Dispersant for suspension polymerization and method for producing vinyl polymer

Abstract

A dispersant for suspension polymerization may, even when a usage amount thereof is low, enable obtaining polymer particles having a small average particle diameter with few coarse particles, and having favorable plasticizer absorptivity. Such a dispersant may include a vinyl alcohol polymer having a structure of following formula (1) and satisfy inequality (2) 0.4≤[X]×102/[Ra,1]2≤3.0  (2). In formula (1), R is a hydrocarbon group having 4 or more carbon atoms. In inequality (2), [X] is a mole percentage content of the structure of formula (1) with respect to total structural units of the vinyl alcohol polymer; and [Ra,1] is an HSP distance ((J/cm3)1/2) between the structure of formula (1) and vinyl chloride.

Dependencies are inferred from the claim text.