KR20190021536A - Capsule comprising phase separable solvents and preparation method thereof - Google Patents

Abstract

The present invention relates to a capsule including a phase-separated solvent and a manufacturing method thereof. The capsule comprises: a first solvent in which a colored pigment responsive to a magnetic field is dispersed; and a second solvent in which a colored pigment not responsive to the magnetic field is dispersed. The present invention relates to the capsule in which the first solvent and the second solvent are mixed before the magnetic field is applied, and the first solvent and the second solvent are phase-separated into a first solvent phase and a second solvent phase together with the application of the magnetic field; and to the manufacturing method of the capsule.

Description

[0001] CAPSULE COMPRISING PHASE SEPARABLE SOLVENTS AND PREPARATION METHOD THEREOF [0002]

The present invention relates to a capsule comprising a solvent for phase separation and a method for producing the same, and more particularly, to a capsule containing a solvent for dispersing a colored pigment which is not reacted with a magnetic field, The present invention relates to a capsule which is phase-separated by application of a magnetic field and a method for producing the same.

Recently, various technologies for applying nanoparticles to a display, a printing apparatus, a film, and the like have been developed, and techniques capable of being utilized as a display device by generating a color variable effect by application of a magnetic field have been developed.

For example, techniques for producing microcapsules containing nanoparticles or nanocomposites as color variable materials by a magnetic field have been developed (Korean Patent Publication Nos. 10-2015-0017796, 10-2015-0020491, 10- These microcapsules are prepared by sealing materials such as liquids and solids with fine capsule wall materials. The microcapsules can be prepared by emulsion polymerization, multiple emulsion polymerization, condensation polymerization, solvent extraction And various methods such as evaporation method, suspension suspension method, coacervation method, extrusion method and spray method.

However, liquid microcapsules in which nanoparticles or nanocomposites are dispersed are extremely difficult to manufacture and have a very limited production process, and excessive amounts of polar or nonpolar solvents must be used in the course of preparation and cleaning, and nanoparticles A large amount of energy is required to be rearranged by application of an external electric field or a magnetic field, and the dispersibility is deteriorated due to a change in external conditions and a minute change in manufacturing process conditions, which causes many problems in mass production. In particular, since the distance between nanoparticles or nanocomposite particles distributed in the capsules is not constant, energy for re-arrangement is large and there is a problem that the color variable effect is not sufficient.

In view of such circumstances, Korean Patent Laid-Open Publication No. 10-2017-0064917 has developed various types of materials such as an emulsion, a jelly-like ball, and a sphere including a nanocomposite, It is required to develop a new type of material capable of detecting a distinct color change due to a large contrast ratio.

Korean Patent Publication No. 10-1340360 Korean Patent Publication No. 10-1335719 Korean Patent Publication No. 10-1543457 Korean Patent Publication No. 10-1379420 Korean Patent Publication No. 10-2017-0064917

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems of the prior art as described above, and it is an object of the present invention to provide a capsule having a capsule having a large color contrast ratio through the effect of separating into two phases by application of a magnetic field, And a process for producing the same.

Disclosure of Invention Technical Problem [8] In order to solve the above problems, the capsule of the present invention includes a first solvent in which a color pigment responsive to a magnetic field is dispersed; And a second solvent in which a colored pigment that does not react with a magnetic field is dispersed.

At this time, the colored pigment responsive to the magnetic field may be colored magnetic beads, and the colored magnetic beads may include colored pigments, magnetic particles, and resins.

In addition, the capsules may be prepared by mixing the first solvent and the second solvent before application of a magnetic field, and applying the magnetic field to the capsules so that the first solvent and the second solvent are phase-separated into a first solvent phase and a second solvent phase .

In addition, a method of manufacturing a capsule including a phase-separating solvent according to the present invention includes: dispersing a colored pigment in a first solvent in response to a magnetic field; Dispersing a colored pigment that does not react with the magnetic field in a second solvent; And mixing and encapsulating the first solvent and the second solvent.

The capsule according to the present invention includes a solvent which is phase-separated in one capsule, so that the effect of separating the capsule into two phases by application of a magnetic field shows a significant improvement in color contrast ratio.

1 is a schematic diagram showing the configuration and operation principle of a conventional display device.
2 is a schematic view showing a change in an external magnetic field applied to a capsule including a solvent for phase separation according to the present invention.
3 is a schematic view of a display device to which the capsule of the present invention is applied.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of example, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention.

It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention.

The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views, and length and area, thickness, and the like may be exaggerated for convenience.

A capsule comprising a phase-separated solvent according to the present invention comprises: a first solvent in which a colored pigment responsive to a magnetic field is dispersed; And a second solvent in which a colored pigment that does not react with a magnetic field is dispersed.

The capsules are composed of two or more solvents in the capsule, and each phase has different composition or different physicochemical properties. That is, the two solvents used for the central substance may be composed of a solvent which forms a homogeneous phase at a high temperature or a specific condition and then divides into two phases at room temperature. They may also be composed of solvents which do not mix with each other, such as water and oil.

A device or a capsule capable of displaying information by magnetism according to the prior art is as shown in Fig.

Referring to FIG. 1, in a conventional capsule, a solvent is collected in one phase, and a capsule is formed using a core material in which a plurality of particles are dispersed. In addition, a film or a substrate is formed on the upper and lower sides of the capsule to form the capsule and the film. When a magnetic pen or the like which applies an external magnetic field is approached to the film or the board, the magnetic particles inside the capsule are tilted toward one side to display a color and the other external magnetic body is approached to partially erase the film or the board Or by disposing the magnetic particles on one side toward the external magnetic body on the opposite side of the board to thereby erase the information indicated by the magnetic pen or the like on the film or board.

However, such prior art capsules have limited particle mobility in the core material, and thus there is a disadvantage that the shape is left unchanged even when the magnetic is removed, and the contrast ratio is low.

In contrast, the capsule according to the present invention is composed of first and second solvents which can form two phases as shown in FIG.

These solvents are not mixed with each other at room temperature and can be separated into upper and lower portions due to the difference in specific gravity. For example, hexane and perfluorohexane, which form a uniform phase at 70 to 80 ° C and are separated at room temperature, can be used as the first and second solvents.

Thus, when the magnetic field is applied, the change from the basic color to the high contrast color appears, and when the magnetic field is removed, the basic color can be returned immediately (within a few seconds). This characteristic differs greatly from the structure in which magnetic particles in a capsule must be dispersed by applying an external magnetic field to the opposite side of the film or board in order to erase the information displayed in the prior art.

The inside of the capsule is composed of two phases, and the two phases consist of a first solvent in which a colored pigment responsive to a magnetic field is dispersed and a second solvent in which a colored pigment not reacting to a magnetic field is dispersed. The two solvents are not mixed at room temperature and their positions may be different in the center material depending on the specific gravity.

For example, in the case where the capsule of the present invention is interposed between an upper film or a top board generating a magnetic field in FIG. 2 and a lower film or a lower board not generating a magnetic field, The phase by the first solvent is located at the top and the phase by the second solvent is at the bottom by the board. Thereafter, if an external self-center is applied to the lower film or the lower board, the position of the first solvent image and the second solvent image are changed, so that the color change occurs on the film or the board. .

The colored pigment responsive to the magnetic field of the present invention for realizing this effect may be a colored magnetic bead including a colored pigment, a magnetic particle, and a resin.

The magnetic particles are magnetized by a magnetic field to induce the alignment of the particles and remain magnetized by remnant magnetization after the magnetic field is cut off. Such materials include various types of photonic crystal materials, ferromagnetic materials, superparamagnetic materials, and mixtures of two or more particles having different saturation magnetization values.

The photonic crystal material may be silicon, titanium, barium, strontium, iron, nickel, cobalt, lead, aluminum, A compound such as an oxide or a nitride containing elements such as copper (Cu), silver (Ag), gold (Au), tungsten (W), molybdenum (Mo), zinc (Zn), zirconium . It is also possible to use styrene, pyridine, pyrrole, aniline, pyrrolidone, acrylate, urethane, thiophene, carbazole, An organic polymer or polystyrene comprising at least one monomer selected from the group consisting of fluorine, vinylalcohol, ethylene glycol and ethoxy acrylate, polyethylene, poly A polymer material such as polypropylene, polyvinyl chloride, or polyethylene terephthalate may be used.

The photonic crystal material may be formed as a form in which particles having no charge or a material having a charge in a cluster are coated. For example, the surface is processed (or coated) by an organic compound having a surface treated (or coated) with an organic compound having a hydrocarbon group, a carboxylic acid group, an ester group or an acyl group Or coated with a compound containing a halogen (F, Cl, Br, I, etc.) element, an amine, a thiol or a phosphine Particles coated with a surface by a coordination compound, and particles having a charge by forming radicals on the surface. By coating the surface of the photonic crystal material with a material such as silica, polymer, or polymeric monomer, the particles can have high dispersibility and stability in the solvent.

The photonic crystal material may have a particle diameter of several nanometers to several hundreds of micrometers, but is not limited thereto. When the particles are arranged at a predetermined distance by an external electric field, the refractive index of the particles and the solvent It is possible to set the size of the particle that can include the photonic crystal wavelength band of the visible light region in association with the refractive index of the visible light region.

Further, in order to configure the photonic crystal material to have an intrinsic color, a specific color may be imparted through adjustment of oxidation water or coating of an inorganic pigment, pigment, or the like. For example, Zn, Pb, Ti, Cd, Fe, As, Co, Mg, Al and the like containing a chromophore may be used in the form of oxides, emulsions and lactates as the inorganic pigments coated on the photonic crystal material. Fluorescent dyes, acid dyes, basic dyes, mordant dyes, sulphide dyes, vat dyes, disperse dyes, reactive dyes and the like can be used.

In addition, the photonic crystal material may be a material having a specific structural color so as to display a specific color. For example, particles such as silicon oxide (SiO _x ) and titanium oxide (TiO _x ) may be a material that is uniformly arranged at regular intervals in a medium having a different refractive index and reflects light of a specific wavelength. Since the photonic crystal particles have different structure colors depending on the viewing angle, the photonic crystal particles move due to the arrangement of the magnetic particles when the magnetic field is applied, and thus the different structure colors can be expressed according to the direction and intensity of the magnetic have.

In order to improve the dispersibility and stability of the color display material, silica, polymer, polymeric monomer, etc. may be coated on the surface of the particles.

In one embodiment, the colored magnetic beads are composed of pigment particles, iron nanoparticles, and a resin, and the surface of the particles thus produced can be hydrophobically surface-treated to be dispersed in the oil phase. In this case, the content of the iron nanoparticles may be in the range of 5 to 100% by weight with respect to the colored magnetic beads.

The method for producing a capsule including a phase-separating solvent according to the present invention includes the steps of dispersing a colored pigment in a first solvent in response to a magnetic field; Dispersing a colored pigment that does not react with the magnetic field in a second solvent; And mixing and encapsulating the first solvent and the second solvent.

In one embodiment, capsules can be prepared from the first and second solvents, which are homogeneous at high temperature or under certain conditions and divided into two phases at room temperature.

That is, a colored pigment which does not react with a magnetic field is dispersed in a solvent having a relatively high specific gravity among the two solvents, and a colored pigment or colored magnetic beads responsive to a magnetic field are dispersed in a solvent having a low specific gravity. The colored magnetic beads, like the colored magnetic beads used in the prior art, may be colored magnetic beads including colored pigments, magnetic particles, and resins.

At this time, each particle may be surface-treated or a dispersant may be varied so as not to be dispersed in different solvents. The solvent in which each particle is dispersed is prepared as a single solvent under a condition that a uniform phase can be formed, and the encapsulation process is performed while maintaining the above conditions.

When the capsule is made into a structure as shown in FIG. 2, the central material is divided into two phases upon returning to room temperature. The colored pigment or colored magnetic beads, which are dispersed in the magnetic field, The colorless pigment dispersed phase is located at the bottom of the core material.

In another embodiment, water and oil that do not mix with each other may be encapsulated as a core material. In this case, a colored pigment that does not react with a magnetic field is dispersed in water having a high specific gravity, The colored magnetic beads are dispersed. The thus-prepared water and oil are emulsified into a W / O phase to carry out a capsule process.

In this case, it is preferable to use an oil having a specific gravity lower than that of water as the oil to be used in order to realize the phase separation effect. For example, paraffinic oils and vegetable oils used in foods.

After the preparation of the capsules, the oil phase in which the colored magnetic beads are dispersed in response to the magnetic field and the water phase in which the color pigment not reacting to the magnetic field is dispersed is located at the bottom of the center material.

In the present invention, the particles dispersed in the first and second solvents may be subjected to surface treatment in order to improve the dispersibility of the particles in the respective solvents. In the case of particles using water as a solvent, hydrophilic functional groups such as -OH, -NH ₂ , -NH ₃ , -COO, -COOH and the like are chemically bonded to the surface of the particles to improve dispersibility, A hydrophobic functional group can be imparted to the surface by a chemical bond.

When water and oil are used as the first and second solvents, a dispersant for dispersing hydrophilic and hydrophobic particles may be contained in each solvent.

As a material constituting the wall of the capsule, any one of melamine, gelatin, urethane, urea, chitosan, epoxy, and polymethyl methacrylate may be used.

When the capsule made by the above method is made into a film and a board and a magnetic field is applied at the lower part, the phase of dispersed colored magnetic beads in response to the magnetic field located at the upper end of the central material is moved to the lower end of the core material, The dispersed phase migrates to the top of the central substance and a clear color change can be observed. When the magnetic field is removed again, the two phases return to the original position due to the specific gravity and return to the original color.

3 is a schematic view of a display device to which the capsule of the present invention is applied. The capsule of the present invention can constitute a display device as shown in FIG. 3, wherein a film or board constituting a protective layer is formed on the upper and lower portions of the capsule, and a lower magnetic layer is interposed therebetween with spacers .

At this time, the protective layer may be made of an elastic material. In addition, air, polymer, rubber, or the like may be provided in the space formed by the spacer, and elasticity may be imparted to restore the original shape. With this structure, a display device according to various purposes can be constructed.

In this type of display device, since the phase of the first solvent is in the lower part of the capsule due to the magnetic field applied by the lower magnetic layer in the normal state, the basic color of the colored pigment contained in the second solvent Is displayed.

In this state, when a magnetic pen or the like approaches the upper protective layer, the phase of the first solvent moves to the upper side while the phase of the second solvent moves to the lower side. Therefore, The color change due to the first solvent occurs. Further, when the external magnetic material is removed, the phase of the second solvent returns to the upper portion of the capsule within a few seconds, so that the basic color is displayed on the display device.

By this operation, the display device to which the capsule according to the present invention is applied exhibits remarkably improved color contrast ratio and fast color changing speed.

While the present invention has been described with reference to the preferred embodiments thereof, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be made by those skilled in the art without departing from the spirit of the invention, The examples are to be regarded as being within the scope of the invention and the appended claims.

Claims (5)

A first solvent in which a colored pigment responsive to a magnetic field is dispersed;
A second solvent in which a colored pigment that does not react with a magnetic field is dispersed;
≪ / RTI > wherein the capsule comprises a phase-separated solvent.
The method according to claim 1,
Wherein the colored pigment responsive to the magnetic field is a colored magnetic bead.
The method of claim 2,
Wherein the colored magnetic beads comprise a colored pigment, magnetic particles, and a resin.
The method according to claim 1,
The capsule is characterized in that the first solvent and the second solvent are mixed before application of a magnetic field and the phase separation of the first solvent and the second solvent into a first solvent phase and a second solvent phase with application of a magnetic field ≪ / RTI > wherein the capsule comprises a phase-separated solvent.
Dispersing a colored pigment responsive to a magnetic field in a first solvent;
Dispersing a colored pigment that does not react with the magnetic field in a second solvent;
Mixing and encapsulating the first solvent and the second solvent;
Wherein the solvent is phase separated. ≪ RTI ID = 0.0 > 11. < / RTI >

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