Sulfur-containing urethane-based resin and composition and process for producing the resin
US6100362A · kind A · utility
41Cited by
2References
19Claims
0Family size
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Key dates
| Filing date | Oct 7, 1997 |
| Grant date | Aug 8, 2000 |
| Priority date | — |
| Expiry date | Oct 7, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/041
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A polythiol having four or more functional groups, a process for producing the polythiol comprising reacting thiourea with a specific compound, a sulfur-containing urethane-based resin prepared from the polythiol and a lens made of the resin. The resin has a high refractive index, and low dispersion of refractive index, is lightweight, colorless and transparent, has no optical distortion, and has excellent characteristics in weatherability, dye-affinity, heat resistance, impact resistance and machinability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.