US4921904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Superabsorbent polymers
Assignee: Stockhausen Louisiana Ltd
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Filing: 1988-12-19
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Granted: 1990-05-01
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Expires: 2008-12-19
Abstract
Abstract A substantially water-insoluble, slightly cross-linked, partially neutralized, hydrogen-forming polymer composition consisting essentially of (a) from about 50 mole percent to 99.999 mole percent of polymerizable acid group-containing monomers, and (b) from about 0.001 mole percent to 10 mole percent of a water-soluble polyamine; said hydrogel-forming polymer composition having been formed by reacting a water-soluble acid group-containing vinyl polymer with a water-soluble polyamine at a temperature sufficient to convert the substantial portion of the amino groups of the water-soluble polyamine into amido groups.
Inventors
- 👤 John W. Sparapany
- 👤 Dennis P. Bakalik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:03
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/30; C08F8/32; C08F2810/00; C08F2810/20
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
107 words
A substantially water-insoluble, slightly cross-linked, partially neutralized, hydrogel-forming polymer composition consisting essentially of (a) from about 50 mole percent to 99.999 mole percent of polymerizable acid group-containing monomers; (b) from about 0.001 mole percent to 10 mole percent of a water-soluble polyamine; and (c) from about 0.01 to about 8 mole percent of a water-soluble aliphatic or substituted aliphatic primary or secondary monoamine; said hydrogel-forming polymer composition having been formed by reacting a water-soluble acid group-containing vinyl polymer with the water-soluble polyamine and the monoamine at a temperature sufficient to convert a substantial portion of the amino groups of the water-soluble polyamine and monoamine into amido groups.
Claim 2
Dependent Claim
107 words
A substantially water-insoluble, slightly cross-linked, partially neutralized, hydrogel-forming polymer composition consisting essentially of (a) from about 50 mole percent to 99.999 mole percent of polymerizable acid group-containing monomers; (b) from about 0.001 mole percent to 10 mole percent of a water-soluble polyamine; and (c) from about 0.01 to about 8 mole percent of a water-soluble aliphatic or substituted aliphatic primary or secondary monoamine; said hydrogel-forming polymer composition having been formed by reacting a water-soluble acid group-containing vinyl polymer with the water-soluble polyamine and the monoamine at a temperature sufficient to convert a substantial portion of the amino groups of the water-soluble polyamine and monoamine into amido groups.
Claim 3
Dependent Claim
50 words
The hydrogel-forming composition of claim 1 wherein the unsaturated polymerizable acid group-containing monomer is acrylic acid, the water-soluble aliphatic or substituted aliphatic primary or secondary amine is from the group consisting of diisopropylamine and tert-butylamine and the water-soluble polyamine is from the group consisting of ethylenediamine, 1,4-diaminobutane, 1,8-diaminooctane and tris(2-aminoethyl)amine.
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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) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |