Patent ID: 7153797

Claim:
An alkali-free aluminoborosilicate glass consisting of by weight % based on oxide, SiO 2 >58–65, B 2 O 3 >6–11.5, Al 2 O 3 >14–20, MgO >3–6, CaO >4.5–10, SrO 0–1.5, BaO >1.5–6, with SrO + BaO >3, ZnO 0–<2, ZrO 2 0–2, TiO 2 0–2, with ZrO 2 + TiO 2 0–2, As 2 O 3 0–1.5, Sb 2 O 3 0–1.5, CeO 2 0–1.5, Cl − 0–1.5, F − 0–1.5, SO 4 2− 0–1.5, and wherein As 2 O 3 + Sb 2 O 3 + SnO 2 + CeO 2 + Cl − + F − + SO 4 2− 0–1.5, and an added amount of SnO 2 >0–1.5% SnO 2 , and essentially no alkali oxides.