Coatings for ferrous substrates
AssigneeMerck & Co., Inc.
InventorsLeonard S. Lee, Yoshio Uyeda, Samuel W. Sopp
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Abstract
Novel amorphous magnesia-silica complexes containing from about 0.001 to 2.0 percent by weight of an alkali metal oxide, wherein the mole ratio of MgO:SiO.sub.2 of said complexes is from about 1:25 to 14:1.
Claims6
A composition useful in the coating of magnetic ferrous material prior to the step of annealing said coated material comprising MgO, Mg(OH).sub.2 or mixtures thereof and at least one magnesia-silica complex wherein the mole ratio of the MgO:SiO.sub.2 is from about 1:25 to 14:1, said complex containing from about 0.001 to 2.0% by weight of an alkali metal oxide, said magnesia-silica complex being amorphous as indicated by its X-ray powder diffraction pattern and exhibiting the following differential thermal behavior characteristics:
- an endothermic peak at about 250.degree.C.;
- an exothermic peak at about 820.degree. and at 980.degree.C.
A magnesia-silica complex containing from about 0.001 to 2.0% by weight of an alkali metal oxide wherein the mole ratio of MgO:SiO.sub.2 is from about 1:25 to 14:1, said magnesia-silica complex being amorphous as indicated by its X-ray powder diffraction pattern and exhibiting the following differential thermal behavior characteristics:
- an endothermic peak at about 250.degree.C., an exothermic peak at about 820.degree.C. and 980.degree.C.
Dependencies are inferred from the claim text.