Sealable multilayer films

A heat-sealable composite film comprising a biaxially oriented polypropylene film as a base film, said base film having two surfaces and, on at least one surface thereof is disposed, a layer combination which comprises

• (A) a heat-sealable outer layer of polyethylene or of an ethylene copolymer containing at least 3% by weight of ethylene;
• (B) an adhesion-promoting layer of modified polyolefin;
• (C) gas-barrier layer of hydrolyzed ethylene/vinyl acetate copolymer containing from 50 to 80 mole percent of vinyl acetate units of which at least 90% are hydrolyzed;
• (D) an adhesion-promoting layer of modified polyolefin;
• and
• (E) a layer of polyethylene or of an ethylene copolymer containing at least 3% by weight of ethylene;
• each of the two layers A and B or D and E or layers B and C or C and D are combinable into one single layer by mixing the corresponding polymers;
• layer A containing an additive combination comprising
• (a) from 0.3 to 1% by weight, based on the sealable layer, of a long-chain aliphatic amine,
• (b) from 0.1 to 0.7% by weight, based on the sealable layer, of a dispersed thermoplastic polymer which is incompatible with the polyethylene or ethylene copolymer and which has a softening point at most 50.degree. C. below or above the softening point of the polyethylene or ethylene copolymer, and
• (c) from 0.1 to 1.2% by weight, based on the sealable layer, of a polydialkyl siloxane having a viscosity of between about 10.sup.5 and 10.sup.6 m.Pa.s at 20.degree. C.