Gypsum composition for denture investment
AssigneeG-C Dental Industrial Corp.
InventorsNobukazu Ohi, Koji Ohno, Satoshi Tosaki
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Abstract
A gypsum composition for denture investment consists of 100 parts by weight of a mixture of 50-90 parts by weight of .alpha.-Gypsum hemihydrate (.alpha.-CaSO.sub.4.1/2H.sub.2 O) with 10-50 parts by weight of .beta.-Gypsum hemihydrate (.beta.-CaSO.sub.4.1/2H.sub.2 O) and 0.2-2.0 parts by weight of a soluble potassium salt. As the soluble potassium salt, use may be made of one or more of potassium sulfate, potassium chloride and potassium tartrate. The gypsum composition may further include 0.5-5.0 parts by weight of dihydrate gypsum.
Claims3
A gypsum composition for denture investment consisting of 100 parts by weight of a mixture of 50-90 parts by weight of .alpha.-Gypsum hemihydrate (.alpha.-CaSO.sub.4.1/2H.sub.2 O), 10-50 parts by weight of .beta.-Gypsum hemihydrate (.beta.-CaSO.sub.4.1/2H.sub.2 O), 0.2-2.0 parts by weight of a soluble potassium salt, and 0.5-5.0 parts by weight of gypsum dihydrate.
Dependencies are inferred from the claim text.