Process for producing rubber-based composite material

A process for producing a rubber-based composite material comprising the steps of laminating a rubber compound onto a substrate, with a bonding layer of metal or metal compound 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 the primer layer comprises an organic material,
• 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 metal or metal compound is selected from the group consisting of cobalt, cobalt alloys containing higher than 50% by weight of cobalt, cobalt oxides, cobalt nitrides, and cobalt carbides, 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:
• x−19≧y≧0.2x−12
• wherein x is the amount (atom %) of cobalt in the bonding layer, and y is the slope (kgf·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%.

A process for producing a rubber-based composite material comprising the steps of laminating a rubber compound onto a substrate, with a bonding layer of metal or metal compound 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 the primer layer comprises aluminum,
• 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 metal or metal compound is selected from the group consisting of cobalt, cobalt alloys containing higher than 50% by weight of cobalt, cobalt oxides, cobalt nitrides, and cobalt carbides, 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:
• x−19≧y≧0.2x−12
• wherein x is the amount (atom %) of cobalt in the bonding layer, and y is the slope (kgf·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%.