become different states; and then, A liquid crystal layer forming step of forming a liquid crystal layer containing a liquid crystal compound between the pair of substrates.

Furthermore, a substrate for forming a liquid crystal display element, which is a substrate for forming a liquid crystal display element provided with a liquid crystal alignment film, characterized in that the liquid crystal alignment film is made of a polymer containing a free radical generating structure that generates free radicals by light irradiation. It is formed of a liquid crystal alignment agent of a substance, and free radicals are generated from at least a part of the aforementioned free radical generating structure due to light irradiation.

In addition, a liquid crystal display element assembly includes: a liquid crystal display element forming substrate provided with a pair of liquid crystal alignment films; and a liquid crystal layer provided between the pair of liquid crystal display element substrates, and is characterized by: The liquid crystal alignment film forming the substrate for the pair of liquid crystal display elements is formed of a liquid crystal alignment agent of the same composition containing a polymer having a radical generating structure that generates free radicals upon irradiation of light, and light is applied to at least one of them. irradiation, so that the amount of light irradiation of the two becomes different. Effect of the invention

According to the present invention, it is possible to provide a method for manufacturing a liquid crystal display element by using a liquid crystal display element containing a material that generates free radicals due to light irradiation, as well as a substrate for a liquid crystal display element and a liquid crystal display element assembly used in the manufacturing method. The liquid crystal alignment agent of the polymer of the free radical generating structure, before forming the liquid crystal layer, irradiates light to at least one side of the liquid crystal alignment film in advance, and at least one of the free radical generating structures of the free radical generating structure of the liquid crystal alignment film on one side is Part of it is inactivated, or the light irradiation is performed in such a way that the amount of light irradiation is different between the two sides, so that the free radical generating ability of both sides becomes different, thereby forming a liquid crystal layer with different alignment states on both sides of the liquid crystal layer. , it is easier to manufacture a liquid crystal display element having liquid crystal layers with different alignment states on both sides.

Furthermore, according to the present invention, a vertically aligned liquid crystal display element with fast response speed can be provided, which is particularly suitable for a liquid crystal alignment agent for PSA type liquid crystal display elements.

Form of carrying out the invention

The present invention will be described in detail below. <Manufacturing method of liquid crystal display element> The method of manufacturing a liquid crystal display element of the present invention is characterized by including: on each of a pair of substrate surfaces, specific polymerization containing a radical generating structure that generates radicals by light irradiation The step of forming a liquid crystal alignment film using liquid crystal alignment agents of the same composition to form a liquid crystal alignment film; applying light irradiation to at least one of the aforementioned pair of substrates so that the amount of light irradiation to the two liquid crystal alignment films becomes different states. a liquid crystal alignment film light irradiation step; and then a liquid crystal layer forming step of forming a liquid crystal layer including a liquid crystal compound between the pair of substrates.

In the liquid crystal alignment film forming step of the present invention, a substrate on which a liquid crystal alignment film formed of a liquid crystal alignment agent of the same composition is formed is prepared. The liquid crystal alignment agent used here is a liquid crystal alignment agent containing a polymer having a free radical generation structure that generates free radicals due to light irradiation. The details of this liquid crystal alignment agent will be described later.

In the present invention, a liquid crystal alignment film light irradiation step is then provided, which is to apply light irradiation to at least one of a pair of substrates so that the amount of light irradiation to the two liquid crystal alignment films becomes different. This liquid crystal alignment film light irradiation step is to irradiate the liquid crystal alignment film of the substrate used on one side to invalidate at least part of the free radical generating ability of the free radical generating structure of the liquid crystal alignment film on one side, or to The amount of light irradiation of the two becomes different. The light irradiation is carried out in different ways, so that the free radical generating ability of the two sides becomes different.

Here, the light irradiation inactivates at least part of the free radical generating structure of the liquid crystal alignment film, that is, free radicals are generated at this time point and no free radicals are generated thereafter. Specifically, the light irradiation may be performed with light of a wavelength required to passivate the radical generating structure.

Specifically, the step of irradiating the liquid crystal alignment film with light includes, for example, irradiating the liquid crystal alignment film of one side of the substrate with light to inactivate at least part of the free radical generating structure and inactivate the free radical generating ability. Thereby, one becomes a liquid crystal alignment film without the ability to generate free radicals, and the other becomes a liquid crystal alignment film with the ability to generate free radicals, or one becomes a liquid crystal alignment film with a low ability to generate free radicals, and the other becomes a free radical alignment film. A liquid crystal alignment film with high radical generating ability, which makes the free radical generating ability of both sides different.

Furthermore, for example, the liquid crystal alignment films of the substrates on both sides can be irradiated with light, but the amounts of light irradiation on both sides are made different, so that the amounts of deactivated free radical generating structures are made different on both sides. Thereby, one becomes a liquid crystal alignment film with low free radical generating ability, and the other becomes a liquid crystal alignment film with high free radical generating ability, so that the free radical generating abilities of both sides become different.

In the present invention, a liquid crystal layer forming step of forming a liquid crystal layer containing a polymerizable compound between the pair of substrates is subsequently included. Thereby, since the liquid crystal layer is formed by sandwiching a pair of liquid crystal alignment films with different free radical generating capabilities, an asymmetric liquid crystal layer with different pretilt angles on both sides can be formed.

<Polymer having a free radical generating structure> The polymer having a free radical generating structure contained in the liquid crystal alignment agent used in the present invention will be described with specific examples, but is not limited to the following specific examples. The polymer having a free radical generating structure used in the present invention (hereinafter also referred to as a specific polymer) has as a side chain a site that generates free radicals due to light irradiation, such as ultraviolet irradiation. Examples of the specific polymer include a polymer having a side chain structure represented by the following formula (I), which is a radical generating structure that generates radicals due to ultraviolet irradiation, for example.

Ar represents an aromatic hydrocarbon group selected from a phenylene group, a naphthylene group and a biphenylene group. For these, the organic group can be substituted, and the hydrogen atom can also be substituted with a halogen atom; R ₁ and R ₂ are each independently Alkyl or alkoxy group having 1 to 10 carbon atoms, T ₁ and T ₂ are each independently a single bond or -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, The binding group of -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )-, -N(CH ₃ )CO-, S is a single bond or a carbon atom that is unsubstituted or substituted by a fluorine atom. Alkylene groups with numbers 1 to 20; but the -CH ₂ - or -CF ₂ - of the alkylene group can be optionally substituted by -CH=CH-, and can also be used when any of the groups listed below are not adjacent to each other. Substituted with the following groups: -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocyclic ring, divalent heterocyclic ring, Q represents the following Selected construct.

(R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₃ represents -CH ₂ -, -NR-, -O- or -S-).

In the above formula (I), Ar to which the carbonyl group is bonded is related to the absorption wavelength of ultraviolet rays. Therefore, when the wavelength is extended, a structure with a long conjugation length such as a naphthyl group or a biphenyl group is preferred. Furthermore, the substituent may be substituted for Ar, and the substituent is preferably an electron-donating organic group such as an alkyl group, a hydroxyl group, an alkoxy group, an amino group, or the like.

In formula (I), if Ar has a structure such as a naphthylene group or a biphenylene group, the solubility will be poor and the difficulty of synthesis will also be high. As long as the wavelength of ultraviolet rays is in the range of 250 nm to 380 nm, the phenyl group will also obtain sufficient characteristics, so the phenyl group is preferred.

Moreover, R ₁ and R ₂ are each independently an alkyl group, alkoxy group, benzyl group or phenethyl group having 1 to 10 carbon atoms. When they are an alkyl group or an alkoxy group, R ₁ and R ₂ may also form ring.

In formula (I), Q is preferably an electron-donating organic group, and more preferably the above-mentioned group. When Q is an amine derivative, during the polymerization of polyamide, which is a precursor of polyamide imide, there is a possibility that the generated carboxylic acid group and the amine group will form a salt, etc. More preferably, it is a hydroxyl group or an alkoxy group.

As a specific polymer, a polyimide precursor and/or a polyimide is used. When the structure of the above formula (I) is to be introduced into a side chain, the side chain structure of the formula (I) is rationalized from the raw material or The ease of synthesis of the polymer is preferred

The site where radicals are generated by ultraviolet irradiation in the above formula (I) is specifically preferably as follows. In particular, from the viewpoint of the reliability of the liquid crystal display element obtained, (b) or (c) is preferred.

Furthermore, in formula (I), -T ₁ -ST ₂ - serves as a linking group that connects diaminobenzene and a site that generates free radicals due to ultraviolet irradiation; T ₁ and T ₂ are each independently a single bond, -O-, -S-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )- or -N(CH ₃ )CO-; S is a single bond or an alkylene group with 1 to 20 carbon atoms that is unsubstituted or may be substituted by a fluorine atom (but, the -CH ₂ - or -CF ₂ - system of the alkylene group Can be optionally substituted by -CH=CH-. When any of the following groups are not adjacent to each other, they can also be substituted by these groups: -O-, -COO-, -OCO-, -NHCO-, -CONH -, -NH-, divalent carbocyclic or heterocyclic ring). In particular, T ₂ is optimally -O- in view of the ease of synthesis. Furthermore, S is an alkylene group having 2 to 10 carbon atoms, more preferably 4 to 8 carbon atoms, in terms of ease of synthesis or solubility.

Examples of specific polymers used in the present invention include polymers containing a side chain structure represented by the following formula (II).

In formula (II), the dot refers to the bond of the main chain of the polymer, n is an integer selected from 1 to 12, and X represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )- or -N(CH ₃ )CO-; Cy represents a carbonyl carbon with an amide group A cyclic hydrocarbon group having 5 to 14 carbon atoms must be bonded with at least one unsaturated bond, and a part of the carbon atoms constituting the cyclic hydrocarbon may be substituted with a heteroatom.

This specific polymer has an organic group represented by the above formula (II) in the side chain. It is believed that this organic radical is excited by ultraviolet irradiation to generate free radicals, or has the function of chain transfer of other radicals that generate organic radicals, and functions as a free radical generating structure. This structure having the function of free radical chain transfer is also considered to be included in the free radical generating structure of the present invention.

In the aforementioned formula (I), it is important that for the two carbonyl carbons in the imine ring, the bonding Cy is a cyclic hydrocarbon group with at least one unsaturated bond. Particularly preferably, for the two carbonyl carbons, The structure of direct connection of unsaturated bonds. In particular, the greater the number of unsaturated bonds, the higher the absorbance in the ultraviolet region and the longer the absorption wavelength, so it is more suitable for long-wavelength exposure. Furthermore, an aromatic hydrocarbon group or a heterocyclic compound having 6 to 14 carbon atoms is more preferred. In view of the availability of reagents, ease of synthesis, etc., a cyclic hydrocarbon group containing no heteroatoms is preferred. The following shows examples of better Cy, but is not limited thereto. Furthermore, the two points of Cy each represent a bond to the carbonyl carbon of the imine.

On the other hand, the greater the number of carbon atoms that form the ring structure, the easier it is to have a rigid structure. Since it lacks solubility in a solvent, from the viewpoint of monomer synthesis or ease of handling of the monomer, it is preferable. As a cyclic hydrocarbon group with a relatively small number of carbon atoms, particularly preferred examples include cyclohexene, benzene, naphthalene, biphenyl group, and the like. Even better is the structure below.

The hydrogen atom of the cyclic hydrocarbon group directly connected to the amide imine ring may be substituted with a fluorine atom or the like, or may be substituted with an organic group. The substituted organic group is not particularly limited, but it is preferable to introduce an organic group with strong electron donating or electron accepting properties since the effect of extending the absorption wavelength can be expected. On the other hand, since the nitro group or the amino group has the possibility of capturing the generated free radicals, it is preferable to include a monovalent organic group with a molecular weight of 14 to 100. Examples include organic groups such as hydroxyl and hydroxyl groups. , or alkoxy groups, alkyl groups, etc. with relatively small molecular weights. However, since the introduced substituents have the possibility of capturing the generated free radicals, attention must be paid to the selection of substituents. For the above reasons, no substitution is the best.

In the above formula (II), -XC _n (H ₂ ) _n - represents the linking site with the polymer chain. In the present invention, the structure of the imine carbonyl group bonded to the side chain represented by the aforementioned formula (II) is important. Therefore, although the linking site is not particularly limited, if a preferred structure of -X- is given, then X Examples include single bonds, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ ) -or-N(CH ₃ )CO-etc. Furthermore, the alkylene group linked to Can be replaced by fluorine. From the viewpoint of availability of reagents or synthesis, the structural system X that is easiest to synthesize is -O-, and the alkylene group is a straight-chain alkylene group having 1 to 6 carbon atoms.

The present invention is a polymer having an organic group represented by the above formula (II) as a side chain, and the means for introducing the side chain into the polymer is not particularly limited. Examples include a method of polymerizing a monomer having a side chain structure represented by the above formula (II) to obtain a polymer, a method of introducing the polymer through polymer modification, and the like. Preferable is a method of introducing a monomer having an organic group represented by the above formula (I) into a polymer.

The radical-generating structure of the present invention is not limited to those described above. In addition to the side chain structures described above, any side chain structure having a radical-generating structure is applicable. For example, a polymer containing a radical generating structure including a reactive mesogen structure (see Patent Document 3, claim 1, etc.) in the side chain may also be used.

<Side chains that vertically align liquid crystals> The specific polymer contained in the liquid crystal alignment agent used in the present invention has, in addition to the side chains (hereinafter, also, the radical generating structure represented by the above formula (I) or (II) In addition to a specific side chain), it is preferred to have a side chain that vertically aligns the liquid crystal. Side chains that vertically align liquid crystals are represented by the following formula [III-1] or formula [III-2]. Furthermore, in addition to the above-mentioned specific polymers, polymers having side chains that align liquid crystals vertically can also be blended into the liquid crystal alignment agent.

(X ¹ represents a single bond, -(CH ₂ ) _a -(a is an integer from 1 to 15), -O-, -CH ₂ O-, -COO- or -OCO-; X ² represents a single bond or -( CH ₂ ) _b - (b is an integer from 1 to 15); X ³ represents a single bond, - (CH ₂ ) _c - (c is an integer from 1 to 15), -O-, -CH ₂ O-, -COO - ^or -OCO-; An alkyl group, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom is substituted, and X ⁴ can also be A divalent organic group selected from an organic group having a steroid skeleton having a carbon number of 17 to 51; X ⁵ represents a divalent cyclic group selected from a benzene ring, a cyclohexane ring and a heterocyclic ring. Any hydrogen atom on the base can be replaced by an alkyl group with 1 to 3 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, a fluorine-containing alkyl group with 1 to 3 carbon atoms, or a fluorine-containing alkyl group with 1 to 3 carbon atoms. substituted by an alkoxy group or a fluorine atom; n represents an integer ^from 0 to 4; group or a fluorine-containing alkoxy group having 1 to 18 carbon atoms).

Among them, from the viewpoint of availability of raw materials or ease of synthesis, X ¹ is preferably a single bond, -(CH ₂ ) _a - (a is an integer from 1 to 15), -O-, -CH ₂ O - or -COO-, more preferably a single bond, -(CH ₂ ) _a - (a is an integer from 1 to 10), -O-, -CH ₂ O- or -COO-. Among them, X ² is preferably a single bond or -(CH ₂ ) _b - (b is an integer from 1 to 10). Among them, from the viewpoint of ease of synthesis, X ³ is preferably a single bond, -(CH ₂ ) _c - (c is an integer from 1 to 15), -O-, -CH ₂ O- or -COO-, More preferably, it is a single bond, -(CH ₂ ) _c - (c is an integer from 1 to 10, -O-, -CH ₂ O- or -COO-.

Among them, from the viewpoint of ease of synthesis, X ⁴ is preferably a benzene ring, a cyclohexane ring, or an organic group having 17 to 51 carbon atoms having a steroid skeleton. Among them, X ⁵ is preferably a benzene ring or a cyclohexane ring. Among them, n is preferably 0 to 3, more preferably 0 to 2, from the viewpoint of availability of raw materials or ease of synthesis.

Among them, X ⁶ is preferably an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, or a fluorine-containing alkoxy group having 1 to 10 carbon atoms. . More preferably, it is an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. Particularly preferred is an alkyl group having 1 to 9 carbon atoms or an alkoxy group having 1 to 9 carbon atoms.

Preferable combinations of X ¹ , X ² , X ³ , X ⁴ , X ^{5 ,} ) are the same combinations (2-1) to (2-629) disclosed in Tables 6 to 47 on pages 13 to 34 of ). In addition, in the tables of the International Publication, X ¹ to X ⁶ in the present invention are represented as Y1 to Y6, and Y1 to Y6 can be regarded as interchangeable readers and writers with X ¹ to X ⁶ .

In addition, in the tables (2-605) to (2-629) disclosed in the International Publication Gazette, the organic group having a carbon number of 17 to 51 having a steroid skeleton in the present invention is expressed as the carbon number having a steroid skeleton. An organic group with 12 to 25 carbon atoms, but an organic group with a carbon number of 12 to 25 having a steroid skeleton can be regarded as an exchange reader with an organic group with a carbon number of 17 to 51 having a steroid skeleton. Among them, (2-25) to (2-96), (2-145) to (2-168), (2-217) to (2-240), (2-268) to (2- 315), (2-364)～(2-387), (2-436)～(2-483) or the combination of (2-603)～(2-615). The best combinations are (2-49)～(2-96), (2-145)～(2-168), (2-217)～(2-240), (2-603)～(2- 606), (2-607)～(2-609), (2-611), (2-612) or (2-624).

X ⁷ represents a single bond, -O-, -CH ₂ O-, -CONH-, -NHCO-, -CON(CH ₃ )-, -N(CH ₃ )CO-, -COO- or -OCO-. X ⁸ represents an alkyl group having 8 to 22 carbon atoms or a fluorine-containing alkyl group having 6 to 18 carbon atoms. Among them, X ⁷ is preferably a single bond, -O-, -CH ₂ O-, -CONH-, -CON(CH ₃ )- or -COO-, more preferably a single bond, -O-, -CONH- or -COO-. Among them, X ⁸ is preferably an alkyl group having 8 to 18 carbon atoms.

As side chains that vertically align the liquid crystal, it is preferable to use a structure represented by formula [III-1] from the viewpoint of obtaining high and stable vertical alignment of the liquid crystal.

Furthermore, the ability of polymers with side chains that vertically align liquid crystals to vertically align liquid crystals varies depending on the structure of the side chains that vertically align liquid crystals. However, generally speaking, if the side chains that vertically align liquid crystals have As the amount of chains increases, the ability to align the liquid crystal vertically increases, while as it decreases, the ability to align the liquid crystal vertically decreases. Furthermore, if it has a ring structure, it tends to have a higher ability to vertically align liquid crystals than if it does not have a ring structure.

<Photoreactive side chain> The specific polymer contained in the liquid crystal alignment agent of the present invention may, for example, have a photoreactive side chain in addition to a side chain having a radical generating structure represented by the above formula (I) or (II). Reactive side chains. The photoreactive side chain has a functional group (hereinafter also referred to as a photoreactive group) that can react by irradiation with light such as ultraviolet (UV) to form a covalent bond. Furthermore, in addition to the above-mentioned specific polymers, polymers with photoreactive side chains can also be blended into the liquid crystal alignment agent.

The photoreactive side chain can be directly bonded to the main chain of the polymer, or can be bonded through a binding group. The photoreactive side chain is represented by the following formula [IV], for example.

R ⁸ represents a single bond, -CH ₂ -, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, - CON(CH ₃ )-or-N(CH ₃ )CO-. R ⁹ represents a single bond, an alkylene group with 1 to 20 carbon atoms that may be substituted by a fluorine atom, and the -CH ₂ of the alkylene group may be optionally substituted with -CF ₂ - or -CH=CH-, in any of the following When a group is not adjacent to each other, it can also be substituted by the following groups: -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocyclic or heterocyclic rings . R ¹⁰ represents a photoreactive group selected from the following formula. Among them, R ⁸ is preferably a single bond, -O-, -COO-, -NHCO- or -CONH-. R ⁹ can be formed by ordinary organic synthesis techniques, but from the viewpoint of ease of synthesis, it is preferably a single bond or an alkylene group having 1 to 12 carbon atoms.

Y ₁ represents -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH- or -CO-. Y ₂ represents an alkylene group, a divalent carbocyclic ring or a heterocyclic ring having 1 to 30 carbon atoms. One or more hydrogen atoms in the alkylene group, a divalent carbocyclic ring or a heterocyclic ring may be replaced by a fluorine atom or an organic replaced by base. When Y ₂ has the following groups that are not adjacent to each other, -CH ₂ - can also be substituted with these groups: -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH-, -NHCONH-, -CO-. Y ₃ represents -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, -CO- or a single bond. Y ₄ represents cinnamyl group. Y ₅ represents a single bond, an alkylene group with 1 to 30 carbon atoms, a divalent carbocyclic ring or a heterocyclic ring. One or more hydrogen atoms in the alkylene group, a divalent carbocyclic ring or a heterocyclic ring may be fluorinated. substituted by atoms or organic radicals. Y ₅ When the following groups are not adjacent to each other, -CH ₂ - can also be substituted by these groups: -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH-, -NHCONH-, -CO-. Y ₆ represents a photopolymerizable group of an acrylic group or a methacrylic group.

Furthermore, in the formula [IV], the divalent carbocyclic ring or heterocyclic ring substituted for any -CH ₂ - of R ⁹ is specifically exemplified by the following.

From the viewpoint of photoreactivity, R ¹⁰ is preferably a methacrylic acid group, an acrylic acid group or a vinyl group.

The photoreactive side chains are preferably present in an amount that reacts with ultraviolet irradiation to form covalent bonds, thereby accelerating the response speed of the liquid crystal.

<Polymer forming liquid crystal alignment agent> The polymer system having a free radical generating structure used in the present invention is not particularly limited, but polyimide-based polymers, poly(meth)acrylate-based polymers, and polysiloxane polymers can be suitably used. Alkane polymers, etc. Hereinafter, in this specification, a detailed description is limited to the polyimide structure. However, for other polymers, well-known techniques (radical polymerization, sol-gel method, etc.) can also be used to synthesize polymers.

The method of producing the polyimide precursor having a specific side chain and the polyimide obtained by imidizing the polyimide precursor is not particularly limited. Examples include a method of polymerizing a diamine having a specific side chain and a tetracarboxylic dianhydride, a method of polymerizing a diamine having a specific side chain and a tetracarboxylic acid diester, and a method of polymerizing a tetracarboxylic dianhydride containing a specific side chain. Methods of polymerizing carboxylic dianhydride and diamine compounds, methods of polymerizing tetracarboxylic dianhydride and diamine, and then modifying compounds containing specific side chains into polymers through any reaction, etc. Among them, from the viewpoint of ease of production, a method of polymerizing a diamine compound containing a specific side chain and a tetracarboxylic dianhydride or a tetracarboxylic diester is preferred.

Methods for producing a polyimide precursor having specific side chains plus side chains for vertically aligning liquid crystals and a polyimide obtained by imidizing the polyimide precursor can also be cited. The same method as mentioned above. Likewise, a preferred method is a method of polymerizing a diamine compound containing a side chain for vertically aligning liquid crystals and a tetracarboxylic dianhydride or a tetracarboxylic diester. The polyimide having a radical generating structure in the side chain can be prepared using, for example, one or more types of diamines such as the following specific diamines 1 to 3.

<Specific diamine 1> The diamine used in the production of the above-mentioned polymer forming the liquid crystal alignment agent of the present invention (hereinafter also referred to as specific diamine) contains free radicals generated by decomposition by ultraviolet irradiation. The moiety generating the base structure is represented by the following formula (1) as a side chain.

Ar, R ₁ , R ₂ , T ₁ , T ₂ and S in the above formula (1) are as defined above.

The diaminobenzene system in the formula (1) can be any one of o-phenylenediamine, m-phenylenediamine or p-phenylenediamine, but it is preferred in terms of reactivity with acid dianhydride. It is m-phenylenediamine or p-phenylenediamine.

The specific diamine 1 is preferably a structure represented by the following formula from the viewpoint of ease of synthesis, level of versatility, characteristics, etc. Furthermore, n in the formula is an integer from 2 to 8.

<Synthesis of specific diamine 1> In the present invention, specific diamine 1 can be synthesized through each step to form a dinitroform, or a mononitroform having an amine group with a protecting group that can be removed by the reduction step, or a dinitroform. Amine is obtained by converting a nitro group into an amine group or deprotecting a protecting group through a commonly used reduction reaction.

There are various methods for synthesizing diamine precursors. The following shows, for example, the method of synthesizing a site that generates free radicals due to ultraviolet irradiation, introducing a spacer site, and bonding it to dinitrobenzene. Furthermore, n in the formula is an integer from 2 to 8.

In the above reaction, a hydroxyl group present in two places is used, but it can be selectively synthesized by optimizing the type or feed ratio of the base (catalyst).

Furthermore, the base used is not particularly limited, but is preferably an inorganic base such as potassium carbonate, sodium carbonate, cesium carbonate, pyridine, dimethylaminopyridine, trimethylamine, triethylamine, tributylamine, etc. organic bases, etc.

The method for reducing the dinitro compound of the diamine precursor is not particularly limited, but palladium on carbon, platinum oxide, Rae's nickel, platinum on carbon, rhodium-alumina, platinum sulfide on carbon, etc. are usually used as catalysts. In ethyl acetate, toluene, tetrahydrofuran, di A method of reduction by hydrogen, hydrazine, hydrogen chloride, etc. in solvents such as alkanes and alcohols. An autoclave, etc. can be used if necessary.

On the other hand, when palladium carbon or platinum carbon is used when an unsaturated bond site is included in the structure, there is a risk that the unsaturated bond site will be reduced to a saturated bond. Therefore, as a better condition, it is preferable to use reduced iron or platinum carbon. Transition metals such as tin, tin chloride, or poisoned palladium carbon or platinum carbon, platinum carbon doped with iron, etc. are used as catalyst reduction conditions, etc.

In addition, the diamine of the present invention can be obtained by deprotecting the diaminobenzene derivative protected by a benzyl group or the like in the above reduction step in the same manner.

The specific diamine 1 is preferably a diamine component used in the synthesis of polyamic acid. It is preferably 10 to 80 mol%, more preferably 20 to 60 mol%, and particularly preferably 30 to 50 mol%.

<Specific diamine 2> The specific diamine 2 of the present invention is a diamine having an organic group represented by the aforementioned formula (II) as a side chain, and can be represented by the following formula (VI).

In formula (VI), Sp is an alkylene group having 1 to 12 carbon atoms, and the alkylene group may have an unsaturated bond, a branched chain, or a cyclic structure. X represents a single bond or linking group. Cy represents a cyclic hydrocarbon group with 5 to 14 carbon atoms that has at least one unsaturated bond that is bound to the carbonyl carbon of the amide group. Some of the carbon atoms constituting the cyclic hydrocarbon may be substituted with heteroatoms. .

The diaminobenzene in the formula (VI) can be any one of o-phenylenediamine, m-phenylenediamine or p-phenylenediamine, but in terms of reactivity with acid dianhydride, it is preferred. It is m-phenylenediamine or p-phenylenediamine. The preferred structure of formula (VI) is a diamine represented by the following formula (X),

(n in the formula is an integer from 1 to 6)

More preferably, from the viewpoint of ease of synthesis, level of versatility, characteristics, etc., a structure represented by the following formula (XI) is most preferred.

(In the formula, m is an integer from 1 to 3)

<Synthesis of specific diamine 2> In the present invention, specific diamine 2 can be synthesized through each step to form a dinitroform, or a mononitroform having an amine group with a protecting group that can be removed by the reduction step, or a dinitroform. Amine is obtained by converting a nitro group into an amine group or deprotecting a protecting group through a commonly used reduction reaction.

Various methods are considered for the synthesis of diamine precursors. Examples include a method of reacting an alcohol, an alkylamine, an alkyl halide, etc. having a desired amide imine structure with dinitrobenzene to obtain a diamine precursor, or making an alkyl group into which dinitrobenzene has been introduced. A method obtained by reacting an amine with an acid anhydride, or by reacting an alcohol to which dinitrobenzene has been introduced and an N-unsubstituted acyl imine, or by reacting an alkyl base to which dinitrobenzene has been introduced and an N-unsubstituted acyl imine. Condensation method in the presence of alkali or metal catalyst, etc.

The above is a synthesis example in which the bond with the dinitrobody is an ether bond. However, according to the above method, it is also possible to synthesize one in which the bonding group is an ester bond or an amide bond.

The method for reducing the dinitro compound of the diamine precursor is not particularly limited. Usually, palladium carbon, platinum oxide, Rae's nickel, platinum carbon, rhodium-alumina, platinum sulfide carbon, etc. are used as catalysts. Ethyl acetate, toluene, tetrahydrofuran, di A method of reduction by hydrogen, hydrazine, hydrogen chloride, etc. in solvents such as alkanes and alcohols. An autoclave, etc. can be used if necessary.

On the other hand, when palladium carbon or platinum carbon is used when an unsaturated bond site is included in the structure, there is a risk that the unsaturated bond site will be reduced to a saturated bond. Therefore, as a better condition, it is preferable to use reduced iron or platinum carbon. Transition metals such as tin, tin chloride, or poisoned palladium carbon or platinum carbon, platinum carbon doped with iron, etc. are used as catalyst reduction conditions, etc.

In addition, the diamine of the present invention can be obtained by deprotecting the diaminobenzene derivative protected by a benzyl group or the like in the above reduction step in the same manner.

<Specific diamine 3> The specific diamine 3 of the present invention is represented by the following formula (11).

Specific diamine 3 has a photoreactive structure that generates radicals due to ultraviolet irradiation in one of its molecular structures, and has a structure that vertically aligns liquid crystals. That is, the photoreactive structure is a 4-dihydropyran structure bonded to the ^{phenylenediamine} skeleton via The structure of X ₂ -X ₃ -X ₄ . In the above formula (11), each of X ¹¹ , X ¹² , X ¹³ and X ¹⁴ is defined as above. Among them, from the viewpoint of ease of synthesis, X ¹¹ is preferably -O- or -CH ₂ O-. Furthermore, from the viewpoint of high vertical alignment, X ¹² and X ¹³ are preferably cyclohexane rings. In addition, from the viewpoint of availability of raw materials, X ¹⁴ is preferably an alkyl group having 3 to 7 carbon atoms.

Preferable specific examples of the specific diamine 3 include the following.

<Production of specific diamine 3> The method for synthesizing specific diamine 3 in the present invention is not particularly limited. For example, it can be synthesized by the method shown below. That is, a dinitro compound represented by the following general formula (12) corresponding to the specific diamine 3 is synthesized (in the above formula, X ¹¹ to X ¹⁴ are the same as the formula (11)), and the nitro group is reduced and converted into Amino group.

The method for reducing the above-mentioned dinitro compound is not particularly limited, but usually palladium-carbon, platinum-carbon, platinum oxide, reed nickel, iron, tin chloride, platinum black, rhodium-alumina, platinum sulfide carbon etc. as catalyst, in ethyl acetate, toluene, tetrahydrofuran, dihydrofuran A method performed by reaction using hydrogen, hydrazine, hydrogen chloride, ammonium chloride, etc. in solvents such as alkanes and alcohols. The method for synthesizing the dinitro compound represented by the general formula (12) is not particularly limited and can be synthesized by any method. As a specific example, for example, the method shown in the following scheme (13) can be used.

In scheme (13), the dinitro compound A and the compound B having a hydroxyl group can be dissolved in an organic solvent (for example, ethyl acetate, toluene, tetrahydrofuran, dihydrofuran, etc.) alkane, chloroform, dichloromethane, DMF, DMSO, etc.), synthesized by reaction in the presence of a base. As the base, for example, organic amines such as triethylamine, and inorganic salts such as potassium carbonate and sodium hydroxide can be used. In the above dinitrobenzene compound A, X ¹⁵ is any one of chlorine, bromine, iodine, fluorine, -OH, -COOH, -COOCl, -(CH ₂ ) _a OH (a is an integer from 1 to 15) It is composed of X ¹² to X ¹⁴ in the phenol compound B and is the same as the formula 1. In addition, the compound shown here is an example and is not specifically limited.

The specific diamine is preferably a diamine component used in the synthesis of polyamic acid. It is preferably 10 mol% to 80 mol%, more preferably 20 mol% to 60 mol%, and particularly preferably 30 mol%. Ear% ~ 50 mol%.

<Diamine having side chains that vertically align liquid crystals> The method of introducing side chains that vertically align liquid crystals into a polyimide-based polymer is preferably to use a diamine component with a specific side chain structure as part of the diamine component. Diamine.

X represents the structure of the above formula [III-1] or formula [III-2], and n represents an integer of 1 to 4.

R ⁸ , R ⁹ and R ¹⁰ are as defined above.

Y ₁ to Y ₆ are as shown above.

Specific examples of the specific side chain type diamine include structures represented by the following formulas [2a-1] to formulas [2a-31].

(R ¹ represents -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ - or -CH ₂ OCO-, R ² is a linear or branched alkyl group with 1 to 22 carbon atoms, or A linear or branched alkoxy group with a prime number of 1 to 22, a linear or branched fluorine-containing alkyl group or a fluorine-containing alkoxy group with a carbon number of 1 to 22).

(R ³ represents -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ - or -CH ₂ -, and R ⁴ is Linear or branched alkyl group having 1 to 22 carbon atoms, linear or branched alkoxy group having 1 to 22 carbon atoms, linear or branched fluorine-containing group having 1 to 22 carbon atoms alkyl or fluorine-containing alkoxy).

(R ⁵ represents -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -, -CH ₂ -, -O- or -NH-, R ⁶ is fluoro, cyano, trifluoromethane, nitro, azo, formyl, acetyl, acetyloxy or hydroxyl). (R ⁷ is a linear or branched alkyl group having 3 to 12 carbon atoms, and the cis-trans isomers of the 1,4-cyclohexylene group are each trans isomer).

(R ⁸ is a linear or branched alkyl group having 3 to 12 carbon atoms, and the cis-trans isomers of the 1,4-cyclohexylene group are each trans isomer).

(A ₄ is a linear or branched alkyl group having 3 to 20 carbon atoms which may be substituted by a fluorine atom, A ₃ is a 1,4-cyclohexylene group or a 1,4-phenylene group, and A ₂ is an oxygen atom Or COO-＊ (However, the bond with "＊" is bonded with A ₃ ), A ₁ is an oxygen atom or COO-＊ (However, the bond with "＊" is with (CH ₂ )a ₂ )bonding). In addition, a ₁ is an integer of 0 or 1, a ₂ is an integer of 2 to 10, and a ₃ is an integer of 0 or 1).

Among the above formulas [2a-1] to [2a-31], formula [2a-1] to formula [2a-6], formula [2a-9] to formula [2a-13] or formula [2a- 22]～Formula [2a-31].

Moreover, examples of the diamine having a specific side chain structure represented by the aforementioned formula [III-2] include diamines represented by the following formulas [2b-1] to [2b-10].

(A ¹ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group).

In the above formula [2b-5] to formula [2b-10], A ¹ represents -COO-, -OCO-, -CONH-, -NHCO-, -CH ₂ -, -O-, -CO- or -NH -, A ² represents a linear or branched alkyl group having 1 to 22 carbon atoms or a linear or branched fluorine-containing alkyl group having 1 to 22 carbon atoms.

The above-mentioned diamines can also be used as one type or in a mixture of two or more types according to characteristics such as liquid crystal alignment, pretilt angle, voltage holding characteristics, and charge storage when used as a liquid crystal alignment film.

The above-mentioned diamine having side chains that vertically align liquid crystals is preferably 5 to 70 mol% of the diamine component used in the synthesis of polyamide, and more preferably 20 mol% to the diamine component. 60 mol%, particularly preferably 20 mol% to 50 mol%.

<Diamine containing photoreactive side chains> As a method of introducing photoreactive side chains into a polyimide-based polymer, it is preferable to use a diamine having a specific side chain structure as part of the diamine component. The diamine having a photoreactive side chain is a diamine having a side chain represented by formula [VIII] or formula [IX].

(The definitions of R ⁸ , R ⁹ and R ¹⁰ in [VIII] are the same as in the above formula [IV]).

(The definitions of Y ₁ , Y ₂ , Y ₃ , Y ₄ , Y ₅ and Y ₆ in the formula [IX] are the same as those in the above formula [V]).

The bonding positions of the two amino groups (-NH ₂ ) in formula [VIII] and formula [IX] are not limited. Specifically, the bonding group of the side chain includes the 2,3 position, the 2,4 position, the 2,5 position, the 2,6 position, the 3,4 position, and 3, 5 position. Among them, from the viewpoint of reactivity when synthesizing polyamide acid, the 2,4 position, the 2,5 position or the 3,5 position is preferred. If the ease of synthesizing the diamine is also taken into consideration, the 2,4 position or the 3,5 position is more preferred.

Specific examples of the diamine having a photoreactive side chain include the following, but are not limited thereto.

(X ^{9 ,} .

Examples of the diamine having a reactive side chain include a diamine represented by the following formula and having a group that causes a photodimerization reaction and a group that causes a photopolymerization reaction in the side chain.

In the above formula, Y ₁ represents -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH- or -CO-; Y ₂ is an extension with 1 to 30 carbon atoms. Alkyl group, divalent carbocyclic ring or heterocyclic ring, one or more hydrogen atoms of this alkylene group, divalent carbocyclic ring or heterocyclic ring may be replaced by fluorine atoms or organic groups; Y ₂ is the following group When not adjacent to each other, -CH ₂ - can also be substituted by the following groups: -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH-, -NHCONH-, -CO -; Y ₃ represents -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, -CO- or single bond; Y ₄ represents cinnamyl group; Y ₅ It is a single bond, an alkylene group with 1 to 30 carbon atoms, a divalent carbocyclic ring or a heterocyclic ring. One or more hydrogen atoms in the alkylene group, a divalent carbocyclic ring or a heterocyclic ring may be replaced by a fluorine atom or Substituted by organic groups; Y ₅ when the following groups are not adjacent to each other, -CH ₂ - can also be substituted with these groups: -O-, -NHCO-, -CONH-, -COO-, -OCO- , -NH-, -NHCONH-, -CO-; Y ₆ represents a photopolymerizable group of an acrylic group or a methacrylic group.

The above-mentioned diamines having photoreactive side chains can be mixed according to characteristics such as liquid crystal alignment, pretilt angle, voltage holding characteristics, charge storage when used as a liquid crystal alignment film, response speed of liquid crystal when used as a liquid crystal display element, etc. Used for 1 type or 2 or more types.

In addition, the diamine having a photoreactive side chain is preferably 10 to 70 mol% of the diamine component used in the synthesis of the polyamide acid, more preferably 20 to 60 mol%, and particularly preferably 30~50 mol%.

<(B) Component> The liquid crystal alignment agent of the present invention may contain: (A) component, which is a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor. At least one selected polymer, the polyimide precursor having side chains that vertically align liquid crystals and side chains having a free radical generating structure represented by the above formula (I); and (B) component, which is A polymer selected from a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor. The polyimide precursor is composed of the following formula (B- The diamine component of at least one diamine selected from 1) to (B-5) is used as a raw material, or is obtained from a polyimide precursor and the imidization of the polyimide precursor. Polyimide is a polymer selected from the group consisting of a tetracarboxylic dianhydride component and a dianhydride selected from at least one tetracarboxylic dianhydride selected from the following formulas (3) and (4). Obtained from the reaction of amines.

(In the formula, Y ₁ represents an organic group with one valence of a secondary amine, a tertiary amine or a heterocyclic structure, and Y ₂ represents a divalent organic group with a secondary amine, a tertiary amine or a heterocyclic structure).

If at least one kind of tetracarboxylic dianhydride selected from the above formulas (3) and (4) is used as a raw material, the interaction between [liquid crystal and alignment film] due to light irradiation can improve the charge accumulation characteristics. Examples of the tetracarboxylic dianhydride represented by a formula selected from the above formulas (3) and (4) include the following compounds, but are not limited thereto.

As at least one tetracarboxylic dianhydride selected from the above-mentioned formulas (1-1) to (1-4), it is preferable to use the tetracarboxylic dianhydride used in the synthesis of the component (B) of the polyamide acid. The amount of the ingredients can be 10 to 100%, preferably 10 to 60%.

Moreover, as long as the effect of the present invention is not impaired, tetracarboxylic dianhydride other than the above formulas (1-1) to (1-4) may also be used as the raw material of the component (B). Specific examples include the tetracarboxylic dianhydride described in (A) component, but are not limited thereto.

For example, when tetracarboxylic dianhydride having an aliphatic group or alicyclic group is also used as a raw material, it is preferable to use 0 to 90% of the tetracarboxylic dianhydride component used in the synthesis of component (B) of the polyamide. % amount.

When at least one tetracarboxylic dianhydride selected from the above formulas (1-1) to (1-4) is used as the component (B), the diamine component to be reacted is not particularly limited. Specific examples thereof are , examples include the diamines listed in (A) component. However, if at least one diamine selected from the above formulas (B-1) to (B-5) is used, from the viewpoint of charge accumulation characteristics More appropriate.

Furthermore, the polymer of component (B) may also be a polymer selected from a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor. The amine precursor is obtained by using a diamine component containing at least one diamine selected from the following formulas (B-1) to (B-5) as a raw material.

(In the formula, Y ₁ represents an organic group with one valence of a secondary amine, a tertiary amine or a heterocyclic structure, and Y ₂ represents a divalent organic group with a secondary amine, a tertiary amine or a heterocyclic structure).

At least one type of highly polar diamine with a specific structure selected from the above formulas (B-1) to (B-5) is used, and at least one type of amine having a carboxyl group and a nitrogen-containing aromatic heterogeneous compound are used in combination. Cyclic diamines promote charge movement through salt formation or electrostatic interactions of hydrogen bonds, thereby improving charge accumulation characteristics. Examples of at least one diamine selected from the above formulas (B-1) to (B-5) include the following diamines, but are not limited thereto.

<Other diamines> Furthermore, when producing a polyimide precursor and/or polyimide, as long as the effects of the present invention are not impaired, in addition to the above-mentioned diamines, other diamines may be used together as Diamine component. Specific examples include p-phenylenediamine, 2,3,5,6-tetramethylp-phenylenediamine, 2,5-dimethylp-phenylenediamine, m-phenylenediamine, 2,4-dimethyl metaphenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3 ,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphenyl , 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy- 4,4'-Diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3' -Trifluoromethyl-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-Diaminobiphenyl, 4,4'-Diaminodiphenylmethane, 3,3'-Diaminodiphenylmethane, 3,4'-Diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl Ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldiphenyl ether Aniline, 3,3'-sulfonyl diphenylamine, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, Dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodiphenylamine, 3,3'-thiodiphenylamine, 4,4'-diaminodiphenylamine, 3, 3'-Diaminodiphenylamine, 3,4'-Diaminodiphenylamine, 2,2'-Diaminodiphenylamine, 2,3'-Diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'-diaminodiphenyl)amine, N-methyl(3,4'-diamine methyldiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4,4'- Diaminodiphenyl ketone, 3,3'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 1,4-diaminonaphthalene, 2,2'-diamine diphenylketone, 2,3'-diaminodiphenylketone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8- Diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis(4-amine phenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)ethane )propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminobenzene) methyl)methane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene , 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4' -[1,4-phenylenebis(methylene)]diphenylamine, 4,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,4'-[1, 4-phenylenebis(methylene)]diphenylamine, 3,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,3'-[1,4-phenylenebis(methylene)]diphenylamine Bis(methylene)]diphenylamine, 3,3'-[1,3-phenylenebis(methylene)]diphenylamine, 1,4-phenylenebis[(4-aminophenyl) )methanone], 1,4-phenylenebis[(3-aminophenyl)methanone], 1,3-phenylenebis[(4-aminophenyl)methanone], 1,3 -phenylenebis[(3-aminophenyl)methanone], 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate) Benzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminobenzoate) Phenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, bis (3-aminophenyl) )isophthalate, N,N'-(1,4-phenylene)bis(4-aminobenzamide), N,N'-(1,3-phenylene)bis( 4-aminobenzamide), N,N'-(1,4-phenylene)bis(3-aminobenzamide), N,N'-(1,3-phenylene) Bis(3-aminobenzamide), N,N'-bis(4-aminophenyl)p-phenylamide, N,N'-bis(3-aminophenyl)p-phenylamide Diamide, N,N'-bis(4-aminophenyl)m-xylamide, N,N'-bis(3-aminophenyl)m-xylamide, 9,10- Bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenylsine, 2,2'-bis[4-(4-aminophenoxy)benzene base]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2 '-Bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4-aminobenzene) methyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 3,5-diaminobenzoic acid , 2,5-diaminobenzoic acid, 1,3-bis(4-aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4 -Aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis( 3-Aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7-bis (4-Aminophenoxy)heptane, 1,7-(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis (3-Aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10- (4-aminophenoxy)decane, 1,10-(3-aminophenoxy)decane, 1,11-(4-aminophenoxy)undecan, 1,11-( Aromatic diamines such as 3-aminophenoxy) undecane, 1,12-(4-aminophenoxy)dodecane, 1,12-(3-aminophenoxy)dodecane, etc. Amine, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane and other cyclic diamines, 1,3-diaminopropane, 1,4-diamine Butane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diamine Nonane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and other aliphatic diamines.

The above-mentioned other diamines may also be used by mixing one type or two or more types according to characteristics such as liquid crystal alignment, pretilt angle, voltage holding characteristics, and charge storage when used as a liquid crystal alignment film.

<Tetracarboxylic dianhydride> The tetracarboxylic dianhydride component that reacts with the above-mentioned diamine component is not particularly limited. Specific examples include pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, and 1,4,5,8-naphthalenetetracarboxylic acid. , 2,3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3' ,4-biphenyltetracarboxylic acid, bis(3.4-dicarboxyphenyl) ether, 3,3',4,4'-diphenylketonetetracarboxylic acid, bis(3,4-dicarboxyphenyl) Tricholine, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexafluoro-2,2 -Bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethylsilane, bis(3,4-dicarboxyphenyl)diphenylsilane, 2,3, 4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,3',4,4'-diphenyltetracarboxylic acid, 3,4,9, 10-Perylenetetracarboxylic acid, 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic acid, oxybisphthalatetetracarboxylic acid, 1,2,3,4-cyclobutane Alkane tetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4-tetramethyl-1,2 ,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,3-dimethyl-1,2,3,4 -Cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentyl acetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid, bicyclo[3,3,0]octane-2, 4,6,8-tetracarboxylic acid, bicyclo[4,3,0]nonane-2,4,7,9-tetracarboxylic acid, bicyclo[4,4,0]decane-2,4,7.9- Tetracarboxylic acid, bicyclo[4,4,0]decane-2,4,8,10-tetracarboxylic acid, tricyclo[6.3.0.0＜2,6＞]undecane-3,5,9,11 -Tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4-(2,5-bisoxytetrahydrofuran-3-yl)-1,2,3,4-tetralin-1 , 2-dicarboxylic acid, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid, 5-(2,5-bilateral oxytetrahydrofuranyl)-3- Methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo[6,2,1,1,0,2,7]dodecane-4,5,9,10-tetracarboxylic acid, 3,5,6-Tricarboxynorbornane-2:3,5:6 dicarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, etc. Of course, one type or two or more types of tetracarboxylic dianhydride may be used in combination according to characteristics such as liquid crystal alignment properties, voltage holding characteristics, and charge storage when used as a liquid crystal alignment film.

<Polymerizable compound> The liquid crystal alignment agent of the present invention may contain a polymerizable compound having photopolymerizable or photocrosslinking groups at two or more terminals if necessary. The polymerizable compound is a compound having two or more terminals having photopolymerizable or photocrosslinking groups. Here, the term "polymerizable compound having a photopolymerizable group" refers to a compound having a functional group that causes polymerization by irradiation with light. In addition, the so-called compound having a photo-crosslinking group refers to a polymer having a polymerizable compound due to irradiation with light, or a polyimide obtained from a polyimide precursor and the imidization of the polyimide precursor. Compounds with functional groups capable of cross-linking with at least one polymer selected from imines. In addition, the compound having a photo-crosslinking group is a compound having a photo-crosslinking group that also reacts with each other.

By using the liquid crystal alignment agent of the present invention containing the above-mentioned polymerizable compound in a vertical alignment liquid crystal display element such as an SC-PVA type liquid crystal display, the liquid crystal alignment agent has a side chain and a photoreactive side that vertically align the liquid crystal. The response speed can be significantly improved compared to the case where the chain polymer is used or the polymerizable compound is used alone. Even with a small amount of the polymerizable compound added, the response speed can be fully improved.

Examples of the photopolymerizable or photocrosslinkable group include a monovalent group represented by the following formula (X).

(R ¹² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; Z ¹ represents a bivalent aromatic ring or heterocyclic ring that may be substituted by an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms; Z ² represents a monovalent aromatic ring or heterocyclic ring which may be substituted by an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms).

Specific examples of the polymerizable compound include a compound represented by the following formula (XI) having a photopolymerizable group at both terminals, a compound represented by the following formula (XII) having a photopolymerizable group at its terminal and a compound having a photocrosslinked A compound at the end of a group, or a compound represented by the following formula (XIII) having a photo-crosslinking group at each of the two ends.

In addition, in the following formulas (XI) to (XIII), R ¹² , Z ¹ and Z ² are the same as R ¹² , Z ¹ and Z ² in the above formula (X), and Q ¹ is a divalent organic base. Q ¹ is preferably a ring having a phenylene group (-C ₆ H ₄ -), a biphenylene group (-C ₆ H ₄ -C ₆ H ₄ -), a cyclohexylene group (-C ₆ H ₁₀ -), etc. Construct. This is because the interaction with liquid crystal tends to increase.

Specific examples of the polymerizable compound represented by formula [XI] include a polymerizable compound represented by the following formula (4). In the following formula (4), V and W represent a single bond or -R ¹ O-, and R ¹ is a linear or branched alkylene group having 1 to 10 carbon atoms, preferably -R ¹ O- represents, R ¹ is a linear or branched alkylene group having 2 to 6 carbon atoms. Furthermore, V and W may be the same or different, but if they are the same, synthesis is easy.

Furthermore, as the photopolymerization or photocrosslinking group, even if it is a polymerizable compound having an acrylate group or a methacrylate group rather than an a-methylene-g-butyrolactone group, it may have an acrylate group or a methacrylate group. A polymerizable compound having a structure in which a methacrylate group is bonded to a phenylene group via a spacer such as an oxyalkylene group, which is similar to the polymerizable compound having a-methylene-g-butyrolactone groups at both ends. Compounds can also significantly increase response speed. In addition, a polymerizable compound having a structure in which an acrylate group or a methacrylate group is bonded to a phenylene group through a spacer such as an oxyalkylene group has improved thermal stability and can fully withstand high temperatures. , such as a firing temperature above 200°C.

<Synthesis of Polyamic Acid> When polyamic acid is obtained by the reaction of a diamine component and tetracarboxylic dianhydride, well-known synthesis techniques can be used. Generally, it is a method of reacting a diamine component and a tetracarboxylic dianhydride component in an organic solvent. The reaction between the diamine component and the tetracarboxylic dianhydride is advantageous in that it proceeds relatively easily in an organic solvent and does not generate by-products.

The organic solvent used in the above reaction is not particularly limited as long as the produced polyamide acid can be dissolved. Furthermore, even if it is an organic solvent in which polyamic acid is insoluble, it can be mixed with the above-mentioned solvent and used as long as the produced polyamic acid does not precipitate. Furthermore, the moisture in the organic solvent hinders the polymerization reaction and causes hydrolysis of the generated polyamide acid. Therefore, it is preferable to use an organic solvent that has been dehydrated and dried.

Examples of the organic solvent used in the above reaction include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, and N-methylformamide. Amide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-p-imidazolinone, 3-methoxy -N,N-dimethylpropanamide, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfoxide, hexamethylstyrene, g-butyrolactone , isopropyl alcohol, methoxymethylpentanol, dipentene, ethylpentanone, methylnonanone, methylethylketone, methylisoamylketone, methylisopropylketone, methylsol Cellulose agent, ethyl cellosolve acetate, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, 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 monobutyl ether, propylene glycol tert-butyl Ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl 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 mono Propyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl Ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dibutyl ether Alkane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethyl carbonate, propyl carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, ester n-Butyl acid, propylene glycol monoethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methylethyl 3-ethoxypropionate, 3-methoxypropanate Ethyl acid ester, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl, 3-methoxypropionic acid butyl, diglyme, 4-hydroxyl -4-Methyl-2-pentanone, 2-ethyl-1-hexanol, etc. These organic solvents can be used alone or in mixture.

The method for reacting the diamine component and the tetracarboxylic dianhydride component in an organic solvent can be by stirring a solution in which the diamine component is dispersed or dissolved in the organic solvent, and directly adding or dispersing or dissolving the tetracarboxylic dianhydride component. The method of adding the diamine component to an organic solvent is conversely, the method of adding the diamine component to a solution in which the tetracarboxylic dianhydride component is dispersed or dissolved in the organic solvent is to alternately add the tetracarboxylic dianhydride component and the diamine component. Any of methods, etc. In addition, when the diamine component or the tetracarboxylic dianhydride component is composed of a plurality of compounds, they can be reacted in a premixed state, or they can be reacted individually in sequence, and then the individually reacted low molecular weight compounds can be reacted. The mixture reacts to form a high molecular weight body.

The temperature when reacting the diamine component and the tetracarboxylic dianhydride component is, for example, -20°C to 150°C, preferably -5°C to 100°C. Moreover, for example, in the reaction, the total concentration of the diamine component and the tetracarboxylic dianhydride component is preferably 1 to 50 mass%, more preferably 5 to 30 mass%, relative to the reaction liquid.

In the above-mentioned polymerization reaction, the ratio of the total molar number of the tetracarboxylic dianhydride component to the total molar number of the diamine component can be selected according to the molecular weight of the polyamic acid to be obtained. Like a normal polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the polyamide produced will be. If a preferable range is found, it is 0.8 to 1.2.

The method of synthesizing the polyamic acid used in the present invention is not limited to the above-mentioned method. It can be the same as the general method of synthesizing polyamic acid. Even if the above-mentioned tetracarboxylic dianhydride is replaced, a tetracarboxylic acid with a corresponding structure can be used. Tetracarboxylic acid derivatives such as acids or tetracarboxylic acid dihalides can also be reacted by well-known methods to obtain the corresponding polyamide.

An example of a method for imidizing the above-mentioned polyamic acid to form a polyimide includes thermal imidization in which a solution of polyamic acid is directly heated and added to the solution of polyamic acid. Catalyst imidization of catalyst. In addition, the imidization rate from polyamide acid to polyimide does not necessarily need to be 100%.

The temperature when the polyamide acid is thermally imidized in the solution is 100°C to 400°C, preferably 120°C to 250°C, and the water generated by the imidization reaction is preferably excluded from the system. Do it as you go.

The catalytic imidization of polyamic acid can be carried out by adding an alkaline catalyst and an acid anhydride to a solution of polyamic acid and stirring at -20 to 250°C, preferably at 0 to 180°C. The amount of the alkaline catalyst is 0.5 to 30 mol times of the amide acid group, preferably 2 to 20 mol times, and the amount of the acid anhydride is 1 to 50 mol times of the amide acid group, preferably 3 to 30 mol times. Examples of the alkaline catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is preferred because it has moderate alkalinity required to advance the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, acetic anhydride is preferred because purification after completion of the reaction becomes easier. The rate of imidization caused by catalyst imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

In addition, the polyamic acid ester can be synthesized by the reaction of tetracarboxylic acid diester dichloride and the same diamine as the synthesis of the above-mentioned polyamic acid, or the synthesis of the tetracarboxylic acid diester and the above-mentioned polyamic acid. The same diamine is produced by reacting in the presence of an appropriate condensing agent or base. Alternatively, it can be obtained by pre-synthesizing polyamic acid using the above method and esterifying the carboxylic acid in the amide acid using a polymer reaction. Specifically, for example, by reacting tetracarboxylic acid diester dichloride and diamine in the presence of a base and an organic solvent at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 For hours, preferably 1 to 4 hours, polyamide ester can be synthesized. Then, the polyamide imide can also be obtained by heating the polyamide ester at a high temperature to promote dealcoholization and ring closure.

When recovering the polyimide precursor or polyimide such as polyamide acid or polyamide ester produced from the reaction solution, the reaction solution can be put into a weak solvent to precipitate. Examples of weak solvents used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water, and the like. The polymer system precipitated by being put into a weak solvent can be recovered by filtration and then dried under normal pressure or reduced pressure, at normal temperature or by heating. In addition, if the recovered polymer is redissolved in an organic solvent and the reprecipitation recovery operation is repeated 2 to 10 times, the impurities in the polymer can be reduced. Examples of weak solvents in this case include alcohols, ketones, hydrocarbons, etc. It is preferable to use three or more types of weak solvents selected from these to further improve the purification efficiency.

<Liquid crystal alignment agent> The agent of the present invention contains at least one specific polymer having a free radical generating structure in the side chain. The content of the specific polymer is preferably 0.5 to 20 mass%, more preferably 0.5 to 15 mass%. Particularly preferred is 1 to 10% by mass.

In addition, the liquid crystal alignment agent of the present invention may also contain other polymers other than the above-mentioned polymers. At this time, the content of the other polymer in the total polymer components is preferably 0.5 to 80 mass%, more preferably 20 to 50 mass%.

The molecular weight of the polymer contained in the liquid crystal alignment agent is determined by GPC (gel permeation chromatography) when considering the strength of the liquid crystal alignment film obtained by applying the liquid crystal alignment agent, the workability of the coating film formation, and the uniformity of the coating film. ) method, the weight average molecular weight is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000.

The solvent system contained in the liquid crystal alignment agent is not particularly limited, as long as it can combine a polymer having a structure represented by the above formula (I) in the side chain and optionally containing two or more terminals having photopolymerization or photointersection. The components such as the linked polymerizable compound may be dissolved or dispersed. For example, organic solvents such as those exemplified in the above-mentioned synthesis of polyamic acid can be cited. Among them, from the viewpoint of solubility, N-methyl-2-pyrrolidone, g-butyrolactone, N-ethyl-2-pyrrolidone, and 1,3-dimethyl-2 -Imidazolinone, 3-methoxy-N,N-dimethylpropylamide. Of course, a mixed solvent of two or more types may also be used.

In addition, it is preferable to mix a solvent that improves the uniformity or smoothness of the coating film into a solvent with high solubility of the components contained in the liquid crystal alignment agent. Examples of the solvent include isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, and butyl cellosolve acetate. Ester, ethyl cellosolve 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 monobutyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol , diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether Ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxy Butyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate , butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate Ester, ethyl acetate, n-butyl acetate, propylene glycol monoethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methylethyl 3-ethoxypropionate Ester, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1- Methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate Acetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propyl Alcohol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, 2-ethyl-1-hexanol, etc. A plurality of types of these solvents can also be mixed. These solvents are preferably 5 to 80 mass % of the total solvents contained in the liquid crystal alignment agent, and more preferably 20 to 60 mass %.

The liquid crystal alignment agent may also contain components other than the above. Examples thereof include compounds that improve film thickness uniformity or surface smoothness when applying a liquid crystal alignment agent, compounds that improve the adhesion between a liquid crystal alignment film and a substrate, and the like.

Examples of compounds that improve film thickness uniformity or surface smoothness include fluorine-based surfactants, polysiloxane-based surfactants, and nonionic surfactants. More specifically, examples include Eftop EF301, EF303, EF352 (manufactured by TOHKEM PRODUCTS Co., Ltd.), Megafac F171, F173, R-30 (manufactured by Dainippon Ink Co., Ltd.), Fluorad FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), etc. The usage ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass relative to 100 parts by mass of the total polymer contained in the liquid crystal alignment agent.

Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include functional silane-containing compounds or epoxy group-containing compounds. Examples include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, and 2-aminopropyltriethoxysilane. , N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3- Ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-amino Propyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4 ,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate , 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyl Triethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-amine Trimethoxysilane, N-bis(oxyethylene)-3-aminopropyltriethoxysilane, ethylene glycol diepoxypropyl ether, polyethylene glycol diepoxypropyl ether, propylene glycol Diglycidyl ether, tripropylene glycol dipoxypropyl ether, polypropylene glycol dipoxypropyl ether, neopentyl glycol dipoxypropyl ether, 1,6-hexanediol dipoxypropyl ether, Glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraepoxypropyl-2,4-hexanediol, N,N ,N',N'-tetraepoxypropyl m-xylylenediamine, 1,3-bis(N,N-diepoxypropylaminomethyl)cyclohexane, N,N,N',N '-Tetraepoxypropyl-4,4'-diaminodiphenylmethane, 3-(N-allyl-N-epoxypropyl)aminopropyltrimethoxysilane, 3-(N , N-Diepoxypropyl)aminopropyltrimethoxysilane, etc.

In addition, in order to further increase the film strength of the liquid crystal alignment film, 2,2'-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane or tetrakis(methoxymethyl) can also be added. Phenol compounds such as bisphenol. Relative to 100 parts by mass of the total amount of the polymer contained in the liquid crystal alignment agent, these compounds are preferably 0.1 to 30 parts by mass, and more preferably 1 to 20 parts by mass.

Furthermore, in the liquid crystal alignment agent, in addition to the above, within the scope that does not impair the effects of the present invention, a dielectric for the purpose of changing the electrical properties such as the dielectric constant or conductivity of the liquid crystal alignment film can also be added. body or conductive substance.

By coating this liquid crystal alignment agent on a substrate and firing it, a liquid crystal alignment film that vertically aligns liquid crystals can be formed. Through the use of the liquid crystal alignment agent of the present invention, the response speed of the liquid crystal display element using the obtained liquid crystal alignment film can be accelerated. In addition, the liquid crystal alignment agent of the present invention may contain a polymerizable compound having photopolymerization or photocrosslinking groups at two or more terminals, which is not included in the liquid crystal alignment agent or is contained in the liquid crystal together with the liquid crystal alignment agent. , and even in the so-called PSA mode, the photoreaction is highly sensitive, and the tilt angle can be provided with a small amount of ultraviolet irradiation.

For example, the cured film obtained by applying the liquid crystal alignment agent of the present invention to a substrate, drying and firing if necessary, can also be used directly as a liquid crystal alignment film. In addition, the cured film is rubbed, or irradiated with polarized light or light of a specific wavelength, or subjected to treatment with ion beam, or used as an alignment film for PSA, and irradiated with UV while a voltage is applied to the liquid crystal display element after liquid crystal filling. It's possible. In particular, it can be used as an alignment film for PSA.

At this time, the substrate used is not particularly limited as long as it is highly transparent, and a glass plate, polycarbonate, poly(meth)acrylate, polyether ester, polyarylate, or polyamine-based substrate can be used. Formate, polystyrene, polyether, polyetherketone, trimethylpentene, polyolefin, polyethylene terephthalate, (meth)acrylonitrile, triacetyl cellulose, diethyl cellulose , cellulose acetate butyrate, plastic substrates, etc. In addition, from the viewpoint of simplification of the manufacturing process, it is preferable to use a substrate on which ITO electrodes for driving liquid crystals are formed. In addition, in a reflective liquid crystal display element, if the substrate is only on one side, an opaque material such as a silicon wafer can also be used. In this case, the electrode can also use a material that reflects light such as aluminum.

The coating method of the liquid crystal alignment agent is not particularly limited, and examples include printing methods such as screen printing, offset printing, and flexographic printing, inkjet methods, spray methods, roller coating methods, or dipping, roller coater, narrow Slit coaters, spinners, etc. From the viewpoint of productivity, the transfer printing method is widely used in industry and is also applicable to the present invention.

The coating film formed by applying the liquid crystal alignment agent in the above method can be fired to become a cured film. Although the drying step after coating the liquid crystal alignment agent is not necessarily necessary, the time from coating to firing is shorter when each substrate is not fixed or is not fired immediately after coating. It is better to carry out the drying step. This drying is not particularly limited as long as the solvent is removed to such an extent that the shape of the coating film is not deformed due to transportation of the substrate, etc. The drying method is not particularly limited. For example, a method of drying on a hot plate with a temperature of 40°C to 150°C, preferably 60°C to 100°C, for 0.5 minutes to 30 minutes, preferably 1 minute to 5 minutes, is given.

The firing temperature of the coating film formed by applying the liquid crystal alignment agent is not limited, but is, for example, 100 to 350°C, preferably 120 to 300°C, and more preferably 150 to 250°C. The firing time is 5 minutes to 240 minutes, preferably 10 minutes to 90 minutes, more preferably 20 minutes to 90 minutes. The heating system can be carried out by commonly known methods, such as hot plates, hot air circulation furnaces, infrared furnaces, etc.

In addition, the thickness of the liquid crystal alignment film obtained by firing is not particularly limited, but is preferably 5 to 300 nm, and more preferably 20 to 200 nm.

<Manufacturing method of liquid crystal display element> The method of manufacturing a liquid crystal display element of the present invention first implements the liquid crystal alignment film forming step of forming a liquid crystal alignment film on each of a pair of substrate surfaces as described above.

Next, a liquid crystal alignment film light irradiation step is performed in which light irradiation is applied to at least one of the pair of substrates so that the amount of light irradiation to the liquid crystal alignment films of the two substrates becomes different.

This liquid crystal alignment film light irradiation step is to irradiate the liquid crystal alignment film of the substrate used on one side to invalidate at least part of the free radical generating ability of the free radical generating structure of the liquid crystal alignment film on one side, or to The light irradiation is performed in such a way that the amount of light irradiation is different between the two, so that the free radical generating ability of both sides becomes different.

Specifically, the step of irradiating the liquid crystal alignment film with light includes, for example, irradiating the liquid crystal alignment film of one side of the substrate with light to inactivate at least part of the free radical generating structure and inactivate the free radical generating ability. Thereby, one becomes a liquid crystal alignment film without the ability to generate free radicals, and the other becomes a liquid crystal alignment film with the ability to generate free radicals, or one becomes a liquid crystal alignment film with a low ability to generate free radicals, and the other becomes a free radical alignment film. A liquid crystal alignment film with high radical generating ability, which makes the free radical generating ability of both sides different.

For example, the liquid crystal alignment films of the substrates on both sides may be irradiated with light, but the amount of light irradiation may be different on both sides, and the amount of deactivated free radical generating structures may be different on both sides. Thereby, one becomes a liquid crystal alignment film with low free radical generating ability, and the other becomes a liquid crystal alignment film with high free radical generating ability, so that the free radical generating abilities of both sides become different.

In this way, the liquid crystal alignment film of the present invention using liquid crystal alignment agents of the same composition is based on the functions of various side chains of the above-mentioned polymers, etc., and has the specified liquid crystal alignment ability, but has different free radical generating abilities as described above. The amount of free radicals generated by ultraviolet rays during PSA treatment varies depending on the substrate. Therefore, at the interface of each substrate, the reaction speed of the polymeric compound is different, and the liquid crystal alignment ability is also different.

As light irradiation for passivating the radical generating structure, a wavelength of about 250 nm to 600 nm can be used, and the wavelength is preferably adjusted to suit the radical generating structure.

For example, in the structure represented by formula (I), since many have absorbers of approximately 250 nm to 420 nm, it is preferable to irradiate ultraviolet rays of 250 nm to 420 nm in accordance with the absorption wavelength. The optimal amount of light irradiation must match the desired panel characteristics. However, long-term light irradiation will cause a longer lead time in the component manufacturing process, so it is best to change it appropriately. Generally speaking, by irradiating light in accordance with the maximum absorption wavelength of the radical-generating structure, the radical-generating structure can be efficiently passivated. If the impact on the production line's lead time or damage to other components is considered, the appropriate amount of light irradiation is preferably 500mJ/cm ² ~ 100J/cm ² , and more preferably 1J/cm ² ~ 70J/cm ² . Particularly preferred is 1J/cm ² to 40J/cm ² .

Therefore, although the liquid crystal alignment agent is formed with the same composition, if a liquid crystal layer is formed between a pair of substrates having liquid crystal alignment films with different liquid crystal alignment capabilities, the portion close to the surface of the liquid crystal layer will be based on the adjacent liquid crystal alignment The alignment state is formed by the liquid crystal alignment ability of the film, so the alignment states on the two sides become different. Specifically, in the case of having side chains that align vertically, an asymmetric liquid crystal layer with different pretilt angles on both sides can be realized.

In the method for manufacturing a liquid crystal display element of the present invention, a liquid crystal layer forming step of forming a liquid crystal layer containing a liquid crystal compound between the pair of substrates is subsequently included. In this way, since the liquid crystal layer is formed by sandwiching a pair of liquid crystal alignment films with different free radical generating capabilities, it can become an asymmetric liquid crystal layer with different pretilt angles on both sides.

<Substrate for Liquid Crystal Display Elements> When a liquid crystal alignment agent containing a specific polymer with a free radical generating structure is used to form a liquid crystal alignment film, the free radical generating structure is usually used to generate free radicals due to light irradiation when forming the liquid crystal layer. By.

However, in the present invention, the liquid crystal alignment film of the substrate used on at least one side is irradiated with light before being disposed with the liquid crystal layer, thereby inactivating at least part of the free radical generating structure and inactivating the free radical generating ability.

In this way, the substrate for a liquid crystal display element of the present invention is a substrate for a liquid crystal display element before a liquid crystal layer is provided. A liquid crystal alignment agent containing a specific polymer having a free radical generating structure is used to form a liquid crystal alignment film, and the liquid crystal alignment film is irradiated with light. At least part of the free radical generating structure is neutralized.

<Liquid crystal display element assembly> The liquid crystal display element assembly of the present invention uses the above-mentioned substrate for the liquid crystal display element of the present invention, and a substrate with a liquid crystal alignment film formed with a liquid crystal alignment agent of the same composition, sandwiched therebetween to form a liquid crystal layer of liquid crystal material. Furthermore, the substrate for a liquid crystal display element of the present invention uses a pair of substrates that have been irradiated with different light irradiation amounts in advance, and holds a liquid crystal raw material to be a liquid crystal layer between them.

<Liquid crystal display element> The liquid crystal display element manufactured by the manufacturing method of the liquid crystal display element of the present invention can use the above-mentioned substrate for the liquid crystal display element of the present invention to produce a liquid crystal cell by a well-known method. A pair of liquid crystal alignment films with different production capabilities are sandwiched to form a liquid crystal layer, so it can become an asymmetric liquid crystal layer with different pretilt angles on both sides.

A specific example of a liquid crystal display element is a liquid crystal display element having a vertical alignment method of a liquid crystal cell. The liquid crystal cell has two substrates arranged facing each other, a liquid crystal layer provided between the substrates, and a liquid crystal layer between the substrates and the liquid crystal layer. The above-mentioned liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention is disposed in between. Specifically, a liquid crystal alignment film is formed by coating the liquid crystal alignment agent of the present invention on two substrates and firing, and irradiating at least one of them with light to inactivate at least a part of the free radical generating structure, so as to The free radical generating structure has different free radical generating capabilities. The liquid crystal alignment film is arranged with two substrates facing each other, and a liquid crystal layer composed of liquid crystal is sandwiched between the two substrates. That is, the liquid crystal alignment film is placed in contact with the liquid crystal alignment film. The layer is produced by irradiating the liquid crystal alignment film and the liquid crystal layer with ultraviolet rays while applying a voltage. Thereby, a vertically aligned liquid crystal display element having an asymmetrical liquid crystal cell with different pretilt angles on both sides is obtained.

Using a liquid crystal alignment film formed with the liquid crystal alignment agent of the present invention, the liquid crystal alignment film and the liquid crystal layer are irradiated with ultraviolet rays while applying a voltage to polymerize the polymerizable compound, and at the same time, the photoreactive side chains of the polymer are polymerized with each other or The photoreactive side chains of the substance react with the polymerizable compound, thereby fixing the alignment of the liquid crystal more efficiently and becoming a liquid crystal display element with significantly excellent response speed.

The substrate used for the liquid crystal display element of the present invention is not particularly limited as long as it is highly transparent, but is usually a substrate on which a transparent electrode for driving liquid crystal is formed. As a specific example, the same substrate as described in the above-mentioned liquid crystal alignment film can be cited. Although conventional substrates provided with electrode patterns or protrusion patterns can be used, in the liquid crystal display element of the present invention, since the above-mentioned liquid crystal alignment agent of the present invention is used, even on one side of the substrate, for example, 1 to 10 μm can be formed. The line/slit electrode pattern can also operate in a structure that does not form a slit pattern or a protrusion pattern on the counter substrate. With the liquid crystal display element with this structure, the manufacturing process can be simplified and high quality can be obtained. transmittance.

In addition, as a high-performance device such as a TFT-type device, a device such as a transistor formed between an electrode for driving a liquid crystal and a substrate can be used.

In the case of a transmissive liquid crystal display element, a substrate is generally used as described above. However, in a reflective liquid crystal display element, if the substrate is only on one side, an opaque substrate such as a silicon wafer may also be used. At this time, a material that reflects light, such as aluminum, may also be used in the electrode formed on the substrate.

The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited. Liquid crystal materials used in conventional vertical alignment methods, such as negative-type liquid crystals such as MLC-6608 or MLC-6609 manufactured by MERCK, can be used. In addition, in the PSA mode, for example, a liquid crystal containing a polymerizable compound represented by the following formula can be used.

In the present invention, a well-known method can be cited as a method of sandwiching the liquid crystal layer between two substrates. For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared. Spacers such as beads are spread on the liquid crystal alignment film of one substrate, and the other substrate is attached to the other substrate so that the surface on which the liquid crystal alignment film is formed is on the inside. Method of injecting liquid crystal and sealing. Also, prepare a pair of substrates for forming a liquid crystal alignment film. After spreading spacers such as beads on the liquid crystal alignment film of one substrate, drop liquid crystal, and then attach the other substrate so that the side with the liquid crystal alignment film is on the inside. Liquid crystal cells can also be made by using a substrate and sealing it. The thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

The step of producing a liquid crystal cell by applying a voltage to the liquid crystal alignment film and the liquid crystal layer while irradiating ultraviolet rays includes, for example, applying a voltage between electrodes provided on the substrate to apply an electric field to the liquid crystal alignment film and the liquid crystal layer. This method maintains this electric field and irradiates ultraviolet light. Here, the voltage applied between the electrodes is, for example, 5 to 30 Vp-p, and preferably 5 to 20 Vp-p. The irradiation dose of ultraviolet rays is, for example, 1 to 60 J/cm ² , preferably 40 J/cm ² or less. The lower the irradiation dose of ultraviolet rays, the lower the reliability due to damage to the components constituting the liquid crystal display element, and by reducing the The manufacturing efficiency increases with the ultraviolet irradiation time, so it is preferable.

As mentioned above, when a voltage is applied to the liquid crystal alignment film and the liquid crystal layer while ultraviolet rays are irradiated, the polymerizable compound reacts to form a polymer. The polymer memorizes the tilt direction of the liquid crystal molecules, thereby accelerating the response of the resulting liquid crystal display element. speed. Furthermore, when a voltage is applied to the liquid crystal alignment film and the liquid crystal layer while ultraviolet rays are irradiated, the polyimide precursor is composed of a polyimide precursor having side chains that vertically align liquid crystals and photoreactive side chains. The photoreactive side chains of at least one selected polymer in the polyimide obtained by imidization of the precursor react with each other, or the photoreactive side chains of the polymer react with the polymerizable compound, Therefore, the response speed of the resulting liquid crystal display element can be accelerated. Example

Below, further details will be described based on the examples, but the present invention is not limited by these examples at all.

<Synthesis of Liquid Crystal Alignment Agent> The abbreviations used in the preparation of the following liquid crystal alignment agent are as follows. (Acid dianhydride) BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride CBDA: 1,2,3,4-cyclobutane tetracarboxylic dianhydride PMDA : Pyromellitic dianhydride

(Diamine) DBA: 3,5-diaminobenzoic acid 3AMPDA: 3,5-diamino-N-(pyridin-3-ylmethyl)benzamide TCA: 2,3,5-tricarboxylic acid Cyclopentylacetic dianhydride DSDA: 3,3',4,4'-diphenyl tetracarboxylic dianhydride

Diamine with a free radical generating structure represented by the following formula DA-1 obtained in the synthesis example

Vertically aligned diamines represented by the following formulas DA-2 to DA-3

Diamine compounds represented by the following formulas DA-4 to DA-7.

A vertically aligned diamine represented by the following formula DA-8.

<Solvent> NMP: N-methyl-2-pyrrolidinone BCS: Butyl cellosolve

＜Additive＞ 3AMP: 3-Pyridylmethylamine

In addition, the molecular weight measurement conditions of polyimide are as follows. Device: ambient gel permeation chromatography (GPC) device (SSC-7200) manufactured by SENSHU Scientific Co., Ltd., column: column (KD-803, KD-805) manufactured by Shodex Co., Ltd., column temperature: 50°C, eluent : N,N'-dimethylformamide (As additives, lithium bromide-hydrate (LiBr・H ₂ O) is 30mmol/L, phosphoric acid・anhydrous crystal (o-phosphoric acid) is 30mmol/L, tetrahydrofuran (THF) (10ml/L), flow rate: 1.0ml/minute, standard samples for calibration curve preparation: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weight approximately 9000,000, 150,000, 100,000, 30,000), and Polymer Laboratories Corporation Polyethylene glycol (molecular weight approximately 12,000, 4,000, 1,000).

In addition, the imidization rate of polyimide was measured as follows. Place 20 mg of polyimide powder into an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Scientific Co., Ltd.), add 1.0 ml of deuterated dimethylsulfoxide (DMSO-d ₆ , 0.05% TMS mixture), and apply ultrasonic waves to completely dissolve it. For this solution, proton NMR at 500 MHz was measured using an NMR meter (JNW-ECA500) manufactured by JEOL DATUM Corporation. The rate of imidization is determined by using the proton from the structure that has no change before and after the imidization as the reference proton, and using the cumulative peak value of this proton and the proton from the NH group of the amide acid that appears around 9.5 to 10.0 ppm. The cumulative value of the wave peak is calculated by the following formula. Furthermore, in the following formula, x is the cumulative peak value of protons derived from the NH group of amide, y is the cumulative peak value of reference protons, and a is relative to polyamic acid (imidization rate: 0%) In this case, the proton of the NH group of the amide acid is 1, which is the ratio of the number of standard protons. Imination rate (%) = (1-a・x/y)×100

(Synthesis Example 1) Dissolve BODA (3.75g, 15.0mmol), DA-1 (4.96g, 15.0mmol), and DA-2 (5.71g, 15.0mmol) in NMP (51.9g), and react at 60°C for 5 Hours later, CBDA (2.88g, 14.7mmol) and NMP (17.3g) were added, and the mixture was reacted at 40° C. for 10 hours to obtain a polyamic acid solution.

NMP was added to this polyamide solution (50g) to dilute it to 6.5% by mass, and acetic anhydride (8.8g) and pyridine (2.7g) as imidization catalysts were added, and the reaction was carried out at 75° C. for 2.5 hours. The reaction solution was put into methanol (700 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100° C. to obtain polyimide powder (A). The polyimide has an imidization rate of 71%, a number average molecular weight of 12,000, and a weight average molecular weight of 49,000.

NMP (44.0 g) was added to the obtained polyimide powder (A) (6.0 g), and stirred at 70° C. for 20 hours to dissolve. 6.0g of 3AMP (1wt% NMP solution), NMP (4.0g), and BCS (40.0g) were added to this solution, and the liquid crystal alignment agent (A1) was obtained by stirring at room temperature for 5 hours.

(Synthesis Example 2) Dissolve BODA (3.75, 15.0mmol), DA-3 (3.91g, 9.0mmol), DBA (0.91g, 6.0mmol), and DA-1 (4.96g, 15.0mmol) in NMP (49.3g ), after reacting at 60°C for 5 hours, CBDA (2.88g, 14.7mmol) and NMP (16.4g) were added, and the mixture was reacted at 40°C for 10 hours to obtain a polyamic acid solution.

NMP was added to this polyamide solution (50g) to dilute it to 6.5% by mass, and acetic anhydride (9.3g) and pyridine (2.9g) as imidization catalysts were added, and the reaction was carried out at 70° C. for 3 hours. The reaction solution was put into methanol (700 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100° C. to obtain polyimide powder (B). The polyimide has an imidization rate of 71%, a number average molecular weight of 13,000, and a weight average molecular weight of 51,000.

NMP (44.0 g) was added to the obtained polyimide powder (B) (6.0 g), and stirred at 70° C. for 20 hours to dissolve it. 6.0g of 3AMP (1wt% NMP solution), NMP (4.0g), and BCS (40.0g) were added to this solution, and the liquid crystal alignment agent (B1) was obtained by stirring at room temperature for 5 hours.

(Synthesis Example 3) Dissolve BODA (1.50g, 6.0mmol), DBA (1.83g, 12.0mmol), 3AMPDA (2.18g, 9.0mmol), and DA-2 (3.43g, 9.0mmol) in NMP (41.1g) , after reacting at 60°C for 3 hours, add PMDA (1.31g, 6.0mmol), then add CBDA (3.47g, 17.7mmol) and NMP (13.71g), and react at 25°C for 10 hours to obtain a polyamic acid solution .

NMP was added to this polyamide solution (50g) to dilute it to 6.5% by mass, and acetic anhydride (11.1g) and pyridine (3.4g) as imidization catalysts were added, and the reaction was carried out at 60° C. for 3 hours. The reaction solution was put into methanol (700 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100° C. to obtain polyimide powder (C). The polyimide has an imidization rate of 79%, a number average molecular weight of 11,000, and a weight average molecular weight of 24,000.

NMP (44.0g) was added to the obtained polyimide powder (C) (6.0g), and stirred at 70° C. for 20 hours to dissolve it. 6.0g of 3AMP (1 mass% NMP solution), NMP (4.0g), and BCS (40.0g) were added to this solution, and the liquid crystal alignment agent (C1) was obtained by stirring at room temperature for 5 hours.

(Synthesis Example 4) Mix 3.0 g of the liquid crystal alignment agent (A1) obtained in Synthesis Example 1 as the first component and 7.0 g of the liquid crystal alignment agent (C1) obtained in Synthesis Example 3 as the second component, and stir for 1 hour. Prepare liquid crystal alignment agent (A2).

(Synthesis Example 5) Mix 3.0 g of the liquid crystal alignment agent (B1) obtained in Example 1 as the first component and 7.0 g of the liquid crystal alignment agent (C1) obtained in Synthesis Example 3 as the second component, and stir for 1 hour. Prepare liquid crystal alignment agent (B2).

(Synthesis Example 6) TCA Dissolve TCA (11.1g, 50.0mmol), DA-1 (6.61g, 20.0mmol), DA-4 (3.97g, 20.0mmol), and DA-8 (4.95g, 10.0mmol) in NMP (106.5g) was reacted at 60° C. for 6 hours to obtain a polyamide solution.

NMP was added to this polyamide solution (50g) to dilute it to 6.5% by mass, and acetic anhydride (9.5g) and pyridine (3.0g) as imidization catalysts were added, and the reaction was carried out at 100° C. for 3 hours. The reaction solution was put into methanol (700 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100° C. to obtain polyimide powder (D). The polyimide has an imidization rate of 67%, a number average molecular weight of 13,000, and a weight average molecular weight of 31,000.

NMP (44.0 g) was added to the obtained polyimide powder (D) (6.0 g), and stirred at 70° C. for 20 hours to dissolve. NMP (10.0g) and BCS (40.0g) were added to this solution, and the liquid crystal alignment agent (D1) was obtained by stirring at room temperature for 5 hours.

(Synthesis Example 7) BEMS Dissolve BODA (5.00g, 20.0mmol), DA-1 (3.96g, 12.0mmol), DA-5 (2.11g, 8.0mmol), and DA-2 (7.61g, 20.0mmol) in After reacting at 60° C. for 5 hours, CBDA (3.84 g, 20.0 mmol) and NMP (22.5 g) were added to NMP (67.6 g), and the mixture was reacted at 40° C. for 10 hours to obtain a polyamic acid solution.

NMP was added to this polyamide solution (50g) to dilute it to 6.5% by mass, and acetic anhydride (3.6g) and pyridine (14.0g) as imidization catalysts were added, and the reaction was carried out at 50°C for 3 hours. The reaction solution was put into methanol (700 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100° C. to obtain polyimide powder (E). The polyimide has an imidization rate of 51%, a number average molecular weight of 18,000, and a weight average molecular weight of 53,000.

NMP (44.0 g) was added to the obtained polyimide powder (E) (6.0 g), and stirred at 50° C. for 10 hours to dissolve it. 6.0g of 3AMP (1wt% NMP solution), NMP (4.0g), and BCS (40.0g) were added to this solution, and the liquid crystal alignment agent (E1) was obtained by stirring at room temperature for 5 hours.

(Synthesis Example 8) DSDA Dissolve BODA (5.00g, 20.0mmol), DBA (3.04g, 20.0mmol), DA-7 (4.93g, 12.0mmol), DA-2 (3.04g, 8.0mmol) in NMP ( 65.2g), after reacting at 60°C for 3 hours, CBDA (1.41g, 7.0mmol) was added and reacted at 40°C for 1 hour. Then, DSDA (4.30 g, 12.0 mmol) and NMP (21.7 g) were added, and the mixture was reacted at 25° C. for 10 hours to obtain a polyamic acid solution.

NMP was added to this polyamide solution (50g) to dilute it to 6.5% by mass, and acetic anhydride (9.3g) and pyridine (2.9g) as imidization catalysts were added, and the reaction was carried out at 80° C. for 2 hours. The reaction solution was put into methanol (700 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100° C. to obtain polyimide powder (F). The polyimide has an imidization rate of 76%, a number average molecular weight of 13,000, and a weight average molecular weight of 34,000.

NMP (44.0 g) was added to the obtained polyimide powder (F) (6.0 g), and stirred at 70° C. for 20 hours to dissolve it. 6.0g of 3AMP (1wt% NMP solution), NMP (4.0g), and BCS (40.0g) were added to this solution, and the liquid crystal alignment agent (F1) was obtained by stirring at room temperature for 5 hours.

(Synthesis Example 9) A199 Mix BODA (2.50g, 10.0mmol), DA-6 (3.49g, 14.0mmol), and DA-2 (2.28g, 6.00mmol) in NMP (40.2g), and react at 50°C After 3 hours, CBDA (1.76 g, 9.00 mmol) was added, and the mixture was reacted at 40° C. for 3 hours to obtain a polyamic acid solution.

(Synthesis Example 10) Mix 5.0 g of the liquid crystal alignment agent (D1) obtained in Synthesis Example 6 as the first component and 5.0 g of the liquid crystal alignment agent (F1) obtained in Synthesis Example 8 as the second component, and stir for 1 hour. Prepare liquid crystal alignment agent (D2).

(Synthesis Example 11) Mix 5.0 g of the liquid crystal alignment agent (E1) obtained in Synthesis Example 7 as the first component and 5.0 g of the liquid crystal alignment agent (G1) obtained in Synthesis Example 9 as the second component, and stir for 1 hour. Prepare liquid crystal alignment agent (E2).

Table 1 shows the compositions of liquid crystal alignment agents A1, B1, and C1. In addition, Table 2 shows the compositions of liquid crystal alignment agents D1, E1, F1, and G1.

<Preparation of Liquid Crystal Cell> (Example 1) Using the liquid crystal alignment agent (A2) obtained in Synthesis Example 4, a liquid crystal cell was produced according to the procedure shown below. The liquid crystal alignment agent (A2) obtained in Synthesis Example 4 was spin-coated on the ITO surface of an ITO electrode substrate with a pixel size of 100 μm x 300 μm and an ITO electrode pattern with a line/space of 5 μm each, and was heated at 80°C. After the board is dried for 90 seconds, it is fired in a hot air circulation oven at 230°C for 30 minutes to form a liquid crystal alignment film (A2-1) with a film thickness of 100 nm.

In addition, the liquid crystal alignment agent (A2) was spin-coated on the ITO surface without the electrode pattern, dried on a hot plate at 80°C for 90 seconds, and then fired in a hot air circulation oven at 230°C for 30 minutes. A liquid crystal alignment film (A2-2) with a film thickness of 100 nm was formed.

Next, each of the above-mentioned liquid crystal alignment films (A2-1, A2-2) is irradiated with UV of a high-pressure mercury lamp with a wavelength of 325 nm or less at 10 J/cm ² to cause structural passivation of the free radicals present in the alignment film (Pre -UV). To measure the irradiation dose, a UV-35 photoreceptor was connected to UV-M03A manufactured by ORC Corporation.

For the above two substrates, 4 μm bead spacers were spread on the liquid crystal alignment film of one of the substrates, and a sealant (Mitsui Chemicals' heat-curable sealant XN-1500T) was printed thereon. Then, the surface of another substrate on which the liquid crystal alignment film is formed is used as the inner side, and is bonded to the previous substrate, and then the sealant is hardened to form a cavity cell. Negative liquid crystal MLC-3023 (trade name manufactured by MERCK Corporation) containing a polymerizable compound for PSA was injected into this empty cell by a reduced pressure injection method to prepare a liquid crystal cell.

With a DC voltage of 15 V applied to the liquid crystal cell, UV (1st-UV) of a high-pressure mercury lamp of 10 J/cm ² of 365 nm passing through a bandpass filter was irradiated from the outside of the liquid crystal cell. Then, with no voltage applied to the liquid crystal cell, a fluorescent UV lamp (FLR40SUV32/A-1) was used to irradiate it for 30 minutes (2nd-UV) to passivate the unreacted polymeric compound present in the liquid crystal cell. .

Then, the pretilt angle and response speed of the pixel part of the liquid crystal cell are measured (liquid crystal cell with symmetrical pretilt angle). The results are shown in Table 2.

"Measurement of pretilt angle" uses LCD analyzer LCA-LUV42A manufactured by Minling Technology.

"Measurement method of response speed" First, in a measuring device composed of a backlight, a set of polarizing plates set to the crossed Nicols state, and a light quantity detector, a liquid crystal cell is arranged between a set of polarizing plates. At this time, it is assumed that the pattern of the ITO electrode forming the lines/gaps has an angle of 45° with respect to the orthogonal Nicols. Then, a rectangular wave with a voltage of ±7V and a frequency of 1kHz is applied to the above-mentioned liquid crystal cell, and the change in brightness until saturation observed by the light quantity detector is read with an oscilloscope. The brightness when no voltage is applied is regarded as 0%. The value of the saturated brightness with a voltage of ±7V is taken as 100%, and the time it takes for the brightness to change from 10% to 90% is taken as the response speed.

Furthermore, except that the liquid crystal alignment film (A2-1) is not irradiated with Pre-UV, a liquid crystal cell having an asymmetric pretilt angle is produced in the same procedure as above, and the response speed is measured. The results are shown in Table 3.

(Examples 2 to 3) Except for irradiating 20 to 40 J/cm ² as Pre-UV irradiation in Example 1 instead of 10 J/cm ² , the same operation as in Example 1 was performed to prepare a liquid crystal cell and conduct testing of the liquid crystal cell. Determination of pretilt angle.

(Example 4) The same procedure as Example 1 was performed except that 1 J/cm ² of UV from a high-pressure mercury lamp with a wavelength of 313 nm passing through a bandpass filter was used instead of 10 J/cm 2 as Pre-UV irradiation ⁱⁿ Example 1. Operate, make a liquid crystal cell, and measure the pretilt angle of the liquid crystal cell.

(Examples 5 to 8) Except for changing the alignment agent used from the liquid crystal alignment agent (A2) to the liquid crystal alignment agent (B2), the same operations as in Examples 1 to 4 were performed to prepare a liquid crystal cell and perform preliminary preparation of the liquid crystal cell. Determination of inclination angle. Furthermore, the alignment film coated on the ITO surface of the 1TO electrode substrate with a pixel size of 100μm x 300μm and an ITO electrode pattern with a line/space of 5μm each is used as (B2-1). The alignment film on the ITO surface where the electrode pattern is formed is (B2-2).

(Comparative Example 1) Except for not irradiating Pre-UV in Example 1, the same operation as Example 1 was performed to prepare a liquid crystal cell and measure the pretilt angle of the liquid crystal cell.

(Comparative Example 2) Except that Pre-UV was not irradiated in Example 5, the same operation as in Example 5 was performed to prepare a liquid crystal cell and measure the pretilt angle of the liquid crystal cell.

(Examples 9 to 12) Except that the liquid crystal alignment agent (A2) was changed to the liquid crystal alignment agent (D2), the same operations as in Examples 1 to 4 were performed to prepare a liquid crystal cell, and the pretilt angle of the liquid crystal cell was measured. Furthermore, the alignment film coated on the ITO surface of the 1TO electrode substrate with a pixel size of 100μm x 300μm and an ITO electrode pattern with a line/space of 5μm each is used as (D2-1). The alignment film on the ITO surface forming the electrode pattern is (D2-2).

(Examples 13 to 16) Except that the liquid crystal alignment agent (A2) was changed to the liquid crystal alignment agent (E2), the same operation as in Examples 1 to 4 was performed to prepare a liquid crystal cell, and the pretilt angle of the liquid crystal cell was measured. Furthermore, the alignment film coated on the ITO surface of a 1TO electrode substrate with a pixel size of 100 μm x 300 μm and an ITO electrode pattern with a line/space of 5 μm each is used as (E2-1). The alignment film on the ITO surface forming the electrode pattern is (E2-2).

(Comparative Example 3) Except that Pre-UV was not irradiated in Example 9, the same operation as in Example 9 was performed to prepare a liquid crystal cell, and the pretilt angle of the liquid crystal cell was measured.

(Comparative Example 4) Except for not irradiating Pre-UV in Example 13, the same operation as in Example 13 was performed to prepare a liquid crystal cell and measure the pretilt angle of the liquid crystal cell.

First, it is confirmed from the results in Table 3 and Table 5 that the radical generating structure in the alignment film is passivated by Pre-UV irradiation of the substrate, making it difficult to exhibit the pretilt angle and response speed during PSA treatment (1st-UV). Also slowed down. On the other hand, it can be seen that in the comparative example, since Pre-UV irradiation was not performed, the free radical generating structure remained in the alignment film. Even if the relatively weak energy wavelength of 365 nm was used in the PSA treatment (1st-UV), sufficient pre-UV was obtained. Inclination angle and response speed.

Secondly, from the results in Table 4 and Table 6, it can be seen that when only one side of the substrate is irradiated with Pre-UV, a sufficient response speed is obtained. It is considered that the pretilt angle of the side irradiated with Pre-UV (in this embodiment, the side without the ITO electrode pattern) should be the pretilt angle recorded in the embodiments of Table 3 and Table 5, but on the side without Pre-UV irradiation side (the ITO electrode pattern side in this embodiment) becomes the pretilt angle described in the comparative examples of Table 3 and Table 5.

By performing Pre-UV irradiation on only one side of the substrate in this way, a liquid crystal display element with an asymmetric pretilt angle can be produced using one type of liquid crystal alignment agent without impairing the response speed required for the liquid crystal display element.

Claims (17)

A method for manufacturing a liquid crystal display element, characterized by comprising: using a liquid crystal alignment agent of the same composition containing a specific polymer having a free radical generating structure that generates free radicals upon irradiation of light, on each of a pair of substrate surfaces, a liquid crystal alignment film forming step for forming a liquid crystal alignment film; a liquid crystal alignment film light irradiation step of applying light irradiation to at least one of the pair of substrates so that the light irradiation amounts of the two liquid crystal alignment films become different states; and then , a liquid crystal layer forming step of forming a liquid crystal layer containing a liquid crystal compound between the pair of substrates, wherein in the aforementioned liquid crystal alignment film light irradiation step, only the liquid crystal alignment film of one substrate is irradiated with light, and the liquid crystal alignment film of the other substrate is irradiated with light. The liquid crystal alignment film is not exposed to light. The method of manufacturing a liquid crystal display element according to claim 1, wherein the liquid crystal layer is a PSA type liquid crystal layer, and in the step of forming the liquid crystal layer, free radicals are generated from the free radical generating structure by irradiating light while applying a voltage. The manufacturing method of a liquid crystal display element of claim 2, wherein in the step of irradiating the liquid crystal alignment film, only the liquid crystal alignment film of one substrate is irradiated with light, and the liquid crystal alignment film of the other substrate is not irradiated with light. The manufacturing method of a liquid crystal display element as claimed in claim 1, wherein the specific polymer includes a polymer having a side chain structure represented by the following formula (I);

(Ar represents an aromatic hydrocarbon group selected from phenylene group, naphthylene group and biphenylene group. For them, the organic group can be substituted, and the hydrogen atom can also be substituted with a halogen atom; R ₁ and R ₂ are each independently is an alkyl or alkoxy group with 1 to 10 carbon atoms, and T ₁ and T ₂ are each independently a single bond or -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH- , -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )-, -N(CH ₃ )CO- binding group, S is a single bond or an unsubstituted or carbon substituted by a fluorine atom Alkylene group with 1 to 20 atoms; only -CH ₂ - or -CF ₂ - of the alkylene group can be optionally substituted by -CH=CH-. When any of the groups listed below are not adjacent to each other, they can also The following groups can be substituted: -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocyclic ring, divalent heterocyclic ring, Q represents the following selected construct); -OR

R is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms, and R ₃ represents -CH ₂ -, -NR-, -O- or -S-. The method for manufacturing a liquid crystal display element according to claim 4, wherein the specific polymer having a side chain structure represented by formula (I) is selected from a polyimide precursor having a side chain structure represented by formula (I). material and its imidization At least one polymer of the group consisting of polyimides is obtained. The manufacturing method of a liquid crystal display element as claimed in claim 1, wherein the specific polymer includes a polymer having a side chain structure represented by the following formula (II);

(In formula (II), the point refers to the bond of the main chain of the polymer, n is an integer selected from 1 to 12, and X represents a single bond, -O-, -COO-, -OCO-, -NHCO- , -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )- or -N(CH ₃ )CO-; Cy represents a carbonyl group with an amide group A cyclic hydrocarbon group with 5 to 14 carbon atoms that must be bonded to at least one unsaturated bond, and a part of the carbon atoms constituting the cyclic hydrocarbon may be substituted with heteroatoms). For example, the method for manufacturing a liquid crystal display element of Claim 6, wherein n in the aforementioned formula (II) is an integer from 1 to 6, Cy is a cyclic hydrocarbon group shown below, and each of the two points represents the carbonyl carbon of the imine group. bond;

For example, the method for manufacturing a liquid crystal display element according to claim 6 or 7, wherein n in the aforementioned formula (II) is an integer from 1 to 6, X represents -O-, and Cy represents cyclohexene, benzene, naphthalene, or biphenyl. . The manufacturing method of a liquid crystal display element as claimed in claim 4, wherein the specific polymer further has side chains that vertically align the liquid crystal. The manufacturing method of a liquid crystal display element as claimed in claim 6, wherein the specific polymer further has side chains that vertically align the liquid crystal. The manufacturing method of a liquid crystal display element as claimed in claim 9 or 10, wherein the side chain that vertically aligns the liquid crystal is at least one selected from the following formulas (III-1) and (III-2);

(X ¹ represents a single bond, -(CH ₂ ) _a -(a is an integer from 1 to 15), -O-, -CH ₂ O-, -COO- or -OCO-; X ² represents a single bond or -( CH ₂ ) _b -(b is an integer from 1 to 15); X ³ represents a single bond, -(CH ₂ ) _c -(c is an integer from 1 to 15), -O-, -CH ₂ O-, -COO - ^or -OCO-; Alkyl group, alkoxy group with 1 to 3 carbon atoms, fluorine-containing alkyl group with 1 to 3 carbon atoms, fluorine-containing alkoxy group with 1 to 3 carbon atoms or a fluorine atom, and X ⁴ can also be A divalent organic group selected from an organic group having a steroid skeleton having a carbon number of 17 to 51; X ⁵ represents a divalent cyclic group selected from a benzene ring, a cyclohexane ring and a heterocyclic ring. Any hydrogen atom on the base can be replaced by an alkyl group with 1 to 3 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, a fluorine-containing alkyl group with 1 to 3 carbon atoms, or a fluorine-containing alkyl group with 1 to 3 carbon atoms. Substituted by an alkoxy group or a fluorine atom; n represents an ^integer from 0 to 4; group or a fluorine-containing alkoxy group with 1 to 18 carbon atoms); -X ⁷ -X ⁸ [III-2] (X ⁷ represents a single bond, -O-, -CH ₂ O-, -CONH-, -NHCO -, -CON(CH ₃ )-, -N(CH ₃ )CO-, -COO- or -OCO-; X ⁸ represents an alkyl group with 8 to 22 carbon atoms or a fluorine-containing alkyl group with 6 to 18 carbon atoms ). The method for manufacturing a liquid crystal display element according to any one of claims 1 to 3, wherein the specific polymer contains a polyimide precursor having a diamine component represented by the following formula (1) as a structural unit and the At least one polymer in the polyimide obtained by imidization;

(Ar represents an aromatic hydrocarbon group selected from phenylene group, naphthylene group and biphenylene group. For them, the organic group can be substituted, and the hydrogen atom can also be substituted with a halogen atom; R ₁ and R ₂ are each independently is an alkyl or alkoxy group with 1 to 10 carbon atoms, and T ₁ and T ₂ are each independently a single bond or -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH- , -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )-, -N(CH ₃ )CO- binding group, S is a single bond or an unsubstituted or carbon substituted by a fluorine atom Alkylene group with 1 to 20 atoms; only -CH ₂ - or -CF ₂ - of the alkylene group can be optionally substituted by -CH=CH-. When any of the groups listed below are not adjacent to each other, they can also The following groups can be substituted: -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocyclic ring, divalent heterocyclic ring, Q represents the following selected construct); -OR

R is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms, and R ₃ represents -CH ₂ -, -NR-, -O- or -S-). The method for manufacturing a liquid crystal display element according to claim 12, wherein the specific polymer further contains: a polyimide precursor having a diamine component containing a diamine represented by the following formula (VII) as a constituent unit and At least one polymer in the polyimide obtained by imidization;

(X represents the structure of the above-mentioned formula [III-1] or formula [III-2], and n represents an integer from 1 to 4). The method for manufacturing a liquid crystal display element according to claim 12, wherein the specific polymer further contains: a polyimide precursor having a diamine component containing a diamine represented by the following formula (VIII) or (IX) as a structural unit and at least one polymer in the polyimide obtained by imidizing the same;

(R ⁸ represents a single bond, -CH ₂ -, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )- or -N(CH ₃ )CO-; R ⁹ represents a single bond, an alkylene group with 1 to 20 carbon atoms that can be substituted by a fluorine atom, and the -CH ₂ - system of the alkylene group can be -CF ₂ - or -CH=CH- is optionally substituted. When any of the following groups are not adjacent to each other, they can also be substituted with these groups: -O-, -COO-, -OCO-, -NHCO -, -CONH-, -NH-, divalent carbocyclic or heterocyclic ring; R ¹⁰ represents a photoreactive group selected from the following formula);

(Y ₁ represents -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH- or -CO-, Y ₂ is an alkylene group with 1 to 30 carbon atoms, Bivalent carbocyclic or heterocyclic ring, one or more hydrogen atoms of the alkylene group, bivalent carbocyclic ring or heterocyclic ring may be replaced by fluorine atoms or organic groups; Y ₂ in the following groups are mutually exclusive When ortho, -CH ₂ - can also be substituted with the following groups: -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH-, -NHCONH-, -CO-; Y ₃ represents -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, -CO- or a single bond; Y ₄ represents cinnamyl group; Y ₅ is a single bond , an alkylene group with 1 to 30 carbon atoms, a divalent carbocyclic ring or a heterocyclic ring. One or a plurality of hydrogen atoms in the alkylene group, a divalent carbocyclic ring or a heterocyclic ring may be replaced by a fluorine atom or an organic group. Substitution; Y ₅ when the following groups are not adjacent to each other, -CH ₂ - can also be substituted with these groups: -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH -, -NHCONH-, -CO-; Y ₆ represents a photopolymerizable group of an acrylic group or a methacrylic group). The method for manufacturing a liquid crystal display element according to any one of claims 1 to 3, wherein the polymer includes the following (A) component and the following (B) component; (A) component: composed of a polyimide precursor and At least one polymer selected from a polyimide obtained by imidizing a polyimide precursor having side chains that vertically align liquid crystals and the following formula (1) Indicates the side chain of a site that generates free radicals due to ultraviolet irradiation;

(Ar represents an aromatic hydrocarbon group selected from phenylene group, naphthylene group and biphenylene group. For them, the organic group can be substituted, and the hydrogen atom can also be substituted with a halogen atom; R ₁ and R ₂ are each independently is an alkyl or alkoxy group with 1 to 10 carbon atoms, and T ₁ and T ₂ are each independently a single bond or -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH- , -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )-, -N(CH ₃ )CO- binding group, S is a single bond or an unsubstituted or carbon substituted by a fluorine atom Alkylene group with 1 to 20 atoms; only -CH ₂ - or -CF ₂ - of the alkylene group can be optionally substituted by -CH=CH-. When any of the groups listed below are not adjacent to each other, they can also The following groups can be substituted: -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocyclic ring, divalent heterocyclic ring, Q represents the following selected construct); -OR

(R is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms); (B) component: a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor. The selected polymer, this polyimide precursor is obtained by using a diamine component containing at least one diamine selected from the following formulas (B-1) to (B-5) as a raw material; or, from A polymer selected from a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor, wherein the polyimide precursor is composed of the following formula (3) and (4) The tetracarboxylic dianhydride component of at least one selected tetracarboxylic dianhydride is used as a raw material;

(Y ₁ is an organic group with one valence of secondary amine, tertiary amine or heterocyclic structure, Y ₂ is an organic group with two valences of secondary amine, tertiary amine or heterocyclic structure);

(n and m are 0 or 1, X and y are single bonds, carbonyl groups, esters, phenyl groups, and sulfonyl groups). A substrate for forming a liquid crystal display element, which is a substrate for forming a liquid crystal display element provided with a liquid crystal alignment film, characterized by: the aforementioned liquid crystal alignment film It is formed from a liquid crystal alignment agent containing a polymer having a radical generating structure that generates free radicals by light irradiation, and free radicals are generated from at least a part of the radical generating structure by light irradiation, and when the light is irradiated, , only the liquid crystal alignment film of one substrate is irradiated with light, and the liquid crystal alignment film of the other substrate is not irradiated with light, so that the amounts of light irradiation of the two liquid crystal alignment films are in different states. A liquid crystal display element assembly, which includes: a liquid crystal display element forming substrate provided with a pair of liquid crystal alignment films; and a liquid crystal layer provided between the pair of liquid crystal display element substrates, characterized by: The aforementioned liquid crystal alignment film used to form a substrate for the corresponding liquid crystal display element is formed of a liquid crystal alignment agent of the same composition containing a polymer with a free radical generation structure that generates free radicals due to light irradiation, and only aligns the liquid crystal of one substrate. The film is irradiated with light, and the liquid crystal alignment film of the other substrate is not irradiated with light, so that the amounts of light irradiation of the two are different.