Rhodia Chimie

Rhodia Operations

Rhone-poulenc Chimie

Perstorp France

Vencorex France

Denis Revelant

Jean-Marie Bernard

Hubert Gayet

Martine Vibert

Johannes Schwarz

Fr&eacute;d&eacute;ric Dallemer

Pascal Vacus

Philippe Marion

Dominique Horbez

François Metz

Minou Nabavi

Henri Chiarelli

Francois Vachet

Faouzi Joulak

Marie Chauve

Fr&eacute;d&eacute;ric Leising

Eugénie Charriere

Stephanie Foucher

Jerome Armand

Eug&eacute;nie Charriere

Jean-Claude Parron

Jean-Pierre Corbet

Philippe Galy-Jammou

Michel Carlo

Stéphane Randu

Eugènie Charriere

Cédric Amouyal

Nicolas Perret

Stéphanie Foucher

Jean-Marie Alphonse Etienne Bernard

A process for extraction of ferulic acid present in an aqueous phase, obtained by treatment of at least one plant material, and also containing polysaccharides, is described, said process comprising at least the following steps:

Optimized process for extraction of ferulic acid with pretreatment

The invention relates to a natural vanillin, which is in the form of an amorphous solid of which the color, in ethanolic solution at 10% by weight, is less than or equal to 200 Hazen, preferably less than or equal to 100 Hazen.

Method for the purification of natural vanillin

The invention concerns a method for preparing an oxysulphide and fluorinated derivative, said method comprising the reacting, in the presence of an organic solvent, of: i) at least one compound of formula Ea-COOR (I), in which Ea represents the fluorine atom or a group having 1 to 10 carbon atoms chosen from fluoroalkyls, perfluoroalkyls and fluoroalkenyls and R represents hydrogen, a monovalent cation or an alkyl group, and ii) a sulphur oxide, said method being such that the initial molar ratio (sulphur oxide/compound of formula (I)) is less than 0.4 and the concentration of sulphur oxide dissolved in the reaction medium is kept constant for the entire duration of the reaction to a value of between 0.2% and 3% by weight by means of continually adding said sulphur oxide to the reaction medium.

Method for preparing oxysulphide and fluorinated derivatives by sulphination

The invention relates to a method for the purification of natural vanillin, comprising at least one step in which the natural vanillin is evaporated.

A process for phosgenating an amine comprising employing a plug-flow type reactor with internal recycle is disclosed. The process can be continuous, which makes it possible to prepare, in a single stage, a (poly)isocyanate with a good yield, without formation of byproducts and on simplifying the plant in order to carry out the process so as to promote safety.

Use of a piston reactor to implement a phosgenation process

The invention relates to a composition and a method of preparing one such composition and an isocyanatoalkoxysilane; the polyisocyanate composition contains at least two different oligomeric compounds comprising at least three units and at most five units selected from aminoalkylsilane units and diamine units and at least one function selected from isocyanate functions and from those derived therefrom, the aforementioned compounds having at least two aminoalkylsilane units and another compound having at least two diamine units; the invention is suitable for coatings.

Synthesis of biurets and isocyanates with alkoxysilane functions, formulations containing same and use thereof

The invention relates to a process for the synthesis of a polyisocyanate composition comprising acylureas. According to the invention, a starting composition comprising a compound having at least two isocyanate functional groups is subjected to a reaction with at least two acid functional groups, with at least one of the acid functional groups having a pKa value of less than or equal to 3, and at least one of the acid functional groups having a pKa value of more than 3 and less than or equal to 6, at a temperature at least equal to 50 &#xb0; C., wherein the acid functional group having a pKa value of less than or equal to 3 and the acid functional group having a pKa value of more than 3 and less than or equal to 6 are present on two different acids or on the same acid.

Synthesis of acylureas and composition comprising acylureas

A low viscosity polyisocyanate composition containing at least one isocyanate dimer having a uretidinedione unit is prepared from a reaction medium containing at least one isocyanate monomer in which the isocyanate groups are borne by spcarbon atoms. The reaction medium is heated, in the absence of a dimerization catalyst, to a temperature of at least 50&#xb0; C. and not more than 200&#xb0; C. for a period of not more than 24 hours.

Method for the preparation of low-viscosity (poly) isocyanates

A method is described for preparing a tricondensate polyfunctional isocyanate composition, preferably having at least an isocyanurate and/or biuret group, which includes adding to a tricondensate polyfunctional isocyanate, or a mixture of different tricondensate polyfunctional isocyantes, obtained by (cyclo)condensation, in particular (cyclo)trimerization of one or several identical or different isocyanate monomers and optionally of another monomer, an allophanate of one or several identical or different isocyanates, or a mixture of different allophanates. The isocyanates or isocyanate monomer mixtures used for preparing the polyfunctional isocyanate(s) may be identical to or different from the isocyanate(s) or isocyanate mixture used for preparing the allophanate(s).

Method for preparing low viscosity tricondensate polyfunctional isocyanates

A method is described of preparing (poly)isocyanurate polyisocyanates by catalytic cyclotrimerization of isocyanates. A catalytic system is used which includes a cyclotrimerization catalyst based on a quatemary ammonium salt and imidazole as a cocatalyst.

Catalyst and a method for the trimerization of isocyanates

This invention relates to a process for the preparation of aqueous emulsions of blocked (poly)isocyanates, this process comprising the steps consisting successively in:

Method for masking polyisocyanates in emulsion

The invention concerns a (cyclo)trimerisation method for isocyanates having at least two isocyanate functions, characterised in that it comprises: a) reacting initial isocyanate monomers having at least two isocyanate functions, optionally in the presence of other monomers reactive with the isocyanate monomers having at least two isocyanate functions at a temperature of at least 20&deg; C., advantageously at least 50&deg; C., and lower than 200&deg; C., advantageously lower than 150&deg; C., in the presence of a compound comprising at least one rare earth alcoholate function; b) stopping the reaction by inactivating the catalyst or its derivative forms in the reaction medium at a transformation rate of at least 2.5% and at most 90% of the initial isocyanate functions; and optionally c) distilling the reaction medium to eliminate the unreacted monomers.

Condensation polymerization method for isocyanates

The invention concerns a method for cyclotrimerization of isocyanate functions by action of a catalyst based on quaternary ammonium or phosphonium. The invention is characterised in that said isocyanate functions are branched and said onium ions are selected among those whereof the total amount of carbons is not more than 30 and not less than 12; and whereof the counterion is selected among the anions corresponding to weak acids whereof the pK is not less than 8, preferably not less than 10, more preferably not less than 12, whereof the substituents are aliphatic compounds and do not have an unsaturation in beta; and said onium ions comprise at least 2 radicals of more than 6, advantageously more than 10, preferably more than 12 carbon atoms.

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Genas, France

Denis Revelant