Centre National De La Recherche Scientifique

Luzenac Europe Sas

Imerys Talc Europe

Université Paul Sabatier (toulouse Iii)

Centre National De La Recherche Scientifique-cnrs

Eric Ferrage

Pierre Micoud

Christophe Le Roux

Jean-Pierre Bonino

Francois Martin

Angela Dumas

Jocelyne Ferret

Didier Arseguel

Sabine Petit

Alain Decarreau

Olivier Grauby

Cedric Lebre

François Martin

Cederic Lebre

Patrice Bacchin

Stéphane Vaillant

William Vautrin

Philippe Barthes

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 (SiGe)MO(OH), wherein M is at least one divalent metal and is of formula MgCOZnCuMnFeNiCr, and x is a real number of the interval [0; 1]. According to said method, a gel containing silicon, germanium and metal, of formula &#x2014;(SiGe)MO, n'HO&#x2014;, in the liquid state, is subjected to a hydrothermal treatment over a defined period of time and at a temperature of between 300&#xb0; C. and 600&#xb0; 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.

Method for preparing talcose compositions comprising synthetic mineral particles containing silicon, germanium and metal

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&#xb0; 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 &#x2014;(Si)MgO(OH)&#x2014; 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.

Method for preparing a synthetic talc composition from a kerolite composition

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 &#x2014;(SiGe)MO(OH)&#x2014;, 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 &#x2014;(SiGe)MO(OH), (M)&#x3b5;'.nHO. The composition is prepared by subjecting a gel containing silicon, germanium and metal, of chemical formula &#x2014;(SiGe)MO,nHO&#x2014;, 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&#xb0; C. and 300&#xb0; C., the time and temperature being selected according to the desired structural characteristics for the swelling TOT-TOT interlayer particles to be prepared.

Preparation of a composition of a swelling tot-tot interlayer

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.

Composite material composed of a metal matrix and of talc

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Toulouse, France

Eric Ferrage