Improvement in rubber compositions

Abstract

Abstract In making a rubber mix including artificial resin, which is to be hardened, as for example during an eventual vulcanization, the mix is cooled after any step in the processing operations involving an increased temperature which would tend to harden the resin. Further precautions include adding the resin as the last ingredient when mixing in fillers and controlling the mastication or other operations so that the mix is exposed to hardening temperatures for as short a time as possible. The resin may be a partly condensed phenol-aldehyde.ALSO:In making a rubber mix including a natural or artificial resin, which is to be hardened as for example during an eventual vulcanization, the mix is cooled after any step in the processing operations involving an increased temperature which would tend to harden the resin. Further precautions include adding the resin as the last ingredient when mixing in fillers, or where the resin is one such as shellac which is hardened by such basic oxides as zinc or magnesium oxides or lime, adding the basic oxides as the last ingredient, and controlling mastication or other operations so that the mix is exposed to hardening temperatures for as short a time as possible. The resin may also be a partly condensed phenol-aldehyde.

Inventors

No inventors recorded.

Bibliographic Details