JPH0892324A - Liquid crystal polymer and method for producing the same - Google Patents

Abstract

(57) [Summary] [Purpose] Electron-donating carbazole ring-containing (meth)
Provided is a liquid crystal polymer obtained by copolymerizing an acrylate and an electron-accepting (meth) acrylate. A liquid crystal polymer obtained by copolymerizing a carbazole ring-containing (meth) acrylate represented by the following general formula (I) and a (meth) acrylate represented by the following general formula (II).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel liquid crystal polymer obtained by copolymerizing an electron-donating carbazole ring-containing (meth) acrylate with an electron-accepting (meth) acrylate, and more specifically, a non-linear optical material. , A liquid crystal polymer having useful properties as a memory material, a photoconductive material, a high refractive index material and the like.

[0002]

2. Description of the Related Art Conventionally, studies have been conducted to form a stable liquid crystal by mixing an electron-donating (donor) low-molecular liquid crystal and an electron-accepting (acceptor) low-molecular liquid crystal. Furthermore, in recent years, attempts have been made to form a stable liquid crystal polymer by charge transfer interaction by copolymerizing the above polymerizable liquid crystal compound.

[0003]

The above-mentioned electron-donating liquid crystal compounds which have been studied so far are all compounds having a methoxyphenyl group or a dimethylaminophenyl group as an electron-donating group. As a result of examining electron-donating groups other than the above, the present inventors have found that a compound having a carbazole ring also forms a stable liquid crystal polymer. As a result of further studies, by copolymerizing an electron-donating (meth) acrylate having a carbazole ring and an electron-accepting (meth) acrylate, a liquid crystal that cannot be predicted from each homopolymer (homopolymer). It was found that a polymer was obtained. An object of the present invention is to provide a novel liquid crystal polymer.

[0004]

According to the present invention, there is provided a liquid crystal polymer represented by the following general formula (A). R ₁ or R ₄ is hydrogen or a methyl group, R ₂ or R ₅ is an alkylene group which may have a branched chain having 2 to 15 carbon atoms, R ₆ is a nitro group or a cyano group, and R ₃ is Hydrogen, a methyl group, an ethyl group or a phenyl group, X is none, -CH = CH-, -N = CH-, -CH = N, -C
OO- or -OCO-, y and 1-y represent the mole fraction of each repeating unit. )

Further, according to the present invention, there is provided a method for producing a liquid crystal polymer, which comprises copolymerizing monomers represented by the following general formulas (I) and (II). (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and X have the same meanings as described above.)

[0006]

[Function] By copolymerizing a carbazole ring-containing (meth) acrylate, which is an electron-donating liquid crystal compound, and a (meth) acrylate, which is an electron-accepting liquid crystal compound, a stable liquid crystal compound that does not cause phase separation between the two compounds ( Polymer) can be formed. This liquid crystal polymer is a liquid crystal polymer having properties useful as a photoconductive material, a high refractive index material, a non-linear optical material, etc. by the action of the contained carbazole ring. Further, the liquid crystal polymer of the present invention is a liquid crystal having a high thermal stability since the temperature range usable as the liquid crystal is widened due to the presence of the carbazole ring. Further, it can induce a smectic phase, so that it is also useful as a memory material.

The first monomer constituting the liquid crystal polymer of the present invention is an electron-donating carbazole ring-containing (meth) acrylate represented by the above general formula (I). The carbazole ring-containing (meth) acrylate can be synthesized, for example, by the following method. (I) 2-nitro-biphenyl is used as a starting material to synthesize 9-methyl-2-carbazolylcarboxaldehyde. (Ii) Using p-nitrophenol as a starting material, 4 (6
-Hydroxyalkoxy) aniline is synthesized. (Iii) reacting the compounds synthesized in (i) and (ii) to give 4 (6-hydroxyalkoxy) -N- (9
-Methyl-2-carbazolylmethylene) aniline is synthesized. 4 (6- (meth) acryloyloxyalkyloxy] -N- (9-methyl-2-carbazolylmethylene), which is obtained by reacting the compound of (iv) and (iii) with a (meth) acrylic acid halide. ) Synthesize aniline.

The second monomer constituting the liquid crystal polymer of the present invention is the electron-accepting (meth) acrylate represented by the above general formula (II). This second monomer can be synthesized, for example, by the following method. (A) The 4 (6-hydroxyalkoxy) aniline synthesized in (ii) above is reacted with 4-substituted-benzaldehyde (substituent is a nitro group or a cyano group).

The reaction product of (4) is reacted with a (meth) acrylic acid halide to synthesize the desired 4 [6- (meth) acryloyloxyalkoxy] -N-[(substituted) -benzylidene] aniline. (B) 4-nitro-phenylacetic acid and 4-hydroxy-
4-hydroxy-4'-reacted with benzaldehyde
Synthesize nitrosostilbene. 4- [6- (hydroxyalkyl) oxy]-by reacting the reaction product of
4'-nitrosostilbene is synthesized. The desired 4-[[6- (acryloyloxy or methacryloyloxy) alkyl] oxy] -4'-nitrosostilbene is synthesized by reacting the reaction product of (1) with a (meth) acrylic acid halide.

(C) 4-Nitroaniline is converted to a diazonium salt and reacted with phenol. 4-hydroxy-4'-nitrosobenzene obtained in Step 4 was reacted with a hydroxyalkyl halide to give 4-
[6- (Hydroxyalkyl) oxy] -4'-nitroazobenzene is synthesized. The desired 4-[[6- (acryloyloxy or methacryloyloxy) alkyl] oxy] -4'-nitroazobenzene is synthesized by reacting the reaction product of (1) with a (meth) acrylic acid halide. (D) Hydroxyalkyl halide and 4-hydroxy-benzoic acid are reacted to synthesize 4-hydroxyalkyleneoxy-benzoic acid.

The product of (4) is reacted with (meth) acrylic acid to give 4-[[6- (acryloyloxy or methacryloyloxy) alkyl] oxy] -benzoic acid. The desired 4-[[6- (acryloyloxy or methacryloyloxy) alkyl] oxy] -4'-phenylbenzoic acid is synthesized by reacting the reaction product of (1) with nitrophenol.

The liquid crystal polymer of the present invention can be obtained by copolymerizing the monomers represented by the above general formulas (I) and (II). Polymerization is usually carried out using dimethylformamide (DMF), benzene, toluene,
Chloroform, chlorobenzene, tetrahydrofuran,
Known compounds such as azobis compounds such as azobisisobutyronitrile, persulfates such as potassium persulfate, and organic peroxides such as benzoyl peroxide are used in a solvent that dissolves these monomers such as 1,4-dioxane. It is carried out using a radical polymerization initiator. The polymerization solvent is not limited to the above examples, and any solvent that is inert to the polymerization initiator and dissolves the monomer can be used. The polymerization temperature is also not particularly limited and is usually in the range of room temperature to 100 ° C. The molecular weight of the liquid crystal polymer can be varied over a wide range by optionally using a polymerization temperature, a polymerization time, or a chain transfer agent conventionally used in radical polymerization.

The preferable molar fraction (y) of the monomer represented by the above formula (I) in the liquid crystal polymer is 0.01 to 0.
99. The number average molecular weight of the liquid crystal polymer (in terms of standard polystyrene measured by GPC) is 1,000 to 1.0.
It is 0,000. A liquid crystal polymer having an optimum molecular weight is prepared according to the purpose of use.

[0014]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Monomer Production Example 1 Carbazole ring-containing monomer 4-[[6- (methacryloyloxy) hexyl] oxy] -N-[(9-
Methyl-2-carbazolyl) methylene] aniline (M6
(Abbreviated as Cz) was produced according to Example 1 of Japanese Patent Application No. 4-151198.

[0015] Monomer a is 4 monomeric Production Example 2 Formula (II) - [[6- (methacryloyloxy) hexyl] oxy]-N-(4'-nitro-benzylidene) aniline (abbreviated as M6NO ₂₎
Was synthesized by the following method. (1) 4- [6- (hydroxyhexyl) oxy] ani
Synthesis of phosphorus 4-nitrophenol (19.4 g, 0.14 mol) and KOH in 300 ml of ethanol / water (1/1) mixture.
6-chlorohexanol (0.17 mol) in a solution containing
Was added dropwise, and the mixture was reacted under reflux for 48 hours. Generated 4-
[6- (Hydroxyhexyl) oxy] nitrobenzene (0.07 mol) was reduced with anhydrous sodium sulfide (0.14 mol) in an aqueous 50% ethanol solution under reflux for 20 hours to give 4- [6- (hydroxyhexyl)]. Oxy] aniline was obtained. (2) 4- [6- (hydroxyhexyl) oxy] -N
Synthesis of-(4'-nitrobenzylidene) aniline 4- [6- (hydroxyhexyl) oxy] aniline (0.03 mol) and 4-nitrobenzaldehyde (0.
(03 mol) was heated at 70 ° C. for 1 hour. The crystals were recrystallized from ethanol and purified to obtain the title compound. (3) 4-[[6- (methacryloyloxy) hexyl
]] Oxy] -N- (4'-nitrobenzylidene) ani
Phosphorus synthesis chloroform 150ml of (M6NO ₂ and abbreviated) 4- [6- (hydroxymethyl) oxy]-N-(4'-nitro-benzylidene) aniline (0.03 mol) and triethylamine (0.15
To a solution of methacrylic acid chloride (0.1 mol) in 50 ml of chloroform.
After adding at 0 ° C., the mixture was reacted at room temperature for 12 hours to obtain the title monomer.

Monomer Production Examples 3 and 4 4-[[6- (methacryloyloxy) hexyl] oxy] -N- (4'-cyanobenzylidene) aniline (abbreviated as M6CN) which is a monomer of the formula (II) and 4-[[6- (methacryloyloxy) hexyl] oxy] -N- (4'-methoxybenzylidene) aniline (abbreviated as M6OMe) used in Comparative Example was prepared from 4-nitro of (2) in Monomer Production Example 2. It was prepared in the same manner as in Preparation Example 2 except that benzaldehyde was replaced with 4-methoxybenzaldehyde or 4-cyanobenzaldehyde and the reaction was carried out, and these products were used in (3).

[0017] Example 1 (M6Cz / M6NO preparation of ₂ copolymer) 4 in glass polymerization tube test tube-like - [[6- (methacryloyloxy) hexyl] oxy] -N - [(9-methyl-2 -Carbazolyl) methylene] aniline (M6Cz)
And 4-[[6- (methacryloyloxy) hexyl] oxy-N- (4'-nitrobenzylidene) aniline (M
6NO ₂ and abbreviated) and 50/50 (mixture azobisisobutyronitrile (AIBN) 3 mole dissolved in benzene (solid content 30 wt% of the molar ratio)), degassing, after sealed, Polymerization was carried out at 70 ° C. for 20 hours (Polymer No.
4). Similarly, the charging ratio of M6Cz / M6NO ₂ was 15/85, 30/70, 60/40, 70/30, 8
Polymerization was carried out by changing it to 0/20, 100/0, 100/0. After completion of the polymerization, the content of the polymerization tube was dropped into ether to coagulate the produced polymer, and the polymer was dried under reduced pressure.

Each of the obtained polymers was dissolved in deuterated chloroform and analyzed by ¹ H-NMR (400 MHz) (Omega 400WB NMR manufactured by GE). The intensity of the peak (2) of 3.61 ppm derived from the methyl group proton of M6Cz methylcarbazolyl in the obtained spectrum and 0.94 derived from the methyl group proton of the nitrobenzylidene methacrylate of M6Cz and M6NO _2. The ratio of both monomers in the polymer was determined from the intensity ratio of the peak (1) of 1.29 ppm. Polymer No. The NMR spectrum of 4 is shown in FIG. or,
The phase transition temperature of each polymer was determined by DSC (DSC7 manufactured by Perkin Elmer) (cooling and heating rate 10 ° C./min). First, the temperature of the polymer was raised to around 200 ° C., cooled to around 0 ° C., and then measured again under the condition of raising the temperature. Table 1 shows the above results. Furthermore, the phase transition is performed by a polarization microscope (BHS-751 manufactured by Olympus Optical Co., Ltd.) in which a hot stage (FP80HT manufactured by METTLER; control unit: FP82HT manufactured by METTLER) is installed.
It confirmed by observing with P). The relationship between the composition ratio of the polymer and the phase transition temperature is shown in FIG.

[0019]

[Table 1] Note) g: Glass phase N: Nematic phase S: Smectic phase I: Isotropic phase

Comparative Example 1 (Production of M6Cz / M6OMe Copolymer) A test tube-like glass polymerization tube was provided with 4-[[6- (methacryloyloxy) hexyl] oxy] -N-[(9-methyl-2- Carbazolyl) methylene] aniline (M6Cz)
50-50 (molar ratio) mixture of 4-[[6- (methacryloyloxy) hexyl] oxy] -N- (4'-methoxybenzylidene) aniline (M6OMe) and azobisisobutyronitrile (AIBN) After dissolving 3 mol in benzene (solid content 30% by weight), degassing and sealing the tube,
Polymerization was carried out at 70 ° C. for 20 hours (Polymer No. 11).
Similarly, the charge ratio of M6Cz / M6OMe is 25 /
Polymerization was carried out by changing to 75, 75/25, 100/0, 100/0. After completion of the polymerization, the content of the polymerization tube was dropped into ether to coagulate the produced polymer, and the polymer was dried under reduced pressure.

Each of the obtained polymers was dissolved in deuterated chloroform and analyzed by ¹ H-NMR (400 MHz) (Omega 400WB NMR manufactured by GE). In the obtained spectrum, -N of M6Cz methylcarbazolyl
= The intensity of the peak (3) at 8.46 ppm derived from the CH-proton and the methoxybenzylidene-at M6OMe
The ratio of both monomers in the polymer was determined from the intensity ratio of the peak (4) at 8.20 ppm derived from the N = CH-proton. Polymer No. The NMR spectrum of 11 is shown in FIG. In the same manner as in Example 1, the phase transition temperature of each polymer obtained was determined by DSC. The above results are shown in Table 2, and the relationship between the composition ratio of the polymer and the phase transition temperature is shown in FIG.

[0022]

[Table 2] Note) g: glass phase N: nematic phase I: isotropic phase

Example 2 (Production of M6Cz / M6CN Copolymer) In the same manner as in Example 1, 4-[[6- (methacryloyloxy) hexyl] oxy] -N-[(9-methyl-2
-Carbazolyl) methylene] aniline (M6Cz) / 4
-[[6- (methacryloyloxy) hexyl] oxy] -N- (4'-cyanobenzylidene) aniline (M
A polymer of 6OCN) = 44/64 was obtained (composition ratio was determined in the same manner as in Example 1). Similarly, M6Cz
/ M6CN charge ratio 15/85, 30/70, 6
Polymerization was carried out by changing to 0/40, 70/30, 85/15 and 100/0. After completion of the polymerization, the content of the polymerization tube was dropped into ether to coagulate the produced polymer, and the polymer was dried under reduced pressure. The phase transition temperature of each of the obtained polymers was determined in the same manner as in Example 1. The relationship between the composition ratio and the phase transition temperature is shown in Table 3 and FIG.

[Table 3]

Example 3 (Production of M6Cz / MnNO ₂ Copolymer) In the same manner as in Example 1, 4-[[6- (methacryloyloxy) hexyl] oxy] -N-[(9-methyl-2
-Carbazolyl) methylene] aniline (abbreviated as M6Cz) and the carbon number (n) of the alkylene chain is 2 to 6 and 11
Of 4-[[6- (methacryloyloxy) alkylene (having a carbon number of n)] oxy] N- (4'-nitrobenzylidene) aniline (abbreviated as MnNO ₂ ) in Table 4 A polymer having a composition ratio (the composition ratio was in accordance with the method of Example 1) was obtained. MnNO ₂ with different n was produced by changing 6-chlorohexanol of (1) of Monomer Production Example 2 to a predetermined n of ω-hydroxyalkyl halide (n = 2, 3, 5, 11). When n = 4, a protective group was added as described below for synthesis. 4-Chlorobutane and 3,4-dihydro-2-pyran were reacted to obtain 4-tetrahydro-2-pyranyloxy) -1-chlorobutane. This was reacted with p-nitrophenol in the presence of KOH to give 4-
[(4-Tetrahydro-2-pyranoxy-butyl) oxy] nitrobenzene was obtained. Treatment with sulfuric acid removed the protecting group to give 4-[(4-hydroxybutyl) oxy] nitrobenzene. Hereinafter, M4NO ₂ was obtained in the same manner as in Monomer Production Example 2. Table 4 shows the phase transition temperatures of the obtained liquid crystal polymers. The relationship between n of MnNO ₂ and the phase transition temperature is shown in FIG.

[0025]

[Table 4] Note) g: Glass phase N: Nematic phase S: Smectic phase I: Isotropic phase

Example 4 (Production of A3Cz / MnNO ₂ Copolymer) In the same manner as in Example 1, 4-[[3- (acryloyloxy) propyl] oxy] -N-[(9-methyl-2-
Carbazolyl) methylene] aniline (abbreviated as A3Cz) and 4-[[6- (methacryloyloxy) alkylene (having n carbon atoms)] oxy] -N- whose alkylene chain has 2 to 6 and 11 carbon atoms (n). (4'-nitrobenzylidene) by copolymerizing a respective aniline (abbreviated as MnNO ₂₎ to obtain a liquid crystal polymer composition ratio described in Table 5. still,
A3Cz was synthesized in Monomer Production Example 1 by replacing 6-chlorohexanol with 3-chloropropanol and methacrylic acid chloride with acrylic acid chloride. The composition ratio of the monomer in the liquid crystal polymer was determined by the same method as in Example 1. Table 5 shows the phase transition temperatures of the liquid crystal polymers.
The relationship between n of MnNO ₂ and the phase transition temperature is shown in FIG.
FIG. 7 shows the relationship between the composition ratio and the phase transition temperature in the Cz / M3NO ₂ copolymer.

[0027]

[Table 5] Note) g: Glass phase N: Nematic phase S: Smectic phase I: Isotropic phase

Example 5 (Production of A11Cz / MnNO ₂ Copolymer) In the same manner as in Example 1, 4-[[11- (acryloyloxy) undecyl] oxy] -N-[(9-methyl-
2-carbazolyl) methylene] aniline (abbreviated as A11Cz) and 4-[[6- (methacryloyloxy) alkylene (having n carbon atoms)] oxy-N having 2 to 6 and 11 carbon atoms (n) in the alkylene chain. - (4'-nitrobenzylidene) aniline composition ratio of each and copolymerization to Table 6, wherein the (MnNO ₂ and abbreviated) (composition ratio obtained according to the method of example 1) to obtain a polymer having a. Table 6 shows the number average molecular weight and the phase transition temperature. The relationship between n of MnNO ₂ and the phase transition temperature is shown in FIG.
FIG. 9 shows the relationship between the composition ratio and the phase transition temperature in the O ₂ copolymer.

[0029]

[Table 6] Note) g: Glass phase N: Nematic phase S: Smectic phase I: Isotropic phase

Example 6 In the same manner as in Example 1, 4-[[3- (acryloyloxy) -S-(+)-2-methyl-propyl] oxy]
-N-[(9-methyl-2-carbazolyl) methylene]
Aniline (abbreviated as AkCz) 4 - abbreviated [[3- (methacryloyloxy) -S - (+) - propyl] oxy - 2-methyl]-N-(4'-nitro-benzylidene) aniline (MkNO ₂ Was copolymerized to obtain a liquid crystal polymer having a composition ratio shown in Table 7 (determined according to the method of Example 1). Incidentally, AkCz is 6-
Chlorohexanol as (S)-(+)-3-bromo-2
-Methyl-1-propanol was synthesized by changing methacrylic acid chloride to acrylic acid chloride. Also, Mk
NO ₂ was synthesized in Monomer Production Example 2 by replacing 6-chlorohexanol with (S)-(+)-3-bromo-2-methyl-1-propanol. The phase transition temperature of the obtained liquid crystal polymer is shown in Table 7, and the relationship between the composition ratio of the liquid crystal polymer and the phase transition temperature is shown in FIG.

[0031]

[Table 7] Note) g: Glass phase N ^* : Chiral nematic phase S: Smectic phase I: Isotropic phase

Monomer Production Example 5 4-[[6-
(Methacryloyloxy) hexyl] oxy] -4'-
Nitrostilbene (abbreviated as M6SBNO _2), 4-
[[6- (methacryloyloxy) hexyl] oxy]
4'(abbreviated as M6AzNO ₂₎ nitroazobenzene and 4 - [[6- (methacryloyloxy) hexyl] oxy] -4'-nitrophenyl benzoate (M
6PBNO ₂ ) was synthesized by the following method. (1) Synthesis of 4 -hydroxy-4′-stilbene 4-nitrophenylacetic acid (0.15 mol) and 4-hydroxybenzaldehyde (0.15 mol) were heated at 140 ° C. for 6 hours in the presence of 25 ml of piperidine. did. The reaction mixture was added to 250 ml of 30% aqueous NaOH,
After boiling for 0.5 hour, it was neutralized with hydrochloric acid. The product was recrystallized from acetone and purified to obtain the desired product. (2) Compound of 4-hydroxy-4'-nitroazobenzene
In a solution of 50 ml of concentrated hydrochloric acid and 50 ml of water, with stirring, 4-
Add nitroaniline (0.145 mol) and raise the temperature to 5 ° C.
It was kept below and diazotized. To this, a solution (ice cooled) of phenol (0.145 mol) and NaOH (28 g) dissolved in 100 ml of water was gradually added. After the reaction was completed, it was neutralized with hydrochloric acid. The product was isolated and recrystallized from methanol to give the desired product. (3) 4- [6- (hydroxyhexyl) oxy]-
4'-nitrostilbene (or -4'-nitroazoben
Synthesis of 4-hydroxy-4'-stilbene (or -4'-nitroazobenzene) (0.04 mol) and KOH (0.02)
6-chlorohexanol (0.062 mol) in a solution of 200 mol of ethanol / water (1/1)
Was added and the mixture was refluxed for 30 hours. The product was recrystallized with toluene to obtain the desired product.

(4) 4-[[6- (methacryloyloxy
Si) hexyl] oxy] -4'-nitrostilbene (also
The 4'-nitroazobenzene) (M6SBNO ₂ substantially
Serial to) (or M6AzNO ₂ and abbreviated synthesis chloroform 130ml) of 4- [6- (hydroxymethyl) oxy] -4'-nitrostilbene (or 4 '
-Nitroazobenzene) (0.02 mol) and triethylamine (0.1 mol) were dissolved in a solution of methacrylic acid chloride (0.06 mol) dissolved in 50 ml of chloroform at 0 ° C. The mixture was reacted at room temperature for 12 hours, passed through a silica gel column with chloroform as a developing solution, and then recrystallized with ethanol to obtain a target substance. (5) 4-[[6- (methacryloyloxy) hexyl
]] Oxy] -4'-nitrophenyl benzoate (M
6PBNO ₂ and abbreviated) Synthesis of 4 - [[6- (methacryloyloxy) hexyl] oxy] benzoic acid (6.53 mmol), 4-
Nitrophenol (19.6 mmol), 4-dimethylaminopyridine (4.35 mmol) and N, N'-dicyclohexylcarbodiimide (13 mmol) were dissolved in methylene chloride and reacted at room temperature for 48 hours. The reaction product was passed through a silica gel column with chloroform / methanol (40/1) as a developing solution, and then recrystallized with ethanol to obtain a target substance.

Example 7 (Production of M6Cz / M6SBNO ₂ or M6AzNO ₂ or M6PBNO ₂ Copolymer) In the same manner as in Example 1, 4-[[6- (methacryloyloxy) hexyl] oxy] -N-[( 9-methyl-2
-Carbazolyl) methylene] aniline (M6Cz) and 4
- [[6- (methacryloyloxy] hexyl] oxy -N-4'-nitro-stilbene (M6SBNO ₂₎ or 4 - [[6- (methacryloyloxy) hexyl] oxy -N-4'-nitro-azobenzene (M6AzNO ₂₎
Or 4-[[6- (methacryloyloxy) hexyl]
Oxy] N-4'-nitrophenyl benzoate (M6
PBNO ₂ ) was copolymerized at a molar ratio of 55/45 to obtain a liquid crystal polymer having a composition ratio shown in Table 8 (determined according to the method of Example 1) and a phase transition temperature. Further, the relationship between the composition ratio of each liquid crystal polymer and the phase transition temperature is shown in FIG.
It shows in (C).

[0035]

[Table 8] Note) g: Glass phase S: Smectic phase I: Isotropic phase

[0036]

INDUSTRIAL APPLICABILITY The liquid crystal polymer of the present invention can have a liquid crystal manifesting temperature range in a wide range by changing the combination of monomers and the composition ratio. It is also possible to induce a smectic phase. Therefore, the liquid crystal polymer of the present invention is a polymer useful as a photoconductive material, a high refractive index material or a memory material.

[0037]

[Brief description of drawings]

1A shows an NMR spectrum of a liquid crystal polymer of Example 1, and FIG. 1B shows an NMR spectrum of a liquid crystal polymer of Comparative Example 1.

FIG. 2 shows the relationship between the composition ratio of the liquid crystal polymer of Example 1 and the phase transition temperature.

3 shows the relationship between the composition ratio of the liquid crystal polymer of Comparative Example 1 and the phase transition temperature.

FIG. 4 shows the relationship between the composition ratio of the liquid crystal polymer of Example 2 and the phase transition temperature.

5 shows the relationship between the carbon number (n) of the alkylene chain in the liquid crystal polymer of Example 3 and the phase transition temperature.

FIG. 6 shows the relationship between the carbon number (n) of the alkylene chain in the liquid crystal polymer composed of A3Cz and MnNO _{2 of} Example 4 and the phase transition temperature.

7 shows the relationship between the composition ratio and the phase transition temperature of the liquid crystal polymer composed of A3Cz and M3NO _{2 in} Example 4. FIG.

8 shows the relationship between the number of carbon atoms (n) in the alkylene chain and the phase transition temperature of the liquid crystal polymer composed of A11Cz and MnNO _{2 in} Example 5. FIG.

9 shows the relationship between the composition ratio and the phase transition temperature of the liquid crystal polymer composed of A11Cz and M11NO _{2 in} Example 5. FIG.

10 shows the relationship between the composition ratio and the phase transition temperature of the liquid crystal polymer composed of AkCz and MkNO _{2 in} Example 6. FIG.

FIG. 11 shows the relationship between the composition ratio of the liquid crystal polymer of Example 7 and the phase transition temperature.

Claims (2)

[Claims] 1. A liquid crystal polymer represented by the following general formula (A): R ₁ or R ₄ is hydrogen or a methyl group, R ₂ or R ₅ is an alkylene group having a branched chain having 2 to 15 carbon atoms, and R ₃ is hydrogen, a methyl group, an ethyl group or a phenyl group. R ₆ is a nitro group or a cyano group, X is none, —CH═CH—, —N═CH—, —CH═N—, —
COO- or -OCO-, y and 1-y represent the mole fraction of each repeating unit. ) 2. A method for producing a liquid crystal polymer, which comprises copolymerizing monomers represented by the following general formulas (I) and (II). (In the formula, R ₁ or R ₄ is hydrogen or a methyl group, R ₂ or R ₅ is an alkylene group having a carbon number of 2 to 15 and may have a branched chain, and R ₃ is hydrogen, a methyl group, or an ethyl group. A group or a phenyl group, R ₆ is a nitro group or a cyano group, X is none, —CH═CH—, —N═CH—, —CH═N.
Represents-, -COO- or -OCO-, respectively. )