US4990551A
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Absorbing polymer
Assignee: Chemie Linz GmbH
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Filing: 1989-10-13
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Granted: 1991-02-05
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Expires: 2009-10-13
Abstract
Abstract Absorbing polymer consisting of a polymer A which is an optionally modified polyvinyl alcohol or an optionally modified polysaccharide or a mixture of these, and of a polymer B which is a maleic anhydride homo- or copolymer having a hydrolysis time of 5 to 120 minutes, the anhydride groups being open and 0.005 to 5 mol % of the acid functions being esterified with hydroxyl groups of polymer A, and the remaining acid functions being present as free acid groups, as salts or as acid amide groups, an absorbing product containing this polymer and a process for their preparation.
Inventors
- 👤 Georg Haubl
- 👤 Willibald Scheuchenstuhl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:28
CPC Classifications
C; C08; C08L; C08L1/00; C08L1/08; C08L1/26; C08L1/28; C08L1/286; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/225; A61L15/42; A61L15/60; C08L29/00; C08L29/02; C08L35/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
131 words
A water absorbing polymer consisting of a polymer a and a polymer b, comprising polymer a being present in an amount of 10 to 99 percent by weight and being a polyvinyl alcohol wherein a part of the hydroxy groups may be esterified or etherified or a polysaccharide wherein a part of the hydroxy groups may be esterified or etherified, or a mixture of these, and polymer B being present in an amount of 1 to 90 percent by weight and being a maleic anhydride homo- or copolymer having a hydrolysis time of 5 to 120 minutes, the anhydride groups being opened and 0.005 to 5% of the acid functions in polymer A and the remaining acid functions being present as free acid groups, as salts or as acid amide groups.
Claim 2
Dependent Claim
131 words
A water absorbing polymer consisting of a polymer a and a polymer b, comprising polymer a being present in an amount of 10 to 99 percent by weight and being a polyvinyl alcohol wherein a part of the hydroxy groups may be esterified or etherified or a polysaccharide wherein a part of the hydroxy groups may be esterified or etherified, or a mixture of these, and polymer B being present in an amount of 1 to 90 percent by weight and being a maleic anhydride homo- or copolymer having a hydrolysis time of 5 to 120 minutes, the anhydride groups being opened and 0.005 to 5% of the acid functions in polymer A and the remaining acid functions being present as free acid groups, as salts or as acid amide groups.
Claim 3
Dependent Claim
16 words
The water absorbing polymer according to claim 1, wherein polymer A is a modified polyvinyl alcohol.
Claim 4
Dependent Claim
13 words
The water absorbing polymer according to claim 1, wherein polymer A is carboxymethylcellulose.
Claim 5
Dependent Claim
18 words
The water absorbing polymer according to claim 1, wherein polymer B is a maleic anhydride/methyl vinyl ether copolymer.
Claim 6
Dependent Claim
20 words
The water absorbing polymer according to claim 1, wherein the hydrolysis time of polymer B is 10 to 60 minutes.
Claim 7
Dependent Claim
36 words
The water absorbing polymer according to claim 1, wherein polymer A is present in an amount of 40 to 95 percent by weight and polymer B in an amount of 5 to 60 percent by weight.
Claim 8
Dependent Claim
94 words
A process for the preparation of a water absorbing polymer comprising combining a polyvinyl alcohol wherein a part of the hydroxy groups may be esterified or etherified, a polysaccharide wherein a part of the hydroxy group may be esterified or etherified or mixtures of these with a maleic anhydride homo- or copolymer having a hydrolysis time of 5 to 120 minutes, and the mixture being treated at a temperature of 20° to 120° C. with 0.5 to 1.6 equivalents, added all at once, of an inorganic or organic base per equivalent of maleic anhydride.
Claim 9
Dependent Claim
94 words
A process for the preparation of a water absorbing polymer comprising combining a polyvinyl alcohol wherein a part of the hydroxy groups may be esterified or etherified, a polysaccharide wherein a part of the hydroxy group may be esterified or etherified or mixtures of these with a maleic anhydride homo- or copolymer having a hydrolysis time of 5 to 120 minutes, and the mixture being treated at a temperature of 20° to 120° C. with 0.5 to 1.6 equivalents, added all at once, of an inorganic or organic base per equivalent of maleic anhydride.
Claim 10
Dependent Claim
19 words
The water absorbing product, comprising the absorbing polymer according to claim 1 being bonded to one or more supports.
Claim 11
Dependent Claim
20 words
The water absorbing product according to claim 8, comprising the support or supports being one or more lengths of paper.
Claim 12
Dependent Claim
43 words
The process for the preparation of an absorbing product according to claim 8, comprising applying a polymer A, a polymer B and an aqueous solution of an inorganic or organic base to and/or between one or more supports, with optional heating, and drying.
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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) | 1994-02-04 | 1994-08-06 | 1995-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-04 | 1998-08-06 | 1999-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-04 | 2002-08-06 | 2003-02-05 | $7700.00 | Window Closed / Lapsed |