JP6458484B2 - Liquid crystal aligning agent, liquid crystal aligning film and method for producing the same, liquid crystal display element, retardation film and method for producing the same - Google Patents

Description

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film and a manufacturing method thereof, relates to a liquid crystal display device and phase difference film and a manufacturing how.

  Conventionally, as a liquid crystal display element, various drive systems having different electrode structures, liquid crystal molecule properties, manufacturing processes, and the like have been developed. For example, TN type, STN type, VA type, in-plane switching type (IPS type), Various liquid crystal display elements such as an FFS type are known. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. As a material for the liquid crystal alignment film, polyamic acid or polyimide is generally used from the viewpoints of various properties such as heat resistance, mechanical strength, and affinity with liquid crystal.

  In recent years, large-screen high-definition liquid crystal televisions are mainly used, and small display terminals such as smartphones and tablet PCs are widely used, and the demand for high-definition liquid crystal displays is increasing. Conventionally, various liquid crystal aligning agents have been proposed in order to improve the display quality of the liquid crystal display (for example, see Patent Document 1). Patent Document 1 discloses a reaction between a diamine having a biphenyl structure such as 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4-bis (4-aminophenoxy) biphenyl, and tetracarboxylic dianhydride. It is disclosed that a polyimide resin film is formed on a substrate using a polymer composition containing a polymer obtained by the above, and the obtained polyimide resin film is rubbed to form a liquid crystal alignment film. In the device described in Patent Document 1, a uniform liquid crystal display is realized by making it possible to suppress a decrease in tilt angle even when a strong rubbing process is performed.

  In addition, various optical materials are used for liquid crystal display elements. Above all, retardation films eliminate the object of viewing color dependency and the viewing angle dependency that the display color and contrast ratio change depending on the visual direction. It is used for the purpose. As such retardation films, those having a liquid crystal alignment film formed on the surface of a substrate such as a TAC film and a liquid crystal layer formed by curing a polymerizable liquid crystal on the surface of the liquid crystal alignment film are known. ing. In recent years, a liquid crystal alignment film in a retardation film has been produced by using a photo-alignment method that imparts liquid crystal alignment ability by irradiating a radiation-sensitive organic thin film formed on the substrate surface with polarized or non-polarized radiation. Various liquid crystal aligning agents for retardation films for producing a liquid crystal aligning film by such a method have been proposed (for example, see Patent Document 2).

Japanese Patent No. 3365563 JP 2012-37868 A

  As a result of studies by the present inventors, the liquid crystal alignment film formed by the liquid crystal aligning agent described in Patent Document 1 does not have sufficient alignment regulating power of liquid crystal molecules, and for example, a liquid crystal display of a horizontal electric field method such as an IPS method or an FFS method. It was found that afterimages and image sticking are likely to occur when applied to an element. Further, when liquid crystal alignment ability is imparted to the coating film by rubbing treatment, it is required to be stable against rubbing, that is, to have high rubbing resistance, in order to increase the alignment regulating power of liquid crystal molecules. On the other hand, if a rigid structure is introduced into the polymer in order to increase the rubbing resistance, there is a concern that the applicability (printability) of the liquid crystal aligning agent is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal aligning agent that can improve all of the coating property to the substrate, the rubbing resistance of the coating film, and the afterimage characteristics of the liquid crystal display element. Another object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a retardation film having good liquid crystal alignment.

  As a result of intensive studies to solve the problems of the prior art as described above, the present inventors can solve the above problems by including a polymer having a specific structure as the polymer component of the liquid crystal aligning agent. As a result, the present invention has been completed. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film and method for producing the same, liquid crystal display element, retardation film and method for producing the same, polymer and compound.

  In one aspect, the present invention provides a liquid crystal aligning agent containing a polymer (P) having a partial structure represented by the following formula (1) in the main chain.

（式（１）中、Ｗ^１及びＷ^２は、それぞれ独立に、ベンゼン環、シクロヘキサン環、シクロペンタン環又はピリジン環を環骨格とする２価の環状基である。Ｘ^１は、単結合、−Ｏ−、＊−ＣＯＯ−、＊−ＯＣＯ−、−ＣＯ−、＊−ＮＲ^１０ＣＯ−又は＊−ＣＯＮＲ^１０−（但し、Ｒ^１０は、水素原子又は炭素数１〜３のアルキル基である。「＊」はＷ^１との結合手を示す。）である。Ｘ^２は、−Ｏ−、＊−ＣＯＯ−、＊−ＯＣＯ−、−ＣＯ−、＊−ＮＲ^１１ＣＯ−又は＊−ＣＯＮＲ^１１−（但し、Ｒ^１１は、水素原子又は炭素数１〜３のアルキル基である。「＊」はＷ^２との結合手を示す。）である。Ｒ^１は、単結合、炭素数１〜２０のアルカンジイル基、炭素数２〜２０のアルケンジイル基、炭素数１〜２０のアルカンジイル基若しくは炭素数２〜２０のアルケンジイル基の一部の水素原子を置換基で置き換えてなる２価の基、又は炭素数１〜２０のアルカンジイル基若しくは炭素数２〜２０のアルケンジイル基の一部のメチレン基を−Ｏ−若しくは−Ｓ−で置き換えてなる２価の基である。Ｒ^２は、単結合、−Ｏ−、＊−ＣＯＯ−、＊−ＯＣＯ−、−ＣＯ−、＊−ＮＲ^１２ＣＯ−、＊−ＣＯＮＲ^１２−（但し、Ｒ^１２は、水素原子又は炭素数１〜３のアルキル基である。「＊」はＷ^１との結合手を示す。）、炭素数１〜５のアルカンジイル基、炭素数２〜５のアルケンジイル基、炭素数１〜５のアルカンジイル基若しくは炭素数２〜５のアルケンジイル基の一部の水素原子を置換基で置き換えてなる２価の基、又は炭素数１〜５のアルカンジイル基若しくは炭素数２〜５のアルケンジイル基の一部のメチレン基を−Ｏ−若しくは−Ｓ−で置き換えてなる２価の基である。ｐは０〜２の整数を示す。但し、ｐ＝０のとき、Ｗ^１は、シクロヘキサン環、シクロペンタン環又はピリジン環を環骨格とする２価の環状基である。Ｗ^１及びＷ^２が共に置換又は無置換のフェニレン基である場合、Ｒ^１は単結合にならない。）

(In Formula (1), W ¹ and W ² are each independently a divalent cyclic group having a benzene ring, a cyclohexane ring, a cyclopentane ring or a pyridine ring as a ring skeleton. X ¹ is a single bond, —O—, * —COO—, * —OCO—, —CO—, * —NR ¹⁰ CO— or * —CONR ¹⁰ — (where R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “*” Represents a bond to W ^1. ) X ² is —O—, * —COO—, * —OCO—, —CO—, * —NR ¹¹ CO— or * —CONR. ^11- (wherein R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “*” Represents a bond with W ² ) R ¹ is a single bond, 1 carbon atom. ~ 20 alkanediyl group, C2-20 alkenediyl group, C1-20 alkanediyl Or a divalent group obtained by replacing a part of hydrogen atoms of an alkenediyl group having 2 to 20 carbon atoms with a substituent, or an alkanediyl group having 1 to 20 carbon atoms or a part of an alkenediyl group having 2 to 20 carbon atoms R ² is a single bond, —O—, * —COO—, * —OCO—, —CO—, * —NR ¹² , which is a divalent group formed by replacing a methylene group with —O— or —S—. CO—, * —CONR ¹² — (wherein R ¹² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, “*” represents a bond to W ¹ ), and 1 to 5 carbon atoms. An alkanediyl group, an alkenediyl group having 2 to 5 carbon atoms, an alkanediyl group having 1 to 5 carbon atoms, or a divalent group obtained by substituting a part of hydrogen atoms of an alkenediyl group having 2 to 5 carbon atoms with a substituent, or C1-C5 alkanediyl group or charcoal A divalent group obtained by replacing a part of the methylene group of the alkenediyl group of formulas 2 to 5 with -O- or -S-, p represents an integer of 0 to 2, provided that when p = 0. W ¹ is a divalent cyclic group having a cyclohexane ring, cyclopentane ring or pyridine ring as a ring skeleton, and when both W ¹ and W ² are substituted or unsubstituted phenylene groups, R ¹ is a single bond. Must not.)

  In one aspect, the present invention provides a liquid crystal alignment film formed using the liquid crystal alignment agent. Moreover, a liquid crystal display element provided with the said liquid crystal aligning film and a phase difference film provided with the said liquid crystal aligning film are provided. Furthermore, in another aspect, the step of coating the liquid crystal aligning agent on a substrate to form a coating film, the step of irradiating the coating film with light, and the polymerization on the coating film after the light irradiation And a step of applying and curing a liquid crystal.

  In one aspect, the present invention is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, and is obtained by polymerizing a monomer containing a compound represented by the following formula (d). A polymer is provided. Moreover, the compound represented by a following formula (d) is provided.

（式（ｄ）中、Ｘ^３及びＸ^４は、それぞれ独立に単結合、−Ｏ−、＊−ＣＯＯ−、＊−ＯＣＯ−、−ＣＯ−、＊−ＮＲ^１４ＣＯ−又は＊−ＣＯＮＲ^１４−（但し、Ｒ^１４は、水素原子又は炭素数１〜３のアルキル基である。「＊」はアミノフェニル基との結合手を示す。）である。Ｒ^３は、炭素数１〜２０のアルカンジイル基、炭素数２〜２０のアルケンジイル基、フェニレン基、ピペリジンジイル基、炭素数１〜２０のアルカンジイル基若しくは炭素数２〜２０のアルケンジイル基の一部の水素原子を置換基で置き換えてなる２価の基、又は炭素数１〜２０のアルカンジイル基若しくは炭素数２〜２０のアルケンジイル基の一部のメチレン基を−Ｏ−若しくは−Ｓ−で置き換えてなる２価の基である。Ｒ^４及びＲ^５は、それぞれ独立にハロゲン原子、又は炭素数１〜６のアルキル基若しくはアルコキシ基である。ｑは０又は１である。ｍ及びｎは、それぞれ独立に０〜４の整数である。Ｒ^４，Ｒ^５が複数存在する場合、複数のＲ^４，Ｒ^５は、それぞれ同じでも異なっていてもよい。Ｗ^１、Ｗ^２、Ｘ^１、Ｘ^２、Ｒ^１、Ｒ^２及びｐは前記式（１）とそれぞれ同義である。）

(In formula (d), X ³ and X ⁴ are each independently a single bond, —O—, * —COO—, * —OCO—, —CO—, * —NR ¹⁴ CO— or * —CONR ¹⁴ —. (However, R ¹⁴ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “*” Represents a bond with an aminophenyl group.) R ³ is an alkane having 1 to 20 carbon atoms. A part of hydrogen atoms of a diyl group, an alkenediyl group having 2 to 20 carbon atoms, a phenylene group, a piperidinediyl group, an alkanediyl group having 1 to 20 carbon atoms, or an alkenediyl group having 2 to 20 carbon atoms is replaced with a substituent. It is a divalent group or a divalent group obtained by replacing a part of methylene groups of an alkanediyl group having 1 to 20 carbon atoms or an alkenediyl group having 2 to 20 carbon atoms with —O— or —S—. ⁴ and R ⁵ are independent Is a halogen atom, or an alkyl group or alkoxy group having 1 to 6 carbon atoms, q is 0 or 1. m and n are each independently an integer of 0 to ^4. R ⁴ and R ⁵ are plural. When present, the plurality of R ⁴ and R ⁵ may be the same or different, and W ¹ , W ² , X ¹ , X ² , R ¹ , R ² and p have the same meanings as those in the formula (1), respectively. .)

  According to the liquid crystal aligning agent of this invention, the applicability | paintability with respect to a board | substrate, the rubbing tolerance of a coating film, and the afterimage characteristic of a liquid crystal display element can be made favorable. Moreover, according to the liquid crystal aligning agent of this invention, a retardation film with favorable liquid crystal aligning property can be obtained.

The schematic block diagram of a FFS type liquid crystal display element. The plane schematic diagram of the top electrode used for manufacture of the liquid crystal display element for rubbing orientation. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode. The figure which shows the drive electrode of 4 systems. The plane schematic diagram of the top electrode used for manufacture of the liquid crystal display element for photo-alignment. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode.

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

<Polymer (P)>
The liquid crystal aligning agent of this invention contains the polymer (P) which has the partial structure represented by the said Formula (1) in a principal chain as a polymer component.

W ¹ and W ² in the above formula (1) are divalent cyclic groups having a benzene ring, a cyclohexane ring, a cyclopentane ring or a pyridine ring as a ring skeleton. In the present specification, the “n-valent cyclic group” is an n-valent group obtained by removing n hydrogen atoms from atoms constituting a ring (in the case of W ¹ and W ² , carbon atoms). The moiety may have a substituent.
Specific examples of W ¹ and W ² include, for example, 1,4-phenylene group, 1,3-phenylene group, 1,4-cyclohexylene group, 1,3-cyclohexylene group, 1,3-cyclopentylene group. , A pyridine-2,5-diyl group, and a divalent group in which a substituent is introduced into the ring portion of each group. Examples of the substituent that the ring skeleton of W ¹ and W ² may have include, for example, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), an alkyl group having 1 to 6 carbon atoms, carbon Examples are an alkoxy group of formulas 1-6. W ¹ and W ² may be the same as or different from each other.
Of these, W ¹ and W ² are preferably cyclohexane rings at least from the ring skeleton of W ^{1 in} terms of high AC afterimage reduction effect, and in terms of ease of synthesis and cost, W ¹ and W ² The ring skeleton of W ² is preferably a benzene ring.
When W ¹ or W ² is a cyclohexylene group, the configuration of the divalent organic group bonded to the cyclohexane ring may be either cis or trans, but it must be trans in that the effect of improving AC afterimage characteristics is high. Is preferable, and a trans-1,4-hexylene group is more preferable.

X ¹ is a single bond, —O—, * —COO—, * —OCO—, —CO—, * —NR ¹⁰ CO— or * —CONR ¹⁰ — (where R ¹⁰ is a hydrogen atom or a carbon number of 1; It is an alkyl group of ˜3, “*” represents a bond to W ¹ ). Preferably, a single bond, -O -, * - COO - , * - OCO -, * - NHCO -, * - N (CH 3) CO -, * - CONH- or * -CON (CH ₃₎ - and is More preferably, they are a single bond, -O-, * -COO- or * -OCO-. X ² represents —O—, * —COO—, * —OCO—, —CO—, * —NR ¹¹ CO— or * —CONR ¹¹ — (where R ¹¹ represents a hydrogen atom or a carbon number of 1 to 3). An alkyl group, “*” represents a bond to W ² ). Preferably, -O -, * - COO - , * - OCO -, * - NHCO -, * - N (CH 3) CO -, * - CONH- or * -CON (CH ³⁾ - and, more preferably Is —O—, * —COO— or * —OCO—.

R ¹ is a single bond, an alkanediyl group having 1 to 20 carbon atoms, an alkenediyl group having 2 to 20 carbon atoms, an alkanediyl group having 1 to 20 carbon atoms, or a partial hydrogen atom of an alkenediyl group having 2 to 20 carbon atoms. Or a divalent group obtained by substituting with a substituent, or a part of the methylene group of an alkanediyl group having 1 to 20 carbon atoms or an alkenediyl group having 2 to 20 carbon atoms is replaced with -O- or -S-. Is a valent group.
Here, specific examples of the alkanediyl group having 1 to 20 carbon atoms include, for example, methylene group, ethylene group, propanediyl group, butanediyl group, pentanediyl group, hexanediyl group, heptanediyl group, octanediyl group, nonanediyl group, decandiyl group. Group, dodecanediyl group, tetradecanediyl group, pentadecanediyl group, hexadecanediyl group, octadecanediyl group and the like, and these may be linear or branched. Preferably it is linear. Specific examples of the alkenediyl group having 2 to 20 carbon atoms include vinylene group, propenediyl group, butenediyl group, pentenediyl group, hexenediyl group, heptenediyl group, octenediyl group, nonenediyl group, decenediyl group, dodecenediyl group, and tetradecenediyl group. Yl group, pentadecenediyl group, hexadecenediyl group, octadecenediyl group and the like. These may be linear or branched, but are preferably linear.
Examples of the substituent that the alkanediyl group and alkenediyl group may have include a halogen atom and an alkoxy group.
R ¹ is an alkanediyl group having 1 to 20 carbon atoms, an alkenediyl group having 2 to 20 carbon atoms, an alkanediyl group having 1 to 20 carbon atoms, or 2 to 2 carbon atoms in that rubbing resistance and solubility can be improved. A divalent group in which a part of the hydrogen atoms of the alkenediyl group of 20 is replaced with a substituent, or a methylene group of a part of the alkanediyl group having 1 to 20 carbon atoms or the alkenediyl group having 2 to 20 carbon atoms is —O A divalent group substituted by-or -S- is preferable, and an alkanediyl group having 1 to 20 carbon atoms is more preferable.
The carbon number of R ¹ when R ¹ is not a single bond is 2 or more from the viewpoint of improving the rubbing resistance and the difficulty of visually recognizing display unevenness around the sealant in the liquid crystal display element (bezel unevenness resistance). It is preferable. Moreover, it is preferable that it is C10 or less from the point which makes the solubility of a polymer favorable, It is more preferable that it is 8 or less, It is further more preferable that it is 6 or less.

R ² is a single bond, —O—, * —COO—, * —OCO—, —CO—, * —NR ¹² CO—, * —CONR ¹² — (where R ¹² is a hydrogen atom or a carbon number of 1 An alkyl group having ˜3, “*” represents a bond to W ¹ ), an alkanediyl group having 1 to 5 carbon atoms, an alkenediyl group having 2 to 5 carbon atoms, and an alkanediyl having 1 to 5 carbon atoms. Group or a divalent group obtained by replacing a part of hydrogen atoms of an alkenediyl group having 2 to 5 carbon atoms with a substituent, or a part of an alkanediyl group having 1 to 5 carbon atoms or an alkenediyl group having 2 to 5 carbon atoms In which the methylene group is replaced by —O— or —S—. Here, specific examples of the alkanediyl group having 1 to 5 carbon atoms include groups having 1 to 5 carbon atoms among the examples of R ¹ , and specific examples of the alkenediyl group having 2 to 5 carbon atoms include: Among the examples of R ¹ , groups having 2 to 5 carbon atoms can be mentioned. In R ² , examples of the substituent that the alkanediyl group and alkenediyl group may have include a halogen atom and an alkoxy group.
R ² is a single bond, * —COO—, * —OCO—, * —NHCO—, * —N (CH ₃ ) CO— because it has a high effect of improving the AC afterimage characteristics and bezel unevenness resistance of the liquid crystal display element. , * —CONH—, * —CON (CH ₃ ) — (“*” represents a bond to W ¹ ), an alkanediyl group having 1 to 3 carbon atoms, or a hydrogen atom of the alkanediyl group as a fluorine atom It is preferable that it is a divalent group formed by substitution with a single bond, * -COO- or * -OCO-.

p is an integer of 0 to 2, and p is preferably 0 or 1 in view of the solubility of the polymer.
The group represented by “—W ¹ — (R ² —W ² ) p—” is a cyclohexylene group or a bicyclohexylene group from the viewpoint of the balance between the AC afterimage characteristics of the liquid crystal display element and the solubility of the polymer. , “—Ar ¹ —Ar ² —” (Ar ¹ is a phenylene group, Ar ² is a cyclohexylene group), or “—Ar ³ —COO—Ar ⁴ —” (Ar ³ and Ar ⁴ are each independently a phenylene group) Or a cyclohexylene group).
In the above formula (1), when p = 0, W ¹ is a divalent cyclic group having a cyclohexane ring, a cyclopentane ring or a pyridine ring in the ring skeleton.
When W ¹ and W ² are both substituted or unsubstituted phenylene groups, R ¹ is other than a single bond, that is, an alkanediyl group having 1 to 20 carbon atoms, an alkenediyl group having 2 to 20 carbon atoms, or 1 to 1 carbon atoms. A divalent group obtained by substituting some of the hydrogen atoms of a 20 alkanediyl group or an alkenediyl group having 2 to 20 carbon atoms with a substituent, or an alkanediyl group having 1 to 20 carbon atoms or an alkenediyl group having 2 to 20 carbon atoms This is a divalent group obtained by replacing a part of the methylene group of the group with —O— or —S—. When the ring skeleton of W ¹ and W ² is a benzene ring, introduction of a spacer structure in the main chain of the polymer is preferable because the effect of improving coating properties, rubbing resistance, and afterimage characteristics is high.

When R ¹ is a single bond, p is preferably 1 or 2. In this case, it is preferable in that the obtained liquid crystal display element is highly effective in improving the bezel unevenness resistance and the afterimage characteristics.

Specific examples of the partial structure represented by the above formula (1) include structures represented by the following formulas (1-1) to (1-30), for example.

  Partial structures represented by the above formula (1-1) to formula (1-6), formula (1-10) to formula (1-23), and formula (1-27) to formula (1-30), respectively. The configuration of the divalent organic group bonded to the cyclohexane ring may be either trans or cis. In addition, the polymer (P) has the above formula (1-1) to formula (1-6), formula (1-10) to formula (1-23), and formula (1-27) to formula (1-30). ) As a partial structure represented by each of them may have both a trans type and a cis type. As the steric configuration, the above formula (1-1) to formula (1-6), formula (1-10) to formula (1-23) and formula (1-27) which one molecule of the polymer (P) has. The ratio of the trans type is preferably 50 mol% or more, more preferably 70 mol% or more, and more preferably 90 mol% with respect to the sum of the partial structures represented by each of the formulas (1-30) More preferably, it is the above.

Examples of the main chain (main skeleton) of the polymer (P) include a skeleton composed of polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, and the like. In the present specification, the “main chain” of a polymer refers to a structure formed by repeating bonding of monomers. As said polymer (P), 1 type (s) or 2 or more types of the polymer selected from these can be suitably selected according to the use etc. of a liquid crystal aligning agent, and can be used. Such a polymer (P) can be obtained by polymerization using a compound having a structure represented by the above formula (1) as a monomer.
The polymer (P) is preferably at least one selected from the group consisting of polyamic acid, polyimide and polyamic acid ester.

[Polyamic acid (P)]
When the polymer (P) is a polyamic acid (hereinafter also referred to as “polyamic acid (P)”), the polyamic acid (P) is obtained by, for example, reacting a tetracarboxylic dianhydride and a diamine. Can be obtained. Specifically, for example, polymerization is performed using (i) a tetracarboxylic dianhydride having a structure represented by the above formula (1) (hereinafter also referred to as “specific tetracarboxylic dianhydride”) as a monomer. A method; (ii) a method in which a diamine having a structure represented by the above formula (1) (hereinafter also referred to as “specific diamine”) is used as a monomer; and (iii) the specific tetracarboxylic dianhydride and It can obtain by the method of superposing | polymerizing using the said specific diamine for a monomer.

（式（ｔ）中、Ａ^１１及びＡ^１２は、それぞれ独立にベンゼン環又はシクロヘキサン環である。Ｘ^１３及びＸ^１４は、それぞれ独立に単結合、−Ｏ−、＊−ＣＯＯ−、＊−ＯＣＯ−、−ＣＯ−、＊−ＮＲ^１５ＣＯ−又は＊−ＣＯＮＲ^１５−（但し、Ｒ^１５は、水素原子又は炭素数１〜３のアルキル基である。「＊」は酸無水物基を有するベンゼン環との結合手を示す。）である。Ｒ^１３は、単結合、炭素数１〜２０のアルカンジイル基、炭素数２〜２０のアルケンジイル基、炭素数１〜２０のアルカンジイル基若しくは炭素数２〜２０のアルケンジイル基の一部の水素原子を置換基で置き換えてなる２価の基、又は炭素数１〜２０のアルカンジイル基若しくは炭素数２〜２０のアルケンジイル基の一部のメチレン基を−Ｏ−若しくは−Ｓ−で置き換えてなる２価の基である。ｒは０又は１である。但し、Ｒ^１３が単結合のときｒ＝０である。Ｗ^１、Ｗ^２、Ｘ^１、Ｘ^２、Ｒ^１、Ｒ^２及びｐは上記式（１）とそれぞれ同義である。） (Specific tetracarboxylic dianhydride)
Specific tetracarboxylic dianhydrides used in the above method (i) and method (iii) include, for example, aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. Things can be mentioned. Preferable specific examples include compounds represented by the following formula (t).

(In formula (t), A ¹¹ and A ¹² are each independently a benzene ring or a cyclohexane ring. X ¹³ and X ¹⁴ are each independently a single bond, —O—, * —COO—, * —OCO. ^{-, - CO -, * -} NR 15 CO- or * -CONR ¹⁵ -. ^{(However, R 15} is hydrogen atom or an alkyl group having 1 to 3 carbon atoms "*" is a benzene having an acid anhydride group R ¹³ is a single bond, an alkanediyl group having 1 to 20 carbon atoms, an alkenediyl group having 2 to 20 carbon atoms, an alkanediyl group having 1 to 20 carbon atoms, or a carbon number. A divalent group obtained by substituting a part of hydrogen atoms of an alkenediyl group having 2 to 20 with a substituent, or an alkanediyl group having 1 to 20 carbon atoms or a part of methylene group of an alkenediyl group having 2 to 20 carbon atoms -O- or- A divalent group substituted by S-, r is 0 or 1. However, when R ¹³ is a single bond, r = 0, W ¹ , W ² , X ¹ , X ² , R ¹ , R ² and p have the same meanings as those in the above formula (1).)

X ¹³ and X ^{14 in} the above formula (t) are preferably a single bond, —O—, * —COO— or * —OCO—. With respect to specific examples and preferred groups of R ¹³ , the above description of R ¹ can be applied.
Specific examples of the compound represented by the above formula (t) include, for example, compounds represented by the following formulas (an-1) to (an-6).

As the compound represented by each of the above formulas (an-3) to (an-6), either a trans-type compound or a cis-type compound in which the configuration of the divalent organic group bonded to the cyclohexane ring is trans. Alternatively, a mixture of a trans isomer and a cis isomer may be used.
In addition, the specific tetracarboxylic dianhydride used for the synthesis | combination of the said polyamic acid can be used individually by 1 type or selecting 2 or more types suitably.

(Other tetracarboxylic dianhydrides)
In the method (ii), polymerization using a tetracarboxylic dianhydride having no structure represented by the above formula (1) (hereinafter also referred to as “other tetracarboxylic dianhydride”) as a monomer. To synthesize the polyamic acid (P). Moreover, in the said method (i) and method (iii), although the said specific tetracarboxylic dianhydride may be used independently as a tetracarboxylic dianhydride used for a synthesis | combination, with specific tetracarboxylic dianhydride Other tetracarboxylic dianhydrides may be used.

Examples of the other tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. Specific examples of these include aliphatic tetracarboxylic dianhydrides such as butane tetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-di Oxotetrahydrofuran-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-To Carboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-di Anhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1] .0 ^2,6] undecane -3,5,8,10- tetraone, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene -2, 3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic acid dianhydride, cyclopentanetetracarboxylic dianhydride, ethylene glycol bis (anhydro trimellitate), 1,3-propylene glycol bis (anhydro Trimellitate ) Etc .;
Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride and the like; respectively, and tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, other tetracarboxylic dianhydrides can be used alone or in combination of two or more.

  Other tetracarboxylic dianhydrides used for the synthesis of the polyamic acid (P) are bicyclo [2.2.1] heptane-2,3 in that liquid crystal alignment and solubility in a solvent can be improved. , 5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxo Tetrahydrofuran-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 2: 4,6: 8 dianhydride, preferably contains at least one compound selected from the group consisting of dianhydrides cyclohexane tetracarboxylic acid and pyromellitic dianhydride.

The ratio of the specific tetracarboxylic dianhydride used in the case of the above method (i) should be 3 mol% or more with respect to the total amount of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid (P). It is preferably 5 mol% or more, more preferably 10 mol% or more. The upper limit of the usage rate is not particularly limited, and can be arbitrarily set within a range of 100 mol% or less.
Moreover, although the usage rate of the specific tetracarboxylic dianhydride in the case of the said method (iii) can be suitably set according to the usage rate of specific diamine, the tetracarboxylic acid used for the synthesis | combination of polyamic acid (P) is used. For example, the amount of acid dianhydride may be 0.5 mol% or more, preferably 1 mol% or more, more preferably 3 mol% or more, and 5 mol% or more. More preferably.

（式（ｄ）中、Ｘ^３及びＸ^４は、それぞれ独立に単結合、−Ｏ−、＊−ＣＯＯ−、＊−ＯＣＯ−、−ＣＯ−、＊−ＮＲ^１４ＣＯ−又は＊−ＣＯＮＲ^１４−（但し、Ｒ^１４は、水素原子又は炭素数１〜３のアルキル基である。「＊」はアミノフェニル基との結合手を示す。）である。Ｒ^３は、炭素数１〜２０のアルカンジイル基、炭素数２〜２０のアルケンジイル基、フェニレン基、ピペリジンジイル基、炭素数１〜２０のアルカンジイル基若しくは炭素数２〜２０のアルケンジイル基の一部の水素原子を置換基で置き換えてなる２価の基、又は炭素数１〜２０のアルカンジイル基若しくは炭素数２〜２０のアルケンジイル基の一部のメチレン基を−Ｏ−若しくは−Ｓ−で置き換えてなる２価の基である。Ｒ^４及びＲ^５は、それぞれ独立にハロゲン原子、又は炭素数１〜６のアルキル基若しくはアルコキシ基である。ｑは０又は１である。ｍ及びｎは、それぞれ独立に０〜４の整数である。Ｒ^４，Ｒ^５が複数存在する場合、複数のＲ^４，Ｒ^５は、それぞれ同じでも異なっていてもよい。Ｗ^１、Ｗ^２、Ｘ^１、Ｘ^２、Ｒ^１、Ｒ^２及びｐは上記式（１）とそれぞれ同義である。） (Specific diamine)
As specific diamine used for the synthesis | combination of the said polyamic acid (P), an aliphatic diamine, an alicyclic diamine, an aromatic diamine etc. can be mentioned, for example. Among these, aromatic diamines are preferable, and specifically, a compound represented by the following formula (d) is preferable.

(In formula (d), X ³ and X ⁴ are each independently a single bond, —O—, * —COO—, * —OCO—, —CO—, * —NR ¹⁴ CO— or * —CONR ¹⁴ —. (However, R ¹⁴ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “*” Represents a bond with an aminophenyl group.) R ³ is an alkane having 1 to 20 carbon atoms. A part of hydrogen atoms of a diyl group, an alkenediyl group having 2 to 20 carbon atoms, a phenylene group, a piperidinediyl group, an alkanediyl group having 1 to 20 carbon atoms, or an alkenediyl group having 2 to 20 carbon atoms is replaced with a substituent. It is a divalent group or a divalent group obtained by replacing a part of methylene groups of an alkanediyl group having 1 to 20 carbon atoms or an alkenediyl group having 2 to 20 carbon atoms with —O— or —S—. ⁴ and R ⁵ are independent Is a halogen atom, or an alkyl group or alkoxy group having 1 to 6 carbon atoms, q is 0 or 1. m and n are each independently an integer of 0 to ^4. R ⁴ and R ⁵ are plural. When present, the plurality of R ⁴ and R ⁵ may be the same or different, and W ¹ , W ² , X ¹ , X ² , R ¹ , R ^2, and p are as defined in the above formula (1). .)

X ³ and X ^{4 in} the above formula (d) are preferably a single bond, —O—, * —COO— or * —OCO—. However, when R ¹ is a single bond, X ³ and X ⁴ are particularly preferably a single bond. With respect to specific examples and preferred groups of R ³ , the above description of R ¹ can be applied. m and n are preferably 0.
Specific examples of the compound represented by the formula (d) include compounds represented by the following formulas (D-1) to (D-36).

Formula (D-1) to Formula (D-3), Formula (D-5), Formula (D-7), Formula (D-8), Formula (D-10) to Formula (D-24) and As the compound represented by each of the formula (D-29) to the formula (D-35), either a trans-type compound or a cis-type compound in which the configuration of the divalent organic group bonded to the cyclohexane ring is used. Alternatively, a mixture of a trans isomer and a cis isomer may be used. Formula (D-1) to Formula (D-3), Formula (D-5), Formula (D-7), Formula (D-8), Formula (D-10) to Formula (D-24) and When using the compound represented by each of formula (D-29) to formula (D-35), the proportion of the trans isomer (the total amount when two or more compounds are used) is 50 mol%. Preferably, the content is 70 mol% or more, and more preferably 90 mol% or more. As specific diamine used for the synthesis | combination of the said polyamic acid, 1 type of these compounds can be used individually or in combination of 2 or more types as appropriate.
Of the compounds represented by formula (D-1) to formula (D-36), the formula (D-5) and formula (D-10) to formula (D-17) respectively. The compound to be obtained corresponds to a diamine having a partial structure in which R ^{1 in the} above formula (1) is a single bond and p is 1 or 2.

(Other diamines)
In the said method (i), the said polyamic acid (P) is synthesize | combined by superposition | polymerization using the diamine (henceforth "other diamine") which does not have the structure represented by the said Formula (1) for a monomer. . Moreover, in the said method (ii) and method (iii), although the said specific diamine may be used independently as a diamine used for a synthesis | combination, you may use another diamine with a specific diamine.

Examples of the other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Specific examples thereof include aliphatic diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;

（式（Ｄ−１ａ）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−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る。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。） Examples of the aromatic diamine include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfide, 4,4′-diaminodiphenylamine, 1,7- Bis (4-aminophenoxy) heptane, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 4,4′-diamino Diphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexa Fluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-pheny Diisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, N, N′-bis (4-amino) Phenyl) -benzidine, 3,5-diaminobenzoic acid, dodecanoxy-2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4- Diaminobenzene, 3,5-diaminobenzoate cholestanyl, 3,6-bis (4-aminobenzoyloxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 2, 4-diamino-N, N-diallylaniline, 4-aminobenzylamine, 1- ( , 4-Diaminophenyl) piperazine-4-carboxylic acid, 1,3-bis (N- (4-aminophenyl) piperidinyl) propane, 1- (4-aminophenyl) -2,3-dihydro-1,3 3-trimethyl-1H-indene-5-amine, 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine, 4-aminophenyl-4 ′ -Aminobenzoate, 4,4 '-[4,4'-propane-1,3-diylbis (piperidine-1,4-diyl)] dianiline, and the following formula (D-1a)

(In Formula (D-1a), X ^I and X ^II are each independently a single bond, —O—, —COO— or —OCO—, and 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, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1, provided that a and b are not 0 at the same time.)

A compound represented by:
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and the diamines described in JP-A 2010-97188 can be used.

Examples of the divalent group represented by “—X ^I — (R ^I —X ^II ) _d —” in the formula (D-1a) include alkanediyl groups having 1 to 3 carbon atoms, * —O—, * —COO— or * —O—C ₂ H ₄ —O— (however, a bond marked with “*” is bonded to a diaminophenyl group) is preferred. Specific examples of the group “—C _c H _{2c + 1} ” include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group. Group, n-nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group Group, n-eicosyl group and the like. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to other groups.

なお、上記ポリアミック酸の合成に使用するその他のジアミンとしては、これらの化合物の１種を単独で又は２種以上を適宜選択して使用することができる。 Specific examples of the compound represented by the formula (D-1a) include compounds represented by the following formulas (D-1-1) to (D-1-4).

In addition, as another diamine used for the synthesis | combination of the said polyamic acid, 1 type of these compounds can be used individually or in combination of 2 or more types as appropriate.

In the case of the above method (ii), the proportion of the specific diamine used is preferably 3 mol% or more, preferably 5 mol% or more, based on the total amount of diamine used for the synthesis of the polyamic acid (P). More preferably, it is more preferably 10 mol% or more. The upper limit of the usage rate is not particularly limited, and can be arbitrarily set within a range of 100 mol% or less. When the improvement effect (for example, a voltage holding ratio, liquid crystal orientation, etc.) by addition of other diamine is aimed at, it is preferable that the usage-amount of the said specific diamine shall be 95 mol% or less.
Moreover, although the usage-amount of the specific diamine in the case of the said method (iii) can be suitably set according to the usage-amount of specific tetracarboxylic dianhydride, it is the diamine used for the synthesis | combination of polyamic acid (P). For example, it can be 0.5 mol% or more, preferably 1 mol% or more, more preferably 3 mol% or more, and still more preferably 4 mol% or more based on the total amount.

When the liquid crystal aligning agent of the present invention is used for production of a TN type, STN type or vertical alignment type liquid crystal display element, at least a part of the polymer (P) contained in the liquid crystal aligning agent is pretilt with respect to the coating film. A polymer having a group capable of imparting an angle development ability (hereinafter also referred to as a “pretilt angle expression group”) may be used. Examples of the pretilt angle-expressing group include an alkyl group having 4 to 20 carbon atoms, a fluoroalkyl group having 4 to 20 carbon atoms, an alkoxy group having 4 to 20 carbon atoms, a group having a steroid skeleton having 17 to 51 carbon atoms, And a group having a ring structure.
For example, in order to obtain a polyamic acid (P) having a pretilt angle-expressing group, it is carried out by polymerization containing a diamine having a pretilt angle-expressing group in the monomer composition in terms of ease of introduction of the pretilt angle-expressing group. preferable. Specifically, it can synthesize | combine by using the diamine which has the said pretilt angle expression group as another diamine.
When using a diamine having a pretilt angle-expressing group, the amount used is preferably 3 mol% or more based on the total diamine used in the synthesis, in terms of expressing sufficiently high pretilt angle characteristics, It is more preferable to set it as 5-70 mol%.

  When the liquid crystal aligning ability is imparted to the coating film prepared using the liquid crystal aligning agent of the present invention by a photo-alignment method, at least a part of the polymer (P) contained in the liquid crystal aligning agent is used as a photo-alignment structure. It is good also as a polymer which has. Here, the photo-alignment structure is a concept including both a photo-alignment group and a decomposition type photo-alignment part. Specifically, as the photoalignment structure, a group that exhibits photoalignment by photoisomerization, photodimerization, photolysis, or the like can be employed. For example, an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton. A group having a cinnamic acid structure containing cinnamic acid or a derivative thereof as a basic skeleton, a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, coumarin or a derivative thereof Examples include a coumarin-containing group containing a derivative as a basic skeleton, a polyimide-containing structure containing polyimide or a derivative thereof as a basic skeleton, and the like.

  When the polyamic acid (P) has a photo-alignment structure, the photo-alignment structure is preferably a decomposition-type photo-alignment part, specifically, a bicyclo [2.2.2] octene skeleton or a cyclobutane skeleton. It is preferable that it is a polymer which has. A polyamic acid (P) having a bicyclo [2.2.2] octene skeleton or a cyclobutane skeleton is used as another tetracarboxylic dianhydride as a bicyclo [2.2.2] oct-7-ene-2,3, It can be obtained by using at least one of 5,6-tetracarboxylic dianhydride and cyclobutanetetracarboxylic dianhydride.

[Synthesis of Compound Represented by Formula (1) above]
The compound represented by the above formula (1) can be synthesized by appropriately combining organic chemistry methods. As an example, for the specific diamine, a dinitro intermediate having a nitro group is synthesized in place of the primary amino group in formula (d), and then the nitro group of the obtained dinitro intermediate is converted into an appropriate reduction system. The method of amination using is mentioned.

The method for synthesizing the dinitro intermediate can be appropriately selected depending on the target compound. For example, a hydroxyl group-containing compound having a group represented by “—W ¹ — (R ² —W ² ) p—”, a group represented by “—X ³ —R ¹ —”, and a carboxyl having a nitrophenyl group. a method of reacting an acid; and a hydroxyl group-containing compound having a group represented by ^{"- (R 2 -W 2) p-} - W 1 " ^- is represented by "(R 3 ^-X 4) q-" And a carboxylic acid having a nitrophenyl group; a carboxylic acid having a group represented by “—W ¹ — (R ² —W ² ) p—” and “—X ³ —R ¹ — And a hydroxyl group-containing compound having a nitrophenyl group; a carboxylic acid having a group represented by “—W ¹ — (R ² —W ² ) p—”, and “— ( R ³ -X ⁴ ) q- "and a hydroxyl group-containing compound having a nitrophenyl group. A method of reacting a carboxylic acid having a group represented by “—R ¹ —X ¹ —W ¹ — (R ² —W ² ) p—” with nitrophenol or a derivative thereof; “—R A method of reacting a halide having a group represented by “ ^1- X ¹ -W ^1- (R ² -W ² ) p-” with nitrophenol or a derivative thereof; “—W ^1- (R ² -W ² ) a method in which a carboxylic acid having a group represented by p-X ² -R ³ -is reacted with nitrophenol or a derivative thereof; "-W ^1- (R ² -W ² ) p-X ^2-" A method of reacting a halide having a group represented by “R ³ —” with nitrophenol or a derivative thereof; a halogen compound having a group represented by “—X ³ —R ¹ —” and a nitrophenyl group; Table with ^{- "(R 2 -W 2) p- -W} 1 " A method of reacting a hydroxyl group-containing compound having the group; ^"- X 4 -R ^{3 -"} and halide having a group and a nitro phenyl group represented by ^{"- W 1 - (R 2 -W} 2) p - a method of reacting a hydroxyl group-containing compound having the group represented by ";" ^{- R 1 -W 1 - (R} 2 -W 2) and hydroxyl group-containing compound having a group represented by ^p- "nitrobenzoyl A method of reacting with chloride; a method of reacting nitrobenzoyl chloride with a primary amine having a group represented by “—R ¹ —W ¹ — (R ² —W ² ) p—”; “—R ¹ -W 1 ^- with an acid chloride having the (R ² -W 2) a group represented by ^p- ", a method of reacting a 4-nitroaniline or a derivative thereof; one way of such alone Or by combining two or more methods as appropriate It can be.

The reaction for obtaining the dinitro intermediate is preferably carried out in an organic solvent. Here, the organic solvent may be any solvent that does not affect the reaction, and examples thereof include methanol, ethanol, tetrahydrofuran, toluene, dichloromethane, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone and the like. Can do. Moreover, you may perform the said reaction in catalyst presence as needed.
The reduction reaction of the dinitro intermediate can be preferably carried out in an organic solvent using a catalyst such as palladium carbon, platinum oxide, zinc, iron, tin, nickel or the like. Examples of the organic solvent used here include ethyl acetate, toluene, tetrahydrofuran, and alcohols. However, the synthesis procedure of the specific diamine is not limited to the above method.

[Synthesis of polyamic acid (P)]
The ratio of the tetracarboxylic dianhydride and the diamine used for the synthesis reaction of the polyamic acid (P) is such that the acid anhydride group of the tetracarboxylic dianhydride is 0. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable.

In synthesizing the polyamic acid (P), a terminal-modified polymer may be synthesized using an appropriate molecular weight regulator together with the tetracarboxylic dianhydride and diamine as described above. By using such a terminal-modified polymer, the coating property (printability) of the liquid crystal aligning agent can be further improved without impairing the effects of the present invention.
Examples of the molecular weight regulator include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. Can be mentioned. The use ratio of the molecular weight regulator is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine used.

The polyamic acid synthesis reaction is preferably carried out in an organic solvent. Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (first group organic solvent), or one or more 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 (second-group organic solvent). In the latter case, the proportion of the second group organic solvent used is preferably 50% by weight or less, more preferably 40% by weight, based on the total amount of the first group organic solvent and the second group organic solvent. Or less, more preferably 30% by weight or less.
Particularly preferred are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol and halogen. It is preferable to use one or more selected from the group consisting of fluorinated phenols as a solvent, or to use a mixture of one or more of these and another organic solvent in the above range.
The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. Is preferred. The reaction temperature in the synthesis reaction of polyamic acid is preferably -20 ° C to 150 ° C, and more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

  As described above, a reaction solution obtained by dissolving the polyamic acid (P) is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid (P) contained in the reaction solution, or the isolated polyamic acid. You may use for refinement | purification of a liquid crystal aligning agent, after refine | purifying (P). When the polyamic acid (P) is dehydrated and cyclized into a polyimide, the reaction solution may be subjected to the dehydration and cyclization reaction as it is, and the polyamic acid (P) contained in the reaction solution is isolated and then dehydrated and cyclized. You may use for reaction or you may use for dehydration ring closure after refine | purifying the isolated polyamic acid (P). Isolation and purification of the polyamic acid can be performed according to known methods.

[Polyamic acid ester (P)]
The polyamic acid ester (hereinafter also referred to as polyamic acid ester (P)) as the polymer (P) is, for example, [I] a polyamic acid (P) obtained by the above synthesis reaction, a hydroxyl group-containing compound, or an acetal. A method of reacting an esterifying agent such as a compound, a halide or an epoxy group-containing compound, a method of reacting a [II] tetracarboxylic acid diester and a diamine, and a reaction of [III] a tetracarboxylic acid diester dihalide and a diamine. It can be obtained by the method of making it.

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

  The tetracarboxylic acid diester used in Method [II] can be obtained by ring-opening tetracarboxylic dianhydride using the above alcohols. The tetracarboxylic acid diester dihalide used in the method [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. The diamine used in the methods [II] and [III] preferably contains the above-mentioned specific diamine, and other diamines may be used as necessary. The polyamic acid ester (P) may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist.

[Polyimide (P)]
The polyimide (hereinafter also referred to as polyimide (P)) as the polymer (P) can be obtained, for example, by dehydrating and ring-closing and imidizing the polyamic acid (P) synthesized as described above. .

  The polyimide (P) may be a completely imidized product obtained by dehydrating and ring-closing all of the amic acid structure of the polyamic acid (P) that is the precursor, and only a part of the amic acid structure is dehydrating and ring-closing. Alternatively, it may be a partially imidized product in which an amic acid structure and an imide ring structure coexist. As for the polyimide contained in the liquid crystal aligning agent of this invention, it is preferable that the imidation ratio is 30% or more, It is more preferable that it is 40 to 99%, It is still more preferable that it is 50 to 99%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

  The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the solution as necessary. . Of these, the latter method is preferred.

  In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. 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 (P) is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, and the liquid crystal after isolating the polyimide. You may use for preparation of an aligning agent, or you may use for preparation of a liquid crystal aligning agent, after purifying the isolated polyimide. These purification operations can be performed according to known methods. In addition, polyimide (P) can also be obtained by imidation of polyamic acid ester (P).

The polyamic acid (P), the polyamic acid ester (P) and the polyimide (P) obtained as described above have a solution viscosity of 20 to 1,800 mPa · s when this is a 15% by weight solution. It is preferable to have a solution viscosity of 50 to 1,500 mPa · s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 15% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer.
The weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the polyamic acid (P), polyamic acid ester (P) and polyimide (P) is preferably 1,000 to 500,000. More preferably, it is 2,000-300,000. Moreover, the molecular weight distribution (Mw / Mn) represented by the ratio between Mw and the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By being in such a molecular weight range, it is possible to ensure good orientation and stability of the liquid crystal display element.

<Other ingredients>
Although the liquid crystal aligning agent of this invention contains the said polymer (P), you may contain the other component as needed. Other components that may be added to the liquid crystal aligning agent include, for example, other polymers other than the polymer (P), compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy group-containing compound”). ), A functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, and the like.

[Other polymers]
The above other polymers can be used for improving solution properties and electrical properties. Such other polymers are polymers that do not have the partial structure represented by the above formula (1) in the main chain, and the main skeleton is not particularly limited. Specifically, for example, polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate and the like as the main skeleton Can be mentioned. Among these, at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane is preferable. Other polymers can be synthesized by a conventionally known method. In addition, when providing the liquid crystal aligning ability with the photo-alignment method with respect to the coating film formed using the liquid crystal aligning agent of this invention, you may use the polymer which has the said photo-alignment structure as said other polymer.
When adding another polymer to a liquid crystal aligning agent, it is preferable that the mixture ratio shall be 50 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent, The amount is more preferably 40 parts by weight, and still more preferably 0.1 to 30 parts by weight.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesion and electrical properties with the substrate surface in the liquid crystal alignment film. Examples of such epoxy group-containing compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylylene diene Amine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diamy Diphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine. In addition, as an example of the epoxy group-containing compound, an epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598 can be used.
When adding these epoxy compounds to a liquid crystal aligning agent, it is preferable that the mixture ratio shall be 40 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent, 0.1-30 More preferred are parts by weight.

[Functional silane compounds]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3,6- Methyl azananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid And xylpropyltrimethoxysilane.
When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 2 parts by weight or less with respect to a total of 100 parts by weight of the polymer contained in the liquid crystal aligning agent. It is more preferable to set it to -0.2 weight part.

[Metal chelate compounds]
When the polymer component of the liquid crystal aligning agent has an epoxy structure, the metal chelate compound is a liquid crystal aligning agent (particularly a liquid crystal for a retardation film) for the purpose of ensuring the mechanical strength of the film formed by low-temperature treatment. Contained in the alignment agent). As the metal chelate compound, it is preferable to use an acetylacetone complex or acetoacetic acid complex of a metal selected from aluminum, titanium and zirconium. Specifically, for example, diisopropoxyethyl acetoacetate aluminum, tris (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, diisopropoxybis (ethylacetoacetate) titanium, diisopropoxybis (acetylacetonate) Examples thereof include titanium, tri-n-butoxyethyl acetoacetate zirconium, and di-n-butoxybis (ethyl acetoacetate) zirconium. When the metal chelate compound is added, the use ratio thereof is preferably 50 parts by weight or less, more preferably 0.1 to 40 parts by weight, with respect to a total of 100 parts of the components including the epoxy structure, More preferably, it is 1-30 weight part.

[Curing accelerator]
When the polymer component in the liquid crystal aligning agent has an epoxy structure, the curing accelerator is a liquid crystal in order to ensure the mechanical strength of the liquid crystal alignment film to be formed and the stability over time of the liquid crystal alignment. It is contained in an aligning agent (particularly, a liquid crystal aligning agent for a retardation film). As the curing accelerator, for example, a compound having a phenol group, a silanol group, a thiol group, a phosphoric acid group, a sulfonic acid group, a carboxyl group, a carboxylic anhydride group, or the like can be used. A compound having is preferred. Specific examples thereof include compounds having a phenol group such as cyanophenol, nitrophenol, methoxyphenoxyphenol, thiophenoxyphenol, 4-benzylphenol; compounds having a silanol group such as trimethylsilanol, triethylsilanol, 1 , 1,3,3-tetraphenyl-1,3-disiloxanediol, 1,4-bis (hydroxydimethylsilyl) benzene, triphenylsilanol, tri (p-tolyl) silanol, diphenylsilanediol, etc. be able to. When the curing accelerator is added, the use ratio thereof is preferably 50 parts by weight or less, more preferably 0.1 to 40 parts by weight with respect to 100 parts by weight of the total components including the epoxy structure, and further Preferably it is 1-30 weight part.

[Surfactant]
The surfactant can be contained in a liquid crystal aligning agent (particularly, a liquid crystal aligning agent for a retardation film) for the purpose of improving the applicability of the liquid crystal aligning agent to the substrate. Examples of such surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, silicone surfactants, polyalkylene oxide surfactants, and fluorine-containing surfactants. be able to. The proportion of the surfactant used is preferably 10 parts by weight or less, and more preferably 1 part by weight or less with respect to 100 parts by weight of the total amount of the liquid crystal aligning agent.
In addition to the above, other components include compounds having at least one oxetanyl group in the molecule, antioxidants, and the like.

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

  Examples of the organic solvent to be used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, Ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, 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 Recall 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, etc. be able to. These can be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of this invention is apply | coated to a substrate surface so that it may mention later, Preferably the coating film which becomes a liquid crystal aligning film or a coating film used as a liquid crystal aligning film is formed by heating. At this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. There is a tendency.

  The particularly preferable solid content concentration range varies depending on the use of the liquid crystal aligning agent and the method used when the liquid crystal aligning agent is applied to the substrate. For example, when a liquid crystal aligning agent for a liquid crystal aligning film is applied to a substrate by a spinner method, the solid content concentration (the ratio of the total weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) Is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, 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 weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s. The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC. Moreover, about the liquid crystal aligning agent for retardation films, the solid content density | concentration of a liquid crystal aligning agent is 0.2 to 10 weight% from a viewpoint which makes the applicability | paintability of a liquid crystal aligning agent, and the film thickness of the coating film formed moderate. It is preferable that it is the range of 3-10 weight%.

<Liquid crystal display element and retardation film>
By using the liquid crystal aligning agent of the present invention described above, a liquid crystal aligning film can be produced. Moreover, the liquid crystal aligning film formed using the liquid crystal aligning agent of this invention is preferably applicable to the liquid crystal aligning film for liquid crystal display elements (for liquid crystal cells), and the liquid crystal aligning film for retardation films. Below, the liquid crystal display element and retardation film of this invention are demonstrated.

[Liquid crystal display element]
The liquid crystal display element of this invention comprises the liquid crystal aligning film formed using the said liquid crystal aligning agent. The operation mode of the liquid crystal display element of the present invention is not particularly limited. For example, TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB type, etc. It can be applied to the operation mode.

  The liquid crystal display element of this invention can be manufactured according to the process including the following processes (1-1)-(1-3), for example. In the step (1-1), a substrate to be used is different depending on a desired operation mode. Step (1-2) and step (1-3) are common to each operation mode.

[Step (1-1): Formation of coating film]
First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.
(1-1A) When manufacturing a TN-type, STN-type, or VA-type liquid crystal display element, for example, first, a pair of two substrates on which patterned transparent conductive films are provided, and each transparent conductive film is formed. On the surface, the liquid crystal aligning agent of the present invention is preferably applied by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method, respectively. As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In order to obtain a patterned transparent conductive film, for example, after forming a transparent conductive film without a pattern, a method of forming a pattern by photo-etching; a method of using a mask having a desired pattern when forming a transparent conductive film; And so on. When applying the liquid crystal aligning agent, 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. It is also possible to perform a pretreatment to apply the above in advance.

  After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely and heat imidating the amic acid structure which exists in a polymer as needed. The firing temperature (post-bake temperature) at this time is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake 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.

  (1-1B) When manufacturing an IPS type or FFS type liquid crystal display element, an electrode forming surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and an electrode are provided. The liquid crystal aligning agent of this invention is each apply | coated to one surface of the counter substrate which is not formed, Then, a coating film is formed by heating each application surface. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed The same as (1-1A). As the metal film, for example, a film made of a metal such as chromium can be used.

  In both cases (1-1A) and (1-1B), after applying a liquid crystal aligning agent on the substrate, the organic solvent is removed to form a liquid crystal alignment film or a liquid crystal alignment film. The At this time, by further heating after the formation of the coating film, the dehydration ring-closing reaction of the polyamic acid, polyamic acid ester and polyimide blended in the liquid crystal aligning agent of the present invention may be advanced to obtain a more imidized coating film.

[Step (1-2): Orientation ability imparting treatment]
When manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal display element, the process which provides liquid crystal aligning ability to the coating film formed at the said process (1-1) is implemented. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Examples of the orientation-imparting treatment include rubbing treatment in which the coating film is rubbed in a fixed direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, and photo-alignment in which the coating film is irradiated with polarized or non-polarized radiation. Processing. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step (1-1) can be used as it is as a liquid crystal alignment film. May be. In addition, since the coating film obtained using the liquid crystal aligning agent of this invention has favorable rubbing tolerance, it is possible to provide a high orientation control force to a coating film by a rubbing process.

In the photo-alignment treatment, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as the radiation applied to the coating film, for example. 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, irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When non-polarized radiation is irradiated, the irradiation direction is an oblique direction.
As a light source to be 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, or the like can be used. Ultraviolet rays in a preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter or a diffraction grating. The radiation dose is preferably 100 to 50,000 J / m ² , more preferably 300 to 20,000 J / m ² . Moreover, you may perform light irradiation with respect to a coating film, heating a coating film, in order to improve the reactivity. The temperature at the time of heating is 30-250 degreeC normally, Preferably it is 40-200 degreeC, More preferably, it is 50-150 degreeC.

  In addition, the liquid crystal alignment film after the rubbing treatment is further subjected to a process for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays or a surface of the liquid crystal alignment film. A resist film is formed on the part, and a rubbing process is performed in a direction different from the previous rubbing process, followed by a process of removing the resist film, so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region. . In this case, it is possible to improve the visibility characteristics of the obtained liquid crystal display element. A liquid crystal alignment film suitable for a VA liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element.

[Step (1-3): Construction of liquid crystal cell]
Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates disposed to face each other. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example. The first method is a conventionally known method. First, two substrates are arranged opposite to each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole. The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealant is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped at predetermined locations on the liquid crystal alignment film surface. After that, the other substrate is bonded so that the liquid crystal alignment film faces, and the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, thereby manufacturing a liquid crystal cell. can do. Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase and then gradually cooled to room temperature. It is desirable to remove.

As a sealing agent, what is normally used as an adhesive agent for liquid crystals can be used, for example, an epoxy resin containing a curing agent can be used. Moreover, you may use as a sealing agent what further contains the aluminum oxide sphere as a spacer.
Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. 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. Cyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

  And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned.

[Phase difference film]
Next, a method for producing a retardation film using the liquid crystal aligning agent of the present invention will be described. In the production of the retardation film of the present invention, it is possible to form a uniform liquid crystal alignment film while suppressing the generation of dust and static electricity during the process, and an appropriate photomask is used during radiation irradiation. It is preferable to use the photo-alignment method in that a plurality of regions having different liquid crystal alignment directions can be arbitrarily formed on the substrate. Specifically, it can be produced through the following steps (2-1) to (2-3).

[Step (2-1): Formation of coating film by liquid crystal aligning agent]
First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, and a coating film is formed. As the substrate used here, a transparent substrate made of a synthetic resin such as triacetyl cellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polyamide, polyimide, polymethyl methacrylate, polycarbonate, etc. is preferably exemplified. Can do. Of these, TAC is generally used as a protective layer for a polarizing film in a liquid crystal display device. In addition, polymethyl methacrylate can be preferably used as a substrate for a retardation film in that the hygroscopicity of the solvent is low, the optical properties are good, and the cost is low. In addition, for the substrate used for the application of the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the coating film, a conventionally known pretreatment is performed on the surface of the substrate surface on which the coating film is formed. May be implemented.

  In many cases, the retardation film is used in combination with a polarizing film. At this time, it is necessary to attach the retardation film by precisely controlling the angle with respect to the polarization axis of the polarizing film in a specific direction so that the desired optical characteristics can be exhibited. Accordingly, by forming a liquid crystal alignment film having a liquid crystal alignment ability in a predetermined angle direction on a substrate such as a TAC film or polymethyl methacrylate, the angle of the retardation film is controlled on the polarizing film. The step of bonding can be omitted. Thereby, it can contribute to the improvement of productivity of a liquid crystal display element. In order to form a liquid crystal alignment film having a liquid crystal alignment ability in a direction of a predetermined angle, it is preferable to carry out by a photo-alignment method using the liquid crystal aligning agent of the present invention.

The liquid crystal aligning agent can be applied onto the substrate by an appropriate application method such as a roll coater method, a spinner method, a printing method, an ink jet method, a bar coater method, an extrusion die method, a direct gravure coater method, a chamber. Doctor coater method, offset gravure coater method, single roll kiss coater method, reverse kiss coater method using small diameter gravure roll, 3 reverse roll coater method, 4 reverse roll coater method, slot die method, air doctor coater method A positive rotation roll coater method, a blade coater method, a knife coater method, an impregnation coater method, an MB coater method, an MB reverse coater method, and the like can be employed.
After coating, the coated surface is heated (baked) to form a coating film. The heating temperature at this time is preferably 40 to 150 ° C, more preferably 80 to 140 ° C. The heating time is preferably 0.1 to 15 minutes, and more preferably 1 to 10 minutes. The film thickness of the coating film formed on the substrate is preferably 1 to 1,000 nm, more preferably 5 nm to 500 nm.

[Step (2-2): Light irradiation step]
Next, the coating film formed on the substrate as described above is irradiated with light, thereby imparting liquid crystal alignment ability to the liquid crystal alignment film. Here, examples of the light to be irradiated include ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm. Among these, ultraviolet rays containing light having a wavelength of 300 to 400 nm are preferable. Irradiation light may be polarized or non-polarized. As the polarized light, it is preferable to use light including linearly polarized light.
When the light to be used is polarized light, the light irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized light, it is necessary to carry out from a direction oblique to the substrate surface.
Examples of the light source used include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and a mercury-xenon lamp (Hg-Xe lamp). Polarized light can be obtained by means of using these light sources in combination with, for example, a filter or a diffraction grating.
The dose of light is preferably set to 0.1 mJ / cm ² or more 1,000 mJ / cm less than ^2, more preferably, to 1 to 500 mJ / cm ^2, further be 2~200mJ / cm ² preferable.

[Step (2-3): Formation of Liquid Crystal Layer]
Next, a polymerizable liquid crystal is applied and cured on the coating film after the light irradiation as described above. Thereby, the coating film (liquid crystal layer) containing a polymerizable liquid crystal is formed. The polymerizable liquid crystal used here is a liquid crystal compound or a liquid crystal composition that is polymerized by at least one treatment of heating and light irradiation. As such a polymerizable liquid crystal, a conventionally known liquid crystal can be used. Specifically, for example, Non-Patent Document 1 ("UV curable liquid crystal and its application", Liquid Crystal, Vol. 3, No. 1 (1999). Year), pp 34-42). Further, cholesteric liquid crystal; discotic liquid crystal; twisted nematic alignment type liquid crystal to which a chiral agent is added may be used. The polymerizable liquid crystal may be a mixture of a plurality of liquid crystal compounds. The polymerizable liquid crystal may further be a composition containing a known polymerization initiator, an appropriate solvent, and the like.
In order to apply the polymerizable liquid crystal as described above on the formed liquid crystal alignment film, for example, an appropriate application method such as a bar coater method, a roll coater method, a spinner method, a printing method, or an ink jet method can be employed. .

Next, the coating film of the polymerizable liquid crystal formed as described above is subjected to at least one treatment selected from heating and light irradiation to cure the coating film to form a liquid crystal layer. It is preferable to perform these treatments in a superimposed manner because good alignment can be obtained.
The heating temperature of the coating film is appropriately selected depending on the type of polymerizable liquid crystal used. For example, when using RMS03-013C manufactured by Merck, it is preferable to heat at a temperature in the range of 40 to 80 ° C. The heating time is preferably 0.5 to 5 minutes.
As irradiation light, non-polarized ultraviolet rays having a wavelength in the range of 200 to 500 nm can be preferably used. The irradiation dose of light, preferably in the 50~10,000mJ / cm ^2, and more preferably a 100~5,000mJ / cm ^2.
The thickness of the liquid crystal layer to be formed is appropriately set depending on desired optical characteristics. For example, when manufacturing a half-wave plate in visible light having a wavelength of 540 nm, a thickness is selected such that the retardation of the formed retardation film is 240 to 300 nm. The thickness is selected such that the phase difference is 120 to 150 nm. The thickness of the liquid crystal layer from which the desired retardation is obtained varies depending on the optical characteristics of the polymerizable liquid crystal used. For example, when RMS03-013C manufactured by Merck is used, the thickness for manufacturing a quarter-wave plate is in the range of 0.6 to 1.5 μm.

  The retardation film obtained as described above can be preferably applied as a retardation film of a liquid crystal display element. The liquid crystal display element to which the retardation film manufactured using the liquid crystal aligning agent of the present invention is applied is not limited in its operation mode. For example, TN type, STN type, IPS type, FFS type, VA type and the like are known. It can be applied to various modes. The retardation film is used by attaching the substrate-side surface of the retardation film to the outer surface of the polarizing plate disposed on the viewing side of the liquid crystal display element. Therefore, it is preferable that the retardation film substrate is made of TAC or an acrylic base, and the retardation film substrate also functions as a protective film for the polarizing film.

  Here, there is a roll-to-roll method as a method for producing a retardation film on an industrial scale. In this method, a film is unwound from a wound body of a long base film, a liquid crystal alignment film is formed on the unwound film, and a polymerizable liquid crystal is applied and cured on the liquid crystal alignment film. It is the method of performing the process and the process which laminates | stacks a protective film as needed in the continuous process, and collect | recovering the film after passing through these processes as a wound body. The retardation film formed using the liquid crystal aligning agent of the present invention has good adhesion to the substrate, and the liquid crystal alignment film and the substrate are hardly peeled even when stored as a wound body. Therefore, it is possible to suppress a decrease in product yield when producing a retardation film by a roll-to-roll method, which is preferable from the viewpoint of productivity.

  The liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, The present invention can be used for various display devices such as various monitors, liquid crystal televisions, and information displays.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

In the following Examples and Synthesis Examples, the polymer weight average molecular weight Mw, imidization rate and epoxy equivalent, and the solution viscosity of the polymer solution were measured by the following methods. Hereinafter, the compound represented by Formula X may be simply referred to as “Compound X”.
[Weight average molecular weight Mw of polymer]
Mw is a polystyrene equivalent value measured by GPC under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Imidation rate of polymer]
A solution containing polyimide is poured into pure water, and the resulting precipitate is sufficiently dried at room temperature under reduced pressure, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR is measured at room temperature using tetramethylsilane as a reference substance. did. From the obtained ¹ H-NMR spectrum, the imidation ratio was determined using the following mathematical formula (1).
Imidation ratio (%) = (1-A ¹ / A ² × α) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of a polymer (polyamic acid). The number ratio of other protons to one proton of NH group in)
[Epoxy equivalent]
The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.
[Solution viscosity of polymer solution]
The solution viscosity (mPa · s) of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer.

<Synthesis of Compound having Structure Represented by Formula (1)>
[Example 1-1; Synthesis of Compound (DA-1)]
Compound (DA-1) was synthesized according to the following scheme 1.

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

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

[Example 1-4; Synthesis of Compound (DA-4)]
Compound (DA-4) was synthesized according to the following scheme 4.

[Example 1-5; Synthesis of Compound (DA-5)]
Compound (DA-5) was synthesized according to the following scheme 5.

  The 4,4′-dihydroxybicyclohexyl used in the reaction was synthesized using a mixture of structural isomers of cis and trans isomers.

[Example 1-6; Synthesis of Compound (DA-6)]
Compound (DA-6) was synthesized according to the following scheme 6.

[Example 1-7; Synthesis of Compound (AN-4)]
Compound (AN-4) was synthesized according to the following scheme 7.

[Example 1-8; Synthesis of Compound (DA-14)]
Compound (DA-14) was synthesized according to the following scheme 8.

[Example 1-9; Synthesis of Compound (DA-15)]
Compound (DA-15) was synthesized according to the following scheme 9.

<Synthesis of polymer>
[Example 2-1; Synthesis of polymer (PA-1)]
9.62 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride (93 mol parts with respect to 100 mol parts of the total amount of diamine used in the synthesis), and compound ( DA-1) 12.83 g (50 mol parts), and 1,5-bis (4-aminophenoxy) pentane 7.55 g (50 mol parts) 85 g of N-methyl-2-pyrrolidone (NMP) The mixture was dissolved in a mixed solvent of 85 g of γ-butyrolactone (GBL) and reacted at 30 ° C. for 6 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol, and then dried at 40 ° C. under reduced pressure for 15 hours to obtain 28.3 g of polyamic acid (hereinafter referred to as polymer (PA-1)). The obtained polymer (PA-1) was prepared to be 15% by weight with a solvent composition of NMP: GBL = 50: 50, and the viscosity of this solution was measured to be 561 mPa · s. Further, when this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Example 2-2 to Example 2-11 and Synthesis Example 1; Synthesis of polyamic acid]
In Example 2-1 above, polyamic acid was obtained in the same manner as in Example 2-1, except that the types and amounts of tetracarboxylic dianhydride and diamine used in the reaction were changed as shown in Table 1 below. In addition, the numerical value of Table 1 shows the use ratio (mol%) with respect to the whole quantity of the tetracarboxylic dianhydride used for reaction about the tetracarboxylic dianhydride, About the diamine, the diamine used for reaction The ratio of use (mol%) to the total amount of is shown. Each of the polymer solutions obtained in the examples was allowed to stand at 20 ° C. for 3 days. None of them was gelled, and the storage stability was good.

Abbreviations of tetracarboxylic dianhydride and diamine in Table 1 are as follows.
(Tetracarboxylic dianhydride)
AN-1; 1,2,3,4-cyclobutanetetracarboxylic dianhydride AN-2; pyromellitic dianhydride AN-3; 2,3,5-tricarboxycyclopentylacetic acid dianhydride AN-5; 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione AN-6; bicyclo [ 3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride AN-7; 5- (2,5-dioxotetrahydrofuran-3-yl)- 3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione (diamine)
DA-7; 4,4′-bis (4-aminophenoxy) biphenyl DA-8; 4,4′-diaminodiphenylmethane DA-9; 1,5-bis (4-aminophenoxy) pentane DA-10; 4′-diaminodiphenylamine DA-11; 3,5-diaminobenzoic acid DA-12; 3,5-diaminobenzoic acid cholestanyl DA-13; 4- (tetradecaoxy) benzene-1,3-diamine (PA-9) is particularly suitable for a TN type liquid crystal display element, and the polymer (PA-10) is suitable for a VA type (vertical alignment type) liquid crystal display element.

[Example 2-12; Synthesis of polymer (PI-1)]
16.43 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride (98 mol parts with respect to 100 mol parts of the total amount of diamine used in the synthesis), and compound (DA- 1) 18.21 g (50 mol parts) of the compound and 15.36 g (50 mol parts) of the compound (DA-9) were dissolved in 200 g of NMP and reacted at room temperature for 6 hours. Next, 250 g of NMP was added, 11.6 g of pyridine and 14.97 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 80 ° C. for 5 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and then dried under reduced pressure at 40 ° C. for 15 hours to obtain polyimide (PI-1) having an imidation ratio of about 68%. The obtained polyimide (PI-1) was prepared so that it might become 15 weight% with NMP. It was 893 mPa * s when the viscosity of this solution was measured.

[Synthesis Example 2; Synthesis of polyorganosiloxane (S-1)]
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine, and room temperature. Mixed. 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the reaction was carried out at 80 ° C. for 6 hours while mixing under reflux. After completion of the reaction, the organic layer is taken out, washed with 0.2 wt% ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure to have an oxiranyl group. Polyorganosiloxane was obtained as a viscous transparent liquid. When ¹ H-NMR analysis was performed on the polyorganosiloxane having an oxiranyl group, a peak based on the oxiranyl group was obtained in the vicinity of the chemical shift (δ) = 3.2 ppm according to the theoretical intensity. It was confirmed that no side reaction occurred. The epoxy equivalent of the polyorganosiloxane having an oxiranyl group was measured and found to be 186 g / equivalent.
Next, in a 100 mL three-necked flask, 9.3 g of the polyorganosiloxane having the oxiranyl group obtained above, 26 g of methyl isobutyl ketone, 3 g of 4-phenoxycinnamic acid and UCAT 18X (trade name, manufactured by San Apro Co., Ltd.) 0.10 g Was reacted at 80 ° C. for 12 hours with stirring. After completion of the reaction, the reaction mixture was poured into methanol to collect a precipitate, which was dissolved in ethyl acetate to form a solution. The solution was washed with water three times, and then the solvent was distilled off to remove the oxiranyl group. 6.3 g of a polyorganosiloxane (S-1) having a cinnamic acid structure was obtained as a white powder. The weight average molecular weight Mw in terms of polystyrene measured by gel permeation chromatography for this polyorganosiloxane (S-1) was 3,500.

<Preparation and evaluation of liquid crystal aligning agent>
[Example 3-1: rubbing alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent As a polymer, 100 parts by weight of the polymer (PA-1) obtained in Example 2-1 was mixed solvent (GBL) composed of γ-butyrolactone (GBL), NMP and butyl cellosolve (BC). : NMP: BC = 40: 40: 20 (weight ratio)) to obtain a solution having a solid content of 3.5% by weight. The liquid crystal aligning agent (R-1) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm.

(2) Evaluation of applicability The liquid crystal aligning agent (R-1) prepared above was applied on a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 1 minute, and then the interior was filled with nitrogen. By heating (post-baking) in a substituted 200 ° C. oven for 1 hour, a coating film having an average film thickness of 1,000 mm was formed. This coating film was observed with a microscope having a magnification of 100 times and 10 times to examine the presence or absence of film thickness unevenness and pinholes. Evaluation is that the film thickness unevenness and the pinhole are not observed even when observed with a 100 × microscope, the coating property is “good”, and the 100 × microscope observes at least one of the film thickness unevenness and the pinhole. However, when both the film thickness unevenness and the pinhole were not observed with a 10 × microscope, the coating property was “OK”. At least one of the film thickness unevenness and the pinhole was clearly observed with a 10 × microscope. The case was evaluated as “bad” coating property. In this example, neither film thickness unevenness nor pinhole was observed even with a 100 × microscope, and the coating property was “good”.

(3) Evaluation of rubbing resistance The coating film obtained above was rubbed at a roll rotation speed of 1000 rpm, a stage moving speed of 20 cm / sec, and a hair foot indentation length of 0.4 mm by a rubbing machine having a roll wrapped with a cotton cloth. The treatment was performed 7 times. Foreign matter (a piece of coating film) due to rubbing scraping on the obtained substrate was observed with an optical microscope, and the number of foreign matters in a 500 μm × 500 μm region was measured. In the evaluation, the rubbing resistance was “good” when the number of foreign substances was 3 or less, and the rubbing resistance “good” when 4 or more and 7 or less were present, and the rubbing resistance “bad” when 8 or more. As a result, the rubbing resistance of this coating film was “good”.

(4) Manufacture of FFS type liquid crystal display element by rubbing process The FFS type liquid crystal display element 10 shown in FIG. 1 was produced. First, a glass substrate 11a having an electrode pair on one side of which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order, and an electrode The liquid crystal aligning agent (R-1) prepared in the above (1) is paired with the opposite glass substrate 11b not provided with the glass substrate 11a, and the surface of the glass substrate 11a having the transparent electrode and one surface of the opposite glass substrate 11b. The coating film was formed by coating using a spinner. Next, this coating film was pre-baked for 1 minute on a hot plate at 80 ° C., and then heated (post-baked) at 230 ° C. for 15 minutes in an oven in which the inside of the chamber was replaced with nitrogen, so that the average film thickness was 1,000 mm. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 2A is a top view of the top electrode 13, and FIG. 2B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2A. In this example, the line width d1 of the electrodes was 4 μm, and the distance d2 between the electrodes was 6 μm. Further, as the top electrode 13, four types of drive electrodes of electrode A, electrode B, electrode C, and electrode D were used. FIG. 3 shows the configuration of the drive electrode used. In this case, the bottom electrode 15 functions as a common electrode that acts on all of the four drive electrodes, and each of the four drive electrode regions serves as a pixel region.

  Subsequently, the surface of the coating film formed on the glass substrates 11 a and 11 b was rubbed with cotton to form the liquid crystal alignment film 12. In FIG.2 (b), the rubbing direction with respect to the coating film formed on the glass substrate 11a is shown by the arrow. Next, after applying the product name “XN-21-S” (manufactured by Mitsui Chemicals) as a sealant to the outer edge of the surface having the liquid crystal alignment film in one of the pair of substrates, Then, the substrates were bonded together via a spacer having a diameter of 3.5 μm so that the rubbing directions of the substrates 11a and 11b were antiparallel, and the sealant was cured. Next, liquid crystal MLC-6221 (manufactured by Merck & Co., Inc.) was injected between the pair of substrates through the liquid crystal injection port to form the liquid crystal layer 16. Furthermore, the liquid crystal display element 10 was produced by bonding a polarizing plate (not shown) on both outer surfaces of the substrates 11a and 11b so that the polarization directions of the two polarizing plates were orthogonal to each other.

(5) Evaluation of liquid crystal orientation For the FFS type liquid crystal display device manufactured as described above, the presence or absence of abnormal domains in the change in brightness when a voltage of 5 V is turned ON / OFF (applied / released) is observed with a microscope at a magnification of 50 times. did. In the evaluation, when the abnormal domain was not observed, the liquid crystal alignment was “good”, and when the abnormal domain was observed, the liquid crystal alignment was “bad”. In this liquid crystal display element, the liquid crystal orientation was “good”.
(6) Evaluation of voltage holding ratio For the FFS type liquid crystal display device manufactured as described above, a voltage of 5 V was applied at 23 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and 167 milliseconds after the application release. When the voltage holding ratio (VHR) of was measured, it was 99.6%. In addition, as a measuring apparatus, Toyo Technica Co., Ltd. make and VHR-1 were used.

(7) Unevenness around sealant (bezel unevenness resistance)
The FFS type liquid crystal display device manufactured above was stored for 30 days under conditions of 25 ° C. and 50% RH, and then driven with an AC voltage of 5 V to observe the lighting state. Evaluation is "good" bezel unevenness resistance if the luminance difference (more black or more white) is not visually recognized around the sealant, but "good" if the luminance difference disappears within 10 minutes after lighting. A case where a luminance difference was visually recognized even after 10 minutes passed was defined as “bad”. As a result, the luminance difference of the liquid crystal display element was not visually recognized, and the bezel unevenness resistance was determined to be “good”.

(8) Pretilt angle characteristics For the FFS type liquid crystal display device manufactured above, the tilt angle of the liquid crystal molecules from the substrate surface was measured by a crystal rotation method using He-Ne laser light, and this value was defined as the pretilt angle θ. . Non-Patent Document 2 (TJScheffer et.al., J. Appl. Phys. Vol. 48, p1783 (1977)) and Non-Patent Document 3 (F. Nakano et.al., JPN. J. Appl). Phys. Vol. 19, p2013 (1980)).
When the pretilt angle θ is less than 1.0 °, the pretilt angle evaluation is “good”, and when the pretilt angle θ is 1.0 ° or more is evaluated as “bad”, the pretilt angle of the liquid crystal display element is The angle was 0.5 °, and the pretilt angle characteristic was judged as “good”.

(9) Contrast evaluation after driving stress (AC afterimage characteristics evaluation)
An FFS type liquid crystal cell was produced by performing the same operation as in the above (4) except that the polarizing plate was not bonded to both outer surfaces of the substrate. About this FFS type liquid crystal cell, after driving for 30 hours at an AC voltage of 10 V, using a device in which a polarizer and an analyzer are arranged between a light source and a light quantity detector, the minimum relative value expressed by the following formula (2) is used. The transmittance (%) was measured.
Minimum relative transmittance (%) = (β−B ⁰ ) / (B ¹⁰⁰ −B ⁰ ) × 100 (2)
(In Formula (2), B ⁰ is the transmission amount of light under blank and crossed Nicols. B ¹⁰⁰ is the transmission amount of light under blank and paranicols. Β is the polarizer under crossed Nicols. (This is the minimum light transmission amount with the liquid crystal display element sandwiched between the analyzers.)
The black level in the dark state is expressed by the minimum relative transmittance of the liquid crystal display element. In the FFS type liquid crystal display element, the smaller the black level in the dark state, the better the contrast. AC residual image characteristics with a minimum relative transmittance of less than 1.0% are considered “good”, those with 1.0% or more and less than 1.5% are “good”, and those with 1.5% or more are “bad”. It was. As a result, the minimum relative transmittance of this liquid crystal display element was 0.2%, and the AC afterimage characteristics were determined to be “good”.

[Example 3-2 to Example 3-8 and Comparative Example 1]
In Example 3-1 above, a liquid crystal aligning agent was prepared in the same manner as in Example 3-1, except that the polymer shown in Table 2 was used, and an FFS type liquid crystal display device was produced. Various evaluations were performed. The evaluation results are shown in Table 2 below. In Table 2, the numerical value of the amount of the polymer indicates the blending ratio (parts by weight) of each polymer with respect to 100 parts by weight as a whole of the polymer components in the liquid crystal aligning agent.

As shown in Table 2, in Examples 3-1 to 3-8, the coating property of the liquid crystal alignment agent, the rubbing resistance of the coating film, the liquid crystal alignment property, the voltage holding ratio, the unevenness resistance around the sealing agent, the pretilt angle characteristics, and The AC afterimage characteristics were all “good” or “good”, and various characteristics were balanced. In contrast, the liquid crystal display element of Comparative Example 1 was evaluated as “possible” for the coating property and the rubbing resistance, but the voltage holding ratio, the unevenness resistance around the sealant, the pretilt angle characteristics, and the AC afterimage characteristics were all. It was a result inferior to an Example.
The reason why the bezel unevenness resistance is “good” or “possible” in the examples using the polymer (P) having the partial structure represented by the above formula (1) is not clear, but one reason is Hydrophobic resistance is increased by the spacer structure (-R ^1- ) and mesogen structure (-W ^1- (R ² -W ² ) p-) in the polymer (P), and the water absorption rate is decreased, thereby preventing hydrolysis. As a result of improving the property, it is estimated that the occurrence of unevenness is suppressed.

[Example 4-1: Photo-alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent As a polymer, 100 parts by weight of the polymer (PA-2) obtained in Example 2-2 was mixed with γ-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve. It was dissolved in a mixed solvent consisting of (BC) (GBL: NMP: BC = 40: 40: 20 (weight ratio)) to obtain a solution having a solid content concentration of 3.5% by weight. A liquid crystal aligning agent (R-9) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm.

(2) Evaluation of surface irregularity of coating film After applying liquid crystal aligning agent (R-9) prepared above on a glass substrate using a spinner and prebaking for 1 minute on an 80 ° C. hot plate, A coating film having an average film thickness of 1,000 mm was formed by heating (post-baking) for 1 hour in an oven at 200 ° C. in which the inside of the chamber was replaced with nitrogen. This coating film was observed with an atomic force microscope (AFM), and the center average roughness (Ra) was measured. The evaluation was performed with a surface roughness of “good” when less than 2.0 nm, “good” when 2.0 nm or more and less than 5.0 nm, and “bad” when 5.0 nm or more. In this example, Ra was 0.9 nm, and the surface roughness was “good”.
(3) Evaluation of orientation The coating film obtained above is irradiated with polarized ultraviolet rays 300 J / m ² containing a 313 nm emission line from the normal direction of the substrate using an Hg-Xe lamp and a Grand Taylor prism. Treated. The refractive index anisotropy (nm) of this glass substrate with an alignment film was measured using a liquid crystal alignment film inspection apparatus (RayScan) manufactured by MORITEX. The evaluation was “good” when 0.020 nm or more, “good” when less than 0.020 nm and less than 0.010 nm, and “bad” when less than 0.010 nm. As a result, this substrate was 0.036 nm and was “good”.

(4) Manufacture of FFS type liquid crystal display element by photo-alignment method First, the liquid crystal prepared in (1) above on each surface of a pair of glass substrates 11a and 11b similar to (4) in Example 3-1. The orientation agent (R-9) was applied using a spinner to form a coating film. Next, this coating film was pre-baked for 1 minute on a hot plate at 80 ° C., and then heated (post-baked) at 230 ° C. for 15 minutes in an oven in which the inside of the chamber was replaced with nitrogen, so that the average film thickness was 1,000 mm. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 4A is a top view of the top electrode 13, and FIG. 4B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 4A. In this example, a substrate having a top electrode having a line width d1 of electrodes of 4 μm and a distance d2 between the electrodes of 6 μm was used. As the top electrode 13, four drive electrodes of electrode A, electrode B, electrode C, and electrode D were used as in (4) of Example 3-1 (see FIG. 3).
Next, each surface of these coating films is irradiated with polarized ultraviolet rays 300 J / m ² including a 313 nm emission line from the substrate normal direction using an Hg-Xe lamp and a Grand Taylor prism, respectively, to form a liquid crystal alignment film. A pair of substrates was obtained. At this time, the irradiation direction of the polarized ultraviolet ray is from the normal direction of the substrate, and the polarization plane direction is set so that the direction of the line segment in which the polarization plane of the polarized ultraviolet ray is projected onto the substrate is the direction of the double-headed arrow in FIG. The light irradiation process was performed.

Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer periphery of the surface having one liquid crystal alignment film of the above substrates by screen printing, and then the liquid crystal alignment film surfaces of a pair of substrates Were placed so that the planes of polarization of polarized ultraviolet rays projected onto the substrate were parallel and pressure bonded, and the adhesive was heat cured at 150 ° C. for 1 hour. Next, liquid crystal “MLC-6221” manufactured by Merck Co., Ltd. was filled into the substrate gap from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, this was heated to 150 ° C. and then gradually cooled to room temperature.
Next, an FFS type liquid crystal display element was manufactured by laminating polarizing plates on both outer surfaces of the substrate. At this time, one of the polarizing plates is stuck so that the polarization direction thereof is parallel to the direction of projection of the polarization plane of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one has the polarization direction first. The polarizing plate was stuck so as to be orthogonal to the polarization direction of the polarizing plate.

(5) Evaluation of liquid crystal orientation About the photo-alignment FFS type liquid crystal display element manufactured above, liquid crystal orientation was evaluated like (5) of the said Example 3-1. As a result, this liquid crystal display element had “good” liquid crystal alignment.
(6) Evaluation of voltage holding ratio With respect to the photo-alignment type FFS liquid crystal display device manufactured as described above, the voltage holding ratio (VHR) was measured and the voltage holding ratio was evaluated in the same manner as (6) of Example 3-1 above. . As a result, VHR was 99.4%.
(7) Bezel unevenness resistance About the photo-alignment FFS type liquid crystal display element manufactured above, bezel unevenness resistance was evaluated in the same manner as (7) of Example 3-1. As a result, no luminance difference was visually recognized in this liquid crystal display element, and the bezel unevenness resistance was determined to be “good”.
(8) AC afterimage evaluation AC afterimage evaluation was performed in the same manner as in Example 3-1 (9). In addition, in the afterimage evaluation of AC, evaluation was performed using a liquid crystal cell in which no polarizing plate was bonded, as in (9) of Example 3-1. As a result, the minimum relative transmittance was 0.1%, and the contrast characteristics were judged as “good”.

[Example 4-2 and Example 4-3]
In Example 4-1 above, a liquid crystal aligning agent was prepared in the same manner as in Example 4-1, except that the polymer shown in Table 3 below was used, and an FFS type liquid crystal display element was produced. Various evaluations were performed. The evaluation results are shown in Table 3 below. In Table 3, the numerical value of the amount of the polymer indicates the blending ratio (parts by weight) of each polymer with respect to 100 parts by weight of the whole polymer component in the liquid crystal aligning agent.

[Example 5-1: retardation film]
(1) Preparation of liquid crystal aligning agent 100 parts by weight of the polymer (PA-2) obtained in Example 2-2 and 5 parts by weight of the polyorganosiloxane (S-1) obtained in Synthesis Example 2 were mixed with NMP and BC. Was dissolved in a mixed solvent (NMP: BC = 50: 50 (weight ratio)) to obtain a solution having a solid content concentration of 5.5% by weight. A liquid crystal aligning agent (R-10) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm.
(2) Manufacture of retardation film The liquid crystal aligning agent (R-10) prepared above is applied to one surface of a TAC film as a substrate using a bar coater, and baked in an oven at 120 ° C for 2 minutes. A coating film having a thickness of 100 nm was formed. Next, the surface of the coating film was irradiated perpendicularly from the substrate normal line with polarized ultraviolet rays of 10 mJ / cm ² containing an emission line of 313 nm using a Hg—Xe lamp and a Grand Taylor prism. Next, the polymerizable liquid crystal (RMS03-013C, manufactured by Merck & Co., Inc.) was filtered through a filter having a pore size of 0.2 μm, and this polymerizable liquid crystal was applied onto the coated film after light irradiation by a bar coater. A coating film was formed. After baking for 1 minute in an oven adjusted to a temperature of 50 ° C., an unpolarized ultraviolet ray containing 365 nm emission line was irradiated at 1,000 mJ / cm ² from a direction perpendicular to the coating surface using an Hg-Xe lamp. A retardation film was produced by curing a polymerizable liquid crystal to form a liquid crystal layer.

(3) Evaluation of liquid crystal orientation About the retardation film manufactured by said (2), liquid crystal orientation is observed by observing the presence or absence of an abnormal domain by visual observation under crossed Nicols and a polarizing microscope (magnification 2.5 times). evaluated. The evaluation was that the alignment was good visually and the abnormal domain was not observed with a polarizing microscope, the liquid crystal orientation was “good”, and the abnormal domain was not observed with the polarizing microscope, but the abnormal domain was observed with a polarizing microscope. The case where the liquid crystal orientation was “possible”, and the case where an abnormal domain was observed visually and with a polarizing microscope was regarded as “Poor”. As a result, this retardation film was evaluated as “good” for liquid crystal alignment.

(4) Adhesiveness Using the retardation film produced in (2) above, the adhesiveness of the coating film formed with the liquid crystal aligning agent to the substrate was evaluated. First, using an equally spaced spacer with a guide, a cutter knife was used to cut from the surface on the liquid crystal layer side of the retardation film to form 10 × 10 lattice patterns within a range of 1 cm × 1 cm. The depth of each cut was made to reach the middle of the substrate thickness from the surface of the liquid crystal layer. Next, after attaching a cellophane tape so as to cover the entire surface of the lattice pattern, the cellophane tape was peeled off. The notches in the lattice pattern after peeling were observed visually under crossed Nicols to evaluate the adhesion. The evaluation was that the adhesion was “good” when no peeling was observed at the portion along the cut line and at the intersection of the lattice pattern, and the number of lattices where peeling was observed in the above portion was the number of the entire lattice pattern. On the other hand, when the amount is less than 15%, the adhesion is “possible”, and when the number of lattices where peeling is observed in the above portion is 15% or more with respect to the total number of lattice patterns, the adhesion is “bad”. went. As a result, this retardation film had good adhesion.

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display element, 11a, 11b ... Glass substrate, 12 ... Liquid crystal aligning film, 13 ... Top electrode, 14 ... Insulating layer, 15 ... Bottom electrode, 16 ... Liquid crystal layer

Claims (10)

Polyamic acid, and at least one selected from the group consisting of polyamic acid ester and polyimide, and containing the following formula (d) that is obtained by polymerizing a monomer containing a compound represented by the polymer (P) the liquid crystal Alignment agent.

(In the formula (1), W ¹ is a substituted or unsubstituted cyclohexylene group, W ² is benzene ring, cyclohexane ring, a divalent cyclic group and the cyclopentane ring or a pyridine ring ring skeleton X ¹ is a single bond, —O—, * —COO—, * —OCO—, —CO—, * —NR ¹⁰ CO— or * —CONR ¹⁰ — (where R ¹⁰ is a hydrogen atom or carbon X is a bond to W ^1. ) X ² is —O—, * —COO—, * —OCO—, —CO—, *. —NR ¹¹ CO— or * —CONR ¹¹ — (where R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, “*” represents a bond to W ² ). ¹ is a single bond, alkanediyl group having 1 to 20 carbon atoms, alkenediyl group having 2 to 20 carbon atoms, carbon A divalent group obtained by substituting a part of hydrogen atoms of an alkanediyl group having 1 to 20 carbon atoms or an alkenediyl group having 2 to 20 carbon atoms with a substituent, or an alkanediyl group having 1 to 20 carbon atoms or 2 to 20 carbon atoms R ² is a single bond, —O—, * —COO—, * —OCO—, —, wherein a part of the methylene group of the alkenediyl group is replaced by —O— or —S—. CO—, * —NR ¹² CO—, * —CONR ¹² — (wherein R ¹² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “*” Represents a bond to W ^1. ) A part of the hydrogen atoms of the alkanediyl group having 1 to 5 carbon atoms, the alkenediyl group having 2 to 5 carbon atoms, the alkanediyl group having 1 to 5 carbon atoms or the alkenediyl group having 2 to 5 carbon atoms is replaced with a substituent. A divalent group or 1 to 5 carbon atoms Rukanjiiru a group or divalent group a part of the methylene group consisting replaced by -O- or -S- in alkenediyl group having 2 to 5 carbon atoms .p represents 1 or 2. ^{X 3} and ^{X 4} each independently a single bond, -O -, * - COO - , * - OCO -, - CO -, * - NR 14 CO- or * -CONR ¹⁴ - ^{(where, R 14} is a hydrogen atom or a carbon atoms R ³ is an alkanediyl group having 1 to 20 carbon atoms, an alkenediyl group having 2 to 20 carbon atoms, phenylene, and “*” represents a bond with an aminophenyl group. Group, a piperidinediyl group, a divalent group obtained by substituting a part of hydrogen atoms of an alkanediyl group having 1 to 20 carbon atoms or an alkenediyl group having 2 to 20 carbon atoms, or an alkane having 1 to 20 carbon atoms Diyl group or Some of the methylene groups alkenediyl group prime 2-20 is a divalent group formed by substituted with -O- or -S-. R ⁴ and R ⁵ are each independently a halogen atom, or an alkyl group or alkoxy group having 1 to 6 carbon atoms. q is 0 or 1. m and n are each independently an integer of 0 to 4. If R ^{4, R 5} there are a plurality, the plurality of ^R 4, ^{R 5} may be the same or different. ) R ¹ replaces part of hydrogen atoms of an alkanediyl group having 1 to 20 carbon atoms, an alkenediyl group having 2 to 20 carbon atoms, an alkanediyl group having 1 to 20 carbon atoms, or an alkenediyl group having 2 to 20 carbon atoms. A divalent group formed by replacing a group, or a divalent group formed by replacing a part of the methylene group of an alkanediyl group having 1 to 20 carbon atoms or an alkenediyl group having 2 to 20 carbon atoms with -O- or -S- The liquid crystal aligning agent of Claim 1 which is group. The polymer (P) is a polymer obtained by polymerizing a monomer containing tetracarboxylic dianhydride. As the tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3 , 5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxo Tetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, bicyclo [3.3.0] octane-2,4 6,8-tetracarboxylic acid 2: 4 : 8 dianhydride, at least one selected from the group consisting of cyclohexane tetracarboxylic acid dianhydride and pyromellitic dianhydride, the liquid crystal aligning agent according to claim 1 or 2. The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-3 . The liquid crystal aligning film obtained by apply | coating the liquid crystal aligning agent as described in any one of Claims 1-3 to a board | substrate, forming a coating film, and light-irradiating this coating film. The liquid crystal aligning film obtained by apply | coating the liquid crystal aligning agent as described in any one of Claims 1-3 to a board | substrate, and carrying out a rubbing process. The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-3 on a board | substrate, and forming a coating film, and the process of light-irradiating this coating film and providing liquid crystal aligning ability are included. A method for producing a liquid crystal alignment film. The liquid crystal display device comprising a liquid crystal alignment film according to any one of claims 4-6. A retardation film comprising a liquid crystal alignment film according to claim 4 or 5. The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-3 on a board | substrate, and forming a coating film,
Irradiating the coating film with light;
A method of producing a retardation film, comprising: applying a polymerizable liquid crystal on the coating film after the light irradiation and curing the liquid crystal.

Images