Hard enamel frits for coating metals, porcelain etc. - mixing sintered frit contg. oxide(s) of aluminium, silicon, vanadium, phosphorus, alkali metal, zirconium, and titanium, with standard frit

摘要

Strong, wear-resistant, acid-resistant porcelain enamels for application to metals, porcelain, pottery, etc., are made by first sintering together a mixt. of (by wt.) 10-70% Al2O3, 10-30, SiO2, up to 5% V2O5, up to 5% P2O5, up to 12% alkali oxides R2O, up to 20% ZrO2 and up to 20% TiO2 at 800-1000 degrees C. The cooled glassy solidified solid is then ground (wet or dry) to the desired fineness and mixed with known porcelain enamel or glazing frits in amts of up to 50 wt.%. The slip is then applied to the substrate to be coated, e.g. by dipping or spraying, and baked at 550-1200 degrees C. The prods. give strong wear- and acid resistant finishes to stainless steel, sheet iron, aluminium alloys, cast iron, and glazing layers on porcelain, pottery and stoneware, e.g. in the form of cooking utensils, wall panels, floor tiles etc. The finishes have a hardness on the MOHS scale and DIN 51150 class A-AA scale of 7 which gives improved resistance to scratching etc.