| 摘要 |
1,052,681. #-caprolactam. TEIJIN Ltd. Feb. 26, 1964 [March 7, 1963; March 22, 1963; April 20, 1963; June 24, 1963; Jan. 13, 1964], No. 8077/64. Heading C2C. #-caprolactam is prepared by heating #- caprolactone, #-hydroxycaproamide, or an alkyl, cycloalkyl, aralkyl or aryl ester or the ammonium or alkali metal salt of #-hydroxycaproic acid, with ammonia to a temperature of 200- 400‹ C. in the presence of at least one noble metal-containing, nickel-containing or cobaltcontaining hydrogenation catalyst in an atmosphere of hydrogen or nitrogen or both. Catalysts which may be used include palladium. platinum, rhodium, ruthenium, osmium or iridium, or an oxide of one of these metals, unsupported or supported on a carrier, metallic nickel, nickel supported on a carrier or nickel compounds, metallic cobalt or cobalt supported on a carrier. Suitable carriers include carbon, alumina, silica, alumina-silica or kieselguhr. The catalysts may be used in an amount 0À01- 50%, preferably 0À05-50%, of the starting material. Catalysts may be in the form of powder, granules or pellets and may be used e.g. as a suspension, fixed bed, moving bed or fluidised bed. The reaction can be performed batchwise or in a continuous system, and a part or all of the reactants and/or catalysts may be recycled during the operation. The preferred mol. ratio between the starting material and the aqueous ammonia in terms of pure ammonia is 1 : 25, preferably 1: 2-15. Generally the concentration of aqueous ammonia used is 0À1-35% preferably 8-28% by weight. |
