Yabashi Industries, Co., Ltd.

Tetsushi Iwashita

Yoshio Ota

Kunio Nomura

Iwao Motoyama

Norifumi Goto

Toshihiro Kasuga

Yoshihiro Abe

A process for producing hydroxyapatite fibers is disclosed. The process comprises the steps of preparing a mixture of (1) calcium metaphosphate fibers and (2) calcium oxide, calcium hydroxide and/or calcium carbonate powder; heating the mixture to convert the calcium metaphosphate to hydroxyapatite; and removing calcium oxide in the heat-treated mixture by dissolving off from the resulting mixture.

Process for producing hydroxyapatite fibers

Disclosed is a novel process of producing plate-shaped calcium carbonate particles. The process comprises the steps of adding aqueous calcium hydrogen carbonate solution with a temperature of less than 50.degree. C. into an aqueous medium bath held at a temperature of not less than 50.degree. C. to generate plate-shaped calcium carbonate particles in the bath, the temperature of the bath being kept not less than 50.degree. C. during the addition of the aqueous calcium hydrogen carbonate solution; and recovering the generated plate-shape calcium carbonate particles.

Process of producing plate-shaped calcium carbonate particles

Disclosed is a novel process of producing needle-shaped calcium carbonate particles. In the process of the present invention, aqueous calcium hydroxide solution is added to an aqueous medium bath with a temperature of not less than 60.degree. C. into which carbon dioxide gas or a carbon dioxide-containing gas is being blown to generate needle-shaped calcium carbonate particles. The temperature of the aqueous medium bath is kept not less than 60.degree. C. during the addition of the aqueous calcium hydroxide solution. Then the generated needle-shaped calcium carbonate particles are recovered.

Growing community of inventors

Ogaki, Japan

Tetsushi Iwashita