| 摘要 |
<p>1536935 Spheroidal closed-cell elastomeric foams UOP Inc 29 March 1976 [27 March 1975] 12493/76 Heading C3C [Also in Division B1] A mobile, spheroidal, closed-cell elastomeric foamed contact element, which is used for the contacting of countercurrently flowing gas and liquid streams, is made by heating and compression moulding a blend of a partially crosslinked nitrile rubber, polyvinyl chloride and a blowing agent to provide a compression moulded blend which is then heated to further crosslink the rubber and activate the blowing agent. The elements may have a smooth skinned surface. In the Example (1) a mixture of nitrile rubber, PVC, carbon black, hydrated alumina, plasticizer, blowing agent, paraffin wax, sulphur, zinc oxide, antimony oxide, octamine (the reaction product of diphenylamine and diisobutylamine), mercaptobenzothiazole, zinc diethyl dithio-carbamate and chorthotolylguanidine was heated, compression moulded to form spherical elements and post cured in a hot air stream to form self-skinned closed-cell foamed spheroids.</p> |
