Patent ID: 7087660

Claim:
A process of providing a rubber composition for a component of an article of manufacture (e.g. a tire) comprises applying a directed high frequency energy to an unvulcanized, silica-rich diene-based rubber composition which contains at least one polymer and/or elastomer having a Tm or Tg of at least 0° C., and sulfur curative, wherein said rubber composition has a temperature below 35° C., in at least one directed high frequency energy station to thereby internally preheat the rubber composition by directed high frequency energy to a temperature of at least about 40° C. and a maximum of about 90° C.; wherein said directed high frequency energy is applied to said rubber composition within said directed energy station(s) by at least one radio frequency radiation directed energy station by application of radio frequency in a range of from about 0.5 to about 100 MHz and/or at least one microwave frequency radiation directed energy station by application of microwave frequency in a range of from about 900 to about 930 or from about 2300 to about 2600 MHz; wherein said diene-based rubber composition is comprised of, based upon parts by weight per 100 parts by weight to the total of diene-based elastomer(s) and said polymer and/or elastomer having a Tm or Tg of at least 0° C. (phr): (A) at least about 20 phr of a polymer or elastomer having a Tm or Tg of least 0° C., (B) at least about 20 phr of at least one diene-based elastomer having a Tm or Tg lower than 0° C., (C) a dispersion throughout said rubber composition of about 40 to about 80 phr of particulate reinforcement therefor composed of (1) about 30 to about 75 phr of synthetic precipitated silica, (2) from zero to about 10 phr of rubber reinforcing carbon black, and (3) from zero to about 30 phr of at least partially exfoliated, intercalated clay platelets, (4) about 0.1 to about 4 phr of sulfur, and optionally (5) about 10 to about 40 phr of rubber processing oil. wherein said polymer and/or elastomer having a Tm or Tg of at least 0° C. is comprised of at least one of trans 1,4polybutadiene-polymer, 3,4-polyisoprene elastomer, styrene/butadiene copolymer elastomer having a styrene content of at least about 30 percent, styrene/butadiene copolymer elastomer with a polybutadiene component having trans 1,4 content of at least about 70 percent, isoprene/butadiene copolymer with a polybutadiene component having a trans 1,4 content of at least about 70 percent, natural cis 1,4-polyisoprene rubber and polystyrene polymer so long as said polymer and/or elastomer has a Tm or Tg of at least 0° C.