Abstract: Thermally-stable silicone elastomers are prepared from organopolysiloxane compositions by polyaddition, polycondensation or vulcanization reactions in the presence of peroxide; the thermal stability of the silicone elastomers is achieved by the inclusion of an additive derived from an iron (III) complex.

Abstract: Thermally-stable silicone elastomers are prepared from organopolysiloxane compositions by polyaddition, polycondensation or vulcanization reactions in the presence of peroxide; the thermal stability of the silicone elastomers is achieved by the inclusion of an additive derived from an iron (III) complex.

Abstract: The invention concerns the use in a stabilizing composition for halogenated polymers, of at least a silylated compound of formula: (R1)4-x-Si[O—C(R2)=CH2-C(?O)(R3)]x, wherein R1, identical or different, represent an aliphatic or aromatic radical; said radicals being selected such that the silylated compound has a boiling point higher than at least 30° C. relative to the working temperature of said polymer; R3 represents an aliphatic radical R or a radical —OR1; R2, R and R1, identical or different, represent an aliphatic radical, linear or not, comprising 1 to 10 carbon atoms, or an aromatic radical, preferably comprising 6 carbon atoms, optionally substituted by at least an aliphatic radical comprising 1 to 10 carbon atoms; x is equal to 1 or 2.

Abstract: The present invention relates to the use of a stabilising composition free of derivatives of 6-aminouracyl or 6-aminothiouracyl type, and comprising at least one ?-diketone bearing two aromatic nuclei, at least one of which bears at least one substituent on one of the two orthopositions or on the paraposition; the said substituent being chosen from —R, —OR, —SR, —COOH, —O—CF3 and —S—CF3 radicals, in which formulae R is an alkyl radical. The invention also relates to halogenated polymers comprising such a stabilising composition.

Abstract: The invention relates to an active substance vector multiparticulate system and to the production and use thereof. The object of the invention is an active-substance vector multiparticulate system comprising one or several active substances included in a hydrophilic organic matrix comprising at least one hydrosoluble and/or hydrodispersable anionic polymer which is insolubilized by a metallic cation. The invention can be specifically used in the food industry, detergents and agrochemistry.

Abstract: The present invention relates to the use of a stabilising composition free of derivatives of 6-aminouracyl or 6-aminothiouracyl type, and comprising at least one &bgr;-diketone bearing two aromatic nuclei, at least one of which bears at least one substituent on one of the two orthopositions or on the paraposition; the said substituent being chosen from —R, —OR, —SR, —COOH, —O—CF3 and —S—CF3 radicals, in which formulae R is an alkyl radical. The invention also relates to halogenated polymers comprising such a stabilising composition.

Abstract: The present invention relates to a procedure for stabilising halogenated polymers using at least one compound chosen from the pyrroles or derivatives, carrying, in the &agr;-position, nitrogen, a carboxylic acid function in acid or salified form, or a possibly substituted aryl radical. The invention also relates to a stabilizing composition comprising at least one pyrrole or derivative and at least one additive chosen from among the amino-uracyles, the dihydropyridines or their mixtures.

Abstract: Nanoparticles are prepared by dissolving a poly(ethylene oxide) and/or poly(propylene oxide) polylactic copolymer in an organic solvent followed by formation of nanoparticles by mixing the solution containing the polymer with an aqueous solution and by precipitation, without using an additional colloidal protective agent or by microfluidization and solvent evaporation. Nanoparticles prepared by this method are disclosed.

Abstract: The invention discloses nanoparticles offering an extended time before capture by the reticulo-endothelial system. Said particles are composed of an ethylene and/or propylene polyoxide polylactic copolymer optionally mixed with a polylactic polymer.

Abstract: A nutrient or medicinal composition for administration to ruminants, which comprises one or more biologically active substances coated with a composition comprising a chitosan salt and at least one fat.

Abstract: A process for coating at least one medicinal and/or foodstuff active principle useful for ruminants. At least one monomer is polymerized in an oil-in-water emulsion in the presence of a surfactant to synthesize a pH-sensitive-polymer composition, the composition being obtained in an oil-in-water emulsion. Without isolation of the pH-sensitive polymer, the oil-in-water emulsion is used to coat the active principle, preferably methionine or lysine or a derivative thereof. The pH-sensitive polymer is not dissolved in an organic solvent(s) in either the polymerization or coating steps. The pH-sensitive polymer is stable at pH 6 but at pH 2, the coated active principle is released.

Abstract: A new method of coating an active principle which comprises the step of coating an active principle with an aqueous emulsion or dispersion containing one or more pH-sensitive polymers.

Abstract: Silicone dosage forms adapted for the continuous and controlled release of iodine values, notably to domestic water supplies for the treatment of the various disease states attributed to iodine deficiency, are heat-shaped from (A) a thermoplastic silicone copolymer, and (B) a therapeutically effective amount of at least one water soluble, nontoxic, organic and/or inorganic iodine compound which is in solid state at ambient temperature.

Abstract: Particles of active substance are encapsulated by spraying them with a thermoplastic silicone copolymer in solution in an organic solvent or in an aqueous dispersion or emulsion and removing the solvent or water by drying with hot air. The spraying/drying process employed is, for example, the Wurster process. The copolymer employed can be made up of a succession of polydiorganosiloxane segments or blocks and of organic segments or blocks (polyesters, polyethers, polyurethanes, polystyrenes, and the like). It can also be a polydiorganosiloxane grafted with organic chains. The active substance is in the form of particles with a particle size of between 50 .mu.m and 5 mm. It may be a catalyst, a perfume, a colorant, a cosmetic product, a medication, a plant-protection product, plant seeds, and the like.The invention is especially useful for controlling the release of active substance in an aqueous medium.

Abstract: Thermally stable copolyimidoamides containing recurring diorganopolysiloxane structural units are improvedly prepared by directly interreacting, in a solvent medium:(i) a diisocyanate of the formula: ##STR1## (ii) a monoanhydride of a tricarboxylic acid of the formula: ##STR2## (iii) a siloxane diisocyanate of the formula: ##STR3##

Abstract: Substrates, e.g., silicon wafers, coated with a UV-curable organopolysiloxane composition including a crosslinking catalyst therefor (e.g., a platinum group metal compound) and an amount of a crosslinking inhibitor (e.g., an azodicarboxylate) which is effective at ambient temperature, but ineffective to prevent crosslinking on exposure of the composition to ultraviolet radiation, are well adapted for the imaging of negative intelligence patterns thereon.

Abstract: The present invention relates to electrically conductive potentially adhesive compositions and to films formed from these compositions which are capable of being employed in particular for the adhesive bonding of the surfaces of electronic devices.These compositions are characterized in that they comprise a thermoplastic polyblock organopolysiloxane copolymer with elastomeric properties and particles whose surface at least is electrically conductive and, if appropriate, a solvent or diluent.

Abstract: The present invention relates to electrically conductive, potentially adhesive compositions and to films formed from these compositions which are capable of being employed in particular for the adhesive bonding of the surfaces of electronic devices.These compositions are characterized in that they comprise a thermoplastic block copolymer containing polysiloxane and urethane groups, with elastomeric properties and particles whose surface at least is electrically conductive and, if appropriate, a solvent or diluent.

Abstract: Dimethyldichlorosilane is selectively and efficiently prepared by reacting methyl chloride with a solid contact mass comprising silicon and a catalytically effective amount of copper or a copper compound, said copper catalyst comprising (i) from about 10 to 1000 ppm of tin, antimony, or admixture thereof, or of a tin or antimony compound, or admixture thereof, (ii) from about 0.01 to 2% by weight of at least one of the metallic additives beryllium, calcium and magnesium, or compound thereof, and, optionally, (iii) from about 0.01 to 3% by weight of zinc or a zinc compound.

Abstract: Dimethyldichlorosilane is directly prepared from methyl chloride and silicon, in high productivity, selectivity and degree of silicon conversion, by reacting methyl chloride with a solid contact mass comprising silicon and a catalytically effective amount of a catalyst which includes (1) elemental copper or a copper compound, (2) from about 30 to 1,000 ppm (calculated as metallic tin and/or antimony) of at least one of the metals tin and antimony, or at least one compound of at least one of the metals tin and antimony, and (3) from about 0.05 to 4% by weight, (calculated as cesium metal) of cesium or a cesium compound, or admixture of cesium with up to 90% by weight of the admixture of lithium, sodium, potassium or rubidium, the amounts of said components (2) and (3) being based upon the total weight of said solid contact mass.