Strong dental porcelain and method for its manufacture
AssigneeDen-Mat Corporation
InventorsRobert L. Ibsen, Thomas C. Chadwick, Sally A. Pritchard
Life of this patent
Estimating the term…
Abstract
A dental porcelain having the following composition: ______________________________________ Ingredient Weight by Percent ______________________________________ SiO.sub.2 52.7%-64.6% Al.sub.2 O.sub.3 6.3%-16.4% Li.sub.2 O 0%-0.5% Na.sub.2 O 3.9%-14.2% K.sub.2 O 4.5%-11.7% MgO 0%-.3% CaO 1.6%-3.3% Sro 0.9%-2.3% BaO 0.3%-8.1% TiO.sub.2 0.1%-3.6% B.sub.2 O.sub.3 0.2%-5.0% ______________________________________ made by blending powdered first-fire frit with pacifiers, heating this first-fire frit to 2000.degree. F., and rapidly cooling the charge.
Claims13
A base frit for dental porcelain, including in combination a portion of feldspar comprising:
- ______________________________________ Ingredient Weight by Percent ______________________________________ SiO.sub.2 67.1% Al.sub.2 O.sub.3 18.5% Na.sub.2 O 3.0% K.sub.2 O 10.5%, and CaO 0.9% ______________________________________
- mixed with a Glass 1, comprising:
- ______________________________________ Ingredient Weight by Percent ______________________________________ SiO.sub.2 55.4% Al.sub.2 O.sub.3 7.19% Na.sub.2 O 6.68% K.sub.2 O 20.2% MgO 1.92% CaO 8.32% SrO 0.05% BaO 0.22% TiO.sub.2 0.02% ______________________________________
- and then mixed with a Glass 2, comprising:
- ______________________________________ Ingredient Weight by Percent ______________________________________ SiO.sub.2 46.0% Al.sub.2 O.sub.3 0.74% Na.sub.2 O 20.0% K.sub.2 O 0.06% CaO 3.8% SrO 3.5% BaO 12.5% TiO.sub.2 5.6% B.sub.2 O.sub.3 7.8%, ______________________________________
- and then mixed with lithium carbonate.
The composition 1 wherein 82.9 parts by weight of feldspar, 14.6 parts by weight of glass 1 and 2.0 parts by weight of glass 2 are mixed with 1.5 parts by weight of lithium carbonate to produce 100 parts of base frit.
A method for making base frit for dental porcelain, comprising mixing a feldspar compound of
- ______________________________________ Ingredient Weight by Percent ______________________________________ SiO.sub.2 67.1% Al.sub.2 O.sub.3 18.5% Na.sub.2 O 3.0% K.sub.2 O 10.5%, and CaO 0.9% ______________________________________
- with a Glass 1, comprising:
- ______________________________________ Ingredient Weight by Percent ______________________________________ SiO.sub.2 55.4% Al.sub.2 O.sub.3 7.19% Na.sub.2 O 6.68% K.sub.2 O 20.2% MgO 1.92% CaO 8.32% SrO 0.05% BaO 0.22% TiO.sub.2 0.02% ______________________________________
- and then mixing with a Glass 2, comprising:
- ______________________________________ Ingredient Weight by Percent ______________________________________ SiO.sub.2 46.0% Al.sub.2 O.sub.3 0.74% Na.sub.2 O 20.0% K.sub.2 O 0.06% CaO 3.8% SrO 3.5% BaO 12.5% TiO.sub.2 5.6% B.sub.2 O.sub.3 7.8%, ______________________________________
- and then mixing with lithium carbonate.
A dental porcelain having the following composition:
- ______________________________________ Ingredient Weight by Percent ______________________________________ SiO.sub.2 52.7%-64.6% Al.sub.2 O.sub.3 6.3%-16.4% Li.sub.2 O 0%-0.5% Na.sub.2 O 3.9%-14.2% K.sub.2 O 4.5%-11.7% MgO 0%-.3% CaO 1.6%-3.3% SrO 0.9%-2.3% BaO 0.3%-8.1% TiO.sub.2 0.1%-3.6% B.sub.2 O.sub.3 0.2%-5.0% ______________________________________
Dependencies are inferred from the claim text.