Matte, heat-sealable, shrinkable, biaxially oriented, multilayer polypropylene film, process for the production thereof, and the use thereof

A heat-sealable, shrinkable multilayer polypropylene film having at least one matte surface, comprising:

• at least one base layer which comprises a propylene polymer or a propylene polymer mixture;
• and at least one outer layer which comprises a mixture or a blend of two components I and II, wherein
• component I is selected from the group consisting of
• a copolymer of ethylene and propylene,
• a copolymer of ethylene and butylene,
• a copolymer of propylene and butylene,
• a copolymer of ethylene and another .alpha.-olefin having 5 to 10 carbon atoms,
• a copolymer of propylene and another .alpha.-olefin having 5 to 10 carbon atoms,
• a terpolymer of ethylene and propylene and butylene,
• a terpolymer of ethylene and propylene and another .alpha.-olefin having 5 to 10 carbon atoms,
• mixtures or blends thereof and
• a blend of two or more of said copolymers and terpolymers, mixed with one or more of said copolymers and terpolymers,
• and
• component II is selected from the group consisting of an HDPE and a blend of two components A and B, where
• blend component A is essentially an HDPE and
• blend component B is selected from the group consisting of
• a copolymer of ethylene and propylene,
• a copolymer of ethylene and butylene,
• a copolymer of propylene and butylene,
• a copolymer of ethylene and another .alpha.-olefin having 5 to 10 carbon atoms,
• a copolymer of propylene and another .alpha.-olefin having 5 to 10 carbon atoms,
• a terpolymer of ethylene and propylene and butylene,
• a terpolymer of ethylene and propylene and another .alpha.-olefin having 5 to 10 carbon atoms, and
• mixtures or blends thereof
• and wherein
• the multilayer film has, at 120.degree. C., a longitudinal shrinkage of greater than about 8%, and a transverse shrinkage of greater than 10%,
• the multilayer film has, at 90.degree. C., a longitudinal shrinkage of less than or equal to about 10%, and a transverse shrinkage of less than or equal to 10%, and
• the at least one outer layer has a minimum heat-sealing temperature of less than or equal to about 124.degree. C., and wherein said multilayer film is produced by a process comprising the steps of:
• coextruding the melts corresponding to the individual layers of the film through a flat-film die,
• taking the coextruded film off over a take-off roll whose temperature is between about 40 and 100.degree. C.,
• biaxially stretching the film at a longitudinal stretching ratio of about 4:1 to 9:1 and a transverse stretching ratio of about 6:1 to 10:1, heat-setting the biaxially stretched film and subsequently winding the film up.