Cellulosic substrate coating composition and process

摘要

Coating compositions comprise a solution in an organic solvent of at least one polyepoxide and at least one copolymer of 75-95 mol per cent of vinylidene dichloride and 5-25 mol per cent of at least one a ,b -unsaturated aliphatic carboxylic acid or anhydride wherein the polyepoxide is an epoxidized silicone oil. The compositions may also contain tertiary amine or Lewis acid catalysts. Coating or laminating resin compositions of the above type according to Specification 1,061,590 in which the polyepoxides are epoxidized linseed or soy bean oil; 3,4-epoxycyclohexylmethyl 3,4 - epoxycyclohexanecarboxylate; an epoxylated novolak resin; a resorcinol diglycidyl ether; a glycidyl polyether of bisphenol A; and an epoxidized polybutadiene are also used in the examples.ALSO:A process for coating cellulosic substrates comprises applying to at least one face of the substrate a solution containing at least one polyepoxide and at least one copolymer of 75-95 mol% of vinylidene dichloride and 5-25 mol% of at least one a ,b -unsaturated aliphatic carboxylic acid or anhydride, removing the solvent and crosslinking the copolymer with the polyepoxide in which the substrate is paper, glassine or wood. The coatings may be applied by dipping, brushing or roller coating. Anchoring agents such as melamine- and urea-formaldehyde resins may be present. The wooden substrate may be a medical tongue-depressor stick.