| abstract |
Stabilizer compositions comprising a polymer stabilizer and a carbonate ester of cyclic dihydroxy compounds protect synthetic resins against the harmful effects of light having a wavelength less than 400 nanometers. The carbonate ester can be represented by the formula <IMAGE> in which a is a number from 1 to 50, A is hydrogen or <IMAGE> B is R' or -G-OH, R and R' are independently alkyl, alkoxyalkyl, cycloalkyl, aryl, aryloxyalkyl, aralkyl, or alkaryl groups, and G in at least one occurrence is a residue of a cycloaliphatic or non-aromatic oxygen heterocyclic dihydroxy compound having 3 to 20 carbon atoms and 1 or 2 rings of 3 to 12 members, of which up to 4 can be oxygen. Additional occurrences of G can be aliphatic glycol or bisphenol residues if desired. The polymer stabilizer included in the stabilizer compositions with carbonate esters of cyclic dihydroxy compounds can include metal carboxylate salts 1,2-epoxides, phenols, organic phosphites, esters of thiodipropionic acid, 2-hydroxybenzophenones, 2(2'-hydroxyaryl)benzotriazoles, nickel phenolates, and carboxylic acids of 2,2,6,6-tetraalkylpiperidine-4-alcohols. There are also provided stabilized synthetic resin compositions comprising a stabilizer composition including a carbonate ester of a cyclic dihydroxy compound as defined. |