Process of preparing rubberized compositions

Claim 1

THE PROCESS OF PREPARING A POWDERY, FREE-FLOWING, RUBBER-HARD BITUMEN COMPOSITION COMPRISING THE STEPS OF (1) ADJUSTING THE WATER CONTENT OF A SLURRY OF A POWDERED HARD BITUMEN COMPOSITION HAVING A SOFTENING POINT ABOVE 200*F. BUT NOT OVER 400*F. UNTIL A SLURRY OF ABOUT 25% BY WEIGHT OF HARD BITUMEN AND ABOUT 75% BY WEIGHT OF WATER IS FORMED, SAID HARD BITUMEN PARTICLES RANGING IN SIZE FROM ABOUT 5 MICRONS IN DIAMETER TO ABOUT 50 MICRONS IN DIAMETER, 90% OF SAID PPARTICLES BEING LESS THAN 10 MICRONS IN DIAMETER, (2) MAINTAINING THE PH OF SAID SLURRY ABOVE 7.0, (3) SAID HARD BITUMEN SLURRY BEING MIXED WITH A DIENE POLYMER RUBBER LATEX, SAID RUBBER BEING PRESENT IN SAID MIXTURE IN THE PROPORTION OF ABOUT 5 TO 40% BY WEIGHT OF SAID RUBBER TO ABOUT 95 TO 60% BY WEIGHT OF SAID HARD BITUMEN COMPOSITION, (4) ADDING A COAGULANT TO CO-PRECIPITATE THE RUBBER AND HARD BITUMEN TO FORM A COMPOSITION WHEREIN THE HARD BITUMEN PARTICLES ARE COATED WITH FILMS OF RUBBER, (5) DRYING AND PULVERIZING THE CO-PRECIPITATED MIXTURE IN ORDER TO RUPTURE SSAID FILMS OF RUBBER TO CAUSE SURFACE AREAS OF SAID HARD BITUMEN PARTICLES TO PROTRUDE THROUGH THE FILMS AND (6) RECOVERING COMPOSITE PARTICLES COMPRISED OF HARD BITUMEN AND ASSSOCIATED DISCONTINUOUSS RUBBER PARTICLES TO PROVIDE A POWDER WHEREIN AT LEAST 95% WILL PASS THROUGH A 60MESH U.S. STANDARD SIEVE.