Patent ID: 6878759

Claim:
A process, comprising: a) suspending: at least one filler selected from the group consisting of silicatic filler, oxidic filler, and a mixture thereof, 0.5 to 7% by weight, based on the weight of the filler, of at least one polysiloxane hydrophobicizing agent, and 0.1 to 2% by weight, based on the weight of the filler, of at least one non-ionic surfactant, in water at a temperature of 10 to 60° C., to prepare a suspension having a solids content of 0.5 to 15% by weight, based on the weight of the suspension; b) contacting a rubber latex emulsion and the suspension, to prepare a mixture; c) contacting the mixture with at least one acid to lower the pH of the mixture to 2.5-7, to prepare a filled rubber powder precipitate and a liquid; d) separating at least a portion of the liquid from the filled rubber powder precipitate, to form a filtercake comprising the filled rubber powder precipitate; e) optionally shaping, comminuting, or pelletizing the filtercake, and f) drying to a moisture level of 3% by weight.