The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 13, 2010
Filed:
Jan. 07, 2009
Terutaka Maehara, Chiyoda-ku, JP;
Manabu Nishizawa, Chiyoda-ku, JP;
Junichiro Kase, Chiyoda-ku, JP;
Syuji Matsumoto, Chiyoda-ku, JP;
Terutaka Maehara, Chiyoda-ku, JP;
Manabu Nishizawa, Chiyoda-ku, JP;
Junichiro Kase, Chiyoda-ku, JP;
Syuji Matsumoto, Chiyoda-ku, JP;
Asahi Glass Company, Limited, Tokyo, JP;
Abstract
To provide an alkali-free glass substrate, which has a high Young's modulus, a low linear expansion coefficient, a high strain point and a low density, does not devitrify in the float forming process and is excellent in acid resistance. An alkali-free glass substrate, which contains neither alkali component nor BaO and consists essentially of, as represented by mol % based on oxide, from 57.0 to 65.0% of SiO, from 10.0 to 12.0% of AlO, from 6.0 to 9.0% of BO, from 5.0 to 10.0% of MgO, from 5.0 to 10.0% of CaO and from 2.5 to 5.5% of SrO, provided that MgO+CaO+SrO is from 16.0 to 19.0%, MgO/(MgO+CaO+SrO)≧0.40, and BO/(SiO+AlO+BO)≦0.12; wherein Young's modulus ≧75 GPa; the linear expansion coefficient at from 50 to 350° C. is from 30×10/° C. to 40×10/° C.; the strain point ≧640° C.; the temperature T(the viscosity η satisfies log η=2)≦1,620° C.; the temperature T(the viscosity η satisfies log η=4)≦1,245° C.; the devitrification temperature ≦T; and weight loss per unit area is at most 0.6 mg/cm, when immersed in 0.1N HCl at 90° C. for 20 hours.