Patent ID: 8906506

Claim:
A glass article formed from a glass containing a total of 10 percent by weight or more of potassium oxide K 2 O and zinc oxide ZnO, substantially containing neither lead oxide PbO nor barium oxide BaO, and having the following glass composition comprising: SiO 2 in a content of more than 65 percent by weight and 70 percent by weight or less; Al 2 O 3 in a content of 1 percent by weight or more and 3 percent by weight or less; Na 2 O in a content of 8 percent by weight or more and less than 10 percent by weight; K 2 O in a content of 8 percent by weight or more and 9.9 percent by weight or less; MgO in a content of 2 percent by weight or more and 3 percent by weight or less; CaO in a content of 3 percent by weight or more and 4.2 percent by weight or less; SrO in a content of more than 3.2 percent by weight and less than 4.2 percent by weight; ZnO in a content of 0.5 percent by weight or more and 2 percent by weight or less; TiO 2 in a content of 0.5 percent by weight or more and 2 percent by weight or less; Sb 2 O 3 in a content of 0 percent by weight or more and 0.4 percent by weight or less; and one or more of SnO 2 , Y 2 O 3 , La 2 O 3 , and ZrO 2 in a total content of 0 percent by weight or more and 1.2 percent by weight or less.