Opacified enamel for direct-on enamelling on unpickled steel plate
AssigneeBayer Aktiengesellschaft
InventorWolfgang Podesta
Life of this patent
Estimating the term…
Abstract
A CeO.sub.2 -containing enamel frit is disclosed which, upon enamelling, produces an opaque enamel coating with excellent adhesion and acid resistance. The frit can be used to enamel an unpickled or lightly pickled steel plate or article.
Claims9
An enamel frit for the direct-on enamelling of non-nickel-plated enamelling steel to form an opaque, acid-resistant enamel coating having good adhesion to the steel, the frit comprising the following glass-forming constituents:
- 40 to 60% by weight SiO.sub.2 +ZrO.sub.2 with an SiO.sub.2 to ZrO.sub.2 molar ratio of greater than 10;
- 10 to 20% by weight alkali metal oxide with an Na.sub.2 O to (Li.sub.2 O+K.sub.2 O) molar ratio of greater than 0.8;
- 8to 18% by weight B.sub.2 O.sub.3 ;
- 0 to 15% by weight of combined CaO, BaO, MgO and ZnO;
- 0 to 8% by weight TiO.sub.2 ;
- 0 to 4% by weight P.sub.2 O.sub.5 ;
- 0 to 4% by weight Al.sub.2 O.sub.3 ;
- 0.3 to 5% by weight fluorine in form of fluorides;
- 0.2 to 3.5% by weight NiO;
- 0.2 to 3.5% by weight CoO;
- 0 to 2% by weight Sb.sub.2 O.sub.3 ;
- 0.2 to 2.5% by weight CuO;
- 2.5 to 9% by weight CeO.sub.2 ;
- and other coloring constituents in quantities of up to 6% by weight, wherein the CeO.sub.2 has a purity of at least 92% and is not contaminated with natural minerals.
An enamel frit for the direct-on enamelling of non-nickel-plated enamelling steel to form an opaque, acid-resistant enamel coating having good adhesion to the steel, the frit comprising the following glass-forming constituents:
- 40 to 60% by weight SiO.sub.2 +ZrO.sub.2 with an SiO.sub.2 to ZrO.sub.2 molar ratio of greater than 10;
- 10 to 20% by weight alkali metal oxide with an Na.sub.2 O to (Li.sub.2 O+K.sub.2 O) molar ratio of greater than 0.8;
- 8 to 18% by weight B.sub.2 O.sub.3 ;
- 0to 15% by weight of combined CaO, BaO, MgO and ZnO;
- 0 to 8% by weight TiO.sub.2 ;
- 0 to 4% by weight P.sub.2 O.sub.5 ;
- 0 to 4% by weight Al.sub.2 O.sub.3 ;
- 0.3 to 5% by weight fluorine in form of fluorides;
- 0.2 to 3.5% by weight NiO;
- 0.2 to 3.5% by weight CoO;
- 0 to 2% by weight Sb.sub.2 O.sub.3 ;
- 0.2 to 2.5% by weight CuO;
- 4.0 to 9% by weight CeO.sub.2 ;
- and other coloring constituents in quantities of up to 6% by weight, wherein the CeO.sub.2 has a purity of at least 92% and is not contaminated with natural minerals.
Dependencies are inferred from the claim text.