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US3948740A
Expired / Lapsed
US
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Polymerization of water soluble monomers with radiation and chemical initiator
Assignee: Hercules LLC
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Filing: 1973-05-04
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Granted: 1976-04-06
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Expires: 1993-05-04
Abstract
Abstract Improved process for the preparation of water-soluble substantially linear, high molecular weight polymers comprising irradiating an aqueous solution of an ethylenically unsaturated monomer and a chemical, free-radical initiator under conditions to cause radiation-induced polymerization of the monomer, terminating radiation of the system when less than all the monomer has been converted to polymer and when the temperature of the system is such that the chemical, free-radical initiator dissociates with the proper rate to sustain polymerization, and continuing the polymerization to completion by the free radicals generated by the thermal decomposition of the chemical initiator. The radiation-induced polymerization is terminated before more than 95% of the monomer is converted to polymer and preferably before 90% of the monomer is converted to polymer. The remaining monomer is converted to polymer by the free radicals generated by the thermal decomposition of the chemical initiator. Reaction conditions include: monomer concentrations from 10% to 60% by weight, radiation intensities of 1,000 to 1,000,000 rads per hour, and radiation dose from 1,000 to 150,000 rads.
Inventors
- 👤 Charalambos J. Phalangas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:13
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/46; C08F2/54; C08F2/04; C08F2/10; C08F20/00; C08F20/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
248 words
A process of preparing water-soluble, substantially linear, high molecular weight polymers which comprises irradiating an aqueous solution comprising from about 10% to about 60% by weight of (1) at least one water-soluble, ethylenically unsaturated monomer conforming to the formula ##EQU3## wherein R is hydrogen, methyl, or ethyl and Y is --NH 2 , --OM, ##EQU4## wherein M is a cation, R 1 , R 2 , and R 3 are 1 to 4 carbon alkyl groups, and X is an anion, and from about 5 to about 5,000 ppm of a chemical, free-radical initiator for the polymerization of ethylenically unsaturated compounds, said initiator having a dissociation rate constant above about 1 × 10.sup. -4 reciprocal seconds at 100°C., does not substantially catalyze the polymerization of ethylenically unsaturated monomers at temperatures below about 50°C., and does substantially catalyze the polymerization of ethylenically unsaturated monomers at temperatures below about 100°C., with high energy ionizing radiation at an intensity of from about 1,000 rads to about 1,000,000 rads per hour to a dose of from about 1,000 to about 150,000 rads, to form a reaction mass in which from about 30% to about 95% by weight of the water-soluble ethylenically unsaturated monomer initially present in aqueous solution has been converted to water-soluble polymer and in which chemically induced polymerization occurs, terminating the high energy ionizing radiation of the reaction mass before formation of water-insoluble polymer in the reaction mass, and allowing the chemically induced polymerization of the reaction mass to continue.
Claim 2
Dependent Claim
248 words
A process of preparing water-soluble, substantially linear, high molecular weight polymers which comprises irradiating an aqueous solution comprising from about 10% to about 60% by weight of (1) at least one water-soluble, ethylenically unsaturated monomer conforming to the formula ##EQU3## wherein R is hydrogen, methyl, or ethyl and Y is --NH 2 , --OM, ##EQU4## wherein M is a cation, R 1 , R 2 , and R 3 are 1 to 4 carbon alkyl groups, and X is an anion, and from about 5 to about 5,000 ppm of a chemical, free-radical initiator for the polymerization of ethylenically unsaturated compounds, said initiator having a dissociation rate constant above about 1 × 10.sup. -4 reciprocal seconds at 100°C., does not substantially catalyze the polymerization of ethylenically unsaturated monomers at temperatures below about 50°C., and does substantially catalyze the polymerization of ethylenically unsaturated monomers at temperatures below about 100°C., with high energy ionizing radiation at an intensity of from about 1,000 rads to about 1,000,000 rads per hour to a dose of from about 1,000 to about 150,000 rads, to form a reaction mass in which from about 30% to about 95% by weight of the water-soluble ethylenically unsaturated monomer initially present in aqueous solution has been converted to water-soluble polymer and in which chemically induced polymerization occurs, terminating the high energy ionizing radiation of the reaction mass before formation of water-insoluble polymer in the reaction mass, and allowing the chemically induced polymerization of the reaction mass to continue.
Claim 3
Dependent Claim
31 words
A process of claim 1 wherein the radiation intensity is from about 5,000 to about 200,000 rads per hour and the radiation dose is from about 1,000 to about 40,000 rads.
Claim 4
Dependent Claim
31 words
A process of claim 1 wherein the radiation intensity is from about 5,000 to about 100,000 rads per hour and the radiation dose is from about 1,000 to about 15,000 rads.
Claim 5
Dependent Claim
15 words
A process of claim 1 wherein M is alkali metal, --H, or --NH 4 .
Claim 6
Dependent Claim
51 words
A process of claim 1 wherein the aqueous solution contains at least one monomer selected from the group consisting of acrylamide and methacrylamide and at least one monomer selected from the group consisting of alkali metal and ammonium salts of acrylic acid and alkali metal and ammonium salts of methacrylic acid.
Claim 7
Dependent Claim
18 words
A process of claim 5 wherein the ethylenically unsaturated monomer is a mixture of acrylamide and sodium acrylate.
Claim 8
Dependent Claim
13 words
A process of claim 1 wherein the chemical, free-radical initiator is 2,2'-azo-bis(2-methyl propionitrile).
Claim 9
Dependent Claim
13 words
A process of claim 1 wherein the chemical, free-radical initiator is 4,4'-azo-bis(4-cyanolvaleric acid).
Claim 10
Dependent Claim
18 words
A process of claim 5 wherein the monomer concentration is from about 15% to about 45% by weight.
Claim 11
Dependent Claim
17 words
A process of claim 5 wherein the radiation intensity is from 5,000 to 100,000 rads per hour.
Claim 12
Dependent Claim
15 words
A process of claim 5 wherein the radiation dose is from 1,000 to 40,000 rads.
Claim 13
Dependent Claim
19 words
A process of claim 5 wherein the irradiation is terminated before 90% of the monomer is converted to polymer.
Claim 14
Dependent Claim
35 words
A process of claim 12 wherein the monomer concentration is 15% to 45%, the radiation intensity is from 5,000 to 100,000 rads per hour, and the total radiation dose is from 1,000 to 15,000 rads.
Claim 15
Dependent Claim
57 words
A process of claim 13 wherein the monomer is a mixture of from 40% to 95% of acrylamide and from 5% to 60% of sodium acrylate and the polymer produced has a Huggins constant of not more than 0.8 and an intrinsic viscosity of at least 5 deciliters per gram in 2 normal sodium chloride at 25.5°C.
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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 |