Crystallized glass, substrate for magnetic disc, magnetic disc and method of producing crystallized glass
US6270876A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1999 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Nov 8, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24355
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A crystallized glass has a main crystal phase of .alpha.-quartz (SiO.sub.2) and lithium disilicate (Li.sub.2.multidot.2SiO.sub.2) and has a thermal expansion coefficient of (90.about.130).times.10.sup.-7 /K at -50.degree. C..about.70.degree. C. The crystallized glass mentioned above, has a following chemical composition; 70 wt %.ltoreq.SiO.sub.2.ltoreq.80 wt %, 5 wt %.ltoreq.Al.sub.2 O.sub.3.ltoreq.9 wt %, 7 wt %.ltoreq.Li.sub.2 O.ltoreq.10 wt %, 1 wt %.ltoreq.P.sub.2 O.sub.5.ltoreq.3 wt %, 0 wt %.ltoreq.K.sub.2 O.ltoreq.3 wt %, 0 wt %.ltoreq.CaO.ltoreq.3 wt %, 0 wt %.ltoreq.BaO.ltoreq.4 wt %, 0 wt %.ltoreq.ZnO.ltoreq.4 wt %, 0 wt %.ltoreq.Sb.sub.2 O.sub.3.ltoreq.1 wt %, 0 wt %.ltoreq.ZrO.sub.2.ltoreq.6 wt %, 0 wt %.ltoreq.Nb.sub.2 O.sub.5.ltoreq.6 wt %, 0 wt %.ltoreq.SnO.sub.2.ltoreq.4 wt %, 0 wt %.ltoreq.MoO.sub.3.ltoreq.3 wt %, 0.7 wt %.ltoreq.(Nb.sub.2 O.sub.5 +SnO.sub.2 +MoO.sub.3).ltoreq.6 wt %.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.