JPH05125163A - Production of thermotropic liquid crystalline polyester - Google Patents

Abstract

PURPOSE:To readily and continuously obtain the subject polyester excellent in uniformity and fluidity by adding an aliphatic carboxylic acid anhydride to a specific product, esterifying the product, then adding a specific aromatic dicarboxylic acid and a specified acyloxy aromatic carboxylic acid to the prepared ester and carrying out polycondensation. CONSTITUTION:The objective polyester is obtained by reacting (A) a hydroxy aromatic carboxylic acid ester expressed by formula I (Ar<1> is 6-18C aromatic hydrocarbon; X<1> is 1-6C saturated hydrocarbon) with a diol expressed by formula II (R<1> is 1-15C saturated aliphatic hydrocarbon) in the presence of an organometallic compound, esterifying the resultant product with an aliphatic carboxylic acid anhydride such as acetic anhydride, subsequently further adding an aromatic dicarboxylic acid such as terephthalic acid expressed by formula III (Ar<2> is Ar<1>) and an acyloxy aromatic carboxylic acid such as 4-actoxybenzoic acid expressed by formula IV (Ar<3> is Ar<1>; X<2> is X<1>) to the resultant ester and carrying out polycondensation.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a thermotropic liquid crystalline polyester (hereinafter referred to as a liquid crystalline polyester). The liquid crystalline polyester produced according to the present invention has excellent heat resistance and excellent fluidity and uniformity.

[0002]

2. Description of the Related Art In recent years, with the development of electric / electronic fields and automobile fields, demands for higher performance of plastics have increased, and many plastics have been developed and provided to the market. Among them, a group of polymer compounds that exhibit optical anisotropy when melted and whose molecular chains are arranged in parallel are called thermotropic liquid crystalline polymers, which are excellent in moldability and improve the mechanical properties of the molded body. It's getting a lot of attention.

A typical example of the liquid crystalline polyester is a copolyester having only an ester bond of a polyethylene terephthalate unit and a parahydroxybenzoic acid unit (WJ Jackson et al., Journal of Polymer Scien.
ce Polymer Chemical Edition Volume 14, Pages 2043 (1976
), U.S. Pat. No. 3,804,805, JP-A-51
-8395 gazette etc.).

In the above-mentioned Japanese Patent Laid-Open No. 51-8395, a polyethylene terephthalate unit and paraacetoxybenzoic acid (hereinafter referred to as p-ABA) are mixed to give 24
A method for producing a liquid crystalline polyester by polymerizing by heating at 0 to 300 ° C. is described. p-AB
It is known that increasing the content of the component A improves the heat resistance of the liquid crystalline polyester.
-When the ABA component is 75 mol% or more of the total aromatic groups in the polymer, the polymer considered to be produced by the block-polymerization of p-ABA is mixed as an insoluble and infusible foreign substance (Comparative Example 1), The resulting liquid crystalline polyester has a problem that the fluidity is deteriorated and the moldability is deteriorated.
The generation of the foreign matter can be seen from the presence of a large amount of insoluble substances when dissolved in a good solvent for this type of polymer.

[0005]

DISCLOSURE OF THE INVENTION The object of the present invention is p-
An object of the present invention is to provide a method for simply and continuously producing a uniform liquid crystalline polyester which can contain a large amount of structural units of hydroxyaromatic carboxylic acid represented by ABA, has excellent heat resistance and fluidity.

[0006]

According to the present invention, a hydroxyaromatic carboxylic acid ester represented by the following general formula [I] and a diol represented by the following general formula [II] are reacted in the presence of an organometallic compound catalyst. The reaction product thus obtained is esterified by adding an aliphatic carboxylic acid anhydride, and then an aromatic dicarboxylic acid represented by the following general formula [III] and an acyloxy group represented by the following general formula [IV]. A method for producing a thermotropic liquid crystalline polyester, which comprises adding an aromatic carboxylic acid and conducting polycondensation.

[0007]

[Chemical 2] (In the formula, X ¹ and X ² are saturated aliphatic hydrocarbon groups having 1 to 6 carbon atoms, R ¹ is a saturated aliphatic hydrocarbon group having 1 to 15 carbon atoms, Ar ¹ , Ar ² and Ar ³ is each independently an aromatic hydrocarbon group having 6 to 18 carbon atoms)

X ¹ and X ² are saturated aliphatic hydrocarbon groups having 1 to 6 carbon atoms, specifically, methyl group, ethyl group,
A propyl group, a butyl group, a pentyl group, or a hexyl group, which may be linear or cyclic or branched. R ¹ is a saturated aliphatic hydrocarbon group having 1 to 15 carbon atoms, and specifically, methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, Decylene group,
It is an undecylene group, a dodecylene group, a tridecylene group, a tetradecylene group, or a pentadecylene group, and may have a linear or cyclic or branched chain. Ar ¹ ,
Ar ² and Ar ³ are each independently an aromatic hydrocarbon group having 6 to 18 carbon atoms, and specific examples thereof include a phenylene group, a naphthylene group, a biphenylene group, an anthrylene group and a terphenylene group. May have an alkyl group, an alkoxyl group, a phenyl group, a halogen atom or the like as a substituent.

Starting Material Hydroxy Aromatic Carboxylic Acid Ester The position of the hydroxyl group in the hydroxy aromatic carboxylic acid ester represented by the general formula [I] may be ortho, meta or para, but is preferably the para position. Specific examples thereof include methyl 4-hydroxybenzoate and 4
-Ethyl hydroxybenzoate, propyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, pentyl 4-hydroxybenzoate, hexyl 4-hydroxybenzoate, methyl 3-hydroxybenzoate, methyl 2-hydroxybenzoate, 2- Methyl hydroxy-6-naphthoate, ethyl 2-hydroxy-6-naphthoate, propyl 2-hydroxy-6-naphthoate, 2-hydroxy-6
-Butyl naphthoate, pentyl 2-hydroxy-6-naphthoate, hexyl 2-hydroxy-6-naphthoate,
Methyl 1-hydroxy-4-naphthoate, methyl 1-hydroxy-5-naphthoate, methyl 1-hydroxy-6-naphthoate, methyl 2-hydroxy-7-naphthoate, 4-hydroxy-4′-biphenylcarboxylic acid Methyl, ethyl 4-hydroxy-4′-biphenylcarboxylate, propyl 4-hydroxy-4′-biphenylcarboxylate, butyl 4-hydroxy-4′-biphenylcarboxylate, pentyl 4-hydroxy-4′-biphenylcarboxylate, Hexyl 4-hydroxy-4′-biphenylcarboxylate, methyl 3-hydroxy-4′-biphenylcarboxylate, methyl 2-hydroxy-4′-biphenylcarboxylate, methyl 4-hydroxy-3′-biphenylcarboxylate, 4- Methyl hydroxy-2′-biphenylcarboxylate and the like can be mentioned.

Diol Examples of the diol represented by the general formula [II] include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4. -Butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10- Examples thereof include fatty acid diols such as decanediol, and alicyclic diols such as 1,4-cyclohexanedimethanol and tricyclodecanedimethanol.

Aliphatic Carboxylic Anhydride Specific examples of the aliphatic carboxylic acid anhydride used as the esterifying agent include acetic anhydride, propionic anhydride, butyric anhydride and the like. Aromatic Dicarboxylic Acid Specific examples of the aromatic dicarboxylic acid represented by the general formula [III] include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 1,8-naphthalenedicarboxylic acid. Acid, 4,4'-biphenyldicarboxylic acid, 4,4 "-terphenylenedicarboxylic acid, 2,6-anthracenedicarboxylic acid, 1,5-
Examples thereof include anthracene dicarboxylic acid and 9,10-anthracene dicarboxylic acid.

Acyloxy Aromatic Carboxylic Acid The position of the acyloxy group in the acyloxy aromatic carboxylic acid represented by the general formula [IV] may be ortho, meta or para, but the para position is particularly preferable. Specific examples thereof include 4-acetoxybenzoic acid, 4-propionoxybenzoic acid, 4-butyroxybenzoic acid, 4-valeroxybenzoic acid, 4-caproxybenzoic acid, 3-acetoxybenzoic acid, 2-acetoxybenzoic acid, 2-acetoxy. -6-
Naphthoic acid, 1-acetoxy-4-naphthoic acid, 1-acetoxy-5-naphthoic acid, 1-acetoxy-6-naphthoic acid, 2-acetoxy-7-naphthoic acid, 4-acetoxy-4'-biphenylcarboxylic acid, 3-acetoxy
4'-biphenylcarboxylic acid, 2-acetoxy-4'-
Biphenylcarboxylic acid, 4-acetoxy-3'-biphenylcarboxylic acid, 4-acetoxy-2'-biphenylcarboxylic acid and the like can be mentioned.

Production of Liquid Crystalline Polyester In the present invention, a reaction product obtained by reacting [1] a hydroxyaromatic carboxylic acid ester with a diol in the presence of an organometallic compound catalyst is added to [2] an aliphatic carboxylic acid. A method for producing a thermotropic liquid crystalline polyester, which comprises adding an anhydride to effect esterification, and then further adding [3] an aromatic dicarboxylic acid and a hydroxyaromatic carboxylic acid for polycondensation.

[1] Transesterification Reaction This reaction is carried out by charging a raw material hydroxyaromatic carboxylic acid ester and a diol, further adding an organometallic compound catalyst, and heating. The molar ratio of the hydroxy aromatic carboxylic acid ester and the diol is /=0.1 to 2.0, preferably 0.5 to 2.
It is 0. As the organometallic compound catalyst, an organotitanium compound having an alkyl group having 1 to 6 carbon atoms, an alkoxy group, or an aryl group as an organic group, an organoaluminum compound,
Examples include tin organic compounds, organic magnesium compounds, organic lead compounds, and aluminates.

Examples of organic titanium compounds include tetra-
Examples thereof include n-butyl titanate, tetraisopropoxide titanate, titanium butoxide, tetra-2-ethylhexyl titanate and the like. Examples of the organoaluminum compound include trimethylaluminum chloride, triethylaluminum chloride, diethylaluminum chloride and the like. Examples of the organic tin compound include di-n-butyltin oxide, di-n-butyltin dilaurate, di-n-butyltin diacetate and the like. Examples of organomagnesium compounds include:
Methyl magnesium chloride, methyl magnesium bromide, ethyl magnesium chloride, ethyl magnesium bromide, propyl magnesium chloride, propyl magnesium bromide and the like can be mentioned.

Examples of organic lead compounds include tetraethyl lead,
Examples thereof include tetrapropyl lead and tetrabutyl lead. Examples of the aluminate include calcium aluminate, barium aluminate, beryllium aluminate, strontium aluminate and the like. Among these, organic titanium compounds and organic tin compounds are preferable in terms of reaction activity.

The amount of catalyst is 0.001-1 based on the raw materials (hydroxyaromatic carboxylic acid ester and diol).
It is 0% by weight, preferably 0.05 to 1% by weight. The reaction temperature is 150 to 275 ° C, preferably 200 to 250 ° C
Is. The reaction pressure is in the range of 0.01 mmHg to 10 atm. Although the reaction time varies depending on the reaction temperature and the like, for example, when the reaction temperature is 200 to 250 ° C.
12 hours.

The reaction is preferably carried out under an inert gas stream. Nitrogen, argon or the like can be used as the inert gas, and it is preferable to continuously introduce it into the system. As the reaction progresses, the alcohol represented by the following general formula [V] is eliminated.

[0019]

[Chemical 3]

(Wherein X ¹ is a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms) The theoretical amount of this alcohol and, when the reaction is carried out in excess of diol, the excess amount of diol is removed from the system. It is necessary to distill off, and it is preferable to carry out the reaction under reduced pressure in the latter half of the reaction from the viewpoint of the reaction time. Specifically, in the latter half of the reaction, the reaction is performed at a vacuum degree of 1 mmHg or less for about 1 to 6 hours. The dealcoholization reaction is terminated by distilling the alcohol and the excess diol out of the theoretical amount system.

[2] Esterification Following the dealcoholization reaction described above, an aliphatic carboxylic acid anhydride is added to the reaction product, and the reaction is performed for about 1 to 4 hours.
The hydroxy terminal is esterified by heating under reflux at 0 to 200 ° C. The degree of esterification can be confirmed by measuring a hydroxyl value or the like. The amount of the aliphatic carboxylic acid anhydride used is 0.8 to 2.0 equivalents, preferably 1.
It is 0 to 1.5 equivalents. The esterification reaction is preferably carried out under an inert gas stream. Nitrogen, argon, etc. can be used as the inert gas, and it is preferable to continuously introduce them into the system.

[3] Polycondensation Following the above-mentioned esterification, an aromatic dicarboxylic acid and a hydroxyaromatic carboxylic acid are further added to the reaction product to cause polycondensation to obtain a liquid crystalline polyester. it can.

The amount of the aromatic dicarboxylic acid compound used is
It is substantially equivalent to the diol. That is, the molar ratio is /=1.8 to 2.2, preferably 1.9.
The range is from 2.1 to 2.1. The amount of acyloxyaromatic carboxylic acid used is in the range of 0.1 to 20 mole times that of the diol.

In the polycondensation reaction, raw materials (a reaction product of an esterification reaction, an aromatic dicarboxylic acid and an acyloxy aromatic carboxylic acid) are charged, and a reaction temperature is 200 to 350.
C., preferably 250 to 325.degree. C. for polycondensation. The reaction time of the polycondensation reaction after the esterification varies depending on the reaction temperature, but for example, the reaction temperature is 250 to
It takes about 5 to 10 hours to gradually raise the temperature to 5 ° C.

The polymerization reaction is preferably carried out under an inert gas stream. Nitrogen, argon, etc. can be used as the inert gas, and it is preferable to continuously introduce them into the system. As the polycondensation reaction proceeds, an aliphatic carboxylic acid is produced as a by-product. In the latter stage of the polycondensation reaction, by-produced aliphatic carboxylic acid, and when an excess amount of aliphatic carboxylic acid anhydride is charged, it is necessary to efficiently remove the excess amount of aliphatic carboxylic acid anhydride. From the viewpoint of reaction time, etc., it is preferable to finally carry out the reaction under reduced pressure. Specifically, at the end of the reaction, the reaction is performed at a vacuum degree of 1 mmHg or less for about 1 hour, and more preferably, the reaction is performed at a vacuum degree of 0.1 mmHg or less for about 0.5 hour. The reaction is terminated by distilling the aliphatic carboxylic acid out of the stoichiometric amount system.

The liquid crystalline polymer produced according to the present invention has a total number of moles of aromatic groups (corresponding to Ar ¹ + Ar ² + Ar ³ ).
The molar ratio of the structural unit of hydroxybenzoic acid (corresponding to Ar ¹ + Ar ³ ) is 68 to 96%, preferably 70 to 95.
It occupies%. The liquid crystalline polymer produced according to the present invention should have a sufficiently large molecular weight. This liquid crystalline polymer has an intrinsic viscosity of 0.4 or more, preferably 0.6 or more, measured with pentafluorophenol as a solvent. In addition, the liquid crystal starting temperature is 160
℃ or above.

Use of Liquid Crystalline Polyester The liquid crystalline polyester of the present invention is used for injection molding, extrusion molding,
It can be subjected to ordinary melt molding such as compression molding and blow molding, and can be processed into three-dimensional molded products, films, fibers, containers and the like. Further, a polymer alloy can also be obtained by mixing with another thermoplastic resin. At the time of molding, the liquid crystalline polyester of the present invention is added with additives such as a reinforcing agent such as glass fiber and carbon fiber, a filler, an antioxidant, a stabilizer, a plasticizer, and a release agent to obtain a molded product. Can be provided with desired characteristics.

[0028]

According to the present invention, a liquid crystalline polyester which can contain a large amount of structural units of hydroxyaromatic carboxylic acid, is highly uniform, has excellent fluidity, and has excellent heat resistance can be easily prepared. And it can be manufactured continuously.

[0029]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The logarithmic viscosity of the liquid crystalline polyester, the thermogravimetric reduction start temperature (TGA), and the melting temperature (TGA)
m) and liquid crystallinity were determined as follows. (1) Logarithmic viscosity It was measured in a pentafluorophenol solvent at 50 ° C. using an Ubbelohde viscometer. However, in the table, the horizontal line indicates that it was not dissolved in pentafluorophenol. (2) Thermogravimetric reduction start temperature (TGA) Using TG / DTA20 manufactured by SEIDO I & E, measurement was performed in nitrogen at a heating rate of 10 ° C / min. (3) Melting temperature (Tm) and liquid crystallinity It was visually confirmed using a polarizing microscope with a hot stage.

<Example 1> (Transesterification reaction) In a 300 ml separable flask equipped with a stirring blade, a thermometer, a distilling tube, and a nitrogen introducing tube, 60.8604 g (0.4 mo) of methyl hydroxybenzoate was added.
l), 37.242 g of ethylene glycol (0.6 mo
1) and 0.1 g of tetra-n-butyl titanate (0.1% by weight based on the total weight of raw materials) were charged. After replacing the inside of the reaction system with argon three times, the mantle heater was heated to 200 ° C. and heated for 30 minutes to melt the contents. Start agitation and turn on the mantle heater at 225 ° C for 30 minutes, then 25
When the reaction was carried out at 0 ° C. for 3.5 hours, a theoretical amount of methanol and about 70% of the theoretical amount of excess ethylene glycol were distilled. Then, reduce the pressure to 1 mmHg or less at 250 ° C.,
A theoretical amount of ethylene glycol was distilled off under reduced pressure for 6 hours. (Esterification) 41.59 ml of acetic anhydride (0.44 mol, 1.1) was obtained in the same separable flask without isolation of the reaction product obtained by the above reaction.
(Equivalent weight) was added and the mixture was heated under reflux at 180 ° C. for 2 hours to acetylate the hydroxyl terminal.

(Polycondensation) 33.228 g (0.2 mol) of terephthalic acid and 72.064 g (0.4 mol) of p-acetoxybenzoic acid were further added to the above reaction product, followed by 1 hour at 200 ° C. At 250 ° C for 1 hour, 2
When the reaction was carried out at 75 ° C. for 2 hours, 300 ° C. for 2 hours and 325 ° C. for 1 hour, about 90% of the theoretical amount of acetic acid was distilled. Furthermore, the pressure is reduced to 1 mmHg or less at 325 ° C. and 3
The pressure was reduced to 0 minutes and the theoretical amount of acetic acid was distilled. After completion of the polycondensation, the contents were taken out from the separable flask while it was hot. Melting anisotropy of this polymer was confirmed by a polarization microscope with a hot stage. The physical properties of this liquid crystalline polyester are shown in Table 1, and the infrared spectrum is shown in FIG.

Comparative Example 1 73.41 g (0.3% of polybutylene terephthalate) was added to a reactor similar to that of Example 1.
33 mol) and p-acetoxybenzoic acid 120.11 g
(0.667 mol) was charged. After purging with argon three times, the metal bath was heated to 200 ° C. and heated for 30 minutes to melt the contents. Then, stirring was started, and when a metal bath was heated at 250 ° C. for 2 hours and then at 275 ° C. for about 1 hour, a white solid was precipitated. I tried to measure the intrinsic viscosity of this white solid, but it did not dissolve in a mixed solvent of phenol / 1,1,2,2-terolachloroethane = 1/1 (weight ratio), p-chlorophenol, and pentafluorophenol. The logarithmic viscosity could not be measured.

<Examples 2 to 5> The reaction was performed in the same manner as in Example 1 except that the amount of acetic anhydride was changed. The results are shown in Table 1.

[0034]

[Table 1]

<Examples 5 and 6> The reaction was performed in the same manner as in Example 1 except that the final temperature of the dealcoholization reaction was changed. The results are shown in Table 2.

[0036]

[Table 2]

<Examples 7 and 8> The reaction was carried out in the same manner as in Example 1 except that the final temperature of the polycondensation reaction was changed. The results are shown in Table 3.

[0038]

[Table 3]

<Example 9> The reaction was performed in the same manner as in Example 1 except that the catalyst for the dealcoholization reaction was changed. The results are shown in Table 4.

[0040]

[Table 4]

<Examples 10 to 11> In Example 1,
The reaction was performed in the same manner as in Example 1 except that butanediol and cyclohexanedimethanol were used instead of ethylene glycol. The results are shown in Table 5.

[0042]

[Table 5]

<Examples 12 and 13> In Example 1,
The reaction was carried out in the same manner as in Example 1 except that 4,4′-biphenyldicarboxylic acid and 2,6-naphthalenedicarboxylic acid were used instead of terephthalic acid. The results are shown in Table 6.

[0044]

[Table 6]

<Example 14> The reaction was performed in the same manner as in Example 1 except that the amount of p-acetoxybenzoic acid [IV] was changed. The results are shown in Table 7.

[0046]

[Table 7]

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[Procedure amendment]

[Submission date] December 9, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

The liquid crystalline polymer produced according to the present invention has a total number of moles of aromatic groups (corresponding to Ar ¹ + Ar ² + Ar ³ ).
The molar ratio of the structural unit of hydroxybenzoic acid (corresponding to Ar ¹ + Ar ³ ) is 68 to 96%, preferably 70 to 95.
It occupies%. The liquid crystalline polymer produced according to the present invention should have a sufficiently large molecular weight. The liquid crystalline polymer, a logarithmic viscosity measured pentafluorophenol as a solvent is 0.3 or more, preferably 0.6 or more. In addition, the flow starting temperature is 160
℃ or above.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

[0029]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The logarithmic viscosity of the liquid crystalline polyester, the thermogravimetric reduction start temperature (TGA), the flow start temperature
The liquid crystallinity was determined as follows. (1) Logarithmic viscosity It was measured in a pentafluorophenol solvent at 50 ° C. using an Ubbelohde viscometer. (2) Thermogravimetric reduction start temperature (TGA) Using TG / DTA20 manufactured by SEIDO I & E, measurement was performed in nitrogen at a heating rate of 10 ° C / min. (3) Flow start temperature and liquid crystallinity It was visually confirmed using a polarizing microscope with a hot stage.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

<Example 1> (Transesterification reaction) Stirring blade, thermometer, distilling tube, Argo
In a 300 ml separable flask equipped with a gas inlet tube, 60.8604 g of methyl hydroxybenzoate (0.
4 mol) and 37.242 g of ethylene glycol (0.
6 mol) and 0.1 g of tetra-n-butyl titanate (0.1% by weight based on the total weight of raw materials) were charged. After replacing the inside of the reaction system with argon three times, turn on the mantle heater 20.
The contents were melted by heating to 0 ° C. for 30 minutes. When stirring was started and the mantle heater was reacted at 225 ° C. for 30 minutes and then at 250 ° C. for 3.5 hours, the theoretical amount of methanol and about 70% of the theoretical amount of excess ethylene glycol were distilled. Next, the pressure was reduced to 1 mmHg or less at 250 ° C., and a theoretical amount of ethylene glycol was distilled off under reduced pressure for 6 hours. (Esterification) 41.59 ml of acetic anhydride (0.44 mol, 1.1) was obtained in the same separable flask without isolation of the reaction product obtained by the above reaction.
(Equivalent weight) was added and the mixture was heated under reflux at 180 ° C. for 2 hours to acetylate the hydroxyl terminal.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

(Polycondensation) 33.228 g (0.2 mol) of terephthalic acid and 72.064 g (0.4 mol) of p-acetoxybenzoic acid were further added to the above reaction product, followed by 1 hour at 200 ° C. At 250 ° C for 1 hour, 2
When the reaction was carried out at 75 ° C. for 2 hours, 300 ° C. for 2 hours and 325 ° C. for 1 hour, about 90% of the theoretical amount of acetic acid was distilled. Furthermore, the pressure is reduced to 1 mmHg or less at 325 ° C. and 3
The pressure was reduced to 0 minutes and the theoretical amount of acetic acid was distilled. After completion of the polycondensation, the contents were taken out from the separable flask while it was hot. Melting anisotropy of this polymer was confirmed by a polarization microscope with a hot stage. Table 1 shows the physical properties of this liquid crystalline polyester.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

Comparative Example 1 Reactor similar to Example 1
In addition, 63.99 g (0.3
33 mol) and p-acetoxybenzoic acid 120.11 g
(0.667 mol) was charged. Place 3 times with argon
After changing, heat the metal bath to 200 ℃ and heat for 30 minutes.
The thing was melted. Then, start stirring and start the metal bath.
2 hours at 250 ° C, then 1 hour at 275 ° C
Around the time, white solids began to precipitate. The ultimate viscosity of this white solid
Tried to measure the degree, but phenol / 1,1,2,2-tetra
Chloroethane = 1/1 (weight ratio) mixed solvent, p-chloro
Soluble in rophenol and pentafluorophenol
Therefore, the logarithmic viscosity could not be measured. <Comparative Example 2 > 73.41 g (0.333 mol) of polybutylene terephthalate and 120.11 g (0.667 m) of p-acetoxybenzoic acid were added to the same reactor as in Example 1.
ol) and. After purging with argon three times, the metal bath was heated to 200 ° C. and heated for 30 minutes to melt the contents. Then, stirring is started and the metal bath is heated at 250 ° C. for 2 hours.
After about 1 hour at 275 ° C., a white solid had started to precipitate. Tried to measure the intrinsic viscosity of the white solid, a mixed solvent of phenol / 1,1,2,2-Te DOO la tetrachloroethane = 1/1 (weight ratio), p-chlorophenol, soluble in pentafluorophenol No, the logarithmic viscosity could not be measured.

[Procedure correction 6]

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[Correction method] Change

[Correction content]

[0034]

[Table 1]

[Procedure Amendment 7]

[Document name to be amended] Statement

[Item name to be corrected] 0040

[Correction method] Change

[Correction content]

[0040]

[Table 4]

[Procedure Amendment 8]

[Document name to be amended] Statement

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[Correction method] Change

[Correction content]

[0042]

[Table 5]

[Procedure Amendment 9]

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[0044]

[Table 6]

[Procedure Amendment 10]

[Document name to be amended] Statement

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[Correction method] Change

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[0046]

[Table 7]

Claims (1)

[Claims] 1. A reaction product obtained by reacting a hydroxyaromatic carboxylic acid ester represented by the following general formula [I] with a diol represented by the following general formula [II] in the presence of an organometallic compound catalyst. After adding an aliphatic carboxylic acid anhydride for esterification, an aromatic dicarboxylic acid represented by the following general formula [III] and an acyloxy aromatic carboxylic acid represented by the following general formula [IV] are further added. A method for producing a thermotropic liquid crystalline polyester, which comprises polycondensation. [Chemical 1] (In the formula, X ¹ and X ² are saturated aliphatic hydrocarbon groups having 1 to 6 carbon atoms, R ¹ is a saturated aliphatic hydrocarbon group having 1 to 15 carbon atoms, Ar ¹ , Ar ² and Ar ³ is each independently an aromatic hydrocarbon group having 6 to 18 carbon atoms)