Polythiol useful for preparing sulfur-containing urethane-based resin and process for producing the same
US5608115A · kind A · utility
33Cited by
2References
15Claims
0Family size
Assignee
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Key dates
| Filing date | Jan 17, 1995 |
| Grant date | Mar 4, 1997 |
| Priority date | — |
| Expiry date | Jan 17, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/041
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A novel 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.