US4138362A
Expired / Lapsed
US
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Formation of microcapsules by interfacial cross-linking, microcapsules produced, and microcapsular dispersion
Assignee: Champion International Corp
•
Filing: 1977-01-18
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Granted: 1979-02-06
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Expires: 1997-01-18
Abstract
Abstract Pressure-rupturable, oil-containing microcapsules are produced by admixing a water-immiscible, oily material containing an oil-soluble, non-polymeric polyfunctional isocyanate cross-linking agent, and an aqueous solution of a polymeric emulsifying agent in the form of a water-soluble polymer containing recurring --NH 2 or ═NH groups or a water-soluble natural gum containing recurring hydroxy groups. An oil-in-water emulsion is formed containing the isocyanate dispersed in the form of microscopic emulsion droplets in the aqueous continuous phase containing the emulsifying agent, and a solid capsule wall is formed by the cross-linking of the emulsifying agent by the isocyanate. Emulsions utilizing the natural polymeric emulsifying agents preferably contain a viscosity lowering agent in the form of a urea-formaldehyde or alkali metal periodate in order to obtain a higher solids coat weight while at an efficient coating viscosity.
Inventors
- 👤 Anthony E. Vassiliades
- 👤 Cheng H. Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:13
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/16; B41; B41M; B41M5/00; B41M5/124; B41M5/165; Y; Y10; Y10S; Y10S428/00; Y10S428/914; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249994; Y10T428/249995; Y10T428/249997; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
159 words
A process for the production of pressure-rupturable, oil-containing microcapsules, which comprises admixing: (A) a water-immiscible, oily material containing an oil-soluble, non-polymeric cross-linking agent, said cross-linking agent consisting essentially of a polyfunctional isocyanate; and (B) an aqueous solution comprising a viscosity-lowering agent and a polymeric emulsifying agent, said viscosity-lowering agent being selected from the group consisting of an alkali metal periodate, a water soluble urea-aldehyde prepolymer and mixtures thereof, said emulsifying agent being selected from the group consisting of water-soluble natural polymers containing recurring --NH 2 of ═NH groups, and water-soluble natural gums containing recurring hydroxy groups, said admixing being conducted under conditions effective to form an oil-in-water emulsion, wherein said oily material containing said polyfunctional isocyanate is dispersed in the form of microscopic emulsion droplets in an aqueous, continuous phase, containing said emulsifying agent, and thereby surrounding each of said droplets with a solid cross-linked capsule wall formed by the cross-linking of said emulsifying agent by said polyfunctional isocyanate.
Claim 2
Dependent Claim
159 words
A process for the production of pressure-rupturable, oil-containing microcapsules, which comprises admixing: (A) a water-immiscible, oily material containing an oil-soluble, non-polymeric cross-linking agent, said cross-linking agent consisting essentially of a polyfunctional isocyanate; and (B) an aqueous solution comprising a viscosity-lowering agent and a polymeric emulsifying agent, said viscosity-lowering agent being selected from the group consisting of an alkali metal periodate, a water soluble urea-aldehyde prepolymer and mixtures thereof, said emulsifying agent being selected from the group consisting of water-soluble natural polymers containing recurring --NH 2 of ═NH groups, and water-soluble natural gums containing recurring hydroxy groups, said admixing being conducted under conditions effective to form an oil-in-water emulsion, wherein said oily material containing said polyfunctional isocyanate is dispersed in the form of microscopic emulsion droplets in an aqueous, continuous phase, containing said emulsifying agent, and thereby surrounding each of said droplets with a solid cross-linked capsule wall formed by the cross-linking of said emulsifying agent by said polyfunctional isocyanate.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein said viscosity lower agent is an alkali metal periodate.
Claim 4
Dependent Claim
16 words
The process of claim 1 wherein said viscosity lowering agent is a water soluble urea-aldehyde prepolymer.
Claim 5
Dependent Claim
20 words
The process of claim 1 wherein said emulsifying agent is a natural polymer containing recurring --NH 2 or ═NH groups.
Claim 6
Dependent Claim
16 words
The process of claim 4 wherein said polymeric emulsifying agent is gelatin, casein, chitin or chitosan.
Claim 7
Dependent Claim
11 words
The process of claim 5 wherein said emulsifying agent is chitosan.
Claim 8
Dependent Claim
11 words
The process of claim 5 wherein said emulsifying agent is gelatin.
Claim 9
Dependent Claim
15 words
The process of claim 6 wherein said viscosity lowering agent is an alkli metal periodate.
Claim 10
Dependent Claim
16 words
The process of claim 7 wherein said viscosity lowering agent is a water soluble urea-aldehyde prepolymer.
Claim 11
Dependent Claim
19 words
The process of claim 1 wherein said polymeric emulsifying agent is a water-soluble natural gum containing recurring hydroxy groups.
Claim 12
Dependent Claim
16 words
The process of claim 10 wherein said gum is gum arabic, gum tragacanth, or guar gum.
Claim 13
Dependent Claim
11 words
The process of claim 11 wherein said gum is gum arabic.
Claim 14
Dependent Claim
20 words
The process of claim 1 wherein said emulsifying agent is a synthetic polymer containing recurring --NH 2 or ═NH groups.
Claim 15
Dependent Claim
14 words
The process of claim 13 wherein said emulsifying agent is urea-formaldehyde or melamine-formaldehyde prepolymer.
Claim 16
Dependent Claim
11 words
The process of claim 14 wherein said emulsifying agent is urea-formaldehyde.
Claim 17
Dependent Claim
19 words
The process of claim 11 wherein said viscosity lowering agent is an alkali metal periodate or a urea-aldehyde prepolymer.
Claim 18
Dependent Claim
15 words
The process of claim 16 wherein said viscosity lowering agent is an alkali metal periodate.
Claim 19
Dependent Claim
11 words
A microcapsular dispersion produced according to the process of claim 1.
Claim 20
Dependent Claim
8 words
Microcapsules produced by the process of claim 1.
Claim 21
Dependent Claim
8 words
Microcapsules produced by the process of claim 3.
Claim 22
Dependent Claim
8 words
Microcapsules produced by the process of claim 6.
Claim 23
Dependent Claim
8 words
Microcapsules produced by the process of claim 7.
Claim 24
Dependent Claim
21 words
The process of claim 1 wherein said oily material additionally contains a chromogenic compound capable of reacting with a Lewis acid.
Claim 25
Dependent Claim
13 words
The process of claim 1 wherein said oily material additionally contains carbon black.
Claim 26
Dependent Claim
13 words
The process of claim 1 wherein said aqueous solution additionally contains carbon black.
Claim 27
Dependent Claim
28 words
The process of claim 1 wherein said polyfunctional isocyanate comprises an isocyanate adduct selected from the group consisting of hexamethylenediisocyanate the hexanetriol, and toluene diisocyanate and trimethylol propane.
Claim 28
Dependent Claim
11 words
The process of claim 1 wherein said polyisocyanate is, toluene diisocyanate.
Claim 29
Dependent Claim
21 words
The process of claim 1 wherein a mixture of an alkali metal periodate and a water soluble urea-formaldehyde polymer is used.
Claim 30
Dependent Claim
108 words
A process for the production of pressure-rupturable, oil-containing microcapsules, which comprises admixing: (A) a water-immiscible, oily material containing an oil-soluble, non-polymeric cross-linking agent, said cross-linking agent consisting essentially of a polyfunctional isocyanate; and (B) an aqueous solution of a polymeric emulsifying agent, said emulsifying agent being chitin or chitosan, said admixing being conducted under conditions effective to form an oil-in-water emulsion, wherein said oily material containing said polyfunctional isocyanate is dispersed in the form of microscopic emulsion droplets with a solid, cross-linked capsule wall formed by the cross-linking of said emulsifying agent by said poly-functional isocyanate, said polymeric emulsifying agent being the sole coreactant for said polyfunctional isocyanate.
Claim 31
Dependent Claim
108 words
A process for the production of pressure-rupturable, oil-containing microcapsules, which comprises admixing: (A) a water-immiscible, oily material containing an oil-soluble, non-polymeric cross-linking agent, said cross-linking agent consisting essentially of a polyfunctional isocyanate; and (B) an aqueous solution of a polymeric emulsifying agent, said emulsifying agent being chitin or chitosan, said admixing being conducted under conditions effective to form an oil-in-water emulsion, wherein said oily material containing said polyfunctional isocyanate is dispersed in the form of microscopic emulsion droplets with a solid, cross-linked capsule wall formed by the cross-linking of said emulsifying agent by said poly-functional isocyanate, said polymeric emulsifying agent being the sole coreactant for said polyfunctional isocyanate.
Claim 32
Dependent Claim
11 words
The process of claim 29 wherein said emulsifying agent is chitosan.
Claim 33
Dependent Claim
8 words
Microcapsules produced by the process of claim 29.
Claim 34
Dependent Claim
8 words
Microcapsules produced by the process of claim 30.
Claim 35
Dependent Claim
28 words
The process of claim 29 wherein said polyfunctional isocyanate comprises an isocyanate adduct selected from the group consisting of hexamethylenediisocyanate and hexanetriol, and toluene diisocyanate and trimethylol propane.
Claim 36
Dependent Claim
11 words
The process of claim 29 wherein said polyisocyanate is toluene diisocyanate.
Claim 37
Dependent Claim
117 words
A process for the production of pressure-rupturable, oil-containing microcapsules, which comprises admixing: (A) a water-immiscible, oily material containing an oil-soluble, non-polymeric cross-linking agent, said cross-linking agent consisting essentially of a polyfunctional isocyanate; and (B) an aqueous solution of a polymeric emulsifying agent, said emusifying agent being a water soluble synthetic polymer containing recurring --NH 2 or ═NH groups, said admixing being conducted under conditions effective to form an oil-in-water emulsion, wherein said oily material containing said polyfunctional isocyanate is dispersed in the form of microscopic emulsion droplets with a solid, cross-linked capsule wall formed by the cross-linking of said emulsifying agent by said poly-functional isocyanate, said polymeric emulsifying agent being the sole coreactant for said polyfunctional isocyanate.
Claim 38
Dependent Claim
117 words
A process for the production of pressure-rupturable, oil-containing microcapsules, which comprises admixing: (A) a water-immiscible, oily material containing an oil-soluble, non-polymeric cross-linking agent, said cross-linking agent consisting essentially of a polyfunctional isocyanate; and (B) an aqueous solution of a polymeric emulsifying agent, said emusifying agent being a water soluble synthetic polymer containing recurring --NH 2 or ═NH groups, said admixing being conducted under conditions effective to form an oil-in-water emulsion, wherein said oily material containing said polyfunctional isocyanate is dispersed in the form of microscopic emulsion droplets with a solid, cross-linked capsule wall formed by the cross-linking of said emulsifying agent by said poly-functional isocyanate, said polymeric emulsifying agent being the sole coreactant for said polyfunctional isocyanate.
Claim 39
Dependent Claim
14 words
The process of claim 35 wherein said emulsifying agent is urea-formaldehyde or melamine-formaldehyde prepolymer.
Claim 40
Dependent Claim
11 words
The process of claim 36 wherein said emulsifying agent is urea-formaldehyde.
Claim 41
Dependent Claim
8 words
Microcapsules produced by the process of claim 37.
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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) | 1982-02-05 | 1982-08-07 | 1983-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-05 | 1986-08-07 | 1987-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-05 | 1990-08-07 | 1991-02-06 | $7700.00 | Window Closed / Lapsed |