Side-chain liquid crystal polymer, liquid crystal polymer film, and method for producing the same

Abstract

To provide a side-chain liquid crystal polymer that can lower the light energy needed for photoalignment and can form a liquid crystal polymer film having high birefringence, and a method for producing a liquid crystal polymer film using the same.SOLUTION: The side-chain liquid crystal polymer includes at least a side chain (1) having a specific side-chain structure including a cinnamic acid group, a cinnamoyl group, or a chalcone group, and a side chain (2) having a specific side-chain structure including a mesogenic group and an aldehyde group or an amino group. The production method includes at least: a film forming step of forming a polymer film including the side-chain liquid crystal polymer; a light irradiation step of irradiating the resulting polymer film with light in an amount of 1 to 350 mJ / cm2, wherein the light causes a photoreaction of the photosensitive group and enables anisotropic orientation of the mesogenic component; a heat alignment step of heating the light-irradiated polymer film to induce orientation of the unoriented mesogenic component; a condensable compound application step of applying a condensable compound to the polymer film; and a condensation reaction step of performing a condensation reaction.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a side-chain liquid crystal polymer that can be used to form a liquid crystal polymer film by photoalignment, and a method for producing a liquid crystal polymer film using the same. The present invention also relates to a side-chain liquid crystal polymer that constitutes a liquid crystal polymer film, a liquid crystal polymer film containing the same, and an optically anisotropic element using a liquid crystal polymer film. [Background technology]

[0002] Liquid crystal polymer films made of photosensitive liquid crystal polymers are used in the manufacture of optical devices and display devices by utilizing photoalignment. By designing the chemical structure of the photosensitive liquid crystal polymer and the manufacturing method of the liquid crystal polymer film, the properties of the liquid crystal polymer film have been expressed and improved.

[0003] For example, Patent Document 1 (Japanese Patent No. 6518934) proposes a liquid crystal polymer film having optical anisotropy and liquid crystal alignment ability, which is produced by forming a photosensitive liquid crystal polymer film by subjecting a film of a polymer capable of forming a photosensitive liquid crystal polymer by a condensation reaction, and then irradiating the obtained photosensitive liquid crystal polymer film with light capable of anisotropically aligning the mesogen moiety.

[0004] Patent document 2 (Japanese Patent No. 6644310) proposes a liquid crystal polymer film with an orientation divided into out-of-plane and in-plane orientation, which is produced by laminating an easily removable masking material on a photosensitive liquid crystal polymer film, heat-treating the laminate, and then irradiating it with light that can anisotropically orient the mesogenic portion.

[0005] Patent Document 3 (Japanese Patent No. 7072159) proposes a liquid crystal polymer film with excellent light resistance, which is produced by irradiating a photoalignable polymer film containing a copolymer having side chain (1) capable of forming a liquid crystal structure and having a photosensitive group removable by hydrolysis reaction, and side chain (2) capable of forming a liquid crystal structure and having a functional group having a catalytic effect on hydrolysis reaction, or a polymer composite containing a polymer having side chain (1) and a polymer having side chain (2), with light capable of anisotropically aligning the liquid crystal structure, and then heating and causing a hydrolysis reaction to remove the photosensitive group.

[0006] Patent Document 4 (JP 2023-088428 A) proposes that a polymer film containing a side-chain type liquid crystal polymer having a mesogenic component and a side chain having a hydrolyzable group and a side chain having a photosensitive group is irradiated with light that causes the photosensitive group to photoreact and anisotropically align the mesogenic component, and then heated and hydrolyzed to generate a side chain residue, which is then subjected to a condensation reaction with a condensable compound, thereby producing a liquid crystal polymer film having specified physical properties and characteristics.

[0007] In the materials for forming the liquid crystal polymer film described in Patent Documents 1 to 4, when a film is formed on a substrate and then irradiated with linearly polarized ultraviolet light, an axially selective photoreaction occurs due to the photosensitive groups contained in the polymer side chains. Furthermore, when such a film is heated, the side chains that have undergone an axially selective photoreaction due to the liquid crystallinity of the material itself can be oriented to the side chains that have not reacted to the irradiation of linearly polarized ultraviolet light. As a result, the entire film can be molecularly oriented. This film can be used as a liquid crystal alignment film because it exhibits the ability to align liquid crystal molecules. Furthermore, it can be used as a retardation film because it exhibits birefringence due to molecular orientation.

[0008] In addition, Patent Document 5 (International Publication No. 2022 / 019121) describes that a liquid crystal alignment layer of a polarizing plate can be formed by applying a composition containing a polymer having a photoreactive group and a solvent to a support and irradiating the support with polarized light. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 6518934 [Patent Document 2] Patent No. 6644310 [Patent Document 3] Patent No. 7072159 [Patent Document 4] JP 2023-088428 A [Patent Document 5] International Publication No. 2022 / 019121 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in Patent Documents 1 to 4, the photosensitive liquid crystal polymers specifically used in the examples as materials for forming the liquid crystal polymer film are only described as having benzylideneaniline groups as photosensitive groups, and it takes 1 J / cm to photoreact the benzylideneaniline groups to orient the molecules. 2 Since such extremely high light energy is required, there is a problem in that the efficiency of photoalignment is low.

[0011] On the other hand, Patent Document 5 describes that cinnamoyl and chalcone groups are preferred as photoreactive groups because the amount of polarized light irradiation required for photoalignment is relatively small. However, Patent Document 5 only describes a polymer having only a side chain with a cinnamic acid structure at the end as a polymer having a photoreactive group, and although such a polymer has excellent photoalignment efficiency, the polymer film formed using such a polymer has low birefringence, and there is room for improvement when used as an optical anisotropic element.

[0012] Therefore, the present invention has been made based on such problems, and aims to provide a liquid crystal polymer that can reduce the light energy required for photo-alignment and form a liquid crystal polymer film with a high birefringence, and a method for manufacturing a liquid crystal polymer film using the same. [Means for solving the problem]

[0013] The inventors of the present invention have conducted intensive research to solve the above problems, and have found that a side-chain type liquid crystal polymer having at least a side chain (1) having a cinnamic acid group, a cinnamoyl group, or a chalcone group, and a side chain (2) having a mesogen group and an aldehyde group or an amino group can reduce the light energy required for photo-alignment because the side chain (1) has a specific photosensitive group, and can align the mesogen group of the side chain (2) together with the photo-alignment of the side chain (1) because the side chain (2) has a mesogen group. Furthermore, since the side chain (2) has an aldehyde group or an amino group, which is a condensable group capable of forming a Schiff base, it is possible to introduce a desired chemical structure while maintaining the alignment by condensing with a desired condensable compound after photo-alignment, and the birefringence of the resulting liquid crystal polymer film can be improved, thus completing the present invention.

[0014] That is, the present invention can be configured in the following manner. [Aspect 1] A side chain type liquid crystal polymer comprising at least a side chain (1) having a side chain structure represented by the following formula (1-1) and / or formula (1-2), and a side chain (2) having a side chain structure represented by the following formula (2): [ka] (In the formula, a is an integer of 0 to 2 (preferably 0 to 1); p is an integer of 0 to 12; q is 0 or 1; X1 is a single bond, C 1-3 an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; R1 and R2 are the same or different and each are a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. [ka] (In the formula, b and c are the same or different and each is an integer of 0 to 2 (preferably 0 to 1); p' is an integer of 0 to 12; q' is 0 or 1; X2 and X3 are the same or different and each is a single bond, C 1-3 an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; Z is -OCO-CH=CH-, -CH=CH-COO-, -CO-CH=CH-, or -CH=CH-CO-; R3, R4, R5, R6, and R7 are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. [ka] (In the formula, d and e are the same or different and each represent 0 or 1; r is an integer of 0 to 12; s is 0 or 1; X4 and X6 are the same or different and each represent a single bond, C 1-3 X5 is -COO-, -OCO-, -C≡C-, or -CH=CH-; Q1 is an aldehyde group or an amino group; R8, R9, R 10 and R 11 are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. [Aspect 2] 2. The side chain type liquid crystal polymer according to embodiment 1, comprising a side chain having a carboxy group. [Aspect 3] A film-forming step of forming a polymer film containing the side chain type liquid crystal polymer according to aspect 1 or 2 and optionally a condensable compound, wherein the condensable compound has an amino group or an aldehyde group capable of condensing with Q1 in formula (2) of the side chain (2) of the side chain type liquid crystal polymer to form a Schiff base; The obtained polymer film is irradiated with light of 1 to 350 mJ / cm, which is capable of photoreacting with the photosensitive group and anisotropically aligning the mesogen component of the side-chain liquid crystal polymer. 2 (Preferably 3 to 100 mJ / cm 2 , more preferably 5 to 50 mJ / cm 2 ) a light irradiation step of irradiating the a heat alignment step of heating the light-irradiated polymer film to induce alignment of the unoriented mesogen components; If the polymer membrane does not contain the condensable compound, a condensable compound application step of applying the condensable compound to the polymer membrane; a condensation reaction step in which a condensation reaction is carried out between the side chain (2) of the side chain type liquid crystal polymer and the condensable compound; A method for producing a liquid crystal polymer film, comprising at least the steps of: Aspect 4 A method for producing a liquid crystal polymer film according to aspect 3, wherein the condensable compound is a compound represented by the following formula (4) and / or formula (5): [ka] (In the formula, g is an integer of 0 to 3; Y1 is a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CO-CH=CH-, -CH=CH-CO-, -CH=N-, or -N=CH-; Q2 is an amino group or an aldehyde group; R 14 is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, a cyano group, an amino group, an aldehyde group, a carboxy group, or a cinnamic acid group; R 15 and R 16 are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. [ka] (In the formula, h and i are the same or different and are integers of 0 to 2; Y2 and Y3 are the same or different and are a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CO-CH=CH-, -CH=CH-CO-, -CH=N-, or -N=CH-; Q3 is an amino group or an aldehyde group; R 17 is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, a cyano group, an amino group, or an aldehyde group; R 18 , R 19 , R 20 , R 21, R 22 , and R 23 are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. Aspect 5 A side chain type liquid crystal polymer comprising at least a side chain (1) having a side chain structure represented by the following formula (1-1) and / or formula (1-2), and a side chain (2') having a side chain structure represented by the following formula (2'-1) and / or formula (2'-2): [ka] (In the formula, a is an integer of 0 to 2 (preferably 0 to 1); p is an integer of 0 to 12; q is 0 or 1; X1 is a single bond, C 1-3 an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; R1 and R2 are the same or different and each are a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. [ka] (In the formula, b and c are the same or different and each is an integer of 0 to 2 (preferably 0 to 1); p' is an integer of 0 to 12; q' is 0 or 1; X2 and X3 are the same or different and each is a single bond, C 1-3 an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; Z is -OCO-CH=CH-, -CH=CH-COO-, -CO-CH=CH-, or -CH=CH-CO-; R3, R4, R5, R6, and R7 are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. [ka] (In the formula, d and e are the same or different and each represent 0 or 1; g is an integer of 0 to 3; r is an integer of 0 to 12; s is 0 or 1; X4 and X6 are the same or different and each represent a single bond, C 1-3an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; X5 is -COO-, -OCO-, -C≡C-, or -CH=CH-; Y1 is a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CO-CH=CH-, -CH=CH-CO-, -CH=N-, or -N=CH-; Q is -CH=N- or -N=CH-; R 14 R is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, a cyano group, an amino group, an aldehyde group, a carboxy group, or a cinnamic acid group; R, R, R 10 , R 11 , R 15 and R 16 are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. [ka] (In the formula, d and e are the same or different and each represent 0 or 1; h and i are the same or different and each represent an integer of 0 to 2; r is an integer of 0 to 12; s is 0 or 1; X4 and X6 are the same or different and each represent a single bond, C 1-3 X5 is -COO-, -OCO-, -C≡C-, or -CH=CH-; Y2 and Y3 are the same or different and are a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CO-CH=CH-, -CH=CH-CO-, -CH=N-, or -N=CH-; Q is -CH=N- or -N=CH-; R 17 R is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, a cyano group, an amino group, or an aldehyde group; R, R, R 10 , R 11 , R 18 , R 19 , R 20 , R 21 , R 22 , and R 23are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. Aspect 6 A liquid crystal polymer film comprising the side chain type liquid crystal polymer according to embodiment 5, the liquid crystal polymer film having a birefringence at 500 nm of 0.20 or more (preferably 0.22 or more, more preferably 0.30 or more). Aspect 7 An optically anisotropic element comprising the liquid crystal polymer film according to embodiment 6.

[0015] In this specification, a side chain liquid crystal polymer having at least side chain (1) and side chain (2) may be referred to as a first side chain liquid crystal polymer, and a side chain liquid crystal polymer having at least side chain (1) and side chain (2') may be referred to as a second side chain liquid crystal polymer. Effect of the Invention

[0016] The first side-chain type liquid crystal polymer of the present invention can be used for producing a liquid crystal polymer film, and since the side chain (1) has a specific photosensitive group, the light energy required for photoalignment can be reduced, and a desired chemical structure can be introduced by a condensation reaction with a condensable compound in the side chain (2) in a state where the side chain is molecularly oriented by a photoreaction.

[0017] In the present invention, it is possible to produce a liquid crystal polymer film having a high birefringence, which is composed of the second side-chain type liquid crystal polymer, and this liquid crystal polymer film can be effectively used as an optically anisotropic element. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a graph showing polarized UV-vis absorption spectra of the polymer film after the film formation process (as coated), the liquid crystal polymer film after the light irradiation process (exposed), the liquid crystal polymer film after the heat orientation process (annealed), and the liquid crystal polymer film after the condensation reaction process (AF introduced) obtained in Example 1, where (⊥) indicates absorption when the electric field vector of the detection light is perpendicular, and (||) indicates absorption when the electric field vector of the detection light is parallel. [Diagram 2] FIG. 13 is a graph showing polarized UV-vis absorption spectra of the polymer film after the film formation process (as coated), the liquid crystal polymer film after the light irradiation process (exposed), the liquid crystal polymer film after the heat orientation process (annealed), and the liquid crystal polymer film after the condensation reaction process (AN introduced) obtained in Example 2, where (⊥) indicates absorption when the electric field vector of the detection light is perpendicular, and (||) indicates absorption when the electric field vector of the detection light is parallel. [Diagram 3] FIG. 13 is a graph showing polarized UV-vis absorption spectra of the polymer film after the film formation process (as coated), the liquid crystal polymer film after the light irradiation process (exposed), the liquid crystal polymer film after the first thermal orientation process (1st annealed), the liquid crystal polymer film after the condensation reaction process (AF introduced), and the liquid crystal polymer film after the second thermal orientation process (2nd annealed) obtained in Example 3, in which (⊥) indicates absorption when the electric field vector of the detection light is perpendicular, and (||) indicates absorption when the electric field vector of the detection light is parallel. [Figure 4] FIG. 13 is a graph showing polarized UV-vis absorption spectra of the polymer film after the film formation process (as coated), the liquid crystal polymer film after the light irradiation process (exposed), the liquid crystal polymer film after the condensation reaction process (AF introduced), and the liquid crystal polymer film after the thermal orientation process (annealed) obtained in Example 4, in which (⊥) indicates absorption when the electric field vector of the detection light is perpendicular, and (||) indicates absorption when the electric field vector of the detection light is parallel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] (First side-chain liquid crystal polymer) The first side chain type liquid crystal polymer has at least a side chain (1) having a side chain structure represented by the following formula (1-1) and / or formula (1-2) (hereinafter, may be referred to as side chain structure (1-1) or (1-2)), and a side chain (2) having a side chain structure represented by the following formula (2) (hereinafter, may be referred to as side chain structure (2)).

[0020] <Side chain structure (1-1)> [ka] In the formula, a is an integer of 0 to 2 (preferably 0 to 1); p is an integer of 0 to 12; q is 0 or 1; X1 is a single bond, C 1-3 R1 and R2 are the same or different and each represents a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 R1 and R2 each represent a substituent at a substitutable position on the benzene ring, and may be the same or different substituents at these positions.

[0021] <Side chain structure (1-2)> [ka] In the formula, b and c are the same or different and each is an integer of 0 to 2 (preferably 0 to 1) (preferably, at least one of b and c is 0); p' is an integer of 0 to 12; q' is 0 or 1; X2 and X3 are the same or different and each is a single bond, C 1-3 an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; Z is -OCO-CH=CH-, -CH=CH-COO-, -CO-CH=CH-, or -CH=CH-CO-; R3, R4, R5, R6, and R7 are the same or different and each is a hydrogen atom, an alkyl group (e.g., 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4R3, R4, R5 and R6 each represent a substituent at a substitutable position on the benzene ring, and may be the same or different from each other.

[0022] <Side chain structure (2)> [ka] In the formula, d and e are the same or different and each represent 0 or 1 (preferably, at least one of d and e is 0); r is an integer of 0 to 12; s is 0 or 1; X4 and X6 are the same or different and each represent a single bond, C 1-3 X5 is -COO-, -OCO-, -C≡C-, or -CH=CH-; Q1 is an aldehyde group or an amino group; R8, R9, R 10 and R 11 are the same or different and may be a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 alkyloxy group), halogen atom or cyano group. 10 and R 11 each represents a substituent at a substitutable position on a benzene ring, and represents the same or different substituents at these positions.

[0023] The first side-chain type liquid crystal polymer has a specific photosensitive group and a side chain (1) having a mesogen component, which is a rigid portion that exhibits liquid crystallinity, and has the property of inducing molecular orientation by the photoreaction of the photosensitive group. In Patent Documents 1 to 4, a photosensitive liquid crystal polymer having a benzylideneaniline group as the photosensitive group is actually used, but the benzylideneaniline group is a photosensitive group that causes a photoisomerization reaction, and 1 J / cm is required for molecular orientation by photoreaction. 2Since such a very high light energy as described above is required, the efficiency of photoalignment is poor. In the present invention, the photosensitive group is a cinnamic acid group or a derivative thereof in the side chain structure (1-1), and / or a cinnamoyl group, a chalcone group or a derivative thereof in the side chain structure (1-2). These photosensitive groups are photosensitive groups that undergo a photodimerization reaction and have a high photoreaction rate, so that photoalignment can be achieved with a relatively low light energy.

[0024] In this specification, the mesogenic component is composed of two or more aromatic rings and a linking group connecting them, and may be a mesogenic group formed by a covalent bond with the linking group, or may be a mesogenic structure formed by dimerization of the linking group formed by a hydrogen bond, that is, a structure capable of forming a dimer by hydrogen bonding with other polymers or other side chains of the same polymer. As the mesogenic component of the side chain (1), when a in the side chain structure (1-1) is 1 or 2, the benzene ring has a mesogenic group covalently bonded with the linking group X1. When a in the side chain structure (1-1) is 0, the carboxy group (cinnamic acid group) has hydrogen bonding properties, so that it is possible to form a mesogenic structure by dimerization through hydrogen bonding with the terminal carboxy group of the side chain of the other polymer or the same polymer. In addition, in the side chain structure (1-2), the benzene ring has a mesogenic group covalently bonded with the linking group Z (and X2, X3). In these mesogen components, molecular orientation is induced by the photoreaction of the photosensitive group.

[0025] The first side chain type liquid crystal polymer has a side chain (2) having a mesogen group and an aldehyde group or an amino group, and can align the mesogen group together with the photo-alignment of the side chain (1). The aldehyde group or amino group can act as a condensable group capable of forming a Schiff base, and a desired chemical structure can be introduced while maintaining the alignment by condensing with a desired condensable compound (amine compound or aldehyde compound) after photo-alignment. For example, even if a side chain type liquid crystal polymer having a side chain structure capable of expressing a high birefringence is designed, such a side chain type liquid crystal polymer may be difficult to dissolve in a solvent, and it is difficult to form a liquid crystal polymer film using such a side chain type liquid crystal polymer. However, in the present invention, such a side chain structure can be introduced later, and therefore a liquid crystal polymer film having a high birefringence can be produced.

[0026] In the first side chain type liquid crystal polymer, the molar ratio (1) / (2) of the monomer unit having the side chain structure (1) to the monomer unit having the side chain structure (2) may be 1 / 99 to 90 / 10, preferably 2 / 98 to 70 / 30, more preferably 3 / 97 to 60 / 40. From the viewpoint of light resistance after the liquid crystal polymer film is formed, the molar ratio may be preferably 2 / 98 to 50 / 50, more preferably 3 / 97 to 30 / 70.

[0027] The first side-chain type liquid crystal polymer may have a side chain having a carboxy group. The carboxy group is a functional group that has a catalytic effect on the condensation reaction between the aldehyde group or amino group in the side chain (2) and a condensable compound (amine compound or aldehyde compound), so that the condensation reaction in the side chain (2) can be efficiently promoted without separately adding a catalyst such as an acid. In addition, a process for removing the catalyst such as an acid is not required, and the method for producing the liquid crystal polymer film is simplified.

[0028] The side chain having a carboxy group may be a side chain (1) having a side chain structure (1-1), or may be a side chain other than the side chain (1) and the side chain (2). An example of a side chain having a carboxy group other than the side chains (1) and (2) is a side chain (3) having a side chain structure represented by the following formula (3) (hereinafter, sometimes referred to as side chain structure (3)).

[0029] <Side chain structure (3)> [ka] In the formula, f is an integer of 0 to 2 (preferably 0 to 1); t is an integer of 0 to 12; u is 0 or 1; X7 is a single bond, C 1-3 an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; R 12 and R 13 are the same or different and may be a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 alkyloxy group), halogen atom or cyano group. 12 and R 13 each represents a substituent at a substitutable position on a benzene ring, and represents the same or different substituents at these positions.

[0030] The first side chain type liquid crystal polymer may have a side chain other than the side chain (1) and the side chain (2). For example, the first side chain type liquid crystal polymer may further have a side chain (3), or may have other side chains as long as the effects of the present invention are not impaired. The first side chain type liquid crystal polymer may have only the side chain (1) and the side chain (2), and optionally only the side chain (3).

[0031] The first side chain type liquid crystal polymer may have a main chain structure having a linear or cyclic skeletal chain such as a polyacrylate, polymethacrylate, polyvinyl, polysiloxane, polyether, or polymaleimide, and the like, and the side chain structure (1-1) and / or (1-2), the side chain structure (2), and optionally the side chain structure (3) may be bonded to this main chain structure.

[0032] The side chain structures (1-1) and (1-2), the side chain structure (2), and the side chain structure (3) represent the chemical structures at the ends of the side chains in the repeating units, and various chemical structures may be included between these side chain structures and the main chain structure as long as the effects of the present invention are not impaired.

[0033] The method for producing the first side chain type liquid crystal polymer is not particularly limited, and the polymer can be produced by a known polymerization method using a monomer having the above-mentioned side chains.

[0034] (Method of manufacturing liquid crystal polymer film) The method for producing a liquid crystal polymer film includes a film-forming step of forming a polymer film containing a first side-chain liquid crystal polymer and, optionally, a condensable compound, the condensable compound having an amino group or an aldehyde group capable of forming a Schiff base by condensation with Q1 in the side chain structure (2) of the first side-chain liquid crystal polymer; The obtained polymer film is irradiated with light of 1 to 350 mJ / cm, which is capable of photoreacting with the photosensitive group and anisotropically aligning the mesogen component of the first side-chain liquid crystal polymer. 2 a light irradiation step of irradiating the a heat alignment step of heating the light-irradiated polymer film to induce alignment of the unoriented mesogen components; If the polymer membrane does not contain a condensable compound, a condensable compound application step of applying a condensable compound to the polymer membrane; a condensation reaction step of carrying out a condensation reaction between the side chain (2) of the first side chain type liquid crystal polymer and a condensable compound; At least:

[0035] [Film formation process] In the film formation step, a polymer film containing the first side chain type liquid crystal polymer may be formed, or a polymer film containing the first side chain type liquid crystal polymer and a condensable compound may be formed. When forming a polymer film containing the first side chain type liquid crystal polymer, a solution in which the first side chain type liquid crystal polymer is dissolved in an organic solvent may be used to form the film. When forming a polymer film containing the first side chain type liquid crystal polymer and a condensable compound, a solution in which the first side chain type liquid crystal polymer and a condensable compound are dissolved in an organic solvent may be used to form the film.

[0036] The condensable compound is a compound having an amino group or an aldehyde group, and can be condensed with Q1 in the side chain structure (2) of the first side chain type liquid crystal polymer in the condensation reaction step described later to form a Schiff base. When Q1 in the side chain structure (2) is an aldehyde group, a condensable compound having an amino group is used, and when Q1 is an amino group, a condensable compound having an aldehyde group is used. The condensable compound may be present during film formation, but since a partial condensation reaction may occur when the first side chain type liquid crystal polymer and the condensable compound are mixed, from the viewpoint of efficient photo-alignment in the light irradiation step described later, it is preferable to apply the condensable compound to the polymer film in the condensable compound application step after the light irradiation step.

[0037] In the film formation step, the material used to form the polymer film may further contain a compound other than the first side-chain type liquid crystal polymer and the condensable compound. Such a compound may be a polymer compound or a low molecular weight compound. For example, a compound having a functional group that has a catalytic effect on the condensation reaction may be contained. Examples of the functional group that has a catalytic effect on the condensation reaction include acidic functional groups such as a carboxy group and a sulfo group, and preferably a compound having a carboxy group may be contained, and more preferably, a low molecular weight compound having a carboxy group (e.g., formic acid, acetic acid, propionic acid, etc.) may be contained from the viewpoint of removal after the condensation reaction step.

[0038] The organic solvent can be appropriately selected according to the type of the first side chain type liquid crystal polymer or condensable compound to be dissolved, and is preferably a non-halogen solvent, such as alcohol solvents such as ethanol, propanol, butanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, ester solvents such as ethyl acetate, butyl acetate, methoxypropyl acetate, ether solvents such as diethyl ether, tetrahydrofuran, tetrahydropyran, dioxane, 1,3-dioxolane, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol 1-monomethyl ether 2-acetate, hydrocarbon solvents such as hexane, cyclohexane, methylcyclohexane, toluene, xylene, nitrile solvents such as acetonitrile, amide solvents such as N-methylpyrrolidone, dimethylacetamide, etc. These solvents may be used alone or in combination of two or more. In the present invention, since a desired chemical structure can be introduced by a condensation reaction described later, the choice of solvents for the first side-chain liquid crystal polymer can be expanded regardless of the solubility of the side-chain liquid crystal polymer after the introduction. Also, when a polymer film is used as a substrate described later, a solvent that is a good solvent for the first side-chain liquid crystal polymer and does not dissolve the polymer film can be selected.

[0039] When forming the film, the solution may be applied to a substrate. The substrate may be appropriately selected from various polymer films and inorganic materials such as glass and quartz substrates. For example, the polymer film may be a polyester film such as polyethylene terephthalate; an acrylic resin film such as polymethyl methacrylate; a cellulose polymer film such as diacetyl cellulose and triacetyl cellulose; a polycarbonate polymer film such as bisphenol A-carbonate copolymer; a linear, branched or cyclic polyolefin film such as polyethylene, polypropylene, ethylene-propylene copolymer, cycloolefin polymer, and cycloolefin copolymer; a polyamide film; an imide polymer film; a sulfone polymer film, etc. When a liquid crystal polymer film is used in an optically anisotropic element, a transparent one (transparent substrate) among the above substrates may be used as a part of the optically anisotropic element.

[0040] In addition, among the above substrates, a substrate made of a material having low adhesion to the liquid crystal polymer film may be used as the release substrate. When using a release substrate, since it is possible to peel off after the liquid crystal polymer film is formed, it is not necessary to consider the optical properties of the substrate itself, and an opaque substrate may be used. For example, after forming the liquid crystal polymer film on the substrate, it is bonded to another optical member via an adhesive or the like, and then the release substrate is peeled off and used, so that the liquid crystal polymer film can be used as a configuration without a substrate.

[0041] Examples of the film formation method that can be used include coating / printing methods such as gravure coating, flexo coating, die coating, bar coating, slit coating, spin coating, knife coating, spray coating, and screen printing, and direct drawing methods using an inkjet printer.

[0042] [Light irradiation process] In the light irradiation step, the polymer film obtained in the film formation step is irradiated with light of 1 to 350 mJ / cm, which is capable of photoreacting the photosensitive group in the side chain (1) of the first side chain type liquid crystal polymer and anisotropically aligning the mesogen component of the first side chain type liquid crystal polymer. 2 In the present invention, since the first side-chain type liquid crystal polymer has a specific photosensitive group, a polymer film in which anisotropy is generated by an axially selective photoreaction can be obtained with a relatively low dose of light irradiation. The dose of light irradiation is not particularly limited as long as it is possible to generate anisotropy (photoalignment) by an axially selective photoreaction, but is preferably 3 to 100 mJ / cm. 2 , more preferably 5 to 50 mJ / cm 2 Such light may be linearly polarized or elliptically polarized, although linearly polarized light is preferred.

[0043] The light to be irradiated is not particularly limited as long as it has a wavelength at which the photosensitive group of the first side chain type liquid crystal polymer undergoes a photoreaction, such as infrared rays, visible light, ultraviolet rays (e.g., near ultraviolet rays, far ultraviolet rays, etc.), X-rays, or charged particle beams (e.g., electron beams, etc.). Although the wavelength of the light differs depending on the side chain structure of the first side chain type liquid crystal polymer, the wavelength of the light can be appropriately set depending on the type of photosensitive group, and may be 200 to 500 nm, with 250 to 400 nm being particularly effective in many cases.

[0044] [Thermal orientation process] In the thermal orientation step, the polymer film irradiated in the light irradiation step may be heated. When the polymer film in which anisotropy has been generated due to an axially selective photoreaction is heated, the first side-chain liquid crystal polymer in the polymer film becomes capable of molecular motion, and since the material itself has liquid crystallinity, the molecular motion cooperatively induces the orientation of the unoriented mesogen components along the side chains that have undergone the photoreaction.

[0045] When molecular orientation occurs due to photoreaction, the orientation of the unoriented mesogen components is cooperatively induced along the molecular orientation, resulting in a film in which the side chains are uniformly oriented in the direction perpendicular to the electric field vibration direction of the irradiated polarized light component (e.g., linearly polarized light) throughout the entire polymer film, amplifying the anisotropy of the polymer film itself. This amplification of anisotropy produces optical anisotropy (birefringence).

[0046] The heat orientation step may be carried out multiple times. For example, after the light irradiation step and the first heat orientation step, the condensation reaction step described below may be carried out, and then the second heat orientation step may be carried out.

[0047] The heating temperature is not particularly limited as long as it induces cooperative molecular orientation of the first side-chain liquid crystal polymer in the polymer film, but is preferably set to a temperature equal to or higher than the liquid crystal phase transition temperature of the material (first side-chain liquid crystal polymer) forming the polymer film itself and lower than the isotropic phase transition temperature. In addition, when the heat orientation step is performed after the condensation reaction step, it is preferably set to a temperature equal to or higher than the liquid crystal phase transition temperature of the side-chain liquid crystal polymer after the condensation reaction (for example, the second side-chain liquid crystal polymer described later) and lower than the isotropic phase transition temperature. In the case where the unreacted first side-chain liquid crystal polymer remains even after the condensation reaction step, it is preferably set to a temperature equal to or higher than the liquid crystal phase transition temperature of the mixture of the first side-chain liquid crystal polymer and the side-chain liquid crystal polymer after the condensation reaction and lower than the isotropic phase transition temperature. For example, it may be 80 to 300°C, preferably 85 to 280°C, more preferably 90 to 250°C.

[0048] The heating time is not particularly limited as long as it induces cooperative molecular orientation of the first side-chain liquid crystal polymer in the polymer film, but can be appropriately set depending on the type of the first side-chain liquid crystal polymer, the heating temperature, etc., and may be, for example, 1 minute or more, preferably 3 minutes or more, and more preferably 5 minutes or more. The upper limit of the heating time is not particularly limited, but may be about 60 minutes (preferably about 40 minutes, more preferably about 20 minutes) from the viewpoint of economy.

[0049] [Condensable compound application process] In the condensable compound application step, if the polymer film does not contain a condensable compound, a condensable compound may be applied to the polymer film to undergo a condensation reaction with the side chain (2) of the first side chain type liquid crystal polymer in the condensation reaction step described below. Note that even if the polymer film contains a condensable compound, the condensable compound application step may be performed. The condensable compound application step is preferably performed at least after the light irradiation step, and may be performed before the heat orientation step or after the heat orientation step. When the condensable compound application step is performed before the heat orientation step, the condensation reaction step described below may be performed simultaneously with the heat orientation step, or the heat orientation step may be performed after the condensation reaction step described below.

[0050] As described above, the condensable compound is a compound having an amino group or an aldehyde group, and can be condensed with Q1 in the side chain structure (2) of the first side chain type liquid crystal polymer to form a Schiff base in the condensation reaction step described later. When Q1 in the side chain structure (2) is an aldehyde group, a condensable compound having an amino group is used, and when Q1 is an amino group, a condensable compound having an aldehyde group is used. Preferably, the condensable compound may have an aromatic amino group or an aromatic aldehyde group. When Q1 in the side chain structure (2) is an aldehyde group, the side chain (2) has an aromatic aldehyde group, so that by using a condensable compound having an aromatic amino group, a benzylideneaniline group can be formed by a dehydration condensation reaction between the aromatic aldehyde group and the aromatic amino group as shown in the following reaction formula 1, and a mesogen component can be introduced. Similarly, when Q1 in the side chain structure (2) is an amino group, the side chain (2) has an aromatic amino group, so that a mesogenic component can be introduced by using a condensable compound having an aromatic aldehyde group.

[0051] [ka]

[0052] The condensable compound may be preferably a compound represented by the following formula (4) and / or formula (5) (hereinafter, sometimes referred to as condensable compound (4) or (5)).

[0053] <Condensation compound (4)> [ka] In the formula, g is an integer of 0 to 3; Y1 is a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CO-CH=CH-, -CH=CH-CO-, -CH=N-, or -N=CH-; Q2 is an amino group or an aldehyde group; R 14 is a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 alkyloxy group), halogen atom, cyano group, amino group, aldehyde group, carboxy group, or cinnamic acid group; R 15 and R 16 are the same or different and may be a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 alkyloxy group), halogen atom, or cyano group. 15 and R 16 Each represents a substituent at a substitutable position on the benzene ring, and represents the same or different substituents at these positions. In the above formula (4), when g is 2 or 3, multiple chemical structures in parentheses are bonded, and the Y and R 16 may be the same or different.

[0054] In the above formula (4), when Q1 in the side chain structure (2) of the first side chain type liquid crystal polymer is an aldehyde group, Q2 is an amino group, and when Q1 is an amino group, Q2 is an aldehyde group, and either can form a Schiff base by condensation reaction.

[0055] In terms of improving the birefringence of the side chain type liquid crystal polymer obtained by condensation, the condensable compound (4) is preferably such that g is an integer of 1 to 3 in the above formula (4).

[0056] The condensable compound (4) is a compound represented by the above formula (4), in which Q2 is an amino group and R 14 When Q2 is an aldehyde group, R can undergo a condensation reaction with the aldehyde group in the side chain (2) of the first side chain type liquid crystal polymer, and when R undergoes a condensation reaction with both amino groups, it can form a crosslink. 14 is an aldehyde group, either of them can undergo a condensation reaction with the amino group in the side chain (2) of the first side chain type liquid crystal polymer, and when they undergo a condensation reaction with both aldehyde groups, crosslinking can occur.

[0057] <Condensation compound (5)> [ka] In the formula, h and i are the same or different and are integers of 0 to 2; Y2 and Y3 are the same or different and are a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CO-CH=CH-, -CH=CH-CO-, -CH=N-, or -N=CH-; Q3 is an amino group or an aldehyde group; R 17 is a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 alkyloxy group), halogen atom, cyano group, amino group, or aldehyde group; R 18 , R 19 , R 20 , R 21 , R 22 , and R 23 are the same or different and may be a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6Alkyloxy groups, preferably C 1-4 alkyloxy group), halogen atom, or cyano group. 18 , R 19 , R 20 , and R 21 Each represents a substituent at a substitutable position on the benzene ring, and represents the same or different substituents at these positions. When h and i are 2, multiple chemical structures in parentheses are bonded, and their Y2 and R 18 and Y and R 21 may be the same or different.

[0058] The condensable compound (5) has a fluorene skeleton and can improve the birefringence of the side-chain liquid crystal polymer obtained by condensation.

[0059] In the above formula (5), when Q1 in the side chain structure (2) of the first side chain type liquid crystal polymer is an aldehyde group, Q3 is an amino group, and when Q1 is an amino group, Q3 is an aldehyde group, and either can form a Schiff base by condensation reaction.

[0060] The condensable compound (5) is a compound represented by the above formula (5), in which Q3 is an amino group and R 17 When Q3 is an aldehyde group, R 17 is an aldehyde group, either of them can undergo a condensation reaction with the amino group in the side chain (2) of the first side chain type liquid crystal polymer, and when they undergo a condensation reaction with both aldehyde groups, crosslinking can occur.

[0061] In the condensable compound application step, the condensable compound may be applied as is if it is a liquid, or may be applied in the form of a solution if it is a solid. The application method is not particularly limited as long as it is a method such as coating, dropping, immersion, etc., in which the condensable compound is applied so as to come into contact with the first side-chain liquid crystal polymer in the polymer film. For example, the coating method can utilize various film-forming methods described in the film formation step above, and by performing patterned coating using a printing method or a printer, it is possible to form a side-chain liquid crystal polymer into which the condensable compound is introduced by condensation reaction only in the region where the condensable compound is applied, and form an optically anisotropic layer having different optical properties from the region where the condensable compound is not applied.

[0062] [Condensation reaction process] In the condensation reaction step, a condensation reaction may be carried out between the side chain (2) of the first side chain type liquid crystal polymer and a condensable compound. The condensation reaction step can introduce a desired side chain structure into the side chain type liquid crystal polymer, and a liquid crystal polymer film having a desired physical property (e.g., birefringence, etc.) improved can be obtained. For example, the birefringence can be improved compared to a polymer film composed of the first side chain type liquid crystal polymer.

[0063] The condensation reaction step may be performed after the heat orientation step, simultaneously with the heat orientation step, or before the heat orientation step. When the condensation reaction step is performed after the heat orientation step, the heat orientation step, the condensable compound application step, and the condensation reaction step may be performed in this order. When the condensation reaction step is performed simultaneously with the heat orientation step, the light irradiation step, the condensable compound application step (can be omitted if the polymer film contains a condensable compound), and both the heat orientation step and the condensation reaction step may be performed in this order. When the condensation reaction step is performed before the heat orientation step, the light irradiation step, the condensable compound application step (can be omitted if the polymer film contains a condensable compound), the condensation reaction step, and the heat orientation step may be performed in this order. The order of these steps can be selected depending on the chemical structure and liquid crystal phase transition temperature of the first side chain type liquid crystal polymer, the chemical structure, properties, and boiling point or sublimation point of the condensable compound, etc.

[0064] The condensation reaction step may be carried out at room temperature or under heating. When the condensation reaction step is carried out after or simultaneously with the thermal orientation step, the heating temperature is preferably lower than the isotropic phase transition temperature of the liquid crystal of the first side chain liquid crystal polymer. When the condensation reaction step is carried out before the thermal orientation step, the heating temperature is preferably lower than the liquid crystal transition temperature of the first side chain liquid crystal polymer. The heating temperature is preferably set to a temperature equal to or lower than the boiling point or sublimation point of the condensable compound. For example, the heating temperature may be 40 to 180°C, preferably 50 to 160°C, and more preferably 60 to 140°C.

[0065] The time for the condensation reaction can be appropriately set depending on the type of condensable compound, reaction conditions such as heating temperature, etc. For example, when heating at a predetermined temperature, the time for the condensation reaction may be, for example, in the range of 1 minute to 120 minutes, preferably about 3 minutes to 90 minutes, and more preferably about 5 minutes to 60 minutes.

[0066] When the condensable compound remains as an unreacted product after the condensation reaction, it may be removed from the system by evaporation, sublimation, washing, or the like.

[0067] As described above, in the method for producing a liquid crystal polymer film, the orientation of the side-chain type liquid crystal polymer induced by the light irradiation process and the heat orientation process can be maintained while a desired side chain structure can be introduced later by the condensation reaction process. Therefore, it is possible to suppress constraints on the production conditions regardless of the chemical structure of the side-chain type liquid crystal polymer constituting the final liquid crystal polymer film, and it is possible to produce a liquid crystal polymer film with improved specified physical properties.

[0068] (Second Side-Chain Liquid Crystal Polymer) The second side chain type liquid crystal polymer has at least a side chain (1) having a side chain structure represented by the following formula (1-1) and / or formula (1-2), and a side chain (2') having a side chain structure represented by the following formula (2'-1) and / or formula (2'-2) (hereinafter, these may be referred to as side chain structures (2'-1) and (2'-2)).

[0069] <Side chain structure (1-1)> [ka] In the formula, a is an integer of 0 to 2 (preferably 0 to 1); p is an integer of 0 to 12; q is 0 or 1; X1 is a single bond, C 1-3 R1 and R2 are the same or different and each represents a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 R1 and R2 each represent a substituent at a substitutable position on the benzene ring, and may be the same or different substituents at these positions.

[0070] <Side chain structure (1-2)> [ka] In the formula, b and c are the same or different and each is an integer of 0 to 2 (preferably 0 to 1) (preferably, at least one of b and c is 0); p' is an integer of 0 to 12; q' is 0 or 1; X2 and X3 are the same or different and each is a single bond, C 1-3 an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; Z is -OCO-CH=CH-, -CH=CH-COO-, -CO-CH=CH-, or -CH=CH-CO-; R3, R4, R5, R6, and R7 are the same or different and each is a hydrogen atom, an alkyl group (e.g., 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 R3, R4, R5 and R6 each represent a substituent at a substitutable position on the benzene ring, and may be the same or different from each other.

[0071] <Side chain structure (2'-1)> [ka] In the formula, d and e are the same or different and each represents 0 or 1 (preferably, at least one of d and e is 0); g is an integer of 0 to 3; r is an integer of 0 to 12; s is 0 or 1; X4 and X6 are the same or different and each represents a single bond, C 1-3 an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; X5 is -COO-, -OCO-, -C≡C-, or -CH=CH-; Y1 is a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CO-CH=CH-, -CH=CH-CO-, -CH=N-, or -N=CH-; Q is -CH=N- or -N=CH-; R 14 is a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 R8, R9, R10 are each an alkyloxy group, a halogen atom, a cyano group, an amino group, an aldehyde group, a carboxy group, or a cinnamic acid group; 10 , R 11 , R 15 and R 16 are the same or different and may be a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 alkyloxy group), halogen atom or cyano group. 10 , R 11 , R 15 and R 16Each represents a substituent at a substitutable position on the benzene ring, and represents the same or different substituents at these positions. In the above formula (2'-1), when g is 2 or 3, multiple chemical structures in parentheses are bonded, and their Y1 and R 16 may be the same or different.

[0072] <Side chain structure (2'-2)> [ka] In the formula, d and e are the same or different and each represent 0 or 1 (preferably, at least one of d and e is 0); h and i are the same or different and each represent an integer of 0 to 2; r is an integer of 0 to 12; s is 0 or 1; X4 and X6 are the same or different and each represent a single bond, C 1-3 X5 is -COO-, -OCO-, -C≡C-, or -CH=CH-; Y2 and Y3 are the same or different and are a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CO-CH=CH-, -CH=CH-CO-, -CH=N-, or -N=CH-; Q is -CH=N- or -N=CH-; R 17 is a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C 1-6 Alkyloxy groups, preferably C 1-4 R8, R9, R 10 , R 11 , R 18 , R 19 , R 20 , R 21 , R 22 , and R 23 are the same or different and may be a hydrogen atom, an alkyl group (e.g., C 1-6 Alkyl groups, preferably C 1-4 alkyl groups), alkyloxy groups (e.g., C1-6 Alkyloxy groups, preferably C 1-4 alkyloxy group), halogen atom, or cyano group. 10 , R 11 , R 18 , R 19 , R 20 , and R 21 Each represents a substituent at a substitutable position on the benzene ring, and represents the same or different substituents at these positions. When h and i are 2, multiple chemical structures in parentheses are bonded, and their Y2 and R 18 and Y and R 21 may be the same or different.

[0073] The second side chain liquid crystal polymer is obtained by condensing the side chain (2) of the first side chain liquid crystal polymer with the condensable compound (4) and / or the condensable compound (5). Therefore, the second side chain liquid crystal polymer may have a side chain (2) having the side chain structure (2) of the first side chain liquid crystal polymer that remains uncondensed. The second side chain liquid crystal polymer may have a side chain other than the side chain (1), the side chain (2) and the side chain (2') like the first side chain liquid crystal polymer, for example, a side chain (3) having the side chain structure (3), or may have other side chains within a range that does not impair the effects of the present invention.

[0074] The second side chain type liquid crystal polymer has a side chain structure (2'-1) in which Q is -CH=N-, and R 14 is an amino group, and Q is -N=CH-, and R 14 is an aldehyde group, R 14 The amino group or aldehyde group may also be present in a side chain in which a crosslinked structure is formed by condensation reaction with the side chain structure (2). The second side chain type liquid crystal polymer may also be present in the side chain structure (2'-2) in which Q is -CH=N- and R 17 is an amino group, and Q is -N=CH-, and R 17is an aldehyde group, R 17 There may also be present a side chain in which the amino group or aldehyde group undergoes a condensation reaction with the side chain structure (2) to form a crosslinked structure.

[0075] The second side chain type liquid crystal polymer may have a main chain structure having a linear or cyclic skeletal chain such as a polyacrylate, polymethacrylate, polyvinyl, polysiloxane, polyether, or polymaleimide, and this main chain structure may be bonded to side chain structures (1-1) and / or (1-2), side chain structures (2'-1) and / or (2'-2), and optionally side chain structure (2) and optionally side chain structure (3).

[0076] The side chain structures (1-1) and (1-2), the side chain structures (2'-1) and (2'-2), the side chain structures (2), and the side chain structures (3) represent chemical structures at the ends of the side chains in the repeating units, and various chemical structures may be included between these side chain structures and the main chain structure as long as the effects of the present invention are not impaired.

[0077] (liquid crystal polymer film) The liquid crystal polymer film may be obtained by the above-mentioned manufacturing method, and may be a liquid crystal polymer film formed by a polymer film formed using a first side-chain liquid crystal polymer, in which the orientation induced by the light irradiation step and the heat orientation step is maintained, and which is composed of a side-chain liquid crystal polymer formed by a condensation reaction with a condensable compound. The liquid crystal polymer film preferably has predetermined physical properties and characteristics, and may have, for example, improved physical properties (e.g., birefringence, etc.) compared to a polymer film formed of the first side-chain liquid crystal polymer and photo-oriented.

[0078] The liquid crystal polymer film may contain a second side-chain liquid crystal polymer and have a birefringence of 0.20 or more. Such a liquid crystal polymer film can be obtained by photo-orienting a polymer film formed using a first side-chain liquid crystal polymer through a light irradiation step and a heat orientation step, and by condensing the side chain (2) of the first side-chain liquid crystal polymer with the condensable compound (4) and / or the condensable compound (5).

[0079] From the viewpoint of controlling optical anisotropy, the liquid crystal polymer film may have a birefringence of 0.20 or more, preferably 0.22 or more, more preferably 0.30 or more. The upper limit of the birefringence is not particularly limited, but may be, for example, 1 or less. In this specification, the birefringence can be calculated by retardation value / film thickness, and is a measured value at 500 nm.

[0080] The liquid crystal polymer film may have a dichroic ratio D of 0.5 or more. The dichroic ratio D is a parameter that quantifies the polarization characteristics, and is defined by the following formula. D = (A⊥-A||) / (A⊥+A||) In the formula, A⊥ represents the absorbance when the electric field vector of the irradiated polarized UV light and the detection light during polarized UV-vis spectrum measurement are perpendicular, and A|| represents the absorbance when the electric field vector of the irradiated polarized UV light and the detection light during polarized UV-vis spectrum measurement are perpendicular.

[0081] The higher the dichroic ratio D, the higher the molecular orientation, and the liquid crystal polymer film can maintain the orientation induced by the light irradiation step and the heat orientation step, even if the side chain (2) having a mesogen group of the first side-chain type liquid crystal polymer is subjected to a condensation reaction. The dichroic ratio D is preferably 0.55 or more, more preferably 0.6 or more. The upper limit of the dichroic ratio D is not particularly limited, but may be 1 or less. In this specification, the dichroic ratio D is a measurement value of absorption at the same wavelength measured in a polarized absorption spectrum, and the wavelength is appropriately selected depending on the chemical structure, and is a measurement value of absorption at the wavelength showing the highest value D.

[0082] The thickness of the liquid crystal polymer film can be appropriately adjusted depending on the application, etc., and may be, for example, 50 nm to 10 μm, preferably 100 nm to 5 μm, and more preferably 150 nm to 1 μm.

[0083] The liquid crystal polymer film can be used as a member of an optically anisotropic element. The optically anisotropic element may include a transparent substrate and the above-mentioned liquid crystal polymer film formed on the transparent substrate. Due to the improvement of optical properties, the optically anisotropic element can be used as a retardation film, a liquid crystal alignment film, a pattern retarder, a polarizing diffraction grating, a radial polarizing converter, a polarizing Fresnel lens, etc., used in optical devices and display devices. EXAMPLES

[0084] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples, various physical properties were measured by the following methods. In the following examples and comparative examples, various physical properties were measured by the following methods.

[0085] The molecular weight was measured using a GPC apparatus (PU-2080, RI-2031, manufactured by JASCO Corporation) equipped with a Shodex column manufactured by Showa Denko K.K. as a column and tetrahydrofuran (THF) as an eluent, and calculated in terms of polystyrene.

[0086] The birefringence was calculated from the film thickness measured using an interference film thickness meter (F-20, manufactured by Filmetrics Inc.) and the phase difference value measured at the wavelength described below using a phase difference measurement device (AxoScan, manufactured by AXOMETRICS Inc.) using the following formula. Birefringence = Retardation value / film thickness

[0087] The dichroic ratio was measured using a spectrophotometer equipped with a Glan-Taylor polarizing prism (U-3010, Hitachi High-Tech Science Corporation) and calculated from the polarized absorption spectrum. The dichroic ratio D indicates the dichroic ratio at the absorption wavelength showing the highest value D. The dichroic ratio (D) is defined by the following formula. D = (A⊥-A||) / (A⊥+A||) (In the formula, A⊥ represents the absorbance when the electric field vector of the irradiated polarized UV light and the detection light during polarized UV-vis spectrum measurement are perpendicular, and A|| represents the absorbance when the electric field vector of the irradiated polarized UV light and the detection light during polarized UV-vis spectrum measurement are perpendicular.)

[0088] (Monomer 1) 4-(6-hydroxyhexyloxy)cinnamic acid was synthesized by heating p-coumaric acid and 6-chloro-1-hexanol under alkaline conditions. A large excess of methacrylic acid was added to this product in the presence of p-toluenesulfonic acid to cause an esterification reaction, synthesizing monomer 1 shown in the following chemical formula.

[0089] [ka]

[0090] (Monomer 2) 4-Hydroxybenzoic acid and 6-chloro-1-hexanol were heated under alkaline conditions to synthesize 4-(6-hydroxyhexyloxy)benzoic acid. Then, a large excess of methacrylic acid was added to this product in the presence of p-toluenesulfonic acid to cause an esterification reaction. Next, this product was reacted with 4-hydroxybenzaldehyde using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride as a condensation agent in the presence of 4-dimethylaminopyridine to synthesize monomer 2 shown in the following chemical formula. [ka]

[0091] (Monomer 3) Monomer 2 and compound 1 (2-aminofluorene) described below were dissolved in tetrahydrofuran and reacted under acetic acid acidity to synthesize monomer 3 represented by the following chemical formula. [ka]

[0092] (Copolymer 1) Monomer 1 and monomer 2 were dissolved in THF so that the molar ratio of monomer 1 to monomer 2 was monomer 1:monomer 2 = 50:50, and azobisisobutyronitrile (AIBN) was added as a reaction initiator to polymerize to obtain copolymer 1. Copolymer 1 had a number average molecular weight of 21,000 and a weight average molecular weight of 72,000. This copolymer 1 exhibited liquid crystallinity in the temperature range from 76°C to 144°C.

[0093] (Copolymer 2) Monomer 1 and monomer 2 were dissolved in THF so that the molar ratio of monomer 1 to monomer 2 was 50:50, and AIBN was added as a reaction initiator to polymerize to obtain copolymer 2. Copolymer 2 had a number average molecular weight of 46,000 and a weight average molecular weight of 100,000. Copolymer 2 exhibited liquid crystallinity in the temperature range of 89°C to 152°C.

[0094] (Copolymer 3) Monomer 1 and monomer 2 were dissolved in THF so that the molar ratio of monomer 1 to monomer 2 was 20:80, and AIBN was added as a reaction initiator to polymerize to obtain copolymer 3. The number average molecular weight of copolymer 3 was 47,000 and the weight average molecular weight was 94,000. This copolymer 3 exhibited liquid crystallinity in the temperature range from 62°C to 127°C.

[0095] (Copolymer 4) Monomer 1 and monomer 3 were dissolved in THF so that the molar ratio of monomer 1 to monomer 3 was 50:50, and AIBN was added as a reaction initiator to polymerize to obtain copolymer 4. Copolymer 4 had a number average molecular weight of 16,000 and a weight average molecular weight of 27,000. Copolymer 4 exhibited liquid crystallinity in the temperature range of 100°C to 265°C.

[0096] (Copolymer 5) Monomer 1 and monomer 3 were dissolved in THF so that the molar ratio of monomer 1 to monomer 3 was monomer 1:monomer 3=5:95, and polymerization was carried out by adding AIBN as a reaction initiator. Copolymer 5 was precipitated during the polymerization.

[0097] (Compound 1) Commercially available 2-aminofluorene (AF; manufactured by Tokyo Chemical Industry Co., Ltd.) was purified by recrystallization from ethanol before use.

[0098] (Compound 2) Commercially available p-anisidine (AN; manufactured by Tokyo Chemical Industry Co., Ltd.) was purified by recrystallization from ethanol before use.

[0099] Example 1 Copolymer 1 was dissolved in THF to prepare a solution, which was then coated on a quartz substrate to a thickness of 200 nm using a spin coater and dried at room temperature to form a polymer film. The polymer film was then irradiated with ultraviolet light from an ultra-high pressure mercury lamp through a 365 nm bandpass filter and a polarizer to convert it into linearly polarized ultraviolet light at 7 mJ / cm. 2 After irradiation, the film was heated at 90°C for 10 minutes. The change in the polarized UV-vis absorption spectrum of the liquid crystal polymer film obtained is shown in Figure 1. As shown in Figure 1, the film showed slight anisotropy due to light irradiation, confirming that molecular orientation occurred due to the photoreaction. It was also confirmed that the anisotropy was amplified by the heat treatment after irradiation. The dichroic ratio D 318 was 0.57, and the birefringence at 500 nm was 0.18.

[0100] Next, an AF solution (4 wt%) prepared by dissolving Compound 1 in an acetic acid / ethylene glycol solution (pH = 1.9) was dropped onto the obtained liquid crystal polymer film, and the film was kept at 60°C for 90 minutes. Then, the film was washed with diethyl ether and methanol. The dichroic ratio D 318The refractive index of the liquid crystal polymer film at 500 nm was 0.32, which was higher than that of the polymer film made from the raw material.

[0101] Example 2 A liquid crystal polymer film was obtained in the same manner as in Example 1, except that compound 2 was used instead of compound 1 and the film was immersed in an AN solution (10 wt%) prepared by dissolving compound 2 in an acetic acid / methanol solution (pH=4) for 20 minutes. 318 The refractive index was 0.60 and the birefringence at 500 nm was 0.22. The change in the polarized UV-vis absorption spectrum of the obtained liquid crystal polymer film is shown in Figure 2.

[0102] Example 3 Copolymer 2 was dissolved in THF to prepare a solution, which was then coated on a quartz substrate to a thickness of 200 nm using a spin coater and dried at room temperature to form a polymer film. The polymer film was then irradiated with ultraviolet light from an ultra-high pressure mercury lamp through a 365 nm bandpass filter and a polarizer to convert it into linearly polarized ultraviolet light at 6 mJ / cm. 2 After the irradiation, the liquid crystal polymer film was heated at 105°C for 10 minutes. The dichroic ratio D 319 was 0.59, and the birefringence at 500 nm was 0.17.

[0103] Next, an AF solution (4 wt%) prepared by dissolving Compound 1 in an acetic acid / ethylene glycol solution (pH = 1.9) was dropped onto the obtained liquid crystal polymer film, and the film was kept at 60°C for 90 minutes. Then, the film was washed with diethyl ether and methanol. The dichroic ratio D 319 The molecular orientation due to the light irradiation and heat treatment was confirmed to be maintained even after the condensation reaction.

[0104] The liquid crystal polymer film thus obtained was then subjected to a heat treatment at 150° C. for 10 minutes. 319The refractive index at 500 nm was 0.33. The change in the polarized UV-vis absorption spectrum of the obtained liquid crystal polymer film is shown in FIG.

[0105] Example 4 Copolymer 3 was dissolved in THF to prepare a solution, which was then coated on a quartz substrate to a thickness of 200 nm using a spin coater and dried at room temperature to form a polymer film. The polymer film was then irradiated with ultraviolet light from an ultra-high pressure mercury lamp through a 365 nm bandpass filter and a polarizer to convert it into linearly polarized ultraviolet light at 7 mJ / cm. 2 Irradiated.

[0106] Next, an AF solution (4 wt%) prepared by dissolving Compound 1 in an acetic acid / ethylene glycol solution (pH = 1.8) was dropped onto the obtained liquid crystal polymer film, and the film was then kept at 60°C for 90 minutes, followed by washing with diethyl ether and methanol.

[0107] The obtained liquid crystal polymer film was then heat-treated at 200° C. for 10 minutes. 319 The refractive index was 0.73 and the birefringence at 500 nm was 0.40. The change in the polarized UV-vis absorption spectrum of the obtained liquid crystal polymer film is shown in FIG.

[0108] Comparative Example 1 Copolymer 4 was dissolved in THF to prepare a solution, which was then coated on a quartz substrate to a thickness of 200 nm using a spin coater and dried at room temperature to form a polymer film. The polymer film was then irradiated with ultraviolet light from an ultra-high pressure mercury lamp through a 365 nm bandpass filter and a polarizer to convert it into linearly polarized ultraviolet light at 7 mJ / cm. 2 After the irradiation, the liquid crystal was heated in the liquid crystal temperature range, but it was confirmed that no anisotropy was observed and no molecular orientation was induced.

[0109] Comparative Example 2 Copolymer 5 was not soluble in THF and could not form a polymer film. [Industrial Applicability]

[0110] In the present invention, the light energy required for photo-alignment can be reduced, and a liquid crystal polymer film with high birefringence can be produced. The liquid crystal polymer film of the present invention can be formed on a transparent substrate and used not only as an optically anisotropic element, a retardation film, an optical compensation film, etc., but also as a liquid crystal alignment film by utilizing the alignment property of the liquid crystal polymer. It can also be used as a liquid crystal display element comprising a pair of liquid crystal alignment films and a liquid crystal layer disposed between a pair of optical elements.

[0111] As described above, the preferred embodiments of the present invention have been described. However, various additions, modifications, and omissions can be made without departing from the spirit of the present invention, and such additions, modifications, and omissions are also included within the scope of the present invention.

Claims

1. A side chain type liquid crystal polymer comprising at least a side chain (1) having a side chain structure represented by the following formula (1-1) and / or formula (1-2), and a side chain (2) having a side chain structure represented by the following formula (2): 【Chemistry 1】 (wherein a is an integer from 0 to 2; p is an integer from 0 to 12; q is 0 or 1; X １ is a single bond, C １－３ an alkylene group, —CH═CH—, —C≡C—, —COO—, or —OCO—; R １ and R ２ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. 【Chemistry 2】 (wherein b and c are the same or different and each is an integer of 0 to 2; p' is an integer of 0 to 12; q' is 0 or 1; X ２ and X ３ are the same or different and each represents a single bond, C １－３ an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; Z is -OCO-CH=CH-, -CH=CH-COO-, -CO-CH=CH-, or -CH=CH-CO-; R ３ , R ４ , R ５ , R ６ and R ７ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. 【Chemistry 3】 (wherein, d and e are the same or different and each is 0 or 1; r is an integer from 0 to 12; s is 0 or 1; X ４ and X ６ are the same or different and each represents a single bond, C １－３ an alkylene group, —CH═CH—, —C≡C—, —COO—, or —OCO—; ５ is —COO—, —OCO—, —C≡C—, or —CH═CH—; Q １ is an aldehyde group or an amino group; R ８ , R ９ , R １０ and R １１ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group.

2. 2. The side chain type liquid crystal polymer according to claim 1, comprising a side chain having a carboxy group.

3. A film-forming process for forming a polymer film containing the side-chain liquid crystal polymer according to claim 1 or 2 and, optionally, a condensable compound, wherein the condensable compound is a compound represented by the formula (2) of the side chain (2) of the side-chain liquid crystal polymer, １ a membrane forming step, The obtained polymer film is irradiated with light of 1 to 350 mJ / cm, which is capable of photoreacting with the photosensitive group and anisotropically aligning the mesogen component of the side chain type liquid crystal polymer. ２ a light irradiation step of irradiating the a heat alignment step of heating the light-irradiated polymer film to induce alignment of the unoriented mesogen components; If the polymer membrane does not contain the condensable compound, a condensable compound application step of applying the condensable compound to the polymer membrane; a condensation reaction step in which a condensation reaction is carried out between the side chain (2) of the side chain type liquid crystal polymer and the condensable compound; A method for producing a liquid crystal polymer film, comprising at least the steps of:

4. The method for producing a liquid crystal polymer film according to claim 3 , wherein the condensable compound is a compound represented by the following formula (4) and / or formula (5): 【Chemistry 4】 (wherein g is an integer from 0 to 3; Y １ is a single bond, —O—, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CO-CH═CH—, —CH═CH-CO—, —CH═N—, or —N═CH—; Q ２ is an amino group or an aldehyde group; R １４ is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, a cyano group, an amino group, an aldehyde group, a carboxy group, or a cinnamic acid group; R １５ and R １６ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. 【Chemistry 5】 (wherein h and i are the same or different and are integers of 0 to 2; Y ２ and Y ３ are the same or different and each is a single bond, —O—, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CO-CH═CH—, —CH═CH-CO—, —CH═N—, or —N═CH—; Q ３ is an amino group or an aldehyde group; R １７ is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, a cyano group, an amino group, or an aldehyde group; R １８ , R １９ , R ２０ , R ２１ , R ２２ , and R ２３ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group.

5. A side chain type liquid crystal polymer comprising at least a side chain (1) having a side chain structure represented by the following formula (1-1) and / or formula (1-2), and a side chain (2') having a side chain structure represented by the following formula (2'-1) and / or formula (2'-2): 【Chemistry 6】 (wherein a is an integer from 0 to 2; p is an integer from 0 to 12; q is 0 or 1; X １ is a single bond, C １－３ an alkylene group, —CH═CH—, —C≡C—, —COO—, or —OCO—; R １ and R ２ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. 【Chemistry 7】 (wherein b and c are the same or different and each is an integer of 0 to 2; p' is an integer of 0 to 12; q' is 0 or 1; X ２ and X ３ are the same or different and each represents a single bond, C １－３ an alkylene group, -CH=CH-, -C≡C-, -COO-, or -OCO-; Z is -OCO-CH=CH-, -CH=CH-COO-, -CO-CH=CH-, or -CH=CH-CO-; R ３ , R ４ , R ５ , R ６ and R ７ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. 【Chemistry 8】 (wherein, d and e are the same or different and each is 0 or 1; g is an integer of 0 to 3; r is an integer of 0 to 12; s is 0 or 1; X ４ and X ６ are the same or different and each represents a single bond, C １－３ an alkylene group, —CH═CH—, —C≡C—, —COO—, or —OCO—; ５ is —COO—, —OCO—, —C≡C—, or —CH═CH—; Y １ is a single bond, —O—, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CO-CH═CH—, —CH═CH-CO—, —CH═N—, or —N═CH—; Q is —CH═N— or —N═CH—; R １４ is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, a cyano group, an amino group, an aldehyde group, a carboxy group, or a cinnamic acid group; R ８ , R ９ , R １０ , R １１ , R １５ and R １６ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group. 【Chemistry 9】 (wherein, d and e are the same or different and are 0 or 1; h and i are the same or different and are integers of 0 to 2; r is an integer of 0 to 12; s is 0 or 1; X ４ and X ６ are the same or different and each represents a single bond, C １－３ an alkylene group, —CH═CH—, —C≡C—, —COO—, or —OCO—; ５ is —COO—, —OCO—, —C≡C—, or —CH═CH—; Y ２ and Y ３ are the same or different and each is a single bond, —O—, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CO-CH═CH—, —CH═CH-CO—, —CH═N—, or —N═CH—; Q is —CH═N— or —N═CH—; R １７ is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, a cyano group, an amino group, or an aldehyde group; R ８ , R ９ , R １０ , R １１ , R １８ , R １９ , R ２０ , R ２１ , R ２２ , and R ２３ are the same or different and each is a hydrogen atom, an alkyl group, an alkyloxy group, a halogen atom, or a cyano group.

6. 6. A liquid crystal polymer film comprising the side chain type liquid crystal polymer according to claim 5, having a birefringence of 0.20 or more at 500 nm.

7. An optically anisotropic element comprising the liquid crystal polymer film according to claim 6.

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