JPS6322826A - Production of aromatic polyester - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aromatic polyesters with improved melt polymerizability and mechanical properties.

Fully aromatic polyesters have been known for a long time, and for example, roseoxybenzoic acid homopolymers and copolymers have already been produced and commercially available. However, these polymers have drawbacks such as low molecular weight and difficulty in processing due to relatively high melting points or decomposition temperatures lower than the melting point. Also, this polymer cannot be melt-extruded into suitable fibers. For example, fibers that are melt extruded at very high temperatures generally have a hollow internal structure and low tensile strength.

To improve this, various new fully aromatic polyesters have been proposed. Examples include polyesters of aromatic dicarboxylic acids and aromatic diols, and copolyesters of these and aromatic oxycarboxylic acids. However, even these fully aromatic polyesters have the disadvantage that it is difficult to obtain polymers with consistent properties due to their low molecular weight, tendency to thermally decompose rather than melt, or non-uniformity in the polymerization reaction. Kimono has not been obtained.

The present inventors have conducted various studies in order to find a completely aromatic polyester that is free from these five conventional defects, and have found that a small amount of 2-hydroxynaphthalene-6-carboxylic acid is completely aromatic polyester. It was discovered that in polymerization reactions to obtain polymers, it lowers the melting point and viscosity of the system, allowing the reaction to proceed smoothly, helping to stabilize the arrangement of repeating structural units in the polymer, and improving the mechanical properties of the polymer. Thus, the present invention was completed.

The present invention is characterized in that parahydroxybenzoic acid, aromatic dicarboxylic acid, and aromatic diol are subjected to condensation polymerization in the presence of 10 to 20 mol% of 2-hydroxynaphthalene-6-carboxylic acid or a derivative thereof. This is a method for producing aromatic polyester.

The parahydroxybenzoic acid, aromatic dicarboxylic acid, and aromatic diol used in the present invention may all be derivatives thereof.

Parahydroxybenzoic acid and its derivatives include, for example, hydroxybenzoic acid, 3-chloro-4-oxybenzoic acid, 2-chloro-4-oxybenzoic acid, 2,3-
Dichloro-4-oxybenzoic acid, 3,5-dichloro-4
-oxybenzoic acid, 2,5-dichloro-4-oxybenzoic acid, 6-promo-4-oxybenzoic acid, 3-methyl-
4-oxybenzoic acid, 3,5-dimethyl-4-oxybenzoic acid, 2,6-dimethyl-4-oxybenzoic acid, 3-
Methoxy-4-oxybenzoic acid, 3,5-dimethoxy-
Nuclear substitutes such as 4-oxybenzoic acid and acyl or aryl ester derivatives at the hydroxyl group are used. Acyl derivatives in the hydroxyl group, particularly acetyl derivatives, are preferred.

Aromatic dicarboxylic acids and derivatives thereof include terephthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-
Oxy-bisbenzoic acid, 4,4'-ethylenedioxy-
Examples include bisbenzoic acid, 4,4'-thio-bisbenzoic acid, and esters thereof such as aryl esters. Aromatic diols include 4.4'-biphenol, hydroquinone, bisphenol A, 1.1'
Examples include -thio-4,4'-biphenol, and acyl derivatives in the hydroxyl group, preferably acetyl derivatives. The aromatic rings of these aromatic dicarboxylic acids and aromatic diols may be substituted with one or several alkyl groups or alkoxy groups having 1 to 4 carbon atoms, or halogen atoms such as F, C1, and Br. Furthermore, monomers such as resorcinol, isophthalic acid, and metahydroxybenzoic acid may also be added in an amount of 10 mol % or less as long as they do not impair the properties of the resulting resin.

The amount of 2-hydroxynaphthalene-6-carboxylic acid or its derivative used is 10 mol% or more and 20 mol% or less of the total monomer amount. If the amount of 2-hydroxynaphthalene-6-carboxylic acid or its derivative used exceeds 20 mol%,
This tends to hinder the smooth progress of the reaction and lowers the melting point of the resulting aromatic polyester to a level that is much lower than necessary for improving melt polymerizability, which is unfavorable in terms of the heat resistance of the resin. Since this monomer is relatively expensive, it is also economically unfavorable.

The polycondensation reaction of the present invention can be carried out by various methods to obtain random copolymers, block copolymers, or highly ordered copolymers. - The polymerization method may be either a bulk polymerization method or a suspension polymerization method using an appropriate heat medium. The reaction temperature is 150-400°C, preferably 200°C
At temperatures as low as ˜400° C., especially 250-660° C., vacuum can be utilized to facilitate the removal of volatile components such as acetic acid, water, alcohol, phenol, etc. formed during the final stages of condensation.

Catalysts can also be used to reach the desired degree of polymerization in a short time. As a catalyst, approximately 0.0% of the total amount of leather is used.
0.001 to 1% by weight, preferably about 0.01 to 0.2% by weight of known transesterification catalysts can be used. As this transesterification catalyst, dialkyltin oxide,
Diaryltin oxides, titanium dioxide, titanium alkoxides, alkoxytitanium silicates, alkali and alkaline earth metal salts of carboxylic acids, gaseous acid catalysts such as Lewis acids such as BF, hydrogen halides such as hydrogen chloride, etc. can be given.

The wholly aromatic copolyester obtained by the method of the present invention has a relatively low viscosity when melted, and therefore can be melt-processed. Generally the products are soluble in pentafluorophenol. It usually has a weight average molecular weight of about 2,000 to 200,000, preferably about 10,000 to 5oooo.

The molecular weight can also be increased through solid state polymerization operations, for example by heating particulate polymers or spun fibers or formed films at temperatures below their melting point in an inert atmosphere, such as a nitrogen atmosphere, for several minutes to several days. . Heating under reduced pressure is also possible. Prior to this heat treatment, 60
When dissolved in pentafluorophenol at a concentration of 0.1% at °C, at least about 2.5, preferably about 3.5
It shows an intrinsic viscosity of Intrinsic viscosity is obtained by the following formula.

The fully aromatic copolyesters obtained by the process of the present invention can be readily melt processed to form a variety of shaped articles, such as shaped three-dimensional articles, fibers, films, tapes, and the like. The fibers can be used particularly advantageously as tire cords, as well as conveyor belts, hoses, cables, resin reinforcements, etc.

The film can be used as packaging tape, cable wrap, magnetic tape, electrical insulation film, etc. Further, as molded three-dimensional articles, it is suitable for mechanical parts, electronic open range parts, heating containers, etc.

Example 1 Paraacetoxybenzoic acid 27. O,! 17 (0,1
5 mol), 4,4'-biphenol diacetate) 40
．． 5.9 (0.15 mol), terephthalic acid 24. q
g (0°15 mol) and 2-acetoxynaphthalene-
115 g (0.05 mol) of 6-carboxylic acid is stirred in a nitrogen stream at 250°C for 2.5 hours and then at 280°C for 1 hour, and acetic acid is distilled off. Next, the degree of vacuum was gradually increased at 3100C for about 10 minutes, and the reaction was completed by holding at 0.1 torr for 30 minutes. In the future, the polymer will be finely pulverized to 150
Dry under ventilation for 1 hour at °C.

Polymer approximately 72I! is obtained, which exhibits an intrinsic viscosity of 5.9, measured at 60 DEG C. in a 0.1% strength by weight pentafluorophenol solution.

The polymer is melt extruded into continuous filaments of approximately 20 denier/filament and rapidly cooled in air (20° C., relative humidity 65%).

The obtained fiber has the following properties: Strength (g/denier) 191 Tensile modulus (l/denier) 590 Elongation (%) 1.8 Strength after heat treatment at 250°C for 90 hours (1/denier) 26.8 Tensile modulus (l/denier) 63゜Elongation rate (%) 2.
4, low shrinkage at high temperatures, approximately 1
It exhibits dimensional stability and excellent hydrolysis resistance at temperatures from 50 to 200°C.

Example 2 Paraacetoxybenzoic acid 2 y, o 9 (o, 1
s mol), hydroquinone diacetate 29.1 g (
0.15 mol), 24.9 g (0.15 mol) of terephthalic acid and 1 of 2-acetoxynaphthalene-6-carboxylic acid.
1.5 g (0.05 mol) was used and the reaction and treatment were carried out in the same manner as in Example 1.

Approximately 62 g of polymer are obtained, which exhibits an intrinsic viscosity of 4.7, measured in pentafluorophenol solution at 60 DEG C. and a concentration of 0.1% by weight.

The polymer is melt extruded into continuous filaments of approximately 20 denier/filament and rapidly cooled in air (20° C., relative humidity 65%).

The obtained fibers have the following properties: Strength 1/denier) 12.6 Tensile modulus (,9/denier) 486 Elongation (%) 3.2 Strength after heat treatment at 250°C for 90 hours CEI/denier) 17.6 Tensile modulus ( g/denier) 498 elongation rate (%)
It exhibits an average single fiber property of 3.4 and low shrinkage at high temperatures, approx.
It exhibits dimensional stability and good hydrolysis resistance at temperatures up to 50-2 CIO C.

Example 3 Paraacetoxybenzoic acid 1522.7g (8.45 mol), biphenol diacetate) 351.49 (1,
30 moles), 215.9 g (1,60 moles) of terephthalic acid and 44 g (1,60 moles) of 2-acetoxynaphthalene-6-carboxylic acid.
8.9 g (1.95 mol) was heated at 250°C in a nitrogen stream.
2 hours at 260°C, 2 hours at 280°C, 2
The mixture was heated and stirred at 90°C and 300°C for 1 hour each, and acetic acid was distilled out of the system.

Then, the pressure was gradually reduced to 600℃, and the pressure was reduced to 2torr for 5 hours.
After reducing the pressure to
After further polymerization at r for 15 hours, a polymer is obtained.

The intrinsic viscosity of the obtained polymer, measured at 60°C in pentafluorophenol at a concentration of 0.1% by weight, is:
It was 7.6. In addition, as a result of measurement using a differential scanning calorimeter (DSC) at a heating rate of 20°C/min, the temperature was 271°C.
A melting point peak was observed.

This polymer was dried in a ventilation oven at 120°C overnight, and
When the material was injection molded at 10° C. and its physical properties were measured, it was found to have high strength as shown below.

Tensile strength (ky/cm2) (ASTM D 638 Type I) 1.98
0 Example 4 Rose acetoxybenzoic acid 28.16 kl? (156°4
mol), biphenol diacetate) 6.76 kg (25
, 0 mol), 4.15 kg (25° 0 mol) of terephthalic acid and 10 mol of 2-acetoxynaphthalene-6-carboxylic acid.
．． 0.7 kg (43.8 mol) was placed in a 1504 stainless steel reaction vessel, the atmosphere was replaced with nitrogen, and then heated to 250°C, 280°C, and 610°C while passing a small amount of nitrogen.
The reaction was carried out for 2.5 hours each, and acetic acid was distilled out of the system. Then, the pressure was gradually reduced at 510°C, and the temperature was increased to 40
torr and further increased to 10 torr for 4 hours.
Thereafter, polymerization is performed at 3 to 10 torr for 8 hours to obtain a polymer.

When the properties of this polymer were measured in the same manner as in Example 3, the intrinsic viscosity was z2, and the melting point peak by DSC was 2.
Observed at 51°C. In addition, the physical properties of this polymer using an injection molded test piece showed high strength as shown below.

Tensile strength (kg/cm”) 1.
890 bending strength (kg/c7n2)
1.280 Thermal deformation intensity ('C)
164 Izot impact strength (kg・crn/cIrL
)65 Example 5 Baracetoxybenzoic acid 1396.6 & (7,75
mol), biphenol diacetate 667.9g (1,
25 mol), terephthalic acid 207.6 fi (1,2
5 mol) and 517.99 (2.25 mol) of 2-acetoxynaphthalene-6-carboxylic acid under nitrogen atmosphere,
The reaction is carried out by heating and stirring at 250°C, 280°C, 300°C and 620°C for 1 hour each, and acetic acid is distilled out of the system.

Next, at 320°C, the temperature was gradually increased from normal pressure to 2 to 3 to
The pressure is reduced to rr over 2 hours, and the reaction is further carried out at 1 torr or less for 2 hours to obtain a polymer.

The properties of this polymer were investigated in the same manner as in Example 6 (however, only the test piece molding temperature was changed to 270°C). The intrinsic viscosity of this polymer is 97, and according to DSC,
A melting peak was observed at 250°C. In addition, the physical properties of the polymer injection molded test piece showed high strength and high elastic modulus as shown below.

Claims (1)

[Claims] An aromatic polyester characterized by polycondensing parahydroxybenzoic acid, aromatic dicarboxylic acid, and aromatic diol in the presence of 10 to 20 mol% of 2-hydroxynaphthalene-6-carboxylic acid or a derivative thereof. Manufacturing method.