Coupling agents for mineral-filled elastomer compositions

A method for preparing a silane coupling agent for coupling an elastomer and a filler wherein said silane comprises at least one hydrolysable group that, upon compounding said silane with said elastomer and filler, is released to yield a compound that improves downstream processability of the compounded composition or the properties of the final rubber product or both, wherein said method comprises transesterifying JSG1-(SiX1X2X3) or X1X2X3Si-G2-Sx-G3-SiX1 X2X3 or mixtures thereof with an etheralcohol of the general formula (8) given below Formula 8:

• HO-G-(O-G-)qOH, wherein each occurrence of G is independently selected from the group consisting of hydrocarbon fragments obtained by removal of one hydrogen atom from any of the groups including aryl groups and any branched or straight chain alkyl, alkenyl, arenyl, or aralkyl groups, and
• each occurrence of the subscript, q, is independently an integer from 1 to 100:
• and wherein,:
• each occurrence of the subscript, x, is independently an integer from 2 to 20;
• each occurrence of X1 is independently selected from the group of hydrolysable moieties consisting of -Y1, —OH, —OR1, and R1C(═O)O—, wherein each occurrence of R1 is independently any hydrocarbon fragment obtained by removal of one hydrogen atom from a hydrocarbon having from 1 to 20 carbon atoms, R1 includes aryl groups and any branched or straight chain alkyl, alkenyl, arenyl, or aralkyl groups, and each occurrence of —Y1 is independently —O-G-(O-G-)pOR or —O-G-(O-G-)pOH, where each occurrence of R is independently selected from the group consisting of the members listed above for R1, and each occurrence of the subscript, p, is independently an integer from 1 to 100;
• each occurrence of X2 and X3 is independently selected from the group consisting of hydrogen, R1, and X1;
• each occurrence of G1, G2, and G3 is independently selected from the group consisting of hydrocarbon fragments obtained by removal of one hydrogen atom of any of the groups listed above for R1;
• each occurrence of J is independently selected from the group consisting of R1C(═O)—, R1C(═S)—, R12P(═O)—, R12P(═S)—, R1S(═O)—, and R1S(═O)2—, wherein each separate occurrence of R1 is as defined above.