US4273672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microencapsulation process
Assignee: Champion International Corp
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Filing: 1974-03-06
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Granted: 1981-06-16
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Expires: 1994-03-06
Abstract
Abstract Microcapsules are formed in the absence of coacervation by providing an oil-in-water emulsion containing a polymeric, emulsifying agent having cross-linkable groups or complexing sites and admixing with the emulsion a cross-linking agent or a complexing agent which forms an impermeable coating around the dispersed oil droplets. The emulsifying agent may be non-proteinaceous or the protein, gelatin. Impermeable capsule walls are formed solely by the addition of the cross-linking or complexing agent and extraneous hardening agents are obviated. Moreover, the emulsifying agent may be a preformed, polymeric, cross-linking agent which eliminates the need for any separate cross-linking agent.
Inventors
- 👤 Anthony E. Vassiliades
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:28
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/124; B41M5/165; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/18; Y; Y10; Y10S; Y10S428/00; Y10S428/914; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2987
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
149 words
A process for the formation of microcapsules having non-proteinaceous walls, in the absence of coacervation, which comprises the steps of: (A) forming a primary oil-in-water emulsion, which emulsion comprises a water-immiscible oily material dispersed in the form of microscopic droplets in a colloidal solution of a non-proteinaceous, polymeric emulsifying agent having about the same hydrophil-lipophil balance as the oily material, said emulsifying agent being selected from the group consisting of an emulsifying agent possessing cross-linkable groups and an emulsifying agent possessing complexing sites; and (B) forming an impermeable coating around said dispersed oil droplets solely by adding to the aqueous phase of said emulsion a member different from said emulsifying agent and selected from the group consisting of gum tragacanth and a borate under conditions of brisk agitation, said member reacting with said non-proteinaceous emulsifying agent so as to form a non-proteinaceous impermeable coating around said dispersed oil droplets.
Claim 2
Dependent Claim
149 words
A process for the formation of microcapsules having non-proteinaceous walls, in the absence of coacervation, which comprises the steps of: (A) forming a primary oil-in-water emulsion, which emulsion comprises a water-immiscible oily material dispersed in the form of microscopic droplets in a colloidal solution of a non-proteinaceous, polymeric emulsifying agent having about the same hydrophil-lipophil balance as the oily material, said emulsifying agent being selected from the group consisting of an emulsifying agent possessing cross-linkable groups and an emulsifying agent possessing complexing sites; and (B) forming an impermeable coating around said dispersed oil droplets solely by adding to the aqueous phase of said emulsion a member different from said emulsifying agent and selected from the group consisting of gum tragacanth and a borate under conditions of brisk agitation, said member reacting with said non-proteinaceous emulsifying agent so as to form a non-proteinaceous impermeable coating around said dispersed oil droplets.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein said added member is gum tragacanth.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein said added member is a borate.
Claim 5
Dependent Claim
11 words
The process of claim 3 wherein said borate is sodium borate.
Claim 6
Dependent Claim
12 words
The process of claim 4 wherein said emulsifying agent is polyvinyl alcohol.
Claim 7
Dependent Claim
19 words
The process of claim 2 wherein said emulsifying agent is a copolymer of methyl vinyl ether and maleic anhydride.
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) | 1984-06-15 | 1984-12-15 | 1985-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-15 | 1988-12-15 | 1989-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-15 | 1992-12-15 | 1993-06-16 | $7700.00 | Window Closed / Lapsed |