| 摘要 |
The method of inhibiting the polymerization of a mono-ethylenically unsaturated carboxylic acid, anhydride, ester or neutralized or partially neutralized salt, e.g., an acrylic acid or ester, in an aqueous solution and in the presence of oxygen, the method comprising the step of mixing with the aqueous solution an inhibitor comprising (i) at least 50 ppm of an N-oxyl compound, e.g., 4-hydroxy-TEMPO, and (ii) a manganese ion, the N-oxyl compound and manganese ion present in a N-oxyl compound to manganese ion weight ratio of 50:1 to less than 100:1 based on the mono-ethylenically unsaturated carboxylic acid, anhydride, ester or salt. |
