US4252785A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled release composition
Assignee: Hexcel Corp
•
Filing: 1979-07-09
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Granted: 1981-02-24
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Expires: 1999-07-09
Abstract
Abstract A microporous controlled release composition, comprising at least about 20%, by weight, based on the total weight of the composition, of a solid, low molecular weight urea-formaldehyde resin having a molar ratio of urea to formaldehyde of from about 2:1 to about 3.5:1, and at least one active material contained in and releasable from said resin over a sustained period of time when said resin is in an aqueous medium.
Inventors
- 👤 Donald J. Isoldi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:33
CPC Classifications
A; A61; A61L; A61L9/00; A61L9/015; A61L9/04; A61L9/042; A61K; A61K9/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2031; A61L9/05; C; C11; C11D; C11D17/00; C11D17/04; C11D17/041
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
101 words
A microporous controlled release composition in the form of a solid block, comprising from about 20% to about 90% by weight, of a solid, low molecular weight urea-formaldehyde resin having a molar ratio of urea to formaldehyde of from about 2:1 to about 3.5:1, at least about 4% by weight up to about 25%, by weight, of an active material comprising a germicide contained in and releasable from said resin over a sustained period of time when said resin is in an aqueous medium, all based on the total weight of the composition, and the balance, if any, being a diluent.
Claim 2
Dependent Claim
101 words
A microporous controlled release composition in the form of a solid block, comprising from about 20% to about 90% by weight, of a solid, low molecular weight urea-formaldehyde resin having a molar ratio of urea to formaldehyde of from about 2:1 to about 3.5:1, at least about 4% by weight up to about 25%, by weight, of an active material comprising a germicide contained in and releasable from said resin over a sustained period of time when said resin is in an aqueous medium, all based on the total weight of the composition, and the balance, if any, being a diluent.
Claim 3
Dependent Claim
22 words
The composition according to claim 1, wherein said urea to formaldehyde molar ratio is from about 2:1 to less than about 3:1.
Claim 4
Dependent Claim
17 words
The composition according to claim 2, wherein said molar ratio is from about 2:1 to about 2.8:1.
Claim 5
Dependent Claim
26 words
The composition according to claim 1, wherein said urea-formaldehyde resin comprises from about 50 to about 80% by weight, based on the weight of said composition.
Claim 6
Dependent Claim
27 words
The composition according to claim 1, wherein said active material is at least one further material selected from the group consisting of detergents, deodorizers, fragrances and dyes.
Claim 7
Dependent Claim
60 words
The composition according to claim 1, comprising from about 50 to about 80% by weight of said urea-formaldehyde resin, up to about 15% by weight of said active material, based on the total weight of said composition, and the balance being said diluent, the molar ratio of urea to formaldehyde in said resin being from about 2:1 to about 2.8:1.
Claim 8
Dependent Claim
13 words
The composition according to claim 6, wherein said molar ratio is about 2:1.
Claim 9
Dependent Claim
14 words
The composition according to claim 1, wherein said germicide is a quaternary ammonium salt.
Claim 10
Dependent Claim
18 words
The composition according to claim 1, wherein said active material comprises a germicide, a detergent and a fragrance.
References Cited (Backward Citations)
US2541248A
Cited
CA697623A
Cited
US795757A
Cited
US1408535A
Cited
GB524125A
Cited
GB587263A
Cited
US2490958A
Cited
US2491287A
Cited
US2700683A
Cited
US2851424A
Cited
US3102108A
Cited
US3074845A
Cited
GB920524A
Cited
US3223513A
Cited
US3162573A
Cited
US3076744A
Cited
US3183200A
Cited
US3584113A
Cited
DE1936748A1
Cited
US4018741A
Cited
US3516846A
Cited
US4160754A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |