US4228031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making impermeable microcapsules
Assignee: New Oji Paper Co Ltd
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Filing: 1978-05-04
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Granted: 1980-10-14
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Expires: 1998-05-04
Abstract
Abstract The method of making impermeable microcapsules comprises the steps of preparing an aqueous dispersion of microcapsules having a capsule wall of a water-insoluble polyamine-epoxy resin and adding to the aqueous dispersion an electrolyte to dehydrate the microcapsules.
Inventors
- 👤 Hiroshi Iwasaki
- 👤 Shigeo Okamoto
- 👤 Mitsuru Kondo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:03
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/20; B01J13/206; Y; Y10; Y10S; Y10S428/00; Y10S428/914; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2987
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
63 words
A method for making impermeable microcapsules comprising the steps of preparing coacervates by complex coacervation between a cationic polyamine-epoxy resin and an anionic colloid material, curing by heating to form microcapsules each having a capsule wall of irreversibly hardened and water insoluble polyamine-epoxy resin, preparing an aqueous dispersion of said microcapsules and adding to said aqueous dispersion an electrolyte to dehydrate said microcapsules.
Claim 2
Independent Claim
63 words
A method for making impermeable microcapsules comprising the steps of preparing coacervates by complex coacervation between a cationic polyamine-epoxy resin and an anionic colloid material, curing by heating to form microcapsules each having a capsule wall of irreversibly hardened and water insoluble polyamine-epoxy resin, preparing an aqueous dispersion of said microcapsules and adding to said aqueous dispersion an electrolyte to dehydrate said microcapsules.
Claim 3
Dependent Claim
34 words
A method for making impermeable microcapsules as defined in claim 1, in which said electrolyte is a member selected from the group consisting of water-soluble alkali metal salts, water-soluble ammonium salts and mixtures thereof.
Claim 4
Dependent Claim
43 words
A method for making impermeable microcapsules as defined in claim 2, in which said electrolyte is added to said aqueous dispersion in an amount of 1 to 200 parts by weight with respect to 100 parts by weight of microcapsule wall forming material.
Claim 5
Dependent Claim
43 words
A method for making impermeable microcapsules as defined in claim 3, in which said electrolyte is added to said aqueous dispersion in an amount of 5 to 100 parts by weight with respect to 100 parts by weight of microcapsule wall forming material.
Claim 6
Dependent Claim
35 words
A method for making impermeable microcapsules as defined in claim 1, in which said microcapsules are dehydrated to such an extent that each of said microcapsules are deformed into a hollow or depressed ball form.
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) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |