Abstract: The invention relates to a novel process for the preparation of silicate comprising: reacting rice husk ash with a silicate precursor P1 to obtain a silicate S2 having a SiO2/MxO molar ratio MR2, in which the precursor P1 is either a silicate S1 having a SiO2/MxO molar ratio MR1 such that MR2>MR1, or a mixture of sand with metal hydroxide.

Abstract: A process for preparing precipitated silica comprising a reaction of a silicate with an acidifying agent to obtain a suspension of precipitated silica (S1), followed by a separation step to obtain a cake, a disintegration step of said cake to obtain a suspension of precipitated silica (S2), and a drying step of this suspension, wherein the disintegration step is performed by mixing using a twin-screw mixer or by extrusion.

Abstract: The invention relates to a novel process for the preparation of silicate comprising: reacting rice husk ash with a silicate precursor P1 to obtain a silicate S2 having a SiO2/MxO molar ratio MR2, in which the precursor P1 is either a silicate S1 having a SiO2/MxO molar ratio MR1 such that MR2>MR1, or a mixture of sand with metal hydroxide.

Abstract: The invention relates to the use of a polycarboxylic acid in the preparation of an elastomer composition comprising a precipitated silica as reinforcing inorganic filler and an elastomer, in which said polycarboxylic acid and said precipitated silica are incorporated, independently of each other, into an elastomer. The invention also relates to elastomer compositions and to a process for preparing the same.

Abstract: A process for preparing precipitated silica comprising a reaction of a silicate with an acidifying agent to obtain a suspension of precipitated silica (S1), followed by a separation step to obtain a cake, a disintegration step of said cake to obtain a suspension of precipitated silica (S2), and a drying step of this suspension, wherein the disintegration step is performed by mixing using a twin-screw mixer or by extrusion.

Abstract: In an elastomer composition, which preferably comprises an isoprene elastomer, use of an inorganic filler with a compound having the following formula (I), and which is optionally, in all or part, in a polymerized form: wherein R is R6 or OR8; wherein R1, R2, R3, R4, R5, and R6, independently from each other, are chosen from: hydrogen, alkyl, aryl, alkaryl, aralkyl, cycloalkyl, heterocycloalkyl, and alkenyl groups; and wherein R7 and R8, independently from each other, are chosen from: hydrogen, alkyl, aryl, alkaryl, aralkyl, cycloalkyl, alkenyl groups, and metals selected from the group consisting of Na, Li, and Ca.

Abstract: The invention concerns a method for enhancing water-repellency repellency treatment of mineral hydraulic binder compositions and compositions obtainable by said method and their uses in the building sector, said method comprising the step of adding a sufficient amount of at least one monovalent cation salt of a carboxylic acid to said composition.

Abstract: The present invention relates to a method for partial or total oxidation of one or several thiocarbonylthio ends of a polymer, obtained by radical polymerisation controlled by reversible addition-cleavage with thiocarbonylthio agents, Said method comprising the step of contacting said polymer with an ozone-containing gas, during which ozone reacts with the one or several thiocarbonylthio ends.

Abstract: The present invention relates to a method for partial or total oxidation of one or several thiocarbonylthio ends of a polymer, obtained by radical polymerisation controlled by reversible addition-cleavage with thiocarbonylthio agents, Said method comprising the step of contacting said polymer with an ozone-containing gas, during which ozone reacts with the one or several thiocarbonylthio ends.

Abstract: The invention concerns a method for enhancing water-repellency repellency treatment of mineral hydraulic binder compositions and compositions obtainable by said method and their uses in the building sector, said method comprising the step of adding a sufficient amount of at least one monovalent cation salt of a carboxylic acid to said composition.

Abstract: The invention concerns a silicon dispersion hardenable by cross-linking and useable particularly as putty, paint or film coating. The dispersion according to the instant invention contains hydroxylated condensable constituents and is free from hydrolyzable substituents capable of being transformed into volatile organic compounds, is free from volatile organic compounds and polyvinil alcohol, and contains an &agr;,&ohgr;-diOH polyorganosiloxane (A), an adherence promoter (B) with NH2 functions and OH functions, and, optionally, a catalyst (C), a surfactant (D), a cross-linking agent (E), fillers (F), a dispersing agent (G), a plasticizer (H), an antifungal agent (I), an antifoaming agent (J), a stabilizer (K) or a base (L). The invention is useful for putty or film coatings prepared with this dispersion.

Abstract: The invention concerns a method for preparing polyorganosiloxanes with high purity ester function (acetoxyalkyl or acetoxyalkenyl), consisting in: hydrosilylation between a hydrogenopolyorganosiloxane oil and &agr;-olefin alcohol; esterification of the resulting hydroxy-alkylated or polyorganosiloxane with an acetyl halide; elimination of &agr;-olefin derivatives and the halohydric acid formed. The resulting polyorganosiloxanes with ester function (acetoxyalkyl) have global siloxane, &agr;-olefin unit and/or &agr;-olefin impurities contents corresponding to a number of &agr;-olefin groups for 100 g of polyorganosiloxane, with ester function less than 10−3 mol.

Abstract: The present invention relates to multifunctionalized polyorganosiloxanes comprising, per molecule at least one functional siloxy unit Y having C1-C5 alkoxy radical and at least one other functional siloxy unit W having an halogenated or polyhalogenated alkyl, aralkyl or aryl; polyether ether; epoxidized alkyl; alkoxyalkyl; hydroxylated, carbonylated or esterified alkyl; phenol; and alkoxysilyl; and optionally at least one siloxy unit having a SiH group. The alkoxy functionality Y is introduced onto a suitable polyhydroorganosiloxane by a dehydrogenation/condensation reaction from the alcohol from which Y derives and then the non-hydrogen functionality W by a hydrosilylation reaction from the olefinic compound from which W derives. The multifunctionalized polyorganosiloxanes can be used as antiadhesion modulators in silicone compositions.

Abstract: The invention concerns a silicon dispersion hardenable by cross-linking and useable particularly as putty, paint or film coating. The dispersion according to the instant invention contains hydroxylated condensable constituents and is free from hydrolyzable substituents capable of being transformed into volatile organic compounds, is free from volatile organic compounds and polyvinil alcohol, and contains an &agr;,&ohgr;-diOH polyorganosiloxane (A), an adherence promoter (B) with NH2 functions and OH functions, and, optionally, a catalyst (C), a surfactant (D), a cross-linking agent (E), fillers (F), a dispersing agent (G), a plasticizer (H), an antifungal agent (I), an antifoaming agent (J), a stabilizer (K) or a base (L). The invention is useful for putty or film coatings prepared with this dispersion.

Abstract: The present invention relates to multifunctionalized alkoxy, the alkoxy functionality Y being introduced onto a suitable polyhydroorganosiloxane by a dehydrogenation/condensation reaction from the alcohol from which Y derives and then the functionality W by a hydrosilylation reaction from the olefinic compound form which W derives. The multifunctionalized alkoxy polyorganosiloxanes can be used as antiadhesion modulators in silicone compositions and as silica covering agents in silicone compositions containing fillers.

Abstract: The present invention relates to chemically stable, polyfunctional, perfluorinated polyorganosiloxanes (POS) comprising on the one hand fluorinated lateral grafts resulting from the hydrosilylation of perfluorinated olefins with SiH units and having alkyl and/or alkyl ester linkages but not ether linkages, and on the other hand other, non-perfluorinated functional units E capable of giving them diverse and varied physical and chemical properties and opening up avenues in numerous applications. Examples of these POS according to the invention are those of the following formula: According to another of its features, the invention relates to a process for the preparation of these polyfunctional perfluorinated POS. Applications: antifoams, agents for lowering surface tension, dirt repellents, antiadhesives, lubricants, oleophobic and/or hydrophobic agents, coatings etc.

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: The present invention relates to multifunctionalized alkoxy, the alkoxy functionality Y being introduced onto a suitable polyhydrooorganosiloxane by a dehydrogenation/condensation reaction from the alcohol from which Y derives and then the functionality W by a hydrosilylation reaction from the olefinic compound from which W derives. The multifunctionalized alkoxy polyorganosiloxanes can be used as antiadhesion modulators in silicone compositions and as silica covering agents in silicone compositions containing fillers.

Abstract: Chemically stable, perfluorinated, 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: Stable and flowable aqueous dispersions of at least one water-insoluble material are formulated by dispersing such water-insoluble material, e.g., solid particulates of a plant protection compound, into a homogeneous, stable and flowable aqueous composition that includes (1) at least one water-soluble derivative of a plant protection active agent bearing at least one ionizable functional group and at least one hydrophilic functional group, (2) at least one nonionic surface-active agent and/or at least one aliphatic, cycloaliphatic or arylaliphatic alcohol having from 4 to 15 carbon atoms, and (3) water, this composition exhibiting optical birefringence and a yield point of at least 0.1 pascal.