High-refractivity plastic lens resin formed by reacting at least one polyisocyanate with at least one polythiol
US4775733A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1987 |
| Grant date | Oct 4, 1988 |
| Priority date | — |
| Expiry date | Feb 27, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G18/773
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed herein are a high-refractivity plastic lens resin obtained by polymerizing under heat at least one polyisocyanate (I): ##STR1## wherein X means a hydrogen, chlorine or bromine atom or a methyl or ethyl group, Z is a hydrogen atom or a methyl group, a stands for an integer of 1-4, b is an integer of 2-4, and a+b is not greater than 6 (a+b.ltoreq.6), with at least one polythiol (II): ##STR2## wherein R means a methyl, ethyl, chloromethyl or bromomethyl group, m stands for an integer of 0-2 and n is 4-m and/or at least one polythiol (III): ##STR3## wherein X means a hydrogen, chlorine or bromine atom or a methyl or ethyl group, Y denotes an oxygen or sulfur atom, r stands for 0 or 1, s is an integer of 0-2, p is an integer of 2-4, q is an integer of 1-4 and p+q is not greater than 6 (p+q.ltoreq.6), in such amounts that the --NCO/--SH molar ratio falls within 0.5-3.0, as well as a lens made of the above resin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.