JPH0252034A - Novel granulated material and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain a granulated material, in forming fine oleophilic particles into the granulated material using a water immiscible solvent and wax, by forming a dispersion system by heating wax in the solvent and adding a heated aqueous surfactant solution to said dispersing system to mix the same therewith and subsequently quenching the resulting mixture to encapsulate fine particles. CONSTITUTION:Oleophilic fine particles are mixed with a water immiscible solvent such as kerosene and wax is added to the resultant mixture in an amount effective for encapsulation. At this time, wax is melted in said solvent under heating to form a dispersion system. A heated aqueous surfactant solution is added to and mixed with the dispersion system and the obtained mixture is quenched. By this method, a granulated material wherein a large number of fine particles are encapsulated with wax and a surfactant is adhered to the surface of encapsulating wax is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel granule encapsulated using wax and a method for producing the same. Specifically, the present invention relates to a granule and a method for producing the same, in which an unexpected effect is achieved by modifying and effectively combining a submerged curing method and a submerged granulation method as microencapsulation methods. The granules and the method for producing the same according to the present invention are useful in the industrial and pharmaceutical fields related to conventional microcapsules, and are particularly useful in producing dense and strong ceramics when the raw material fine particles are ceramic raw materials.

BACKGROUND TECHNOLOGY AND PROBLEMS As main conventional microencapsulation methods for fine particle materials, there are known coacervation methods, in-liquid curing methods, interfacial polymerization methods, in-liquid granulation methods, and the like. Conventional manufacturing methods each have their own characteristics, but all of them tend to form adhesion areas between granulated particles, and the shape of the granulated bodies tends to be non-uniform. Ta. Particularly in the case of ceramic materials, if there are adhering portions between granules, abnormal grain growth tends to occur during shaping and sintering, resulting in a decrease in strength.

The main object of the present invention is to provide a granule that substantially eliminates the above problems, is essentially spherical, and has substantially no adhesion between granule particles, and a method for producing the same. be.

Means for Solving the Problems According to the present invention, a dispersion system consisting of lipophilic fine particles, a water-immiscible solvent and a wax of encapsulated insecticides is formed by heating and dissolving the wax in the solvent. A warm aqueous surfactant solution is added to the system and mixed; then rapidly cooled. A large number of the fine particles are encapsulated in the wax, and the surface of the encapsulated wax is coated with the surfactant. A method of making deposited granules is provided. In the above, when the fine particles to be granulated are non-oleophilic fine particles, the above-mentioned granules can be advantageously obtained by treating with a lipophilic coupling agent to make the fine particles lipophilic. In this way, a large number of lipophilic fine particles are encapsulated in wax to form an essentially spherical granule structure, and a surfactant is attached to the surface of the granule to form a granule. There is provided a granule comprising the fine particles and the encapsulated wax, characterized by a structure that prevents adhesion between bodies.

Specific aspects of the invention (1) Fine particles to be granulated The fine particles to be granulated are powders with a particle size of about 10 microns or less, and usually about 5 microns or less.

Non-oleophilic particles are generally hydrophilic particles, typically alumina, zirconia, mullite, titania, barium titanate, ferrite, and carbonized compounds (silicon carbide, etc.)
, oxidized compounds (such as silicon nitride), metal powders, metal compound powders such as other metal oxides, and mixtures thereof.

Examples of the lipophilic fine particles include fine particles of industrial organic compounds and punching agents.

(2) Dimensions of the granules The resulting encapsulated granules are essentially spherical, with a particle size of about 5 to 500 microns, usually about 10 to 500 microns.
250 microns and typically on the order of about 20-150 microns.

(3) Coupling agent The lipophilic-14 coupling agent for treating non-oleophilic fine particles is an organic compound that substantially chemically bonds to the surface of the fine particles to form an organic surface portion. . Typically, aluminum-based coupling agents (e.g. acetalkoxyaluminum diisopropylate, trade name AL-
M series); titanate coupling agents (e.g., tetraoctyl bis(ditridecylphosphite) titanate, trade name KR-series);
M series) etc. are exemplified. The amount used is generally about 0.2 to 2.6 times the amount of fine particles.

(4) Wax Wax is an organic substance that is solid at room temperature and dissolves or melts when heated: animal-based, plant-based,
Examples include mineral and petroleum-based natural waxes: synthetic waxes such as hydrocarbon-based waxes, modified waxes, hydrogenated oil-based waxes, fatty acid-based waxes, derivatives thereof, and blended waxes thereof. The wax is generally used in a state in which it is heated and dissolved in a water-immiscible solvent (for example, a lipophilic solvent such as kerosene).

Generally about 0.1 to 35% based on the weight of the fine particles to be granulated.
It is usually used in an amount of about 0.2 to 15.

(5) Surfactant The surfactant is a non-oil miscible solution such as a dilute aqueous solution (concentration is about 0.1 to 171 iffi$, usually about 0.55 iffi)
used as. The type of surfactant is not particularly limited as long as it does not adversely affect the mixed system. As a preferred example, a nonionic surfactant having an IILB of about 4 is advantageously used. Usually higher fatty acids (lauric acid,
Stearic acid, etc.) or alkali or alkaline earth metal salts of higher unsaturated fatty acids (oleic acid, linoleic acid, lylunic acid, etc.) are preferably used. The use of surfactants increases the wetting properties of the wax component, increases granulation properties, and prevents adhesion between granules.

(6) Water-immiscible solvent The water-immiscible solvent used to form the dispersion system of wax and fine particles to be granulated is not particularly limited, but is usually kerosene (
Lipophilic solvents such as kerosene) can be advantageously used.

(7) Examples of each component m The amount of each component described above can be changed depending on the equipment, process, etc. The table below shows alumina fine particles,
An example of the formulation used in the case of a granule dispersion system consisting of beeswax, kerosene, surfactant and water is shown below. The same applies when other ingredients are used.

Granule dispersion system No., solid content in kerosene alumina beeswax (m
l) (g) (heavy ffi$) (capacity z)! 50 12 1.00
5.72 50 24 0.50
1Q, 73 50 36 0.30
15.34 50 4B 0.25
19.45 50 60 0.2
0 23. +6 50 84 1.
00 29.67 50 96 1
．． 00 32.48 50 1Q8
1.00 35.19 50 120
0.80 37.5 (8) Production Examples Production process examples for the above (7) amounts of each component are summarized below.

O Agents used Ajinomoto: Aluminum-based coupling agent ^ 1 ° Rat/Titanate-based coupling agent KR46B, manufactured by σ, or Shin-Etsu Chemical Co., Ltd., manufactured by C, manufactured by Wako Pure Chemical, manufactured by Wako Pure Chemical 1, manufactured by Kao, manufactured by N, Silane coupling agent KBM, Sodium oleate, beeswax Nonion 0P-0-30 (1) Coupling agent treatment ■ Put 600 g of alumina, 5 Hml of distilled water, and 6.0 ml of a coupling agent into a bot mill and mix for about 1 hour.

Take out the slurry of (1) and (2) and dry it at 120° C. for 12 to 24 hours (until the solvent disappears).

■If it has solidified after drying, crush it in an automatic mortar.

(IT) Granulation process ■ Kerosene 501 and the above (7) component molecules fi12 to 12
Add 0 grams of treated alumina and mix.

■ Add beeswax to ■ according to the amount of ingredients in (7) above and heat (90°C). ...Liquid A① Take 2.5 g of sodium oleate, dissolve it in 500 ml of distilled water, and keep it heated (90°C).

...Liquid B ■Take 80ml of Liquid B into another beaker, add 10sl of it to the liquid, and stir vigorously. ...Liquid C■ Rapidly cool down Liquid C to 5℃ while stirring.

...Liquid D ■Take the liquid onto a slide glass and observe the granules with an optical microscope to confirm spherical granules.

■If a dispersion system is not required, deliquify it.

Actions and Effects The granules according to the present invention effectively granulate fine particles in water by utilizing the difference in surface tension between the oil component and water. Non-oleophilic particles such as alumina can be made lipophilic particles by treatment with a coupling agent. This allows the powder to be stably dispersed in a lipophilic system such as kerosene or beeswax.

Lipophilic systems such as kerosene and beeswax are immiscible with water, so if left untreated, lipophilic granules will stick to each other.
A surfactant such as sodium oleate is added to improve the affinity of the granules with water. This effect allows FAilItI systems such as alumina, kerosene, and beeswax to stably exist in water.

FIG. 1 shows a schematic diagram of spherical granules stably dispersed in water. This illustrates the operation and effect of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a spherical granule stably dispersed in water according to the present invention.

Claims (6)

[Claims] (1) Forming a dispersion system consisting of lipophilic fine particles, a water-immiscible solvent, and an effective amount of wax for encapsulation, in which the wax is heated and dissolved in the solvent; a heated aqueous surfactant solution is added to the system. A method for producing a granule in which a large number of the fine particles are encapsulated in the wax and a surfactant is attached to the surface of the encapsulated wax, which is characterized by the steps of adding and mixing; and then rapidly cooling. (2) The manufacturing method according to claim 1, wherein the lipophilic fine particles are lipophilic fine particles obtained by treating non-lipophilic fine particles with a lipophilic coupling agent. (3) The manufacturing method according to claim 2, wherein the non-oleophilic fine particles are inorganic fine particles. (4) The structure is essentially a spherical granule in which a large number of lipophilic fine particles are encapsulated in wax, and a surfactant is attached to the surface of the granule to form a structure between the granules. A granule comprising the fine particles and an effective amount of wax for encapsulation, characterized by a structure that prevents adhesion of the particles. (5) The granule according to claim 4, wherein the lipophilic fine particles are lipophilic fine particles obtained by treating non-lipophilic fine particles with a lipophilic coupling agent. (6) The granule according to claim 5, wherein the non-oleophilic fine particles are inorganic fine particles.