US4124748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross-linked saponified absorbent polymer
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1976-11-19
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Granted: 1978-11-07
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Expires: 1996-11-19
Abstract
Abstract A highly absorbent polymer is obtained by saponifying a crosslinked copolymer of a vinyl ester and an ethylenically unsaturated carboxylic acid or the derivative thereof. The absorbent polymer is suitable as a material, for example, for separation and purification of substances and a seed culturing media for plants.
Inventors
- 👤 Masanori Fujimoto
- 👤 Kozo Tsuji
- 👤 Tsuneyuki Nagase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:23
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12; C08F220/00; C08F220/02; C08F220/04; C08F220/06; C08F263/00; C08F263/02; C08F263/04; C08F8/44; C08F2800/00; C08F2800/10; C08F2810/00; C08F2810/50
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
190 words
A method for the preparation of a water insoluble, water absorbent polymer having a water absorbency of more than 10 times its own weight of water, comprising the steps of: (I) providing a crosslinked copolymer consisting of (1) a vinyl ester of a saturated carboxylic acid, (2) 5-95 mole % of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, tert-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, acrylamide or methacrylamide and (3) a crosslinking agent made by either (a) polymerising (1) and (2) in the presence of 0.005 to 20 mole % of (3) based on the total monomers, or (b) crosslinking a copolymer consisting essentially of (1) and (2) in the presence of 0.005 to 20 mole % of (3) based on the total monomer units in the copolymer, and (II) saponifying said crosslinked copolymer to obtain a saponified copolymer having a saponification degree of at least 50 mole % of (1), and at least 30 mole % of (2) in the crosslinked copolymer, respectively.
Claim 2
Independent Claim
190 words
A method for the preparation of a water insoluble, water absorbent polymer having a water absorbency of more than 10 times its own weight of water, comprising the steps of: (I) providing a crosslinked copolymer consisting of (1) a vinyl ester of a saturated carboxylic acid, (2) 5-95 mole % of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, tert-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, acrylamide or methacrylamide and (3) a crosslinking agent made by either (a) polymerising (1) and (2) in the presence of 0.005 to 20 mole % of (3) based on the total monomers, or (b) crosslinking a copolymer consisting essentially of (1) and (2) in the presence of 0.005 to 20 mole % of (3) based on the total monomer units in the copolymer, and (II) saponifying said crosslinked copolymer to obtain a saponified copolymer having a saponification degree of at least 50 mole % of (1), and at least 30 mole % of (2) in the crosslinked copolymer, respectively.
Claim 3
Dependent Claim
17 words
A method according to claim 1 wherein said copolymer contains 20 to 80 mole % of (2).
Claim 4
Dependent Claim
17 words
A method according to claim 1 wherein said copolymer contains 30 to 70 mole % of (2).
Claim 5
Dependent Claim
16 words
A method according to claim 1 wherein (1) is vinyl acetate, vinyl propionate or vinyl stearate.
Claim 6
Dependent Claim
42 words
A method according to claim 1 wherein the cross-linked copolymer is that obtained by crosslinking a copolymer of (1) and (2) in the presence of 0.005 to 20 mole % of crosslinking agent based on the total monomer units in the copolymer.
Claim 7
Dependent Claim
23 words
A method according to claim 1 wherein the amount of the crosslinking agent is in the range from 0.005 to 10 mole %.
Claim 8
Dependent Claim
22 words
A method according to claim 5 wherein the crosslinking agent is a polyallyl compound, a polyvinyl compound, allyl acrylate or allyl methacrylate.
Claim 9
Dependent Claim
18 words
A method according to claim 7 wherein the polyvinyl compound is divinyl benzene, ethyleneglycol diacrylate or glycerine trimethacrylate.
Claim 10
Dependent Claim
20 words
A method according to claim 1 wherein saponification is effected until at least 90 mole % of (1) is saponified.
Claim 11
Dependent Claim
20 words
A method according to claim 1 wherein saponification is effected until at least 70 mole % of (2) is saponified.
Claim 12
Dependent Claim
26 words
A method according to claim 1 wherein all or substantially all of component (2) in the saponified copolymer is an alkali salt of the carboxylic acid.
Claim 13
Dependent Claim
18 words
A method according to claim 11 wherein the alkali salt is an alkali metal salt or ammonium salt.
Claim 14
Dependent Claim
15 words
A method according to claim 12 wherein the salt is a sodium or potassium salt.
Claim 15
Dependent Claim
10 words
An absorbent polymer obtained by the method of claim 11.
Claim 16
Dependent Claim
46 words
A method according to claim 1 wherein the copolymer contains 30 to 70 mol % of (2), and saponification is effected until at least 90 mol % of (1) is saponified and all or substantially all of component (2) is converted into an alkali salt thereof.
Claim 17
Dependent Claim
10 words
An absorbent polymer obtained by the method of claim 15.
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) | 1981-11-06 | 1982-05-08 | 1982-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-06 | 1986-05-08 | 1986-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-06 | 1990-05-08 | 1990-11-07 | $7700.00 | Window Closed / Lapsed |