Process for removing metals from vinylphenol-type polymers
US5929204A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1998 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Jan 30, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F6/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Vinylphenol-type polymers are useful materials and are used in many fields such as photoresist, packaging material for IC, printed circuit board, lense, etc. When the polymers are used in an electronic field such as photoresist and packaging material for IC, it is desired to reduce metal concentration in the polymer in the order of ppb units. A simple and effective process for removing metals from vinylphenol-type polymers is disclosed. The process comprises passing an organic solvent solution of a vinylphenol-type polymer either through (a) a filter containing an ion exchange material and/or a chelate-forming material and generating a zeta (.zeta.) potential by a cationic charge modifying agent or through (b) (i) a filter containing an ion exchange material and/or a chelate-forming material and (ii) a filter generating a zeta (.zeta.) potential by a cationic charge modifying agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.