Patent ID: 7763558

Claim:
A glass composition comprised of the following components: Oxide Component Mole % SiO 2 66-69.5 Al 2 O 3 0-2 B 2 O 3 3-7 CaO 3-8.5 MgO 0-6 BaO 0.1-0.5 Na 2 O 13-17 K 2 O 0-2 wherein the composition and fibers prepared therefrom exhibit a biosolubility of at least 100 ng/cm 2 /hr; a difference between the liquidus temperature and the HTV value of at least 200° C.; a softening point of at least 675° C.; a moisture resistance more positive than 0.6 ΔG hyd kcal/mole; a crystallization rate such that crystals no larger than 5 μm in size after 24 hour exposure and crystals no larger than 25 μm in size after 72 hours exposure are observed; and a surface tension of less than 300 dyne/cm at 1000° C.