KR101844738B1 - Resin composition, liquid crystal orientation agent, and phase difference agent - Google Patents

Abstract

 [PROBLEMS] To provide a resin composition capable of orienting polymerizable liquid crystals with high sensitivity after thermal curing by using photo-alignment technology, and exhibiting high birefringence, high solvent resistance, heat resistance and high transparency. (A) a resin composition comprising (A) an acrylic copolymer having a photo-dimerization site comprising a hydrophobic group and a thermally crosslinked site comprising a hydrophilic group, (B) a polyimide precursor having an aromatic ring site, (C) ) Component and the component (B). The component (A) may be an acrylic copolymer obtained by a polymerization reaction of a monomer mixture containing a monomer having a photo-dimerization site and a monomer having a thermal crosslinking site. The component (A) may be an acrylic copolymer obtained by a polymerization reaction of a monomer mixture containing from 25 mol% to 90 mol% of a monomer having a photo-dimerization site relative to the total of all monomer mixtures. The component (A) may also be an acrylic copolymer obtained by a polymerization reaction between a monomer having a photo-dimerization site and a monomer containing a monomer having a thermal cross-linking site.

Description

RESIN COMPOSITION, LIQUID CRYSTAL ORIENTATION AGENT, AND PHASE DIFFERENCE AGENT)

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

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

For example, in the case of a VA mode liquid crystal display, a biaxial plate in which the refractive indices in three directions, i.e., the in-plane x and y directions and the thickness direction, of the film are different from each other may be used alone or as a phase difference film, The positive A plate and the negative C plate are combined to form a retardation film, thereby compensating for the viewing angle. The former is produced by biaxial stretching and the latter is produced by uniaxial stretching. Here, when the refractive indices of the plate in the film plane in the x and y directions are nx and ny and the refractive index in the thickness direction is nz, the positive A plate is a retardation film having a property of nx> ny = nz. 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 in order to achieve a high contrast ratio, a low cost, and a light weight by introducing a retardation material into a liquid crystal cell of a liquid crystal display. It has been proposed to use a polymerizable liquid crystal solution for the formation of such a phase difference material. Specifically, a polymerizable liquid crystal solution is applied to a suitable site in a liquid crystal cell, the desired alignment is made, and then light curing is performed to form a retardation.

In the case of the positive A plate, a polymerizable liquid crystal exhibiting horizontal orientation is used. In addition, in the case of the negative C plate, a polymerizable liquid crystal exhibiting a cholestric orientation or a discotic orientation is used. In the case of a biaxial plate, a polymerizable liquid crystal exhibiting biaxial alignability is used. For this reason, in order to introduce a retarder having a biaxial phase difference into the liquid crystal cell, a polymerizable liquid crystal exhibiting biaxial alignability or a polymerizable liquid crystal exhibiting cholesteric alignment and a polymerizable liquid crystal exhibiting horizontal orientation are stacked .

However, the polymerizable liquid crystal exhibiting biaxial orientation is known to be difficult to form a thick film, but no material capable of fully expressing necessary retardation characteristics has yet been found. In addition, when a polymerizable liquid crystal exhibiting cholesteric orientation and a polymerizable liquid crystal exhibiting horizontal orientation are laminated, the manufacturing process becomes complicated, resulting in problems such as an increase in manufacturing cost and a decrease in throughput.

2 is a schematic diagram of a liquid crystal cell in which a liquid crystal alignment film is formed by a conventional technique. In the figure, the liquid crystal layer 208 is interposed between the two substrates 201 and 211. On the substrate 211, an ITO 210 and an orientation film 209 are formed. An overcoat (hereinafter, referred to as a CF overcoat) 203, an orientation film 204, a retardation film 205, an ITO film 206, and an alignment film 204 are sequentially formed on a substrate 201, (207) are formed in this order.

In the conventional liquid crystal cell, in order to align the polymerizable liquid crystal for the retardation reformation before curing, it is necessary to separately provide a film capable of aligning liquid crystals, that is, an alignment film. The alignment film is formed through processes such as rubbing treatment and polarization irradiation. 2, conventionally, after the orientation film 204 is formed on the CF overcoat 203, a retardation film 205 obtained from a polymerizable liquid crystal such as a liquid crystal monomer is formed thereon. That is, after the color filter 202 is formed, it is necessary to form two layers of the CF overcoat 203 and the orientation film 204 again, which complicates the manufacturing process.

From this point of view, it is strongly desired to provide a film that simultaneously satisfies a plurality of different required characteristics and a material for forming the film. Concretely, there is a demand for a film serving as an alignment film and a CF overcoat, and a material for forming the film. As a result, the liquid crystal display can be advantageously used for manufacturing a liquid crystal display at a low cost, reducing the number of processes, and improving productivity.

In addition, it is required to shorten the time required for the alignment treatment for the film that also serves as the alignment film and CF overcoat. Therefore, in the manufacturing process of the alignment film, the application of the photo-alignment technique becomes necessary. Therefore, it is strongly demanded that a film that also serves as an alignment film and a CF overcoat is made of a photo-orientable material.

Furthermore, a film that also serves as an alignment film and CF overcoat is required to have a large birefringence. This is because the characteristic of the negative C plate can be imparted as the birefringence increases. Further, by having high birefringence characteristics, the film thickness of the biaxially oriented polymerizable liquid crystal laminated thereon can be made thinner, and further, the biaxiality can be expressed by applying the horizontally oriented polymerizable liquid crystal.

Generally, acrylic resin having high transparency is used for the CF overcoat. Further, the acrylic resin is cured by heat or light, thereby exhibiting heat resistance and solvent resistance (see, for example, Patent Document 1 or 2).

However, according to the study by the present inventors, transparency and solvent resistance can be obtained in the conventional CF overcoat made of a thermosetting or photo-curable acrylic resin, but it has been proved that sufficient polarizing UV irradiation can not exhibit sufficient liquid crystal alignability . Therefore, it can be interpreted that the conventional CF overcoat can not be applied directly to the film that also serves as the alignment film and the CF overcoat.

Further, it has been reported that a polyamic acid having high transparency and high refractive index is obtained by using a polyamic acid comprising a tetracarboxylic dianhydride having a biphenyl skeleton and a diamine having an alicyclic structure (see Patent Document 3). However, even if the polyamic acid is irradiated with polarized light, sufficient liquid crystal alignability can not be exhibited. That is, such a high refractive index polyamic acid can not be directly applied to a film serving as both the alignment film and CF overcoat.

Further, it has been reported that sufficient liquid crystal alignability can be obtained by irradiating polarized UV to an acrylic resin having a light dimerization site such as a cinnamoyl group or a knocker group in the side chain (see Patent Document 4). However, according to the study of the present inventors, it has been found that even when a polarizing UV exposure dose (for example, 100 mJ / cm ² ) sufficient for orienting a liquid crystal for display is irradiated, it is insufficient to function as a film also serving as the CF- I know that. Specifically, when the polymerizable liquid crystal solution is applied onto the acrylic resin after irradiating polarized UV to the acrylic resin, resistance of the acrylic resin to the solution is low, so that the film of the acrylic resin in the lower layer is dissolved. Therefore, sufficient orientation property to the polymerizable liquid crystal can not be exhibited.

On the other hand, the reaction rate of the photo-dimerization 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 alignment property of the polymerizable liquid crystal can be improved by the increase of the exposure dose. However, considering that the photo-alignment technique has been studied for the purpose of shortening the time for orientation processing from the beginning, it is impossible to allow the increase in the exposure amount to be followed by the prolongation of the exposure time.

Further, according to the study by the present inventors, it has been found that even if the reaction rate is improved, the photo-dimerization reaction for expressing liquid crystal alignability alone can not be said to be sufficient as a crosslinking reaction, and sufficient heat resistance as a film can not be realized. That is, it is known that the film made of the acrylic resin has a large film shrinkage due to the heat treatment for producing the liquid crystal cell when the reaction rate is improved.

Japanese Patent Application Laid-Open No. 2000-103937 Japanese Patent Application Laid-Open No. 2000-119472 WO 2008010483A1 Japanese Patent No. 4011652

The present invention is based on the above findings and the results of the examination. That is, an object of the present invention is to provide a resin composition capable of orienting a polymerizable liquid crystal with high sensitivity after thermal curing using a photo-alignment technique and exhibiting high birefringence, high solvent resistance, heat resistance and high transparency will be.

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

According to a first aspect of the present invention,

(A) an acrylic copolymer having a thermal crosslinking site composed of a light dimerization site and a hydrophilic group, which is a hydrophobic group, and

(B) a polyimide precursor having an aromatic ring moiety,

(C) a resin composition containing a cross-linking agent for crosslinking the component (A) and the component (B).

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 comprising a monomer having a photo-dimerization 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 polymerization reaction of a monomer mixture containing from 25 mol% to 90 mol% of a monomer having a light dimerization site, based on the total amount of the entire monomer mixture Chain is preferable.

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

In the first aspect of the present invention, it is preferable that the thermally crosslinking site of the component (A) is a hydroxyl group or a carboxyl group.

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

In the first aspect of the present invention, the component (B) is a polyimide precursor comprising a structural unit obtained by copolymerization reaction of a tetracarboxylic dianhydride and a diamine compound, wherein at least one of the tetracarboxylic dianhydride and the diamine compound Having a biphenyl structure.

In the first aspect of the present invention, it is preferable that the tetracarboxylic dianhydride is biphenyltetracarboxylic dianhydride.

In the first aspect of the present invention, the component (B) is preferably a polyimide precursor having a trifluoromethyl group in its structural unit.

In the first aspect of the present invention, the polyimide precursor of component (B) preferably has an alicyclic structure in its main chain.

In the first aspect of the present invention, the component (B) is a polyimide precursor comprising a structural unit obtained by copolymerization reaction of a tetracarboxylic dianhydride and a diamine compound, wherein at least one of the tetracarboxylic dianhydride and the diamine compound Having an alicyclic structure.

In the first aspect of the present invention, the crosslinking agent of the component (C) is preferably a crosslinking agent having a methylol group or an alkoxymethylol group.

In the first aspect of the present invention, it is preferable to contain 10 to 100 parts by mass of the component (C) based on 100 parts by mass of the total amount of the component (A) and the component (B).

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

In the first aspect of the present invention, it is preferable to contain 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).

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

A third aspect of the present invention relates to a retarder 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, a cured film is obtained which not only has high birefringence, high transparency, high solvent resistance, and high heat resistance, but also enables photo alignment of liquid crystal.

According to the second aspect of the present invention, it is possible to obtain a liquid crystal alignment material having a high birefringence and excellent in light transmittance, solvent resistance and orientation.

According to the third aspect of the present invention, a retardation that can be arranged in the liquid crystal cell is obtained. The contrast ratio can be improved in the liquid crystal cell using this phase difference material.

1 is a schematic structural view of a liquid crystal cell according to the present embodiment.
2 is a schematic diagram of a conventional liquid crystal cell.

The present invention relates to a resin composition, a liquid crystal aligning material formed using the resin composition, and a retardation material formed by using a cured film obtained from the resin composition. More specifically, the present invention relates to a resin composition capable of forming a cured film having a high birefringence and high transparency, a liquid crystal aligning ability, a high solvent resistance and a heat resistance, a liquid crystal alignment material formed using the resin composition, To a phase difference material formed by using the above-mentioned 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 is also suitable for forming a built-in retardation layer since it has an alignment function for a polymerizable liquid crystal for forming a retardation 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 refers to a resin composition for forming a thermosetting film having a photo-alignment property, that is, a resin composition for forming a photo-alignment thermosetting film. The thermally cured film having photo-alignment means a cured film which is cured by heating and is induced (induced) in the alignment performance of the liquid crystal by polarized light exposure.

The resin composition of this embodiment contains an acrylic copolymer having a photo-dimerization 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).

More specifically, the photo-dimerization site of the acrylic copolymer as component (A) is composed of a hydrophobic group, and the thermal crosslinking site of the acrylic copolymer is composed of a hydrophilic group. The polyimide precursor (B) has an aromatic ring moiety. Furthermore, the crosslinking agent as the component (C) can be obtained by crosslinking the component (A) and the component (B).

That is, in the resin composition of the present embodiment,

(A) an acrylic copolymer having a light dimerization site composed of a hydrophobic group and a thermal crosslinking site composed of a hydrophilic group,

(B) a polyimide precursor having an aromatic ring moiety,

(C) a crosslinking agent for crosslinking the component (A) and the component (B).

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

By containing the component (A), the resin composition of this embodiment can impart the liquid crystal alignment performance to the cured film obtained by using the resin composition by the photo alignment treatment. That is, when the acrylic copolymer as the component (A) has a thermal crosslinking site composed of a light dimerization site and a hydrophilic group comprising a hydrophobic group, thermal crosslinking reaction at a thermal crosslinking site, which will be described later, do. At this time, the photo-dimerization site composed of the 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 conditions, when the photo-dimerization reaction is promoted by polarized UV exposure or the like, excellent liquid crystal aligning performance is expressed near the surface of the cured film. Therefore, when the polymerizable liquid crystal is coated on the cured film, the polymerizable liquid crystal having high hydrophobicity and the light-dimerization sites of the hydrophobic group of the acrylic copolymer interact efficiently, and liquid crystal alignment can be realized with high sensitivity.

The component (A) has a thermal crosslinking site. This thermal cross-linking site may be composed of a hydrophilic group, thereby allowing the cross-linking agent of component (C) described below to efficiently cause a thermal cross-linking reaction. As a result, in addition to the photo-dimerization site, a crosslinking site due to a thermal reaction can also be introduced, so that the number of crosslinking sites can be increased. Therefore, dissolution of the cured film due to application of the polymerizable liquid crystal solution onto the cured film can be prevented. Further, it is also possible to suppress the heat shrinkage of the cured film under the heating environment in the manufacturing process of the liquid crystal cell.

Further, by containing the component (B), the resin composition of this embodiment can adjust the birefringence of the cured film obtained using this resin composition. That is, the polyimide precursor of the component (B) becomes a polyimide by a thermal reaction to form a cured film. By selecting a molecular structure including a benzene ring structure and a biphenyl structure in the main chain of the polyimide precursor, It is possible to impart a high birefringence property to the film.

On the other hand, at this time, the light transmittance, that is, the transparency, of the cured film may be deteriorated. However, by selecting the molecular structure of the compound constituting the polyimide precursor, the transmittance can be suppressed from lowering. For example, by selecting a compound having an alicyclic structure as a compound constituting the polyimide precursor, high transparency can be imparted to the cured film. That is, by appropriately designing the molecular structure of the polyimide precursor, it is possible to impart both high birefringence and high transparency to the cured film.

In addition, the resin composition of the present embodiment contains the component (C), so that a crosslinked site due to a thermal reaction can be introduced into the cured film obtained using the resin composition. That is, as described above, the component (C) causes a thermal crosslinking reaction with the component (A). Further, between the component (B) and the carboxyl group of the polyimide precursor, a cross-linking reaction occurs between the component (C) and the carboxyl group.

The crosslinking reaction between the component (B) and the component (C) can be controlled by controlling the content of the carboxyl group in the polyimide precursor, and furthermore, the crosslinking reaction between the component (A) . As a result, it is possible to realize an effective crosslinking reaction by the thermal reaction in the entire cured film obtained from the resin composition, and to form a hardened film by introduction of the crosslinking site.

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

≪ Component (A) >

The component (A) of the present embodiment is an acrylic copolymer having a light dimerization site and a thermal crosslinking site. The photo-dimerization site of the acrylic copolymer of the component (A) is composed of a hydrophobic group, and the thermal crosslinking site is composed of a hydrophilic group. Next, specific examples will be described.

In the present embodiment, as the acrylic copolymer, a copolymer obtained by polymerizing a monomer having an unsaturated double bond such as an acrylate ester, a methacrylate ester, or styrene can be used.

(Hereinafter also referred to as a specific copolymer) having a photo-dimerization site and a thermal crosslinking site as the component (A) may be an acrylic copolymer having such a structure, and the skeleton of the polymer main chain constituting the acrylic copolymer The kind of the side chain and the like are not particularly limited.

The light dimerization site is a site where a dimer is formed by light irradiation. Specific examples thereof include a cinnamoyl group, a chalcone group, a coumarin group, and an anthracene group. Among them, a cinnamyl group having high transparency in the visible light region and photo-dimerization reactivity is preferable. Particularly preferred partial structure of the neomamoyl group is represented by the following formulas [A1] and [A2].

[Chemical Formula 1]

In the 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 be substituted by any one of a halogen atom and 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 through a covalent bond, an ether bond, an ester bond, an amide bond or an 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.

The thermal crosslinking site is a site where it bonds with the crosslinking agent by heating, and specific examples thereof include a hydroxyl group, a carboxyl group and a glycidyl group.

The acrylic copolymer as the component (A) preferably has a weight average molecular weight of 3,000 to 200,000, more preferably 4,000 to 150,000, and still more preferably 5,000 to 100,000. If the weight average molecular weight is more than 200,000 and too large, 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 too small, less than 3,000, curing becomes insufficient at the time of thermal curing, and the solvent resistance and heat resistance may be lowered.

As described above, as a method of synthesizing an acrylic copolymer having a photo-dimerization site and a thermal crosslinking site in the side chain of the component (A), a method of copolymerizing a monomer having a photo-dimerization site and a monomer having a thermal crosslink site Is suitable.

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

(2)

In the 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 be substituted by one of a halogen atom and a cyano group, respectively. 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 through a covalent bond, an ether bond, an ester bond, an amide bond or an 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 or an alicyclic group. Here, the alkylene group having 1 to 20 carbon atoms may be branched or may be linear. X ⁴ and X ⁶ represent a polymerizable group. Specific examples of the polymerizable group include an acryloyl group, a methacryloyl group, a styrene group, a maleimide group, an acrylamide group and a 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. For example, 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, 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-6-hydroxy norbornene-2-carboxy-6-lactone and 5-methacryloyloxy-6-hydroxy norbornene-2-carboxy-6- Containing monomer, acrylic acid, methacrylic acid, croton , Mono (2- (acryloyloxy) ethyl) phthalate, mono (2- (methacryloyloxy) ethyl) phthalate, N- (carboxyphenyl) maleimide, N- (carboxyphenyl) methacrylamide and N (Hydroxyphenyl) methacrylamide, N- (hydroxyphenyl) acrylamide, N- (hydroxyphenyl) maleimide and N (hydroxyphenyl) acrylamide, - (hydroxyphenyl) maleimide, and monomers having a glycidyl group such as glycidyl methacrylate and glycidyl acrylate, and the like.

In addition, in the present embodiment, when a specific copolymer is obtained, in addition to the monomer having a light-dimerization site and a thermal crosslinking site (hereinafter also referred to as a specific functional group), a monomer capable of copolymerizing with such a monomer, can do.

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 the acrylic ester compound include acrylic acid esters such as 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, methoxy triethylene glycol acrylate, 2- Acrylate, 2-aminoethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2- 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, anthrylmethyl methacrylate Methyl methacrylate, isopropyl methacrylate, isopropyl methacrylate, isopropyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, Methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-aminomethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methoxybutyl methacrylate, Adamantyl methacrylate,? -Butyrolactone methacrylate, 2-propyl-2-adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate and 8-ethyl -8-tricyclo And decyl 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, -Epoxy-5-hexene, and 1,7-octadiene monoepoxide.

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

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 preferably from 5 to 90 mol% based on the total amount of the total monomers, from 10 to 75 mol% And is preferably a monomer having no specific functional group of 65 mol% by mass. When the content of the monomer having the photo-dimerization portion is less than 25 mol%, it is difficult to impart high sensitivity and good liquid crystal alignability. 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 good sensitivity and good liquid crystal alignability.

In the present embodiment, a method of obtaining a specific copolymer is not particularly limited. For example, a polymerization reaction is carried out at a temperature of 50 to 110 占 폚 in a solvent in which a monomer having a specific functional group and, if necessary, a monomer having no specific functional group, and a polymerization initiator are coexisted to obtain a specific copolymer . The solvent to be used at this time is not particularly limited as long as it dissolves a monomer having a specific functional group and, if necessary, a monomer having no specific functional group, and a polymerization initiator. On the other hand, this solvent is also described in the < solvent >

The specific copolymer obtained by the above method is usually in a solution state dissolved in a solvent.

Further, the specific copolymer solution obtained by the above method is put into diethyl ether and water under stirring to reprecipitate, and the resultant precipitate is filtered and washed, and then dried at room temperature or under reduced pressure or dried under heating to obtain It can be a powder of a copolymer. By this operation, the polymerization initiator coexisting with the specific copolymer and the unreacted monomer can be removed, and as a result, the purified specific copolymer powder can be obtained. When the powder can not be sufficiently purified by one 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 the refined powder may be used in the form of a solution which is redissolved in a solvent to be described later.

Further, in the present embodiment, the specific copolymer of component (A) may be a mixture of plural kinds of specific copolymers.

&Lt; Component (B) >

In the present embodiment, the component (B) is a polyimide precursor. The polyimide precursor as component (B) has an aromatic ring moiety. 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.

(3)

In the formula (1), A ₁ is an organic group containing at least one structure having an alicyclic structure or an aromatic ring moiety such as a skeleton directly bonded with 1 to 3 benzene rings, a naphthalene ring skeleton and an anthracene ring skeleton, and 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 group containing a trifluoromethyl group or a trifluoromethyl group, and R ⁵ and R ⁶ are each independently A hydrogen atom or an organic group having 1 to 7 carbon atoms. 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 having a structure represented by T1 to T9 shown in the following Table 1, and the like. 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 group containing a trifluoromethyl group or a trifluoromethyl group. Specific examples of the organic group including a benzene ring having an alicyclic structure or a group containing a trifluoromethyl group or a trifluoromethyl group include organic groups represented by S1 to S7 shown in Table 2 below have.

In the present embodiment, the polyimide precursor as the component (B) may contain other structural units in addition to the structural units represented by the above formula (1). Here, the other structural unit is not particularly limited. In addition, one or more structural units other than the structural unit represented by the formula (1) may be contained.

The weight average molecular weight of the polyimide precursor as the component (B) is 1000 to 100000, preferably 1500 to 60000. When the weight average molecular weight of the polyimide precursor is less than 1,000, the solvent resistance is lowered and the orientation sensitivity may be lowered. On the other hand, if the weight average molecular weight of the polyimide precursor is more than 100000, the viscosity of the solution becomes too high and the handling property is lowered.

&Lt; Production method of component (B)

In the present embodiment, the polyimide precursor of component (B) is obtained by copolymerizing a tetracarboxylic dianhydride and a diamine compound.

As the tetracarboxylic dianhydride, tetracarboxylic dianhydride containing at least one alicyclic structure, tetracarboxylic dianhydride containing at least one structure in which 1 to 3 benzene rings are directly connected, or naphthalene ring containing at least 1 Tetracarboxylic dianhydride is preferable.

Specific examples of the acid dianhydride include, for example, pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, Anthracene tetracarboxylic acid dianhydride, 1,2,5,6-anthracene tetracarboxylic dianhydride, 3,3 ', 3,6'4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride and 2,3,3', 4'-biphenyltetracarboxylic dianhydride, 1, , 2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo [ 3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride and the like.

In the present embodiment, other tetracarboxylic acid dianhydrides may be contained as the tetracarboxylic acid dianhydride component. In this case, the other tetracarboxylic acid dianhydrides may be one kind or a plurality of kinds.

Specific examples of other tetracarboxylic dianhydrides include, for example, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,3,3', 4'-benzophenonetetracarboxylic acid 2 (3,4-dicarboxyphenyl) sulfone dianhydride, 2,2-bis (3,4-dicarboxyphenyl) methane dianhydride, bis (3,4- Dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 2,5-dicarboxy methylterephthalic acid dianhydride, 4,6- (2,5-dioxotetrahydro-3-furanyl) benzene, 1, 2-dioxotetrahydro-3-furanylphthalic anhydride, 4-bis (2,6-dioxotetrahydro-4-pyranyl) benzene, 1,4-bis (2,6-dioxotetrahydro-4-methyl-4-pyranyl) benzene, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid 2 Water, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride , 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 4- (2,5-dioxotetrahydro-3-furanyl) Cyclohexane-1,2-dicarboxylic anhydride, tetracyclo [2,2,1,1] decane-2,3,7,8-tetracarboxylic dianhydride, 5- (2,5-dioxo Furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2.2.2] octo-7-ene-2,3,5,6-tetracarboxylic acid Examples of the dianhydrides include, but are not limited to, primary dianhydrides, 3,3 ', 4,4'-dicyclohexyltetracarboxylic dianhydrides, 2,3,5,6-norbornane tetracarboxylic dianhydrides, 3,5,6- Norbornene-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 acid 2 Water, hexafluoro bicyclo ^{[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-dioxotetrahydro-3-furanyl) hexane, 1,4-bis (2,6-dioxotetrahydro-4-pyranyl) hexane, 3,4-dicarboxy- , 4-tetrahydro-1-naphthalenesuccinic dianhydride, 1,2-diphenyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2,3,4,5,6,7, Octahydro-2,3,6,7-anthracene tetracarboxylic dianhydride, and the like.

As the diamine component to be a raw material of the polyimide precursor as the component (B), a diamine compound containing an alicyclic structure or a trifluoromethyl group is preferable, and other diamine compounds may be used in combination. Specific examples of such diamine compounds include, for example, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, bis (4-aminocyclohexyl) methane, bis Cyclohexyl) methane, 1,4'-bicyclohexyldiamine, 2,2'-trifluoromethyl-4,4'-diaminobiphenyl, 3,3'-trifluoromethyl- Diaminobiphenyl, 4,4'-diaminodiphenylmethane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2- Bis (3-aminophenyl) hexafluoropropane, 2,2-bis (3-amino-4-methylphenyl) propane, Hexafluoropropane and 1,3-bis (4-aminophenoxy) propane.

In the present embodiment, one or more other diamine compounds other than the above-mentioned diamine compound may be used.

Examples of other diamine compounds include bis (4-aminophenyl) sulfone, bis (3-aminophenyl) sulfone, bis (Dicarboxyphenyl) sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- Amino-3-hydroxyphenyl) sulfone, bis (4-amino-3,5-dihydroxyphenyl) sulfone, bis , 3,3'-diamino-4,4'-dichlorodiphenylsulfone, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,5- Diaminobenzene, 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, 2,4-diaminoaniline, N Aminobenzylamine, 2- (4-aminophenyl) ethylamine, 2- (3-aminophenyl) ethylamine, 5-naphthalene diamine, 2,7-naphthalene diamine, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'- diaminobiphenyl, 2,2'- , 4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'- diaminobiphenyl, 3,3'-di 4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, Diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'- Aminodiphenyl ether, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, N-methyl (4,4'- (3,3'-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, 4,4'-di Diaminobenzophenone, 4,4'-diaminobenzanilide, 1,2-bis (4-aminophenyl) ethane, 1,2,3,4-diaminobenzophenone, Bis (3-aminophenyl) ethane, 4,4'-diaminotran, 1,3-bis (4-aminophenyl) propane, Bis (4-aminophenoxy) pentane, 1,4-bis (4-aminophenoxy) Bis (4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,9- (4-aminophenoxy) undecane, 1,12-bis (4-aminophenoxy) dodecane, Bis (4-aminophenyl) pentanedioate, bis (4-aminophenyl) hexanedioate, bis (4-aminophenyl) ) Heptane dioate, bis (4- Bis (4-aminophenyl) decanedioate, 1,4-bis (4-aminophenyl) benzene, 1,3- Aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3- Bis (4-aminophenyl) isophthalate, bis (4-aminophenyl) isophthalate, bis (4-aminophenyl) isophthalate, bis , 4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone] Phenylenebis (3-aminobenzoate), 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis , 1,3-phenylenebis (4-aminobenzoate), 1,3-phenylenebis (3-aminobenzoate), N, N ' Aminobenzamide), N, N '- (1,4-phenylene) bis (3-aminobenzamide), N, N' Aminophenyl) terephthalamide, bis (4-aminophenyl) isophthalamide, bis (4-aminophenyl) Bis (4-aminophenoxy) phenyl] propane, 4,4'-bis (4-aminophenoxy) diphenyl sulfone, 2,6- Diamino pyridine, 2,4-diamino pyridine, 2,4-diamino-1,3,5-triazine, 2,6-diaminodibenzofurane, 2,7-diaminodibenzofurane, 3 , 6-diaminodibenzofuran, 2,6-diaminocarbazole, 2,7-diaminocarbazole, 3,6-diaminocarbazole, 2,4-diamino- Triazine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole, 1,3-diaminopropane, 1,4-diaminobutane, Aminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, and 1,12-diaminododecane.

In the polyimide precursor of the component (B), the blending ratio of the total amount of the tetracarboxylic acid dianhydride (the total amount of the acid component) and the total amount of the diamine compound (the total amount of the diamine component), that is, the total mole number of the diamine compound / The total molar number of the carboxylic anhydride compound is preferably 0.5 to 1.5. As in the case of the usual polycondensation reaction, the closer the molar ratio is to 1, the larger the degree of polymerization of the resulting polyimide precursor leads to an increase in the molecular weight.

The terminal of the polyimide precursor of the component (B) varies depending on the blending ratio of the acid component and the diamine component, but is not particularly limited in the present embodiment.

When the diamine component is polymerized in excess, the terminal amino group may 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 anhydride, And hydrophthalic anhydride.

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

The reaction between the acid component and the diamine component is usually carried out in a solvent. Examples of usable solvents in this case include N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, N-vinylpyrrolidone, N-methylcaprolactam, dimethyl Methoxypropionate, methyl 2-methoxypropionate, ethyl 3-methoxypropionate, 2-methoxypropionate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, Ethyl propionate, ethyl 3-ethoxypropionate, ethyl 2-ethoxypropionate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, propylene glycol dimethyl ether, 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 It may be a recall monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone and 2-heptanone and the like. These may be used alone or in combination. Further, even in the case of a solvent which does not dissolve the polyimide precursor, it may be mixed with the above-mentioned solvent so long as the polyimide precursor produced by the polymerization reaction does not precipitate.

The solution containing the polyimide precursor thus obtained can be used as it is for preparing a resin composition for forming a thermosetting film. Further, the polyimide precursor may be used after being precipitated and recovered in a poor solvent such as water, methanol and ethanol, and recovered.

&Lt; Component (C) >

The component (C) of this embodiment is a crosslinking agent. This cross-linking agent can be obtained by crosslinking the component (A) and the component (B).

As the crosslinking agent as the component (C), for example, an epoxy compound, a methylol compound or an isocyanate compound can be mentioned, and it is preferably a methylol compound having two or more methylol groups or alkoxymethylol groups.

Specific examples thereof include compounds such as methoxymethylated glycoluril, methoxymethylated benzoguanamine and methoxymethylated melamine. Also, for example, there may be mentioned hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis (butoxymethyl) glycoluril, 1,3,4,6-tetrakis (Hydroxymethyl) urea, 1,1,3,3-tetrakis (butoxymethyl) urea, 1,1,3,3-tetrakis (methoxymethyl) (Hydroxymethyl) -4,5-dihydroxy-2-imidazolidinone and 1,3-bis (methoxymethyl) -4,5-dimethoxy-2-imide Jolinon, and the like. Commercially available products include methoxymethyl type melamine compounds (trade names: CYMEL 300, CYMEL 301, CYMEL 303 and CYMEL 350) manufactured by Nihon Cytec Industries Inc., butoxymethyl type melamine compounds (trade names: MYCOAT 506 and MYCOAT 508) (UFR300, U-VAN10S60, U-VAN10R, U-VAN11HV) and DIC (trade name: UFR65), butylated urea resin ), Urea / formaldehyde resin (high condensation type, trade name: BECKMINE J-300S, BECKMINE P-955, BECKMINE N). It may also be a compound obtained by condensing a melamine compound, a urea compound, a glycoluril compound and a benzoguanamine compound in which the hydrogen atom of the amino group is substituted with a methylol group or an alkoxymethyl group. For example, a high molecular weight compound prepared by a melamine compound (trade name: CYMEL 303) and a benzoguanamine compound (trade name: CYMEL 1123) described in US Pat. No. 6,323,310 may be mentioned.

Further, as the component (C), there may be mentioned a hydroxymethyl group such as N-hydroxymethylacrylamide, N-methoxymethylmethacrylamide, N-ethoxymethylacrylamide and N-butoxymethylmethacrylamide, or an alkoxymethyl group A polymer prepared using a substituted acrylamide compound or a methacrylamide compound may also be used. Such polymers include, for example, poly (N-butoxymethylacrylamide), copolymers of N-butoxymethylacrylamide and styrene, copolymers of N-hydroxymethylmethacrylamide and methylmethacrylate, A copolymer of N-ethoxymethylmethacrylamide and benzylmethacrylate, and a copolymer of N-butoxymethylacrylamide and benzylmethacrylate and 2-hydroxypropylmethacrylate. 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 may be used alone or in combination of two or more.

The content of the crosslinking agent in the component (C) in the resin composition of the present embodiment is preferably such that the total amount of the acrylic copolymer having at least the photo-dimerization site and the thermal crosslinking site of the component (A) and the polyimide precursor of the component (B) Is preferably 10 to 100 parts by mass based on the mass part. If the ratio is less than 10 parts by mass, the solvent resistance and heat resistance of the cured film obtained from the resin composition deteriorate, and the sensitivity at the time of photo-curing decreases. On the other hand, if it is more than 100 parts by mass, not only the photo-alignment property is lowered but also the storage stability is lowered.

&Lt; Component (D) >

The resin composition of the present embodiment may contain an acid or a thermal acid generator as the component (D). The component (D) is effective in promoting the thermosetting property of the resin composition of the present embodiment.

Examples of the acid or thermal acid generator as the component (D) include sulfonic acid group-containing compounds, hydrochloric acid or salts thereof, and compounds capable of generating acids by pyrolysis at the time of prebaking or postbaking, that is, pyrolysis at 80 to 250 ° C to generate acids It is not particularly limited as long as it is a compound. Such compounds include, for example, inorganic acids such as hydrochloric acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, pentanesulfonic acid, octanesulfonic acid, benzenesulfonic acid, p- toluenesulfonic acid, camphorsulfonic acid, trifluoromethanesulfonic acid, , 2-naphthalenesulfonic acid, mesitylenesulfonic acid, p-xylene-2-sulfonic acid, m-xylene-2-sulfonic acid, 4-ethylbenzenesulfonic acid, 1H, 1H, 2H, 2H-perfluorooctane Sulfonic acids such as perfluoro (2-ethoxyethane) sulfonic acid, pentafluoroethane sulfonic acid, nonafluorobutane-1-sulfonic acid, and dodecylbenzene sulfonic acid, and hydrates and salts thereof.

Examples of the compound capable of generating an acid by heat include bis (tosyloxy) ethane, bis (tosyloxy) propane, bis (tosyloxy) butane, p-nitrobenzyltosylate, , 2,3-phenylenetris (methylsulfonate), p-toluenesulfonic acid pyridinium salt, p-toluenesulfonic acid morpholinium 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 -Hydroxybutyl p-tosylate, N-ethyl-4-toluenesulfonamide, and other compounds represented by the following formulas (5) to (9) and (14) to (49) .

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

The content of the component (D) in the resin composition of the present embodiment is preferably 0.01 to 5 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B). When the amount is less than 0.01 part by mass, the thermosetting property is deteriorated and the solvent resistance is insufficient, and the sensitivity to light irradiation is sometimes lowered. On the other hand, if it exceeds 5 parts by mass, the storage stability of the composition may be lowered.

&Lt; Component (E) >

In the present embodiment, a sensitizer may be contained as the component (E). This component (E) is effective in promoting the photo-dimerization reaction after the formation of the thermosetting film of the present embodiment.

Examples of the sensitizer as the component (E) include benzophenone, anthracene, anthraquinone, thioxanthone and its derivatives, and nitrophenyl compounds. Of these, benzophenone derivatives and nitrophenyl compounds are particularly preferred. Specific examples thereof include N, N-diethylaminobenzophenone, 2-nitrofluorene, 2-nitrofluorenone, 5-nitroasenaphthene, 9-hydroxymethylanthracene, 4-nitrocinnamic acid or 4- Norbornylphenyl, and the like. Particularly, N, N-diethylaminobenzophenone, which is a benzophenone derivative, is preferable. On the other hand, the sensitizer is not limited to the above. The sensitizer may be used alone or in combination with two or more compounds.

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

<Solvent>

The resin composition of this embodiment can be used in the form of a solution dissolved in a solvent. The solvent used is one which dissolves the components (A), (B) and (C). If necessary, the components (D) and (E) are dissolved, and when other additives to be described later are contained, they are dissolved. The type and structure of the solvent are not particularly limited as long as they are solvents having such solubility. Specifically, the solvent used for the polymerization of the component (A) or the component (B) may be mentioned. These solvents may be used singly or in combination of two or more.

<Other additives>

The resin composition of the present embodiment may contain a silane coupling agent, a surfactant, a rheology modifier, a pigment, a dye, a storage stabilizer, a defoaming agent, and an antioxidant, if necessary, within a range that does not impair the effect of the present invention Other additives may be included.

<Resin composition>

The resin composition of the present embodiment contains an acrylic copolymer having a photo-dimerization 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) , An acid or a thermal acid generator as the component (D), a sensitizer as the component (E), and other additives. The resin composition is usually used as a solution in which these are dissolved in a solvent.

In the resin composition, the blending ratio of the component (A) and the component (B) is preferably from 5:95 to 60:40 in terms of the mass ratio. If the content of the component (A) is too small, the orientation defects may occur. On the other hand, if the content of the component (A) is larger than this compounding ratio, not only the birefringence is reduced but also the coating film may become cloudy.

On the other hand, the hydroxyl 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. And the component (B) is further in the range of 5:95 to 40:60, the oriented component is bleed in the upper layer, so that the orientation sensitivity is raised and a high birefringence is obtained.

Here, the hydroxyl group of the component (A) refers to the number of mmol of potassium hydroxide necessary for neutralizing the acetic acid required for acetylating the free (free) hydroxyl group contained in 1 g of the component (A). The acid number of the component (B) refers to the number of mmol of potassium hydroxide necessary to neutralize the free acid group contained in 1 g of the component (B).

Preferable examples of the resin composition of the present embodiment are as follows.

[1] A resin composition containing 10 to 100 parts by mass of the component (C) based on 100 parts by mass of the total amount of the component (A) and the component (B)

[2] A resin composition containing 10 to 100 parts by mass of the component (C) and a solvent, based on 100 parts by mass of the total amount of the component (A) and the component (B).

[3] A resin composition containing 10 to 100 parts by mass of the component (C), 0.01 to 5 parts by mass of the component (D), and a solvent based on 100 parts by mass of the total amount of the component (A) and the component (B).

The mixing ratio and 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 a solvent, but the general solid content ratio is 1 to 80 mass%. Among them, the content is preferably 3 to 60% by mass, and more preferably 5 to 40% by mass. Here, the solid content means that the solvent is removed 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 can be mentioned a method of dissolving the component (A) in a solvent, mixing the component (B), further the component (C) and the component (D) in a predetermined ratio to prepare a homogeneous solution . Further, in a suitable step of the preparation method, other additives may be further added and mixed if necessary.

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

The solution of the resin composition of the present embodiment prepared as described above is preferably used after being filtered using a filter having a pore diameter of about 0.2 mu m or the like.

<Coating film, cured film and liquid crystal alignment layer>

A coating film can be formed by the following method using the resin composition of the present embodiment.

First, a resin composition is coated on a substrate by a method such as rotational coating, flow coating, roll coating, slit coating, rotary coating followed by slit, inkjet coating, or printing. Subsequently, preliminary drying (prebaking) with a hot plate, an oven, or the like can form a coating film. Thereafter, this coating film is heat-treated (post-baked) to form a cured 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, or an ITO substrate can be used. Further, for example, a substrate coated with a metal such as aluminum, molybdenum, or chromium may be used. Further, for example, a resin film such as a triacetylcellulose film, a polyester film, and an acrylic film may be used as a substrate.

As the prebaking condition of the coating film, for example, a heating temperature and a heating time suitably selected from a temperature range of 70 to 160 DEG C and a time of 0.3 to 60 minutes are employed. The heating temperature and heating time are preferably from 80 to 140 占 폚 for 0.5 to 10 minutes.

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

By curing the resin composition of the present embodiment under the above conditions, it is possible to sufficiently planarize the steps of the substrate by the color filter (CF) or the like and to form a cured film having high transparency. On the other hand, the film 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 step difference of the substrate to be used and the optical and electrical properties.

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

After the phase difference material is coated on the liquid crystal alignment layer formed from the resin composition of the present embodiment as described above, the phase difference material is heated to the phase transition temperature of the liquid crystal to make the phase difference material into a liquid crystal state, and then photo- Thus, a layer having optical anisotropy, that is, a phase difference material can be formed on the liquid crystal alignment layer. The configuration in which the retarder is disposed inside the liquid crystal cell through this method can improve the contrast ratio of the liquid crystal cell as compared with the conventional configuration in which the retarder is disposed outside the liquid crystal cell.

As the retardation material, for example, a liquid crystal monomer having a polymerizable group or a composition containing the liquid crystal monomer 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 a retardation material has orientation properties such as horizontal alignment, cholesteric alignment, vertical alignment, hybrid alignment, and biaxial alignment, and they can be used separately according to the required retardation.

Further, the two substrates having the liquid crystal alignment layer formed as described above are bonded to each other so that the liquid crystal alignment layers are opposed to each other with the spacer interposed therebetween. Thereafter, liquid crystal is injected between the substrates to form liquid crystal display Device.

As described above, the resin composition of the present embodiment can be suitably used for constituting various optically 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. Particularly, it is suitable as a material for forming an interlayer insulating film of a TFT type liquid crystal element and an insulating film of an organic EL element, in addition to the overcoat material (CF overcoat material) of the color filter CF.

When the resin composition of the present embodiment is used as a CF overcoat material, the resulting CF overcoat covers not only the level difference of the color filter but also functions as a liquid crystal alignment material. Therefore, it can be used as a CF overcoat having an orientation property.

1 is a schematic structural view of a liquid crystal cell according to the present embodiment. In this drawing, the liquid crystal layer 108 is interposed between the two substrates 101 and 111. On the substrate 111, an ITO 110 and an orientation film 109 are formed. A color filter 102, a CF overcoat 103, a retarder 105, an ITO 106, and an alignment film 107 are formed on the substrate 101 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 may not be required.

(Example)

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

[Abbreviations used in Examples]

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-Cyclobutane tetracarboxylic dianhydride

TFMB: 2,2'-Trifluoromethyl-4,4'-diaminobiphenyl

<Cross-linking agent>

CYM: CYMEL 303 (manufactured by Mitsui Cytec, Ltd.)

&Lt; 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 obtained acrylic copolymer were measured using a GPC apparatus (Shodex (registered trademark) columns KF803L and KF804L, manufactured by JASCO Corporation) and elution solvent tetrahydrofuran at a flow rate of 1 (Column temperature: 40 占 폚) at a flow rate of 1 ml / min. On the other hand, the following number average molecular weight (hereinafter referred to as Mn) and weight average molecular weight (hereinafter referred to as Mw) are expressed as polystyrene conversion values.

Mn and Mw of the polyimide precursor were measured using a GPC apparatus (Shodex (registered trademark) columns KD803 and KD805, manufactured by Shodex) and eluting solvent N, N-dimethylformamide (lithium bromide- H ₂ O) is 30mmol / L, phosphoric acid anhydrous crystal (o- phosphoric acid) is 30mmol / L, tetra hydro furan to the 10㎖ / L), the flow rate 1㎖ / min eluted by flowing (column temperature 50 ℃) in the column to the . On the other hand, the following Mn and Mw are shown in terms of polyethylene glycol and polyethylene oxide.

&Lt; Synthesis Example 1 &

An acrylic polymer solution (solid content concentration of 27 mass% was obtained) (P1) by dissolving 42.0 g of CIN, 18.0 g of HEMA and 1.3 g of AIBN in 166.8 g of CHN and reacting at 80 DEG C for 20 hours. The acrylic polymer thus obtained had Mn of 8,500 and Mw of 16,500.

&Lt; 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 DEG C for 20 hours to obtain a polyimide precursor solution (solid content concentration of 20 mass%) (P2). The obtained polyimide precursor had Mn of 12,600 and Mw of 27,500.

&Lt; 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 (solid content concentration: 12 mass%) (P3). The obtained polyimide precursor had Mn of 7,000 and Mw of 15,800.

&Lt; 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 (solid content concentration of 15 mass%) (P4). The obtained polyimide precursor had an Mn of 12,400 and a Mw of 43,000.

&Lt; Examples 1 to 3 and Comparative Examples 1 to 4 >

Each of the compositions of Examples 1 to 3 and Comparative Examples 1 to 4 was prepared with the compositions shown in Table 3, and the solvent resistance, transmittance, orientation and birefringence were evaluated for each.

[Evaluation of Solvent Resistance]

Each of the compositions 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 캜 for 120 seconds. Thereafter, this coated film was post-baked in a hot-air circulating oven at 230 캜 for 30 minutes to form a cured film having a film thickness of 2.0 탆. The film thickness was measured using DEKTAK 150 manufactured by VEECO.

Next, this cured film was immersed in CHN or NMP for 60 seconds, and then dried at a temperature of 100 DEG C for 60 seconds, and the film thickness was measured. The film thickness after the immersion of CHN or NMP was not changed, and the film thickness after the immersion was decreased by x.

[Evaluation of light transmittance (transparency)] [

Each of the compositions of Examples 1 to 3 and Comparative Examples 1 to 4 was coated on a quartz substrate using a spin coater and prebaked on a hot plate at a temperature of 80 캜 for 120 seconds. Thereafter, this coated film was post-baked in a hot-air circulating oven at 230 캜 for 30 minutes to form a cured film having a film thickness of 2.0 탆. The film thickness was measured using DEKTAK 150 manufactured by VEECO.

Next, the cured film was measured for transmittance at a wavelength of 400 nm using an ultraviolet visible spectrophotometer (SHIMADZU UV-2550 model number manufactured by Shimadzu Corporation).

[Evaluation of orientation sensitivity]

Each of the compositions of Examples 1 to 3 and Comparative Examples 1 to 4 was coated on an ITO substrate by using a spin coater and then prebaked on a hot plate at a temperature of 80 DEG C for 120 seconds. Thereafter, this coated film was post-baked in a hot-air circulating oven at 230 캜 for 30 minutes to form a cured film having a film thickness of 2.0 탆. The film thickness was measured using DEKTAK 150 manufactured by VEECO.

Next, linearly polarized light having a wavelength of 313 nm was irradiated as polarized UV from the direction perpendicular to the cured film on the ITO substrate. Subsequently, a solution of a retardation material made of a liquid crystal monomer was coated on the substrate using a spin coater, and then baked on a hot plate at 80 DEG C for 60 seconds to form a coating film having a film thickness of 1.4 mu m. Next, the coating film on this substrate was exposed to UV light of 1,000 mJ / cm ^{2 in} a nitrogen atmosphere to cure the retardation material. The substrate thus produced was sandwiched by a polarizing plate, the phase difference state of the cured retardation material was confirmed, and the exposure amount of the polarized UV required to exhibit the alignment property of the cured film was determined as the alignment sensitivity. Also, when the UV light of 3,000 mJ / cm &lt; ² &gt;

[Evaluation of birefringence index]

Each of the compositions of Examples 1 to 3 and Comparative Examples 1 to 4 was coated on a quartz substrate using a spin coater and prebaked on a hot plate at a temperature of 80 캜 for 120 seconds. Thereafter, this coated film was subjected to post-baking in a hot-air circulating oven at 230 캜 for 30 minutes to form a cured film having a thickness of 2.0 탆. The film thickness was measured using DEKTAK 150 manufactured by VEECO.

The cured film was measured for birefringence at a wavelength of 590 nm using a phase difference film measuring apparatus (Axo Scan, AXOMETRICS Inc.).

[Evaluation results]

The evaluation results are shown in Table 4.

In the case of the cured film formed from the compositions of Examples 1 to 3, the orientation sensitivity was high. Therefore, it can be seen that the compositions of Examples 1 to 3 can form a liquid crystal alignment material efficiently. In addition, it was highly transparent and exhibited resistance to both CHN and NMP. In addition, high birefringence was exhibited.

On the other hand, in the case of the cured film formed from the composition of Comparative Example 1, the birefringence and the solvent resistance were low, and an exposure amount of 300 times in the case of Examples 1 to 3 was required in order to exhibit the orientation. In addition, in the case of the cured film formed from the compositions of Comparative Examples 2 to 4, high birefringence and solvent resistance were observed, but the alignment properties were not exhibited.

As described above, it can be seen that the cured film obtained from the resin composition of the present invention has a high birefringence, and is also excellent in light transmittance, solvent resistance, and orientation. Therefore, according to the resin composition of the present invention, it can be seen that not only the above-mentioned various characteristics can provide an excellent cured film, that is, a liquid crystal alignment material, but also a phase difference material can be formed.

(Industrial applicability)

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 is also useful as a protective film for various displays such as a thin film transistor (TFT) type liquid crystal display element and an organic EL element, A material for forming a cured film such as an insulating film, particularly, a material for forming an interlayer insulating film of a TFT type liquid crystal element, a protective film of a color filter, or an insulating film of an organic EL element.

Claims (17)

(A) an acrylic copolymer having a thermal crosslinking site composed of a light dimerization site and a hydrophilic group, which is a hydrophobic group, and
(B) a polyimide precursor having an aromatic ring moiety,
(C) a crosslinking agent for crosslinking the component (A) and the component (B).
The method according to claim 1,
Wherein the component (A) is an acrylic copolymer obtained by a polymerization reaction of a monomer mixture comprising a monomer having a photo-dimerization site and a monomer having a thermal crosslinking site.
3. The method of claim 2,
Wherein the component (A) is an acrylic copolymer obtained by a polymerization reaction of a monomer mixture containing from 25 mol% to 90 mol% of a monomer having a photo-dimerization site, based on the total amount of the entire monomer mixture.
The method according to claim 1,
Wherein the photo-dimerization site of the component (A) is a cinnamoyl group.
The method according to claim 1,
Wherein the thermal crosslinking site of the component (A) is a hydroxyl group or a carboxyl group.
The method according to claim 1,
Wherein the polyimide precursor of the component (B) has a biphenyl structure in its main chain.
The method according to claim 6,
The component (B) is a polyimide precursor comprising a structural unit obtained by a copolymerization reaction of a tetracarboxylic dianhydride and a diamine compound, wherein at least one of the tetracarboxylic dianhydride and the diamine compound has a biphenyl structure By weight based on the total weight of the resin composition.
8. The method of claim 7,
Wherein the tetracarboxylic acid dianhydride is biphenyltetracarboxylic dianhydride.
8. The method of claim 7,
Wherein the component (B) is a polyimide precursor having a trifluoromethyl group in the structural unit.
The method according to claim 1,
Wherein the polyimide precursor of component (B) has an alicyclic structure in its main chain.
11. The method of claim 10,
The component (B) is a polyimide precursor comprising a structural unit obtained by a copolymerization reaction of a tetracarboxylic dianhydride and a diamine compound, wherein the tetracarboxylic dianhydride and the diamine compound have an alicyclic structure in at least one of the diamine compounds By weight of the resin composition.
The method according to claim 1,
Wherein the crosslinking agent of the component (C) is a crosslinking agent having a methylol group or an alkoxymethylol group.
The method according to claim 1,
And 10 to 100 parts by mass of the component (C) based on 100 parts by mass of the total amount of the component (A) and the component (B).
The method according to claim 1,
(D) further comprises an acid or a thermal acid generator.
15. The method of claim 14,
And 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).
A liquid crystal alignment material obtained by using the resin composition according to any one of claims 1 to 15.
A retardation film which is formed by using a cured film obtained from the resin composition according to any one of claims 1 to 15.

Images