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:
Sep. 25, 2012
Filed:
Jan. 12, 2010
Mineko Yamamoto, Tokyo, JP;
Yasuo Hayashi, Tokyo, JP;
Hideki Kushitani, Tokyo, JP;
Tomoyuki Tsujimura, Tokyo, JP;
Mineko Yamamoto, Tokyo, JP;
Yasuo Hayashi, Tokyo, JP;
Hideki Kushitani, Tokyo, JP;
Tomoyuki Tsujimura, Tokyo, JP;
Asahi Glass Company, Limited, Tokyo, JP;
Abstract
To provide a method whereby it is possible to produce an alkali-free glass having little bubbles therein and excellent in homogeneity and flatness. A method for producing an alkali-free glass, which comprises melting a glass raw material containing a silicon source, followed by forming, wherein as the silicon source, a silica sand is used which has a median particle diameter Dof from 20 μm to 80 μm and which contains particles having a particle diameter of at most 2 μm at a ratio of at most 0.3 vol % and particles having a particle diameter of at least 100 μm at a ratio of at most 2.5 vol %.