Gypsum composition for mold production

Abstract

An object of the present invention is to provide a mold-making gypsum composition that can contribute, in a case of, for example, making a model of dentures, to improvements in workability in a step of making a gypsum mold (mold) which is necessary for making a model of artificial gingiva (gum) part made of a resin and which is different individually and is required to have an elaborate shape. In detail, the present invention provides a mold-making gypsum composition such that a slurry-like malaxated product obtained by adding water to the mold-making gypsum composition exhibits favorable fluidity and therefore the mold-making gypsum composition is used for tertiary investing for filling a void in a polymerization flask in making a mold, and thereby workability can be improved and a favorable mold in which occurrence of cracks of gypsum is suppressed when the mold-making gypsum composition is set can be formed. The present invention is a cast-making gypsum composition containing gypsum hemihydrate, wherein the gypsum hemihydrate contains α gypsum hemihydrate and β gypsum hemihydrate in a ratio of 25:75 to 65:35.

Dependencies are inferred from the claim text.