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. 23, 2002
Filed:
Apr. 19, 2000
Schott Glas, Mainz, DE;
Abstract
The glass or glass-ceramic has the following composition (in % by weight based on oxide content): SiO , 25 to 50; B O , >5 to 16; Al O , 10 to 17; P O , 0 to 8; Li O,5 to 15; Na O, 0 to 10; K O, 0 to 10; MgO, 10 to 30; CaO, 0 to 10; SrO, 0 to 8; ZnO, 0 to 8; TiO , 0.1 to 10; ZrO , 0 to 8; and at least one refining agent, in an amount as needed according to its purpose. The sum total amount of divalent metal oxides (RO) present is less or equal to than 45% by weight based on oxide content and the sum total amount of alkali metal oxides (R O) present is less than or equal to 30% by weight based on oxide content. The glass or glass-ceramic material generally has elasticity modulus values (E)>90×10 N/mm and <125×10 N/mm , specific elasticity modulus values (E/&rgr;)>30×10 N cm/g and <45×10 N cm/g and thermal expansion coefficient values (&agr; )>7.0×10 /K and <11.0×10 /K. The material is outstandingly suitable for making fixed disk substrates.