Daiichi Kigenso Kagaku Kogyo Co., Ltd.

Taichi Kunisada

Sadahiro Yagishita

Taku Nishikawa

Takuji Nabeta

Keita Kanenishi

Nobutaka Nochioka

This zirconia powder contains 2.5 to 3.5 mol % of yttria; has a specific surface area of 5 to 20 m/g; and has crystal phases that include a monoclinic crystal phase percentage of 20 to 40% and a tetragonal crystal phase percentage of 60 to 80%. When the zirconia powder is molded under a mold pressure of 0.8 t/cmand then sintered under a condition of 2 hours at 1450° C. to obtain a sintered body, the sintered body has crystal phases that include a monoclinic crystal phase percentage of 1 to 3%, a tetragonal crystal phase percentage of 77 to 94%, and a cubic crystal phase percentage of 5 to 20%.

Zirconia powder, method for producing zirconia powder, method for producing zirconia sintered body, and zirconia sintered body

Provided are a zirconia sol having a transmittance of 45% or more at a wavelength of 400 nm, having a transmittance of 75% or more at a wavelength of 550 nm, and containing zirconia particles in an amount of 20 wt % or more, and a method for manufacturing the zirconia sol.

Zirconia sol and method for manufacturing same

In order to provide a zirconium boride that provides high caloric value at the time of its combustion with a compound having radicals such as perchlorate and can combust in a short period of time, while providing high physical stability, an amount of radical derived from lattice defect detected by ESR spectroscopy, is set to 0.1&#xd7;10spin/mg or more.

Zirconium boride and method of its manufacture

A method for producing an aqueous zirconium chloride solution includes: grinding zircon sand to an average particle diameter of 10 &#x3bc;m or less; adding a sodium compound to the ground zircon sand to thereby obtain a mixture; firing the mixture in an iron container at 400&#xb0; C. or less to thereby obtain a decomposed product; firing the decomposed product in a stainless-steel container at 400 to 1,100&#xb0; C. to thereby obtain a fired product; dispersing the fired product in water to prepare a dispersion, and washing the fired product with water while adjusting the temperature of the dispersion to 70&#xb0; C. or less, thereby obtaining a water-washed cake; washing the water-washed cake with hydrochloric acid with a pH of 1 to 6 to thereby obtain zirconium hydrate; and dissolving the zirconium hydrate in hydrochloric acid, and then removing insoluble components to thereby obtain a salt solution.

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Osaka, Japan

Taichi Kunisada