Rhone-poulenc Chimie

Rhone-poulenc Specialites Chimiques

Rhone-poulenc Industries

Rhone-poulenc Recherches

Claude Millet

Jean-Marc Frances

Jacques Cavezzan

Adrien Dromard

Gerard Soula

Michel M Gay

Michel Bargain

Michel Letoffe

Paul Rostaing

Serge Serafini

Organopolysiloxane compositions curable into elastomeric state, whether in single- or two-component form, comprise an .alpha.,.omega.-dihydroxypolydiorganopolysiloxane oil, a crosslinking agent therefor, optionally, inorganic fillers and an adhesion promoter, and a catalytically effective amount of a pentacoordinated tin monochelate produced by reacting a tin oxide with a .beta.-dicarbonyl compound and a carboxylic acid.

Tin monochelate catalysis of organopolysiloxane compositions

Organopolysiloxane compositions curable into elastomeric state, whether in single- or two-component form, comprise an .alpha.,.omega.-dihydroxypolydiorganopolysiloxane oil, a crosslinking agent therefor, optionally, inorganic fillers and an adhesion promoter, and a catalytically effective amount of a pentacoordinated tin monochelate produced by reacting a .beta.-dicarbonyl compound with an organotin salt.

Novel organotin curing catalysts for, e.g., the RTV organopolysiloxanes, whether single- or two-component such compositions, are comprised of admixture of (i) a diorganotin bis(.beta.-diketonate) and (ii) an organotin (IV) compound devoid of .beta.-diketonato functional group. The silicone elastomers produced thereby are notably well adopted for use in the building industry.

Organotin curing catalyst for vulcanizable organopolysiloxanes

Novel blowing agents for foamable organopolysiloxane compositions, notably the platinum-catalyzed such organopolysiloxane compositions, comprise admixture of calcium carbonate and an organic carboxylic acid.

Blowing agent admixture for foamable organopolysiloxane compositions

Novel silicone/polylactone graft copolymers, well suited as polymer composition additives, especially those destined for biomedical applications, have the average general formula: ##STR1## in which p is an integer or decimal ranging from 1.5 to 6, q is an integer or decimal ranging from 0 to 20, A is a divalent hydrocarbon having from 2 to 20 carbon atoms, n is an integer ranging from 3 to 12, m is an integer ranging from 2 to 25, the radicals R', which may be identical or different, are each hydrogen or C.sub.1 -C.sub.4 alkyl, and R is a hydrocarbon having up to 24 carbon atoms.

Novel silicone/polylactone graft copolymer

Polysiloxanes of relatively low molecular weight are catalytically polymerized/rearranged into high molecular weight polysiloxanes in the presence of a cationic catalyst comprising a porous, inorganic mineral particulate support having an average pore diameter in excess of 20 .ANG. and a pore volume ranging from 0.2 to 2 ml/g, said porous support being coated with less than 15 mg/m.sup.2 of a film of polymeric material comprising pendant sulfonic or phosphonic acid functions, and said polymeric material being characterized by an ion exchange capacity of less than 2 milliequivalents per gram.

Catalytic preparation of high molecular weight polysiloxanes

High molecular weight organopolysiloxanes, e.g., polydimethylpolysiloxane oils and gums, are facilely and rapidly prepared by polymerizing/rearranging a lower molecular weight organopolysiloxane in the presence of a catalytically effective amount of an alkaline catalyst and a tris-(oxaalkyl)-amine accelerator having the formula (I):

Polymerization of polysiloxanes

High molecular weight organopolysiloxanes are rapidly prepared, without formation of the low molecular weight polysiloxanes, by polycondensing a hydroxysilylated polysiloxane in the presence of a catalytic amount of a catalyst system including (i) an alkali or alkaline earth metal, and (ii) a polyheteromacropolycyclic co-catalyst having the structural formula: ##STR1## wherein .SIGMA. is a divalent radical having the structural formula ##STR2## or a divalent radical having the structural formula: ##STR3## further wherein each R, which may be identical or different, is a divalent hydrocarbon radical, each Q, which also may be identical or different, is a divalent hydrocarbon radical, an oxygen atom or a sulfur atom, and m, n and p are each integers equal to 1, 2 or 3.

Polycondensation of hydroxysilylated polysiloxanes

Organopolysiloxanes are polymerized in the presence of an alkaline catalyst and a complex oxygen, sulfur or nitrogen heterocyclic compound.

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Saint-Priest, France

Claude Millet