Claims
- 1. A process for producing microcapsules which consists essentially of
- adding a substance to be encapsulated to a dispersion (hydrosol) of fine colloidal particles in which water is used as dispersion medium, said fine colloidal particles having .zeta.-potentials on their surfaces,
- dispersing said dispersion in an oil medium to form an emulsion, and
- adding a coagulating effective amount of an electrolyte to said emulsion so as to sufficiently neutralize said .zeta.-potentials and thereby cause coagulation of the fine colloidal particles in said emulsion.
- 2. A process according to claim 1, wherein the emulsion is a W/O emulsion prepared by adding a water-soluble substance to be encapsulated to a dispersion (hydrosol) of fine colloidal particles in which water is used as dispersion medium, and dispersing said dispersion in an oil medium.
- 3. A process according to claim 1, wherein the emulsion is an O/W/O emulsion prepared by adding an oil-soluble substance to be encapsulated to a dispersion (hydrosol) of fine colloidal particles in which water is used as dispersion medium to form an O/W emulsion, and dispersing said emulsion in an oil medium.
- 4. A process according to claim 1, wherein the emulsion is a W(S)/O emulsion prepared by dispersing a water-insoluble powdery substance to be encapsulated in a dispersion (hydrosol) of fine colloidal particles in which water is used as dispersion medium, and dispersing said dispersion in an oil medium.
- 5. A process according to any one of claims 1, 2, 3 or 4, wherein the hydrosol is a hydrosol of an inorganic compound.
- 6. A process according to any one of claims 1, 2, 3 or 4, wherein the hydrosol is a hydrosol of at least one substance selected from the group consisting of silicon oxide, zirconium oxide, aluminum oxide, titanium oxide, styrene polymers and acrylic polymers.
- 7. A process according to any one of claims 1, 2, 3, or 4, wherein the electrolyte is at least one substance selected from the group consisting of chlorides, bromides, nitrates, sulfates and polyelectrolytes.
- 8. A process according to any one of claims 1, 2, 3 or 4, wherein the substance to be encapsulated is a core material, a combination of the core material and at least one substance selected from the group consisting of a polymer substance, a host compound forming a clathrate, a reactive monomer and a reactive prepolymer, or a clathrate of the core material.
Priority Claims (2)
Number |
Date |
Country |
Kind |
2-132685 |
May 1990 |
JPX |
|
2-410135 |
Dec 1990 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 07/820,607 filed Jan. 21, 1992, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (7)
Number |
Date |
Country |
50-62879 |
May 1975 |
JPX |
54-6251 |
Mar 1979 |
JPX |
54-10936 |
May 1979 |
JPX |
57-122931 |
Jul 1982 |
JPX |
59-222224 |
Dec 1984 |
JPX |
61-57236 |
Mar 1986 |
JPX |
62-241540 |
Oct 1987 |
JPX |
Non-Patent Literature Citations (2)
Entry |
Database WPI, AN=78-27830A [15], Derwent Publications Ltd, London, GB; & JP-A-53 022 530 (Agency of Ind. Sci. Tech.) Mar. 2, 1978. |
Patent Abstracts of Japan, vol. 13, No. 69, (C-569)[3417], 16th Feb. 1989; & JP-A-63 258 642 (Agency of Ind. Science & Technology) Oct. 26, 1988. |
Continuations (1)
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Number |
Date |
Country |
Parent |
820607 |
Jan 1992 |
|