COMPARISON OF VARIOUS ANTIMONATES AS OPACIFIERS IN DRY‐PROCESS ENAMELS FOR CAST IRON*

Abstract

AbstractAntimonates of potassium, lithium, barium, calcium, magnesium, strontium, zinc, aluminum, lead, and tin were substituted for sodium antimonate in an acid‐resisting dry‐process enamel for cast iron. The sodium antimonate content of this high‐lead enamel was also varied to permit comparisons of all antimonates with sodium antimonate, as a standard, on an equivalent antimony pentoxide basis. Reflectance, color, and acid‐resistance data on all enamels are presented.A number of the antimonates were compared as replacements for sodium antimonate in non‐acid‐resisting enamels of the lead‐bearing and leadless types. Reflectance and color data are given.In acid‐resisting enamels, antimonates of potassium and barium compared reasonably well with sodium antimonate in opacifying power without introducing objectionable colors. Barium antimonate also produced improved acid resistance.In non‐acid‐resisting enamels, only barium antimonate produced results approaching sodium antimonate in both leadless and lead‐bearing types.The data indicate that the antimonates do not contribute equally to opacity and color, even though all contain antimony in pentavalent form. Barium antimonate most closely approaches sodium antimonate in effectiveness. The behavior of the antimonates suggests an explanation for the variations often encountered with antimony oxide enamels.