Patent ID: 7015272

Claim:
A process of preparing a rubber composition, based upon parts by weight per 100 parts by weight rubber (phr) comprises: (A) preparing a pre-formed composite by blending in an internal rubber mixer, to a temperature in a range of from about 150° C. to about 180° C. ingredients which comprises: (1) 100 phr of at least one conjugated diene-based elastomer; (2) about 20 to about 120 phr of reinforcing filler comprised of carbon black and precipitated silica with a carbon black to silica of a weight ratio in a range of from about 1/5 to about 5/1; (4) coupling agent for said precipitated silica, where said silica is used, having a moiety reactive with hydroxyl groups on the surface of said silica and another moiety interactive with said diene-based elastomer; (5) about 0.1 to about 3 phr of m-phenylene bismaleimide; (6) about 2 to about 40 phr of ultra high molecular weight crystalline and linear polyethylene (UHMWPE) having a melting point in a range of from about 125° C. to about 140° C., an average molecular weight in a range of from about 2 to about 20 million g/mol, wherein said mixing temperature is at least 10° C. higher than said melting point of said UHMWPE, wherein said mixing is conducted by mixing the ingredients at said temperature within said temperature range over a period of from about 2 to about 4 minutes and thereafter continuing to mix the ingredients within 10° C. of said temperature over a period of from about 2 to about 4 minutes, followed by (B) Cooling said pre-formed composite to a temperature below 40° C., wherein said cooled pre-formed composite is a temperature in a range of about 90° C. to about 115° C. mixed in an internal rubber mixer with vulcanizing ingredients comprised of sulfur and at least one sulfur vulcanization accelerator to a temperature in a range of from about 90° C. to about 115° C.