Hydroquinones

A hydroquinone compound of the formula:

• ##STR14## wherein p is 1 or 2 and q is 0 or 1, provided that p+q is 1 or 2;
• R is a group of the formula ##STR15## wherein Q is a number selected from the groups:
• (i) --OX wherein X is R.sub.5 or COR.sub.7 wherein R.sub.5 is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms,
• R.sub.7 is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms, a straight or branched chain alkenyl group having from 3 to 20 carbon atoms, a cycloalkyl group having from 3 to 12 carbon atoms, an aralkyl group having from 7 to 13 carbon atoms or an unsubstituted or mono- or di-C.sub.1 -C.sub.4 -alkyl substituted aryl group having from 6 to 10 carbon atoms, and
• (ii) --PO(OR.sub.10)((O).sub.x R.sub.11) wherein X is 1, R.sub.10 and R.sub.11 are the same or different and each is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms,
• n is an integer from 2 to 20:
• k is 1 or 2;
• R.sub.2 and R.sub.3 are the same or different and each is a straight or branched chain alkyl group having from 1 to 5 carbon atoms;
• and
• R.sub.1 is a straight or branched chain alkyl group having from 1 to 8 carbon atoms, or a group of formula II as hereinbefore defined and, when R.sub.1 is a group of formula II, then R.sub.1 and R may be the same or different;
• or a salt thereof with an organic or inorganic acid or base.