JP6682795B2 - Method for producing liquid crystal alignment film, method for producing liquid crystal element, and polymer composition for photoalignment - Google Patents

Description

  The present invention relates to a method for producing a liquid crystal alignment film, a method for producing a liquid crystal element, and a polymer composition for photo-alignment.

  2. Description of the Related Art Conventionally, as liquid crystal elements, various driving methods having different electrode structures and physical properties of liquid crystal molecules to be used have been developed. For example, TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, VA ( Various liquid crystal elements such as vertical alignment (IPS) type, IPS (In-Plane Switching) type, FFS (fringe field switching) type, and optical compensation vent type (OCB type) are known. These liquid crystal elements have a liquid crystal alignment film for aligning liquid crystal molecules. As a material for the liquid crystal alignment film, polyamic acid, polyimide or the like is generally used because it has various properties such as heat resistance, mechanical strength, and affinity with liquid crystal.

  The liquid crystal aligning agent is usually prepared as a liquid composition in which a polymer component is dissolved in a solvent, and a liquid crystal aligning film is formed by applying the liquid composition onto a substrate and heating. Here, as a solvent for the liquid crystal aligning agent, an aprotic polar solvent such as N-methyl-2-pyrrolidone or γ-butyrolactone is generally used in order to uniformly dissolve the polymer. Further, as the solvent, for the purpose of improving the coating property (printability) of the liquid crystal aligning agent when the liquid crystal aligning agent is applied to the substrate, a surface tension such as butyl cellosolve is used together with the aprotic polar solvent. In some cases, an organic solvent having a relatively low value is used together (see, for example, Patent Document 1 and Patent Document 2). In recent years, N-ethyl-2-pyrrolidone, N-pentyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc. are used as a solvent instead of N-methyl-2-pyrrolidone or γ-butyrolactone. It has been attempted (see, for example, Patent Document 3).

  A photo-alignment method has been proposed as an alternative to the rubbing method as a method for imparting a liquid crystal alignment ability to a polymer thin film formed by a liquid crystal aligning agent. This photo-alignment method is a method of controlling the alignment of liquid crystal molecules by giving anisotropy to a radiation-sensitive organic thin film formed on a substrate by irradiating the film with polarized or unpolarized radiation. is there. According to this method, as compared with the conventional rubbing method, it is possible to suppress the generation of dust and static electricity in the process, and thus it is possible to suppress the occurrence of display defects and the reduction in yield due to dust and the like. Is. Further, there is an advantage that the liquid crystal alignment ability can be uniformly given to the organic thin film formed on the substrate.

  Various liquid crystal aligning agents to which the photo-alignment method can be applied have been conventionally proposed (see, for example, Patent Document 4). In Patent Document 4, a polyimide film is formed using a polymer solution containing a polyimide precursor obtained by the reaction of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and a diamine, and the polyimide film surface It is disclosed that liquid crystal aligning ability is imparted to the film by irradiating the film with ultraviolet rays.

JP, 2010-97188, A JP, 2010-156934, A JP, 2014-63133, A Japanese Patent No. 3893659

  As one of the important display characteristics when the liquid crystal element is used as a display device, it is required that image sticking is small. For example, a horizontal alignment type liquid crystal display device such as an IPS system or an FFS system has a wide viewing angle characteristic and a good contrast characteristic, but on the other hand, an afterimage (image sticking) due to the accumulation of residual charges may be a problem. In recent years, the demand for higher performance of liquid crystal display devices has further increased, and liquid crystal displays exhibiting good coatability (printability) as good as or more than conventionally used solvents while having good afterimage characteristics. A technique capable of obtaining an element is desired.

  The present invention has been made in view of the above problems, and when applying a photo-alignment method, the printability when applying the polymer composition to the substrate is good, and a liquid crystal element having excellent afterimage characteristics is obtained. It is an object to provide a method for producing a liquid crystal alignment film that can be used.

  The present inventor, as a result of intensive studies to achieve the above-mentioned problems of the prior art, when producing a liquid crystal alignment film using a photo-alignment method, a specific compound as a solvent component to be contained in the polymer composition It has been found that the above problems can be solved by using, and the present invention has been completed. Specifically, the present invention provides the following method for producing a liquid crystal alignment film, a method for producing a liquid crystal element, and a polymer composition for photo-alignment.

[1] A step of applying a polymer composition containing the following components (A) and (B) onto a substrate to form a coating film, and irradiating the surface of the substrate coated with the polymer composition with light. A method for producing a liquid crystal alignment film, which comprises:
Component (A): A polymer having at least one selected from the group consisting of a partial structure represented by the following formula (1-1) and a partial structure represented by the following formula (1-2).
Component (B): A compound represented by the following formula (3).

（式（１−１）及び式（１−２）中、Ｒ^１は、それぞれ独立に水素原子又は１価の有機基であり、Ｒ^２〜Ｒ^５は、それぞれ独立に水素原子、ハロゲン原子又は１価の有機基である。Ｘ^１は２価の有機基である。）

（式（３）中、Ｒ^１０は、炭素数２〜５の１価の炭化水素基、又は当該炭化水素基における炭素−炭素結合間に「−Ｏ−」を有する１価の基である。）

(In formula (1-1) and formula (1-2), R ¹ is each independently a hydrogen atom or a monovalent organic group, and R ^{2 to} R ⁵ are each independently a hydrogen atom, a halogen atom or It is a monovalent organic group. X ¹ is a divalent organic group.)

(In the formula (3), R ¹⁰ is a monovalent hydrocarbon group having 2 to 5 carbon atoms, or a monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group. )

[2] A step of forming a liquid crystal alignment film on a pair of substrates by the manufacturing method according to the above [1], and a pair of substrates having the liquid crystal alignment film are arranged so that the liquid crystal alignment films face each other via a liquid crystal layer. And a step of constructing a liquid crystal cell by arranging the liquid crystal cell in the liquid crystal display panel.
[3] A polymer composition for photo-alignment containing the component (A) and the component (B).

  The polymer composition used in the method for producing a liquid crystal alignment film has good printability, and when a photo-alignment method is applied, a liquid crystal device having excellent afterimage characteristics can be obtained.

  The liquid crystal alignment film according to the present invention comprises a step of forming a coating film by applying a polymer composition containing the following components (A) and (B) onto a substrate (film forming step), It is manufactured by a method including a step of irradiating the surface of the substrate coated with the combined composition with light (light irradiation step). The details will be described below.

（式（１−１）及び式（１−２）中、Ｒ^１は、それぞれ独立に水素原子又は１価の有機基であり、Ｒ^２〜Ｒ^５は、それぞれ独立に水素原子、ハロゲン原子又は１価の有機基である。Ｘ^１は２価の有機基である。） <Polymer composition>
[(A) component]
The component (A) contained in the polymer composition according to the present invention is selected from the group consisting of a partial structure represented by the following formula (1-1) and a partial structure represented by the following formula (1-2). It is a polymer having at least one kind (hereinafter also referred to as “polymer (A)”).

(In formula (1-1) and formula (1-2), R ¹ is each independently a hydrogen atom or a monovalent organic group, and R ^{2 to} R ⁵ are each independently a hydrogen atom, a halogen atom or It is a monovalent organic group. X ¹ is a divalent organic group.)

In the above formulas (1-1) and (1-2), as the monovalent organic group for R ¹ , for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent group having a fluorine atom, -Si ^(R _{6) 3} (where a plurality of ^{R 6} are each independently an alkyl group or an alkoxy group.), and the like.
Here, in the present specification, the “hydrocarbon group” is meant to include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The “chain hydrocarbon group” means a straight chain hydrocarbon group or a branched chain hydrocarbon group which does not include a cyclic structure in the main chain and is composed of only a chain structure. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it does not need to be composed only of an alicyclic hydrocarbon structure, and may include a part of which has a chain structure. The “aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, the structure need not be composed of only the aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

Examples of the monovalent hydrocarbon group for R ¹ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group and a dodecyl group. Chain hydrocarbon group such as vinyl group, acyl group, ethynyl group, propynyl group; alicyclic hydrocarbon group such as cyclohexyl group, methylcyclohexyl group; aromatic hydrocarbon group such as phenyl group, methylphenyl group, benzyl group , Etc. can be mentioned. From the viewpoint of liquid crystal alignment, the monovalent hydrocarbon group of R ¹ is preferably an alkyl group, more preferably an alkyl group having 1 to 12 carbon atoms, and an alkyl group having 1 to 4 carbon atoms. It is more preferable that the group is a methyl group or an ethyl group.
Examples of the monovalent group having a fluorine atom for R ¹ include a fluorinated alkyl group, a fluorinated alkoxy group, and a fluorinated ester group. These monovalent groups preferably have 1 to 12 carbon atoms, and more preferably 1 to 4 carbon atoms. ^{R 6} in the group "-Si ^(R _{6) 3"} is preferably 1 or 2 carbon 1 to 4 carbon atoms, more preferably carbon. The two R ^{1 s} in formula (1-1) may be the same or different.

Examples of the monovalent organic group of R ^{2 to} R ⁵ include, for example, an alkyl group, an alkoxy group, a fluorinated alkyl group, a fluorinated alkoxy group, a fluorinated alkyl ester group, and —Si (R ⁶ ) ₃ (provided that plural R groups ⁶ is each independently an alkyl group or an alkoxy group.) And the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Note that R ^{2 to} R ⁵ may be the same as or different from each other.
With respect to the alkyl group of R ^{2 to} R ⁵ , the fluorinated alkyl group, the fluorinated alkoxy group, the fluorinated alkyl ester group and “—Si (R ⁶ ) ₃ ”, the above description of R ¹ can be applied. As the alkoxy group, those having 1 to 12 carbon atoms such as methoxy group, ethoxy group and propoxy group are preferable, and those having 1 to 4 carbon atoms are more preferable.

（式（２）中、Ｙ^１は、単結合、エステル結合、−ＮＲ^７−、−ＣＯＮＲ^７−（ただし、Ｒ^７は水素原子又は炭素数１〜６の１価の炭化水素基である。）、チオエステル結合、エーテル結合、チオエーテル結合又は炭素数２〜１２の２価の有機基である。） X ¹ in the formulas (1-1) and (1-2) is a divalent organic group, and the structure thereof is not particularly limited, but in the formula (1-1) included in the polymer (A), It is preferable that X ¹ in at least a partial structure of the partial structure represented by the formula (1-2) is represented by the following formula (2).

(In the formula (2), Y ¹ is a single bond, an ester bond, —NR ⁷ —, —CONR ⁷ — (wherein R ⁷ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms). ), A thioester bond, an ether bond, a thioether bond, or a divalent organic group having 2 to 12 carbon atoms.)

（式（２−１）中、ｒは２〜１２の整数である。） In the above formula (2), the hydrocarbon group having 1 to 6 carbon atoms of R ⁷ may be any of a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group, but is preferably It is an alkyl group. R ⁷ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
As the divalent organic group having 2 to 12 carbon atoms, at least one methylene group of a divalent hydrocarbon group or a divalent hydrocarbon group is ester bond, —NR ⁷ —, —CONR ⁷ —, thioester bond. , An ether bond, a thioether bond, a carbonate group, a carbamate group, or a group substituted with a urea bond. Among these, Y ¹ is a group represented by the following formula (2-1), —NR ⁷ —, or —NR ⁷ — or a divalent organic group having 2 to 12 carbon atoms and having a urea bond. It is preferable.

(In the formula (2-1), r is an integer of 2 to 12.)

The polymer (A) is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and has a cyclobutane ring structure in its main chain. Such a polymer (A) is a specific tetracarboxylic acid derivative which is at least one selected from the group consisting of tetracarboxylic dianhydrides having a cyclobutane ring structure, tetracarboxylic acid diesters and tetracarboxylic acid diester dihalides, and diamines. Can be obtained by reacting.
The “cyclobutane ring structure” contained in the polymer (A) and the specific tetracarboxylic acid derivative is meant to include the case where the ring portion has a substituent. The divalent organic group of X ^{1 in} the above formulas (1-1) and (1-2) is a partial structure derived from diamine, that is, a residue obtained by removing two primary amino groups from diamine.

（式（Ｔ−１）中、Ｒ^２〜Ｒ^５は、それぞれ独立に水素原子、ハロゲン原子又は１価の有機基である。） (Polyamic acid)
Regarding the polyamic acid as the polymer (A) (hereinafter also referred to as “polyamic acid (A)”), the tetracarboxylic dianhydride used in the synthesis is a tetracarboxylic dianhydride having a cyclobutane ring structure (hereinafter referred to as “ Also referred to as "specific tetracarboxylic acid dianhydride". The specific tetracarboxylic dianhydride is represented by the following formula (T-1).

(In formula (T-1), R ^{2 to} R ⁵ are each independently a hydrogen atom, a halogen atom, or a monovalent organic group.)

上記特定テトラカルボン酸二無水物としては１種を単独で又は２種以上を組み合わせて使用することができる。 For illustration and preferred examples of the monovalent organic group ^R 2 to R ⁵ in the formula (T-1) can be applied to the description of ^R 2 to R ⁵ in the formula (1).
Specific examples of the compound represented by the formula (T-1) include 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1-methyl-1,2,3,4-cyclobutanetetracarboxylic acid. Acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3-trimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1-ethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 3-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1-ethyl-3-methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, the following formula (T-1 -1) to formula (T-1-16) Such compounds represented by formulas and the like.

As the specific tetracarboxylic dianhydride, one kind may be used alone, or two or more kinds may be used in combination.

The tetracarboxylic dianhydride used in the synthesis of the polyamic acid (A) may be only a specific tetracarboxylic dianhydride, but a tetracarboxylic dianhydride having no cyclobutane ring structure (hereinafter referred to as “other Also referred to as a “tetracarboxylic dianhydride”.
Examples of other tetracarboxylic acid dianhydrides include aliphatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, and aromatic tetracarboxylic acid dianhydrides. Specific examples of these include aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butanetetracarboxylic acid dianhydride;

（式（Ｔ−２）中、Ｘ^２及びＸ^３は、それぞれ独立に単結合、酸素原子、硫黄原子、−ＣＯ−、＊−ＣＯＯ−、＊−ＯＣＯ−、＊−ＣＯ−ＮＲ^９−、＊−ＮＲ^９−ＣＯ−（ただし、Ｒ^９は水素原子又は炭素数１〜６の１価の炭化水素基である。「＊」は、Ｒ^８との結合手を示す。）である。Ｒ^８は、炭素数１〜１０のアルカンジイル基、当該アルカンジイル基の炭素−炭素結合間に−Ｏ−を含む２価の基、シクロヘキシレン基、フェニレン基又はビフェニレン基である。）
などを；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のテトラカルボン酸二無水物を用いることができる。 Examples of the alicyclic tetracarboxylic acid dianhydride include 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 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 acid anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2 : , 5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, 4,9-dioxatricyclo [3. 5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride and the like;
As the aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, the following formula (T-2)

(In formula (T-2), X ² and X ³ are each independently a single bond, an oxygen atom, a sulfur atom, —CO—, * —COO—, * —OCO—, * —CO—NR ⁹ —, * ^-NR 9 -CO- (provided that, ^{R 9} is a monovalent hydrocarbon group having 1 to 6 carbon hydrogen atom or a carbon. "*" indicates a bond to ^{R 8.)} is .R ⁸ is an alkanediyl group having 1 to 10 carbon atoms, a divalent group containing —O— between carbon-carbon bonds of the alkanediyl group, a cyclohexylene group, a phenylene group or a biphenylene group.)
And the like; and tetracarboxylic dianhydrides described in JP 2010-97188 A can be used.

なお、その他のテトラカルボン酸二無水物は、１種を単独で又は２種以上組み合わせて使用することができる。 Specific examples of the alkanediyl group having 1 to 10 carbon atoms of R ^{8 in} the above formula (T-2) include, for example, methylene group, ethylene group, propylene group, butanediyl group, pentanediyl group, hexanediyl group, heptanediyl group, octane. Examples thereof include a diyl group, a nonanediyl group and a decanediyl group. The number of oxygen atoms between carbon-carbon bonds of the alkanediyl group may be one or two or more.
Specific examples of the compound represented by the above formula (T-2) include compounds represented by the following formulas (T-2-1) to (T-2-6).

In addition, other tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

  Other tetracarboxylic acid dianhydrides used in the synthesis include 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 5- (2,5) from the viewpoint of affinity with liquid crystal, solubility in a solvent and the like. -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 dianhydride, cyclopentanetetracarboxylic acid dianhydride, cyclohexanetetracarboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, p-phenylenebis (trimellitic acid Noester anhydride), pyromellitic dianhydride, and at least one compound selected from the group consisting of the compounds represented by the formula (T-2). The amount of these preferable tetracarboxylic acid dianhydrides (the total amount when two or more kinds are used) is based on the total amount of the other tetracarboxylic acid dianhydrides used for the synthesis of the polyamic acid (A). It is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 20 mol% or more.

  When other tetracarboxylic dianhydrides are used in the synthesis of the polyamic acid (A), the proportion of the specific tetracarboxylic dianhydride used is such that the liquid crystal aligning ability is sufficiently imparted to the coating film by the photoalignment method. From the viewpoint of, it is preferably 30 mol% or more, more preferably 40 mol% or more, and more preferably 50 mol% with respect to the total amount of the tetracarboxylic dianhydride used in the synthesis of the polyamic acid (A). More preferably, it is at least mol%.

（式（Ｄ−１）中、Ｙ^１は上記式（２）と同義である。） (Diamine)
Examples of the diamine used for the synthesis of the polyamic acid (A) include aliphatic diamine, alicyclic diamine, aromatic diamine, diaminoorganosiloxane and the like. The diamine used for the synthesis preferably contains a diamine having a partial structure represented by the above formula (2) (hereinafter also referred to as “specific diamine”). Specific preferred examples of the specific diamine include compounds represented by the following formula (D-1).

(In the formula (D-1), Y ¹ has the same meaning as the above formula (2).)

Description of illustrative and preferred specific examples of Y ¹ in the formula (D-1) can be applied to the description of Y ¹ in the formula (2). The primary amino group in the aminophenyl group is preferably in the 3-position or 4-position with respect to the other groups.

のそれぞれで表される化合物等が挙げられる。なお、特定ジアミンとしては１種を単独で又は２種以上を組み合わせて使用することができる。 Specific examples of the specific diamine include, for example, 4,4′-diaminobiphenyl, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenylpropane, 4,4′-ethynylenedianiline, 4,4 ′. -Diaminobenzanilide, 4,4'-diaminostilbene, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylamine, N, N-bis (4-aminophenyl) methylamine, 4-aminophenyl-4 '-Aminobenzoate, 4,4'-diaminoazobenzene, 1,2-bis (4-aminophenoxy) ethane, 1,3-bis (4-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) Butane, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis ( 4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,3-bis (4-aminophenethyl) urea, bis [2- (4-aminophenyl) ethyl] hexanedioic acid, 4 , 4'-diaminodiphenyl ether, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 1,4-bis- (4-aminophenyl) -piperazine, N, N'-bis (4-aminophenyl) -benzidine, the following formula (D-1 -1) and formula (D-1-2)

And the like. In addition, as a specific diamine, 1 type can be used individually or in combination of 2 or more types.

（式（Ｄ−２）中、ｒは２〜１２の整数である。） Among these, the diamine used for the synthesis of the polyamic acid (A) preferably contains a diamine having a partial structure represented by the above formula (2-1), —NR ⁷ — or a urea bond. As preferred specific examples, a compound represented by the following formula (D-2), 4,4′-diaminodiphenylamine, N, N-bis (4-aminophenyl) methylamine, 1,3-bis (4-amino) Phenethyl) urea.

(In the formula (D-2), r is an integer of 2 to 12.)

When synthesizing the polyamic acid (A), the use ratio of the specific diamine is preferably 10 mol% or more, and 20 mol% or more with respect to the total amount of the diamine used for synthesizing the polyamic acid (A). More preferably, it is more preferably 30 mol% or more, and particularly preferably 40 mol% or more.
The proportion of the diamine having the partial structure represented by (2-1) above, —NR ⁷ — or urea bond, is 3 mol with respect to the total amount of the diamine used for the synthesis of the polyamic acid (A). % Or more, preferably 5 mol% or more, more preferably 10 mol% or more, particularly preferably 20 mol% or more.

  The diamine used for synthesizing the polyamic acid may be only the above specific diamine, or may be used in combination with other diamine other than the specific diamine. As the other diamine, for example, aliphatic diamine, alicyclic diamine, aromatic diamine, diaminoorganosiloxane and the like can be used. Specific examples thereof include aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and 1,3-bis (aminomethyl) cyclohexane. As the alicyclic diamine, for example, 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine) and the like;

（式（Ｅ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、＊−ＣＯＯ−又は＊−ＯＣＯ−（ただし、「＊」はＸ^Ｉとの結合手を示す。）であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。但し、ａ及びｂが同時に０になることはない。）
で表される化合物などの配向性基含有ジアミン： As the aromatic diamine, for example, dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, cholesteryloxydiaminobenzene. , Cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostanyl diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) 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-((amino Phenoxy Methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, N- (2,4-diaminophenyl) -4 -(4-heptylcyclohexyl) benzamide, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, —O—, * —COO— or * —OCO— (where “*” is a bond to X ^I. R ^I is an alkanediyl group having 1 to 3 carbon atoms, R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, and b is 0. Is an integer of 2 to 2, c is an integer of 1 to 20, and d is 0 or 1. However, a and b are not 0 at the same time.)
Oriented group-containing diamines such as compounds represented by:

（式（Ｄ−１−４）中、「Ｂｏｃ」はｔｅｒｔ−ブトキシカルボニル基を表す。）
のそれぞれで表される化合物などを；
ジアミノオルガノシロキサンとして、例えば、１，３−ビス（３−アミノプロピル）−テトラメチルジシロキサンなどを；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のジアミンを用いることができる。 p-phenylenediamine, 4,4'-diaminodiphenylmethane, 2,4-diamino-N, N-diallylaniline, 1,5-diaminonaphthalene, 2,2'-bis (trifluoromethyl) -4,4'- Diaminobiphenyl, 2,7-diaminofluorene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-amino Phenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'- Carboxylic acid, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 3,6-diaminoacridine, N -Ethyl-3,6-diaminocarbazole, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, the following formula (D-1-3) to formula (D-1-5)

(In formula (D-1-4), "Boc" represents a tert-butoxycarbonyl group.)
A compound represented by each of
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and diamines described in JP 2010-97188 A can be used.

In the above formula (E-1) ^{"-X I - (R I -X II} ) d - " Examples of the divalent group represented by the alkanediyl group having 1 to 3 carbon atoms, * - O -, * It is preferably —COO— or * —O—C ₂ H ₄ —O— (however, the bond marked with “*” bonds to the diaminophenyl group). Examples of the group “—C _c H _{2c + 1} ” include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group. Examples thereof include a group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, and an eicosyl group, and these are preferably linear. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or the 3,5-position with respect to the other groups.

なお、その他のジアミンは１種を単独で又は２種以上を組み合わせて使用することができる。 Specific examples of the compound represented by the formula (E-1) include compounds represented by the following formulas (E-1-1) to (E-1-4).

The other diamines may be used alone or in combination of two or more.

  As the other diamine, from the viewpoint of suitably obtaining the effect of the present invention, among the above, the compound represented by the formula (D-1-4), paraphenylenediamine, and 2,4-diamino-N, N- It is preferable to contain at least one of diallylaniline, and it is more preferable to contain the compound represented by the formula (D-1-4). The preferable ratio of these other diamines to be used is preferably 1 mol% or more, more preferably 3 mol% or more, and more preferably 5 mol%, based on the total amount of diamines used for the synthesis of the polyamic acid (A). It is even more preferable that the content be at least%.

(Synthesis of polyamic acid)
The polyamic acid (A) can be obtained by reacting the above-mentioned tetracarboxylic dianhydride and diamine together with a molecular weight modifier, if necessary. The ratio of the tetracarboxylic dianhydride and the diamine used for the synthesis reaction of the polyamic acid (A) was such that the acid anhydride group of the tetracarboxylic dianhydride was 0. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable.

  Examples of the molecular weight modifier include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. Can be mentioned. The use ratio of the molecular weight modifier is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, with respect to 100 parts by mass in total of the tetracarboxylic dianhydride and the diamine used.

The synthesis reaction of the polyamic acid (A) is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20 ° C. to 150 ° C., more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.
Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons. Among these organic solvents, at least one selected from the group consisting of an aprotic polar solvent and a phenolic solvent (first group of organic solvents), or at least one selected from the first group of organic solvents. And a mixture of at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (organic solvent of the second group). In the latter case, the use ratio of the second group organic solvent is preferably 50 mass% or less, and more preferably 40 mass% with respect to the total amount of the first group organic solvent and the second group organic solvent. It is below, and more preferably 30% by mass or less.

  Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea and hexamethylphosphor. At least one selected from the group consisting of lutriamide, m-cresol, xylenol and halogenated phenol is used as a solvent, or a mixture of at least one of these with other organic solvent is used within the above range. Preference is given to using. Examples of the other organic solvent used at this time include butyl cellosolve, 2-butoxy-1-propanol, and diethylene glycol diethyl ether. The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine is 0.1 to 50% by mass based on the total amount (a + b) of the reaction solution. Is preferred.

  As described above, the reaction solution obtained by dissolving the polyamic acid (A) is obtained. This reaction solution may be directly used for preparation of the polymer composition, or may be used for preparation of the polymer composition after isolation of the polyamic acid (A) contained in the reaction solution, or it may be isolated. The polyamic acid (A) may be purified and then used for the preparation of the polymer composition. Isolation and purification of the polyamic acid (A) can be performed according to a known method.

[Polyamic acid ester]
The polyamic acid ester according to the present invention is a polymer having a cyclobutane ring structure in its main chain. Such polyamic acid ester includes, for example, [I] a method of reacting the polyamic acid (A) obtained by the above synthetic reaction with an esterifying agent, [II] a tetracarboxylic acid diester having a cyclobutane ring structure, and a diamine. Method of reacting, method of reacting [III] tetracarboxylic acid diester dihalide having cyclobutane ring structure with diamine, [IV] Reaction of tetracarboxylic acid dianhydride, diamine and esterifying agent in organic solvent Method, etc.
In the present specification, the “tetracarboxylic acid diester” means a compound in which two of four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are carboxyl groups. The “tetracarboxylic acid diester dihalide” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are halogenated.

  Examples of the esterifying agent used in the method [I] include a hydroxyl group-containing compound, an acetal compound, a halide, and an epoxy group-containing compound. Specific examples thereof include hydroxyl group-containing compounds such as alcohols such as methanol, ethanol and propanol, phenols such as phenol and cresol, and the like; acetal compounds such as N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethylacetal and the like; halides such as methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride and 1,1,1-trifluoro-2-iodoethane; epoxy group-containing Examples of the compound include propylene oxide and the like.

The tetracarboxylic acid diester used in the method [II] is obtained, for example, by ring-opening the tetracarboxylic acid dianhydride exemplified in the synthesis of the polyamic acid (A) above with alcohols such as methanol and ethanol. You can The tetracarboxylic acid diester used in the method [II] contains a compound having a cyclobutane ring structure, and if necessary, a compound having no cyclobutane ring may be used in combination.
Examples of the diamine used in the method [II] include the diamines exemplified in the synthesis of polyamic acid. The reaction of method [II] is preferably carried out in an organic solvent in the presence of a suitable dehydration catalyst. Examples of the organic solvent include the organic solvents exemplified as those used for the synthesis of polyamic acid. Examples of the dehydration catalyst include 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium halide, carbonylimidazole, and a phosphorus-based condensing agent. The reaction temperature at this time is preferably −20 to 150 ° C., more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 24 hours, more preferably 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 a suitable chlorinating agent such as thionyl chloride. The tetracarboxylic acid diester dihalide used in the method [III] contains a compound having a cyclobutane ring structure, and if necessary, a compound having no cyclobutane ring may be used in combination.
Examples of the diamine used in the method [III] include the diamines exemplified in the synthesis of polyamic acid. The reaction of method [III] is preferably carried out in an organic solvent in the presence of a suitable base. Examples of the organic solvent include the organic solvents exemplified as those used for the synthesis of polyamic acid. As the base, for example, tertiary amines such as pyridine and triethylamine; alkali metals such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium and potassium can be preferably used. The reaction temperature at this time is preferably −20 to 150 ° C., more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

Method [IV] is preferable when silyl-type polyamic acid ester is synthesized. Examples of the esterifying agent used at this time include silylamide-based silylating agents such as bis (trimethylsilyl) acetamide, bis (trimethylsilyl) trifluoroacetamide, and bis (trimethylsilyl) urea.
As the organic solvent used in the above reaction, the description of the organic solvent that can be used in the synthesis of polyamic acid can be applied. The reaction temperature is preferably -20 ° C to 250 ° C, more preferably -10 to 200 ° C. The reaction time is preferably 1 to 20 hours, more preferably 2 to 15 hours. The amount of the silylating agent used is preferably 0.1 to 3 mol, and more preferably 0.5 to 2 mol, based on the amount of the diamine used.

The polyamic acid ester obtained above may be further reacted with a compound capable of reacting with an amino group at the end of the polymer to synthesize a terminal-modified polymer. Examples of such a terminal modifier include chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, isoxazole-5-carboxylic acid chloride, and 2-furoyl chloride.
The reaction between the polyamic acid ester and the terminal modifying agent can be carried out in an organic solvent, preferably in the presence of a base. At this time, the use ratio of the terminal modifier is preferably 0.005 to 0.6 mol, and more preferably 0.01 to 0.2 mol, based on 1 mol of the diamine used in the reaction. . As the base, for example, tertiary amines such as pyridine and triethylamine can be preferably used. As the organic solvent, the description of the organic solvent that can be used for the synthesis of polyamic acid can be applied, and for example, N, N-dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone and the like are preferably used. be able to.

  Thus, a reaction solution containing the polyamic acid ester as the polymer (A) is obtained. The polyamic acid ester contained in the polymer composition may have only an amic acid ester structure, or may be a partial esterified product having both an amic acid structure and an amic acid ester structure. The reaction solution obtained by dissolving the polyamic acid ester may be used as it is for the preparation of the polymer composition, and may be used for the preparation of the polymer composition after isolating the polyamic acid ester contained in the reaction solution. Alternatively, the isolated polyamic acid ester may be purified and then subjected to the preparation of the polymer composition. Isolation and purification of the polyamic acid ester can be performed according to known methods.

[Polyimide]
The polyimide contained in the polymer composition can be obtained, for example, by subjecting the polyamic acid (A) synthesized as described above to dehydration ring closure to imidize.

  The polyimide may be a complete imidized product obtained by dehydrating and ring-closing all of the amic acid structure of the precursor polyamic acid (A), or by dehydrating and ring-closing only a part of the amic acid structure. It may be a partial imidized product having both a structure and an imide ring structure. The imidation ratio of the polyimide used in the reaction is preferably 20% or more, more preferably 30 to 99%, further preferably 40 to 99%. This imidization ratio is a percentage of the ratio of the number of imide ring structures to the total number of amic acid structures and imide ring structures of polyimide. Here, a part of the imide ring may be an isoimide ring.

  The dehydration ring closure of the polyamic acid (A) is preferably carried out by heating the polyamic acid (A) or by dissolving the polyamic acid (A) in an organic solvent, and adding a dehydrating agent and a dehydration ring closure catalyst to this solution. According to the method of heating. Of these, the latter method is preferable.

  In the method of adding a dehydrating agent and a dehydration ring-closing catalyst to the solution of the polyamic acid (A), an acid anhydride such as acetic anhydride, propionic anhydride, trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per 1 mol of the amic acid structure of the polyamic acid (A). As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect 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 those used for the synthesis of the polyamic acid (A). The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

  In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used for preparation of the polymer composition as it is, or may be used for preparation of the polymer composition after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, and after isolation of the polyimide. May be used for preparing the polymer composition, or the isolated polyimide may be purified and then used for preparing the polymer composition. These purification operations can be performed according to known methods. In addition, the polyimide can also be obtained by imidization of a polyamic acid ester.

  The polyamic acid, polyamic acid ester, and polyimide as the polymer (A) obtained as described above have a solution viscosity of 10 to 800 mPa · s when the solution is made into a solution having a concentration of 10% by mass. It is preferable that it has a solution viscosity of 15 to 500 mPa · s. The solution viscosity (mPa · s) of polyamic acid, polyamic acid ester and polyimide is 10% by mass prepared using a good solvent for these polymers (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is the value measured at 25 ° C. using the E-type rotational viscometer for the polymer solution of.

  The polyamic acid as the polymer (A), the polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polyamic acid ester and the polyimide is preferably 1,000 to 500,000, More preferably, it is 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 15 or less, more preferably 10 or less. Within such a molecular weight range, good alignment and stability of the liquid crystal display device can be secured.

（式（３）中、Ｒ^１０は、炭素数２〜５の１価の炭化水素基、又は当該炭化水素基における炭素−炭素結合間に「−Ｏ−」を有する１価の基である。） [(B) component]
The polymer composition according to the present invention contains a compound represented by the following formula (3) as a solvent component.

(In the formula (3), R ¹⁰ is a monovalent hydrocarbon group having 2 to 5 carbon atoms, or a monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group. )

Regarding the compound represented by the above formula (3), the monovalent hydrocarbon group having 2 to 5 carbon atoms of R ¹⁰ is preferably a chain hydrocarbon group, for example, an alkyl group having 2 to 5 carbon atoms or alkenyl. Group, alkynyl group and the like. In addition, examples of the monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group include an alkoxyalkyl group having 2 to 5 carbon atoms.
Specific examples thereof include an alkyl group having 2 to 5 carbon atoms such as an ethyl group, a propyl group, a butyl group and a pentyl group; an alkenyl group having 2 to 5 carbon atoms such as a vinyl group and a 1-propenyl group. , 2-propenyl group, 3-butenyl group and the like; as alkynyl group having 2 to 5 carbon atoms, for example, ethynyl group, 2-propynyl group, 2-butynyl group and the like; as alkoxyalkyl group having 2 to 5 carbon atoms, Examples thereof include a methoxymethyl group, a methoxyethyl group, a methoxypropyl group, a methoxybutyl group, an ethoxymethyl group, an ethoxyethyl group; and the like, which may be linear or branched. Among them, R ¹⁰ is preferably an alkyl group having 2 to 5 carbon atoms or an alkoxyalkyl group, and particularly preferably an ethyl group.

  Specific examples of the compound represented by the above formula (3) include, for example, N-ethyl-2-pyrrolidone, N- (n-propyl) -2-pyrrolidone, N-isopropyl-2-pyrrolidone, N- (n- Butyl) -2-pyrrolidone, N- (t-butyl) -2-pyrrolidone, N- (n-pentyl) -2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N -Methoxybutyl-2-pyrrolidone and the like. Among these, N-ethyl-2-pyrrolidone, N- (n-pentyl) -2-pyrrolidone, N- (t-butyl) -2-pyrrolidone and N-methoxypropyl-2-pyrrolidone are preferably used. In particular, N-ethyl-2-pyrrolidone can be used particularly preferably. In addition, the compound represented by the said Formula (3) can be used individually by 1 type or in combination of 2 or more types.

  The content ratio of the compound represented by the above formula (3) in the polymer composition is 40 to 2,000 parts by mass with respect to 100 parts by mass of the total amount of the polymer components contained in the polymer composition. It is preferable that the amount is 50 to 1,500 parts by mass.

[Other ingredients]
The polymer composition according to the present invention contains the above-mentioned component (A) and component (B), but other components than the component (A) and component (B) within a range that does not impair the effects of the present invention. May be further contained.

(Other solvents)
The polymer composition according to the present invention may contain a solvent other than the compound represented by the above formula (3), if necessary. Examples of such other solvents include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons. Among these, other solvents include at least one selected from the group consisting of an aprotic polar solvent and a phenolic solvent (organic solvent A), and a group consisting of alcohols, ketones, esters and ethers (organic solvent B It is preferable to use a mixture with one or more selected from the above) or one or more selected from the organic solvent B.

Specific examples of other solvents include organic solvent A such as N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 3-butoxy-N. , N-dimethylpropanamide and the like;
Examples of the organic solvent B include 4-hydroxy-4-methyl-2-pentanone, 1-butoxy-2-propanol, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methylmethoxypropionate, ethylethoxypropionate. , Ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether , Diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, diacetone alcohol, propylene glycol diacetate, dipropylene glycol monomethyl ether , Dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl propyl ether, dipropylene glycol methyl ether acetate and the like. Can .

When the polymer composition according to the present invention contains other solvent, the compounding ratio of the compound represented by the above formula (3) (when two or more kinds are contained, the total amount thereof) is It is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and further preferably 30 parts by mass or more based on 100 parts by mass in total of the solvent contained. Further, the upper limit of the content ratio of the compound represented by the above formula (3) is 100 parts by mass in total of the solvent contained in the polymer composition, from the viewpoint of improving coatability (printability) on the substrate. On the other hand, the amount is preferably 95 parts by mass or less, and more preferably 90 parts by mass or less.
When one or more kinds selected from the organic solvent A is blended with the polymer composition according to the present invention, the content ratio of the organic solvent A is from the viewpoint of the printability of the polymer composition and the afterimage characteristic of the liquid crystal display device. With respect to the total amount of the organic solvent A and the compound represented by the above formula (3), it is preferably 40% by mass or less, more preferably 30% by mass or less, and 20% by mass or less. It is more preferable that the content is 10% by mass or less.
In addition, it is preferable to use the compound represented by the above formula (3) as a solvent component of the polymer composition because the coating property (printability) on the substrate can be improved. In particular, it is preferable in that the polymer does not easily deposit on the printing machine even when the printing process is continuously performed and the continuous printability is good.

  Other components that may be added to the polymer composition include, in addition to the above components, for example, other polymers other than the polymer (A) (for example, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly ( Styrene-phenylmaleimide) derivative, poly (meth) acrylate, polyimide having neither a partial structure represented by the above formula (1-1) nor a partial structure represented by the above formula (1-2), and a precursor thereof Body), a compound having at least one epoxy group in the molecule, a functional silane compound, a compound having at least one oxetanyl group in the molecule, an imidization accelerator, an antioxidant, a surfactant, a photosensitizer , And photopolymerizable compounds. The use ratio of these other components can be appropriately set within a range that does not impair the effects of the present invention.

The polymer composition according to the present invention preferably contains, as a polymer component, a polymer having at least one of an amino group and a urea bond (hereinafter, also referred to as “polymer (G)”). Even when such a polymer (G) is used, it is possible to reduce the residual image while maintaining good printability. The polymer (G) may be a polymer contained in the component (A) or may be another polymer. When the polymer (G) is another polymer, the polymer (G) is preferably at least one selected from the group consisting of polyimide and its precursor. If the polymer (G) is, for example, a polyimide precursor or a polyimide, it can be obtained by using a diamine having —NR ⁷ — or a urea bond in the polymerization.
The blending ratio of the polymer (G) may be 10% by mass or more based on the total amount of the polymer components contained in the polymer composition (the total amount of the polymer (A) and other polymers). The content is preferably 20% by mass or more, more preferably 40% by mass or more.
The blending ratio of the polymer (A) is preferably 3% by mass or more, more preferably 5% by mass or more, and more preferably 10% by mass based on the total amount of the polymer (A) and other polymers. It is more preferable that the content is at least mass%.

  The solid content concentration in the polymer composition (the ratio of the total mass of components other than the solvent of the polymer composition to the total mass of the polymer composition) is appropriately selected in consideration of viscosity, volatility and the like. , And preferably in the range of 1 to 10 mass%. That is, the polymer composition is applied to the surface of the substrate as described below, and preferably heated to form a coating film to be a liquid crystal alignment film. At this time, if the solid content concentration is less than 1% by mass, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, the film thickness of the coating film becomes excessive and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the polymer composition increases and the coating property deteriorates. Tend to do.

  The particularly preferable range of the solid content concentration varies depending on the method used when the polymer composition is applied to the substrate. For example, when the spinner method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5 mass%. In the case of using the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by mass, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by mass, and thus the solution viscosity is in the range of 3 to 15 mPa · s. The temperature at the time of preparing the polymer composition is preferably 10 to 50 ° C, more preferably 20 to 30 ° C.

<Film formation step>
The film forming step according to the present invention is a step of forming a coating film by applying the polymer composition prepared above onto a substrate. In this step, the substrate used differs depending on the desired drive mode of the liquid crystal display element.
(1-1) For example, when manufacturing a TN type, STN type or VA type liquid crystal display element, first, two substrates provided with a patterned transparent conductive film are made into a pair, and each transparent conductive film is formed. The polymer composition prepared above is applied onto the surface, preferably by an offset printing method, a spin coating method, a roll coater method or an inkjet printing method. As the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, poly (alicyclic olefin) can be used. As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Co., USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ) and the like are used. Can be used. To obtain a patterned transparent conductive film, for example, a method of forming a pattern-free transparent conductive film and then forming a pattern by photo-etching; a method of using a mask having a desired pattern when forming the transparent conductive film; You can When applying the polymer composition, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or a functional titanium compound is formed on the surface of the substrate surface on which the coating film is formed. A pretreatment of applying a compound or the like in advance may be performed.

  After the application of the polymer composition, preheating is preferably carried out for the purpose of preventing dripping of the applied polymer composition (prebaking step). The prebaking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The prebake time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Then, a baking (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, thermal imidization of the amic acid structure present in the polymer. The baking temperature (post-baking temperature) at this time is preferably higher than the pre-baking temperature, specifically, preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

  (1-2) In the case of manufacturing an IPS-type or FFS-type liquid crystal display element, an electrode formation surface of a substrate provided with an electrode made of a comb-shaped patterned transparent conductive film or a metal film, and an electrode are provided. The polymer composition is applied to one surface of the counter substrate which is not formed, and then each applied surface is heated to form a coating film. The materials 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 pretreatment of the substrate, and the preferable film thickness of the coating film formed are as described above. It is the same as (1-1). As the metal film, for example, a film made of a metal such as chromium can be used.

  In each of the cases (1-1) and (1-2) described above, a coating film is formed by applying the polymer composition on the substrate and then removing the organic solvent. At this time, by further heating after forming the coating film, a dehydration ring-closing reaction of the polyamic acid, polyamic acid ester and polyimide blended in the polymer composition may proceed to give a more imidized coating film.

<Light irradiation process>
The light irradiation step according to the present invention is a step of irradiating the surface of the substrate coated with the polymer composition with polarized or unpolarized radiation. Irradiation is performed by [1] irradiating the substrate surface after the post-baking step, [2] irradiating the substrate surface after the pre-baking step and before the post-baking step, [3] pre-baking step, and At least one of the post-baking steps can be performed by, for example, a method of irradiating the substrate surface during heating. In the case of this production method, the method [1] is preferred.

As the radiation applied to the substrate surface, for example, ultraviolet rays and visible rays containing light with a wavelength of 150 to 800 nm can be used. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed in a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized radiation, the irradiation direction is an oblique direction.
As the light source used, for example, a low pressure mercury lamp, a high pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. Ultraviolet rays in a preferable wavelength range can be obtained by means of using a light source in combination with a filter, a diffraction grating, or the like. The dose of radiation is preferably 100 to 50,000 J / m ² , and more preferably 300 to 20,000 J / m ² .

<Heating process>
The method for producing a liquid crystal alignment film according to the present invention is a step of heating the coating film after forming the coating film on the substrate and after irradiating the substrate surface coated with the polymer composition with light (heating step ) Is preferably further included. By carrying out such a heating step, the afterimage characteristic of the liquid crystal element to be obtained (particularly, reduction of afterimage due to AC voltage) can be improved, which is preferable.

  In the heating step for the coating film after the light irradiation, the heating temperature is preferably 80 ° C or higher, more preferably 80 to 300 ° C, and further preferably 120 to 250 ° C. The heating time is preferably 1 to 30 minutes, more preferably 5 to 15 minutes. The mode of heating is not particularly limited, and examples thereof include a method of heating the substrate on a hot plate and a method of heating the entire substrate in an oven.

<Contact process>
The method for producing a liquid crystal alignment film according to the present invention is, after forming a coating film on a substrate, and after irradiating the substrate surface coated with the polymer composition with light, from the group consisting of an organic solvent and water. It is preferable to further include a step (contact step) of bringing at least one selected solvent (S) into contact with the coating film. By carrying out such a contact step, the residual amount of the solvent (particularly the compound represented by the above formula (3)) in the film can be reduced, and the afterimage characteristic of the obtained liquid crystal element can be improved, which is preferable. Further, it is particularly preferable to perform the contacting step before the heating step because the temperature at which the coating film is heated in the heating step can be set to a lower temperature.

[Solvent (S)]
When an organic solvent is used as the solvent (S), the organic solvent is compatible with the compound represented by the formula (3) (hereinafter, also referred to as “specific compound”), and the organic solvent is compatible with the polymer (A). On the other hand, compounds that are poorly soluble or insoluble are preferred. According to such a compound, it is possible to reduce the remaining amount of the specific compound in the film while suppressing the deterioration of the film quality due to the contact with the solvent (S). As the solvent (S), a compound having a lower boiling point than the specific compound can be preferably used from the viewpoint of minimizing the amount remaining in the film after the contacting step.

Specific examples of the organic solvent used as the solvent (S) include alcohols, ketones, esters and ethers. Preferred specific examples thereof include alcohols having 1 to 5 carbon atoms such as methanol, ethanol, isopropanol, isobutanol, and isopentyl alcohol; and ketones such as acetone, methyl ethyl ketone, diethyl ketone, and methyl isopropyl ketone. A ketone having 3 to 5 carbon atoms; an ester, for example, an ester having 3 to 5 carbon atoms such as ethyl lactate, methyl acetate, ethyl acetate, and methyl methoxypropionate; an ether, for example, 4 to 4 carbon atoms such as diisopropyl ether and tetrahydrofuran The ether of 6 can be mentioned as a preferable example. As the solvent (S), one type of these organic solvents may be used alone, two or more types may be used in combination, or a mixed solvent of water and an organic solvent may be used. Good.
Among the above, the solvent (S) used in this step may be a single solvent of water, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, ethyl lactate or ethyl acetate, or a mixed solvent of two or more thereof. preferable. When a mixed solvent of water and an organic solvent is used as the solvent (S), the concentration of the organic solvent with respect to the total amount of the solvent (S) is preferably 5 to 55% by mass, and 10 to 50% by mass. Is more preferable.

  The method of bringing the liquid crystal alignment film on the substrate into contact with the solvent (S) is not particularly limited, but, for example, a shower method, a spray method, a dip (immersion) method, a paddle (liquid deposition) method, or the like can be applied. When contacting with the solvent (S), a part of the surface of the liquid crystal alignment film may be contacted with the solvent (S), but it is preferable to contact the entire surface of the liquid crystal alignment film with the solvent (S). . At this time, in order to enhance the effect of extracting / removing the solvent from the liquid crystal alignment film, for example, a series of treatments of supplying and contacting the solvent (S) onto the substrate is performed a plurality of times, or if the dipping method is used. It is also effective to stir or shake the solvent (S). When the treatment of bringing the liquid crystal alignment film and the solvent (S) into contact with each other is performed plural times, the solvent (S) to be used may be changed in each step. For example, when two steps of the first contact step and the second contact step are performed as the contact step, the solvent (S) used in the first contact step is more than the solvent (S) used in the second contact step ( It is preferable to select the solvent (S) so that the boiling point of S) becomes low.

  The temperature at the time of contact between the solvent (S) and the liquid crystal alignment film is preferably 0 to 50 ° C, more preferably 10 to 40 ° C. The contact time is preferably 5 seconds to 30 minutes, more preferably 30 seconds to 15 minutes. The amount of the solvent (S) used in contact with the liquid crystal alignment film can be appropriately set according to the method of contact with the solvent (S).

  Specific modes of the method for producing a liquid crystal alignment film according to the present invention include, for example, [1] a mode in which a film forming step and a light irradiation step are performed, and a heating step and a contact step are not performed, and [2] a film forming step and A mode in which the heating process is performed and the contact process is not performed after the light irradiation process is performed, [3] A mode in which the contact process is performed and the heating process is not performed after the film forming process and the light irradiation process are performed, [4] A mode in which the heating step and the contact step are performed in this order after the film formation step and the light irradiation step, [5] A mode in which the contact step and the heating step are performed in this order after the film formation step and the light irradiation step are performed, etc. Is mentioned. Among these [1] to [5], [2] or [5] is preferable, and [5] is more preferable, from the viewpoint of further improving the afterimage characteristics of the liquid crystal element.

[Liquid crystal element]
The liquid crystal device according to the present invention comprises a liquid crystal alignment film formed by using the above method. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited and includes, for example, various types such as TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB type. It can be applied to operating modes. Among these, when applied to an IPS type or FFS type liquid crystal display element, the effect of reducing an afterimage due to an AC voltage is high, and a liquid crystal display element having excellent afterimage characteristics is preferable.

In order to manufacture the liquid crystal device according to the present invention, first, two substrates on which a liquid crystal alignment film is formed by the above method are prepared, and a liquid crystal is arranged between the two substrates which are arranged to face each other to form a liquid crystal cell. To manufacture. For manufacturing the liquid crystal cell, for example, the following two methods can be mentioned. The first method is a conventionally known method. First, two substrates are opposed to each other with a gap (cell gap) so that the respective liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together by using a sealant. Then, liquid crystal is injected and filled into the 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 an ODF (One Drop Fill) method. In this method, first, for example, an ultraviolet light curable sealant is applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film is formed, and then a predetermined liquid crystal alignment film surface is applied. After the liquid crystal is dropped at several points, the other substrate is attached so that the liquid crystal alignment films face each other and the liquid crystal is spread over the entire surface of the substrate. Next, a liquid crystal cell is manufactured by irradiating the entire surface of the substrate with ultraviolet light to cure the sealing agent. In either case, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used has an isotropic phase, and then gradually cooled to room temperature, so that the flow orientation at the time of filling the liquid crystal is improved. It is desirable to remove it.

As the sealing agent, for example, a curing agent and an epoxy resin containing aluminum oxide spheres as a spacer can be used.
Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal, and among them, nematic liquid crystal is preferable, for example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl liquid crystal. A cyclohexane-based liquid crystal, a pyrimidine-based liquid crystal, a dioxane-based liquid crystal, a bicyclooctane-based liquid crystal, a cubane-based liquid crystal, or the like can be used. In addition to these liquid crystals, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate; chiral agents such as those sold under the product names "C-15" and "CB-15" (manufactured by Merck). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate or the like may be added and used.

  Subsequently, if necessary, a polarizing plate is attached to the outer surface of the liquid crystal cell to obtain a liquid crystal element. As a polarizing plate to be attached to the outer surface of a liquid crystal cell, a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretched and oriented to absorb iodine and sandwiched between cellulose acetate protective films or the H film itself is used. A polarizing plate consisting of

  The liquid crystal device according to the present invention can be effectively applied to various devices, for example, watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, and various types. It can be used for various display devices such as monitors, liquid crystal televisions, information displays, phase difference films, light control films, and the like.

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples. The abbreviations of the compounds used in the examples and comparative examples, and the methods for measuring each property are as follows.
NMP: N-methyl-2-pyrrolidone NEP: N-ethyl-2-pyrrolidone BPA: 3-butoxy-N, N-dimethylpropanamide BC: Butyl cellosolve Compound (a-1): 1,3-dimethyl-1,2 , 3,4-Cyclobutanetetracarboxylic dianhydride Compound (a-2): 1,2,3,4-cyclobutanetetracarboxylic dianhydride Compound (a-3): represented by the following formula (a-3) Compound (a-4): Compound represented by the above formula (T-1-7) Compound (a-5): 1R, 2S, 4S, 5R-1,2,4,5-cyclohexanetetracarboxylic Acid dianhydride (compound represented by the following formula (a-5))
Compound (b-1): 1,2-bis (4-aminophenoxy) ethane Compound (b-2): Compound represented by the above formula (D-1-4)

The weight average molecular weight of each polymer in the synthesis example was measured by the following method.
[Weight average molecular weight of polymer]
The weight average molecular weight Mw of the polymer is a polystyrene conversion value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Corp., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²

<Synthesis of Polymer (A)>
[Synthesis Example 1: Synthesis of polymer (A-1)]
100 mol parts of the compound (a-1) as the tetracarboxylic acid dianhydride and 100 mol parts of the compound (b-1) as the diamine were dissolved in NEP and reacted at room temperature for 8 hours. As a result, a polyamic acid solution having a solid content concentration of 15 mass% was obtained. The obtained polyamic acid was used as a polymer (A-1). The weight average molecular weight Mw of the polymer (A-1) was 60,000.
[Synthesis Example 2: Synthesis of polymer (A-2)]
100 parts by mol of the compound (a-2) as tetracarboxylic dianhydride and 100 parts by mol of the compound (b-1) as diamine were dissolved in NMP and reacted at room temperature for 8 hours. As a result, a polyamic acid solution having a solid content concentration of 15 mass% was obtained. Further, 135 g of the obtained polyamic acid was added, 155 g of NEP was added, and the mixture was stirred for 30 minutes. 22.22 g of acetic anhydride and 6.86 g of pyridine were added to the obtained polyamic acid solution, and the mixture was heated at 50 ° C. for 3 hours for chemical imidization. The obtained reaction solution was poured into 1,100 g of methanol while stirring, and the deposited precipitate was collected by filtration, subsequently washed with 1,100 g of methanol three times, and washed with 200 g of methanol twice. The resin powder thus obtained was dried at 60 ° C. for 12 hours to obtain a polyimide resin powder (this was designated as a polymer (A-2)). The weight average molecular weight Mw of the polymer (A-2) was 44,000.

[Synthesis Example 3: Synthesis of polymer (A-3)]
100 mol parts of the compound (b-1) as a diamine and 220 mol parts of pyridine as a base were added and dissolved in NMP. Next, 100 mol parts of the compound (a-3) as a tetracarboxylic acid dianhydride was added while stirring the diamine solution, and the mixture was reacted at 15 ° C. for 24 hours. After stirring for 24 hours, 30 mol parts of acryloyl chloride was added, and the mixture was reacted at 15 ° C for 4 hours. The obtained solution of polyamic acid ester was put into 2-propanol with stirring, and the white precipitate thus deposited was collected by filtration. Subsequently, white polyamic acid ester resin powder (this was designated as polymer (A-3)) was obtained by washing with 2-propanol five times and drying. The weight average molecular weight Mw of the polymer (A-3) was 32,000.
[Synthesis Example 4: Synthesis of polymer (A-4)]
100 mol parts of the compound (a-4) as tetracarboxylic dianhydride and 100 mol parts of the compound (b-1) as diamine were dissolved in NEP and reacted at room temperature for 8 hours. As a result, a polyamic acid solution having a solid content concentration of 15 mass% was obtained. The obtained polyamic acid was used as a polymer (A-4). The weight average molecular weight Mw of the polymer (A-4) was 53,000.

[Synthesis Example 5: Synthesis of polymer (A-5)]
NEP was used as 100 parts by mole of compound (a-1) as tetracarboxylic dianhydride, 90 parts by mole of compound (b-1) as diamine, and 10 parts by mole of 1,3-bis (4-aminophenethyl) urea. And was allowed to react at room temperature for 8 hours. As a result, a polyamic acid solution having a solid content concentration of 15 mass% was obtained. The obtained polyamic acid was used as a polymer (A-5). The weight average molecular weight Mw of the polymer (A-5) was 56,000.
[Synthesis Example 6: Synthesis of polymer (A-6)]
100 parts by mole of compound (a-1) as tetracarboxylic dianhydride, 50 parts by mole of compound (b-1) as diamine, 20 moles of paraphenylenediamine and 30 moles of 4,4′-diaminodiphenylamine. Was dissolved in NEP and reacted at room temperature for 8 hours. As a result, a polyamic acid solution having a solid content concentration of 15 mass% was obtained. The obtained polyamic acid was used as a polymer (A-6). The weight average molecular weight Mw of the polymer (A-6) was 43,000.

[Synthesis Example 7: Synthesis of polymer (A-7)]
NEP was used as 100 parts by mole of compound (a-1) as tetracarboxylic dianhydride, 70 parts by mole of compound (b-1) as diamine and 30 parts by mole of 2,4-diamino-N, N-diallylaniline. And was allowed to react at room temperature for 8 hours. As a result, a polyamic acid solution having a solid content concentration of 15 mass% was obtained. The obtained polyamic acid was used as a polymer (A-7). The weight average molecular weight Mw of the polymer (A-7) was 31,000.
[Synthesis Example 8: Synthesis of polymer (A-8)]
85 mol parts of the compound (b-1) and 15 mol parts of the compound (b-2) as a diamine, and 220 mol parts of pyridine as a base were added and dissolved in NMP. Next, 100 mol parts of the compound (a-3) as a tetracarboxylic acid dianhydride was added while stirring the diamine solution, and the mixture was reacted at 15 ° C. for 24 hours. After stirring for 24 hours, 30 mol parts of acryloyl chloride was added, and the mixture was reacted at 15 ° C for 4 hours. The solution of the obtained polyamic acid ester was put into 2-propanol while stirring, and the white precipitate thus deposited was collected by filtration, followed by washing with 2-propanol five times and drying to obtain a white polyamic acid ester. Resin powder (this was used as a polymer (A-8)) was obtained. The weight average molecular weight Mw of the polymer (A-8) was 37,000.

[Synthesis Example 9: Synthesis of polymer (A-9)]
40 mol parts of the compound (b-1) as a diamine, 10 mol parts of the compound (b-2) and 50 mol parts of paraphenylenediamine, and 220 mol parts of pyridine as a base were added and dissolved in NMP. Next, 100 mol parts of the compound (a-3) as a tetracarboxylic acid dianhydride was added while stirring the diamine solution, and the mixture was reacted at 15 ° C. for 24 hours. After stirring for 24 hours, 30 mol parts of acryloyl chloride was added, and the mixture was reacted at 15 ° C for 4 hours. The obtained solution of polyamic acid ester was put into 2-propanol with stirring, and the white precipitate thus deposited was collected by filtration. Then, it wash | cleaned 5 times with 2-propanol and dried, and the white polyamic-acid-ester resin powder (this was made into the polymer (A-9)) was obtained. The weight average molecular weight Mw of the polymer (A-9) was 41,000.

<Synthesis of other polymers>
[Synthesis Example 10: Synthesis of polymer (G-1)]
100 mol parts of the compound (a-5) as a tetracarboxylic dianhydride and 100 mol parts of 4,4′-diaminodiphenylamine as a diamine were dissolved in NEP and reacted at room temperature for 8 hours. As a result, a polyamic acid solution having a solid content concentration of 15 mass% was obtained. The obtained polyamic acid was used as a polymer (G-1). The weight average molecular weight Mw of the polymer (G-1) was 32,000.

<Preparation of polymer composition>
[Example 1]
31.8 g of NEP as the component (B) and 28.2 g of BC as the other solvent were added to 40 g of the NEP solution containing 15% by mass of the polymer (A-1) as the component (A), and the mixture was stirred at room temperature for 1 hour. Then, a polymer composition (B-1) was obtained.
[Example 2]
To 6 g of the polymer (A-2) as the component (A), 65.8 g of NEP as the component (B) and 28.2 g of BC as the other solvent were added, and the mixture was stirred at room temperature for 24 hours to obtain the polymer composition (B -2) was obtained.
[Example 3]
To 6 g of the polymer (A-3) as the component (A), 56.4 g of NEP as the component (B), and 18.8 g of NMP and 18.8 g of BC as other solvents were added, and the mixture was stirred at room temperature for 24 hours. A polymer composition (B-3) was obtained.
[Example 4]
31.8 g of NEP as the component (B) and 28.2 g of BC as the other solvent were added to 40 g of the NEP solution containing 15% by mass of the polymer (A-4) as the component (A), and the mixture was stirred at room temperature for 1 hour. Then, a polymer composition (B-4) was obtained.
[Example 5]
To 40 g of NEP solution containing 15% by mass of polymer (A-5) as component (A), 41.2 g of NEP as component (B) and 18.8 g of BC as other solvent were added, and the mixture was stirred at room temperature for 1 hour. Then, a polymer composition (B-5) was obtained.
[Example 6]
31.8 g of NEP as the component (B) and 28.2 g of BC as the other solvent were added to 40 g of the NEP solution containing 15% by mass of the polymer (A-6) as the component (A), and the mixture was stirred at room temperature for 1 hour. Then, a polymer composition (B-6) was obtained.
[Example 7]
20 g of NEP solution containing 15 mass% of polymer (A-7) as component (A), and 3 g of polymer (A-8), 30.0 g of NEP as component (B), and BC as other solvent. 47.0 g was added and stirred at room temperature for 24 hours to obtain a polymer composition (B-7).
[Example 8]
3 g of polymer (A-9) as component (A) and 20 g of NEP solution containing 15% by weight of polymer (G-1) as other polymer, 30.0 g of NEP as component (B), and others 47.0 g of BC was added as the solvent of and the mixture was stirred at room temperature for 24 hours to obtain a polymer composition (B-8).
[Comparative Example 1]
To 6 g of the polymer (A-3) as the component (A), 65.8 g of NMP and 28.2 g of BC were added as other solvents, and the mixture was stirred at room temperature for 24 hours to obtain a polymer composition (R-1). .
[Comparative Example 2]
To 6 g of the polymer (A-3) as the component (A), 65.8 g of BPA and 28.2 g of BC were added as other solvents, and the mixture was stirred at room temperature for 24 hours to obtain a polymer composition (R-2). .

[Example 9]
<Evaluation of printability>
The polymer composition (B-1) prepared above was used to evaluate the printability (continuous printability) when printing was continuously performed on a substrate for a long time. The evaluation was performed as follows. First, with respect to the prepared polymer composition, a dropping amount of the polymer composition on the anilox roll was used by using a liquid crystal alignment film printer (manufactured by Nissha Printing Co., Ltd., Angstromer type “S40L-532”). It was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film under the condition of 20 drops (about 0.2 g) back and forth. The application to the substrate was performed 20 times using a new substrate at 1 minute intervals. Subsequently, the polymer composition was dispensed (one way) on the anilox roll at 1-minute intervals, and each time, the operation of bringing the anilox roll and the printing plate into contact (hereinafter referred to as idle operation) was performed 10 times in total (during this period). , Does not print on glass substrates). It should be noted that this idle operation is not performed in the actual manufacturing process of the liquid crystal display element, but is an operation performed in order to perform printing intentionally under severe conditions.

  After 10 idle runs, main printing was performed using a glass substrate. In this printing, after idle operation, 5 substrates were put in at intervals of 30 seconds, each substrate after coating the polymer composition was heated (prebaked) at 80 ° C. for 1 minute to remove the solvent, and then 200 By heating (post-baking) at 10 ° C. for 10 minutes, a coating film having a film thickness of about 80 nm was formed. The printability was evaluated by observing this coating film with a microscope at a magnification of 20 times. The evaluation is good when the polyimide deposition is not observed from the first main printing after the idle operation (○), the polyimide deposition is observed from the first main printing after the idle operation, but the main printing is performed 5 times. The case where the precipitation of polyimide was not observed during this period was evaluated as (Δ), and the case where the precipitation of polyimide was observed even after the main printing was repeated 5 times was regarded as defective (x). It is known from experiments that a liquid crystal aligning agent having good printability improves (disappears) the precipitation of the polymer during continuous loading of the substrate. As a result of the evaluation, the printability was “good” in this example.

<Manufacture of liquid crystal display element which is aligned by light irradiation treatment>
A glass substrate was prepared which had two systems of metal electrodes (electrodes A and B) made of chrome patterned in a comb shape and to which voltage could be independently applied to the electrodes A and B. The glass substrate and a counter glass substrate not provided with an electrode are paired, and the polymer composition (B-1) prepared above is provided on the surface of the glass substrate having the electrode and the one surface of the counter glass substrate. Each was applied using a spin coater. Then, prebaking was performed for 1 minute on a hot plate at 80 ° C., and heating (post-baking) was performed at 230 ° C. for 1 hour in an oven whose inside was replaced with nitrogen. Then, the substrate surface on the side coated with the polymer composition was irradiated with polarized ultraviolet rays at a dose of 10,000 J / m ² from the direction perpendicular to the substrate surface using a Hg-Xe lamp and a Glan-Taylor prism. Further, as a contact step with the solvent (S), the substrate was dipped in ethyl lactate for 3 minutes and then dipped in pure water for 1 minute. Then, as a heating step, heating was performed on a hot plate at 230 ° C. for 5 minutes. As a result, a pair of substrates having a liquid crystal alignment film with a film thickness of 0.1 μm was obtained.

  Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm by screen printing to the outer periphery of the surface having the liquid crystal alignment film of one of the pair of substrates, the liquid crystal alignment film surface of the pair of substrates was applied. The substrates were faced to each other and overlapped with each other so that the orientations of the respective substrates upon irradiation with polarized ultraviolet light were opposite to each other, and pressure bonding was performed, and the adhesive was thermally cured at 150 ° C. for 1 hour. Next, a liquid crystal “MLC-7028” manufactured by Merck Ltd. was filled in the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow orientation at the time of liquid crystal injection, this was heated at 150 ° C. and then gradually cooled to room temperature. Next, by attaching polarizing plates to both outer surfaces of the substrate so that their polarization directions are orthogonal to each other and the projection axis of the optical axis of the polarized ultraviolet rays of the liquid crystal alignment film is orthogonal to the substrate surface, a liquid crystal display is obtained. The device was manufactured.

<Evaluation of AC afterimage>
Using the liquid crystal display device manufactured as described above, the AC afterimage characteristic (burn-in characteristic) was evaluated. First, the liquid crystal display element was placed in an environment of 25 ° C. and 1 atm, and an AC voltage of 4 V was applied to the electrode A for 2 hours without applying a voltage to the electrode B. Immediately thereafter, a voltage of 4 V AC was applied to both the electrodes A and B. The time from when the voltage of 4 V AC was started to be applied to both electrodes until the difference in light transmittance between the electrodes A and B could not be visually confirmed was measured. When the time was less than 30 seconds, the AC afterimage characteristic was “excellent (⊚)”, and when it was 30 seconds or more and less than 60 seconds, the image sticking characteristic was “good (◯)” and 60 seconds or more and less than 100 seconds. In this case, the image sticking characteristic is “OK”, and when it is 100 seconds or more, the image sticking characteristic is “NO” (X). As a result, this liquid crystal display element was found to have "excellent" burn-in characteristics.

[Example 10]
The printability was evaluated in the same manner as in Example 9 except that the polymer composition used was changed to (B-2). For manufacturing a liquid crystal display device, polarized ultraviolet light was applied perpendicularly to the substrate surface at a dose of 20,000 J / m ² using a Hg-Xe lamp and a Glan-Taylor prism on the surface of the substrate coated with the polymer composition. Evaluation was performed in the same manner as in Example 9 except that irradiation was performed from the direction to obtain a pair of substrates having a liquid crystal alignment film with a thickness of 0.1 μm. In addition, in this Example 10, the treatment of bringing the coating film into contact with the solvent (S) after irradiation with polarized ultraviolet light and the subsequent heat treatment were not performed. In this example, the printability was evaluated as “good” and the AC afterimage characteristic was evaluated as “good”.
[Examples 11, 13, 14 and Comparative Examples 3, 4]
Evaluation was performed in the same manner as in Example 9 except that the polymer composition used was changed as shown in Table 1 below. The results are shown in Table 1 below.

[Examples 12, 15, 16]
The printability was evaluated in the same manner as in Example 9 except that the type of the polymer composition used was changed as shown in Table 1 below. Regarding the production of the liquid crystal display device, the irradiation amount of polarized ultraviolet rays was changed to 2,000 J / m ² , the treatment of bringing the coating film into contact with the solvent (S) after irradiation with polarized ultraviolet rays, and the polarized light. A liquid crystal alignment film was prepared in the same manner as in Example 9 except that the heating time in the heat treatment after ultraviolet irradiation was changed to 10 minutes, and various evaluations were performed. The evaluation results are shown in Table 1 below.

  In Table 1, the numerical value in the parentheses in the column of (A) component and other polymers indicates the ratio (parts by mass) of each compound to 100 parts by mass in total of the polymer components used for preparing the polymer composition. Show. The numerical value in the column of the solvent composition indicates the usage ratio (parts by mass) of each compound to 100 parts by mass in total of the solvents used for preparing the polymer composition.

  As shown in Table 1, in Examples 9 to 16 using the polymer composition containing the compound represented by the above formula (3), the printability of the polymer composition was good, and the liquid crystal The afterimage characteristics of the display element were evaluated as "excellent" or "good". In particular, in Examples 9 and 11 to 16 in which at least one of the contact treatment with the solvent (S) after the light irradiation and the heat treatment after the light irradiation was carried out, the afterimage characteristics of the liquid crystal display element were excellent. It was On the other hand, in the comparative example, either the printability or the afterimage characteristic was inferior to that of the example.

Claims (10)

A polymer composition containing the following components (A) and (B) (except when containing a compound represented by the following formula (1)) is applied onto a substrate to form a coating film. And a step of irradiating the surface of the substrate coated with the polymer composition with light, the method for producing a liquid crystal alignment film.
Component (A): Among the polymers having at least one selected from the group consisting of the partial structure represented by the following formula (1-1) and the partial structure represented by the following formula (1-2), the following formula ( The polymer which has a substituent in the ring part of the cyclobutane ring structure in 1-1) and Formula (1-2). However, a polymer obtained by using a diamine represented by the following formula 1A is excluded.
Component (B): A compound represented by the following formula (3).

(In formula (1-1) and formula (1-2), R ¹ is each independently a hydrogen atom or a monovalent organic group, and R ^{2 to} R ⁵ are each independently a hydrogen atom, a halogen atom or It is a monovalent organic group. X ¹ is a divalent organic group.)

(In the formula (3), R ¹⁰ is a monovalent hydrocarbon group having 2 to 5 carbon atoms, or a monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group. )

(In the formula (1), P has at least one group in which the same carbon atom is substituted with at least two nitrogen atoms, and at least one of the nitrogen atoms is replaced with a hydrogen atom by heat. is substituted with a monovalent thermal desorption group having 1 to 24 carbon atoms, X is a single bond, -O -, - CONH -, - NHCO -, - CON (CH 3) -, - N (CH 3) CO-, -COO-, -OCO- and -S- represents at least one kind of bonding group selected from the group consisting of, Q represents a benzene ring, or a benzene ring-containing hydrocarbon group having 6 to 24 carbon atoms. Represents.)

  The liquid crystal according to claim 1, wherein the polymer composition contains a polymer having at least one of an amino group and a urea bond as the component (A) or as a polymer different from the component (A). Alignment film manufacturing method.   The method for producing a liquid crystal alignment film according to claim 1, further comprising heating the coating film after forming the coating film and after irradiating the surface of the substrate with light.   The method further comprising the step of contacting the coating film with at least one solvent (S) selected from the group consisting of an organic solvent and water after the coating film is formed and after the substrate surface is irradiated with light. Or the method for producing a liquid crystal alignment film according to item 2. Further comprising the step of heating the coating film after forming the coating film and after irradiating the substrate surface with light,
The step of bringing the solvent (S) into contact with the coating film is a step performed after the coating film is formed and after the substrate surface is irradiated with light, and before the coating film is heated. The method for producing a liquid crystal alignment film according to claim 4. The method for producing a liquid crystal alignment film according to claim 1, wherein X ¹ is a group represented by the following formula (2).

(In the formula (2), Y ¹ is a single bond, an ester bond, —NR ⁷ —, —CONR ⁷ — (wherein R ⁷ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms). ), A thioester bond, an ether bond, a thioether bond, or a divalent organic group having 2 to 12 carbon atoms.)   The liquid crystal alignment film according to any one of claims 1 to 6, wherein the content ratio of the component (B) is 10 parts by mass or more based on 100 parts by mass of the total amount of the solvents contained in the polymer composition. Manufacturing method.   A step of forming a liquid crystal alignment film on a pair of substrates by the manufacturing method according to claim 1, and a pair of substrates having the liquid crystal alignment film, the liquid crystal alignment film being provided via a liquid crystal layer. And a step of constructing a liquid crystal cell by arranging so as to face each other. A polymer composition for photo-alignment containing the following components (A) and (B) (excluding the case where the compound represented by the following formula (1) is contained).
Component (A): Among the polymers having at least one selected from the group consisting of the partial structure represented by the following formula (1-1) and the partial structure represented by the following formula (1-2), the following formula ( The polymer which has a substituent in the ring part of the cyclobutane ring structure in 1-1) and Formula (1-2). However, a polymer obtained by using a diamine represented by the following formula 1A is excluded.
Component (B): A compound represented by the following formula (3).

(In formula (1-1) and formula (1-2), R ¹ is each independently a hydrogen atom or a monovalent organic group, and R ^{2 to} R ⁵ are each independently a hydrogen atom, a halogen atom or It is a monovalent organic group. X ¹ is a divalent organic group.)

(In the formula (3), R ¹⁰ is a monovalent hydrocarbon group having 2 to 5 carbon atoms, or a monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group. )

(In the formula (1), P has at least one group in which the same carbon atom is substituted with at least two nitrogen atoms, and at least one of the nitrogen atoms is replaced with a hydrogen atom by heat. is substituted with a monovalent thermal desorption group having 1 to 24 carbon atoms, X is a single bond, -O -, - CONH -, - NHCO -, - CON (CH 3) -, - N (CH 3) CO-, -COO-, -OCO- and -S- represents at least one kind of bonding group selected from the group consisting of, Q represents a benzene ring, or a benzene ring-containing hydrocarbon group having 6 to 24 carbon atoms. Represents.)

  The polymer composition for optical alignment according to claim 9, comprising a polymer having at least one of an amino group and a urea bond as the component (A) or as a polymer different from the component (A).