Method for treating the surface of a substrate based on sulphur polymer, intended to be covered with a coating
View Patent ↗The invention relates to a method for treating at least one surface of a substrate based on sulphur polymer intended to be covered with a coating, said method comprising, prior to depositing the coating onto the surface of the substrate, a step of bringing the surface of the substrate into contact with a treating composition comprising at least one reducing agent.
1. A method for coating at least one surface of a substrate comprising a sulphur polymer, comprising, prior to depositing the coating onto the surface of the substrate, a treating step of said surface using a treating composition comprising at least one reducing agent which is able to reduce C—S, S—S, CON bonds and salts in the sulphur polymer forming the substrate, causing the sulphur polymer to functionalize through the creation of SH bonds near the surface by contact with the reducing agent,
wherein the treating step comprises at least the steps of:
dipping the substrate into at least a bath comprising the treating composition, and
rinsing off the substrate by dipping it into a deionized water bath.
2. The method of claim 1 , wherein the at least one reducing agent is a thioacid or salt thereof.
3. The method of claim 1 , wherein the at least one reducing agent is thioglycolic acid, potassium thioglycolate, sodium thioglycolate, calcium thioglycolate, magnesium thioglycolate, glycerol monothioglycolate, ammonium thioglycolate, an amine thioglycolate, diammonium dithioglycolate, thiolactic acid, ammonium thiolactate, guanidine thioglycolate, thiomalic acid, 2-mercaptoproprionic acid, 3-mercaptoproprionic acid, lipoic acid, dihydrolipoic acid, thiosalicylic acid, dithioerythritol, thioglycerol, thioglycol, dithioerythritol, dithiothreitol, 1,3-dithiopropanol, thioxanthine, cysteine, homocysteine, N-acetyl-L-cysteine, cysteamine, N-acetyl-cysteamine, N-propionyl-cysteamine, pantheteine, NaHSO 3 , LiS, Na 2 S, K 2 S, MgS, CaS, SrS, BaS, (NH 4 ) 2 S, sodium dihydrolipoate 6,8-dithiooctanoate, sodium 6,8-dithiooctanoate, a hydrogen sulfide salt, thioglycolamide, glutathione, thioglycol hydrazide, keratinase, hydrazine sulfate, hydrazine disulfate, triisocyanate, 2,3-dimercaptosuccinic acid, N-(mercaptoalkyl)-ω-hydroxyalkyl amide, N-mono or N,N-dialkylmercapto-4-butyramide, aminomercapto-alkyl amide, N-(mercaptoalkyl)succinamic acid derivative and N-(mercaptoalkyl)succinimide derivative, alkylamino mercaptoalkyl amide, azeotropic mixture of 2-hydroxypropyl thioglycolate and (2-hydroxy-1-methyl)ethyl thioglycolate, mercaptoalkyl aminoamide, N-mercapto-alkylalkane diamide and formamidine sulfinic acid derivative, sulfite, or bisulfite, or salts thereof.
4. The method of claim 3 , wherein the at least one reducing agent is sodium thioglycolate, potassium thioglycolate, ammonium thioglycolate or amine thioglycolate.
5. The method of claim 3 , wherein the amine thioglycolate is monoethanol amine thioglycolate.
6. The method of claim 3 , wherein the hydrogen sulfide salt is NaSH or KSH.
7. The method of claim 1 , wherein the pH value of the treating composition is higher than 10.
8. The method of claim 7 , wherein the pH value of the treating composition is higher than 12.
9. The method of claim 1 , wherein the treating composition comprises from 2 to 30% by weight, based on the total weight of the composition, of the at least one reducing agent.
10. The method of claim 9 , wherein the treating composition comprises from 2 to 15% by weight, based on the total weight of the composition, of the at least one reducing agent.
11. The method of claim 10 , wherein the treating composition comprises from 5 to 10% by weight, based on the total weight of the composition, of the at least one reducing agent.
12. The method of claim 1 , wherein the treating composition comprises at least one metal sulphur.
13. The method of claim 1 , wherein the method does not comprise a subsequent step of applying a soda solution onto the substrate.
14. The method of claim 1 , further comprising an additional treating step with an oxidizing composition comprising at least one oxidizing agent.
15. The method of claim 14 , wherein the at least one oxidizing agent is hydrogen peroxide, alkali bromate, polythionate and/or a persalt.
16. The method of claim 15 , wherein the persalt is further defined as a perborate, percarbonate, persulfate and/or permanganate.
17. The method of claim 14 , wherein the at least one oxidizing agent is H 2 O 2 or KMnO 4 .
18. The method of claim 14 , wherein the oxidizing composition comprises from 2 to 15% by weight, based on the total weight of the composition, of the at least one oxidizing agent.
19. The method of claim 18 , wherein the oxidizing composition comprises from 5 to 10% by weight, based on the total weight of the composition, of the at least one oxidizing agent.
20. The method of claim 1 , further comprising an additional treating step with a phosphorylation composition comprising at least one phosphorylating agent.
21. The method of claim 20 , wherein the at least one phosphorylating agent is a trialkylphosphite, phosphonic acid and/or phosphinic acid.
22. The method of claim 20 , wherein the phosphorylation composition comprises from 2 to 15% by weight, based on the total weight of the composition, of the at least one phosphorylating agent.
23. The method of claim 22 , wherein the phosphorylation composition comprises from 5 to 10% by weight, based on the total weight of the composition, of the at least one phosphorylating agent.
24. The method of claim 1 , wherein the sulphur polymer in the substrate is a polythio(meth)acrylate, polythiourethane, polythiourethane-urea and/or polyepisulfide.
25. The method of claim 24 , wherein the sulphur polymer is a polythiourethane resulting from the polymerization of at least one polyisocyanate monomer and at least one polythiol monomer.
26. The method of claim 25 , wherein the polyisocyanate monomer is the compound of formula C 6 H 4 (CH 2 NCO) 2 and the polythiol monomer is the compound of formula C(CH 2 OC(O)CH 2 CH 2 SH) 4 .
27. The method of claim 25 , wherein the polyisocyanate monomer is the compound of formula C 6 H 4 (CH 2 NCO) 2 or the bis(isocyanomethyl) norbornane, and the polythiol monomer is the compound of formula:
28. The method of claim 1 , wherein the substrate has a roughness Ra lower than 4 nm.
29. The method of claim 1 , wherein the substrate has a roughness Ra ranging from 1 to 4 nm.
30. The method of claim 1 , wherein the substrate has a roughness Ra ranging from 5 to 30 to nm.
31. The method of claim 1 , wherein the substrate is further defined as an ophthalmic lens.
32. The method of claim 31 , wherein the ophthalmic lens is a glass for eyeglasses.
33. The method of claim 1 , wherein the coating is an abrasion-resistant polymer coating.
34. The method of claim 33 , wherein the polymer coating is a coating based on an epoxyalkoxysilane hydrolyzate.
35. The method of claim 34 , wherein the polymer coating is an epoxydialkoxysilane or an epoxytrialkoxysilane hydrolyzate.
36. The method of claim 33 , wherein the thickness of the coating is 1 to 10 μm.
37. The method of claim 36 , wherein the thickness of the coating is 2 to 6 μm.
38. The method of claim 37 , wherein the thickness of the coating is 3 to 5 μm.