||||||||||||III USOO5292.917A United States Patent (19) (1) Patent Number: 5,292,917 Nishihira Et Al
||||||||||||III USOO5292.917A United States Patent (19) (1) Patent Number: 5,292,917 Nishihira et al. 45 Date of Patent: Mar. 8, 1994 54 PROCESS FOR PURIFYING DIMETHYL 58) Field of Search ......................................... 558/277 CARBONATE 56 References Cited 75 Inventors: Keigo Nishihira; Shinichi Yoshida; Shuji Tanaka, all of Ube, Japan U.S. PATENT DOCUMENTS 4,467,109 8/1984 Tahara et al. ....................... 560/193 73) Assignee: Ube Industries, Ltd., Yamaguchi, Japan 4,663,477 5/1987 Crandall et al. .................... 560/204 Primary Examiner-Mary C. Lee 21 Appl. No.: 56,891 Assistant Examiner-Michael Ambrose 22 Filed: May 5, 1993 Attorney, Agent, or Firn-Finnegan, Henderson, Farabow, Garrett & Dunner Related U.S. Application Data 57 ABSTRACT 63 Continuation of Ser. No. 837,881, Feb. 9, 1992. Disclosed a process for purifying dimethyl carbonate (30) Foreign Application Priority Data which comprises distillating a mixture of dimethyl car bonate and methanol in the presence of dimethyl oxa Feb. 26, 1991 (JP Japan .................................. 2-053148 late to separate and remove methanol. 51) int. Cli.............................................. CO7C 69/96 52 U.S.C. .................................................... 558/277 4 Claims, 1 Drawing Sheet U.S. Patent Mar. 8, 1994 5,292,917 F. G. ... O O.9 | | | | | | U-2 O. 8 | | | | I-4-31 O.7 | || 424 y O.6 41 || 4 || O.5 4 || 4 || | O. 4 /YA/P | 14 | ||| | ||| | | O.3 // 1 | | | | | | O.2 //1 || | | | | | O. 4 || | | | | || O O O. O.2 O.3 O.4 O5 O.6 O.7 O.8 O.9 1.O X o Without addition of dimethyl oxalate O Addition of dimethyl oxalate F.
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