Endoscope optical system including composition having durability to a sterilization treatment
US6558316B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 2001 |
| Grant date | May 6, 2003 |
| Priority date | — |
| Expiry date | Jun 27, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C3/155
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A composition has a durability to a sterilization treatment using vapor under high temperature and pressure and capable of transmitting or absorbing light. The composition comprises a group A including 15 to 23 mol % of lanthanum oxide, 3 to 8 mol % of gadolinium oxide, 3 to 8 mol % of tantalum oxide, and 8 mol % or less of yttrium oxide; a group B including 30 to 45 mol % of boron oxide, 20 mol % or less of silicon oxide, and 20 mol % or less of germanium oxide; zero mol % of alkaline metal oxide or alkaline earth metal oxide; and a group D including 0.3 to 15 mol % of niobium oxide and 3 to 15 mol % of zirconium oxide. A mol % ratio A/B between the group A and group B is 80% or more, and a dissolving-out rate of metal ion of the composition is 0.002×10−6 mol/hour or less per square centimeter. In case of applying the composition to an endoscope including an observation system and an illuminating system, an optical element disposed at the outer surface of the observation system and an optical element disposed at the outer surface of the illuminating system are formed of the composition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.