Polyamide-polyimide block copolymers - have good temp. stability and low thermal expansion coefficients, and are useful for prodn. of flexible printed circuit boards

摘要

Polyamide-polyimide block copolymers (PA-PI) with a reduced viscosity of 0.1-2 dl/g (1g of polymer in 100ml N-methyl pyrrolidone) contain polyamide blocks contg. one or more repeating structural elements of formula (I) and polyimide blocks contg. one or more repeating structural elements of formula (II). Also claimed is (i) a compsn. (c) comprising (A) 50-99 wt. % PA-PI and (B) 1-50 wt. % of at least on polymer form polyfunctional epoxides, polyamides, polyether imides, polyester imides, polyamides, polyhydantion, polyarylene ethers and polyether sulphones; (ii) the use of (PA-PI) or (c) for the prodn. of coatings; and (iii) a laminate contg. one metal foil, pref. copper coated with (PA-PI) or (c). In the formula (I) and (II) R is e.g. -(CH2)n-; n is 2-12; R2 is e.g. 2-12 alkylene; R3 is e.g. gp. of formula (Va); and Q is -CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2, -S-, -O-, -SO2-, -NHCO-, or -CO-. USE/ADVANTAGE - (PA-PI) are useful as the base material in conjunction with metal foil for the so-called flexible laminates possessing good mechanical, thermal and electrical properties, for the electronic industry in the prodn. of flexible printed circuit boards. (PA-PI) have good temp. stability and low thermal expansion coefft. and laminates contg. (PA-PI) are less prone to warping and curling.