초록 ▼

Boron-free glass fibers suitable for textile and reinforcements are described. The glass fibers have compositions consisting essentially of SiO.sub.2, CaO, Al.sub.2 O.sub.3, and MgO. In a preferred embodiment, the glass contains essentially no fluorine, sulfate, or titania These glass fiber composit

Boron-free glass fibers suitable for textile and reinforcements are described. The glass fibers have compositions consisting essentially of SiO.sub.2, CaO, Al.sub.2 O.sub.3, and MgO. In a preferred embodiment, the glass contains essentially no fluorine, sulfate, or titania These glass fiber compositions advantageously have broad or large values for delta T (i.e., the difference between the log 3 or forming temperature--the temperature at which the glass has a viscosity of approximately 1000 poise--and the liquidus temperature), e.g., a delta T of at least about 125.degree. F. (52.degree. C.), more preferably of at least about 150.degree. F. (66.degree. C.).

대표청구항 ▼

[ We claim:] [1.] Continuous glass fiber having a composition essentially free of boron and consisting essentially of 59.0 to 62.0 weight percent SiO.sub.2, 20.0 to 24.0 weight percent CaO, 12.0 to 15.0 weight percent Al.sub.2 O.sub.3, 1.0 to 4.0 weight percent MgO, 0.0 to 0.5 weight percent F.sub.2

[ We claim:] [1.] Continuous glass fiber having a composition essentially free of boron and consisting essentially of 59.0 to 62.0 weight percent SiO.sub.2, 20.0 to 24.0 weight percent CaO, 12.0 to 15.0 weight percent Al.sub.2 O.sub.3, 1.0 to 4.0 weight percent MgO, 0.0 to 0.5 weight percent F.sub.2, 0.1 to 2.0 weight percent Na.sub.2 O, 0.0 to 0.9 weight percent TiO.sub.2, 0.0 to 0.5 weight percent Fe.sub.2 O.sub.3, 0.0 to 2.0 weight percent K.sub.2 O, and 0.0 to 0.5 weight percent SO.sub.3, wherein the composition has (i) a viscosity of 1000 poise at a forming temperature of from 2100.degree. F. (1149.degree. C.) to 2500.degree. F. (1371.degree. C.) and (ii) a liquidus temperature at least 100.degree. F. (38.degree. C.) below the forming temperature.