Piperidine phosphite stabilizers for polymers and polymers stabilized thereby

Claim 1

Compositions comprising synthetic thermoplastic polymers stabilized to sunlight, to heat and to ageing, and having incorporated therein, in an amount sufficient to prevent degradation of the polymer, a compound having general formula: ##STR6## wherein: each of R 1 , R 2 , R 3 and R 4 , which may be the same or different, may be an alkyl having 1 to 4 carbon atoms; R 5 may be a hydrogen atom or an alkyl having 1 to 4 carbon atoms; A is an alkylene group having 2 to 12 carbon atoms or a cycloalkylene group containing 3 to 12 carbon atoms; x is an integer from 1 to 10, and R 6 , R 7 , R 8 and R 9 , which may be the same or different, are each a linear or branched alkyl group having 1 to 20 carbon atoms or a simple or substituted aryl group having 6 to 20 carbon atoms or R 6 and R 7 together and R 8 and R 9 together may form a linear or branched alkylene group having 2 to 20 carbon atoms, or a simple or substituted arylene group having 6 to 20 carbon atoms or a simple or substituted cycloalkylene group having 3 to 20 carbon atoms.