Polystyrene Adhering Heat-Sealable Plastic Film

摘要

The invention relates to heat-sealable synthetic films which have at least a two-phase structure in the thickness range up to 400 mu m and are suitable for the sealing closure of plastic vessels, characterized in that the synthetic films KF are built up from a) a high molecular weight or crosslinked polymer P which has a molecular weight Mw of greater than 50,000 and a glass transition temperature Tg of less than 10 DEG C and in addition is covalently bonded to an extent of at least 2 % by weight. b) a copolymer CPP which bonds to polystyrene, has a glass transition temperature Tg of above 20 DEG C and is built up from alpha ) 20-80 % by weight of at least one monomer of the formula I in which R1 is methyl or ethyl (preferably methyl) ss) 80-20 % by weight of at least one monomer of the formula II in which R2 is an alkyl radical having 4 to 18, preferably 4 to 12, carbon atoms or a cycloalkyl radical different from cyclopentyl or cyclohexyl, and gamma ) 0-10, preferably 0-5, % by weight of a monomer which is copolymerizable with monomers I and II, is different from these and is not cyclohexyl methacrylate.