JP7816136B2 - Compounds containing photoreactive groups, polymers, and retardation films - Google Patents

Description

The present invention relates to a compound containing a photoreactive group. More specifically, it relates to a polymer of a compound containing a photoreactive group and a retardation film containing the polymer.

Optical thin films, such as retardation films, are used in various image display devices to expand the viewing angle. Existing retardation films are thin films made by stretching resins, such as polycarbonate resin, cyclic polyolefin, and cellulose acylate (see, for example, Patent Documents 1 to 3). However, stretched films have issues such as being prone to cracking and light leakage due to residual stress distortion. In recent years, the use of optically anisotropic layers using liquid crystal compounds has been proposed as an alternative to stretched birefringent films. To align the liquid crystal compounds, such optically anisotropic layers require an alignment layer to be provided on the support on which the optically anisotropic layer is formed. Known examples of such alignment layers include those that have undergone rubbing or photoalignment (see, for example, Patent Documents 4 to 6). However, both require complex manufacturing equipment and processes.

Patent Publication No. 2012-111964 JP 2006-281628 Patent Publication No. 2012-230282 JP 8-160430 Special Publication No. 2003-505561 International Publication No. 2010-150748

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide an optical thin film that is oriented without the need for an alignment film, and that exhibits sufficient phase difference without the occurrence of cracks or the like resulting from processing history.

As a result of extensive research into resolving the above-mentioned problems, the inventors discovered that compounds containing photoreactive groups with specific structures can be made into polymers containing the compounds, thereby solving the above-mentioned problems and exhibiting sufficient phase difference in thin film form, making the polymers usable for optical applications such as viewing angle compensation, and thus completing the present invention.

That is, one aspect of the present invention relates to a compound represented by the following formula (1):
(In formula (1), X ₁ to X ₃ each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring or the alicyclic hydrocarbon group may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Here, the substituents in X ₁ to X ₃ each independently represent one kind of the group consisting of a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, and when X ₁ to X ₃ are unsubstituted, they are hydrogen atoms. Y ₁ and Y ₂ each independently represent one kind of the group consisting of a hydroxy group, a carboxyl group, and an amino group. _{Ar 1} and Ar ₂ each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Here, Ar ₁ and Ar The substituents in Ar 1 and Ar ₂ each independently represent one of the group consisting of a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, and when Ar ₁ and Ar ₂ do not have a substituent, they are hydrogen atoms. _{R 1} to R ₄ each independently represent one of the group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. _{L 1} and L ₄ each independently represent one of the group consisting of a single bond, -O-, or -NR ₅ -. Here, R ₅ represents one of the group consisting of a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _{L 2} and L ₃ each independently represent one of the group consisting of a single bond, or -O-, -CO-O-, -CO-NR ₆ -, -CO-, or -CR ₇ R ₈ -. Here, R ₆ represents one of the group consisting of a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R _{R 7} and R ₈ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms. a and b each independently represent 0 or 1.

Another aspect of the present invention relates to a polymer having a structural unit A represented by the following formula (2) and at least one of a structural unit B represented by the following formula (3) or a structural unit C represented by the following formula (4):
In formula (2), X ₁ to X ₃ each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring or the alicyclic hydrocarbon group may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Here, the substituents in X ₁ to X ₃ each independently represent one kind of the group consisting of a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, and when X ₁ to X ₃ do not have a substituent, it is a hydrogen atom. Y ₃ and Y ₄ each independently represent one kind of the group consisting of —O—, —CO—, or —NR ₉ —. Here, R ₉ represents one kind of the group consisting of a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _{Ar 1} and Ar Ar 1 and _{Ar 2} each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Here, the substituents in Ar ₁ and Ar ₂ each independently represent one kind of the group consisting of a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, and when Ar ₁ and Ar ₂ do not have a substituent, they are hydrogen atoms.
R ₁ to R ₄ each independently represent a group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. _{L 1} and L ₄ represent a single bond or a group consisting of -O- or -NR ₅ -. Here, R ₅ represents a hydrogen atom or a group consisting of an alkyl group having 1 to 5 carbon atoms. _{L 2} and L ₃ represent a single bond or a group consisting of -O-, -CO-O-, -CO-NR ₆ -, -CO- or -CR ₇ R ₈ -.
Here, _R6 represents a hydrogen atom or a C1-C5 alkyl group. _R7 and _R8 each independently represent a hydrogen atom, a halogen atom, or a C1-C5 alkyl group. a and b each independently represent 0 or 1.
(In formula (3), _Y5 and _Y6 each independently represent a group consisting of —O—, —CO—, and —NR ₁₀ —. Here, R ₁₀ represents a hydrogen atom or a group consisting of an alkyl group having 1 to 5 carbon atoms. _X4 to _X6 each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring or the alicyclic hydrocarbon group may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. R ₁₁ and R ₁₂ each independently represent a hydrogen atom or a group consisting of an alkyl group having 1 to 5 carbon atoms. c represents 0 or 1.)
(In formula (4), _Y7 and _Y8 each independently represent one selected from the group consisting of -O-, -CO-, and _-NR13- . Here, _R13 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Z represents one selected from the group consisting of an alicyclic hydrocarbon group having 5 to 7 carbon atoms, a linear alkylene group having 2 to 20 carbon atoms, and a branched alkylene group having 4 to 20 carbon atoms.)

Another aspect of the present invention relates to a polymer having a structural unit D represented by the following formula (5) and at least one of a structural unit B represented by formula (3) or a structural unit C represented by formula (4):
(In formula (5), _Y9 and _Y10 each independently represent a single bond or a member selected from the group consisting of —O—, —CO—, and _—NR14— . Here, _R14 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _Ar3 and _Ar4 each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. _R15 to _R18 each independently represent a member selected from the group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. _L5 represents a single bond or a member selected from the group consisting of —O— and _—NR25— . Here, _R25 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Each of d to f independently represents 0 or 1.)

Another aspect of the present invention relates to an optical thin film containing the polymer.

Another aspect of the present invention relates to a retardation film including the thin film.
Furthermore, another aspect of the present invention relates to a liquid crystal alignment film comprising the thin film.

According to the present invention, it is possible to provide an optical thin film that exhibits excellent liquid crystal alignment properties by irradiating it with polarized ultraviolet light or obliquely incident ultraviolet light and by heat treatment, without requiring an alignment film, and a retardation film made from the same.

(Compound represented by formula (1))
The compound according to one embodiment of the present invention will be described in detail below.

One aspect of the present invention is a compound represented by the above formula (1) containing a photoreactive group (hereinafter referred to as the "compound of the present invention").

The photoreactive group is a group that generates alignment ability upon irradiation with light. Specifically, upon irradiation with light, it causes a photoreaction that is the origin of alignment ability, such as a molecular dimerization reaction, an isomerization reaction, a photocrosslinking reaction, or a photodecomposition reaction.
As the photoreactive group, those having unsaturated bond, especially double bond are preferred.Specific examples include cinnamoyl group, vinyl group, polyene group, stilbene group, stilbazole group, stilbazolium group, chalcone group, aromatic Schiff base, group having aromatic hydrazone structure, benzophenone group, coumarin group, anthraquinone group, maleimide group, azobenzene group, azonaphthalene group, aromatic heterocyclic azo group, bisazo group, formazan group, and group having azoxybenzene as basic structure.Among these, cinnamoyl group is preferred from the viewpoint that the light irradiation amount required for photoalignment is relatively small and has excellent thermal stability and stability over time.

In formula (1), X ₁ to X ₃ each independently represent either an aromatic ring having 5 to 7 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring or the alicyclic hydrocarbon group may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Examples of the substituents in X ₁ to X ₃ include halogen atoms, alkyl groups having 1 to 5 carbon atoms, and alkoxy groups having 1 to 5 carbon atoms. When X ₁ to X ₃ are unsubstituted, they are hydrogen atoms. X ₁ to X ₃ are preferably a member of the group consisting of a benzene ring, a methylbenzene ring, a t-butylbenzene ring, a dimethylbenzene ring, a tetrafluorobenzene ring, or a cyclohexane ring, and more preferably a trans-cyclohexane ring.

_Y1 and _Y2 each independently represent one of the group consisting of a hydroxy group, a carboxyl group, and an amino group, _{and are} preferably a hydroxy group.

Ar ₁ and Ar ₂ each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Examples of the substituents in Ar ₁ and Ar ₂ include a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. When Ar ₁ and Ar ₂ do not have a substituent, they are hydrogen atoms. Ar ₁ and Ar ₂ are preferably benzene rings which may have a substituent, and more preferably benzene rings.

R ₁ to R ₄ each independently represent one of the group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. _{R 1} to R ₄ are preferably a hydrogen atom or a cyano group, and more preferably a hydrogen atom.

_L1 and _L4 each independently represent a single bond or one of the group consisting of -O- and _-NR5- . _L1 and _L4 are preferably -O- or _-NR5- . _R5 in _L1 and _L4 represents a hydrogen atom or one of the group consisting of alkyl groups having 1 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms for _R5 include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.

_L2 and _L3 each independently represent a single bond or a group selected from the group consisting of -O-, -CO-O-, -CO-NR ₆ -, -CO-, and -CR ₇ R ₈ -. However, the left-right relationship of _L2 and L ₃ may be reversed. _L2 and _L3 are preferably a single bond or -CO-NR ₆ -, more preferably a single bond. R6 in _L2 and _L3 represents a hydrogen atom or a group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms _{in R6} include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. _R7 and _R8 in _L2 and _L3 each independently represent a hydrogen atom, a halogen atom, or a group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms. Examples of the halogen atom in _R7 and _R8 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 5 carbon atoms in R ₇ and R ₈ include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.

a and b each independently represent 0 or 1.

The compound represented by formula (1) is preferably a compound represented by the following formula (11):
In formula (11), X ₁ to X ₃ , Ar ₁ , Ar ₂ , R ₁ to R ₄ , L ₁ to L ₄ , a, and b are the same as in formula (1).

The compound represented by formula (1) is more preferably a compound represented by the following formula (12).

In formula (12), _X7 and _X8 each independently represent either an aromatic ring having 5 to 7 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent. Here, examples of the substituent in _X7 and _X8 include a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. When _X7 and _X8 do not have a substituent, they are hydrogen atoms.
_X7 and _X8 are preferably one member of the group consisting of a benzene ring, a methylbenzene ring, a t-butylbenzene ring, a dimethylbenzene ring or a cyclohexane ring, and more preferably either a benzene ring or a cyclohexane ring.
_X7 is preferably either an unsubstituted aromatic ring having 5 to 7 carbon atoms or an unsubstituted alicyclic hydrocarbon group having 5 to 7 carbon atoms.

In formula (12), L ₆ represents a single bond or one of the group consisting of —O—, —CO—O—, —CO—NR ₂₁ —, —CO—, and —CR ₂₂ R ₂₃ —.
_L6 is preferably a single bond.
R ₂₁ in L ₆ represents either a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
Examples of the alkyl group having 1 to 5 carbon atoms for R ₂₁ include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.
R ₂₂ and R ₂₃ in L ₆ each independently represent one of the group consisting of a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms, provided that the left and right relationships of L ₆ may be reversed.
Examples of the halogen atom in R ₂₂ and R ₂₃ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group having 1 to 5 carbon atoms in R ₂₂ and R ₂₃ include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.

In formula (12), m and l each independently represent 0 or 1.
In formula (12), R ₁₉ and R ₂₀ each independently represent one of the group consisting of a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms.
Examples of the alkyl group having 1 to 5 carbon atoms in R ₁₉ and R ₂₀ include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms in R ₁₉ and R ₂₀ include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group.
In formula (12), _n1 and _n2 each independently represent an integer of 0 to 4.

Each ester bond in formula (12) may be independently replaced with an amide bond, which may have a substituent. Examples of the substituent include a halogen atom and an alkyl group having 1 to 5 carbon atoms.

The compound of the present invention is more preferably a compound represented by the following formula (13):

(In formula (13), Y ₁₁ represents one member of the group consisting of a benzene ring, a biphenyl ring, a cyclohexane ring, and a bicyclohexane ring, each of which may have a substituent. _{R 19} and R ₂₀ each independently represent a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. _{n 1} and n ₂ each independently represent an integer of 0 to 4.)

In formula (13), Y ₁₁ represents one of the group consisting of an optionally substituted benzene ring, a biphenyl ring, a cyclohexane ring, and a bicyclohexane ring, where examples of the substituent on Y ₁₁ include a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, and when Y ₁₁ is unsubstituted, it is a hydrogen atom.
_Y11 is preferably one member of the group consisting of a benzene ring, a biphenyl ring, and a cyclohexane ring, each of which may have a substituent, and more preferably one member of the group consisting of a benzene ring, a methylbenzene ring, a t-butylbenzene ring, a tetramethylbiphenyl ring, and a cyclohexane ring.

Examples of the alkyl group having 1 to 5 carbon atoms in R ₁₉ and R ₂₀ include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms in R ₁₉ and R ₂₀ include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group.

Each ester bond in formula (13) may be independently replaced with an amide bond which may have a substituent. Examples of the substituent include a halogen atom and an alkyl group having 1 to 5 carbon atoms.

The compound of the present invention can be synthesized by combining general techniques in organic synthetic chemistry. For example, as a method for synthesizing a compound represented by formula (1) in which _Y1 and _Y2 are hydroxy groups, a method can be exemplified in which the hydroxy groups are protected (Synthesis Scheme A1), and then the compound with the protected hydroxy groups is subjected to a condensation reaction with a dihydroxy compound or an amine compound (Synthesis Scheme A2), followed by deprotection (Synthesis Scheme A3), as shown in the following synthesis scheme.

(Synthesis Scheme A1)

(Synthetic Scheme A2)

(Synthesis Scheme A3)
(In the synthesis schemes A1 to A3, PG represents a protecting group.)

The protecting group PG used in the synthesis scheme is not particularly limited. Specific examples of substituted methyl ether protecting groups include methoxymethyl, methylthiomethyl, benzyloxymethyl, t-butoxymethyl, 4-pentenyloxymethyl, tetrahydropyranyl, tetrahydrofuranyl, and tetrahydrothiofuranyl. Examples of substituted ethyl ether protecting groups include 1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 2-hydroxyethyl, 2-bromoethyl, t-butyl, cyclohexyl, and benzyl. Examples of methoxy-substituted benzyl ether protecting groups include p-methoxybenzyl, 3,4-dimethoxybenzyl, 2,6-dimethoxybenzyl, p-phenylbenzyl, p-cyanobenzyl, diphenylmethyl, 4-methoxydiphenylmethyl, triphenylmethyl, tri(p-methoxyphenyl)methyl, and di(p-methoxyphenyl)phenylmethyl. Examples of silyl ether protecting groups include trimethylsilyl, triethylsilyl, triisopropylsilyl, dimethylisopropylsilyl, t-butyldimethylsilyl, tribenzylsilyl, triphenylsilyl, diphenylmethylsilyl, t-butylmethoxyphenylsilyl, and t-butoxydiphenylsilyl. Of these, from the viewpoints of cost and simplicity, tetrahydropyranyl and t-butyldimethylsilyl are particularly preferred.

The condensing agent used in the condensation reaction in Synthesis Scheme A2 is not particularly limited. Specific examples of carbodiimide condensing agents include 1,3-bis(2,2-dimethyl-1,3-dioxolan-4-ylmethyl)carbodiimide, N,N'-diisopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide, N,N'-di-t-butylcarbodiimide, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide. Examples of ester condensing agents include N-hydroxysuccinimide, bis(2-oxo-3-oxazolidinylphosphinic acid chloride, bis(pentafluorophenyl) carbonate), isobutyl chloroformate, 4-nitrophenyl chloroformate, diphenylphosphinic acid chloride, bis(4-nitrophenyl) carbonate, 2,2'-dipyridyl disulfide, 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine, N-hydroxyphthalimide, 4-nitrophenol, 2-methyl-6-nitrobenzoic acid anhydride, 4-nitrophenyl trifluoroacetate, 4-trifluoromethylbenzoic acid anhydride, and 2,4,6-trichlorobenzoyl chloride. Examples of carbodiimidazole condensing agents include 1,1'-carbonyldibenzoyl Examples of the condensing agent include thiocarbonyl chloride, trichloromethyl carbonate, and O,O'-di-2-pyridyl thiocarbonate. Examples of the triflate condensing agent include 2-[N,N'-bis(trifluoromethanesulfonyl)amino]-5-chloropyridine, 4-nitrophenyl trifluoromethanesulfonate, and N-phenylbis(trifluoromethanesulfonimide). Of these, from the viewpoints of cost and simplicity, N,N'-dicyclohexylcarbodiimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and 1,1'-carbonyldiimidazole are particularly preferred.

The method used for deprotection in Synthesis Scheme A3 is not particularly limited. A deprotection method appropriate for the protecting group used may be used.

When the compound represented by formula (1) is a compound represented by formula (12), the following synthesis schemes 4 to 6 can be exemplified.

(Synthetic Scheme A4)

(Synthesis Scheme A5)

(Synthesis Scheme A6)
(In the synthesis schemes A4 to A6, PG represents a protecting group.)

The protecting group PG used in the synthesis scheme is not particularly limited. Specific examples of substituted methyl ether protecting groups include methoxymethyl, methylthiomethyl, benzyloxymethyl, t-butoxymethyl, 4-pentenyloxymethyl, tetrahydropyranyl, tetrahydrofuranyl, and tetrahydrothiofuranyl. Examples of substituted ethyl ether protecting groups include 1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 2-hydroxyethyl, 2-bromoethyl, t-butyl, cyclohexyl, and benzyl. Examples of methoxy-substituted benzyl ether protecting groups include p-methoxybenzyl, 3,4-dimethoxybenzyl, 2,6-dimethoxybenzyl, p-phenylbenzyl, p-cyanobenzyl, diphenylmethyl, 4-methoxydiphenylmethyl, triphenylmethyl, tri(p-methoxyphenyl)methyl, and di(p-methoxyphenyl)phenylmethyl. Examples of silyl ether protecting groups include trimethylsilyl, triethylsilyl, triisopropylsilyl, dimethylisopropylsilyl, t-butyldimethylsilyl, tribenzylsilyl, triphenylsilyl, diphenylmethylsilyl, t-butylmethoxyphenylsilyl, and t-butoxydiphenylsilyl. Of these, from the viewpoints of cost and simplicity, tetrahydropyranyl and t-butyldimethylsilyl are particularly preferred.

The condensing agent used in the condensation reaction in Synthesis Scheme A5 is not particularly limited. Specific examples of carbodiimide condensing agents include 1,3-bis(2,2-dimethyl-1,3-dioxolan-4-ylmethyl)carbodiimide, N,N'-diisopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide, N,N'-di-t-butylcarbodiimide, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide. Examples of ester condensing agents include N-hydroxysuccinimide, bis(2-oxo-3-oxazolidinylphosphinic acid chloride, bis(pentafluorophenyl) carbonate), isobutyl chloroformate, 4-nitrophenyl chloroformate, diphenylphosphinic acid chloride, bis(4-nitrophenyl) carbonate, 2,2'-dipyridyl disulfide, 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine, N-hydroxyphthalimide, 4-nitrophenol, 2-methyl-6-nitrobenzoic acid anhydride, 4-nitrophenyl trifluoroacetate, 4-trifluoromethylbenzoic acid anhydride, and 2,4,6-trichlorobenzoyl chloride. Examples of carbodiimidazole condensing agents include 1,1 Examples of the condensing agent include 1,1'-carbonyldiimidazole, 1,1'-carbonyldi(1,2,4-triazole), and 1,1'-oxalyldiimidazole. Examples of the phosgene condensing agent include thiocarbonyl chloride, trichloromethyl carbonate, and O,O'-di-2-pyridyl thiocarbonate. Examples of the triflate condensing agent include 2-[N,N'-bis(trifluoromethanesulfonyl)amino]-5-chloropyridine, 4-nitrophenyl trifluoromethanesulfonate, and N-phenylbis(trifluoromethanesulfonimide). Of these, N,N'-dicyclohexylcarbodiimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide are particularly preferred from the standpoints of cost and simplicity.

The method used for deprotection in Synthesis Scheme A6 is not particularly limited. A deprotection method appropriate for the protecting group used may be used.

(polymer)
The polymer according to one embodiment of the present invention will be described in detail below.

Another embodiment of the present invention is a polymer (hereinafter referred to as "polymer 1 of the present invention") having a structural unit A represented by the following formula (2) and at least one of a structural unit B represented by the following formula (3) or a structural unit C represented by the following formula (4). In particular, polymer 1 of the present invention is preferably a polymer having a structural unit A represented by formula (2) and a structural unit B represented by formula (3).
In formula (2), X ₁ to X ₃ each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring or the alicyclic hydrocarbon group may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Here, the substituents in X ₁ to X ₃ each independently represent one kind of the group consisting of a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, and when X ₁ to X ₃ do not have a substituent, it is a hydrogen atom. Y ₃ and Y ₄ each independently represent one kind of the group consisting of —O—, —CO—, or —NR ₉ —. Here, R ₉ represents one kind of the group consisting of a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _{Ar 1} and Ar Ar 1 and _{Ar 2} each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Here, the substituents in Ar ₁ and Ar ₂ each independently represent one kind of the group consisting of a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, and when Ar ₁ and Ar ₂ do not have a substituent, they are hydrogen atoms.
R ₁ to R ₄ each independently represent a group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. _{L 1} and L ₄ represent a single bond or a group consisting of -O- or -NR ₅ -. Here, R ₅ represents a hydrogen atom or a group consisting of an alkyl group having 1 to 5 carbon atoms. _{L 2} and L ₃ represent a single bond or a group consisting of -O-, -CO-O-, -CO-NR ₆ -, -CO- or -CR ₇ R ₈ -.
Here, _R6 represents a hydrogen atom or a C1-C5 alkyl group. _R7 and _R8 each independently represent a hydrogen atom, a halogen atom, or a C1-C5 alkyl group. a and b each independently represent 0 or 1.

(In formula (3), _Y5 and _Y6 each independently represent a group consisting of —O—, —CO—, and —NR ₁₀ —. Here, R ₁₀ represents a hydrogen atom or a group consisting of an alkyl group having 1 to 5 carbon atoms. _X4 to _X6 each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring or the alicyclic hydrocarbon group may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. R ₁₁ and R ₁₂ each independently represent a hydrogen atom or a group consisting of an alkyl group having 1 to 5 carbon atoms. c represents 0 or 1.)

(In formula (4), _Y7 and _Y8 each independently represent one selected from the group consisting of -O-, -CO-, and _-NR13- . Here, _R13 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Z represents one selected from the group consisting of an alicyclic hydrocarbon group having 5 to 7 carbon atoms, a linear alkylene group having 2 to 20 carbon atoms, and a branched alkylene group having 4 to 20 carbon atoms.)

In formula (2), X ₁ to X ₃ , Ar ₁ , Ar ₂ , R ₁ to R ₄ , L ₁ to L ₄ , a and b are the same as in formula (1).
_Y3 and _Y4 each independently represent one of the group consisting of -O-, -CO-, and _-NR9- , where _R9 represents one of the group consisting of a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _Y3 and _Y4 are preferably -O-.

In formula (3), _Y5 and _Y6 each independently represent one of the group consisting of -O-, -CO-, and _-NR10- , where _R10 represents one of the group consisting of a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _Y5 and _Y6 are preferably -O- or -CO-.
_X4 to _X6 each independently represent either an aromatic ring having 5 to 7 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring or the alicyclic hydrocarbon group may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Examples of the substituents in _X4 to _X6 include halogen atoms, alkyl groups having 1 to 5 carbon atoms, and alkoxy groups having 1 to 5 carbon atoms. When _X4 to _X6 are unsubstituted, they are hydrogen atoms. _X4 to _X6 are preferably a member of the group consisting of a benzene ring, a methylbenzene ring, a t-butylbenzene ring, a dimethylbenzene ring, a tetrafluorobenzene ring, or a cyclohexane ring, and more preferably a benzene ring or a trans-cyclohexane ring.
_R11 and _R12 each represent a hydrogen atom or a C1 to C5 alkyl group. Examples of the C1 to C5 alkyl group represented by _R5 include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.
c represents 0 or 1.

In formula (4), _Y7 and _Y8 each independently represent one of the group consisting of -O-, -CO-, and _-NR13- , where _R13 represents one of the group consisting of a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _Y7 and _Y8 are preferably -CO-.
Z represents one member of the group consisting of an alicyclic hydrocarbon group having 5 to 7 carbon atoms, a linear alkylene group having 2 to 20 carbon atoms, and a branched alkylene group having 4 to 20 carbon atoms. Z is preferably an alicyclic hydrocarbon group having 5 to 7 carbon atoms or a linear alkylene group having 2 to 20 carbon atoms, and more preferably an alicyclic hydrocarbon group having 5 to 7 carbon atoms or a linear alkylene group having 2 to 10 carbon atoms.

The polymer 1 of the present invention is preferably a polymer having a structural unit _A1 containing a cinnamoyl group represented by the following formula (14) and a structural unit _C1 represented by the following formula (15).
(In formula (14), _X7 and _X8 each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent. _L6 represents a single bond or a member selected from the group consisting of -O-, -CO-O-, -CO- _NR21- , -CO-, and _-CR22R23- . Here, _R21 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _R22 and _R23 each independently represent a member selected from the group consisting of a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms. m and l each independently represent 0 or 1. _{R19 and R20} each independently represent a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. _n1 and _n2 each independently represent an integer of 0 to 4.)

(In formula (15), Z represents either a linear alkylene group having 2 to 20 carbon atoms or a branched alkylene group having 4 to 20 carbon atoms.)

In the polymer 1 of the present invention, the structural unit _A1 is preferably a structural unit _A2 represented by the following formula (16).
(In formula (16), Y ₁₁ represents one member of the group consisting of a benzene ring, a biphenyl ring, a cyclohexane ring, and a bicyclohexane ring, each of which may have a substituent. _{R 19} and R ₂₀ each independently represent a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. _{n 1} and n ₂ each independently represent an integer of 0 to 4.)

The method for synthesizing polymer 1 of the present invention is not particularly limited, and it can be synthesized by polymerization methods known in the art, such as melt polymerization or solution polymerization using the corresponding dicarboxylic acid chloride. Of these, solution polymerization, which allows polymerization under mild conditions, is particularly preferred. Specifically, the compound of the present invention can be subjected to interfacial polycondensation in a solvent with at least one compound having structural unit B or a compound having structural unit C.

A polymer that does not contain the structural unit A represented by formula (3) does not undergo photoreaction, and therefore a thin film made of the polymer does not exhibit excellent liquid crystal alignment properties even when irradiated with polarized ultraviolet light or obliquely incident ultraviolet light and subjected to heat treatment.
A polymer that does not contain the structural unit B represented by formula (3) and the structural unit C represented by formula (4) has low thermal alignment properties, and therefore a thin film made of the polymer does not exhibit excellent liquid crystal alignment properties even when irradiated with polarized ultraviolet light or obliquely incident ultraviolet light and subjected to heat treatment.

Another embodiment of the present invention is a polymer having a structural unit D represented by formula (5) and at least one of the structural unit B represented by formula (3) and the structural unit C represented by formula (4) (hereinafter referred to as "polymer 2 of the present invention"). In particular, polymer 2 of the present invention is preferably a polymer having a structural unit D represented by formula (5) and a structural unit B represented by formula (3).
(In formula (5), _Y9 and _Y10 each independently represent a single bond or a member selected from the group consisting of —O—, —CO—, and _—NR14— . Here, _R14 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. _Ar3 and _Ar4 each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. _R15 to _R18 each independently represent a member selected from the group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. _L5 represents a single bond or a member selected from the group consisting of —O— and _—NR25— . Here, _R25 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Each of d to f independently represents 0 or 1.)

In formula (5), _Y9 and _Y10 each independently represent a single bond or one of the group consisting of -O-, -CO-, and _-NR14- , where _R14 represents a hydrogen atom or one of the group consisting of an alkyl group having 1 to 5 carbon atoms. _Y9 and _Y10 are preferably a single bond, -CO-, or -O-.
_Ar3 and _Ar4 each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. Examples of the substituents in _Ar3 and _Ar4 include halogen atoms, alkyl groups having 1 to 5 carbon atoms, and alkoxy groups having 1 to 5 carbon atoms. When _Ar3 and _Ar4 do not have a substituent, they are hydrogen atoms. _Ar3 and _Ar4 are preferably benzene rings which may have a substituent, and more preferably benzene rings.
R ₁₅ to R ₁₈ each independently represent one of the group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. _{R 15} to R ₁₈ are preferably a hydrogen atom.
_L5 represents a single bond or one member of the group consisting of —O— and —NR ₂₅ —, where R ₂₅ represents a hydrogen atom or one member of the group consisting of an alkyl group having 1 to 5 carbon atoms. _L5 is preferably a single bond or —O—.
d to f each independently represent 0 or 1.

In the polymer 2 of the present invention, the structural unit D represented by formula (5) is preferably any one of structural units D-1 to D-5 represented by the following formulas (6) to (10).

The method for synthesizing polymer 2 of the present invention is not particularly limited, and it can be synthesized by polymerization methods known in the art, such as melt polymerization or solution polymerization using the corresponding dicarboxylic acid chloride. Of these, solution polymerization, which allows polymerization under mild conditions, is particularly preferred. Specifically, it involves interfacial polycondensation of a compound having structural unit D with at least one of a compound having structural unit B or a compound having structural unit C in a solvent.

A polymer that does not contain the structural unit D represented by formula (5) does not undergo photoreaction, and therefore a thin film made of the polymer does not exhibit excellent liquid crystal alignment properties even when irradiated with polarized ultraviolet light or obliquely incident ultraviolet light and subjected to heat treatment.
A polymer that does not contain the structural unit B represented by formula (3) and the structural unit C represented by formula (4) has low thermal alignment properties, and therefore a thin film made of the polymer does not exhibit excellent liquid crystal alignment properties even when irradiated with polarized ultraviolet light or obliquely incident ultraviolet light and subjected to heat treatment.

Polymers 1 and 2 of the present invention may be blended with other polymers, crystal nucleating agents, surfactants, polymer electrolytes, conductive complexes, inorganic fillers, pigments, antistatic agents, antiblocking agents, lubricants, etc., within the scope of the invention.

Polymers 1 and 2 of the present invention can be used in the form of a thin film. This allows them to exhibit optical properties and be used as an optical thin film (hereinafter referred to as "thin film of the present invention"). There are no particular restrictions on the method for producing the thin film, and examples include melt casting and solution casting.

(Melt film forming method)
Specific examples of the melt film-forming method include melt extrusion using a T-die, calendar molding, heat pressing, co-extrusion, co-melting, multi-layer extrusion, and inflation molding, and are not particularly limited.

(Solution casting method)
The solution casting method is a method in which a solution in which a polymer is dissolved in a solvent (hereinafter referred to as "casting dope") is cast onto a support substrate, and the solvent is then removed by heating or the like to obtain a thin film. Methods for casting the casting dope onto the support substrate include spin coating, T-die coating, doctor blade coating, bar coater coating, roll coater coating, and lip coater coating. In particular, the most common industrial method is to continuously extrude the casting dope from a die onto a belt-shaped or drum-shaped support substrate. Examples of support substrates that can be used include glass substrates, metal substrates such as stainless steel and ferrotype substrates, and films such as polyethylene terephthalate, polyethylene naphthalate, cycloolefin polymer, and polyimide.

(Surfactant)
The thin film of the present invention may contain at least one surfactant to reduce thickness unevenness. Examples of surfactants that can be contained include alkyl carboxylates, alkyl phosphates, alkyl sulfonates, fluoroalkyl carboxylates, fluoroalkyl phosphates, fluoroalkyl sulfonates, polyoxyethylene derivatives, fluoroalkylethylene oxide derivatives, polyethylene glycol derivatives, alkyl ammonium salts, and fluoroalkyl ammonium salts, with fluorine-containing surfactants being particularly preferred.

As described above, the thin film of the present invention can be suitably used as an optical thin film, and in particular, since it exhibits retardation, it can be suitably used as a retardation film.
The thin film of the present invention exhibits retardation when irradiated with ultraviolet light. The ultraviolet light may be polarized ultraviolet light or obliquely incident ultraviolet light. In this case, the wavelength of the ultraviolet light is preferably 200 nm or more and 400 nm or less. The irradiation energy amount is preferably 10 mJ/ ^cm2 or more and 10,000 mJ/ ^cm2 or less.
In order to exhibit optical properties, the photoreaction rate of the photoreactive groups of polymers 1 and 2 in the thin film of the present invention is preferably 50% or less. The photoreaction rate can be measured, for example, by the method described in the reference Macromolecules 30, 903, 1997. More specifically, the photoreaction rate can be calculated from the change in the spectrum by measuring the transmission spectrum before and after irradiation with ultraviolet light using a general spectrophotometer.
The thin film of the present invention is further subjected to heat treatment after the ultraviolet irradiation, thereby exhibiting retardation. The heat treatment temperature is preferably within a range in which polymers 1 and 2 exhibit liquid crystallinity, and can be, for example, 50°C or higher and 400°C or lower.
The thin film of the present invention can be used as a retardation film by being irradiated with polarized ultraviolet light or obliquely incident ultraviolet light and then subjected to a heat treatment to develop three-dimensional refractive index anisotropy.

The thin film of the present invention exhibits phase difference and can therefore be used as a retardation film. When used as a retardation film, it may be used as a single film or as a multi-layer film laminated with other films. The film laminated on the thin film of the present invention may be the thin film of the present invention, or may be a polymerizable liquid crystal film, a film, a stretched film, or a sputtered film.

The thin film of the present invention aligns liquid crystal compounds on the film, and can therefore be used as a liquid crystal alignment film.

The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited to these examples.
<Measurement of Nuclear Magnetic Resonance Spectrum>
¹ H-NMR spectra were measured using a nuclear magnetic resonance spectrometer (manufactured by JEOL Ltd., trade name: ECZ 400S).
<Polarized UV irradiation>
Ultraviolet light was irradiated using a mercury light source (manufactured by Asahi Spectroscopy, product name: REX-250) equipped with a bandpass filter (248 nm). When irradiating polarized ultraviolet light, only P-polarized light was irradiated using a polarizing beam splitter of the corresponding wavelength.
<Heat treatment>
The heat treatment was carried out using either a safety oven with a safety door (manufactured by ESPEC, product name: SPH-202 or SPH-102), a hot plate (manufactured by AS ONE, product name: DSHP-1L), or an inert oven with a non-oxidizing atmosphere (manufactured by ESPEC, product name: IPHH-202).

<Measurement of phase difference characteristics>
The retardation characteristics of the retardation film were measured using a sample tilting automatic birefringence meter (manufactured by AXOMETRICS, trade name: AxoScan) with light having a wavelength of 589 nm.
<Thin film thickness measurement>
The thickness of the thin film was measured using a spectroscopic ellipsometer (manufactured by J.A. Woollam, trade name: RC2-U).
<Calculation of photoreaction rate>
The transmission spectrum was measured before and after irradiation with polarized ultraviolet light using a spectrophotometer (manufactured by HITACHI, trade name: U-4100), and the photoreaction rate was calculated from the change in the spectrum.
<Polarizing microscope observation>
The low molecular weight liquid crystal on the thin film was observed using a microscope (Olympus, product name: BX53), a polarizing condenser (Olympus, product name: U-POC-2), and an analyzer (Olympus, product name: U-AN360P-2), and the liquid crystal orientation was observed.

[Synthesis Example 1]
Angew. Chem. Int. Ed. 56(35), 10573, 2017. 4-t-butyldimethylsilyl-coumaric acid (5 g) with a protected phenol moiety, hydroquinone (0.97 g), and 4-dimethylaminopyridine (0.22 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. Dicyclohexanecarbodiimide (4.1 g) was added to the solution, which was then returned to room temperature and allowed to react overnight. The reaction was terminated by adding a methanol solution of oxalic acid, and the solvent was distilled off under reduced pressure.
The residue was redissolved in ethyl acetate, and the insoluble by-product urea derivative was filtered off. The filtrate was washed with aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated under reduced pressure. The filtrate was dissolved in ethyl acetate, passed through a small amount of silica gel column to remove the remaining urea derivative, and again concentrated under reduced pressure to obtain a crude ester. This crude ester was dissolved in THF (100 ml) at room temperature under a nitrogen stream, and tetrabutylammonium fluoride (20 ml) as a deprotecting agent was added. After stirring for one hour, the reaction solution was concentrated under reduced pressure. The residue was redissolved in tetrahydrofuran (THF) and recrystallized from THF/hexane to obtain 4.16 g of Compound 1. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, CD ₃ OD): δ7.79-7.75 (m, 2H), 7.46-7.42 (m, 4H), 7.19 (s, 4H), 6.73-6.68 (m, 4H), 6.43-6.35 (m, 2H).
(Compound 1)

[Synthesis Example 2]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (10 g) with a protected phenol moiety, 2-methylhydroquinone (2.45 g), and 4-dimethylaminopyridine (0.49 g) as a base catalyst were dissolved in dehydrated dichloromethane (150 ml) at 0°C under a nitrogen stream. Dicyclohexanecarbodiimide (9.1 g) was added to the solution, which was then allowed to react overnight after being returned to room temperature. The reaction was terminated by adding a methanol solution of oxalic acid, and the solvent was distilled off under reduced pressure.
The residue was redissolved in THF (100 ml), 2M HCl (30 ml) was added, and the mixture was stirred at room temperature for 4 hours. The reaction mixture was separated into ethyl acetate and aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated under reduced pressure. The residue was recrystallized from ethanol and water to obtain 3.82 g of compound 2. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ CO): δ7.81 (d, J = 16.0Hz, 1H), 7.77 (d, J = 16.0Hz, 1H), 7.65-7.62 (m, 4H), 7.14-7.10 (m, 2H), 7 06-7.03 (m, 1H) 6.92-6.90 (m, 4H), 6.59 (d, J = 16.0Hz, 1H), 6.54 (d, J = 16.0, 1H), 2.18 (s, 3H).
(Compound 2)

[Synthesis Example 3]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (10 g) with a protected phenol moiety, 2-t-butylhydroquinone (3.28 g), and 4-dimethylaminopyridine (0.98 g) as a base catalyst were dissolved in dehydrated dichloromethane (150 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (6.88 g) was added to the solution, which was then allowed to react overnight after being returned to room temperature. The reaction was quenched by adding a methanol solution of oxalic acid, and the solvent was distilled off under reduced pressure.
The residue was redissolved in THF (100 ml), 2M HCl (30 ml) was added, and the mixture was stirred at room temperature for 4 hours. The reaction mixture was separated into ethyl acetate and aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated under reduced pressure. The residue was redissolved in ethanol and recrystallized from ethanol/water to obtain 5.81 g of compound 3. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ CO): δ7.84-7.71 (m, 2H), 7.67-7.59 (m, 4H), 6.96-6.95 (m, 1H), 6.93-6.88 (m, 4H), 6.82-6.81 (m, 2H), 6.68-6.49 (m, 2H), 1.37 (s, 9H).
(Compound 3)

[Synthesis Example 4]
Angew. Chem. Int. Ed. 56(35), 10573, 2017. Using the method described in [translate], phenol-protected 4-t-butyldimethylsilyl-coumaric acid (5 g), tetramethylbiphenol (2.13 g), and 4-dimethylaminopyridine (0.22 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. Dicyclohexanecarbodiimide (4.1 g) was added to the solution, which was then returned to room temperature and allowed to react overnight. The reaction was terminated by adding a methanol solution of oxalic acid, and the solvent was removed under reduced pressure.
The residue was redissolved in ethyl acetate, and the insoluble by-product urea derivative was filtered off. The filtrate was washed with aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated under reduced pressure. The filtrate was dissolved in ethyl acetate, passed through a small amount of silica gel column to remove the remaining urea derivative, and concentrated under reduced pressure again to obtain a crude ester. This crude ester was dissolved in THF (100 ml) at room temperature under a nitrogen stream, and tetrabutylammonium fluoride (20 ml) as a deprotecting agent was added. After stirring for one hour, the reaction solution was concentrated under reduced pressure. The residue was redissolved in THF and recrystallized from THF/hexane to obtain 2.13 g of Compound 4. The results of the ¹ H-NMR spectrum are shown below.
^1H -NMR (400MHz, _CD3 OD): δ7.84-7.74 (m, 2H), 7.59-7.44 (m, 4H), 7.39-7.12 (m, 4H), 6.73-6.68 (m, 4H), 6.49-6.39 (m, 2H), 2.24-2.17 (m, 12H).
(Compound 4)

[Synthesis Example 5]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (8.79 g) with the phenolic moiety protected, cyclohexanediol (cis/trans = 15/85) (2.01 g), and 4-dimethylaminopyridine (0.87 g) as a base catalyst were dissolved in dehydrated dichloromethane (150 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (6.88 g) was added to the solution, which was then allowed to react overnight after being returned to room temperature. The reaction was quenched by adding a methanol solution of oxalic acid, and the solvent was distilled off under reduced pressure.
The residue was redissolved in THF (100 ml), 2M HCl (20 ml) was added, and the mixture was stirred at room temperature for 4 hours. The reaction mixture was partitioned between ethyl acetate and aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated under reduced pressure. The residue was redissolved in ethanol and recrystallized from ethanol/water to obtain 0.7 g of compound 5.
(Compound 5)

[Synthesis Example 6]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (10 g) with a protected phenol moiety, trans-cyclohexanediol (2.29 g), and 4-dimethylaminopyridine (2.5 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (8.49 g) was added to the solution, which was then allowed to react overnight after being returned to room temperature. Water was added to quench the reaction, and the solvent was removed under reduced pressure.
The residue was redissolved in tetrahydrofuran (200 ml), 2N hydrogen chloride (40 ml) was added, and the mixture was stirred at room temperature for two hours. The precipitate was filtered to obtain 6.74 g of compound 6. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ7.53-7.49 (m, 6H), 6.76-6.73 (m, 4H), 6.38-6.31 (m, 2H), 4.79 (brs, 2H), 1.94 (brs, 4H), 1.54 (brs, 4H).
(Compound 6)

[Synthesis Example 7]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-ferulic acid (6.82 g) with a protected phenol moiety, 2-methylhydroquinone (1.52 g), and 4-dimethylaminopyridine (0.60 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (4.18 g) was added to the solution, which was then allowed to react overnight after being returned to room temperature. Water was added to quench the reaction, and the solvent was removed under reduced pressure.
The residue was redissolved in a chloroform/methanol (3/1) mixed solvent (130 ml), p-toluenesulfonic acid (0.12 g) was added, and the mixture was stirred at room temperature for four hours. The reaction solution was separated into chloroform/aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated under reduced pressure. The residue was redissolved in ethanol and recrystallized from ethanol/water to obtain 0.22 g of compound 7. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ): δ7.88-7.79 (m, 4H), 7.20-7.10 (m, 4H), 6.95-6.93 (m, 2H) 6.65-6.49 (m, 3H), 3.94-3.87 (m, 6H), 2.25-2.23 (m, 3H).
(Compound 7)

[Synthesis Example 8]
5.12 g of Compound 8 was obtained by the same method as that described in Japanese Patent No. 4320089. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ9.97-9.22 (br, 7.03 (d, J = 8.7 Hz, 2H), 6.86 (d, J = 8.7 Hz, 2H), 6.58 (d, J = 8.7 Hz, 2H), 6.50 (d, J = 8.7 Hz, 2H), 3.20 (s, 3H).
(Compound 8)

[Synthesis Example 9]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (10 g) with a protected phenol moiety, compound 8 (4.8 g), and 4-dimethylaminopyridine (0.5 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (8.49 g) was added to the solution, and the mixture was allowed to warm to room temperature and react overnight. Water was added to quench the reaction, and the solvent was distilled off under reduced pressure. The resulting solid was purified by silica gel chromatography (chloroform/methanol).
The resulting solid was redissolved in tetrahydrofuran (100 ml), and 2N hydrogen chloride (40 ml) was added, followed by stirring at room temperature for 8 hours. The precipitate was filtered to obtain 12.6 g of Compound 9. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ7.70 (d, J=16.0Hz, 2H), 7.59 (d, J=8.8Hz, 4H), 7.40-7.15 (m, 4H), 7.10- 7.03 (m, 4H), 6.78 (d, J=8.0Hz, 4H), 6.54 (d, J=16.0Hz, 2H), 3.36-3.34 (m, 3H).
(Compound 9)

[Synthesis Example 10]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (20 g) with a protected phenol moiety, 4-N-methylaminophenol sulfate (6.80 g), and 4-dimethylaminopyridine (1.0 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (17.0 g) was added to the solution, which was then returned to room temperature and allowed to react overnight. The reaction was terminated by adding a methanol solution of oxalic acid, and the solvent was distilled off under reduced pressure. The reaction solution was washed with aqueous sodium bicarbonate and dried over sodium sulfate, after which the solvent was distilled off. The residue was purified by silica gel chromatography (chloroform/methanol) to obtain a powder.
The obtained powder was redissolved in tetrahydrofuran (50 ml), 2N hydrogen chloride (20 ml) was added, and the mixture was stirred at room temperature overnight. The reaction solution was filtered to obtain 15.0 g of compound 10. The results of ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ7.77-7.74 (m, 1H), 7.66-7.58 (m, 3H), 7.42-7.34 (m, 3H), 7.26-7.20 (m , 3H), 6.81-6.77 (m, 3H), 6.70-6.68 (m, 2H), 6.63-6.56 (m, 1H), 3.26 (s, 3H).
(Compound 10)

[Synthesis Example 11]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (10 g) with a protected phenol moiety, tetrafluorohydroquinone (3.59 g), and 4-dimethylaminopyridine (0.5 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (8.49 g) was added to the solution, and the mixture was allowed to warm to room temperature and react overnight. Water was added to quench the reaction, and the solvent was distilled off under reduced pressure. The resulting solid was purified by silica gel chromatography (chloroform).
The resulting solid was redissolved in tetrahydrofuran (100 ml), and 2N hydrogen chloride (40 ml) was added, followed by stirring at room temperature for 6 hours. The precipitate was filtered to obtain 8.05 g of compound 11. The results of ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ7.91 (d, J=16.0Hz, 2H), 7.70 (d, J=8.8Hz, 4H), 6.81 (d, J=8.4Hz, 4H), 6.75 (d, J=16.0Hz, 2H).
(Compound 11)

[Synthesis Example 12]
4-Hydroxybenzaldehyde (28 g), methyl cyanoacetate (25 g), and piperidine (2.5 ml) were dissolved in ethanol (200 ml) and heated under reflux for 3 hours under a nitrogen atmosphere. The reaction solution was poured into water, and the precipitate was filtered to obtain a solid.
Using the method described in Chinese Journal of Chemistry, 23, 1523, 2005, the obtained solid phenol-protected tetrahydropyranyl-α-cyanocoumaric acid (11 g), trans-cyclohexanediol (2.29 g), and 4-dimethylaminopyridine (0.5 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (8.49 g) was added to the solution, which was then returned to room temperature and reacted overnight. Water was added to quench the reaction, and the solvent was distilled off under reduced pressure. The resulting solid was purified by silica gel chromatography (chloroform/methanol).
The resulting solid was redissolved in tetrahydrofuran (100 ml), and 2N hydrogen chloride (40 ml) was added, followed by stirring at room temperature overnight. The precipitate was filtered to obtain 3.61 g of compound 12. The results of ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ8.19 (s, 2H), 7.96 (d, J = 8.8Hz, 4H), 6.90 (d, J = 8.4Hz, 4H), 4.98 (s, 2H), 1.98-1.96 (m, 4H), 1.72-1.66 (m, 4H).
(Compound 12)

[Synthesis Example 13]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (10 g) with a protected phenol moiety, piperazine (1.70 g), and 4-dimethylaminopyridine (0.5 g) as a base catalyst were dissolved in dehydrated dichloromethane (100 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (8.49 g) was added to the solution, which was then returned to room temperature and reacted overnight. Water was added to quench the reaction, and the solvent was distilled off under reduced pressure. The resulting solid was washed with water/methanol to obtain a powder.
The obtained powder was redissolved in tetrahydrofuran (200 ml), 2N hydrogen chloride (40 ml) was added, and the mixture was stirred at room temperature for 3 hours. The reaction solution was filtered to obtain 7.44 g of compound 13. The results of ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ7.52 (d, J=8.8, 4H), 7.40 (d, J=15.2Hz, 2H), 7.02 (d, J=15.6Hz, 2H), 6.74 (d, J=8.8Hz, 4H), 5.12 (m, 8H).
(Compound 13)

[Synthesis Example 14]
According to the method described in Chinese Journal of Chemistry, 23, 1523, 2005, tetrahydropyranyl-coumaric acid (20 g) with a protected phenol moiety, 2,3-dimethylhydroquinone (7.42 g), and 4-dimethylaminopyridine (1.97 g) as a base catalyst were dissolved in dehydrated dichloromethane (300 ml) at 0°C under a nitrogen stream. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (18.28 g) was added to the solution, which was then allowed to cool to room temperature and react overnight. Water was added to quench the reaction, and the mixture was extracted with dichloromethane. The dichloromethane was then distilled off to obtain a powder.
The obtained powder, terephthalic acid chloride (0.34 g), and triethylamine (0.37 g) were dissolved in chloroform and stirred at room temperature for 1 hour. The reaction solution was washed with sodium bicarbonate water, and the solvent was then distilled off. The resulting solution was recrystallized from hexane to obtain a solid.
The resulting solid was redissolved in dichloromethane (200 ml), p-toluenesulfonic acid (0.67 g) was added, and the mixture was stirred at room temperature for 3 hours. After the solvent was distilled off, the residue was washed with acetone to obtain 2.96 g of compound 14. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ CO): δ8.42 (s, 4H), 7.83 (d, J=16.0Hz, 2H), 7.65 (d, J=8.4Hz, 4H), 7.16 (d, J=8.8Hz, 2H), 7. 06 (d, J=8.8Hz, 2H), 6.92 (d, J=8.4Hz, 4H), 6.62 (d, J=16.0, 2H), 2.18 (s, 6H), 2.15 (s, 6H).
(Compound 14)

[Synthesis Example 15]
A mixture of 4-methoxy-N-methylaniline (3.00 g, 21.9 mmol), tetrahydrofuran (20 mL), and water (20 mL) was ice-cooled under a nitrogen stream, and then sodium bicarbonate (11 g) was added. While stirring, a solution of terephthaloyl chloride (2.17 g, 10.7 mmol) in tetrahydrofuran (20 mL) was slowly added, and the mixture was stirred for 3 hours under ice-cooling. Water (500 mL) was added to the reaction mixture, and the resulting solid was collected by filtration and washed with 2N hydrochloric acid (200 mL) and methanol (300 mL) to obtain N,N'-bis(4-methoxyphenyl)-N,N'-dimethyl-1,4-benzenedicarboxamide (3.91 g, yield: 90%). The results of the ^1H -NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ7.07 (s, 4H), 6.83 (d, J=8.0 Hz, 4H), 6.67 (d, J=8.0 Hz, 4H), 3.73 (s, 6H), 3.38 (s, 6H).
The N,N'-bis(4-methoxyphenyl)-N,N'-dimethyl-1,4-benzenedicarboxamide (1.00 g, 2.47 mmol) obtained above was dissolved in dichloromethane (25 mL), and then a 1 mol/L solution of boron tribromide in dichloromethane (7.4 mL) was added over 5 minutes under ice-cooling. The reaction system was allowed to warm to room temperature and stirred for 15 hours, and the reaction mixture was added to ice-cooled water (300 mL). The solid formed in the system was collected by filtration and washed with water (500 mL) to obtain compound 15 (776 mg, 83%) as a brown solid. The results of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ SO): δ9.55-9.28 (br, 2H), 6.98 (s, 4H), 6.87-6.67 (m, 4H), 6.58-6.49 (m, 4H), 3.20 (s, 6H).
(Compound 15)

[Synthesis Example 16]
4-(Methylamino)benzoic acid (7.56 g) was dissolved in N-methylpyrrolidone (25 ml) under a nitrogen stream. Terephthalic acid chloride (5.08 g) was added and the mixture was stirred at room temperature for two hours. Water was added to the reaction mixture, which was then filtered. The residue was washed with water/methanol to obtain a solid.
A mixture of the obtained solid and thionyl chloride (20 ml) was stirred under reflux for 3 hours, and thionyl chloride was distilled off to obtain 1.71 g of Compound 16.
(Compound 16)

[Synthesis Example 17]
4-N-methylaminophenol sulfate (8.65 g) was dissolved in a mixed solvent of tetrahydrofuran (50 ml) and water (50 ml) at 0°C under a nitrogen stream. Sodium hydrogen carbonate (20.1 g) and 1,4-cyclohexanedicarboxylic acid chloride (5.0 g) were added, and the mixture was stirred for 1 hour under ice-cooling. Tetrahydrofuran was distilled off, and the precipitate was filtered. The precipitate was washed with 2N hydrogen chloride and methanol to obtain 4.94 g of compound 17.
(Compound 17)

[Synthesis Example 18]
4-Hydroxybenzaldehyde (22.8 g), 4-hydroxyacetophenone (25.4 g), and boron trifluoride diethyl ether complex (catalytic amount) were dissolved in methanol (100 ml) under a nitrogen atmosphere and stirred for 4 hours under reflux. After distilling off the methanol, the mixture was recrystallized from toluene to obtain 45.5 g of Compound 18.
(Compound 18)

[Synthesis Example 19]
A mixture of 1,4-phenylenediacrylic acid (1.3 g) and thionyl chloride (15 ml) was stirred under reflux for 3 hours. After the thionyl chloride was distilled off, the residue was recrystallized from toluene to obtain 1.2 g of Compound 19.
(Compound 19)

[Synthesis Example 20]
4-Formylbenzoic acid (10 g), malonic acid (10.4 g), and piperidine (1.5 ml) as a base catalyst were dissolved in pyridine (50 ml) under a nitrogen stream. The mixture was stirred under reflux for five hours. Water was added to quench the reaction, and 2N hydrogen chloride was added to produce a precipitate. The precipitate was collected by filtration and washed with water/methanol to obtain a solid.
A mixture of the obtained solid (3.1 g) and thionyl chloride (15 ml) was stirred under reflux for 3 hours. After thionyl chloride was distilled off, the residue was recrystallized from toluene to obtain 1.8 g of Compound 20.
(Compound 20)

[Synthesis Example 21]
A mixture of 4-methoxycinnamic acid (25 g), thionyl chloride (50 ml) and a catalytic amount of N,N-dimethylformamide (catalytic amount) was stirred under reflux for 1 hour, and the thionyl chloride was distilled off to obtain a solid.
The obtained solid, 4-methoxyphenol (18.3 g), and triethylamine (14.9 g) were dissolved in tetrahydrofuran (25 ml) under a nitrogen stream and stirred overnight. Water was added to obtain a precipitate.
The resulting precipitate was redissolved in dichloromethane (140 ml), and a 1 mol/L solution of boron tribromide in dichloromethane (46.5 ml) was added. After stirring overnight under a nitrogen atmosphere, the reaction mixture was added dropwise to ice-cold water. The precipitate was collected by filtration and washed with water to obtain 1.65 g of compound 21.
(Compound 21)

[Example 1]
In a three-neck flask equipped with a dropping funnel, 15 ml of water was placed, and 1.4 mmol of compound 1 and 4.0 mmol of sodium hydroxide were dissolved and stirred. 0.8 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the inside of the apparatus was purged with nitrogen. A solution of 1.4 mmol of sebacoyl chloride (compound 22) dissolved in 15 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for 3 hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 1 (yield 70%). 4.0% by mass of polymer 1 was dissolved in 32.0% by mass of pentafluorophenol and 64.0% by mass of chloroform. This was cast onto a quartz substrate, spin-coated at 1500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.9 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate 16.4%) and then heated at 260°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.
(Compound 22)

[Example 2]
30 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 3.0 mmol of compound 2 and 6.0 mmol of sodium hydroxide were dissolved and stirred. 1.2 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.0 mmol of sebacoyl chloride (compound 22) dissolved in 30 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for 3 hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 2 (yield 90%). 3.0 mass % of polymer 2 was dissolved in 97.0 mass % chloroform. This was cast onto a quartz substrate, spin-coated at 1500 rpm for 60 seconds, and dried in an oven at 70°C for 30 minutes to obtain a thin film (film thickness 0.5 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate 19.7%) and then heated at 200°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 3]
A three-neck flask equipped with a dropping funnel was charged with 9.4 ml of water, and 1.9 mmol of compound 2 and 3.8 mmol of sodium hydroxide were dissolved and stirred. 0.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 0.4 mmol of compound 22 and 1.5 mmol of compound 23 dissolved in 9.4 ml of chloroform was transferred to the dropping funnel and added dropwise, followed by stirring at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 3 (yield 82%). 6.0% by mass of polymer 3 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 7000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate 5.4%) and then heated at 240°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.
(Compound 23)

[Example 4]
30 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 3.0 mmol of compound 3 and 6.0 mmol of sodium hydroxide were dissolved and stirred. 1.2 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.0 mmol of sebacoyl chloride (compound 22) dissolved in 30 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for 3 hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 4 (yield 66%). 10.0 mass % of polymer 4 was dissolved in 90.0 mass % chloroform. This was cast onto a quartz substrate, spin-coated at 1500 rpm for 60 seconds, and dried in an oven at 70 °C for 30 minutes to obtain a thin film (film thickness 2.6 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate 15.7%) and then heated at 110°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 5]
A three-neck flask equipped with a dropping funnel was charged with 10 ml of water, and 2.0 mmol of compound 4 and 4.0 mmol of sodium hydroxide were dissolved and stirred. 0.8 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 2.0 mmol of sebacoyl chloride (compound 22) dissolved in 10 ml of dichloromethane was charged to the dropping funnel and added dropwise, followed by stirring at room temperature for 3 hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 5 (yield 92%). 10.0 mass % of polymer 5 was dissolved in 90.0 mass % chloroform. This was cast onto a quartz substrate, spin-coated at 1500 rpm for 60 seconds, and dried in an oven at 70°C for 30 minutes to obtain a thin film (film thickness 0.6 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate 8.5%) and then heated at 240°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 6]
7.5 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 1.5 mmol of compound 5 and 3.0 mmol of sodium hydroxide were dissolved and stirred. 0.6 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 1.5 mmol of sebacoyl chloride (compound 22) dissolved in 7.5 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for 3 hours. The reaction solution was poured into methanol, and the precipitate was filtered and then dried in vacuo to obtain polymer 6 (yield 49%). 3.6% by mass of polymer 6 was dissolved in 32.1% by mass of pentafluorophenol and 64.3% by mass of chloroform. This was cast onto a quartz substrate, spin-coated at 1500 rpm for 60 seconds, and dried in an oven at 70°C for 30 minutes to obtain a thin film. The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate 13.4%) and then heated at 100°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 7]
A three-neck flask equipped with a dropping funnel was charged with 18.5 ml of water, and 0.7 mmol of compound 6, 2.9 mmol of compound 8, and 7.5 mmol of sodium hydroxide were dissolved and stirred. 1.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.7 mmol of compound 22 dissolved in 18.5 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 7 (yield 61%). 6.0% by mass of polymer 7 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 4000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm² (photoreaction rate of 50% or less) and then heated at 190°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 8]
A three-neck flask equipped with a dropping funnel was charged with 18.5 ml of water, and 0.7 mmol of compound 6, 2.9 mmol of compound 8, and 7.5 mmol of sodium hydroxide were dissolved and stirred. 1.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 0.7 mmol of compound 22 and 2.9 mmol of compound 23 dissolved in 18.5 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 8 (yield 83%). 6.0% by mass of polymer 8 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 5000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 9]
A three-neck flask equipped with a dropping funnel was charged with 18.5 ml of water, and 0.4 mmol of compound 6, 3.3 mmol of compound 8, and 7.5 mmol of sodium hydroxide were dissolved and stirred. 1.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.7 mmol of compound 23 dissolved in 18.5 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 9 (yield 88%). 6.0% by mass of polymer 9 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 3000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 10]
A three-neck flask equipped with a dropping funnel was charged with 15.5 ml of water, and 0.6 mmol of compound 6, 2.4 mmol of compound 15, and 6.2 mmol of sodium hydroxide were dissolved and stirred. 1.3 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.1 mmol of compound 23 dissolved in 15.5 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 10 (yield 90%). 5.0% by mass of polymer 10 was dissolved in 95.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 6000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 11]
A three-neck flask equipped with a dropping funnel was charged with 6.0 ml of water, and 1.2 mmol of compound 6 and 2.5 mmol of sodium hydroxide were dissolved and stirred. 0.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 1.2 mmol of compound 16 dissolved in 18.0 ml of chloroform was charged to the dropping funnel, added dropwise, and then stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then dried in vacuo to obtain polymer 11 (yield 96%). 6.0% by mass of polymer 11 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 7000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.8 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 12]
A three-neck flask equipped with a dropping funnel was charged with 13.2 ml of water, and 0.6 mmol of compound 6, 2.0 mmol of compound 8, and 5.3 mmol of sodium hydroxide were dissolved and stirred. 1.1 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 2.1 mmol of compound 23 and 0.5 mmol of compound 16 dissolved in 13.2 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 12 (yield 88%). 6.0% by mass of polymer 12 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 4500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 13]
A three-neck flask equipped with a dropping funnel was charged with 13.2 ml of water, and 0.6 mmol of compound 6, 1.6 mmol of compound 15, and 4.5 mmol of sodium hydroxide were dissolved and stirred. 1.0 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 1.8 mmol of compound 23 and 0.5 mmol of compound 16 dissolved in 11.2 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 13 (yield 82%). 6.0% by mass of polymer 13 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 5000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 14]
A three-neck flask equipped with a dropping funnel was charged with 12 ml of water, and 0.3 mmol of compound 6, 2.2 mmol of compound 17, and 4.8 mmol of sodium hydroxide were dissolved and stirred. 1.0 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 2.4 mmol of compound 23 dissolved in 12 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 14 (yield 73%). 6.0% by mass of polymer 14 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 6500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 15]
2.2 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 0.63 mmol of compound 7 and 0.92 mmol of sodium hydroxide were dissolved and stirred. 0.2 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 0.63 mmol of sebacoyl chloride (compound 22) dissolved in 2.2 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for 3 hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 15 (yield 100%). 7.0% by mass of polymer 15 was dissolved in 93.0% by mass of 1,1,1,3,3,3-hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 2500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (film thickness 0.9 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 5000 mJ/ ^cm2 (photoreaction rate 8.7%) and then heated at 150°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 16]
A three-neck flask equipped with a dropping funnel was charged with 14 ml of water, and 0.6 mmol of compound 9, 2.2 mmol of compound 8, and 5.6 mmol of sodium hydroxide were dissolved and stirred. 1.1 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 2.8 mmol of compound 23 dissolved in 14 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 16 (yield 91%). 6.0% by mass of polymer 16 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 4000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 17]
A three-neck flask equipped with a dropping funnel was charged with 12 ml of water, and 2.4 mmol of compound 9 and 4.8 mmol of sodium hydroxide were dissolved and stirred. 0.9 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 2.4 mmol of compound 23 dissolved in 12 ml of chloroform was charged to the dropping funnel, added dropwise, and then stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then dried in vacuo to obtain polymer 17 (yield 90%). 6.0% by mass of polymer 17 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 6000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 18]
A three-neck flask equipped with a dropping funnel was charged with 11.4 ml of water, and 2.2 mmol of compound 10 and 4.4 mmol of sodium hydroxide were dissolved and stirred. 0.6 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 2.2 mmol of compound 22 dissolved in 11.4 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 18 (yield 63%). 6.0% by mass of polymer 18 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 3000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 100°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 19]
A three-neck flask equipped with a dropping funnel was charged with 10 ml of water, and 1.9 mmol of compound 10 and 3.8 mmol of sodium hydroxide were dissolved and stirred. 0.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the inside of the apparatus was purged with nitrogen. A solution of 0.4 mmol of compound 22 and 1.5 mmol of compound 23 dissolved in 10 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then dried in vacuo to obtain polymer 19 (yield 71%). 6.0% by mass of polymer 19 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 3000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 20]
A three-neck flask equipped with a dropping funnel was charged with 10 ml of water, and 1.9 mmol of compound 10 and 3.8 mmol of sodium hydroxide were dissolved and stirred. 0.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the inside of the apparatus was purged with nitrogen. A solution of 1.9 mmol of compound 23 dissolved in 10 ml of chloroform was charged to the dropping funnel, added dropwise, and then stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then dried in vacuo to obtain polymer 20 (yield 76%). 6.0% by mass of polymer 20 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 4000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate 0.6%) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 21]
A three-neck flask equipped with a dropping funnel was charged with 16 ml of water, and 0.3 mmol of compound 11, 2.8 mmol of compound 8, and 6.4 mmol of sodium hydroxide were dissolved and stirred. 1.3 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.2 mmol of compound 23 dissolved in 16 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then dried in vacuo to obtain polymer 21 (yield 86%). 6.0% by mass of polymer 21 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 5000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 22]
30.0 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 0.6 mmol of compound 12, 2.4 mmol of compound 8, and 12.0 mmol of sodium hydroxide were dissolved and stirred. 2.4 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.0 mmol of compound 23 dissolved in 30.0 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then dried in vacuo to obtain polymer 22 (yield 55%). 6.0% by mass of polymer 22 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 2000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 210°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 23]
30.0 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 0.6 mmol of compound 13, 2.4 mmol of compound 8, and 12.0 mmol of sodium hydroxide were dissolved and stirred. 2.4 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.0 mmol of compound 23 dissolved in 30.0 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 23 (yield 73%). 6.0% by mass of polymer 23 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 3000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 24]
A three-neck flask equipped with a dropping funnel was charged with 16.8 ml of water, and 2.1 mmol of compound 14 and 4.2 mmol of sodium hydroxide were dissolved and stirred. 1.3 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the inside of the apparatus was purged with nitrogen. A solution of 2.1 mmol of compound 22 dissolved in 16.8 ml of dichloromethane was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 24 (yield 90%). 6.0 wt % of polymer 24 was dissolved in 31.3 wt % pentafluorophenol and 62.6 wt % chloroform. This was cast onto a quartz substrate, spin-coated at 4000 rpm for 60 seconds, and dried in an oven at 150 °C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 260°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 25]
30.0 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 0.6 mmol of compound 18, 2.4 mmol of compound 8, and 12.0 mmol of sodium hydroxide were dissolved and stirred. 2.4 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.0 mmol of compound 23 dissolved in 30.0 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 25 (yield 49%). 6.0% by mass of polymer 25 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 2500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 26]
A three-neck flask equipped with a dropping funnel was charged with 100 ml of water, and 5 mmol of compound 18 and 20 mmol of sodium hydroxide were dissolved and stirred. 4 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the inside of the apparatus was purged with nitrogen. A solution of 5 mmol of compound 22 dissolved in 50 ml of dichloromethane was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 26 (yield 23%). 10.0% by mass of polymer 26 was dissolved in 90.0% by mass of tetrahydrofuran. This was cast onto a quartz substrate, spin-coated at 1500 rpm for 60 seconds, and dried in an oven at 80°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 100°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 27]
A three-neck flask equipped with a dropping funnel was charged with 11 ml of water, and 2.2 mmol of compound 8 and 4.4 mmol of sodium hydroxide were dissolved and stirred. 0.9 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 2.2 mmol of compound 19 dissolved in 22 ml of chloroform was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 27 (yield 91%). 6.0% by mass of polymer 27 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 3000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate 0.6%) and then heated at 300°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 28]
A three-neck flask equipped with a dropping funnel was charged with 14 ml of water, and 2.8 mmol of compound 8 and 5.7 mmol of sodium hydroxide were dissolved and stirred. 1.1 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the inside of the apparatus was purged with nitrogen. A solution of 2.8 mmol of compound 20 dissolved in 28 ml of chloroform was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 28 (yield 94%). 6.0% by mass of polymer 28 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 4500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 29]
30.0 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 0.6 mmol of compound 21, 2.4 mmol of compound 8, and 12.0 mmol of sodium hydroxide were dissolved and stirred. 2.4 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.0 mmol of compound 23 dissolved in 30.0 ml of chloroform was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 29 (yield 38%). 6.0% by mass of polymer 29 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 2500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.

[Example 30]
A three-neck flask equipped with a dropping funnel was charged with 16.5 ml of water, and 3.3 mmol of compound 8 and 6.6 mmol of sodium hydroxide were dissolved and stirred. 1.4 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 3.3 mmol of compound 24 dissolved in 16.5 ml of chloroform was charged to the dropping funnel, added dropwise, and then stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 30 (yield 92%). 6.0% by mass of polymer 30 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 3000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/ ^cm2 (photoreaction rate of 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited. The retardation is shown in Table 1.
(Compound 24)

[Example 31]
6.0% by mass of polymer 3 was dissolved in 94.0% by mass of hexafluoro-2-propanol. This solution was cast onto a quartz substrate, spin-coated at 7000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 1.0 μm). The obtained thin film was irradiated with 248 nm ultraviolet light at an incident angle of 60° at 500 mJ/ ^cm2 (photoreaction rate 50% or less), and then heated at 250°C, whereupon a high retardation was exhibited. The retardation values are shown in Table 1.

[Comparative Example 1]
A three-neck flask equipped with a dropping funnel was charged with 6.8 ml of water, and 1.4 mmol of compound 1 and 2.7 mmol of sodium hydroxide were dissolved and stirred. 0.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 1.4 mmol of 4,4'-biphenyldicarbonyl chloride dissolved in 6.8 ml of dichloromethane was added dropwise to the dropping funnel, followed by stirring at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 1' (yield: 54%). 4.7% by mass of polymer 1' was dissolved in 31.8% by mass of pentafluorophenol and 63.5% by mass of chloroform. This was cast onto a quartz substrate, spin-coated at 1500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film. The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/cm ² and then heated at 350° C., but no high retardation was observed. The retardation is shown in Table 1.

[Comparative Example 2]
A three-necked flask equipped with a dropping funnel was charged with 6.5 ml of water, and 1.3 mmol of compound 15 and 2.6 mmol of sodium hydroxide were dissolved and stirred. 0.5 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 1.3 mmol of terephthaloyl chloride dissolved in 6.5 ml of dichloromethane was added dropwise to the dropping funnel, and the mixture was stirred at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 2' (yield 99%). 3.0% by mass of polymer 2' was dissolved in 97.0% by mass of chloroform. This was cast onto a quartz substrate, spin-coated at 7000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film. The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/cm ² and then heated at 250° C., but no high retardation was exhibited. The retardation is shown in Table 1.

[Comparative Example 3]
50 ml of water was placed in a three-neck flask equipped with a dropping funnel, and 10.0 mmol of 4,4'-dihydroxybiphenyl and 20.0 mmol of sodium hydroxide were dissolved and stirred. 4.0 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 10.0 mmol of sebacoyl chloride (compound 22) dissolved in 50 ml of dichloromethane was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for 3 hours. The reaction solution was poured into methanol, and the precipitate was filtered and then vacuum dried to obtain polymer 3' (yield 94%). 2.5% by mass of polymer 3' was dissolved in 32.5% by mass of pentafluorophenol and 65.0% by mass of chloroform. This was cast onto a quartz substrate, spin-coated at 1500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film. The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/cm ² and then heated at 200° C., but no high retardation was exhibited. The retardation is shown in Table 1.

[Comparative Example 4]
A three-neck flask equipped with a dropping funnel was charged with 11 ml of water, and 2.2 mmol of hydroquinone and 4.5 mmol of sodium hydroxide were dissolved and stirred. 0.9 ml of a 2.0 wt % aqueous solution of tetra-n-butylammonium bromide was added as a catalyst, and the atmosphere inside the apparatus was replaced with nitrogen. A solution of 2.2 mmol of compound 19 dissolved in 11 ml of chloroform was placed in the dropping funnel and added dropwise, followed by stirring at room temperature for three hours. The reaction solution was poured into methanol, and the precipitate was filtered and then dried in vacuo to obtain polymer 4' (yield 86%). 6.0% by mass of polymer 4' was dissolved in 94.0% by mass of hexafluoro-2-propanol. This was cast onto a quartz substrate, spin-coated at 7000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film. The obtained thin film was irradiated with 248 nm polarized ultraviolet light at 1000 mJ/cm ² and then heated at 250° C., but no high retardation was exhibited. The retardation is shown in Table 1.

As is clear from Table 1, the polymers of Examples 1 to 31 were confirmed to exhibit unexpected retardation Re upon irradiation with polarized UV light or obliquely incident UV light and heat treatment. The unique performance of the polymers of the present application becomes even more apparent when compared with Comparative Examples 1 to 4.

[Example 32]
3.5% by mass of polymer 10 was dissolved in 96.5% by mass of hexafluoro-2-propanol. This solution was cast onto a quartz substrate, spin-coated at 4500 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 0.5 μm). The obtained thin film was irradiated with 500 mJ/ ^cm2 of polarized ultraviolet light at 248 nm (photoreaction rate 50% or less) and then heated at 250°C, whereupon a high retardation was observed.
Using two 25 μm thick PET films (manufactured by Toray Industries, product name: Lumirror(R) T60) cut to 1.5 mm x 20 mm as spacers, two quartz plates with the thin film laminated thereon were stacked so that the thin film was facing inward and the direction of irradiation with polarized UV light was parallel. The quartz plates were then bonded with instant adhesive (manufactured by Toagosei, Aron Alpha 201) around the periphery, excluding the liquid crystal injection area, to form an empty liquid crystal cell. After bonding, 4-cyano-4'-pentylbiphenyl heated to 50°C was injected into the empty liquid crystal cell to form a liquid crystal cell. The resulting liquid crystal cell was observed using a polarizing microscope in three directions, with the polarizer angle at 0°, 45°, and 90° relative to the direction of irradiation of the thin film with polarized UV light. The microscope image changed from dark to light to dark, confirming that the liquid crystal directors were uniformly aligned.
In this specification, the liquid crystal director refers to a vector of the direction in which the major axes of liquid crystal molecules are aligned (main alignment axis).

[Example 33]
4.2% by mass of polymer 27 was dissolved in 95.8% by mass of hexafluoro-2-propanol. This solution was cast onto a quartz substrate, spin-coated at 4000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 0.5 μm). The obtained thin film was irradiated with 500 mJ/ ^cm2 of polarized ultraviolet light at 248 nm (photoreaction rate 50% or less) and then heated at 250°C, whereupon a high retardation was exhibited.
Using two 25 μm thick PET films (manufactured by Toray Industries, product name: Lumirror(R) T60) cut to 1.5 mm x 20 mm as spacers, two quartz plates with the thin film laminated thereon were stacked so that the thin film was facing inward and the direction of irradiation with polarized UV light was parallel. The quartz plates were then bonded with instant adhesive (manufactured by Toagosei, Aron Alpha 201) around the periphery, excluding the liquid crystal injection area, to form an empty liquid crystal cell. After bonding, 4-cyano-4'-pentylbiphenyl heated to 50°C was injected into the empty liquid crystal cell to form a liquid crystal cell. The resulting liquid crystal cell was observed using a polarizing microscope in three directions, with the polarizer angle at 0°, 45°, and 90° relative to the direction of irradiation of the thin film with polarized UV light. The microscope image changed from dark to light to dark, confirming that the liquid crystal directors were uniformly aligned.

[Comparative Example 5]
A 10.0% by weight solution of methyl methacrylate polymer was dissolved in 90.0% by weight of toluene. The solution was cast onto a quartz substrate, spin-coated at 5000 rpm for 60 seconds, and dried in an oven at 150°C for 30 minutes to obtain a thin film (thickness 0.5 μm). The resulting thin film was irradiated with 248 nm polarized ultraviolet light at 500 mJ/ ^cm2 and then heated at 250°C, but no high retardation was observed.
Using two 25 μm thick PET films (manufactured by Toray Industries, product name: Lumirror(R) T60) cut to 1.5 mm x 20 mm as spacers, two quartz plates with the thin film laminated thereon were stacked so that the thin film was facing inward and the direction of irradiation with polarized UV light was parallel. The quartz plates were then bonded with instant adhesive (manufactured by Toagosei, Aron Alpha 201) around the periphery, excluding the liquid crystal injection area, to form an empty liquid crystal cell. After bonding, 4-cyano-4'-pentylbiphenyl heated to 50°C was injected into the empty liquid crystal cell to form a liquid crystal cell. The resulting liquid crystal cell was observed using a polarizing microscope in three directions, with the polarizer angled at 0°, 45°, and 90° relative to the direction of irradiation of the thin film with polarized UV light. The microscope image remained bright at all times, confirming that the liquid crystal directors were not uniformly aligned.

It was confirmed that the polymers of Examples 32 and 33 were capable of aligning liquid crystal compounds by irradiation with ultraviolet light and heat treatment.

Claims (5)

A polymer having a structural unit A represented by the following formula (2), and having at least one of a structural unit B represented by the following formula (3) or a structural unit C represented by the following formula (4).
In formula (2), X ₁ to X ₃ each independently represent a benzene ring which may have a substituent. Here, the substituents in X ₁ to X ₃ each independently represent one kind of the group consisting of a halogen atom and a methyl group, and when X ₁ to X ₃ do not have a substituent, they are hydrogen atoms. Y ₃ and Y ₄ represent —O—. _{Ar 1} and Ar ₂ each independently represent a benzene ring which does not have a substituent.
R ₁ to R ₄ each independently represent a hydrogen atom or a cyano group. _{L 1} and L ₄ represent a -O- or -NR ₅ - group. R ₅ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. L ₂ and L ₃ represent a single bond or a -CO-O- or -CO-NR ₆ - group.
Here, _R6 represents a hydrogen atom or one of the group consisting of alkyl groups having 1 to 5 carbon atoms. a and b each independently represent 0 or 1.
(In formula (3), _Y5 and _Y6 each independently represent a group consisting of —O—, —CO—, and —NR ₁₀ —. Here, R ₁₀ represents a hydrogen atom or a group consisting of an alkyl group having 1 to 5 carbon atoms. _X4 to _X6 each independently represent an aromatic ring having 5 to 7 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 5 to 7 carbon atoms which may have a substituent, and any carbon atom in the aromatic ring or the alicyclic hydrocarbon group may be substituted with a nitrogen atom, an oxygen atom, or a sulfur atom. R ₁₁ and R ₁₂ each independently represent a hydrogen atom or a group consisting of an alkyl group having 1 to 5 carbon atoms. c represents 0 or 1.)
(In formula (4), _Y7 and _Y8 each independently represent one selected from the group consisting of -O-, -CO-, and _-NR13- . Here, _R13 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Z represents one selected from the group consisting of an alicyclic hydrocarbon group having 5 to 7 carbon atoms, a linear alkylene group having 2 to 20 carbon atoms, and a branched alkylene group having 4 to 20 carbon atoms.) The polymer according to claim 1, having a structural unit A represented by formula (2) and a structural unit B represented by formula (3). An optical thin film comprising the polymer described in claim 1 or claim 2. A retardation film comprising the thin film described in claim 3. A liquid crystal alignment film comprising the thin film described in claim 3.