Copolymers of butene-1 and propylene! - with improved hot strength, for prodn. of heat-sealable film (NL 21.7.80)

摘要

Copolymers of propylene and but-1-ene contg. 10-40 wt. % butene-1 units, in which the proportion of isolated ethyl branches from butene-1 (i.e. those occurring singly between propylene units) is at least equal to the square of the proportion of propylene units in the copolymer. Melt enthalpy of the copolymer after heat treatment is 15 cal./g. max., generally 5-12 cal./g. Used for prodn. of heat-sealable film by coating on thermoplastic film, e.g. isotactic PP. Heat-sealing can be effected at 90-150 degrees C, giving bonds with good hot and cold strength. The films have excellent transparency and very good scratch resistance.