JPWO2012018121A1 - Resin composition, liquid crystal alignment material and retardation material - Google Patents

Abstract

Provided is a resin composition capable of orienting a polymerizable liquid crystal with high sensitivity after thermal curing using photo-alignment technology, and exhibiting high birefringence, high solvent resistance, heat resistance and high transparency. To do. A resin composition comprises (A) an acrylic copolymer having a photodimerization site comprising a hydrophobic group and a thermal crosslinking site comprising a hydrophilic group, and (B) a polyimide precursor having an aromatic ring site. And (C) a crosslinking agent that crosslinks the component (A) and the component (B). The component (A) can also be an acrylic copolymer obtained by a polymerization reaction of a monomer mixture containing a monomer having a photodimerization site and a monomer having a thermal crosslinking site. Moreover, (A) component can be made into the acrylic copolymer obtained by the polymerization reaction of the monomer mixture which contains 25 to 90 mol% of monomers which have a photodimerization site | part with respect to the sum total of all the monomer mixtures. Moreover, (A) component can also be made into the acrylic copolymer obtained by the polymerization reaction of the monomer containing the monomer which has a photodimerization site | part, and the monomer which has a thermal crosslinking site | part. [Selection] Figure 1

Description

  The present invention relates to a resin composition, a liquid crystal alignment material, and a retardation material.

  Conventionally, for the purpose of compensating the viewing angle of a liquid crystal display, a retardation film is disposed outside the liquid crystal cell. In this case, the type of the retardation film varies depending on the liquid crystal display mode in the liquid crystal display.

  For example, in the case of a VA mode liquid crystal display, a biaxial plate having different in-plane x and y directions and three refractive indexes in the thickness direction is used as a retardation film alone, or it is produced by uniaxial stretching. The viewing angle is compensated by combining the positive A plate and the negative C plate into a retardation film. The former is produced by biaxial stretching, and the latter is produced by uniaxial stretching. Here, the positive A plate is a retardation film having a characteristic of nx> ny = nz, where nx and ny are the refractive indexes in the x and y directions in the film plane of the plate, and nz is the refractive index in the thickness direction. It is. The negative C plate is a retardation film having a characteristic of nx = ny> nz.

  On the other hand, in recent years, studies have been made to achieve high contrast, low cost, and light weight by introducing a phase difference material into a liquid crystal cell of a liquid crystal display. And it has been proposed to use a polymerizable liquid crystal solution to form such a retardation material. Specifically, a phase difference material is formed by applying a polymerizable liquid crystal solution to an appropriate portion in a liquid crystal cell, and performing photo-curing after a desired orientation.

  In the case of a positive A plate, a polymerizable liquid crystal exhibiting horizontal alignment is used. In the case of a negative C plate, a polymerizable liquid crystal exhibiting cholesteric alignment or discotic alignment is used. Furthermore, in the case of a biaxial plate, a polymerizable liquid crystal exhibiting biaxial orientation is used. Therefore, in order to introduce a retardation material having a biaxial retardation into the liquid crystal cell, a polymerizable liquid crystal exhibiting biaxial alignment is used, or a polymerizable liquid crystal exhibiting cholesteric alignment and horizontal alignment are used. It was necessary to laminate and use the polymerizable liquid crystal shown.

  However, it is known that a polymerizable liquid crystal exhibiting biaxial orientation is difficult to increase in thickness, and a material capable of sufficiently expressing the required retardation characteristics has not been found. In addition, when a polymerizable liquid crystal exhibiting cholesteric alignment and a polymerizable liquid crystal exhibiting horizontal alignment are stacked, the manufacturing process becomes complicated, and therefore, an increase in manufacturing cost and a decrease in throughput have been problems.

  FIG. 2 is a schematic configuration diagram of a liquid crystal cell in which a liquid crystal alignment film is formed by a conventional technique. In this figure, the liquid crystal layer 208 is sandwiched between two substrates 201 and 211. On the substrate 211, an ITO 210 and an alignment film 209 are formed. On the substrate 201, a color filter 202, a color filter (CF) overcoat (hereinafter referred to as a CF overcoat) 203, an alignment film 204, a phase difference material 205, an ITO 206, an alignment A film 207 is formed in this order.

  In the conventional liquid crystal cell, since the polymerizable liquid crystal for forming the retardation material described above is aligned before curing, it is necessary to separately provide a film capable of aligning the liquid crystal in the lower layer, that is, an alignment film. . The alignment film is formed through processes such as rubbing treatment and polarized light irradiation. That is, as shown in FIG. 2, conventionally, after the alignment film 204 is formed on the CF overcoat 203, a retardation material 205 obtained from a polymerizable liquid crystal such as a liquid crystal monomer is formed thereon. It was common. That is, after the color filter 202 is formed, it is necessary to further form two layers of the CF overcoat 203 and the alignment film 204, which complicates the manufacturing process.

  For these reasons, it is strongly desired to provide a film that satisfies a plurality of different required characteristics at the same time and a material for forming the film. Specifically, a film that doubles as an alignment film and a CF overcoat and a material for forming this film are required. Thereby, when manufacturing a liquid crystal display, it is possible to enjoy great advantages such as cost reduction, reduction in the number of processes, and improvement in throughput.

  Further, for a film that doubles as an alignment film and a CF overcoat, a reduction in the time required for the alignment treatment is required. Therefore, it is necessary to apply a photo-alignment technique in the manufacturing process of the alignment film. Therefore, it is strongly desired that the film serving both as the alignment film and the CF overcoat is formed using a photo-alignment material.

  Furthermore, a film serving as both an alignment film and a CF overcoat is required to have a high birefringence. This is because the characteristics of the negative C plate can be imparted by increasing the birefringence. In addition, by providing high birefringence characteristics, it is possible to reduce the thickness of the biaxially oriented polymerizable liquid crystal layered thereon, and biaxiality can be achieved simply by applying a horizontally oriented polymerizable liquid crystal. Can also be expressed.

  Generally, a highly transparent acrylic resin is used for the CF overcoat. And heat resistance and solvent resistance are expressed by hardening an acrylic resin with a heat | fever or light (for example, refer patent document 1 or 2).

  However, according to the study of the present inventor, although a conventional CF overcoat made of a thermosetting or photocurable acrylic resin can provide transparency and solvent resistance, it can be irradiated with polarized UV light. It has been found that sufficient liquid crystal orientation cannot be exhibited. Therefore, it is understood that the conventional CF overcoat cannot be applied as it is to a film serving as both the alignment film and the CF overcoat.

  It has also been reported that a polyamic acid having a high transparency and a high birefringence is obtained using a polyamic acid composed of a tetracarboxylic dianhydride having a biphenyl skeleton and a diamine having an alicyclic structure (Patent Document 3). reference). However, even if this polyamic acid is irradiated with polarized light, sufficient liquid crystal orientation cannot be exhibited. In other words, such a high refractive index polyamic acid cannot be applied as it is to a film serving both as the alignment film and the CF overcoat.

Moreover, it has been reported that sufficient liquid crystal alignment can be obtained by irradiating polarized UV to an acrylic resin having a photodimerization site such as a cinnamoyl group or a chalcone group in the side chain (see Patent Document 4). However, according to the study of the present inventor, even when irradiation with a polarized UV exposure (for example, 100 mJ / cm ² ) sufficient for aligning a normal liquid crystal for display, the film serving as the alignment film and the CF overcoat is used. Has proven to be insufficient to function as. Specifically, when a polymerizable liquid crystal solution is applied onto the acrylic resin after being irradiated with polarized UV, the lower acrylic resin film is dissolved due to low resistance to the acrylic resin solution. . For this reason, sufficient orientation with respect to the polymerizable liquid crystal cannot be expressed.

In addition, the reaction rate of the photodimerization reaction in the acrylic resin can be improved by a large amount of polarized UV exposure of 1 J / cm ² or more. Therefore, there is a possibility that the orientation of the polymerizable liquid crystal can be improved by increasing the exposure amount. However, considering that the photo-alignment technique has been studied for the purpose of shortening the time for the alignment process in the first place, it is not possible to allow an increase in exposure amount that leads to a longer exposure time.

  Furthermore, according to the study of the present inventor, even if the reaction rate is improved, the photodimerization reaction for realizing the liquid crystal orientation is not sufficient as a crosslinking reaction, and sufficient heat resistance as a film is realized. It has also been found that it cannot be done. That is, it has been found that the film made of the above acrylic resin undergoes large film shrinkage by the heat treatment for manufacturing the liquid crystal cell when the reaction rate is improved.

JP 2000-103937 A JP 2000-119472 A WO2008010483A1 publication Patent 4011652

  The present invention has been made based on the above knowledge and examination results. That is, the object of the present invention is to align the polymerizable liquid crystal with high sensitivity after thermosetting by utilizing photo-alignment technology, and also has high birefringence, high solvent resistance, heat resistance and high transparency. It is in providing the resin composition shown.

  Other objects and advantages of the present invention will become apparent from the following description.

The first aspect of the present invention is:
(A) an acrylic copolymer having a photodimerization site comprising a hydrophobic group and a thermal crosslinking site comprising a hydrophilic group;
(B) a polyimide precursor having an aromatic ring moiety;
(C) It is related with the resin composition containing the crosslinking agent which bridge | crosslinks (A) component and (B) component.

  In the first aspect of the present invention, the component (A) is preferably an acrylic copolymer obtained by a polymerization reaction of a monomer mixture containing a monomer having a photodimerization site and a monomer having a thermal crosslinking site.

  In the first aspect of the present invention, the component (A) is an acrylic copolymer obtained by a polymerization reaction of a monomer mixture containing 25 to 90 mol% of a monomer having a photodimerization site with respect to the total amount of all the monomer mixtures. A polymer is preferred.

  In the first aspect of the present invention, the photodimerization site of the component (A) is preferably a cinnamoyl group.

  In the first aspect of the present invention, the thermal crosslinking site of the component (A) is preferably a hydroxyl group or a carboxyl group.

  In the first embodiment of the present invention, the polyimide precursor of component (B) preferably has a biphenyl structure in the main chain.

  1st aspect of this invention WHEREIN: (B) component is a polyimide precursor containing the structural unit obtained from the copolymerization reaction of tetracarboxylic dianhydride and a diamine compound, Comprising: Tetracarboxylic dianhydride and diamine It is preferable that at least one of the compounds has a biphenyl structure.

  In the first aspect of the present invention, the tetracarboxylic dianhydride is preferably biphenyltetracarboxylic dianhydride.

  1st aspect of this invention WHEREIN: It is preferable that (B) component is a polyimide precursor which has a trifluoromethyl group in a structural unit.

  1st aspect of this invention WHEREIN: It is preferable that the polyimide precursor of (B) component has an alicyclic structure in a principal chain.

  1st aspect of this invention WHEREIN: (B) component is a polyimide precursor containing the structural unit obtained from the copolymerization reaction of tetracarboxylic dianhydride and a diamine compound, Comprising: Tetracarboxylic dianhydride and diamine It is preferable that at least one of the compounds has an alicyclic structure.

  1st aspect of this invention WHEREIN: It is preferable that the crosslinking agent of (C) component is a crosslinking agent which has a methylol group or an alkoxymethylol group.

  In the 1st aspect of this invention, it is preferable to contain (C) component of 10 thru | or 100 mass parts based on 100 mass parts of total amounts of (A) component and (B) component.

  In the 1st aspect of this invention, it is preferable to contain an acid or a thermal acid generator as (D) component further.

  In the 1st aspect of this invention, it is preferable to contain 0.1 thru | or 10 mass parts (D) component based on 100 mass parts of total amounts of (A) component and (B) component.

  A second aspect of the present invention relates to a liquid crystal alignment material characterized by being obtained using the resin composition of the first aspect of the present invention.

  A third aspect of the present invention relates to a retardation material characterized by being formed using a cured film obtained from the resin composition of the first aspect of the present invention.

  According to the resin composition of the first aspect of the present invention, in addition to having a high birefringence, high transparency, high solvent resistance and high heat resistance, a cured film capable of photoalignment of liquid crystal is obtained. It is done.

  According to the second aspect of the present invention, a liquid crystal aligning material having a high birefringence and excellent in light transmittance, solvent resistance and orientation can be obtained.

  According to the 3rd aspect of this invention, the phase difference material which can be arrange | positioned in a liquid crystal cell is obtained. In the liquid crystal cell using the retardation material, the contrast ratio can be improved.

It is a typical block diagram of the liquid crystal cell by this Embodiment. It is a typical block diagram of the conventional liquid crystal cell.

  The present invention relates to a resin composition, a liquid crystal alignment material formed using the resin composition, and a retardation material formed using a cured film obtained from the resin composition. More specifically, a resin composition capable of forming a cured film having a high birefringence, high transparency, liquid crystal alignment ability, high solvent resistance, and heat resistance, and the resin composition are used. Liquid crystal aligning material, and a phase difference material formed using the liquid crystal aligning material. The resin composition of the present invention is suitable as a film having a function as a CF overcoat in a liquid crystal display, and also has an alignment function with respect to the polymerizable liquid crystal for forming a retardation layer. It is also suitable for forming a layer.

  Hereinafter, the resin composition, the liquid crystal alignment material, and the retardation material of the present invention will be described in detail with specific examples.

  The resin composition of the present embodiment is a resin composition for forming a thermosetting film having photo-alignment properties, that is, a resin composition for forming a photo-alignment thermosetting film. Further, the thermosetting film having photo-alignment means a cured film that is cured by heating and induces alignment performance of liquid crystal by polarized light exposure.

  The resin composition of the present embodiment contains an acrylic copolymer having a photodimerization site and a thermal crosslinking site as the component (A), a polyimide precursor as the component (B), and a crosslinking agent as the component (C). To do.

  More specifically, the photodimerization site of the acrylic copolymer, which is component (A), consists of a hydrophobic group, and the thermal crosslinking site of the acrylic copolymer consists of a hydrophilic group. Moreover, the polyimide precursor which is (B) component has an aromatic ring site | part. Furthermore, the crosslinking agent as the component (C) can crosslink the component (A) and the component (B).

That is, the resin composition of the present embodiment is
(A) an acrylic copolymer having a photodimerization site consisting of a hydrophobic group and a thermal crosslinking site consisting of a hydrophilic group;
(B) a polyimide precursor having an aromatic ring site;
(C) It is comprised containing the crosslinking agent which bridge | crosslinks (A) component and (B) component.

  Further, in the resin composition of the present embodiment, in addition to the component (A), the component (B) and the component (C), an acid or photoacid generator as the component (D) and / or (E) It can contain a sensitizer as a component.

  In the resin composition of this Embodiment, by containing (A) component, with respect to the cured film obtained using this resin composition, liquid crystal aligning performance can be provided by photo-alignment processing. That is, when the acrylic copolymer as component (A) has a photodimerization site consisting of a hydrophobic group and a thermal cross-linking site consisting of a hydrophilic group, the heat at the thermal cross-linking site described later by heating after coating. The crosslinking reaction proceeds and cures. At this time, the photodimerization site comprising a hydrophobic group exists not only in the vicinity of the surface of the cured film but also in a free state protruding from the surface. Under such a state, when the photodimerization reaction proceeds by polarized UV exposure or the like, excellent liquid crystal alignment performance appears in the vicinity of the surface of the cured film. Therefore, when a polymerizable liquid crystal is applied on the cured film, the highly hydrophobic polymerizable liquid crystal and the photodimerization site composed of the hydrophobic group of the acrylic copolymer efficiently interact with each other with high sensitivity. The liquid crystal alignment can be realized.

  Further, the component (A) has a thermal crosslinking site. This thermal cross-linking site can be made of a hydrophilic group, whereby a thermal cross-linking reaction can be efficiently caused with the later-described (C) cross-linking agent. As a result, in addition to the photodimerization site, a cross-linking site by a thermal reaction can be introduced, so that the number of cross-linking sites can be increased. Therefore, dissolution of the cured film due to the application of the polymerizable liquid crystal solution on the cured film can be prevented. Moreover, it can also suppress that a cured film heat-shrinks in the heating environment in the manufacturing process of a liquid crystal cell.

Moreover, the resin composition of this Embodiment can adjust the birefringence of the cured film obtained using this resin composition by containing (B) component. That is, the polyimide precursor of component (B) becomes a polyimide by thermal reaction to form a cured film, but by selecting a molecular structure including a benzene ring structure or a biphenyl structure in the main chain of this polyimide precursor It is possible to impart high birefringence to the cured film.
At this time, there is a concern that the light transmittance of the cured film, that is, the transparency may be lowered, but by selecting the molecular structure of the compound constituting the polyimide precursor, it is possible to suppress the decrease in the transmittance. is there. For example, by selecting a compound having an alicyclic structure as the compound constituting the polyimide precursor, it becomes possible to impart high transparency to the cured film. That is, both high birefringence and high transparency can be imparted to the cured film by appropriately designing the molecular structure of the polyimide precursor.

  Furthermore, the resin composition of this Embodiment can introduce | transduce the bridge | crosslinking site | part by a thermal reaction with respect to the cured film obtained using this resin composition by containing (C) component. That is, as described above, the component (C) causes a thermal crosslinking reaction with the component (A). In addition, a crosslinking reaction occurs between the component (B) and the carboxyl group of the polyimide precursor and the component (C).

  By adjusting the content of the carboxyl group in the polyimide precursor, the cross-linking reaction between the component (B) and the component (C) can be controlled, and as a result, between the component (A) and the component (C). It is possible to control the crosslinking reaction. As a result, in the entire cured film obtained from the resin composition, an efficient crosslinking reaction by a thermal reaction is realized, and a strong cured film can be formed by introducing a crosslinking site.

  Hereinafter, the components (A) to (C) will be described in detail.

<(A) component>
The component (A) in the present embodiment is an acrylic copolymer having a photodimerization site and a thermal crosslinking site. (A) The photodimerization site | part of the acrylic copolymer of a component consists of a hydrophobic group, and a thermal-crosslinking site | part consists of a hydrophilic group. Next, these will be described with specific examples.

In the present embodiment, as the acrylic copolymer, a copolymer obtained by polymerizing a monomer having an unsaturated double bond such as acrylic ester, methacrylic ester or styrene can be used.
The acrylic copolymer having a photodimerization site and a thermal crosslinking site as the component (A) (hereinafter also referred to as a specific copolymer) may be an acrylic copolymer having such a structure. There are no particular limitations on the skeleton of the main chain and the types of side chains of the polymer.

  A photodimerization site | part is a site | part which forms a dimer by light irradiation, A cinnamoyl group, a chalcone group, a coumarin group, an anthracene group etc. are mentioned as the specific example. Among these, a cinnamoyl group having high transparency in the visible light region and photodimerization reactivity is preferable. Particularly preferred cinnamoyl group partial structures are shown in the following formulas [A1] and [A2].

上記式中、Ｘ¹は、水素原子、炭素原子数１乃至１８のアルキル基、フェニル基またはビフェニル基を表す。ここで、フェニル基およびビフェニル基は、それぞれハロゲン原子およびシアノ基のうちのいずれかによって置換されていてもよい。Ｘ²は、水素原子、シアノ基、炭素原子数１乃至１８のアルキル基、フェニル基、ビフェニル基またはシクロヘキシル基を表す。ここで、炭素原子数１乃至１８のアルキル基、フェニル基、ビフェニル基またはシクロヘキシル基は、共有結合、エーテル結合、エステル結合、アミド結合または尿素結合を介して結合してもよい。
Ｒ¹、Ｒ²、Ｒ³およびＲ⁴は、それぞれ独立に水素原子、炭素原子数１乃至４のアルキル基、炭素原子数１乃至４のアルコキシ基、ハロゲン原子、トリフルオロメチル基またはシアノ基を表す。

In the above formula, X ¹ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, a phenyl group or a biphenyl group. Here, the phenyl group and the biphenyl group may each be substituted with either a halogen atom or a cyano group. X ² represents a hydrogen atom, a cyano group, an alkyl group having 1 to 18 carbon atoms, a phenyl group, a biphenyl group, or a cyclohexyl group. Here, the alkyl group having 1 to 18 carbon atoms, the phenyl group, the biphenyl group, or the cyclohexyl group may be bonded via a covalent bond, an ether bond, an ester bond, an amide bond, or a urea bond.
R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a trifluoromethyl group or a cyano group. Represent.

  The thermal crosslinking site is a site that binds to a crosslinking agent by heating, and specific examples thereof include a hydroxy group, a carboxyl group, or a glycidyl group.

  The acrylic copolymer as component (A) preferably has a weight average molecular weight of 3,000 to 200,000, more preferably 4,000 to 150,000, and 5,000 to 100,000. More preferably. If the weight average molecular weight is over 200,000, the solubility in a solvent may be lowered, and the handling property may be lowered. On the other hand, if the weight average molecular weight is less than 3,000 and is too small, curing may be insufficient during thermosetting, and solvent resistance and heat resistance may be reduced.

  As described above, as a synthesis method of an acrylic copolymer having a photodimerization site and a thermal crosslinking site in the side chain of component (A), a monomer having a photodimerization site and a monomer having a thermal crosslinking site are copolymerized. Is preferred.

  Examples of the monomer having a photodimerization site include monomers having a cinnamoyl group, a chalcone group, a coumarin group, or an anthracene group. Among these, a monomer having a cinnamoyl group having favorable transparency in the visible light region and good photodimerization reactivity is preferable. In particular, a monomer having a cinnamoyl group having a structure represented by the above formula [A1] or [A2] is preferable. Specific examples of such monomers are shown in the following formulas [A3] and [A4].

上記式中、Ｘ¹は、水素原子、炭素原子数１乃至１８のアルキル基、フェニル基またはビフェニル基を表す。ここで、フェニル基およびビフェニル基は、それぞれハロゲン原子およびシアノ基のいずれかによって置換されていてもよい。Ｘ²は、水素原子、シアノ基、炭素原子数１乃至１８のアルキル基、フェニル基、ビフェニル基またはシクロヘキシル基を表す。ここで、炭素原子数１乃至１８のアルキル基、フェニル基、ビフェニル基およびシクロヘキシル基は、共有結合、エーテル結合、エステル結合、アミド結合または尿素結合を介して結合してもよい。Ｘ³およびＸ⁵は、それぞれ独立に単結合、炭素原子数１乃至２０のアルキレン基、芳香環基または脂環基を表す。ここで、炭素原子数１乃至２０のアルキレン基は、分岐状でも直鎖状でもよい。Ｘ⁴およびＸ⁶は、重合性基を表す。この重合性基の具体例としては、例えば、アクリロイル基、メタクリロイル基、スチレン基、マレイミド基、アクリルアミド基およびメタクリルアミド基などが挙げられる。
Ｒ¹、Ｒ²、Ｒ³およびＲ⁴は、それぞれ独立に水素原子、炭素原子数１乃至４のアルキル基、炭素原子数１乃至４のアルコキシ基、ハロゲン原子、トリフルオロメチル基またはシアノ基を表す。例えば、４−（６−メタクリルオキシヘキシル−１−オキシ）ケイ皮酸メチルエステル及び６−（アクリロイルオキシ）ヘキシル−３−（４−メトキシフェニル）アクリレートなどが挙げられる。

In the above formula, X ¹ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, a phenyl group or a biphenyl group. Here, the phenyl group and the biphenyl group may each be substituted with either a halogen atom or a cyano group. X ² represents a hydrogen atom, a cyano group, an alkyl group having 1 to 18 carbon atoms, a phenyl group, a biphenyl group, or a cyclohexyl group. Here, the alkyl group having 1 to 18 carbon atoms, the phenyl group, the biphenyl group, and the cyclohexyl group may be bonded via a covalent bond, an ether bond, an ester bond, an amide bond, or a urea bond. X ³ and X ⁵ each independently represent a single bond, an alkylene group having 1 to 20 carbon atoms, an aromatic ring group or an alicyclic group. Here, the alkylene group having 1 to 20 carbon atoms may be branched or linear. X ⁴ and X ⁶ represent a polymerizable group. Specific examples of this polymerizable group include acryloyl group, methacryloyl group, styrene group, maleimide group, acrylamide group, and methacrylamide group.
R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a trifluoromethyl group or a cyano group. Represent. Examples include 4- (6-methacryloxyhexyl-1-oxy) cinnamic acid methyl ester and 6- (acryloyloxy) hexyl-3- (4-methoxyphenyl) acrylate.

  Examples of the monomer having a thermal crosslinking site include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2,3 -Dihydroxypropyl acrylate, 2,3-dihydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, caprolactone 2- (acryloyloxy) ethyl ester, caprolactone 2- (methacryloyloxy) ethyl ester, poly (ethylene glycol) ethyl ether acrylate, Poly (ethylene glycol) ethyl ether methacrylate, 5-acryloyloxy Monomers having a hydroxy group such as -6-hydroxynorbornene-2-carboxyl-6-lactone and 5-methacryloyloxy-6-hydroxynorbornene-2-carboxyl-6-lactone, acrylic acid, methacrylic acid, crotonic acid, Mono- (2- (acryloyloxy) ethyl) phthalate, mono- (2- (methacryloyloxy) ethyl) phthalate, N- (carboxyphenyl) maleimide, N- (carboxyphenyl) methacrylamide and N- (carboxyphenyl) acrylamide Monomers having a carboxyl group such as hydroxystyrene, N- (hydroxyphenyl) methacrylamide, N- (hydroxyphenyl) acrylamide, N- (hydroxyphenyl) maleimide and N- (H Rokishifeniru) monomers having a phenolic hydroxyl group such as maleimide, as well, and the like monomers having a glycidyl group such as glycidyl methacrylate and glycidyl acrylate.

  In the present embodiment, when a specific copolymer is obtained, in addition to a monomer having a photodimerization site and a thermal crosslinking site (hereinafter also referred to as a specific functional group), such a monomer can be copolymerized. Thus, a monomer having no specific functional group can be used in combination.

  Specific examples of the monomer having no specific functional group include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds and vinyl compounds. Specific examples thereof include the following. However, it is not limited to these.

  Examples of acrylic ester compounds include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, glycidyl acrylate, 2,2,2-trifluoroethyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, 2-aminoethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2- Methyl-2-adamantyl acrylate, 2-propyl-2-adamantyl acrylate DOO, such as 8-methyl-8-tricyclodecyl acrylate, and 8-ethyl-8-tricyclodecyl acrylate.

  Examples of the methacrylic acid ester compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, glycidyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, 2-aminomethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2- Methyl-2-adamantyl methacrylate , .Gamma.-butyrolactone methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate and 8-ethyl-8-tricyclodecyl methacrylate.

  Examples of the vinyl compound include methyl vinyl ether, benzyl vinyl ether, vinyl naphthalene, vinyl carbazole, allyl glycidyl ether, 3-ethenyl-7-oxabicyclo [4.1.0] heptane, 1,2-epoxy-5-hexene and Examples include 1,7-octadiene monoepoxide.

  Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, bromostyrene, and the like.

  Examples of the maleimide compound include maleimide, N-methylmaleimide, N-phenylmaleimide and N-cyclohexylmaleimide.

  The amount of each monomer used to obtain the specific copolymer is a monomer having a photodimerization site of 25 to 90 mol%, a monomer having a thermal crosslinking site of 10 to 75 mol%, based on the total amount of all monomers. 0 to 65 mol% by weight of a monomer having no specific functional group is preferable. When the content of the monomer having a photodimerization site is less than 25 mol%, it is difficult to impart high sensitivity and good liquid crystal alignment. On the other hand, when the content of the monomer having a thermal crosslinking site is less than 10 mol%, it is difficult to impart sufficient thermosetting property, and it is difficult to maintain high sensitivity and good liquid crystal alignment.

  In the present embodiment, the method for obtaining the specific copolymer is not particularly limited. For example, by performing a polymerization reaction at a temperature of 50 to 110 ° C. in a solvent in which a monomer having a specific functional group, a monomer having no specific functional group, and a polymerization initiator coexist if desired. A specific copolymer can be obtained. The solvent used at this time is not particularly limited as long as it dissolves a monomer having a specific functional group, a monomer having no specific functional group, and a polymerization initiator, if desired. This solvent will also be described in the <Solvent> column described later.

The specific copolymer obtained by the above method is usually in a solution state dissolved in a solvent.
Moreover, the solution of the specific copolymer obtained by the above method is poured into diethyl ether or water under stirring and reprecipitated, and after the generated precipitate is filtered and washed, under normal pressure or reduced pressure, It can be dried at room temperature or heat to obtain a powder of the specific copolymer. By such an operation, the polymerization initiator coexisting with the specific copolymer and the unreacted monomer can be removed, and as a result, a purified powder of the specific copolymer can be obtained. If sufficient purification cannot be achieved by a single operation, the obtained powder may be redissolved in a solvent and the above operation may be repeated.

In the present embodiment, the specific copolymer may be used in the form of a powder, or may be used in the form of a solution obtained by re-dissolving the purified powder in a solvent described later.
In the present embodiment, the specific copolymer of component (A) may be a mixture of a plurality of types of specific copolymers.

<(B) component>
The component (B) in the present embodiment is a polyimide precursor. (B) The polyimide precursor as a component has an aromatic ring part. In order to achieve a high birefringence, a polyimide precursor having a structural unit represented by the following formula (1) is preferable among the polyimide precursors.

上記式（１）中、Ａ₁は、脂環構造またはベンゼン環が１乃至３個直結した骨格、ナフタレン環骨格およびアントラセン環骨格等の芳香環部位を有する構造を少なくとも１つ含む有機基であり、Ｂ₁は、脂環構造またはトリフルオロメチル基もしくはトリフルオロメチル基を含む基を有するベンゼン環等の芳香環部位を有する構造を少なくとも一つ含む有機基であり、Ｒ⁵、Ｒ⁶は、それぞれ独立して水素原子または炭素原子数１乃至７の有機基を表す。ここで、式（１）中、少なくともＡ₁またはＢ₁のいずれか一方は、芳香環部位を有する構造を含む有機基である。

In the above formula (1), A ₁ is an organic group containing at least one structure having an aromatic ring portion such as a alicyclic structure or a skeleton in which 1 to 3 benzene rings are directly linked, a naphthalene ring skeleton, and an anthracene ring skeleton. , B ₁ is an organic group containing at least one structure having an alicyclic structure or an aromatic ring moiety such as a benzene ring having a trifluoromethyl group or a group containing a trifluoromethyl group, and R ⁵ and R ⁶ are Each independently represents a hydrogen atom or an organic group having 1 to 7 carbon atoms. Here, in Formula (1), at least _{one of} A _{1 and} B ₁ is an organic group including a structure having an aromatic ring moiety.

Specific examples of A ₁ in the formula (1) include organic groups including structures represented by T1 to T9 shown in Table 1 below. However, it is not limited to these.

In the present embodiment, B ₁ in the formula (1) is an organic group containing at least one benzene ring having an alicyclic structure or a trifluoromethyl group or a group containing a trifluoromethyl group. Here, specific examples of the organic group containing a benzene ring having an alicyclic structure or a trifluoromethyl group or a group containing a trifluoromethyl group include organic groups represented by S1 to S7 shown in Table 2 below. Can be mentioned.

  In this Embodiment, the polyimide precursor as (B) component may contain other structural units other than the structural unit represented by the said Formula (1). Here, other structural units are not particularly limited. Moreover, 1 type or multiple types of structural units other than the structural unit represented by Formula (1) may be included.

  (B) The weight average molecular weight of the polyimide precursor as a component is 1000-100000, Preferably it is 1500-60000. If the weight average molecular weight of the polyimide precursor is less than 1000, the solvent resistance may decrease and the orientation sensitivity may decrease. On the other hand, when the weight average molecular weight of a polyimide precursor exceeds 100,000, the viscosity of a solution is too high and handling property falls.

<Production method of component (B)>
In this Embodiment, the polyimide precursor of (B) component is obtained by copolymerizing a tetracarboxylic dianhydride and a diamine compound.

  Examples of the tetracarboxylic dianhydride include a tetracarboxylic dianhydride including at least one alicyclic structure, a tetracarboxylic dianhydride including at least one structure in which 1 to 3 benzene rings are directly connected, or a naphthalene ring. A tetracarboxylic dianhydride containing at least one is preferable.

  Specific examples of the acid dianhydride include, for example, pyromellitic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic acid Anhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,5,6-anthracenetetracarboxylic dianhydride 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride and 2,3,3 ′, 4′-biphenyltetracarboxylic Acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid Dianhydride Such as bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid dianhydride.

  In the present embodiment, other tetracarboxylic dianhydrides other than those described above may be included as the tetracarboxylic dianhydride component. In this case, other tetracarboxylic dianhydrides may be one kind or plural kinds.

Specific examples of other tetracarboxylic dianhydrides include, for example, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ′, 4′-benzophenonetetracarboxylic dianhydride Bis (3,4-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 2,2 -Bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 2,5-dicarboxymethyl terephthalic acid dianhydride, 4,6-dicarboxymethylisophthalic dianhydride, 4- (2,5-dioxotetrahydro-3-furanyl) phthalic anhydride, 1,4-bis (2,5-dioxoteto Lahydro-3-furanyl) benzene, 1,4-bis (2,6-dioxotetrahydro-4-pyranyl) benzene, 1,4-bis (2,5-dioxotetrahydro-3-methyl-3-furanyl) Benzene, 1,4-bis (2,6-dioxotetrahydro-4-methyl-4-pyranyl) benzene, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3 , 4,5-tetrahydrofurantetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 4- (2,5-dioxotetrahydro-3-furanyl) -cyclohex 1,2-dicarboxylic anhydride, tetracyclo [2,2,1,1,1] decane-2,3,7,8-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydro -3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5,6-norbornanetocararbonic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid Dianhydride, tricyclo [4.2.1.0 ^2,5 ] nonane-3,4,7,8-tetracarboxylic dianhydride, tetracyclo [4.4.1.0 ^2,5 . 0 ^7,10 ] undecane-3,4,8,9-tetracarboxylic dianhydride, hexacyclo [6.6.0.1 ^2,7 . 0 ^3,6 . 1 ^9,14 . 0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic dianhydride, 1,4-bis (2,5-di-oxo-3-furanyl) hexane, 1,4-bis (2, 6-dioxotetrahydro-4-pyranyl) hexane, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, 1,2-diphenyl-1,2,3 Examples include 4-cyclobutanetetracarboxylic dianhydride and 1,2,3,4,5,6,7,8-octahydro-2,3,6,7-anthracenetetracarboxylic dianhydride.

  (B) As a diamine component used as the raw material of the polyimide precursor which is a component, the diamine compound containing an alicyclic structure or a trifluoromethyl group is preferable, and you may use together with other diamine compounds. Specific examples of such a diamine compound include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, bis (4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane, 1,4, for example. '-Bicyclohexyldiamine, 2,2'-trifluoromethyl-4,4'-diaminobiphenyl, 3,3'-trifluoromethyl-4,4'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 2, 2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (3-amino-4-methylphenyl) propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis (3-amino) , And the like 4-methylphenyl) hexafluoropropane and 1,3-bis (4-aminophenoxy) propane.

  In this Embodiment, 1 type or multiple types of other diamine compounds other than the above-mentioned diamine compound can be used.

  Examples of other diamine compounds include bis (4-aminophenyl) sulfone, bis (3-aminophenyl) sulfone, bis (4-amino-3-carboxyphenyl) sulfone, and bis (4-amino-3,5- Dicarboxyphenyl) sulfone, bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] Sulfone, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino-3-hydroxyphenyl) sulfone, bis (4-amino-3,5-dihydroxyphenyl) sulfone, 3,3′-diamino- 4,4'-dichlorodiphenylsulfone, p-phenylenediamine, m-phenylenediamine 2,4-diaminotoluene, 2,5-diaminotoluene 2,6-diaminotoluene, 2,4-dimethyl-1,3-diaminobenzene, 2,5-dimethyl-1,4-diaminobenzene, 2,3, 5,6-tetramethyl-1,4-diaminobenzene, 2,4-diaminophenol, 2,5-diaminophenol, 4,6-diaminoresorcinol, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid N, N-diallyl-2,4-diaminoaniline, N, N-diallyl-2,5-diaminoaniline, 4-aminobenzylamine, 3-aminobenzylamine, 2- (4-aminophenyl) ethylamine, 2 -(3-aminophenyl) ethylamine, 1,5-naphthalenediamine, 2,7-naphthalenediamine, 4,4'-diaminobiphenyl 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3 ′ -Dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4 , 4′-diaminobiphenyl, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4 '-Diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, N-methyl (4,4′-diaminodiphenyl) amine, N-methyl (3,3′-diaminodiphenyl) amine, N-methyl (3,4′-diaminodiphenyl) amine, 4,4′-diaminobenzophenone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzanilide, 1,2-bis (4-aminophenyl) ethane, 1,2-bis (3-aminophenyl) ethane 4,4′-diaminotolane, 1,3-bis (4-aminophenyl) propane, 1,3-bis (3-aminophenyl) propane, 2,2-bis (4-aminophenyl) propane, 2, 2-bis (3-aminophenyl) propane, 1,4-bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1, -Bis (4-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,10-bis (4-aminophenoxy) decane, 1,11-bis (4-aminophenoxy) undecane, 1,12-bis (4-aminophenoxy) dodecane, bis (4-aminophenyl) propanedioate, Bis (4-aminophenyl) butanedioate, bis (4-aminophenyl) pentanedioate, bis (4-aminophenyl) hexane geoate, bis (4-aminophenyl) heptanedioate, bis (4-aminophenyl) ) Octanedioate, bis (4-aminophenyl) nonanegioate, bis (4-aminophenyl) Candioate, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminobenzyl) benzene, bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, Bis (4-aminophenyl) isophthalate, bis (3-aminophenyl) isophthalate, 1,4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone], 1,3-phenylenebis [(3-aminophen Nyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylenebis (4-aminobenzoate), 1,3 -Phenylenebis (3-aminobenzoate), N, N '-(1,4-phenylene) bis (4-aminobenzamide), N, N'-(1,3-phenylene) bis (4-aminobenzamide) N, N ′-(1,4-phenylene) bis (3-aminobenzamide), N, N ′-(1,3-phenylene) bis (3-aminobenzamide), bis (4-aminophenyl) terephthalamide Bis (3-aminophenyl) terephthalamide, bis (4-aminophenyl) isophthalamide, bis (3-aminophenyl) isophthalamide, 2,2-bis [4 (4-Aminophenoxy) phenyl] propane, 4,4′-bis (4-aminophenoxy) diphenylsulfone, 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5 -Triazine, 2,6-diaminodibenzofuran, 2,7-diaminodibenzofuran, 3,6-diaminodibenzofuran, 2,6-diaminocarbazole, 2,7-diaminocarbazole, 3,6-diaminocarbazole, 2,4-diamino -6-isopropyl-1,3,5-triazine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole, 1,3-diaminopropane, 1,4-diaminobutane, , 5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 9 diaminononane, 1,10-diaminodecane, 1,11 and di-aminoundecanoic and 1,12-diamino dodecane.

  In the polyimide precursor of the component (B), the blending ratio of the total amount of tetracarboxylic dianhydride (total amount of acid component) and the total amount of diamine compound (total amount of diamine component), that is, <diamine compound The total number of moles> / <total number of moles of tetracarboxylic dianhydride compound> is preferably 0.5 to 1.5. As in the normal polycondensation reaction, the closer the molar ratio is to 1, the higher the degree of polymerization of the polyimide precursor that is produced, and thus the molecular weight increases.

  (B) Although the terminal of the polyimide precursor of a component changes depending on the compounding ratio of an acid component and a diamine component, it is not specifically limited in this Embodiment.

  When the polymerization is carried out using an excess of the diamine component, the terminal amino group can be protected by reacting the terminal amino group with a carboxylic acid anhydride. Examples of such carboxylic anhydrides include phthalic anhydride, trimellitic anhydride, maleic anhydride, naphthalic anhydride, hydrogenated phthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic acid An acid anhydride, itaconic anhydride, tetrahydrophthalic anhydride, etc. can be mentioned.

  In the production of the polyimide precursor of the component (B), the reaction temperature between the acid component and the diamine component can be selected from -20 to 150 ° C, preferably -5 to 100 ° C. For example, a polyimide precursor can be obtained by setting the reaction temperature to 5 to 40 ° C. and the reaction time to 1 to 48 hours. The reaction temperature for protecting the terminal amino group with an acid anhydride can be selected from -20 to 150 ° C, preferably -5 to 100 ° C.

  The reaction between the acid component and the diamine component is usually performed in a solvent. Examples of the solvent that can be used in this case include N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, N-vinylpyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, dimethylsulfone, Hexamethyl sulfoxide, m-cresol, γ-butyrolactone, methyl 3-methoxypropionate, methyl 2-methoxypropionate, ethyl 3-methoxypropionate, ethyl 2-methoxypropionate, ethyl 3-ethoxypropionate, 2-ethoxy Ethyl propionate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, propylene glycol dimethyl ether Ter, dipropylene glycol dimethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether , Cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone and 2-heptanone. These may be used alone or in combination. Furthermore, even if it is a solvent which does not melt | dissolve a polyimide precursor, if it is the range which does not precipitate the polyimide precursor produced | generated by the polymerization reaction, it can also be mixed and used for the said solvent.

  The solution containing the polyimide precursor thus obtained can be used as it is for the preparation of the resin composition for forming a thermosetting film. The polyimide precursor can also be used after being recovered by precipitation isolation in a poor solvent such as water, methanol and ethanol.

<(C) component>
(C) component of this Embodiment is a crosslinking agent. This crosslinking agent can crosslink the component (A) and the component (B).

  Examples of the crosslinking agent (C) include an epoxy compound, a methylol compound or an isocyanate compound, and a methylol compound having two or more methylol groups or alkoxymethylol groups is preferable.

  Specific examples include compounds such as methoxymethylated glycoluril, methoxymethylated benzoguanamine and methoxymethylated melamine. Further, for example, hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis (butoxymethyl) glycoluril, 1,3,4,6-tetrakis (hydroxymethyl) glycoluril, 1,3- Bis (hydroxymethyl) urea, 1,1,3,3-tetrakis (butoxymethyl) urea, 1,1,3,3-tetrakis (methoxymethyl) urea, 1,3-bis (hydroxymethyl) -4,5 -Dihydroxy-2-imidazolinone and 1,3-bis (methoxymethyl) -4,5-dimethoxy-2-imidazolinone. Further, as commercially available products, methoxymethyl type melamine compounds (trade names Cymel 300, Cymel 301, Cymel 303, Cymel 350) manufactured by Nippon Cytec Industries, Ltd., butoxymethyl type melamine compounds (trade names My Coat 506, My Coat 508) ), Compounds such as glycoluril compounds (trade names Cymel 1170, Powder Link 1174), methylated urea resins (trade names UFR65), butylated urea resins (trade names UFR300, U-VAN10S60, U-VAN10R, U-VAN11HV) Also, urea / formaldehyde resin (high condensation type, trade name becamine J-300S, becamine P-955, becamine N) manufactured by DIC Corporation and the like can be mentioned. Further, it may be a compound obtained by condensing a melamine compound, urea compound, glycoluril compound and benzoguanamine compound in which the hydrogen atom of the amino group is substituted with a methylol group or an alkoxymethyl group. For example, the high molecular weight compound manufactured from the melamine compound (trade name Cymel 303) and the benzoguanamine compound (trade name Cymel 1123) described in US Pat. No. 6,323,310 can also be mentioned.

  In addition, as component (C), an acrylamide compound or methacrylic acid substituted with a hydroxymethyl group or an alkoxymethyl group such as N-hydroxymethylacrylamide, N-methoxymethylmethacrylamide, N-ethoxymethylacrylamide, N-butoxymethylmethacrylamide, etc. A polymer produced using an amide compound can also be used. Examples of such a polymer include poly (N-butoxymethylacrylamide), a copolymer of N-butoxymethylacrylamide and styrene, a copolymer of N-hydroxymethylmethacrylamide and methylmethacrylate, N-ethoxymethylmethacrylamide and benzyl. Examples thereof include a copolymer of methacrylate and a copolymer of N-butoxymethylacrylamide, benzyl methacrylate and 2-hydroxypropyl methacrylate. The weight average molecular weight of such a polymer is, for example, 1,000 to 500,000, for example, 2,000 to 200,000, or 3,000 to 150,000, or 3, 000 to 50,000.

  The crosslinking agent of component (C) exemplified above can be used alone or in combination of two or more.

  The content of the crosslinking agent of component (C) in the resin composition of the present embodiment is such that the acrylic copolymer having at least a photodimerization site and a thermal crosslinking site of component (A) and the polyimide precursor of component (B) It is preferable to set it as 10 thru | or 100 mass parts based on 100 mass parts of total amounts. If this ratio is less than 10 parts by mass, the solvent resistance and heat resistance of the cured film obtained from the resin composition are lowered, and the sensitivity during photo-alignment is lowered. On the other hand, if it is more than 100 parts by mass, there is a concern that the photo-alignment property is lowered and the storage stability is lowered.

<(D) component>
The resin composition of this Embodiment can contain an acid or a thermal acid generator as (D) component. This component (D) is effective in that the thermosetting property of the resin composition of the present embodiment is promoted.

  As the acid or thermal acid generator as component (D), a sulfonic acid group-containing compound, hydrochloric acid or a salt thereof, and a compound that generates an acid by thermal decomposition during pre-baking or post-baking, that is, thermal decomposition at 80 to 250 ° C. The compound is not particularly limited as long as it is a compound that generates an acid. Examples of such compounds include hydrochloric acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, pentanesulfonic acid, octanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, camphorsulfonic acid, trifluoromethanesulfone. Acid, p-phenolsulfonic acid, 2-naphthalenesulfonic acid, mesitylenesulfonic acid, p-xylene-2-sulfonic acid, m-xylene-2-sulfonic acid, 4-ethylbenzenesulfonic acid, 1H, 1H, 2H, 2H- Examples include sulfonic acids such as perfluorooctanesulfonic acid, perfluoro (2-ethoxyethane) sulfonic acid, pentafluoroethanesulfonic acid, nonafluorobutane-1-sulfonic acid, dodecylbenzenesulfonic acid, and hydrates and salts thereof. It is done.

  Examples of the compound that generates an acid by heat include bis (tosyloxy) ethane, bis (tosyloxy) propane, bis (tosyloxy) butane, p-nitrobenzyl tosylate, o-nitrobenzyl tosylate, 1,2,3- Phenylenetris (methylsulfonate), p-toluenesulfonic acid pyridinium salt, p-toluenesulfonic acid morphonium salt, p-toluenesulfonic acid ethyl ester, p-toluenesulfonic acid propyl ester, p-toluenesulfonic acid butyl ester, p- Toluenesulfonic acid isobutyl ester, p-toluenesulfonic acid methyl ester, p-toluenesulfonic acid phenethyl ester, cyanomethyl p-toluenesulfonate, 2,2,2-trifluoroethyl p-toluenesulfonate, 2-hydroxy Chill p- tosylate, other N- ethyl-4-toluenesulfonamide, the following equation (5) to (9) include a compound represented by the formula (14) through (49).

  The content of the component (D) in the resin composition of the present embodiment is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). If it is less than 0.01 parts by mass, the thermosetting property is lowered and the solvent resistance becomes insufficient, and the sensitivity to light irradiation may be lowered. On the other hand, when it exceeds 5 mass parts, the storage stability of a composition may fall.

<(E) component>
In this Embodiment, you may contain a sensitizer as (E) component. This component (E) is effective in that it promotes the photodimerization reaction after forming the thermosetting film of the present embodiment.

  Examples of the sensitizer as component (E) include benzophenone, anthracene, anthraquinone, thioxanthone and derivatives thereof, and nitrophenyl compounds. Of these, benzophenone derivatives and nitrophenyl compounds are particularly preferred. Specific examples include N, N-diethylaminobenzophenone, 2-nitrofluorene, 2-nitrofluorenone, 5-nitroacenaphthene, 9-hydroxymethylanthracene, 4-nitrocinnamic acid, 4-nitrobiphenyl, and the like. In particular, N, N-diethylaminobenzophenone which is a derivative of benzophenone is preferable. The sensitizer is not limited to the above. The sensitizers can be used alone or in combination of two or more compounds.

  The use ratio of the sensitizer of component (E) in the present embodiment is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts per 100 parts by mass of component (A). Part by mass. If this proportion is less than 0.1 parts by mass, the effect as a sensitizer may not be sufficiently obtained. On the other hand, if it is more than 20 parts by mass, the transmittance may be lowered and the coating film may be roughened.

<Solvent>
The resin composition of the present embodiment can be used in a solution state dissolved in a solvent. The solvent to be used is one that dissolves the component (A), the component (B), and the component (C). If necessary, the component (D) and the component (E) are dissolved, and if other additives described below are contained, the component is dissolved. is there. The type and structure of the solvent are not particularly limited as long as the solvent has such dissolving ability. Specifically, the solvent used for superposition | polymerization of (A) component or (B) component can be mentioned. These solvents can be used singly or in combination of two or more.

<Other additives>
Further, the resin composition of the present embodiment is not limited to the effects of the present invention, and if necessary, a silane coupling agent, a surfactant, a rheology modifier, a pigment, a dye, a storage stabilizer, an antifoaming agent. Other additives such as additives and antioxidants can be included.

<Resin composition>
The resin composition of the present embodiment comprises an (A) component, an acrylic copolymer having a photodimerization site and a thermal crosslinking site, a (B) component polyimide precursor, and a (C) component crosslinking agent. If desired, it may contain one or more of an acid or thermal acid generator as component (D), a sensitizer as component (E), and other additives. And a resin composition is normally used as a solution which these melt | dissolved in the solvent.

In the resin composition, the blending ratio of the component (A) to the component (B) is preferably 5:95 to 60:40 in terms of parts by mass. When the content of the component (A) is too smaller than this blending ratio, there is a concern that alignment failure may occur. On the other hand, when the content of the component (A) is too larger than this blending ratio, the birefringence becomes small and the coating film may become cloudy.
In addition, since the hydroxyl group value of the component (A) is usually 1 to 3 mmol / g and the acid value of the component (B) is usually 2 to 4 mmol / g, the components (A) and (B ) When the blending ratio of the component is further in the range of 5:95 to 40:60, the orientation component is bleed in the upper layer, the orientation sensitivity is increased, and a higher birefringence is obtained.
Here, the hydroxyl group value of component (A) is the number of mmols of potassium hydroxide required to neutralize acetic acid necessary for acetylating the free hydroxyl group contained in 1 g of component (A). Say. Moreover, the acid value of (B) component means the mmol number of potassium hydroxide required to neutralize the free acid group contained in 1 g of (B) component.

Preferred examples of the resin composition of the present embodiment are as follows.
[1]: A resin composition containing 10 to 100 parts by mass of component (C) based on 100 parts by mass of the total amount of component (A) and component (B).
[2]: A resin composition containing 10 to 100 parts by mass of component (C) and a solvent based on 100 parts by mass of the total amount of component (A) and component (B).
[3]: Based on 100 parts by mass of the total amount of component (A) and component (B), 10 to 100 parts by mass of component (C), 0.01 to 5 parts by mass of component (D), and solvent A resin composition to contain.

  The blending ratio and the preparation method when the resin composition of the present embodiment is used as a solution will be described in detail below.

  The ratio of the solid content in the resin composition of the present embodiment is not particularly limited as long as each component is uniformly dissolved in the solvent, but the general solid content ratio is 1 to 80% by mass. is there. Among these, Preferably it is 3 thru | or 60 mass%, More preferably, it is 5 thru | or 40 mass%. Here, solid content means what remove | excluded the solvent from all the components of the resin composition.

  The method for preparing the resin composition of the present embodiment is not particularly limited. For example, there is a method in which the component (A) is dissolved in a solvent, and the component (B), and further the component (C) and the component (D) are mixed in this solution at a predetermined ratio to obtain a uniform solution. In addition, in an appropriate stage of the preparation method, other additives may be added and mixed as necessary.

  In preparing the resin composition of the present embodiment, an acrylic polymer solution obtained by a polymerization reaction in a solvent can be used as it is. In this case, the component (A), the component (B), the component (C), the component (D), and the like are added to the solution of the component (A) as described above to obtain a uniform solution. At this time, a solvent may be further added for the purpose of adjusting the concentration. Here, the solvent used in the process of producing the acrylic polymer and the solvent used for concentration adjustment when preparing the resin composition may be the same solvent, and different appropriate solvents may be selected and used. May be.

  The resin composition solution of the present embodiment prepared as described above is preferably used after being filtered using a filter having a pore size of about 0.2 μm.

<Coating film, cured film and liquid crystal alignment layer>
Using the resin composition of the present embodiment, a coating film can be formed by the following method.
First, the resin composition is applied onto the substrate by a method such as spin coating, flow coating, roll coating, slit coating, spin coating following the slit, ink jet coating, or printing. Subsequently, a coating film can be formed by predrying (prebaking) with a hot plate or oven. Then, a cured film is formed by heat-treating (post-baking) this coating film.

  As the substrate to which the resin composition is applied, for example, a silicon / silicon dioxide-coated substrate, a silicon nitride substrate, a glass substrate, a quartz substrate, an ITO substrate, or the like can be used. In addition, for example, a substrate coated with a metal such as aluminum, molybdenum, or chromium can be used. Furthermore, for example, a resin film such as a triacetyl cellulose film, a polyester film, and an acrylic film can be used as the substrate.

  As pre-baking conditions for the coating film, for example, a heating temperature and a heating time appropriately selected from the range of a temperature of 70 to 160 ° C. and a time of 0.3 to 60 minutes are employed. The heating temperature and the heating time are preferably 80 to 140 ° C. and 0.5 to 10 minutes.

  As the post-baking conditions for the coating film, a heating temperature appropriately selected from a temperature range of 140 to 250 ° C. according to the heating method and the like can be adopted. The same applies to the heating time. For example, the heating time may be 5 to 30 minutes on the hot plate, and 30 to 90 minutes in the oven.

  Under the above conditions, by curing the resin composition of the present embodiment, it is possible to sufficiently cover and flatten the step of the substrate due to the color filter (CF), A cured film having high transparency can be formed. Note that the thickness of the cured film can be set to, for example, 0.1 to 30 μm, and can be appropriately selected in consideration of the level difference of the substrate to be used and the optical and electrical properties.

  The cured film thus obtained can function as a liquid crystal alignment layer for aligning a liquid crystal alignment material, that is, a compound having liquid crystallinity, by performing polarized light irradiation. At this time, the polarized light used for polarized light irradiation is preferably polarized UV (ultraviolet). As the polarized UV, ultraviolet light having a wavelength of 150 to 450 nm is usually used. Then, linearly polarized light is irradiated from the perpendicular or oblique direction to the cured film at room temperature or in a heated state.

  After coating the retardation material on the liquid crystal alignment layer formed from the resin composition of the present embodiment as described above, after heating to the phase transition temperature of the liquid crystal to make the retardation material in a liquid crystal state, Light cure. Thereby, a layer having optical anisotropy, that is, a retardation material can be formed on the liquid crystal alignment layer. With this method, the configuration in which the phase difference material is arranged inside the liquid crystal cell can improve the contrast ratio of the liquid crystal cell as compared with the conventional configuration in which the phase difference material is arranged outside the liquid crystal cell.

  As the retardation material, for example, a liquid crystal monomer having a polymerizable group or a composition containing the same is used. When the substrate on which the liquid crystal alignment layer is formed is a film, it is useful as an optically anisotropic film. Such retardation materials include materials having orientation such as horizontal orientation, cholesteric orientation, vertical orientation, hybrid orientation, and biaxial orientation, and can be used properly according to the required retardation.

  Also, the two substrates having the liquid crystal alignment layer formed as described above are bonded so that the liquid crystal alignment layers face each other via a spacer, and then liquid crystal is injected between these substrates. Thus, a liquid crystal display element in which liquid crystal is aligned can be obtained.

  Thus, the resin composition of this Embodiment can be used suitably for comprising various optical anisotropic films and liquid crystal display elements.

  The resin composition of the present embodiment is also useful as a material for forming a cured film such as a protective film, a planarizing film, and an insulating film in various displays such as a thin film transistor (TFT) type liquid crystal display element and an organic EL element. is there. In particular, in addition to the overcoat material (CF overcoat material) of the color filter (CF), it is also suitable as a material for forming an interlayer insulating film of a TFT type liquid crystal element, an insulating film of an organic EL element, and the like.

  When the resin composition of this embodiment is used as a CF overcoat material, the obtained CF overcoat not only covers and flattens the steps of the color filter, but also functions as a liquid crystal alignment material. Therefore, it can be used as a CF overcoat having orientation.

  FIG. 1 is a schematic configuration diagram of a liquid crystal cell according to the present embodiment. In this figure, the liquid crystal layer 108 is sandwiched between two substrates 101 and 111. An ITO 110 and an alignment film 109 are formed on the substrate 111. On the substrate 101, a color filter 102, a CF overcoat 103, a retardation material 105, an ITO 106, and an alignment film 107 are formed in this order. In this case, since the CF overcoat 103 also functions as an alignment film, a film corresponding to the alignment film 204 in FIG. 2 can be dispensed with.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these Examples.

[Abbreviations used in Examples]
The meanings of the abbreviations used in the following examples are as follows.
<Acrylic polymer>
HEMA: 2-hydroxyethyl methacrylate CIN: 4- (6-methacryloxyhexyl-1-oxy) cinnamic acid methyl ester AIBN: α, α′-azobisisobutyronitrile <polyimide precursor>
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride ODPA: 4,4′-oxydiphthalic anhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride TFMB: 2 , 2′-Trifluoromethyl-4,4′-diaminobiphenyl <crosslinking agent>
CYM: Cymel 303 (Mitsui Cytec)
<Acid or thermal acid generator>
PTSA: p-toluenesulfonic acid monohydrate <solvent>
CHN: cyclohexanone NMP: N-methylpyrrolidone

The number average molecular weight and the weight average molecular weight of the acrylic copolymer obtained in accordance with the following synthesis examples were measured using a GPC apparatus (Shodex (registered trademark) columns KF803L and KF804L) manufactured by JASCO Corporation and the elution solvent tetrahydrofuran at a flow rate of 1 ml / The measurement was performed under the condition that the column was eluted in a column (column temperature: 40 ° C.). The following number average molecular weight (hereinafter referred to as Mn) and weight average molecular weight (hereinafter referred to as Mw) were expressed in terms of polystyrene.
Further, Mn and Mw of the polyimide precursor were obtained by using a GPC apparatus (Shodex (registered trademark) columns KD803 and KD805) manufactured by Shodex, and elution solvent N, N, -dimethylformamide (as an additive, lithium bromide-hydrated). Product (LiBr · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystals (o-phosphoric acid) 30 mmol / L, tetrahydrofuran 10 ml / L) into the column at a flow rate of 1 ml / min (column temperature 50 ° C.) The measurement was performed under the condition of flowing and eluting. The following Mn and Mw are expressed in terms of polyethylene glycol and polyethylene oxide.

<Synthesis Example 1>
CIN 42.0 g, HEMA 18.0 g, and AIBN 1.3 g were dissolved in 166.8 g CHN and reacted at 80 ° C. for 20 hours to obtain an acrylic polymer solution (a solid content concentration of 27% by mass was obtained) (P1) . Mn of the obtained acrylic polymer was 8,500 and Mw was 16,500.

<Synthesis Example 2>
16.0 g of TFMB was dissolved in 114.1 g of NMP. Thereafter, 12.5 g of BPDA was added and reacted at 40 ° C. for 20 hours to obtain a polyimide precursor solution (a solid content concentration of 20% by mass was obtained) (P2). Mn of the obtained polyimide precursor was 12,600 and Mw was 27,500.

<Synthesis Example 3>
5.1 g of TFMB was dissolved in 72.2 g of NMP. Thereafter, 4.7 g of ODPA was added and reacted at room temperature for 20 hours to obtain a polyimide precursor solution (a solid content concentration of 12% by mass was obtained) (P3). Mn of the obtained polyimide precursor was 7,000 and Mw was 15,800.

<Synthesis Example 4>
233.8 g of TFMB was dissolved in 2111.6 g of NMP. Thereafter, 142.9 g of CBDA was added and reacted at room temperature for 20 hours to obtain a polyimide precursor solution (a solid concentration of 15% by mass was obtained) (P4). Mn of the obtained polyimide precursor was 12,400 and Mw was 43,000.

<Examples 1 to 3 and Comparative Examples 1 to 4>
Each composition of Example 1 thru | or Example 3 and Comparative Example 1 thru | or Comparative Example 4 was prepared with the composition shown in Table 3, and the solvent tolerance, the transmittance | permeability, orientation, and birefringence were evaluated about each. .

[Evaluation of solvent resistance]
Each composition of Examples 1 to 3 and Comparative Examples 1 to 4 was applied to a silicon wafer using a spin coater, and then prebaked on a hot plate at a temperature of 80 ° C. for 120 seconds. Thereafter, this coating film was post-baked at 230 ° C. for 30 minutes in a hot air circulating oven to form a cured film having a thickness of 2.0 μm. The film thickness was measured using DEKTAK150 manufactured by VEECO.
Next, this cured film was immersed in CHN or NMP for 60 seconds, and then dried at a temperature of 100 ° C. for 60 seconds, and the film thickness was measured. The case where there was no change in film thickness after immersion in CHN or NMP was marked with ○, and the case where the film thickness decreased after immersion was marked with x.

[Evaluation of light transmittance (transparency)]
The compositions of Examples 1 to 3 and Comparative Examples 1 to 4 were applied on a quartz substrate using a spin coater, and then prebaked on a hot plate at a temperature of 80 ° C. for 120 seconds. Thereafter, this coating film was post-baked at 230 ° C. for 30 minutes in a hot air circulating oven to form a cured film having a thickness of 2.0 μm. The film thickness was measured using DEKTAK150 manufactured by VEECO.
Next, the transmittance of the cured film at a wavelength of 400 nm was measured using an ultraviolet-visible spectrophotometer (SHIMADZU UV-2550 model number, manufactured by Shimadzu Corporation).

[Evaluation of orientation sensitivity]
Each composition of Examples 1 to 3 and Comparative Examples 1 to 4 was applied on an ITO substrate using a spin coater, and then prebaked on a hot plate at a temperature of 80 ° C. for 120 seconds. Thereafter, this coating film was post-baked at 230 ° C. for 30 minutes in a hot air circulating oven to form a cured film having a thickness of 2.0 μm. The film thickness was measured using DEKTAK150 manufactured by VEECO.
Next, linearly polarized light with a wavelength of 313 nm was irradiated as polarized UV from a direction perpendicular to the cured film on the ITO substrate. Next, a retardation material solution composed of a liquid crystal monomer was applied onto the substrate using a spin coater, and then prebaked on a hot plate at 80 ° C. for 60 seconds to form a coating film having a thickness of 1.4 μm. Next, the coating film on the substrate was exposed to 1,000 mJ / cm ² of UV light in a nitrogen atmosphere to cure the retardation material. The thus prepared substrate was sandwiched between polarizing plates, the phase difference state of the cured retardation material was confirmed, and the exposure amount of polarized UV necessary for the cured film to exhibit orientation was determined to obtain the orientation sensitivity. Moreover, the thing which does not show orientation even if exposed to 3000 mJ / cm < ² > UV light was set as x.

[Evaluation of birefringence]
The compositions of Examples 1 to 3 and Comparative Examples 1 to 4 were applied on a quartz substrate using a spin coater, and then prebaked on a hot plate at a temperature of 80 ° C. for 120 seconds. Thereafter, this coating film was post-baked in a hot air circulating oven at a temperature of 230 ° C. for 30 minutes to form a cured film having a thickness of 2.0 μm. The film thickness was measured using DEKTAK150 manufactured by VEECO.
About this cured film, the birefringence at the time of wavelength 590nm was measured using the phase difference film measuring apparatus (AXOMETRIC Inc. Axo Scan).

[Evaluation results]
Table 4 shows the results of the above evaluation.

  In the cured films formed from the compositions of Examples 1 to 3, the alignment sensitivity was high. Therefore, it turned out that the composition of Example 1 thru | or Example 3 can form a liquid crystal aligning material efficiently. In addition, transparency was high and resistance to both CHN and NMP was observed. Moreover, the high birefringence was shown.

  On the other hand, the cured film formed from the composition of Comparative Example 1 has a low birefringence and solvent resistance, and requires 300 times the amount of exposure as in Examples 1 to 3 to exhibit orientation. It was. In addition, the cured films formed from the compositions of Comparative Examples 2 to 4 exhibited high birefringence and solvent resistance, but did not exhibit orientation.

  As described above, it has been found that the cured film obtained from the resin composition of the present invention has a high birefringence and is excellent in light transmittance, solvent resistance and orientation. Therefore, according to the resin composition of the present invention, it is possible to provide a cured film having excellent properties as described above, that is, a liquid crystal alignment material, and further, it is possible to form a retardation material. It was.

  The resin composition according to the present invention is very useful as an optically anisotropic film or a liquid crystal alignment material for a liquid crystal display element, and further, a protective film in various displays such as a thin film transistor (TFT) type liquid crystal display element and an organic EL element, It is also suitable as a material for forming a cured film such as a flattening film and an insulating film, particularly as a material for forming an interlayer insulating film of a TFT type liquid crystal element, a protective film for a color filter or an insulating film for an organic EL element.

Claims (17)

(A) an acrylic copolymer having a photodimerization site comprising a hydrophobic group and a thermal crosslinking site comprising a hydrophilic group;
(B) a polyimide precursor having an aromatic ring moiety;
(C) The resin composition containing the crosslinking agent which bridge | crosslinks this (A) component and this (B) component.   The resin composition according to claim 1, wherein the component (A) is an acrylic copolymer obtained by a polymerization reaction of a monomer mixture containing a monomer having a photodimerization site and a monomer having a thermal crosslinking site. object.   The component (A) is an acrylic copolymer obtained by a polymerization reaction of a monomer mixture containing 25 mol% to 90 mol% of a monomer having a photodimerization site with respect to the total amount of all monomer mixtures. The resin composition according to claim 2.   The resin composition according to any one of claims 1 to 3, wherein the photodimerization site of the component (A) is a cinnamoyl group.   The resin composition according to any one of claims 1 to 4, wherein the thermal crosslinking site of the component (A) is a hydroxyl group or a carboxyl group.   The resin composition according to claim 1, wherein the polyimide precursor of the component (B) has a biphenyl structure in the main chain.   The component (B) is a polyimide precursor containing a structural unit obtained by a copolymerization reaction of a tetracarboxylic dianhydride and a diamine compound, and at least one of the tetracarboxylic dianhydride and the diamine compound The resin composition according to claim 6, which has a biphenyl structure.   The resin composition according to claim 7, wherein the tetracarboxylic dianhydride is biphenyltetracarboxylic dianhydride.   The resin composition according to claim 7 or 8, wherein the component (B) is a polyimide precursor having a trifluoromethyl group in the structural unit.   The resin composition according to any one of claims 1 to 9, wherein the polyimide precursor of the component (B) has an alicyclic structure in the main chain.   The component (B) is a polyimide precursor containing a structural unit obtained by a copolymerization reaction of a tetracarboxylic dianhydride and a diamine compound, and at least one of the tetracarboxylic dianhydride and the diamine compound It has an alicyclic structure, The resin composition of Claim 10 characterized by the above-mentioned.   The resin composition according to any one of claims 1 to 11, wherein the crosslinking agent of the component (C) is a crosslinking agent having a methylol group or an alkoxymethylol group.   13. The component (C) is contained in an amount of 10 to 100 parts by mass based on 100 parts by mass of the total amount of the component (A) and the component (B). 2. The resin composition according to item 1.   The resin composition according to any one of claims 1 to 13, further comprising an acid or a thermal acid generator as component (D).   The resin composition according to claim 14, comprising 0.1 to 10 parts by mass of the component (D) based on 100 parts by mass of the total amount of the component (A) and the component (B). object.   A liquid crystal alignment material obtained by using the resin composition according to any one of claims 1 to 15.   A phase difference material formed using a cured film obtained from the resin composition according to claim 1.

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