Magnetic head
US5245492A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1992 |
| Grant date | Sep 14, 1993 |
| Priority date | — |
| Expiry date | Apr 6, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C8/245
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A magnetic head comprising magnetic core halves which are sealed with a sealing glass which consists essentially of 1 to 75 wt. % of TeO.sub.2, 1 to 30 wt. % of B.sub.2 O.sub.3, 1 to 75 wt. % of PbO, 1 to 25 wt. % of CdO, 0 to 15 wt. % of ZnO, 0 to 25 wt. % of Bi.sub.2 O.sub.3, 0 to 5 wt. % of A.sub.2 O wherein A is an alkali metal, 0 to 35 wt. % of ARO wherein AR is an alkaline earth metal, 0 to 35 wt. % of La.sub.2 O.sub.3, 0 to 5 wt. % of at least one oxide selected from the group consisting of Al.sub.2 O.sub.3, SiO.sub.2, TiO.sub.2 and ZrO.sub.2, 0 to 10 wt. % of at least one oxide selected from the group consisting of Ta.sub.2 O.sub.5, Nb.sub.2 O.sub.5, WO.sub.3 and MoO.sub.3, 0 to 30 wt. % of PbF.sub.2, and 0 to 2 wt. % of CoO, has a coefficient of thermal expansion of from 82.times.10.sup.-7 /.degree.C. to 137.times.10.sup.-7 /.degree.C. in a temperature range between 30.degree. C. and 300.degree. C., a working temperature of from 430.degree. to 620.degree. C. and water resistance of the first class, which glass is not deeply colored and is not devitrified during the assembly of the magnetic head.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.