Metallic or metallized, graphenized reinforcement
A threadlike metallic or metallized reinforcer, for example a thread, film, tape or cord made of carbon steel, at the periphery of which is positioned a layer of metal referred to as “surface metal” chosen from copper, nickel and copper/nickel alloys, is characterized in that this surface metal layer is itself coated, at least in part, with at least one layer of graphene; preferably, there is grafted, to this graphene, at least one functional group which can crosslink to a polymer matrix. This reinforcer of the invention is effectively protected from corrosion by virtue of the graphene present at the surface; advantageously, it can be adhesively bonded directly, without adhesion primer or addition of metal salt, to an unsaturated rubber matrix, such as natural rubber, by virtue of the possible functionalization of this graphene.
1. A threadlike metallic or metallized reinforcer, at the periphery of which is positioned a layer of surface metal selected from the group consisting of copper, nickel and copper/nickel alloys, wherein the layer of surface metal is itself coated, at least in part, with at least one layer of graphene.
2. The reinforcer according to claim 1 , wherein the reinforcer is in the form of an individual thread or an assembly of threads.
3. The reinforcer according to claim 1 , wherein the reinforcer is in the form of a tape or a film.
4. The reinforcer according to claim 1 , wherein the surface metal is copper.
5. The reinforcer according to claim 1 , wherein the reinforcer is an entirely metallic reinforcer.
6. The reinforcer according to claim 5 , wherein the metal at the core of the metallic reinforcer is a steel.
7. The reinforcer according to claim 6 , wherein the steel is a carbon steel.
8. The reinforcer according to claim 6 , wherein the steel is coated, at least in part, with a substrate metal which acts as substrate for the layer of the surface metal.
9. The reinforcer according to claim 8 , wherein the substrate metal is selected from the group consisting of aluminum, cobalt, tin, manganese, molybdenum, zinc and alloys comprising at least one of these elements.
10. The reinforcer according to claim 9 , wherein the substrate metal is selected from the group consisting of cobalt, zinc and alloys comprising at least one of these elements.
11. The reinforcer according to claim 10 , wherein the substrate metal is brass.
12. The reinforcer according to claim 1 , wherein the thickness of the reinforcer, or its diameter when its cross section is circular in shape, is between 0.05 and 5 mm.
13. The reinforcer according to claim 12 , wherein the thickness of the reinforcer, or its diameter when its cross section is circular in shape, is between 0.1 and 1 mm.
14. The reinforcer according to claim 1 , wherein the number of graphene layers varies from 1 to 5.
15. The reinforcer according to claim 14 , wherein the number of graphene layers varies from 2 to 4.
16. The reinforcer according to claim 1 , wherein there is grafted, to the graphene, at least one functional group which can crosslink to a polymer matrix.
17. The reinforcer according to claim 16 , wherein the functional group comprises at least one function selected from the group consisting of NH 2 , NHR, —OH, —COOH, —CHO, —SH, —S X —, halogen, acrylate, methacrylate, epoxy, vinyl, vinyloxy or isocyanate functions,
where R is a hydrocarbon radical and x is greater than 1.
18. The reinforcer according to claim 17 , wherein the functional group corresponds to the formula:
wherein m is equal to 0 or to 1; n is an integer from 1 to 5; Z is an optional, at least divalent, bonding group.
19. The reinforcer according to claim 18 , wherein the functional group corresponds to the formula: