Abstract: 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.

Abstract: The invention relates to a vulcanizable rubber composition which comprises a) one or more rubbers cross-linkable by means of amine, b) one or more white fillers and c) one or more polyorganosiloxanes with at least two NH2 groups per molecule. In the rubber compositions the total quantity of organosilane is limited. The rubber compositions after vulcanization result in a good compression set.

Abstract: The invention relates to the use of polyorganosiloxanes having 3 or more siloxane units, which have one or more organic fractions R1, where R1 has one or more carbon-carbon multiple bonds and at least 4 carbon atoms, and wherein the presence of hydrocarbon fractions having a chain length of 5 to 50 carbon atoms is excluded, as additives in the processing of rubber. The polyorganosiloxanes are used in the processing and vulcanisation of rubber in a quantity of 0.1 to 10 phr and incorporated by reaction in same. Said polyorganosiloxanes produce a reduction in the viscosity of the rubber during processing and optionally an improvement in the mechanical properties of the vulcanised rubber.