JPH0567334B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing pharmaceuticals, foods, feeds, catalysts, carbon, and other industrial materials as additives in the production and processing thereof.

BACKGROUND ART Conventionally, various methods have been proposed for producing oily material powder by cooling and solidifying oily material particles using a liquid as a refrigerant.

For example, a method of manufacturing a capsule body by pouring wax in which powder as a core substance is dispersed into water and stirring the resulting atomized wax containing the core substance is cooled and solidified with water ( (U.S. Pat. No. 3,856,699) is known.

However, this method has the disadvantage that wax particles with a low specific gravity are thrown into water with a high specific gravity, so that the wax particles do not settle and are not sufficiently cooled by the water. However, in order to cause wax particles to settle in water, it is necessary to select a powder with a high specific gravity as the core material powder to be dispersed in the wax, which results in the problem that the types of core materials that can be used are limited. There is.

In addition, when the oily substance particles are in the form of capsules, Japanese Patent Publication No. 51-8875, Japanese Patent Application Laid-open No. 51-8875,
Methods such as those disclosed in Japanese Patent Application Laid-open No. 8176, Japanese Patent Application Laid-Open No. 51-8177, and Japanese Patent Application Laid-Open No. 51-8178 are known. In these methods, a composite jet stream of concentric cylindrical liquid encapsulating material and capsule filling material is extruded into a cooling liquid to atomize it, and the capsule wall material is cooled while the fine particles are precipitated in the cooling liquid. , which is solidified to form a capsule. However, these methods have the disadvantage that the droplets do not become spherical when the interfacial tension between the cooling liquid and the capsule wall material is small.

On the other hand, in recent years, a method has been proposed for producing capsules of oil-based substances by using gases such as air, nitrogen, or carbon dioxide as a refrigerant (Japanese Patent Application Laid-Open No. 1983-1989-1).
201635). The method consists of atomizing the core material, molten fat, and heated pressurized air into a cooling gas using a triple concentric cylindrical nozzle to solidify the wall material and form the capsule body. However, although this method is effective when producing capsules with small particle sizes, it has the drawback that as the particle size increases, the cooling efficiency deteriorates, making it unavoidable to increase the size of the apparatus. Further, even when the particle size is small, it is difficult to obtain a uniform particle size.

Problems to be Solved by the Invention The present invention has been made in order to solve the problems seen in the above-mentioned prior art, and has good cooling efficiency for forming oily substance granules.
It is an object of the present invention to provide a method for efficiently and advantageously producing a powder or granular material of an oily substance, in which the magnitude of interfacial tension can be easily adjusted. Furthermore, it is an object of the present invention to obtain a spherical powder having a uniform particle size and a shape close to a circle in a high yield.

The present invention will be explained in detail below.

Means for Solving the Problems The feature of the present invention is to atomize the molten oil by spouting an alcohol aqueous solution from the inner pipe of a cylindrical double nozzle and a molten oil from the outer pipe, and then injecting the molten oil into particles in the alcohol aqueous solution. This is a method of producing a spherical powder of an oil-based substance by dropping it dropwise into a liquid and solidifying it by cooling.

Examples of the alcohol in the aqueous alcohol solution used as a refrigerant include isobutyl alcohol, ethanol, methanol, and butanol, and the present invention uses these aqueous solutions.

The appropriate alcohol concentration in the alcohol aqueous solution is 70-90%, and the temperature is 20-50℃.
is used. This temperature is 0℃ when we call it cooling.
Since the powder is not placed in close contact with the powder, the resulting spherical powder will not crack.

In the present invention, an aqueous solution of these alcohols is referred to as an aqueous alcohol solution.

These alcohol aqueous solutions used as refrigerants in the present invention have a sufficiently large interfacial tension with the particles of the oily substance, so that the particles can be efficiently shaped into spheres. In addition, in the present invention, even if the organic solution is made up of a single component and the interfacial tension is not sufficiently large as in the case of conventional refrigerants, water having a large interfacial tension is added to form a mixed solution that can be used at the interface with the particles. Since the tension is increased, fine particles can be obtained.

Incidentally, the size of the interfacial tension of an aqueous alcohol solution is an important factor that determines the shape of the powder when oily substance particles are cooled and solidified to form a powder. When the tension is small, the particles no longer form a spherical shape due to cooling and solidification.

The molten oily substances used in the present invention include various hydrogenated oils and fats such as palm hydrogenated oil, soybean hydrogenated oil, rapeseed hydrogenated oil, and cottonseed hydrogenated oil, beeswax,
Examples include waxes such as carnauba wax and resins such as polystyrene.

In the present invention, after these oily substances are heated and melted, an aqueous alcohol solution is ejected from the inner pipe of a concentric cylindrical double nozzle, and a molten oil is ejected from the outer pipe to atomize the atomized atomized material. The liquid is added dropwise to the liquid and solidified by cooling to produce a spherical powder of oily substance.

In this way, the alcohol aqueous solution is ejected from the inner pipe of the concentric cylindrical double nozzle, and the molten oil is ejected from the outer pipe to atomize the particles. It is formed into a spherical shape due to tension, and is cooled and solidified while settling in the liquid, becoming a spherical powder.

It is possible to obtain capsules with a high circularity (perimeter of a circle equal to the projected area of the particle/outline length of the projected particle) of 0.85 or more, close to 1.

In addition, in the present invention, the particles of the molten oily substance may be in the form of capsules containing a core material, or in the form of particles consisting of a W/O emulsion, or in the form of a dispersion in which a fine powder substance is dispersed in the molten oily substance. It may also be used in the form of particles consisting of. These particles can be generated in air or liquid by a known atomization method such as a pressurization method, a rotating disk method, or a vibration method, and the resulting particle size is
Particles of 10 μm to several mm are suitable as oily substance particles.

By using the method of the present invention, oil particles do not float on the surface due to the specific gravity of the alcohol aqueous solution, and there is no need to cool the alcohol solution at a low temperature, resulting in a high-yield spherical powder. Granules can be obtained.

Incidentally, the spherical powder of the present invention has a microcapsule (MC) conversion rate (MC conversion rate = Y・A/B×100,
However, in the formula, Y is the amount of MC recovered (g/5min),
A: Amount of core liquid in 1g of MC, B: Actual flow rate of core liquid (ml/
5min), it is possible to obtain 80% or more and close to 100%.

The present invention will be specifically described below with reference to examples.

Example 1 A 90% ethanol aqueous solution at room temperature was fed at a rate of 5 g/min from the inner tube of a concentric cylindrical double nozzle, and 35 g/min of balm hardened fat (melting point 58 degrees Celsius) melted at a temperature of 90 degrees Celsius was fed from the outer tube.
They were ejected and atomized at min. 90% of 40℃, concentration adjusted to increase interfacial tension
The particles were dropped into an ethanol aqueous solution and solidified by cooling. As the particles settled in the liquid, their walls solidified to form spherical capsules. The capsules were separated into liquid and capsules using a sieve and dried through ventilation. The particle size of the obtained capsules is approximately 0.8 mm.
It was hot.

Effects of the Invention As described above, according to the present invention, by cooling and solidifying molten particles of an oily substance using an alcohol aqueous solution as a refrigerant, spherical powder particles made of an oily substance can be produced with a high circularity. It has the advantage of being able to be manufactured efficiently.

Claims (1)

[Claims] 1 A spherical shape of an oil-based substance characterized by ejecting an alcohol aqueous solution from the inner tube of a concentric cylindrical double nozzle and a molten oil substance from the outer tube to atomize the particles, which are then dropped into the alcohol aqueous solution and solidified by cooling. Manufacturing method for powder products.