| abstract |
PURPOSE: To prepare a crosslinked polyester film useful for a flexible printed circuit board, etc. and having improved mechanical properties, electrical characteristics and high temperature-dimension stability, by compounding a polyester with a photopolymerizable unsaturated compound, melt forming the compound to a film, and thereafter crosslinking the formed product. n CONSTITUTION: (A) A substantially saturated linear polyester is mixed with (B) an allyl group or substituted allyl group-containing compound I (R 1 WR 3 are H or organic group), or a copolyester consisting of a compound I (R 4 WR 7 are H or organic group; Q is direct linkage or difunctional organic group; n and m are 0 or ≥1, n+m≥1; l is ≥1), and formed into a film. The film is crosslinked by irradiating with actinic radiation, e.g. ultraviolet ray, etc., to give the desired film containing ≥70 wt.% of material insoluble in ortho-chlorophenol (100°C, 1 hr), and having an elongation of ≥10% at a room temperature, a strength of ≥10 kg/cm 2 at 260°C and a shrinkage factor of ≤5%. n COPYRIGHT: (C)1979,JPO&Japio |