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 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 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.

A process for producing tyres with auxiliary components for vehicle wheels is described. The process includes i) covering the external surface of an expandable chamber for tyre vulcanisation and moulding apparatuses with a first substantially cross-linkable polysiloxane composition and ii) covering the radially inner surface of the impermeable elastomeric material layer of the green tyre with a second substantially non-cross-linkable polysiloxane composition. An expandable chamber for tyre vulcanisation and moulding apparatuses and, a process for treating the expandable chamber are also described.

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, is provided. The first layer and the second layer are crosslinked. The laminate, in particular when it is used as a coating for the outer surface of an expandable bladder for a tire curing mold, makes it possible to eliminate molding defects on the inner liner of the tire.