JPH01132628A - Aromatic polyester - Google Patents

Abstract

PURPOSE:To obtain an aromatic polyester satisfactorily possessing both of melt moldability and heat resistance and being capable of giving a molding having sufficiently practical mechanical properties and a high whiteness, containing three kinds of specified repeating units at a specified ratio. CONSTITUTION:This aromatic polyester contains 30-80mol% repeating structural units of formula I, 10-35mol% repeating structural units of formula III, wherein Ar1 is selected from the groups of formulas IV and V, 50-100mol% of Ar1 groups are bivalent aromatic groups of formula IV,and Ar2 is a bivalent aromatic group.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aromatic polyester having excellent physical properties and good melt moldability.

[Conventional technology]

Various attempts have been made to obtain polyester for a long time. For example, polyethylene terephthalate (hereinafter referred to as 1'-PETJ), which is a polyester obtained by the polycondensation reaction of dicarboxylic acid and diol, has a melting point of 260"C.
It is known as a general-purpose polyester with excellent moldability. In addition, an aromatic polyester having a repeating structural unit of -←o-(D-co+) obtained by polycondensation of p-, which is a type of oxyacid, and droxybenzoic acid (for example, Econol manufactured by Sumitomo Chemical Co., Ltd.) E-101
), special polyesters with high crystallinity and excellent heat resistance that do not decompose at all even at 800"C are also known.Furthermore, polyesters obtained by polycondensation reaction of dicarboxylic acids, diols, and oxyacids are also known. As polyester,
Japanese Patent Publication No. 47-47870 discloses a polyester obtained by polycondensation reaction of terephthalic acid, hydroquinone and p-hydroxybenzoic acid.

ing.

[Problem that the invention seeks to solve]

However, moldability and heat resistance are said to be in a contradictory relationship, and although it has both of these properties well, realesters are not yet known.

That is, although the above PET has excellent moldability, it
Further, although aromatic polyesters such as ECONOL E-101 have excellent heat resistance, their melting point exceeds 500 DEG C., making melt moldability extremely difficult. Also, special public service No. 47-47870
Since the polyester disclosed in the publication is easily colored during polymerization and molding, most of the molded products obtained are not satisfactory in terms of whiteness.

The object of the present invention is to create an aromatic polyester that has a good combination of moldability (particularly melt moldability) and heat resistance, has sufficiently practical mechanical properties, and can yield molded products with high whiteness. It is about providing.

[Means for solving problems]

The present inventors have continued research on heat-resistant aromatic polyester containing a +08 CO+ repeating structural unit. As a result, by performing a polycondensation reaction of specific monomer components in a specific ratio, molded products with excellent moldability and heat resistance, good mechanical properties, etc., and high whiteness can be produced. The present inventors have discovered that aromatic polyesters can be obtained, and have completed the present invention.

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

+o Art-C0-)-(A) -t 0CHICH,0CO-@=c00C3CHtO
+ (B)+C0-Ar2-CO+(C) (wherein ArlE is selected from the group consisting of
is a monovalent divalent aromatic group, and Arl is a divalent aromatic group. ) The aromatic polyester of the present invention has the following (A)', (B)
' and (C)' The compound represented by (A)'80-8
0 mol%, (B)'10-35 mol% and (C)'10
It can be produced by carrying out a polycondensation reaction at a ratio of ~35 mol%.

(A)' HO-Ar, -COOH or its ester-forming derivative (B) IHo-cH! ch-oco-@)-cooch
ch-oH or an ester-forming derivative thereof (C) HOCO-Ar, -COOH or a sonoester-forming derivative (wherein Ar is selected from the group consisting of -8← and [ΣSip', and , 50 to 100 mol% of it is -
0-, and A rfi is a divalent aromatic group. ) The constituent proportion (mol) of each repeating structural unit represented by the above formula (c), @ and 0 is (A) 8
0-80%, (B) 10-86% and (C) 10-86%
The 35% bori ester is crystalline and has excellent heat resistance, and also exhibits optical anisotropy when melted and has good moldability.
Moreover, molded products with high whiteness can be obtained.

If the proportion of the structural unit (A) exceeds 80%, there will be parts in the polyester that do not melt when heated, resulting in poor moldability, and if it is less than 80%, the polyester will have poor crystallinity or anisotropy during melting. At least 50 of the straight number ζ structural units (A) are
% is not Σ, crystallinity or anisotropy during melting decreases, which is unfavorable in terms of both formability and physical properties. When the proportion of structural units (B) and (C) is between 10 and 35%, the polyester provides well-balanced characteristics.

The compounds represented by (A)′ above include p-hydroxybenzoic acid, p-formoxybenzoic acid, p-acetoxybenzoic acid, p-probyloxybenzoic acid, methyl p-hydroxybenzoate, phenyl p-hydroxybenzoate, p-
Benzyl hydroxybenzoate, methyl p-acetoxybenzoate, 2-hydroxy-6-naphthoic acid, 2-acetoxy-6-naphthoic acid, methyl 2-hydroxy-6-naphthoate, phenyl 2-hydroxy-6-naphthoate,
Examples include methyl 2-acetoxy-6-naphthoate.

As the compound represented by (B)′ above, bis-(β-
Examples include hydroxyethyl) terephthalate, bis-(β-acetoxyethyl) terephthalate, and bis-(β-probyloxyethyl) terephthalate.

As the compound represented by (C)' above, 2,6-dicarboxynaphthalene, 2,7-dicarboxynaphthalene,
Terephthalic acid, isophthalic acid, 4,4'-dicarboxydiphenyl, 1,2-bis(4-carboxyphenoxy)ethane, and methyl esters of these dicarboxylic acids,
It is obtained by polycondensing a compound represented by pheni(C)· in a polymerization tank. The method of charging these compounds into the polymerization tank may be a batch method or a divided method, and the process may be a batch method, a continuous method, or a combination thereof.

The temperature of the polycondensation reaction in the present invention is preferably 250 to 350°C, more preferably 280 to 280°C. If the temperature is lower than 250°C, the reaction is difficult to occur, and if it exceeds 350°C, decomposition etc. Side reactions may occur. A multi-step reaction temperature may be used, and in some cases, the polycondensation reaction system may be heated to a target temperature and then immediately lowered. The time for the polycondensation reaction is preferably 0.5 to 10 hours at the temperature of the polycondensation reaction. The polycondensation reaction can be carried out under normal pressure, reduced pressure, or a combination thereof. The polycondensation reaction proceeds conveniently without a solvent, but if necessary, hydrocarbons with a high boiling point, ethers, silicone oil, fluorine oil, etc. may be used as a solvent.

The polycondensation reaction in the present invention proceeds conveniently without a catalyst, but if necessary, a tin compound, an antimony compound,
Titanium compounds, germanium compounds, phosphorus compounds, amine compounds, etc. can be used as catalysts. (A)
In addition to the compounds represented by ', CB)' and (C)', stabilizers, fillers, etc. can also be used in combination to carry out the polycondensation reaction of the present invention.

In the case of the aromatic polyester of the present invention, a method for measuring its molecular weight has not yet been found, or even if it has been found, the precision and reproducibility of the measured values may not be good. Therefore, instead of the molecular weight of the aromatic polyester obtained,
Flow temperature (described later) was used to represent the melt fluidity of the thermoplastic resin due to heating. A resin with a low flow temperature indicates a resin with high melt fluidity, that is, a low molecular weight. Flow temperature j of the aromatic polyester of the present invention, t170~880°C1 Preferably 200~300
It is ℃. If the flow temperature is less than 170'C, the molecular weight is low and the heat resistance is poor, resulting in problems in moldability or insufficient physical properties of the molded product. Moreover, it is often impossible to mold products with a flow temperature exceeding 380° C. (The problem of thermal decomposition occurs at high temperatures.

〔Effect of the invention〕

According to the present invention, the aromatic polyester containing repeating structural units represented by the above formulas (e), (c), and 0 in a specific ratio has good moldability (particularly melt moldability) and heat resistance. It is an aromatic polyester that has sufficient practical mechanical properties and provides molded products with a high degree of whiteness.

As shown in Comparative Example 1, which will be 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. In addition, the aromatic polyester of the type described in Japanese Patent Publication No. 47-47870 (Comparative Example 2) cited in the section of the prior art was
Although the moldability and heat resistance were relatively good, it required a molding temperature of 350°C or higher, and although it was colored during polymerization and molding, only molded products with significantly inferior whiteness were obtained.

On the other hand, the polyester obtained in the examples of the present invention exhibits optical anisotropy when melted and can be molded at 350°C or lower, so it has good moldability and heat resistance and is sufficiently practical. This makes it possible to obtain an aromatic polyester that has certain mechanical properties and provides molded products with a high degree of whiteness.

The aromatic polyester of the present invention is crystalline and stable during melt molding at high temperatures and during use. Not only can it be used, but also the aromatic polyester and glass fiber, mica, talc, silica, potassium titanate, wollastonite,
Compositions made of calcium carbonate, quartz, iron oxide, graphite, carbon fiber, etc. have excellent mechanical properties, electrical properties, chemical resistance, and oil resistance, so they are used in mechanical parts, electrical/electronic parts, automobile parts, etc. Can be used.

〔Example〕

Examples of the present invention will be shown below, but the present invention is not limited thereto. In addition, the method of measuring physical properties in Examples is as follows.

Flow temperature: ■ Shimadzu flow tester ■ CFT-
When a sample resin heated and melted at a heating rate of 4°C/min was extruded using a nozzle with an inner diameter of 1ff and a length of 10ff under a load of 10°kq/d, the melt viscosity was 48. It was expressed as the temperature at a point showing .000 poise.

Melting anisotropy: Polyester powder with a particle size of 250 μm or less was placed on a heating stage, heated at 25° C./min under polarized light, and visually observed.

Weight loss: Change in weight over time when approximately 20 sample resins with a particle size of 250 μm or less were heated in air at a temperature increase rate of 10°C/min using a thermobalance TG-DTA standard type manufactured by Rigaku Denki ■. was measured. Further, from this measured value, the temperature at which the weight loss rate was 2.5% with respect to the original weight was determined.

Tensile test: In accordance with ASTM D-688, a dumbbell-shaped test piece was used, the number of samples was 6, the distance between gauge lines was 40 fins, and the tensile rate was 5 ff/min.

Heat distortion temperature: Pressure 18 according to ASTM D-648
．． Measured at 6 to 9/d.

Whiteness of molded product: Using a plate-shaped molded product with a size of 40ff x 40111, a digital color difference meter ND- manufactured by Nippon Seishoku Kogyo ■ was used.
Measured using Model 101-DP. The measured value is 0 for pure black,
Pure white is 100, and titanium oxide standard product (whiteness 94.
5) was corrected.

Example 1 Molar ratio of repeating structural units (6):(c):(C)=60
:20:20 is shown as an example.

It has comb-shaped stirring blades and the gap between the tank wall of the polymerization tank and the stirring blade is small.
p-hydroxybenzoic acid 828F (6,000
mol)゛, bis-(β-hydroxyethyl) terephthalate 508F (2,00 mol), terephthalic acid 882f
(2,00 mol) and acetic anhydride 1128f (11,00 mol)
Mol) was prepared.

The contents were heated to 140°C while stirring under a nitrogen atmosphere.
The acetylation reaction was carried out for 2 hours while refluxing. A portion of this reaction product was sampled, dissolved in methanol, and analyzed by liquid chromatography (column: Microbondapak C18 manufactured by Waters, carrier solvent: methanol/water = 2/l vol ratio), and it was found that it was the starting material. Neither hydroxyl forms of p-hydroxybenzoic acid nor bis-(β-hydroxyethyl) terephthalate were detected.

After the acetylation, the temperature was gradually raised to 80°C while stirring.
Polymerization was carried out at 0°C for 80 minutes, at 315°C for 80 minutes, and further at 815°C for 2 hours under reduced pressure of 4.9 torr. During this time, free acetic acid and excess acetic anhydride during the acetylation reaction and acetic acid by-produced during the polycondensation reaction were continued to be distilled off. After the system was cooled, a white reaction product was removed. This was pulverized into particles with a particle size of 1ff or less using a pulverizer, and then dried under reduced pressure in a rotary kiln at 280°C for 8 hours.
) was obtained in powder form.

This polymer consists of xylene, tetrahydrofuran, chloroform, phenol and tetrachloroethane in a 6:4 ratio (
volume) mixture, and m-cresol, respectively.

The flow temperature of this polymer is 288°C and 325°C.
Melting anisotropy was observed above °C.

Furthermore, it was confirmed that it was crystalline by wide-angle X-ray diffraction measurement using an X-ray diffractometer RAD-C model manufactured by Rigaku Denki Co., Ltd. This polymer shows no weight loss up to 800°C, and the temperature at which it shows a weight loss of 2.5% relative to the original weight is 4.
It was 20°C't-.

This polymer has a diameter of 600 f, a diameter of 18 μm, and an average length of 50 μm.
A mixture consisting of 400f of glass fibers of 810°
It was possible to granulate well with C, and pellets were obtained. These pellets were molded using a Neomat ON 47/28 injection molding machine manufactured by Sumitomo Heavy Industries ■ at a cylinder temperature of 840°C.
The injection molding process was successfully carried out, and a test piece was obtained. The test piece has a tensile strength of 1,060 and a modulus of elasticity of 9/d1 of 5. IX
10 kq/d1 heat distortion temperature 20B”C.

The whiteness was 82.

Example 2 Molar ratio of repeating structural units (c): (B): (C) = 60
: 20 : 20 example is shown.

p-hydroxybenzoic acid 552f in the same manner as in Example 1
(4,00 mol), 2-hydroxy-6-naphthoic acid 8
76f (2,00 mol), bis-(β-hydroxyethyl) terephthalate 508f (2,00 mol), terephthalic acid 882f (2,00 mol) and acetic anhydride 1.1
28f (11,00 mol) was charged, and an acetylation reaction and a polycondensation reaction were performed under the same conditions as in Example 1, and a white reaction product was taken out. This was pulverized into particles with a particle size of 1ff or less using a pulverizer, and then dried in a rotary kiln at 235°C under reduced pressure for 8 hours to obtain the target polymer 1,688f (95.5% of the theoretical yield) in pulverized form. I got it.

This polymer was insoluble in each of the same solvents as in Example 1. The polymer flow temperature is 275°C and 315°C.
Melting anisotropy was observed above °C. Furthermore, wide-angle X-ray diffraction confirmed that it was crystalline. This polymer showed no weight loss up to 800°C, and the temperature at which it reached a weight fraction of 2.5% relative to the original weight was 415°C.

Further, using this polymer and glass fiber, Example 1
A test piece obtained by injection molding at 350°C in the same manner as above had a tensile strength of 990klj/d,
Elastic modulus 4.7×10&s/ci, heat distortion temperature 195°C
1 whiteness was 81.

Comparative Example 1 Molar ratio of carryover structural units (9):■:(C)=84:8
: Shows an example of 8.

p-, hydroxy, benzoic acid 1,
159N (8,40 mol), bis-(β-hydroxyethyl) terephthalate 208f (Q, 80 mol),
Terephthalic acid 188y (0.80 mol) and acetic anhydride 1
, 128y (11,00 mol) were charged.

Acetylation and polycondensation reactions were carried out under the same conditions as in Example 1, and a pale yellow reaction product was taken out. This has a particle size of 1ff.
Powder Z・ (94.6% of the theoretical yield) crushed into the following particles! Obtained.

This polymer did not melt even at 400°C and could not be molded.

Comparative Example 2 An aromatic polyester of the type described in Japanese Patent Publication No. 47-47870 cited in the prior art section was synthesized in the same manner as in Example 1 except that bis-(β-hydroxyethyl) terephthalate was used. did.

That is, p-hydroxybenzoic acid 828F (6,00
mole). Hydroquinone 281F (2,10 mol), terephthalic acid 882F (2,00 mol) and acetic anhydride 1,1
23f (11,00 mol) was charged, and acetylation and polycondensation reactions were carried out under the same conditions as in Example 1, and a light yellowish brown reaction mixture was taken out. This was crushed into particles with a particle size of 1 fl or less using a pulverizer, and then dried under reduced pressure in a rotary kiln at 245°C for 8 hours to obtain the target polymer 1,1729 (98.1% of the theoretical yield) in powder form. Obtained.

The flow temperature of this polymer was 870° C., and wide-angle X-ray diffraction showed that it was crystalline. This polymer showed no weight loss up to 350°C, and the temperature at which it showed a weight loss rate of 2.5% relative to the original weight was 461°C.

Further, a test piece made of a polymer and glass fiber obtained in the same manner as in Example 1 except that this polymer was used and injection molding was performed at 335°C had a tensile strength of 1.
97cd at 070.

Elastic modulus 5.8 x 10 kg/d1 Heat distortion temperature 26
The temperature was 7° C. and the whiteness was 62, and the whiteness was particularly inferior to Examples 1.2 and 8.

Example 8 Molar ratio of repeating structural units (6):(B):(Q=60:
An example of 20:20 is shown.

p-hydroxybenzoic acid 828f (6,00 mol), bis-(β-hydroxyethyl) terephthalate 508g
(2,00 mol), 2゜6-dicarboxynaphthalene 4
82 F (2,00 mol) and acetic anhydride 1,1289 (
11,00 mol) was charged, and an acetylation reaction and a polycondensation reaction were performed under the same conditions as in Example 1, and a white reaction product was taken out. After pulverizing this into particles of 1ff or less,
Dry in a kiln at 240°C under reduced pressure for 4 hours to obtain the desired polymer 1,521f (95.8F based on the theoretical yield).
) was obtained in powder form.

The primers were insoluble in the same solvents as in Example 1. The flow temperature of this polymer is 290°C;
Melting anisotropy was observed above 840'C. Furthermore, it was confirmed by wide-angle X-ray diffraction that it was crystalline. This polymer showed no weight loss up to 800''C, and the temperature at which it showed a weight loss of 2.5% relative to the original weight was 420°C.

A test piece made of a polymer and glass fiber obtained in the same manner as in Example 1 except for using this polymer had a tensile strength of 980 kli/d1 and an elastic modulus of 4.7 x 1.
0 kl/14. Heat distortion temperature 208°C1 Whiteness 88
Met.

Claims (1)

[Scope of Claims] An aromatic polyester consisting of repeating structural units represented by the following formula (A) 80 to 80 mol%, (B) 10 to 35 mol%, and (C) 10 to 35 mol%. ■O-Ar_1-CO■(A) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(B) ■CO-Ar_2-CO■(C) (In the formula, Ar_1 is ▲There are mathematical formulas, chemical formulas, tables, etc.▼
and ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and 50 to 100 mol% of them are ▲mathematical formulas,
There are chemical formulas, tables, etc. ▼ is a divalent aromatic group, and Ar_2 is a divalent aromatic group. )