US3959569A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of water-absorbent articles
Assignee: Dow Chemical Co
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Filing: 1974-08-02
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Granted: 1976-05-25
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Expires: 1994-08-02
Abstract
Abstract Water-absorbent articles are prepared by contacting a fibrous material with a dry granular or powdered water-swellable gel and steaming the mixture. Adherence of the gel is improved by pretreatment of the fibrous base with a cationic polymer such as polyethylenimine. Fabrics or fluffs coated with particulate gels such as crosslinked partially hydrolyzed polyacrylamide are useful in various applications where it is desirable to hold or absorb an aqueous fluid in a particular location.
Inventors
- 👤 Nelson D. Burkholder, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:42
CPC Classifications
D; D06; D06M; D06M11/00; D06M11/01; D06M11/05; D06M15/00; D06M15/19; D06M15/21; D06M15/285; D06M15/356; D06M15/3562; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31725; Y10T428/31779; Y10T428/31783; Y10T428/31855; Y10T428/3188
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
70 words
A process for preparing water-absorbent articles consisting essentially of: a. distributing a dry granular/powdered water-swellable cross-linked polymeric gel onto/into a fibrous material, and b. subjecting the so-contained fibrous material to the action of steam for a period of time and at a pressure and temperature to soften at least the surface of the gel, thereby to cause the gel to become sticky and to firmly adhere to the fibrous material.
Claim 2
Dependent Claim
70 words
A process for preparing water-absorbent articles consisting essentially of: a. distributing a dry granular/powdered water-swellable cross-linked polymeric gel onto/into a fibrous material, and b. subjecting the so-contained fibrous material to the action of steam for a period of time and at a pressure and temperature to soften at least the surface of the gel, thereby to cause the gel to become sticky and to firmly adhere to the fibrous material.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the polymer is a cross-linked polyacrylamide.
Claim 4
Dependent Claim
52 words
The process of claim 2 wherein the polymer gel is a cross-linked polyacrylamide prepared by aqueous ethylenic polymerization in the presence of 0.002-0.5 mole percent of a diene cross-linking monomer and subsequently partially hydrolyzed with alkali metal hydroxide to convert 10-50 percent of the carboxamide groups in the polyacrylamide to carboxylate groups.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the polymer gel is a cross-linked polyacrylate.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein the polymer gel is a cross-linked polyvinylpyrrolidone.
Claim 7
Dependent Claim
14 words
The process of claim 1 wherein the polymer gel is a cross-linked acrylamide-N-vinylpyrrolidone copolymer.
Claim 8
Dependent Claim
16 words
The process of claim 1 wherein the polymer gel is a cross-linked, base-neutralized styrene-maleic anhydride copolymer.
Claim 9
Dependent Claim
26 words
The process of claim 1 wherein the fibrous support is impregnated with 0.1-5% by weight of a water-soluble, cationic polymer prior to application of the steam.
Claim 10
Dependent Claim
24 words
The process of claim 8 wherein the cationic polymer is a polyacrylamide wherein 5-35% of the carboxamide groups have been converted to N-(dimethylaminomethyl)carboxamide groups.
Claim 11
Dependent Claim
8 words
The product of the process of claim 1.
Claim 12
Dependent Claim
16 words
The product of the process of claim 2 wherein the fibrous support is a cellulosic material.
References Cited (Backward Citations)
US3297476A
Cited
US3476581A
Cited
US3669792A
Cited
US3676171A
Cited
US3676172A
Cited
US3758641A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |