Benzotriazole ortho-ester ultraviolet stabilizers

Claim 1

An organic composition susceptible to ultraviolet degradation stabilized against such degradation with a stabilizing amount of a composition of matter having the following formula: ##STR18## wherein Z is an integer 1, 2 or 3; R 1 , R 2 , R 3 and R 4 are hydrogen, chloro, bromo lower alkyl, substituted lower alkyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, lower alkylaryl, alkoxy, amino, substituted amino, cyano, carboxy and the substituents R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , combined with the carbon atoms to which they are attached, are joined alkylene groups completing a carbocyclic ring, which ring can also be substituted with one or more of the substituents listed above for R 1 , R 2 , R 3 and R 4 ; R 8 may be halogen, hydroxy, halogen, C 1 -C 12 substituted or unsubstituted alkyl, amino, alkylamino, dialkylamino, arylamino, dirarylamino, alkoxy, aryl, or aryloxy; and I is the same as R 1 , R 2 , R 3 and R 4 and is present on all positions of the benzenoid ring, except the carbon atom attached to the carbonyl linking substituent, said I substituents can all be one of the substituents listed above or different listed substituents.