Patent ID: 9090757
Filing Date: 2015-07-28
Classification: C08J,C08K

Abstract:
1. A method of preparing rubber composition containing reinforcing filler comprised of, based upon parts by weight per 100 parts by weight rubber (phr): (A) Blending in at least one sequential preparatory mixing step at a temperature in a range of from about 70° C. to about 170° C., (1) 100 phr of at least one diene-based elastomer, (2) about 30 to about 120 phr of rubber reinforcing filler comprised of about 0.5 to about 30 phr of graphene together with a specialized coupling agent, and (a) rubber reinforcing carbon black, or (b) combination of rubber reinforcing carbon black and precipitated silica, together with silica coupler for the precipitated silica having a moiety reactive with hydroxyl groups on the precipitated silica and another, different, moiety interactive with said diene-based elastomer(s), wherein said specialized coupling agent has a moiety with pi electrons to create a pi-pi network with the graphene and another polysulfide or thiol moiety to interact with said diene-based elastomer(s), wherein said specialized coupling agent is represented by Formula III as at least one of 1,3-di-(2-pyrenyl) alkyl polysulphide as Formula III(a) and thiolalkyl pyrene as Formula III(b) where n is a value of from 1 through 3 and x is a value of from 2 through 4: wherein said thiol moiety of said specialized coupler is chemically blocked from appreciably interacting with said diene-based elastomer(s) with a compound containing least one of dithiobenzoate, trithiocarbonate and thioester, (B) Blending in a subsequent final mixing step at a temperature in a range of from about 60° C. to about 120° C. sulfur curatives comprised of sulfur and at least one sulfur cure accelerator.