SURFACE SULFURIZATION OF A METAL BODY BY FLAME SPRAY PYROLYSIS
The surface of a body, in particular a metal reinforcer, at least the surface of which comprises a layer of metal referred to as surface metal capable of forming sulphides, is sulfurized. The metal can be chosen from copper, zinc and their alloys. The process comprises at least one stage of flame spray pyrolysis (FSP) of a sulphur-donating precursor, for example, thiophene, which generates hydrogen sulphide in the flame. The metal bodies or reinforcers thus treated can be directly adhesively bonded, without adhesion primer or addition of metal salt, such as a cobalt salt, to matrices of unsaturated rubber such as natural rubber.
1 .- 15 . (canceled)
16 . A process for the surface sulfurization of a body, the surface of which comprises a layer of metal capable of forming sulfides, the process comprising the step of:
conducting at least one stage of flame spray pyrolysis of a sulfur precursor which generates hydrogen sulfide in the flame.
17 . The process according to claim 16 , wherein the metal is selected from the group consisting of aluminium, silver, cobalt, copper, tin, iron, manganese, molybdenum, nickel, zinc and alloys comprising at least one of these elements.
18 . The process according to claim 17 , wherein the metal is selected from the group consisting of copper, zinc and alloys comprising at least one of these elements.
19 . The process according to claim 18 , wherein the metal is brass.
20 . The process according to claim 16 , wherein the sulfur precursor is liquid.
21 . The process according to claim 16 , wherein the sulfur precursor is sulfur or a sulfur-donating organic compound.
22 . The process according to claim 21 , wherein the sulphur-donating organic compound comprises from 1 to 15 carbon atoms.
23 . The process according to claim 22 , wherein the sulfur-donating organic compound is liquid and is selected from the group consisting of monosulfide, disulfide or polysulfide compounds of saturated or unsaturated aliphatic or cycloaliphatic type or aromatic type.
24 . The process according to claim 23 , wherein the sulfur-donating organic compound is selected from the group consisting of thiophene and its derivatives, thiocarbonyl compounds, aliphatic or aromatic thiols, aliphatic or aromatic organic disulfides, aliphatic or aromatic organic polysulfides, acyclic or cyclic thioethers, thioesters, and mixtures thereof.
25 . The process according to claim 24 , wherein the sulfur-donating organic compound is selected from the group consisting of thiophene and its derivatives, aliphatic or aromatic organic disulfides, aliphatic or aromatic organic polysulfides, acyclic or cyclic thioethers, and mixtures thereof.
26 . The process according to claim 21 , wherein the sulfur-donating organic compound is a compound devoid of a nitrogen atom.
27 . The process according to claim 26 , wherein the sulfur-donating organic compound is a compound devoid of an oxygen atom.
28 . The process according to claim 27 , wherein the sulfur-donating organic compound is a compound consisting exclusively of carbon, sulfur and hydrogen atoms.
29 . The process according to claim 28 , wherein the sulfur-donating organic compound is thiophene or a thiophene derivative.
30 . The process according to claim 16 , wherein a surface temperature of the metal during the sulfurization treatment is between 50° C. and 500° C.
31 . The process according to claim 30 , wherein the surface temperature is between 100° C. and 350° C.
32 . The process according to claim 16 , wherein the body is a wire, a cord, a film or a plate.