JPH0710909B2 - Aromatic polyester - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aromatic polyester having excellent heat resistance, flexural rigidity and mechanical strength such as tensile strength and impact strength, and high temperature hydrolysis resistance. More specifically, it relates to an aromatic polyester capable of molding a molded body or fibers excellent in these properties.

[Conventional technology]

Paraoxybenzoic acid polyester is conventionally known as an aromatic polyester having excellent heat resistance. The polyester has drawbacks such as that it is difficult to obtain a polyester having a large molecular weight, and that it is not possible to adopt a usual melt molding method such as injection molding or extrusion molding because thermal decomposition is remarkable during melting. Is industrially rarely used.

Further, as an attempt to improve these drawbacks of the paraoxybenzoic acid polyester, many aromatic polyesters obtained by co-condensing various aromatic dicarboxylic acid components and various aromatic diol components have been proposed [for example, JP-A-47-47870, JP-A-47-11697,
JP-A-55-66927, JP-A-54-50594, JP-A-54-77691, JP-A-55-144024, JP-A-5
6-99225, JP 56-136818, JP 56-
141317, JP-A-57-87423, JP-A-58-172
No. 0, JP-A-58-29819, JP-A-58-29820, JP-A-58-32630, JP-A-59-62630, JP-A-55-135134, JP-A-56-47423, JP-A-56-50921, JP-A-56-50922,
JP-A-58-67719, JP-A-53-35794, JP-A-58-53920, JP-A-53-91721, JP-A-58
-194530, JP 59-41328, JP 50-6
6593, JP-A-50-108392, JP-A-58-6562
9, JP-A-59-918117, JP-A-53-24391, JP-A-55-149321, JP-A-52-98087, JP-A-52-98088, JP-A-52-121619, JP-A-53-47492, JP-A-53-110696, JP-A-53-136098, JP-A-54-43296, JP-A-54-136098 JP, JP-A-56-59843, JP-A-58-45224, etc.]. According to the methods proposed in these prior arts, the copolycondensation surely results in melting at a lower temperature than that of the paraoxybenzoic acid polyester, so that the melt moldability is improved, but the heat resistance is also increased. In many cases, the mechanical properties such as bending rigidity, tensile strength and impact strength are deteriorated, and chemical resistance and water resistance are deteriorated.

Further, among these prior arts, JP-A-53-30290 discloses a paraoxybenzoic acid component unit, a hydroquinone component unit, and an aromatic dicarboxylic acid component unit containing 2,6-dicarboxynaphthalene as a main component. Aromatic polyesters have been proposed and it is stated that some 1,4-dicarboxynaphthalene may be copolycondensed. However, the aromatic polyester obtained here has a melting point. On the other hand, the aromatic polyester of the present invention is 1,4-
By using dicarboxynaphthalene as the aromatic dicarboxylic acid, it has no melting point and has a softening temperature in a relatively low temperature region as described later, and is excellent in moldability.

[Problems to be solved by the invention]

The present inventors have conducted extensive studies on a novel aromatic polyester excellent in heat resistance, melt moldability, bending rigidity, tensile strength, and impact resistance, and as a result, found that a paraoxybenzoic acid component unit was selected. From the aromatic oxycarboxylic acid component unit (A) containing the main component, the specific aromatic diol component unit (B) and the aromatic dicarboxylic acid component unit (C) containing the 1,4-dicarboxynaphthalene component unit as the main component The inventors have found that an aromatic polyester having the following specific composition achieves the above-mentioned object, and arrived at the present invention.

[Means for solving problems]

According to the present invention, (A) an aromatic oxycarboxylic acid component unit containing a paraoxybenzoic acid component unit as a main component is in the range of 40 to 90 mol%, (B) a hydroquinone component unit, 4,4'-dihydroxydiphenyl An aromatic diol component unit whose main component is a component unit, a 2,6-dihydroxynaphthalene component unit and a 4,4'-dihydroxydiphenyl ether component unit, in the range of 5 to 30 mol%, and (C ) 1,4-dicarboxynaphthalene component unit as the main component of aromatic dicarboxylic acid component unit in the range of 5 to 30 mol%, and melt viscosity measured at a temperature of 250 to 450 ° C for 100 sec ^-1 Is provided in the range of 10 ² to 10 ⁷ poise.

[Work]

The aromatic oxybenzoic acid component unit (A) containing a paraoxybenzoic acid component unit as a main component constituting the aromatic polyester of the present invention may be composed of only the paraoxybenzoic acid component unit, or may be composed of the paraoxybenzoic acid component unit. In addition, a small amount of 6-oxy-2-naphthoic acid component unit or metaoxybenzoic acid component unit may be contained. The content of the paraoxybenzoic acid component unit in the aromatic oxycarboxylic acid component unit (A) is, for example, 60 mol% or more, preferably 80%.
It is in the range of mol% or more.

The content of the oxybenzoic acid component unit (A) constituting the aromatic polyester of the present invention is in the range of 40 to 90 mol%, preferably 40 to 70 mol%.

The aromatic diol component unit (B) constituting the aromatic polyester of the present invention is a hydroquinone component unit, a 4,4'-dihydroxydiphenyl ether component unit, a 2,6-dihydroxynaphthalene component unit and a 4,4'-dihydroxydiphenyl component unit. An aromatic diol component unit containing a component unit selected from the enyl component units as a main component, and a hydroquinone component unit, 4,4′-dihydroxydiphenyl ether component unit, 2,6-dihydroxynaphthalene component unit or 4,4 ′
-Dihydroxydiphenyl component units may be included alone, or a small amount of other aromatic diol component units may be contained in addition to these aromatic diol component units. The content of the hydroquinone component unit or the 4,4'-dihydroxydiphenyl component unit in the aromatic diol component unit (B) is, for example, 60 mol% or more, preferably 80 mol% or more.

Other than the hydroquinone component unit, 4,4'-dihydroxydiphenyl ether component unit, 2,6-dihydroxynaphthalene component unit or 4,4'-dihydroxydiphenyl component unit contained in the aromatic diol component unit (B) As the aromatic diol component unit of, resorcin, 3,4 '
-Dihydroxydiphenyl, 3,4'-dihydroxydiphenyl ether, phenylhydroquinone, chlorohydroquinone, methylhydroquinone, 2,2-bis (4-hydroxyphenyl) propane, etc., containing 6 to 6 carbon atoms
Fifteen aromatic diol component units can be exemplified.

The content of the aromatic diol component unit (B) constituting the aromatic polyester of the present invention is in the range of 5 to 30 mol%, preferably 10 to 25 mol%.

The aromatic dicarboxylic acid component unit (C) constituting the aromatic polyester of the present invention is an aromatic dicarboxylic acid component unit containing a 1,4-dicarboxynaphthalene component unit as a main component, and a 1,4-dicarboxynaphthalene component. It may be composed of only a unit, or may contain other aromatic dicarboxylic acid component units as a minor component in addition to the 1,4-dicarboxynaphthalene component unit. The content of the 1,4-dicarboxynaphthalene component unit in the aromatic dicarboxylic acid component unit (C) is, for example, 60 mol% or more, preferably 80 mol% or more.

1,4-contained in the aromatic dicarboxylic acid component unit (C)
Aromatic dicarboxylic acid component units other than dicarboxynaphthalene component units include 4,4'-dicarboxydiphenyl ether, 3,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl and terephthalic acid. , Isophthalic acid, 2,6-dicarboxynaphthalene, 2,7-
8 to 15 carbon atoms such as dicarboxynaphthalene
The aromatic dicarboxylic acid component unit can be exemplified.

The content of the aromatic dicarboxylic acid component unit (C) constituting the aromatic polyester of the present invention is in the range of 5 to 30 mol%, preferably 10 to 25 mol%.

In the aromatic polyester of the present invention, the aromatic oxycarboxylic acid component unit (A) has the general formula [I] [In the formula, -Ar ¹ -is the same as above. And may contain a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms.], The aromatic diol component unit (B) is represented by the general formula [II]- O—Ar ² —O— [II] [wherein —Ar ² — is the same as above. Or And may contain a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms in addition to the above.], The aromatic dicarboxylic acid component unit (C) is generally Formula (III) [In the formula, -Ar ³ -is the same as above. And may contain a divalent aromatic group having 6 to 13 carbon atoms in addition to the above.]. In the aromatic polyester of the present invention, the aromatic oxycarboxylic acid component unit (A), the aromatic diol component unit (B) and the aromatic dicarboxylic acid component unit (C) are randomly arranged to form an ester bond. The oxybenzoic acid component unit (A) may be arranged at the molecular end of the formed and linear aromatic polyester, or the aromatic diol component unit (B) may be arranged. The aromatic dicarboxylic acid component unit (C) may be arranged. Further, the carboxyl group at the molecular end of the aromatic polyester of the present invention may be esterified with a monovalent alcohol such as methanol, ethanol or isopropanol or a monovalent alcohol such as phenol or cresol,
Similarly, the hydroxyl group at the terminal of the molecule may be esterified with a monovalent carboxylic acid such as acetic acid, propionic acid or benzoic acid.

A temperature of 250 to 450 ° C. of the aromatic polyester of the present invention,
For example, 30 ° C from the softening point (Ts) of the aromatic polyester
Melt viscosity measured at 100 sec ^-1 at elevated temperature is 10 ² to 10 ⁷
Poises, preferably 2 × 10 ² to 10 ⁶ poises, particularly preferably 5 × 10 ² to 10 ⁵ poises.

The melting point (Tm) and glass transition temperature (Tg) of the aromatic polyester of the present invention are usually not detected by a differential scanning calorimeter (DSC), and the softening point (Ts) measured by a thermomechanical analyzer (TMA) is usually 200 to 450 ° C, preferably
It is in the range of 250 to 400 ° C.

The elastic modulus of the aromatic polyester fiber of the present invention is usually 100 to 2000 g / d, preferably 200 to 1500 g / d, and the strength is usually 5 to 50 g / d, preferably 10 to 40 g.
/ d, and the elongation is usually 1 to 10%, preferably 2 to 6%.

The aromatic polyester of the present invention can be produced by the following method. That is, the oxycarboxylic acid ester-forming derivative, the aromatic dicarboxylic acid or its ester-forming derivative, and the ester-forming derivative of the aromatic diol are reacted at a high temperature under melting conditions and reduced pressure conditions, and the low-temperature product formed by the reaction is reacted. The aromatic polyester can be produced by distilling the boiling point compound out of the reaction system. For example, the acetic acid ester of the oxycarboxylic acid, the bisacetic acid ester of the aromatic dicarboxylic acid and the aromatic diol are usually added at a temperature of 200 to 450 ° C., preferably 250 to 400 ° C. under a normal pressure to a reduced pressure of 0.1 mmHg. The aromatic polyester of the present invention can be produced by a method of carrying out a polycondensation reaction while distilling off the acetic acid produced by the reaction. Further, the phenol ester of the oxycarboxylic acid, the bisphenol ester of the aromatic dicarboxylic acid and the aromatic diol are usually added at a temperature of 200 to 450 ° C., preferably 250 to 400 ° C. under a normal pressure to a pressure of 0.1 mmHg. The aromatic polyester of the present invention can be produced by a method of carrying out a polycondensation reaction while distilling off the phenol produced by the reaction. Although a catalyst may not be used in the polycondensation reaction, examples of the catalyst that can be used in the polycondensation reaction include aluminum acetate, calcium acetate, magnesium acetate, potassium acetate, sodium acetate, potassium phosphate, sodium sulfate, acetic acid. copper,
Examples thereof include antimony oxide, tetrabutoxy titanium, tin acetate and the like. The proportion used is usually 0.0001 to 1% by weight, preferably 0.001 based on the polycondensation raw material.
To 0.1% by weight.

The aromatic polyester of the present invention can be used for various heat resistant molding applications. For example, in addition to the fact that a molded body can be manufactured by ordinary injection molding and extrusion molding, it can be molded into a fibrous shape by a melt spinning method which is usually performed with polyethylene terephthalate or the like.

〔The invention's effect〕

The aromatic polyester of the present invention has excellent heat resistance and mechanical strength such as flexural rigidity, tensile strength and impact strength, high temperature hydrolysis resistance, and further excellent melt moldability. It can be used in the fields of body and fiber.

〔Example〕

The aromatic polyester of the present invention will be specifically described with reference to examples.

The performance of the aromatic polyester was evaluated according to the following method.

Tm, Tg: Perkin Elmer differential scanning calorimeter (DSC II
Sample type from polymerized polyester using
And raise the temperature from 50 ° C to 450 ° C at a rate of 20 ° C / min,
Then, the temperature is lowered to 50 ℃ at 40 ℃ / min, and again to 450 ℃ at 20 ℃.
Melting temperature Tm measured by temperature rise / min and endotherm thermogram
Is the endothermic peak value at the first and second temperature rises,
Tg was calculated from the value of the second temperature increase (first inflection point).

Ts: Using a 942 type thermomechanical analyzer (TMA) manufactured by Dupont Co., a press sheet with a thickness of 1 mm, a quartz glass needle (diameter 25 mil) at a temperature rising rate of 20 ° C / min and a load of 50 g.
The point where the needle was inserted by 0.1 mm was defined as the softening point Ts.

Melt viscosity: Measured at a shear rate of 100 sec ^-1 using a Shimadzu-made capillary rheometer. However, the softening point (T
s) was measured at a temperature higher by 30 ° C.

Spinning: Using a melt tension tester manufactured by Toyo Seiki Seisaku-sho, spinning was performed from a cylindrical die having a nozzle diameter of 0.2 mm and a nozzle length of 1 mm. The spun raw yarn was wound on a roll using a conventional variable speed motor. The spinning temperature of the polymer was appropriately selected at a temperature of 400 degrees or less. Further, the raw yarn spun from the die was not particularly cooled.

Heat treatment: The heat treatment of the spun raw yarn was carried out under a nitrogen stream or under reduced pressure under relaxed conditions.

Tensile test: Instron universal testing machine 11
It was measured at room temperature (23 ° C) using a 23 type. At this time, the test length between the clamps was 100 mm and the tensile speed was 100 mm / min.
However, the tensile modulus was calculated using the stress at 1% strain.

〔Example〕

Example 1 50 mol% paraoxybenzoic acid unit, 2 hydroquinone units
A polyester composed of 5 mol% and 25 mol% of 1,4-dicarboxynaphthalene unit was synthesized as follows.

Into a 500 ml reactor, 0.5 mol of paraacetoxybenzoic acid, 0.26 mol of paradiacetoxybenzene and 0.25 mol of 1,4-dicarboxynaphthalene were charged and reacted at 275 ° C for 1 hour with stirring to distill off acetic acid, then 2 The temperature was raised to 350 ° C. over time, and the reaction was carried out at 350 ° C. and 0.5 mmHg for 1 hour.

Tm and Tg of the polyester were not detected, Ts was 286 ° C., and melt viscosity measured at 316 ° C. and 100 sec ⁻¹ was 3400 poise. 30 denier fiber was spun at 360 ℃ and 290 ℃
When heat treated for 24 hours, elastic modulus 730 g / d, strength 24.3 g /
Fibers with elongation of 3.3% could be obtained.

Example 2 Paraoxybenzoic acid unit 60 mol%, Hydroquinone unit 2
A polyester composed of 0 mol% and 1,4-dicarboxynaphthalene unit of 20 mol% was synthesized as follows.

A 500 ml reactor was charged with 0.6 mol of paraacetoxybenzoic acid, 0.21 mol of paradiacetoxybenzene and 0.20 mol of 1,4-dicarboxynaphthalene and reacted at 275 ° C for 1 hour with stirring to distill off acetic acid, then 2 The temperature was raised to 350 ° C. over time, and the reaction was carried out at 350 ° C. and 0.5 mmHg for 1 hour.

Tm and Tg of the polyester were not detected, Ts was 308 ° C., and the melt viscosity measured at 338 ° C. and 100 sec ⁻¹ was 2600 poise. 32 denier fiber was spun at 360 ℃ and
When heat treated for 24 hours, elastic modulus 780 g / d, strength 23.1 g / d
d, fiber having an elongation of 3.0% could be obtained.

Comparative Example 1 Paraoxybenzoic acid unit 30 mol%, hydroquinone unit 3
A polyester composed of 5 mol% and 35 mol% of 1,4-dicarboxynaphthalene unit was synthesized as follows.

A 500 ml reactor was charged with 0.3 mol of paraacetoxybenzoic acid, 0.36 mol of paradiacetoxybenzene and 0.35 mol of 1,4-dicarboxynaphthalene, reacted at 275 ° C for 1 hour under stirring to distill off acetic acid, then 2 The temperature was raised to 350 ° C. over time, and the reaction was carried out at 350 ° C. and 0.5 mmHg for 1 hour.

Tm of the polyester was not detected, Tg was 107 ° C,
s was 143 ° C., and the melt viscosity measured at 173 ° C. and 100 sec ⁻¹ was 10 ⁷ poise or more. 24 denier fiber was spun at 360 ℃ and heat treated at 150 ℃ for 48 hours. Elastic modulus 380g /
A fiber having d, strength of 9.6 g / d and elongation of 2.5% could be obtained.

Example 3 A polyester consisting of 80 mol% of paraoxybenzoic acid unit, 10 mol% of 4,4'-dihydroxydiphenyl unit and 10 mol% of 1,4-dicarboxynaphthalene unit was synthesized as follows.

In a 500 ml reactor, 0.8 mol of paraacetoxybenzoic acid, 4,
Charge 4'-diacetoxydiphenyl 0.1mol, 1,4-dicarboxynaphthalene 0.1mol, react with stirring at 275 ℃ for 1 hour, distill off acetic acid, then raise to 350 ℃ over 2 hours. The reaction was carried out at 350 ° C. and 0.5 mmHg for 1 hour.

Tg and Tg of the polyester were not detected, Ts was 298 ° C., and melt viscosity measured at 328 ° C. and 100 sec ⁻¹ was 3100 poise. 28 denier fiber is spun at 360 ℃ and 290 ℃
When heat-treated for 24 hours, the elastic modulus is 760 g / d and the strength is 25.1 g /
Fibers with elongation of 3.3% could be obtained.

Comparative Example 2 A polyester comprising 30 mol% of paraoxybenzoic acid unit, 35 mol% of 4,4'-dihydroxydiphenyl unit and 35 mol% of 1,4-dicarboxynaphthalene unit was synthesized as follows.

In a 500 ml reactor, 0.3 mol of paraacetoxybenzoic acid, 4,
Charge 4'-diacetoxydiphenyl 0.35mol, 1,4-dicarboxynaphthalene 0.35mol, react at 275 ℃ with stirring for 1 hour, distill off acetic acid, then raise to 350 ℃ over 2 hours. The reaction was carried out at 350 ° C. and 0.5 mmHg for 1 hour.

Tm of the polyester was not detected, Tg was 116 ° C.
s was 156 ° C., and the melt viscosity measured at 186 ° C. and 100 sec ⁻¹ was 10 ⁷ poise or more. 34 denier fiber was spun at 360 ℃ and heat treated at 160 ℃ for 48 hours.
Fibers having d, strength of 10.4 g / d and elongation of 3.0% could be obtained.

Example 4 A polyester comprising 80 mol% of paraoxybenzoic acid unit, 10 mol% of 2,6-dihydroxynaphthalene unit and 10 mol% of 1,4-dicarboxynaphthalene unit was synthesized as follows.

In a 500 ml reactor, 0.8 mol of paraacetoxybenzoic acid, 2,6
-Prepared with 0.1 mol of diacetoxynaphthalene and 0.1 mol of 1,4-dicarboxynaphthalene, reacted at 275 ° C for 1 hour with stirring to distill acetic acid, and then heated to 350 ° C over 2 hours, and 350 ° C. , 0.5 mmHg for 1 hour.

Tm and Tg of the polyester were not detected, Ts was 276 ° C., and the melt viscosity measured at 306 ° C. and 100 sec ⁻¹ was 4500 poise. 25 denier fiber is spun at 360 ° C and then at 270 ° C
When heat-treated for 48 hours, elastic modulus 690g / d, strength 22.3g /
Fibers with d and elongation of 3.2% could be obtained.

Comparative Example 3 A polyester composed of 30 mol% of paraoxybenzoic acid unit, 35 mol% of 2,6-dihydroxynaphthalene unit and 35 mol% of 1,4-dicarboxynaphthalene unit was synthesized as follows.

In a 500 ml reactor, 0.30 ml of paraacetoxybenzoic acid, 2,6
-Prepare 0.35 mol of diacetoxynaphthalene and 0.35 mol of 1,4-dicarboxynaphthalene, react with stirring at 275 ° C for 1 hour, distill off acetic acid, then raise to 350 ° C over 2 hours, 350 ° C , 0.5 mmHg for 1 hour.

Tm of the polyester was not detected, Tg was 114 ° C.
s was 142 ° C., and the melt viscosity measured at 172 ° C. and 100 sec ⁻¹ was 10 ⁷ poise or more. 29 denier fiber was spun at 360 ℃ and heat treated at 150 ℃ for 48 hours. Elastic modulus 410g /
Fibers having d, strength of 11.2 g / d and elongation of 2.7% could be obtained.

Example 5 A polyester composed of 80 mol% of paraoxybenzoic acid unit, 10 mol% of 4,4′-dihydroxydiphenyl ether unit and 10 mol% of 1,4-dicarboxynaphthalene unit was synthesized as follows.

In a 500 ml reactor, 0.8 mol of paraacetoxybenzoic acid, 4,
Charge 4'-diacetoxydiphenyl ether 0.1mol, 1,4-dicarboxynaphthalene 0.1mol, react with stirring at 275 ° C for 1 hour, distill off acetic acid, then over 2 hours
The temperature was raised to 350 ° C., and the reaction was carried out at 350 ° C. and 0.5 mmHg for 1 hour.

Tm and Tg of the polyester were not detected, Ts was 263 ° C., and the melt viscosity measured at 293 ° C. and 100 sec ⁻¹ was 5600 poise. Spun 29 denier fiber at 360 ° C and 260 ° C
When heat-treated for 48 hours, elastic modulus 530g / d, strength 20.4g /
d, fiber having an elongation of 3.8% could be obtained.

Comparative Example 4 A polyester comprising 30 mol% of paraoxybenzoic acid unit, 35 mol% of 4,4'-dihydroxydiphenyl ether unit and 35 mol% of 1,4-dicarboxynaphthalene unit was synthesized as follows.

In a 500 ml reactor, 0.3 mol of paraacetoxybenzoic acid, 4,
Charge 0.35mol of 4'-diacetoxydiphenyl ether and 0.35mol of 1,4-dicarboxynaphthalene, react at 275 ℃ under stirring for 1 hour, distill off acetic acid, then over 2 hours
The temperature was raised to 350 ° C., and the reaction was carried out at 350 ° C. and 0.5 mmHg for 1 hour.

Tm of the polyester was not detected, Tg was 110 ° C.,
s was 135 ° C., and the melt viscosity measured at 165 ° C. and 100 sec ⁻¹ was 10 ⁷ poise or more. When 32 denier fiber was spun at 360 ℃ and heat treated at 140 ℃ for 48 hours, elastic modulus 180g /
Fibers with d, strength of 8.4 g / d and elongation of 4.7% could be obtained.

Claims (1)

[Claims] 1. An (A) aromatic oxycarboxylic acid component unit comprising a paraoxybenzoic acid component unit as a main component is 40 to 90.
Mol% range, mainly composed of (B) hydroquinone component unit, 4,4'-dihydroxydiphenyl component unit, 2,6-dihydroxynaphthalene component unit and 4,4'-dihydroxydiphenyl ether component unit The aromatic diol component unit as a component is in the range of 5 to 30 mol%, and (C) the aromatic dicarboxylic acid component unit containing 1,4-dicarboxynaphthalene component unit as the main component is in the range of 5 to 30 mol%, An aromatic polyester having a melt viscosity measured at 100 sec ^-1 at a temperature of 250 to 450 ° C. in the range of 10 ² to 10 ⁷ poises.