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US 2003/0125474 A1Published application
Rubber composition
OwnerFumito Yatsuyanagiinventor
Life of this patent
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OwnerFumito Yatsuyanagiinventor
Estimating the term…
A rubber composition of (i) 100 parts by weight of a starting rubber of (A) 40 to 120 parts of SBR and carbon black (CB) having an N2SA of at least 70 m2/g, (B) 40 to 120 parts by weight of an NR-CB rubber composition of NR and CB having an N2SA of at least 70 m2/g, and (C) BR and/or SBR having a Tg higher by at least 10° C. than that of the SBR in the SBR-CB rubber composition (A), wherein the rubber composition has a ratio of the average value FMB of the concentration of CB to the amount of rubber in the CB-containing rubber compositions (A) and (B) and the concentration FCOM of CB to the amount of rubber in the rubber composition of 1.2 to 3.0. In addition a rubber composition containing a CB-containing natural rubber master batch obtained by mixing a natural rubber (NR) starting latex and carbon black (CB) in a water-based medium and coagulating and drying it, an additional starting rubber having a glass transition temperature (Tg) of −50° C. to −20° C. and silica in an internal mixer.
A rubber composition (COM) comprising (i) 100 parts by weight of a starting rubber composed of (A) 40 to 120 parts by weight of an SBR-carbon black (CB) rubber composition having a weight ratio of CB having a nitrogen specific surface area (N2SA) of at least 70 m2/g to at least one styrene-butadiene copolymer rubber (SBR) of 0.4 to 1, (B) 40 to 120 parts by weight of an NR-CB rubber composition having a weight ratio of carbon black (CB) having a nitrogen specific surface area (N2SA) of at least 70 m2/g to natural rubber (NR) of 0.4 to 1, and (C) a butadiene rubber (BR) and/or styrene-butadiene copolymer rubber (SBR) having a Tg higher by at least 10° C. than the Tg of the SBR starting rubber in the SBR-CB rubber composition (A) and (ii) 80 parts by weight or less of a total softening agent, which are obtainable by mixing in an internal mixer, said rubber composition having a ratio FMB/FCOM of an average value FMB of the concentration of CB based upon the total amount of rubber in the CB-containing rubber compositions (A) and (B) and a concentration FCOM of carbon black (CB) based upon the amount of rubber in said rubber composition (COM) of 1.2 to 3.0.
A rubber composition comprising (i) a carbon black (CB)-containing natural rubber master batch which is obtainable by mixing a natural rubber (NR) starting latex and carbon black (CB) in a water-based medium, followed by coagulating and drying, (ii) an additional starting rubber having a glass transition temperature (Tg) of −50° C. to −20° C. and (iii) silica, wherein the components (i), (ii) and (iii) are obtainable by mixing in an internal mixer.
Dependencies are inferred from the claim text.