Abstract: A process for producing a cationic polymer, which comprises polymerizing a vinyl monomer represented by the general formula, ##STR1## wherein R.sub.1 represents --H or --CH.sub.3, R.sub.2 represents --CH.sub.2 CH.sub.2 -- or ##STR2## R.sub.3 and R.sub.4 represent --CH.sub.3 or --CH.sub.2 CH.sub.3, R.sub.5 represents --C.sub.n H.sub.2n+1, in which n is an integer of 0 to 4, ##STR3## or --CH.sub.2 COOH, and X.sup.- represents Cl.sup.-, CH.sub.3 SO.sub.4.sup.-, CH.sub.3 SO.sub.3.sup.-, or 1/2 SO.sub.4.sup.--, either alone or in admixture with up to 25% by weight, based on the total weight of the monomers, of other copolymerizable vinyl monomers in the presence of 7 to 18% by weight, based on the weight of the polymerization system, of water and, if necessary, choline chloride by use of a polymerization initiator and elevating the temperature, in the final polymerization stage, to 110.degree. to 150.degree. C.

Abstract: A method for producing a water-soluble cationic polymer by polymerizing, in the presence of water, a high concentration of (a) at least one vinyl monomer represented by the following general formula (I)ch.sub.2 .dbd.cr.sub.1 coor.sub.2 n.sup..sym. r.sub.3 r.sub.4 r.sub.5 x.sup..crclbar. (i)wherein R.sub.1 is --H or --CH.sub.3 ; R.sub.2 is --CH.sub.2 CH.sub.2 -- or --CH.sub.2 CH(OH)CH.sub.2 --; R.sub.3 and R.sub.4, which may be the same or different, each is --CH.sub.3 or --CH.sub.2 CH.sub.3 ; R.sub.5 is --C.sub.n H.sub.2n+1 where n is 0 or an integer of 1 to 4, --CH.sub.2 C.sub.6 H.sub.5, or --CH.sub.2 COOH; and X is Cl.sup.-, Br.sup.-, 1/2SO.sub.4.sup.-- or CH.sub.3 SO.sub.4.sup.

Abstract: In a process for producing a water-soluble polymer in an easily grindable glassy state by subjecting to aqueous solution polymerization a mixture comprising a monomer composed mainly of a vinyl monomer represented by the general formula (I): ##STR1## and water in an amount of 7 to 18% by weight based on the total weight of the monomer and water, a water-soluble salt in a powdery form is added to and dispersed in the polymerization system and the polymerization is carried out in the state that the powdery salt is dispersed, whereby a water-soluble polymer excellent in flocculating action and dissolving workability is obtained.