JP2794812B2 - Method for producing aromatic polyester - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an aromatic polyester capable of obtaining a molded article having less anisotropy by an economically advantageous method.

[Conventional technology]

 Various attempts have been made to obtain heat-resistant polyesters since ancient times.
Is coming. For example, p-hydro which is a kind of oxyacid
Obtained by polycondensation of xybenzoic acidAromatic polyester having repeating structural units such as
For example, Econol manufactured by Sumitomo Chemical Co., Ltd. E-101)
As shown in the figure, the electrode is highly crystalline and does not decompose at
Special polyester with excellent heat stability is also known
You.

However, this polymer has a drawback of poor moldability due to infusibility and insolubility. As an improved method, a polyester obtained by polycondensing a dicarboxylic acid and a diol with an oxyacid, for example, terephthalic acid disclosed in JP-B-47-47870,
Polyesters obtained by the polycondensation of hydroquinone or diphenol and p-hydroxybenzoic acid have been described. A major feature of this polyester is that it can be melt-molded. In particular, polyesters using 4,4'-dihydroxydiphenyl as a diphenol have excellent melt stability, and in recent years have attracted much attention as a molten liquid crystal polymer because fibers and thin molded articles can be formed.

[Problems to be solved by the invention]

However, in the liquid crystal polymer having the above structure, p-hydroxybenzoic acid is easily self-condensed in polycondensation,
There was a strong problem in the anisotropy of the molded article, which is considered to be due to the repeating units being continuous, that is, having a block structure. In order to suppress the blocking property, there is a method in which terephthalic acid dichloride and p-hydroxybenzoic acid are reacted in advance as disclosed in JP-B-62-54810. According to this method, the blocking property of the p-hydroxybenzoic acid unit can be suppressed, and the anisotropy of the molded article is improved. However, since terephthalic acid dichloride is used, as a result of the reaction with p-hydroxybenzoic acid, hydrogen chloride gas is generated, so that it is necessary to use a hydrochloric acid-resistant material as a reactor material, and as a reaction medium, It was necessary to use an inert organic solvent.

An object of the present invention is to provide an aromatic polyester which maintains good heat resistance and mechanical properties of a conventional aromatic polyester, has excellent moldability (particularly, melt moldability), and provides a molded article with less anisotropy. It is to provide in a way.

[Means for solving the problem]

The present inventors have solved this problem, As a result of intensive studies on heat-resistant aromatic polyesters that can be melt-molded and that contain structural units, the polycondensation reaction of a specific monomer component at a specific ratio has excellent moldability and heat resistance. However, they have found that an aromatic polyester having good mechanical properties can be obtained economically, and have completed the present invention.

That is, according to the present invention, compounds represented by the following formulas (A) and (B) are charged into a reaction vessel in a molar ratio of (A) / (B) of 2 or more, reacted, and then alkanoylated. Formula (C)
A polycondensation with a compound represented by the formula:

(A) HO-X-COOH (where X is And more than 50 mol% of the It is. ) (However, R ₁ is selected from an acetyl group, a propionyl group, and a benzoyl group.) (C) HOCO-Ar-COOH (where Ar is a divalent aromatic group, and 50 mol% or more of Ar is And / or Selected from. As yet another embodiment, the compounds represented by the formulas (A) and (B) are charged into a reaction vessel such that the molar ratio of (A) / (B) becomes 2 or more, and the reaction is carried out. And
The present invention relates to a method for producing an aromatic polyester, which comprises polycondensing with compounds represented by formulas (C) and (D).

(A) HO-X-COOH (where X is And more than 50 mol% of the It is. ) (However, R ₁ is selected from an acetyl group, a propionyl group, and a benzoyl group.) (C) HOCO-Ar-COOH (where Ar is a divalent aromatic group, and 50 mol% or more of Ar is And / or Selected from. ) (D) R ₂ O-X-COOR ₃ (where X is And more than 50 mol% of them Wherein R ₂ is selected from an acetyl group, a propionyl group and a benzoyl group, and R ₃ is selected from hydrogen and an alkyl group having 1 to 6 carbon atoms. Hereinafter, the present invention will be described in detail.

Examples of the compound represented by the above formula (A) include p-
Examples thereof include hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid. From the properties of the aromatic polyester obtained, 50% by mole or more of the aromatic polyester must be p-hydroxybenzoic acid.

As an example of the compound represented by the above formula (B), 4,4'-
Diacetoxydiphenyl, 4,4'-dipropoxydiphenyl, 4,4'-dibenzoyloxydiphenyl and the like can be mentioned.

Examples of the compound represented by the above formula (C) include terephthalic acid, isophthalic acid, 4,4'-dicarboxydiphenyl, 2,6-dicarboxynaphthalene, and alkyl and aryl esters thereof.

Examples of the compound represented by the above formula (D) include p-acetoxybenzoic acid, p-proproxybenzoic acid, p-benzyloxybenzoic acid, methyl p-acetoxybenzoate, 2-acetoxy-6-naphthoic acid and the like. I can give it.

The reaction temperature of the compounds represented by the formulas (A) and (B) is 180
280 ° C., preferably 200-250 ° C., below which the reaction is extremely slow, and above this temperature may be accompanied by decomposition, which is not preferred. The reaction can be carried out using a transesterification catalyst such as an acetate compound such as Mn or Co as a catalyst. The compound represented by (B) may be synthesized in advance, or may be synthesized immediately before the reaction using, for example, acetic anhydride.

The yield of the reaction can be determined from the yields of acetic acid, propionic acid, and benzoic acid resulting from the reaction, and can be used if the yield is 80% or more of the theoretical amount.

In this reaction, the molar ratio (A) / (B) of the compounds represented by (A) and (B) must be 2 or more, and preferably 2 to 4. If it is less than 2, the structure is not sufficiently controlled, and if it is more than 4, the unreacted compound (A) increases even if the structure can be controlled, and the effect is reduced.

The alkanoylation after the reaction may be carried out using an acid anhydride, for example, acetic anhydride, propionic anhydride or the like, at around the boiling point of the acid anhydride. The reaction time is 2 to 20 hours, preferably 3 to 10 hours.

After the reaction product of the compound represented by (A) and (B) is alkanoylated, the compound represented by (C) and, if necessary, the compound represented by (D) are further added to carry out a polycondensation reaction.

In addition, at the time of alkanoylation of the reaction product of the compound represented by (A) and (B), the compound represented by (C) and, if necessary, the compound represented by (D) may be present. The compounds (B), (C) and (D) are (A)
Is 40 to 70 mol%, (B) is 15 to 25 mol%, and (C) is 15 to
It is preferable that 25 mol%, (D) is 0 to 20 mol%, and the sum of (A) and (D) is 50 to 70 mol% for the charging reaction. If the ratio of (A) and (D) is below or above the above range, problems arise in fluidity, strength and the like.

The polycondensation process may be batch, continuous or a combination thereof. The temperature of the polycondensation reaction is preferably from 250 to 390C, more preferably from 280 to 350C. 250 temperature
When the temperature is lower than ℃, the reaction hardly occurs. When the temperature exceeds 390 ° C., side reactions such as decomposition may occur.

A multi-stage reaction temperature may be employed, or in some cases, the polycondensation reaction system may be heated to a target temperature and then immediately cooled. The time for the polycondensation reaction is preferably 0.5 to 10 hours.

The polycondensation reaction can be carried out at normal pressure, reduced pressure or a combination thereof.

Although the polycondensation reaction proceeds sufficiently without a solvent, a hydrocarbon, an ether, a silicone oil, a fluorine oil or the like having a high boiling point may be used as a solvent, if necessary. The polycondensation reaction in the present invention is sufficiently reacted without a catalyst, but a tin compound, a titanium compound, an antimony compound, a germanium compound, a phosphorus compound, an amine compound, or the like can be used as a catalyst if necessary.

In addition to the compounds represented by (A), (B), (C) and (D), the polycondensation reaction of the present invention can also be carried out using a stabilizer, a filler or the like in combination.

In the case of the aromatic polyester obtained in the present invention,
Whether a method to measure the molecular weight has not been found yet,
Or even if found, the accuracy and reproducibility of the measured values may not be good. Therefore, instead of the molecular weight of the obtained aromatic polyester, a flow temperature (described later) was adopted as an index indicating the melt flowability of the thermoplastic resin by heating. A resin having a lower flow temperature has a higher fluidity, that is, a resin having a lower molecular weight.

In the polycondensation reaction, it is preferable from the viewpoint of handling of the obtained aromatic polyester that the reaction is carried out until the flow temperature of the obtained aromatic polyester is usually 240 to 330 ° C. After polymerization, the flow temperature of the aromatic polyester is preferably from 280 to 4
The temperature is in the range of 10 ° C, more preferably 320 to 400 ° C. The flow temperature of the aromatic polyester obtained by the polycondensation reaction is 240
If the temperature is lower than ℃, it is difficult to process the polymer thereafter, if the flow temperature is higher than 330 ℃, withdraw from the polymerization tank,
This is not preferred because of problems in handling and polymer quality.

The aromatic polyester obtained in the present invention can be used after being formed into fibers, films and various shapes, and the aromatic polyester and glass fibers, mica, talc, silica, potassium titanate, wollast Knight, calcium carbonate, quartz, iron oxide, graphite,
The composition comprising an inorganic material such as carbon fiber has mechanical properties,
It has excellent electrical properties, chemical resistance and oil resistance, and can be used for mechanical parts, electric / electronic parts, automobile parts and the like.

〔The invention's effect〕

The aromatic polyester produced in the present invention is crystalline and is stable at the time of melt molding at a high temperature or at the time of use. Furthermore, it is possible to obtain a molded product having excellent melt processability and small anisotropy.

Further, according to the present invention, the above-mentioned aromatic polyester can be economically produced.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. The methods for measuring physical properties in the examples are as follows.

"Flow temperature": Flow tester CFT manufactured by Shimadzu Corporation
When extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm under a pressure of 100 kg / cm ² under a pressure of 100 kg / cm ² , the melt viscosity of the sample resin was measured to be 48,000, measured by a mold of type −500 and melted by heating at a heating rate of 4 ° C./min.
It was defined as the temperature indicating poise.

"Weight loss ratio": Approximately 20 mg of a sample resin having a particle size of 250 μm or less using a thermobalance TG-DTA standard type manufactured by Rigaku Corporation.
Was heated in air at a heating rate of 10 ° C./min, and the time-dependent change in weight was measured. From this measured value, the temperature at which the weight loss rate was 2.5% of the original weight was determined.

"Tensile strength": According to ASTM D-638, a dumbbell type test piece was used, the number of samples was 6, the distance between marked lines was 40 mm, and the tensile strength was 5 mm / min.

"Heat deformation temperature": Measured under a pressure of 18.6 kg / cm ² according to ASTM D-648.

"Mold shrinkage ratio": A molded product of 10 cm square and 2 mm thick is made by injection molding, and the direction perpendicular to the resin flow direction (MD) (TD).
The shrinkage ratio in each direction was determined from the dimensions of the molded product with respect to the dimensions of the injection mold.

Example 1 718 g of p-hydroxybenzoic acid (A) was added to a polymerization tank having a comb-shaped stirring blade and a small gap between the tank wall of the polymerization tank and the stirring blade.
(5.2 mol), 4,4'-diacetoxydiphenyl (B) 70
2 g (2.6 mol) were charged.

The temperature was increased while stirring the contents in a nitrogen gas atmosphere.
The reaction was carried out at 0 ° C. for 4 hours, and acetic acid by-produced by the reaction was continuously distilled off. Calculated from the amount of distilled acetic acid, the reaction rate is 82%
Met. The reaction mixture was cooled, and 550 g (5.39 mol) of acetic anhydride and 432 g (2.6 mol) of terephthalic acid (C) were charged.
The reaction was carried out at 40 ° C. under reflux for 8 hours. Compound (A),
The molar percentages of (B) and (C) were 50, 25 and 25 mol%, respectively.

The content was heated at a rate of 2 ° C./min while stirring under a nitrogen gas atmosphere, and polymerized at 320 ° C. for 1 hour and 20 minutes. During this time, acetic acid by-produced by the polycondensation reaction was continuously distilled off. During the polymerization, the polymer was sampled and its flow temperature was measured. The flow temperature after 1 hour at 320 ° C. was 269 ° C., and when 1 hour and 20 minutes passed, the polyester was withdrawn from the lower part of the polymerization tank in a molten state, and the flow temperature was 278 ° C.
Met. When the polymerization tank was disassembled later, almost no polyester adhered to the tank wall or the valve section. The yield of the obtained polyester is 1,425 g (9
8.6%).

When the removed polyester was pulverized by a pulverizer into particles having an average particle diameter of 1 mm or less, optical anisotropy was observed in a molten state at 320 ° C. or higher. The polyester particles have a content of 12
In a stainless steel rotary kiln, and raise the temperature from room temperature to 240 ° C in one hour under nitrogen atmosphere, from 240 ° C to 350 ° C
The temperature was raised at 350 ° C. for 2 hours, and then removed. Weight loss in the solid state polymerization was 4.1%.

This polymer powder is xylene, tetrahydrofuran,
6 with chloroform, phenol and tetrachloroethane:
4 The mixture (volume) was insoluble in m-cresol, and the flow temperature was 376 ° C. Wide-angle X-ray diffraction confirmed that the film was crystalline. This polymer is
The temperature at which there was no weight loss up to 300 ° C. and at which a weight loss of 1.0% with respect to the original weight was obtained was 480 ° C., and even at 500 ° C., weight loss was less than 2%.

600g of this polyester and 13μm in diameter, average length 50μm
A mixture comprising 400 g of the above glass fiber was able to be favorably granulated at 370 ° C. to obtain pellets. The pellets could be injection-molded favorably at a cylinder temperature of 390 ° C. using an injection molding machine Neomat N47 / 28 manufactured by Sumitomo Heavy Industries, Ltd. to obtain test specimens. The obtained test piece has a tensile strength of 1,320k
g / cm ² , elastic modulus 7.6 × 10 ⁴ kg / cm ² , heat deformation temperature 319 ° C., and whiteness 73. Mold shrinkage 0.12% by MD, 0.27 by TD
% And the anisotropy were small.

Comparative Example 1 936 g (5.2 mol) of p-acetoxybenzoic acid (D), 702 g (2.6 mol) of 4,4'-diacetoxydiphenyl (B), and 432 g of terephthalic acid (C) were placed in the same polymerization tank as in Example 1.
(2.6 mol). The molar percentage of the compounds (B), (C) and (D) in the preparation was 25,
25 and 50 mol%. While stirring the contents in a nitrogen gas atmosphere, the temperature was raised at a rate of 2 ° C./min in the same manner as in Example 1,
Polymerization was carried out under the same conditions as in Example 1, during which acetic acid by-produced by the polycondensation reaction was continuously distilled off. After the completion of the polymerization, the polyester was discharged in a molten state from a valve at the lower part of the polymerization tank. The yield of the obtained polyester was 1,412 g (97.7% of the theoretical yield).

The removed polyester was pulverized in the same manner as in Example 1 and the flow temperature was measured. As a result, it was 290 ° C., and optical anisotropy was observed in a molten state of 325 ° C. or more. When the polyester particles were subjected to solid-state polymerization under the same conditions as in Example 1, the weight loss in the solid-state polymerization was 5.2%, and the flow temperature was 391 ° C.

This polymer is also crystalline, has no weight loss up to 300 ° C., has a weight loss rate of 1.0% of its original weight at 475 ° C., and has a weight loss of less than 2% even at 500 ° C. .

600g of this polyester and 13μm in diameter, average length 50μm
And 400 g of glass fiber were mixed in the same manner as in Example 1, and granulated.
Injection molding was performed. The obtained test piece has a tensile strength of 1,450 kg /
cm ² , modulus of elasticity 8.1x10 ⁴ kg / cm ² , heat deformation temperature 326 ° C, whiteness 7
The shrinkage of the molded product was 0.00% in MD and 0.45% in TD, indicating that the anisotropy was large and inferior to Example 1.

Example 2 In the same polymerization tank used in Example 1, 1,076 g (7.8 mol) of p-hydroxybenzoic acid (A) and 702 g (2.6 mol) of 4,4'-diacetoxydiphenyl (B) were charged.

The temperature was increased while stirring the contents in a nitrogen gas atmosphere.
The reaction was carried out at 0 ° C. for 4 hours, and acetic acid by-produced by the reaction was continuously distilled off. Calculated from the amount of distilled acetic acid, the reaction rate is 89%
Met. The reaction mixture was cooled, and 875 g (8.58 mol) of acetic anhydride and 432 g (2.6 mol) of terephthalic acid (C) were charged.
The reaction was carried out at 40 ° C. under reflux for 8 hours. Compound (A),
The molar percentages of (B) and (C) were 60, 20, and 20 mol%, respectively.

The content was heated at a rate of 2 ° C./min while stirring under a nitrogen gas atmosphere, and polymerized at 320 ° C. for 1 hour and 20 minutes. During this time, acetic acid by-produced by the polycondensation reaction was continuously distilled off. During the polymerization, the polymer was sampled and its flow temperature was measured. The flow temperature after 1 hour at 320 ° C. was 272 ° C., and when 1 hour and 20 minutes passed, the polyester was withdrawn from the lower part of the polymerization tank in a molten state, and the flow temperature was 284 ° C.
Met. When the polymerization tank was disassembled later, almost no polyester adhered to the tank wall or the valve section. The yield of the obtained polyester was 1,740 g (9
9.0%).

When the removed polyester was pulverized by a pulverizer into particles having an average particle diameter of 1 mm or less, optical anisotropy was observed in a molten state at 320 ° C. or higher. The polyester particles have a content of 12
In a stainless steel rotary kiln, and raise the temperature from room temperature to 240 ° C in one hour under nitrogen atmosphere, from 240 ° C to 350 ° C
The temperature was raised at 350 ° C. for 2 hours, and then removed. Weight loss in the solid state polymerization was 3.8%.

This polymer powder is xylene, tetrahydrofuran,
6 with chloroform, phenol and tetrachloroethane:
4 The mixture was insoluble in the mixture (volume) and m-cresol, and the flow temperature was 383 ° C. Wide-angle X-ray diffraction confirmed that the film was crystalline. This polymer is
The temperature at which there was no weight loss up to 300 ° C. and at which a weight loss of 1.0% with respect to the original weight was obtained was 480 ° C., and even at 500 ° C., weight loss was less than 2%.

600g of this polyester and 13μm in diameter, average length 50μm
A mixture comprising 400 g of the above glass fiber was able to be favorably granulated at 370 ° C. to obtain pellets. The pellets could be injection-molded favorably at a cylinder temperature of 390 ° C. using an injection molding machine Neomat N47 / 28 manufactured by Sumitomo Heavy Industries, Ltd. to obtain test specimens. The obtained test piece has a tensile strength of 1,270k.
g / cm ² , elastic modulus 7.8 × 10 ⁴ kg / cm ² , heat distortion temperature 330 ° C., and whiteness 78. Mold shrinkage 0.11% by MD, 0.24 by TD
% And the anisotropy were small.

Comparative Example 2 In the same polymerization tank as in Example 1, 1,404 g (7.8 mol) of p-acetoxybenzoic acid (D), 702 g (2.6 mol) of 4,4'-diacetoxydiphenyl (B), and 432 g of terephthalic acid (C)
(2.6 mol). The molar percentage of the compounds (B), (C) and (D) in the preparation was 20,
20, 60 mol%. While stirring the contents in a nitrogen gas atmosphere, the temperature was raised at a rate of 2 ° C./min in the same manner as in Example 2,
Polymerization was carried out under the same conditions as in Example 2, during which acetic acid by-produced by the polycondensation reaction was continuously distilled off. After the completion of the polymerization, the polyester was discharged in a molten state from a valve at the lower part of the polymerization tank. The yield of the obtained polyester was 1,726 g (98.2% of the theoretical yield).

The removed polyester was pulverized in the same manner as in Example 1 and the flow temperature was measured. As a result, it was 280 ° C., and optical anisotropy was observed in a molten state at 320 ° C. or higher. When the polyester particles were subjected to solid-state polymerization under the same conditions as in Example 2, the weight loss in the solid-state polymerization was 4.3%, and the flow temperature was 389 ° C.

This polymer is also crystalline, has no weight loss up to 300 ° C., has a weight loss rate of 1.0% of its original weight at 475 ° C., and has a weight loss of less than 2% even at 500 ° C. .

600g of this polyester and 13μm in diameter, average length 50μm
And 400 g of glass fiber were mixed in the same manner as in Example 1, and granulated.
Injection molding was performed. The obtained test piece has a tensile strength of 1,480 kg /
cm ² , modulus of elasticity 8.4 × 10 ⁴ kg / cm ² , heat deformation temperature 332 ° C, whiteness 7
The shrinkage of the molded product was 0.01% in MD and 0.48% in TD, indicating that the anisotropy was large and inferior to Example 2.

Example 3 In the same polymerization tank as in Example 1, 718 g (5.2 mol) of p-hydroxybenzoic acid (A) and 702 g (2.6 mol) of 4,4'-diacetoxydiphenyl (B) were charged.

The temperature was increased while stirring the contents in a nitrogen gas atmosphere.
The reaction was carried out at 0 ° C. for 4 hours, and acetic acid by-produced by the reaction was continuously distilled off. Calculated from the amount of distilled acetic acid, the conversion is 84%
Met. The reaction mixture was cooled, and 550 g (5.39 mol) of acetic anhydride and 488 g (2.6 mol) of p-acetoxybenzoic acid (D) were added.
And 432 g (2.6 mol) of terephthalic acid (C) and 140 ° C
For 8 hours under reflux. Compounds (A), (B),
The molar percentages of (C) and (D) are 40, 20, 20, and 20 respectively.
Mol%.

The content was heated at a rate of 2 ° C./min while stirring under a nitrogen gas atmosphere, and polymerized at 320 ° C. for 1 hour and 20 minutes. During this time, acetic acid by-produced by the polycondensation reaction was continuously distilled off. When the polyester was extracted in a molten state from the lower part of the polymerization tank, the flow temperature was 272 ° C. When the polymerization tank was disassembled later, almost no polyester adhered to the tank wall or the valve section. The yield of the obtained polyester is
It was 1,652 g (94.0% of the theoretical yield).

When the removed polyester was pulverized by a pulverizer into particles having an average particle diameter of 1 mm or less, optical anisotropy was observed in a molten state at 320 ° C. or higher. The polyester particles have a content of 12
In a stainless steel rotary kiln, and raise the temperature from room temperature to 240 ° C in one hour under nitrogen atmosphere, from 240 ° C to 350 ° C
The temperature was raised at 350 ° C. for 2 hours, and then removed. Weight loss in the solid state polymerization was 3.9%.

This polymer powder is xylene, tetrahydrofuran,
6 with chloroform, phenol and tetrachloroethane:
4 The mixture (volume) was insoluble in m-cresol, and the flow temperature was 388 ° C. Wide-angle X-ray diffraction confirmed that the film was crystalline. This polymer is
The temperature at which there was no weight loss up to 300 ° C. and at which a weight loss of 1.0% with respect to the original weight was obtained was 480 ° C., and even at 500 ° C., weight loss was less than 2%.

600g of this polyester and 13μm in diameter, average length 50μm
The mixture consisting of 400 g of the above glass fiber was granulated well at 380 ° C. to obtain pellets. The pellets could be injection-molded favorably at a cylinder temperature of 390 ° C. using an injection molding machine Neomat N47 / 28 manufactured by Sumitomo Heavy Industries, Ltd. to obtain test specimens. The obtained test piece has a tensile strength of 1,320k
g / cm ² , elastic modulus 7.9 × 10 ⁴ kg / cm ² , heat deformation temperature 335 ° C., and whiteness 82. Mold shrinkage 0.12% by MD, 0.28 by TD
% And the anisotropy were small.

Example 4 In the same polymerization vessel as in Example 1, 552 g (4.0 mol) of p-acetoxybenzoic acid (D), 376 g (2.0 mol) of 2-hydroxy-6-naphthoic acid (A '), 4,4'-diacetoxy 702 g (2.6 mol) of diphenyl (B) were charged.

The temperature was increased while stirring the contents in a nitrogen gas atmosphere.
The reaction was carried out at 0 ° C. for 4 hours, and acetic acid by-produced by the reaction was continuously distilled off. Calculated from the amount of distilled acetic acid, the conversion is 85%
Met. The reaction mixture was cooled and charged with 673 g (6.60 mol) of acetic anhydride and 432 g (2.6 mol) of terephthalic acid (C).
The reaction was carried out at 40 ° C. under reflux for 8 hours. Compound (A) +
The molar percentage of (A '), (B) and (C) was 53.
6, 23.2 and 23.2 mol%.

The content was heated at a rate of 2 ° C./min while stirring under a nitrogen gas atmosphere, and polymerized at 320 ° C. for 1 hour, during which acetic acid by-produced by the polycondensation reaction was continuously distilled off. When polyester was extracted from the lower part of the polymerization tank in a molten state,
Its flow temperature was 268 ° C. When the polymerization tank was disassembled later, almost no polyester adhered to the tank wall or the valve section. The yield of polyester obtained is 1,44
2 g (98.0% of the theoretical yield).

When the removed polyester was pulverized by a pulverizer into particles having an average particle diameter of 1 mm or less, optical anisotropy was observed in a molten state at 320 ° C. or higher. The polyester particles have a content of 12
In a rotary kiln made of stainless steel and heated from room temperature to 240 ° C in one hour under nitrogen atmosphere, and from 240 ° C to 290 ° C
The temperature was raised for 4 hours, kept at 290 ° C. for 2 hours, and then removed. Weight loss in the solid state polymerization was 1.7%.

This polymer powder is xylene, tetrahydrofuran,
6 with chloroform, phenol and tetrachloroethane:
4 The mixture (volume) was insoluble in m-cresol, and the flow temperature was 326 ° C. Wide-angle X-ray diffraction confirmed that the film was crystalline. This polymer is
Up to 300 ° C the weight loss rate is 0.1%, based on the original weight
The temperature at which the weight loss rate was 1.0% was 420 ° C.

600g of this polyester and 13μm in diameter, average length 50μm
The mixture consisting of 400 g of the above glass fiber was granulated well at 320 ° C. to obtain pellets. These pellets could be injection-molded favorably at a cylinder temperature of 350 ° C. using an injection molding machine Neomat N47 / 28 manufactured by Sumitomo Heavy Industries, Ltd. to obtain test specimens. The obtained test piece has a tensile strength of 1,260 k
g / cm ² , elastic modulus 7.8 × 10 ⁴ kg / cm ² , heat deformation temperature 283 ° C., and whiteness 86. Mold shrinkage 0.10% by MD, 0.17 by TD
% And the anisotropy were small.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-149321 (JP, A) JP-A-55-94930 (JP, A) JP-A-2-235922 (JP, A) JP-A-2- 153922 (JP, A) JP-A-2-235923 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 63/00-63/91

Claims (3)

(57) [Claims] (1) A compound represented by the following formulas (A) and (B) is charged into a reaction vessel in a molar ratio of (A) / (B) of 2 or more, reacted, and then alkanoylated. A method for producing an aromatic polyester, comprising polycondensing with a compound represented by the formula (C). (A) HO-X-COOH (where X is And more than 50 mol% of the It is. ) (However, R ₁ is selected from an acetyl group, a propionyl group, and a benzoyl group.) (C) HOCO-Ar-COOH (where Ar is a divalent aromatic group, and 50 mol% or more of Ar is And / or Selected from. ) 2. A compound represented by the following formulas (A) and (B) is charged into a reaction vessel in a molar ratio of (A) / (B) of 2 or more, reacted, and then alkanoylated. A method for producing an aromatic polyester, comprising polycondensing with a compound represented by formulas (C) and (D). (A) HO-X-COOH (where X is And more than 50 mol% of the It is. ) (However, R ₁ is selected from an acetyl group, a propionyl group, and a benzoyl group.) (C) HOCO-Ar-COOH (where Ar is a divalent aromatic group, and 50 mol% or more of Ar is And / or Selected from. ) (D) R ₂ O-X-COOR ₃ (where X is And more than 50 mol% of them Wherein R ₂ is selected from an acetyl group, a propionyl group and a benzoyl group, and R ₃ is selected from hydrogen and an alkyl group having 1 to 6 carbon atoms. ) 3. The synthesis of the aromatic polyesters formed from the compounds of the formula (A) or further of the formula (D) and of the formulas (B) and (C), the formulas (A), (B) and (C) ), The compound represented by (D): (A): 40 to 70 mol%, (B): 15 to
25 mol%, (C): 15 to 25 mol%, (D): 0 to 20 mol%, and the sum of the compounds represented by the formulas (A) and (D) is 50 to
The reaction according to claim 1, wherein the reaction is carried out at 70 mol%.
3. The method for producing an aromatic polyester according to item 2.