Patent ID: 8349751

Claim:
A glass composition, comprising, by mass % based on oxides: from 55 to 75% of SiO 2 , from 5 to 15% of Al 2 O 3 , from 0 to 4% of MgO, more than 5.5% and at most 12% of CaO, from 5 to 18% of SrO, from 0 to 13% of BaO, from 0.5 to 6% of ZrO 2 , from 0 to 10% of Na 2 O, from 0 to 15% of K 2 O, from 6 to 20% of Na 2 O+K 2 O, from 17 to 25% of MgO+CaO+SrO+BaO, and from 15 to 25% of CaO+SrO, wherein the composition is a glass matrix composition; the composition is suitable for a substrate; and the composition has a glass transition point of at least 600° C., an average thermal expansion coefficient of from 75×10 −7 to 90×10 −7 /° C. within a range of from 50 to 350° C., and an abrasion resistance of at least 98.