Pigmented decontaminating gel and method for decontaminating surfaces using said gel

Patent metadata

Field	Value
Publication number	US-10653131-B2
Application number	US-201414780632-A
Country	US
Kind code	B2
Filing date	Mar 27, 2014
Priority date	Mar 29, 2013
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

A decontamination gel is provided consisting of a colloidal solution comprising 0.1% to 30% by mass, preferably 0.1% to 25% by mass, still more preferably from 5% to 25% by mass, even more preferably 8% to 20% by mass, based on the mass of the gel, of at least one inorganic viscosifying agent; 0.1 to 10 mol/L of gel, preferably 0.5 to 10 mol/L of gel, still more preferably 1 to 10 mol/L of gel of at least one active decontamination agent; 0.01% to 10% by mass, preferably 0.1% to 5% by mass based on the mass of the gel of at least one mineral pigment; optionally, 0.1% to 2% by mass based on the mass of the gel, of at least one surfactant; optionally, 0.05% to 5% by mass, preferably 0.05% to 2% by mass, based on the mass of the gel, of at least one super-absorbent polymer; and the balance of solvent.

First claim

The invention claimed is:

1. A decontamination gel consisting of a colloidal solution comprising:
0.1% to 30% by mass, based on the mass of the gel, of at least one inorganic viscosifying agent;
0.1 to 10 mol/L of gel, of at least one active decontamination agent;
0.01% to 0.1% by mass, based on the mass of the gel, of an iron oxide pigment;
optionally, 0.1% to 2% by mass based on the mass of the gel, of at least one surfactant;
optionally, 0.05% to 5% by mass, based on the mass of the gel, of at least one super-absorbent polymer;
and the balance of solvent.

2. The decontamination gel according to claim 1 , wherein the iron oxide pigment is selected so that it gives the gel a color different from the color of a surface to be decontaminated on which the gel is applied.

3. The decontamination gel according to claim 1 , wherein the iron oxide pigment is a micronized pigment and the average size of the particles of the iron oxide pigment is from 0.05 to 5 μm.

4. The decontamination gel according to claim 1 , wherein the inorganic viscosifying agent is selected from a group consisting of oxides of metals, oxides of metalloids, hydroxides of metals, hydroxides of metalloids, oxyhydroxides of metals, oxyhydroxides of metalloids, aluminosilicates, clays, and mixtures thereof.

5. The decontamination gel according to claim 4 , wherein the inorganic viscosifying agent is selected from a group consisting of pyrogenated silicas, precipitated silicas, hydrophilic silicas, hydrophobic silicas, acid silicas, basic silicas, and mixtures thereof.

6. The decontamination gel according to claim 5 , wherein the inorganic viscosifying agent consists of a mixture of precipitated silica and of a pyrogenated silica.

7. The decontamination gel according to claim 4 , wherein the inorganic viscosifying agent consists of one or several aluminas representing from 5% to 30% by mass, based on the mass of the gel.

8. The decontamination gel according to claim 1 , wherein the active decontamination agent is selected from a group consisting of bases, acids, oxidizers, quaternary ammonium salts, reducing agents, and mixtures thereof.

9. The decontamination gel according to claim 1 , wherein the super-absorbent polymer is selected from a group consisting of sodium poly(meth) acrylates, starches grafted with a (meth)acrylic polymer, hydrolysed starches grafted with a (meth)acrylic polymer; polymers based on starch, on a gum, and on a cellulose derivative; and mixtures thereof.

10. The decontamination gel according to claim 1 , wherein the surfactant is selected from non-ionic surfactants and mixtures thereof.

11. The decontamination gel according to claim 1 , wherein the solvent is selected from a group consisting of water, organic solvents and mixtures thereof.

12. A method for decontaminating at least one surface of a substrate made of a solid material, said surface being contaminated with at least one contaminating species found on said surface and optionally under said surface in the depth of the substrate, wherein at least one cycle is carried out, comprising the following successive steps:
a) applying the gel according to claim 1 on said surface;
b) maintaining the gel on the surface for at least a sufficient duration so that the gel destroys and/or inactivates and/or absorbs the contaminating species, and so that the gel dries and forms a dry and solid residue containing said contaminating species;
c) removing the dry and solid residue containing said contaminating species.

13. The method according to claim 12 , wherein the iron oxide pigment contained in the gel is selected so that it gives the gel a color different from the color of the surface to be decontaminated on which the gel is applied.

14. The method according to claim 12 , wherein the substrate is a porous substrate, optionally, a porous mineral substrate.

15. The method according to claim 12 , wherein the solid material is selected from a group consisting of metals and metal alloys; polymers; glasses; cements and cement materials; mortars and concretes; plasters; bricks; natural or artificial stone; and ceramics.

16. The method according to claim 12 , wherein the contaminating species is selected from chemical, biological, nuclear or radioactive contaminating species.

17. The method according to claim 16 , wherein the contaminating species is a biological species.

18. The method according to claim 12 , wherein the gel is applied on the surface in an amount from 100 g to 2,000 g of gel per m 2 of surface.

19. The method according to claim 12 , wherein during step b), drying is carried out at a temperature of 1° C. to 50° C., and under relative humidity from 20% to 80%.

20. The method according to claim 12 , wherein the gel is maintained on the surface for a duration from 2 to 72 hours.

21. The method according to claim 12 , wherein the gel is maintained on the surface until it exhibits a reduction of its visible and ultraviolet absorbance.

22. The method according to claim 12 , wherein the dry and solid residue appears as particles with a size from 1 to 10 mm.

23. The method according to claim 12 , wherein the dry and solid residue is removed from the solid surface by brushing and/or suction.

24. The method according to claim 12 , wherein the described cycle is repeated from 1 to 10 times by using the same gel during all the cycles or by using different gels during one or several cycle(s).

25. The method according to claim 12 , wherein during step b), the gel, before total drying, is re-wetted with a solution of the active decontamination agent of the gel of step a) in the solvent of this gel.

26. The decontamination gel according to claim 1 , wherein upon being sprayed and thereafter maintained on a surface for 3 to 24 hours such that the decontamination gel dries, the dried decontamination gel exhibits a relative decrease in visible and ultraviolet light absorbance from 30 to 99% compared to the decontamination gel as sprayed.

27. The decontamination gel according to claim 8 , wherein the active decontamination agent is a base selected from the group consisting of sodium hydroxide, potassium hydroxide, and mixtures thereof.

28. The decontamination gel according to claim 8 , wherein the active decontamination agent is an acid selected from the group consisting of nitric acid, phosphoric acid, hydrochloric acid, sulfuric acid, hydrogenoxalates, and mixtures thereof.

29. The decontamination gel according to claim 8 , wherein the active decontamination agent is an oxidizer selected from the group consisting of peroxides, permanganates, persulfates, ozone, hypochlorites, salts of cerium IV, and mixtures thereof.

30. The decontamination gel according to claim 8 , wherein the active decontamination agent is a quaternary ammonium salt selected from the group consisting of hexadecylpyridinium salts.

31. The decontamination gel according to claim 10 , wherein the non-ionic surfactants are selected from the group consisting of block, sequenced copolymers and ethoxylated fatty acids.

32. The decontamination gel according to claim 31 , wherein the block, sequenced copolymers are copolymers of ethylene oxide and propylene oxide.

33. The method according to claim 15 , wherein the solid material is a metal or metal alloy selected from the

Assignees

• Commissariat Energie Atomique

Inventors

• Ludwig Amélie
• Goettmann Frédéric
• Frances Fabien

Classifications

• C11D3/124

  Silicon containing, e.g. silica, silex, quartz or glass beads · CPC title

• A61L2/16

  using chemical substances · CPC title

• C11D3/10

  Carbonates {; Bicarbonates} · CPC title

• A62D2101/02

  Chemical warfare substances, e.g. cholinesterase inhibitors · CPC title

• C11D17/003

  Colloidal solutions, e.g. gels; Thixotropic solutions or pastes · CPC title