US 4,233,074 AGranted

Photographic polyester film base with subbing layer containing phosphoric acid derivative

AssigneeCiba-Geigy Corporation

InventorsGeoffrey M. Dodwell, Norman E. Gambles

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Abstract

Provided is a method of preparing film base material consisting of biaxially oriented synthetic linear polyester which comprises stretching extruded synthetic polyester material in one direction and then coating on this material a copolymer in form of an aqueous latex of vinylidene chloride, a plasticising comonomer for the vinylidene chloride and optionally other comonomers together with 10 to 40 percent by weight of solids in the latex of at least one phosphoric acid derivative of the formula ##STR1## wherein M is hydrogen, ammonium or an alkali metal, R is methyl, ethyl or an ethylene oxide and/or propylene oxide units containing group, and R.sub.1 is hydrogen, methyl or ethyl, drying this coating and completing the orientation of the polyester film material. A photographic silver halide emulsion can be coated directly on this base without the need to apply any intermediate gelatin subbing layer. The adhesion between the film base and the photographic emulsion layers is improved and further the separation or frilling of these layers when the final photographic film is processed can be avoided. Due to the also improved surface conductivity of the film base there is no need for a separate antistatic layer.

Claims16

Dependent claims

A method of preparing film base material consisting of biaxially oriented synthetic linear polyester which comprises stretching extruded synthetic polyester material in one direction and then coating on this material a copolymer in the form of an aqueous latex consisting essentially of

(a) 20 to 95% by weight of vinylidene chloride;
(b) 5 to 50% by weight of a plasticising comonomer selected from the group consisting of (1) an alkyl acrylate or methacrylate, where the alkyl moiety contains 1 to 6 carbon atoms (2) acrylonitrile and (3) vinyl chloride;
(c) 0 to 20% by weight of a copolymerisable acid;
and
(d) 0 to 25% by weight of other comonomers different from (a) to (c) together with 10 to 40 percent by weight of solids in the latex of at least one phosphoric acid derivative of the formula ##STR13## wherein M is an alkali metal, ammonium or hydrogen, R.sub.1 is methyl, ethyl or hydrogen and R is methyl, ethyl or an ethylene oxide group of the formula --(CH.sub.2 CH.sub.2 O).sub.n R.sub.2 or a propylene oxide group of the formula ##STR14## wherein R.sub.2 in each case is alkyl or optionally substituted acyl, aryl or aralkyl and n is 1 to 20, or a mixed ethylene oxide/propylene oxide group of the formula ##STR15## where the ethylene oxide and propylene oxide moieties are arranged either in blocks or randomly in the chain and the sum of p and q is n, drying this coating and completing the orientation of the polyester film material.

2 more elements

Dependencies are inferred from the claim text.