Trace metal ion reduction by Ion Exchange Pack
US5955570A · kind A · utility
3Cited by
4References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1998 |
| Grant date | Sep 21, 1999 |
| Priority date | — |
| Expiry date | Jul 1, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/115
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides methods for solutions having a very low level of metal ions, utilizing a specially designed Ion Exchange Pack. A method is also provided for producing photoresist composition having a very low level of metal ions from novolak resins purified in a process using such an Ion Exchange Pack.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.