Methods of making blocked-mercapto alkoxy-modified silsesquioxane compounds

摘要

Methods of forming blocked-mercapto alkoxy-modified silsesquioxanes are provided. The blocked-mercapto alkoxy-modified silsesquioxane compounds contain an alkoxysilane group that participates in an alkoxysilane-silica reaction as a silica dispersing agent in rubber, with the release of zero to about 0.1% by weight of the rubber as alcohol (a volatile organic compound (VOC)), during compounding and further processing. The blocked-mercapto alkoxy-modified silsesquioxane compounds also contain a blocked mercapto group which, when de-blocked, allows the mercapto group to interact with the polymer(s) in a rubber composition. Further described are rubber compounds containing the blocked-mercapto alkoxy-modified silsesquioxanes.

主权项

1. A method of forming a blocked-mercapto alkoxy-modified silsesquioxane comprising combining:
a. one or more compounds selected from the group consisting of alkoxy-modified silsesauioxanes having the formula I b. a compound having the formula II c. an acid scavenger,wherein w, x, y and z represent mole fractions, z does not equal zero, w, x, or y but not all can be zero, and w+x+y+z=1.00; wherein R1, R2 , R3 and R4 are the same or different and selected from the group consisting of (i) H or alkyl groups having one to about 20 carbon atoms, (ii) cycloalkyl groups having 3 to about 20 carbon atoms, (iii) alkylaryl groups having 7 to about 20 carbon atoms, and (iv) R6X1, and (v) R6X1R7Z; wherein X1 is selected from the group consisting of Cl, Br, SH, SaR8, NR82, OR8, CO2H, SCOR8, CO2R8, OH, olefins, epoxides, amino groups, vinyl groups, acrylates and methacrylates; wherein at least one of R1, R2 , R3 and R4 is R6SH; wherein a =1 to about 8; Z is independently selected from NH, NR8, 0, and S; R6 is selected from the group consisting of alkylene groups having one to about 20 carbon atoms, and cycloalkylene groups having 3 to about 20 carbon atoms, and a single bond; R5 and R8 are independently selected from the group consisting of alkyl groups having one to about 20 carbon atoms, cycloalkyl groups having 3 to about 20 carbon atoms, and alkylaryl groups having 7 to about 20 carbon atoms; R7 is selected from alkyl groups having one to about 6 carbon atoms; R9 is selected from the group consisting of alkyl groups having one to about 20 carbon atoms, cycloalkyl groups having 3 to about 20 carbon atoms, alkylaryl groups having 7 to about 20 carbon atoms, and OR8; and X2 is selected from the group consisting of CO2R8 and halogen.