Patent Number: 6,251,812

Title: Glass composition and substrate for information recording media comprising the same

Abstract: A glass composition is disclosed which has a high modulus of elasticity (Young's modulus) and a high rigidity (modulus of elasticity/specific gravity) and is capable of being effectively inhibited from bending or vibrating. Also disclosed is a substrate for information recording media, which comprises the glass composition. The glass composition comprises the following components in terms of mol %: 50 to 64% SiO.sub.2, 6 to 18% Al.sub.2 O.sub.3, 7 to 15% Li.sub.2 O, 3 to 12% Na.sub.2 O, 0 to 2% K.sub.2 O, 0 to 10% TiO.sub.2, 0 to 4% ZrO.sub.2, 0 to 6% MgO, 0 to 9% CaO, and 0 to 6% SrO, provided at the content of RO (RO=MgO+CaO+SrO) is from 2 to 15%.

Inventors: Koyama; Akihiro (Osaka, JP), Kishimoto; Shoichi (Osaka, JP), Kurachi; Junji (Osaka, JP), Yamamoto; Nobuyuki (Osaka, JP)

Assignee: Nippon Sheet Glass Co., Ltd.

International Classification: C03C 3/076 (20060101); C03C 21/00 (20060101); C03C 3/087 (20060101); C03C 3/085 (20060101); C03C 003/085 (); C03C 003/087 (); B32B 017/00 ()

Expiration Date: 06/26/2018