| 摘要 |
1,178,072. Purifying esters. MELLEBEZONS. 15 Jan., 1968 [9 Feb., 1967], No. 2216/68. Heading C2C. The invention relates to a process of purifying high-boiling esters (boiling above 250‹ C.) obtained by esterifying an acid or acid anhydride with a molar excess of an alcohol having at least 4 carbon atoms followed by neutralizing and washing with water. According to the invention the esters so obtained are stripped with superheated steam and/or a hot vehicle gas by a process effected in at least two stages under successively decreasing pressures. Thus, the process may comprise a first stripping effected under atmospheric or moderately raised pressure. a second stripping under moderate vacuum and a third stripping under high vacuum, or the second or third stripping may be omitted. Specified esters which may be treated include di-decyl phthalate, di-tridecyl phthalate, di-n-butyl phthalate, dihexyl phthalate, dioctyl phthalate and di-2-ethyl hexyl sebacate. Apparatus is described and examples are given. Specification 934,027 is referred to. |
