Abstract: A method for preparing polyorganosiloxanes (POS) by a ring-opening polymerization and/or linear, non-linear or cyclic POS redistribution in the presence of a nucleophilic carbene. The initial efficiency of the POS conversion is substantially increased at low temperature, resulting in less residual content of initial POS.

Abstract: Process for the preparation of a functionalized silicone oil by hydrosilylation of synthons in the presence of at least one organohydrosilicon compound, characterized in that: (1) the synthons hydrosilylated with the organohydrosilicon compound are identical or different, and comprise at least one hydrocarbon-comprising ring in which is included at least one oxygen atom, (2) the said hydrosilylation reaction is carried out in the presence of a homogeneous catalytic system comprising (i) a metal, preferably a complexed metal, chosen from the group consisting of cobalt, rhodium, ruthenium, platinum and nickel and (ii) a heterocyclic organic compound chosen from lactones, lactams, cyclic carbonates and cyclic carbamates.

Abstract: The invention concerns a silicone composition crosslinkable into elastomer by hydrosilylation, in the presence of carbene-based metal catalysts. The invention aims at providing a composition of that type, stable over long periods at room temperature (one day to several months), without loss of its characteristic of being heat-curable by hydrosilylation and without generating secondary isomerization or coloring reactions. The invention is characterised in that the composition comprises: a polyorganovinylsiloxane(polydimethyl)(methylvinyl) siloxane; a polyorganohydrogenosiloxane; a platinum catalyst formed by a complex of formula C3 and optionally an acetylene crosslinking inhibitor, optionally a siliceous filler. The invention also concerns novel hydrosilylation catalysts of the metal complex type of formula C3 above.

Abstract: The invention relates to a silicone composition which can be crosslinked by dehydrogenative condensation between reactive ?SiH and ?SiOH units and which employs a catalytic iridium complex capable of being obtained by reacting together: on the one hand, an iridium complex of formula (I): (Ir???2)n in which: A/ n is 1 or 2 and: if n is 1, ? is a 3-electron radical ligand LX, if n is 2, ? is a 1-electron radical ligand X which behaves like a 3-electron ligand LX with the two iridium atoms, B/ ??, which are identical or different, preferably identical, each represent a 2-electron ligand L, on the other hand, a ligand ?d chosen from R2S, R2O, NR3, carbenes and organophosphorus compounds.

Abstract: Process for the preparation of a functionalized silicone oil by hydrosilylation of synthons in the presence of at least one organohydrosilicon compound, characterized in that: (1) the synthons hydrosilylated with the organohydrosilicon compound are identical or different, and comprise at least one hydrocarbon-comprising ring in which is included at least one oxygen atom, (2) the said hydrosilylation reaction is carried out in the presence of a homogeneous catalytic system comprising (i) a metal, preferably a complexed metal, chosen from the group consisting of cobalt, rhodium, ruthenium, platinum and nickel and (ii) a heterocyclic organic compound chosen from lactones, lactams, cyclic carbonates and cyclic carbamates.

Abstract: An ?SiH/?SiOH silicone composition polymerizable/crosslinkable by dehydrogenating condensation in the presence of a catalyst judiciously selected to achieve at least one of the following: kinetics, concentration/efficiency ratio of the catalyst, cost, lowering of the catalyst activation temperature (room temperature), control of the release of gaseous hydrogen and the quality of the polymerized product and the crosslinked network, and finally limitation of the secondary reactions. This composition includes: —A— at least one ?SiH POS; —B— at least one ?SiOH POS; —C— at least one metal catalyst selected from the group of organometallic complexes including at least one of the following metals: Ir, Ru, Mn; —D— optionally at least one crosslinking inhibitor; —E— optionally at least one POS resin; and —F— optionally at least one filler. Also disclosed is the catalyst —C— and processes which involve crosslinking of silicone by dehydrogenating condensation (non-stick coating on paper).

Abstract: The present invention relates to the use as catalyst for the hydrosilylation of at least one unsaturated reactant (A) with at least one silicone monomer, oligomer and/or polymer (B) having per molecule at least one reactive ?SiH unit, in the presence of a homogeneous catalyst system comprising (i) a platinum group metal, preferably a complexed metal, and (ii) a heterocyclic organic compound of lactone type.

Abstract: The invention concerns a silicone composition crosslinkable into elastomer by hydrosilylation, in the presence of carbene-based metal catalysts. The invention aims at providing a composition of that type, stable over long periods at room temperature (one day to several months), without loss of its characteristic of being heat-curable by hydrosilylation and without generating secondary isomerization or colouring reactions. The invention is characterised in that the composition comprises: a polyorganovinylsiloxane (polydimethyl)(methylvinyl) siloxane; a polyorganohydrogenosiloxane; a platinum catalyst formed by a complex of formula C3 and optionally an acetylene crosslinking inhibitor, optionally a siliceous filler. The invention also concerns novel hydrosilylation catalysts of the metal complex type of formula C3 above. The life span of the potted single-constituent compositions of the invention is significantly increased.

Abstract: The invention relates to an ≡SiH/≡SiOH silicone composition polymerizable/crosslinkable by dehydrogenating condensation in the presence of a catalyst judiciously selected to achieve at least one of the specifications listed hereafter: kinetics, concentration/efficacy ratio of the catalyst, cost, lowering of the catalyst activation temperature (room temperature), control of the release of gaseous hydrogen and the quality of the polymerized product and the crosslinked network, and finally limitation of the secondary reactions.