Abstract: The invention concerns guar-free fluids capable of being used in oil mining and containing deacetylated xanthan gum in the form of a polypentamer, combined with at least one compound increasing the medium ionic strength. The invention also concerns the use, as filtrate reducer with improved properties, of deacetylated xanthan gum in the form of a polypentamer, combined with a compound increasing the medium ionic strength and a standard filtrate reducer.

Abstract: The present invention relates to a drilling fluid comprising cellulose nanofibrils comprising at least 80% of cells with primary walls and charged with carboxylic acids and with acidic polysaccharides, alone or as a mixture. This additive, alone, gives the drilling fluid shear-thinning properties and is stable up to temperatures of about 180° C.

Abstract: The present invention relates to dispersions in an aqueous phase of forming coatings after curing.

Abstract: The present invention relates to a composition comprising at least one masked or unmasked polyisocyanate in the form of an aqueous emulsion whose mean size is between 0.1 and 10 micometers; and at least one polyhydroxylated polymer, advantageously a polyol, in the form of a second aqueous dispersion whose mean size is between 10 and 200 nanometers wherein the content of polyhydroxylated polymer, advantageously of polyol, expressed in mass percent, is at least equal to 5/6R-20, with R equal to the ratio of the mean size (d50) of the emulsion to that of the dispersion of polyhydroxylated polymer, advantageously of polyol.

Abstract: Process for the preparation of an aqueous tar suspoemulsion by mixing a mixture including (a) a viscous tar composition formed from a tar, from inorganic solids and, optionally, from water, (b) water (W), (c) a surface-active agent (SA) exhibiting an HLB of at least 10 and, optionally, (d) a thickening water-soluble polymer (TWP) with a molecular mass of greater than 10,000, the relative amounts of constituents (W), (SA) and, optionally, (TWP) being such that the viscosity of the (W)+(SA)+optional (TWP) mixture is preferably equal to or greater than the viscosity of the said tar, and then optional dilution of the mixture obtained with water or with an aqueous acidic solution. The process is particularly advantageous when applied to to the residues, containing sulphuric acid, resulting from the synthesis of white oils from petroleum fractions. The present invention further relates to a method for fluidizing acidic tars/sludges including contacting the tar/sludge with sulfuric acid and a surfactant.

Abstract: A process for the preparation of an aqueous tar suspoemulsion includes the steps of mixing a mixture including (a) a viscous tar composition formed from a tar, from inorganic solids and, optionally, from water; (b) water (W); (c) a surface-active agent (SA) exhibiting a hydrophilicity/lipophilicity balance (HLB) of at least 10; and, optionally, (d) a thickening water-soluble polymer (TWP) with a molecular mass of greater than 10,000. The relative amounts of constituents (W), (SA) and, optionally, (TWP) are such that the viscosity of the (W)+(SA)+optional (TWP) mixture is preferably equal to or greater than the viscosity of the tar. An optional embodiment of the process provides for dilution of the mixture obtained with water or with an aqueous acidic solution.

Abstract: The subject of the present invention is a composition comprising:at least one masked or unmasked polyisocyanate in the form of an aqueous emulsion whose mean size is between 0.1 and 10 micrometers and preferably smaller than 2 and larger than 0.2 micrometers,at least one polyhydroxylated polymer, advantageously a polyol, in the form of a second aqueous dispersion whose mean size is between 10 and 200 nanometers.This composition is defined in that the quantity of polyol in the mixture is chosen so as to meet one of the following two constraints:the polyol content, expressed in mass per cent, is at least equal to 35-0.75 R, advantageously at least equal to 40-0.75 R, preferably to 45-0.75 R;the polyol content, expressed in mass per cent, does not exceed 45-2 R, advantageously does not exceed 40-2 R, preferably 35-2 Rwith R equal to the ratio of the mean size (d.sub.50) of the emulsion to that of the polyol dispersion.Application to organic synthesis.

Abstract: The subject of the present invention is a composition comprising:at least one masked or unmasked polyisocyanate in the form of an aqueous emulsion whose mean size is between 0.1 and 10 micrometers and preferably smaller than 2 and larger than 0.2 micrometers,at least one polyhydroxylated polymer, advantageously a polyol, in the form of a second aqueous dispersion whose mean size is between 10 and 200 nanometers.This composition is defined in that the quantity of polyol in the mixture is chosen so as to meet one of the following two constraints:the polyol content, expressed in mass per cent, is at least equal to 35-0.75R, advantageously at least equal to 40-0.75R, preferably to 45-0.75R;the polyol content, expressed in mass per cent, does not exceed 45-2R, advantageously does not exceed 40-2R, preferably 35-2Rwith R equal to the ratio of the mean size (d.sub.50) of the emulsion to that of the polyol dispersion.

Abstract: The subject of the present invention is a composition comprising:at least one masked or unmasked polyisocyanate in the form of an aqueous emulsion whose mean size is between 0.1 and 10 micrometres and preferably smaller than 2 and larger than 0.2 micrometres,at least one polyhydroxylated polymer, advantageously a polyol, in the form of a second aqueous dispersion whose mean size is between 10 and 200 nanometres.This composition is defined in that the quantity of polyol in the mixture is chosen so as to meet one of the following two constraints:the polyol content, expressed in mass percent, is at least equal to 35-0.75R, advantageously at least equal to 40-0.75R, preferably to 45-0.75R;the polyol content, expressed in mass percent, does not exceed 45-2R, advantageously does not exceed 40-2R, preferably 35-2Rwith R equal to the ratio of the mean size (d.sub.50) of the emulsion to that of the polyol dispersion.Application to organic synthesis.

Abstract: The subject of the present invention is a composition comprising at least one masked or unmasked polyisocyanate in the form of an aqueous emulsion and at least one polyhydroxylated polymer, advantageously a polyol, in the form of a second aqueous dispersion. This composition is further defined in that the polyol content, expressed in mass per cent, is at least equal to 35-0.75 R and the polyol content, expressed in mass per cent, does not exceed 45-2 R with R equal to the ratio of the mean size (d.sub.50) of the emulsion to that of the polyol dispersion.