US4683274A
Expired / Lapsed
US
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Process for producing a water-absorbent resin
Assignee: Sumitomo Seika Chemicals Co Ltd
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Filing: 1985-05-28
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Granted: 1987-07-28
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Expires: 2005-05-28
Abstract
Abstract A water-absorbent resin usable as a suitable water absorbent in sanitary materials and other fields can be produced by subjecting an aqueous solution of an α,β-unsaturated carboxylic acid and of an alkali metal salt thereof to polymerization with a radical polymerization initiator in a petroleum-based hydrocarbon solvent in the presence or absence of a crosslinking agent and, in this polymerization, using a saccharose-fatty acid ester as a protective colloid agent.
Inventors
- 👤 Morio Nakamura
- 👤 Shigeji Obayashi
- 👤 Takushi Yamamoto
- 👤 Toshikazu Nakanishi
- 👤 Hitoshi Tanaka
- 👤 Yuji Sakamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:51
CPC Classifications
C; C08; C08F; C08F20/00; C08F20/02; C08F20/04; C08F20/06; A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; C08F2/00; C08F2/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
137 words
A process for producing a water-absorbent resin wherein an aqueous solution of an α,β-unsaturated carboxylic acid and of an alkali metal salt thereof is subjected to polymerization with a radical polymerization initiator in a petroleum-based hydrocarbon solvent in the presence or absence of a crosslinking agent, characterized by using as a colloid agent, a saccharose-fatty acid ester having an HLB of 2 to 16 in an amount of 0.1 to 10% by weight based on the total of the α, β-unsaturated carboxylic acid and the alkali metal salt thereof, the fatty acid component of the saccharose-fatty acid ester being at least one member selected from the group consisting of stearic acid, palmitic acid, lauric acid and oleic acid and the number of esters per unit of saccharose being at least one selected from mono-, di-, and tri-.
Claim 2
Dependent Claim
137 words
A process for producing a water-absorbent resin wherein an aqueous solution of an α,β-unsaturated carboxylic acid and of an alkali metal salt thereof is subjected to polymerization with a radical polymerization initiator in a petroleum-based hydrocarbon solvent in the presence or absence of a crosslinking agent, characterized by using as a colloid agent, a saccharose-fatty acid ester having an HLB of 2 to 16 in an amount of 0.1 to 10% by weight based on the total of the α, β-unsaturated carboxylic acid and the alkali metal salt thereof, the fatty acid component of the saccharose-fatty acid ester being at least one member selected from the group consisting of stearic acid, palmitic acid, lauric acid and oleic acid and the number of esters per unit of saccharose being at least one selected from mono-, di-, and tri-.
Claim 3
Dependent Claim
14 words
A process according to claim 1, wherein the α,β-unsaturated carboxylic acid is acrylic acid.
Claim 4
Dependent Claim
35 words
A process according to claim 1, wherein the petroleum-based hydrocarbon solvent is one member or a mixture of at least two members selected from the group consisting of n-hexane, n-heptane, cyclohexane, benzene, toluene and xylene.
Claim 5
Dependent Claim
13 words
A process according to claim 3, wherein the petroleum-based hydrocarbon solvent is n-heptane.
Claim 6
Dependent Claim
14 words
A process according to claim 1, wherein the radical polymerization initiator is potassium persulfate.
Claim 7
Dependent Claim
12 words
A process according to claim 1, wherein the crosslinking agent is N,N-methylenebisacrylamide.
Claim 8
Dependent Claim
15 words
A process according to claim 1, wherein the crosslinking agent is ethylene glycol diglycidyl ether.
Claim 9
Dependent Claim
16 words
A process according to claim 1, wherein the saccharose-fatty acid ester consists mainly of saccharose distearate.
Claim 10
Dependent Claim
18 words
A process according to claim 1, wherein the saccharose-fatty acid ester consists mainly of saccharose di- and tristearates.
Claim 11
Dependent Claim
18 words
A process according to claim 1, wherein the saccharose-fatty acid ester consists mainly of saccharose mono- and distearates.
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) | 1990-07-27 | 1991-01-26 | 1991-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-27 | 1995-01-26 | 1995-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-27 | 1999-01-26 | 1999-07-28 | $7700.00 | Window Closed / Lapsed |