ENAMEL Russian patent published in 1997 - IPC

FIELD: coatings. SUBSTANCE: invention relates to applying protective coatings, in particular, for enameling of steel objects, hot water-supply pipelines among them. Enamel contains following ingredients, wt.-%: silicon oxide, 52-58; zirconium silicate, 0.5- 6.0; boron oxide, 2-6; sodium oxide, 12-18; potassium oxide, 2-6; cobalt oxide, 0.2-0.7; calcium oxide, 1-6; manganese oxide, 1.0-2.5; calcium fluoride, 5-8; titanium oxide, 1-5; and aluminum oxide, 2-6. Characteristics: heat resistance 300-330 C; weight loss after boiling in distilled water for 48 h - -.02-0.08 mg/sq.cm, in 0.1 N NaOH solution for 24 h - 0.25-0.30 mg/sq.cm, and in 20% HCl for 4 h - 0.35- 0.7 mg/sq.cm. EFFECT: improved quality of enamel when applied with thickness to 400 mcm. 3 tbl