US5571657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modified cation exhange process
Assignee: Shipley Co Inc
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Filing: 1993-09-30
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Granted: 1996-11-05
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Expires: 2013-09-30
Abstract
Abstract The invention is a process of removing metal ion contaminants from an organic solution, especially one having acid labile components. The process comprises modifying a cationic exchange resin by treatment with ammonia or amine and contacting said modified ion exchange resin with an organic solution containing metal ion contaminants. The process is especially useful for treating photoresist compositions.
Inventors
- 👤 Charles R. Szmanda
- 👤 Richard J. Carey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:10
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/038; G03F7/022; G03F7/023; G03F7/0233; G03F7/0236; G03F7/039
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
100 words
A process for removing metal ions from an organic photoresist solution having ethyl lactate as the solvent comprising one or more acid labile photoresist components without formation of by-products, said process comprising the steps of providing said organic solution, providing a cation exchange resin modified by having strong acid protons displaced with ammonium ions by contact of the cation exchange resin with ammonium hydroxide, and contacting said organic solution with said modified cation exchange resin for a time sufficient to remove essentially all of said metal ions from said solution by exchange of said metal ions with said ammonium ions.
Claim 2
Dependent Claim
100 words
A process for removing metal ions from an organic photoresist solution having ethyl lactate as the solvent comprising one or more acid labile photoresist components without formation of by-products, said process comprising the steps of providing said organic solution, providing a cation exchange resin modified by having strong acid protons displaced with ammonium ions by contact of the cation exchange resin with ammonium hydroxide, and contacting said organic solution with said modified cation exchange resin for a time sufficient to remove essentially all of said metal ions from said solution by exchange of said metal ions with said ammonium ions.
Claim 3
Dependent Claim
18 words
The process of claim 1 where the solution is passed through a column of the cation exchange resin.
Claim 4
Dependent Claim
15 words
The process of claim 1 where the solution is slurried with the cation exchange resin.
Claim 5
Dependent Claim
27 words
The process of claim 1 where the modified cation exchange resin is dehydrated by contact with an organic solvent prior to contact with said organic photoresist solution.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-11-05 | 2000-05-06 | 2000-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-05 | 2004-05-06 | 2004-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-05 | 2008-05-06 | 2008-11-05 | $7700.00 | Window Closed / Lapsed |