Patent US7079386B1 successfully refreshed from Google Patents.
US4798741A
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US
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Preparation of microencapsulated pigment
Assignee: EIDP Inc
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Filing: 1986-12-15
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Granted: 1989-01-17
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Expires: 2006-12-15
Abstract
Abstract Pigment particles of a suitable size are microencapsulated by mixing them in a gelatin solution, coacervating the gelatin to coat them, cooling to set the gelatin, adding formaldehyde to harden the particles, sequestering unreacted formaldehyde with a bisulfite, adding gelatin to coat the hardened particles, precipitating the particles chemically or physically, and washing the precipitate.
Inventors
- 👤 Jeffrey W. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:09
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/025; G; G03; G03C; G03C1/00; G03C1/002; G03C5/00; G03C5/26; G03C5/29; G03C5/315
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
76 words
A process for the preparation of a microencapsulated pigment comprising: A. mixing pigment particles having a particle size of 20 μm or less in a gelatin solution, B. coacervating the gelatin to coat the pigment particles, C. cooling to set the gelatin, D. adding formaldehyde to harden the particles, E. sequestering unreacted formaldehyde with a bisulfite, F. adding gelatin to coat the hardened particles, G. precipitating the particles chemically or physically, and H. washing the precipitate.
Claim 2
Dependent Claim
76 words
A process for the preparation of a microencapsulated pigment comprising: A. mixing pigment particles having a particle size of 20 μm or less in a gelatin solution, B. coacervating the gelatin to coat the pigment particles, C. cooling to set the gelatin, D. adding formaldehyde to harden the particles, E. sequestering unreacted formaldehyde with a bisulfite, F. adding gelatin to coat the hardened particles, G. precipitating the particles chemically or physically, and H. washing the precipitate.
Claim 3
Dependent Claim
15 words
A process according to claim 1 wherein ethanol is added in steps B and G.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein the mixing is accomplished by ultrasonic mixing.
Claim 5
Dependent Claim
12 words
A process according to claim 1 wherein the pigment is carbon black.
Claim 6
Dependent Claim
25 words
A process according to claim 1 wherein the microencapsulated pigment has a gelatin to pigment ratio of from 1.5 to 1 to 0.5 to 1.
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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) | 1992-01-17 | 1992-07-18 | 1993-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-17 | 1996-07-18 | 1997-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-17 | 2000-07-18 | 2001-01-17 | $7700.00 | Window Closed / Lapsed |