Mitsui-cyanamid, Ltd.

Hiroshi Itoda

Naotaka Watanabe

Reiko Funato

Akio Kitamura

Takeo Arai

Yoshio Hosoya

Kenichi Akune

Yukihiro Inomiya

Disclosed are a polymer emulsion prepared by neutralizing a seed polymer with an acid or a salt or by quaternizing it with a quaternizing agent and a method of preparing the polymer emulsion. The surfaces of the emulsion grains are very densely cationated. The seed polymer is formed by polymerizing a monomer of formula (I) or a mixture of the monomer (I) and copolymerizable ethylenic unsaturated monomer(s) (II) and a seed latex of a carboxyl-modified synthetic rubber latex or synthetic resin emulsion. ##STR1## R.sub.1 is H or CH.sub.3 ; R.sub.2 is a 2-5C alkylene; R.sub.3 and R.sub.4 each are H or a 1-5C alkyl; A is--COO--or--CONH--; and R.sub.1, R.sub.3 and R.sub.4 are so selected that the monomer is hardly soluble or insoluble in water. As a consequence of being very densely cationated by post-modification, the cationic polymer emulsion is useful in various fields as binders, fixers or other additives.

Polymer emulsion and method for preparing the same

A pile driving and pile removing method comprises the step of causing a water-in-oil type water swellable polymer particle emulsion to be present on the pile surface or in the vicinity thereof during driving or extraction. The presence of the emulsion reduces the frictional resistance between the pile and the ground, enabling smooth and easy driving and removing of the pile.

Pile driving and pile removing method

Disclosed is a paper-making process for preparing a paper from a paper stock suspension, which is characterized by adding water-swellable cationic polymer particles optionally together with an acrylamide polymer to the suspension as a retention-improving agent. In the process, the stability of the retention even under high shearing force in the paper-making step is improved, the load for recovery of white water and treatment of waste water drained is reduced and the abrasion of paper-making wires is reduced.

Paper-making process

A method of treating starch-containing water comprises the step of adding water swellable, cationic polymerizate particles to the starch-containing water. The starch is soluble starch. The water-swellable cationic polymer particles are polymer particles of a crosslinking monomer and either a cationic vinyl monomer or a cationic vinyl monomer and a nonionic vinyl monomer.

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Kanagawa, Japan

Hiroshi Itoda