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:
Apr. 17, 2001
Filed:
Nov. 03, 1999
Applicant:
Inventors:
Assignee:
Schott Glas Mainz, , DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B 3/02 ;
U.S. Cl.
CPC ...
B32B 3/02 ;
Abstract
Magnetic disks comprising a substrate and glass materials which are used in the manufacture of hard disc substrates. The glasses can have the following compositions (in per cent by weight on an oxide basis): SiO,10-30, Al,O,0-5, B,O,0-8, Li,O 0-8, Na,O 1-10, with Li,O+Na,O 5-10, K,O 0-3, MgO 5-16, CaO 0-15, with MgO+CaO>15-25, SrO+BaO 0-8, ZrO,0-8, TiO,7-25, La,O,0-10, Nb,O,O,0-10, CeO,0-1, As,O,+Sb,O,+F 0.1-1. These glasses can have high dimensional stability as a result of their high specific modulus of elasticity, to be especially suited for hard disk substrates.