An oriented, heat-set polyethylene terephthalate film coated with a plasticized nitrocellulose resin containing a sulfonamide-aldehyde resin

Claim 1

A PROCESS FOR PREPARING PACKAGING FILM WHICH COMPRISES STRETCHING A BASE FILM OF POLYETHYLENE TEREPHTHALATE 2.5 TO 3.25 TIMES ITS ORIGINAL DIMENSION IN AT LEAST ONE DIRECTION, HEAT-SETTING SAID POLYETHYLENE TEREPHTHALATE FILM BY HOLDING IT UNDER TENSION AT A TEMPERATURE OF 150* TO 200*C., COATING SAID HEAT-SET POLYETHYLENR TEREPHTHALATE FILM WITH A COMPOSITION COMPRISING AT LEAST 25% NITROCELLULOSE HAVING A NITROGEN CONTENT BETWEEN 10.5% AND 12.2%, AT LEAST 25% OF PLASTICIZER CONTAINING AT LEAST ONE COMPOUND SELECTED FROM THE GROUP CONSISTING OF DIBUTYL PHTHALATE, DICYCLOHEXYL PHTHALATE, BENZYL BUTYL PHTHALATE, CYCLOHEXYL BUTYL PHTHALATE, BUTYL PHTHALYBUTYL GLYCOLATE DIBUTYL SEBACATE, BUTYL BENZOYL BENZOATE, DICYCLOHEXYL ADIPATE, TRIPHENYL PHOSPHATE, AND TRICRESYL PHOSPHATE AND MORE THAN 10% OF AN ARYL SULFONAMIDE-FORMALDEHYDE RESIN, AND DRYING THE COATED FILM A T A TEMPERATURE OF 100* TO 120*C.