Granular calcuim hypochlorite composition and process for preparation thereof
AssigneeTosoh Corporation
InventorsHiroyuki Saitoh, Tsugio Murakami
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Abstract
A granular calcium hypochlorite composition comprising a particle of calcium hypochlorite dihydrate and/or calcium hypochlorite anhydride, the surface of which has been covered with a double decomposition product of calcium hypochlorite and an alkali metal hydroxide. This composition is prepared by adhering an aqueous alkali metal hydroxide solution to the particle of calcium hypochlorite dihydride or calcium hypochlorite anhydride, and the drying the particle.
Claims9
A granular calcium hypochlorite composition comprising a particle of at least one calcium hypochlorite compound selected from the group consisting of calcium hypochlorite dihydrate and calcium hypochlorite anhydride, said particle having a structure in which the surface portion is substituted with a double decomposition product of calcium hypochlorite with an alkali metal hydroxide, said calcium hypochlorite dihydrate grown from seed crystals using, as the seed crystal, prismatic calcium hypochlorite dihydrate in which the lengths of axes a, b and c satisfy the requirements of 0.5.ltoreq.b/a.ltoreq.2.0 and c/a.gtoreq.1.5 and the length of the axis c is at least 5 microns, and said calcium hypochlorite anhydride is prepared by dehydrating particles of said calcium hypochlorite dihydrate.
A process for the preparation of a granular calcium hypochlorite composition comprising a particle of at least one calcium hypochlorite compound selected from the group consisting of calcium hypochlorite dihydrate and calcium hypochlorite anhydride, said particle having a structure in which the surface portion is substituted with a double decomposition product of calcium hypochlorite with an alkali metal hydroxide, wherein said process comprises:
- (1) adhering an aqueous alkali metal hydroxide solution to a particle of calcium hypochlorite compound selected from the group consisting of calcium hypochlorite dihydrate and calcium hypochlorite anhydride, and then
- (2) heating the calcium hypochlorite particles, wherein said calcium hypochlorite dihydrate is grown from seed crystals using, as the seed crystal, prismatic calcium hypochlorite dihydrate in which the lengths of axes a, b and c satisfy the requirements of 0.5.ltoreq.b/a.ltoreq.2.0 and c/a.gtoreq.1.5 and the length of the axis c is at least 5 microns, and said calcium hypochlorite anhydrite is prepared by dehydrating particles of said calcium hypochlorite dihydrate.
Dependencies are inferred from the claim text.