DIMENSIONALLY STABLE POLYESTER FILM SUPPORTS

摘要

1533555 Priming layers on polyesters AGFA-GEVAERT 13 Feb 1976 [7 Nov 1975] 46200/75 Heading B2E [Also in Divisions G2 G3 and G5] A process for the manufacture of a dimensionally stable polyester film support carrying a primer coating for improving the adhesion thereto of subsequently applied coatings, comprises applying to an unstretched or only monoaxially stretched polyester film support a layer of a coating composition from an aqueous dispersion, drying said layer, stretching it biaxially or in a direction perpendicular to the said first stretching operation (if any) together with the polyester film support and heat-setting the polyester film, wherein said coating composition, before drying and heat-setting, comprises a mixture of: (A) 52 to 79% by weight of a copolymeric binder comprising 60 to 95% by weight of methyl methacrylate units, and 3 to 20% by weight of divinyl or diallyl monomer units, (B) 0.5 to 3% by weight of a water-insoluble wax-like material and/or of a water-insoluble polymer characterised by the presence of repeating units corresponding to the formula: wherein each of X, X1, X2, and X3 represents hydrogen or fluorine, or each of X, X1, and X2 represents hydrogen and X3 represents a methyl group, or X represents chlorine and each of X1, X2, and X3 represents fluorine, and (C) 20 to 40% by weight of a separate plasticiser which is wholly or almost entirely eliminated from the coating composition during the heat-setting. The coating composition may also contain up to 5% by weight of a hydrophilic polymer (e.g. hydroxyethyl cellulose or polyvinyl alcohol), and of an unsaturated acid. The support may be used for motion film material having silver halide emulsion layer on one surface and at the opposite surface the primer layer, magnetic recording stripe, and between the primer layer and the recording stripe an antihalation or antistatic layer. The magnetic stripe-forming coating may contain a polyfunctional compound which reacts with the binder of the intermediate layer and cross-links it under the magnetic stripe.