Patent ID: 8378008

Claim:
A process for producing a mineral filler composition having short-chain and long-chain organosilano groups on its surface comprising: (a) combining: (i) a particulate mineral filler; (ii) one or more short-chain organosilanes having the general formula: R 1 Si(OR) 3 , wherein R 1 is an unsubstituted alkyl group containing one to three carbon atoms; and each occurrence of R is independently selected from the group consisting of hydrogen and a hydrocarbon group containing one to six carbon atoms; and (iii) one or more long-chain organosilanes having the general formula: R 4 Si(OR) 3 , wherein R 4 is an unsubstituted alkyl group containing eight to twelve carbon atoms; and each occurrence of R is independently selected from the group consisting of hydrogen and a hydrocarbon group containing one to six carbon atoms; and wherein the long-chain organosilanes are in an amount of from about three mole percent to about fifty five mole percent of the combined molar amount of long-chain and short-chain organosilane compounds; and (b) mixing the combined filler, short-chain organosilanes and long-chain organosilanes to react the filler, the short-chain organosilanes and the long-chain organosilanes, thereby producing the mineral filler composition having short-chain and long-chain organosilano groups on its surface.