Abstract: Aqueous emulsions of oils, gums or preferably masked (poly)isocyanate resins are prepared by kneading a mixture containing (1) a preferably masked (poly)isocyanate phase (A) with a viscosity of at least 3 Pa.s or a consistency of at least 200, and (2) an aqueous phase including water, at least one surfactant (B) and optionally at least one water-soluble thickening polymer (C). The relative amounts of water (B) and optionally (C) being such that the aqueous phase has a viscosity or consistency preferably no lower than that of the preferably masked (poly)isocyanate phase (A). The kneading is performed for a sufficient time and with sufficient shear to give an oil-in-water emulsion with a particle size of 0.1-5 &mgr;m, and optionally diluting the medium with water.

Abstract: The invention relates to a process for drying a gaseous or liquid mixture by passing the said mixture into an adsorber, characterized in that the water adsorption equilibrium zone of the adsorber comprises an upstream alumina zone and a downstream molecular sieve zone.

Abstract: Fluorocarbon compounds are synthesized by reacting a substrate hydrocarbyl compound containing at least one sp3-hybridized halophoric carbon atom bearing at least two halogen atom substituents, at least one of which is a halogen atom having an atomic number greater than that of fluorine and the at least one halophoric carbon atom being bonded to at least one chalcogen, with at least one reactant which comprises a complex of a Bronstedt base with a defined amount n of hydrofluoric acid, n being at least 3 and not greater than 20.

Abstract: The invention relates to an aqueous suspension of precipitated silica, characterized in that its solids content is between 10 and 40% by weight, its viscosity is lower than 4×10−2 Pa.s at a shear rate of 50 s−1 and the quantity of silica present in the supernatant obtained after centrifuging the said suspension at 7500 revolutions per minute for 30 minutes represents more than 50% of the weight of the silica present in the suspension. The particle size distribution of the agglomerates in suspension is such that their median diameter D50 is smaller than 5 &mgr;m and the deagglomeration factor FD is greater than 3 ml. This suspension can be employed for the production of anticorrosion coatings and for the preparation of concretes, of paper or of inorganic adhesives.

Abstract: Use, for thickening oily media, of silicone waxes which have aliphatic fatty alcohol or acid ester functional groups of formula —(CH2)n—A-R, in which formula n is equal to at least 2, A an —OCO— or —COO—group and R a C21-C30 aliphatic group, more particularly those which have behenate functional groups —(CH2)3—O—CO—(CH2)20—CH3, bonded directly to silicon atoms of the polyorganosiloxane chain.

Abstract: New optically active bis[1-phospha-2,3-diphenyl-4,5-dimethylnorbornadiene] diphosphines and new optically active transition metal complexes with said phosphines are described. The complexes are useful as catalysts to promote hydrogenation of substrates.

Abstract: A process for the preparation of precipitated silica is disclosed. The precipitated silica has a refractive index from about 1.440 to about 1.450, among other properties. The silica is prepared by a method including; a first step of using an initial feedstock of water, an electrolytic salt and a fraction of the total amount of silicate employed; a second step including preneutralizing the feedstock with the acidifying agent until about 50 to 85% of the amount of M2O present has been neutralized; a third step including introducing into the preneutralized feedstock the remaining fraction of alkali metal silicate in aqueous solution and the acidifying agent, under conditions such that the pH of the reaction medium remains substantially constant and from about 8.6 to about 9.

Abstract: The present invention provides stable, high solids, aqueous emulsions of high viscosity masked (poly)isocyanates, water, surface active agents, and, optionally, thickening water-soluble polymers. The emulsions of the present invention are formulated in as little as 20 parts by weight water or less. The present invention further provides processes for forming such emulsions.

Abstract: Precious metal values, e.g., platinum, palladium and rhodium, and, optionally, other valuable elements, e.g., one or more rare earths and cerium in particular, are recovered from a wide variety of compositions of matter and articles of manufacture, for example waste or spent catalysts such as vehicular postcombustion catalysts, by (i) optionally comminuting such composition/article into a finely divided state, (ii) intimately admixing the composition/article with sulfuric acid, (iii) calcining the resulting admixture at a temperature ranging from 150° to 450° C., and (iv) leaching the calcined admixture in an aqueous medium, whether simultaneously or separately, with H+ ions and chloride ions, whereby obtaining (1) a solid residue substantially depleted of such precious metal values and, optionally, of such other elements, and (2) at least one liquid solution comprising such precious metal values and, optionally, such other elements.

Abstract: The present invention relates to optically active diphosphines. It is also targeted at their preparation according to a process for the resolution of the racemic mixture of the said phosphines to optically active isomers. The subject of the invention is new optically active bis[1-phospha-2,3-diphenyl-4,5-dimethylnorbornadiene] diphosphines and a process for resolving the racemic bis[1-phospha-2,3-diphenyl-4,5-dimethylnorbornadiene] mixture which comprises reacting it with a palladium or platinum complex as chiral auxiliary in an organic solvent, thus forming diastereoisomer complexes, and then resolving the said optically pure complexes. The invention also relates to new optically active metal complexes comprising the said phosphines and to their use in a process for the preparation of optically active carboxylic acids and/or derivatives according to a process for the hydrogenation of &agr;,&bgr;-unsaturated carboxylic acids and/or derivatives.

Abstract: Fluorocarbon compounds are synthesized by reacting a substrate hydrocarbyl compound containing at least one sp3-hybridized halophoric carbon atom bearing at least two halogen atom substituents, at least one of which is a halogen atom having an atomic number greater than that of fluorine and the at least one halophoric carbon atom being bonded to at least one chalcogen, with at least one reactant which comprises a complex of a Bronstedt base with a defined amount n of hydrofluoric acid, n being at least 3 and not greater than 20.

Abstract: A detergent composition containing alkali-metal silicate with an average molar ratio of SiO2/M2O of 1-4.2, preferably 2.5-4.2, wherein M is an alkali metal, the composition being non-corrosive to glass, crystal, porcelain and decorative prints thereon upon repeated washing. The composition being such that when disposed in a washing medium at a normal working concentration, a protonated silicic monomer Si(OH)4 is produced in a concentration of at least 2.5×10−3 mol/liter of the washing medium.

Abstract: Essentially spherical precipitated silica beads, well adapted for the reinforcement of elastomeric matrices, have a mean particle size of at least 80 &mgr;m, a BET specific surface area ranging from 60 to 130 m2/g, a fill density in packed state ranging from 0.28 to 0.37, and a total pore volume ranging from 1.6 to 3.3 cm3/g.

Abstract: Thermally/chemically stable and nontoxic inorganic pigments/colorants, characteristically green and well suited for the coloration of a wide variety of materials and substrates, for example, plastics, ceramics, etc., comprise at least one mixed oxide of the formula: R2MxM′yO5 in which R is at least one element selected from among yttrium and a rare earth having an atomic number ranging from 62 to 71, inclusive, M and M′, which may be identical or different, are each at least one metallic element exhibiting at least one valence state of +2, and x and y are numbers, the sum x+y of which is equal to 2.

Abstract: A mechanically strong, vulcanized elastomeric matrix having an effective amount of a reinforcing filler material homogeneously dispersed and distributed therethrough, the reinforcing filler material comprising finely divided precipitated silica particulates and the precipitated silica particulates deriving from a powder having a CTAB specific surface ranging from 100 to 140 m2/g, a median diameter &phgr;50, after ultrasonic disintegration, less than 2.8 &mgr;m, exhibiting an ultrasonic disintegration factor FD greater than 3 ml, having a BET specific surface ranging from 100 to 200 m2/g, having a mean particle size greater than 15 &mgr;m, a packing density in the tamped state of at least 0.17, and a DOP oil uptake ranging from 150 to 400 ml/100 g.

Abstract: The invention relates to a composition based on zirconium oxide and comprising cerium oxide which has a specific surface of at least 30 m2/g after calcination for 6 hours at 900° C. and which is provided in the form of a pure solid solution of cerium oxide in zirconium oxide. According to another embodiment, this composition can additionally comprise a doping element and can exhibit a specific surface of at least 25 m2g after calcination for 6 hours at 1000° C. A process for the preparation of these compositions comprises the following stages: a mixture is prepared, in liquid medium, containing a zirconium compound and a cerium(IV) compound; the said mixture is heated at a temperature greater than 100° C.

Abstract: Storage-stable colloidal organic sols comprise suspended tetravalent metal oxide particulates in an organic diluent medium, notably cerium dioxide particulates, the tetravalent metal oxide particulates having a particle size d90 no greater than 200 nanometers and being complexed with at least one amphiphilic organic acid, and either said tetravalent metal oxide particulates comprising agglomerates of crystallites, the d80 of which being no greater than 5 nanometers and at least 90% of said agglomerates comprising from 1 to 5 crystallites, and/or said at least one amphiphilic organic acid has from 11 to 50 carbon atoms and is branched in at least one of the &agr;-, &bgr;-, &ggr;- or &dgr;-positions relative to the atom bearing the acidic hydrogen.

Abstract: The present invention relates to an electroactivated material comprising fibers and a binder and additionally having an electrocatalytic agent in the form of particles comprising a precious metal oxide or in the form of particles comprising a support and a coating based on such an oxide. The electroactivated material can be used especially as cathode component of an electrolysis cell and in particular of a cell for the electrolysis of aqueous sodium chloride solutions. The present invention also relates to a composite material comprising the said material and to processes for the preparation of each of the two materials.

Abstract: Chemicaly stable, perflourinated, linear or cyclic polyorganosiloxanes (POS), and a process for the preparation thereof. Antifoams, agents for lowering surface tension, dirt repellents, antiadhesives, lubricants, oleophobic and/or hydrophobic agents, coatings and other compositions containing the perfluorinated POS are disclosed.

Abstract: Essentially spherical silica-based granular particulates, whether having a mean particle size of at least 300 &mgr;m and a density of from 0.15 to 0.32, or a mean particle size of from 80 &mgr;m to 400 &mgr;m and a density of at least 0.32, are well adapted as reinforcing filler material for a variety of elastomeric matrices, e.g., rubber.