摘要 |
<p>Glass fibers having the following constituents in the ranges of proportions indicated: SiO2, 57-70 wt. %; Al2O3, 2-7 wt. %; CaO, 5-10 wt. %; MgO, 0-4 wt. %; B2O3, 0-4.5 wt. %; and F, 0.5-4 wt. %; and wherein B2O3 and F are present in amounts according to the relationship: 3</=B2O3+1.5 F</=6.5 and wherein the fibers also contain the alkali oxides Na2O and K2O, in amounts according to the relationship: 16 wt. %<Na2O+K2O<20 wt. %. The glass fibers are used advantageously in thermal and/or acoustic insulation.</p> |