| 摘要 |
<p>Reduced boron containing glass fibers are provided which have a refractive index similar to that of higher boron-containing glass fiber compositions. The glass fibers with a refractive index in the range of greater than 1.5495 to around 1.57 have in weight percent SiO2 55-56.5, CaO - 20-23, Al2O3 14.5-15.5, B2O3 - 5 to 5.8, R2O 1-1.5, wherein R is an alkali metal and F2 - 0.4 to 0.6. In addition, the glass fiber composition can have minor constituents such as TiO2 of up to around 0.6 weight percent and an MgO of up to around 0.3 weight percent and ferric oxide of up to around 0.3 weight percent. Basically, the glass fibers have a reduced content of both B2O3 and CaO over standard glass fiber compositions such as E-glass and 621-glass and also has elevated amounts of alkali and of refractory constituents such as SiO2 and Al2O3. The glass fibers are formed with an elevated temperature of 40 to 50.degree.F (22-28.degree.C) above the temperature used to form glass fibers from E-glass and 621-glass.</p> |
