GB1306944A - Polyester films and sheets - Google Patents

Abstract

1306944 Photographic silver halide materials EASTMAN KODAK CO 24 Sept 1970 [25 Sept 1969] 47275/69 Heading G2C [Also in Division B2j A photographic support having improved adhesion for gelatino silver halide emulsions comprises a polyester sheet having a permanent coating comprising a copolymer of styrene or a substituted styrene and an unsaturated carboxylic acid component, the copolymer having an inherent viscosity of 0À3-6À0 dl/g at 3‹ C in chlorobenzene at a concentration of 0À25 g/100ml, in amount so as to provide in the coating 0À5-15% by weight of -COOH groups with a total coating weight. The polyester may be prepared from terephthalic, isophthalic, naphthalene-dicarboxylic, 4'-oxydibenzoic, 4, 4'- diphenic, 4,4'-sulphonyl-dibenzoic or 4, 4'- ethylene dioxydibenzoic acid and a glycol of 2-10 carbon atoms. The styrene copolymers may have inherent viscosities of 0À3 to 6À0 at 23‹C. in chlorobenzene. The unsaturated carboxylic acid may be acrylic, methacrylic, itaconic, fumaric maleic or citraconic, or the halfesters such as monomethyl fumarate and monohexyl maleate, as well as anhydrides of these acids. The styrene may contain a chlorine, bromine or lower alkyl substitute, such as p-chlorostyrene, o-chlorstyrene and p-methylstyrene. The desired carboxyl content can also be obtained by mixing polystyrene with styrene copolmer that contains a relatively large amount of carboxyl groups. The coatings may be applied as a solution in organic solvent such as chloroform, methylene chloride, benzene, toluene, dioxane, ketones and isopropyl alcohol and a small amount of a high boiling solvent may be present such as pheno lactones, diarylethyls, polyaryls, chlorinated diphenyls, alkylene carbonates and triaryl phosphates. The coated films have excellent adhesion to photographic emulsions, such as those of silver bromide in gelatine.