| 摘要 |
<p>The present invention provides a composition for use in forming a white porcelain enamel coating on aluminized or galvanized steel. The composition according to the present invention includes a solids portion including a glass component and a white pigment. The glass component includes one or more glass frits including by weight from about 30% to 50% P2O5, from about 15% to about 30% Al2O3, from about 8% to about 40% X2O where X = Na and/or K, up to about 30% TiO2, up to about 12% B2O3, up to about 10% K2O, up to about 10% ZnO, up to about 8% SiO2, up to about 7% La2O3, up to about 5% Li2O, and up to about 15% F. The white pigment include TiO2. The present invention also provides a method of forming a white porcelain enamel coating on an aluminized or galvanized steel substrate that includes providing a steel substrate having an aluminized or galvanized surface, providing a composition for use in forming a white porcelain enamel coating as previously described, applying the composition to the aluminized or galvanized surface, and firing the composition to form a white porcelain enamel coating. And, the present invention also provides a section of aluminized or galvanized steel having a white porcelain enamel coating disposed thereon, with the white porcelain enamel coating exhibiting an acid resistance of AA or better according to ISO 2722, a class 1 bond adherence rating according to EN 12209, and an opacity of L ≥ 94 according to the CIE L*a*b* uniform color space, where L* = 116 (Y/Y0)<1/3> - 16 for Y/Y0&rang& 0.008856.</p> |
