2-[2-Hydroxy-3,5-di-(.alpha.,.alpha.-dimethylbenzyl)phenyl]-2H-benzotriazol e exhibits outstanding efficacy in protecting organic substrates from light-induced deterioration as well as good resistance to loss by volatilization or exudation during the high temperature processing of stabilized compositions.
2-[2-Hydroxy-3,5-di-(.alpha.,.alpha.-dimethylbenzyl)phenyl]-2H-benzotriazol e exhibits outstanding efficacy in protecting organic substrates from light induced deterioration as well as good resistance to loss by volatilization or exudation during the high temperature processing of stabilized compositions. The combination of the benzotriazole UV absorber with a hindered amine light stabilizer is particularly efficacious in protecting thermoset and thermoplastic acrylic resin automotive finishes and enamels.
High caustic coupling process for preparing substituted
申请人:Ciba-Geigy Corporation
公开号:US04275004A1
公开(公告)日:1981-06-23
Substituted 2-nitro-2'hydroxyazobenzenes are prepared by adding an aqueous mineral acid solution of a diazotized o-nitroaniline to a strongly alkaline lower alkanol or aqueous lower alkanol solution of a substituted phenol, containing sufficient alkali metal hydroxide to assure a pH value substantially over 11 and an excess of hydroxyl ion in the reaction mixture even after all the acidic diazonium salt solution is added, wherein the reaction solvent mixture is at least 50% by weight of lower alkanol, at a reaction temperature between -15.degree. C. and +30.degree. C. The o-nitroazobenzenes obtained are intermediate products useful in the manufacture of benzotriazole UV absorbers.
2-[2-Hydroxy-3,5-di-(.alpha.,.alpha.-dimethylbenzyl)phenyl]-2H-benzotriazol e exhibits outstanding efficacy in protecting organic substrates from light induced deterioration as well as good resistance to loss by volatilization or exudation during the high temperature processing of stabilized compositions. The combination of the benzotriazole UV absorber with a hindered amine light stabilizer is particularly efficacious in protecting thermoset and thermoplastic acrylic resin automotive finishes and enamels.