Patent ID: 7144836

Claim:
A glass composition comprising: SiO 2 55 to 59 percent by weight; Al 2 O 3 10 to 14 percent by weight; CaO 21 to 26 percent by weight; MgO 1 to 3.25 percent by weight; TiO 2 0 to 1.75 percent by weight; Na 2 O 0 to 2 percent by weight; K 2 O 0 to 2 percent by weight; Na 2 O + K 2 O 0 to 2 percent by weight; Fe 2 O 3 0 to 0.5 percent by weight; B 2 O 3 essentially none; Li 2 O 0.25 to 1.25 percent by weight; ZnO 0.25 to 1.5 percent by weight; wherein the glass composition has a log 3 forming temperature no greater than 1220° C., and the difference between the log3 forming temperature and the liquidus temperature is at least 50° C.