Abstract: In a pneumatic safety tire comprising reinforcing rubber layers having an approximately crescent sectional shape for supporting a portion of the load which are disposed on the inner circumferential face of the carcass layer at side walls, a fiber cord constituting a belt reinforcing layer has a size of 1,000 to 7,000 dtex as the entire cord, comprises at least 50% by mass of a polyketone fiber and exhibits a maximum stress of thermal contraction of 0.1 to 1.8 cN/dtex. Buckling deformation of the tread portion can be suppressed, and the run flat performance is improved while the ride quality during driving under the normal internal pressure is not adversely affected and changes in the manufacturing process are not required.

Abstract: In a pneumatic safety tire comprising reinforcing rubber layers having an approximately crescent sectional shape for supporting a portion of the load which are disposed on the inner circumferential face of the carcass layer at side walls, a fiber cord constituting a belt reinforcing layer has a size of 1,000 to 7,000 dtex as the entire cord, comprises at least 50% by mass of a polyketone fiber and exhibits a maximum stress of thermal contraction of 0.1 to 1.8 cN/dtex. Buckling deformation of the tread portion can be suppressed, and the run flat performance is improved while the ride quality during driving under the normal internal pressure is not adversely affected and changes in the manufacturing process are not required.

Abstract: A rubber-fiber composite material of the present invention comprises a non-woven fabric and a rubber which coats the non-woven fabric. At least a part of the non-woven fabric is made of an organic fiber having a single fiber diameter of 10 to 35 ?m, a fiber length of 30 to 100 mm and a tensile modulus of 50 GPa or higher. By the use of the non-woven fabric at least a part of which is made of the organic fiber having the above properties, a sufficient impregnation of rubber into the inside of the non-woven fabric is ensured to enable the production of the rubber-fiber composite material having a high stiffness. Using the rubber-fiber composite material of the present invention as the reinforcing material for rubber articles, the resultant rubber articles have enhanced stiffness, improved durability and reduced weight.

Abstract: A rubber-fiber composite material of the present invention comprises a non-woven fabric and a rubber which coats the non-woven fabric. At least a part of the non-woven fabric is made of an organic fiber having a single fiber diameter of 10 to 35 ?m, a fiber length of 30 to 100 mm and a tensile modulus of 50 GPa or higher. By the use of the non-woven fabric at least a part of which is made of the organic fiber having the above properties, a sufficient impregnation of rubber into the inside of the non-woven fabric is ensured to enable the production of the rubber-fiber composite material having a high stiffness. Using the rubber-fiber composite material of the present invention as the reinforcing material for rubber articles, the resultant rubber articles have enhanced stiffness, improved durability and reduced weight.

Abstract: A pneumatic tire which comprises a pair of right and left bead portions, a carcass layer disposed extending between the bead portions, a tread portion arranged at an outside of the carcass layer in a radial direction of the tire, a pair of side wall portions arranged at right and left sides of the tread portion and at least one pair of rubber members selected from a pair of rubber members constituted with a rigid rubber and arranged in the bead portions and a pair of rubber members disposed in the side wall portions, wherein at least one pair of rubber members selected from a pair of rubber members arranged in the bead portions and a pair of rubber members disposed in the side wall portions are constituted with rubber composition having a minimum value of a dynamic storage modulus within a temperature range of 200 to 250° C. which is 75% of a dynamic storage modulus at 50° C. or more.

Abstract: The present invention provides a runflat tire having an effectively improved runflat durability while continuously running under a runflat condition due to a low tire pressure or puncture, without sacrificing other characteristics such as riding comfort during an ordinal driving at normal internal pressure. A runflat tire 1 according to the first aspect comprises a belt 8 consisting of at least one rubber-coated cord layer laid between a crown portion of a carcass 7 and a tread portion 5, the carcass consisting of at least one ply toroidally extending bead portions 3, sidewall portions 4 and the tread portion; a reinforcing rubber 11 which has a generally crescent sectional shape and is arranged at the interior surface side at least of sidewall portions 4; and a ring-shaped rim guard portion 13 protruding outwardly in the tire's width direction arranged at the exterior surface position of the tire immediately above a rim flange Rf.

Abstract: A rubber-fiber composite material of the present invention comprises a non-woven fabric and a rubber which coats the non-woven fabric. At least a part of the non-woven fabric is made of an organic fiber having a single fiber diameter of 10 to 35 &mgr;m, a fiber length of 30 to 100 mm and a tensile modulus of 50 GPa or higher. By the use of the non-woven fabric at least a part of which is made of the organic fiber having the above properties, a sufficient impregnation of rubber into the inside of the non-woven fabric is ensured to enable the production of the rubber-fiber composite material having a high stiffness. Using the rubber-fiber composite material of the present invention as the reinforcing material for rubber articles, the resultant rubber articles have enhanced stiffness, improved durability and reduced weight.

Abstract: A pneumatic tire which comprises a pair of right and left bead portions, a carcass layer disposed extending between the bead portions, a tread portion arranged at an outside of the carcass layer in a radial direction of the tire, a pair of side wall portions arranged at right and left sides of the tread portion and at least one pair of rubber members selected from a pair of rubber members constituted with a rigid rubber and arranged in the bead portions and a pair of rubber members disposed in the side wall portions, wherein at least one pair of rubber members selected from a pair of rubber members arranged in the bead portions and a pair of rubber members disposed in the side wall portions are constituted with rubber composition having a minimum value of a dynamic storage modulus within a temperature range of 200 to 250° C. which is 75% of a dynamic storage modulus at 50° C. or more.