Resin purification process
US5939511A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1998 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | Apr 8, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G8/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention is directed to purification of phenolic resins and to a process for preparing an organic photoresist coating composition. The process comprises reacting one or more phenols to form a crude phenolic resin. The crude phenolic resin formed is then separated from its reaction mixture and dissolved in an aqueous insoluble organic solvent in an organic solvent that is a solvent for the photoresist coating composition. The solution so formed is then mixed with an aqueous phase to extract water soluble impurities from the resin solution into the aqueous phase. Finally, the purified resin solution is further diluted with additional photoresist solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.