| 摘要 |
A quick setting cement, particularly for use in dentistry, comprises a mono-metallic phosphate of a polyvalent metal of the third to the eleventh series which can form a water-insoluble tri-metallic phosphate by admixture with water, in admixture with an oxide and/or a silicate of a metal as above excluding those compositions described and claimed in Specifications 943,677 and 943,678. The phosphate is preferably an orthophosphate, and may be coated with a metal hydroxide or oxide such as zinc hydroxide, or with zinc orthophosphate. The composition may also include borax as set retarder. As metal cation for the phosphate the following are specified and exemplified: Mg, Al, Ca, Ti, Cr, Mn, Fe (ferrous and ferric), Co, Ni, Cu, Zn, Ag, Cd, Sn, Sb, Ba and Pb. The cement composition is made by dehydrating the monometallic phosphate at 150-350 DEG C and mixing the resulting dehydrated phosphate with the calcined metal oxide or silicate. |
