| abstract |
THE PREPARATION OF RUBBER CRUMB PREFERABLY IN THE FORM OF BLACK MASTERBATCH CRUMB IN WHICH THE LATEX IS COAGULATED DURING A FIRST COAGULATION STEP TO PRODUCE THE RUBBER CRUMB AND A SERUM WHICH CONTAINS SOME UNCOAGULATED POLYMERIC MATERIAL WHICH SUBSEQUENTLY COAGULATES TO FORM A RUBBER LAYER ON THE SURFACE OF THE CRUMB AND IN WHICH CARBON BLACK IS INTRODUCED SUBSEQUENT TO COAGULATION TO BE TAKEN UP WITH THE RUBBER LAYER THAT IS FORMED DURING COAGULATION OF THE UNCOAGULATED POLYMERIC MATERIAL REMAINING IN THE SERUM TO PRODUCE A LESS TACKY CRUMB AND WHICH INCLUDES THE MODIFICATIONS WHEREIN IN ADDITION TO OR SEPARATE AND APART FROM THE CARBON BLACK, ADDITIONS CAN BE MADE OF SALTS, OXIDES AND CARBONATES OF METALS CAPABLE OF REACTION TO FORM A SOAP WITH THE ORGANIC ACIDS REMAINING INT HE CRUMB AND WHICH INCLUDES THE FURTHER MODIFICATION OF TREATING THE SURFACE OF THE CRUMB WITH A LOW MOLECULAR WEIGHT ALCOHOL OR LOW MELTING POINT PARAFFIN DURING THE ELEVATED TEMPERATURE WATER WASHING STEP TO TAKE UP CARBON BLACK OR OTHER COMPOUNDS DESCRIBED IN A LAYER FORMED ON THE SURFACE OF THE CRUMB. |