US4066568A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing microcapsules
Assignee: Nippon Pulp Industry Co Ltd
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Filing: 1976-07-30
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Granted: 1978-01-03
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Expires: 1996-07-30
Abstract
Abstract Microcapsules are produced by dispersing and emulsifying hydrophobic material such as water insoluble material, color forming material, color forming assistant, oil and mixture of oil and various medicines dissolved therein in gelatin aqueous solution so as to produce minute particles, adding coacervate forming agent composed of phytic acid and/or its salt to the above system to form gelatin and coacervate on the surface of minute cores of the hydrophobic material thereby forming coating film thereon into capsule form.
Inventors
- 👤 Atushi Nakazawa
- 👤 Muneichi Ono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:49
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/10; Y; Y10; Y10S; Y10S436/00; Y10S436/829; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2987
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
107 words
In a method of producing microcapsules in which hydrophobic material, namely water insoluble powder or oil or oil with a material dissolved therein, is dissolved in gelatin aqueous solution, thereby causing a dispersion emulsion and forming minute particles, and gelatin and coacervate are formed on the surface of the minute cores of the hydrophobic material by adding coacervate forming agent to this system, thereby forming a capsule like film, the improvement wherein a phase is formed which is thick in gelatin by adding phytic acid and/or alkali metal salt or alkaline earth metal salt as said coacervate forming agent, thereby forming capsules around said hydrophobic material cores.
Claim 2
Dependent Claim
107 words
In a method of producing microcapsules in which hydrophobic material, namely water insoluble powder or oil or oil with a material dissolved therein, is dissolved in gelatin aqueous solution, thereby causing a dispersion emulsion and forming minute particles, and gelatin and coacervate are formed on the surface of the minute cores of the hydrophobic material by adding coacervate forming agent to this system, thereby forming a capsule like film, the improvement wherein a phase is formed which is thick in gelatin by adding phytic acid and/or alkali metal salt or alkaline earth metal salt as said coacervate forming agent, thereby forming capsules around said hydrophobic material cores.
Claim 3
Dependent Claim
21 words
Method as claimed in claim 1, wherein a water insoluble powder, dispersion agent and/or additional wall film forming material are added.
Claim 4
Dependent Claim
59 words
Method as claimed in claim 1, wherein said hydrophobic material is color developing material having an electron giving property which is normally colorless or of a light color and/or an electron giving material selected from the group consisting of a phenol compound, an organic acid and their polymers which allow said color developing material to color develop when heated.
Claim 5
Dependent Claim
23 words
Method as claimed in claim 1, wherein the amount of phytic acid and/or its salts used is below 0.2g per 1g of gelatin.
Claim 6
Dependent Claim
21 words
Method as claimed in claim 1, wherein said gelatin aqueous solution is an aqueous solution of acid or alkali treated gelatin.
Claim 7
Dependent Claim
23 words
Method as claimed in claim 1, wherein as said hydrophobic material, benzoylleucomethyleneblue and crystal violet lactone are used which are pressure sensitive dyes.
Claim 8
Dependent Claim
24 words
Method as claimed in claim 1, wherein as said hydrophobic material, polyisobutylene and terpene system thermoplastic resin are used which are pressure sensitive adhesives.
Claim 9
Dependent Claim
28 words
Method as claimed in claim 1, wherein as hydrophobic material, basic color development dye composed of crystal violet lactone and/or phenol nature material composed of 4,4'-isopropylidenediphenol are used.
Claim 10
Dependent Claim
79 words
In a method of producing microcapsules in which hydrophobic material, namely water insoluble powder or oil or oil with a material dissolved therein is encapsulated, comprising forming a dispersion emulsion of said hydrophobic material in an aqueous solution of polycation and forming a coacervate by adding a polyanion and acid, the improvement wherein said polycation is gelatin and said polyanion and said acid both consist essentially of phytic acid and/or the alkali metal or alkaline earth metal salt thereof.
Claim 11
Dependent Claim
79 words
In a method of producing microcapsules in which hydrophobic material, namely water insoluble powder or oil or oil with a material dissolved therein is encapsulated, comprising forming a dispersion emulsion of said hydrophobic material in an aqueous solution of polycation and forming a coacervate by adding a polyanion and acid, the improvement wherein said polycation is gelatin and said polyanion and said acid both consist essentially of phytic acid and/or the alkali metal or alkaline earth metal salt thereof.
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) | 1981-01-02 | 1981-07-04 | 1982-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-02 | 1985-07-04 | 1986-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-02 | 1989-07-04 | 1990-01-03 | $7700.00 | Window Closed / Lapsed |