1.Main Composition
a) SiO2: 80±0.5%
b) B2O3:13±0.2%
c) Al2O3:2.4±0.2%
d) Na2O(+K2O):4.3±0.2%
2.Physical and Chemical Properties
a) Coefficient of mean linear thermal expansion(20/300℃):3.3±0.1(10-6K-1)
b) Transformation temperature: 525±15℃
c) Melting point::1,260±20℃
d) Softening point:820±10℃
e) Density at 20℃:2.23g/cm2
f) Hydrolytic resistance at 98℃: ISO719-HGB1
g) Hydrolytic resistance at 121℃: ISO720-HGA1
h) Acid resistance class:ISO1776-1
i) Alkali resistance class:ISO695-A2