Esters of 3-tert-butyl- and 3-tert-butyl-5-alkyl-4-hydroxyphenyl (alkane) carboxylic acids with oxyethylates of polythiols

An ester of a 3-tert-butyl or 3-tert-butyl-5-alkyl-4-hydroxyphenyl-(alkane) carboxylic acid of formula I ##STR25## with an oxethylate of a polythiol aromatic of formulae II or III having 2 to 6 thiol groups ##STR26## or with an oxethylate of a dithiolcycloalkane of formula IV, which contains a maximum of 6 alkylene oxide units, ##STR27## wherein X is (CH.sub.2).sub.m SH

• X' is (CH.sub.2).sub.r SH
• X" is (CH.sub.2).sub.s SH, wherein m, r and s represents 0 or 1,
• R, R', R" being identical or different are each H, alkyl, halogen or hydroxyl,
• R.sub.3 is H, C.sub.1 to C.sub.4 alkyl,
• R.sub.4, R.sub.5 being identical or different are each C.sub.2 to C.sub.4 alkylene,
• q=0 to 7, ##STR28## n=2 to 6, inclusive, for z or z'=0, n=1 to 5, inclusive, for z or z'.noteq.0,
• o+p=n
• O.ltoreq.a, z.ltoreq.a+z.ltoreq.6-n (in formula II)
• O.ltoreq.b, c, z'.ltoreq.4.ltoreq.8-n (in formula III).