TWI675096B - Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal display element, retardation film, and its production method, polymer and diamine - Google Patents

Abstract

The invention provides a liquid crystal alignment agent, a liquid crystal alignment film, a liquid crystal display element, a retardation film and a manufacturing method thereof, a polymer, and a diamine. The liquid crystal alignment agent can display high reliability and display unevenness around the sealant. Fewer liquid crystal display elements. In the present invention, the liquid crystal alignment agent contains a compound (A) having a partial structure represented by the following formula (1). (In the formula (1), R ¹ is a protective group for an amine group. Two "* 1" represent a bonding bond to a hydrocarbon group)

Description

Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal display element, retardation film and manufacturing method thereof, polymer and diamine

The invention relates to a liquid crystal alignment agent, a liquid crystal alignment film and a manufacturing method thereof, a liquid crystal display element, a retardation film and a manufacturing method thereof, a polymer, and a compound.

Liquid crystal display elements are classified into several modes according to the initial alignment state of liquid crystal molecules in the liquid crystal layer, or operation when a voltage is applied, such as known Twisted Nematic (TN) type or Super Twisted Nematic (STN) type, Vertical Alignment (VA) type, In-Plane Switching (IPS) type, fringe field switching (FFS) type and other liquid crystal display elements. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. From the viewpoints of various properties such as heat resistance, mechanical strength, and affinity with liquid crystals, polyimide or a precursor thereof is usually used as a material of the liquid crystal alignment film.

In recent years, large-screen and high-definition LCD TVs have become the mainstay. In addition, the popularization of small display terminals such as smart phones or tablet personal computers (Personal Computers, PCs) has further increased the demand for high-definition LCD screens. Under such a background, various liquid crystal alignment agents have been proposed in order to improve the display quality or reliability of a liquid crystal screen (for example, refer to Patent Document 1). Patent Document 1 discloses that a polyamic acid or polyimide is contained in a liquid crystal alignment agent, and the polyamidic acid or polyimide is obtained by using a group having "-NHA (where A is tertiary Oxycarbonyl) "aromatic diamine.

In addition, various optical materials are used for liquid crystal display elements. Among them, a retardation film is used for the purpose of eliminating the coloration of the display, or the viewing angle dependency of the display color and the contrast changing depending on the visual direction. Regarding this retardation film, a retardation film having the following members is known: a liquid crystal alignment film formed on the surface of a substrate such as a triacetyl cellulose (TAC) film, and a liquid crystal alignment film formed on the surface A liquid crystal layer formed by curing a polymerizable liquid crystal. In addition, in recent years, a light alignment method is used when manufacturing a liquid crystal alignment film in a retardation film, and the light alignment method imparts liquid crystal alignment by irradiating polarized or non-polarized radiation to a radiation-sensitive organic film formed on a substrate surface. A variety of liquid crystal alignment agents for retardation films for producing liquid crystal alignment films by this method have been proposed (for example, refer to Patent Document 2). [Prior Art Literature]

[Patent Literature] [Patent Literature 1] International Publication No. 2013/115228 [Patent Literature 2] Japanese Patent Laid-Open No. 2012-37868

[Problems to be solved by the invention]

A liquid crystal display is manufactured by arranging a pair of substrates on which a liquid crystal alignment film is formed facing each other and arranging liquid crystal between the pair of substrates facing each other. In this case, the pair of substrates are bonded using a sealant such as epoxy resin. . Here, in a touch screen type display screen represented by a smart phone or a tablet PC, an attempt has been made to achieve narrow margins in order to make the movable area of the touch screen wider and take into account the miniaturization of the LCD screen. With the narrowing of such a liquid crystal screen, display unevenness caused by a decrease in the performance of the liquid crystal alignment film may be seen around the sealant of the display screen. In order to achieve high definition of a liquid crystal display, it is required to make a liquid crystal alignment film that is not easy to see display unevenness around the sealant (high tolerance to uneven frame).

In addition, along with the high definition of liquid crystal screens in recent years, the requirements for display quality have become increasingly strict, and high reliability of liquid crystal display elements is expected. Furthermore, when a retardation film is produced using a liquid crystal alignment agent, the adhesiveness to a substrate is required to withstand long-term use (adhesive reliability).

The present invention has been made in view of the problems described above, and it is an object of the present invention to provide a liquid crystal alignment agent that can obtain a liquid crystal display element that exhibits high reliability and has less display unevenness around the sealant. In addition, another object of the present invention is to provide a liquid crystal alignment agent capable of obtaining a retardation film having excellent adhesion and reliability. [Technical means to solve the problem]

The present inventors have made intensive research in order to solve the problems of the prior art as described above, and have found that a liquid crystal alignment agent containing a compound having a specific structure can obtain a display having both high reliability and a sealant periphery. The uniformly reduced liquid crystal display element has completed the present invention. Specifically, according to the present invention, the following liquid crystal alignment agent, liquid crystal alignment film and manufacturing method thereof, liquid crystal display element, retardation film and manufacturing method thereof, polymer, and compound are provided.

The present invention provides, as one embodiment, a liquid crystal alignment agent, the liquid crystal alignment agent containing a compound (A) having a partial structure represented by the following formula (1). [Chemical 1] (In the formula (1), R ¹ is a protective group for an amine group. Two "* 1" represent a bonding bond to a hydrocarbon group)

The present invention provides a liquid crystal alignment film formed using the liquid crystal alignment agent as another embodiment. In addition, the present invention provides, as another embodiment, a method for manufacturing a liquid crystal alignment film. The method for manufacturing a liquid crystal alignment film includes the steps of: coating the liquid crystal alignment agent on a substrate to form a coating film; and The film is irradiated with light to give the liquid crystal alignment ability.

The present invention provides a liquid crystal display element including the liquid crystal alignment film as another embodiment. The present invention also provides a retardation film including the liquid crystal alignment film. Furthermore, the present invention provides a method for manufacturing a retardation film, which includes the steps of: coating the liquid crystal alignment agent on a substrate to form a coating film; irradiating the coating film with light; and irradiating the coated film with light. The subsequent coating film is coated with a polymerizable liquid crystal and hardened.

The present invention provides, as another embodiment, a polymer, the polymer is at least one polymer selected from the group consisting of a polyimide precursor and a polyimide, and the polymer is A diamine containing a nitrogen-containing heterocyclic structure having a partial structure represented by the formula (1) in a ring skeleton is obtained by use in a reaction. In addition, the present invention provides, as another embodiment, a diamine having a nitrogen-containing heterocyclic structure containing a partial structure represented by the formula (1) in a ring skeleton. [Effect of the invention]

According to the liquid crystal alignment agent containing the compound (A), it is possible to obtain a liquid crystal display element that exhibits high reliability and has little display unevenness around the sealant. In addition, a retardation film having good adhesion reliability can be obtained.

Hereinafter, each component contained in the liquid crystal aligning agent of this invention, and another component arbitrarily mix | blended as needed are demonstrated.

<Compound (A)> The liquid crystal alignment agent of this invention contains the compound (A) which has a partial structure represented by following formula (1). [Chemical 2] (In the formula (1), R ¹ is a protective group for an amine group. Two "* 1" represent a bonding bond to a hydrocarbon group)

R ¹ in formula (1) is not particularly limited as long as it is a group that functions as a protective group for an amine group, and examples thereof include ^one that is released by at least one of heat, light, acid, and base. Valence organic group and the like. R ^{1 is} preferably a monovalent organic group which is released by at least heat. Specific examples thereof include a urethane-based protective group, a fluorenyl-based protective group, a fluorenimine-based protective group, and sulfonium. An amine-based protecting group, a group represented by each of the following formulae (1-1) to (1-5), and the like. [Chemical 3] (In the formulae (1-1) to (1-5), Ar ¹ represents a monovalent aromatic ring group having 6 to 10 carbon atoms, R ¹¹ is an alkyl group having 1 to 12 carbon atoms, and R ¹² is a monovalent organic group. . "*" Indicates a bonding bond to a nitrogen atom)

Ar ^{1 in} the formula (1-2) is a group obtained by removing one hydrogen atom from an aromatic ring having 6 to 10 carbon atoms. Specific examples include phenyl and naphthyl. Examples of the alkyl group having 1 to 12 carbon atoms of R ¹¹ in the formula (1-4) include methyl, ethyl, propyl, butyl, pentyl, and hexyl. These groups may be linear or linear. It is branched. Examples of the monovalent organic group of R ¹² include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. Among these groups, R ^{12 is} preferably an aryl group having 6 to 10 carbon atoms, and more preferably an aromatic ring group such as a phenyl group or a naphthyl group.

Among these, from the viewpoint of high release from heat, or from the point that the compound derived from R ¹ that is released by heating during film formation can be discharged to the outside of the film as a gas, R ^{1 is} preferably Urethane-based protective group. Specific examples thereof include a third butoxycarbonyl group, a benzyloxycarbonyl group, a 1,1-dimethyl-2-haloethoxycarbonyl group, and a 1,1-dimethyl-2-cyanoethoxy group. Carbonyl, 9-fluorenylmethoxycarbonyl, allyloxycarbonyl, 2- (trimethylsilyl) ethoxycarbonyl, and the like. Among them, a third butoxycarbonyl group (BOC group) is preferred.

The hydrocarbon group to which the bond "* 1" in the formula (1) is bonded may be any of a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. A chain hydrocarbon group is preferred, and specific examples include methylene, ethylidene, and propylidene. When the hydrocarbon group to which "* 1" is bonded is a chain hydrocarbon group, the hydrocarbon group may constitute at least a part of a chain structure or may also constitute a part of a cyclic structure. Among these, in terms of the reliability of the liquid crystal display element and the high improvement effect of suppressing display unevenness around the sealant, the compound (A) preferably has a ring skeleton containing the compound represented by the formula (1). A compound having a partially structured nitrogen-containing heterocyclic structure (hereinafter also referred to as a "specific heterocyclic structure").

Examples of the cyclic skeleton of the specific heterocyclic structure include a piperidine ring, a piperazine ring, a pyrrolidine ring, a hexamethyleneimine ring, a heptamethyleneimine ring, a homopiperazine ring, and a dehydroquinoline ring. , Morpholine ring, 1,2,3,4-tetrahydroquinoline ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, indole ring, benzimidazole ring, purine ring, oxazole ring, and the like. Among them, the ring skeleton of the specific heterocyclic structure is preferably a piperidine ring, a piperazine ring, a pyrrolidine ring, or a hexamethyleneimine ring. These rings may also have a substituent. Examples of the substituent include a methyl group and an ethyl group.

Specific examples of the specific heterocyclic structure include, for example, n-valent groups obtained by removing n hydrogen atoms from each of the structures represented by the following formulae (2-1) to (2-4). The number of specific heterocyclic structures in the compound (A) is not particularly limited, and may be one or plural. The compound (A) may have only one specific heterocyclic structure or two or more specific heterocyclic structures. [Chemical 4]

The embodiment in which the compound (A) is contained in the liquid crystal alignment agent is not particularly limited. For example, the compound (A) may be at least a part of a polymer component in the liquid crystal alignment agent, or may be at least a part of an additive component prepared separately from the polymer component in the liquid crystal alignment agent.

When Compound (A) is a Polymer When Compound (A) is a polymer having a partial structure represented by the formula (1) (hereinafter also referred to as "polymer (A)"), the polymer The main skeleton of (A) is not particularly limited, and examples thereof include a polyimide precursor, polyimide, polysiloxane, polyester, polyimide, a cellulose derivative, a polyacetal, and a polyimide. Main skeletons such as styrene derivatives, poly (styrene-phenylmaleimide) derivatives, and poly (meth) acrylates. In addition, (meth) acrylate means including an acrylate and a methacrylate. Examples of the polyimide precursor include polyamic acid and polyamidate. The polymer (A) may be used singly or in combination of two or more kinds. Among these polymers, the polymer (A) is preferably selected from the group consisting of a polyimide precursor, a polyimide, a polyimide, a polyimide, a polyorganosiloxane, and a poly (meth) acrylic acid. At least one of the group consisting of an ester and a polyester is more preferably at least one polymer selected from the group consisting of a polyimide precursor and a polyimide.

The polymer (A) may have a partial structure represented by the formula (1) in any of a main chain and a side chain of the polymer. Herein, the "main chain" of a polymer in this specification refers to a "backbone" portion of a polymer including the longest atomic chain. In addition, the "backbone" portion is allowed to contain a ring structure. Therefore, "having a partial structure represented by the formula (1) in the main chain" means that the structure constitutes a part of the main chain. The "side chain" of a polymer refers to a portion branched from the "backbone" of a polymer.

[Polyamine acid] The polyamino acid as the polymer (A) can be obtained, for example, by reacting a tetracarboxylic dianhydride with a diamine. This polyamic acid can be obtained by polymerization including a tetracarboxylic dianhydride having a partial structure represented by the formula (1) in a monomer composition, and At least one type of diamine represented by a partial structure. From the viewpoint of a high degree of freedom in selecting a compound, it is preferable to use a diamine (hereinafter also referred to as a “specific diamine”) having a partial structure represented by the formula (1).

(Tetracarboxylic dianhydride) Examples of the tetracarboxylic dianhydride used to synthesize polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. Specific examples of these tetracarboxylic dianhydrides include, for example, aliphatic tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, and the like; and alicyclic tetracarboxylic dianhydride, for example, 1,2,3, 4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b -Tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b -Tetrahydronaphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran -2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3 , 5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [ 5.3.1.0 ^2,6 ] Undecane-3,5,8,10-tetraone, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene -2,3,5,6-Tetracarboxylic dianhydride, ethylenediamine tetraacetic dianhydride, cyclopentanetetracarboxylic dianhydride, ethylene glycol bis (trimellitic anhydride), 1,3-propanediol bis ( Trimellitic anhydride), etc.

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, etc. In addition, Japanese Patent Laid-Open No. 2010 can be used. Tetracarboxylic dianhydride described in Japanese Patent Publication No. 97188. In addition, the tetracarboxylic dianhydride used for synthesizing a polyamic acid may be used individually by 1 type, and may use 2 or more types together.

Among them, the tetracarboxylic dianhydride preferably contains a compound selected from the group consisting of bicyclic [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3 , 4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5, 9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5, 9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8- At least one compound in the group consisting of dianhydride, cyclohexanetetracarboxylic dianhydride and pyromellitic dianhydride. Relative to the total amount of tetracarboxylic dianhydride used to synthesize polyamidic acid, the amount of these preferred compounds (the total amount when two or more are used) is preferably set to 5 mol% or more It is more preferable to set it to 10 mol% or more, and it is more preferable to set it to 20 mol% or more.

(Diamine) As long as the specific diamine has a partial structure represented by the formula (1), the remaining structure is not particularly limited, and preferred specific examples include the following formulae (3-1) to (3) -4) Compounds and the like represented by each. [Chemical 5] (In formulas (3-1) and (3-2), R ² is a monovalent group obtained by removing a hydrogen atom from a ring portion of a specific heterocyclic structure, and X ¹ and X ² are a single bond or two, respectively. X ³ is a trivalent linking group. In formula (3-3), R ³ is a divalent group obtained by removing two hydrogen atoms from a ring portion of a specific heterocyclic structure, and X ⁵ and X ⁶ are respectively Is independently a single bond or a divalent linking group. In the formula (3-4), X ⁷ and X ⁸ are each independently a single bond or a divalent linking group, R ¹ is a protective group for an amine group, and R ⁵ and R ⁶ Are each independently a divalent hydrocarbon group. N is an integer of 1 to 4)

Examples of the divalent linking groups of X ¹ , X ² , X ⁵ , X ⁶ , X ⁷ and X ⁸ in the formulae (3-1) to (3-4) include: -O-, -S -, -CO-, -COO-, -COS-, -NR ^4- , -CONR ^4- , -CO-NR ⁴ -CO- (where R ⁴ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) , A divalent hydrocarbon group having 1 to 20 carbon atoms, at least one methylene group of the hydrocarbon group is passed through -O-, -S-, -CO-, -COO-, -COS-, -NR ^5- , -CONR ^5- , -CO-NR ⁵ -CO- (wherein R ⁵ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) and the like. In the divalent linking group, a hydrogen atom in the hydrocarbon group may be further substituted with, for example, a halogen atom.

Herein, the "hydrocarbon group" as used herein means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group which are not composed of a cyclic structure in the main chain and are composed of only a chain structure. Among them, it may be saturated or unsaturated. The "alicyclic hydrocarbon group" refers to a hydrocarbon group having a structure containing only an alicyclic hydrocarbon as a ring structure and having no aromatic ring structure. However, it does not need to consist only of the structure of an alicyclic hydrocarbon, It also includes the group which has a chain structure in a part. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to consist only of an aromatic ring structure, and it may include a chain structure or an alicyclic hydrocarbon structure in part.

Specific examples of the case where X ¹ , X ² , X ⁵ , X ⁶ , X ⁷ , and X ⁸ are divalent hydrocarbon groups, and examples of the chain hydrocarbon group include methylene, ethylene, propanediyl, and butane. Diyl, pentanediyl, hexanediyl, heptanediyl, octanediyl, nonanediyl, decanediyl and other alkanediyl groups; vinylidene, propylenediyl, butenediyl, These groups may be linear or branched, such as pentene diyl and olefin diyl such as hexene diyl. Examples of the alicyclic hydrocarbon group include a cyclohexyl group. Examples of the aromatic hydrocarbon group include a phenylene group, a biphenylene group, and a naphthyl group.

Examples of the trivalent linking group of X ³ include a nitrogen atom and a trivalent hydrocarbon group having 1 to 3 carbon atoms. Preferable specific examples of R ² include, for example, a group obtained by removing a hydrogen atom from a ring portion of each of the structures represented by the formulae (2-1) to (2-4). Preferable specific examples of R ³ include, for example, a group obtained by removing two hydrogen atoms from a ring portion of each of the structures represented by the formulae (2-1) to (2-4). In addition, in the case of R ³ , the two hydrogen atoms removed may be hydrogen atoms bonded to the same atom, or may be hydrogen atoms bonded to different atoms, respectively. The divalent hydrocarbon group of R ⁵ and R ⁶ in the formula (3-4) is preferably a chain hydrocarbon group, and examples thereof include methylene, ethylene, and propyl. R amino protecting group R ¹ may be applied to the formula (1) described in ^1.

The bonding position of the primary amine group in the formulae (3-1) to (3-4) is not particularly limited. For example, in the case of the formula (3-1), the two amine groups of the diaminophenyl group are preferably located at the 2,4-position or the 3,5-position with respect to other groups. In the case of the formulas (3-2) to (3-4), one amino group of the aminophenyl group is preferably located at the 3 or 4 position with respect to other groups, and more preferably at the 4 position. Bit.

Regarding specific examples of the specific diamine, the compound represented by the formula (3-1) includes, for example, a compound represented by each of the following formula (X-1) and formula (X-2); and the formula ( Examples of the compound represented by 3-2) include compounds represented by the following formula (X-3); examples of the compound represented by the formula (3-3) include the following formula (X-4) Compounds represented by the formulae; Examples of the compound represented by the formula (3-4) include compounds represented by the following formulae (Y-1) to (Y-8). The specific diamines may be used singly or in combination of two or more. [Chemical 6] [Chemical 7]

The specific diamine can be synthesized by appropriately combining ordinary methods of organic chemistry. One example is the method of synthesizing a dinitro intermediate containing a nitro group instead of a primary amine group of a diamine having a partial structure represented by the formula (1), and then using a suitable reduction system to dilute the obtained dinitro group. A method for the amination of a nitro group of a base intermediate.

The method for synthesizing the dinitro intermediate can be appropriately selected according to the target compound. For example, a method of reacting a hydroxyl-containing compound having a partial structure represented by the formula (1) with a halogenated dinitrobenzene, preferably in an organic solvent, if necessary, in the presence of a catalyst; A method of reacting an amine group-containing compound having a partial structure represented by the formula (1) with a halogenated dinitrobenzene in an organic solvent, if necessary, in the presence of a catalyst, and the like. The reduction reaction of the dinitro intermediate is preferably performed in an organic solvent using a catalyst such as palladium carbon, platinum oxide, zinc, iron, tin, nickel, or the like. Examples of the organic solvent used herein include ethyl acetate, toluene, tetrahydrofuran, and alcohols. However, the synthesis order of a specific diamine is not limited to the method.

The diamine used to synthesize the polyamidic acid as the polymer (A) may be only a specific diamine, or a diamine other than the specific diamine may be used in combination.

Examples of other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, and diamine organosiloxanes. As specific examples of these diamines, examples of the aliphatic diamine include m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine. , 1,3-bis (aminomethyl) cyclohexane, etc .; Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine). )Wait;

Examples of the aromatic diamine include dodecyloxydiaminobenzene, tetradecyloxydiaminobenzene, pentadecyloxydiaminobenzene, cetyloxydiaminobenzene, and ten Octaalkoxydiaminobenzene, cholesteryloxydiaminobenzene, cholestoxydiaminobenzene, cholesteryl diaminobenzoate, cholesteryl diaminobenzoate Lanosteryl diaminobenzoate, 3,6-bis (4-aminobenzyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl ) -4-heptylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4- ( (Aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, N- (2,4-diaminophenyl) -4- (4-heptylcyclohexyl) ) Diamine containing an alignment group such as benzamidine and a compound represented by the following formula (E-1), [Chem. 8] (In formula (E-1), X ^I and X ^II are each independently a single bond, -O-, -COO-, or -OCO-, R ^I is an alkanediyl group having 1 to 3 carbon atoms, and R ^II is a single Bond or alkanediyl having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1. Wherein a and b are not 0 at the same time) ;

P-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenylsulfide, 4-aminobenzene -4'-aminobenzoate, 4,4'-diaminoazobenzene, 1,5-bis (4-aminophenoxy) pentane, 1,7-bis (4-amine Phenylphenoxy) heptane, bis [2- (4-aminophenyl) ethyl] adipic acid, N, N-bis (4-aminophenyl) methylamine, 1,5-diamine Naphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4 '-Diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2 -Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylene isopropylidene Group) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 2, 4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminooxazole, N-methyl-3,6-diaminooxazole, N, N'-bis (4 -Aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -Piperazine, 3,5-diaminobenzoic acid, etc .; diamine Examples of the organosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisilaxane, and the like. In addition, the disiloxane described in Japanese Patent Laid-Open No. 2010-97188 can be used. amine.

The divalent group represented by "-X ^I- (R ^I -X ^II ) _d- " in the formula (E-1) is preferably an alkanediyl group having 1 to 3 carbon atoms, * -O-, * -COO- or * -OC ₂ H ₄ -O- (wherein the bond with "*" is bonded to the diaminophenyl group). Examples of the group "-C _c H _{2c + 1} " include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, and deca Trialkyl, tetradecyl, pentadecyl, hexadecyl, hexadecyl, octadecyl, nonadecanyl, eicosyl, and the like are preferably linear. The two amine groups of the diaminophenyl group are preferably located at the 2,4- or 3,5-position relative to the other groups.

Specific examples of the compound represented by the formula (E-1) include compounds represented by the following formulae (E-1-1) to (E-1-4). [Chemical 9] In addition, other diamines used for synthesizing polyamidic acid may be used alone or two or more of them may be appropriately selected and used.

When the liquid crystal alignment agent of the present invention is used for a liquid crystal display element of the TN type, the STN type, or the vertical alignment type, it is preferable to introduce into the side chain of a polyamic acid to impart a liquid crystal alignment ability to a coating film. Group (liquid crystal alignment group). Here, the liquid crystal alignment group is a group capable of imparting liquid crystal alignment to a coating film without depending on light irradiation, and specific examples thereof include an alkyl group having 4 to 20 carbon atoms and a fluorine group having 4 to 20 carbon atoms. An alkyl group, an alkoxy group having 4 to 20 carbon atoms, a group having a steroid skeleton with 17 to 51 carbon atoms, a group in which a plurality of rings are bonded directly or via a linking group, and the like. The polyamidic acid having a liquid crystal alignment group can be obtained, for example, by polymerization of a diamine containing the alignment group-containing diamine in a monomer composition. In the case of using a diamine containing an alignment group, from the viewpoint of exhibiting good liquid crystal alignment, the compounding amount is preferably set to 3 mol% or more relative to all diamines used for synthesis. More preferably, it is set to 5 mol% to 70 mol%.

From the viewpoint that the reliability of the liquid crystal display element and the effect of improving the non-uniformity of the frame are sufficiently obtained, the ratio of the specific diamine to the total amount of the diamine used for the synthesis of the polyamic acid is preferably set. It is 0.5 mol% or more, more preferably 2 mol% or more, and even more preferably 10 mol% or more. In addition, the upper limit of the use ratio of the specific diamine is not particularly limited. It is preferably set to 100 mol% or less, more preferably set to 80 mol% or less, and further preferably set to 70 mol%. the following.

When a liquid crystal alignment ability is imparted to a coating film formed of a liquid crystal alignment agent by a photo alignment method, a polymer having a photo alignment structure may be used as at least a part of the polymer (A). Specific examples of the photo-alignment structure include groups that exhibit photo-alignment by photoisomerization, photodimerization, photodecomposition, and the like. Specific examples include an azo-containing group containing an azo compound or a derivative thereof as a basic skeleton, a cinnamic acid-containing group containing cinnamic acid or a derivative thereof as a basic skeleton, and chalcone A chalcone-containing group containing a basic skeleton as a basic skeleton, a benzophenone-containing group containing a benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing a coumarin or a derivative thereof as a basic skeleton Coumarin-containing group, cyclobutane-containing structure containing cyclobutane or its derivative as the basic skeleton, bicyclic-containing [2.2.2] octene or its derivative containing the bicyclic-containing [2.2.2 A structure of octene, a structure containing a partial structure represented by the following formula (4) as a basic skeleton, and the like. [Chemical 10] (In formula (4), X ⁷ is a sulfur atom, an oxygen atom, or -NH-. "*" Represents a bonding bond, respectively. At least one of the two "*" is bonded to an aromatic ring)

The polyamidic acid having a photo-alignment structure can be obtained, for example, by polymerizing at least one of a tetracarboxylic dianhydride having a photo-alignment structure and a diamine having a photo-alignment structure in a raw material. In this case, from the viewpoint of sensitivity to light, the use ratio of the monomer having a photo-alignment structure is preferably set to 20 mol% or more with respect to the total amount of the monomers used to synthesize the polymer. It is more preferable to set it to 30 mol% to 80 mol%.

(Synthesis of Polyamic Acid) Polyamic acid can be obtained by reacting a tetracarboxylic dianhydride and a diamine as necessary with a molecular weight modifier, as described above. Regarding the use ratio of tetracarboxylic dianhydride and diamine for the synthesis reaction of polyamic acid, it is preferable that the acid anhydride group of tetracarboxylic dianhydride is 0.2 equivalent to 2 with respect to the amine group of diamine. The ratio of equivalents is more preferably such that the anhydride group of tetracarboxylic dianhydride becomes 0.3 to 1.2 equivalents. Examples of the molecular weight adjusting agent include acid anhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; phenyl isocyanate and naphthalene isocyanate Monoisocyanate compounds such as esters. The use ratio of the molecular weight adjuster is preferably set to 20 parts by weight or less, and more preferably set to 10 parts by weight or less, based on 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used.

The synthesis reaction of the polyamic acid is preferably performed in an organic solvent. The reaction temperature at this time is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours.

Examples of the organic solvent used for the reaction include aprotic polar solvents, phenol-based solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenol-based solvent (organic solvent of the first group), or an organic solvent selected from the first group is preferably used. A mixture of one or more of them and one or more selected from the group consisting of an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, and a hydrocarbon (the organic solvent of the second group). In the latter case, the use ratio of the organic solvent in the second group is preferably 50% by weight or less, and more preferably 40% by weight, relative to the total amount of the organic solvent in the first group and the organic solvent in the second group. Hereinafter, it is more preferably 30% by weight or less.

As for the particularly preferable organic solvent, it is preferably selected from the group consisting of N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, and dimethylsulfine. One or more of the group consisting of γ-butyrolactone, tetramethylurea, hexamethylphosphonium triamine, m-cresol, xylenol and halogenated phenol is used as a solvent, or in the range of the ratio Instead, a mixture of one or more of these solvents with other organic solvents is used. The use amount (x) of the organic solvent is preferably set such that the total amount (y) of tetracarboxylic dianhydride and diamine is 0.1% to 50% by weight relative to the total amount (x + y) of the reaction solution. the amount.

As described above, a reaction solution obtained by dissolving polyamic acid can be obtained. The reaction solution can be directly used to prepare a liquid crystal alignment agent, or the polyamic acid contained in the reaction solution can be separated and used to prepare a liquid crystal alignment agent, or the separated polyamino acid can be purified and used for preparation. Liquid crystal alignment agent. In the case where the polyamidic acid is dehydrated and closed to form a polyamidoimide, the reaction solution may be directly used for dehydration and closed-loop reaction, or the polyamidic acid contained in the reaction solution may be separated and then supplied for dehydration. The ring-closing reaction, or the separated polyamidic acid may be purified and then used for dehydration ring-closing reaction. Isolation and purification of polyamic acid can be performed according to a well-known method.

[Polyamidate] The polyamidate as the polymer (A) can be obtained, for example, by the following method: [I] reacting the polyamino acid obtained by the synthesis reaction with an esterifying agent Method; [II] A method of reacting a tetracarboxylic acid diester with a diamine; [III] A method of reacting a tetracarboxylic acid diester dihalide with a diamine, and the like. The term "tetracarboxylic acid diester" as used herein refers to a compound in which two of the four carboxyl groups of a tetracarboxylic acid are esterified and the remaining two are carboxyl groups. The "tetracarboxylic acid diester dihalide" refers to a compound in which two of the four carboxyl groups of a tetracarboxylic acid are esterified and the remaining two are halogenated.

Examples of the esterifying agent used in the method [I] include a hydroxyl-containing compound, an acetal-based compound, a halide, and an epoxy-containing compound. Specific examples of these compounds include, for example, hydroxyl-containing compounds such as alcohols such as methanol, ethanol, and propanol; phenols such as phenol and cresol; and acetal compounds such as N, N-dimethyl. Formamidine diethyl acetal, N, N-diethylformamide diethyl acetal, etc .; Examples of the halide include methyl bromide, bromoethane, stearyl bromide, methyl chloride, and stearyl chloride. , 1,1,1-trifluoro-2-iodoethane, etc .; Examples of the epoxy group-containing compound include propylene oxide.

The tetracarboxylic acid diester used in the method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the synthesis of the polyamic acid with an alcohol such as methanol or ethanol. The tetracarboxylic acid derivative used in the method [II] may be only a tetracarboxylic acid diester, or a tetracarboxylic dianhydride may be used in combination. As for the diamine, the specific diamine exemplified in the synthesis of polyamidic acid may be used alone, or it may be used in combination with other diamines.

The reaction of the method [II] is preferably performed in an organic solvent in the presence of a suitable dehydration catalyst. Examples of the organic solvent include organic solvents exemplified as organic solvents for synthesizing polyamic acid. Examples of the dehydration catalyst include halogenated 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium, carbonylimidazole, and phosphorus-based condensation agents. The reaction temperature at this time is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours.

The tetracarboxylic acid diester dihalide used in the method [III] can be obtained, for example, by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. The tetracarboxylic acid derivative used in the method [III] may be only a tetracarboxylic acid diester dihalide, or a tetracarboxylic dianhydride may be used in combination. As for the diamine, the specific diamine exemplified in the synthesis of polyamidic acid may be used alone, or it may be used in combination with other diamines.

The reaction of the method [III] is preferably performed in an organic solvent in the presence of a suitable base. Examples of the organic solvent include organic solvents exemplified as organic solvents for synthesizing polyamic acid. Examples of the base that can be preferably used include tertiary amines such as pyridine and triethylamine; alkali metals such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium, and potassium. The reaction temperature at this time is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours.

The polyamidate contained in the liquid crystal alignment agent may have only a pseudoamidate structure, or may be a partially esterified product in which a pseudoamidate structure and a pseudoamidate structure coexist. In addition, the reaction solution obtained by dissolving the polyfluorene ester may be directly used for preparing the liquid crystal alignment agent, or the polyphosphonium acid ester contained in the reaction solution may be separated and used for preparing the liquid crystal alignment agent, or the liquid crystal alignment agent may be used, or The separated polyamidate is purified and used to prepare a liquid crystal alignment agent. Isolation and purification of polyamidate can be performed according to a well-known method.

[Polyimide] The polyimide as the polymer (A) can be obtained, for example, by dehydrating and closing the polyamidic acid synthesized as described above, and then performing imidization.

The polyimide may be a complete fluorinated imide obtained by dehydrating and ring-closing all the fluorinated acid structures of the polyfluorinated acid as a precursor thereof, or may be a dehydration and closed-loop only a part of the fluorinated acid structure. Part of the sulfonium imide compound having an amine acid structure and a sulfonium ring structure. The polyfluorene imine used in the reaction is preferably a hydrazone imidization rate of 20% or more, more preferably 30% to 99%, and still more preferably 40% to 99%. The fluorene imidization ratio is a percentage representing the ratio of the number of fluorene imine ring structures of the polyfluorene imine to the total number of fluorene acid structures and the number of fluorene imine ring structures. Here, a part of the fluorene imine ring may be an isofluorene ring.

The dehydration ring closure of the polyamic acid is preferably performed by the following method: a method of heating the polyamic acid; or dissolving the polyamic acid in an organic solvent, and adding a dehydrating agent and a dehydration ring closing catalyst to the solution , If necessary, the method of heating. In the method of adding a dehydrating agent and a dehydration ring-closing catalyst to a solution of a polyamic acid, for example, an acid anhydride such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. The use amount of the dehydrating agent is preferably set to 0.01 mol to 20 mol relative to 1 mol of the fluoric acid structure of the polyamic acid. Examples of the dehydration ring-closing catalyst include tertiary amines such as pyridine, trimethylpyridine, dimethylpyridine, and triethylamine. The use amount of the dehydration closed-loop catalyst is preferably set to 0.01 mol to 10 mol relative to 1 mol of the dehydrating agent used. Examples of the organic solvent used for the dehydration ring-closure reaction include the organic solvents exemplified as the organic solvent used for synthesizing polyamic acid. The reaction temperature of the dehydration ring-closing reaction is preferably 0 ° C to 180 ° C, and more preferably 10 ° C to 150 ° C. The reaction time is preferably 1.0 to 120 hours, and more preferably 2.0 to 30 hours.

In this manner, a reaction solution containing polyimide can be obtained. The reaction solution can be directly used for preparing liquid crystal alignment agent, or the dehydrating agent and dehydration ring-closing catalyst can be removed from the reaction solution and used for preparing liquid crystal alignment agent, or the polyfluorene imide can be separated and used for preparing liquid crystal alignment agent, or The separated polyfluorene imine can also be purified and used to prepare a liquid crystal alignment agent. These purification operations can be performed according to well-known methods. In addition, polyfluorene imine can also be obtained by hydrazone imidization of a polyfluoride.

The polyimide precursor and polyimide obtained as described above preferably have a solution viscosity of 20 mPa · s to 1,800 mPa · s when they are made into a solution having a concentration of 15% by weight. It has a solution viscosity of 50 mPa · s to 1,500 mPa · s. In addition, the solution viscosity (mPa · s) of the polymer is a good solvent (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) using the polymer at 25 ° C using an E-type rotational viscometer. ) A value obtained by measuring the prepared polymer solution having a concentration of 15% by weight. The weight average molecular weight (Mw) of the polyfluorene imide precursor and the polyfluorene imide measured by Gel Permeation Chromatography (GPC) in terms of polystyrene is preferably 1,000 to 500,000, and more It is preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 5 or less, and more preferably 3.5 or less. By being in such a molecular weight range, good alignment and stability of a liquid crystal display element can be ensured.

[Polysiloxane] The polysiloxane as the polymer (A) can be obtained, for example, by hydrolyzing and condensing a hydrolyzable silane compound. Specifically, the following method [1] or [2] can be cited. [1] Hydrolyzable silane compound (ms-1) having an epoxy group, or the silane compound (ms-1) and other silane compounds The mixture obtained is hydrolyzed and condensed to synthesize an epoxy group-containing polysiloxane, and then the obtained epoxy group-containing polysiloxane and a carboxylic acid having a partial structure represented by the formula (1) (hereinafter also referred to as "Specific carboxylic acid") method; [2] hydrolyzing a silane compound (ms-2) having a partial structure represented by the formula (1), or the silane compound (ms-2) and another silane Method of hydrolyzing and condensing a mixture of compounds. Among these methods, the method [1] is simple, and the introduction rate of the partial structure represented by the formula (1) in the polymer (A) is improved, which is preferable in this respect.

Specific examples of the silane compound (ms-1) include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropyl Methyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4- Epoxycyclohexyl) ethyltriethoxysilane, 3- (3,4-epoxycyclohexyl) propyltrimethoxysilane, and the like. The silane compound (ms-1) can be used singly or in combination of two or more kinds.

The other silane compounds are not particularly limited as long as they are hydrolyzable silane compounds, and examples thereof include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, Alkoxysilanes such as phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxy Silane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (3-cyclohexylamino) propyltrimethoxy Nitrogen and sulfur-containing alkoxysilanes such as N- (sulfanyl) silane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane; 3- (meth) acryloxypropyltrimethoxy Silane, 3- (meth) acryloxypropyltriethoxysilane, 6- (meth) acryloxyhexyltrimethoxysilane, 3- (meth) acryloxypropylmethyl Dimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, etc. Unsatisfactory An alkoxysilane with a bond; in addition to this, trimethoxysilylpropylsuccinic anhydride and the like are mentioned. Other silane compounds may be used alone or in combination of two or more.

As described above, the hydrolysis and condensation reaction of the silane compound is performed by reacting one or two or more silane compounds with water, preferably in the presence of a suitable catalyst and an organic solvent. In the method of [1], from the viewpoint that a partial structure represented by the formula (1) can be sufficiently introduced into a polymer and a side reaction caused by an excessive amount of epoxy groups is suppressed, The epoxy equivalent of the epoxy group-containing polysiloxane is preferably 100 g / mole to 10,000 g / mole, and more preferably 150 g / mole to 1,000 g / mole. Therefore, when synthesizing an epoxy group-containing polysiloxane, it is preferable to adjust the use ratio of the silane compound (ms-1) so that the epoxy equivalent of the obtained polysiloxane is within the above range. In the hydrolysis / condensation reaction, the use ratio of water is preferably 0.5 to 100 mol, and more preferably 1 to 30 mol, relative to 1 mol of the silane compound (total amount).

Examples of the catalyst used in the hydrolysis and condensation reaction include an acid, an alkali metal compound, an organic base, a titanium compound, and a zirconium compound. The amount of catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, etc., and should be appropriately set. For example, it is preferably 0.01 to 3 times mole, more preferably 0.05 to moles relative to the total amount of the silane compound. ~ 1 Mohr. Examples of the organic solvent used in the hydrolysis and condensation reaction include hydrocarbons, ketones, esters, ethers, and alcohols. Among these organic solvents, it is preferred to use an organic solvent that is insoluble in water or poorly soluble in water. The use ratio of the organic solvent is preferably 10 to 10,000 parts by weight, and more preferably 50 to 1,000 parts by weight with respect to 100 parts by weight of the total silane compound used for the reaction.

The hydrolysis and condensation reaction is preferably carried out by heating with an oil bath or the like, for example. In the hydrolysis and condensation reaction, the heating temperature is preferably set to 130 ° C or lower, and more preferably set to 40 ° C to 100 ° C. The heating time is preferably set to 0.5 to 12 hours, and more preferably set to 1 to 8 hours. The mixture can be stirred during heating, or it can be placed under reflux. After the reaction is completed, the organic solvent layer separated and extracted from the reaction solution is preferably washed with water. In this washing, washing with water containing a small amount of salt (for example, about 0.2% by weight of an ammonium nitrate aqueous solution, etc.) facilitates the washing operation, which is preferable in this respect. The washing is performed until the water layer after the washing becomes neutral, and then, if necessary, the organic solvent layer is dried with a desiccant such as anhydrous calcium sulfate and molecular sieve, and then the solvent is removed, thereby obtaining the desired polysiloxane. The method for synthesizing polysiloxane is not limited to the hydrolysis and condensation reaction described above. For example, the method can be carried out by a method in which a hydrolyzable silane compound is reacted in the presence of oxalic acid and alcohol.

In the method of [1], the epoxy group-containing polysiloxane obtained by the reaction is reacted with a specific carboxylic acid. Thereby, the epoxy group which a polysiloxane containing an epoxy group has reacted with a carboxylic acid, and the polysiloxane which has a partial structure represented by said Formula (1) can be obtained. The specific carboxylic acid is not particularly limited as long as it has a partial structure represented by the formula (1). From the viewpoint of high reliability of the liquid crystal display element and high improvement effect of suppressing display unevenness around the sealant, it is preferable. Is a carboxylic acid having a specific heterocyclic structure, and specific examples thereof include compounds represented by the following formulae (A-3) to (A-6). [Chemical 11] The specific carboxylic acid may be used singly or in combination of two or more kinds.

When synthesizing the polysiloxane as the polymer (A), the carboxylic acid used in the reaction with the polysiloxane containing an epoxy group may be only a specific carboxylic acid, or a carboxylic acid other than the specific carboxylic acid may be used in combination. . The other carboxylic acid is not particularly limited as long as it does not have a partial structure represented by the formula (1), and examples thereof include a carboxylic acid having the liquid crystal alignment group. Other carboxylic acids may be used alone or in combination of two or more.

The use ratio of the carboxylic acid reacted with the polysiloxane containing epoxy groups is preferably set to 0.001 mol to 1.5 mol, more than 1 mol of the total epoxy groups of the polysiloxane. Preferably, it is set to 0.01 mol to 1.0 mol. The use ratio of the specific carboxylic acid is preferably set to 5 mol% or more, and more preferably set to 10 mol% or more with respect to the total amount of the carboxylic acid reacted with the epoxy group-containing polysiloxane.

The reaction of the epoxy group-containing polysiloxane with a carboxylic acid is preferably carried out in the presence of a catalyst and an organic solvent. The catalyst may be, for example, a compound known as a so-called hardening accelerator that accelerates the reaction of an organic base or an epoxy compound. Among them, tertiary organic amines or quaternary organic amines are preferred. The use ratio of the catalyst is preferably 100 parts by weight or less, more preferably 0.01 to 100 parts by weight, and still more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the epoxy group-containing polysiloxane.

Examples of the organic solvent used in the reaction include hydrocarbons, ethers, esters, ketones, amidines, and alcohols. Among these organic solvents, at least one selected from the group consisting of ethers, esters, and ketones is preferable from the viewpoints of the solubility of the raw materials and products and the ease of purification of the products. Specific examples include 2-butanone, 2-hexanone, methyl isobutyl ketone, and butyl acetate. The organic solvent is preferably used at a solid content concentration (a ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) of 0.1% by weight or more, and more preferably a solid The component concentration is used at a ratio of 5 to 50% by weight.

The reaction temperature of the reaction is preferably 0 ° C to 200 ° C, and more preferably 50 ° C to 150 ° C. The reaction time is preferably from 0.1 to 50 hours, and more preferably from 0.5 to 20 hours. After the reaction is completed, the organic solvent layer separated and extracted from the reaction solution is preferably washed with water. After washing with water, if necessary, the organic solvent layer is dried with an appropriate desiccant, and then the solvent is removed to obtain the desired polysiloxane.

The polystyrene-equivalent weight-average molecular weight (Mw) measured by GPC of polysiloxane as the polymer (A) is preferably in the range of 100 to 50,000, and more preferably in the range of 200 to 10,000. . When the weight average molecular weight of the polysiloxane is within the above range, it is easy to handle the liquid crystal alignment film when it is produced, and the obtained liquid crystal alignment film has sufficient material strength and characteristics.

[Poly (meth) acrylate] The poly (meth) acrylate as the polymer (A) can be obtained, for example, by using a (meth) acrylic monomer (ma-1) having an epoxy group. ) Or a mixture of the (meth) acrylic monomer (ma-1) and other (meth) acrylic monomers in the presence of a polymerization initiator, and then polymerizing the resulting polymer (hereinafter also referred to as " Epoxy-containing poly (meth) acrylates ") react with specific carboxylic acids.

Examples of the (meth) acrylic monomer (ma-1) include an unsaturated carboxylic acid ester having an epoxy group. Specific examples thereof include glycidyl (meth) acrylate, glycidyl α-ethylacrylate, glycidyl α-n-propylacrylate, glycidyl α-n-butylacrylate, (meth) 3,4-epoxybutyl acrylate, 3,4-epoxybutyl α-ethyl acrylate, 3,4-epoxycyclohexyl methyl (meth) acrylate, 6,7-cyclo (meth) acrylate Oxoheptyl, 6,7-epoxyheptyl acrylate, 4-hydroxybutyl glycidyl acrylate, (3-ethyloxetane-3-yl) methyl methacrylate Wait. The (meth) acrylic monomer (ma-1) may be used alone or in combination of two or more thereof.

Examples of other (meth) acrylic monomers include unsaturated carboxylic acids such as (meth) acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, and vinylbenzoic acid; Base) methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, allyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, (formyl) ) -2-ethylhexyl acrylate, lauryl (meth) acrylate, trimethoxysilyl propyl (meth) acrylate, methoxyethyl (meth) acrylate, -N (meth) acrylate , Unsaturated carboxylic acids such as N-dimethylaminoethyl ester, methoxypolyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate Esters; unsaturated polycarboxylic anhydrides such as maleic anhydride, itaconic anhydride, cis-1,2,3,4-tetrahydrophthalic anhydride. In addition, other (meth) acrylic monomers can be used alone or in combination of two or more of them.

When synthesizing poly (meth) acrylate, the total amount (mole number) of epoxy groups per 1 g of epoxy group-containing poly (meth) acrylate is preferably 5.0 × 10 ^-5 mole / g or more , More preferably 1.0 × 10 ^-4 moles / g to 1.0 × 10 ^-2 moles / g, and still more preferably 5.0 × 10 ^-4 moles / g to 5.0 × 10 ^-3 moles / g. Therefore, the use ratio of the (meth) acrylic monomer (m-1) is preferably such that the total mole number of epoxy groups per 1 g of the epoxy group-containing poly (meth) acrylate is as described above. Way of range adjustment.

Moreover, you may use other monomers other than a (meth) acrylic-type monomer at the time of superposition | polymerization. Examples of other monomers include conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene; aromatics such as styrene, methylstyrene, and divinylbenzene; Group vinyl compounds and the like. The use ratio of other monomers is preferably set to 30 mol% or less, and more preferably set to 20 mol% or less with respect to the total of the monomers used to synthesize the poly (meth) acrylate.

The polymerization reaction using a (meth) acrylic monomer is preferably performed by radical polymerization. Examples of the polymerization initiator used in the polymerization reaction include initiators generally used in radical polymerization, and examples thereof include 2,2'-azobis (isobutyronitrile) and 2,2'-azobis ( 2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) and other azo compounds; benzamidine peroxide, lauryl peroxide醯, organic peroxides such as tributyl peroxy trimethylacetate, 1,1'-bis (third butyl peroxy) cyclohexane; hydrogen peroxide; oxidation including these peroxides and reducing agents Reduced initiators, etc. Among these compounds, an azo compound is preferred, and 2,2'-azobis (isobutyronitrile) is more preferred. The polymerization initiator may be used alone or in combination of two or more of these compounds. The use ratio of the polymerization initiator is preferably set to 0.01 to 50 parts by weight, and more preferably set to 0.1 to 40 parts by weight with respect to 100 parts by weight of all monomers used for the reaction.

The polymerization reaction of the (meth) acrylic monomer is preferably performed in an organic solvent. Examples of the organic solvent used in this reaction include alcohols, ethers, ketones, amidines, esters, and hydrocarbon compounds. Among these organic solvents, at least one selected from the group consisting of an alcohol and an ether is preferably used, and a partial ether of a polyhydric alcohol is more preferably used. Preferred examples thereof include diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether acetate, and the like. The organic solvent may be used alone or in combination of two or more of them.

In the polymerization reaction of the (meth) acrylic monomer, the reaction temperature is preferably set to 30 ° C to 120 ° C, and more preferably 60 ° C to 110 ° C. The reaction time is preferably set to 1 to 36 hours, and more preferably set to 2 to 24 hours. In addition, the amount (a) of the organic solvent is preferably set such that the total amount (b) of the monomers used for the reaction is 0.1% to 50% by weight relative to the total amount (a + b) of the reaction solution. the amount.

The epoxy group-containing poly (meth) acrylate obtained by the reaction is then reacted with a specific carboxylic acid. The description of specific carboxylic acids to which polysiloxane can be applied. In this reaction, a specific carboxylic acid may be used alone, or a carboxylic acid other than the specific carboxylic acid may be used in combination. The use ratio of the carboxylic acid to be reacted with the epoxy group-containing poly (meth) acrylate is preferably 1 mole relative to the total epoxy group contained in the epoxy group-containing poly (meth) acrylate. It is set to 0.001 mol to 0.95 mol. It is more preferably 0.01 mol to 0.9 mol, and still more preferably 0.05 mol to 0.8 mol.

The reaction of the epoxy group-containing poly (meth) acrylate with a carboxylic acid is preferably carried out in the presence of a catalyst and an organic solvent. Examples of the catalyst used in the reaction include compounds exemplified as a catalyst usable in the synthesis of polysiloxane. Among these compounds, a quaternary ammonium salt is preferred. The amount of the catalyst to be used is preferably 100 parts by weight or less, more preferably 0.01 to 100 parts by weight, and still more preferably 0.1 to 20 parts by weight based on 100 parts by weight of the epoxy-containing poly (meth) acrylate. Parts by weight.

Examples of the organic solvent used in the reaction include organic solvents that can be used in the polymerization of a (meth) acrylic monomer, and an ester is preferred among them. The organic solvent is preferably used at a solid content concentration (a ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) of 0.1% by weight or more, and more preferably a solid The component concentration is used at a ratio of 5 to 50% by weight. The reaction temperature is preferably set to 0 ° C to 200 ° C, and more preferably 50 ° C to 150 ° C. The reaction time is preferably set to 0.1 to 50 hours, and more preferably set to 0.5 to 20 hours.

In this manner, a solution containing poly (meth) acrylate as the polymer (A) can be obtained. The reaction solution can be directly used to prepare a liquid crystal alignment agent, or the poly (meth) acrylate contained in the reaction solution can be separated and used to prepare a liquid crystal alignment agent, or the separated poly (meth) acrylic acid can also be used. The ester was purified and used to prepare liquid crystal alignment agent. Isolation and purification of poly (meth) acrylate can be performed according to a well-known method. The method of synthesizing the poly (meth) acrylate as the polymer (A) is not limited to the method described above. For example, it can also be obtained by making a (meth) acrylic monomer having a partial structure represented by the formula (1), or the (meth) acrylic monomer and other (meth) acrylic acid A method of polymerizing a mixture of monomers in the presence of a polymerization initiator.

From the viewpoint of making the formed liquid crystal alignment film good in liquid crystal alignment and ensuring the stability of the liquid crystal alignment over time, the polystyrene-equivalent number average molecular weight measured by GPC on poly (meth) acrylate (Mn) is preferably 250 to 500,000, more preferably 500 to 100,000, and still more preferably 1,000 to 50,000.

[Polyester] The polyester as the polymer (A) can be obtained, for example, by reacting a dicarboxylic acid having a partial structure represented by the formula (1) with a diepoxy compound. Here, the diepoxy compound is, for example, in addition to ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexane Examples of the diol diglycidyl ether include diepoxy compounds described in Japanese Patent Laid-Open No. 2013-113937. Regarding the ratio of the diepoxy compound and the dicarboxylic acid compound used in the synthesis reaction of the polyester, the epoxy group of the diepoxy compound is preferably 0.2 equivalent to 2 with respect to 1 equivalent of the carboxyl group contained in the dicarboxylic acid compound. The equivalent is more preferably 0.3 to 1.2 equivalents.

The reaction of the dicarboxylic acid and the diepoxy compound is preferably performed in the presence of an organic solvent. Examples of the organic solvent used include: N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N, N-dimethylimidazolidine Aprotic polar solvents such as ketones, dimethyl sulfene, γ-butyrolactone, tetramethylurea, and hexamethylphosphonium triamine; phenol solvents such as m-cresol, xylenol, phenol, and halogenated phenol, etc. . The reaction temperature is preferably 0 ° C to 250 ° C, and more preferably 50 ° C to 180 ° C. The reaction time is preferably 0.5 hours to 24 hours, and more preferably 2 hours to 12 hours.

In this manner, a solution containing a polyester as the polymer (A) can be obtained. The reaction solution may be directly used to prepare a liquid crystal alignment agent, or the polyester contained in the reaction solution may be separated and used to prepare a liquid crystal alignment agent, or the separated polyester may be purified and then used to prepare a liquid crystal alignment agent. Isolation and purification of the polyester can be performed according to a known method.

The polyester obtained as described above preferably has a solution viscosity of 20 mPa · s to 1,800 mPa · s when it is made into a solution having a concentration of 15% by weight, and more preferably 50 mPa · s to 1,500 mPa. · Solution viscosity of s. In addition, the solution viscosity (mPa · s) of the polyester is determined by using an E-type rotational viscometer at 25 ° C for a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) using the polymer. A value obtained by measuring a prepared polymer solution having a concentration of 15% by weight. In addition, from the viewpoint of making the formed liquid crystal alignment film have good liquid crystal alignment and ensuring the stability of the liquid crystal alignment over time, the polystyrene-equivalent number average molecular weight (Mn) measured by GPC on polyester It is preferably 250 to 500,000, more preferably 500 to 100,000, and still more preferably 1,000 to 50,000.

• When the compound (A) is an additive The compound (A) (hereinafter also referred to as "low-molecular compound (A)") as an additive preferably has a molecular weight of 1,000 or less. The low molecular weight compound (A) is more preferably 800 or less, more preferably 700 or less, and particularly preferably 500 or less. In addition, from the viewpoint of suppressing the volatilization of the compound (A) during post-baking, the molecular weight of the low-molecular compound (A) is preferably 100 or more, and more preferably 150 or more. As long as the low-molecular compound (A) has a partial structure represented by the formula (1), the remaining structure is not particularly limited, and it has a high effect of improving the reliability of the liquid crystal display element and suppressing display unevenness around the sealant. In view of this, compounds having a specific heterocyclic structure are preferred. The low-molecular compound (A) may have only one partial structure represented by the formula (1), or may have a plurality of partial structures represented by the formula (1). Preferably one to four.

The low-molecular compound (A) preferably has a partial structure represented by the formula (1), and has a functional group (hereinafter also referred to as a " Specific functional groups "). The so-called "interaction" refers to the formation of covalent bonds between molecules, or the formation of weaker molecular forces (such as ion-dipole interaction, dipole-dipole interaction, hydrogen bonding, Van der Waals). Electromagnetic forces such as forces acting between molecules). By having such a functional group, the effect of suppressing the dissolution of the low-molecular compound (A) from the liquid crystal alignment film is improved, and the effect of introducing the partial structure represented by the formula (1) can be sufficiently obtained. .

The specific functional group can be appropriately selected depending on the functional group of the polymer component. For example, in the case of a liquid crystal alignment agent containing polyfluorene imine or a precursor thereof as a polymer component, the specific functional group is preferably a functional group that interacts with a carboxyl group or a fluorimine group, and specifically, for example, Examples thereof include an epoxy group, an amino group, a carboxyl group, and an alkoxysilyl group. The number of the specific functional groups in the low-molecular compound (A) is preferably one or more, and more preferably one to four.

Specific examples of the low-molecular compound (A) include, for example, compounds represented by the following formulae (A-1) and (A-2), and each of the formulae (A-3) to (A-6) Represented compounds, etc. [Chemical 12] The low-molecular compound (A) may be used alone or in combination of two or more.

The compounding ratio of the compound (A) is preferably appropriately selected depending on whether the compound (A) is a polymer or an additive. For example, the blending ratio of the polymer (A) is preferably set to 5 parts by weight or more, more preferably 10 parts by weight or more, based on 100 parts by weight of the total polymer components contained in the liquid crystal alignment agent. It is preferable to set it as 30 weight part or more. If the ratio is less than 5 parts by weight, unevenness around the sealant is likely to occur, and the reliability of the obtained liquid crystal display element tends to be poor. In addition, the blending ratio of the low-molecular compound (A) is preferably set to 0.05 parts by weight or more, more preferably 0.1 part by weight or more, and even more preferably set to 100 parts by weight of the total polymer component. It is 0.2 parts by weight or more. In addition, the upper limit of the blending ratio of the low-molecular compound (A) is preferably set to 50 parts by weight or less, more preferably set to 30 parts by weight or less, and more preferably 100 parts by weight of the total polymer component. It is set to 20 parts by weight or less. When the content ratio of the low-molecular compound (A) is set to less than 0.05 parts by weight, it is difficult to obtain an effect of reducing unevenness around the sealant or an effect of improving afterimage characteristics. Poor reliability.

In addition, the use of a liquid crystal alignment agent containing the compound (A) having a partial structure represented by the formula (1) can suppress display unevenness around the sealant and improve the reliability of the liquid crystal display element. Yes, but as a hypothesis, the protective group (R ¹ ) in the partial structure represented by the formula (1) may be considered, for example, heating during post-baking, or light irradiation on the liquid crystal alignment film, or acid or alkali Partial structure (secondary amine group) after detachment shows high basicity, thereby showing high reliability and excellent frame unevenness tolerance. In addition, when the cyclic skeleton contains a partial structure represented by the formula (1), it is presumed that one of the reasons is that the steric hindrance is larger than that of the non-cyclic structure, and aggregation is suppressed. As a result, the effect of improving the reliability and the non-uniformity of the frame is further improved.

In addition, when a compound having a secondary or tertiary amine group such as piperidine or piperazine is introduced into a liquid crystal alignment agent, the compound is liable to cause precipitation due to its high polarity. In contrast, it is considered that by protecting the secondary amine group with R ¹ , the solubility of the compound in a solvent is improved, and thus it can be applied to a liquid crystal alignment agent. The liquid crystal alignment film obtained by using the liquid crystal alignment agent containing the compound (A) also has a high voltage retention ratio (initial VHR) at the start of voltage application, and can be preferably used for low-frequency driving liquid crystal displays in recent years, for example. element.

<Other Components> When the liquid crystal alignment agent of the present invention contains the compound (A) as an additive component, it contains a polymer component together with the low-molecular compound (A) as an additive. As the polymer component, a polymer having a partial structure represented by the formula (1), a polymer not having a partial structure represented by the formula (1) (hereinafter referred to as "other polymer"), or A mixture of these polymers.

(Other polymers) The main skeleton of other polymers is not particularly limited, and examples thereof include polyimide precursors, polyimides, polysiloxanes, polyesters, polyimides, cellulose derivatives, Main skeletons such as polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, and poly (meth) acrylate. Among these polymers, it is preferable to be selected from the group consisting of polyimide precursors, polyimide, polyamido, polyorganosiloxane, poly (meth) acrylate, and polyester. At least one, more preferably at least one selected from the group consisting of a polyimide precursor, a polyimide, and a polysiloxane. In addition, other polymers may be used singly or in combination of two or more kinds.

When the liquid crystal alignment agent of the present invention contains the polymer (A), the other polymer may be contained together with the polymer (A) for the purpose of improving electrical characteristics, solution characteristics, and the like. The blending ratio of other polymers in this case is preferably set to 30 parts by weight or less, and more preferably set to 0.1 to 20 parts by weight with respect to 100 parts by weight of the total polymer contained in the liquid crystal alignment agent. Furthermore, it is more preferable to set it as 0.3 weight part-10 weight part.

In addition, the liquid crystal aligning agent of this invention may contain components other than the above as needed. Examples of the component include a compound having at least one epoxy group in the molecule, a compound having at least one oxetanyl group in the molecule, a functional silane compound, a metal chelate compound, a hardening accelerator, a surfactant, and an anti- Oxidants, sensitizers, preservatives, etc. The blending ratio of these components can be appropriately selected depending on various compounds within a range that does not impair the effect of the present invention.

<Solvent> The liquid crystal alignment agent of the present invention is prepared in the form of a liquid composition in which the compound (A) and other components used as necessary are preferably dispersed or dissolved in an appropriate Made in solvent.

Examples of the organic solvent used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamidine, N, N-dimethyl Acetylamine, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate , Ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ether acetate , Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate Esters, diisobutanone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, propylene carbonate, and the like. These organic solvents can be used alone or in combination of two or more.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total weight of components other than the solvent of the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity and volatility, and is preferably 1 The range is from 10% by weight to 10% by weight. That is, the liquid crystal alignment agent is coated on the surface of the substrate as described later, and preferably is heated to form a coating film as a liquid crystal alignment film or a coating film as a liquid crystal alignment film. At this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it is difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large, and it is difficult to obtain a good liquid crystal alignment film. In addition, there are cases where the viscosity of the liquid crystal alignment agent increases and the coating property decreases. tendency.

A particularly preferable range of the solid content concentration varies depending on the application of the liquid crystal alignment agent or the method used when the liquid crystal alignment agent is applied to the substrate. For example, when a liquid crystal alignment agent for a liquid crystal display element is coated on a substrate by a spinner method, it is particularly preferable that the solid content concentration (the total weight of all components except the solvent in the liquid crystal alignment agent is in the liquid crystal alignment). The proportion of the total weight of the agent) is in a range of 1.5% to 4.5% by weight. When the printing method is used, it is particularly preferable to set the solid content concentration to a range of 3% to 9% by weight, and thereby set the solution viscosity to a range of 12 mPa · s to 50 mPa · s. In the case of using the inkjet method, it is particularly preferable to set the solid content concentration to a range of 1% to 5% by weight, and thereby set the solution viscosity to a range of 3 mPa · s to 15 mPa · s. The temperature when preparing the liquid crystal alignment agent is preferably 10 ° C to 50 ° C, and more preferably 20 ° C to 30 ° C. In addition, regarding the liquid crystal alignment agent for a retardation film, from the viewpoint of making the coatability of the liquid crystal alignment agent and the film thickness of the formed coating film appropriate, the solid content concentration of the liquid crystal alignment agent is preferably 0.2% by weight. The range is from% to 10% by weight, and more preferably from 3% to 10% by weight.

<Liquid crystal display element and retardation film> A liquid crystal alignment film can be manufactured by using the liquid crystal alignment agent demonstrated above. In addition, the liquid crystal alignment film formed using the liquid crystal alignment agent can be preferably used for a liquid crystal alignment film for a liquid crystal display element and a liquid crystal alignment film for a retardation film. Hereinafter, a liquid crystal display element and a retardation film will be described.

[Liquid crystal display element] The liquid crystal display element of the present invention includes a liquid crystal alignment film formed using the liquid crystal alignment agent. The working mode of the liquid crystal display element is not particularly limited, and it can be applied to various working modes such as TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, and OCB type.

The liquid crystal display element can be manufactured, for example, by a method including the following steps (1-1) to (1-3). In step (1-1), the substrate to be used differs depending on the required operation mode. Steps (1-2) and (1-3) are common to each working mode.

[Step (1-1): Formation of Coating Film] First, a liquid crystal alignment agent is coated on a substrate, and then the coated surface is heated to form a coating film on the substrate. (1-1A) When manufacturing, for example, a TN, STN, or VA type liquid crystal display element, first, two substrates provided with a patterned transparent conductive film are used as a pair, and each transparent conductive film is The formation surface is preferably coated with a liquid crystal alignment agent by an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method, respectively. As the substrate, for example, a transparent substrate including glass such as float glass, soda glass, polyethylene terephthalate, polybutylene terephthalate, polyether fluorene, polycarbonate, and poly (alicyclic ring) can be used. Olefins) and other plastics. The transparent conductive film provided on one surface of the substrate can be used: a NESA film (registered trademark of PPG, USA) containing tin oxide (SnO ₂ ), and indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) Indium Tin Oxide (ITO) film. In order to obtain a patterned transparent conductive film, for example, the following methods can be used: a method of forming a pattern by photoetching after forming a patternless transparent conductive film; and using a mask having a desired pattern when forming the transparent conductive film Method, etc. When the liquid crystal alignment agent is applied, in order to improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a surface on which the coating film is formed on the substrate surface may be previously coated with a functional silane compound, a functional titanium compound, or the like. Pre-processing.

After the liquid crystal alignment agent is applied, it is preferable to perform pre-heating (pre-baking) for the purpose of preventing dripping of the applied liquid crystal alignment agent and the like. The pre-baking temperature is preferably 30 ° C to 200 ° C, more preferably 40 ° C to 150 ° C, and particularly preferably 40 ° C to 100 ° C. The pre-baking time is preferably 0.25 minutes to 10 minutes, and more preferably 0.5 minutes to 5 minutes. Then, the sintering (post-baking) step is performed for the purpose of completely removing the solvent and, if necessary, thermally imidate the sulfamic acid structure present in the polymer. The calcination temperature (post-baking temperature) at this time is preferably 80 ° C to 300 ° C, and more preferably 120 ° C to 250 ° C. The post-baking time is preferably 5 minutes to 200 minutes, and more preferably 10 minutes to 100 minutes. The film thickness of the film formed in this manner is preferably 0.001 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm.

(1-1B) When manufacturing an IPS-type or FFS-type liquid crystal display element, the electrode formation surface of a substrate provided with an electrode including a transparent conductive film or a metal film patterned in a comb-tooth shape, and A liquid crystal alignment agent is coated on one side of the substrate facing the electrode, and each coated surface is heated to form a coating film. About the material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pre-treatment of the substrate, and a preferred film of the formed coating film The thickness is the same as that of (1-1A). As the metal film, for example, a film containing a metal such as chromium can be used.

In any of the cases (1-1A) and (1-1B), after the liquid crystal alignment agent is coated on the substrate, the organic solvent is removed to form a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. At this time, when at least any one of polyamic acid, polyamic acid ester, and polyimine is blended into a liquid crystal alignment agent, the liquid crystal may be aligned by further heating after forming a coating film. The polyamidic acid, polyamidate, and polyimide blended in the agent are subjected to a dehydration ring-closing reaction to form a further imidized coating film.

[Step (1-2): Alignment Capability Provisioning Process] When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, applying the coating film formed in the step (1-1) is performed. Processing of liquid crystal alignment capability. Thereby, the alignment ability of liquid crystal molecules is given to a coating film, and it becomes a liquid crystal alignment film. Examples of the alignment ability providing treatment include a rubbing treatment in which a coating film is rubbed in a certain direction by a roller wound with a cloth including fibers such as nylon, rayon, and cotton, and the coating film is irradiated with polarized or non-polarized light. Processing, etc. On the other hand, in the case of manufacturing a VA-type liquid crystal display element, the coating film formed in the step (1-1) may be directly used as a liquid crystal alignment film, and an alignment ability imparting treatment may be performed on the coating film.

In the photo-alignment treatment, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as the radiation to be applied to the coating film. When the radiation is polarized, it may be linearly polarized or partially polarized. In addition, when the radiation used is linearly polarized or partially polarized, the irradiation may be performed from a direction perpendicular to the substrate surface, or from an oblique direction, or a combination of these directions may be performed. In the case of irradiating non-polarized light, the direction of irradiation is set to the oblique direction. The light source used may be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, and the like. Ultraviolet rays in a preferable wavelength range can be obtained by a method in which a light source is used in combination with, for example, a filter and a diffraction grating. The radiation dose is preferably 100 J / m ² to 50,000 J / m ² , and more preferably 300 J / m ² to 20,000 J / m ² . In addition, in order to improve the reactivity, light irradiation to the coating film may be performed while the coating film is warmed. The temperature during heating is usually 30 ° C to 250 ° C, preferably 40 ° C to 200 ° C, and more preferably 50 ° C to 150 ° C.

In addition, the liquid crystal alignment film after the rubbing treatment may be further processed to make the liquid crystal alignment film have different liquid crystal alignment capabilities depending on the region: irradiate a part of the liquid crystal alignment film with ultraviolet rays, thereby making a part of the liquid crystal alignment film Treatment of changing the pretilt angle; or after forming a resist film on a part of the surface of the liquid crystal alignment film, performing a rubbing treatment in a direction different from the previous rubbing treatment, and then removing the resist film. In this case, the visual field characteristics of the obtained liquid crystal display element can be improved. A liquid crystal alignment film suitable for a VA type liquid crystal display element can also be suitably used for a polymer sustained alignment (Polymer sustained alignment (PSA) type) liquid crystal display element.

[Step (1-3): Construction of a liquid crystal cell] (1-3A) Prepare two liquid crystal alignment substrates as described above, and arrange liquid crystal between the two substrates facing each other to manufacture a liquid crystal. unit. When manufacturing a liquid crystal cell, the following two methods are mentioned, for example. The first method is a conventionally known method. First, two substrates are arranged to face each other with a gap (cell gap) so that the liquid crystal alignment films face each other. Then, the peripheral portions of the two substrates are bonded using a sealant, and liquid crystal is injected and filled into a cell gap defined by the substrate surface and the sealant, and then the injection hole is sealed to manufacture a liquid crystal cell. The second method is a method called a One Drop Fill (ODF) method. A predetermined position on one of the two substrates on which the liquid crystal alignment film is formed is coated with, for example, a UV-curable sealant, and liquid crystal is dripped at predetermined locations on the liquid crystal alignment film surface. After that, another substrate is bonded so that the liquid crystal alignment film faces each other, and the liquid crystal is pushed away on the entire surface of the substrate. Then, the entire surface of the substrate is irradiated with ultraviolet light to harden the sealant, thereby manufacturing a liquid crystal cell. When using any method, it is desirable to further heat the liquid crystal cell manufactured as described above to obtain the isotropic temperature of the liquid crystal used, and then slowly cool it to room temperature to remove the liquid crystal filling. Mobile alignment.

As the sealant, for example, an epoxy resin containing a hardener and alumina balls as a spacer can be used. Examples of the liquid crystal include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferred. For example, Schiff base liquid crystals, oxyazo liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, and ester liquid crystals can be used. , Terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubic liquid crystal and the like. In addition, these liquid crystals may be added with, for example, the following components: cholesteric liquid crystals such as cholesteryl chloride, cholesterol nonanoate, and cholesteryl carbonate; trade names "C-15", " CB-15 "(manufactured by Merck) and other chiral agents; p-decyloxybenzylidene-amino-2-methylbutyl cinnamate and other ferroelectric liquid crystals.

(1-3B) When manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in (1-3A) except that a photopolymerizable compound is injected or dripped with the liquid crystal. Then, a voltage is applied between the conductive films included in the pair of substrates, and the liquid crystal cell is irradiated with light in this state. The voltage applied here can be set to, for example, 5 V to 50 V DC or AC. In addition, as the light to be irradiated, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used, and ultraviolet rays including light having a wavelength of 300 to 400 nm are preferred. As a light source for irradiating light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. In addition, the ultraviolet rays in the preferable wavelength range can be obtained by a method in which a light source is used in combination with, for example, a filter and a diffraction grating. The light irradiation amount is preferably 1,000 J / m ² to 200,000 J / m ² , and more preferably 1,000 J / m ² to 100,000 J / m ² .

(1-3C) In the case where a coating film is formed on a substrate using a liquid crystal alignment agent containing a compound (polymer or additive) having a photopolymerizable group, a method of manufacturing a liquid crystal display element by going through the following steps may be used: A liquid crystal cell is constructed in the same manner as described in (1-3A), and a voltage is applied between the conductive films included in the pair of substrates, and the liquid crystal cell is irradiated with light in this state. According to this method, the advantage of the PSA mode can be realized with a small amount of light irradiation. The applied voltage can be set to, for example, DC or AC of 0.1 V to 30 V. Regarding the conditions of the light to be irradiated, the description of (1-3B) can be applied.

Then, a polarizing plate is bonded to the outer surface of the liquid crystal cell, thereby obtaining a liquid crystal display element. Examples of the polarizing plate adhered to the outer surface of the liquid crystal cell include a polarizing plate obtained by sandwiching a polarizing film called an “H film” with a cellulose acetate protective film, or a polarizing plate including the H film itself. The "H film" is made by extending the alignment of polyvinyl alcohol and absorbing iodine.

[Phase Difference Film] Next, a method for manufacturing a retardation film using a liquid crystal alignment agent will be described. When manufacturing a retardation film, it is possible to form a uniform liquid crystal alignment film while suppressing generation of dust or static electricity in a step, and to arbitrarily form a liquid crystal alignment direction on a substrate by using an appropriate mask when irradiating radiation. From the viewpoint of different regions, it is preferable to use a photo-alignment method. Specifically, it can be manufactured by going through the following steps (2-1) to (2-3).

[Step (2-1): Formation of Coating Film Using Liquid Crystal Alignment Agent] First, a liquid crystal alignment agent is applied on a substrate to form a coating film. The substrate used here may be appropriately exemplified: it contains triethylfluorene cellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyetherfluorene, polyamine, polyimide, Transparent substrate of synthetic resins such as polymethyl methacrylate and polycarbonate. Among these, TAC is generally used as a protective layer of a polarizing film in a liquid crystal display element. In addition, polymethyl methacrylate can be suitably used as a substrate for a retardation film in terms of low hygroscopicity of a solvent, good optical properties, and low cost. In addition, for a substrate for applying a liquid crystal alignment agent, in order to improve the adhesion between the substrate surface and the coating film, the surface on which the coating film is formed on the substrate surface may be subjected to a previously known pretreatment.

The retardation film is often used in combination with a polarizing film. In this case, in order to exhibit the required optical characteristics, it is necessary to precisely control the angle with respect to the polarizing axis of the polarizing film in a specific direction, and attach the retardation film. Therefore, by forming a liquid crystal alignment film having a liquid crystal alignment ability in a direction of a predetermined angle on a substrate such as a TAC film or polymethyl methacrylate, it is possible to omit and control the retardation film while bonding it. Steps on polarizing film. In addition, this can contribute to improvement in productivity of the liquid crystal display element. In order to form a liquid crystal alignment film having a liquid crystal alignment capability in a direction of a predetermined angle, it is preferable to manufacture the liquid crystal alignment film by a photo alignment method using a liquid crystal alignment agent.

An appropriate coating method can be used for coating the liquid crystal alignment agent on the substrate. For example, a roll coater method, a spinner method, a printing method, an inkjet method, a bar coater method, an extrusion die method, Direct gravure coater method, closed doctor coater method, offset gravure coater method, single-roll anastomosis coater method, reverse-rotation anastomosis coater method using a small-diameter gravure roll, Three reverse roll coater method, four reverse roll coater method, slot die method, air knife coater method, forward roll coater method, blade coater method, A knife coater method, an impregnating coater method, an MB coater method, an MB reverse coater method, and the like. After coating, the coating surface is heated (baking) to form a coating film. The heating temperature at this time is preferably set to 40 ° C to 150 ° C, and more preferably set to 80 ° C to 140 ° C. The heating time is preferably set to 0.1 to 15 minutes, and more preferably set to 1 to 10 minutes. The film thickness of the coating film formed on the substrate is preferably 1 nm to 1,000 nm, and more preferably 5 nm to 500 nm.

[Step (2-2): Light Irradiation Step] Then, the coating film formed on the substrate as described above is irradiated with light, thereby giving the coating film a liquid crystal alignment ability to prepare a liquid crystal alignment film. Regarding the type, wavelength, irradiation direction, and light source of the light to be irradiated, the description of the light alignment process of the step (1-2) can be applied. The light irradiation amount is preferably set to 0.1 mJ / cm ² to 1,000 mJ / cm ² , more preferably 1 mJ / cm ² to 500 mJ / cm ² , and even more preferably ² mJ / cm ² . cm ² to 200 mJ / cm ² .

[Step (2-3): Formation of Liquid Crystal Layer] Then, a polymerizable liquid crystal is applied and cured on the coating film after light irradiation as described above. Thereby, a coating film (liquid crystal layer) containing a polymerizable liquid crystal is formed. The polymerizable liquid crystal used here is a liquid crystal compound or a liquid crystal composition that is polymerized by at least one of heating and light irradiation. Such polymerizable liquid crystals can be conventionally known liquid crystals. Specifically, for example, non-patent document 1 ("UV-curable liquid crystal and its application"), liquid crystal, Vol. 3 No. 1 (1999), pp34 ～ 42) The nematic liquid crystal as described in 42). In addition, it may be a cholesteric liquid crystal, a disc liquid crystal, a torsional nematic liquid crystal of a chiral agent, or the like. The polymerizable liquid crystal may be a mixture of a plurality of liquid crystal compounds. The polymerizable liquid crystal may be a composition further containing a well-known polymerization initiator, a suitable solvent, and the like. When coating the polymerizable liquid crystal as described above on the formed liquid crystal alignment film, for example, a suitable method such as a bar coater method, a roll coater method, a spinner method, a printing method, or an inkjet method can be used. Coating method.

Then, the coating film of the polymerizable liquid crystal formed as described above is subjected to one or more treatments selected from heating and light irradiation, thereby curing the coating film to form a liquid crystal layer. From the viewpoint of obtaining good alignment, it is preferable to perform these processes in an overlapping manner. The heating temperature of the coating film is appropriately selected depending on the type of the polymerizable liquid crystal used. For example, when RMS03-013C manufactured by Merck is used, it is preferable to perform heating at a temperature in a range of 40 ° C to 80 ° C. The heating time is preferably from 0.5 minutes to 5 minutes. As the irradiation light, non-polarized ultraviolet rays having a wavelength in a range of 200 nm to 500 nm can be preferably used. The light irradiation amount is preferably set to 50 mJ / cm ² to 10,000 mJ / cm ² , and more preferably 100 mJ / cm ² to 5,000 mJ / cm ² . The thickness of the formed liquid crystal layer is appropriately set according to the required optical characteristics. For example, in the case of manufacturing a 1/2 wavelength plate of visible light with a wavelength of 540 nm, the thickness of the formed retardation film is selected to have a thickness of 240 nm to 300 nm. For a 1/4 wavelength plate, the phase difference is selected. It has a thickness of 120 nm to 150 nm. The thickness of the liquid crystal layer that can obtain the target retardation varies depending on the optical characteristics of the polymerizable liquid crystal used. For example, in the case of using RMS03-013C manufactured by Merck, the thickness for manufacturing a quarter-wave plate is in a range of 0.6 μm to 1.5 μm.

The retardation film obtained as described above can be preferably used as a retardation film of a liquid crystal display element. The working mode of the liquid crystal display element using the retardation film manufactured by using the liquid crystal alignment agent of the present invention is not limited, and it can be applied to various well-known modes such as TN type, STN type, IPS type, FFS type, and VA type. The retardation film is used by attaching a substrate-side surface of a retardation film to an outer surface of a polarizing plate arranged on a viewing side of a liquid crystal display element. Therefore, it is preferable to set it as the embodiment which made the substrate of a retardation film into TAC or an acrylic base material, and made the substrate of this retardation film also function as a protective film of a polarizing film.

Here, a method for producing a retardation film on an industrial scale is a roll-to-roll method. This method is a method in which the following processes are performed in continuous steps, and the film after these steps is recovered as a rolled body: the film is rolled out from the rolled body of the long substrate film, and A process of forming a liquid crystal alignment film on the exit film; a process of coating and curing a polymerizable liquid crystal on the liquid crystal alignment film; and a process of laminating a protective film as necessary. The retardation film formed using the liquid crystal alignment agent of the present invention has good adhesion to a substrate, and even when the liquid crystal alignment film and the substrate are stored in the form of a roll, the liquid crystal alignment film and the substrate are not easily separated. Therefore, it is possible to suppress a decrease in product yield when the retardation film is produced by the roll-to-roll method, and it is also preferable from the viewpoint of productivity.

The liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable game consoles, word processors, notebook computers, car navigation systems, video cameras, personal digital assistants (PDAs), digital cameras, Various display devices such as mobile phones, smart phones, various monitors, LCD TVs, and information displays. [Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to these examples.

In the following examples, the weight-average molecular weight Mw of the polymer, the fluorene imidization ratio, the epoxy equivalent weight, and the solution viscosity of the polymer solution were measured by the following methods. In addition, the compound represented by Formula X may be simply referred to as "compound X" hereinafter. [Polymer average molecular weight Mw] Mw is a polystyrene conversion value measured by GPC under the following conditions. Column: TSKgelGRCXLII manufactured by Tosoh Co., Ltd. Solvent: Tetrahydrofuran Temperature: 40 ° C Pressure: 68 kgf / cm ² [Polyimide ratio of polymer] Put a solution containing polyimide into pure water After the obtained precipitate was sufficiently dried at room temperature under reduced pressure, the precipitate was dissolved in deuterated dimethylsulfine, and tetramethylsilane was used as a standard substance to measure ¹ H-nuclear magnetic resonance (Nuclear Magnetic Resonance) at room temperature. , NMR). Based on the obtained ¹ H-NMR spectrum, the hydrazone imidization ratio was determined using the following formula (EX-1).醯 Imination ratio (%) = (1-A ¹ / A ² × α) × 100… (EX-1) (In the formula (EX-1), A ¹ is the source that appears near the chemical shift of 10 ppm. The peak area of the NH-based proton, A ² is the peak area derived from other protons, and α is the proportion of the number of other protons in the polymer precursor (polyamic acid) relative to one proton of the NH group) [Epoxy equivalent] The epoxy equivalent is measured by the hydrochloric acid-methyl ethyl ketone method described in Japanese Industrial Standards (JIS) C 2105. [Solution Viscosity of Polymer Solution] The solution viscosity (mPa · s) of the polymer solution was measured at 25 ° C using an E-type viscometer.

<Synthesis of Compound> [Synthesis Example 1-1; Synthesis of Compound (X-1)] A compound (X-1) was synthesized according to the following scheme 1. In addition, "Boc" in the scheme represents a third butoxycarbonyl group (the same applies hereinafter). [Chemical 13]

[Synthesis Example 1-2; Synthesis of Compound (X-2)] Compound (X-2) was synthesized according to the following scheme 2. [Chemical 14]

[Synthesis Example 1-3; Synthesis of Compound (X-3)] Compound (X-3) was synthesized according to the following scheme 3. [Chemical 15]

[Synthesis Example 1-4; Synthesis of Compound (X-4)] A compound (X-4) was synthesized according to the following scheme 4. [Chemical 16]

<Synthesis of Polymer> [Synthesis Example 2-1; Synthesis of Polymer (PA-1)] 10.68 g of tetracarboxylic dianhydride (100 mol parts with respect to the total amount of diamine used for synthesis) 91 mol parts) of pyromellitic dianhydride, and 1.15 g (same as 5 mol parts) of compound (X-4) as diamine, 16.55 g (as 80 mol parts) of bis [2- (4-Aminophenyl) ethyl] hexanedicarboxylic acid and 1.60 g (same as 15 mol parts) of 4,4'-diaminodiphenylamine were dissolved in 85 g of N-methyl-2- In a mixed solvent of pyrrolidone (NMP) and 85 g of γ-butyrolactone (GBL), the reaction was performed at 30 ° C. for 6 hours. Then, the reaction mixture was poured into a large amount of excess methanol to precipitate a reaction product. After the recovered precipitate was washed with methanol, and dried under reduced pressure at 40 ° C. for 15 hours, 27.9 g of a polyamic acid (hereinafter referred to as a polymer (PA-1)) was obtained. The obtained polymer (PA-1) was prepared with a solvent composition of NMP: GBL = 50: 50 so as to be 15% by weight, and the viscosity of the solution was measured. As a result, it was 461 mPa · s. In addition, the polymer solution was left to stand at 20 ° C for 3 days. As a result, the polymer solution did not gel, and storage stability was good.

[Synthesis Example 2-2 to Synthesis Example 2-6] It was obtained in the same manner as in Synthesis Example 2-1 except that the types and amounts of tetracarboxylic dianhydride and diamine used in the reaction were changed as shown in Table 1 below. Polyamic acid (Polymer (PA-2) to Polymer (PA-6)). The polymer solutions obtained in Synthesis Example 2-2 to Synthesis Example 2-6 were left to stand at 20 ° C for 3 days. As a result, they did not gel, and the storage stability was good.

[Table 1]

Regarding the numerical values in Table 1, the tetracarboxylic dianhydride represents the use ratio (mol%) with respect to the total amount of the tetracarboxylic dianhydride used in the reaction, and the diamine represents the total amount with respect to the diamine used in the reaction. Use ratio (mol%). The abbreviations of tetracarboxylic dianhydride and diamine in Table 1 are as follows. (Tetracarboxylic dianhydride) AN-1: 1,2,3,4-cyclobutane tetracarboxylic dianhydride AN-2: pyromellitic dianhydride AN-3: 2,3,5-tricarboxylic ring Amylacetic dianhydride AN-4: 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3 -Diketone AN-5: 5- (2,5-Dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan- 1,3-dione AN-6: Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (diamine) DA-1: described Compound DA-2 represented by Formula (X-1): Compound DA-3 represented by Formula (X-2): Compound DA-4 represented by Formula (X-3): Formula (X-3) X-4) Compound DA-5: bis [2- (4-aminophenyl) ethyl] adipate DA-6: 4,4'-diaminodiphenylamine DA-7: 3,5-Diaminobenzoic acid DA-8: N- (2,4-diaminophenyl) -4- (4-heptylcyclohexyl) benzamide DA-9: 4- (tetrade Alkoxy) benzene-1,3-diamine DA-10: Cholesteryl 3,5-diaminobenzoate DA-11: 4,4'-diaminodiphenylmethane In addition, the polymer (PA-4) is particularly suitable for TN type liquid crystal display elements, and polymer (PA-5) is especially suitable for VA type liquid crystal display (Including the PSA display).

[Synthesis Example 3-1; Synthesis of Polymer (PI-1)] 21.19 g of tetracarboxylic dianhydride (98 mol parts relative to 100 mol parts of the total amount of diamine used for synthesis) Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, and 3.69 g (10 mol parts) of the compound (X -4), 19.94 g (same as 60 moles) of bis [2- (4-aminophenyl) ethyl] adipate, and 5.16 g (same as 30 moles) of 4,4'-diamine Diphenylamine was dissolved in 200 g of NMP and reacted at room temperature for 6 hours. Then, 250 g of NMP was added, 6.70 g of pyridine and 8.65 g of acetic anhydride were added, and a dehydration ring-closure reaction was performed at 100 ° C for 5 hours. Then, the reaction mixture was poured into a large amount of excess methanol to precipitate a reaction product. After the recovered precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours, a polyfluorene imine (polymer (PI-1)) having a fluorinated imidization ratio of about 50% was obtained. The obtained polymer (PI-1) was prepared by NMP so that it might become 15 weight%. When the viscosity of this solution was measured, it was 530 mPa * s. In addition, the obtained polymer solution was left to stand at 20 ° C for 3 days. As a result, it did not gel, and storage stability was good.

[Synthesis Example 4-1; Synthesis of Polymer (p-1)] The polymer (p-1) was obtained by the same method as described in International Publication No. 2013/115228. First, in a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 3.35 g (15.00 mmol) of the compound represented by the following formula (u-1) was weighed out, and 34.8 g of NMP was added to dissolve it. Cool to about 10 ° C under a nitrogen atmosphere. Then, 2.85 g (14.60 mmol) of cyclobutanetetracarboxylic dianhydride was added little by little, and the mixture was returned to room temperature and reacted for 6 hours to obtain a 15% by weight polyamic acid solution. The weight average molecular weight of the obtained polyamic acid (polymer (p-1)) was 23,000. [Chemical 17]

[Synthesis Example 5-1; Synthesis of Polymer (PSi-1)] To a reaction vessel including a stirrer, a thermometer, a dropping funnel, and a reflux condenser, 100.0 g of 2- (3,4-epoxycyclohexyl) was added. ) Ethyltrimethoxysilane, 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine were mixed at room temperature. After 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, the reaction was performed at 80 ° C. for 6 hours while mixing under reflux. After the reaction, the organic layer was taken out and washed with a 0.2% by weight ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to form a thick transparent liquid. A polyorganosiloxane having an oxetanyl group is obtained. When ¹ H-NMR analysis was performed on this polyorganosiloxane having an oxetanyl group, it was confirmed that a peak based on oxetanyl group such as the theoretical intensity was obtained at a chemical shift (δ) = 3.2 ppm. It was confirmed that No side reactions of oxepropyl group occurred in the reaction. The epoxy equivalent of this polyorganosiloxane having an oxetanyl group was measured and found to be 186 g / equivalent. Then, in a 100 mL three-necked flask, 9.3 g of the obtained polyorganosiloxane having oxetanyl group, 26 g of methyl isobutyl ketone, and 3 g of 4-phenoxycinnamic acid were added. And 0.10 g of UCAT 18X (trade name, manufactured by San-Apro), and reacted at 80 ° C. with stirring for 12 hours. After the reaction was completed, the reaction mixture was poured into methanol, and the resulting precipitate was recovered, dissolved in ethyl acetate to make a solution, and the solution was washed three times with water, and then the solvent was distilled off to give a white color. As a powder, 6.3 g of polyorganosiloxane (PSi-1) having an oxepropyl group and a cinnamic acid structure were obtained. The polystyrene-equivalent weight average molecular weight Mw obtained by measuring this polyorganosiloxane (PSi-1) by GPC was 3,500.

<Preparation and Evaluation of Liquid Crystal Alignment Agent> [Example 1: Friction Alignment FFS Liquid Crystal Display Element] (1) Preparation of Liquid Crystal Alignment Agent The polymer (PA-1) obtained in Synthesis Example 2-1 as a polymer Dissolved in a mixed solvent containing γ-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP), and butyl cellosolve (BC) (GBL: NMP: BC = 40: 40: 20 (weight ratio)) A solution having a solid content concentration of 4.5% by weight was prepared. This solution was filtered with a filter having a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (R-1).

(2) Evaluation of applicability The prepared liquid crystal alignment agent (R-1) was coated on a glass substrate using a spinner, pre-baked with a heating plate at 80 ° C for one minute, and then replaced with nitrogen in the library. Heating (post-baking) was performed in an oven at 200 ° C. for 1 hour, thereby forming a coating film having an average film thickness of 0.1 μm. This coating film was observed with a microscope with a magnification of 100 times and 10 times, and the unevenness of the film thickness and the presence or absence of pinholes were investigated. Regarding the evaluation, the case where both uneven film thickness and pinholes were not observed even when observed with a 100-times microscope was regarded as "good" coating property, and uneven film thickness and needles were observed under a 100-times microscope. The case where at least any one of the holes is not observed with a film thickness unevenness and both pinholes under a 10-times microscope is considered to be “could”, and the film thickness unevenness is clearly observed with a 10-times microscope. The case of at least one of the pinholes was evaluated as "poor" in coating properties. In this example, both the film thickness unevenness and the pinhole were not observed even under a microscope 100 times, and the coating property was "good". (3) Evaluation of friction resistance The obtained coating film was subjected to 7 times using a friction machine having a roll around which a cotton cloth was wound at a roll speed of 1000 rpm, a table moving speed of 20 cm / sec, and a gross press-in length of 0.4 mm. Friction treatment. Observe the foreign matter (fragments of the coating film) on the obtained substrate by rubbing with an optical microscope, and measure the number of foreign matter in a region of 500 μm × 500 μm. Regarding the evaluation, the case where the number of foreign objects is 3 or less is regarded as "good" for friction resistance, the case where 4 or more and 7 or less is regarded as "good" for friction resistance, and the case where 8 or more is regarded as friction resistance "Bad" for evaluation. As a result, the friction resistance of the coating film was "good"

(4) Manufacturing of FFS-type liquid crystal display element by rubbing treatment The FFS-type liquid crystal display element 10 shown in Fig. 1 was manufactured. First, a glass substrate 11a having an electrode pair on one side and a bottom electrode 15 without a pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order, and As a pair, the opposite glass substrate 11b without electrodes is applied to the surface of the glass substrate 11a having a transparent electrode and the surface of the opposite glass substrate 11b, and the liquid crystal alignment agent (R) prepared in (1) is applied using a spinner, respectively. -1) to form a coating film. Then, the coating film was pre-baked for 1 minute using a heating plate at 80 ° C., and then heated (post-baking) at 230 ° C. for 15 minutes in an oven replaced with nitrogen at a temperature of 230 ° C. to form a coating film having an average film thickness of 0.1 μm. . A schematic plan view of the top electrode 13 used here is shown in FIG. 2. 2 (a) is a plan view of the top electrode 13, and FIG. 2 (b) is an enlarged view of a portion C1 surrounded by a dotted line in FIG. 2 (a). In this embodiment, the line width d1 of the electrodes is set to 4 μm, and the distance d2 between the electrodes is set to 6 μm. The top electrode 13 is a four-system drive electrode using an electrode A, an electrode B, an electrode C, and an electrode D. The structure of the driving electrode used is shown in FIG. The bottom electrode 15 functions as a common electrode acting on all of the four-system driving electrodes, and the regions of the four-system driving electrodes become pixel regions, respectively.

Then, each surface of the coating film formed on the glass substrate 11 a and the glass substrate 11 b was subjected to a rubbing treatment with cotton to prepare a liquid crystal alignment film 12. In FIG. 2 (b), the rubbing direction with respect to the coating film formed on the glass substrate 11 a is indicated by arrows. Then, a pair of substrates was coated with a trade name "XN-21-S" (manufactured by Mitsui Chemicals) as a sealant on the outer edge of the surface of the substrate having the liquid crystal alignment film on one of the substrates. The rubbing directions of the substrates 11b are antiparallel to each other, and the spacers are bonded via a spacer having a diameter of 3.5 μm to harden the sealant. Then, a liquid crystal MLC-6221 (manufactured by Merck) is injected between the pair of substrates from the liquid crystal injection port to form a liquid crystal layer 16. Furthermore, a polarizing plate (not shown) is bonded to both outer surfaces of the substrate 11 a and the substrate 11 b so that the polarization directions of the two polarizing plates are orthogonal to each other, thereby producing a liquid crystal display element 10.

(5) Evaluation of liquid crystal alignment For the FFS liquid crystal display device manufactured as described above, the presence or absence of abnormal regions of change in light and dark when a voltage of 5 V was applied / released (ON / OFF) was observed with a microscope at a magnification of 50 times. . Regarding the evaluation, the case where the abnormal region was not observed was regarded as the liquid crystal alignment "good", and the case where the abnormal region was observed was regarded as the liquid crystal alignment "poor". The liquid crystal alignment of this liquid crystal display element was "good". (6) Evaluation of voltage holding ratio For the manufactured FFS liquid crystal display device, a voltage of 5 V was applied at 23 ° C for an application time of 60 microseconds and a span of 167 milliseconds, and then measured 1,000 milliseconds after the release was applied. After the voltage retention rate (VHR), the result was 95.4%. The measurement device used was VHR-1 manufactured by TOYO Technica.

(7) Evaluation of afterimage characteristics (DC afterimage evaluation) The manufactured liquid crystal display element was placed in an environment of 25 ° C. and one atmospheric pressure. The bottom electrode is used as a common electrode for all four-system drive electrodes, and the potential of the bottom electrode is set to 0 V potential (ground potential). The electrodes B and D were short-circuited with a common electrode to set a 0 V application state, and a combined voltage including an AC voltage of 3.5 V and a DC voltage of 1 V was applied to the electrodes A and C for 2 hours. Immediately after 2 hours, a voltage of AC 1.5 V was applied to all of the electrodes A to D. Then, from the moment when the AC voltage of 1.5 V was applied to all the driving electrodes, until the driving stress application area (the pixel area of the electrode A and the electrode C) and the driving stress non-application area (the electrode area of the electrode B and the electrode D) were not visually confirmed. Pixel area) as the afterimage erasure time. In addition, the shorter this time, the less likely an afterimage is to occur. The case where the afterimage erasing time is less than 30 seconds is regarded as "good", the case where 30 seconds or more is less than 120 seconds is regarded as "good", and the case where 120 seconds or more is regarded as "bad" to evaluate. As a result, this implementation The afterimage erasing time of the liquid crystal display element of the example was 2 seconds, and the afterimage characteristics were evaluated as "good". (8) Light resistance In the same manner as in (6), the voltage holding ratio of the manufactured FFS-type liquid crystal display element was measured, and this value was used as the initial VHR (VHR _BF ). Then, the liquid crystal display element after the initial VHR measurement was left in an 80 ° C. oven under a light emitting diode (LED) lamp for 500 hours, and then left at room temperature to naturally cool to room temperature. The liquid crystal cell after light irradiation was again measured for the voltage holding ratio by the same method as described above. This value was taken as the voltage retention rate (VHR _AFBL ) after light irradiation. The reduction amount ΔVHR _BL (%) of the voltage holding ratio was calculated from the following formula (EX-2) and evaluated as light resistance. ΔVHR _BL = ((VHR _BF -VHR _AFBL ) ÷ VHR _BF ) × 100… (EX-2) When ΔVHR is less than 3%, the light resistance is judged to be “good”, and 3% to less than 5% The case is judged as "OK", and the case of 5% or more is judged as "Defective". As a result, the ΔVHR _BL of the liquid crystal display element of this example was 1.2%, and the light resistance was "good".

(9) Unevenness resistance around the sealant (unevenness resistance of the frame) The FFS liquid crystal display element manufactured as described above was stored at 25 ° C and 50% RH for 30 days, and then driven at an AC voltage of 5 V and driven. Observe the lighting status. Regarding the evaluation, if the brightness difference (black fine lines or white fine lines) is not seen around the sealant, it is considered "good", and if the brightness difference is seen but the brightness difference disappears within 20 minutes after lighting, it is considered "may" , The case where the brightness difference was seen even after 20 minutes was regarded as "bad". As a result, the brightness difference of this liquid crystal display element was not recognized, and it was judged as "good."

[Example 2 to Example 7, Comparative Example 1, Comparative Example 2 and Reference Example] In Example 1, the solid content (polymer and additives contained in the liquid crystal alignment agent) was changed as shown in Table 2 below. A liquid crystal alignment agent was prepared in the same manner as in Example 1 except for the type and amount of), and an FFS-type liquid crystal display element was produced by a rubbing method and various evaluations were performed. The evaluation results are shown in Table 2 below. In addition, in Examples 5 to 7 and Comparative Example 2, additives were blended in the liquid crystal alignment agent. In Table 2, the numerical value of an additive shows the compounding ratio (weight part) with respect to 100 weight part of additives of a polymer component. In addition, the reference example was precipitated when 5 parts by weight of piperidine was added with respect to 100 parts by weight of the polymer component, so no subsequent study was performed.

[Table 2]

In Table 2, the abbreviations of the additives are as follows. A-1: the compound represented by the formula (A-1) A-2: the compound represented by the formula (A-2) a-1: piperidine

As shown in Table 2, in Examples 1 to 7, the coating property and friction resistance of the liquid crystal alignment agent, and the liquid crystal alignment property, voltage holding ratio (initial VHR), afterimage characteristics, and light resistance of the liquid crystal display element. And the frame unevenness tolerance is a result of "good" or "may", and a balance of various characteristics has been achieved. From these facts, it was found that the liquid crystal alignment agent containing the compound (A) having a specific heterocyclic structure can obtain a liquid crystal display element having both high reliability and resistance to frame unevenness. In addition, the obtained liquid crystal display element also had high evaluation of DC afterimage characteristics (burning characteristics called "DC afterimage" caused by residual charge accumulated by application of a DC voltage). In contrast, Comparative Example 1 and Comparative Example 2 were inferior to the examples in a number of evaluation items of liquid crystal alignment, voltage retention, afterimage characteristics, light resistance, and frame unevenness resistance.

[Example 8: Photo-alignment FFS-type liquid crystal display element] (1) Preparation of liquid crystal alignment agent The polymer (PA-2) obtained in Synthesis Example 2-2 as a polymer was dissolved in γ-butyrolactone ( GBL), a mixed solvent of N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) (GBL: NMP: BC = 40: 40: 20 (weight ratio)), the solid content concentration is made 4.5 % By weight solution. This solution was filtered through a filter having a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (R-8).

(2) Evaluation of applicability The prepared liquid crystal alignment agent (R-8) was coated on a glass substrate using a spinner, and pre-baked with a heating plate at 80 ° C for one minute. Heating (post-baking) was performed in an oven at 200 ° C. for 1 hour, thereby forming a coating film having an average film thickness of 0.1 μm. When the applicability was evaluated in the same manner as in (2) of Example 1, the applicability of the coating film was "good". (3) Evaluation of alignment property Using the Hg-Xe lamp and glan-taylor prism on the obtained coating film, 300 J / m ² of bright line with 313 nm was irradiated from the direction of the substrate normal. The ultraviolet rays are polarized to perform alignment processing. This glass substrate with an alignment film was measured for refractive index anisotropy α (nm) using a liquid crystal alignment film inspection device (LayScan) manufactured by MORITEX. Regarding the evaluation, a case of 0.020 nm or more was regarded as "good", a case of less than 0.020 nm and 0.010 nm or more was regarded as "good", and a case of less than 0.010 nm was regarded as "bad". As a result, the substrate was α = 0.035 nm, and the alignment was “good”.

(4) Manufacturing of FFS-type liquid crystal display element using photo-alignment method First, each surface of a pair of glass substrate 11a and glass substrate 11b similar to (4) of the first embodiment is coated with a spinner. The liquid crystal alignment agent (R-8) prepared in (1) is applied to form a coating film. Then, the coating film was pre-baked for 1 minute using a heating plate at 80 ° C., and then heated (post-baking) at 230 ° C. for 15 minutes in an oven replaced with nitrogen at a temperature of 230 ° C. to form a coating film having an average film thickness of 0.1 μm. . A schematic plan view of the top electrode 13 used here is shown in FIG. 4. 4 (a) is a plan view of the top electrode 13, and FIG. 4 (b) is an enlarged view of a portion C1 surrounded by a dotted line in FIG. 4 (a). In this embodiment, a substrate having a top electrode with a line width d1 of the electrodes of 4 μm and a distance d2 between the electrodes of 6 μm is used. In addition, the top electrode 13 is a four-system drive electrode using an electrode A, an electrode B, an electrode C, and an electrode D as in the first embodiment (see FIG. 3). Then, each surface of these coating films was irradiated with 300 J / m ² polarized ultraviolet light including a bright line of 313 nm from the direction of the substrate normal using an Hg-Xe lamp and a Glan-Taylor prism to obtain a pair of liquid crystal alignment films. Substrate. At this time, the irradiation direction of the polarized ultraviolet rays is set to irradiate from the substrate normal direction, and the polarized surface direction is set so that the direction of the line segment projecting the polarized surface of the polarized ultraviolet rays on the substrate becomes the direction of the two-headed arrow in FIG. Light irradiation treatment is performed.

Then, on the outer periphery of the surface of the substrate having the liquid crystal alignment film of one of the substrates, an epoxy resin adhesive containing alumina balls having a diameter of 5.5 μm was applied by screen printing, and then The liquid crystal alignment film faces face to face, and the directions of projecting the polarized surface of the polarized ultraviolet rays on the substrate are parallel and overlapped and crimped, and the adhesive is thermally hardened at 150 ° C. for 1 hour. Then, the liquid crystal injection port was filled with a liquid crystal "MLC-6221" manufactured by Merck, and then the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, it was heated to 150 ° C. and then slowly cooled to room temperature. Then, polarizing plates are bonded to both outer surfaces of the substrate, thereby manufacturing an FFS-type liquid crystal display element. At this time, one of the polarizing plates is attached so that its polarization direction is parallel to the projection direction of the polarized ultraviolet rays of the liquid crystal alignment film facing the substrate surface, and the other is such that its polarization direction is the same as that of the previous polarizing plate. Attach in an orthogonal manner.

(5) Evaluation of liquid crystal alignment As in (5) of Example 1, evaluation of liquid crystal alignment was performed on the manufactured photo-alignment FFS-type liquid crystal display element. As a result, the liquid crystal alignment of this liquid crystal display element was "good". (6) Evaluation of voltage holding ratio The voltage holding ratio (VHR) was measured on the manufactured photo-alignment type FFS liquid crystal display element in the same manner as in (6) of Example 1 above, and the voltage holding ratio was evaluated. As a result, the VHR was 97.5%. (7) Evaluation of afterimage characteristics (DC afterimage evaluation) In the same manner as in (7) of Example 1, the afterimage characteristics of the manufactured photo-alignment type FFS liquid crystal display element were evaluated. As a result, the afterimage erasing time was 1 second, and the afterimage characteristics were evaluated as “good”. (8) Light resistance The voltage retention (VHR _BF and VHR _AFBL ) was measured in the same manner as in (8) of Example 1, and the light resistance of the liquid crystal display element was evaluated based on changes in the voltage retention before and after the application of light stress. As a result, ΔVHR _BL was 0.6%, and it was determined that the light resistance was “good”. (9) Unevenness resistance around the sealant (unevenness resistance of the frame) In the same manner as in (9) of Example 1, the unevenness resistance of the frame was evaluated. As a result, no difference in the brightness of the liquid crystal display element was observed, and it was determined that the frame unevenness tolerance was “good”.

[Example 9: retardation film] (1) Preparation of liquid crystal alignment agent 100 parts by weight of the polymer (PSi-1) obtained in Synthesis Example 5-1 and 10 parts by weight of the compound (A-1) were dissolved. In a mixed solvent (PGMEA: MEK: BTLAC = 30: 30: 40 (weight ratio)) containing propylene glycol monomethyl ether acetate (PGMEA), 2-butanone (MEK), and butyl acetate (BTLAC), A solid content concentration of 4.5% by weight was obtained. This solution was filtered through a filter having a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (R-9).

(2) Production of retardation film On one side of the TAC film as a substrate, the prepared liquid crystal alignment agent (R-9) was coated with a bar coater, and baked in an oven at 120 ° C for 2 minutes. A coating film with a thickness of 100 nm was formed. Then, the coating film surface was irradiated with polarized ultraviolet rays of 10 mJ / cm ² including a bright line of 313 nm from a substrate normal line using a Hg-Xe lamp and a Glan-Taylor prism. Then, the polymerizable liquid crystal (RMS03-013C, manufactured by Merck) was filtered with a filter having a pore size of 0.2 μm, and the polymerizable liquid crystal was coated on a coating film after light irradiation by a bar coater to A coating film of a polymerizable liquid crystal is formed. After baking in an oven whose temperature was adjusted to 50 ° C for 1 minute, the coating film surface was irradiated with a non-polarized ultraviolet light of 1,000 mJ / cm ² including a bright line of 365 nm from a vertical direction using a Hg-Xe lamp to polymerize The liquid crystal is hardened to form a liquid crystal layer, thereby producing a retardation film.

(3) Evaluation of liquid crystal alignment The presence or absence of an abnormal region was observed in the retardation film manufactured in the above (2) by visual inspection under a crossed nicol and a polarizing microscope (magnification of 2.5 times). The liquid crystal alignment was evaluated. Regarding the evaluation, a case where the alignment is good when visually inspected and an abnormal region is not observed by a polarizing microscope is regarded as "good", and a case where no abnormal region is visually observed but an abnormal region is observed by a polarizing microscope is regarded as liquid crystal alignment The property was "OK", and the observation of the abnormal region by visual inspection and a polarizing microscope was evaluated as "poor" liquid crystal alignment. As a result, this retardation film was evaluated as "good" in liquid crystal alignment.

(4) Adhesion The adhesion between the coating film formed of the liquid crystal alignment agent and the substrate was evaluated using the retardation film produced in the above (2). First, using a spacer with a guide, use a cutter knife to make cuts from the surface on the liquid crystal layer side of the retardation film, and form a 10 in a range of 1 cm × 1 cm. X 10 grid patterns. The depth of each cut is set from the liquid crystal layer surface to the middle of the substrate thickness. Then, a cellophane tape is adhered so as to cover the entire surface of the lattice pattern, and then the transparent tape is peeled. The cut portion of the grid pattern after peeling was observed by visual inspection under orthogonal Nicols, and the adhesion was evaluated. Regarding the evaluation, the case where peeling was not confirmed at the part along the cut line and the intersection of the grid pattern was regarded as "good" adhesion, and the number of the grids where peeling was observed in the part was compared with the overall grid pattern. When the number is less than 15%, the adhesiveness is considered “acceptable”, and when the number of peeled lattices observed in the part is 15% or more with respect to the total number of the lattice pattern, the adhesiveness is considered as adhesiveness "Bad" for evaluation. As a result, the retardation film was "good" in adhesion.

10‧‧‧ Liquid crystal display element

11a, 11b‧‧‧ glass substrate

12‧‧‧LCD alignment film

13‧‧‧Top electrode

14‧‧‧ Insulation

15‧‧‧ bottom electrode

16‧‧‧LCD layer

A, B, C, D‧‧‧ electrodes

Part C1‧‧‧

d1‧‧‧line width

d2‧‧‧distance

FIG. 1 is a schematic configuration diagram of an FFS-type liquid crystal display element. FIG. 2 is a schematic plan view of a top electrode for manufacturing a frictionally aligned liquid crystal display element. FIG. 2 (a) is a top view of the top electrode, and FIG. 2 (b) is a partial enlarged view of the top electrode. FIG. 3 is a diagram showing four-system drive electrodes. FIG. 4 is a schematic plan view of a top electrode for manufacturing a photo-alignment type liquid crystal display element. FIG. 4 (a) is a top view of the top electrode, and FIG. 4 (b) is a partial enlarged view of the top electrode.

Claims (11)

A liquid crystal alignment agent, which contains a compound (A) selected from the group consisting of polyimide precursors, polyimide, polysiloxane, poly (meth) acrylate and polyester At least one polymer in the group of, and the compound (A) has the ring skeleton of the piperidine ring, piperazine ring, pyrrolidine ring or hexamethyleneimine ring containing the formula (1) Represents a partial structure of a nitrogen-containing heterocyclic structure,

In formula (1), R ¹ is a protective group of an amine group; two "* 1" s represent a bonding bond bonded to a hydrocarbon group. The liquid crystal alignment agent according to item 1 of the patent application scope, which contains a specific polymer as the compound (A), wherein the specific polymer is selected from the group consisting of a polyimide precursor and a polyimide At least one of the groups, and the specific polymer is a polymer obtained by using a diamine having the nitrogen-containing heterocyclic structure in the reaction. According to the liquid crystal alignment agent described in Item 2 of the patent application range, the specific polymer is a polymer obtained by using at least one compound selected from the group consisting of the following compounds in the reaction: bicyclic [2.2.1] Heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxyl Cyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-di Ketone, 5- (2,5-dioxytetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-di Ketone, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, cyclohexane tetracarboxylic dianhydride and pyromellitic dianhydride. A liquid crystal alignment film is formed using the liquid crystal alignment agent as described in any one of claims 1 to 3 in the patent application. A liquid crystal alignment film formed by applying a liquid crystal alignment agent as described in any one of patent application items 1 to 3 to a substrate, and irradiating the coating film with light And get. A liquid crystal alignment film obtained by applying the liquid crystal alignment agent as described in any one of patent application items 1 to 3 to a substrate, and then performing a rubbing treatment. A liquid crystal display device provided with the liquid crystal alignment film according to any one of claims 4 to 6. A retardation film comprising the liquid crystal alignment film as described in item 5 of the patent application. A method for manufacturing a phase difference film, comprising the steps of: applying a liquid crystal alignment agent as described in any one of the patent application items 1 to 3 to a substrate to form a coating film; Performing light irradiation; and coating and curing the polymerizable liquid crystal on the coating film after the light irradiation. A polymer which is at least one polymer selected from the group consisting of polyimide precursors and polyimide, and which is to have a piperidine ring, piperazine ring, pyrrolidine ring or hexa The diamine containing a nitrogen-containing heterocyclic structure having a partial structure represented by the following formula (1) in the ring skeleton of the methyleneimine ring is used in the reaction,

In formula (1), R ¹ is a protective group of an amine group; two "* 1" s represent a bonding bond bonded to a hydrocarbon group. A diamine having a nitrogen-containing heterocyclic structure containing a partial structure represented by the following formula (1) in the ring skeleton of a piperidine ring, piperazine ring, pyrrolidine ring or hexamethyleneimine ring,

In formula (1), R ¹ is a protective group of an amine group; two "* 1" s represent a bonding bond bonded to a hydrocarbon group.