The invention relates to a laminate comprising a first layer and a second layer directly covering the first layer, the first layer being a layer of a silicone rubber composition comprising a micrometric silicone powder and a mixture of crosslinkable organopolysiloxanes, the second layer being a layer of a silicone rubber composition comprising a hydrophobic silica and a mixture of crosslinkable organopolysiloxanes, the first layer and the second layer being crosslinked. The laminate, in particular when it is used as a coating for the outer surface of an expandable bladder for a tyre curing mould, makes it possible to eliminate moulding defects on the inner liner of the tyre.

A tire vulcanizing apparatus 1 comprises: a vulcanizing mold 2 for vulcanization-molding an unvulcanized tire T, a tire-vulcanizing bladder assembly 3 inflatable with a fluid to press the unvulcanized tire against the vulcanizing mold, a supply means 4 for the fluid, and a discharge means 5 for the fluid from the assembly 3. The tire-vulcanizing bladder assembly 3 compresses an outside bladder 8 for abutting on the inner surface of the unvulcanized tire, and an inside bladder 9 disposed in the outside bladder. The fluid includes a first fluid G1 supplied between the outside and inside bladders, and a second fluid G2 supplied to the inside bladder.

A pneumatic tire is vulcanized using a bladder provided with a coating layer formed of a release agent, and includes a sealant layer disposed on an inner surface of a tread portion in a tire circumferential direction. The amount of silicon of the release agents detected in at least a placement region of the sealant layer by fluorescence X-ray analysis is from 0.1 wt. % to 10.0 wt. %.

A curing bladder (7) for a tire has a shape exhibiting symmetry of revolution with a central axis and comprises a flexible wall made of cross-linked rubber, the external surface (20) of the wall comprising an air drainage zone (21) and an air removal zone (22) adjacent to the drainage zone, the bladder (7) being equipped with an air drainage structure comprising elements recessed into the external surface, the recessed elements forming a network of channels (30) extending in the air drainage zone (21) and as far as the air removal zone (22). The depth of a channel (30) of the network, defining the shortest path (31) connecting any point of the network of channels, which is situated in the air drainage zone (21), and the air removal zone (22), increases along the length of the path.

A pneumatic tire is vulcanized by using a bladder provided with a coating layer formed by a release agent, and the release agent has a thickness, detected by an electron microscope, of 0.1 μm to 100 μm on an inner surface of a tread portion 1.

A process for modifying an expandable curing bladder for a tire, which bladder has a surface intended to come into contact with a tire casing is provided. The process comprises a step of applying to the surface a layer of a silicone rubber composition comprising a first liquid organopolysiloxane bearing chain-end alkenyl groups, a second liquid organohydropolysiloxane and a photoactivatable hydrosilylation catalyst, and a step of exposing the silicone rubber composition covering the surface to irradiation with ultraviolet-visible light.

The invention relates to rubber compositions that are provided with polyorganosiloxanes as plasticizers. The rubber compositions can be vulcanized by means of a cross-linking resin and they are particularly suitable for use as curing bladders in the production of tires. The invention further relates to the use of polyorganosiloxanes as corresponding plasticizers.

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 molding a tire that has a container (12) that includes the steps of placing an uncured tire into a mold, and providing a bladder (16) that has a flexible portion (18) and an insert (20) that has a cavity configured for molding the container into the tire. The bladder has a fluid therein and is inflated within the mold, and material of the uncured tire flows into the cavity of the insert (20). Sufficient heat and pressure is applied to the uncured tire to at least partially cure the tire when the uncured tire is in the mold. The material in the insert (20) forms the container (12) such that the container is integrally formed with other portions of the tire. The mold is opened to retrieve the tire.

The present invention relates to new vulcanisable elastomeric compositions for components of tyres, comprising modified silicate fibres as fillers. The silicate fibres are modified according to the process with controlled pH of the invention. In addition, the invention regards components of tyres, comprising elastomeric materials obtainable by vulcanisation of said compositions, and tyres for vehicles comprising one or more of said components. The vulcanised elastomeric materials according to the invention are characterised by good static and dynamic mechanical properties, in particular by particularly low hysteresis. Advantageously the tyres of the invention comprising one or more of said components have a limited rolling resistance.