Patent US4046741A successfully refreshed from Google Patents.
US4046741A
Expired / Lapsed
US
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Post-treatment of polyurea microcapsules
Assignee: Zeneca Inc
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Filing: 1976-02-17
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Granted: 1977-09-06
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Expires: 1996-02-17
Abstract
Abstract Post-treatment of microcapsules having polyurea walls with ammonia or amines to reduce the residual isocyanate level and modify permeability of the microcapsule wall. Flowable formulations of the polyurea microcapsules then can be stored at pH values below 8 without generating carbon dioxide from the reaction of residual isocyanate groups with water.
Inventors
- 👤 Herbert B. Scher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:17
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/302; B; B01; B01J; B01J13/00; B01J13/02; B01J13/20; C08G18/08; C08G18/10; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2989
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
23 words
Method of reducing residual isocyanate level in polyurea microcapsules comprising post-treatment of said polyurea microcapsules with an excess of ammonia or an amine.
Claim 2
Dependent Claim
23 words
Method of reducing residual isocyanate level in polyurea microcapsules comprising post-treatment of said polyurea microcapsules with an excess of ammonia or an amine.
Claim 3
Dependent Claim
26 words
The method of claim 1 in which said amine is an organic dialkylamine wherein said alkyl groups each contain from 1 to 6 carbon atoms, inclusive.
Claim 4
Dependent Claim
12 words
The method of claim 1 in which said post-treatment is with ammonia.
Claim 5
Dependent Claim
31 words
In the process of microencapsulation of core material by interfacial polymerization of an organic isocyanate intermediate, the improvement comprising post-treating formed polyurea microcapsules with an excess of ammonia or an amine.
Claim 6
Dependent Claim
31 words
In the process of microencapsulation of core material by interfacial polymerization of an organic isocyanate intermediate, the improvement comprising post-treating formed polyurea microcapsules with an excess of ammonia or an amine.
Claim 7
Dependent Claim
34 words
In the process of claim 4 in which post-treatment is with an excess of an amine which is an organic dialkylamine wherein said alkyl groups each contain from 1 to 6 carbon atoms, inclusive.
Claim 8
Dependent Claim
16 words
In the process of claim 4 in which said post-treatment is with an excess of ammonia.
Claim 9
Dependent Claim
31 words
Improved polyurea microcapsules having reduced residual isocyanate levels and modified permeability of the microcapsule wall prepared by post-treatment of the formed polyurea microcapsules with an excess of an amine or ammonia.
Claim 10
Dependent Claim
31 words
Improved polyurea microcapsules having reduced residual isocyanate levels and modified permeability of the microcapsule wall prepared by post-treatment of the formed polyurea microcapsules with an excess of an amine or ammonia.
Claim 11
Dependent Claim
35 words
Improved polyurea microcapsules of claim 7 in which said post-treatment is with an excess of an amine which is an organic dialkylamine wherein said alkyl groups each contain from 1 to 6 carbon atoms, inclusive.
Claim 12
Dependent Claim
16 words
Improved polyurea microcapsules of claim 7 in which said post-treatment is with an excess of ammonia.
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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) | 1980-09-05 | 1981-03-07 | 1981-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-05 | 1985-03-07 | 1985-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-05 | 1989-03-07 | 1989-09-06 | $7700.00 | Window Closed / Lapsed |