Rhodia Chimie

Rhone-poulenc Specialites Chimiques

Rhone-poulenc Chimie

Thann Et Mulhouse, Corp.

Jean-Francois Colombet

Claude Magnier

William Bett

Jean-Philippe Browaeys

Mikel Morvan

Gilles Guerin

Gilles Orange

Regis Poisson

Patrick Dougier

Bruno Thiebaut

Dominique Lemos

Jean-Claude Guelen

Alain Vesco

A water-redispersible powder composition comprising: at least a water-soluble film forming polymer, the polymer being prepared from at least an ethylenically unsaturated monomer; and at least a naphthalenesulphonate.

Water-redispersible film-forming polymer powders prepared from ethylenically unsaturated monomers and containing naphthalenesulphonates

Phosphomagnesium cement compound comprising a polymer in particle form

Water-redispersible powders of film-forming polymers prepared from

The present invention relates to water-redispersible pulverulent composition comprising:

Water-redispersible pulverulent composition of film-forming polymers

Water-dispersible, storage-stable pulverulent compositions of matter, well adopted as adjuvants for hydraulic binders used in the construction industry, comprise particulates of a water-insoluble film-forming vinyl and/or acrylic polymer, e.g., a vinyl ester, alkyl(meth)acrylate or vinylaromatic homopolymer or copolymer, containing from 0.5 to 20 parts by weight of at least one silicone, e.g., an alkali or alkaline earth metal organosiliconate or a liquid organopolysiloxane, per 100 parts by weight of such film-forming polymer.

Water-redispersible powders of vinyl/acrylic polymers

A fine powder of stabilized zirconia a process for its preparation and application of the powder in ceramic compositions to obtain good mechanical, thermomechanical and electrical properties. A zirconia hydrate sol having a pH between 0.5 and 5 and containing elementary acicular crystals having dimensions of from about 10 to 500 .ANG. which are agglomerated into submicron aggregates of from abuot 100 to 5000 .ANG. in diameter is mixed with a solution of a stabilizing agent, preferably yttrium; the suspension is dried; the dried suspension is calcined at a temperature of from about 700.degree. C. to 1,300.degree. C. for preferably from about 30 minutes to 24 hours; and if needed, the powder obtained is milled.

Stabilized zirconia a process for its preparation and its application in

Submicronic zirconia particulates containing stabilizing amounts of yttrium or cerium, well adapted for ceramics applications, are produced by (i) admixing an aqueous suspension of zirconium fluosulfate particles having a pH of from about 0 to 3 with an aqueous solution of a salt of yttrium or cerium, (ii) neutralizing the resulting mixture at a pH of at least 7, (iii) separating a mixture of zirconium/yttrium or zirconium/cerium hydroxides from the medium of neutralization, (iv) washing said mixture of hydroxides to eliminate sulfate and fluoride ions therefrom, and then (v) calcining said mixture of hydroxides.

Stabilized zirconia particulates

A fine powder of neodymium titanate or barium neodymium titanate, a process for its preparation and applications in ceramic compositions. A suspension of particles is formed by mixing a solution of neodymium nitrate or a solution of barium and neodymium nitrates with a sol of titania having a pH of from about 0.8 to 2.5 which contains elementary crystallites of TiO.sub.2 having a size of from about 10 to about 100 .ANG. in diameter which are agglomerated into submicron masses of from about 200 to about 1,000 .ANG. in diameter. The suspension obtained is dried, and the dried product is calcined at a temperature between 800.degree. C. and 1,300.degree. C., preferably for about 1 to 24 hours. If necessary, the powder obtained is milled. The fine powder obtained has a low fritting temperature and its density after heating for 2 hours at 1,300.degree. C. is greater than or equal to 95% of the theoretical density of the desired titanate powder.

Neodymium titanate and barium neodymium titanate, processes for their

Finely divided powders of alkaline earth metal titanates, well suited for the fabrication of, e.g., ceramic resistors and condensers, are facilely prepared by (i) admixing a solution of an alkaline earth metal nitrate with a titanium sol having a pH ranging from 0.8 to 2.5 and which comprises elementary crystallites of TiO.sub.2 having particle sizes ranging from 10 to 100 .ANG., agglomerated into submicronic masses having particle sizes ranging from 200 to 1000 .ANG., (ii) next drying the suspension which results, (iii) calcining said dried suspension at a temperature ranging from 700.degree. to 1300.degree. C. for from 30 minutes to 24 hours, under a NO.sub.x partial pressure decreasing from 1 to 0, and then (iv) optionally grinding the powder resulting from said step (iii).

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Rueil Malmaison, France

Jean-Francois Colombet