Patent ID: 8324123

Claim:
A glass plate which comprises, as a glass matrix composition as represented by mass % based on oxide: SiO 2 53 to 74, Al 2 O 3 15 to 23, B 2 O 3 0 to 3, MgO 2 to 17, CaO 0 to 12, SrO 0 to 6, MgO + CaO + SrO 6 to 28, Na 2 O 0 to 9, K 2 O 0 to 6, Na 2 O + K 2 O 0.8 to 11, wherein said glass plate comprises from 100 to 500 ppm of SO 3 , has an average coefficient of thermal expansion from 50 to 350° C. of at most 60×10 −7 /° C., has a strain point of at least 600° C., and has a heat shrinkage (C) of at most 20 ppm.