1,3,8-Triazaspiro 4.5!decane-2,4-dione polymer stabilizers

Claim 1

A piperidine compound having the formula (I): ##STR25## wherein R a represents methyl group; R b represents ethyl group; R c represents an alkyl group of 1 to 5 carbons; R d represents ethyl group; or R c and R d , together with the carbon atom to which they are attached, represent a cycloalkyl group of 5 to 7 carbons; one of R e and R e' represents hydrogen atom and the other of R e and R e' represents a lower alkyl group of 1 to 4 carbons or an allyl group; n is 1 or 2; Y represents hydrogen atom or, when neither X nor Z represents hydrogen atom, Y represents hydrogen methyl group, ethyl group, allyl group or benzyl group; X represents hydrogen atom, or an alkyl group of 1 to 4 carbons; when n = 1: Z represents hydrogen atom, an alkyl group of 1 to 18 carbons 2,3-epoxypropyl group, or phenyl group when n = 2: X represents an alkylene group of 1 to 10 carbons and acid addition salts thereof wherein the acids are selected from the group consisting of sulphuric acid, hydrochloric acid or phosphoric acid; formic acid, acetic acid, valeric acid, stearic acid, oxalic acid, adipic acid, sebacic acid, maleic acid, benzoic acid, p-t-butylbenzoic acid, 4-hydroxy-3,5-di-t-butylbenzoic acid, salicylic acid or terephthalic acid; methanesulphonic acid or p-toluene-sulphonic acid; or phenylphosphonic acid.