TWI865663B - Cured film forming composition, orientation material and phase difference material - Google Patents

Abstract

The present invention provides a cured film forming composition that can provide an alignment material with excellent alignment sensitivity, excellent alignment, and excellent adhesion to a TAC film, and has improved storage stability. The cured film forming composition contains: (A) a compound having a photo-alignment group and any substituent selected from a hydroxyl group, a carboxyl group, and an amino group, (B) a hydrophilic polymer having one or more substituents selected from a hydroxyl group, a carboxyl group, and an amino group, (C) a polymer obtained by polymerizing a monomer containing an N-hydroxymethyl compound or an N-alkoxymethyl (meth) acrylamide compound, (D) a crosslinking catalyst, and a solvent containing both an alcohol having 1 to 5 carbon atoms and an alkyl ester having 1 to 4 carbon atoms of a fatty acid having 1 to 4 carbon atoms. The cured film forming composition is used to form a cured film, and the alignment material is formed using a photo-alignment technique. A polymerizable liquid crystal is coated on the alignment material and hardened to obtain a phase difference material.

Description

Cured film forming composition, orientation material and phase difference material

The present invention relates to a hardened film forming composition, an orientation material and a phase difference material.

In the case of a 3D display using circular polarization glasses, a phase difference material is usually arranged on a display element such as a liquid crystal panel that forms an image. The phase difference material is a patterned phase difference material formed by regularly arranging two phase difference regions with different phase difference characteristics in a plurality of ways. In addition, hereinafter, in this specification, a phase difference material patterned by arranging such a plurality of phase difference regions with different phase difference characteristics is referred to as a patterned phase difference material.

Patterned phase difference material can be produced, for example, by optically patterning a phase difference material formed by polymerized liquid crystal as disclosed in Patent Document 1. The optical patterning of the phase difference material formed by polymerized liquid crystal utilizes the known photo-alignment technology in the formation of alignment materials for liquid crystal panels. That is, a coating formed by a photo-alignment material is provided on a substrate, and two polarized lights with different polarization directions are irradiated thereon. Then, a photo-alignment film is obtained as an alignment material forming two liquid crystal alignment regions with different alignment control directions of the liquid crystal. A solution-like phase difference material containing polymerized liquid crystal is applied on the photo-alignment film to realize the alignment of the polymerized liquid crystal. Afterwards, the aligned polymerized liquid crystal is hardened to form a patterned phase difference material.

The anti-reflection film of the organic EL display is composed of a linear polarizer and a 1/4 wavelength phase difference plate. The external light toward the panel surface of the image display panel is converted into linear polarization by the linear polarizer, and then converted into circular polarization by the 1/4 wavelength phase difference plate. Although the external light caused by the circular polarization is reflected by the surface of the image display panel, the rotation direction of the polarization plane is reversed during the reflection. As a result, the reflected light is opposite to when it comes, and after being converted into linear polarization in the direction of light shielding by the linear polarizer, it is then shielded by the linear polarizer. As a result, the emission to the outside is significantly suppressed.

Regarding the 1/4 wavelength phase difference plate, Patent Document 2 proposes a method of forming a 1/4 wavelength phase difference plate by combining a 1/2 wavelength plate and a 1/4 wavelength plate, and forming the optical film by reverse dispersion characteristics. In the case of this method, in the wide wavelength band for color image display, a liquid crystal material using positive dispersion characteristics can be used to form an optical film by reverse dispersion characteristics.

In recent years, liquid crystal materials that can be used in the phase difference layer have been proposed to have reverse dispersion characteristics (patent documents 3, 4). Based on these reverse dispersion characteristics of liquid crystal materials, instead of combining a 1/2 wavelength plate and a 1/4 wavelength plate to form a 1/4 wavelength phase difference plate with two phase difference layers, the reverse dispersion characteristics can be ensured by forming the phase difference layer with a single layer, thereby realizing an optical film that can ensure the desired phase difference in a wide wavelength band with a simple structure.

An alignment layer is used to align the liquid crystal. As methods for forming the alignment layer, there are known methods such as friction method and photo-alignment method. The photo-alignment method does not cause static electricity or dust, which are problems of the friction method, and can control the quantitative alignment. Processing is more useful.

In the formation of alignment materials using the photo-alignment method, acrylic resins or polyimide resins having photo-dimerization sites such as cinnamyl groups and chalcone groups on the side chains are known as available photo-alignment materials. It has been reported that these resins show the ability to control liquid crystal alignment (hereinafter also referred to as liquid crystal alignment) by polarized UV irradiation (see Patent Documents 5 to 7).

Furthermore, in photoalignment agents using cinnamic acid moieties, there are examples of introducing thermal crosslinking to improve alignment sensitivity and impart solvent resistance (see patent documents 8 and 9).

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2005-49865

[Patent Document 2] Japanese Patent Publication No. 10-68816

[Patent Document 3] U.S. Patent No. 8119026 Specification

[Patent Document 4] Japanese Patent Publication No. 2009-179563

[Patent Document 5] Japanese Patent Gazette No. 3611342

[Patent Document 6] Japanese Patent Publication No. 2009-058584

[Patent Document 7] Japanese Patent Publication No. 2001-517719

[Patent Document 8] International Patent Application Publication No. WO2011/126022

[Patent Document 9] International Patent Application Publication No. WO2014/010688

On the other hand, when the cured film is introduced into the thermal crosslinking system, especially when the crosslinking agent and the crosslinking catalyst coexist, if the cured film forming composition can be stably preserved, the processing efficiency will be great. Therefore, a simple method to improve its preservation stability is sought. Here, in patent document 8, it is recorded that when using a TAC substrate, an alcohol solvent is better, and the reason for this is that the TAC film shows resistance. On the other hand, these patent documents do not record that the alcohol solvent is added to stabilize the varnish, and they also do not record that a fatty acid ester solvent is mixed with the alcohol solvent to dissolve TAC in order to ensure the adhesion between the TAC film and the alignment material.

The present invention is completed based on the above insights or review results. That is, its purpose is to provide a cured film forming composition that has excellent orientation sensitivity and can provide an orientation material with excellent orientation and excellent adhesion to the TAC film while maintaining improved stability.

Other purposes and advantages of the present invention can be understood from the following description.

The first aspect of the present invention is related to a hardened film forming composition, which is characterized by containing: (A) a compound having a photo-alignment group and any substituent selected from hydroxyl, carboxyl and amino groups, (B) a hydrophilic polymer having one or more substituents selected from hydroxyl, carboxyl and amino groups, (C) a polymer obtained by polymerizing a monomer containing an N-hydroxymethyl compound or an N-alkoxymethyl (meth) acrylamide compound, (D) a crosslinking catalyst, and a solvent containing both an alcohol having 1 to 5 carbon atoms and an alkyl ester having 1 to 4 carbon atoms of a fatty acid having 1 to 4 carbon atoms.

In the first aspect of the present invention, the photo-alignment group of the preferred component (A) is a functional group of a photodimerization or photoisomerization structure.

In the first aspect of the present invention, the photo-alignment group of the preferred component (A) is cinnamic acid group.

In the first aspect of the present invention, the photo-alignment group of the preferred component (A) is an azobenzene structured group.

In the first aspect of the present invention, the preferred component (B) is at least one polymer selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols and polycaprolactone polyols.

In the first aspect of the present invention, the preferred component (B) is cellulose or its derivatives.

In the first aspect of the present invention, the preferred component (B) is an acrylic polymer having at least one of a polyethylene glycol ester group and a hydroxyl alkyl ester group having 2 to 5 carbon atoms and at least one of a carboxyl group and a phenolic hydroxyl group.

In the first aspect of the present invention, the preferred component (B) is an acrylic polymer obtained by polymerizing a monomer containing at least one of a monomer having a polyethylene glycol ester group and a monomer having a hydroxyalkyl ester group having 2 to 5 carbon atoms and a monomer having a carboxyl group and a monomer having a phenolic hydroxyl group.

Furthermore, in the first aspect of the present invention, the preferred component (B) is an acrylic polymer having a hydroxy alkyl group in the side chain.

In the first aspect of the present invention, it is preferred to further contain an adhesion-enhancing component as component (E).

In the first aspect of the present invention, the preferred ratio of component (A) to component (B) is 5:95 to 60:40 in terms of mass ratio.

In the first aspect of the present invention, it is preferred that 10 to 150 parts by mass of component (C) be contained based on 100 parts by mass of the total amount of the compound of component (A) and the polymer of component (B).

In the first aspect of the present invention, it is preferred that 0.01 to 10 parts by mass of component (D) be contained per 100 parts by mass of the total amount of the compound of component (A) and the polymer of component (B).

The second aspect of the present invention is related to an alignment material, which is characterized by being obtained by using the cured film forming composition of the first aspect.

The third aspect of the present invention is related to a phase difference material, which is characterized by being formed using a cured film obtained from the cured film forming composition of the first aspect.

According to the first aspect of the present invention, a cured film forming composition having excellent orientation sensitivity and being able to impart excellent orientation and excellent adhesion to the TAC film can be provided while maintaining improved stability.

According to the second aspect of the present invention, an alignment material having excellent alignment sensitivity, pattern formation and transparency, and also excellent alignment uniformity can be provided.

According to the third aspect of the present invention, a phase difference material that can be optically patterned and can be formed efficiently even on alkaline glass can be provided.

<Curing film forming composition>

The cured film forming composition of this embodiment contains a low molecular weight photo-alignment component (A), a hydrophilic polymer (B), a polymer (C) formed by polymerizing monomers containing an N-hydroxymethyl compound or an N-alkoxymethyl (meth) acrylamide compound, and a crosslinking catalyst (D). In addition to the components (A), (B), (C), and (D), the cured film forming composition of this embodiment may further contain a component (E) that improves the adhesion of the cured film. Other additives may be contained as long as they do not impair the effects of the present invention.

The following is a detailed description of each ingredient.

<(A) Ingredients>

The (A) component contained in the cured film forming composition of this embodiment is the above-mentioned low molecular weight photo-alignment component.

Therefore, the low molecular weight photo-alignment component of component (A) may be a compound having a photo-alignment group and any substituent selected from hydroxyl, carboxyl and amino groups. The compound having a photo-alignment group and any substituent selected from hydroxyl, carboxyl and amino groups is as described above, the photo-reactive group constitutes the hydrophobic photo-reactive part of the photo-reactive component, and the hydroxyl group etc. constitute the hydrophilic thermal-reactive part.

In addition, in the present invention, the photo-alignment group refers to a functional group at the structural site of photodimerization or photoisomerization.

The so-called photodimerization structural site is a site that forms a dimer by light irradiation, and specific examples thereof include cinnamyl, chalcone, coumarin, anthracene, etc. Among them, cinnamyl, which has high transparency in the visible light region and photodimerization reactivity, is preferred. Moreover, the photoisomerization structural site refers to a structural site that changes into a cis-isomer and a trans-isomer by light irradiation, and specific examples thereof include a site formed by an azobenzene structure, a stilbene structure, etc. Among them, the highly reactive azobenzene structure is preferred. Compounds having a photoalignment group and a hydroxyl group are represented by the following formula, for example.

In the above formula, ^A1 and ^A2 independently represent a hydrogen atom or a methyl group, ^X1 represents a structure formed by bonding 1 to 3 units selected from alkylene groups having 1 to 18 carbon atoms, phenylene groups, biphenylene groups, or combinations thereof, through one or more bonds selected from single bonds, ether bonds, ester bonds, amide bonds, carbamate bonds, amine bonds, or combinations thereof. ^X2 represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 18 carbon atoms, a phenyl group, a biphenylene group, or a cyclohexyl group. In this case, the alkyl group having 1 to 18 carbon atoms, the phenyl group, the biphenylene group, and the cyclohexyl group may also be bonded through a covalent bond, an ether bond, an ester bond, an amide bond, or a urea bond. ^X5 represents a hydroxyl group, a carboxyl group, an amino group or an alkoxysilyl group. ^{X represents a single bond, an oxygen atom or a sulfur atom. X6} represents a hydroxyl group, an alkyl group, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms or a phenyl group. ^X7 independently represents a single bond, an alkylene group having 1 to 20 carbon atoms, an aromatic cyclic group or an aliphatic cyclic group. The alkylene group having 1 to 20 carbon atoms may be branched or linear.

Furthermore, among these substituents, the phenyl group, phenyl group, biphenyl group and biphenyl group may also be substituted by one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a trifluoromethyl group and a cyano group, which may be the same or different.

In the above formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ 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.

Specific examples of the compound having a photo-aligning group and a hydroxyl group as component (A) include 4-(8-hydroxyoctyloxy)cinnamic acid methyl ester, 4-(6-hydroxyhexyloxy)cinnamic acid methyl ester, 4-(4-hydroxybutoxy)cinnamic acid methyl ester, 4-(3-hydroxypropoxy)cinnamic acid methyl ester, 4-(2-hydroxyethoxy)cinnamic acid methyl ester, 4-hydroxymethoxycinnamic acid methyl ester, Methyl cinnamate, methyl 4-hydroxycinnamate, ethyl 4-(8-hydroxyoctyloxy)cinnamate, ethyl 4-(6-hydroxyhexyloxy)cinnamate, ethyl 4-(4-hydroxybutoxy)cinnamate, ethyl 4-(3-hydroxypropoxy)cinnamate, ethyl 4-(2-hydroxyethoxy)cinnamate, ethyl 4-hydroxymethoxycinnamate, ethyl 4-hydroxycinnamate, ethyl 4-( 8-Hydroxyoctyloxy) cinnamic acid phenyl ester, 4-(6-hydroxyhexyloxy) cinnamic acid phenyl ester, 4-(4-hydroxybutoxy) cinnamic acid phenyl ester, 4-(3-hydroxypropoxy) cinnamic acid phenyl ester, 4-(2-hydroxyethoxy) cinnamic acid phenyl ester, 4-hydroxymethoxy cinnamic acid phenyl ester, 4-hydroxycinnamic acid phenyl ester, 4-(8-hydroxyoctyloxy) cinnamic acid biphenyl ester, 4-( 6-hydroxyhexyloxy) cinnamic acid biphenyl ester, 4-(4-hydroxybutoxy) cinnamic acid biphenyl ester, 4-(3-hydroxypropoxy) cinnamic acid biphenyl ester, 4-(2-hydroxyethoxy) cinnamic acid biphenyl ester, 4-hydroxymethoxy cinnamic acid biphenyl ester, 4-hydroxycinnamic acid biphenyl ester, 8-hydroxyoctyl cinnamic acid, 6-hydroxyhexyl cinnamic acid, 4-hydroxybutyl cinnamic acid, cinnamic acid 3-Hydroxypropyl cinnamate, 2-hydroxyethyl cinnamate, hydroxymethyl cinnamate, 4-(8-hydroxyoctyloxy)benzophenone, 4-(6-hydroxyhexyloxy)benzophenone, 4-(4-hydroxybutoxy)benzophenone, 4-(3-hydroxypropoxy)benzophenone, 4-(2-hydroxyethoxy)benzophenone, 4-hydroxymethoxybenzophenone, 4-hydroxybenzophenone , 4-(8-hydroxyoctyloxy)chalcone, 4-(6-hydroxyhexyloxy)chalcone, 4-(4-hydroxybutoxy)chalcone, 4-(3-hydroxypropoxy)chalcone, 4-(2-hydroxyethoxy)chalcone, 4-hydroxymethoxychalcone, 4-hydroxychalcone, 4'-(8-hydroxyoctyloxy)chalcone, 4'-(6-hydroxyhexyloxy)chalcone , 4'-(4-hydroxybutoxy)chalcone, 4'-(3-hydroxypropoxy)chalcone, 4'-(2-hydroxyethoxy)chalcone, 4'-hydroxymethoxychalcone, 4'-hydroxychalcone, 7-(8-hydroxyoctyloxy)coumarin, 7-(6-hydroxyhexyloxy)coumarin, 7-(4-hydroxybutoxy)coumarin, 7-(3-hydroxypropoxy) )coumarin, 7-(2-hydroxyethoxy)coumarin, 7-hydroxymethoxycoumarin, 7-hydroxycoumarin, 6-hydroxyoctyloxycoumarin, 6-hydroxyhexyloxycoumarin, 6-(4-hydroxybutoxy)coumarin, 6-(3-hydroxypropoxy)coumarin, 6-(2-hydroxyethoxy)coumarin, 6-hydroxymethoxycoumarin, 6-hydroxycoumarin.

Specific examples of compounds having a photo-alignment group and a carboxyl group include cinnamic acid, ferulic acid, 4-nitrocinnamic acid, 4-methoxycinnamic acid, 3,4-dimethoxycinnamic acid, coumarin-3-carboxylic acid, 4-(N,N-dimethylamino)cinnamic acid, etc.

Specific examples of compounds having a photo-alignment group and an amino group include methyl-4-aminocinnamic acid, ethyl-4-aminocinnamic acid, methyl-3-aminocinnamic acid, ethyl-3-aminocinnamic acid, etc.

The low molecular weight photo-alignment component of component (A) can be exemplified by the above specific examples, but is not limited to them.

Furthermore, when the photo-alignment component of component (A) is a compound having a photo-alignment group and a hydroxyl group, a compound having two or more photo-alignment groups and/or two or more hydroxyl groups in the molecule can be used as component (A). Specifically, a compound having one hydroxyl group and two or more photo-alignment groups in the molecule, or a compound having one photo-alignment group and two or more hydroxyl groups in the molecule, or a compound having two or more photo-alignment groups and two or more hydroxyl groups in the molecule can be used as component (A). For example, as an example of a compound having two or more photo-alignment groups and two or more hydroxyl groups in the molecule, a compound represented by the following formula can be exemplified.

By appropriately selecting these compounds, the molecular weight of the photo-alignment component of component (A) can be controlled to be higher. As a result, as described later, when the photo-alignment component of component (A) and the polymer of component (B) are subjected to a thermal reaction with the crosslinking agent of component (C), the sublimation of the photo-alignment component of component (A) can be suppressed. Therefore, the cured film forming composition of this embodiment can form an alignment material with high photoreaction efficiency as a cured film.

Furthermore, the compound as the component (A) in the cured film forming composition of this embodiment may also be a mixture of a plurality of compounds having a photo-alignment group and any one substituent selected from a hydroxyl group, a carboxyl group, and an amino group.

<(B) Ingredients>

The component (B) contained in the cured film forming composition of this embodiment is a hydrophilic polymer.

Therefore, the polymer of component (B) may be a polymer having one or more substituents selected from hydroxyl groups, carboxyl groups, and amino groups (hereinafter also referred to as a specific polymer).

In the cured film forming composition of this embodiment, the specific polymer as the component (B) is preferably a highly hydrophilic polymer having high hydrophilicity in a manner that is more hydrophilic than the component (A). Therefore, the specific polymer is preferably a polymer having a hydrophilic group such as a hydroxyl group, a carboxyl group, or an amine group, and specifically, it is preferably a polymer having one or more substituents selected from a hydroxyl group, a carboxyl group, and an amine group.

Examples of polymers as component (B) include acrylic polymers, polyamides, polyimides, polyvinyl alcohols, polyesters, polyester polycarboxylates, polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, polyalkylene imines, polyallylamines, celluloses (cellulose or its derivatives), phenol novolac resins, melamine formaldehyde resins, etc., polymers with linear or branched structures, cyclic polymers such as cyclodextrins, etc.

Among them, the acrylic polymer can be a polymer obtained by polymerizing monomers having unsaturated double bonds such as acrylic acid, methacrylic acid, and styrene.

The specific polymer as component (B) is preferably hydroxyalkyl cellulose, cellulose, acrylic polymer having at least one of polyethylene glycol ester group and hydroxyalkyl ester group with 2 to 5 carbon atoms and at least one of carboxyl group and phenolic hydroxyl group, acrylic polymer having aminoalkyl group on the side chain, acrylic polymer having hydroxyalkyl group on the side chain such as polyhydroxyethyl methacrylate, polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol.

A preferred example of the specific polymer of component (B) is an acrylic polymer having at least one of a polyethylene glycol ester group and a hydroxyl alkyl ester group having 2 to 5 carbon atoms and at least one of a carboxyl group and a phenolic hydroxyl group. As long as it is an acrylic polymer having such a structure, the main polymer chain skeleton and side chain types constituting the acrylic polymer are not particularly limited.

As a structural unit having at least one of a polyethylene glycol ester group and a hydroxyalkyl ester group having 2 to 5 carbon atoms, a preferred structural unit is represented by the following formula [B1].

As a structural unit having at least one of a carboxyl group and a phenolic hydroxyl group, a preferred structural unit is represented by the following formula [B2].

In the above formulae [B1] and [ _B2 ], ^X3 and ^X4 independently represent a hydrogen atom or a methyl group. ^Y1 represents a H-( _OCH2CH2 ) _n- group (where n is 2 to 50, preferably 2 to 10) or a hydroxyalkyl group having 2 to 5 carbon atoms, and ^Y2 represents a carboxyl group or a phenolic hydroxyl group.

The weight average molecular weight of the acrylic polymer of component (B) is preferably 3,000 to 200,000, more preferably 4,000 to 150,000, and even more preferably 5,000 to 100,000. If the weight average molecular weight is too large, exceeding 200,000, the solubility in the solvent may be reduced and the handling property may be reduced. If the weight average molecular weight is too small, less than 3,000, the curing may be insufficient during thermal curing, and the solvent resistance and heat resistance may be reduced. In addition, the weight average molecular weight is a value obtained by gel permeation chromatography (GPC) using polystyrene as standard data. The same applies to the following in this specification.

The method for synthesizing the acrylic polymer as an example of component (B) is relatively simple, in which a monomer having at least one of a polyethylene glycol ester group and a hydroxyalkyl ester group having 2 to 5 carbon atoms (hereinafter also referred to as a b1 monomer) is copolymerized with a monomer having at least one of a carboxyl group and a phenolic hydroxyl group (hereinafter also referred to as a b2 monomer).

Examples of the monomer having a polyethylene glycol ester group include monoacrylate or monomethacrylate of H-(OCH ₂ CH ₂ ) _n -OH. The value of n is 2 to 50, preferably 2 to 10.

Examples of the above-mentioned monomer having a hydroxyalkyl ester group with 2 to 5 carbon atoms include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, and 4-hydroxybutyl methacrylate.

Examples of the above-mentioned monomers having a carboxyl group include acrylic acid, methacrylic acid, and vinyl benzoic acid.

Examples of the above-mentioned monomer having a phenolic hydroxyl group include p-hydroxystyrene, m-hydroxystyrene, and o-hydroxystyrene.

Furthermore, in this embodiment, when synthesizing the acrylic polymer of component (B), monomers other than monomer b1 and monomer b2 may be used in combination, specifically monomers that do not have either a hydroxyl group or a carboxyl group, within the scope that does not impair the effects of the present invention.

Examples of such monomers include acrylate compounds such as methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl methacrylate, butyl acrylate, isobutyl acrylate, and tert-butyl acrylate; methacrylate compounds such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, and tert-butyl methacrylate; maleimide compounds such as maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide; acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds.

The usage amount of the b1 monomer and the b2 monomer used in the acrylic polymer for obtaining the component (B) is preferably 2 mol% to 95 mol% of the b1 monomer and 5 mol% to 98 mol% of the b2 monomer based on the total amount of all monomers of the acrylic polymer for obtaining the component (B).

When a monomer having only a carboxyl group is used as the b2 monomer, the preferred b1 monomer is 60 mol% to 95 mol% and the preferred b2 monomer is 5 mol% to 40 mol% based on the total amount of all monomers used to obtain the acrylic polymer of component (B).

On the other hand, when a monomer having only a phenolic hydroxyl group is used as the b2 monomer, the preferred b1 monomer is 2 mol% to 80 mol%, and the b2 monomer is 20 mol% to 98 mol%. If the b2 monomer is too small, the liquid crystal orientation is likely to be insufficient, and if it is too large, the compatibility with the (A) component is likely to decrease.

The method for obtaining the acrylic polymer of component (B) is not particularly limited, and it can be obtained by, for example, conducting a polymerization reaction at a temperature of 50°C to 110°C in a solvent in which b1 monomer, b2 monomer, monomers other than the desired b1 monomer and b2 monomer, and a polymerization initiator are coexistent. At this time, the solvent used is not particularly limited as long as it can dissolve b1 monomer, b2 monomer, monomers other than the desired b1 monomer and b2 monomer, and a polymerization initiator. Specific examples are described in the <Solvent> section described later.

A preferred example of the specific polymer of component (B) is an acrylic polymer having an aminoalkyl group in the side chain, for example, a polymerized aminoalkyl ester monomer such as aminoethyl acrylate, aminoethyl methacrylate, aminopropyl acrylate, and aminopropyl methacrylate, or a copolymerized aminoalkyl ester monomer with the above-mentioned b1 monomer, the above-mentioned b2 monomer, and monomers other than these monomers, for example, one or more monomers selected from the group consisting of monomers having neither a hydroxyl group nor a carboxyl group.

A preferred example of the specific polymer of component (B) is an acrylic polymer having a hydroxyalkyl group in the side chain, for example, a polymer obtained by polymerizing a hydroxyalkyl ester monomer such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxypentyl acrylate, and hydroxypentyl methacrylate, or a copolymerization of the hydroxyalkyl ester monomer with the above-mentioned b1 monomer, the above-mentioned b2 monomer, and a monomer other than these monomers, for example, one or more monomers selected from the group consisting of monomers not having either a hydroxyl group or a carboxyl group.

The acrylic polymer of component (B) obtained by the above method is usually in the form of a solution dissolved in a solvent.

Furthermore, the solution of the acrylic polymer of component (B) obtained by the above method is put into diethyl ether or water in stirring to reprecipitate, and the resulting precipitate is filtered and washed, and then dried at room temperature or heated under normal pressure or reduced pressure to obtain acrylic polymer powder of component (B). The polymerization initiator and unreacted monomers coexisting with the acrylic polymer of component (B) can be removed by the above operation, and as a result, a purified acrylic polymer powder of component (B) can be obtained. When the purification cannot be fully achieved by one operation, the obtained powder can be dissolved in a solvent again and the above operation can be repeated.

Preferred examples of polyether polyols as the specific polymer of component (B) include polyethylene glycol, polypropylene glycol and propylene glycol. Further examples include polyols such as bisphenol A, triethylene glycol and sorbitol to which propylene oxide or polyethylene glycol, polypropylene glycol and the like are added or condensed. Specific examples of polyether polyols include ADEKA POLYETHER P series, G series, EDP series, BPX series, FC series, CM series, UNIOX (registered trademark) HC-40, HC-60, ST-30E, ST-40E, G-450, G-750, UNIOL (registered trademark) TG-330, TG-1000, TG-3000, TG-4000, HS-1600D, DA-400, DA-700, DB-400, NONION (registered trademark) LT-221, ST-221, OT-221, etc. manufactured by ADEKA.

A preferred example of the specific polymer as the component (B) is polyester polyol obtained by reacting a polycarboxylic acid such as adipic acid, sebacic acid, isophthalic acid, and a diol such as ethylene glycol, propylene glycol, butanediol, polyethylene glycol, and polypropylene glycol. Specific examples of polyester polyols include PLOYLIGHT (registered trademark) OD-X-286, OD-X-102, OD-X-355, OD-X-2330, OD-X-240, OD-X-668, OD-X-2108, OD-X-2376, OD-X-2044, OD-X-688, OD-X-2068, OD-X-2547, OD-X-2420, OD-X-2523, OD-X-2555, OD-X-2560 manufactured by DIC, POLYOL manufactured by KURARAY P-510, P-1010, P-2010, P-3010, P-4010, P-5010, P-6010, F-510, F-1010 , F-2010, F-3010, P-1011, P-2011, P-2013, P-2030, N-2010, PNNA-2016, etc.

An example of a polycaprolactone polyol as a preferred example of a specific polymer as component (B) is a polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone using a polyol such as trihydroxymethylpropane or ethylene glycol as an initiator. Specific examples of polycaprolactone polyols include PLOYLIGHT (registered trademark) OD-X-2155, OD-X-640, OD-X-2568 manufactured by DIC, and PLACCEL (registered trademark) 205, L205AL, 205U, 208, 210, 212, L212AL, 220, 230, 240, 303, 305, 308, 312, 320 manufactured by DAICEL Chemical.

An example of a polycarbonate polyol as a preferred example of a specific polymer as component (B) is a product obtained by reacting a polyol such as trihydroxymethylpropane or ethylene glycol with diethyl carbonate, diphenyl carbonate, ethylene carbonate, etc. Specific examples of polycarbonate polyols include PLACCEL (registered trademark) CD205, CD205PL, CD210, CD220, C-590, C-1050, C-2050, C-2090, C-3090, etc. manufactured by DAICEL Chemical.

Examples of cellulose that is a preferred example of the specific polymer as component (B) include hydroxyalkylcelluloses such as hydroxyethylcellulose and hydroxypropylcellulose, hydroxyalkylalkylcelluloses such as hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, and hydroxyethylethylcellulose, and cellulose, and hydroxyalkylcelluloses such as hydroxyethylcellulose and hydroxypropylcellulose are preferred.

Examples of the cyclodextrin as a preferred example of the specific polymer as component (B) include cyclodextrins such as α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, methylated cyclodextrins such as methyl-α-cyclodextrin, methyl-β-cyclodextrin, and methyl-γ-cyclodextrin, hydroxymethyl-α-cyclodextrin, hydroxymethyl-β-cyclodextrin, hydroxymethyl-γ-cyclodextrin, 2-hydroxyethyl-α-cyclodextrin, and 2-hydroxyethyl-β-cyclodextrin. , 2-hydroxyethyl-γ-cyclodextrin, 2-hydroxypropyl-α-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, 2-hydroxypropyl-γ-cyclodextrin, 3-hydroxypropyl-α-cyclodextrin, 3-hydroxypropyl-β-cyclodextrin, 3-hydroxypropyl-γ-cyclodextrin, 2,3-dihydroxypropyl-α-cyclodextrin, 2,3-dihydroxypropyl-β-cyclodextrin, 2,3-dipropyl-γ-cyclodextrin, etc.

Melamine formaldehyde resin, which is a preferred example of the specific polymer of component (B), is a resin obtained by polycondensation of melamine and formaldehyde and is represented by the following formula.

In the above formula, R represents a hydrogen atom or an alkyl group with 1 to 4 carbon atoms.

The melamine formaldehyde resin of component (B) is preferably alkylated with hydroxymethyl groups produced by the polycondensation of melamine and formaldehyde from the viewpoint of storage stability.

The method for obtaining the melamine formaldehyde resin of component (B) is not particularly limited. Generally, melamine and formaldehyde are mixed, and after being adjusted to a weak alkaline state using sodium carbonate or ammonia, the mixture is heated at 60-100°C for synthesis. The hydroxymethyl group can then be alkylated by reacting with an alcohol.

The weight average molecular weight of the melamine formaldehyde resin of component (B) is preferably 250 to 5,000, more preferably 300 to 4,000, and even more preferably 350 to 3,500. When the weight average molecular weight is too large, exceeding 5,000, the solubility in solvents may be reduced, thereby reducing the handling properties. When the weight average molecular weight is too small, less than 250, the curing may be insufficient during thermal curing, thereby reducing the solvent resistance and heat resistance.

In the present invention, the melamine formaldehyde resin of component (B) is in liquid form, or can be used in the form of a solution in which the purified liquid is dissolved in the solvent described below.

Furthermore, in the present invention, the melamine formaldehyde resin of component (B) may also be a mixture of multiple melamine formaldehyde resins of component (B).

A preferred example of a phenol novolac resin as the specific polymer of component (B) is phenol formaldehyde polycondensate, etc.

In the cured film forming composition of this embodiment, the polymer of component (B) may be in powder form, or may be used in solution form by dissolving the purified powder in the solvent described below.

Furthermore, in the cured film forming composition of this embodiment, the polymer of component (B) may be a mixture of multiple polymers of component (B).

<(C) Ingredients>

The (C) component contained in the hardened film forming composition of this embodiment is a polymer obtained by polymerizing a monomer containing an N-hydroxymethyl compound or an N-alkoxymethyl (meth) acrylamide compound.

Examples of such polymers include polymers obtained by homopolymerizing monomers such as N-alkoxymethylacrylamide or N-hydroxymethylacrylamide or copolymerizing with copolymerizable monomers. Examples of such polymers include poly(N-butoxymethylacrylamide), poly(N-ethoxymethylacrylamide), poly(N-methoxymethylacrylamide), poly(N-hydroxymethylacrylamide), copolymers of N-butoxymethylacrylamide and styrene, copolymers of N-hydroxymethylacrylamide and methyl methacrylate, copolymers of N-ethoxymethylmethacrylamide and benzyl methacrylate, and copolymers of N-butoxymethylacrylamide, benzyl methacrylate, and 2-hydroxypropyl methacrylate. The weight average molecular weight of these polymers is 1,000~500,000, preferably 2,000~200,000, more preferably 3,000~150,000, and even more preferably 3,000~50,000.

The polymers of the (C) components may be used alone or in combination of two or more.

The content of the polymer formed by polymerizing the monomer containing N-hydroxymethyl compound or N-alkoxymethyl (meth) acrylamide compound in the (C) component of the cured film forming composition of this embodiment is preferably 10 to 150 parts by mass, and more preferably 20 to 100 parts by mass, based on 100 parts by mass of the total amount of the compound of the (A) component and the polymer of the (B) component. When the content of the polymer formed by polymerizing the monomer containing N-hydroxymethyl compound or N-alkoxymethyl (meth) acrylamide compound in the (C) component is too small, the solvent resistance and heat resistance of the cured film obtained from the cured film forming composition are reduced, and the sensitivity during photoalignment is reduced. On the other hand, when the content is too large, the photoalignment and storage stability are lowered.

<(D) Ingredients>

The cured film forming composition of this embodiment further contains a crosslinking catalyst as component (D) in addition to component (A), component (B), and component (C).

The crosslinking catalyst as component (D) may be, for example, an acid or a thermal acid generator. The component (D) is effective in promoting the thermal curing reaction of the cured film forming composition of this embodiment.

The component (D) is not particularly limited as long as it is a sulfonic acid group-containing compound, hydrochloric acid or its salt, and a compound that generates an acid by thermal decomposition during pre-baking or post-baking, that is, a compound that generates an acid by thermal decomposition at a temperature of 80°C to 250°C. 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, trifluoromethanesulfonic acid, p-phenolsulfonic acid, 2-naphthalenesulfonic acid, trimethylbenzenesulfonic acid, p-xylene-2-sulfonic acid, m-xylene-2-sulfonic acid, 4-ethylbenzenesulfonic acid, 1H,1H,2H,2H-perfluorooctanesulfonic acid, perfluoro(2-ethoxyethane)sulfonic acid, pentafluoroethanesulfonic acid, nonafluorobutane-1-sulfonic acid, dodecylbenzenesulfonic acid and the like, or hydrates or salts thereof. Examples of compounds that generate an acid by heat include bis(toluenesulfonyloxy)ethane, bis(toluenesulfonyloxy)propane, bis(toluenesulfonyloxy)butane, p-nitrobenzyl toluenesulfonate, o-nitrobenzyl toluenesulfonate, 1,2,3-phenylenetri(methylsulfonate), p-toluenesulfonate pyridinium salt, p-toluenesulfonate morpholinium salt, p-toluenesulfonate ethyl ester, p-toluenesulfonate propyl ester, p-toluenesulfonate butyl ester, p-toluenesulfonate isobutyl ester, p-toluenesulfonate methyl ester, p-toluenesulfonate phenethyl ester, p-toluenesulfonate cyanomethyl ester, p-toluenesulfonate 2,2,2-trifluoroethyl ester, p-toluenesulfonate 2-hydroxybutyl ester, N-ethyl-p-toluenesulfonamide, and compounds represented by the following formulas.

The content of component (D) of the cured film forming composition of this embodiment is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 6 parts by mass, and even more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the total amount of the compound of component (A) and the polymer of component (B). By making the content of component (D) 0.01 parts by mass or more, sufficient heat curing and solvent resistance can be imparted, and further high sensitivity to light irradiation can be imparted.

<(E) Ingredients>

The cured film forming composition of the present invention may also contain a component that improves the adhesion of the formed cured film (hereinafter also referred to as an adhesion-enhancing component) as component (E).

The adhesion-enhancing component (E) improves the adhesion between the alignment material obtained from the cured film-forming composition of the present invention and the polymerizable liquid crystal layer, and can link the polymerizable functional group of the polymerizable liquid crystal to the crosslinking reaction site of the alignment material through covalent bonding. As a result, the phase difference material of the present embodiment, which is formed by laminating the cured polymerizable liquid crystal on the alignment material of the present embodiment, can maintain strong adhesion even under high temperature and high humidity conditions, and can show high durability against peeling, etc.

As component (E), monomers and polymers having a group selected from a hydroxyl group and an N-alkoxymethyl group and a polymerizable group are preferred.

Examples of these (E) components include compounds having a hydroxyl group and a (meth)acryloyl group, compounds having an N-alkoxymethyl group and a (meth)acryloyl group, and polymers having an N-alkoxymethyl group and a (meth)acryloyl group. Specific examples are shown below.

As an example of the component (E), a multifunctional acrylate containing a hydroxyl group (hereinafter also referred to as a multifunctional acrylate containing a hydroxyl group) can be cited.

Examples of hydroxyl-containing multifunctional acrylates as component (E) include pentaerythritol triacrylate and dipentaerythritol pentaacrylate.

As an example of the component (E), a compound having one acrylic group and one or more hydroxyl groups can also be cited.

Furthermore, the compound as component (E) is exemplified by a compound having at least one polymerizable group containing a C=C double bond and at least one N-alkoxymethyl group in one molecule.

Examples of polymerizable groups containing a C=C double bond include acrylic acid, methacrylic acid, vinyl, allyl, maleimide, etc.

A preferred example of a compound having at least one polymerizable group containing a C=C double bond and at least one N-alkoxymethyl group in one molecule is a compound represented by the following formula (X1).

(In the formula, R ³¹ represents a hydrogen atom or a methyl group, and R ³² represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms)

Specific examples of the compound represented by the above formula (X1) include hydroxymethyl or alkoxymethyl substituted acrylamide compounds or methacrylamide compounds such as N-hydroxymethyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylamide. In addition, the so-called (meth)acrylamide means both methacrylamide and acrylamide.

Other preferred embodiments of the compound having a polymerizable group containing a C=C double bond and an N-alkoxymethyl group as component (E) include the following compounds.

The content of component (E) in the liquid crystal alignment agent of the embodiment of the present invention is preferably 1 to 100 parts by mass, and more preferably 5 to 70 parts by mass, relative to 100 parts by mass of the alignment component of component (A).

<Solvent>

The curable film forming composition of this embodiment is mainly used in a solution state dissolved in a solvent. The solvent used at this time is a solvent containing a carbon number of 1 to 4 alkyl ester of a fatty acid with a carbon number of 1 to 4. As long as it can dissolve the (A) component, the (B) component and the (C) component and the (D) component as required and/or other additives described below, its composition, type, etc. are not particularly limited.

The alkyl ester of the fatty acid having 1 to 4 carbon atoms is preferably a fatty acid alkyl ester represented by the formula R ¹ COOR ² (wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and R ² is an alkyl group having 1 to 4 carbon atoms). Preferred specific examples include methyl formate, ethyl formate, n-propyl formate, isopropyl formate, n-butyl formate, isobutyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, or isobutyl propionate. Particularly preferred are methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate or isopropyl propionate. One or more of these may be used.

Examples of alcohols with carbon numbers of 1 to 5 include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, 3-butanol, and n-pentanol. Among them, first- and second-grade alcohols are preferred in terms of easy capping.

Furthermore, the curable film forming composition of the present invention may contain other solvents in addition to the alcohol having 1 to 5 carbon atoms and the alkyl ester having 1 to 4 carbon atoms of the fatty acid having 1 to 4 carbon atoms.

Specific examples of other solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellulose acetate, ethyl cellulose acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-butanone, 3-methyl-2-pentanone, 2-pentanone, 2-heptanone, γ-butyrolactone, Ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxylate, ethyl hydroxylate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl lactate, butyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, etc.

These solvents can be used alone or in combination of two or more.

<Other additives>

Furthermore, the hardened film forming composition of this embodiment may contain sensitizers, silane coupling agents, surfactants, rheology modifiers, pigments, dyes, storage stabilizers, defoamers, antioxidants, etc. as needed, as long as the effects of the present invention are not impaired.

For example, the sensitizer is effective in promoting the photoreaction after forming a heat-cured film using the cured film forming composition of this embodiment.

As an example of other additives, the sensitizer includes benzophenone, anthracene, anthraquinone, thioxanthone, and their derivatives, as well as nitrophenyl compounds. Among them, benzophenone derivatives and nitrophenyl compounds are preferred. Specific examples of preferred compounds include N-diethylaminobenzophenone, 2-nitrofluorene, 2-nitrofluorene, 5-nitroanthracene, 4-nitrophenyl, 4-nitrocinnamic acid, 4-nitrostilbene, 4-nitrobenzophenone, 5-nitroindole, and the like. In particular, N,N-diethylaminobenzophenone, which is a benzophenone derivative, is preferred.

The sensitizers are not limited to the above ones. Moreover, the sensitizers can be used alone or in combination of two or more compounds.

The usage ratio of the sensitizer in the hardened film forming composition of this embodiment is preferably 0.1 to 20 parts by mass, and more preferably 0.2 to 10 parts by mass, relative to 100 parts by mass of the total mass of the specific copolymer of component (A) and the acrylic polymer of component (B). If the ratio is too small, the effect of the sensitizer may not be fully obtained, and if it is too large, the transmittance may be reduced and the coating may be rough.

<Preparation of hardened film forming composition>

The curing film forming composition of this embodiment contains: (A) a compound having a photo-alignment group and any substituent selected from hydroxyl, carboxyl and amino groups, (B) a hydrophilic polymer having one or more substituents selected from hydroxyl, carboxyl and amino groups, (C) a polymer obtained by polymerizing monomers containing N-hydroxymethyl compounds or N-alkoxymethyl (meth) acrylamide compounds, (D) a crosslinking catalyst, and a solvent containing both an alcohol having 1 to 5 carbon atoms and an alkyl ester having 1 to 4 carbon atoms of a fatty acid having 1 to 4 carbon atoms. In addition, other additives may be contained within the scope that does not impair the effects of the present invention.

The mixing ratio of component (A) to component (B) is preferably 5:95 to 60:40 in terms of mass ratio based on the liquid crystal orientation and solvent resistance.

The ratio of the alcohol solvent containing 1 to 5 carbon atoms to the alkyl ester solvent containing 1 to 4 carbon atoms of fatty acids containing 1 to 4 carbon atoms is preferably 10:90 to 90:10 in terms of mass ratio. When the above-mentioned other solvents are contained, the total amount of the alcohol solvent containing 1 to 5 carbon atoms and the alkyl ester solvent containing 1 to 4 carbon atoms of fatty acids containing 1 to 4 carbon atoms in the whole solvent is preferably 30% to 99% by mass.

The mixing ratio and preparation method of the curing film forming composition of this embodiment when used as a solution are described in detail below.

The solid content ratio in the hardened film forming composition of this embodiment is not particularly limited as long as each component can be uniformly dissolved in the solvent, but is 1% to 80% by mass, preferably 3% to 60% by mass, and more preferably 5% to 40% by mass. Here, the so-called solid content refers to the content of all components of the hardened film forming composition minus the solvent.

The preparation method of the curable film forming composition of this embodiment is not particularly limited. As an example of the preparation method, for example, in a solvent derived from component (B) or component (C), component (A) and component (E) as needed, and then a carbon number 1-4 alkyl ester of a fatty acid having a carbon number of 1-4, and then a carbon number 1-5 alcohol solvent, and then component (D) are added to form a uniform solution, or at an appropriate stage of the preparation method, component (E) or other additives are further added as needed and mixed.

Furthermore, the prepared solution of the hardened film forming composition is preferably filtered through a filter with a pore size of about 0.2μm before use.

<Hard film, orientation material and phase difference material>

The solution of the curable film forming composition of the present embodiment is applied to a substrate (e.g., a silicon/silicon dioxide coated substrate, a silicon nitride substrate, a substrate coated with a metal such as aluminum, molybdenum, chromium, etc.) by a bar coater, a rotary coater, a flow coater, a roller coater, a slit coater, a slit followed by a rotary coater, an inkjet coater, a printing coater, etc. The coating is formed on a substrate (such as a substrate, a glass substrate, a quartz substrate, an ITO substrate, etc.) or a film (such as a triacetyl cellulose (TAC) film, a cycloolefin polymer film, a polyethylene terephthalate film, an acrylic film, etc.), and then heated and dried with a heating plate or an oven to form a cured film.

As the heating and drying conditions, as long as the components of the alignment material formed by the cured film do not dissolve to the extent of the polymerizable liquid crystal solution coated thereon, the crosslinking reaction can be carried out by the crosslinking agent. For example, the heating temperature and heating time can be appropriately selected from the range of 60°C to 200°C and 0.4 minutes to 60 minutes. The heating temperature and heating time are preferably 70°C to 160°C and 0.5 minutes to 10 minutes.

The thickness of the cured film formed using the curable composition of this embodiment is, for example, 0.05 μm to 5 μm, which can be appropriately selected in consideration of the step difference or optical and electrical properties of the substrate used.

The cured film formed in this way can function as a component for aligning the alignment material, i.e., liquid crystal, etc., by irradiating with polarized UV.

As a method of polarized UV irradiation, ultraviolet light or visible light with a wavelength of 150nm to 450nm is usually used, and linear polarization is irradiated from a vertical or oblique direction at room temperature or in a heated state.

Since the alignment material formed by the cured film composition of this embodiment has solvent resistance and heat resistance, after coating the phase difference material formed by the polymerizable liquid crystal solution on the alignment material, the phase difference material is heated to the phase transition temperature of the liquid crystal to make it liquid crystal and align on the alignment material. Then, the phase difference material in the alignment state is directly cured and can be used as a layer with optical anisotropy to form a phase difference material.

As the phase difference material, for example, a liquid crystal monomer having a polymerizable group and a composition containing the same are used. Moreover, when the substrate forming the alignment material is a film, the film having the phase difference material of the present embodiment is useful as a phase difference film. The phase difference material forming such phase difference materials may be in a liquid crystal state, or may be in a horizontal alignment, cholesterol alignment, vertical alignment, mixed alignment, etc. on the alignment material, and may be used separately according to the required phase difference.

In addition, when manufacturing a patterned phase difference material used in a 3D display, the cured film formed by the cured film composition of the present embodiment by the above method can be exposed to polarized UV from a specific reference in a direction of, for example, +45 degrees through a mask of line and space patterns. Next, after removing the mask, the polarized UV is exposed in a direction of -45 degrees to obtain an alignment material having two liquid crystal alignment areas with different alignment control directions of the liquid crystal. Subsequently, after applying the phase difference material formed by a polymerizable liquid crystal solution, it is heated to the phase transition temperature of the liquid crystal to make the phase difference material become a liquid crystal state and align on the alignment material. Then, the phase difference material in the alignment state is directly cured to obtain a patterned phase difference material in which two phase difference areas with different phase difference characteristics are arranged in multiple and regular patterns.

Furthermore, by using two substrates with the alignment material of the present embodiment formed as described above, and attaching the alignment materials on the two substrates to each other with a spacer interposed therebetween, and then injecting liquid crystal between the substrates, a liquid crystal display element with aligned liquid crystal can also be formed.

Therefore, the cured film forming composition of this embodiment can be appropriately used in the manufacture of various phase difference materials (phase difference films) or liquid crystal display elements, etc.

[Implementation example]

The following examples are given to illustrate the present invention in detail, but they are not to be construed as limiting the present invention to these examples.

[Abbreviations used in the examples]

The abbreviations used in the following embodiments have the following meanings.

<Raw materials>

BMAA: N-Butoxymethylacrylamide

AIBN: α,α’-azobis(isobutyronitrile)

<Ingredient A>

MCA: 4-Methoxycinnamic acid

<Ingredient B> PB-1

<Ingredient C>

HPC-SSL: Hydroxypropyl Cellulose

<Ingredient D>

PTSA: p-Toluenesulfonic acid monohydrate

<Ingredient E>

KAYARAD PET-30

<Solvent>

Each resin composition of the embodiment and comparative example contains a solvent, and the solvent used is propylene glycol monomethyl ether (PM), butyl acetate (BA), ethyl acetate (EA), 2-propanol (IPA), and modified ethanol (IPM: ethanol/methanol/IPA=85.5/1.1/13.4).

<Determination of molecular weight of polymer>

The molecular weight of the acrylic acid copolymer in the polymerization example was measured as follows using a gel permeation chromatography (GPC) apparatus (HLC-8320) manufactured by TOSOH Co., Ltd. and columns manufactured by TOSOH Co., Ltd. (TSKgel ALPHA4000, TSKgel ALPHA3000).

In addition, the following number average molecular weight (hereinafter referred to as Mn) and weight average molecular weight (hereinafter referred to as Mw) are expressed in terms of polystyrene conversion.

Column temperature: 40℃

Solvent: Tetrahydrofuran

Flow rate: 1.0mL/min

Standard samples for calibration line: Standard polystyrene manufactured by TOSOH Co., Ltd. (molecular weight 427,000, 190,000, 37,900, 18,100, 5,970, 2,420, 1,010)

<Viscosity measurement of liquid crystal alignment materials>

Device: EMS-1000 manufactured by Kyoto Electronics Co., Ltd.

Measuring temperature: 25℃

Probe size: 2.0mm

Rotation speed: 700rpm

Measuring time: 1 second

<Synthesis of component B> <Polymerization Example 1>

100.0g of BMAA and 1.0g of AIBN as a polymerization catalyst were dissolved in 193.5g of PM and reacted at 80°C for 20 hours to obtain an acrylic polymer solution. The Mn of the obtained acrylic polymer was 10,000 and the Mw was 23,000. The acrylic polymer solution was slowly added dropwise to 2000.0g of hexane to precipitate solids, and the polymer (PB-1) was obtained by filtration and reduced pressure drying.

<Preparation Example 1>

Mix 0.054g of MCA as component (A), 0.378g of PB-1 obtained in polymerization example-1 as component (B), 0.144g of HPC-SSL as component (C), and 0.144g of PET-30 (manufactured by Nippon Kayaku Co., Ltd.) as component (E), add 2.484g of PM, 4.968g of BA, and 0.828g of IPA as solvents, stir for 1 hour, and visually confirm that the solution is dissolved. Next, the obtained solution is filtered with a filter with a pore size of 0.2μm to prepare a liquid crystal alignment agent (A-1).

<Preparation examples 2~6>

Except for using the types and amounts of each component shown in Table 1 below, the same operation as Preparation Example 1 was followed to prepare (A-2)~(A-5) and (B-1).

<Preparation of catalyst solution> <Adjustment Example 7>

Add 2.0g of PTSA as component (D) and 18.0g of PM as solvent and stir for 1 hour to visually confirm that it has dissolved. The solution is filtered with a filter with a pore size of 0.2μm to prepare a catalyst solution (D-1).

<Preparation of curing film forming composition (liquid crystal alignment agent)> <Implementation Example 1>

Add 2.00g of A-1 obtained in Preparation Example 1, 0.06g of D-1 obtained in Preparation Example 7, and 0.60g of EA as a diluent and stir for 1 minute to obtain the liquid crystal alignment agent AL-1.

<Implementation Example 2>

Except for using A-2 obtained in Preparation Example 2, the preparation was carried out in the same manner as in Example 1 to obtain the liquid crystal alignment agent AL-2.

<Implementation Example 3>

Except for using A-3 obtained in Preparation Example 3, the preparation was carried out in the same manner as in Example 1 to obtain the liquid crystal alignment agent AL-3.

<Implementation Example 4>

Except for using A-4 obtained in Preparation Example 4, the preparation was carried out in the same manner as in Example 1 to obtain the liquid crystal alignment agent AL-4.

<Implementation Example 5>

Except for using A-5 obtained in Preparation Example 5, the preparation was carried out in the same manner as in Example 1 to obtain the liquid crystal alignment agent AL-5.

<Comparison Example 1>

Except for using B-1 obtained in Preparation Example 6, the preparation was carried out in the same manner as in Example 1 to obtain the liquid crystal alignment agent BL-1.

<Preparation of polymerizable liquid crystal solution for horizontal alignment> <Preparation Example 9>

Add 1.57g of LC-242 (produced by BASF) for polymeric liquid crystal for horizontal alignment, 0.047g of Irgacure907 (produced by BASF) for photoradical initiator, 0.008g of BYK-361N for leveling material, and then add 6.55g of NMP and 9.83g of cyclopentanone as solvents, stir for 2 hours and visually confirm dissolution to obtain 9 mass% polymeric liquid crystal solution LC-1.

<Formation of liquid crystal alignment film and production of phase difference film> <Implementation Example 7>

The liquid crystal alignment agent (AL-1) obtained in Example 1 is applied to the TAC film used as the substrate with a wet film thickness of 10 μm using a rod coater. Heat drying is performed at 120°C for 1 minute in a heat circulation oven to form a cured film on the film. Next, the surface of the cured film is vertically irradiated with 313nm linear polarized light at an exposure amount of 10mJ/ ^cm2 to form a liquid crystal alignment film. A polymerizable liquid crystal solution LC-1 for horizontal alignment is applied to the above-mentioned liquid crystal alignment film with a wet film thickness of 34μm using a rod coater. Next, after heat drying at 120°C for 2 minutes in an oven, non-polarized light of 365nm is vertically irradiated at an exposure amount of 500mJ/ ^cm2 under nitrogen to cure the polymerizable liquid crystal and produce a phase difference film.

<Implementation Examples 8~11, Comparative Examples 3~4>

Use (AL-2)~(AL-5) and (BL-1) as liquid crystal alignment agents and perform the same operation as Example 7 to prepare a phase difference film.

Each phase difference film produced above was evaluated by the following method. The evaluation results are shown in Table 2.

<Orientation evaluation>

A pair of polarizing plates is used to sandwich the phase difference film on the substrate, and the phase difference characteristics under the orthogonal polarizers are visually observed. The ones that show the phase difference without defects are recorded as ○ in the "Orientation" column, and the ones that do not show the phase difference are recorded as ×.

<Adhesion evaluation>

Use a cutter to cut 100 grids of cuts in a chessboard pattern at 1mm intervals on the phase difference film on the prepared substrate, and then use an adhesive tape (CELTAPE (registered trademark) manufactured by NICHBAN Co., Ltd., 24mm wide) to strongly press it, then peel it off in one go, and evaluate it by the number of grids left. If all of the grids remain, record it as ○ in the "Adhesion" column, if part of it is peeled off, record it as △, and if all of it is peeled off, record it as ×.

<Evaluation of viscosity of liquid crystal alignment agent>

The viscosity of the liquid crystal alignment agents AL-1 to AL-6 prepared in Examples 1 to 6 and BL-1 and BL-2 prepared in Comparative Examples 1 to 2 was measured. The liquid crystal alignment agents obtained in Examples 1 to 6 and Comparative Examples 1 to 2 were stored at room temperature for a specific period of time and the viscosity was also measured and recorded in Table 3.

From the results in Table 2, it can be seen that the composition of the liquid crystal alignment agent has achieved alignment and adhesion. However, from the results in Table 3, by adding lower alcohol as a solvent composition, the viscosity of the liquid crystal alignment agent after preparation can be stabilized.

[Industrial availability]

The cured film forming composition of the present invention is very useful as a liquid crystal alignment film for forming a liquid crystal display element, or as an alignment material for an optical anisotropic film provided inside or outside a liquid crystal display element, and is particularly suitable as a material for forming a patterned phase difference material in a 3D display. Furthermore, it is also suitable as a material for forming a cured film such as a protective film, a flattening film, and an insulating film in various displays such as thin film transistor (TFT) type liquid crystal display elements or organic EL elements, and is particularly suitable as 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 (13)

A curable film forming composition comprising: (A) a compound having a photo-alignment group and any substituent selected from a hydroxyl group, a carboxyl group and an amino group, (B) a hydrophilic polymer having one or more substituents selected from a hydroxyl group, a carboxyl group and an amino group, (C) a polymer obtained by polymerizing a monomer containing an N-hydroxymethyl compound or an N-alkoxymethyl (meth)acrylamide compound, (D) a crosslinking catalyst, (E) a compound selected from a compound having a hydroxyl group and a (meth)acryl group, a compound having an N-alkoxymethyl group and a (meth)acryl group, and An adhesion-enhancing component of at least one of the group of polymers having N-alkoxymethyl and (meth)acryloyl groups, and a solvent comprising an alcohol having 1 to 5 carbon atoms and an alkyl ester having 1 to 4 carbon atoms of a fatty acid having 1 to 4 carbon atoms, wherein the alcohol having 1 to 5 carbon atoms is at least one selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol and n-pentanol, and the content of the component (C) is 10 to 150 parts by mass based on 100 parts by mass of the total amount of the compound of the component (A) and the polymer of the component (B). The cured film forming composition of claim 1, wherein the photo-alignment group of component (A) is a functional group of a photodimerization or photoisomerization structure. In the hardened film forming composition of claim 1 or 2, the photo-alignment group of component (A) is cinnamoyl. In the cured film forming composition of claim 1 or 2, the photo-alignment group of component (A) is an azobenzene structured group. In the cured film forming composition of claim 1 or 2, component (A) has two or more hydroxyl groups. The curing film forming composition of claim 1 or 2, wherein the component (B) is at least one polymer selected from the group consisting of polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol. In the hardened film forming composition of claim 1 or 2, component (B) is cellulose or its derivative. The curing film forming composition of claim 1 or 2, wherein the component (B) is an acrylic polymer having at least one of a polyethylene glycol ester group and a hydroxyl alkyl ester group having 2 to 5 carbon atoms and at least one of a carboxyl group and a phenolic hydroxyl group. The hardened film forming composition of claim 1 or 2, wherein component (B) is an acrylic polymer having a hydroxy alkyl group in the side chain. For example, in the hardened film forming composition of claim 1 or 2, the ratio of component (A) to component (B) is 5:95 to 60:40 by mass. The cured film forming composition of claim 1 or 2 contains 0.01 to 10 parts by mass of component (D) based on 100 parts by mass of the total amount of the compound of component (A) and the polymer of component (B). An alignment material characterized by being obtained using a hardened film forming composition as described in any one of claims 1 to 11. A phase difference material characterized by being formed by using a cured film obtained from a cured film forming composition according to any one of claims 1 to 11.