Abstract: The invention relates to a method for preparing a composition, that is a talcose composition, comprising synthetic mineral particles which contain silicon, germanium and metal, have a crystalline and lamellar structure, and are of formula (SixGe1?x)4M3O10(OH)2, wherein M is at least one divalent metal and is of formula Mgy(1)COy(2)Zny(3)Cuy(4)Mny(5)Fey(6)Niy(7)Cry(8), and x is a real number of the interval [0; 1]. According to said method, a gel containing silicon, germanium and metal, of formula —(SixGe1?x)4M3O11, n?H2O—, in the liquid state, is subjected to a hydrothermal treatment over a defined period of time and at a temperature of between 300° C. and 600° C., said time and temperature being selected according to the desired particle size and structural stability for the mineral particles containing silicon, germanium and metal, to be prepared.

Abstract: The invention relates to a method for preparing a synthetic talc composition. According to said method, a kerolite composition is subjected to an anhydrous thermal treatment carried out at a pressure lower than 5 bar, from over a few hours up to over a few days, at a treatment temperature higher than 300° C. The invention also relates to a synthetic talc composition prepared in this way, the synthetic talc particles of the composition being exclusively of chemical formula —(Si4)Mg3O10(OH)2— and identifiable, during X-ray diffraction, by the presence of a characteristic diffraction peak located at a distance of between 9.40-9.68 and corresponding to a plane (001). Said synthetic talc particles also have a thermally stable crystalline structure of stacked laminae, which is very similar to that of a natural talc and has a particle size smaller than approximately ten micrometers.

Abstract: A method for preparing a composition including mineral particles, that is swelling TOT-TOT interlayer particles, formed by interlayering between: at least one non-swelling mineral phase formed by a stack of elementary laminae of the phyllogermanosilicate 2/1 type and of formula —(SixGe1?x) 4M3O10(OH)2—, and at least one swelling mineral phase formed by a stack of elementary laminae of the phyllogermanosilicate 2/1 type and at least one interlaminar space between two consecutive elementary laminae, the swelling mineral phase being of formula —(SixGe1?x)4M3??O10(OH)2, (M2+)??.nH2O. The composition is prepared by subjecting a gel containing silicon, germanium and metal, of chemical formula —(SixGe1?x)4M3O11,nH2O—, in the liquid state to a hydrothermal treatment which is carried out over a defined period of time and at a temperature of between 150° C. and 300° C.

Abstract: The invention relates to a lubricating metal coating and to a process for its preparation. The material constituting the coating in a composite material comprising a metal matrix within which talc particles are distributed as lamellae, the metal matrix being composed of a metal chosen from Fe, Co, Ni, Mn, Cr, Cu, W, Mo, Zn, Au, Ag, Pb or Sn or of an alloy of these metals or of a metal/semimetal alloy. The coating is obtained by a process consisting in carrying out an electrolytic deposition using a solution of precursors of the metal matrix of the coating which additionally comprises talc particles in suspension, which particles are modified at the surface by irreversible adsorption of a cellulose-derived compound by replacement of all or part of the hydroxyl groups.

Abstract: The invention relates to a method for preparing a composition, that is a talcose composition, comprising synthetic mineral particles which contain silicon, germanium and metal, have a crystalline and lamellar structure, and are of formula (SixGe1?x)4 M3O10(OH)2, wherein M is at least one divalent metal and is of formula Mgy(1)COy(2)Zny(3)Cuy(4)Mny(5)Fey(6)Niy(7)Cry(8), and x is a real number of the interval [0; 1]. According to said method, a gel containing silicon, germanium and metal, of formula —(SixGe1?x)4M3O11, n?H2O—, in the liquid state, is subjected to a hydrothermal treatment over a defined period of time and at a temperature of between 300° C. and 600° C., said time and temperature being selected according to the desired particle size and structural stability for the mineral particles containing silicon, germanium and metal, to be prepared.

Abstract: The invention relates to a method for preparing a composition comprising mineral particles, that is swelling TOT-TOT interlayer particles, formed by interlayering between: at least one non-swelling mineral phase formed by a stack of elementary laminae of the phyllogermanosilicate 2/1 type and of formula —(SixGe1-x)4M3O10(OH)2—, and at least one swelling mineral phase formed by a stack of elementary laminae of the phyllogermanosilicate 2/1 type and at least one interlaminar space between two consecutive elementary laminae, said swelling mineral phase being of formula —(SixGe1-x)4M3-?O10(OH)2, (M2+)??.nH2O. In order to prepare said composition, a gel containing silicon, germanium and metal, of chemical formula —(SixGe1-x)4M3O11,nH2O—, in the liquid state, is subjected to a hydrothermal treatment which is carried out over a defined period of time and at a temperature of between 150° C. and 300° C.

Abstract: The invention relates to a method for preparing a synthetic talc composition. According to said method, a kerolite composition is subjected to an anhydrous thermal treatment carried out at a pressure lower than 5 bar, from over a few hours up to over a few days, at a treatment temperature higher than 300° C. The invention also relates to a synthetic talc composition prepared in this way, the synthetic talc particles of the composition being exclusively of chemical formula —(Si4)Mg3O10(OH)2— and identifiable, during X-ray diffraction, by the presence of a characteristic diffraction peak located at a distance of between 9.40-9.68 and corresponding to a plane (001). Said synthetic talc particles also have a thermally stable crystalline structure of stacked laminae, which is very similar to that of a natural talc and has a particle size smaller than approximately ten micrometers.

Abstract: The invention relates to a lubricating metal coating and to a process for its preparation. The material constituting the coating in a composite material comprising a metal matrix within which talc particles are distributed as lamellae, the metal matrix being composed of a metal chosen from Fe, Co, Ni, Mn, Cr, Cu, W, Mo, Zn, Au, Ag, Pb or Sn or of an alloy of these metals or of a metal/semimetal alloy. The coating is obtained by a process consisting in carrying out an electrolytic deposition using a solution of precursors of the metal matrix of the coating which additionally comprises talc particles in suspension, which particles are modified at the surface by irreversible adsorption of a cellulose-derived compound by replacement of all or part of the hydroxyl groups.