Method of preparing vitreous ceramic composition suitable for coating ceramic articles
AssigneeCeramica Filippo Marazzi S.p.A.
InventorsFilippo Marazzi, Mariano Paganelli
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Abstract
A vitreous ceramic composition for coating ceramic articles with a zinc and alumina base capable of separating rapidly up to 50% of crystalline phase consisting essentially of gahnite. The percentages by weight of the principal ingredients of the composition are the following. SiO.sub.2 30-50%; Al.sub.2 O.sub.3 10-25%; ZnO 8-25%; B.sub.2 O.sub.3 5-20%; TiO.sub.2 0-7%; other selected oxides can be added to change the fusability characteristics and heat expansion coefficients on the basis of specific applications of the composition.
Claims8
A method of preparing frits, useful in the coating of ceramic pieces, consisting of the steps of:
- preparing a vitreous ceramic composition by mixing the following ingredients expressed in weight percent to form a mixture thereof:
- ______________________________________ SiO.sub.2 30-50% Al.sub.2 O.sub.3 10-25% ZnO 8-25% B.sub.2 O.sub.3 5-20%;
- and TiO.sub.2 0-7%;
- ______________________________________
- heating said mixture to a temperature at least sufficient for melting said composition to produce a vitreous mass which will separate rapidly up to 50% of the crystalline phase made up essentially of gahnite;
- and
- suddenly cooling said vitreous mass.
Dependencies are inferred from the claim text.