| 摘要 |
Mixed esters are prepared by an interesterification process from a citric acid difatty alcohol ester and a pentaerythritol difatty acid ester in the molar ratio of 1:1. The citric acid ester is prepared at 140-170 DEG C. under a pressure of about 25 mm Hg by the addition to the alcohol of only as much aqueous citric acid as reacts simultaneously with the alcohol. Examples describe the preparation of a citric acid dioctadecyl ester, and a pentaerythritol di-coconut oil fatty acid ester and a mixed ester therefrom. Citric acid dilauryl ester and pentaerythritoldistearic acid ester, or pentaerythritol dicoconut oil fatty acid ester; citric acid-di-Guerbet (C22) alcohol ester and pentaerythritol distearic acid ester; citric acid-dioctadecanediol ester and pentaerythritol dicoconut oil fatty acid ester; citric acid-dioctadecanediol ester and pentaerythritol distearic acid ester; citric acid-didodecyl ester and pentaerythritol dicoconut oil fatty acid ester are also mentioned and the products are heat stable, show improved water-binding properties, and are suitable for use as emulsifiers for ointment bases.ALSO:Emulsifiers for ointment bases comprise mixed esters prepared by the interesterification of a citric acid difatty alcohol ester and a pentaerythritol difatty acid ester in a molar ratio of 1 : 1. The preparation of a mixed ester of a citric acid dioctadecyl ester and a pentaerythritol di-coconut oil fatty acid ester is described and it is used in an ointment base with "Vaseline" (Registered Trade Mark), decyl oleate, cetyl alcohol, ozocerite, hard paraffin, viscous paraffin, and aluminium stearate. Mixed esters of citric acid-dilauryl ester and pentaerythritol-distearric acid ester; citric acid-dilauryl ester and pentaerythritol-dicoconut oil fatty acid ester, citric acid-di-Guerbet (C22) alcohol ester and pentaerythritol-distearic acid ester; citric acid-dioctadecanediol ester and pentaerythritol-dicoconut oil fatty acid ester; citric acid-dioctadecanediol ester and pentaerythritoldistearic acid ester; and citric acid-didodecyl ester and pentaerythritol-dicoconut oil fatty acid ester are also mentioned. |
