A rubber composition for a bladder used for manufacturing a bladder for vulcanizing tire, in which 1 to 5 parts by mass of a polymer having a weight average molecular weight Mw of 1,000,000 or more is blended in 100 parts by mass of a rubber component containing butyl rubber as a main component, and a method for manufacturing a bladder for vulcanization of tires characterized in that the bladder for vulcanization of tires is manufactured by an extrusion molding and an injection molding of a rubber composition for a bladder, in the rubber composition for a bladder, 1 to 5 parts by mass of a polymer having a weight average molecular weight Mw of 1,000,000 or more is blended with 100 parts by mass of a rubber component containing butyl rubber as a main component, and the injection molding of the rubber composition for a bladder is carried out while performing vacuum suction.

A compounded elastomer exhibiting excellent mechanical and heat transfer properties is described. The elastomer can include two or more different carbon blacks, and one of the carbon blacks is a partially crystallized carbon black.

A mold release composition is provided contains a minimum of three reactive moieties per molecule to provide for both mold adhesion and crosslink density. The composition is soluble in a VOC-free organic solvent or water, alone or with resort to an emulsifier. The composition can be used as a semi-permanent mold release in some embodiments.

A mold release composition is provided contains a minimum of three reactive moieties per molecule to provide for both mold adhesion and crosslink density. The composition is soluble in a VOC-free organic solvent or water, alone or with resort to an emulsifier. The composition can be used as a semi-permanent mold release in some embodiments.

A rubber composition for a bladder used for manufacturing a bladder for vulcanizing tire, in which 1 to 5 parts by mass of a polymer having a weight average molecular weight Mw of 1,000,000 or more is blended in 100 parts by mass of a rubber component containing butyl rubber as a main component, and a method for manufacturing a bladder for vulcanization of tires characterized in that the bladder for vulcanization of tires is manufactured by an extrusion molding and an injection molding of a rubber composition for a bladder, in the rubber composition for a bladder, 1 to 5 parts by mass of a polymer having a weight average molecular weight Mw of 1,000,000 or more is blended with 100 parts by mass of a rubber component containing butyl rubber as a main component, and the injection molding of the rubber composition for a bladder is carried out while performing vacuum suction.

The present invention is to provide a rubber composition for vulcanizing bladder excellent in thermal conductivity and a vulcanizing bladder formed of the rubber composition, with which vulcanization efficiency can be improved. The rubber composition for vulcanizing bladder comprises, based on 100 parts by mass of a rubber component comprising 80% by mass or more of a butyl rubber, 20 to 200 parts by mass of at least one type of metal filler selected from the group consisting of metal powder, metal oxide powder, metal hydroxide powder and metal nitride powder, said metal filler having a Mohs hardness of 8 or lower and a mean particle size of 0.3 to 50 m, and 20 to 80 parts by mass of a carbon black. The vulcanizing bladder is formed of the rubber composition for vulcanizing bladder.

A method for manufacturing a pneumatic tire uses a tire vulcanizing bladder including a plurality of vent lines, and is characterized in that the pneumatic tire includes an inner liner on an inner surface thereof, the inner liner has an SIBS layer containing a styrene-isobutylene-styrene triblock copolymer, the SIBS layer has a thickness of more than or equal to 0.05 mm and less than or equal to 0.6 mm, the SIBS layer contains more than or equal to 0.5% by mass and less than or equal to 40% by mass of a polymer obtained by polymerization of a monomer unit having 4 carbon atoms, and the vent lines each include a first vent line at a part corresponding to from a tire bead toe part to a tire buttress part, and a second vent line at a part corresponding to from the tire buttress part to a tire crown part.

Provided are a vulcanization device for a pneumatic tire and a method for vulcanizing a pneumatic tire. A pressurizing medium having a relatively low pressure is supplied through a pressurizing medium low-pressurization/supply line into a vulcanization bladder having a tube-like shape inserted into a green tire in a vulcanization mold to inflate the vulcanization bladder. Thereafter, a heating medium is supplied through a heating medium supply line into the vulcanization bladder (2). Then, a pressurizing medium having a relatively high pressure is supplied through a pressurizing medium supply line into the vulcanization bladder to increase internal pressure of the vulcanization bladder while the media in the vulcanization bladder are circulated through a circulation line extending outside the vulcanization bladder, thereby vulcanizing the green tire.

A method of manufacturing a tire curing bladder, the method includes the steps of (i) providing a cured tire curing bladder; and (ii) applying an air barrier composition to the cured tire curing bladder to form an air barrier layer. A method of restoring the air retention of a tire curing bladder, the method includes the steps of (i) providing a used tire curing bladder; and (ii) applying an air barrier composition to the used tire curing bladder to form an air barrier layer.

A vulcanizing bladder 3 comprises a first bladder 11 configured to contact with an inner circumferential surface of an unvulcanized tire (T) and a second bladder 12 arranged inside the first bladder 11. A first fluid G1 is to be supplied between the first bladder 11 and the second bladder 12, and a second fluid G2 is to be supplied to an inside of the second bladder 12. At least one of an inner circumferential surface 11s of the first bladder 11 and an outer circumferential surface 12s of the second bladder 12 is provided with a guide groove 31 extending in a tire axial direction through which the first fluid G1 can pass.