Societe Nationale Elf Aquitaine (production)

Ato Chimie

Georges Sturtz

Pierre Poisson

Bernard Guerin

Jean-Claude Gautier

Thierry Pensec

New diphosphonic acid diesters in which the two phosphorus atoms are bound by a hydrocarbon group while each of the two acid functions of the diphosphonate is esterified by a radical having at least three carbon atoms are prepared by the treatment with a weak base of a corresponding tetramethyl diphosphonate, thereupon replacement of the cations of the base in the resultant disalt, by a radical R by means of a halide of said radical, and finally hydrolysis of the mixed diphosphonate thus obtained. The new compounds are suitable for various known uses of the different diphosphonates and in particular for the complexing of heavy metals; they are used in particular for the extraction of uranium and metals associated with it.

Diphosphonic extractants

Triphosphonic ester, each of the three phosphorus atoms of which is bound to a carbon atom of the same hydrocarbon group, having 2 or 4 free acid functions or two salt functions, is prepared by reacting an alkaline-metal derivative of a phosphite diester with a diphosphonic acid tetra-ester, followed by hydrolysis of the compound obtained. The triphosphonic esters may be used for various known uses of phosphonates, including the extraction of heavy metals.

Triphosphonic esters

The invention relates to a fire-resistant synthetic resin composition containing a polycarbonate, more specifically a bisphenol A derivative, a phosphorous fireproofing additive derived from phosphonic acid, and possibly other additives and/or fillers. The fireproofing additive is a Li, Na or K hemiester of a phosphonic acid derived from an aromatic or cycloaliphatic hydrocarbon, or from a polynuclear aromatic compound, and is added at the rate of 0.01 to 0.4 weight % in relation to polycarbonate. This small amount of additive improves the fire-resistant properties of the polycarbonate, without affecting its mechanical properties.

Hemiesters of phosphonic acids

Triphosphonic esters, each of the three phosphorus atoms of which is bound to a carbon atom of the same hydrocarbon group, having 2 or 4 free acid functions or two salt functions, may be used for various known uses of phosphonates, including the extraction of heavy metals.

Extraction of uranium with triphosphonic esters

New diphosphonic acid diesters in which the two phosphorus atoms are bound by a hydrocarbon group while each of the two acid functions of the diphosphonate is esterified by a radical having at least three carbon atoms are suitable for various known uses of the different diphosphonates and in particular for the complexing of heavy metals; they are used in particular for the extraction of uranium and metals associated with it.

Extraction of uranium with diphosphonic compounds

Fire-resistant synthetic resin composition containing a polycarbonate, a

New fire-resistant transparent (co)polycarbonates containing alkaline diesters or hemiesters of bis (hydroxy-4-phenyl) alkylphosphonic acids, with the following general formulae (I) or (II): ##STR1## (I) where n=1, 2 or 3 (II) where n=0, 1, 2 or 3 and

Fire-resistant (co)polycarbonates containing alkaline diesters or

Novel alkaline hemiesters of bis-(hydroxy-4-phenyl)-alkylphosphonic acids of the general formula: ##STR1## in which: n is equal to 0, 1, 2 or 3,

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Brest, France

Georges Sturtz