Process for tinting a resin for optical materials
US6365223B1 · kind B1 · utility
4Cited by
6References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 28, 2000 |
| Grant date | Apr 2, 2002 |
| Priority date | — |
| Expiry date | Jan 28, 2020 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD06P1/67316
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A process for tinting a resin for optical materials, the resin containing sulfur, includes dipping the resin for optical materials into a liquid containing an inorganic acid and/or an organic acid and thereafter tinting the resin. Where the organic acid is included in the liquid, the organic acid is a mixture of a first compound (I) having sulfo group and a second compound (II) having phenolic hydroxyl group but not having sulfo group, with a ratio (I)/(II) of the first compound to the second compound, in an amount by weight, being 0.01 to 2.0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.