JPS62256826A - Aromatic polyester - Google Patents

Abstract

PURPOSE:To obtain an aromatic polyester excellent in heat resistance, mechanical strength and high-temperature hydrolysis resistance, containing aromatic diol units comprising a hydroquinone component and aromatic dicarboxylic acid units comprising a terephthalic acid component as structural components. CONSTITUTION:An aromatic polyester consisting of 0-80mol% hydroxybenzoic acid component units (A) based on p-hydroxybenzoic acid component units, 10-50mol% aromatic diol component units (B) based on 3-18C prim. or sec. hydrocarbon group-substituted hydroquinone component units and 10-50mol% aromatic dicarboxylic acid component units (C) based on terephthalic acid component units and having a melt viscosity in the range of 10<2>-10<6> P as determined at 250-450 deg.C with a shear rate of 100/sec. The content of said hydroxybenzoic acid component units (A) is preferably in the range of 10-60mol%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aromatic polyester that is excellent in heat resistance, bending rigidity, mechanical strength such as tensile strength and impact strength, and high temperature hydrolysis resistance. More specifically, the present invention relates to an aromatic polyester that can be used to form molded articles or fibers having excellent properties.

[Conventional technology]

Paraoxybenzoic acid polyester has been known as an aromatic polyester with excellent heat resistance. This polyester has drawbacks such as the difficulty in obtaining large intermolecular molecules and significant thermal decomposition during melting, making it impossible to use ordinary melt molding methods such as injection molding and extrusion. However, it is hardly used industrially.

In addition, in an attempt to improve these drawbacks of paraoxybenzoic acid polyester, many aromatic polyesters have been proposed in which various aromatic dicarboxylic acid components and various aromatic diol components are co-condensed (for example, Publication No. 47-47870, Japanese Unexamined Patent Publication No. 47-11
697, JP 55-66927, JP 54-50594, JP 54-77691, JP 55-144024, JP 56-9
9225, JP 56-136818, JP 56-141317, JP 57-8742
Publication No. 3, JP-A-58-1720, JP-A-58-
29819, JP 58-29820, JP 58-32630, JP 59-62630
No. 135134, Japanese Patent Application Laid-Open No. 1983
-47423 publication, Japanese Patent Application Laid-open No. 56-50921,
JP-A-56-50922, JP-A-58-6771
9, JP-A-53-35794, JP-A-58
-53920 publication, JP-A-53-91721 publication,
JP-A-58-194530, JP-A-59-413
No. 28, JP-A-50-66593, JP-A-Sho 5
0-108392, JP 58-65629, JP 59-918117, JP 53-2
4391, JP 55-149321, JP 52-98087, JP 52-98088
Publication No. 121619/1983, Japanese Patent Application Laid-Open No. 1982-121619
-47492, JP 53-110696, JP 53-136098, JP 54-43
296, JP-A-54-136098, JP-A-56-59843, JP-A-58-45224, etc.]. According to the methods proposed in these prior art, it is true that melt moldability is improved because the copolycondensation melts at a lower temperature than paraoxybenzoic acid polyester, but the heat resistance decreases accordingly. Furthermore, mechanical properties such as flexural rigidity, tensile strength, and impact strength deteriorate, and chemical resistance and water resistance often deteriorate.

Also, among these prior art, Japanese Patent Application Laid-Open No. 52-11472
Publication No. 4 proposes an aromatic polyester consisting of a hydroxybenzoic acid component unit, an alkyl group-substituted dioxybenzene component unit, and an aromatic dicarboxylic acid component unit, and methylhydroquinone is used as the alkyl group-substituted dioxybenzene component unit. Specifically, a terephthalic acid component unit is specifically exemplified as an aromatic dicarboxylic acid component unit. However, aromatic polyesters consisting of hydroxybenzoic acid component units, methylhydroquinone component units, and terephthalic acid component units, which are specifically considered from such exemplified components, have a high melting temperature and cannot be said to have excellent melt moldability.

Furthermore, JP-A-58-29819 proposes an aromatic polyester consisting of an aromatic oxycarboxylic acid component unit, a tertiary alkyl group-substituted hydroquinone component unit, and an aromatic dicarboxylic acid component unit. In the examples, an aromatic polyester comprising a roseoxybenzoic acid component unit, a tertiary alkylhydroquinone component unit, and a terephthalic acid component unit is specifically exemplified. However, although the aromatic polyester has a lower melting temperature and improved melt moldability, the thermal decomposition of the tertiary alkyl hydroquinone component unit is large, resulting in poor heat resistance and strength.

[Problem that the invention seeks to solve]

The present inventors have intensively investigated a new aromatic polyester that has excellent heat resistance, melt moldability, and mechanical properties such as flexural rigidity, tensile strength, and impact strength. An aromatic compound with a specific composition consisting of an oxybenzoic acid component unit (A) having a main component, a specific aromatic diol component unit (B), and an aromatic dicarboxylic acid component unit (C) having a terephthalic acid component unit as a main component. It was discovered that polyester achieves the above object, and the present invention was achieved.

Means for Solving Problem C] According to the present invention, (8) the oxybenzoic acid component unit whose main component is a hydroxybenzoic acid component unit is in the range of 0 to 80 mol %, (B) the number of carbon atoms is 3 to 80 mol % 10 to 50 mol% of aromatic diol component units mainly composed of hydroquinone component units substituted with 18 primary or secondary hydrocarbon groups, and (C) terephthalic acid component units as the main component. 10 to 50 mol% of aromatic dicarboxylic acid component units, and 250 to 450"C1100s
A melt-formable aromatic polyester is provided having a melt viscosity measured on an ec-cage in the range of 10'' to 106 voids.

Oxybenzoic acid component unit (
A) may consist only of paraoxybenzoic acid component units, or may contain a small amount of metaoxybenzoic acid component units in addition to paraoxybenzoic acid component units. The content of paraoxybenzoic acid component units in the oxybenzoic acid component unit (A) is in the range of 60 mol% or more, preferably 80 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 O to 80 mol%, preferably 1O to 60 mol%.

The aromatic diol component unit (B) constituting the aromatic polyester of the present invention is an aromatic diol component whose main component is a hydroquinone component unit substituted with a primary or secondary hydrocarbon group having 3 to 18 carbon atoms. units, and these substituted hydroquinones include n-propylhydroquinone, isopropylhydroquinone, 2,3-di-n-
Propylhydroquinone, 2,5-di-n-propylhydroquinone, 2,6-di-n-propylhydroquinone, n-butylhydroquinone, 5ee-butylhydroquinone, isobutylhydroquinone, n-hexylhydroquinone, n-octylhydroquinone, n- Examples include decylhydroquinone and n-octadecylhydroquinone. These I? It may consist only of the A-hydroquinone component unit, or it may contain a small amount of other aromatic diol component units in addition to the substituted hydroquinone component unit. The content of these substituted hydroquinone component units in the aromatic diol component units is, for example, 60 mol% or more, preferably 80 mol% or more.

The aromatic diol component units other than the hydroquinone derivative component unit contained in the aromatic diol component unit (B) include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 3 .4'-dihydroxydiphenyl ether, bis(4-hydroxyphenyl)methane, ■, 1
- Aromatic compounds having 6 to 15 carbon atoms such as bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, 2,6-hydroxynaphthalene, 2,7-hydroxynaphthalene, etc. Examples include diol component units.

The content of the aromatic diol component unit (B) constituting the aromatic polyester of the present invention is in the range of 10 to 50 mol%, preferably 20 to 45 mol%.

The aromatic dicarboxylic acid component unit (C) constituting the aromatic polyester of the present invention is an aromatic dicarboxylic acid component unit whose main component is a terephthalic acid component unit, and may consist only of terephthalic acid component units, In addition to the terephthalic acid component unit, a small amount of other aromatic dicarboxylic acid component units may be contained. The content of the component units is, for example, 60 mol% or more, preferably 80 mol%
This is the above range.

The aromatic dicarboxylic acid component units other than the terephthalic acid component unit contained in the aromatic dicarboxylic acid component unit (C) include 4,4'-dicarboxydiphenyl ether,
3.4'-dicarboxydiphenyl ether, 313'
-Dicarboxydiphenyl ether, 4.4'-dicarboxydiphenyl, isophthalic acid, 2.6-dicarboxynaphthalene, 2.7-dicarboxynaphthalene, 1.
Examples include aromatic dicarboxylic acid component units having 8 to 15 carbon atoms such as 4-dicarboxynaphthalene.

The content of the aromatic dicarboxylic acid component unit (C) constituting the aromatic polyester of the present invention is 10 to 50 mol%
, preferably in the range of 20 to 45 mol%.

In the aromatic polyester of the present invention, the onybenzoic acid component unit (A) has the formula -FQ (1) [wherein the 1,4-bond is the main component as above, the 1,3-bond The aromatic diol component unit (B) may contain an aromatic hydrocarbon group having the general formula %(), where R is the number of carbon atoms. 3 to 18 primary or secondary hydrocarbon groups, n is an integer of 1 or 2.], and the aromatic dicarboxylic acid component unit (C) has the general formula (III) -C-Ar"-C- (mainly composed of II[], which may also contain a divalent aromatic group having 6 to 13 carbon atoms) is formed. .

In the aromatic polyester of the present invention, the oxybenzoic acid component position (A), the aromatic diol component unit (B), and the aromatic dicarboxylic acid component unit (C) are each arranged randomly to form an ester bond. and forms a linear aromatic polyester. At the molecular terminal of the aromatic polyester, the oxybenzoic acid component unit (A) may be located, the aromatic diol component unit (B) may be located, or the aromatic dicarbonate component unit (B) may be located at the molecular terminal of the aromatic polyester. Acid component units (C) may be arranged. Furthermore, the carboxyl group at the molecular terminal of the aromatic polyester of the present invention is methanol,
It may be esterified with a monohydric alcohol such as ethanol or isopropanol, or a monohydric phenol such as phenol or cresol, and the hydroxyl group at the end of the molecule may be esterified with a monohydric alcohol such as acetic acid, propionic acid, or benzoic acid. may be esterified with a carboxylic acid.

A temperature of 250 to 450° C. of the aromatic polyester of the present invention, e.g.
100 sec at a temperature 30°C higher than the SC melting point (Tm)
- Melt viscosity measured at 102 to 10" poise,
The preferred range is 2×10” to 10′ voids.

Glass transition temperature (Tg) of the aromatic polyester of the present invention
is usually not detected by a differential scanning calorimeter (DSC).
The melting point (Tm), measured by C, usually ranges from 200 to 400°C, preferably from 250 to 380°C.

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

The aromatic polyester of the present invention can be produced by the following method. That is, the oxycarboxylic acid ester-forming SA 8, the aromatic dicarboxylic acid or its ester-forming derivative, and the aromatic diol ester-forming derivative are reacted at high temperature under melting conditions and under reduced pressure, and the low An 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 aromatic dicarboxylic acid and the bisacetic acid ester of the aromatic diol are usually added at a concentration of 200 to 450%.
According to the present invention, the polycondensation reaction is carried out by carrying out the reaction at a temperature of preferably 250 to 400"C under normal pressure to a reduced pressure of 0.1 mmHg, and the acetic acid produced by the reaction is distilled off. Aromatic polyesters can be produced.

Although it is not necessary to use a catalyst for the polycondensation reaction, examples of catalysts that can be used for the polycondensation reaction include aluminum acetate, calcium acetate, magnesium acetate, potassium acetate, sodium acetate, potassium phosphate, sodium sulfate,
Examples include copper acetate, antimony oxide, tetrabutoxytitanium, and tin acetate. The proportion used is usually 0.0001 to 1% by weight, preferably 0.001 to 0.1% by weight, based on the polycondensation raw material.

The aromatic polyester of the present invention can be used in various heat-resistant molding applications. For example, in addition to being able to produce a molded body by ordinary injection molding and extrusion molding, it can also be molded into a fibrous form by a melt-spinning method, which is generally used for polyethylene terephthalate.

〔Effect of the invention〕

The aromatic polyester of the present invention has excellent heat resistance and mechanical strength such as flexural rigidity, tensile strength, and impact strength, and has excellent high-temperature hydrolysis resistance. Can be used in body and textile fields.

〔Example〕

The aromatic polyester of the present invention will be specifically explained with reference to Examples.

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

Tm, Tm: PerkinElmer differential scanning calorimeter (D
SCII type), a 10-inch sample was taken from the polymerized polyester, heated from 50°C to 400°C at a rate of 20°C/min, then lowered to 50°C at 40"C for 7 minutes, and heated again. 4
The temperature was raised to 00'C for 7 minutes at 20'C, and the endothermic thermogram was measured. (inflection point).

Melt viscosity: Measured using a capillary rheometer manufactured by S Tsu Seisakusho at a sliding speed of 100 sec-'. However, the measurement was performed at a temperature 30° C. higher than the melting point (Tm) of the second heating.

Spinning: Using a melt tension tester manufactured by Toyo Seiki Seisakusho, spinning was performed from a cylindrical gouie with a nozzle diameter of 0.2 mm and a nozzle length of 1 mm. The spun yarn was wound onto a roll using a conventional variable speed motor. The spinning temperature of the polymer was appropriately selected to be 400 degrees or less. Further, the raw yarn spun from Gui was not particularly cooled.

Heat treatment: Heat treatment of the spun yarn was carried out under nitrogen flow or under reduced pressure conditions.

Tensile test: Instron universal testing machine 1 manufactured by Instron
Measurement was carried out using Model 123 at room temperature (23°C). At this time, the test vehicle between the clamps was 1001, and the tensile speed was 100 mm/min. However, the tensile modulus was calculated using stress at 1% strain.

Example 1 Paraoxybenzoic acid unit 20 molχ, isopropylhydroquinone unit 40 mol%, terephthalic acid unit 40
A polyester consisting of +no12 was synthesized as follows. 500n+j! Into a reactor, 236 g of rose acetoxybenzoin fi, 94.5 g of rose diacetoxyisopropylbenzene, and 66.4 g of terephthalic acid were charged.
React at 275°C for 1 hour with stirring, distill acetic acid,
Next, the temperature was raised to 370°C over 2 hours, and the temperature was increased to 370°C10
, 5 mmHg for 30 minutes.

The T of the 1st LI of the polyester was determined by DSC measurement.
m is 345°C.Tm of the second temperature increase is 336°C,
Tg was not detected. 366°C 1100sec-
'te (7) Melt viscosity was 1300 poise. 3
23 denier fiber was spun at 80"C, 320℃1
When heat treated at mmHg for 24 hours, the elastic modulus was 670.
g/d, strength 20.6 g/d, elongation 3.0
% fiber could be obtained.

Comparative Example 1 Paraoxybenzoic acid unit 20 molχ, methylhydroquinone unit 40 mo L! , terephthal 62 unit 40
A polyester consisting of molχ was synthesized as follows.

In a 500ml reactor, add paraacetoxyammonium, incense H3
6 g of paradiacetoxymethylhenzene, 83.3 g of terephthalic acid, and 66.4 g of terephthalic acid were charged and reacted at 275°C for 1 hour with stirring to distill off acetic acid.
The temperature was raised to 00°C, and the reaction was carried out for 10 minutes at 400°C, Q, and 5 mmHg.

According to DSC measurement of the polyester, Tm and Tg are 40
It was not detected below 0°C. 350 to 450
Attempts were made to spin the material at ℃, but no fibers could be obtained.

Comparative Example 2 2 x O1 x hydroxybenzoic acid units, 40 mol x t-butylhydroquinone units, 40 mo terephthalic acid units
A polyester consisting of lχ was synthesized as follows.

36g of bulk acetoxybenzoic acid in a 500ml reactor
1 paradiacetoxy-t-butylbenzene 100.1
g, 66.4 g of terephthalic acid were charged, reacted at 275°C for 1 hour with stirring, acetic acid was distilled out, and then the temperature was raised to 370°C over 2 hours.
The mixture was allowed to react for 30 minutes.

The Tm of the polyester at the first temperature increase by DSC measurement was 304°C, and the Tl11 at the second temperature increase was 298°C.
g was not detected. At 328℃, 100sec-'? 8 Melt viscosity was 1800 poise. 2 at 380℃
When an 8 denier fiber was spun and heat treated at 270°C lmm) Ig for 24 hours, the elastic modulus was 480 g/d.
It was possible to obtain fibers with a strength of 10.4 g/d and an elongation of 2.2%.

Example 2 A polyester consisting of 20 mol χ of roseoxybenzoic acid units, 40 mol χ of n-hexylhydroquinone units, and 40 mol χ of terephthalic acid units was synthesized as follows. In a 500 ml reactor, 36 g of rose acetoxybenzoic acid, 111.4 g of rose diacetoxy-〇-hexylbenzene, and 66.4 g of terephthalic acid were charged.
The reaction was carried out at 75°C for 1 hour with stirring, acetic acid was distilled out, and then the temperature was raised to 370°C over 2 hours.
The reaction was carried out for 30 minutes at m tl g.

The Tm of the polyester measured by DSC at the first temperature increase was 328° C., and the Tm at the second temperature increase was 319° C., and no Tg was detected. At 349℃, 100sec-'?
8. Melt viscosity was 1600 poise. When a 34 denier fiber was spun at 380°C and heat treated at 300°C for 24 hours at 1 mm 1 g, the elastic modulus was 630 g/d and the strength was 21.8.
It was possible to obtain fibers with g/d and elongation of 3.5%.

Claims (1)

[Claims] (1) (A) Oxybenzoic acid component units mainly composed of paraoxybenzoic acid component units range from 0 to 80 mol%, (B) A primary or secondary hydrocarbon group having 3 to 18 carbon atoms. Aromatic diol component units containing substituted hydroquinone component units as a main component range from 10 to 50 mol%, and (C) aromatic dicarboxylic acid component units containing terephthalic acid component units as a main component range from 10 to 50 mol%. and 250 to 450℃, 100se
Melt viscosity measured at c^-^1 is 10^2 to 10^
A melt-moldable aromatic polyester characterized by having a void size in the range of 6.