| 摘要 |
<p>The present invention concerns an improved process for the preparation of monoesters of polyhydroxy alcohols and in particular for the preparation of polyhydroxy alcohol ester mixtures having high monoester contents. Such materials find application, for example, in the petroleum industry as additives for lubricants and fuels, or in the cosmetics or foods industries. <??>The present invention accordingly provides a process for the preparation of monoesters of one or more polyhydroxy alcohols, comprising: (i) reacting the or each polyhydroxy alcohol with a glyceride ester composition derived from a natural or synthetic source, in the presence of tertiary butanol or tertiary amyl alcohol as reaction medium, and a catalyst; (ii) if necessary, neutralising the catalyst; (iii) removing the tertiary butanol or tertiary amyl alcohol; and (iv) removing the unreacted polyhydroxy alcohol and any liberated glycerol from the product mixture; characterised in that in the reaction (i) the polyhydroxy alcohol is present in mass excess relative to the glyceride ester composition: the mass ratio of reaction medium to polyhydroxy alcohol is at least 0.8 : 1 in the case of tertiary butanol or at least 1.3 : 1 in the case of tertiary amyl alcohol; the reaction is carried out at a temperature at least equal to the reflux temperature of the reaction medium and at a pressure exceeding 1 bar; and the catalyst is selected from basic salts of Group I and Group II metals and non-metallic nitrogenous bases.</p> |
