US4910250A
Expired / Lapsed
US
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Aqueous composition, method of producing a water absorbent polymer
Assignee: Hayashikane Shipbuilding and Engineering Co Ltd
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Filing: 1988-12-19
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Granted: 1990-03-20
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Expires: 2008-12-19
Abstract
Abstract An aqueous composition of an acrylic polymer to which a water soluble peroxide radical initiator has been added, said initiator being adapted to decompose at a temperature of from about 40° C. to about 180° C. and act on the polymer to crosslink the same. Using the aqueous composition, a water absorbent crosslinked polymer and a water absorbent polymer-coated article can be produced through simplified processes. The water absorbent crosslinked polymer exhibits excellent water absorbing and swelling properties so that it can be advantageously utilized for the production of wet absorbent articles such as disposable diaper, sanitary napkin or the like. The water absorbent polymer-coated article is excellent in water absorption properties and can be used safely for the purposes as mentioned above.
Inventors
- 👤 Kazuo Saotome
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:59
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2996; Y10T428/31504; Y10T428/31855; Y10T428/3188; Y10T428/31895; Y10T442/00; Y10T442/20; Y10T442/2484
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
118 words
An aqueous composition consisting essentially of at least about 10% by weight of water, a polymer dissolved or swollen in said water and a persulfate radical initiator substantially dissolved in said water, said polymer having at least 70% by weight, based on the total weight of said polymer, of acrylic acid monomeric units, 60 to 90% of the carboxyl groups of said monomeric units being in the form of an alkali metal salt, with the balance of the polymer comprising monomeric units of methacrylic acid, maleic anhydride, fumaric acid, acrylamide, or methacrylamide, said initiator being adapted to decompose at a temperature of from about 40° to about 180° C. and act on said polymer to crosslink said polymer.
Claim 2
Dependent Claim
118 words
An aqueous composition consisting essentially of at least about 10% by weight of water, a polymer dissolved or swollen in said water and a persulfate radical initiator substantially dissolved in said water, said polymer having at least 70% by weight, based on the total weight of said polymer, of acrylic acid monomeric units, 60 to 90% of the carboxyl groups of said monomeric units being in the form of an alkali metal salt, with the balance of the polymer comprising monomeric units of methacrylic acid, maleic anhydride, fumaric acid, acrylamide, or methacrylamide, said initiator being adapted to decompose at a temperature of from about 40° to about 180° C. and act on said polymer to crosslink said polymer.
Claim 3
Dependent Claim
14 words
A composition according to claim 1, wherein said polymer is a water soluble polymer.
Claim 4
Dependent Claim
25 words
A composition according to claim 1, wherein said initiator is present in an amount of from 0.01 to 10% by weight based on said polymer.
Claim 5
Dependent Claim
25 words
A composition according to claim 3, wherein said initiator is present in an amount of from 0.1 to 5% by weight based on said polymer.
Claim 6
Dependent Claim
25 words
A composition according to claim 4, wherein said initiator is present in an amount of from 0.5 to 3% by weight based on said polymer.
Claim 7
Dependent Claim
25 words
A composition according to claim 1, wherein said water is present in an amount of at least about 20% by weight based on said composition.
Claim 8
Dependent Claim
27 words
A composition according to claim 6, wherein said water is present in an amount of from about 20% to about 60% by weight based on said composition.
Claim 9
Dependent Claim
15 words
A composition according to claim 6, which further comprises a volatile, water soluble organic solvent.
Claim 10
Dependent Claim
17 words
A composition according to claim 8, wherein said organic solvent is an alcohol or a ketone compound.
Claim 11
Dependent Claim
30 words
A composition according to claim 8, wherein said solvent is present in an amount of from 0.1 to 5 in terms of the volume ratio of said solvent to water.
Claim 12
Independent Claim
154 words
A method of producing a water absorbent crosslinked polymer, which comprises the steps of: (1) providing an aqueous mixture consisting essentially of water and a polymer dissolved or swollen in said water, said polymer having at least 70% by weight, based on the total weight of said polymer, of acrylic acid monomeric units 60 to 90% of the carboxyl groups of said monomeric units being in the form of an alkali metal salt; (2) adding a water soluble persulfate radical initiator, said initiator being adapted to decompose at a temperature of from about 40° to about 180° C. and act on said polymer to crosslink said polymer, to said mixture in an amount sufficient to crosslink said polymer and in such an amount that said water substantially dissolves said initiator therein thereby to obtain an aqueous composition; and (3) heating said aqueous composition at a temperature of from about 40° to about 180° C.
Claim 13
Independent Claim
154 words
A method of producing a water absorbent crosslinked polymer, which comprises the steps of: (1) providing an aqueous mixture consisting essentially of water and a polymer dissolved or swollen in said water, said polymer having at least 70% by weight, based on the total weight of said polymer, of acrylic acid monomeric units 60 to 90% of the carboxyl groups of said monomeric units being in the form of an alkali metal salt; (2) adding a water soluble persulfate radical initiator, said initiator being adapted to decompose at a temperature of from about 40° to about 180° C. and act on said polymer to crosslink said polymer, to said mixture in an amount sufficient to crosslink said polymer and in such an amount that said water substantially dissolves said initiator therein thereby to obtain an aqueous composition; and (3) heating said aqueous composition at a temperature of from about 40° to about 180° C.
Claim 14
Dependent Claim
14 words
A method according to claim 11, wherein said polymer is a water soluble polymer.
Claim 15
Dependent Claim
21 words
A method according to claim 11, wherein the aqueous composition has a water content of at least about 10% by weight.
Claim 16
Dependent Claim
21 words
A method according to claim 13, wherein the aqueous composition has a water content of at least about 20% by weight.
Claim 17
Dependent Claim
22 words
A method according to claim 14, wherein the aqueous composition has a water content of about 20 to about 60% by weight.
Claim 18
Dependent Claim
35 words
A composition according to claim 2, wherein said polymer consists of acrylic acid monomeric units, 60 to 90% of the carboxyl groups of the monomeric units being in the form of an alkali metal salt.
References Cited (Backward Citations)
CA1080872A
Cited
US4132695A
Cited
US4066584A
Cited
US4497930A
Cited
US4524186A
Cited
US4587308A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-19 | 1993-09-18 | 1994-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-19 | 1997-09-18 | 1998-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-19 | 2001-09-18 | 2002-03-20 | $7700.00 | Window Closed / Lapsed |