COATING FOR RUBBER ARTICLES

Aqueous coating compositions are provided for applying to the outer surface of rubber articles prior to vulcanization which comprises a mixture comprising (A) from 2 to 80 percent by weight based on the weight of the mixture of a preformed latex binder selected from the class consisting of natural rubber and synthetic polymer obtained from the in-situ polymerization of emulsified monomers, the synthetic polymers are selected from the class consisting of homopolymers of conjugated dienes, copolymers of the conjugated dienes and copolymers of the conjugated dienes and monomers having monoethylenic unsaturation selected from the class consisting of styrene, substituted styrenes, acrylic and methacrylic acids, esters, nitriles and amides thereof and vinyl pyridine, (B) from 1 to 20 percent by weight of the mixture of an emulsifying agent, (C) from 1 to 80 percent by weight based on the weight of the mixture of a filler selected from the class consisting of graphite, carbon black, mineral fillers and mixtures thereof, (D) from 0.1 to 10 percent by weight based on the weight of the mixture of a thickening agent selected from the class consisting of bentonite, starch, synthetic gums and water soluble cellulose derivatives, (E) from 0.05 to 10 percent by weight based on the weight of the mixture of a compound capable of forming protective colloid and sufficient water to provide a composition having a solids concentration of from 2 to 70 percent by weight based on the weight of the mixture and water. The composition is applied to the outer surfaces of rubber articles prior to molding and vulcanization to impart release properties thereto. This improves the appearance and other characteristics e.g. weatherability.