DISPERSANT

PROBLEM TO BE SOLVED: To improve the stability of the latex emulsion to be formed by using two kinds of the repeating units expressed by respectively specific formulas as essential constituting elements and setting the molar rats and weight average mol.wts. of both repeating units at specific ranges. SOLUTION: The repeating units expressed by the formulas I, II are used as the essential constituting elements of the dispersant used for stabilizing the dispersion of a formed polymer. The polymer having the molar ratios of the repeating units 1, 2 within the range of the repeating unit 1/the repeating unit 2=98/2 to 80/20 and the weight average mol.wts. in the range of 2000 to 1000000 range is used. In the formula I, X is a hydrogen atom or methyl group; M is a hydrogen atom, alkaline metal, alkaline earth metal, etc.; SO3 M group exists at the third to fifth positions of a benzene ring. In the formula II, X is a hydrogen atom or methyl group; M is a hydrogen atom, alkaline metal, etc.; n is 0 or 1; one SO3 M group exists at the orhto position of a benzene ring. Such dispersant includes an arom. polymer contg. a sulfonic acid group.