| abstract |
1411656 Stabilizing polymers CIBA-GEIGY AG 23 March 1973 [24 March 1972] 14109/73 Headings C3P and C3R [Also in Division C2] Synthetic organic polymers normally subject to U.V. deterioration are stabilized by the novel piperazine diones of Formula I wherein R<SP>1</SP> and R<SP>2</SP> are the same or different C 1-12 alkyl group or R<SP>1</SP> and R<SP>2</SP>, together with the common carbon atom, form a monocyclic carbocyclic ring having 5-12 ring carbon atoms; n is 1,2 or 3; when n is 1, R<SP>3</SP> is C 1-20 alkyl or benzyl; when n is 2, R<SP>3</SP> is C 1-20 alkylene or a group of formula wherein R<SP>4</SP> to R<SP>7</SP> are either each hydrogen or the same or different C 1-5 alkyl group; and when n is 3, R<SP>3</SP> is a group of formula wherein either each of R<SP>8</SP> to R<SP>10</SP> is hydrogen or the same or different C 1-5 alkyl group. Examples stabilize polyethylene, polypropylene, polystyrene, acrylonitrile-butadiene-styrene terpolymer, polyurethane (from toluene diisocyanate and alkylene polyols), polycarbonate (from bisphenol A and phosgene), polyethyleneterephthalate, polymethylmethacrylate, nylon 6,6 and polyphenyleneoxide with compounds of Formula I and/or with specific hindered phenol antioxidants. |