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.

Disclosed herein are a tire comprising at least one component having a surface coated with a liquid release layer, a process for preparing a tire having at least one component with a surface coated with a release layer, and a cured tire comprising a tire body at least one component with a surface coated with a release layer. The release layer comprises at least one silicone rubber and at least one adhesive polymer which may be present in latex form in the liquid release layer.

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 tire-holding device includes: a shaft body having a portion thereof inserted into a bladder which is fixed to the shaft body, the bladder expanding in a tire to hold the tire; and a support body which comes into contact with the shaft body to support the shaft body, the shaft body includes an inner hole placed inside the bladder, and an outer hole placed outside the bladder and is brought into communication with the inner hole, and the support body includes a support hole, and when the support body supports the shaft body, the outer hole and the support hole come into communication with each other irrespective of a position of the shaft body in its circumferential direction.

A tire vulcanizing machine, rubber vulcanizing apparatus, and in particular, tire vulcanizing equipment, including a mold assembly, a ring seat assembly provided in the mold assembly, a cylinder assembly supporting the ring seat assembly, a sealing hood for sealing a gas in the mold assembly, and a driving member. A gas circulating fan is provided on the ring seat assembly; a rotating shaft for driving the gas circulating fan to rotate is provided in the cylinder assembly; the driving member drives the rotating shaft to rotate; and the sealing hood isolates the driving member.

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.

A rubber composition containing based upon parts by weight per 100 parts by weight rubber (phr): (A) 20-50 phr of a copolymer of ethylene, at least one C3 to C23 -olefin and a least one polyene monomer, whereby the copolymer unit derived from the polyene is 1 to 5 wt. %, by weight of the copolymer (A) and has a Mooney viscosity ML (1+4) at 100 C. from 51 or greater, in particular from 55 to 90 at 100 C., (B) 50-80 phr of butyl-type rubber and (C) a resin-based curative, containing a phenol formaldehyde resin cross-linker as only curing agent and an activator package comprising of metal oxide and a halogen donor where a halogenated component (B) or halogenated cross-linker as part of component (C) not already present.

A release agent for being coated onto a tire bladder made of a zinc-oxide-incorporated butyl rubber during pneumatic-tire molding, the release agent containing (A) organopolysiloxane, which contains a carboxy group indicated by the general formula (1) below

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(in the formula, R.sup.1 is a substituted or unsubstituted C1-C30 monovalent hydrocarbon group excluding R.sup.2, R.sup.2 is a carboxy-group-substituted C1-C30 monovalent organic group, R.sup.3 is R.sup.1 or R.sup.2, and n is an integer of 3 to 2000.). This release agent produces a longer service life of a tire bladder and leads to reduced tire production cost because the amount of silicone that migrates to the tire side is low when the tire is released, and repeated mold-release performance is enhanced.