US4340706A
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Alkali metal acrylate or ammonium acrylate polymer excellent in salt solution-absorbency and process for producing same
Assignee: Sumitomo Seika Chemicals Co Ltd
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Filing: 1980-11-21
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Granted: 1982-07-20
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Expires: 2000-11-21
Abstract
Abstract An alkali metal acrylate polymer obtained by suspending an aqueous solution of acrylic acid and an alkali metal acrylate in an alicyclic or aliphatic hydrocarbon solvent containing a surfactant having an HLB value of 8-12 and subjecting the suspension to inverse suspension polymerization in the presence of a water-soluble radical polymerization initiator has a much higher water-absorbency and particularly salt solution-absorbency than known ones. If said polymer is crosslinked with a crosslinking agent, its stability in the fluid-absorbed state for a long period of time is improved and the absorption rate when absorbing water is also improved.
Inventors
- 👤 Shigeji Obayashi
- 👤 Morio Nakamura
- 👤 Koichi Fujiki
- 👤 Takushi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:25
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/04; C08F220/06; C08F2/00; C08F2/32
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
85 words
A process for producing an alkali acrylate polymer having excellent salt solution-absorbency, characterized by suspending an aqueous solution of acrylic acid and an alkali metal acrylate or ammonium acrylate, wherein the monomer concentration is at least 40% by weight, the mole ratio of the acrylic acid to said acrylate is 50/50 to 2/98, in an alicyclic or aliphatic hydrocarbon solvent containing a surfactant having an HLB value of 8-12 and subjecting it to inverse suspension polymerization in the presence of a water-soluble radical polymerization initiator.
Claim 2
Dependent Claim
85 words
A process for producing an alkali acrylate polymer having excellent salt solution-absorbency, characterized by suspending an aqueous solution of acrylic acid and an alkali metal acrylate or ammonium acrylate, wherein the monomer concentration is at least 40% by weight, the mole ratio of the acrylic acid to said acrylate is 50/50 to 2/98, in an alicyclic or aliphatic hydrocarbon solvent containing a surfactant having an HLB value of 8-12 and subjecting it to inverse suspension polymerization in the presence of a water-soluble radical polymerization initiator.
Claim 3
Dependent Claim
18 words
A process according to claim 1, wherein the surfactant having an HLB value of 8-12 is sorbitan monolaurate.
Claim 4
Dependent Claim
13 words
A process according to claim 1 or 2, wherein the solvent is cyclohexane.
Claim 5
Dependent Claim
102 words
A process for producing an alkali acrylate polymer having excellent salt solution-absorbency, characterized by suspending an aqueous solution of acrylic acid and an alkali metal acrylate or ammonium acrylate, wherein the monomer concentration is at least 40% by weight, the mole ratio of the acrylic acid to said acrylate is 50/50 to 2/98, in an alicyclic or aliphatic hydrocarbon solvent containing a surfactant having an HLB value of 8-12, subjecting it to inverse suspension polymerization in the presence of a water-soluble radical polymerization initiator, thereafter adding a water-soluble diglycidyl ether, haloepoxy, or aldehyde cross-linking agent, subjecting the resulting mixture to crosslinking reaction.
Claim 6
Dependent Claim
102 words
A process for producing an alkali acrylate polymer having excellent salt solution-absorbency, characterized by suspending an aqueous solution of acrylic acid and an alkali metal acrylate or ammonium acrylate, wherein the monomer concentration is at least 40% by weight, the mole ratio of the acrylic acid to said acrylate is 50/50 to 2/98, in an alicyclic or aliphatic hydrocarbon solvent containing a surfactant having an HLB value of 8-12, subjecting it to inverse suspension polymerization in the presence of a water-soluble radical polymerization initiator, thereafter adding a water-soluble diglycidyl ether, haloepoxy, or aldehyde cross-linking agent, subjecting the resulting mixture to crosslinking reaction.
Claim 7
Dependent Claim
18 words
A process according to claim 4, wherein the surfactant having an HLB value of 8-12 is sorbitan monolaurate.
Claim 8
Dependent Claim
13 words
A process according to claim 4 or 5, wherein the solvent is cyclohexane.
Claim 9
Dependent Claim
35 words
A process according to claim 4 or 5, wherein said crosslinking agent is ethylene glycol diglycidyl ether and it is used in an amount of 0.005-5.0% by weight based on the weight of the monomers.
Claim 10
Dependent Claim
24 words
The process of claim 1 or 4 wherein the amount of said surfactant is 1-15% by weight based on the weight of the monomers.
Claim 11
Dependent Claim
20 words
The process of claim 1 or 4 wherein the polymerization is carried out at temperatures of 20° to 100° C.
Claim 12
Dependent Claim
20 words
The process of claim 1 or 4 wherein the polymerization is carried out at temperatures of 40° to 80° C.
Claim 13
Dependent Claim
23 words
The process of claim 1 or 4 wherein said acrylate is selected from the group of sodium acrylate, potassium acrylate or ammonium acrylate.
Claim 14
Dependent Claim
25 words
The process of claim 1 or 4 wherein said solvent is selected from the group of cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, or ligroin.
Claim 15
Dependent Claim
26 words
The process of claim 1 or 4 wherein said initiator is present in an amount of 0.005-1.0 mole perdent based on the total amount of monomers.
Claim 16
Dependent Claim
16 words
The process of claim 1 or 4 wherein said initiator includes potassium persulfate or ammonium persulfate.
Claim 17
Dependent Claim
35 words
The process of claim 1 or 4 wherein said surfactant is selected from the group of sorbitol fatty acid ester, sorbitol fatty acid ester ether, sorbitan fatty acid ester or sorbitan fatty acid ester ether.
Claim 18
Dependent Claim
23 words
The process of claim 4 wherein the amount of said crosslinking agent is 0.005-5% by weight based on the weight of the monomers.
Claim 19
Dependent Claim
34 words
The process of claim 4 or 16 wherein said crosslinking agent is selected from the group of (poly)-ethylene glycol diglycidyl ether, (poly)-propylene glycol diglycidyl ether, (poly)-glycerin diglycidyl ether, epichlorohydrin, α-methylepichlorohydrin, glutaraldehyde, glyoxal, or thiodiacetoaldehyde.
Claim 20
Dependent Claim
14 words
The process of claim 4 or 16 wherein said crosslinking agent includes diglycidyl ether.
Claim 21
Dependent Claim
13 words
The process of claim 4 wherein said crosslinking includes ethylene glycol diglycidyl ether.
Claim 22
Dependent Claim
118 words
The process of claim 1 wherein the amount of said surfactant is 1-15% by weight based on the weight of the monomers, the amount of said initiator is 0.005-1.0 mole percent based on the total amount of monomers, said acrylate is selected from the group of sodium acrylate, potassium acrylate, or ammonium acrylate, said solvent is selected from the group of cyclopentane, methyl cyclohexane, n-pentane, n-hexane, n-heptane, or ligroin, said initiator includes potassium persulfate or ammonium persulfate, said surfactant is selected from the group of sorbitol fatty acid ester, sorbitol fatty acid ester ether, sorbitan fatty acid ester or sorbitan fatty acid ester ether, and wherein the polymerization is carried out at temperatures of 20° to 100° C.
Claim 23
Dependent Claim
31 words
The process of claim 1 or 20 wherein said solvent includes cyclohexane, said surfactant includes sorbitan monolaurate, and wherein the polymerization is carried out at temperatures of 40° to 80° C.
Claim 24
Dependent Claim
163 words
The process of claim 4 wherein the amount of said surfactant is 1 to 15% by weight based on the weight of the monomers, the amount of said initiator is 0.005-1.0 mole percent based on the total amount of monomers, said acrylate is selected from the group of sodium acrylate, potassium acrylate, or ammonium acrylate, the solvent is selected from the group of cyclopentane, methylcyclohexane, n-pentane, n-hexane, n-heptane, or ligroin, said initiator includes potassium persulfate or ammonium persulfate, said surfactant is selected from the group of sorbitol fatty acid ester, sorbitol fatty acid ester ether, sorbitan fatty acid ester, or sorbitan fatty acid ester ether, the amount of said crosslinking agent is 0.005-5% by weight based on the weight of the monomers, said crosslinking agent is selected from the group of (poly)-ethylene glycol diglycidyl ether, (poly)-propylene glycol diglycidyl ether, (poly)-glycerin diglycidyl ether, epichlorohydrin, α-methyl epichlorohydrin, glutaraldehyde, glyoxal, or thiodiacetoaldehyde, and wherein the polymerization is carried out at temperatures of 20° to 100° C.
Claim 25
Dependent Claim
39 words
The process of claim 4 or 22 wherein said solvent includes cyclohexane, said surfactant includes sorbitan monolaurate, said crosslinking agent includes ethylene glycol diglycidyl ether, and wherein the polymerization is carried out at temperatures of 40° to 80° C.
Claim 26
Dependent Claim
17 words
An alkali acrylate polymer having excellent salt solution-absorbency produced by the process of claim 1 or 20.
Claim 27
Dependent Claim
17 words
An alkali acrylate polymer having excellent salt solution-absorbency obtained by the process of claim 4 or 22.
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) | 1985-07-19 | 1986-01-18 | 1986-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-19 | 1990-01-18 | 1990-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-19 | 1994-01-18 | 1994-07-20 | $7700.00 | Window Closed / Lapsed |