POLYISOPRENE RUBBER PRODUCTION PROCESS Russian patent published in 2002 - IPC

FIELD: rubber industry. SUBSTANCE: invention relates to production of polyisoprene rubber from isopentane accomplished in at least one preponderant isopentane- dehydrogenation zone and one preponderant resulting isoamylene-dehydrogenation zone, wherein dehydrogenation is effected on different catalysts and/or at different temperatures and pressures. Crude product is isolated in isolation zone, after which mixture of C5- hydrocarbons is subjected to rectification separation to yield isoprene fraction, which is further purified to remove polymerizationinhibiting impurities and transferred into isoprene-polymerization zone. According to invention, above-mentioned C5- hydrocarbon mixture mainly containing pentadienes, isoamylenes and optionally isopentane is separated from at least piperylenes and then freed from at least cyclopentadiene, alpha- acetylenes, and oxygen-containing compounds. Polymer(s) is treated to separate at least C5 hydrocarbons recycled into dehydrogenation zone(s) and/or into rectification zone(s), and/or partly into polymerization zone. EFFECT: simplified process flow sheet. 13 cl, 5 dwg, 3 tbl, 9 ex