White thermally formable film useful as a display,in illumination technology, for e.g. coatings, comprises a crystallizable thermoplastic, a white pigment, a UV stabilizer, and a fire retardant

摘要

A white heat formable film of thickness 1-350 microns containing a crystallizable thermoplastic as a main constituent, a white pigment, a UV stabilizer, and a fire retardant soluble in the thermoplastic, which is metered in directly during film preparation using master batch technology, while the master batch is subjected to gradual heating under reduced pressure with stirring is new. An Independent claim is included for preparation of the film which involves melting of the thermoplastic in at least one extruder, passage of the polymer mixture obtained, depending on the composition of the film, to a nozzle, or depending on the composition of the top and basic layer, to a multilayer nozzle, extrusion of the mixture on a cooled roller, biaxial stretching and heat fixing of the pre-film obtained, where the polymer melt for the basic layer and top layer contains at least one fire retardant and white pigment, and the polymer melt for the top layer contains at least one UV stabilizer.