Method for manufacturing hollow nanoparticles and film comprising hollow nanoparticles manufactured thereby

Abstract

The method for manufacturing hollow nanoparticles according to an embodiment of the present invention comprises the steps of: forming a core based on a mixed solution containing a polymer and a solvent; forming a first shell on the core to form a core-shell particle; and removing the core from the core-shell particle, wherein the solvent contains an organic solvent and water.

Description

Method for producing hollow nanoparticles and film comprising hollow nanoparticles produced thereby

[0001] The present invention relates to a method for producing hollow nanoparticles and a film comprising hollow nanoparticles.

[0002] Hollow nanoparticles have attracted significant attention as drug delivery vehicles and insulating materials due to their unique physical morphology. Recently, the low-refractive index and low-k properties of hollow nanoparticles have been actively utilized for their efficient application in low-reflection applications such as displays and lenses, as well as in low-k materials for electronic / electrical devices and communication chips.

[0003] A common method for manufacturing hollow nanoparticles is to form a core of metal oxide, form a shell, and then remove the core to manufacture hollow nanoparticles.

[0004] During the manufacturing process, the core can be manufactured under conditions such as ethanol or water, and when the core size is small, it is possible to manufacture cores of uniform size, but when the core size increases, it is difficult to control the uniformity.

[0005] Additionally, hollow metal oxides have recently been used as adhesive films for 5G flexible circuits. In this case, propagation loss increases, so it is desirable to use low-k materials as the circuit's adhesive film. Hollow nanoparticles with a uniform size distribution can be manufactured into films with a low dielectric constant, thereby increasing the need for the production of hollow nanoparticles with a uniform size.

[0006] One object of the present invention to solve the above-mentioned problems is to provide a method for producing hollow nanoparticles having a uniform particle size distribution.

[0007] Specifically, the present invention provides a method for producing hollow nanoparticles having a uniform particle size even when the size of the hollow nanoparticles is large.

[0008] In addition, it provides a film containing hollow nanoparticles having such a uniform particle size and having a low dielectric constant.

[0009] However, the problem to be solved by the present invention is not limited to this, and may be expanded in various ways without departing from the spirit and scope of the present invention.

[0010] A method for manufacturing hollow nanoparticles according to an embodiment of the present invention for achieving the above-described purpose comprises: forming a core based on a mixed solution containing a polymer and a solvent; forming a first shell on the core to form a core-shell particle; and removing the core from the core-shell particle, wherein the solvent may include an organic solvent and water.

[0011] According to one aspect, the weight ratio of the organic solvent and water in the solvent may be 30:70 to 85:15.

[0012] According to one aspect, the diameter of the core may be from 200 nm to 800 nm.

[0013] According to one aspect, the diameter of the hollow nanoparticles may be 200 nm to 2000 nm.

[0014] According to one aspect, the particle size standard deviation of the hollow nanoparticles manufactured through the above manufacturing method may be less than 15.

[0015] According to one aspect, the thickness of the first shell may be from 10 nm to 400 nm.

[0016] According to one aspect, the polymer may include at least one selected from the group consisting of polystyrene, polyethylene, polypropylene, polyethylene glycol, polyfluoroethylene, polysulfonic acid, polyacrylamine, polyoxyethylene, polyoxyethylene glycol, polyoxypropylene alkyl ether, polyoxypropylene monoalkyl ether, polyoxypropylene alkyl, polyoxyethylene tallow amine, polyoxyethylene olyl amine, polyoxyethylene steryl amine, polyoxyethylene lauryl amine, polyoxyethylene sorbitan ester, polyoxyethylene octyl ether, polyoxyethylene glycerin ether, polymethyl methacrylate, polyacrylic acid, polyethylene amine, and polyvinyl acetate.

[0017] According to one aspect, the content of the core polymer in the mixed solution may be from 3 wt% to 20 wt%.

[0018] According to one aspect, the mixed solution may further comprise a polymerization reaction initiator.

[0019] According to one aspect, the content of the polymerization reaction initiator in the mixed solution may be 0.05 wt% to 2 wt%.

[0020] According to one aspect, the mixed solution may further comprise a stabilizer.

[0021] According to one aspect, the content of the stabilizer in the mixed solution may be 0.01 wt% to 0.15 wt%.

[0022] According to one aspect, the method for producing the hollow nanoparticles may not include a step of washing and removing the core.

[0023] According to one aspect, the step of forming a first shell on the core to form a core-shell particle can be performed using a first metal oxide precursor.

[0024] According to one aspect, the first metal oxide precursor can be prepared as a material in the form of a metal salt, an organometallic compound, or a metal compound containing an organic functional group.

[0025] According to one aspect, the metal included in the first metal oxide precursor may be at least one selected from the group consisting of Si, Ge, Sn, Ti, Zr, Al, Mg, Fe, Ag, Au, Cu, Ce, Cs, In, W, Sb, Ga and Zn.

[0026] According to one aspect, after the step of forming a first shell to form a core-shell particle, and before the step of removing a core from the core-shell particle, the method may further include the step of forming a second shell.

[0027] According to one aspect, the step of forming the second shell is performed using a second metal oxide precursor, and the second metal oxide precursor can be manufactured as a material in the form of a metal salt, an organometallic compound, or a metal compound containing an organic functional group.

[0028] According to one aspect, the metal included in the second metal oxide precursor may be at least one selected from the group consisting of Si, Ge, Sn, Ti, Zr, Al, Mg, Fe, Ag, Au, Cu, Ce, Cs, In, W, Sb, Ga and Zn.

[0029] A film according to one embodiment of the present invention may include hollow nanoparticles manufactured by the method described above.

[0030] According to one aspect, the film may have a dielectric constant of 2.4 to 3.0 under 10 GHz conditions.

[0031] According to one aspect, the particle size standard deviation of the hollow nanoparticles included in the film may be less than 15.

[0032] The disclosed technology may have the following effects. However, this does not mean that a particular embodiment must include all or only the following effects, and thus the scope of the disclosed technology should not be construed as being limited thereby.

[0033] The method for manufacturing hollow nanoparticles according to the present embodiment can manufacture hollow nanoparticles having a uniform particle size in a simple manner. Specifically, by adjusting the mixing ratio of water and organic solvent within an appropriate range during the manufacturing process of hollow nanoparticles, hollow nanoparticles having a uniform particle size can be manufactured even when the size of the hollow nanoparticles is larger than 200 nm.

[0034] Additionally, the film according to the present embodiment can have a low dielectric constant by including hollow nanoparticles having a uniform particle size manufactured by this method.

[0035] Figure 1 schematically illustrates a manufacturing process of hollow nanoparticles according to one embodiment.

[0036] Figure 2 schematically illustrates a manufacturing process of hollow nanoparticles according to another embodiment.

[0037] Figures 3 to 12 show TEM images of core and hollow silica manufactured according to the content ratio of each organic solvent and water in Table 1.

[0038] Figures 13 to 22 show TEM images of core and hollow silica manufactured according to the content ratio of each organic solvent and water in Table 2.

[0039] The present invention can be modified in various ways and has various embodiments, and specific embodiments are illustrated in the drawings and described in detail.

[0040] However, this is not intended to limit the present invention to a specific embodiment, but should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

[0041] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a "second component," and similarly, a second component may also be referred to as a "first component." The term "and / or" includes any combination of multiple related items described herein or any item among multiple related items described herein.

[0042] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0043] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0044] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0045] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate an overall understanding in describing the present invention, identical reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted.

[0046]

[0047] Fig. 1 is a schematic diagram illustrating a manufacturing process of hollow nanoparticles according to the present embodiment. Referring to Fig. 1, the method for manufacturing hollow nanoparticles according to the present embodiment includes a step (S10) of forming a core based on a mixed solution containing a polymer and a solvent, a step (S20) of forming a first shell on the core to form a core-shell particle, and a step (S40) of removing the core from the core-shell particle.

[0048] The method for manufacturing hollow nanoparticles according to the present embodiment is characterized by manufacturing hollow nanoparticles having a uniform size, and specifically, by adjusting the content of organic solvent and water at an appropriate ratio to manufacture hollow nanoparticles having a high particle size uniformity.

[0049] Each step is explained in detail below.

[0050] First, a core is formed based on a mixed solution containing a polymer and a solvent. More specifically, but not necessarily limited to, the template core may be synthesized by adding a polymerization initiator to a mixed solution having a monomer ratio within a predetermined range and conducting a polymerization reaction. However, this is not limited thereto.

[0051]

[0052] At this time, the polymer may include at least one selected from the group consisting of polystyrene, polyethylene, polypropylene, polyethylene glycol, polyfluoroethylene, polystyrene sulfonic acid, polyacrylamine, polyethyleneamine, polyoxyethylene, polyoxyethylene glycol, polyoxypropylene alkyl ether, polyoxypropylene monoalkyl ether, polyoxypropylene alkyl, polyoxyethylene tallow amine, polyoxyethylene olyl amine, polyoxyethylene steryl amine, polyoxyethylene lauryl amine, polyoxyethylene sorbitan ester, polyoxyethylene octyl ether, polyoxyethylene glycerin ether, polymethyl methacrylate, polyacrylic acid, and polyvinyl acetate.

[0053] These polymers can be formed by polymerizing monomers such as styrene, ethylene, propylene, fluoroethylene, acrylate, methacrylate, ethylene glycol, acrylic acid, and vinyl acetate.

[0054] The above mixed solution may further include a polymerization initiator. At this time, the polymerization initiator may be one or more of AIBN (azobisisobutyronitrile), BPO (benzoyl peroxide), camphorquinone, APS (Ammonium persulfate), AIBA (2,2'-azobis(2-methylpropionamidine) dihydrochloride), and KPS (Potassium persulfate), but is not limited thereto. The monomer may be polymerized by the polymerization initiator.

[0055] The polymer content in the mixed solution may be 3 wt% to 20 wt%. More specifically, the polymer content may be 5 wt% to 10 wt%. If the polymer content is less than 3 wt%, there may be problems such as reduced yield and presence of unreacted monomers, and if the polymer content exceeds 20 wt%, there may be problems such as reduced particle uniformity.

[0056] The content of the polymerization initiator in the mixed solution may be 0.05 wt% to 2 wt%. More specifically, it may be 0.5 wt% to 2 wt%. If the content of the polymerization initiator in the mixed solution is less than 0.05 wt%, there may be a problem of unreacted monomers existing due to decreased reactivity, and if the content of the polymerization initiator in the mixed solution exceeds 2 wt%, there may be a problem of aggregation between polymers due to increased reactivity.

[0057] In one embodiment of the present specification, a case where polystyrene is used as a polymer is described as an example, but the present invention is not limited thereto. In one embodiment, when the polymer includes polystyrene, the monomer may be styrene, and the polymerization reaction may proceed in the presence of a polymerization initiator. In this case, the polymerization initiator may be, but is not limited to, AIBN (azobisbutyronitrile), BPO (benzoylperoxide), and camphorquinone.

[0058] Additionally, the mixed solution may further contain a stabilizer. The stabilizer may include PVP or PVA. The stabilizer may serve to improve dispersion stability.

[0059] The content of the stabilizer may be 0.01 wt% to 0.15 wt%. Specifically, it may be 0.01 wt% to 0.05 wt%. If the content of the stabilizer in the mixed solution is less than 0.01 wt%, there may be a problem of reduced dispersion stability, and if the content of the stabilizer in the mixed solution is more than 0.15 wt%, there may be a problem of interfering with core-shell formation.

[0060] In this step, the solvent may include an organic solvent and water. At this time, the weight ratio of the organic solvent and water may be 30:70 to 85:15, and preferably 65:35 to 85:15. As will be described separately later, this weight ratio of the organic solvent and water is a content range that can form relatively large hollow nanoparticles with high uniformity, and when the formed hollow nanoparticles are applied to a film, the dielectric constant of the film can be reduced. Specific effects will be described later in separate experimental examples through Tables 1 and 2.

[0061] It is not easy to form hollow nanoparticles having a particle size of 200 nm or more, more specifically 350 nm or more, with a uniform size distribution. However, as in the present example, when the weight ratio of the organic solvent and water is 30:70 to 85:15, preferably 65:35 to 85:15, hollow nanoparticles having a uniform size distribution can be formed.

[0062] Additionally, films containing these hollow nanoparticles can have low dielectric constants. Therefore, films containing hollow nanoparticles manufactured using this method can be applied to various fields, such as adhesive films for 5G circuits.

[0063] The organic solvent may be alcohol, glycol ester, ketone, or a mixed solvent thereof. The alcohol may include methyl alcohol, ethyl alcohol, isopropyl alcohol, etc., the glycol ester may include methyl cellosolve and ethyl cellosolve, and the ketone may include methyl ethyl ketone and methyl isobutyl ketone. The water may be distilled water.

[0064] The diameter of the core formed in this step may be 200 nm to 800 nm. More preferably, it may be 300 nm to 400 nm. However, this is merely an example and the present invention is not limited thereto.

[0065]

[0066] Next, a step (S20) of forming a core-shell particle by forming a first shell on the core is described. The step of forming the first shell on the core can be performed using a first metal oxide precursor.

[0067] At this time, the first metal oxide precursor may be in the form of a combination of a metal salt and an organic functional group. In addition, according to one aspect, the first metal oxide precursor may be manufactured as a material in the form of a metal salt, an organometallic compound, or a metal compound containing an organic functional group.

[0068] The metal included in the first metal oxide precursor may be at least one selected from the group consisting of Si, Ge, Sn, Ti, Zr, Al, Mg, Fe, Ag, Au, Cu, Ce, Cs, In, W, Sb, Ga, and Zn.

[0069] The organic functional group included in the first metal oxide precursor is selected from the group consisting of alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and tert-butyl; alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, and butoxy; aryl groups such as benzyl, phenyl, tolyl, xylyl, and naphthyl; halogen elements such as fluorine, chlorine, and bromine; halogen-substituted alkyl groups such as fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, and trichloromethyl; halogen-substituted aryl groups such as fluorobenzyl, fluorophenyl, fluorotolyl, fluoroxylyl, and fluoronaphthalyl; and reactive functional groups such as acrylic, methacrylic, vinyl, and fluorinated ethylene. It may be at least one selected from the group consisting of complex organic functional groups such as amino alkyl, mercapto, glycidoxy, methacryloxyethyl, and methacryloxypropyl.

[0070] Additionally, the metal of the first metal oxide precursor may be zinc, copper, indium, aluminum, gallium, tin, nickel, yttrium, titanium, zirconium, tantalum or iron.

[0071] For example, the metal oxide constituting the first shell may be SiO2. In this case, it is preferable in terms of refractive index, reflectivity, turbidity, and scratch resistance, and it is also preferable because additional pores are not easily created during the firing process and deformation does not occur easily. In addition, tetraethyl orthosilicate (TEOS) can be used as a metal oxide precursor for forming SiO2, but is not limited thereto.

[0072] The above first shell can be formed using a method such as hydrothermal synthesis, chemical precipitation, chemical synthesis using high-frequency plasma, electrical dispersion reaction, combustion synthesis, sol-gel synthesis, microfluidizer process, microemulsion method, and high-energy mechanical milling.

[0073] At this time, when using a series synthesis method, the porosity and refractive index of the shell can be controlled to a low level.

[0074] For example, the thickness of the first shell manufactured in this step may be 10 nm to 400 nm. More preferably, it may be 30 nm to 60 nm. However, this is merely an example and the present invention is not limited thereto.

[0075] Next, a step (S40) for removing the core from the core-shell particle will be described. This step of removing the core may be performed using a solvent, but this is only an example and is not limited thereto.

[0076] Through this process, hollow nanoparticles can be manufactured. The diameter of the hollow nanoparticles manufactured in this step may be 200 nm to 2000 nm. More specifically, it may be 350 nm to 600 nm. In addition, the particle size standard deviation of the hollow nanoparticles manufactured through this manufacturing method may be between 4 and 15. More specifically, it may be between 4 and 10. In other words, the manufacturing method according to the present embodiment can manufacture hollow nanoparticles having a uniform particle size distribution. This will be described separately through specific examples below.

[0077] Additionally, the method for manufacturing hollow nanoparticles according to the present embodiment may not include a step of washing the core. Typically, methods for manufacturing hollow nanoparticles involve synthesizing the core, then washing, drying, and dispersing the core, and then forming a shell. However, the method for manufacturing hollow nanoparticles according to the present embodiment can form a shell without the step of washing the core after synthesizing the core, thereby simplifying the process.

[0078] According to another embodiment, a method for manufacturing hollow nanoparticles may further include a step of forming a second shell (S30) between the step of forming a first shell on a core to form a core-shell particle (S20) and the step of removing the core from the core-shell particle (S40). Fig. 2 illustrates a process flow diagram according to the present embodiment. Referring to Fig. 2, the method for manufacturing hollow nanoparticles according to the present embodiment is the same as the embodiment of Fig. 1 except that it further includes the step of forming a second shell (S30). Specific descriptions of the same components are omitted.

[0079] The step (S30) of forming the second shell may be performed using a second metal oxide precursor. At this time, the second metal oxide precursor may be in the form of a combination of a metal salt and an organic functional group. In addition, according to one aspect, the second metal oxide precursor may be manufactured as a material in the form of a metal salt, an organometallic compound, or a metal compound containing an organic functional group.

[0080] The metal included in the second metal oxide precursor may be one or more selected from the group consisting of Si, Ge, Sn, Ti, Zr, Al, Mg, Fe, Ag, Au, Cu, Ce, Cs, In, W, Sb, Ga, and Zn.

[0081] The organic functional group included in the second metal oxide precursor is selected from the group consisting of alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and tert-butyl; alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, and butoxy; aryl groups such as benzyl, phenyl, tolyl, xylyl, and naphthyl; halogen elements such as fluorine, chlorine, and bromine; halogen-substituted alkyl groups such as fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, and trichloromethyl; halogen-substituted aryl groups such as fluorobenzyl, fluorophenyl, fluorotolyl, fluoroxylyl, and fluoronaphthalyl; and reactive functional groups such as acrylic, methacrylic, vinyl, and fluorinated ethylene. It may be at least one selected from the group consisting of complex organic functional groups such as amino alkyl, mercapto, glycidoxy, methacryloxyethyl, and methacryloxypropyl.

[0082] For example, as the second metal oxide precursor, one or more of tetraethyl orthosilicate (TEOS), titanium isopropoxide (Ti Isopropoxide), zirconium isopropoxide (Zr Isopropoxide), and aluminum acetylacetonate (Al Acetylacetonate) may be used.

[0083] Then, a method for manufacturing hollow nanoparticles according to this embodiment will be described with reference to a specific experimental example.

[0084] Table 1 below shows hollow nanoparticles manufactured by varying the content ratio of water and organic solvent in the solvent in the step (S10) of forming a core based on a mixed solution containing a polymer and a solvent, and measuring the core particle size and shell thickness, particle standard deviation, dielectric constant, etc.

[0085] In Table 1 below, ethanol was used as the organic solvent.

[0086] EtOH:DI water(wt%)50:5065:3570:3085:1590:10PS coreTEM figure 3 5 7 9 11Hollow silicaTEM figure 4 6 8 10 12Core particle size230nm310nm320nm350nm370nmAverage particle size262nm392nm395nm423.5nm439.1nmParticle standard deviation34.26.224.975.7228.12Average shell thickness21.2nm34.2nm34.8nm37.2nm38.5nmElectrical properties(@10GHz)(~HS 20%)Heritability2.922.752.752.742.82Dielectric loss0.00300.00280.00260.00250.0026

[0087] TEM images of cores and hollow silicas manufactured according to the respective organic solvent and water content ratios in Table 1 are shown in FIGS. 3 to 12. Referring to Table 1 and FIGS. 3 to 12, it was confirmed that the particle size standard deviation of the manufactured hollow nanoparticles was small when the organic solvent and water content ratio was between 65:35 and 85:15. In addition, it was confirmed that the particle size standard deviation of the manufactured hollow nanoparticles increased when the organic solvent and water content ratio was outside the range of 65:35 to 85:15.

[0088] Specifically, referring to Table 1, when the content ratio of organic solvent and water was between 65:35 and 85:15, the standard deviation of particle size was low, less than 10. When the content ratio of organic solvent and water was outside of 65:35 and 85:15, the standard deviation of particle size was high, more than 20.

[0089] This can also be confirmed by comparing Figs. 3 to 12. In the case of Figs. 5 to 10, where the content ratio of organic solvent and water is between 65:35 and 85:15, a uniform particle size can be confirmed in the TEM images. In the case of Figs. 3, 4, 11, and 12, where the content ratio of organic solvent and water is outside of 65:35 to 85:15, it can be confirmed that the particle size appears to vary.

[0090] Therefore, it was confirmed that the use of an organic solvent having the content ratio of organic solvent and water according to this example has a remarkable effect of forming hollow nanoparticles of uniform size.

[0091] In addition, it was confirmed that films containing hollow nanoparticles manufactured within the range had relatively low permittivity. In Table 1, films containing hollow nanoparticles manufactured in each experimental example were manufactured, and the permittivity of the films was measured under 10 GHz conditions.

[0092] As shown in Table 1, the dielectric constant of films containing hollow nanoparticles manufactured with an organic solvent to water content ratio of 65:35 to 85:15 was less than 2.8, but the dielectric constant of films containing hollow nanoparticles manufactured with a content ratio outside of the above was 2.8 or higher. Therefore, it was confirmed that the film containing hollow nanoparticles manufactured using an organic solvent having an organic solvent to water content ratio according to the present example had a low dielectric constant.

[0093] Table 2 below shows the same physical properties as in Table 1 after forming hollow nanoparticles with a larger size than those in Table 1.

[0094]

[0095] EtOH:DI water(wt%)50:5065:3570:3085:1590:10PS coreTEM figure 13 degrees 15 degrees 17 degrees 19 degrees 21Hollow silicaTEM figure 14 degrees 16 degrees 18 degrees 20 degrees 22Core particle size350nm450nm470nm490nm490nmAverage particle size431nm532.1nm535.5nm568.5nm553nmParticle standard deviation16.27.527.117.7917.4Average shell thickness35.9nm44.4nm45.2nm51.0nm50.2nmElectrical properties(@10GHz)(~HS 20%)Heritability2.862.712.702.702.79Heritability loss0.00260.00250.00240.00240.0025

[0096] TEM images of core and hollow silica manufactured according to the content ratio of each organic solvent and water in Table 2 are shown in FIGS. 13 to 22. The size of the hollow nanoparticles manufactured in Table 2 is larger than that of the hollow nanoparticles manufactured in Table 1. Even in this case, it was confirmed that the particle size standard deviation of the manufactured hollow nanoparticles was small when the content ratio of the organic solvent and water was between 65:35 and 85:15. It was confirmed that the particle size standard deviation of the manufactured hollow nanoparticles increased when the content range was outside this range.

[0097] Specifically, referring to Table 2, when the content ratio of organic solvent and water was between 65:35 and 85:15, the standard deviation of particle size was low, less than 10. When the content ratio of organic solvent and water was outside of 65:35 and 85:15, the standard deviation of particle size was high, more than 10.

[0098] This can also be confirmed by comparing Figs. 13 to 22. In the case of Figs. 15 to 20, where the content ratio of organic solvent and water is between 65:35 and 85:15, a uniform particle size can be confirmed in the TEM images. In the case of Figs. 13, 14, 21, and 22, where the content ratio of organic solvent and water is outside of 65:35 to 85:15, it can be confirmed that the particle size appears to vary.

[0099] Therefore, it was confirmed that the use of an organic solvent having the content ratio of organic solvent and water according to this example has a remarkable effect of forming hollow nanoparticles of uniform size.

[0100] In addition, it was confirmed that the hollow nanoparticles manufactured within the range had a relatively low permittivity. In the case of a film including hollow nanoparticles manufactured with an organic solvent and water content ratio of 65:35 to 85:15, the permittivity was less than 2.75, but the permittivity of the light film manufactured outside the content ratio was 2.75 or higher. Therefore, it was confirmed that a film including hollow nanoparticles manufactured using an organic solvent having an organic solvent and water content ratio according to the present example had a low permittivity.

[0101]

[0102] The film according to the present embodiment may include hollow nanoparticles manufactured by the manufacturing method described above. Specifically, the film may include medium-sized nanoparticles having a particle size with a particle size standard deviation of 4 to 15. For example, the particle size standard deviation may be less than 15. In this case, the hollow nanoparticles may be manufactured by the manufacturing method described above and may have a uniform particle size. A film including hollow nanoparticles having such a uniform particle size may have a low permittivity. Specifically, the film may have a permittivity of 2.4 to 3.0 under 10 GHz conditions.

[0103] The description of the hollow nanoparticles included in the film according to the present embodiment is the same as described above. Specific descriptions of the same components are omitted. That is, the hollow nanoparticles included in the film according to the present embodiment have a core / shell structure and may have a diameter of 200 nm to 2000 nm, the core diameter may be 200 nm to 800 nm, and the shell thickness may be 10 nm to 400 nm.

[0104] The film according to this embodiment can be manufactured using the following manufacturing method, but this is merely an example and the present invention is not limited thereto. Specifically, the film can be manufactured through a process of preparing a coating solution by mixing a binder solution, a solvent, and silica, applying the coating solution to a certain thickness, drying to evaporate the solvent, and then curing and firing. After firing, the film can be peeled off using distilled water.

[0105] The binder solution may comprise 40 to 70 wt% of the total coating solution, and may include, but is not limited to, a PST solution (PST-A-G01 from Pisolution Technology Co., Ltd.). However, these materials and contents are merely examples and the present invention is not limited thereto.

[0106] The solvent may be one or more selected from ketones such as methyl ethyl ketone, cyclohexanone, dimethylacetamide, and propylene glycol methyl ether acetate, and may be included in an amount of 30 wt% to 60 wt% of the total content of the coating solution. However, this content is only an example, and the present invention is not limited thereto.

[0107] Silica may be hollow nanoparticles manufactured in the manner described above, and may be included in an amount of 0.5 wt% to 4 wt% based on the total content of the coating solution. That is, the silica of the present embodiment may have a core / shell structure, a diameter of 200 nm to 2000 nm, a core diameter of 200 nm to 800 nm, and a shell thickness of 10 nm to 400 nm. In addition, it may be hollow nanoparticles having a particle size standard deviation of less than 15.

[0108] The drying may be performed at a temperature of, but is not limited to, 60°C to 90°C. The curing may be performed at a temperature of, but is not limited to, 180°C to 210°C. The firing may be performed at a temperature of, but is not limited to, 290°C to 320°C.

[0109]

[0110] Although the present invention has been described with reference to the drawings and embodiments, it does not mean that the scope of protection of the present invention is limited by the drawings or embodiments, and it will be understood that a person skilled in the art can modify and change the present invention in various ways without departing from the spirit and scope of the present invention as described in the following claims.

[0111] Although the present invention described above is described based on a series of functional blocks, it is not limited to the above-described embodiments and the attached drawings, and it will be apparent to those skilled in the art to which the present invention pertains that various substitutions, modifications, and changes are possible within a scope that does not depart from the technical spirit of the present invention.

[0112] The combination of the above-described embodiments is not limited to the above-described embodiments, and various combinations may be provided in addition to the above-described embodiments depending on implementation and / or needs.

[0113] In the above-described embodiments, the methods are described based on a flowchart as a series of steps or blocks. However, the present invention is not limited to the order of the steps, and some steps may occur in a different order or simultaneously with other steps described above. Furthermore, those skilled in the art will understand that the steps depicted in the flowchart are not exclusive, and other steps may be included, or one or more steps in the flowchart may be deleted without affecting the scope of the present invention.

[0114] The above-described embodiments include examples of various aspects. While not all possible combinations to illustrate the various aspects can be described, those skilled in the art will recognize that other combinations are possible. Accordingly, the present invention is intended to encompass all other alterations, modifications, and variations within the scope of the following claims.

Claims

1. A step of forming a core based on a mixed solution containing a polymer and a solvent; A step of forming a first shell on the core to form a core-shell particle; and Comprising a step of removing a core from the core-shell particle, The above solvent is a method for producing hollow nanoparticles comprising an organic solvent and water.

2. In paragraph 1, A method for producing hollow nanoparticles, wherein the weight ratio of the organic solvent and water in the solvent is 30:70 to 85:

15.

3. In paragraph 1, A method for producing hollow nanoparticles having a core diameter of 200 nm to 800 nm.

4. In paragraph 1, A method for producing hollow nanoparticles, wherein the hollow nanoparticles have a diameter of 200 nm to 2000 nm.

5. In paragraph 1, A method for producing hollow nanoparticles, wherein the particle size standard deviation of the hollow nanoparticles produced by the above-mentioned manufacturing method is less than 15.

6. In paragraph 1, A method for producing hollow nanoparticles, wherein the thickness of the first shell is 10 nm to 400 nm.

7. In paragraph 1, A method for producing hollow nanoparticles, wherein the polymer comprises at least one selected from the group consisting of polystyrene, polyethylene, polypropylene, polyethylene glycol, polyfluoroethylene, polysulfonic acid, polyacrylamine, polyoxyethylene, polyoxyethylene glycol, polyoxypropylene alkyl ether, polyoxypropylene monoalkyl ether, polyoxypropylene alkyl, polyoxyethylene tallow amine, polyoxyethylene olyl amine, polyoxyethylene steryl amine, polyoxyethylene lauryl amine, polyoxyethylene sorbitan ester, polyoxyethylene octyl ether, polyoxyethylene glycerin ether, polymethyl methacrylate, polyacrylic acid, polyethylene amine, and polyvinylacetate.

8. In paragraph 1, A method for producing hollow nanoparticles, wherein the content of the core polymer in the above mixed solution is 3 wt% to 20 wt%.

9. In paragraph 1, A method for producing hollow nanoparticles, wherein the above mixed solution further contains a polymerization reaction initiator.

10. In paragraph 9, A method for producing hollow nanoparticles, wherein the content of the polymerization reaction initiator in the above mixed solution is 0.05 wt% to 2 wt%.

11. In paragraph 1, A method for producing hollow nanoparticles, wherein the above mixed solution further contains a stabilizer.

12. In paragraph 11, A method for producing hollow nanoparticles, wherein the content of the stabilizer in the above mixed solution is 0.01 wt% to 0.15 wt%.

13. In paragraph 1, A method for producing hollow nanoparticles, wherein the method does not include a step of washing and removing the core.

14. In paragraph 1, A method for producing hollow nanoparticles, wherein the step of forming a first shell on the core to form a core-shell particle is performed using a first metal oxide precursor.

15. In paragraph 14, A method for producing hollow nanoparticles, wherein the first metal oxide precursor is produced as a material in the form of a metal salt, an organometallic compound, or a metal compound containing an organic functional group.

16. In paragraph 15, A method for producing hollow nanoparticles, wherein the metal included in the first metal oxide precursor is at least one selected from the group consisting of Si, Ge, Sn, Ti, Zr, Al, Mg, Fe, Ag, Au, Cu, Ce, Cs, In, W, Sb, Ga and Zn.

17. In paragraph 1, After the step of forming the first shell to form the core-shell particle, and before the step of removing the core from the core-shell particle, A method for producing hollow nanoparticles, further comprising the step of forming a second shell.

18. In paragraph 17, The step of forming the second shell is performed using a second metal oxide precursor, A method for producing nanoparticles, wherein the second metal oxide precursor is produced as a material in the form of a metal salt, an organometallic compound, or a metal compound containing an organic functional group.

19. In paragraph 18, A method for producing hollow nanoparticles, wherein the metal included in the second metal oxide precursor is at least one selected from the group consisting of Si, Ge, Sn, Ti, Zr, Al, Mg, Fe, Ag, Au, Cu, Ce, Cs, In, W, Sb, Ga and Zn.

20. A film comprising hollow nanoparticles manufactured according to the manufacturing method of claim 1.

21. In paragraph 20, The above film has a dielectric constant of 2.4 to 3.0 under 10 GHz conditions.

22. In paragraph 20, A film wherein the particle size standard deviation of hollow nanoparticles contained in the film is less than 15.

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