Patent US4247487A successfully refreshed from Google Patents.
US4247487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized formaldehyde solutions
Assignee: EIDP Inc
•
Filing: 1972-12-26
•
Granted: 1981-01-27
•
Expires: 1992-12-26
Abstract
Abstract Aqueous solutions of formaldehyde are stabilized against precipitation by the incorporation therein of 0.1 to 1000 p.p.m. of a low molecular weight vinyl polymer containing acetal, acetate, hydroxyl, and optionally, formal, propional or butyral groups. Preferably, the polymer is added to the formaldehyde solution as a methanol solution.
Inventors
- 👤 James S. Percy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:33
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/78; C07C45/86; C08; C08K; C08K5/00; C08K5/04; C08K5/07
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
54 words
A stabilized solution of over 30% by weight of formaldehyde in water containing a stabilizing amount of a formaldehyde-soluble polymer having a number average molecular weight of 300-5000 prepared by acetalization of polyvinyl alcohol with a C 1-4 alkyl aldehyde, the polymer containing along the polymer chain 30-90% acetal groups, 1-40% hydroxyl groups and
Claim 2
Dependent Claim
54 words
A stabilized solution of over 30% by weight of formaldehyde in water containing a stabilizing amount of a formaldehyde-soluble polymer having a number average molecular weight of 300-5000 prepared by acetalization of polyvinyl alcohol with a C 1-4 alkyl aldehyde, the polymer containing along the polymer chain 30-90% acetal groups, 1-40% hydroxyl groups and
Claim 3
Dependent Claim
12 words
The solution of claim 1 wherein the stabilizing amount ranges from 0.1
Claim 4
Dependent Claim
13 words
The solution of claim 1 wherein the stabilizing amount ranges from 1 to
Claim 5
Dependent Claim
111 words
A stabilized solution of over 30% by weight of formaldehyde in water containing 1 to 100 p.p.m. of a vinyl polymer in methanol, said polymer having a number average molecular weight of 300-5000 and being made by (1) polymerizing vinyl acetate in solution in methanol in the presence of azobisisobutyronitrile as an initiator at reflux until 35 to 60% of the vinyl acetate is converted to polyvinyl acetate, then (2) adding water and sulfuric acid while the solution is at reflux and holding at reflux for 30 minutes, thereafter (3) adding a formaldehyde solution and holding the solution at reflux for 6 to 7 hours and then (4) neutralizing with sodium
Claim 6
Dependent Claim
111 words
A stabilized solution of over 30% by weight of formaldehyde in water containing 1 to 100 p.p.m. of a vinyl polymer in methanol, said polymer having a number average molecular weight of 300-5000 and being made by (1) polymerizing vinyl acetate in solution in methanol in the presence of azobisisobutyronitrile as an initiator at reflux until 35 to 60% of the vinyl acetate is converted to polyvinyl acetate, then (2) adding water and sulfuric acid while the solution is at reflux and holding at reflux for 30 minutes, thereafter (3) adding a formaldehyde solution and holding the solution at reflux for 6 to 7 hours and then (4) neutralizing with sodium
Claim 7
Dependent Claim
99 words
A stabilized solution of over 30% by weight of formaldehyde in water containing 1 to 100 p.p.m. of a vinyl polymer in methanol, said polymer having a number average molecular weight of 300-5000 and being made by (1) polymerizing vinyl acetate in solution in methanol in the presence of azobisisobutyronitrile as an initiator at reflux until 35 to 60% of the vinyl acetate is converted to polyvinyl acetate, then (2) adding water and sulfuric acid while the solution is at reflux and holding at reflux for 6 to 7 hours and then (3) neutralizing with sodium hydroxide and filtering
Claim 8
Dependent Claim
99 words
A stabilized solution of over 30% by weight of formaldehyde in water containing 1 to 100 p.p.m. of a vinyl polymer in methanol, said polymer having a number average molecular weight of 300-5000 and being made by (1) polymerizing vinyl acetate in solution in methanol in the presence of azobisisobutyronitrile as an initiator at reflux until 35 to 60% of the vinyl acetate is converted to polyvinyl acetate, then (2) adding water and sulfuric acid while the solution is at reflux and holding at reflux for 6 to 7 hours and then (3) neutralizing with sodium hydroxide and filtering
Claim 9
Dependent Claim
70 words
A stabilized solution of over 30% by weight of formaldehyde in water containing 1 to 100 p.p.m. of a vinyl polymer in methanol, said polymer being made by dissolving a polyvinyl acetate, having a number average molecular weight of 300-5000, in methanol, heating to reflux and adding vinyl acetate or acetaldehyde, concentrated sulfuric acid, and water and holding at reflux for 6 to 7 hours, and then neutralizing with sodium
Claim 10
Dependent Claim
70 words
A stabilized solution of over 30% by weight of formaldehyde in water containing 1 to 100 p.p.m. of a vinyl polymer in methanol, said polymer being made by dissolving a polyvinyl acetate, having a number average molecular weight of 300-5000, in methanol, heating to reflux and adding vinyl acetate or acetaldehyde, concentrated sulfuric acid, and water and holding at reflux for 6 to 7 hours, and then neutralizing with sodium
Claim 11
Dependent Claim
77 words
A stabilized solution of over 30% by weight of formaldehyde in water containing 1 to 100 p.p.m. of a vinyl polymer in methanol, said polymer being made by dissolving a polyvinyl alcohol, having a number average molecular weight of 300-5000, in methanol, heating to reflux and adding vinyl acetate or acetaldehyde, concentrated sulfuric acid, and water and holding at reflux for 6 to 7 hours, and then neutralizing with sodium hydroxide and filtering to remove settled solids.
Claim 12
Dependent Claim
77 words
A stabilized solution of over 30% by weight of formaldehyde in water containing 1 to 100 p.p.m. of a vinyl polymer in methanol, said polymer being made by dissolving a polyvinyl alcohol, having a number average molecular weight of 300-5000, in methanol, heating to reflux and adding vinyl acetate or acetaldehyde, concentrated sulfuric acid, and water and holding at reflux for 6 to 7 hours, and then neutralizing with sodium hydroxide and filtering to remove settled solids.
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) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |