| 摘要 |
Preparation of silicate and/or oxygenic filler-containing rubber powder or granulate, based on aqueous rubber emulsion or latex, involves suspension of silicate and/or filler, polysiloxane hydrophobizing agent and nonionic surfactant in water, adjustment of the pH to 2.5-7, separation of the deposited rubber powder from the solid particles, and drying the powdered or granulated product to a moisture content of less than 3%. A process for preparation of silicate and/or oxygenic filler-containing rubber powder or granulate based on aqueous rubber emulsion or latexes involves: (a) suspension of a silicate and/or oxygenic filler, polysiloxane hydrophobizing agent(s) (in amount 0.5-7% relative to the filler) and nonionic surfactant(s) (in amount 0.1-2% relative to the filler) at 10-60 degrees C in water, giving a suspension of density 0.5-5%, (b) addition of the rubber latex emulsion to the filler suspension with stirring, (c) adjustment of the pH of the aqueous mixture with an acid, preferably sulfuric acid or aluminum sulfate to a pH of 2.5-7, (d) separation of the deposited rubber powder from the process water by, for example, solid/liquid separation of the solid particles, (e) molding of the filter cake, and (f) drying of the powdered or granulated product to an end moisture content of less than 3%. |
