Process for adhering hydrophilic layers to dimensionally stable polyester films

Abstract

Hydrophilic layers are made to adhere to dimensionally stable polyester film supports by applying to an unstretched or only longitudinally stretched polyester film an adhesive layer from an aqueous coating composition comprising a chlorine-containing copolymer formed of 45 to 99.5 % by weight of at least one of the monomers vinylidene chloride and vinyl chloride, 0.5 to 10 % by weight of an ethylenically unsaturated mono- or dicarboxylic acid or of N-vinyl pyrrolidone, and 0 to 54.5 % by weight of at least one monomer taken from acrylamides, methacrylamides, esters of acrylic acid, methacrylic acid and maleic acid, and N-alkyl maleimides. Immediately thereafter, without drying of the adhesive layer, a subbing layer is applied thereto from an aqueous gelatin solution comprising a plasticizer for the gelatin. After drying of the two layers, they are biaxially or transversally stretched together with the polyester film support, and heat-setted. Finally a hydrophilic layer is applied to the subbing layer. The polyester film may be a film of polyethylene terephthalate and the hydrophilic layer applied to the subbing layer may be a light-sensitive gelatin silver halide emulsion layer.

Dependencies are inferred from the claim text.