KR101339099B1 - Magnetic Particle and the Fabrication Method Thereof - Google Patents
Magnetic Particle and the Fabrication Method Thereof Download PDFInfo
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Abstract
The present invention relates to a magnetic particle and a method for producing the same, and more particularly, comprising a magnetic core and a shell, and comprising a continuous or discontinuous void formed between or between the core and the shell, wherein the gap or diameter of the void is at least 10 nm; The present invention relates to a magnetic particle including a polymer layer having a quantum dot emitting by ultraviolet rays and a method of manufacturing the same, which has not only basic magnetic properties but also various visible light emitting properties, thereby enhancing security, high brightness, and controlling specific gravity. The color is different from the color of the dark magnetic material itself, and has the advantage of having a high oil absorption and a large surface area, which is a color ink, general paints, automotive powder pigments, cosmetic pigments, catalyst paints It can be used in, in particular, it is used as the security ink of the deed of oil, there is an advantage that can conceal the area and shape to which the security particles are applied.
Description
The present invention relates to magnetic particles, and more particularly, to a magnetic particle comprising a shell comprising a void portion on a magnetic core and comprising a polymer layer having a quantum dot emitting by ultraviolet rays, and a method of manufacturing the same.
The main application fields of magnetic powder are information such as permanent magnet whose main purpose is to provide magnetic flux, various magnetic sensors that infer the change of external physical quantity by reading the characteristic change of magnetic body according to the change of external magnetic field, and hard disk And a storage device for storing the same, and in the field of anti-counterfeiting, it is generally included in a product for reading a change in characteristics of a magnetic material. However, since the general magnetic powder has a color of dark gray or dark brown, its application is limited in applications requiring bright colors, and there is a disadvantage in that the anti-counterfeiting effect is insufficient only by magnetic properties. Therefore, in order to solve this problem, bright magnetic materials using core-shell technology have been developed. Through this, it is used for various purposes such as color inks, general paints, automotive powder pigments, cosmetic pigments, catalyst paints, and anti-counterfeiting inks by giving the magnetic particles the characteristics of vivid color and high brightness.
Therefore, there has been a market demand for a magnetic material having a variety of specialized colors used for such various uses, and various studies are being conducted on techniques for concealing dark colors of the magnetic material.
As a conventional technique of concealing the dark color of the magnetic material, a white powder and a manufacturing method thereof (Korean Patent Laid-Open Publication No. 10-2006-0028393) provide a method of manufacturing a bright magnetic body using a titanium oxide film and a silver film.
However, in order to use magnetic materials in various fields such as inks, paints, biomaterials, and catalysts, magnetic materials having high oil absorption and high specific surface area are required, as well as brightness and color, specific gravity is adjusted according to the use. It also needs to be supplemented for use in anti-counterfeiting technologies that require more complex and special functions.
The present invention is to provide a magnetic particle having a variety of light emission characteristics in the visible light region can enhance the security function, has a very high brightness, color and specific gravity is controlled, high oil absorption and high specific surface area and a method of manufacturing the same In addition, an exemplary embodiment of the present invention is to provide a security ink that can effectively conceal the area and shape to which the security particles are applied to prevent the forgery and tampering of the oil price certificate.
In one embodiment of the invention comprises a magnetic core and a shell, comprising a continuous or discontinuous gap formed between the core and the shell or in the shell, the gap or diameter of the gap is at least 10nm; Provided are magnetic particles including a polymer layer having a quantum dot emitting light by ultraviolet rays.
In the magnetic particles according to an embodiment of the present invention, the polymer layer may be at least two polymer electrolyte layers, and may have quantum dots in at least one polymer layer.
In the magnetic particles according to an embodiment of the present invention, the quantum dots may be CdSe, CdS, ZnS, InAs, or InP.
In the magnetic particles according to an embodiment of the present invention, the quantum dots may be a mixture of two or more quantum dots having different emission wavelengths.
In the magnetic particle according to the embodiment of the present invention, the continuous gap formed between the core and the shell includes a gap, and the gap of the gap may be at least 10 nm.
In the magnetic particle according to another embodiment of the present invention, the discontinuous pores formed in the shell, the diameter of the pores forming the pores may be at least 50nm.
In the magnetic particles according to another embodiment of the present invention, the shell may include a dielectric material or a metal.
The magnetic particles according to the embodiment of the present invention may include at least one layer of metal shell made of metal on at least one layer of dielectric shell made of a dielectric material including voids.
In the magnetic particles according to an embodiment of the present invention, the gap portion may be a hollow portion having a gap of 10 to 300 nm.
In the magnetic particles according to the embodiment of the present invention, the pores may be pores having a diameter of 50 to 300 nm.
Magnetic particles according to an embodiment of the present invention may have a brightness of 65 or more.
Magnetic particles according to an embodiment of the present invention may be a security particle of the price certificate.
In another embodiment of the present invention, the method includes: applying a plurality of particles or materials for forming pores to be formed of a material that is removable by firing or chemical treatment at a high temperature on a magnetic core; Forming a shell comprising a dielectric material or a metal on the particles obtained from the previous step; It provides a method for producing magnetic particles comprising removing a plurality of particles or materials for forming the voids to form a shell including the voids and forming a polymer layer having quantum dots.
In the method of manufacturing magnetic particles according to an embodiment of the present invention, the method may include forming a metal shell including a metal on a shell including a gap.
In the method for producing magnetic particles according to an embodiment of the present invention, the step of applying the material for forming the voids is performed by a method of polymerizing the polymer forming composition on the magnetic core, the composition for forming a polymer to prepare a polymer It may include a raw material monomer and an initiator for the following.
In the method of manufacturing magnetic particles according to an embodiment of the present invention, the forming of the hollow-forming material layer may include surface modifying the magnetic core using a coupling agent and polymerizing the composition for forming a polymer on the surface-modified magnetic core. It may be carried out by a reaction method.
In the method for producing magnetic particles according to an embodiment of the present invention, the composition for forming a polymer may include an anionic monomer as a coagulation stabilizer.
In the method for producing magnetic particles according to an embodiment of the present invention, the thickness of the pore portion may be controlled according to the content of the raw material monomer and the anionic monomer in the polymer-forming composition.
In this case, the composition for forming a polymer may include a styrene-based monomer as a raw material monomer and a sodium styrene sulfonate as an anionic monomer.
In the method for producing magnetic particles according to an embodiment of the present invention, the surface modification in the step of applying the material for forming the pores may be performed using 3-methacryloxy propyl trimethoxysilane as a coupling agent.
In the manufacturing method of the magnetic particles according to an embodiment of the present invention, the step of applying a plurality of particles for the formation of the pores is mixing and stirring the magnetic core and the pores for forming the particles in water, the separated pore forming particles are applied It can be carried out by a method comprising the step of heat treating the magnetic particles. At this time, the heat treatment may be performed in a temperature range of 100 to 110 ℃.
In this case, the pore forming particles may be vinyl polymer particles having a size of 50 to 300 nm.
Surface modification of the core can also be carried out by applying polyethylene imine.
In the method for producing magnetic particles according to an embodiment of the present invention, the step of forming a shell having pores is performed by a method of removing the magnetic particles obtained from the previous step by treating the pores forming particles or a substance with a solvent in which the substances are dissolved. Can be.
In the method of manufacturing magnetic particles according to an embodiment of the present invention, the forming of the shell having the voids may include removing the magnetic particles obtained from the previous step by firing them in a temperature range in which the material for forming the voids may be fired. Can be performed.
In the method of manufacturing magnetic particles according to an embodiment of the present invention, the step of forming a polymer layer having a quantum dot is a method of coating a dispersion containing a polymer electrolyte material and a quantum dot at least once on the magnetic particles obtained from the previous step It can be performed as.
Magnetic particles according to one embodiment of the present invention is useful as a security particle of the deed, the security particle is a particle provided in the deed to prevent or determine the forgery and tampering of the deed.
An exemplary embodiment of the present invention provides an ink containing the magnetic particles according to the present invention as a security ink used in the manufacture of a deed, in order to prevent or discriminate forgery and tampering of the deed.
Magnetic particles according to the present invention is not only magnetic properties, but also gives a variety of light emission characteristics in the visible light area to enhance the security function, has a very high brightness, there is an advantage that the color is different from the color of the magnetic material of the dark color itself, It can control specific gravity of magnetic particles and has high oil absorption and large surface area. It can be used in color ink, general paint, automotive powder pigment, cosmetic pigment, catalyst paint, and especially security certificate of oil price certificate. Used as, there is an advantage that can conceal the area and shape to which the security particles are applied.
1 is a cross-sectional view showing an example of magnetic particles capable of forming a quantum dot according to the present invention,
2 is a cross-sectional view showing another example of magnetic particles capable of forming quantum dots in accordance with the present invention;
3 is a cross-sectional view showing another example of magnetic particles capable of forming quantum dots according to the present invention,
4 is a cross-sectional view showing another example of magnetic particles capable of forming quantum dots according to the present invention;
5 is a cross-sectional view showing another example of magnetic particles capable of forming quantum dots according to the present invention;
6 is a cross-sectional view showing an example of magnetic particles capable of forming quantum dots in accordance with the present invention.
7 is a cross-sectional view showing another example of magnetic particles capable of forming quantum dots in accordance with the present invention;
8 is a cross-sectional view showing another example of magnetic particles capable of forming quantum dots according to the present invention;
9 is a cross-sectional view showing another example of magnetic particles capable of forming quantum dots according to the present invention;
10 is a cross-sectional view showing another example of magnetic particles capable of forming quantum dots in accordance with the present invention.
Description of the Related Art [0002]
1 to 5,
100: magnetic core
300: shell 200: void portion
310:
320: shell (first shell) made of a dielectric material
321 to 323: first to third dielectric films
400: shell made of a metallic material (second shell)
401 to 402: first to second metal films constituting the second shell layer
6 to 10,
100: magnetic core
200, 200 (I), 200 (II): Shell part including voids
300: air gap (pore)
210 to 230: Dielectric shell films constituting the shell portion including the void portion, 220 is a shell containing the void portion
400: outer shell (shell made of metal)
410 ~ 420: multilayer metal shell films constituting the outer shell
Hereinafter, with reference to the accompanying drawings will be described in detail a magnetic particle and a manufacturing method of the present invention. The following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms, and the following drawings may be exaggerated in order to clarify the spirit of the present invention. Also, throughout the specification, like reference numerals designate like elements.
Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.
In the accompanying drawings, the magnetic particles capable of forming the polymer layer having the quantum dots are illustrated as being spherical, but the shape of the magnetic particles is not limited to the spherical shape, but also includes a plate-shaped case.
Magnetic particles of the present invention is a magnetic core; And a shell comprising a continuous or discontinuous void formed between the core and the shell or in the shell, wherein the gap or diameter of the void is at least 10 nm; It includes a polymer layer having a quantum dot that emits light by ultraviolet rays.
1 to 5 are examples of particles that can be applied to form a polymer layer having a quantum dot that emits light by ultraviolet rays as a magnetic core; And a shell, wherein the particle includes a continuous void portion between the core and the shell, but is not limited thereto. The continuous void portion may be understood as a hollow portion.
As shown in FIG. 1, magnetic particles capable of forming a polymer layer having a quantum dot according to the present invention include a
The
Meanwhile, the
As an example, FIG. 2 illustrates a case where the shell is made of a metal material, and FIG. 3 illustrates a case where the shell is made of a dielectric material.
The
Based on FIG. 2, when the
As shown in FIG. 2, the magnetic particles I include a
The magnetic particles (I) according to the present invention, the
In detail, the
The
The
In this case, the
In detail, when the structure of the
In detail, the sphere of the
Preferably, the metals of the
The air gap between the sphere of the
Magnetic particles having a polymer layer having a quantum dot of the present invention may be manufactured using the magnetic particles (I), wherein the polymer layer having a quantum dot may form an outermost shell or may be formed in the gap portion. .
Here, the polymer layer may be a polymer electrolyte layer in terms of binding the quantum dots, and the polymer electrolyte may vary depending on the type of the quantum dots. For example, as the positively charged polymer electrolyte, polyallylamine hydrochloride (PAH), Polydiallydimethylammonium chloride (PDADMAC), polyethyleneimine (PEI), and the like, and the negatively charged polyelectrolytes include poly (sodium styrenesulfonate (PSS) and polyacrylic acid, PAA) etc. In particular, it may be preferable to have a multilayer structure of at least two layers obtained from such a polymer electrolyte for even distribution of quantum dots. Can have a multilayer structure. In some cases, the polymer layer may have a quantum dot in at least one layer, and thus, the quantum dot may be positioned in the stacked polymer electrolyte layer. It may be CdSe, CdS, ZnS, InAs, or InP having characteristics, in particular, the quantum dots may be a mixture of two or more quantum dots having different emission wavelengths, in which case various emission characteristics may be induced to further enhance security. have.
As described above, the magnetic particles including the polymer layer having the quantum dots may further enhance the security function by providing unique visible light emission characteristics of the quantum dots as well as the magnetic properties expressed in the magnetic core.
According to the present invention, the magnetic particles including the polymer layer having the quantum dots using the magnetic particles (I) have a specific gravity similar to that of oil, have a brightness of 65 or more, and have a different color from that of the core. It is preferable that the thickness of is 10-300 nm.
The method of manufacturing the magnetic particles (I) described above is not particularly limited, but for example, forming a material layer for forming pores on the magnetic core, which is removable by heat treatment or chemical treatment (s11); The method may include forming a shell layer including a metal on the pore forming material layer (s12) and forming a pore by removing the pore forming material layer (s13).
In step s11, the pore forming material layer may be a layer including a vinyl polymer. In particular, considering the magnetic core may be a layer containing a polystyrene polymer preferably.
The formation of the pore forming material layer may be performed using a polymer dissolving solution, but is preferably formed through polymerization of the polymer forming composition on the core in terms of forming a monodisperse layer. In this case, the composition for forming a polymer may include a raw material monomer for preparing a polymer and an initiator for initiating a polymerization reaction, and preferably, the composition for forming a polymer includes a coagulation stabilizer. In the case of including a coagulation stabilizer, the polymerization may be performed on the core to form an even surface without agglomeration of the polymer.
In a specific embodiment of the present invention, the composition for forming a polymer used to form the material layer for forming the pore portion is a raw material monomer is a styrene-based monomer, the aggregation stabilizer may use sodium styrenesulfonate. The initiator used azobisisobutyronitrile (AIBN), but is not limited thereto.
On the other hand, in the formation of a homogeneous single dispersion film in forming such an organic pore forming material layer on the core, the step of forming the pore forming material layer is a surface modification of the magnetic core using a coupling agent Next, a method of polymerizing the polymer-forming composition on the surface-modified core may be considered. At this time, the coupling agent may be adjusted according to the composition for forming the polymer. In one embodiment of the present invention, the coupling agent may be methacryloxy propyl trimethoxysilane.
As such, when the core is surface-modified and polymerized on the surface-modified core to form a polymer layer, the polymer-ferromagnetic composite may be formed, and the obtained polymer layer may have a homogeneously coated film.
Specifically, the magnetic particles or the surface-modified magnetic particles are mixed and stirred, wherein the temperature may be preferably in the range of 20 to 70 ℃ in consideration of polymerization.
Forming a shell made of a metal material in the polymer-ferromagnetic composite obtained through the step s11, that is, step s12 is impregnated with the polymer-ferromagnetic composite in a metal precursor solution in which a precursor of a metal forming a metal film is dissolved, and then a reducing agent To form a metal film in the polymer-ferromagnetic composite.
Next, the pore forming material layer is removed from the magnetic particles formed as the metal shell / pore forming material layer / core obtained through the step s12 (s13), wherein the removing may be performed thermally or chemically and chemically removed. Means that the polymer layer is dissolved and removed by dissolving the polymer, and thermal polymer removal means thermally decomposing the polymer by thermally treating the metal-polymer-ferromagnetic complex in an inert gas.
By preparing the magnetic particles (I) as described above and forming a polymer layer having quantum dots therein, magnetic particles having a polymer layer having quantum dots in the outermost shell can be obtained.
In this case, the forming of the polymer layer having a quantum dot may be performed by coating a dispersion including a polymer electrolyte material and a quantum dot at least once on the magnetic particles obtained from the previous step. When a plurality of coatings are performed to form a polymer layer having multiple quantum dots, the polymer electrolyte material or the quantum dots between the layers may be the same or different.
On the other hand, the magnetic particles (II) as an example of other magnetic particles that can be used to prepare a magnetic particle having a polymer layer having a quantum dot of the present invention will be described in detail. This is the case in which the
In the magnetic particle (II) according to the embodiment of the present invention as described above, the
In detail, the
The
As shown in FIG. 3B, the
The
The thickness of the
In this case, as shown in FIG. 4, the
In detail, the
The air gap between the structure of the
The magnetic particles (II) according to the present invention adopts a configuration of the
In detail, the
In this case, as shown in FIG. 5, the sphere of the
The magnetic particles II having the structure of the
Magnetic particles having a polymer layer having a quantum dot of the present invention may be manufactured using the magnetic particles (II), wherein the polymer layer having a quantum dot may form an outermost shell or may be formed in the gap portion. .
In this case, the polymer layer may be a polymer electrolyte layer in terms of binding the quantum dots, and the polymer electrolyte may vary depending on the type of the quantum dots. For example, as the positively charged polymer electrolyte, polyallylamine hydrochloride (PAH) Polyallyldimethylammonium chloride (PDADMAC), polyethyleneimine (PEI), and the like, and the negatively charged polyelectrolyte are poly (sodium styrenesulfonate, PSS) and polyacrylic acid (PAA). In particular, it may be desirable to have at least two layers of multilayer structures obtained from such a polymer electrolyte for even dispersion of the quantum dots. If you have a multilayer structure If so, at least one polymer layer may have a quantum dot, and accordingly, the quantum dot may be positioned inside the stacked polymer electrolyte layer In the magnetic particles according to the exemplary embodiment of the present invention, the quantum dots emit light by ultraviolet rays. It may be CdSe, CdS, ZnS, InAs, or InP having characteristics, in particular, the quantum dots may be a mixture of two or more quantum dots having different emission wavelengths, in which case various emission characteristics may be induced to further enhance security. have.
As described above, the magnetic particles including the polymer layer having the quantum dots may further enhance the security function by providing unique visible light emission characteristics of the quantum dots as well as the magnetic properties expressed in the magnetic core.
Meanwhile, the method of manufacturing the magnetic particles (II) described above is not limited thereto. For example, the method may further include forming a material layer for forming void portions on the core (s21); Forming a first shell layer including a dielectric material on the pore forming material layer (s22); Forming a second shell layer including the metal on the first shell layer (s23); And removing the pore forming material layer to form the pore (S24).
On the magnetic core, in the forming of the pore forming material layer (s21), the pore forming material layer may be a layer including a vinyl polymer. In particular, considering the magnetic core may be a layer containing a polystyrene polymer preferably.
The formation of the pore forming material layer may be performed using a polymer dissolving solution, but is preferably formed through polymerization of the polymer forming composition on the core in terms of forming a monodisperse layer. In this case, the composition for forming a polymer may include a raw material monomer for preparing a polymer and an initiator for initiating a polymerization reaction, and preferably, the composition for forming a polymer includes a coagulation stabilizer. In the case of including a coagulation stabilizer, the polymerization may be performed on the magnetic core to form an even surface without aggregation of the polymer.
In a specific embodiment of the present invention, the composition for forming a polymer used to form the material layer for forming the pore portion is a raw material monomer is a styrene-based monomer, the aggregation stabilizer may use sodium styrenesulfonate. The initiator used azobisisobutyronitrile (AIBN), but is not limited thereto.
On the other hand, in forming such an organic-type pore forming material layer on the core in the form of a homogeneous single dispersion film, forming the pore forming material layer is a surface-modified core using a coupling agent Next, a method of polymerizing the polymer-forming composition on the surface-modified magnetic core may be considered. At this time, the coupling agent may be adjusted according to the composition for forming the polymer. In one embodiment of the present invention, the coupling agent may be methacryloxy propyl trimethoxysilane.
As such, when the magnetic core is surface-modified and polymerized on the surface-modified magnetic core to form a polymer layer, a polymer-ferromagnetic composite may be formed, and the obtained polymer layer may have a homogeneously coated membrane. .
Specifically, the magnetic particles or the surface-modified magnetic particles are mixed and stirred, wherein the temperature may be preferably in the range of 20 to 70 ℃ in consideration of polymerization.
The forming of the first shell layer and the second shell layer including the metal in the polymer-ferromagnetic composite may include impregnating the polymer-ferromagnetic composite in the metal precursor solution (II), and then adding a reducing agent to the metal in the polymer-ferromagnetic composite. It is preferable to form a film or to form a metal film on the polymer-ferromagnetic composite by physically mixing and stirring a polymer-ferromagnetic composite and a metal particle, and then to oxidize the formed metal film to prepare an inorganic-polymer-ferromagnetic composite.
In a specific embodiment, the thickness of the shell layer may be controlled according to the reaction temperature in forming the shell of the dielectric material. When the dielectric material is titanium oxide, the reaction temperature may be about 20 to 85 ° C.
In addition, the removal of the pore-forming material layer may be performed thermally or chemically, and the chemical polymer removal may be performed by dissolving the polymer layer with an organic solution that dissolves the polymer, and the thermal polymer removal may be performed by removing the metal-inorganic-polymer- It means that the ferromagnetic composite is heat-treated to remove the polymer by thermal decomposition.
On the other hand, steps s23 and s24 may be performed in a reverse order. That is, it is also possible to form a first shell layer, then to form a void, and then to form a second shell layer on the first shell layer.
By preparing the magnetic particles (II) as described above and forming a polymer layer having quantum dots therein, magnetic particles having a polymer layer having quantum dots in the outermost shell can be obtained.
In this case, the forming of the polymer layer having a quantum dot may be performed by coating a dispersion including a polymer electrolyte material and a quantum dot at least once on the magnetic particles obtained from the previous step. When a plurality of coatings are performed to form a polymer layer having multiple quantum dots, the polymer electrolyte material or the quantum dots between the layers may be the same or different.
Meanwhile, the particles shown in FIGS. 6 to 10 are examples of other types of particles that may be applied to form a polymer layer having quantum dots emitting by ultraviolet rays. And a shell, and examples of magnetic particles including discontinuous pores formed in the shell, but are not limited thereto.
First, the magnetic particles shown in FIG. 6 include a
The
Specifically, the
The voids 350 (hereinafter referred to as " pore ") are uniformly and regularly discontinuously distributed in the shell film of the
The
As shown in FIG. 7, the
As shown in FIG. 8, the
In the case where the
That is, it is preferable that the diameter of the
In this case, the meaning of the closed pores means that the particles of the material constituting the
When the
In the
More specifically, when the shell including pores having pores in the
More specifically, when the pores are formed in two or more films selected from two or more films constituting the laminated film, as shown in Fig. 8C, the diameter of the pores is larger than the thickness of the film as long as the laminated films are formed. In addition, pores may be formed across the interface of the two or
The
In detail, the
More specifically, the diameter of the
Preferably, in the magnetic particles (III) described above with reference to FIGS. 6 to 8, the shell material of the
By adopting the dielectric material as the
Similar to the example shown in FIG. 8, when the
On the other hand, as shown in Figure 9, when the
The
In this case, as shown in FIG. 9, the
In detail, when the
In detail, the
The metal of the first
Specifically, the
The
Magnetic particles having a polymer layer having a quantum dot of the present invention may be manufactured using the magnetic particles (III), wherein the polymer layer having a quantum dot may form an outermost shell and formed in a shell including pores. May be
Here, the polymer layer may be a polymer electrolyte layer in terms of binding the quantum dots, and the polymer electrolyte may vary depending on the type of the quantum dots. For example, as the positively charged polymer electrolyte, polyallylamine hydrochloride (PAH), Polydiallydimethylammonium chloride (PDADMAC), polyethyleneimine (PEI), and the like, and the negatively charged polyelectrolytes include poly (sodium styrenesulfonate (PSS) and polyacrylic acid, PAA) etc. In particular, it may be desirable to have at least two layers of multilayer structures obtained from such a polymer electrolyte for evenly dispersing the quantum dots. Can have a multilayer structure. In some cases, the polymer layer may have a quantum dot in at least one layer, and thus, the quantum dot may be positioned in the stacked polymer electrolyte layer. It may be CdSe, CdS, ZnS, InAs, or InP having characteristics, in particular, the quantum dots may be a mixture of two or more quantum dots having different emission wavelengths, in which case various emission characteristics may be induced to further enhance security. have.
As described above, the magnetic particles including the polymer layer having the quantum dots may further enhance the security function by providing unique visible light emission characteristics of the quantum dots as well as the magnetic properties expressed in the magnetic core.
6 to 10 is not particularly limited to the method of manufacturing the magnetic particles shown in FIG. 10, but as an example will be described in consideration of the method of manufacturing the magnetic particles shown in FIG.
First, a plurality of void forming particles are coated on the magnetic core (s11).
The pore-forming particles are made of a material that can be removed by firing or chemical treatment at a high temperature, specifically, vinyl polymer particles, and more specifically, polystyrene particles.
The size of the pore forming particles may be adjusted according to the size of the desired pores, preferably 50 to 300nm.
In order to increase the binding force between the magnetic particles forming the core and the particles for forming the voids, a surface-modified one may be used as the core. That is, the surface modification of the core particles may be performed to increase the bonding force between the polymer particles and the core particles before applying the particles for forming voids on the core.
Surface modification of the core particles includes forming a polymer film using a polymer solution in which a polymer different from the particles for forming voids is dissolved on the surface of the core particles. In a specific embodiment of the present invention, polyethylene imine is used for surface modification to mix particles serving as cores in a solution of polyethylene imine to form a polyethylene imine membrane on the surface thereof.
Meanwhile, in the step of attaching the polymer particles to the surface of the core particles, it is preferable to mix and stir the magnetic core particles and the polymer particles, and to recover the core particles obtained so that the polymer particles are evenly attached to the core particles. In this case, further performing the heat treatment of the separated magnetic particles is preferable in terms of improving the adhesion efficiency of the polymer particles, and preferably, the heat treatment is preferably performed at 100 to 110 ° C. in terms of adhesion efficiency.
After applying a plurality of particles for forming pores on the magnetic core through the step s11, a shell including a dielectric material is formed according to an embodiment of the present invention (step s12).
In this case, the shell including the dielectric material impregnates the magnetic precursor obtained from step s11 in the metal precursor solution (I) in which the precursor of the metal forming the dielectric material film is dissolved, and then adds an oxidant to form a metal oxide film in the polymer-ferromagnetic composite. Alternatively, a method of mixing and stirring the metal precursor solution (I) in which the magnetic body obtained from the step s11 and the metal precursor forming the dielectric film is dissolved may be mentioned.
Next, the particles for forming voids are removed to form a shell (shell containing voids) in which a plurality of pores (pores) are formed (step s13).
Removal of the pore forming particles may be performed thermally or chemically, preferably thermally. The removal of chemical polymer particles means that the polymer particles are dissolved and removed by an organic solution for dissolving the polymer. The removal of the thermal polymer particles means thermally decomposing the pore-forming particles by thermally treating the magnetic material of the previous step.
Next, on the shell with voids, an outer shell containing metal is formed (step s14).
The forming of the outer shell including the metal may be performed by impregnating the metal oxide-polymer-ferromagnetic complex into the metal precursor solution (II) in which the precursor of the metal forming the metal film is dissolved, and then adding a reducing agent to the metal oxide-polymer- A metal film is formed on the ferromagnetic composite, or the metal oxide-polymer-ferromagnetic composite and particles of metal forming the metal film are mixed and stirred to form a metal film on the surface of the metal oxide-polymer-ferromagnetic composite.
As described above, the metal film is a material selected from at least one of copper, nickel, gold, platinum, silver, aluminum and chromium, so that the formation of the metal film is obtained from the previous step.
In the above-described process, steps s13 and s14 may be performed in reverse order. In addition, it is possible to add a predicted process such as a process for forming a multilayer to generate the magnetic particles of the various embodiments described above, and also omit the process according to the deformation of the structure.
By preparing the magnetic particles (III) as described above and forming a polymer layer having quantum dots therein, magnetic particles having a polymer layer having quantum dots in the outermost shell can be obtained.
In this case, the forming of the polymer layer having a quantum dot may be performed by coating a dispersion including a polymer electrolyte material and a quantum dot at least once on the magnetic particles obtained from the previous step. When a plurality of coatings are performed to form a polymer layer having multiple quantum dots, the polymer electrolyte material or the quantum dots between the layers may be the same or different.
The following is described by way of example for the detailed description of the invention, the invention is not limited to the following examples.
<Formation of polymer layer on magnetic core>
Example 1
5 g of iron powder (BASF 025, "core particles") with an average diameter of 1 µm and 3 g of 3-methacryloxy propyl trimethoxysilane (MPS) (Aldrich) were dissolved in 150 ml of ethanol, and then 3 ml of ammonia was added to the solution. After stirring for 24 hours at a rotational speed of 300 rpm, the core particle surface was treated with 3-methacryloxy propyl trimethoxysilane (MPS) (Aldrich) (surface modification of the core particle). The treated core particle powder was separated by magnet and washed twice with ethanol.
2 g of core particle powder treated with 3-methacryloxy propyl trimethoxysilane (MPS) dried after washing, 1.5 ml of styrene monomer, 0.4 g of sodium styrene sulfonate (Aldrich) and 0.4 g of AIBN (2,2'-azobisisobutylronitrile) 0.2 g of (Aldrich) was added to 120 ml of ethanol, and the mixture was stirred at a rotational speed of 300 rpm for 4 hours under a nitrogen atmosphere at a temperature of 65 ° C. to form a polymer layer on the surface of the core particles. The core particle powder in which the polymer layer was formed was separated by a magnet, washed twice with ethanol, and dried. At this time, the thickness of the polymer layer was 30 nm.
[Example 2]
5 g of iron powder (BASF 025, "core particles") with an average diameter of 1 µm and 3 g of 3-methacryloxy propyl trimethoxysilane (MPS) (Aldrich) were dissolved in 150 ml of ethanol, and then 3 ml of ammonia was added to the solution. After stirring for 24 hours at a rotational speed of 300 rpm, MPS (3-methacryloxy propyl trimethoxysilane) was treated on the surface of the core particles (surface modification of the core particles). The treated core particle powder was separated by magnet and washed twice with ethanol.
1 g of core particles powder treated with 3-methacryloxy propyl trimethoxysilane (MPS) dried after washing, 2 ml of styrene monomer, 0.02 g of sodium styrene sulfonate (Nads) (Aldrich) and 0.2 g of potassium persulfate (KPS) 0.2 g Into a mixed solvent of 65 ml and 35 ml of distilled water and mixed, and stirred at a rotational speed of 300 rpm in a nitrogen atmosphere for 4 hours while the temperature of the solution was adjusted to 65 ℃ to form a polymer layer on the core particle surface. The core particle powder in which the polymer layer was formed was separated by a magnet, washed twice with ethanol, and dried. At this time, the thickness of the polymer layer was 30 nm.
[Examples 3 to 5]
5 g of iron powder (BASF 025, "core particles") with an average diameter of 1 µm and 3 g of 3-methacryloxy propyl trimethoxysilane (MPS) (Aldrich) were dissolved in 150 ml of ethanol, and then 3 ml of ammonia was added to the solution. After stirring for 24 hours at a rotational speed of 300 rpm, MPS (3-methacryloxy propyl trimethoxysilane) was treated on the surface of the core particles (surface modification of the core particles). The treated core particle powder was separated by magnet and washed twice with ethanol.
2 g of core particle powder treated with 3-methacryloxy propyl trimethoxysilane (MPS) dried after washing, styrene monomer (Aldrich), sodium styrene sulfonate (NaSS) (Aldrich) and AIBN (2,2'-azobisisobutylronitrile) (Aldrich) 0.2 The mixture was added to 120 ml of ethanol, and the mixture was stirred at a rotational speed of 300 rpm while purging with nitrogen for 4 hours while adjusting the temperature of the solution to 65 ° C. to form a polymer layer on the surface of the core particles. At this time, the change in the thickness of the polymer layer according to the change in the styrene monomer and NaSS content was measured by transmission electron microscope ( FEI, model name Tecnai G2 F30 ) and the results are shown in Table 1 below.
[Example 6]
5 g of iron powder (BASF 025, "core particles") with an average diameter of 1 µm and 3 g of 3-methacryloxy propyl trimethoxysilane (MPS) (Aldrich) were dissolved in 150 ml of ethanol, and then 3 ml of ammonia was added to the solution. After stirring for 24 hours at a rotational speed of 300 rpm, MPS (3-methacryloxy propyl trimethoxysilane) was treated on the surface of the core particles (surface modification of the core particles). The treated core particle powder was separated by magnet and washed twice with ethanol.
After washing, 2 g of dried MPS (3-methacryloxy propyl trimethoxysilane) -treated core particle powder, 1.6 ml of styrene monomer (Aldrich) and 0.2 g of AIBN (2,2'- azobisisobutylronitrile) (Aldrich) were mixed in 120 ml of ethanol. And the temperature of the solution was adjusted to 65 ℃ stirred for 4 hours at a rotational speed of 300 rpm in a nitrogen atmosphere to form a polymer layer on the surface of the core particles.
At this time, the change of the reaction result according to the change of NaSS content was measured by transmission electron microscope ( FEI Co., Model name Tecnai G2 F30 ) is shown in Table 2 below.
From the results of Table 2, it can be seen that NaSS, a coagulation stabilizer, prevents coagulation of the polymer and forms a uniform polymer layer.
<Titanium oxide layer formed on the outer wall of the magnetic core having the polymer layer formed>
[Example 7]
1 g of the core particle powder coated with the washed polymer layer, 1 ml of TBOT (tetrabuthoxy titanium) (Aldrich), and 1 ml of distilled water were charged with 170 ml of ethanol, followed by stirring at a rotational speed of 300 rpm for 2 hours at a temperature of 85 ° C. The titanium oxide layer was coated on the surface of the core particle powder coated with the polymer layer. The titanium oxide-coated core particle powder was separated by a magnet, washed twice with ethanol, and dried.
[Example 8]
1 g of the core particle powder coated with the washed polymer layer, 1 ml of TBOT (tetrabuthoxy titanium) (Aldrich), and 1 ml of distilled water were added to 170 ml of ethanol, followed by stirring at a rotational speed of 300 rpm for 2 hours at room temperature. The core particle powder was separated by a magnet, washed twice with ethanol and dried. The thickness of the titanium oxide layer according to the reaction temperature was measured using a transmission electron microscope (FEI, model name Tecnai G2 F30), and the results are shown in Table 3 below.
<Remove polymer layer to form hollow part>
[Example 9]
1 g of the core particles coated with the polymer layer and the titanium oxide layer were treated with a mixed solvent of acetone, distilled water and THF for 2 hours to form a magnetic core / pore (hollow part) / titanium oxide layer from which the polymer was removed. Magnetic particles were obtained.
The gap thickness was 15 nm.
[Example 10]
1 g of the core layer coated with the polymer layer and the titanium oxide layer prepared were calcined at 400 ° C. for 2 hours to remove the polymer, and the magnetic particles including the magnetic core / void portion (hollow portion) / titanium oxide layer were removed. Got it.
The gap thickness was 15 nm.
The removal of the polymer layer to form the hollow part can be confirmed from the presence or absence of the characteristic peaks (697nm, 753nm) of polystyrene using FT-IR (Thermo, Nicollet).
<Silver layer formed on the outer wall of the magnetic core with a hollow formed>
[Example 11]
4.5 g of glucose, 0.4 g of tartaric acid, and 10 ml of ethanol were dissolved with respect to 100 ml of distilled water, which was maintained at room temperature for 7 days to prepare a reducing solution. 50 ml of distilled water, 0.030 g of sodium hydroxide (SAMCHUN CHEMICAL), 0.7 ml of ammonia water (Fluka), and 0.28 g of silver nitrate (INUISHO) were mixed to prepare a colorless transparent silver rock adsorbent solution.
0.3 g of the core particle powder having the titanium oxide layer including the pores prepared in the above process was suspended in the silver ammonium complex solution, 10 ml of the reducing solution was mixed while ultrasonically irradiating the suspension, and stirring was continued for 20 minutes. The silver layer was coated.
The thickness of the silver layer was 70 nm.
Example 12-14
50 ml of distilled water, 0.030 g of sodium hydroxide (SAMCHUN CHEMICAL), 0.7 ml of ammonia water (Fluka), and 0.28 g of silver nitrate (INUISHO) were mixed to prepare a colorless transparent silver rock adsorbent solution.
0.3 g of the core particle powder having a titanium oxide layer having pores prepared in the process was suspended in a silver ammonia complex solution, and each reducing solution as shown in the following Table 4 was mixed while ultrasonically irradiating the suspension, and 20 Stirring was continued for minutes to coat the silver layer.
The thickness of the silver layer was 70 nm.
Example 15-17
4.5 g of glucose, 0.4 g of tartaric acid, and 10 ml of ethanol were dissolved with respect to 100 ml of distilled water, which was maintained at room temperature for 7 days to prepare a reducing solution. 50 ml of distilled water, 0.030 g of sodium hydroxide (SAMCHUN CHEMICAL), 0.7 ml of ammonia water (Fluka), and 0.28 g of silver nitrate (INUISHO) were mixed to prepare a colorless transparent silver rock adsorbent solution.
0.3 g of the core particle powder having a titanium oxide layer having pores prepared in the above-mentioned process was suspended in a silver ammonia complex solution, and a reducing solution such as Example 15-17 was mixed while irradiating the suspension with ultrasonic waves, and for 20 minutes Stirring was continued to coat the silver layer.
The thickness of the silver layer in each example was 60, 65 and 63 nm, respectively.
+
Polyvinyl pyrrolidone
(Aldrich)
+
Trisodium citrate
(Aldrich)
+
polyethylene imine
(Aldrich)
Experimental Example 1
The magnetic particles including the silver layer obtained according to the above embodiments were evaluated based on the lightness measurement results of L, a, and b values of the color difference meter, and as a result, the brightness was 65 or more.
In addition, the oil absorption amount of the magnetic particles obtained according to the present invention was measured to compare the oil absorption with the magnetic substance itself and the pale magnetic substance having no voids.
Oil absorption measurement was carried out by a general test method for measuring the oil absorption of pigments and extender pigments as part of the Korean Industrial Standard KS M ISO 787 standard.
Oil absorption value is the amount of refined flaxseed that is absorbed in a pigment or sieving pigment sample under defined conditions and expresses the amount of oil in grams per 100g of sample.
[Measurement experiment of oil absorption]
The test sample was placed on a plate and slowly added 4 or 5 drops of linseed oil at a time using a burette. Each time you add oil, use a pallet knife to thoroughly mix the sample and oil. Continue to add oil at the same rate so that the oil and matter will clump. Once the mass is formed, add oil one drop at a time and rub it with a palette knife. Add oil until the batter is evenly beaten. This dough should spread directly onto the plate without cracking or crumbling, and should be adhering immediately.
Table 6 shows the results of the measured oil absorption.
(BASF 025)
(Product of Nittetsu company)
According to the results of Table 6, it can be seen that the oil absorption amount is improved in the case of the magnetic body including the continuous void portion, that is, the hollow portion formed between the core and the shell according to the present invention, whereby the magnetic particles of the present invention are incorporated into the ink composition. It can be expected that the compatibility can be improved, the viscosity control is easy, the printability can be improved, and the thixotropy can be improved.
[Example 18]
1 g of the magnetic particles obtained in Examples 11 to 17 were dispersed in 200 ml of distilled water, 2 g of PSS (poly (sodium styrenesulfonate)) and 0.01 g of CdSe quantum dots having an average diameter of 7 nm were added for 1 hour at a stirring speed of 300 rpm. Retained to coat PSS with quantum dots on the surface of the particles. After separation by centrifugation and washing twice with distilled water, it was dispersed again in 200 ml of distilled water, and 2 g of polyethyleneimine (hereinafter referred to as PEI) and 0.01 g of CdSe quantum dot having an average diameter of 7 nm were added for 1 hour at a stirring speed of 300 rpm. Was held to fix PEI with quantum dots on the surface of the particles. The CdSe-PSS coating method and the CdSe-PEI coating method were repeatedly performed eight times to obtain a shell coated with a polymer electrolyte layer having a total of 10 quantum dots. As a result, magnetic particles were formed into a multilayer polymer electrolyte layer in which a magnetic core / void portion / titanium oxide layer / silver layer / CdSe were introduced.
The magnetic particles thus obtained are light colored magnetic bodies having magnetic properties and emitting 640 nm light.
[Example 19]
A magnetic material was manufactured in the same manner as in Example 18, except that 0.001 g of CdSe having an average diameter of 2.5 nm as a quantum dot was used as a multilayer polymer electrolyte layer into which a magnetic core / void portion / titanium oxide layer / silver layer / CdSe were introduced. Magnetic particles were prepared.
The magnetic particles thus obtained are light colored magnetic bodies that emit light at 520 nm while having magnetic properties.
[Example 20]
A magnetic material was prepared in the same manner as in Example 18, except that 0.005 g of CdSe having an average diameter of 2.5 nm and 0.005 g of CdSe having an average diameter of 7 nm were mixed and used as the magnetic core / pore portion / titanium oxide layer / silver layer /. Magnetic particles were prepared to be a multilayer polymer electrolyte layer in which CdSe was introduced.
The magnetic particles thus obtained are light colored magnetic bodies having magnetic properties and emitting light at 520 nm and 640 nm.
Example 21
A magnetic material was prepared in the same manner as in Example 18 except using 0.001 g of CdS having an average diameter of 3 nm as a quantum dot to form a multilayer polymer electrolyte layer having a magnetic core / void portion / titanium oxide layer / silver layer / CdSe introduced. Magnetic particles were prepared.
The magnetic particles thus obtained are light colored magnetic bodies having magnetic properties and emitting 420 nm light.
[Example 22]
Magnetic material was prepared in the same manner as in Example 18 except that the magnetic core / pore part was mixed with quantum dots by mixing CdSe 0.005g with an average diameter of 2.5 nm, CdSe 0.005g with an average diameter of 7nm, and CdS 0.005g with an average diameter of 3nm. A magnetic particle composed of a multilayer polymer electrolyte layer into which a titanium oxide layer, silver layer, and CdSe were introduced was prepared.
The magnetic particles thus obtained are light colored magnetic bodies that emit light of 420 nm, 520 nm and 640 nm while having magnetic properties.
[Example 23]
1 g of iron powder (BASF 025, "core particles") having an average diameter of 1 μm and 2 g of PEI (polyethylene imine) (Aldrich) were mixed in 300 ml of distilled water, followed by 2 hours at a temperature of 25 ° C. Stirred at a rotational speed of 300 rpm, the core particle surface was treated with PEI. PEI treated core particle powder was separated by a magnet, washed twice with distilled water, and dried.
1 g of PEI-coated core particles and 0.3 g of spherical polystyrene particles (manufactured by hand) having an average diameter of 150 nm were added to 300 ml of distilled water, followed by a rotation speed of 300 rpm for 3 hours at a temperature of 25 ° C. By stirring, a core particle coated with polystyrene particles was prepared. The core particles coated with polystyrene particles were separated by a magnet, washed once with distilled water, and heat-treated at 106 ° C.
1 g of polystyrene-coated core particles, 3 ml of distilled water, and 1 ml of TBOT (tetrabuthoxy titanium) (Aldrich) were added with 330 ml of ethanol, and stirred at a rotational speed of 300 rpm for 3 hours at a temperature of 25 ° C. Titanium oxide was coated on the surface of the polystyrene particles coated core particles. The titanium oxide coated core particles were separated by a magnet, washed twice with ethanol, and dried.
1 g of the polystyrene particles and the titanium oxide layer-coated core particles were heat-treated at 400 ° C. for 2 hours in a nitrogen atmosphere, and thermally decomposed polystyrene particles from the core particles to form pores having a diameter of 150 nm uniformly. Magnetic particles in which a titanium oxide layer having parts were formed were prepared.
[Example 24]
1 g of iron powder (BASF 025, "core particles") having an average diameter of 1 μm and 2 g of PEI (polyethylene imine) (Aldrich) were mixed in 300 ml of distilled water, followed by 2 hours at a temperature of 25 ° C. Stirred at a rotational speed of 300 rpm, the core particle surface was treated with PEI. PEI treated core particles were separated by a magnet, washed twice with distilled water, and dried.
1 g of PEI-coated core particles and 0.3 g of spherical polystyrene particles (manufactured by hand) having an average diameter of 150 nm were added to 300 ml of distilled water, followed by a rotation speed of 300 rpm for 3 hours at a temperature of 25 ° C. By stirring, a core particle coated with polystyrene particles was prepared. The core particles coated with polystyrene particles were separated by a magnet, washed once with distilled water, and dried without heat treatment at 106 ° C.
1 g of polystyrene-coated core particles, 3 ml of distilled water, and 1 ml of TBOT (tetrabuthoxy titanium) (Aldrich) were added with 330 ml of ethanol, and stirred at a rotational speed of 300 rpm for 3 hours at a temperature of 25 ° C. Titanium oxide was coated on the surface of the polystyrene particles coated core particles. The titanium oxide coated core particles were separated by a magnet, washed twice with ethanol, and dried.
The titanium oxide-coated core particles obtained in Examples 23 and 24 were observed with a transmission electron microscope ( product of FEI, model name Tecnai G2 F30 ) to obtain the results as shown in Table 7.
Thereafter, 1 g of the polystyrene particles and the core particles coated with the titanium oxide layer were heat-treated at 400 ° C. for 2 hours in a nitrogen atmosphere, and the polystyrene particles were thermally decomposed to remove the particles, thereby uniformly forming pores having a diameter of 150 nm. Magnetic particles having a titanium oxide layer having voids were formed.
Example 25-26
1 g of iron powder (BASF 025, "core particles") with an average diameter of 1 μm in 250 ml of ethanol, 3.5 ml of distilled water, 0.3 g of spherical polystyrene particles having an average diameter of 100-300 nm (manufactured and used directly) ) Was mixed and then stirred at a rotational speed of 300 rpm for 2 hours at a temperature of 80 ° C. to coat the polystyrene particles and the titanium oxide layer on the surface of the core particles.
In this case, Example 25 used a polystyrene particle having a size of 150nm, and Example 26 used a 270nm.
1 g of the polystyrene particles and the titanium oxide layer-coated core particles were heat-treated at 400 ° C. for 2 hours in a nitrogen atmosphere, and the polystyrene particles were thermally decomposed and removed from the core particles to uniformly form pores having a thickness of 100-300 nm. Magnetic particles having a titanium oxide layer having voids were formed.
[Example 27]
1 g of iron powder (BASF 025, "core particles") having an average diameter of 1 μm in 250 ml of ethanol, 3.5 ml of distilled water, and 0.3 g of spherical polystyrene particles having an average diameter of 270 nm (manufactured and used directly) After mixing, the mixture was stirred at a rotational speed of 300 rpm for 2 hours at a temperature of 80 ° C. to coat the polystyrene particles and the titanium oxide layer on the surface of the core particles.
1 g of the polystyrene particles and the core particles coated with the titanium oxide layer were heat-treated at 400 ° C. for 2 hours in a nitrogen atmosphere, and thermally decomposed to remove the polystyrene particles from the core particles, thereby uniformly forming pores having a diameter of 270 nm. Magnetic particles having a structure of a titanium oxide shell having voids were prepared.
[Example 28]
Instead of heat treating the polystyrene particles prepared in Example 23 and the core particles coated with the titanium oxide layer, 1 g of the polystyrene particles prepared and the core particles coated with the titanium oxide layer were mixed with acetone, distilled water, and THF for 2 hours. Except that the polymer is removed by the treatment method, it can be carried out in the same manner as in Example 1 to obtain a magnetic particle having a shell including a pore portion in which a plurality of pores are formed in the magnetic core.
The removal of the polymer layer to form the hollow part can be confirmed from the presence or absence of a characteristic peak of polystyrene using FT-IR (Thermo, Nicollet).
[Example 29]
4.5 g of glucose, 0.4 g of tartaric acid, and 10 ml of ethanol were dissolved with respect to 100 ml of distilled water, which was maintained at room temperature for 7 days to prepare a reducing solution. 50 ml of distilled water, 0.030 g of sodium hydroxide (SAMCHUN CHEMICAL), 0.7 ml of ammonia water (Fluka), and 0.28 g of silver nitrate (INUISHO) were mixed to prepare a colorless transparent silver rock adsorbent solution.
0.3 g of magnetic particles containing a shell having pores formed with a plurality of pores in the magnetic core obtained from Examples 23 to 28 were suspended in a silver ammonia complex solution, and 10 ml of the reducing solution was mixed while irradiating ultrasonic waves to the suspension. The stirring was continued for 20 minutes to coat the silver layer. The thickness of the silver layer was 70 nm.
Example 30-32
50 ml of distilled water, 0.030 g of sodium hydroxide (SAMCHUN CHEMICAL), 0.7 ml of ammonia water (Fluka), and 0.28 g of silver nitrate (INUISHO) were mixed to prepare a colorless transparent silver rock adsorbent solution.
0.3 g of magnetic particles comprising a shell having pores formed with a plurality of pores in the magnetic core obtained in Examples 23 to 28 were suspended in a silver ammonium complex solution, and the suspension was irradiated with ultrasonic waves, The reducing solution was mixed and stirring was continued for 20 minutes to coat the silver layer. The thickness of the silver layer was 65 nm, 70 nm, and 65 nm, respectively.
(Aldrich)
(Aldrich)
(Aldrich)
Example 33-35
4.5 g of glucose, 0.4 g of tartaric acid, and 10 ml of ethanol were dissolved with respect to 100 ml of distilled water, which was maintained at room temperature for 7 days to prepare a reducing solution. 50 ml of distilled water, 0.030 g of sodium hydroxide (SAMCHUN CHEMICAL), 0.7 ml of ammonia water (Fluka), and 0.28 g of silver nitrate (INUISHO) were mixed to prepare a colorless transparent silver rock adsorbent solution.
0.3 g of magnetic particles comprising a shell having pores formed with a plurality of pores in the magnetic core obtained from Examples 23 to 28 were suspended in a silver ammonia complex solution, and the suspension was irradiated with ultrasonic waves, respectively, as shown in Table 9 below. The reducing solution was mixed and stirring was continued for 20 minutes to coat the silver layer. The thickness of the silver layer was 70 nm, 75 nm, and 65 nm, respectively.
+
Polyvinyl pyrrolidone (Aldrich)
+
Trisodium citrate (Aldrich)
+
polyethylene imine (Aldrich)
Experimental Example 2
For the magnetic particles obtained in Examples 29 to 35, the brightness was evaluated by the lightness measurement results by the L, a, and b values of the color difference meter, and as a result, the brightness was 65 or more.
In addition, the oil absorption amount was measured for comparing the oil absorption amount with the magnetic substance itself and the pale magnetic substance which does not have many void parts about the magnetic particle obtained by this invention.
Oil absorption measurement was carried out by a general test method for measuring the oil absorption of pigments and extender pigments as part of the Korean Industrial Standard KS M ISO 787 standard.
Oil absorption value is the amount of refined flaxseed that is absorbed in a pigment or sieving pigment sample under defined conditions and expresses the amount of oil in grams per 100g of sample.
[Measurement experiment of oil absorption]
The test sample was placed on a plate and slowly added 4 or 5 drops of linseed oil at a time using a burette. Each time you add oil, use a pallet knife to thoroughly mix the sample and oil. Continue to add oil at the same rate so that the oil and matter will clump. Once the mass is formed, add oil one drop at a time and rub it with a palette knife. Add oil until the batter is evenly beaten. This dough should spread directly onto the plate without cracking or crumbling, and should be adhering immediately.
Table 10 shows the results of the measured oil absorption.
(BASF 025)
(Nittetsu company)
According to the results of Table 10, it can be seen that the oil absorption amount is improved in the case of the magnetic particles including the discontinuous pores formed in the shell, that is, the shell in which the plurality of pores are formed, according to the present invention, thereby inking the magnetic particles of the present invention. When blended into the composition, it can be expected that the compatibility can be improved, the viscosity control is easy, the printability can be improved, and the thixotropy can be improved.
[Example 36]
1 g of the magnetic particles obtained in Examples 29 to 35 were dispersed in 200 ml of distilled water, and 2 g of PSS (poly (sodium styrenesulfonate)) and 0.01 g of CdSe quantum dots having an average diameter of 7 nm were added for 1 hour at a stirring speed of 300 rpm. Retained to coat PSS with quantum dots on the surface of the particles. After separation by centrifugation and washing twice with distilled water, it was dispersed again in 200 ml of distilled water, and 2 g of polyethyleneimine (hereinafter referred to as PEI) and 0.01 g of CdSe quantum dot having an average diameter of 7 nm were added for 1 hour at a stirring speed of 300 rpm. Was held to fix PEI with quantum dots on the surface of the particles. The CdSe-PSS coating method and the CdSe-PEI coating method were repeatedly performed eight times to obtain a shell coated with a polymer electrolyte layer having a total of 10 quantum dots. As a result, magnetic particles were formed into a multilayer polymer electrolyte layer in which a magnetic core / void portion / titanium oxide layer / silver layer / CdSe were introduced.
The magnetic particles thus obtained are light colored magnetic bodies having magnetic properties and emitting 640 nm light.
[Example 37]
A magnetic material was manufactured in the same manner as in Example 36, except that 0.001 g of CdSe having an average diameter of 2.5 nm as a quantum dot was used as a multilayer polymer electrolyte layer into which a magnetic core / porous part including titanium oxide layer / silver layer / CdSe was introduced. Magnetic particles were prepared.
The magnetic particles thus obtained are light colored magnetic bodies that emit light at 520 nm while having magnetic properties.
[Example 38]
A magnetic material was manufactured in the same manner as in Example 36, except that 0.005 g of CdSe having an average diameter of 2.5 nm and 0.005 g of CdSe having an average diameter of 7 nm were mixed as a quantum dot, and a titanium oxide layer / silver layer / including magnetic core / pores. Magnetic particles were prepared to be a multilayer polymer electrolyte layer in which CdSe was introduced.
The magnetic particles thus obtained are light colored magnetic bodies having magnetic properties and emitting light at 520 nm and 640 nm.
[Example 39]
A magnetic material was prepared in the same manner as in Example 36, except that the magnetic core / porous part containing titanium oxide layer / silver layer / CdSe was introduced into a multilayer polymer electrolyte layer using 0.001 g of CdS having an average diameter of 3 nm as a quantum dot. Magnetic particles were prepared.
The magnetic particles thus obtained are light colored magnetic bodies having magnetic properties and emitting 420 nm light.
[Example 40]
A magnetic material was prepared in the same manner as in Example 36, except that 0.005 g of CdSe having an average diameter of 2.5 nm, 0.005 g of CdSe having an average diameter of 7 nm, and 0.005 g of CdS having an average diameter of 3 nm were used to mix the magnetic core / pore part. Magnetic particles made of a multilayered polymer electrolyte layer into which a containing titanium oxide layer / silver layer / CdSe were introduced were prepared.
The magnetic particles thus obtained are light colored magnetic bodies that emit light of 420 nm, 520 nm and 640 nm while having magnetic properties.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.
Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .
Claims (30)
It includes a polymer layer having a quantum dot that emits light by ultraviolet rays,
The shell including the void portion,
On at least one layer of dielectric shell made of a dielectric material,
Magnetic particles comprising at least one metal shell made of a metal.
The polymer layer is at least two polymer electrolyte layers, and magnetic particles having quantum dots in at least one polymer layer.
Quantum dots are magnetic particles of CdSe, CdS, ZnS, InAs or InP.
A quantum dot is a magnetic particle that is a mixture of two or more quantum dots having different emission wavelengths.
Magnetic particles comprising a continuous void formed between the core and the shell, wherein the gap of the void is at least 10 nm.
Magnetic particles comprising discontinuous pores formed in the shell, wherein the pores forming the pores are at least 50 nm in diameter.
The pores are magnetic particles having hollow portions having a gap of 10 to 300 nm.
The pores are pores with pores having a diameter of 50 to 300 nm.
Magnetic particles with brightness greater than 65.
Magnetic particles, characterized in that the security particles of the deed.
Forming a shell comprising a dielectric material or a metal on the particles obtained from the previous step;
Removing a plurality of particles or materials for forming the voids to form a shell including the voids;
Forming a metal shell comprising a metal on the shell comprising voids; And
Method for producing a magnetic particle comprising the step of forming a polymer layer having a quantum dot.
The step of applying the material for forming the pore portion is performed by a method of polymerizing the polymer forming composition on the magnetic core, and the polymer forming composition comprises a raw material monomer and an initiator for preparing a polymer. .
Forming the material layer for forming the voids is a method of producing a magnetic particle is carried out by the method of surface-modifying the magnetic core using a coupling agent, and polymerizing the polymer forming composition on the surface-modified magnetic core.
The composition for forming a polymer is a method for producing magnetic particles containing an anionic monomer as a coagulation stabilizer.
A method for producing magnetic particles in which the thickness of the gap portion is controlled according to the content of the raw material monomer and the anionic monomer in the polymer-forming composition.
The composition for forming a polymer comprises a styrene-based monomer as a raw material monomer, and a method for producing magnetic particles comprising sodium styrene sulfonate as an anionic monomer.
Surface modification in the step of applying the material for forming the pore portion is a method for producing magnetic particles is carried out using 3-methacryloxy propyl trimethoxysilane as a coupling agent.
The applying of the plurality of particles for forming the voids comprises mixing and stirring the magnetic core and the particles for forming the voids in a solvent, and performing the heat treatment of the magnetic particles coated with the separated void forming particles. Manufacturing method.
Heat treatment is a method for producing magnetic particles carried out in a temperature range of 100 to 110 ℃.
The method for producing magnetic particles, wherein the pore forming particles are vinyl polymer particles having a size of 50 to 300 nm.
Core is coated with polyethylene imine to produce surface-modified magnetic particles.
Forming the shell having the voids is a method of producing magnetic particles is carried out by the method for removing the magnetic particles obtained from the previous step by removing the particles for forming the voids or a solvent for dissolving the substance.
Forming the shell having a void portion is a method for producing magnetic particles is carried out by firing the magnetic particles obtained from the previous step in a temperature range capable of firing the material for forming the void portion.
Forming the polymer layer having a quantum dot is carried out by coating a dispersion containing a polymer electrolyte material and a quantum dot at least once on the magnetic particles obtained from the previous step.
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| JP2000148156A (en) | 1998-11-05 | 2000-05-26 | Hiroshi Yamada | Bell structured particle, its manufacture, and vibration absorber |
| KR20050018200A (en) * | 2003-08-14 | 2005-02-23 | 한남대학교 산학협력단 | HCMS capsule structures containing metal nanoparticles within the hollow core, and their preparation method |
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| KR20190091149A (en) | 2018-01-26 | 2019-08-05 | 공주대학교 산학협력단 | Fe-Cr-Co-X system Alloy Powder for Counterfeit Prevention, and Method for Manufacturing The Same |
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| KR20120077235A (en) | 2012-07-10 |
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