Particularly useful hindered phenols are of the formula ##STR8## wherein R1 and R3 are hydrocarbon groups having from one to about 20 carbon atoms, and R2 is a hydrogen atom or a hydrocarbon group having from one to about 20 carbon atoms; and bisphenols of the formula ##STR9## wherein R4, R5 and R6 are each a hydrogen atom or a hydrocarbon group having from one to about 20 carbon atoms, one of the