JP2533328B2 - Aromatic polyester - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aromatic polyester having excellent heat resistance and good melt moldability.

[Conventional technology]

 Various attempts have been made to obtain polyester.
There is. For example, polycondensation reaction of dicarboxylic acid and diol
Polyethylene terephthalate, which is the polyester obtained in
(Hereinafter referred to as PET) has a melting point of 260 ° C and excellent moldability.
Known as general purpose polyester. Also, Oki
Polycondensation of p-hydroxybenzoic acid, which is a type of silicic acid,
can get An aromatic polyester having a repeating structural unit such as
For example, Sumitomo Chemical Co., Ltd. Econol E-101)
It has a high crystallinity and does not decompose even at 300 ℃.
Special polyesters with excellent heat resistance are also known
You. Furthermore, dicarboxylic acid, diol and oxy acid
As a polyester obtained by a polycondensation reaction,
54-30290 discloses terephthalic acid and naphthalenedical.
Boronic acid, hydroquinone and p-hydroxybenzoic acid
The polyester obtained by the condensation reaction is shown.

[Problems to be solved by the invention]

 However, it is said that there is a trade-off between moldability and heat resistance.
And has a good combination of both properties.
Tell is unknown. That is, the PET is molded
Although it has excellent properties, it can be used for applications exceeding 200 ° C.
Can't do it again Fragrance like E-101
Group polyesters have excellent heat resistance, but have a melting point of 500 ° C
Since it exceeds the limit, melt moldability is extremely difficult. Furthermore,
The polyester disclosed in JP-A-54-30290 is
Satisfactory because it decomposes during molding due to poor thermal stability
Often does not develop sex.

It is an object of the present invention to provide an aromatic polyester having good moldability (particularly melt moldability) and heat resistance while having sufficiently practical mechanical properties and the like.

[Means for solving problems]

We have We have continued to study heat-resistant aromatic polyesters containing the following repeating structural units. As a result, it was found that by subjecting a specific monomer component to a polycondensation reaction at a specific ratio, an aromatic polyester having excellent mechanical properties and the like while having excellent moldability and heat resistance can be obtained. Then, the present invention has been completed.

That is, the present invention is an aromatic polyester consisting of 30 to 80 mol% of the repeating structural unit represented by the following formula (A), 10 to 35 mol% of (B), and 10 to 35 mol% of (C).

O-Ar ₁ -CO (A) CO-Ar ₂ -CO (C) (where Ar ₁ is Ar ₂ is a divalent aromatic group, and 50 to 100 mol% of Ar ₂ is Which is a divalent aromatic group) The aromatic polyester of the present invention has the following compound (A ′)
30-80 mol%, (B ') 10-35 mol% and (C') 10-
It can be produced by subjecting 35 mol% to a polycondensation reaction.

HO-Ar ₁ -COOH or its ester-forming derivative (A ') Or an ester-forming derivative thereof (B ′) HOCO-Ar ₂ —COOH or an ester-forming derivative (C ′) thereof (wherein Ar ₁ is Ar ₂ is a divalent aromatic group, and 50 to 100 mol% of Ar ₂ is Which is a divalent aromatic group) as the compound represented by the above (A '), p-hydroxybenzoic acid, p-formoxybenzoic acid, p-acetoxybenzoic acid, p-propoxyoxybenzoic acid, p-hydroxybenzoic acid. Methyl, phenyl p-hydroxybenzoate, p
Examples thereof include benzyl hydroxybenzoate and methyl p-acetoxybenzoate.

Examples of the compound represented by the above (B ') include 4,4'-dihydroxydiphenyl and 4,4'-diacetoxydiphenyl.

As the compound represented by the above (C '), 2,6-dicarboxynaphthalene, terephthalic acid, isophthalic acid, 4,
Examples thereof include 4'-dicarboxydiphenyl, 1,2-bis (4-carboxyphenoxy) ethane, their methyl esters and phenyl esters.

The aromatic polyester of the present invention can be obtained by subjecting the compounds represented by (A '), (B') and (C ') to a polycondensation reaction in a polymerization tank. The system for charging these compounds into the polymerization tank may be a batch system or a division system, and the process may be a batch system, a continuous system or a combination thereof.

The temperature of the polycondensation reaction in the present invention is preferably 250 to 390 ° C, more preferably 280 to 350 ° C. Temperature is 250 ℃
If it is lower than 390 ° C, the reaction is unlikely to occur, and if it exceeds 390 ° C, side reactions such as decomposition may occur. A multi-step reaction temperature may be adopted, and in some cases, the polycondensation reaction system may be heated to a target temperature and then immediately cooled. The polycondensation reaction time is 0.5 to 10 at the temperature of the polycondensation reaction.
Time is preferred. The polycondensation reaction can be carried out under normal pressure, reduced pressure or a combination thereof. The polycondensation reaction proceeds conveniently even without a solvent, but hydrocarbons having a high boiling point, ethers, silicone oil, fluorine oil and the like may be used as a solvent, if necessary. The polycondensation reaction in the present invention proceeds conveniently without a catalyst, but tin compounds, antimony compounds, titanium compounds, germanium compounds, phosphorus compounds, amine compounds and the like can be used as catalysts, if necessary. In addition to the compounds represented by (A '), (B') and (C '), a stabilizer, a filler and the like may be used together to carry out the polycondensation reaction of the present invention.

In the case of the aromatic polyester of the present invention, there is a method in which the molecular weight is not yet found, or even if found, the accuracy or reproducibility of the measured value is not good.
Therefore, in place of the molecular weight of the obtained aromatic polyester, a flow temperature (described later) was adopted as an indicator of the melt fluidity due to heating of the thermoplastic resin. A resin having a lower flow temperature has a larger melt fluidity, that is, a resin having a smaller molecular weight. The flow temperature of the aromatic polyester of the present invention is 200 to 380 ° C, preferably 250 to 350 ° C. If the flow temperature is less than 200 ° C, the molecular weight is low and the heat resistance is inferior, resulting in a problem in moldability or insufficient physical properties of the molded product. Also, if the flow temperature exceeds 880 ° C, it is often impossible to mold, and the problem of thermal decomposition occurs at high temperatures.

〔The invention's effect〕

According to the invention, the above formulas (A), (B) and (C)
The aromatic polyester containing a repeating structural unit represented by the following formula in a specific ratio is an aromatic polyester having mechanical properties that are sufficiently practical while having good moldability (particularly melt moldability) and heat resistance. Is. As shown in Comparative Example 1 described later, an aromatic polyester in which the ratio of these repeating structural units was outside the range specified in the present invention could not be melt-molded. Further, the aromatic polyester of the type described in JP-A-54-30290 (Comparative Example 2) cited in the section of the prior art (Comparative Example 2) also had poor melt moldability and was significantly inferior in thermal stability.

On the other hand, in the examples of the present invention, aromatic polyesters can be obtained which have good moldability and heat resistance, but also have sufficiently practical mechanical properties.

The aromatic polyester of the present invention is crystalline and stable during melt molding at high temperature and during use. Furthermore, since it exhibits optical anisotropy when melted, it is excellent in workability and mechanical properties.

The aromatic polyester of the present invention can be used not only by molding into fibers, films and those having various shapes, but also the aromatic polyester and glass fiber, mica,
The composition consisting of talc, silica, potassium titanate, wollastonite, calcium carbonate, quartz, iron oxide, graphite, carbon fiber and the like has mechanical properties, electrical properties,
Since it has excellent chemical resistance and oil resistance, it can be used for machine parts, electric / electronic parts, automobile parts, etc.

〔Example〕

Examples of the present invention will be shown below, but the present invention is not limited thereto. The methods of measuring physical properties in the examples are as follows.

Flow temperature: Capillary rheometer manufactured by Shimadzu Corporation
Flow tester CFT-500), measured at 4 ℃ / min
100kg / cm of sample resin heated and melted at a heating rate²of
When extruded from a nozzle with an inner diameter of 1 mm and a length of 10 mm under load
The temperature at the point where the melt viscosity shows 48,000 poise and
I expressed it.

Optical anisotropy: The optical anisotropy of the sample resin in a molten state was determined by observing the powder of the sample resin placed on a heating stage under polarized light at 25 ° C./min by visual observation.

Weight reduction: Using a thermobalance TG-DTA standard type manufactured by Rigaku Denki Co., Ltd., about 20 mg of a sample resin having a particle size of 250 μm or less was heated in air at a temperature raising rate of 10 ° C./min Was measured. Further, from this measured value, a temperature showing a weight reduction rate of 2.5% with respect to the original weight was obtained.

Tensile test: 10 tests on fiber, 20 between chucks
mm, pulling speed 2 mm / min. About molded products
According to ASTM D-638, using a dumbbell type test piece, the number of samples was 6, the distance between marked lines was 40 mm, and the pulling speed was 5 mm / min.

Heat distortion temperature: Measured according to ASTM D-648 at a pressure of 18.6 kg / cm ² .

Example 1 Molar ratio of repeating structural units (A) :( B) :( C) = 6
An example of 0:20:20 is shown.

P-acetoxybenzoic acid 1.080 g (6.00 mol), 4,4'-diacetoxydiphenyl 545 g (2.02 mol) and 2 in a polymerization tank having a comb-shaped stirring blade and a small gap between the tank wall and the stirring blade. 432 g (2.00 mol) of 6,6-dicarboxynaphthalene was charged. The contents were heated with stirring under a nitrogen gas atmosphere, and polymerized at 300 ° C. for 30 minutes, 320 ° C. for 30 minutes, and further under reduced pressure of 8.0 torr at 320 ° C. for 2 hours. During this period, acetic acid produced as a by-product due to the polycondensation reaction was continuously distilled off. The system was cooled and the light tan reaction mixture was removed. This was pulverized with a pulverizer into particles having an average particle size of 2 mm or less, and then dried under reduced pressure in a rotary kiln at 270 ° C. for 8 hours to obtain 1.432 g (98.6% of the theoretical yield) of the target polymer in powder form. .

This polymer is a 6: 4 mixture of xylene, tetrahydrofuran, chloroform, phenol and tetrachloroethane.
It was insoluble in the (volume) mixture and m-cresol, respectively. The flow temperature of this polymer is 316 ° C. and 340
Optical anisotropy was observed in a molten state at a temperature of ℃ or more, and it was confirmed from wide-angle X-ray diffraction that it was crystalline. This polymer showed no weight loss up to 300 ° C, and the temperature showing a weight loss rate of 2.5% relative to the original weight was 486 ° C.

 This polymer has a pore size of 0.07 mm, a pore length of 0.14 mm, and a pore number of 308.
36 mm with a screw type extruder with a diameter of 30 mm using one die
Melt spinning was performed at 0 ° C. The obtained transparent golden fiber
Neo SK-Oil, a high-temperature heating medium manufactured by Soken Chemical Industry Co., Ltd. 1
It heat-processed at 320 degreeC in 400 for 3 hours. Heat-treated fibers are dense
Degree 1.39g / cc, diameter 19.8μm, breaking strength 25.8g / d, elongation 2.7%
And elastic modulus of 960 g / d, polyethylene terephthalate
The fiber breaking strength of 8.7 g / d and elastic modulus of 85 g / d are greatly increased.
I turned around. This polyethylene terephthalate fiber
Is polyethylene terephthalate RT- manufactured by Toyobo Co., Ltd.
Melt-spin 580 at 300 ° C, draw at approximately 4 times at 150 ° C, and
It has a diameter of 22.3 μm after heat treatment at 3 ° C. for 3 hours.

 Also, 600g of this polymer, diameter 13μm, average length 50μ
A mixture consisting of 400 g of glass fiber of m.
It could be granulated and pellets were obtained. This pellet
Neomat, an injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. N47 /
28 allows good injection molding at a cylinder temperature of 360 ° C.
The test piece was obtained. The test piece has a tensile strength of 1,020 kg / cm
², Modulus of elasticity 6.4 × 10^Fourkg / cm²The heat distortion temperature was 258 ° C.

Example 2 Molar ratio of repeating structural units (A) :( B) :( C) = 5
An example of 0:25:25 is shown.

720 g of p-acetoxybenzoic acid in the same manner as in Example 1.
(4.00 mol), 4,4'-diacetoxydiphenyl 545g
(2.02 mol), 2,6-dicarboxynaphthalene 281 g (1.3
0 mol) and 116 g (0.70 mol) of isophthalic acid were charged to carry out a polycondensation reaction, and a pale yellowish brown reaction mixture was taken out.
After crushing this with a crusher to particles with an average particle size of 2 mm or less,
After drying under reduced pressure in a rotary kiln at 270 ° C. for 8 hours, 1,156 g (98.2% of the theoretical yield) of the target polymer was obtained in the form of powder.

This polymer was insoluble in the same solvent as in Example 1. The polymer flow temperature was 313 ° C., optical anisotropy was observed in the molten state at 340 ° C. or higher, and it was confirmed from wide-angle X-ray diffraction that it was crystalline. This polymer shows no weight loss up to 300 ° C and is 2.5% of its original weight.
The temperature at which the rate of weight loss was% was 462 ° C.

This polymer was melt-spun at 360 ° C. in the same manner as in Example 1, and the obtained transparent golden fiber was heat-treated under vacuum at 320 ° C. for 4 hours. Heat treated fiber has a density of 1.39 g / cc, diameter 2
0.8 μm, breaking strength 21.3 g / d, elongation 2.6% and elastic modulus 830
g / d.

A test piece comprising the polymer and glass fiber obtained in the same manner as in Example 1 except that this polymer was used had a tensile strength of 1,140 kg / d, an elastic modulus of 5.9 × 10 ⁴ kg / cm ² , and a thermal deformation. The temperature was 247 ° C.

Comparative Example 1 Molar ratio of repeating structural units (A) :( B) :( C) = 8
An example of 4: 8: 8 is shown.

In the same manner as in Example 1, 1,512 g of p-acetoxybenzoic acid
(8.40 mol), 4,4'-diacetoxydiphenyl 218g
(0.81 mol) and 173 g of 2,6-dicarboxynaphthalene
(0.80 mol) was charged and polycondensation reaction was carried out to take out a light yellowish brown reaction mixture. This was pulverized with a pulverizer into particles having an average particle size of 2 mm or less, and then dried under reduced pressure in a rotary kiln at 270 ° C. for 8 hours to obtain 1,285 g (98.8% of the theoretical yield) of the target polymer in powder form. . This polymer is 400
It did not melt even at ° C and could not be molded.

Reference Example Molar ratio of repeating structural units (A) :( B) :( C) = 6
An example of 0:20:20 is shown.

720 g of p-acetoxybenzoic acid in the same manner as in Example 1.
(4.00 mol), 2-acetoxy-6-naphthoic acid 460 g
(2.00 mol), 4,4'-diacetoxydiphenyl 545g
(2.02 mol) and 2,6-dicarboxynaphthalene 432 g
(2.00 mol) was charged and polycondensation reaction was carried out to take out a light yellowish brown reaction mixture. This was pulverized with a pulverizer into particles having an average particle size of 2 mm or less, and then dried under reduced pressure in a rotary kiln at 270 ° C. for 8 hours to obtain 1,497 g (96.5% of the theoretical yield) of the target polymer in powder form. .

This polymer was insoluble in the same solvent as in Example 1. The flow temperature of the polymer was 825 ° C., optical anisotropy was observed in the molten state at 350 ° C. or higher, and it was confirmed from wide-angle X-ray diffraction that it was crystalline. This polymer shows no weight loss up to 300 ° C and is 2.5% of its original weight.
The temperature at which the rate of weight loss was% was 477 ° C.

This polymer was melt-spun in the same manner as in Example 1 except that it was spun at 365 ° C., and the obtained transparent golden fiber was heat-treated under vacuum at 320 ° C. for 4 hours. Heat treated fiber has a density of 1.39g / cc, diameter of 22.8μm, breaking strength of 19.3g / d and elongation of 2.9.
% And an elastic modulus of 670 g / d.

Further, the test piece Tensile strength 1,230kg / cm ^2, which, except for the use of this polymer comprising a polymer and glass fiber obtained in the same as in Example 1, the elastic modulus ^{5.7 × 10 4 kg / cm 2} , heat The deformation temperature was 239 ° C.

Example 3 Molar ratio of repeating structural unit (A) :( B) :( C) = 7
An example of 0:15:15 is shown.

1,080 g of p-acetoxybenzoic acid in the same manner as in Example 1.
(6.00 mol), 2-acetoxy-6-naphthoic acid 230 g
(1.00 mol), 4,4'-diacetoxydiphenyl 407g
(1.51 mol) and 324 g of 2,6-dicarboxynaphthalene
(1.50 mol) was charged and polycondensed, and a pale yellowish-brown reaction mixture was taken out. This was crushed with a crusher into particles with an average particle size of 2 mm or less, and then dried under reduced pressure in a rotary kiln at 270 ° C for 8 hours to obtain 1,400 g of the target polymer (97.3% of the theoretical yield) in powder form. It was

This polymer was insoluble in the same solvent as in Example 1. The flow temperature of the polymer was 331 ° C., optical anisotropy was observed in the molten state at 350 ° C. or higher, and it was confirmed from wide-angle X-ray diffraction that it was crystalline. This polymer shows no weight loss up to 300 ° C and is 2.5% of its original weight.
The temperature at which the rate of weight loss was% was 462 ° C.

This polymer was melt-spun in the same manner as in Example 1 except that it was spun at 365 ° C., and the obtained transparent golden fiber was heat-treated under vacuum at 320 ° C. for 4 hours. Heat treated fiber has a density of 1.39g / cc, diameter of 24.1μm, breaking strength of 18.3g / d and elongation of 2.8%.
And the elastic modulus was 660 g / d.

Further, the test piece Tensile strength 1,210kg / cm ^2, which, except for the use of this polymer comprising a polymer and glass fiber obtained in the same as in Example 1, the elastic modulus ^{5.8 × 10 4 kg / cm 2} , heat The deformation temperature was 241 ° C.

Comparative Example 2 In the same manner as in Example 1 except that p-diacetoxybenzene was used in place of 4,4'-diacetoxydiphenyl, the method disclosed in JP-A-54-30290 cited in the section of the prior art was used. An aromatic polyester of the type described was obtained.

That is, 1,080 g (6.00 mol) of p-acetoxybenzoic acid, 392 g (2.02 mol) of p-diacetoxybenzene and 432 g (2.00 mol) of 2,6-dicarboxynaphthalene were charged, and polycondensation reaction was carried out in the same manner as in Example 1. The pale tan reaction mixture was removed. This was crushed into particles having an average particle size of 2 mm or less and dried under reduced pressure in a rotary kiln at 270 ° C. for 8 hours to obtain 1,260 g (96.9% of the theoretical yield) of the target polymer as a powder.

The flow temperature of this polymer was 337 ° C., optical anisotropy was observed in the molten state at 360 ° C. or higher, and it was confirmed from wide-angle X-ray diffraction that it was crystalline. This polymer is
No weight loss up to 300 ℃, 2.5% of the original weight
The temperature showing the rate of weight loss was 441 ° C.

The same spinning as in Example 1 was tried on this polymer, but the thermal stability of the polymer was poor and a large amount of foaming was observed at the spinneret portion, and melt spinning could not be performed.

Further, an attempt was made to prepare a test piece composed of the polymer and the glass fiber in the same manner as in Example 1 except that this polymer was used. However, the granulation property and moldability were poor, and the obtained test piece had silver streaks due to foaming, and the thermal stability was significantly inferior to the test pieces of the examples.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-59-62630 (JP, A) JP-A-55-144024 (JP, A) JP-A-62-235321 (JP, A) JP-A-60- 46225 (JP, A) JP-A-60-229921 (JP, A)

Claims (1)

(57) [Claims] 1. A repeating structural unit (A) 30 represented by the following formula:
Aromatic polyester consisting of -80 mol%, (B) 10-35 mol% and (C) 10-35 mol%. O-Ar ₁ -CO (A) CO-Ar ₂ -CO (C) (where Ar ₁ is Ar ₂ is a divalent aromatic group, and 50 to 100 mol% of Ar ₂ is Is a divalent aromatic group)