Butyl rubber powder, method of making, and asphalt composition containing same

Claim 1

A COMPOSITION COMPRISING ASPHALT AND RUBBER POWDER, SAID RUBBER POWDER BEING THE PRODUCT OF MASTICATING AT A TEMPERATURE FROM 250*F. TO 350*F. A MIXTURE OF 100 PARTS OF A ISOBUTYLENE AND CORRESPONDINGLY OF 95 TO 99.5 PARTS OF ISOBUTYLENE AND CORRESPONDINGLY 5 TO 0.5 PART OF ISOPRENE, 10 TO 100 PARTS OF PLASTICIZER, 10 TO 50 PARTS OF CARBON BLACK, AND 1 TO 10 PARTS OF SULFUR AND 0.5 TO 3 PARTS OF AN ACCELERATOR SELECTED FROM THE GROUP CONSISTING OF 2-MERCAPTOBENZOTHIAZOLE, ZINC SALT OF 2-MERCAPTOBENZOTHIAZOLE, 3-ANILINOMETHYL-2(3)-BENZOTHIAZOLETHIONE, DIBENZOTHIAZYL DISULFIDE, TETRAMETHYL THIURAM MONOSULFIDE, TERTRAMETHYL THIURAM DISULFIDE, TETRAETHYL THIURAM DISULFIDE, ZINC DIMETHYL DITHIOCARBAMATE, ZINC DIETHYL DITHIOCARBAMATE, ZINC DIBUTYL DITHIOCARBAMATE, ZINC NPENTAMETHYLENE DITHIOCARBAMATE, 2,4-DINITROPHENYL DIMETHYL DITHIOCARBAMATE AND SELENIUM DIETHYL DITHIOCARBAMATE, SAID SULFUR AND ACCELERATOR BEING IN AMOUNT THAT WILL CURE THE RUBBER AT 250*F. TO 350*F., UNTIL THE MIXTURE IS VULCANIZED TO THE STAGE WHERE IT FORMS A POWDER, SAID POWDER BEING PRESENT IN SAID COMPOSITION IN AMOUNT FROM 1 TO 20 PARTS OF THE RUBBER CONTENT PER 100 PARTS OF SAID ASPHALT.