US4299723A
Expired / Lapsed
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Microcapsules and their preparation
Assignee: Bayer AG
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Filing: 1980-03-10
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Granted: 1981-11-10
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Expires: 2000-03-10
Abstract
Abstract Microcapsules containing a color-former solution which is encapsulated in the form of a solution in an organic solvent in capsules of the polyaddition product of a diisocyanate corresponding to the following general formula: ##STR1## wherein n=3-6 and a diamine wherein a mixture of an alkyl naphthalene and an isoparaffin containing from 10 to 20 carbon atoms is used as the solvent for the color-former and the microcapsules are tempered for at least 2 hours at a temperature of from 60° to 70° C. after their formation.
Inventors
- 👤 Manfred Dahm
- 👤 Gert Jabs
- 👤 Bernd Koglin
- 👤 Hildegard Schnoring
- 👤 Kurt Riecke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:02
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/16; B41; B41M; B41M5/00; B41M5/124; B41M5/165; B41M5/1655; Y; Y10; Y10S; Y10S428/00; Y10S428/914; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
A microcapsule comprising a capsule wall which surrounds a core, the capsule wall comprising the polyaddition product of a diamine and a diisocyanate of the formula ##STR4## wherein n is an integer of from 3 to 6 and the core comprising a solution of a color-former and an organic solvent comprising a mixture of an alkyl naphthalene and an isoparaffin having from 10 to 20 carbon atoms, said microcapsule having been tempered for at least 2 hours at a temperature of from 60 to 70° C. after its formation.
Claim 2
Dependent Claim
89 words
A microcapsule comprising a capsule wall which surrounds a core, the capsule wall comprising the polyaddition product of a diamine and a diisocyanate of the formula ##STR4## wherein n is an integer of from 3 to 6 and the core comprising a solution of a color-former and an organic solvent comprising a mixture of an alkyl naphthalene and an isoparaffin having from 10 to 20 carbon atoms, said microcapsule having been tempered for at least 2 hours at a temperature of from 60 to 70° C. after its formation.
Claim 3
Dependent Claim
23 words
The microcapsule as claimed in claim 1 wherein the diamine is an aliphatic primary or secondary diamine or hydrazine or a hydrazine salt.
Claim 4
Dependent Claim
37 words
The microcapsule as claimed in claim 1 wherein the organic solvent is a mixture of from 70 to 90 parts by weight of an alkyl naphthalene and from 10 to 30 parts by weight of an isoparaffin.
Claim 5
Dependent Claim
68 words
A process for preparing a microcapsule of claim 1 which comprises dissolving the diisocyanate and color-former in the organic solvent, emulsifying the thusly formed organic phase in an aqueous phase, adding the diamine in the form of an aqueous solution and in a stoichiometric quantity to the thusly formed emulsion and tempering resulting microcapsules for at least 2 hours at a temperature of from 60° to 70° C.
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) | 1984-11-09 | 1985-05-11 | 1985-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-09 | 1989-05-11 | 1989-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-09 | 1993-05-11 | 1993-11-10 | $7700.00 | Window Closed / Lapsed |