| 摘要 |
<p>Prepn. is claimed of aq. of polyacrylic acids, copolymers of these substances or their corresp. salts using polymerisation catalysts formed by NH4, Na or K salts of persulphuric acid, H2O2 and organic peroxides or by oxidn.-redn. pairs of the preceding substances with Na metalisulphite, Na bisulphite and ascorbic acid, in an aq. medium and open atmos. - The improvement is the gradual and programme addition of the monomers and catalysts to a certain initial amt. of water kept at 5-15 deg.C, the reaction medium being heated for 4-5 hrs., to temps. not lower than 70 deg.C and, after cooling, neutralising the reaction prod. with an alkali hydroxide.</p> |
