BIOCIDAL, ANTISEPTIC, NON-SOLVENT-BASED ENVIRONMENTALLY-FRIENDLY COATING CONTAINING METAL PARTICLES HAVING A FLAT LAMELLAR STRUCTURE

Abstract

The present invention relates to a biocidal coating composition for a surface, comprising overlapping flat lamellar metallic nanoparticles and/or microparticles having a diameter of less than 45 microns, in suspension in a binder comprising an epoxy resin, a thixotropic agent and a natural diluent selected from among water, preferably demineralized water, and/or ethylene glycol and/or denatured alcohol. Moreover, the invention also relates to a coating process comprising a step of applying said composition, and to the use of the coating composition according to the invention for coating a surface.

Claims

1. A biocidal coating composition for a surface, comprising overlapping flat lamellar metallic nanoparticles and/or microparticles having a diameter of less than 45 microns, in suspension in a binder comprising: an epoxy resin; a thixotropic agent; a natural diluent selected from among water, preferably demineralized water, and/or ethylene glycol and/or denatured alcohol.

2. A biocidal coating composition for a surface according to claim 1, wherein said metallic nanoparticles and/or microparticles are copper and/or cupronickel nanoparticles and/or microparticles.

3. A biocidal coating composition for a surface according to claim 1, wherein between 10% and 95%, preferably between 40% and 95%, more preferably between 55% and 95% of the total weight of the composition is made up of said nanoparticles and/or microparticles.

4. A biocidal coating composition for a surface according to claim 1, wherein between 1% and 50%, preferably between 5% and 45%, more preferably between 5% and 35% of the total weight of the composition is made up of said epoxy resin.

5. A biocidal coating composition for a surface according to claim 1, wherein between 10% and 45%, preferably between 15% and 45%, more preferably between 28% and 45% of the total weight of the composition is made up of said thixotropic agent.

6. A biocidal coating composition for a surface according to claim 1, wherein said thixotropic agent is colloidal clay made up of a mixture of sodium, magnesium and lithium silicates.

7. A surface coating process comprising at least one step of applying to said surface said coating composition according to claim 1.

8. A surface coating process according to claim 7, wherein it furthermore comprises at least one step of said coating drying after said at least one step of application to said surface.

9. A surface coating process according to claim 7, wherein said at least one step of application is performed using cold metallization.

10. A surface coating process according to claim 9, wherein said at least one step of application using cold metallization is performed with a spray and/or a paint roller and/or a brush and/or by electrodeposition.

11. A surface coating process according to claim 7, wherein said at least one step of application is repeated until a coating having a thickness of at least 600 microns is obtained.

12. Use of the biocidal coating composition for a surface according to claim 1 to coat a surface, porous or nonporous, chosen from among: wood, composite, steel, aluminum, stainless steel, ferrocement, concrete, polyester, epoxide, PCV, rigid or semi-rigid carbon.

13. Use of the biocidal coating composition for a surface according to claim 1 to coat the hull of a boat.

Description

DESCRIPTION OF THE FIGURES

[0092] FIG. 1 provides a schematic example of the application of a coating with metal beads, comprising the substrate, copper beads and air bubbles, as can be found in the prior art, for example, in document FR2894974.

[0093] FIG. 2 is a microscopic view of spherical copper beads.

[0094] FIG. 3 is a schematic example of a lamellar coating according to the invention, the particles of which are flat, ovular and form a “placoid scale” coating.

[0095] FIG. 4 is a microscopic view of flat lamellar “placoid scale” nanoparticles, without binder. The flat lamellar “placoid scale” particles are overlapping.

EXAMPLES

Example 1

[0096] In a test experiment, the coating composition according to the invention is prepared.

[0097] This composition according to the invention is then applied using the procedure according to the experiment, comprising a step of cold metallization, to the surface of the hull of a boat.

[0098] This boat hull coated with the coating composition according to the invention is then submerged for one month in seawater.

[0099] A second boat hull made up of identical material to the coated one is also left for a month in seawater, near the first hull.

[0100] At the end of this month, the boat hulls are compared, and it seems that the hull not coated with the composition according to the invention is in a worse state than the one coated with the composition according to the invention. Indeed, marks indicating an attack by living organisms (bacteria, algae, etc.) can be seen on the untreated hull, whereas the boat hull coated with the composition according to the invention is intact.