Free flowing crumb rubber composition

摘要

By utilizing the process of the present invention, a free-flowing crumb rubber composition can be easily prepared on a commercial scale. This invention more specifically discloses a process for preparing a free-flowing crumb rubber composition which comprises the steps of: (1) extruding a rubbery polymer into a wax emulsion; wherein the rubbery polymer is extruded into pellets having a diameter which is within the range of about 1 mm to about 15 mm; wherein the wax emulsion is comprised of about 35 weight percent to about 89 weight percent water, from about 10 weight percent to about 50 weight percent of a wax, and from about 1 weight percent to about 15 weight percent of an emulsifier; wherein the wax has a melting point which is within the range of about 40 DEG C. to about 175 DEG C.; and wherein the wax emulsion is at a temperature which is within the range of about 5 DEG C. to about 70 DEG C.; (2) agitating the wax emulsion containing the rubbery polymer to produce a wax-coated rubbery polymer; (3) separating the wax-coated rubbery polymer from the wax emulsion so as to recover a wet wax-coated rubbery polymer; and (4) drying the wax-coated rubbery polymer in a gas medium under forced motion to produce the free-flowing crumb rubber composition, wherein the gas medium is at a temperature which is within the range of about 10 DEG C. to about 50 DEG C.