| 摘要 |
Process for the preparation of liquid mixtures of alkylated 2-(2-hydroxy-phenyl)benzotriazoles A process for the preparation of a mixture of 2-(2-hydroxyphenyl)benzo-triazole which is liquid at room temperature by alkylating 2-(2-hydroxy-5-methylphenyl)benzotriazole with a C8-C14.alpha.-olefin in the melt at elevated temperature, in the presence of sulfonic acid as catalyst, comprising using not less than 0.5 mol of the acid catalyst and 1.5 - 3 mol of .alpha.-olefin per mol of 2-(2-hydroxy-5-methylphenyl)benzo-triazole, carrying out the alkylation in the temperature range from 165 to 190.degree.C, separating the crude product phase (upper phase) from the sulfonic acid phase, and working up said crude product phase by distillation by means of a thin-film evaporator, a thin-film evaporator fitted with a distillation column, or a short path distillation apparatus. |
