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US4254249A
Expired / Lapsed
US
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Copolymers of N,N-dimethylacrylamide and acrylamide
Assignee: Monsanto Co
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Filing: 1978-11-17
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Granted: 1981-03-03
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Expires: 1998-11-17
Abstract
Abstract Novel copolymers of N,N-dimethylacrylamide and acrylamide are disclosed where the ratio of NNDMA to AM ranges from 10:90 to 95:5. The hydrolyzed copolymer is also disclosed where hydrolysis ranges from 5% to 65% and the ratio of NNDMA to AM is 5:95 to 95:5. These hydrolyzed copolymers are useful in enhanced oil recovery operations.
Inventors
- 👤 Ian W. Cottrell
- 👤 John K. Baird
- 👤 Jaewon L. Shim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:34
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/52; C08F220/54; Y; Y10; Y10S; Y10S507/00; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
100 words
A hydrolyzed form of the copolymer of N,N-dimethylacrylamide and acrylamide of the formula: ##STR2## where m and n are whole numbers such that the weight:weight ratio of NNDMA to AM ranges from greater than 5:95 to about 95:5; Z is a number such that the viscosity of the hydrolyzed copolymer is at least about 1000 cP (1% w/w solution in deionized water, Brookfield LVF viscometer, spindle 4, 60 rpm); and indicates that the distribution of NNDMA and AM in the polymer chain is random wherein the percent of hydrolysis which produces carboxyl groups ranges from about 5% to about 65%.
Claim 2
Dependent Claim
100 words
A hydrolyzed form of the copolymer of N,N-dimethylacrylamide and acrylamide of the formula: ##STR2## where m and n are whole numbers such that the weight:weight ratio of NNDMA to AM ranges from greater than 5:95 to about 95:5; Z is a number such that the viscosity of the hydrolyzed copolymer is at least about 1000 cP (1% w/w solution in deionized water, Brookfield LVF viscometer, spindle 4, 60 rpm); and indicates that the distribution of NNDMA and AM in the polymer chain is random wherein the percent of hydrolysis which produces carboxyl groups ranges from about 5% to about 65%.
Claim 3
Dependent Claim
16 words
A hydrolyzed copolymer of claim 1 wherein the hydrolysis ranges from about 10% to about 25%.
Claim 4
Dependent Claim
15 words
A hydrolyzed copolymer of claim 2 wherein the NNDMA:AM ratio ranges from 1:3 to 3:1.
Claim 5
Dependent Claim
13 words
A hydrolyzed copolymer of claim 3 wherein the NNDMA:AM ratio is about 1:3.
Claim 6
Dependent Claim
47 words
A process for producing a hydrolyzed form of the copolymer of N,N-dimethylacrylamide and acrylamide of the formula: ##STR3## as defined in claim 1 which comprises reacting an aqueous solution of N,N-dimethylacrylamide and acrylamide in the presence of a free radical initiator, and then hydrolyzing the resultant copolymer.
Claim 7
Dependent Claim
13 words
The process of claim 5 wherein a strong base is the hydrolyzing agent.
Claim 8
Dependent Claim
99 words
A hydrolyzed form of the copolymer of N,N-dimethylacrylamide and acrylamide of the formula: ##STR4## where m and n are whole numbers such that the weight:weight ratio of NNDMA to AM ranges from greater than 5:95 to about 95:5; Z is a number such that the viscosity of the hydrolyzed copolymer is at least about 200 cP (1% w/w solution in brine, Brookfield LVF viscometer, spindle 2, 60 rpm); and indicates that the distribution of NNDMA and AM in the polymer chain is random wherein the percent of hydrolysis which produces carboxy groups ranges from about 5% to about 65%.
Claim 9
Dependent Claim
99 words
A hydrolyzed form of the copolymer of N,N-dimethylacrylamide and acrylamide of the formula: ##STR4## where m and n are whole numbers such that the weight:weight ratio of NNDMA to AM ranges from greater than 5:95 to about 95:5; Z is a number such that the viscosity of the hydrolyzed copolymer is at least about 200 cP (1% w/w solution in brine, Brookfield LVF viscometer, spindle 2, 60 rpm); and indicates that the distribution of NNDMA and AM in the polymer chain is random wherein the percent of hydrolysis which produces carboxy groups ranges from about 5% to about 65%.
Claim 10
Dependent Claim
77 words
A copolymer of N,N-dimethylacrylamide and acrylamide of the formula: ##STR5## where m and n are whole numbers such that the weight:weight ratio of NNDMA to AM ranges from about 1:3 to 3:1; Z is a number such that the viscosity of the polymer is at least about 50 cP (1% w/w solution in deionized water, Brookfield LVF viscometer, Spindle 2, 60 rpm); and indicates that the distribution of NNDMA and AM in the polymer chain is random.
Claim 11
Dependent Claim
77 words
A copolymer of N,N-dimethylacrylamide and acrylamide of the formula: ##STR5## where m and n are whole numbers such that the weight:weight ratio of NNDMA to AM ranges from about 1:3 to 3:1; Z is a number such that the viscosity of the polymer is at least about 50 cP (1% w/w solution in deionized water, Brookfield LVF viscometer, Spindle 2, 60 rpm); and indicates that the distribution of NNDMA and AM in the polymer chain is random.
Claim 12
Dependent Claim
11 words
A copolymer of claim 8 wherein the ratio is about 1:3.
Claim 13
Dependent Claim
11 words
A copolymer of claim 8 wherein the ratio is about 1:1.
Claim 14
Dependent Claim
11 words
A copolymer of claim 8 wherein the ratio is about 3:1.
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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |