JP2838119B2 - Manufacturing method of aromatic polyester - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an aromatic polyester having excellent heat resistance and good melt moldability.

[Conventional technology]

Attempts to obtain heat-resistant polyesters have been made for a long time, and there is much knowledge about aromatic polyesters composed of aromatic dicarboxylic acids and aromatic diphenols, and aromatic polyesters derived from aromatic oxycarboxylic acids.

As a method for producing an aromatic polyester, a suspension polymerization method,
Although the interfacial polymerization method, the solution polymerization method, the bulk polymerization method and the like are known, the former three methods have problems such as post-treatment, for example, solvent removal, polymer washing, and drainage load. Bulk polymerization is preferable in terms of economy, but the equilibrium constant of the polyester polycondensation reaction is smaller than that of polyamide, so to advance the polycondensation reaction, raise the reaction temperature or perform the reaction under reduced pressure,
It was necessary to take a method of rapidly removing by-products. In particular, since a heat-resistant polyester requires a reaction at a high temperature, there is a problem that it is difficult to obtain a polymer in a stable state. Further, low-boiling compounds and unreacted raw materials generated during the polymerization may remain in the polyester and may evaporate during molding to contaminate the environment, or may gradually occur when formed into molded products to destroy the product mechanism.

[Problems to be solved by the invention]

In view of this situation, an object of the present invention is to provide a method for stably producing an aromatic polyester having excellent heat resistance and good moldability, particularly good melt moldability, with a low boiling point substance and a uniform quality. .

[Means for solving the problem]

That is, in the present invention, when producing an aromatic polyester by a bulk polycondensation method without a solvent at the time of substantially polycondensation, the compounds represented by the following formulas (A), (B) and (C) are converted into (A) 30 ~ 80 mol%, (B) 10-35 mol%, and (C)
In a method for producing an aromatic polyester by mixing at 10 to 35 mol% and charging into a reaction vessel and performing polycondensation, the polycondensation reaction is performed at 270 to 350 ° C, and the flow temperature of the generated aromatic polyester is At a temperature of 240 ° C. or higher and a flow temperature of 20 ° C. or lower than the polycondensation temperature, the aromatic polyester as the content of the reaction vessel is recovered in a molten state, and pulverized into particles having a particle size of 3 mm or less. , 2
50 to 370 ° C under an inert gas atmosphere or 1 to 20 under reduced pressure
The present invention relates to a method for producing an aromatic polyester, which is subjected to a time treatment.

(A) R ₁ O-X-COOR ₂ (where X is And more than 50 mol% of them are selected It is. R ₁ is selected from hydrogen, formyl, acetyl, propionyl, and benzoyl; R ₂ is hydrogen, carbon 1
And 6 to 18 aryl groups. (B) R ₃ O—Ar—OR ₃ (where Ar is a divalent aromatic group; R ₃ is selected from hydrogen, acetyl, propionyl, and benzoyl). (C) R ₄ CO— Ar'-COR ₄ (although Ar 'is a divalent aromatic group, Ar' 50 of the
More than mol% It is. R ₄ is selected from OR ₅ and halogen, and R ₅ is selected from hydrogen, alkyl having 1 to 6 carbons, and aryl group having 6 to 18 carbon atoms. The compounds of the above formulas (A), (B) and (C) are mixed in (A) 30-80 mol%, (B) 10-35 mol% and (C) 10-35 mol% , The aromatic polyester obtained by polycondensation is crystalline, mechanical properties,
It has features such as excellent chemical resistance and heat resistance. More preferred mixing ratio of each compound is (A) 40-70.
Mol%, (B) 15-30 mol%, and (C) 15-30 mol%
It is. Further, some of them show anisotropy in a molten state, and also have good melt moldability.

When the proportion of the compound (A) exceeds 80 mol%, a portion which is not melted by heating is often present in the aromatic polyester, so that the melt processability is remarkably deteriorated.
If it is less than 30 mol%, the crystallinity of the aromatic polyester is low,
Not preferred. Of X in compound (A), Is less than 50 mol%, the crystallinity of the target aromatic polyester decreases, which is not preferred.

When the proportion of compounds (B) and (C) is between 10 and 35 mol%, the aromatic polyester exhibits balanced characteristics.

The molar ratio of the compounds (B) and (C) at the time of charging is from 100: 100 to 110: 100 from the viewpoint of the physical properties of the polymer, particularly thermal stability.

Examples of the compound represented by the formula (A) include p-hydroxybenzoic acid, p-formoxybenzoic acid, p-acetoxybenzoic acid, p-proproxybenzoic acid, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate,
phenyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, methyl p-acetoxybenzoate, 2-hydroxy-6-naphthoic acid, 2-acetoxy-6-naphthoic acid, methyl 2-hydroxy-6-naphthoate, 2 −
Examples thereof include phenyl hydroxy-6-naphthoate and methyl 2-acetoxy-6-naphthoate. Particularly preferred compounds are p-hydroxybenzoic acid and / or its ester-forming derivatives.

Examples of the compound represented by the formula (B) include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl,
4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylethane, 4,4'-dihydroxydiphenyl ether, 2,2
-Bis (4-hydroxyphenyl) propane, 4,4'-
Dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfide, 2,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,4-diacetoxybenzene, 1,3-diacetoxybenzene, Examples thereof include 4,4'-dipropionyloxydiphenyl, 2,6-diformoxynaphthalene, and the like, and their alkyl, aryl, alkoxy, and halogen-substituted products of halogen groups.

Particularly preferred compounds are those selected from hydroquinone, 4,4'-dihydroxydiphenyl, and / or ester-forming derivatives thereof.

Examples of the compound represented by the formula (C) include terephthalic acid, isophthalic acid, 4,4'-dicarboxydiphenyl,
1,2-bis (4-carboxyphenoxy) ethane, 2,6-
Dicarboxynaphthalene, 1,4-dicarboxynaphthalene, 1,5-dicarboxynaphthalene, dimethyl terephthalate, dimethyl isophthalate, diphenyl terephthalate, diphenyl isophthalate, terephthalic dichloride, isophthalic dichloride, 4,4'-dimethoxy Examples thereof include carbonyldiphenyl, 2,6-dimethylcarbonylnaphthalene, 1,4-dichlorocarbonylnaphthalene, 1,5-diphenoxycarbonylnaphthalene, and nucleus-substituted alkyl, aryl, alkoxy, and halogen groups thereof.

The aromatic polyester of the present invention can be obtained from the above (A) and (B)
It is obtained by performing a polycondensation reaction of a mixture of the compounds represented by (C) and (C) in a polymerization tank. These compounds may be charged into the polymerization tank either in a batch system or in a divided system. The reaction is carried out at normal pressure under an inert gas such as nitrogen atmosphere.
The process can be performed under reduced pressure, or a combination thereof, and the process can employ batch, continuous, or a combination thereof.

The reaction (for example, an esterification reaction) for converting the compounds represented by the formulas (A), (B) and (C) into a compound that is more easily polycondensed is performed before the polycondensation reaction. Can be carried out in another or the same reaction vessel, followed by a polycondensation reaction.

The temperature of the polycondensation reaction in the present invention is preferably from 270 to 350 ° C, more preferably from 280 to 330 ° C. Temperature 270
If the temperature is lower than ℃, the progress of the reaction is slow, and if it is higher than 350 ° C, the obtained polymer tends to be easily colored. A multi-stage reaction temperature may be employed, and in some cases, during the temperature rise,
Alternatively, as soon as the maximum temperature is reached, the aromatic polyester as a reaction product can be extracted in a molten state and recovered.

Compounds such as Ge, Sn, Ti, Sb, Co, and Mn can be used as a catalyst for the polycondensation reaction.

Known shapes can be used for the reaction tank. In the case of a vertical stirring tank, a multi-stage turbine blade, a paddle blade, or a double helical blade is preferable. In a horizontal stirring tank, one shaft,
Alternatively, blades of various shapes, for example, lens blades, spectacle blades, multi-plate blades, or the like are preferably provided perpendicular to the two stirring axes. Further, the blade may be twisted to improve the stirring performance and the feed mechanism.

The reaction tank is heated by a heating medium, a gas, or an electric heater, but it is preferable to heat the stirring shaft, blades, baffles, and the like for the purpose of uniform heating.

When the reaction tank is divided into multiple stages or partitioned, the reaction temperature of the final part is the polycondensation temperature in the present invention.

The time of the polycondensation reaction should be appropriately determined depending on the reaction conditions and the like, but is preferably 0.5 to 5 hours at the reaction temperature.

What is important in the present invention is that when the flow temperature of the polyester obtained by the polycondensation reaction reaches 240 ° C. or more, and reaches the flow temperature of 20 ° C. or more lower than the polycondensation temperature, the content of the polyester is Is recovered in a molten state. More preferably, when the flow temperature of the obtained polyester reaches 260 ° C. or higher and reaches a flow temperature lower than the polycondensation temperature by 25 ° C. or higher, it is preferable to recover it in a molten state. If the flow temperature is not higher than 240 ° C., the molecular weight of the polyester is not sufficient, and there is a problem in molding process and physical properties. When solid-phase polymerization is performed, fusion between polyesters and by-products occur in large quantities, which is economically undesirable. When the fluidization temperature is close to the polycondensation temperature, the viscosity of the polyester becomes high, so that not only the recovery becomes difficult, but also the stirring and mixing properties deteriorate, and the heat stability is uneven, so that the thermal stability of the polymer is adversely affected.

It is preferable to take out the polyester in a molten state in an inert gas atmosphere, but it may be in air if the water content is low.

An extruder and a gear pump can be considered as a mechanism for taking out the polyester in a molten state, but a simple valve may be used. The extracted material can be finely divided by a strand cutter, a sheet cutter, a crusher or the like according to the purpose.

A solvent, a lubricant, a stabilizer, and an additive can be added to the polycondensation system on the assumption that the melt viscosity does not significantly change.

The aromatic polyester recovered in a molten state can be used as it is, but solid-state polymerization based on the present invention is desirable from the viewpoint of removing unreacted raw materials and improving physical properties.

Mechanically pulverize the obtained aromatic polyester, 3mm
Hereinafter, it is preferable to form particles having a particle size of 0.5 mm or less, and to treat them in a solid state at 250 to 370 ° C. in an inert gas atmosphere or under reduced pressure for 1 to 20 hours. More preferably, the treatment is performed at the highest temperature for 2 to 10 hours.

If the particle size is 3 mm or more, the polymerization rate and the diffusion time of unreacted raw materials and by-products newly generated as a result of the reaction differ between the surface layer and the inside, so the molecular weight distribution is expanded or removed. Undesirably, physical properties such as those to be removed cannot be sufficiently removed.

It is necessary to select a heating rate and a treatment temperature during the solid phase polymerization so that the aromatic polyester particles are not fused. When fusion occurs, the surface area decreases, and the polycondensation reaction and the removal of low-boiling substances become slow, which is not preferable.

As the processing temperature for solid state polymerization, do not fuse, 250 to 3
It is effective to carry out the treatment at 70 ° C. in an inert gas atmosphere or under reduced pressure. If the temperature is lower than this temperature range, the reaction is slow, time-consuming and uneconomical, and if it is higher than 370 ° C., a dispersion reaction occurs, which is not preferable. The atmosphere is preferably an inert gas or a reduced pressure, and the gas leaking from the outside should be an inert gas. In the presence of air, especially oxygen, the polyester is oxidized, which causes poor physical properties and poor coloring. Inert gases include nitrogen, hydrogen, helium,
It is selected from argon and carbon dioxide. Ammonia, amine, and water vapor are not preferable because they cause decomposition of the polyester. As a solid-phase polymerization apparatus, a known dryer, reactor, mixer, electric furnace, or the like can be used.

〔Example〕

Hereinafter, examples of the present invention will be described, but the present invention is not limited thereto.

The flow temperature of the polyester is an index indicating the melt flowability, and is measured by a capillary rheometer (flow tester CFT-500, manufactured by Shimadzu Corporation), and the temperature is increased by 4 ° C./min. It is expressed as the temperature at the point where the melt viscosity shows 48,000 poises when the sample resin heated and melted at a speed is extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm under a load of 100 kg / cm ² under a load of 100 kg / cm ² .

In addition, since the polyester in the present invention is crystalline, there are no solvents that can be uniformly dissolved, and there are many cases where the measurement of the molecular weight is difficult, and the flow temperature is discussed as a standard of the molecular weight.

The optical anisotropy was measured using a particle size 25 placed on a heating stage.
The temperature of a sample resin powder of 0 μm or less was heated at 25 ° C./min under polarized light and visually observed.

Weight loss was measured with the use of a thermal balance TG-DTA standard type manufactured by Rigaku Denki Co., Ltd. with the time-dependent change in weight when about 20 mg of a sample resin having a particle size of 250 μm or less was heated in air at a rate of 10 ° C./min. Was measured. From this measured value, the temperature at which the weight was reduced by 2.5% with respect to the original weight was determined.

The tensile test of the molded article was performed according to ASTM D-638 using dumbbell-shaped test pieces at a sample number of 6, a distance between marked lines of 40 mm, and a pulling speed of 5 mm / min. The heat distortion temperature was measured under a pressure of 18.6 kg / cm ² according to ASTM D-648. The whiteness of the molded article was measured using a digital color difference meter ND-101-DP manufactured by Nippon Denshoku Industries Co., Ltd. using a plate-shaped molded article having a size of 40 mm × 40 mm. The measured value was obtained by correcting pure black to 0 and pure white to 100 and correcting with a standard titanium oxide product (whiteness 94.5).

Example 1 1,152 g of p-acetoxybenzoic acid was added to a polymerization tank having a three-stage paddle blade and having a small gap between the wall of the polymerization tank and the stirring blade.
(6.40 mol), 491 g of 4,4'-diacetoxydiphenyl
(1.82 mol) and 436 g of 4,4'-dicarboxydiphenyl
(1.80 mol). The temperature was increased from 200 ° C at a rate of 1 ° C / min while stirring the contents in a nitrogen gas atmosphere, and the temperature was increased to 320 ° C.
For 2 hours 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. Flowing temperature at 320 ℃ for 1 hour is 260 ℃
At 282 ° C. for 2 hours.

The valve at the lower part of the polymerization tank was opened, and the polyester was discharged into a discharge box under a nitrogen atmosphere. The polyester could be easily extracted in a molten state, and when the reaction tank was disassembled later, the polyester hardly adhered to the tank wall or the valve section. The yield of the obtained polyester was 1,462 g (99.2% of the theoretical yield).

After crushing the removed polyester into particles having an average particle size of 1 mm or less with a crusher, the flow temperature was measured to be 290 ° C.
And optical anisotropy was observed in a molten state at 325 ° C. or higher.

Polyester particles having an average particle size of 1 mm or less are charged into a stainless steel rotary kiln having a content of 12 liters, and the temperature is increased from room temperature to 200 ° C. in 1 hour in a nitrogen atmosphere, and from 200 ° C. to 270 ° C. in 4 hours, and at 270 ° C. for 3 hours. After holding, it was removed. Weight loss in the solid state polymerization was 1.1%.

This polymer powder is xylene, tetrahydrofuran,
6 with chloroform, phenol and tetrachloroethane:
It was insoluble in 4 mixtures (volume) and m-cresol, respectively. The flow temperature of this polymer was 337 ° C.
As a result of wide-angle X-ray diffraction, the crystal was confirmed to be crystalline.
The polymer shows no weight loss up to 300 ° C., the temperature at which the weight loss is 1.0% of the original weight is 445 ° C.,
Even at 500 ° C., weight loss was less than 2%.

600g of this polyester and 13μm in diameter, average length 50μm
The mixture comprising 400 g of the above glass fiber was able to be favorably granulated at 350 ° C. to obtain pellets. The pellets could be injection-molded favorably at a cylinder temperature of 355 ° C. using an injection molding machine Neomat N47 / 28 manufactured by Sumitomo Heavy Industries, Ltd. to obtain test pieces. The obtained test piece has a tensile strength of 1,210k
g / cm ² , elastic modulus 7.2 × 10 ⁴ kg / cm ² , heat distortion temperature 283 ° C., and whiteness 72.

Comparative Example 1 When the polycondensation at 320 ° C. was continued for 2 hours in Example 1, the stirring load became abnormally large, and the stirring was stopped. The flow temperature of the polyester at this time is 311 ° C,
It could not be removed from the reactor.

Comparative Example 2 When the polycondensation temperature reached 320 ° C. in Example 1, the polyester was extracted in the same manner as in Example 1.
The flow temperature of the polyester at this time was 226 ° C.

This polymer shows a 1.7% weight loss up to 250 ° C.
The temperature at which the weight loss rate of 2.5% of the original weight is 277 ° C
Met.

This polyester was pulverized to 1 mm or less, and subjected to solid-phase polymerization under the same apparatus and under the same conditions as in Example 1. However, the whole was remelted, and the flow temperature was 240 ° C., which did not rise to the required molecular weight. Also, reduce the heating rate to 200 hours over 12 hours.
The temperature was raised from 270 ° C to 270 ° C, kept at 270 ° C for 3 hours, and then removed.

Although the sample was in the form of a powder and did not fuse, the weight loss in solid-state polymerization was as large as 6.8%.

 The flow temperature of the polyester was 331 ° C.

600 g of polymer after this treatment, diameter 13 μm, average length 50
granulation of a mixture consisting of 400 g of glass fiber
However, the discharge of the strand was unstable compared to Example 1, which was a problem.

Comparative Example 3 A thermal analysis of the polyester taken out in the molten state in Example 1 showed no weight loss up to 250 ° C., but the temperature at which the weight loss rate of 1.0% with respect to the original weight was: The temperature was 395 ° C, and the temperature at which the weight loss rate was 2.5% was 412 ° C. From this, it is clear that the treatment of Example 1 was able to remove the low-boiling substances.

Example 2 720 g of p-acetoxybenzoic acid in the same manner as in Example 1.
(4.00 mol), 546 g of 4,4'-diacetoxydiphenyl
(2.02 mol) and 332 g (2.00 mol) of terephthalic acid were charged and subjected to polycondensation reaction, and when the flow temperature of the reaction product by sampling reached 286 ° C. (when reacted at 320 ° C. for 2 hours)
Extracted the contents. The light yellow-brown polyester could be recovered in the molten state without any problem.

Polyester yield is 1,103g (99.2% of theoretical yield)
%)Met.

This polymer was observed to have optical anisotropy in the molten state at 325 ° C. or higher, showed no weight loss up to 250 ° C., and had a temperature of 410 ° C. at which a 2.5% weight loss relative to the original weight was obtained.

This polyester was pulverized by a pulverizer into particles having an average particle diameter of 1 mm or less, and then subjected to a solid phase polymerization treatment under the same apparatus and the same conditions as in Example 1. The weight loss in the solid state polymerization was 0.9%, and the flow temperature was 336 ° C.

The polymers were each insoluble in the same solvents as in Example 1. The polymer was found to be crystalline by wide angle X-ray diffraction.

The polymer showed no weight loss up to 300 ° C., the temperature at which the weight loss was 1.0% based on the original weight was 455 ° C., and even at 500 ° C., the weight loss was less than 2%.

This polymer and glass fiber were mixed and granulated in the same manner as in Example 1 except that this polymer was used.
Injection molded at ℃. The granulation property and the moldability were good, and the test piece had a tensile strength of 1,180 kg / cm ² , an elastic modulus of 6.9 × 10 ⁴ kg / cm ² , a heat deformation temperature of 285 ° C., and a whiteness of 72.

Example 3 607 g of p-hydroxybenzoic acid was placed in the same reaction vessel as in Example 1.
(4.40 mol), 406 g (2.00 mol) of terephthalic acid dichloride and 1.8 l of xylene as a reaction medium were charged, and stirred vigorously under a nitrogen atmosphere at 120 ° C. for 1 hour and at 130 ° C. for 1 hour.
The reaction was carried out at 140 ° C. for 4 hours. Hydrogen chloride by-produced in the reaction was neutralized with an aqueous solution of sodium hydroxide. The conversion was 92%. After this, 323 g of 2,6-dihydroxynaphthalene
(2.02 mol) and 448 g (4.40 mol) of acetic anhydride.
The acetylation reaction was performed at 0 ° C. for 4 hours. Heating rate 2 ° C /
The temperature was raised to 320 ° C. in minutes, xylene, acetic anhydride, and acetic acid were removed, and polycondensation was performed substantially without a solvent. At 20 minutes after the flow temperature of the contents reached 275 ° C. in the sampling on the way, the valve at the bottom of the reaction tank was opened, and the polyester could be extracted without any problem. The flow temperature of the removed polyester was 282 ° C.

The polyester yield is 1,100 g (99.3 relative to the theoretical yield).
%)Met.

This polymer was observed to have optical anisotropy in a molten state at 330 ° C. or higher, showed no weight loss up to 250 ° C., and had a temperature of 425 ° C. at which a 2.5% weight loss relative to the original weight was obtained.

After pulverizing this polyester into particles having an average particle diameter of 1 mm or less by a pulverizer, charge it into a stainless steel container having a thickness of about 10 mm, put it in an electric furnace, and raise it from room temperature to 200 ° C. under a nitrogen atmosphere in one hour. From 270 ° C to 270 ° C over 3 hours, from 270 ° C to 360 ° C over 3 hours,
After holding for a time, it was removed. Weight loss in solid state polymerization is 3.
The flow temperature of the obtained polyester was 395 ° C.

The polymers were each insoluble in the same solvents as in Example 1. The polymer was found to be crystalline by wide angle X-ray diffraction.

The polymer showed no weight loss up to 300 ° C., and the temperature at which the weight loss was 1.0% based on the original weight was 485 ° C.

Except that this polymer was used, this polymer and glass fiber were mixed in the same manner as in Example 1, granulated at 360 ° C, and injection-molded at 370 ° C. Good granulation and moldability, tensile strength of test piece 1,050 kg / cm ² , modulus of elasticity 5.4 × 10 ⁴ kg /
cm ² , heat deformation temperature 321 ° C., whiteness 71.

Example 4 576 g of p-acetoxybenzoic acid was placed in the same reaction vessel as in Example 1.
(3.20 mol), 644 g of 2-acetoxy-6-naphthoic acid
(2.80 mol), 1,4-diacetoxy-2-methylbenzene 4
26 g (2.05 mol) and 332 g (2.00 mol) of terephthalic acid were charged, and the contents were stirred at 200 ° C. under a nitrogen gas atmosphere.
Then, the temperature was raised at a rate of 1 ° C./min, and polymerization was carried out at 310 ° C. for 2 hours and 50 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 reaction temperature is 310 ° C, the flow temperature is 242 ° C in 1 hour, 261 ° C in 2 hours, 27 hours in 2 hours 30 minutes.
2 ° C. Then (when the flow temperature reached 272 ° C.), the valve at the bottom of the polymerization tank was opened, and the polyester was discharged into a discharge box under a nitrogen atmosphere. The polyester could be easily extracted in the molten state.

The polyester yield was 1,357 g (99.2% of the theoretical yield).
%) And the flow temperature was 279 ° C.

This polymer was observed to have optical anisotropy in a molten state at 320 ° C. or higher, showed no weight loss up to 250 ° C., and had a temperature of 435 ° C. showing a 2.5% weight loss rate with respect to the original weight.

This polyester was pulverized by a pulverizer into particles having an average particle diameter of 1 mm or less, and then subjected to a solid phase polymerization treatment under the same apparatus and the same conditions as in Example 1. The weight loss in the solid state polymerization was 1.5%, and the flow temperature was 337 ° C.

This polymer was insoluble in the same solvent as in Example 1, and it was confirmed by wide-angle X-ray diffraction that it was crystalline.

The polymer did not show any weight loss up to 300 ° C., the temperature at which the weight loss was 1.0% of the original weight was 480 ° C., and even at 500 ° C., the weight loss was less than 2%.

This polymer and glass fiber were mixed and granulated in the same manner as in Example 1 except that this polymer was used.
Injection molded at ℃. The granulation property and the moldability were good, and the test piece had a tensile strength of 1,400 kg / cm ² , an elastic modulus of 8.3 × 10 ⁴ kg / cm ² , a heat deformation temperature of 280 ° C. and a whiteness of 73.

〔The invention's effect〕

According to the present invention, it is possible to stably produce a uniform and high-quality aromatic polyester having a low boiling point substance.

The aromatic polyester obtained by the present invention can be used by molding into fibers, films, and those having various shapes, as well as polyester and glass fibers, mica, talc, silica, potassium titanate, wollastonite, Calcium carbonate, quartz, iron oxide, graphite,
The composition comprising carbon fiber and the like has excellent mechanical properties, electrical properties, chemical resistance, and oil resistance, and thus can be used for mechanical parts, electric parts, electronic parts, and automobile parts.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Atsukazu Iwata 1-98 Kasuganaka, Konohana-ku, Osaka-shi, Osaka Sumitomo Chemical Co., Ltd. (72) Inventor Kazuo Hayatsu 2-10-10 Tsukahara, Takatsuki-shi, Osaka No. 1 Sumitomo Chemical Co., Ltd. (56) References JP-A-52-92295 (JP, A)

Claims (1)

(57) [Claims] 1. A compound represented by the following formulas (A), (B) and (C): (A) 30 to 80 mol%, (B) 10 to 35 mol%,
(C) 10 to 35 mol% and the molar ratio of (B) to (C) 100: 10
In a method for producing an aromatic polyester by mixing at 0 to 110: 100 and charging into a reaction vessel and performing polycondensation, the polycondensation reaction is performed at 270 to 350 ° C., and the flow temperature of the generated aromatic polyester is At a temperature of 240 ° C. or higher and a flow temperature of 20 ° C. or lower than the polycondensation temperature, the aromatic polyester as the content of the reaction vessel is recovered in a molten state, and pulverized into particles having a particle size of 3 mm or less. , 2
50 to 370 ° C under an inert gas atmosphere or 1 to 20 under reduced pressure
A method for producing an aromatic polyester, which is subjected to a time treatment. (A) R ₁ O-X-COOR ₂ (where X is And more than 50 mol% of the It is. R ₁ is selected from hydrogen, formyl, acetyl, propionyl, and benzoyl; R ₂ is hydrogen, carbon 1
And 6 to 18 aryl groups. (B) R ₃ O—Ar—OR ₃ (where Ar is a divalent aromatic group; R ₃ is selected from hydrogen, acetyl, propionyl, and benzoyl). (C) R ₄ CO— Ar′-COR ₄ (where Ar ′ is a divalent aromatic group, and 50% by mole or more of Ar ′ It is. R ₄ is selected from OR ₅ and halogen; R ₅ is selected from hydrogen, alkyl having 1 to 6 carbons, and aryl group having 6 to 18 carbon atoms. )