Abstract: Silicas in the form of powder and substantially spherical beads or granules are characterized by a CTAB specific surface of 140 and 240 m2/g a high ultrasonic disaggregation factor, an average diameter, which is small after ultrasonic disaggregation, and optionally, a porous distribution, the porous volume formed by the pores with a diameter of 175 to 275 Å being less than 50% of the porous volume formed by the pores with diameters of 400 Å or less. The silicas may be used as reinforcing fillers for elastomers.

Abstract: Novel onium borates of an element of Groups 15 to 17 of the Periodic Table, or borates of an organometallic complex of an element of Groups 4 to 10 of the Periodic Table, well suited for the photochemical/electron beam cationic initiation of polymerization/crosslinking, the anionic borate moiety of which having the formula:[BX.sub.a R.sub.b ].sup.-in which a and b are integers ranging from 0 to 4 and a+b=4; the symbols X are each a halogen atom when a ranges up to 3 and an OH functional group when a ranges up to 2; and the symbols R, which may be identical or different, are each a phenyl radical substituted by at least one element or electron-withdrawing substituent or by at least two halogen atoms, or an aryl radical containing at least two aromatic ring members, or such aryl radical bearing at least one electron-withdrawing substituent.

Abstract: Novel onium borates of an element of Groups 15 to 17 of the Periodic Table, or borates of an organometallic complex of an element of Groups 4 to 10 of the Periodic Table, well suited for the photochemical/electron beam cationic initiation of polymerization/crosslinking, the anionic borate moiety of which having the formula:[BX.sub.a R.sub.b ].sup.-in which a and b are integers ranging from 0 to 4 and a+b=4; the symbols X are each a halogen atom when a ranges up to 3 and an OH functional group when a ranges up to 2; and the symbols R, which may be identical or different, are each a phenyl radical substituted by at least one element or electron-withdrawing substituent or by at least two halogen atoms, or an aryl radical containing at least two aromatic ring members, or such aryl radical bearing at least one electron-withdrawing substituent.

Abstract: The invention relates to aqueous suspensions of precipitated silica and of aluminum sulphate which have a pH lower than 4 and a solids content of between 10 and 50% by weight and which, after a period at rest of 48 hours, are in the form of a gel. The gel is reversible under low shear. The invention also relates to processes for the preparation of these suspensions and to their uses, especially in the field of cement mixes, mortars and concretes.

Abstract: An aqueous emulsion comprising at least one (co)polymer is provided. The (co)polymer is derived from a monomer having formula (1):(R.sub.1 R.sub.2 C.dbd.CR.sub.3 --CO--L--).sub.q A(--NCOblock).sub.p(1)wherein R.sub.1, R.sub.2, and R.sub.3, which are the same or different, represent a hydrogen or a group selected from hydrocarbon chains comprising 1 to 12 carbon atoms, halogens, and electron-withdrawing functional groups; L, which is the same or different, represents a divalent hydrocarbon radical comprising 2 to 12 carbon atoms; A represents an organic backbone which has n free valencies, n is a number between 2 and 7, and is equal to p+q; NCOblock represents a protected isocyanate functional group; p is a number between 1 and 6; and q is a number between 1 and 6.

Abstract: An accelerator system for the cold crosslinking of polymers which harden on exposure to moisture by hydrolysis/condensation, comprising: (C) x parts by weight of a catalyst for crosslinking the said polymers by polycondensation, x ranging from 0.01 to 10; (E) Y parts by weight of a solid inorganic compound containing an amount y of water in the form of water of hydration and/or water adsorbed by capillary condensation, this amount y ranging from 0.5 to 40 parts by weight, and which can represent up to 70% of the weight of the said solid inorganic compound; (F) z parts by weight of fillers, z ranging from 0 to 50; (D) 100-(x+Y+z) parts by weight of a diluent or of a solvent of the said catalyst (C), the diluent or solvent having a dynamic viscosity at 25.degree. C. of the order of 50 to 200,000 mPa.s; the respective amounts of the four constituents (C), (E), (F) and (D) being such that the system obtained exists in the form of a manipulable paste.

Abstract: The aliphatic carboxylic acids, e.g., acetic acid, are selectively prepared, even on an industrial scale, by controlledly oxidizing the corresponding alkanes, e.g., ethane, with a source of oxygen, in the presence of a catalytically effective amount of an advantageously supported heteropolyacid catalyst having the formula (I):[A.sub.a B.sub.b ].sub.f [C.sub.c D.sub.d E.sub.e O.sub.x ].sup.f-(I)in which A is at least one monovalent cation selected from among hydrogen, an alkali metal, or the ammonium ion; B is VO.sup.2 +, VO.sup.3 +, an alkaline earth metal ion, or an ion of a metal of Groups VII A, VIII, I B, IV B and V B of the Periodic Table; C is Mo and/or W; D is phosphorus, arsenic, antimony, silicon, germanium and/or boron; E is vanadium, optionally in combination with at least one metal of Groups V A, VII A and VIII of the Periodic Table or chromium; f=a+.alpha.b wherein .alpha.

Abstract: Essentially spherical precipitated silica beads, well adapted for the reinforcement of elastomeric matrices, have a mean particle size of at least 80 .mu.m, a BET specific surface area ranging from 60 to 130 m.sup.2 /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 cm.sup.3 /g.

Abstract: Composite core/sheath particulates comprising an organic polymer core at least partly coated with calcium carbonate, these core/sheath particulates having a mean particle size not exceeding 5 .mu.m, well suited for reinforcing plastic/elastomer substrates, are conveniently converted, e.g., via calcination, into hollow calcium carbonate microbeads which comprise CaCO.sub.3 shells having a mean particle size not exceeding 5 .mu.m; such hollow microbeads are themselves well suited for enhancing the low-temperature flexibility of elastomer substrates, notably vehicle tires.

Abstract: Vehicular emissions are reduced/purified via combustion of the hydrocarbon fuel therefor, e.g., diesel fuel, in the presence of a cerium compound, preferably a cerium (IV) compound, to produce soots having depressed ignition temperatures that contain effective purifying amounts of aggregates of ceric oxide crystallites, the largest particle size dimension of which ranging from 50 .ANG. (5 nanometers) to 10,000 .ANG. (1,000 nanometers) and the crystallite sizes of which, measured by Debye-Scherrer technique, ranging from 50 .ANG. (5 nanometers) to 250 .ANG. (25 nanometers).

Abstract: Colloidal dispersions of finely divided particulates, well suited for the production of catalysts for the catalytic conversion of exhaust gases emanating from internal combustion engines, notably vehicular exhaust gases, comprise at least one rare earth compound and, optionally, at least one compound of at least one other element selected from among those of groups IVa, VIIa, VIII, Ib, IIb, IIIb and IVb of the Periodic Table, said particulates being at least 50% dispersible in water.

Abstract: Picric acid, namely, 2,4,6-trinitrophenol, is readily and effectively prepared by nitrating o-nitrophenol and/or p-nitrophenol into at least one dinitrophenol in a nitric acid medium of reaction, characteristically essentially consisting of nitric acid or immixture thereof with a strong co-acid, the at least one dinitrophenol remaining soluble in the medium of reaction, and therein completing nitration of the at least one dinitrophenol and precipitating picric acid therefrom.

Abstract: A cosmetic composition comprising an aqueous emulsion of organopolysiloxanes selected from the group consisting of silicone oils, gums, resins and mixtures therein which is prepared in a single kneading step which is sufficient to produce an emulsion having a particle size of 0.1 to 5 micrometers is provided.

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 .alpha.,.beta.-unsaturated carboxylic acids and/or derivatives.

Abstract: The invention relates to a process for the direct oxidation of sulphur compounds into elemental sulphur and/or into sulphates at a temperature below 200.degree. C., in which a supported catalyst whose catalytically active phase comprises copper is used, the copper element being present in a content of at least 2% by weight relative to the catalyst and of at least 15 by weight relative to the sum of the elements of the catalytically active phase.The use of a catalyst of this type ensures a high conversion of the H.sub.2 S while at the same time minimizing the conversion into SO.sub.2.

Abstract: A biodegradation method for polyorganosiloxanes (POS), particularly polydimethylsiloxanes (PDMS), includes contacting the POS with one or more microscopic fungi, preferably in the presence of at least one co-substrate, said fungus being selected from the family of Corticiacea, preferably of the genus Phanaerochaete or Aspergillus, more preferably Aspergillus sydowii BJS94, Phanerochaete sordida and Phanerochaete chrysosporium. A screening method comprises contacting a microscopic fungus with POS, preferably with PDMS, in the presence of a co-substrate, and evaluating the capacity of the fungus to degrade the POS. The fungi disclosed in the invention can be used in the biodegradation method. An isolate of Aspergillus sydowii BJS94 is also disclosed.

Abstract: Pulverulent detergent compositions, particularly suitable for washing and dishwashing machines, include a surfactant and a builder therefor, such builder comprising an alkali metal silicate advantageously having a SiO.sub.2 /M.sub.2 O molar ratio ranging from about 1.6 to 3.5, at least 30% and preferably at least 50% of the silicon atoms of which being in the Q.sub.2 and Q.sub.3 configurations, or such builder comprising said alkali metal silicate sorbed onto a particulate inert support substrate. Also, detergent compositing comprising (a) an aqueous solution of an alkali metal silicate having an SiO.sub.2 /M.sub.2 O molar ratio ranging from about 1.

Abstract: The present invention relates to a process for the hydroxycarbonylation of pentenoic acids. By the process, one or a number of pentenoic acids are hydroxycarbonylated to adipic acid, by carbon monoxide and water, in the presence of a catalyst based on iridium and/or rhodium and of at least one iodinated promoter. The reaction mixture obtained is subjected to a refining operation, after having optionally been concentrated, making it possible to separate at least a part of the catalyst. The catalyst thus separated is recycled to an operation for the hydroxycarbonylation of pentenoic acids, of butadiene, or of butadiene derivatives.

Abstract: Precipitated silica particulates suited for homogeneous incorporation, dispersion and distribution within vulcanized elastomeric matrices reinforced therewith can be formed as either a powder, substantially spherical beads, or granulates. The silica particulates have a CTAB specific surface ranging from 100 to 140 m.sup.2 /g, a median diameter .phi..sub.50, after ultrasonic disintegration, less than 2.8 .mu.m, an ultrasonic disintegration factor F.sub.D greater than 3 ml, a BET specific surface ranging from 100 to 200 m.sup.2 /g, a mean particle size greater than 15 .mu.m when formed as a powder, at least 80 .mu.m when formed a s substantially spherical beads, and at least 1 mm when formed as a granulate, 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 aqueous polyorganosiloxane emulsion, in particular for the coating of textiles or similar materials, which comprises an organopolysiloxane formula which is a precursor of the elastomer comprising a polydiorganosiloxane, preferably an inorganic filler, a catalyst and optionally a crosslinking agent, in the absence of surfactant in this formula, is characterized in that the organopolysiloxane formula is in emulsion in an aqueous protective hydrocolloid solution and in that this emulsion is obtained by direct emulsification of the complete organopolysiloxane formula in the aqueous protective hydrocolloid solution. The protective hydrocolloid is preferably a poly(vinyl alcohol) (PVA) or a PVA mixture.Preparation method relating thereto, coating process using these emulsions and products thus coated.