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Patent US3988277A successfully refreshed from Google Patents.
US3988277A
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Stabilized Mannich base solutions
Assignee: Wyeth Holdings LLC
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Filing: 1974-11-21
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Granted: 1976-10-26
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Expires: 1994-11-21
Abstract
Abstract Aqueous solutions of Mannich bases of polyvinylamides are stabilized against viscosity increase and gelation by addition thereto of an effective amount of a formaldehyde scavenger.
Inventors
- 👤 Charles Richard Witschonke
- 👤 Robert Rabinowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:23
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/16; C08K3/00; C08K3/28; C08K5/17; C08K5/21; C08K5/22; C08K5/29; C08K5/31; C08K5/34; C08K5/35
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
24 words
An aqueous solution of a Mannich base of a polyvinylamide stabilized against viscosity increase and gelation containing a stabilizing amount of a formaldehyde scavenger.
Claim 2
Dependent Claim
24 words
An aqueous solution of a Mannich base of a polyvinylamide stabilized against viscosity increase and gelation containing a stabilizing amount of a formaldehyde scavenger.
Claim 3
Dependent Claim
18 words
The solution of claim 1 wherein said Mannich base is the reaction product of polyacrylamide, formaldehyde, and dimethylamine.
Claim 4
Dependent Claim
19 words
The solution of claim 1 wherein said formaldehyde scavenger is selected from guanidine, hydrazine, ammonia, morpholine, dimethylamine, and urea.
Claim 5
Dependent Claim
12 words
The solution of claim 1 wherein said formaldehyde scavenger is guanidine nitrate.
Claim 6
Dependent Claim
12 words
The solution of claim 2 wherein said formaldehyde scavenger is guanidine nitrate.
Claim 7
Dependent Claim
28 words
The solution of claim 1 wherein said formaldehyde scavenger is present in the amount of about 0.01 to 2.0 weight percent based on the weight of said solution.
Claim 8
Dependent Claim
19 words
The solution of claim 2 wherein said formaldehyde scavenger is selected from hydrazine, ammonia, morpholine, guanidine, dimethylamine and urea.
Claim 9
Dependent Claim
28 words
The solution of claim 2 wherein said formaldehyde scavenger is present in the amount of about 0.01 to 2.0 weight percent based on the weight of said solution.
Claim 10
Dependent Claim
11 words
The solution of claim 1 wherein said formaldehyde scavenger is hydrazine.
Claim 11
Dependent Claim
11 words
The solution of claim 2 wherein said formaldehyde scavenger is hydrazine.
References Cited (Backward Citations)
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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) | 1979-10-26 | 1980-04-26 | 1980-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-26 | 1984-04-26 | 1984-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-26 | 1988-04-26 | 1988-10-26 | $7700.00 | Window Closed / Lapsed |