Chemistry of inorganic compounds – Carbon or compound thereof – Oxygen containing
Reexamination Certificate
2000-03-22
2001-03-06
Bos, Steven (Department: 1754)
Chemistry of inorganic compounds
Carbon or compound thereof
Oxygen containing
C423S592100, C423S604000
Reexamination Certificate
active
06197273
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a process for production of fine spherical particles of a carbonate or a hydroxide of an element selected from nickel, cobalt and copper. More particularly, the invention relates to a process for production of fine spherical particles of a carbonate or a hydroxide of an element selected from nickel, cobalt and copper which are especially useful as a precursor for the manufacture of uniform and fine spherical particles of a metal selected from nickel, copper and cobalt, as well as useful as themselves as a catalyst for use in organic synthesis, a carrier, a pigment, a filler or a glaze.
DESCRIPTION OF PRIOR ART
By way of an example, particles of nickel carbonate are generally known as a fine amorphous or non-spherical powder although it is also known that fine spherical particles of nickel carbonate can be produced by a method in which a W/O emulsion is used as a reaction field, as described in Japanese Patent Application Laid-open No. 2-59432.
Accordingto this method, an aqueous solution of water-soluble nickel salt such as nickel chloride is added to a non-aqueous medium together with a surfactant, and the resulting mixture is stirred, thereby to prepare a W/O emulsion. Then, an aqueous solution of a carbonate or a hydrogencarbonate of an alkali metal is added as a Attachment A neutralizer to the emulsion so that the nickel salt in the solution in the form of droplets is reacted with the neutralizer, thereby to form fine spherical particles of nickel carbonate.
However, according to the method as mentioned above in which an emulsion is used as a reaction field, the emulsion is easily broken not only on account of the neutralizer used but also on account of the salts by-produced when the water-insoluble nickel salt is formed. Therefore, it is difficult to maintain the reaction field stable throughout the reaction and hence it is difficult to obtain fine spherical particles of nickel carbonate in a stable manner.
Even if the method provides fine spherical particles of nickel salt, it is not possible to obtain fine spherical particles of nickel metal since it is difficult to maintain the spherical form of the particles during the process for oxidizing and reducing the nickel salt thus obtained.
The invention has been completed to solve the foregoing problems involved in the production of fine spherical particles of a carbonate or a hydroxide of nickel, cobalt or copper. Therefore, it is an object of the invention to provide a process for production of fine spherical particles of a carbonate or a hydroxide of nickel, cobalt or copper.
SUMMARY OF THE INVENTION
The invention provides a process for production of fine spherical particles of a carbonate or a hydroxide of nickel, cobalt or copper which comprises: dissolving a carbonate or a hydroxide of nickel, cobalt or copper having the general formula (I)
M(CO
3
)
x/2
.(OH)
y
wherein M represents Ni, Co or Cu, and x and y are numerals satisfying the followings: 0≦x≦2, 0≦y≦2 and x+y=2, in aqueous ammonia, converting the resulting solution to a W/O emulsion containing droplets of the solution in a non-aqueous medium, and then removing volatile components including ammonia from within the droplets, thereby precipitating a basic carbonate or a hydroxide of nickel, cobalt or copper in the droplets.
REFERENCES:
patent: 4105743 (1978-08-01), Reinhardt et al.
patent: 4999323 (1991-03-01), Sang et al.
patent: 5278106 (1994-01-01), Nakashima et al.
patent: 53-021099 (1978-02-01), None
patent: 53-017787 (1978-02-01), None
patent: 1-301502 (1989-12-01), None
patent: 2-059432 (1990-02-01), None
Abe Kazunobu
Fukai Kiyoshi
Hatanaka Tsutomu
Kamisaka Shigefumi
Mizutani Hideto
Bos Steven
Sakai Chemical Industry Co. Ltd.
Wenderoth , Lind & Ponack, L.L.P.
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