Patent ID: 7148164
Filing Date: 2006-12-12
Classification: C03C,G02B

Abstract:
1. Low expansion transparent glass-ceramics obtained by heat treating a base glass produced at a melting temperature of 1530° or below, said glass-ceramics comprising RO, where R is Mg, Ca, Ba, Sr or Zn, in a total amount of 6–25 mass % on the basis of total oxides and wherein said ceramic contains 0.5–2 mass % of CaO, 3.5–6 mass % TiO 2 and 0.5–2 mass % MgO on the basis of the amount of total oxides, said glass-ceramics being free of P 2 O 5 , and having an average linear thermal expansion coefficient (α) within a range from +6×10 −7 /° C. to +35×10 −7 /° C. within a temperature range from 100° to 300° and having 80% transmittance wavelength (T 80 ) of 700 nm or below.