Method of coating multi-layer graphic film

Claim 1

In a coating method for preparing a multi-layer material for use in the graphic arts or in X-ray photography in which a web of a polyester film support has applied to one of its sides to form an anchoring layer an aqueous binder latex containing at least one copolymer of vinyl chloride, vinylidene chloride, acrylic or methacrylic acid esters, vinyl esters, or butadiene, the anchoring layer is heated during drying or heat-setting to a temperature above the glass transition temperature of said copolymeric binder and is conveyed while hot by means of conveying rollers contacting said anchoring layer surface, and at least one gelatin-containing hydrophilic layer is applied to the anchoring layer, the improvement of reducing the tendency of said anchoring layer to adhere while hot to said conveying rollers or to a contiguous anchoring layer by incorporating a silane compound in said anchoring layer in the amount of about 5-100% by weight of said copolymer binder, said silane compound corresponding to the formula: ##STR3## wherein: each of R and R' represents hydrogen, alkyl, chloroalkyl, aminoalkyl, alkoxy, hydroxyalkoxy, aminoalkoxy, epoxyalkoxy, alkoxyalkoxy, acetyloxy, vinyl or phenyl, wherein alkyl contains 1 to 4 carbon atoms; and each of R" and R"' represents cyanoalkyl, aminoalkyl, aminoalkoxyalkyl, epoxyalkoxyalkyl, alkoxycarbonylalkyl, (meth)acryloyloxyalkyl, (meth)acrylaminoalkyl, chloroacetamidoalkyl, N-(aminoalkyl)-aminoalkyl, bis-(hydroxyalkyl)-aminoalkyl, alkoxy, hydroxyalkoxy, aminoalkoxy, epoxyalkoxy, alkoxyalkoxy, phenoxy, acetyloxy, and 3-[7-oxabicyclo-(4,1,0)-heptyl]-alkyl, wherein alkyl contains 1 to 4 carbon atoms whereby the tendency of the anchoring layer of becoming tacky during drying of said layer or during transversal stretching, heat-setting or relaxation of the polyester film support to which said layer was applied is reduced and sticking of the anchoring layer to the conveyor rollers with which it is brought into contact before it is sufficiently cooled thus obviated without a corresponding reduction in the adhesion of the anchoring layer to said polyester support.