SEALABLE, FLAME-RESISTANT, CO-EXTRUDED, BIAXIALLY ORIENTED FOIL THAT IS MAT ON ONE SIDE AND A METHOD FOR PRODUCING AND USING SAME

摘要

Coextruded and biaxially oriented polyester film comprises a thermoplastic polyester base layer sandwiched between a heat-sealable layer and a matt layer. Coextruded and biaxially oriented polyester film comprises a thermoplastic polyester base layer sandwiched between a heat-sealable layer and a matt layer, where: (a) at least one of the layers contains a flame retardant; (b) the heat-sealable layer has a minimum weld temperature of 110[deg] C, a weld strength of at least 1.3 N/15 mm, a surface roughness of less than 30 nm and a superficial gas flow time of 500-4000 seconds; and (c) the matt layer has a surface roughness of 200-1000 nm and a superficial gas flow time of less than 50 seconds. An independent claim is also included for a process for producing the film, in which the flame retardant is supplied in the form of a master batch which is precrystallized and/or predried, comprising: coextruding melts corresponding to the individual layers through a flat nozzle; withdrawing the film over one or more rollers; biaxially stretching the film; and thermofixing the film.