Coated rubber bales - sheathed in a compatible film which inhibits blocking in ambient conditions

摘要

Coating (natural) rubber with a material which inhibits adhesion between surfaces in contact under normal conditions of transport or storage, but which becomes compatible with the bulk rubber during hot processing prior to use. Pref. the coating is a block copolymer of styrene and butadiene deposited from solution in a volatile solvent. Esp. for treating bales or lumps of crude rubber prepared for tyre mfr. Avoids incompatible fillers such as talc, as dusting agents and maintains integrity better than less estensible coverings, e.g. polyethylene. Does not form incompatible contamination in masticated rubber or dispersions thereof (i.e. adhesives) but can link into the final rubber structure to prevent subsequent migration. Readily dispersed at normal milling temp. (=90 degrees C).