| abstract |
Piperidine derivatives having the formula <IMAGE> (I) wherein R' represents an alkyl, an acyl, an alkoxycarbonyl, an amino or nitroso group; X represents oxygen or sulfur; Y represents oxygen, sulfur or a group of the formula =N-R'' in which R'' is hydrogen or alkyl; Z represents oxygen or a group of the formula >N-R''' in which R''' is hydrogen or alkyl; n is an integer of 1 to 4; and R represents, when n is 1, alkyl, aryl, cycloalkyl, alkoxycarbonyl, substituted phosphino or substituted phosphinyl, when n is 2, alkylene, alkenylene, arylene, aralkylene; alkylenediphenylene, bis-(alkoxycarbonyl) alkylene, alkylene-bis-(oxycarbonylalkyl), dialkylene ether or diphenylene ether, when n is 3, alkanetriyl,tris-(alkoxycarbonyl)alkanetriyl, alkanetriyl-tris-(oxycarbonylalkyl) or a group of the formula <IMAGE> in which p is an integer of 1 through 8 inclusive, and, when n is 4, alkanetetrayl,tetrakis-(alkoxycarbonyl) alkanetetrayl or alkanetetrayl-tetrakis-(oxycarbonylalkyl). The piperidine derivatives (I) of this invention are prepared in various manners and useful as stabilizers for synthetic polymers against thermal- and photo-deterioration thereof. A typical example of such a stabilizer is 1,3,8-triaza-3,8-dibenzyl-1,7,7,9,9-pentamethyl-spiro[4.5]decane-2,4-d ione. |