Patent ID: 8912267

Claim:
A process for producing polymer-functionalized filler particles comprising: binding a control agent for a controlled free-radical polymerization of monomers on a surface of a filler particle; the control agent containing an R-group; the R-group containing an R1-group selected from the group consisting of a coupleable silyl group and a Diels-Alder-reactive functionality; the control agent further containing a reactive site for the addition of monomers; wherein the R1-group of the control agent becomes bound to the surface of the filler particle; and, performing the controlled free-radical polymerization of the monomers via the reactive site of the control agent bound to the filler particle to prepare a surface-bound block polymer and a second block polymer bound to the surface-bound block polymer; wherein the surface-bound block polymer is selected from the group consisting of a polybutadiene block and a butadiene copolymer block.