JP2007083160A - Ultrasonic dispersion method and ultrasonic dispersion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic dispersion apparatus which obtains a mixed liquid or an emulsion high in the dispersibility of a dispersoid by almost uniformly dispersing the dispersoid in a dispersing medium as fine particles, an ultrasonic dispersion method using it and to suppress a rise in the temperature of the dispersing medium or the dispersoid while preventing the adhesion, solidification or reaction of the dispersing medium or the dispersoid on an ultrasonic generator. <P>SOLUTION: A liquid, wherein the liquid or solid dispersoid 13 to be dispersed in the dispersing medium 12 is floated on the liquid surface H of the dispersing medium 12 being the liquid, is held in a container 11. An ultrasonic generation means 15, which is constituted by providing a vibration part causing ultrasonic vibration above the liquid surface H of the liquid held in the container 11, is provided. The ultrasonic wave oscillated by the ultrasonic generation means 15 is propagated to the liquid surface H of the liquid held in the container 11 through air and the dispersoid 13 is dispersed in the dispersing medium 12 to obtain the mixed liquid or the emulsion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for obtaining a mixed liquid or an emulsion by uniformly dispersing a liquid or solid as a dispersoid in a liquid as a dispersion medium using ultrasonic waves.

  Conventionally, by utilizing ultrasonic energy, a dispersion liquid is dispersed in a dispersion medium liquid, and the dispersion medium and the dispersoid are mixed or emulsified to obtain a mixed liquid or emulsion. A technique for obtaining a mixed liquid by dispersing a solid (a granular material) as a dispersoid in a certain liquid is known.

  For example, in Patent Document 1, an ultrasonic horn that includes an ultrasonic vibrator and generates ultrasonic waves is immersed in a mixed liquid in which a dispersion medium and a dispersoid mixed in a container are mixed, and is generated in a liquid by ultrasonic waves. A technique for generating an emulsion in which a dispersoid is emulsified in a dispersion medium by cavitation is described.

  Also, for example, in Patent Document 2, an ultrasonic vibrator is provided in a container that holds a liquid dispersion medium, ultrasonic waves are propagated to the dispersion medium, and a thin film containing a liquid that is a dispersoid is contained in the dispersion medium. A technique for producing an emulsion in which a dispersoid is emulsified in a dispersion medium is described.

By the way, a mold release agent is applied to a mold used for casting so that the product can be easily released from the mold.
The release agent to be used is an emulsion (emulsion). Generally, commercially available release agent raw materials exist in a granular form and a paste form.
The granular release agent raw material is diluted in advance by adding a liquid (water) to the release agent raw material. Then, the paste-like release agent raw material and additives such as emulsifiers and preservatives are dispersed in a liquid (water) by using an emulsification method using ultrasonic waves as described above. And serve as a release agent.
JP-A-62-57374 JP-A-7-68144

  When the ultrasonic horn is immersed in a liquid composed of a dispersion medium and a dispersoid as in the above patent document, or when a container holding a liquid composed of a dispersion medium and a dispersoid is vibrated with ultrasonic waves, Cavitation occurs, and the liquid temperature rises due to frictional heat of water molecules and heat generation of the horn itself. When the temperature of the liquid rises, a situation where particles of dispersoids are more likely to aggregate is formed, the progress of dispersion of the dispersoid is inhibited, and it is difficult for the emulsion to stably maintain an emulsified state. Become.

  In addition, even when ultrasonic waves are applied to the liquid by an ultrasonic generator such as an ultrasonic horn or an ultrasonic vibrator, the dispersion of the dispersoid in the dispersion medium is mainly in contact with the ultrasonic generator and the liquid. Occurs in the vicinity. However, since cavitation occurs in the liquid to which ultrasonic waves are applied, the particles of the dispersoid are mixed with the dispersion medium in a state where the particles of the dispersoid are large. Many dispersoids exist in places where the action of ultrasonic waves does not spread by rising inside and rising to the liquid level. For this reason, there existed a malfunction that dispersion | distribution took time or the particle | grains of a dispersoid were large even if it disperse | distributed and emulsion was not stabilized.

  In particular, when the ultrasonic horn is immersed in a liquid composed of a dispersion medium and a dispersoid, if the dispersion medium or the dispersoid is a reactive substance, the ultrasonic horn reacts with the reactive substance, In some cases, the liquid components were changed. In addition, the dispersoid may adhere to and solidify on the ultrasonic horn, which may complicate maintenance.

  In addition, when the release agent raw material is made into an emulsified liquid and used as a release agent for a long period of time, there is a difference between the specific gravity of the dispersoid particles in the liquid and the specific gravity of the dispersion medium. Floating) and the liquid is separated. Therefore, an emulsifier is added to the release agent, or the release agent raw material is emulsified every time it is used to produce a release agent.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, in claim 1, a liquid in which a liquid dispersed in the dispersion medium or a dispersoid as a solid is floated is held in a container on the liquid surface of the dispersion medium, which is a liquid. Ultrasonic dispersion that disperses the dispersoid in the dispersion medium by oscillating ultrasonic waves from a position away from the liquid surface of the liquid held in the container and propagating the ultrasonic waves to the liquid surface through a gas. Is the method.

  In the second aspect of the invention, a container that holds a liquid composed of a dispersion medium that is a liquid and a liquid that floats on the liquid surface of the dispersion medium or a dispersoid that is a solid, and a liquid level of the liquid held in the container It is an ultrasonic dispersion device that includes ultrasonic generation means that oscillates an ultrasonic wave at a distant position and propagates the ultrasonic wave to the liquid surface through a gas.

  According to a third aspect of the present invention, the ultrasonic wave generating means, the liquid surface, and the liquid surface are arranged such that the position of the antinode of the amplitude of the ultrasonic wave oscillated by the ultrasonic wave generating means is the liquid level of the liquid held in the container. The relative position of is determined.

  As effects of the present invention, the following effects can be obtained.

In the first and second aspects, the dispersoid can be dispersed in the dispersion medium using ultrasonic energy to obtain a uniform mixed solution or emulsion.
In addition, since cavitation due to ultrasonic waves does not occur in the liquid containing the dispersion medium and the dispersoid, the liquid is agitated to prevent the dispersion from being dispersed in the dispersion medium before becoming fine particles. Since most of the quality can be dispersed as fine particles in the dispersion medium, the dispersibility of the dispersoid in the obtained mixed liquid or emulsion is improved, and the state in which the fine particles of the dispersoid are dispersed in the dispersion medium is stable. Held.
Furthermore, since the ultrasonic generation means and the dispersion medium or dispersoid are not in contact with each other, the temperature rise of the dispersion medium or dispersoid is suppressed, and the adhesion of the dispersion medium or dispersoid to the ultrasonic generation means is prevented, The reaction between the ultrasonic wave generating means and the dispersion medium or dispersoid can be prevented.

  According to the third aspect, the ultrasonic wave generated by the ultrasonic wave generating means can be effectively propagated to the liquid level of the liquid held in the container.

Next, embodiments of the invention will be described.
FIG. 1 is a diagram showing a configuration of an ultrasonic dispersion device according to the present invention, and FIG. 2 is a diagram for explaining how a dispersed phase is dispersed into a continuous phase.

First, the ultrasonic dispersion apparatus according to the present invention will be described.
This ultrasonic dispersion apparatus is an apparatus capable of realizing the ultrasonic dispersion method according to the present invention, and using the ultrasonic dispersion apparatus and the ultrasonic dispersion method, a dispersion medium that is a liquid is used. The liquid dispersoid can be dispersed to obtain a mixed liquid, or it can be uniformly dispersed and emulsified to obtain an emulsion. Moreover, the dispersion liquid of a granular material (solid) can be disperse | distributed to the dispersion medium which is a liquid using an ultrasonic dispersion apparatus and an ultrasonic dispersion method, and a liquid mixture can be obtained.

  As shown in FIG. 1, the ultrasonic dispersion apparatus 10 is mainly provided with a container 11 that holds a liquid and a vibration part that vibrates ultrasonically above the liquid level H of the liquid held in the container 11. And the ultrasonic wave generation means 15.

The container 11 is a container that holds a dispersion medium 12 that is a liquid and a dispersoid 13 that is dispersed in the dispersion medium 12.
The dispersoid 13 is a liquid or a solid (powder body) and constitutes a disperse phase different from the dispersion medium 12 which is a liquid continuous phase.

The dispersoid 13 has a specific gravity smaller than that of the dispersion medium 12, and the dispersoid 13 floats on the liquid surface of the dispersion medium 12 in a state where the dispersion medium 12 and the dispersoid 13 are held in the container 11.
Therefore, the dispersoid 13 appears on the liquid surface H of the dispersion medium 12 or the liquid composed of the dispersion medium 12 and the dispersoid 13 held in the container 11.
Strictly speaking, when the dispersoid 13 is a liquid, the liquid held in the container 11 is composed of the dispersion medium 12 and the dispersoid 13, and the dispersoid 13 appears on the liquid surface H of the liquid. When the dispersoid 13 is solid, the liquid held in the container 11 is the dispersion medium 12, and the dispersoid 13 appears on the liquid surface H of the liquid.
The dispersoid 13 may constitute a part of the liquid level H held in the container 11 or may form a layer on the liquid level H.

The ultrasonic wave generating means 15 oscillates ultrasonic waves toward the liquid level H of the liquid held in the container 11 as described above.
As the ultrasonic wave generation means 15, for example, a conventional horn type ultrasonic oscillation device can be adopted, and the ultrasonic horn constituting the vibration part of the oscillation device is used as a liquid held in the container 11. It is not immersed and is provided in a non-contact state.

  The ultrasonic wave generating means 15 is provided with at least an ultrasonic vibrator, and ultrasonic vibration generated by the ultrasonic vibrator is oscillated into a gas (air) from a vibrating part such as an ultrasonic horn. It propagates to the liquid level H via

  The frequency, amplitude, and wavelength of the ultrasonic wave oscillated from the ultrasonic wave generation means 15 are the amount and viscosity of the liquid held in the container 11, the degree of dispersion of the dispersoid 13 with respect to the dispersion medium 12, and the dispersion medium 12 and dispersoid. It adjusts suitably according to the property of 13 etc.

Further, the ultrasonic wave generating means 15 so that the liquid level H of the liquid held in the container 11 exists at a position where the displacement of the ultrasonic wave oscillated from the ultrasonic wave generating means 15 becomes the maximum value (antinode). 15 and the relative position of the liquid level H are determined.
However, by aligning the ultrasonic antinode and the liquid level H, the liquid level H can be vibrated more greatly with the same energy, and the ultrasonic wave can be more effectively propagated to the liquid level H. Although it is desirable because it is possible, the liquid level H may be aligned with other than the ultrasonic antinode.

And since the energy of the ultrasonic wave oscillated from the ultrasonic wave generation means 15 is attenuated while propagating in the gas, it is more possible to align the antinode of the cycle as soon as possible with the liquid level H. This is desirable because large energy can be transferred to the liquid.
In addition, when the antinode (amplitude peak) of the first cycle of the ultrasonic wave oscillated from the ultrasonic wave generation unit 15 and the liquid level H are aligned, the ultrasonic wave reflected by the liquid level H and the ultrasonic wave generation unit The ultrasonic wave oscillated from 15 may interfere and weaken the wave. In many cases, when the antinode of the second period of the ultrasonic wave oscillated from the ultrasonic wave generation means 15 is aligned with the liquid surface H, the inventor can efficiently transmit the ultrasonic wave to the liquid surface H. It has been confirmed.

A state in which the dispersoid 13 is dispersed in the dispersion medium 12 in the ultrasonic dispersion apparatus 10 configured as described above will be described with reference to FIG.
The ultrasonic wave oscillated by the ultrasonic wave generation means 15 is propagated to the liquid level H of the liquid held in the container 11 through the gas. As a result, the particles of the dispersion medium 12 and the particles of the dispersoid 13 existing in the vicinity of the liquid level H receive ultrasonic energy and vibrate (step S1).
When the particles of the dispersion medium 12 and the particles of the dispersoid 13 vibrate, the particles of the dispersoid 13 diffuse into the dispersion medium 12 (step S2).
If the dispersoid 13 diffuses into the dispersion medium 12, the specific gravity of the dispersion medium 12 in that portion is increased by the dispersoid 13, so that the dispersion medium 12 in which the dispersoid 13 diffuses moves downward in the liquid (step S 3). . Conversely, the dispersion medium 12 in which the dispersoid 13 has not diffused rises in the liquid, and a circulation flow is formed.

  As long as the propagation of the ultrasonic wave to the liquid level H of the liquid held in the container 11 is continued, the above steps S1 to S3 are repeated here on the liquid level H, and the dispersoid 13 is dispersed in the dispersion medium 12. The In this way, the dispersoid 13 is uniformly dispersed in the dispersion medium 12 to produce an emulsion (emulsion) or a uniform mixed solution.

According to the ultrasonic dispersion method, since the ultrasonic generation means 15 and the liquid containing the dispersion medium 12 and the dispersoid 13 are not in direct contact, the temperature rise of the liquid is suppressed, and the dispersoid due to the temperature rise is agglomerated. It is possible to prevent the occurrence of a state that is easy to do.
In addition, there is no risk of liquid adhering and solidifying the ultrasonic wave generating means 15, and maintenance is easy.
Furthermore, there is no possibility that the ultrasonic wave generating means 15 reacts with the liquid, and the liquid components are not changed unintentionally.

  According to the above ultrasonic dispersion method, cavitation does not occur in the liquid due to the ultrasonic wave propagated to the liquid from the ultrasonic wave generation means 15, so there is no possibility that the liquid is agitated by cavitation, and the dispersoid The phenomenon that the 13 particles are dispersed in the dispersion medium 12 in a state in which the particles are not appropriately miniaturized is suppressed. As a result, in the liquid obtained by dispersing the dispersoid 13 in the dispersion medium 12, most of the dispersoid 13 is dispersed in the dispersion medium 12 in an appropriately finely divided state, and in particular, an emulsion is obtained. In some cases, the emulsified state is stably maintained.

  Subsequently, a case where a release agent is generated will be described as an example of performing the ultrasonic dispersion method using the ultrasonic dispersion apparatus 10.

  In the present embodiment, the dispersion medium 12 is water, and the dispersoid 13 is a solid particulate release agent raw material and various additives such as emulsifiers, preservatives, and antifoaming agents. The dispersion medium 12 has a weight 250 times that of the dispersoid 13.

  A dispersion medium 12 is placed in a container 11 of an ultrasonic dispersion apparatus 10 and a dispersoid 13 is added thereto. As a result, the dispersoid 13 floats on the liquid level H of the liquid composed of the dispersion medium 12 held in the container 11. Depending on the relationship between the size of the container 11 and the amount of the dispersoid 13, a layer of the dispersoid 13 may be formed on the liquid surface H.

  Then, when ultrasonic waves are oscillated in the ultrasonic wave generation means 15 disposed above the liquid level H of the liquid held in the container 11 and propagated to the liquid level H, the fine particles of the dispersoid 13 are eventually formed. A dispersed liquid mixture (release agent) uniformly dispersed in the dispersion medium 12 is generated.

  In the above example, the release agent raw material contained in the dispersoid 13 is in the form of a solid powder, but may be in the form of a paste. In this case, a dispersed emulsion (release agent) in which fine particles of the dispersoid 13 are uniformly dispersed in the dispersion medium 12 is generated.

  As described above, in producing the release agent, the release agent raw material can be in the form of solid powder or paste. Conventionally, in order to promote the dispersion by improving the wettability of the release agent raw material and water as the dispersion medium 12, the solid granular release agent raw material is diluted with water and used as a paste. However, if the present invention is adopted, the inventor has confirmed that even if the solid particulate release agent raw material is used as the dispersoid 13 as it is, it is dispersed in the water as the dispersion medium 12. .

  Therefore, conventionally, when using a release agent raw material in the form of a solid granular material, a conventional ultrasonic dispersion device and a dilution mixing device for making the release agent raw material into a paste form have been required. However, in the present invention, it is sufficient to provide only the ultrasonic dispersion device, which can contribute to space and cost reduction. In addition, the paste-like release agent raw material is much heavier than the solid granular material, and the solid granular material can be used as it is, reducing transportation costs and storage space. Can also contribute.

  Further, in the above examples, an emulsifier is added as an additive. However, when the present invention is employed, the dispersoid 13 is prevented from being dispersed in a liquid in the form of large particles by cavitation as compared with the conventional example. Since most of the particles are dispersed as fine particles, the dispersibility of the dispersoid 13 is better than before, and the stability of the state in which the fine particles of the dispersoid 13 are dispersed (emulsification stability) is high. , No emulsifier can be required. If an emulsifier is not required, there is no possibility that the release agent may be altered by the emulsifier, and the cost for the emulsifier can be reduced.

  The ultrasonic dispersion apparatus and ultrasonic dispersion method according to the present invention can be used for cosmetics, medicines, agricultural chemicals, foods, emulsion polymerization of synthetic resins, paints, emulsification of various oils, emulsification of asphalt, and the like.

The figure which showed the structure of the ultrasonic type dispersion apparatus which concerns on this invention. The figure explaining a mode that a dispersed phase disperse | distributes to a continuous phase.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ultrasonic type dispersion apparatus 11 Container 12 Continuous phase 13 Dispersed phase 15 Ultrasonic wave generation means

Claims (3)

A liquid in which a liquid to be dispersed in the dispersion medium or a dispersoid that is a solid is floated is held in a container on a liquid surface of the dispersion medium that is a liquid,
In the ultrasonic generation means, the ultrasonic wave is oscillated from a position away from the liquid level of the liquid held in the container, and the ultrasonic wave is propagated to the liquid level through the gas,
The dispersoid is dispersed in the dispersion medium,
Ultrasonic dispersion method. A container that holds a liquid composed of a dispersion medium that is a liquid and a liquid that floats on the liquid surface of the dispersion medium or a dispersoid that is a solid;
An ultrasonic wave generating means for oscillating ultrasonic waves at a position away from the liquid level of the liquid held in the container and propagating the ultrasonic waves to the liquid level via a gas,
Ultrasonic dispersion device. The relative position between the ultrasonic wave generating means and the liquid level is determined so that the position of the antinode of the amplitude of the ultrasonic wave oscillated by the ultrasonic wave generating means is the liquid level of the liquid held in the container. Characterized by the
The ultrasonic dispersion apparatus according to claim 2.

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