Patent US4820773A successfully refreshed from Google Patents.
US4820773A
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Water absorbent resins prepared by polymerization in the presence of styrene-maleic anhydride copolymers
Assignee: BASF SE
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Filing: 1987-06-25
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Granted: 1989-04-11
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Expires: 2007-06-25
Abstract
Abstract Improved water-absorbing, crosslinked acrylate resins are prepared by aqueous polymerization of (A) acrylic acid neutralized 70 to 100 mole percent for example with ammonia and/or caustic alkali and/or an amine; with (B) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (B); and (C) a water miscible or a water soluble polyvinyl monomer in the presence of (D) a styrene-maleic anhydride copolymer, neutralized 70 to 100 mole percent for example with ammonia, and/or caustic alkali and/or an amine, in an amount of 1% to 25% based on the weight of acrylic acid or acrylate, such that the amount of (C) is 0.001 to 0.6 weight percent based on the total weight of (A), (B), (C) and (D). In addition, surface treating the water-absorbing crosslinked acrylate resins with a polyquaternary amine substantially further increases both the rate of water absorption and the quantity of water absorbed and retained by the resin. The untreated and the surface-treated resins also maintain the necessary "dry feel" required for most applications.
Inventors
- 👤 William Alexander
- 👤 Mark Anderson
- 👤 Barbara R. Regan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:40
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/04; C08F220/06; A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; B; B01; B01J; B01J20/00; B01J20/22; B01J20/26; C08F8/00; C08F8/44; C08F2800/00; C08F2800/20; C08F2810/00; C08F2810/20
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
137 words
A process for preparing a solid water absorbing resin of improved water absorbency comprising mixing a solution of (A) acrylic acid neutralized 70-100 mole percent; (B) a water-soluble styrene-maleic anhydride resin in an amount of about 1% to about 25% based on the weight of acrylic acid and neutralized 70-100 mole percent; and (C) a water-miscible to watersoluble polyvinyl monomer in a combined concentration of (A), (B) and (C) of at least 30 wt. %; with water to form a mixed solution and initiating polymerization of monomers (A) and (C) such that during polymerization, the exothermic heat of reaction is substantially the only heat energy used to accomplish polymerization, crosslinking and to drive off sufficient water to obtain a solid crosslinked resin including resin (B) and having a water content of 15 percent by weight or less.
Claim 2
Dependent Claim
137 words
A process for preparing a solid water absorbing resin of improved water absorbency comprising mixing a solution of (A) acrylic acid neutralized 70-100 mole percent; (B) a water-soluble styrene-maleic anhydride resin in an amount of about 1% to about 25% based on the weight of acrylic acid and neutralized 70-100 mole percent; and (C) a water-miscible to watersoluble polyvinyl monomer in a combined concentration of (A), (B) and (C) of at least 30 wt. %; with water to form a mixed solution and initiating polymerization of monomers (A) and (C) such that during polymerization, the exothermic heat of reaction is substantially the only heat energy used to accomplish polymerization, crosslinking and to drive off sufficient water to obtain a solid crosslinked resin including resin (B) and having a water content of 15 percent by weight or less.
Claim 3
Dependent Claim
22 words
A process as defined in claim 1 wherein the styrene-maleic anhydride resin (B) is essentially non-covalently bound to the solid crosslinked resin.
Claim 4
Dependent Claim
22 words
A process as defined in claim 1 wherein the styrene-maleic anhydride resin (B) is essentially homogeneously distributed throughout the solid crosslinked resin.
Claim 5
Dependent Claim
32 words
A process as defined in claim 1 wherein the combined concentration of the monomers (A) and (C) and resin (B) is at least 30 wt. % and less than 70 wt. %.
Claim 6
Dependent Claim
31 words
A process as defined in claim 1 wherein the styrene-maleic anhydride resin (B) is present in an amount of about 2% to about 12% based on the weight of acrylic acid.
Claim 7
Dependent Claim
22 words
A process as defined in claim 1 wherein the mixed solution has a temperature of 20° to 85° C. prior to polymerization.
Claim 8
Dependent Claim
20 words
A process as defined in claim 1 wherein monomer (C) is selected from the group consisting of N,N-methylenebisacrylamide and N,N-methylenebismethacrylamide.
Claim 9
Dependent Claim
31 words
A process as defined in claim 1 wherein the mixed solution contains 1 to 10 wt. % of an organic solvent based on the weight of monomers (A), (B) and (C).
Claim 10
Dependent Claim
25 words
A process as defined in claim 1 wherein the mixed solution further contains an organic solvent having a boiling point of 40° to 150° C.
Claim 11
Dependent Claim
26 words
A process as defined in claim 1 wherein the styrene-maleic anhydride resin has a styrene to maleic anhydride ratio ranging from approximately 3:1 to approximately 1:1.
Claim 12
Dependent Claim
34 words
A process as defined in claim 1 further comprising surface treating the solid crosslinked resin with a sufficient amount of a polyquaternary amine to substantially increase the water absorption of the solid crosslinked resin.
Claim 13
Dependent Claim
26 words
A process as defined in claim 11 wherein the resin is treated with from about 0.1% to about 5.0% by dry weight of a polyquaternary amine.
Claim 14
Dependent Claim
26 words
A process as defined in claim 11 wherein the resin is treated with from about 0.25% to about 2% by dry weight of a polyquaternary amine.
Claim 15
Dependent Claim
21 words
A process as defined in claim 11 wherein the polyquaternary amine has a molecular weight from about 200 to about 5000.
Claim 16
Dependent Claim
21 words
A process as defined in claim 11 wherein the polyquaternary amine has a molecular weight from about 300 to about 4000.
Claim 17
Dependent Claim
179 words
A process for preparing a solid, water absorbing, crosslinked resin of improved water absorbency comprising: combining a mixture of (A) potassium and/or ammonium acrylate; (B) neutralized, a water-soluble styrene-maleic anhydride resin in an amount of 1% to 25% based on the amount of acrylate computed based on the weight of acrylic acid; and (C) a polyvinyl monomer, with water in an amount of at least 30 combined weight percent of (A) plus (B) plus (C) based on the total weight of (A) plus (B) plus (C) plus water to form a mixture wherein the monomers of the the mixture consist essentially of (A) and (C); adding a polymerization initiator to said mixture capable of initiating, and in an amount sufficient to initiate polymerization of said mixture; copolymerizing said mixture while utilizing the exothermic heat of reaction as substantially the only non-ambient energy source to drive water away from said polyacrylate resin copolymer to form said crosslinked resin copolymer, including the styrene-maleic anhydride resin (B) and having a water content sufficiently low to be powdered without an intermediate drying step.
Claim 18
Dependent Claim
179 words
A process for preparing a solid, water absorbing, crosslinked resin of improved water absorbency comprising: combining a mixture of (A) potassium and/or ammonium acrylate; (B) neutralized, a water-soluble styrene-maleic anhydride resin in an amount of 1% to 25% based on the amount of acrylate computed based on the weight of acrylic acid; and (C) a polyvinyl monomer, with water in an amount of at least 30 combined weight percent of (A) plus (B) plus (C) based on the total weight of (A) plus (B) plus (C) plus water to form a mixture wherein the monomers of the the mixture consist essentially of (A) and (C); adding a polymerization initiator to said mixture capable of initiating, and in an amount sufficient to initiate polymerization of said mixture; copolymerizing said mixture while utilizing the exothermic heat of reaction as substantially the only non-ambient energy source to drive water away from said polyacrylate resin copolymer to form said crosslinked resin copolymer, including the styrene-maleic anhydride resin (B) and having a water content sufficiently low to be powdered without an intermediate drying step.
Claim 19
Dependent Claim
22 words
A process as defined in claim 16 wherein the styrene-maleic anhydride resin (B) is essentially non-covalently bound to the crosslinked resin copolymer.
Claim 20
Dependent Claim
22 words
A process as defined in claim 16 wherein the styrene-maleic anhydride resin (B) is essentially homogenously distributed throughout the crosslinked resin copolymer.
Claim 21
Dependent Claim
34 words
The process of claim 16 further including the step of adjusting the temperature of the mixture to a temperature of 25° to 85° C. prior to adding said polymerization initiator to said monomer mixture.
Claim 22
Dependent Claim
25 words
The process of claim 16 wherein said polymerization initiator is added in an amount of at lest 0.5% total by weight of (A) and (C).
Claim 23
Dependent Claim
38 words
The process of claim 16 wherein the water content of said crosslinked resin copolymer incorporating the styrene-maleic anhydride resin is not greater than about 10% by weight as recovered from the polymerized mixture, without an additional drying step.
Claim 24
Dependent Claim
29 words
The process of claim 16 further including combining a non-aqueous solvent having a boiling point of 40°-150° C. with said (A), (B) and (C) to form a porous resin.
Claim 25
Dependent Claim
22 words
The process of claim 16 including the step of pulverizing said crosslinked resin including the styrene-maleic anhydride resin to form a powder.
Claim 26
Dependent Claim
30 words
The process of claim 16 wherein the combined concentration of the monomers (A) and (B) and resin (B) is at least 30 wt. % and less than 70 wt. %.
Claim 27
Dependent Claim
26 words
The process of claim 16 wherein the styrene-maleic anhydride resin is neutralized and has a styrene to maleic anhydride ratio ranging from approximately 3:1 to 1:1.
Claim 28
Dependent Claim
35 words
The process of claim 16 further comprising contacting the crosslinked resin copolymer with a polyquaternary amine in an amount of from about 0.1% to about 5.0% based on the weight of the crosslinked resin copolymer.
Claim 29
Dependent Claim
44 words
The process of claim 16 including the step of pulverizing the crosslinked resin copolymer to form a powder prior to contacting said powder with a polyquaternary amine in an amount of about 0.1% to 5.0% based on the weight of said crosslinked resin copolymer.
Claim 30
Dependent Claim
32 words
The process of claim 16 wherein the crosslinked resin copolymer is treated with from about 0.25% to about 2.0% of a polyquaternary amine based on the weight of the crosslinked resin copolymer.
Claim 31
Dependent Claim
32 words
The process of claim 27 wherein the crosslinked resin copolymer is treated with from about 0.25% to about 2.0% of a polyquaternary amine based on the weight of said crosslinked resin copolymer.
Claim 32
Dependent Claim
19 words
The process of claim 16 wherein the polyquaternary amine has a molecular weight from about 200 to about 5000.
Claim 33
Dependent Claim
19 words
The process of claim 16 wherein the polyquaternary amine has a molecular weight from about 500 to about 3000.
Claim 34
Dependent Claim
27 words
The process of claim 16 wherein the polyquaternary amine is a condensation product of hexamethylenediamine, dimethylamine and epichlorohydrin; a condensation of dimethylamine and epichlorohydrin; or quaternized polyethylenimine.
Claim 35
Dependent Claim
27 words
The process of claim 16 wherein the polyquaternary amine is dispersed in methanol from about 0.1% to about 20% by weight before contacting the crosslinked resin copolymer.
Claim 36
Independent Claim
163 words
A method of manufacturing a resin composition of improved water absorbency comprising mixing a solution of (A) acrylic acid, neutralized 70 to 100 mole percent, (B) a water-soluble styrene-maleic anhydride in an amount of 1% to 25% based on the weight of acrylic acid and neutralized 70 to 100 mole percent; and (C) acrylamide in a mole ratio of (A):(C) in the range of 70:30 to 100:0; (D) a water soluble or water miscible polyvinyl monomer crosslinking agent in an amount of 0.001 to 0.6 percent by weight of (A) plus (B) plus (C); and water to form a mixed solution; and initiating polymerization of monomers (A), (C) and (D) such that during polymerization, the exothermic heat of reaction is substantially the only heat energy used to accomplish polymerization, crosslinking and to drive off sufficient water to form a water absorbing crosslinked polyacrylate resin composition including the styrene-maleic anhydride resin (B) and having a water content of 15 percent by weight or less.
Claim 37
Independent Claim
163 words
A method of manufacturing a resin composition of improved water absorbency comprising mixing a solution of (A) acrylic acid, neutralized 70 to 100 mole percent, (B) a water-soluble styrene-maleic anhydride in an amount of 1% to 25% based on the weight of acrylic acid and neutralized 70 to 100 mole percent; and (C) acrylamide in a mole ratio of (A):(C) in the range of 70:30 to 100:0; (D) a water soluble or water miscible polyvinyl monomer crosslinking agent in an amount of 0.001 to 0.6 percent by weight of (A) plus (B) plus (C); and water to form a mixed solution; and initiating polymerization of monomers (A), (C) and (D) such that during polymerization, the exothermic heat of reaction is substantially the only heat energy used to accomplish polymerization, crosslinking and to drive off sufficient water to form a water absorbing crosslinked polyacrylate resin composition including the styrene-maleic anhydride resin (B) and having a water content of 15 percent by weight or less.
Claim 38
Dependent Claim
23 words
The method of claim 34 wherein the styrene-maleic anhydride resin (B) is essentially non-covalently bound to the water absorbing crosslinked polyacrylate resin composition.
Claim 39
Dependent Claim
22 words
The method of claim 34 wherein the styrene-maleic anhydride resin is essentially homogenously distributed throughout the water absorbing crosslinked polyacrylate resin composition.
Claim 40
Dependent Claim
29 words
The method of claim 34 wherein the styrene-maleic anhydride resin (B) is present in an amount of about 2% to about 12% based on the weight of acrylic acid.
Claim 41
Dependent Claim
41 words
The method of claim 34 wherein the water content of said crosslinked polyacrylate resin composition including the styrene-maleic anhydride resin is not greater than about 10% by weight as recovered from the mixed solution after polymerization, without an additional drying step.
Claim 42
Dependent Claim
67 words
The method of claim 34 including depositing said solution including the monomer mixture, the styrene-maleic anhydride resin and said initiator onto a support surface in sheet form for polymerization and crosslinking, followed by pulverizing the resultant crosslinked resin to form a powder, and thereafter contacting said powder with a polyquaternary amine in an amount of from about 0.1% to 5.0% based on the weight of said powder.
Claim 43
Independent Claim
202 words
A method of absorbing aqueous liquids comprising mixing a solution of (A) acrylic acid, neutralized 70 to 100 mole percent; (B) a water-soluble styrene-maleic anhydride resin in an amount of 1% to 25% based on the weight of acrylic acid and neutralized 70 to 100 mole percent; and (C) acrylamide in a mole ratio of acrylic acid:acrylamide in the range of 70:30 to 100:0; (D) a water soluble or water miscible polyvinyl monomer crosslinking agent in an amount of 0.001 to 0.6 percent by weight of (A) plus (B) plus (C); and water to form a mixed solution, wherein the concentration of (A), (B), (C) and (D) is below 70 percent by weight of the monomer solution prior to polymerization initiation; and initiating polymerization of monomers (A), (C) and (D) such that during polymerization, the exothermic heat of reaction is substantially the only heat energy used to accomplish polymerization, crosslinking and to drive off sufficient water to form a water absorbing crosslinked polyacrylate resin including the styrene-maleic anhydride resin (B) and having a water content of 15 percent by weight or less, and thereafter contacting said resin with an aqueous liquid to absorb improved quantities of said aqueous liquid into said resin.
Claim 44
Independent Claim
202 words
A method of absorbing aqueous liquids comprising mixing a solution of (A) acrylic acid, neutralized 70 to 100 mole percent; (B) a water-soluble styrene-maleic anhydride resin in an amount of 1% to 25% based on the weight of acrylic acid and neutralized 70 to 100 mole percent; and (C) acrylamide in a mole ratio of acrylic acid:acrylamide in the range of 70:30 to 100:0; (D) a water soluble or water miscible polyvinyl monomer crosslinking agent in an amount of 0.001 to 0.6 percent by weight of (A) plus (B) plus (C); and water to form a mixed solution, wherein the concentration of (A), (B), (C) and (D) is below 70 percent by weight of the monomer solution prior to polymerization initiation; and initiating polymerization of monomers (A), (C) and (D) such that during polymerization, the exothermic heat of reaction is substantially the only heat energy used to accomplish polymerization, crosslinking and to drive off sufficient water to form a water absorbing crosslinked polyacrylate resin including the styrene-maleic anhydride resin (B) and having a water content of 15 percent by weight or less, and thereafter contacting said resin with an aqueous liquid to absorb improved quantities of said aqueous liquid into said resin.
Claim 45
Dependent Claim
58 words
The method of claim 40 further comprising contacting the crosslinked polyacrylate resin with a polyquaternary amine in an amount of from about 0.1% to about 5.0% based on the weight of said resin after forming the polyacrylate resin, and thereafter contacting said polyquaternary amine treated resin with an aqueous liquid to absorb said aqueous liquid into said resin.
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| 3.5 Years (Year 4) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
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