Kao Corporation

Yoshihito Naka

Toshimasa Hamai

Daisuke Hamada

Masaaki Shimoda

Yoshinao Kono

Yoshiaki Tanisho

Keiichiro Sagawa

Shuichi Fujita

Yoshikazu Morii

The present invention provides a dispersant for a hydraulic composition, containing (A) a polymer composed of structural units, not less than 70% by weight of which are derived from a monomer represented by the following formula (1) and (B) a naphthalenesulfonic acid-formaldehyde condensate at a weight ratio of components (A) to (B), (A)/(B), of 1/99 to 75/25:HC&#x2550;CHCOOCHCHOH &#x2003;&#x2003;(1).

Dispersant for hydraulic composition

Method for producing phosphoric acid ester-based polymer by copolymerizing monomer 1 of formula (1), monomer 2 of formula (2), and monomer 3 of formula (3): wherein the variables are as defined in the specification; wherein the variables are as defined in the specification; and wherein the variables are as defined in the specification, at pH &#x2266;7 in solvent having dissolved oxygen concentration of 0.01-4.0 mg/kg, or in presence of phosphonic acid-based chelating agent, or by mixing monomers 1 to 3 at 10-50 &#xb0; C., initiating polymerization within 72 hours, and maintaining the temperature at 10-50 &#xb0; C. until polymerization is initiated. The phosphoric acid ester-based polymer may be used as a dispersant in a hydraulic composition.

Method for producing phosphoric acid ester-based polymer

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Wakayama, Japan

Yoshihito Naka