Surfactant-coated hemihydrate gypsum and production method thereof
AssigneeTokuyama Corporation
InventorsShingo Hiranaka, Hiroyoshi Kato
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Abstract
Surfactant-coated hemihydrate gypsum which is coated with 0.01 to 1 part by weight of a surfactant based on 100 parts by weight of hemihydrate gypsum, wherein the residual rate of the surfactant when the surfactant-coated hemihydrate gypsum is heated up to 300° C. is not less than 40 wt % of the amount of the surfactant before heating.
Claims7
A method of producing a surfactant-coated hemihydrate gypsum, which comprises the step of heating a composition containing at least dihydrate gypsum and a surfactant at 110 to 200° C. to form the surfactant-coated hemihydrate gypsum which is coated with 0.01 to 1 part by weight of surfactant based on 100 parts by weight of hemihydrate gypsum, wherein
- the residual rate of the surfactant when the surfactant-coated hemihydrate gypsum is heated up to 300° C. is not less than 40 wt % of the amount of the surfactant before heating.
Dependencies are inferred from the claim text.