| 摘要 |
1433400 Inhibition of acrylic acid or acrylic acid ester polymerization NIPPON SHOKUBAI KAGAKU KOGYO CO Ltd 12 Dec 1973 [22 Dec 1972] 57624/73 Heading C2C A method for inhibiting the polymerization during distillation of acrylic acid obtained by the vapor phase catalytic oxidation of propylene or acrolein, or of acrylic acid esters derived from said acrylic acid, comprises carrying out the distillation in the presence of (A) at least one compound selected from hydroquinone, hydroquinonemonomethyl ether, cresols, phenols, t.butyl catechol, diphenylamine, a phenothiazine of the formula wherein R 1 and R 2 each separately represents a hydrogen atom or an alkyl group of 1 to 10 carbon atoms and methylene blue, (B) at least one compound selected from copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper dibutyldithiocarbamate and copper salicylate; and (C) molecular oxygen. |
