Patent ID: 6592834
Filing Date: 2003-07-15
Classification: A01N,C01F,C01P,C09C

Abstract:
A process for the production of a material consisting essentially of calcium hydroxide, in which the average secondary particle diameter at a cumulative percentage of 50% by number in a particle size distribution is 2.0 &mgr;m or less and the BET specific surface area is 7 to 20 m2/g and which is surface-treated with 0.1 to 10% by weight of an anionic surfactant, said process consisting essentially of adding a water-soluble calcium salt aqueous solution to an aqueous solution containing at least one equivalent of alkali metal hydroxide to calcium with stirring, allowing the mixture to react at 30 to 90Â° C., then aging the resultant mixture at 40 to 120Â° C. to produce calcium hydroxide, and adding an aqueous solution of 0.1 to 10% by weight, based on the calcium hydroxide, of an anionic surfactant at a temperature where the anionic surfactant is soluble or at a higher temperature, with stirring, to surface-treat the calcium hydroxide, thereby obtaining said material consisting essentially of calcium hydroxide.