Abstract: The invention relates to a process for preparing hydrazine hydrate, comprising a step of hydrolyzing an azine in a distillation column in the presence of at least one silicone of the polydialkylsiloxane, polydiarylsiloxane or polyalkyl-arylsiloxane formula. The invention also relates to the use of at least one silicone of the polydialkylsiloxane formula as an anti-foaming agent in a process for preparing azine hydrate.

Abstract: The present invention relates to a method for reactivating an anthraquinone hydrogenation catalyst for the preparation of hydrogen peroxide, comprising at least one step of bringing said catalyst into contact with an aqueous solution comprising ammonia. The invention also relates to the use of an aqueous ammonia solution for reactivating an anthraquinone hydrogenation catalyst for the preparation of hydrogen peroxide.

Abstract: The present invention relates to an improved process for preparing hydrazine hydrate from the azine of methyl ethyl ketone obtained from methyl ethyl ketone by oxidizing ammonia with hydrogen peroxide in the presence of an activator, characterized in that it comprises a step of recycling the methyl ethyl ketone oxime purge.

Abstract: The present invention relates to an improved process for preparing hydrazine hydrate from the azine of methyl ethyl ketone obtained from methyl ethyl ketone by oxidizing ammonia with hydrogen peroxide in the presence of an activator, characterized in that it comprises a step of recycling the pyrazoline-class heterocycles purge.

Abstract: The present invention relates to a process for the production of hydrogen peroxide by the cyclic Auto-Oxydation-process comprising the two alternate steps of: hydrogenation of a working solution in the presence of a catalyst, wherein said working solution contains at least one quinone dissolved in at least one organic solvent, to obtain at least one corresponding hydroquinone; and oxidation of said at least one hydroquinone; characterized in that the organic solvent has the formula (I): wherein R1 is an aryl group comprising from 6 to 18 carbon atoms and R2 is an alkyl group comprising from 1 to 8 carbon atoms, when R2 is a methyl group, R1 is different from phenyl.

Abstract: A process for synthesizing an azo compound by oxidation of a hydrogen compound in the presence of a catalyst and a compound of formula (I) is described in which R1, R2 and R3 (R1)(R2)C(PO3(R3)2)2??(I) are as defined. The use of a compound of formula (I) as complexing agent for a catalyst is also described.

Abstract: The present invention relates to an improved process for preparing hydrazine hydrate from the azine of methyl ethyl ketone obtained from methyl ethyl ketone by oxidizing ammonia with hydrogen peroxide in the presence of an activator, characterized in that it comprises a step of recycling the methyl ethyl ketone oxime purge.

Abstract: The present invention relates to an improved process for preparing hydrazine hydrate from the azine of methyl ethyl ketone obtained from methyl ethyl ketone by oxidizing ammonia with hydrogen peroxide in the presence of an activator, characterized in that it comprises a step of recycling the pyrazoline-class heterocycles purge.

Abstract: A process for synthesizing an azo compound by oxidation of a hydrogen compound in the presence of a catalyst and a compound of formula (I) is described in which R1, R2 and R3 (R1)(R2)C(PO3(R3)2)2??(I) are as defined. The use of a compound of formula (I) as complexing agent for a catalyst is also described.

Abstract: A process is provided for synthesizing an azo compound, such as AIBN, by oxidation of a hydrazo compound using hydrogen peroxide. This process comprises a step of adding to the reaction medium a particular reducing agent, such as hydrazine.

Abstract: A process is provided for synthesizing an azo compound, such as AIBN, by oxidation of a hydrazo compound using hydrogen peroxide. This process comprises a step of adding to the reaction medium a particular reducing agent, such as hydrazine.

Abstract: The present invention concerns a method for production of foams of thermoplastic polymer such as polyethylene, polypropylene, polystyrene, polyvinyl chloride. More specifically its goal is a method for production of thermoplastic foams comprising a premixing step of at least a thermoplastic polymer in the form of a divided solid with at least an ester of azocarboxylic acid.

Abstract: The invention relates to novolac alkylphenol resins having a low level of free alkylphenol, a method for the production thereof, and the use thereof as tackifying resins and reinforcing resins for rubbers. The resins may be used advantageously in the production of tires.

Abstract: The invention relates to novolac alkylphenol resins having a low level of free alkylphenol, a method for the production thereof, and the use thereof as tackifying resins and reinforcing resins for rubbers. The resins may be used advantageously in the production of tires.

Abstract: The present invention concerns a method of manufacturing a graded index plastic optical fiber having an index that varies continuously between the center and the periphery of the fiber, from at least one polymer P and at least one reactive diluent D1 to allow the refractive index of said fiber to be varied.

Abstract: The present invention concerns a method of manufacturing a graded index plastic optical fiber having an index that varies continuously between the center and the periphery of the fiber, from at least one polymer P and at least one reactive diluent D1 to allow the refractive index of said fiber to be varied.

Abstract: The present invention concerns a method of manufacturing a plastic optical fiber from at least one polymer P, said method being characterized in that said polymer P is a copolymer comprising at least two repeating units P1 and P2 with the following general formulae, i and j corresponding to a repeat number of units: said copolymer P being transparent, amorphous in nature and having a motif P2 content in the range from substantially 30 mole % to 70 mole % when X?F or Cl in P1.

Abstract: The present invention comprises a transparent and partially fluorinated polymer which comprises three repeat units resulting from industrial monomers which are simple to access and which has a glass transition temperature of greater than 25° C., which polymer makes possible the preparation of articles, in particular of articles acting as guide or conductor for light in the region of the wavelengths of visible or near infrared type. This polymer is of use in the manufacture of optical fiber.

Abstract: The invention comprises a vinylene carbonate (VCA) copolymer having as comonomer chlorotrifluoroethylene (CTFE) or tetrafluoroethylene (TFE). This copolymer is transparent, making possible the preparation of objects acting as guide or conductor for light with wavelengths of visible or near infrared type. Furthermore, it exhibits a glass transition temperature of greater than 60° C. which is appropriate for the preparation of optical fibers.

Abstract: The invention relates to a composition including (i) at least one polyamide and at least one copolymer (A) of ethylene with at least one comonomer chosen from unsaturated carboxylic acids, esters of unsaturated carboxylic acids or vinyl esters of saturated carboxylic acids and (ii) being in powder form. These compositions are subsequently deposited on metal substrates and then a highly corrosion-resistant coating is obtained by melting.