Patent US4761255A successfully refreshed from Google Patents.
US4761255A
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Process for the continuous production of microcapsules
Assignee: Bayer AG
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Filing: 1987-04-24
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Granted: 1988-08-02
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Expires: 2007-04-24
Abstract
Abstract A continuous process for the production of microcapsules having polymeric walls and a solid or liquid core which comprises mixing a polyisocyanate with the material to be encapsulated, reacting the resulting mixture, a polyamine, and an aqueous phase containing a dispersion aid, the reaction being initiated in a high-turbulence mixing zone to form an emulsion, and subsequently transferring the reaction product to a multiple-stage cascade of vessels, the temperature being increased from stage to stage and being kept constant during each stage.
Inventors
- 👤 Manfred Dahm
- 👤 Gert Jabs
- 👤 Bernd Koglin
- 👤 Hildegard Schnoring
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:03
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/16; C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/32; C08G18/3225; C08G18/3228; Y; Y10; Y10S; Y10S428/00; Y10S428/914; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2989
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
134 words
In a continuous process for the production of microcapsules having polymeric walls encapsulating a solid or liquid core material in which a polyisocyanate is dispersed with the material to be encapsulated and then reacted with a polyamine in an aqueous phase containing a dispersion aid, the improvement which comprises forming a reaction mixture emulsion in a high turbulence mixing zone which has an average residence time in the mixing zone of less than 5 minutes while continuous recirculating the reaction mixture through the mixing zone from 0.3 to 10 times, and subsequently completing the reaction in the mixture by transferring the reaction mixture emulsion through a multiplestage cascade of a series of individual vessels with the temperature in each individual vessel being kept constant and with the temperature progressively increasing from vessel to vessel.
Claim 2
Dependent Claim
134 words
In a continuous process for the production of microcapsules having polymeric walls encapsulating a solid or liquid core material in which a polyisocyanate is dispersed with the material to be encapsulated and then reacted with a polyamine in an aqueous phase containing a dispersion aid, the improvement which comprises forming a reaction mixture emulsion in a high turbulence mixing zone which has an average residence time in the mixing zone of less than 5 minutes while continuous recirculating the reaction mixture through the mixing zone from 0.3 to 10 times, and subsequently completing the reaction in the mixture by transferring the reaction mixture emulsion through a multiplestage cascade of a series of individual vessels with the temperature in each individual vessel being kept constant and with the temperature progressively increasing from vessel to vessel.
Claim 3
Dependent Claim
26 words
A process, as claimed in claim 1, including a post-reaction for completing the reaction in a zone consisting of a vessel or a cascade of vessels.
Claim 4
Dependent Claim
22 words
A process, as claimed in claim 1, wherein the pH is kept at, or does not fall below, a value of 7.
Claim 5
Dependent Claim
35 words
A process, as claimed in claim 1, wherein the reaction mixture has a residence time in the mixing zone of less than one minute and is recirculated through the mixing zone 0.5 to 3 times.
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) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |