Coprecipitation process

A process for improving the clarity of the serum produced during coprecipitation of a rubber or plastic compounding chemical and a binder, comprising

• (a) intimately mixing at least one finely divided rubber or plastic compounding chemical wherein substantially all of the particles thereof are at least about 0.05 micron in size, with a film-forming binder emulsion comprising a latex of a rubber or plastic polymer and an emulsion of a plasticizer for the polymer in the presence of an amount of water which permits intimate mixture thereof, wherein no compounding chemical is a reinforcing agent or diluent for rubber or plastic stock,
• (b) adding a stoichiometric excess of a coagulating agent during further intimate mixing of the chemical and the binder emulsion to cause complete coagulation thereof, and
• (c) physically separating the substantially clear serum produced upon coagulation from the homogeneous, essentially non-tacky, dustless, friable particles of predispersed chemical which comprise from about 80 to 99.5 percent by weight of said chemical and from about 0.5 to about 20 percent by weight of said binder.

A product comprising (i) substantially clear serum and (ii) homogeneous, essentially non-tacky, dustless, friable particles of predispersed rubber or plastic compounding chemical which comprise from about 80 to about 99.5 percent by weight of said chemical and from about 0.5 to about 20 percent by weight of a binder, said product prepared in accordance with a coprecipitation process comprising,

• (a) intimately mixing at least one finely divided rubber or plastic compounding chemical wherein substantially all of the particles thereof are at least about 0.05 micron in size with a film-forming binder emulsion comprising a latex of a rubber or plastic polymer in the presence of an amount of water which permits intimate mixture thereof, wherein no compounding chemical used is a reinforcing agent or diluent for rubber or plastic stock, and
• (b) adding a stoichiometric excess of a coagulating agent during further intimate mixing of the chemical and the binder emulsion to cause complete coagulation thereof.

A product comprising (i) substantially clear serum and (ii) homogeneous, essentially non-tacky, dustless, friable particles of predispersed rubber or plastic compounding chemical which comprise from about 80 to about 99.5 percent by weight of said chemical and from about 0.5 to about 20 percent by weight of a binder, said product prepared in accordance with a coprecipitation process comprising,

• (a) intimately mixing at least one finely divided rubber or plastic compounding chemical wherein substantially all of the particles thereof are at least about 0.05 micron in size with a film-forming binder emulsion comprising a latex of rubber or plastic polymer and an emulsion of a plasticizer for the polymer in the presence of an amount of water which permits intimate mixture thereof, wherein no compounding chemical is a reinforcing agent or diluent for rubber or plastic stock, and
• (b) adding a stoichiometric excess of a coagulating agent during further intimate mixing of the chemical and the binder emulsion to cause complete coagulation thereof.

Associatively formed products of a coprecipitation process comprising (i) substantially clear serum and (ii) homogeneous, essentially non-tacky, dustless, friable particles of predispersed rubber or plastic compounding chemical which comprise from about 80 to about 99.5 percent by weight of said chemical and from about 0.5 to about 20 percent by weight of a binder comprising a rubber or plastic polymer, wherein substantially all of the particles of the compounding chemical are at least about 0.05 micron in size and no compounding chemical used is a reinforcing agent or diluent for rubber or plastic stock.