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US3948870A
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Method of preparing hydrophilic copolymers of acrylonitrile
Assignee: Czech Academy of Sciences
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Filing: 1973-09-17
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Granted: 1976-04-06
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Expires: 1993-09-17
Abstract
Abstract There is disclosed a method of preparing hydrophilic copolymers of acrylonitrile by initially polymerizing acrylonitrile with about 0.01 to about 30% by weight of a monomer selected from the group consisting of acrylamide; methacrylamide; monomers of the formula CH2=CRCONHR1 wherein R is hydrogen or methyl and R1 is hydrogen, methyl or ethyl; N,N-dialkylacrylamides and methacrylamides and N-alkylol amides, thereafter subjecting said copolymer to hydrolysis by an aqueous acidic solvent for the monomers or swelling agent for the polymer comprising at least one compound selected from the group consisting of nitric acid, sulfuric acid, phosphoric acid, formic acid, zinc chloride and zinc chloride/HCl mixtures and subsequent isolating the product thus formed by removal of the acidic hydrolytic agent therefrom. The products thereof possess such properties as high tensile strength and high swelling capacity and they are accordingly suitable for the production of fibers, membranes, tubing and the like.
Inventors
- 👤 Vladimir Stoy
- 👤 Artur Stoy
- 👤 Jaroslav Prokop
- 👤 Renata Urbanova
- 👤 Josef Kucera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:15
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
163 words
A method of preparing hydrophilic polymers of acrylonitrile comprising the steps of copolymerizing acrylonitrile with about 0.01 to about 30% by weight of a monomer selected from the group consisting of monomers of the formula CH.sub.2 =CRCONHR.sup.1, wherein R is hydrogen or methyl and R 1 is hydrogen, methyl or ethyl, N,N-dialkylacrylamides and methacrylamides and N-alkylolacrylamides and methacrylamides, thereafter subjecting said polymer to treatment with 50 to 95% by weight based on the copolymer of an aqueous acidic hydrolytic agent (b) selected from the group consisting of 40 to 75% nitric acid, 60 to 95% sulfuric acid, and 40 to 95% aqueous zinc chloride solution containing 0.001 to 10% of anhydrous hydrogen chloride, at a temperature between about -25° to 50°C for a period of time sufficient to effect partial homogeneous hydrolysis of said polymer and to convert 1 to 98% of the original nitrile groups into amido groups, and subsequently isolating the product thus formed by separating the acidic hydrolytic agent therefrom.
Claim 2
Independent Claim
163 words
A method of preparing hydrophilic polymers of acrylonitrile comprising the steps of copolymerizing acrylonitrile with about 0.01 to about 30% by weight of a monomer selected from the group consisting of monomers of the formula CH.sub.2 =CRCONHR.sup.1, wherein R is hydrogen or methyl and R 1 is hydrogen, methyl or ethyl, N,N-dialkylacrylamides and methacrylamides and N-alkylolacrylamides and methacrylamides, thereafter subjecting said polymer to treatment with 50 to 95% by weight based on the copolymer of an aqueous acidic hydrolytic agent (b) selected from the group consisting of 40 to 75% nitric acid, 60 to 95% sulfuric acid, and 40 to 95% aqueous zinc chloride solution containing 0.001 to 10% of anhydrous hydrogen chloride, at a temperature between about -25° to 50°C for a period of time sufficient to effect partial homogeneous hydrolysis of said polymer and to convert 1 to 98% of the original nitrile groups into amido groups, and subsequently isolating the product thus formed by separating the acidic hydrolytic agent therefrom.
Claim 3
Dependent Claim
14 words
A method as defined in claim 1 wherein component (a) is acrylamide or methacrylamide.
Claim 4
Dependent Claim
18 words
A method as defined in claim 1 wherein component (a) has the formula CH 2 =CRCONHR 1 .
Claim 5
Dependent Claim
20 words
A method as defined in claim 1 wherein unit (b) is included in amounts of 70 to 95% by weight.
Claim 6
Dependent Claim
25 words
A method as defined in claim 1 wherein component (b) is about 40-75% nitric acid solution or greater than about 55% solution of zinc chloride.
Claim 7
Dependent Claim
19 words
A method as defined in claim 1 wherein component (a) is an aqueous solution of zinc chloride and HCl.
Claim 8
Dependent Claim
15 words
A method as defined in claim 6 carried out in the presence of gaseous HCl.
Claim 9
Dependent Claim
20 words
A method as defined in claim 6 wherein the concentration of zinc chloride is about 60% in said aqueous solution.
Claim 10
Dependent Claim
42 words
A method as defined in claim 1, wherein said copolymer is prepared by aqueous precipitation copolymerization in absence of substantial amount of nonaqueous solvent for the copolymer, and said copolymer is dissolved in the said hydrolytic agent and thereafter subjected to hydrolysis.
Claim 11
Dependent Claim
21 words
A method as defined in claim 1 wherein the hydrolysis is performed at a temperature of about -10°C to about +20°C.
Claim 12
Dependent Claim
22 words
A method as defined in claim 9 wherein the said hydrolytic agent is removed by coagulating the same in an aqueous solution.
Claim 13
Dependent Claim
13 words
A method as defined in claim 11 wherein said aqueous solution is dilute.
Claim 14
Dependent Claim
29 words
A method as defined in claim 11, wherein said hydrolytic agent is removed by washing the same in dilute aqueous solutions of compounds operative to neutralize said hydrolytic agent.
Claim 15
Dependent Claim
19 words
A method as defined in claim 13 wherein said dilute aqueous solutions are operative to precipitate said hydrolytic agent.
References Cited (Backward Citations)
US3200102A
Cited
US3410941A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |