Patent ID: 8029906

Claim:
A method of bonding rubber to a metal substrate, the method comprising: mixing a bis amino-silane with a first aqueous-based medium containing a nanosize particulate material to substantially hydrolyze the bis amino-silane; mixing a bis sulfur-containing silane with a second aqueous-based medium containing a nanosize particulate material to substantially hydrolyze the bis sulfur-containing silane; mixing the substantially hydrolyzed bis amino-silane with the substantially hydrolyzed sulfur-containing silane to form a silane solution comprising the substantially hydrolyzed bis amino-silane, the substantially hydrolyzed bis sulfur-containing silane, and the nanosize particulate materials of the first and second aqueous-based media, wherein the silane solution comprises a ratio of the hydrolyzed bis amino-silane to the hydrolyzed bis sulfur-containing silane of about 1:1 by volume; applying the silane solution to at least a portion of a surface of the metal substrate; drying the silane solution on the metal substrate to form a coating having a thickness in the range from about 0.1 μm to about 1 μm thereon; and applying an uncured, sulfur curable rubber onto the surface of the metal substrate having the coating thereon and sulfur curing the rubber to bond the rubber to the coated metal substrate; wherein the bis amino-silane is a compound of the general formula I: (R 1 O) 3 —Si—R 2 —X—R 2 —Si—(OR 1 ) 3 (formula I) wherein: each R 1 , independently, is selected from the group consisting of a C 1 -C 20 alkyl and C 2 -C 20 acyl; each R 2 , independently, is selected from the group consisting of a substituted or unsubstituted aliphatic and aromatic group; and X is selected from —N(R 3 )—, wherein R 3 is selected from the group consisting of hydrogen, substituted or unsubstituted, straight, branched or cyclic C 1 -C 20 alkyl, alkenyl, and alkynyl groups and substituted or unsubstituted C 3 -C 20 aryl and alkylaryl groups; wherein the bis sulfur-containing silane is a compound of the general formula II: wherein: each R 1 , independently, is selected from the group consisting of substituted or unsubstituted, straight, branched or cyclic C 1 -C 20 alkyl, alkenyl, alkynyl, and acetyl groups and substituted or unsubstituted C 3 -C 20 aryl and alkylaryl groups; Z is -Q-S x -Q-, wherein each Q, independently, is an aliphatic or aromatic group; and x is an integer from 4-10; and wherein the nanosize particulate material is silica.