JP5587811B2 - Method for producing smectic liquid crystal polymer - Google Patents

Description

  The present invention relates to a method for producing a smectic liquid crystal polymer. More specifically, the present invention relates to a production method for obtaining a high molecular weight smectic liquid crystal polymer in a shorter time.

  Various methods are generally known for producing general-purpose plastics and engineering plastics, including the “melt polymerization method” in which polymers are polymerized in a molten state. Since there is an advantage that it can be performed, there is an increasing trend in processes employing a “solid phase polymerization method” in which a low molecular weight polymer in a crystallized state is heated and polymerized in a solid state.

  The liquid crystal polymer is a general term for a substance that exhibits a liquid crystal phase from a certain temperature when the polymer is heated. Conventionally, in the methods for increasing the molecular weight of liquid crystal polymers, which have been widely reported in research, the liquid crystal polymers that have been targeted are polymers whose liquid crystal state is nematic liquid crystals. In the nematic liquid crystal, the constituent molecules have an orientation order, but do not have a three-dimensional positional order. As a method for increasing the molecular weight of such a liquid crystal polymer, as described in Patent Document 1 or 2, heat treatment is generally performed at a temperature lower than the transition point from the solid phase to the liquid crystal phase, which is generally referred to as the melting point. The method to be taken is taken. This is because, when heated to a temperature higher than the liquid crystal phase transition point of the polymer, the polymer particles are fused or bonded to each other, so that a high molecular weight is required for a long time.

  On the other hand, as an example of solid phase polymerization of a smectic liquid crystal polymer, in Patent Document 3, a polyester composed of 4,4′-biphenyldicarboxylic acid and 1,6-hexanediol is used. However, here too, the molecular weight is increased by heat treatment at a temperature lower than the liquid crystal phase transition point, that is, in the solid phase.

Japanese Patent Laid-Open No. 4-225021 JP 2000-248056 A Japanese National Patent Publication No. 4-502481

  It is an object of the present invention to provide a method for producing a high molecular weight smectic liquid crystal polymer in a shorter time.

  The inventors of the present invention, when increasing the molecular weight of a smectic liquid crystal polymer, surprisingly does not cause fusion or adhesion between polymer particles even if the smectic liquid crystal phase is treated in the smectic liquid crystal phase instead of the solid phase. It has been found that higher molecular weight can be achieved in a shorter time than solid-phase polymerization at a temperature lower than the phase transition point, leading to the present invention. That is, the present invention includes the following 1) to 7).

A smectic liquid crystal polymer particles of 1) a solid state, by heating and / or under in vacuo inert atmosphere, to hold 20 hours at a temperature below T _S or T _i less than or T _S or T _N A method for producing a high molecular weight smectic liquid crystal polymer.
(T _S in a temperature raising process, the transition point from the solid phase to the smectic liquid crystal phase, T _i is the transition point to the isotropic phase from smectic liquid crystal phase, T _N is the transition point from smectic liquid crystal phase to the nematic liquid crystal phase Show.)
2) The method for producing a high molecular weight smectic liquid crystal polymer according to 1), wherein the smectic liquid crystal polymer particles in the solid phase have an average particle diameter of 3 mm or less.
3) The method for producing a high molecular weight smectic liquid crystal polymer according to 1) or 2), wherein the smectic liquid crystal polymer particles in the solid phase have a number average molecular weight of 5000 or more.
4) The method for producing a high molecular weight smectic liquid crystal polymer according to any one of 1) to 3), wherein heating is performed under reduced pressure.
5) The high molecular weight smectic liquid crystal polymer is mainly composed of repeating units represented by the following general formula (1) or (2), and the high molecular weight smectic according to any one of 1) to 4): A method for producing a liquid crystal polymer.
_{^{-A 1 -x-A 2 -OCO (}} CH 2) m COO- . . . (1)
_{^{-A 1 -x-A 2 -COO (}} CH 2) m OCO- . . . (2)
(In the formula, A ¹ and A ² each independently represent a substituent selected from an aromatic group, a condensed aromatic group, an alicyclic group, and an alicyclic heterocyclic group. Bond, —O—, —S—, —CH ₂ —CH ₂ —, —C═C—, —C═C (Me) —, —C≡C—, —CO—O—, —CO—NH—. , —CH═N—, —CH═N—N═CH—, —N═N— or —N (O) ═N—, wherein m represents 2 to 20. Indicates an integer.)
6) The method for producing a high molecular weight smectic liquid crystal polymer according to 5), wherein -A ¹ -xA ² -is represented by the following general formula (3):

(In the formula, each R is independently an aliphatic hydrocarbon group, F, Cl, Br, I, CN, or NO ₂ , y is an integer of 2 to 4, and n is an integer of 0 to 4.)
7) The high molecular weight smectic liquid crystal polymer according to any one of 5) or 6), wherein m of the high molecular weight smectic liquid crystal polymer is selected from an even number of 4 to 14. Production method.

  A high molecular weight smectic liquid crystal polymer can be produced in a shorter time.

The present invention is a smectic liquid crystal polymer particles of solid state, by heating and / or under in vacuo inert atmosphere, held for 1 to 20 hours at a temperature below T _S or T _i less than or T _S or T _N It is characterized by that.
The smectic liquid crystal polymer of the present invention is a generic term for polymers that can be smectic liquid crystals in a liquid crystal phase among liquid crystal polymers. Smectic liquid crystals have a layer structure in which molecules are arranged in parallel with the molecular axis, and the center of gravity of the parallel connected parts is on the same plane, and the layers are connected in a layer state substantially perpendicular to the molecular axis. Have It is known that smectic liquid crystals exhibit a peculiar pattern such as a batonets structure, a mosaic structure, a fan-like structure, etc. in microscopic observation under orthogonal polarization.

In general, the thermophysical properties of smectic liquid crystal polymers include the transition point from the solid phase to the smectic liquid crystal phase (hereinafter T _S ) and the transition point from the smectic liquid crystal phase to the isotropic phase (hereinafter T _i ) in the temperature rising process. Show. Depending polymers also indicate transition to a nematic liquid crystal phase (hereinafter T _N) from the smectic liquid crystal phase at a lower than T _i temperature. These phase transition points can be confirmed as the peak top of the endothermic peak in the temperature rising process of DSC measurement. Accordingly to a heat treatment of the polymer of the present invention at a temperature range of less than T _S or T _i less than or T _S or T _N means that the heat treatment at a smectic liquid crystal phase, range preferably maintains the smectic liquid crystal phase Therefore, a temperature range of T _S + 30 ° C., more preferably T _S + 20 ° C. is preferable in that it is difficult to cause fusion between polymer particles.

  The time for holding the polymer at the temperature at which the smectic liquid crystal phase is formed is usually 1 to 20 hours, preferably 2 to 18 hours, and more preferably 4 to 16 hours. When the time is shorter than 1 hour, high molecular weight is often insufficient. If it is longer than 20 hours, the polymer may deteriorate.

  The average particle diameter of the smectic liquid crystal polymer particles of the present invention is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1 mm or less. When the average particle diameter is larger than 3 mm, the removal efficiency from the particle surface of the gaseous or low boiling point reaction by-product generated by the high molecular weight deteriorates, and it may take a long time to increase the high molecular weight.

  The number average molecular weight of the present invention is a high temperature GPC using a solution prepared by dissolving polystyrene in a mixed solvent of p-chlorophenol and toluene in a volume ratio of 3: 8 so as to have a concentration of 2.5% by weight. (Viscotek: 350 HT-GPC System) is a value measured at a column temperature of 80 ° C. and a detector as a differential refractometer (RI).

  The number average molecular weight of the smectic liquid crystal polymer particles of the present invention is preferably 5000 or more, more preferably 8000 or more, and further preferably 10,000 or more. When the number average molecular weight is less than 5000, the polymer particles may be fused.

  The high molecular weight of the present invention can be carried out under an inert atmosphere or under reduced pressure. In an inert atmosphere, nitrogen, argon, or the like can be used, but nitrogen is preferred because it is inexpensive. Here, the inert atmosphere in the present invention refers to a state containing an inert gas such as nitrogen or argon in an amount of 90 mol% or more, preferably 98 mol% or more in the total gas. The inert gas is preferably polymerized while flowing at a constant flow rate. This helps to remove gaseous or low boiling point reaction by-products generated by high molecular weight from the particle surface, and further prevents the reaction by-products from being misted and is effective for separation from the liquid crystal polymer. Because.

  Higher molecular weight is more preferably performed under reduced pressure in that it can be performed in a shorter time. When the molecular weight is increased under reduced pressure, the pressure in the reaction system is preferably 100 torr or less, more preferably 50 torr or less, and even more preferably 10 torr or less.

The production method of the present invention can be suitably used for smectic liquid crystal polymers mainly composed of repeating units represented by the following general formula (1) or (2).
_{^{-A 1 -x-A 2 -OCO (}} CH 2) m COO- . . . (1)
_{^{-A 1 -x-A 2 -COO (}} CH 2) m OCO- . . . (2)
(In the formula, A ¹ and A ² each independently represent a substituent selected from an aromatic group, a condensed aromatic group, an alicyclic group, and an alicyclic heterocyclic group. Bond, —O—, —S—, —CH ₂ —CH ₂ —, —C═C—, —C═C (Me) —, —C≡C—, —CO—O—, —CO—NH—. , —CH═N—, —CH═N—N═CH—, —N═N— or —N (O) ═N—, wherein m represents 2 to 20. Indicates an integer.)

A polymer that takes a smectic liquid crystal phase when heated has a rod-like and rigid mesogenic group and a flexible group in the same molecule, where -A ¹ -xA ² -corresponds to a mesogenic group, and-(CH ₂ ) _m -Corresponds to a flexible group.

Here, mainly means that the amount of the unit represented by the general formula (1) or (2) contained in the main chain of the molecular chain is 50 mol% or more, preferably 70 mol% or more with respect to all the structural units. More preferably 90 mol% or more, and most preferably substantially 100 mol%. When it is less than 50 mol%, a smectic liquid crystal phase may not be exhibited.
Here, A ¹ and A ² each independently represent a hydrocarbon group having a benzene ring having 6 to 12 carbon atoms, a hydrocarbon group having a naphthalene ring having 10 to 20 carbon atoms, or a biphenyl structure having 12 to 24 carbon atoms. A hydrocarbon group having 3 or more benzene rings having 12 to 36 carbon atoms, a hydrocarbon group having a condensed aromatic group having 12 to 36 carbon atoms, and an alicyclic heterocyclic group having 4 to 36 carbon atoms It is preferable that it is selected from.

Specific examples of A ¹ and A ² include phenylene, biphenylene, naphthylene, anthracenylene, cyclohexyl, pyridyl, pyrimidyl, thiophenylene, and the like. These may be unsubstituted or may be a derivative having a substituent such as an aliphatic hydrocarbon group, a halogen group, a cyano group, or a nitro group. x is a bond element, a direct _{bond, -O -, - S -,} - CH 2 -CH 2 -, - C = C -, - C = C (Me) -, - C≡C -, - CO- A divalent substituent selected from the group of O-, -CO-NH-, -CH = N-, -CH = N-N = CH-, -N = N- or -N (O) = N-. Show. Among these, those in which the number of atoms in the main chain of x corresponding to the connector is an even number are preferable. That is, direct bond, —CH ₂ —CH ₂ —, —C═C—, —C═C (Me) —, —C≡C—, —CO—O—, —CO—NH—, —CH═N— And a divalent substituent selected from the group of —CH═N—N═CH—, —N═N— or —N (O) ═N— is preferable. When the number of atoms in the main chain of x is an odd number, a smectic liquid crystal phase may not be exhibited due to an increase in molecular width of the mesogenic group and flexibility due to an increase in the degree of freedom of bond rotation.

  Specific examples of such preferable mesogenic groups include biphenyl, terphenyl, quarterphenyl, stilbene, diphenyl ether, 1,2-diphenylethylene, diphenylacetylene, phenylbenzoate, phenylbenzamide, azobenzene, 2-naphthoate, and phenyl-2-naphthoate. And divalent groups having a structure in which two hydrogens are removed from these derivatives and the like, but are not limited thereto.

The smectic liquid crystal polymer -A ¹ -xA ² -is preferably represented by the following general formula (3). These mesogenic groups are rigid and highly oriented because of their structure, and are easily available or synthesized.

(In the formula, each R is independently an aliphatic hydrocarbon group, F, Cl, Br, I, CN, or NO ₂ , y is an integer of 2 to 4, and n is an integer of 0 to 4.)

M in the general formulas (1) and (2) is preferably an even number of 4 to 14 and more preferably an even number of 6 to 12 because it easily exhibits a smectic liquid crystal phase.
The liquid crystal polymer according to the present invention may be produced by any known method in the prior polymerization step. From the viewpoint of easy structure control, a compound having a hydroxyl group at both ends of a mesogenic group and a compound having a carboxyl group at both ends of a flexible group, or a compound having a carboxyl group or an ester group at both ends of a mesogenic group And a production method in which a compound having a hydroxyl group at both ends of the flexible group is reacted.

  As an example of a method for producing a liquid crystal polymer comprising a compound having a hydroxyl group at both ends of a mesogenic group and a compound having a carboxyl group at both ends of a flexible group, a mesogenic group having a hydroxyl group at both ends is converted to a lower fatty acid such as acetic anhydride. A method of reacting each compound individually or collectively with an acetic acid ester, followed by deacetic acid polycondensation reaction with a compound having a carboxyl group at both ends of the flexible group in another reaction vessel or the same reaction vessel. It is done. The polymerization reaction is carried out at a temperature of usually 230 to 350 ° C., preferably 250 to 330 ° C., in the presence of an inert gas such as nitrogen, under normal pressure or reduced pressure, in the absence of a solvent. It takes 5 hours. When the reaction temperature is lower than 230 ° C., the reaction proceeds slowly, and when it is higher than 350 ° C., side reactions such as decomposition tend to occur. When making it react under reduced pressure, it is preferable to raise a pressure reduction degree in steps. When the pressure is rapidly reduced to a high degree of vacuum, the monomer may volatilize. The ultimate vacuum is preferably 100 torr or less, more preferably 50 torr or less, and particularly preferably 10 torr or less. When the degree of vacuum is 100 torr or more, the polymerization reaction may take a long time. A multi-stage reaction temperature may be employed. In some cases, the reaction product can be withdrawn in a molten state and recovered as soon as the temperature rises or when the maximum temperature is reached.

  The acid anhydride of the lower fatty acid used in the polymerization step includes an acid anhydride of a lower fatty acid having 2 to 5 carbon atoms, such as acetic anhydride, propionic anhydride, monochloroacetic anhydride, dichloroacetic anhydride, trichloroacetic anhydride, anhydrous Examples include monobromoacetic acid, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, etc., but acetic anhydride, propion anhydride Acid and trichloroacetic anhydride are particularly preferably used. The amount of the lower anhydride fatty acid used is 1.01 to 1.50 times equivalent, preferably 1.02 to 1.20 times equivalent to the total of hydroxyl groups of the mesogenic groups used.

  As a method for producing a liquid crystal polymer comprising a compound having a carboxyl group or an ester group at both ends of a mesogenic group and a compound having a hydroxyl group at both ends of a flexible group, a transesterification reaction is performed by melt-kneading in the presence of an appropriate catalyst. The method of performing is mentioned.

Examples of the catalyst include germanium compounds such as germanium oxide, tin compounds such as stannous oxalate, stannous acetate, alkyl tin oxide, and diaryl tin oxide, titanium dioxide, titanium alkoxides, and alkoxytitanium silicate. Titanium compounds such as sodium acetate, potassium acetate, calcium acetate, zinc acetate, metal salts of organic acids such as ferrous acetate, Lewis acids such as BF ₃ and AlCl ₃ , amines, amides, hydrochloric acid, And inorganic acids such as sulfuric acid.

  The liquid crystal polymer according to the present invention may be copolymerized with other monomers to such an extent that the effects of the present invention can be exhibited. For example, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic hydroxyamines, aromatic diamines, aromatic aminocarboxylic acids or caprolactams, caprolactones, aliphatic dicarboxylic acids, aliphatic diols, aliphatic diamines, Examples include alicyclic dicarboxylic acids, and alicyclic diols, aromatic mercaptocarboxylic acids, aromatic dithiols, and aromatic mercaptophenols.

  Specific examples of the aromatic hydroxycarboxylic acid include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 2-hydroxy-5-naphthoic acid, 2-hydroxy 7-naphthoic acid, 2-hydroxy-3-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid and their Examples thereof include alkyl, alkoxy, and halogen-substituted products.

  Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4′-dicarboxybiphenyl, 3 , 4′-dicarboxybiphenyl, 4,4 ″ -dicarboxyterphenyl, bis (4-carboxyphenyl) ether, bis (4-carboxyphenoxy) butane, bis (4-carboxyphenyl) ethane, bis (3- Carboxyphenyl) ether and bis (3-carboxyphenyl) ethane and the like, alkyl, alkoxy or halogen substituted products thereof.

  Specific examples of the aromatic diol include, for example, hydroquinone, resorcin, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 3,3′-dihydroxybiphenyl, 3,4′-dihydroxybiphenyl. 4,4′-dihydroxybiphenyl, 4,4′-dihydroxybiphenol ether, bis (4-hydroxyphenyl) ethane, 2,2′-dihydroxybinaphthyl, and the like, and alkyl, alkoxy or halogen substituted products thereof. .

  Specific examples of the aromatic hydroxyamine include 4-aminophenol, N-methyl-4-aminophenol, 3-aminophenol, 3-methyl-4-aminophenol, 4-amino-1-naphthol, 4-amino- 4'-hydroxybiphenyl, 4-amino-4'-hydroxybiphenyl ether, 4-amino-4'-hydroxybiphenylmethane, 4-amino-4'-hydroxybiphenyl sulfide and 2,2'-diaminobinaphthyl and their alkyls , Alkoxy or halogen-substituted products.

  Specific examples of the aromatic diamine and aromatic aminocarboxylic acid include 1,4-phenylenediamine, 1,3-phenylenediamine, N-methyl-1,4-phenylenediamine, N, N′-dimethyl-1,4. -Phenylenediamine, 4,4'-diaminophenyl sulfide (thiodianiline), 4,4'-diaminobiphenyl sulfone, 2,5-diaminotoluene, 4,4'-ethylenedianiline, 4,4'-diaminobiphenoxyethane 4,4′-diaminobiphenylmethane (methylenedianiline), 4,4′-diaminobiphenyl ether (oxydianiline), 4-aminobenzoic acid, 3-aminobenzoic acid, 6-amino-2-naphthoic acid and 7-amino-2-naphthoic acid and alkyl, alkoxy or halogen substituted products thereof It is below.

  Specific examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, fumaric acid, maleic acid Etc.

  Specific examples of the aliphatic diamine include 1,2-ethylenediamine, 1,3-trimethylenediamine, 1,4-tetramethylenediamine, 1,6-hexamethylenediamine, 1,8-octanediamine, 1,9- Nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine, and the like can be given.

  Specific examples of the alicyclic dicarboxylic acid, aliphatic diol and alicyclic diol include hexahydroterephthalic acid, trans-1,4-cyclohexanediol, cis-1,4-cyclohexanediol, and trans-1,4-cyclohexane. Dimethanol, cis-1,4-cyclohexanedimethanol, trans-1,3-cyclohexanediol, cis-1,2-cyclohexanediol, trans-1,3-cyclohexanedimethanol, ethylene glycol, propylene glycol, butylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, neo Such as pentyl glycol Such Jo or branched chain aliphatic diols, as well as reactive derivatives thereof.

  Specific examples of the aromatic mercaptocarboxylic acid, aromatic dithiol and aromatic mercaptophenol include 4-mercaptobenzoic acid, 2-mercapto-6-naphthoic acid, 2-mercapto-7-naphthoic acid, benzene-1,4- Dithiol, benzene-1,3-dithiol, 2,6-naphthalene-dithiol, 2,7-naphthalene-dithiol, 4-mercaptophenol, 3-mercaptophenol, 6-mercapto-2-hydroxynaphthalene, 7-mercapto-2 -Hydroxynaphthalene and the like, as well as reactive derivatives thereof.

  Hereinafter, the present invention will be specifically described, but the present invention is not limited to these examples. Unless otherwise specified, the reagents listed below were manufactured by Wako Pure Chemical Industries, Ltd.

[Evaluation method]
Number average molecular weight: A sample was prepared by dissolving a sample in a mixed solvent of p-chlorophenol (Tokyo Kasei Kogyo Co., Ltd.) and toluene in a volume ratio of 3: 8 to a concentration of 2.5% by weight. The standard material was polystyrene, and a similar sample solution was prepared. The measurement was performed under the conditions of a high temperature GPC (manufactured by Viscotek, 350 HT-GPC System) at a column temperature of 80 ° C. and a flow rate of 1.00 mL / min. A differential refractometer (RI) was used as a detector.

Incidentally sample after a high molecular weight processing, after which the heated isotropic phase state in one time T _i temperature above were evaluated samples cooled at room temperature to 10 ° C. / min or faster.

  Thermophysical properties: About 8 mg of a high molecular weight liquid crystal polymer is weighed and heated at a rate of 20 ° C./min from 25 ° C. to 300 ° C. using a differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50 ASSY) Next, the temperature was lowered to 25 ° C., the temperature was raised again to 300 ° C. at a rate of 20 ° C./min, and an endothermic thermogram was measured. The phase transition point was determined from the endothermic peak value at the second temperature increase.

  Average particle size: A particle size analyzer (manufactured by Nikkiso Co., Ltd., Microtrac MT3300EXII) was used for the powder having an average particle size of less than 1 mm. Particles having an average particle size of 1 mm or more were measured based on JIS K-0069, and the particle size distribution was calculated based on this particle size distribution.

[Production Example 1]
In a closed reactor equipped with a reflux condenser, a thermometer, a nitrogen introduction tube, and a stirring rod, a molar ratio of 4,4′-dihydroxybiphenyl, dodecanedioic acid and acetic anhydride was 1: 1: 2.1, respectively. The reaction was carried out at 145 ° C under normal pressure and nitrogen atmosphere using sodium acetate as a catalyst to obtain a uniform solution, and then the temperature was raised to 260 ° C at 2 ° C / min while distilling off acetic acid. For 1 hour. Subsequently, while maintaining the temperature, the pressure was reduced to 10 Torr over about 40 minutes, and then the reduced pressure state was maintained. Two hours after the start of decompression, the pressure was returned to normal pressure with nitrogen gas, and the produced polymer was taken out. The number average molecular weight was 23000. The molecular structure and phase transition point are shown in Table 1. The obtained polymer was a smectic liquid crystal polymer, which was a solid phase at 180 ° C. and a smectic liquid crystal phase at 220 ° C.

[Example 1]
The polymer of Production Example 1 was pulverized to an average particle size of 0.2 mm by a pulverizer. Under reduced pressure, it was maintained at 220 ° C. showing a smectic liquid crystal phase for 8 hours, and returned to normal pressure with nitrogen gas, and the polymer was taken out. During this time, there was no fusion of the polymer particles. The number average molecular weight was 44,000.

[Example 2]
A polymer was obtained in the same manner except that Example 1 was changed from a reduced pressure to a nitrogen atmosphere. The number average molecular weight was 36000.

[Example 3]
A polymer was obtained in the same manner except that the average particle size in Example 1 was changed to 4 mm. The number average molecular weight was 38000.

[Comparative Example 1]
A polymer was obtained in the same manner except that the treatment temperature of Example 1 was changed to 180 ° C. in which the polymer was in a solid phase. The number average molecular weight was 32,000.

[Comparative Example 2]
A polymer was obtained in the same manner except that the treatment temperature of Example 1 was 180 ° C. in which the polymer was in a solid phase and the treatment time was 16 hours. The number average molecular weight was 37000.

  According to the present invention, it is possible to increase the molecular weight of a smectic liquid crystal polymer in a shorter time in an industrially simple manner.

Claims (6)

The number average molecular weight of 5,000 or more, 1 smectic liquid crystal polymer particles of solid phase, in an inert atmosphere and / or by heating under reduced pressure, T _S or T _i less than or a temperature below T _S or T _N A method for producing a high molecular weight smectic liquid crystal polymer, characterized by holding for -20 hours.
(T _S in a temperature raising process, the transition point from the solid phase to the smectic liquid crystal phase, T _i is the transition point to the isotropic phase from smectic liquid crystal phase, T _N is the transition point from smectic liquid crystal phase to the nematic liquid crystal phase Show.)   The method for producing a high molecular weight smectic liquid crystal polymer according to claim 1, wherein an average particle diameter of the solid phase smectic liquid crystal polymer particles is 3 mm or less. Characterized by heating under reduced pressure, the manufacturing method of the high molecular weight smectic liquid crystal polymer according to claim 1 or 2. The high molecular weight smectic liquid crystal polymer according to any one of claims 1 to 3 , wherein the high molecular weight smectic liquid crystal polymer is mainly composed of repeating units represented by the following general formula (1) or (2). Manufacturing method.
_{^{-A 1 -x-A 2 -OCO (}} CH 2) m COO- . . . (1)
_{^{-A 1 -x-A 2 -COO (}} CH 2) m OCO- . . . (2)
(In the formula, A ¹ and A ² each independently represent a substituent selected from an aromatic group, a condensed aromatic group, an alicyclic group, and an alicyclic heterocyclic group. Bond, —O—, —S—, —CH ₂ —CH ₂ —, —C═C—, —C═C (Me) —, —C≡C—, —CO—O—, —CO—NH—. , —CH═N—, —CH═N—N═CH—, —N═N— or —N (O) ═N—, wherein m represents 2 to 20. Indicates an integer.) -A 1 ^-x-A 2 ^-, wherein the is represented by the following general formula (3), the production method of the high molecular weight smectic liquid crystal polymer according to claim 4.

(In the formula, each R is independently an aliphatic hydrocarbon group, F, Cl, Br, I, CN, or NO ₂ , y is an integer of 2 to 4, and n is an integer of 0 to 4.) M of said higher molecular weight smectic liquid crystal polymers, characterized in that it is selected from the even number of 4-14, a method for manufacturing high molecular weight smectic liquid crystal polymer according to claim 4 or 5 .