Aqueous binder dispersion for producing vulcanization bonds between rubber and a solid substrate

The improvement in the process of producing composite bodies by bonding vulcanizable rubber compositions to solid metals stable under vulcanization conditions comprising coating a solid metal stable under vulcanizing conditions with an adhesion assistant or binder, laminating a vulcanizable rubber composition thereto and vulcanizing the laminate, the improvement consisting of employing an aqueous binder dispersion consisting essentially of water and at least one emulsifier and a solids content of from 20% to 50% by weight of a solids composition of:

• (a) per 1000 parts by weight of a polymer selected from the group consisting of polyvinylidene chloride, vinylidene chloride/alkyl acrylate copolymers, butadiene/acrylonitrile copolymers and mixtures thereof,
• (b) from 100 to 500 parts by weight of at least one aromatic poly-C-nitroso compound,
• (c) from 50 to 300 parts by weight of masked polyfunctional isocyanates selected from the group consisting of aromatic diisocyanates, alkylene diisocyanates and aromatic polyisocyanates, masked with masking agents selected from the group consisting of tert.-alkanols, compounds containing a carbonyl-activated methylene group, dicarboxylic acid imides and sodium hydride,
• (d) from 20 to 100 parts by weight of a water-soluble polymer selected from the group consisting of polyvinyl pyrrolidone and water-soluble copolymers of vinyl pyrrolidone, and
• (e) from 5 to 500 parts by weight of customary fillers and pigments, adhesion-improving resins based on formaldehyde condensation products, adhesion-improving condensation products based on epichlorohydrin condensation products, emulsifiers and antifoam agents,
• said aqueous binder dispersion not exceeding 5% by weight of the liquid phase of organic solvents, as said adhesion assistant or binder.