Abstract: The present invention provides a vehicle engine oil seal having excellent sliding properties over the entire rotation range of engines from a low rotation range to a high rotation range. The present invention is a vehicle engine oil seal comprising: an elastic member with a seal lip portion having at least a main lip portion, wherein the elastic member is formed of a composition containing a fluororubber and a fluororesin and has projecting portions at least on a surface of the main lip portion, the projecting portions being substantially formed of the fluororesin contained in the composition, the fluororesin is a copolymer including a polymerization unit derived from ethylene and a polymerization unit derived from tetrafluoroethylene, and the fluororubber is a polymer including a polymerization unit derived from vinylidene fluoride.

Abstract: The present invention provides a vehicle transmission having excellent sliding properties over the entire speed range of engines from a low speed range to a high speed range. The present invention is a vehicle transmission oil seal comprising: an elastic member with a seal lip portion having at least a main lip portion, wherein the elastic member is formed of a composition containing a fluororubber and a fluororesin and has projecting portions at least on a surface of the main lip portion, the projecting portions being substantially formed of the fluororesin contained in the composition, the fluororesin is a copolymer including a polymerization unit derived from ethylene and a polymerization unit derived from tetrafluoroethylene, and the fluororubber is a polymer including a polymerization unit derived from vinylidene fluoride.

Abstract: The present invention provides a vehicle valve stem seal having both durability and sliding properties at an extremely high level in addition to usual sealing performance. The present invention is a vehicle valve stem seal comprising an elastic member with a seal lip portion on an end of a valve stem guide, the seal lip portion slidably closely contacting with a valve stem of an engine, wherein the elastic member is formed of a composition containing a fluororubber and a fluororesin and has projecting portions at least on a surface of the seal lip portion, the projecting portions being substantially formed of the fluororesin contained in the composition, the fluororesin is a copolymer including a polymerization unit derived from ethylene and a polymerization unit derived from tetrafluoroethylene, and the fluororubber is a polymer including a polymerization unit derived from vinylidene fluoride.

Abstract: There is provided a vehicle wheel which can reduce a rolling resistance by rising a tire temperature with a simple structure. A heat-insulation rubber is pasted on all circumference surface of a portion of an outer circumference surface of a rim other than a bead seating portion where a bead portion of a tire closely contacts and a rim flange portion. The heat-insulation rubber suppresses any heat transfer from air in a tire air chamber and from the internal surface of the tire to the rim at the outer circumference surface of the rim which contacts the air in the tire air chamber.

Abstract: The present invention provides a vehicle valve stem seal having both durability and sliding properties at an extremely high level in addition to usual sealing performance. The present invention is a vehicle valve stem seal comprising an elastic member with a seal lip portion on an end of a valve stem guide, the seal lip portion slidably closely contacting with a valve stem of an engine, wherein the elastic member is formed of a composition containing a fluororubber and a fluororesin and has projecting portions at least on a surface of the seal lip portion, the projecting portions being substantially formed of the fluororesin contained in the composition, the fluororesin is a copolymer including a polymerization unit derived from ethylene and a polymerization unit derived from tetrafluoroethylene, and the fluororubber is a polymer including a polymerization unit derived from vinylidene fluoride.

Abstract: The rubber composites for tire treads include silica; carbon black; and oil constituents, wherein a ratio (A index) of silica contents, carbon black contents, and oil constituents contents is represented by A index=silica contents/(carbon black contents+silica contents+oil constituents contents)?0.8; and a ratio (B index) of a complex elastic modulus E* at 30° C. and a loss tangent tan ? at 60° C. is represented by B index=E*/tan ??120.

Abstract: The present invention provides a vehicle transmission having excellent sliding properties over the entire speed range of engines from a low speed range to a high speed range. The present invention is a vehicle transmission oil seal comprising: an elastic member with a seal lip portion having at least a main lip portion, wherein the elastic member is formed of a composition containing a fluororubber and a fluororesin and has projecting portions at least on a surface of the main lip portion, the projecting portions being substantially formed of the fluororesin contained in the composition, the fluororesin is a copolymer including a polymerization unit derived from ethylene and a polymerization unit derived from tetrafluoroethylene, and the fluororubber is a polymer including a polymerization unit derived from vinylidene fluoride.

Abstract: The present invention provides a vehicle engine oil seal having excellent sliding properties over the entire rotation range of engines from a low rotation range to a high rotation range. The present invention is a vehicle engine oil seal comprising: an elastic member with a seal lip portion having at least a main lip portion, wherein the elastic member is formed of a composition containing a fluororubber and a fluororesin and has projecting portions at least on a surface of the main lip portion, the projecting portions being substantially formed of the fluororesin contained in the composition, the fluororesin is a copolymer including a polymerization unit derived from ethylene and a polymerization unit derived from tetrafluoroethylene, and the fluororubber is a polymer including a polymerization unit derived from vinylidene fluoride.

Abstract: There are provided the tire motor 5 for increasing or decreasing the tire rotational frequency Nt while the tire 3 is being rotated around the tire rotational shaft 1, the rotational frequency measuring means 6 for measuring the tire rotational frequency Nt, the drum motor 11 for rotating the test drum 12 around the drum rotational shaft 14 at the constant drum speed Vd, the speed meter 15 for measuring the drum speed Vd, the load applying means 4 for pushing the tire 3 against the test drum 12 with the tire load Fz, the radial force load cell 2 for measuring the tire load Fz, the tangential force load cell 2 for measuring the tangential force Fx that is exerted on the tire 3, and the recording means for recording the measurement result of each of the drum speed Vd, the tire rotational frequency Nt, the tangential force Fx and the tire load Fz in association with every measurement time point during increasing or decreasing the tire rotational frequency.

Abstract: There is provided a vehicle wheel which can reduce a rolling resistance by rising a tire temperature with a simple structure. A heat-insulation rubber is pasted on all circumference surface of a portion of an outer circumference surface of a rim other than a bead seating portion where a bead portion of a tire closely contacts and a rim flange portion. The heat-insulation rubber suppresses any heat transfer from air in a tire air chamber and from the internal surface of the tire to the rim at the outer circumference surface of the rim which contacts the air in the tire air chamber.

Abstract: The rubber composites for tire treads include silica; carbon black; and oil constituents, wherein a ratio (A index) of silica contents, carbon black contents, and oil constituents contents is found by: A index=silica contents/(carbon black contents+silica contents+oil constituents contents)?0.8??relational expression (1); and a ratio (B index) of a complex elastic modulus E* at 30° C. and a loss tangent tan ? at 60° C. is found by: B index=E*/tan ??120??relational expression (2).

Abstract: There are provided the tire motor 5 for increasing or decreasing the tire rotational frequency Nt while the tire 3 is being rotated around the tire rotational shaft 1, the rotational frequency measuring means 6 for measuring the tire rotational frequency Nt, the drum motor 11 for rotating the test drum 12 around the drum rotational shaft 14 at the constant drum speed Vd, the speed meter 15 for measuring the drum speed Vd, the load applying means 4 for pushing the tire 3 against the test drum 12 with the tire load Fz, the radial force load cell 2 for measuring the tire load Fz, the tangential force load cell 2 for measuring the tangential force Fx that is exerted on the tire 3, and the recording means for recording the measurement result of each of the drum speed Vd, the tire rotational frequency Nt, the tangential force Fx and the tire load Fz in association with every measurement time point during increasing or decreasing the tire rotational frequency.

Abstract: This invention provides a pneumatic tire (T) including: a tacky sealant layer (5) formed of a rubber component decomposable by a peroxide, and disposed on the inner side of an inner liner (4) in a region corresponding to a tread part (1); and a cover rubber layer (6) covering the inner side of the tacky sealant layer (5). A sheet piece (7) is disposed to traverse an adhesive seal part (Q) and/or (P) at an edge portion of the cover rubber layer (6), while at least one surface of the sheet piece (7) is a release face which can be separated from at least one of the tacky sealant layer (5) and the cover rubber layer (6). A first end of the sheet piece (7) is inserted between the tacky sealant layer (5) and the cover rubber layer (6) while a second end thereof protrudes to the outer side of the adhesive seal part (Q) and/or (P).

Abstract: Provided are a pneumatic tire T and a method of manufacturing the same. The pneumatic tire T includes: a tacky sealant layer 5 which is formed of a rubber component thermally decomposable with a peroxide, and which is disposed on the inner wall surface of the tire at least in a region corresponding to a tread portion 1; a cover rubber layer 6 which covers the tacky sealant layer 5. In the pneumatic tire T, the cover rubber layer 6 is provided with at least one gas vent hole 7a (7b) formed therein. This allows decomposition gas generated from the tacky sealant layer 5 to be discharged through the gas vent hole 7a (7b) to the outside of the tire.

Abstract: Disclosed are a pneumatic tire, which exhibits excellent puncture-preventing function while avoiding inconvenience aroused when a sealant layer is formed based on decomposition reaction of polyisobutylene, a process for producing the same and a sealant rubber composition. This pneumatic tire is provided with the sealant layer in a region of the inner surface of the tire which corresponds at least to a tread. The sealant layer is made of an adhesive sealant obtained by heating a rubber composition containing 0.2 to 20 parts by weight of peroxide per 100 parts by weight of a rubber ingredient containing not less than 50 wt. % of polyisobutylene. 5 to 50 parts by weight of a liquid ethylene/?-olefin copolymer, liquid polybutadiene or liquid polyisoprene are added as an adhesive of the sealant layer.

Abstract: A sealant rubber composition which forms a spongy tacky sealant layer having moderate viscosity properties; and a pneumatic tire having in the tire main body a tacky sealant layer obtained by heating the rubber composition. The rubber composition comprises 0.2 to 20 parts by weight of a peroxide per 100 parts by weight of polymers comprising 95 to 50 parts by weight of a polymer decomposable with the peroxide and 5 to 50 parts by weight of a polymer crosslinkable with the peroxide.

Abstract: A sealant rubber composition which forms a spongy tacky sealant layer having moderate viscosity properties; and a pneumatic tire having in the tire main body a tacky sealant layer obtained by heating the rubber composition. The rubber composition comprises 0.2 to 20 parts by weight of a peroxide per 100 parts by weight of polymers comprising 95 to 50 parts by weight of a polymer decomposable with the peroxide and 5 to 50 parts by weight of a polymer crosslinkable with the peroxide.

Abstract: Disclosed are a pneumatic tire, which exhibits excellent puncture-preventing function while avoiding inconvenience aroused when a sealant layer is formed based on decomposition reaction of polyisobutylene, a process for producing the same and a sealant rubber composition. This pneumatic tire is provided with the sealant layer in a region of the inner surface of the tire which corresponds at least to a tread. The sealant layer is made of an adhesive sealant obtained by heating a rubber composition containing 0.2 to 20 parts by weight of peroxide per 100 parts by weight of a rubber ingredient containing not less than 50 wt. % of polyisobutylene. 5 to 50 parts by weight of a liquid ethylene/&agr;-olefin copolymer, liquid polybutadiene or liquid polyisoprene are added as an adhesive of the sealant layer.