RECLAMATION OF DIFFICULTLY RECLAIMABLE RUBBER

摘要

PROBLEM TO BE SOLVED: To reclaim a difficultly reclaimable rubber to obtain a reclaimed rubber which can give a molding having excellent rubber properties by establishing a state in which a difficultly reclaimable rubber and an easily reclaimable rubber coexist and applying heat and shearing force to the rubbers in this state. SOLUTION: A peroxide-crosslinked difficultly reclaimable rubber and a sulfur- crosslinked easily reclaimable rubber are brought into a state in which at most 90 wt.% difficultly reclaimable rubber exist. The rubbers in this state is heated to 180-350 deg.C under a shearing force of 10-150 kg/cm<2> to effect both the regeneration of the easily reclaimable rubber and the pulverization of the difficultly reclaimable rubber to thereby obtain a reclaimed rubber composed of the easily reclaimable rubber and the difficultly reclaimable rubber in the form of 100μm or smaller (desirably, having a means particle diameter of 10μm or below) fine particles dispersed in the difficultly reclaimable rubber and being capable of giving a molding excellent in rubber properties. It is desirable that the combination of the difficultly reclaimable rubber with the easily reclaimable rubber is selected from combinations of difficultly and easily reclaimable rubbers resembling each other in molecular structure, polarity, or the like such as peroxide-crosslinked EPDM/sulfur-vulcanized EPDM and peroxide- crosslinked styrene-butadiene rubber/sulfur-vulcanized natural rubber.