Dimers derived from unsymmetrical 2,4,5-triphenylimidazole compounds as photoinitiators
US4252887A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 14, 1979 |
| Grant date | Feb 24, 1981 |
| Priority date | — |
| Expiry date | Aug 14, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/121
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Photoimaging compositions comprising (A) 2,4,5-triphenylimidazolyl dimer having selected substituents on the 2,4 and 5 phenyl rings and an extinction coefficient determined in methylene chloride at 10.sup.-5 to 10.sup.-3 mol/liter at 350 nm of at least 4000 liters/mol-cm and at 400 nm of at least 250 liters/mol-cm; and at least one of (B1) leuco dye or (B2) addition polymerizable ethylenically unsaturated monomeric compound. The new imaging compositions are useful in preparing dual response photoimaging products such as proofing papers, printout paper, overlay films and photopolymerizable elements. Improved imaging speed is achieved at equal concentration levels when compared with conventional 2,4,5-triphenylimidazolyl dimers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.