Glass composition for crystallized glass

Details Glass composition for crystallized glass Glass composition for crystallized glass

2001-04-02

2003-10-21

Group, Karl (Department: 1755)

Compositions: ceramic

Ceramic compositions

Devitrified glass-ceramics

C501S010000, C501S069000, C501S004000, C428S690000, C428S690000, C065S033100

Reexamination Certificate

active

06635591

ABSTRACT:

RELATED APPLICATION
This application claims priority to Japanese Patent Application No. 2000-100819 filed in Japan on Apr. 3, 2000, the contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a glass composition, and specifically relates to a glass composition suited for crystallized glass. More specifically, the present invention relates to a composition for crystallized glass disk medium. Such disk medium include hard disks, magnetic disks, optical disks and magnetic-optical disks
DESCRIPTION OF THE PRIOR ART
Aluminum and glass are known materials suitable for use as magnetic disk substrates. Among these substrates, glass substrates have been the focus of most attention due to their superior surface smoothness and mechanical strength. Such glass substrates include chemically reinforced glass substrates strengthened by ion exchange on the surface, and crystallized glass substrates having strengthened bonds by depositing a crystal component on the substrate.
The performance demands of recent substrates have become more severe day by day, and improved performance is particularly sought regarding strength, flex and warp during high-speed rotation. This type of performance can be expressed by the Young's modulus of the substrate material, in which a higher numerical value is desirable.
For example, the composition disclosed in Japanese Laid-Open Patent Application No. 11-322362 attains a Young's modulus value of 130 or greater. However, this prior art requires extremely high thermal processing temperatures which complicate the manufacturing process, that is, this art requires a primary processing temperature of 800° C., and a secondary processing temperature of 1,000° C.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved glass composition.
Another object of the present invention is to provide a glass composition having a high Young's modulus and which is highly suited for mass production.
These objects are attained with a glass composition of the present invention desirably having the main components within the ranges described below:
about 65 wt % or more, but less than about 80 wt % SiO
2
;
about 3 wt % or more, but less than about 15 wt % Al
2
O
3
;
about 0.1 wt % or more, but less than about 12 wt % MgO;
about 3 wt % or more, but less than about 12 wt % Li
2
O; and
about 5 wt % or more, but less than about 22 wt % ZnO.


REFERENCES:
patent: 4042362 (1977-08-01), MacDowell et al.
patent: 4304603 (1981-12-01), Grossman et al.
patent: 4374931 (1983-02-01), Courbin et al.
patent: 4714687 (1987-12-01), Holleran et al.
patent: 5219799 (1993-06-01), Beall et al.
patent: 5352638 (1994-10-01), Beall et al.
patent: 5391522 (1995-02-01), Goto et al.
patent: 5476821 (1995-12-01), Beall et al.
patent: 5489558 (1996-02-01), Moffatt et al.
patent: 5491116 (1996-02-01), Beall et al.
patent: 5567217 (1996-10-01), Goto et al.
patent: 5580363 (1996-12-01), Goto et al.
patent: 5626935 (1997-05-01), Goto et al.
patent: 5676721 (1997-10-01), Fredholm et al.
patent: 5726108 (1998-03-01), Taguchi et al.
patent: 5786286 (1998-07-01), Kohli
patent: 5866489 (1999-02-01), Yamaguchi
patent: 5872069 (1999-02-01), Abe
patent: 5910459 (1999-06-01), Beall et al.
patent: 5968219 (1999-10-01), Gille et al.
patent: 6182472 (2001-02-01), Fredholm et al.
patent: 6327874 (2001-12-01), Goto
patent: 6426311 (2002-07-01), Goto et al.
patent: 6442975 (2002-09-01), Murakami et al.
patent: 6458728 (2002-10-01), Nagata et al.
patent: 9-208260 (1997-08-01), None
patent: 9-314458 (1997-12-01), None
patent: 10-208226 (1998-08-01), None
patent: 10-226532 (1998-08-01), None
patent: 11-16142 (1999-01-01), None
patent: 11-16143 (1999-01-01), None
patent: 11-322362 (1999-11-01), None

Affiliated with

Also associated with

Rating

Glass composition for crystallized glass does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Glass composition for crystallized glass, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Glass composition for crystallized glass will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3134689