JPH0635507B2 - Aromatic polyester copolymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aromatic polyester copolymer having excellent heat resistance stability.

[Prior Art] As a method for improving the heat resistance stability of a polyester copolymer, a method of adding an arylamine compound or a hindered phenol compound at the time of polymerization is known.

Also known is a method of co-polymerizing a dicarboxylic acid having a hindered phenol structure as shown in the following formula (USP4,094,857). [Problems to be Solved by the Invention] However, the above arylamine-based compound has a drawback that when the resin containing it is brought into contact with another resin, the other resin is discolored. There is. Also, hindered phenol compounds are effective stabilizers,
It has a low solubility in resin, and even if it is at a low concentration, it oozes out on the resin surface, causing a so-called bleeding phenomenon. Further, the above-mentioned two kinds of compounds have a drawback that when the resin containing them is brought into contact with a solvent, they are extracted into the solvent, and the effect of addition immediately disappears.

Further, although the method of copolymerizing a dicarboxylic acid having a hindered phenol structure represented by the above structural formula is effective, it is necessary to go through a very complicated synthetic route to obtain such a dicarboxylic acid.

The present inventor has found the present invention as a result of extensive studies to eliminate the above-mentioned drawbacks.

[Means for solving problems]

That is, the present invention is an aromatic polyester copolymer represented by the following structural formula (I) [Here, Ar represents a residue having an aromatic ring having 6 to 20 carbon atoms, B represents a residue represented by the following structural formula (II), an alkylene glycol residue, and a poly (alkylene oxide) glycol residue. It is selected such that the residue represented by the following structural formula (II) occupies 0.1 to 10.0% by weight of the copolymer. Further, m = 50 to 200.

(However, R in the formula is Or And R may be bonded to any position of the benzene ring. X and Y represent an integer of 4 or less satisfying 1 ≦ (X + Y) ≦ 8, and n represents an integer of 1 to 5. )]
Is.

More specifically, a dicarboxylic acid having an aromatic ring having 6 to 20 carbon atoms or an ester derivative thereof, an alkylene glycol, a poly (alkylene oxide) glycol, and a compound having a hydroxyl group at both ends of the structural formula (II). Upon copolymerization with a glycol component selected from, a polyester copolymer formed by polycondensation so that the residue represented by the structural formula (II) accounts for 0.1 to 10.0% by weight of the resulting copolymer. is there.

Examples of the dicarboxylic acid or ester derivative thereof include terephthalic acid, isophthalic acid, phthalic acid, 2,6
-Naphthalenedicarboxylic acid, bis (p-carboxylphenyl) methane, 4,4'-diphenyldicarboxylic acid,
4,4'-diphenyl ether dicarboxylic acid or an ester derivative thereof can be mentioned, and terephthalic acid, isophthalic acid, dimethyl terephthalate and dimethyl isophthalate are particularly preferably used.

The alkylene glycol used in the present invention has a molecular weight of 25.
It means a low molecular weight glycol less than 0, and examples thereof include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol and 1,4-cyclohexanedimethanol. Especially, ethylene glycol and 1,4-butanediol are preferable.

The poly (alkylene oxide) glycol used in the present invention means a high molecular weight glycol having a molecular weight of 250 or more, such as polyethylene glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide).
Examples thereof include glycols, mixtures thereof, and random or block copolymers obtained by copolymerizing these polyether components, with polyethylene glycol and poly (tetramethylene oxide) glycol being particularly preferable. In the present invention, when only alkylene glycol, that is, a low molecular weight glycol having a molecular weight of less than 250 is used, a hard and tough highly crystalline resin is obtained, and a poly (alkylene oxide) glycol, that is, a high molecular weight glycol having a molecular weight of 250 or more is used. When the mixture is used, a flexible elastomer can be obtained according to the copolymerization ratio of the high molecular weight glycol, so that the mixture can be used according to the purpose of use.

The copolymerization amount of the dihydroxy compound in the present invention is
It is necessary that the residue represented by the structural formula (II) accounts for 0.1 to 10.0% by weight, preferably 0.5 to 5.0% by weight, and more preferably 0.5 to 2.0% by weight of the polyester copolymer produced.

If it is less than 0.1% by weight, the heat resistance stability is insufficiently expressed, and if it exceeds 10.0% by weight, the melting point and mechanical properties of the polyester are deteriorated, which is not preferable.

Number average degree of polymerization of the aromatic polyester copolymer of the present invention
(m) is 50 to 200.

In order to produce the polyester copolymer according to the present invention, it is not necessary to use any special method, and a commonly used polymerization method can be widely adopted.

Hereinafter, the present invention will be described with reference to examples. In the examples, the number of parts means part by weight unless otherwise specified.

[Examples] Relative viscosity and intrinsic viscosity in the following Comparative Examples and Examples are o-
It is a value measured at 25 ° C. in 0.5% concentration in chlorophenol.

Comparative Example 1 Synthesis of PBT 33.2 parts of terephthalic acid and 28.8 parts of 1,4-butanediol were reacted in the presence of a tetrabutyl titanate / magnesium acetate catalyst under ordinary polyester polymerization conditions to give polybutylene terephthalate (PBT). Obtained. Melting point by DSC: 225 ° C, relative viscosity: 1.65, number average degree of polymerization: 14
It was 9.

Comparative Example 2 Synthesis of PET Polyethylene terephthalate (PET) was obtained by reacting 33.2 parts of terephthalic acid and 19.8 parts of ethylene glycol in the presence of a tetrabutyl titanate / magnesium acetate catalyst under ordinary polyester polymerization conditions. DSC melting point: 260 ° C, relative viscosity: 1.70, number average degree of polymerization: 16
It was 0.

Comparative Example 3 Synthesis of PBT / PTMG Copolymer 43.5 parts of dimethyl terephthalate, 40.4 parts of 1,4-butanediol and 58.0 parts of poly (tetramethylene oxide) glycol (PTMG) having a number average molecular weight of 1400 together with 0.05 part of tetrabutyl titanate catalyst. Charge the polymerization container,
The polyester was obtained by reacting at 210 ° C. for 2 hours and further at 250 ° C./1 mmHg for 2 hours. The melting point by DSC was 175 ° C., the intrinsic viscosity was 1.10, and the number average degree of polymerization was 63.

Comparative Example 4 Synthesis of PBT / PEG Copolymer 75.0 parts of dimethyl terephthalate, 69.6 parts of 1,4-butanediol and 15.0 parts of polyethylene glycol (PEG) having a number average molecular weight of 4000 are added to a tetrabutyl titanate catalyst.
A polyester was charged together with 0.05 part and polymerized in the same manner as in Comparative Example 3 to obtain polyester. DSC melting point is 22
The inherent viscosity was 1.06, and the number average degree of polymerization was 119.

Comparative Example 5 Synthesis of PBT / PEG Copolymer (Addition at the time of polymerization of hindered phenol) 71.9 parts of dimethyl terephthalate, 1,4-butanediol
66.7 parts and 13.8 parts of polyethylene glycol having a number average molecular weight of 4000 were charged into a polymerization vessel together with 0.05 part of tetrabutyl titanate catalyst, and further IRGANOX 10101.0.
Parts were added and polymerized in the same manner as in Comparative Example 3 to obtain polyester. Melting point by DSC is 228 ° C, intrinsic viscosity is 1.
06, the number average degree of polymerization was 120.

(IRGANOX1010 is a heat-resistant stabilizer manufactured by Ciba-Geigy, and has the following structural formula.

The following examples will be described using a dihydroxy compound having the following structural formula. Hereinafter, this compound is referred to as BDBHP
Abbreviated. This compound was obtained from Adeka Argus Chemical Co., Ltd.

BDBHP However, Example 1 33.2 parts terephthalic acid, 28.8 parts 1,4-butanediol,
0.46 parts of BDBHP was reacted in the presence of 1.3 parts of tetrabutyl titanate / magnesium acetate catalyst under normal polyester polymerization conditions to obtain a polyester. DSC melting point 224 ° C, relative viscosity 1.64, number average degree of polymerization 15
It was 1. ^{When 13} C NMR (solvent CF ₃ COOH) was measured,
An absorption peak based on the methyl group of the tert-butyl group was observed at 30.3 ppm, and an absorption peak based on the benzene ring carbon of the ether bond was observed at 156.2 ppm. From this, B
It was revealed that DBHP was copolymerized to produce the intended polyester copolymer.

Example 2 33.2 parts of terephthalic acid, 19.8 parts of ethylene glycol, B
A polyester was obtained by reacting 0.39 part of DBHP in the presence of 1.3 parts of a tetrabutyl titanate / magnesium acetate catalyst under ordinary polyester polymerization conditions. Melting point by DCS is 259 ° C, relative viscosity is 1.70, number average degree of polymerization is 160.
Met. ^{When 13} C NMR (solvent CF ₃ COOH) was measured,
An absorption peak based on the methyl group of the tert-butyl group was observed at 30.0 ppm, and an absorption peak based on the benzene ring carbon of the ether bond was observed at 157.1 pmm. From this, B
It was revealed that DBHP was copolymerized to produce the intended polyester copolymer.

Example 3 Same as Comparative Example 3 from 42.6 parts of dimethyl terephthalate, 39.5 parts of 1,4-butanediol, 54.3 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of 1400, 1.0 part of BDBHP and 0.05 part of tetrabutyl titanate catalyst. To obtain polyester. The melting point by DCS is 1
It had an intrinsic viscosity of 1.09 and a number average degree of polymerization of 66. ^{When 13} C NMR (solvent CF ₃ COOH) was measured,
Characteristic absorption peaks were observed at 29.8ppm and 155.8ppm,
It was revealed that BDBHP was copolymerized.

Example 4 Polyester was polymerized in the same manner as in Comparative Example 4 from 75.0 parts of dimethyl terephthalate, 69.6 parts of 1,4-butanediol, 14.4 parts of polyethylene glycol having a number average molecular weight of 4000, 1.0 part of BDBHP, and 0.05 part of tetrabutyl titanate catalyst. Obtained. Melting point by DSC is 228 ° C, intrinsic viscosity is 1.
05, the number average degree of polymerization was 121. ^{When 13} C NMR (solvent CF ₃ COOH) was measured,
Characteristic absorption peaks were observed at 30.2ppm and 155.9ppm,
It was revealed that BDBHP was copolymerized.

Example 5 Polyester obtained by polymerization in the same manner as in Comparative Example 4 from 75.3 parts of dimethyltyrephthalate, 69.8 parts of 1,4-butanediol, 14.5 parts of polyethylene glycol having a number average molecular weight of 4000, 0.05 part of BDBHP and 0.05 part of tetrabutyl titanate catalyst. Got Melting point by DSC is 228 ° C, intrinsic viscosity is 1.
It was 06 and the number average degree of polymerization was 120. ¹³ C NMR (solvent CF ₃ COOH) was measured and found to be 3
An absorption peak was observed at 0.1pmm and 156.0ppm.

Example 6 Polyester was polymerized in the same manner as in Comparative Example 4 from 72.2 parts of dimethyl terephthalate, 67.0 parts of 1,4-butanediol, 13.7 parts of polyethylene glycol having a number average molecular weight of 4000, 5.1 parts of BDBHP, and 0.05 parts of tetrabutyl titanate catalyst. Obtained. Melting point by DSC is 226 ° C, intrinsic viscosity is 1.
The number average degree of polymerization was 117 and the number was 117. ^{When 13} C NMR ((solvent CF ₃ COOH) was measured, absorption peaks were observed at 30.2 ppm and 155.8 ppm.

Example 7 Polyester polymerized in the same manner as in Comparative Example 4 from 65.1 parts of dimethyl terephthalate, 60.4 parts of 1,4-butanediol, 12.1 parts of polyethylene glycol having a number average molecular weight of 4000, 15.4 parts of BDBHP and 0.05 parts of tetrabutyl titanate catalyst. Got The melting point by DSC is 222 ° C and the intrinsic viscosity is
It was 1.04 and the number average degree of polymerization was 106. ^{When 13} C NMR (solvent CF ₃ COOH) was measured,
Absorption peaks were observed at 30.2 ppm and 156.0 ppm.

With respect to the polyesters of Comparative Examples 1 and 2 and Examples 1 and 2, press sheets having a thickness of 2 mm and a melting point of + 30 ° C. were prepared.
The No. 10 tensile test piece was punched out. And ASTM D-6
According to No. 38, the tensile properties were measured. Furthermore, after aging at 180 ° C. for 20 days, the tensile properties were measured.

The results are shown in Table 1. By copolymerizing BDBHP, the breaking strength retention rate was close to 100%, and the heat resistance stability was significantly improved.

5 mg of a candle-spun sample of the polyesters of Comparative Examples 3 to 4 and Examples 3 to 7 was taken, and a differential calorimeter (Diff
erential Scanning Calorimeter PERKIN-E
The presence or absence of an oxidation exothermic peak was confirmed using LSC DSC-1B). As an example, Fig. 1 shows DSC chart of PBT / PEG copolymer (measured at a heating rate of 5 ° C / min).
Is shown. A peak due to oxidation heat appears in a polyester having no heat resistance stability or a polyester having insufficient heat resistance stability. On the other hand, such exothermic peak is not observed in the polyester having heat stability.

Comparative Examples 3 to 4 and Examples 3 to 7 were measured by DSC, and the presence / absence of peaks due to oxidation heat was summarized.
The results are shown in Tables 2 and 3.

As is clear from Table 2, PBT / PTMG copolymer,
By copolymerizing 1.0% by weight of BDBHP in any of the PBT / PEG copolymers, the exothermic peak of oxidation disappeared,
It is shown that heat resistance stability is imparted.

Further, from Table 3, when the copolymerization amount of BDBHP is 0.05%, the heat resistance stability is insufficient, and when it is 15.0%, the heat resistance stability is sufficiently imparted, but the melting point is lowered and mechanical properties such as breaking strength are reduced. It is not preferable because the physical properties are deteriorated.

IRGANOX, a hindered phenol-based heat stabilizer
1010 polyester and BDBHHP added during polymerization
Table 4 shows the results of comparison of the bleeding property and the solvent extraction resistance with respect to the polyester copolymerized with.

In Comparative Example 5, the press-molded product bleeds when left to stand, whereas in Example 4, it does not bleed.

Further, when the pellets were stirred in toluene at room temperature and then candle-spun, and the oxidation exothermic peak was measured by DSC, a peak appeared in Comparative Example 5, whereas a peak did not appear in Example 4 and even when contacted with a solvent. It was revealed that the thermal stability did not decrease.

[Effect of the invention] As is clear from the examples, the polyester copolymer according to the present invention is excellent in heat resistance stability, has no bleeding property, and retains heat resistance stability even after contact with a solvent. It is suitable not only for general applications but also for applications in harsh environments.

[Brief description of drawings]

The figure shows the DSC charts of Example 4, Example 5, and Comparative Example 4. 1 …… Example 4 2 …… Example 5 3 …… Comparative Example 4

Claims (1)

[Claims] 1. An aromatic polyester copolymer represented by the following structural formula (I). [Here, Ar represents a residue having an aromatic ring having 6 to 20 carbon atoms, and B is selected from a residue represented by the following structural formula (II), an alkylene glycol residue, and a poly (alkylene oxide) glycol residue. And a residue represented by the following structural formula (II) is selected so as to occupy 0.1 to 10.0% by weight of the copolymer. Further, m = 50 to 200. (However, R in the formula is Or And R may be bonded to any position of the benzene ring. X and Y represent an integer of 4 or less satisfying 1 ≦ (X + Y) ≦ 8, and n represents an integer of 1 to 5. )]