The compounds are hindered phenolic mono- and bicyclic phosphonate compounds having the formula ##STR1## wherein R.sup.1 is alkyl, R.sup.2 is tert-alkyl, R.sup.3 and R.sup.4 are independently hydrogen or alkyl, R.sup.5 is hydrogen, alkyl or phenyl, R.sup.6 is alkyl or phenyl, R.sup.7 is lower alkyl and R.sup.8 is alkyl, phenyl or phenyl substituted with a lower alkyl group. These compounds are usually prepared by reaction of a tert-alkylsubstituted hydroxybenzylphosphonate ester with a suitable 1,2 or 1,3 polyol. Alternatively the compounds can be made by reaction of an alkali metal salt of the substituted benzylphosphonic acid with an appropriate alkylene dihalide. The compounds are useful as stabilizers for organic materials subject to oxidative, thermal or photochemical degradation.
这些化合物是具有以下式子的受阻
酚单环和双环
膦酸酯化合物:##STR1## 其中R.sup.1是烷基,R.sup.2是三联烷基,R.sup.3和R.sup.4分别是氢或烷基,R.sup.5是氢,烷基或苯基,R.sup.6是烷基或苯基,R.sup.7是低级烷基,R.sup.8是烷基,苯基或苯基取代低级烷基。这些化合物通常是通过一个受阻三联烷基取代的羟基
苯基膦酸酯与适当的1,2或1,3多元醇反应制备而成。或者这些化合物也可以通过受阻
苯基膦酸的碱
金属盐与适当的烷基二卤代烷反应制备而成。这些化合物可用作有机材料稳定剂,以防止氧化、热降解或光
化学降解。