Mitsui-Cyanamid, Ltd.

Hitoshi Fujiyoshi

Masako Shirota

Naotaka Watanabe

Takao Arai

Akira Tamura

Takeo Arai

Naotaka Watababe

A polymer emulsion capable of becoming water swellable is provided by mixing a monomer represented by the general formula ##STR1## (wherein R.sub.1 indicates H or CH.sub.3, R.sub.2 and R.sub.3 indicate an alkyl radical represented by CnH.sub.2N+1 in which n is a positive integer, A indicates --O--CH.sub.2 -- or --NH--CH.sub.2 --CH.sub.2 --, and R.sub.1, R.sub.2 and R.sub.3 are selected within the range wherein the monomer exhibits sparing solubility or insolubility in water) with a crosslinking agent and optionally with another vinyl monomer capable of copolymerization therewith, and emulsion polymerizing the so-obtained mixture in water. The so obtained a polymer can be made water swellable by reaction with an acid, a salt or a quaternizing agent.

Polymer emulsion

Disclosed is a mortar.concrete composition comprising a polymer emulsion, a portland cement material and an aggregate, which is characterized in that the polymer emulsion is one prepared by neutralizing a seed polymer with an acid or a salt or by quaternizing it with a quaternizing agent, the surfaces of the emulsion grains being thereby highly densely cationated, where the seed polymer is formed by adding a monomer as represented by the following formula (I) or a mixture of the monomer (I) and copolymerizable ethylenic unsaturated monomer(s) to a seed latex of a carboxyl-modified synthetic rubber latex or synthetic resin emulsion and polymerizing them: ##STR1## The polymer of the invention may noticeably reinforce the strength of the shaped product even when the amount of the polymer added is small. The polymer dispersion of the invention can be applied to not only the conventional ordinary materials but also concrete construction materials, although the application to the latter has heretofore been considered economically impossible.

Mortar concrete composition

A method of preparing a paper having a reinforced strength wherein a polymer latex is added to a paper stock in an amount of from 2.5 to 30% by weight. The polymer latex is prepared by neutralizing a seed polymer with an acid or a salt or by quaternizing it with a quaternizing agent. The surfaces of the emulsion grains are provided with a large number of cationic groups. The seed polymer is formed by adding a monomer represented by the following formula (I) or a mixture of the monomer (I) and copolymerizable ethylenic unsaturated monomer(s) (II) to a seed latex of a carboxyl-modified synthetic rubber latex or synthetic resin emulsion and polymerizing them: ##STR1## R.sub.1 represents H or CH.sub.3 ; R.sub.2 represents an alkylene group having from 2 to 5 carbon atoms;

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Yokohama, Japan

Hitoshi Fujiyoshi