Patent US4766173A successfully refreshed from Google Patents.
US4766173A
Expired / Lapsed
US
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Method for reducing residual acrylic acid in acrylic acid polymer gels
Assignee: Stockhausen Louisiana Ltd
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Filing: 1987-05-11
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Granted: 1988-08-23
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Expires: 2007-05-11
Abstract
Abstract A method for reducing the residual acrylic acid present in water-insoluble polyacrylic acid water absorbent gel polymers which comprises treating these polymers with at least 0.5 mole of either amino acid cysteine or lysine per mole of acrylic acid present in said waters for at least 15 minutes at a temperature of at least 80° C.
Inventors
- 👤 Kristy M. Bailey
- 👤 Patrick J. Marek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:10
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/006; Y; Y10; Y10S; Y10S524/00; Y10S524/916
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
57 words
A method for reducing the residual acrylic acid present in water-insoluble polyacrylic acid water absorbent gel polymers which comprises treating these polymers with at least 0.5 mole of either amino acid cysteine or lysine per mole of residual acrylic acid present in said polymers for at least 15 minutes at a temperature of at least 80° C.
Claim 2
Independent Claim
57 words
A method for reducing the residual acrylic acid present in water-insoluble polyacrylic acid water absorbent gel polymers which comprises treating these polymers with at least 0.5 mole of either amino acid cysteine or lysine per mole of residual acrylic acid present in said polymers for at least 15 minutes at a temperature of at least 80° C.
Claim 3
Dependent Claim
11 words
A method of claim 1 where the amino acid is cysteine.
Claim 4
Dependent Claim
11 words
The method of claim 1 where the amino acid is lysine.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |