1-(sterically hindered hydroxyphenyl)-1-hydroxymethane - phosphonic acids - useful as stabilisers against degradation by light

摘要

Cpds. of formula (I): (where R1 is =12C tert. alkyl ortho to the OH gp.; R2 is H, =20C alkyl or cycloalkyl, or phenyl opt. mono- or di-substd. by lower alkyl; R3 is H, =20C alkyl, or phenyl opt. mono- or di-substd. by lower alkyl; R4 is OH or phenyl opt. substd. by =12C alkyl or phenyl), and their salts with inorganic cations, are prepd. by reacting 1 mole of a cpd. (II): with 0.33-1 mole of XP(Hal)2 (where Hal is halogen; and X is halogen or R4), and hydrolysing the resulting halide to the phosphonic acid, which is opt. converted into a salt. Cpds. (I) are stabilisers for materials sensitive to light; O2 and heat, e.g. plastics, rubber, textiles, etc.