Methods for producing elastomeric compositions

A continuous flow method of preparing elastomer masterbatch of particulate filler dispersed in elastomer, comprising:

• A) establishing a continuous, semi-confined flow of combined elastomer latex and particulate filler under pressure in a coagulum reactor forming an elongate coagulum zone extending with progressively increasing cross-sectional area from an entry end to a discharge end, by simultaneously
• (i) feeding elastomer latex fluid continuously to a mixing zone at the entry end of the coagulum reactor, and
• (ii) entraining the elastomer latex fluid into particulate filler fluid by feeding the particulate filler fluid as a continuous jet into the mixing zone sufficiently energetically against the elastomer latex fluid to substantially completely coagulate the elastomer latex with the particulate filler;
• and
• B) discharging from the discharge end of the coagulum reactor a substantially constant flow of elastomer masterbatch globules concurrently with feeding of the fluid streams in accordance with steps A(i) and A(ii).

A continuous flow method of producing rubber masterbatch by coagulating natural rubber latex with carbon black, comprising:

• A) establishing a continuous, semi-confined flow of mixed natural rubber latex and carbon black in a coagulum reactor forming a generally tubular coagulum zone extending with progressively increasing cross-sectional area from an entry end to an open discharge end, by simultaneously
• (i) feeding a liquid stream of the natural rubber latex continuously to a mixing zone at the entry end of the coagulum reactor, and
• (ii) entraining the natural rubber latex continuously into a liquid slurry of the carbon black by feeding the liquid slurry as a continuous jet into the mixing zone;
• and
• B) simultaneously discharging rubber masterbatch globules from the discharge end of the coagulum reactor.

A continuous flow method of producing elastomer masterbatch comprising particulate filler selected from carbon black, silicon-treated carbon black, fumed silica, precipitated silica, and mixtures thereof finely dispersed in natural rubber, comprising:

• preparing a particulate filler fluid by high energy dispersion of the particulate filler into aqueous liquid in a homogenizer;
• and
• establishing a continuous, semi-confined flow of mixed natural rubber latex and particulate filler in a coagulum reactor forming a generally tubular coagulum zone extending with progressively increasing cross-sectional area from an entry end to a discharge end by simultaneously
• (i) feeding a liquid stream of the natural rubber latex at less than 10 feet per second continuously to a mixing zone defined by a mix head in sealed fluid communication with the entry end of the coagulum reactor, the mixing zone extending coaxially with the coagulum zone, and
• (ii) entraining the natural rubber latex continuously into the particulate filler fluid by feeding the particulate filler fluid into the mixing zone toward the entry end of the coagulum zone, through a feed tube substantially coaxial with the coagulum zone, the particulate filler fluid exiting the feed tube at a velocity of 200 to 500 feet per second;
• simultaneously and continuously discharging from the discharge end of the coagulum reactor masterbatch globules in which coagulation of the natural rubber latex by the particulate filler is substantially complete;
• and
• simultaneously and continuously drying and pelletizing masterbatch globules discharged from the coagulum reactor in a series of dryers.