Title of Invention


Abstract The invention concerns an adjuvant for reducing chromium (VI) ions into chromium (III) comprising a tin (II) complex and a carboxylic acid or one of its salts, as well as a method for preparing same. The invention also concerns a method for preparing a material with reduced chromium (VI) content. The invention further concerns the use of said adjuvant for reducing chromium (VI) ions into chromium (HI).
Full Text

Additive for reducing chromium (VI) ions to chromium (III) ions

Another aim of the present invention was to propose an additive of this type in which
the tin(II) is stable (no precipitation) even in an alkaline medium.
Another aim of the present invention was to propose additive of this type that does
not modify the properties and the behaviour of the added materials.
not modify the properties and the behaviour of the added materials.

Finally. the additive described may also contain other additives conventional for the
desiored application, especially for the preparation of the cementing medium such as

The reaction between the tin(II) compound and the carboxylic acid or its sah is rapid and canplete. The order in which the reagents are introduced is of no paxticular incidence. The réaction leads to the formation of a water-soluble complex, which is stable both in an addic médium and in an alkaline médium (up to pH = 14). The îin(n) thus complexed is stable with respect to oxidation, but available for an oxidation/reduction reaction with chromium(VI).
The additive described is particularly useful for produeing materials having a k)w chromium(VI) content

The NMt tin tests were carried out at 300 K on a Bruker Avance 300 Spectrometer
(111.9 MHz for tin 119) equipped with a 5mm BBI probe.

These tests demonstrate that the additives prepared with a gluconate/tin molar ratio of
greater than 1:1 are stable, i,e clear, even at alkaline PHs. It is assumed that the
greater than 1:1 are stable, i,e, clear, even at alkaline PHs. It is assumed that the
precipitate in the solution in Example 7 orignates from tin(II) present in non-
complexed form, owing to the absence of gluconate in this solution.

The stability of the complex imparts a very considerable degree of formulation
freedom, facilitating in particular, compatibility with a broad rage of additives. It
may also help to stabilise the additive in materials having a very alkaline PH such as,
in particular, cement, thus allowing the reductive effect of the chromium (VI) ions to
be perpetuated. Finally, the stability of the additives provides them witha certain dobustners
with respect to variations in the processing conditions.i a certain

Active according to any one of claims 1 to 6, further comprising an antioxidant agent selected from hydroquinone and the derivatives thereof, propyl gallate, (t-butyl-4-hydroxyanisole, (2,6-di-tert-butyl-p-cresol), ethyl vanillin, rosemary oil, lecithin and vitannn E.
Process for preparing an additive according to any one of claims 1 to 7, including the steps of bringing a tin(II) salt into contact with carboxylic acid or a salt therof, in the present of an appropriate amount of water.
Process according to claim 8, wherein the molar ratio of carboxylic acid or salt thereof to tin(II) compound is from 0,5:1 to 5:1.
Process according to either claim 8 or claim 9. wherein the tin(n) compound is selected from tin chloride, tin sulphate, tin fluoride and tin acetate.

Process for preparing a material having a low chromium(VI) content, including the step of bringing the material into contact with an appropriate amount of additive according to claims 1 to 7.
Process according to claim 11, wherein the material is a hydraulic binder.
Process according to claim 12, wherein the material is selected from cements,
calcium sulphate and its hydrated forms, fly ash and slag. Use of an additive according to any one of claims 1 to 7 for preparing a
material having a low chromium (VI) content.




3124-CHENP-2007 AMENDED CLAIMS 07-10-2011.pdf

3124-CHENP-2007 AMENDED CLAIMS 26-12-2011.pdf

3124-CHENP-2007 CORRESPONDENCE OTHERS 17-01-2011.pdf

3124-CHENP-2007 CORRESPONDENCE OTHERS 26-12-2011.pdf

3124-CHENP-2007 FORM-1 26-12-2011.pdf

3124-CHENP-2007 FORM-3 17-10-2011.pdf

3124-CHENP-2007 FORM-3 26-12-2011.pdf

3124-CHENP-2007 OTHER PATENT DOCUMENT 26-12-2011.pdf

3124-CHENP-2007 POWER OF ATTORNEY 07-10-2011.pdf

3124-CHENP-2007 CORRESPONDENCE OTHERS 17-10-2011.pdf






3124-chenp-2007-form 1.pdf

3124-chenp-2007-form 18.pdf

3124-chenp-2007-form 3.pdf

3124-chenp-2007-form 5.pdf


Patent Number 250647
Indian Patent Application Number 3124/CHENP/2007
PG Journal Number 03/2012
Publication Date 20-Jan-2012
Grant Date 16-Jan-2012
Date of Filing 16-Jul-2007
Name of Patentee CHRYSO
Applicant Address 19, Place de la Résistance, F-92440 Issy Les Moulineaux
# Inventor's Name Inventor's Address
1 ANDREANI, Pierre-Antoine 24, rue de Gérofosse, F-91150 Etampes
2 PELLERIN, Bruno 4, rue Jean Mermoz, F-77210 Avon
3 AYME, Karen 38, rue du Capitaine Giry, F-45300 Pithiviers
PCT International Classification Number C04B 24/40
PCT International Application Number PCT/FR06/00816
PCT International Filing date 2006-04-13
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 0503855 2005-04-18 France