Treated fillers, compositions containing same, and articles prepared therefrom

A process for producing treated precipitated silica comprising:

• (a) combining an alkali metal silicate and an acid to form a slurry comprising untreated silica;
• (b) treating said slurry with a treating composition comprising a treating agent, thereby forming a treated slurry;
• and
• (c) drying said treated slurry to produce a treated precipitated silica,
• wherein said treating agent comprises a polymer comprising (i) at least one first group that interacts with said untreated silica and (ii) at least one second group that interacts with a rubber matrix into which said treated silica is incorporated,
• wherein the treating composition further comprises a coupling agent comprising an organosilane, selected from the group consisting of (4-chloromethyl-phenyl) trimethoxysilane, (4-chloromethyl-phenyl) triethoxysilane, [2-(4-chloromethyl-phenyl)-ethyl]trimethoxysilane, [2-(4-chloromethyl-phenyl)-ethyl]triethoxysilane, (3-chloro-propenyl)-trimethoxysilane, (3-chloro-propenyl)-triethoxysilane, (3-chloro-propyl)-triethoxysilane, (3-chloro-propyl)-trimethoxysilane, trimethoxy-(2-p-tolyl-ethyl)silane, triethoxy-(2-p-tolyl-ethyl)silane, and combinations thereof.

A process for producing a treated precipitated silica comprising:

• (a) combining an alkali metal silicate and an acid to form an untreated slurry comprising untreated silica;
• (b) drying the untreated slurry to produce dried precipitated silica;
• (c) forming an aqueous slurry of the dried precipitated silica with a treating composition comprising a treating agent, a coupling agent, and optionally, a non-coupling agent, to form a treated precipitated silica slurry;
• and
• (d) drying the treated precipitated silica slurry to produce a dried treated precipitated silica,
• wherein said treating agent comprises a polymer comprising (i) at least one first group that interacts with said untreated silica and (ii) at least one second group that interacts with a rubber matrix into which said treated silica is incorporated, and
• wherein said coupling agent of said treating composition comprises an organosilane selected from the group consisting of (4-chloromethyl-phenyl) trimethoxysilane, (4-chloromethyl-phenyl) triethoxysilane, [2-(4-chloromethyl-phenyl)-ethyl]trimethoxysilane, [2-(4-chloromethyl-phenyl)-ethyl]triethoxysilane, (3-chloro-propenyl)-trimethoxysilane, (3-chloro-propenyl)-triethoxysilane, (3-chloro-propyl)-triethoxysilane, (3-chloro-propyl)-trimethoxysilane, trimethoxy-(2-tolyl-ethyl)silane, triethoxy-(2-p-tolyl-ethyl)silane and combinations thereof.