GB1428399A - Synthetic film materials - Google Patents

Abstract

1428399 Subbed polyester films IMPERIAL CHEMICAL INDUSTRIES LTD 16 Nov 1973 [20 Nov 1972 13 July 1973] 53492/72 and 33446/73 Heading B2E [Also in Division G2] A photographic film base material comprises a biaxially oriented film support of a linear polyester and a subbing layer applied to one or both surfaces thereof or to a polymeric layer on one or both surfaces thereof, the subbing layer comprising a mixture of one or more polyurethane resins with (a) one or more homopolymer(s) of polymerisable unsaturated carboxylic acid cyclic anhydrides, (b) one or more copolymer(s) of polymerisable unsaturated carboxylic acid cyclic anhydrides with one or more other copolymerisable monomers, or (c) one or more such homopolymer(s) and one or more such copolymer(s), the mixture containing up to 75% by wt. of the anhydride homopolymer(s) and/or copolymer(s). Suitable anhydrides are maleic, chloromaleic, and other substituted maleic anhydride, itaconic and citraconic anhydrides. Suitable comonomers are styrene, vinyl acetate, ethylene, methyl methacrylate, butadiene, methyl vinyl ether and vinyl halogenoesters such as vinyl monochloroacetate. The polyurethane may be made by reacting one or more di-isocyanate with hydroxy-teriminated polyether, polyester, polyesteramide or mixtures thereof in the presence of a chain extender. Lists of suitable precursors are given. The polymers are preferably dissolved in an organic solvent and dip, head or reverse roller coated. A polyvinylidene chloride/acrylonitrile copolymer or polyethylene isoterephthalate/terephthalate copolymer precoat may be applied before the polyurethane/anhydride subbing layer. A gelatin subbing layer may be applied over the or each polyurethane/anhydride layer, the gelatin layer optionally containing polyvinyl acetate or divide silica, and being applied from solution. Optionally, an antistatic layer comprising potassium ethyl phosphate may be applied from solution to provide an antistatic coating having a resistivity of 10<SP>10</SP> ohms/sq. A top coat of a gelatino-silver halide emulsion may then be applied on one side with an antihalo-coating on the other. The base may comprise polyesters made by condensing one or more dicarboxylic acids, anhydrides or lower alkyl esters (e.g. terephthalic, isophthalic, phthalic, 2, 5-, 2, 6- or 2, 7-naphthalene dicarboxylic, succinic, sebacic, adipic, azelaic, bibenzoic and hexahydroterephthalic acids and bis-p-carboxy phenoxy ethane) with one or more glycols (e.g. ethylene and neopentyl glycols, 1, 3-propanediol, 1, 4-butanediol, and 1, 4-cyclohexanedimethanol).