A modified polyester having excellent mechanical properties such as tenacity which emits only a small amount of a gas by decomposition during use at elevated temperatures for a long period of time and only a small amount of a sublimate in the course of melting it and which is suitable particularly for use as the material of a molding for an electric or electronic component, or a packaging material such as film, sheet or container, characterized by its formation from:
(A) an acid component mainly comprising terephthalic acid, 2,6-naphthalenedicarboxylic acid or a lower alcohol ester thereof,
(B) a diol component mainly comprising an alkylene glycol having 2 to 8 carbon atoms, and
(C) an aromatic sulfonic acid compound of the following general formula (1):
(1) HO(RO)n-Ar-SO₃M
wherein Ar represents a benzene or naphthalene ring,
n represents an integer from 1 to 10,
R represents a group selected from among alkylenes having 2 or 3 carbon atoms and when n is 2 or more, R may be the same as or different from one another, and
M represents an alkali metal selected from lithium, sodium and potassium, and satisfying the following formulae (2) and (3):
(2) 0.25 ≦ x ≦ 100 (meq/kg)
(3) 2 ≦ (x/[CEG]) x 100 ≦ 150 (%)
wherein x represents the amount of the aromatic sulfonic acid compound represented by the above general formula (1) introduced thereinto and [CEG] represents the amount of the carboxy end groups, and
x and [CEG] are each expressed in milliequivalent (meq/kg) per kilogram of the polymer.
In a method of manufacturing the modified polyester, the said components (A), (B) and (C) are reacted together in the presence of a catalyst, component (C) preferably being added before before completion of esterification or transesterification of said acid and diol components (A) and (B).
一种改性聚酯,具有优异的机械性能(如韧性),在高温下长期使用时仅分解释放出少量气体,在熔化过程中仅释放出少量
亚硝酸盐,特别适合用作电气或电子元件的模塑材料,或薄膜、片材或容器等包装材料,其特征在于它是由以下物质形成的:
(A) 酸组分,主要包括
对苯二甲酸、2,6-
萘二
甲酸或其低级醇酯、
(B) 主要由具有 2 至 8 个碳原子的烷二醇组成的二元醇成分,以及
(C) 下述通式(1)的芳香族
磺酸化合物:
(1) HO(RO)n-Ar-SO₃M
其中 Ar 代表苯环或
萘环、
n 代表 1 至 10 的整数、
R 代表选自具有 2 或 3 个碳原子的亚烷基中的一个基团,当 n 为 2 或 2 个以上时,R 可彼此相同或不同,以及
M 代表选自
锂、
钠和
钾的碱
金属,并满足下式(2)和(3):
(2) 0.25 ≦ x ≦ 100 (meq/kg)
(3) 2 ≦ (x/[C
EG]) x 100 ≦ 150 (%)
其中 x 代表引入上述通式(1)所代表的芳香族
磺酸化合物的量,[C
EG] 代表羧基末端基团的量,以及
x和[C
EG]分别以每公斤聚合物的毫当量(meq/kg)表示。
在制造改性聚酯的方法中,所述组分(A)、(B)和(C)在催化剂存在下一起反应,组分(C)最好在所述酸和二元醇组分(A)和(B)完成酯化或酯交换之前加入。