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US 5,351,734 AGranted
Pneumatic tire with foam rubber in the tread
AssigneeBridgestone Corporation
InventorsHiroshi Mouri, Yasuyoshi Kawaguchi, Michio Ishii, Seiichiro Iwafune, Toshiro Iwata
Life of this patent
Estimating the term…
Abstract
Herein disclosed is a pneumatic tire which comprises a case and a tread which covers a crown portion of the case. The tread includes a foamed rubber which has a volume not less than 10% of that of the entire of the tread, and the foamed rubber is formed of a rubber composition which contains rubber components each having a glass transition point not higher than -60.degree. C.
Claims25
A pneumatic tire comprising:
- a case having a crown portion;
- and
- a tread covering said crown portion of the case, said tread including as at least a portion of its outer surface a foamed rubber which has a volume of at least about 10% of the entire volume of said tread, said foamed rubber being formed of a rubber composition which consists essentially of at least one rubber component having a glass transition point not higher than about -60.degree. C.,
- wherein said foamed rubber has an expansion ratio ranging from about 5% to about 50%, has closed cells the mean diameter of which ranges from about 5 .mu.m to about 150 .mu.m, and has at least about 20 closed cells of diameters from about 30 .mu.m to about 200 .mu.m per 1 mm.sup.2.
1 more element
A pneumatic tire comprising:
- a case having a crown portion;
- and
- a tread covering said crown portion of the case, said tread including as at least a portion of its outer surface a foamed rubber which has a volume of at least about 10% and up to about 70% of the entire volume of said tread, said foamed rubber being formed of a rubber composition having a glass transition point not higher than about -60.degree. C.,
- wherein said foamed rubber has an expansion ratio ranging from about 5% to about 50%, has closed cells the mean diameter of which ranges from about 5 .mu.m to about 150 .mu.m, and has at least about 20 closed cells of diameters from about 30 .mu.m to about 200 .mu.m per 1 mm.sup.2.
1 more element
Dependencies are inferred from the claim text.