Alkali-resistant compositions for forming glass fibers

摘要

Alkali-resistant compositions for forming glass fibers characterized by comprising, in molecular weight percentage, 58-77% of SiO2, 4-11% of ZrO2, 16-24% of an alkali metal oxide and 0.5-3.5% of at least one oxide selected from the group consisting of oxides of iron and oxides of copper, with the proviso that the molecular weight percentages of the oxides of iron and the oxides of copper are calculated in terms of the chemical formulas Fe2O3 and CuO, respectively. Alkali-resistant compositions for forming glass fibers characterized by comprising in molecular weight percentage, 56-74% of SiO2, 4-6.9% of ZrO2, 11-20% of an alkali metal oxide, 0.5-3.5% of at least one oxide selected from the group consisting of oxides of iron and oxides of copper with the proviso that the molecular weight percentages of the oxides of iron and the oxides of copper are calculated in terms of the chemical formulas Fe2O3 and CuO, respectively, and up to 12% of an alkaline earth metal oxide.