PURPOSE: A dispersant capable of improving extremely productivity of a polymer when it is used for reversed phase suspension polymerization of a water-soluble ethylenic unsaturated monomer, comprising a specific phosphoric monoester compound containing an ethylenic unsaturated bond in the molecule.
CONSTITUTION: A compounding having a structure shown by the formula I (R1 is H or CH3; R2 is 4W12C alkyl; M is H, alkali metal or ammonium) is used as the aimed dispersant. The compound shown by the formula I, for example, is preferably obtained by reacting a monoalkali metallic salt of a monoalkyl phosphate shown by the formula II (M' is alkali metal) with a glycidyl (meth) acrylate shown by the formula III (M' is alkali metal) to give a phosphoric ester, acidifying optionally the ester and neutralizing it with a base and a compound shown by the formula IV, formula V, etc., may be used.
WAKATSUKI JUNYA
KATO TORU
KONDO AKIHIRO
