Pentaerythritol co-esters derived from pentaerythritol, (3-alkyl-4-hydroxyphenyl)-alkanoic acids or an analog thereof and alkylthioalkanoic acids or lower alkyl esters of such acids are useful as stabilizers of organic material normally susceptible to oxidative and/or thermal deterioration. The co-esters are advantageously prepared by transesterification of such esters with pentaerythritol. Preferred co-esters are (I) pentaerythritol tris[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]-mono[3-n-dodecylthiopropionate] and (II) pentaerythritol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]-bis[3-n-dodecylthiopropionate). The co-esters are especially useful in stabilizing applications for which physical mixtures of (i) (3-alkyl-4-hydroxyphenyl)alkanoic acid esters of polyols with (ii) polyalkanol esters of alkylthioalkanoic acids have heretofore been proposed.
由
季戊四醇、(3-烷基-
4-羟基苯基)-烷酸或其类似物以及烷
硫基烷酸或此类酸的低级烷基酯衍生的
季戊四醇共酯可用作通常易受氧化和/或热变质影响的有机材料的稳定剂。共酯的制备方法主要是将此类酯与
季戊四醇进行酯交换反应。优选的共
酯类有:(I)
季戊四醇三[
3-(3,5-二叔丁基-4-羟基苯基)丙酸酯]-单[3-正
十二烷基
硫代
丙酸酯]和 (II)
季戊四醇双[
3-(3,5-二叔丁基-4-羟基苯基)丙酸酯]-双[3-正
十二烷基
硫代
丙酸酯]。这些共酯在稳定应用方面特别有用,此前已经提出了 (i) (3- 烷基-
4-羟基苯基)烷酸多元醇酯与 (ii) 烷
硫基烷酸多元醇酯的物理混合物。