Polymer with urethane or thiourethane units for use, in particular, as an adhesion primer for bonding metal to rubber
A polymer has urethane or thiourethane units, which can be used, in particular, as an adhesion primer for the adhesive bonding of metal or glass to rubber. The polymer comprises base units comprising at least a sub-unit of formula X 1 CO—NH—, in which X 1 respectively represents O or S, and additional units comprising at least a secondary alcohol function and a thioether function in the α position relative to the alcohol function. The polymer can be used as an adhesion primer for the adhesive bonding of a substrate, for example glass or metal, to an unsaturated rubber, or as a corrosion-resistant protective coating for a metal substrate. A metal reinforcer, such as wire, cord, film or plate, can be coated with the polymer.
1. An adhesion primer for the adhesive bonding of a substrate to an unsaturated rubber comprising a polymer having urethane units comprising from 20 to 200 repeating structural units corresponding to formula (III-1):
—O—C(O)—NH—Z 1 —NH—C(O)—O—Z 2 —CH(OH)—(CH 2 )—S—, (III-1)
wherein Z 1 represents an aromatic group comprising from 6 to 30 carbon atoms, and
wherein Z 2 is an alkylene comprising 1 to 12 carbon atoms.
2. The adhesion primer according to claim 1 , wherein the polymer is derived from a diisocyanate monomer selected from the group consisting of the compounds diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), naphthalene diisocyanate (NDI), 3,3′-bitoluene diisocyanate (TODI), para-phenylene diisocyanate (PPDI), their isomers, and mixtures thereof.
3. The adhesion primer according to claim 2 , wherein the polymer is derived from diphenylmethane diisocyanate (MDI).
4. The adhesion primer according to claim 1 , wherein Z 2 is an alkylene comprising from 1 to 4 carbon atoms.
5. The adhesion primer according to claim 4 , wherein Z 2 is a methylene.
6. A corrosion-resistant protective coating for a substrate having at least a surface which is at least partially metallic, said corrosion-resistant protective coating comprising the adhesion primer according to claim 1 .
7. A substrate coated, at least in part, with the adhesion primer according to claim 1 .
8. The substrate according to claim 7 , wherein the substrate is made of glass or metal.
9. A metal reinforcer coated with the adhesion primer according to claim 1 .
10. The metal reinforcer according to claim 9 , wherein the metal reinforcer is selected from the group consisting of metal wire, cord, film and plate, and
wherein at least a portion of the surface of the metal reinforcer is made of brass-coated steel coated with the adhesion primer.