Patent ID: 6632319
Filing Date: 2003-10-14
Classification: C08J

Abstract:
A process for producing a rubber-based composite material comprising the steps of laminating a rubber compound onto a substrate, with a bonding layer interposed therebetween and with a primer layer between the substrate and the bonding layer, and subsequently vulcanizing the rubber compound with a vulcanizing agent selected from the group consisting of sulfur and an organic sulfur compound and with a vulcanization accelerator,wherein said rubber compound comprises a vulcanizable natural rubber component and/or synthetic rubber component having carbon-carbon double bonds, the amount of said vulcanizing agent is from 0.01 to 2 parts by weight per 100 parts of the rubber component and said bonding layer comprises cobalt oxide, and wherein in the vulcanization step, the amount of the vulcanizing agent and the vulcanization accelerator are determined so as to control the slope of a vulcanization curve of the rubber compound and the amount of cobalt in the bonding layer is selected to satisfy the following equation: â€ƒxâˆ’19&gE;y&gE;0.2xâˆ’12wherein x is the amount (atom %) of cobalt in the bonding layer, and y is the slope (kgfÂ·cm/min) of the vulcanization curve of the rubber compound,thereby obtaining a rubber composition material having an adhesion of rubber failure between the rubber compound and the bonding layer in a wet state, as measured by the T-peel method, of 100%, wherein the primer layer comprises a cobalt oxide more oxidized than the cobalt oxide in the bonding layer.