KR20210147688A - Nanocomposites and curable compositions containing the same - Google Patents

Abstract

The present invention relates to a nanocomposite and an epoxy resin curable composition using the same, and more specially provides a novel nanocomposite using particles containing carbon and metal and a metal-organic framework, and relates to an epoxy resin curable composition capable of manufacturing an epoxy cured product having improved thermal properties, mechanical properties, and storage safety by including the novel nanocomposite. The nanocomposite of the present invention includes a particulate core containing carbon and metal, and a shell prepared by coating a metal-organic framework (MOF) on the surface of the core.

Description

Nanocomposites and curable compositions containing the same}

The present invention relates to a nanocomposite and a curable composition containing the same, and more particularly, a nanocomposite type epoxy curing accelerator capable of producing an epoxy cured product with improved thermal properties, mechanical properties and storage safety, and a curable epoxy composition containing the same is about

Epoxy resin is a typical thermosetting resin, and a mixture of an epoxy resin, a curing agent, and an accelerator is commonly referred to as a one-component epoxy curing system. Epoxy shows high mechanical properties by reacting with a curing agent to form a three-dimensional network structure. However, despite high mechanical properties, it has the same brittleness as glass and is weak against impact.

To compensate for this, a rubbery additive may be used, but in an epoxy one-component curing system, since the epoxy and the curing agent exist in one matrix, it cannot be considered completely free from chemical stability. The storage stability issue in the epoxy one-component curing system is not addressed, and this is one of the issues that must be solved for convenience and economical reasons in the industrial field.

To this end, the present inventor has proposed a curing accelerator for an epoxy resin and an epoxy composition using the same through Korean Patent Registration No. 10-1907419. Such a curing accelerator for an epoxy resin includes a zeolitic imidazolate framework to provide an epoxy composition having excellent storage stability and a catalytic effect at high temperatures.

However, such a conventional epoxy composition does not have sufficient thermal stability and shear strength for application in coating and adhesion systems in cutting-edge industries such as semiconductors, aerospace, automobile industries, etc., and further excellent storage stability is required.

Republic of Korea Patent Registration No. 10-1907419

An object of the present invention is to provide a nanocomposite capable of preparing an epoxy cured product having improved thermal properties, mechanical properties and storage safety, and a curable composition containing the same.

The nanocomposite according to the present invention includes a particle-like core containing carbon and metal, and a shell coated with a metal-organic framework (MOF) on the surface of the core.

In the nanocomposite according to an embodiment of the present invention, carbon may be a spherical carbon-based compound.

In the nanocomposite according to an embodiment of the present invention, the metal-organic framework may include a zeolitic imidazolate framework.

In the nanocomposite according to an embodiment of the present invention, the metal may include at least one selected from silver, gold, copper, aluminum, platinum, palladium, nickel, and iron.

In the nanocomposite according to an embodiment of the present invention, the metal content inside the core is higher than the metal content on the surface of the core.

In the nanocomposite according to an embodiment of the present invention, the surface of the nanocomposite includes a surface area coated with a particulate metal-organic framework and an exposed surface area of the core.

In the nanocomposite according to an embodiment of the present invention, the nanocomposite may include 10 to 350 parts by weight of a metal and 100 to 3000 parts by weight of a metal-organic framework based on 100 parts by weight of fullerene.

In addition, the present invention provides an epoxy curing accelerator comprising the above-described nanocomposite.

In addition, the present invention provides a nanocomposite manufacturing method, the nanocomposite manufacturing method comprising: a first step of manufacturing a core by coating a metal on carbon particles; and a second step of coating a metal-organic framework (MOF) to form a shell on the surface of the core.

In the method for manufacturing a nanocomposite according to an embodiment of the present invention, the first step is to obtain a first reaction solution by introducing and mixing carbon particles: metal precursor in a solvent in a weight ratio of 1:2 to 1:10; , adding water to the first reaction solution and then stirring to obtain a core.

In the nanocomposite manufacturing method according to an embodiment of the present invention, in the second step, the second solution in which the metal-organic framework is dispersed in the second solvent is mixed with the first solution in which the core is dispersed in the first solvent, and the surface of the core It includes coating with a metal-organic framework (MOF).

In the nanocomposite manufacturing method according to an embodiment of the present invention, 300 to 500 parts by weight of the metal-organic framework may be mixed with respect to 100 parts by weight of the core.

In the nanocomposite manufacturing method according to an embodiment of the present invention, the metal precursor may be a water-soluble metal precursor.

In addition, the present invention provides an epoxy resin curable composition comprising the above-described nanocomposite, an epoxy resin and a curing agent.

The epoxy resin curable composition according to an embodiment of the present invention may include 5 to 15 parts by weight of a curing agent, 0.01 to 3 parts by weight of the nanocomposite, based on 100 parts by weight of the epoxy resin.

In addition, the present invention provides a method for producing a cured epoxy product, wherein the method for producing a cured epoxy product includes the steps of mixing the above-described nanocomposite, an epoxy resin and a curing agent to obtain an epoxy resin curable composition, and curing the epoxy resin composition to obtain an epoxy resin It may include a curing step to obtain a cargo.

In the method for manufacturing a cured epoxy product according to an embodiment of the present invention, the curing step may be performed at a temperature of 160 to 200 °C.

In addition, the present invention provides an epoxy cured product manufactured through the above-described epoxy cured product manufacturing method.

When the nanocomposite according to the present invention is mixed with an epoxy resin and used as an epoxy curing accelerator, an epoxy cured product having excellent mechanical properties, thermal properties and storage stability can be prepared.

1 shows an X-ray diffraction (XRD) pattern of a nanocomposite according to an embodiment of the present invention.
2 shows a Fourier-transform infrared spectroscopy (FTIR) spectrum of a nanocomposite according to an embodiment of the present invention.
3 is a scanning electron microscope (SEM) photograph of the nanocomposite according to an embodiment of the present invention.
4 shows the results of energy-dispersive spectroscopy (EDS) of the nanocomposite according to an embodiment of the present invention.
5 to 7 show the results of differential scanning calorimetry (DSC) of the epoxy cured material according to an embodiment of the present invention.
8 is a graph showing the shear strength of an epoxy cured product according to an embodiment of the present invention.
9 to 10 show the results of Dynamic Mechanical Analysis (DMA) of a cured epoxy material according to an embodiment of the present invention.

Hereinafter, the nanocomposite of the present invention and an epoxy resin curable composition using the same will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. At this time, if there is no other definition in the technical terms and scientific terms used, it has the meaning commonly understood by those of ordinary skill in the art to which this invention belongs, and the gist of the present invention in the following description and accompanying drawings Descriptions of known functions and configurations that may be unnecessarily obscure will be omitted.

Also, the singular forms used in the specification and appended claims may also be intended to include the plural forms unless the context specifically dictates otherwise.

In this specification and the appended claims, terms such as first, second, etc. are used for the purpose of distinguishing one element from another, not in a limiting sense.

In this specification and the appended claims, terms such as include or have means that a feature or element described in the specification is present, and unless specifically limited, one or more other features or elements are added. This is not to rule out the possibility in advance.

In this specification and the appended claims, when a part of a film (layer), region, component, etc. is on and on another part, not only when it is directly on the other part in contact with it, but also another film ( layer), other regions, and other components are also included.

The nanocomposite according to the present invention includes a particle-like core containing carbon and metal, and a shell coated with a metal-organic framework (MOF) on the surface of the core. The nanocomposite of the core-shell structure has all of the physicochemical properties of carbon, metal, and metal-organic framework as the metal-organic framework is coated on the surface of the core around the core made of carbon and metal, and can exert a complex function. have.

For example, the nanocomposite according to the present invention may be used as an epoxy curing accelerator. As the nanocomposite has a core-shell structure, it is possible to provide an epoxy cured product with increased mechanical strength and thermal conductivity due to carbon and metal while having a curing promoting ability by a metal-organic framework. In addition, since the nanocomposite is uniformly dispersed in carbon, metal, and metal-organic framework, it is possible to achieve stable function as a curing accelerator and provide excellent storage stability.

The carbon contained in the core may be a carbonaceous particle, preferably a spherical carbon-based compound. As an advantageous example, the spherical carbon-based compound may be fullerene. Fullerene refers to a closed cage molecule formed in hexagons and pentagons having carbon hybridized with ^{sp 2 .} Since fullerene can easily induce changes in physicochemical properties by modifying the surface or trapping other molecules in the internal void space, it is easy to form derivatives.

More specifically, for example, the carbon particle is a fullerene oxide (C ₆₀ (O) _{n obtained by oxidizing Buckminsterfullerene, C 60} ) having a bucky ball structure formed by combining 60 carbon atoms in the shape of a soccer ball. ) can be Buckminster fullerene has the most stable structure among fullerenes and has high thermal conductivity. When the above fullerene-containing nanocomposite is used as a curing accelerator, the curing speed can be increased due to excellent thermal conductivity, and as curing occurs at the same temperature throughout the cured composition in which the resin and curing agent are mixed, a homogeneous cured product is obtained can do. In addition, a cured product having excellent mechanical strength can be provided by fullerene having a stable structure. Fullerene oxide may be selected from (O) ₁ to (O) ₄₀ according to the degree of oxidation modification (O) _n. When the fullerene oxide is used, a metal to be described later may be easily bonded to the surface of the fullerene oxidation-modified.

The metal contained in the core may be one or a combination of two or more selected from the group consisting of silver, gold, copper, aluminum, platinum, palladium, nickel and iron.

When the metal nanocomposite is used as a curing accelerator, it is possible to obtain improved storage stability by increasing activation energy as it comes into contact with a curing reactant instead of a metal-organic framework having a curing accelerator.

In addition, in a cured product cured by using the nanocomposite as a curing accelerator, the metal serves to increase the glass transition temperature, thereby providing a cured product having excellent heat resistance.

As described above, the core contains carbon and metal, and specifically, the metal is particulately coated on the surface of carbon particles or carbon aggregates on which carbon particles are aggregated. As a preferred example, the spherical carbon-based compound or the spherical carbon-based compound may be coated in the form of particles on the surface of the aggregated aggregate, and the spherical carbon-based compound and the metal may be chemically bonded.

As the metal is coated on the surface of the carbon particles or carbon aggregates, a core in which carbon and metal are uniformly mixed with each other is formed, but the carbon particles may have a uniformly dispersed phase in the core.

When the metal is coated on the surface of the carbon body particles or carbon agglomerates, the metal may be coated so that some or all of the carbon body particles or carbon agglomerates are buried. In the case where the carbon particles or a part of the carbon aggregates are buried, a region of the carbon aggregates not covered with the particulate metal may be exposed as the surface of the core. On the other hand, when the carbon particles or carbon aggregates coated with a metal are aggregated to form a core, some or all of the carbon particles may be buried by the metal to be coated, and when a part is buried, the carbon not covered with the metal A sieve particle region may be exposed to the surface of the core.

Accordingly, the metal-coated carbon particles or carbon aggregates may exist as individual primary particles, but may also exist as secondary particles formed by agglomeration of the primary particles. The secondary particles may be generated during a reaction process in which a metal is coated on the surface of the carbon particles or carbon aggregates.

The core having such a structure serves to support the shell, which will be described later, and at the same time increases the structural stability of the nanocomposite. In addition, when the nanocomposite is used as a curing accelerator, the core serves to further increase the activation energy to further enhance storage stability. In addition, it allows the prepared cured product to have excellent mechanical strength and to be cured at a uniform temperature throughout the cured composition due to excellent thermal conductivity.

The core may have an average particle diameter of 0.1 to 100 μm, specifically 10 to 50 μm, and more specifically 20 to 40 μm. The core in this range is preferable because it is easy to coat the surface with a metal-organic skeleton to be described later, but is not limited thereto.

The metal-organic framework contained in the shell includes a zeolitic imidazolate framework (ZIF).

The metal of the metal-organic framework may be a transition metal, and as a specific example, Zn, Mn, Cu, Cd, Be, Mg, Cr, Ca or Co, and preferably Zn may be selected.

The zeolite-type imidazolate structure may be one or a mixture of two or more selected from the group consisting of ZIF-1, ZIF-3, Co-ZIF-4, ZIF-8, ZIF-11 and ZIF-90. When the metal-organic framework is ZIF, it can be thermally stable and can act as a hardening accelerator at high temperatures. In ZIF, carbonization occurs as the temperature rises and the color changes to black, but a nanoporous carbon structure is formed so that the framework can be stably maintained.

More specifically, the metal-organic framework may be ZIF-8. In the case of using ZIF-8, when applied to an epoxy composition, the viscosity change rate may be very low compared to the imidazole catalyst or urea-based phenuron accelerator used in the past. The zeolite-type imidazolate structure may have an average particle diameter of 10 nm to 30 μm, specifically 50 nm to 1000 nm, and more specifically 70 to 500 nm. However, the present invention is not limited thereto. When the metal-organic framework is coated on the surface of the core, part or all of the core may be embedded.

Preferably, a part of the core may be embedded by the shell, which is a metal-organic framework.

As such, when a part of the core is buried by the shell, the surface of the nanocomposite of the present invention includes a surface region of the particulate metal-organic framework and a surface region where the metal of the core is exposed. When such a nanocomposite is used as a curing accelerator, the surface area of the metal-organic framework reacts with the reaction composition, and the surface area where the metal is exposed does not react. Accordingly, by delaying the contact between the metal-organic framework and the reaction composition, the activation energy is increased to have excellent storage stability.

The nanocomposite is 0.1 to 350 parts by weight of a metal based on 100 parts by weight of fullerene, 10 to 3000 parts by weight of a metal organic framework, preferably 1 to 100 parts by weight of a metal based on 100 parts by weight of fullerene, 50 to 500 parts by weight of a metal organic framework may contain wealth. It has sufficient storage stability while fulfilling the role as a hardening accelerator in the above-mentioned range. In addition, it is possible to form an efficient core-shell structure compared to the weight ratio, and as carbon, metal, and metal-organic framework are uniformly dispersed, stable function as a curing accelerator can be expressed.

As the nanocomposite described above includes a core containing carbon and metal, when used as an epoxy curing accelerator, an epoxy cured product having excellent mechanical strength and thermal conductivity can be provided. In addition, the curing speed is enhanced due to excellent thermal conductivity, and a homogeneous cured epoxy product can be obtained by curing at a uniform temperature throughout the epoxy composition. In addition, since the nanocomposite is uniformly dispersed in carbon, metal, and metal-organic framework, it is possible to achieve stable function as a curing accelerator and provide excellent storage stability.

Hereinafter, a method for manufacturing a nanocomposite according to the present invention will be described.

The nanocomposite according to the present invention comprises a first step of manufacturing a core by coating a metal on carbon particles, and a method of coating a metal-organic framework (MOF) to form a shell on the surface of the core Manufactured in two steps.

The first step is a step of forming a particle-like core containing carbon particles and a metal, and adding and mixing the carbon particles and a metal precursor to a solvent to obtain a first reaction solution, and adding water to the first reaction solution After adding and stirring to obtain a core.

The metal precursor is preferably a water-soluble metal precursor so that it can be dissolved in a solvent. The water-soluble metal precursor may include, but is not limited to, metal oxide salts, oxyhydroxide salts, chloride salts, carbonates, acetates, citrates, nitrosylnitrates, nitrates, hydroxides, oxalates, carboxylates, sulfates, etc. .

The solvent is for dispersing the carbon particles and dissolving the metal precursor, and a reducing solvent is suitable. For example, it may be one of ethylene glycol, diethylene glycol, glycerol, methanol, triethylene glycol, propylene glycol, and the like, but is not limited thereto. The solvent is not limited as long as it has an amount capable of uniformly dispersing the carbon particles and the metal. For example, 50 to 100 parts by weight may be added based on 100 parts by weight of carbon.

First, in order to prepare the first reaction solution, the carbon particles: the metal precursor may be added to the solvent in a weight ratio of 1:2 to 1:10. Preferably, it is added to the solvent in a weight ratio of 1:3 to 1:7. In such a range, the formation ratio of the core to weight ratio is high, and thus the process is efficient.

Thereafter, water is mixed with the prepared first reaction solution and stirred to obtain a core. The content of water with respect to the solvent is not limited as long as it can sufficiently form a core. For example, when the prepared first reaction solution is mixed with water, the solvent: water may be mixed in a volume ratio of 1:1 to 10:1, specifically, 2:1 to 8:1 by volume. Agitation is not limited as long as the time and temperature at which the core can be sufficiently formed, but may be, for example, 2 to 6 hours, 10 to 60°C. The formed core is washed in water, dried in an oven, and provided in powder form.

The second step is a step of coating the surface of the core with the metal-organic framework by mixing the first solution in which the core is dispersed in the first solvent and the second solution in which the metal-organic framework is dispersed in the second solvent.

The first solvent is for dispersing the core and may be a glycol-based solvent. The glycol-based solvent may be, for example, one of glycol-based solvents such as ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol, dipropylene glycol, butylene glycol, but is not limited thereto. Any amount of the first solvent in which the core can be sufficiently dispersed is applicable. For example, 50 to 100 parts by weight of the first solvent may be mixed with respect to 100 parts by weight of the core prepared in the first step.

The second solvent is for dispersing the metal-organic framework, and may be, for example, one of alcohol-based solvents such as methanol, ethanol, propanol, butanol, but is not limited thereto. As for the second solvent, any content in which the metal-organic framework can be sufficiently dispersed is applicable. For example, 300 to 700 parts by weight of the first solvent may be mixed with respect to 100 parts by weight of the metal-organic framework.

First, in order to prepare a first solution in which the core is dissolved and a second solution in which the metal-organic framework is dissolved, the core and the metal-organic framework are added to a first solvent and a second solvent, respectively. Thereafter, the first solution and the second solution are mixed in a weight ratio of 1:2 to 1:10. Preferably, it may be mixed in a weight ratio of 1:3 to 1:7. Such a range is such that the surface of the nanocomposite is divided into a surface area coated with a particulate metal-organic framework and an exposed surface area of the core. Accordingly, by delaying the contact between the metal-organic framework and the reaction composition, the activation energy is increased to have excellent storage stability.

Thereafter, the mixed first solution and the second solution are stirred to obtain a nanocomposite. Agitation is not limited as long as the time and temperature at which the nanocomposite can be sufficiently formed, but may be, for example, 2 to 6 hours, 10 to 60°C. The formed nanocomposite is washed with C1 to C3 lower alcohol, dried in an oven, and provided in powder form.

The epoxy resin curable composition according to the present invention includes a nanocomposite, an epoxy resin, and a curing agent. Since the nanocomposite according to the present invention is included in the composition as a curing accelerator, it is possible to promote the curing reaction between the epoxy resin and the curing agent while having thermal stability and long-term storage stability. The epoxy resin curable composition may be a one-component epoxy composition, but is not limited thereto, and the two-component epoxy composition is also included in the scope of the epoxy resin curable composition of the present invention.

The content of the nanocomposite of the present invention is not limited as long as the content is typically used as a curing accelerator in the field. Illustratively, 1 to 30 parts by weight of the curing agent and 0.01 to 3 parts by weight of the nanocomposite may be mixed with respect to 100 parts by weight of the epoxy resin. More specifically, 5 to 15 parts by weight of the curing agent, 0.3 to 1 parts by weight of the nanocomposite may be mixed with respect to 100 parts by weight of the epoxy resin. In the above range, the nanocomposite of the present invention has excellent thermal stability and long-term storage stability, and at the same time, it is preferable because it is sufficient to express physical properties as a curing accelerator, but is not limited thereto.

The epoxy resin may be used without limitation as long as it is a commonly used epoxy resin. Specifically, for example, it may be a bisphenol-based epoxy resin, and specifically, for example, any one or two or more selected from bisphenol A-type epoxy resin, bisphenol M-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, etc. can be used The bisphenol-based epoxy resin may be used as an epoxy resin in a liquid or solid state at room temperature.

The curing agent may be used without limitation as long as it is known in the art as curing the epoxy resin. In order to prepare a one-component adhesive, it is preferable to use a latent curing agent that is solid at room temperature and can melt and react with the epoxy resin when heated, but is not limited thereto. Specifically, for example, an anhydride-based curing agent, a phenol-based curing agent, a dicyandiamide-based curing agent, and an amine-based curing agent may be used. These may be used independently and may mix and use 2 or more types. It may be to use an amine-based curing agent from the viewpoint of being suitably usable in the one-component adhesive composition.

Acid anhydride curing agents include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, glutaric anhydride, methylhexahydro Phthalic anhydride, methyltetrahydrophthalic anhydride, etc. can be used individually or in mixture of 2 or more types.

Examples of the phenolic curing agent include phenolic resins such as formaldehyde condensed resol phenolic resins, nonformaldehyde condensed phenolic resins, novolac-type phenolic resins, novolac-type phenol formaldehyde resins, and polyhydroxystyrene resins; resol-type phenolic resins such as aniline-modified resol resins and melamine-modified resol resins; novolac-type phenolic resins such as phenol novolac resins, cresol novolac resins, tert-butylphenol novolac resins, nonylphenol novolac resins and naphthol novolac resins; special phenolic resins such as dicyclopentadiene-modified phenolic resins, terpene-modified phenolic resins, triphenolmethane-type resins, phenolaralkyl resins having a phenylene skeleton or diphenylene skeleton, and naphtholaralkyl resins; and polyhydroxystyrene resins such as poly(p-hydroxystyrene), etc. may be used. It can be used alone or in combination of two or more.

Any one or a mixture of two or more selected from the group consisting of aliphatic amines, aliphatic polyamines, aromatic polyamines, polyamide polyamines, and modified aromatic amines may be used as the amine-based curing agent. The aliphatic amine may be one or a mixture of two or more selected from dicyandiamine, diethylenetriamine, triethylenetetraamine, diethylaminopropylamine, menthanediamine, N-aminoethylpiperazine, emxylenediamine and isophoronediamine. have. The modified aromatic amine may be one or a mixture of two or more selected from the group consisting of 4,4-diaminodiphenylmethane, metaphenylene diamine, and diaminodiphenyl sulfone.

A well-known additive can be used for an epoxy resin composition as needed. The amount of additives may be used in a total amount of 1 to 90 parts by weight based on 100 parts by weight of the main agent. The additive may further include any one or two or more additives selected from a polyurethane-based toughening agent, a core-shell-type toughening agent, and a filler.

The epoxy resin curable composition may optionally further contain one or more other additives. For example, optional additives include stabilizers, surfactants, rheology modifiers, pigments, dyes, matting agents, degassing agents, fillers, flame retardants, cure initiators, cure inhibitors, wetting agents, colorants, pigments, thermoplastics, processing aids, ultraviolet light Any one or a mixture of two or more selected from (UV) blocking compounds, fluorescent compounds, UV stabilizers, antioxidants, and mold release agents may be further included. Optional additives may be used in a range that does not impair the physical properties of the epoxy composition of the present invention.

In addition, in the range that does not impair the purpose of the present invention, a mold release agent such as a higher fatty acid, a metal salt of a higher fatty acid, an ester wax, or a natural wax, or a coupling agent such as an epoxysilane, an aminosilane, or an alkylsilane, etc. can be used as needed.

In the present invention, an epoxy cured product prepared by curing the epoxy resin curable composition of the present invention is also included in the scope of the present invention.

The shape of the epoxy cured product is not limited, such as a film, a coating film, a structure, and the like, and is not limited as long as it is a cured product in the field to which the epoxy resin curable composition is applicable. As the epoxy cured product includes the nanocomposite of the present invention in which the shell is formed by coating ZIF-8 on the surface of the particle-like core containing fullerene oxide and silver nanoparticles, the structural stability is increased and the degree of resistance to external force is increased do.

Hereinafter, the manufacturing method of the epoxy resin cured material of this invention is demonstrated.

The cured epoxy resin includes a step of mixing the nanocomposite according to the present invention, an epoxy resin, and a curing agent to obtain an epoxy resin curable composition, and a curing step of curing the epoxy resin composition to obtain a cured epoxy product. The curing step is not limited in scope as long as the temperature and time for completely curing the epoxy cured product. However, when the curing reaction is performed at a temperature of 100 to 300 °C, specifically, at a temperature of 160 to 200 °C, the occurrence of cracks may be small.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. However, the following examples and comparative examples are merely examples for explaining the present invention in more detail, and the present invention is not limited by the following examples and comparative examples.

[Production Example]

First, 0.3 g of Zn(NO ₃ ) ₂ H ₂ O and 0.66 g of 2-methylimidazole were dissolved in 11 g of methanol to prepare a precursor solution. The prepared precursor solution was placed in a round flask and vigorously stirred for 5 minutes. This solution was put into an autoclave and reacted in an oven at 150 °C for 5 hours. After cooling, the crystals were separated by centrifugation and washed with methanol. Thereafter, the obtained powder was dried at 75° C. for one day to recover ZIF-8.

[Example 1]

30 mg of fullerene oxide [C ₆₀ (O) ₁ ] and 150 mg of AgNO ₃ were dispersed in 20 ml of diethyl glycol, 5 ml of water was added, and the mixture was stirred at room temperature for 4 hours to obtain a core. Thereafter, the core was washed with water and dried in an oven to obtain a core in powder form.

60 mg of the obtained core was dispersed in 60 ml of diethyl glycol, and 300 mg of the ZIF-8 powder prepared in Preparation Example was dispersed in 60 ml of methanol, and then each was mixed. Then, it was stirred at room temperature for 2 hours to obtain a nanocomposite. Thereafter, after washing with methanol 5 times, and drying in an oven, a powder-type nanocomposite was obtained.

The XRD of the nanocomposite prepared in Example 1 was measured and shown in FIG. 1 . 1 is an XRD pattern of the prepared nanocomposite (ZIF composite), and pure ZIF-8 prepared by the method of Example 1. And the XRD pattern of _{the core (C 60} (O) _1- Ag) prepared by the method of Example 1 was compared.

1 is a [X-ray diffraction pattern] XRD diffraction analysis results in which 2theta values are set from 5 to 90 using Rigaku-UltimaIV equipment. Through the presence of the peak of the nanocomposite of Example 1 at the same position as the peak of the pure ZIF-8, it was found that ZIF-8 was coated on the surface of the nanocomposite. In the case of Ag, it is judged that there is no change in the XRD peak because it is aggregated into particles or spread as a layer on the surface of the carbon aggregate.

In addition, for component and structure analysis of the nanocomposite, [FT-IR] was analyzed within the wavelength range ^{from 4000 cm -1} to 600 cm ^{-1 using the [FT-IR] Thermo Fisher Scientific Nicolet Continuum IR Microscope.}

2 shows the FTIR spectrum of the nanocomposite. As a result of the analysis, it was confirmed that the nanocomposite exhibited a peak similar to that of pure ZIF-8. That is indicated a peak of the 994㎝ ^-1 derived from the CN 1146㎝ ^-1 originated from C = N it can be seen that ZIF-8 has been stably bonded to the core. That is, it can be confirmed that the surface of the nanocomposite is coated with ZIF-8 to form a core-shell structure.

SEM was used to observe the morphology of the prepared nanocomposite. [FE-SEM] Analyzed at 15kV, 2-10μm scale using TESCAN MIRA 3 equipment. 3 is an SEM photograph of the nanocomposite, and FIG. 4 is an EDS analysis result.

Referring to FIG. 3 , both Ag nanoparticles and nanocube-shaped ZIF-8 coated on the _{C 60} (O) _{n surface were observed.} It was confirmed that the prepared nanocomposite had a particle diameter of about 30 μm.

Referring to FIG. 4 , as a result of the EDS analysis, it can be seen that the prepared nanocomposite contains 78 wt% of C, 21 wt% of Zn, and 1 wt% of Ag compared to the total weight.

[Example 2]

Bisphenol A (bisphenol A)-based epoxy resin (DGEBA EPIKOTE 828, Momentive), 25 g, amine curing agent DICY (DICYANEX 1400F, Air Products) 28.1 g as a curing accelerator 0.15 of the nanocomposite prepared in Example 1 g to prepare an epoxy resin curable composition by mixing.

Thereafter, the prepared epoxy resin curable composition was applied to a mold and cured at 180° C. for 20 minutes to prepare an epoxy cured product.

[Comparative Example 1]

In Example 2, an epoxy cured product was prepared in the same manner as in Example 2, except that 0.15 g of 2-MeIM (Sigma-Aldrich), which is commercially available as a curing accelerator, was used instead of the nanocomposite.

[Comparative Example 2]

In Example 2, an epoxy cured product was prepared in the same manner as in Example 2, except that 0.15 g of ZIF-8 prepared in Preparation Example was used as a curing accelerator instead of the nanocomposite.

[Comparative Example 3]

In Example 2, an epoxy cured product was prepared in the same manner as in Example 2, except that 0.15 g of Ag@ZIF-8 mixed with ZIF-8 and silver nanoparticles was used as a curing accelerator instead of the nanocomposite.

Ag@ZIF-8 is _{a solution in which AgNO 3} is dispersed in 20 ml of diethylene glycol and a solution obtained by dispersing 300 mg of ZIF-8 obtained in Preparation Example 1 in 60 ml of methanol, followed by mixing at room temperature for 2 hours It was obtained by stirring during Thereafter, after washing with methanol 5 times, and drying in an oven, Ag@ZIF-8 in powder form was obtained.

[Experimental Example 1]

DSC analysis was performed to confirm the reactivity and thermal transferability of the prepared nanocomposite. DSC analysis was performed using a differential scanning calorimetry (TA DSC Q-200) from -80 °C to 240 °C at 2 °C/min, 5 °C/min, 10 °C/min and 20 °C/min heating rate. observed. The results are shown in FIGS. 5 to 7 and Table 1. 5 is a glass transition temperature (T _g ), FIG. 6 is an exothermic maximum temperature (T _peak ), and FIG. 7 is a DSC result analysis graph showing reaction activation energy. Table 1 shows the calculated reaction activation energy (kJ/mol).

Referring to FIG. 5 , T _g and T _peak change depending on the curing accelerator. In Comparative Example 2, T _g is the lowest, and when Comparative Example 3 is used, it _{can be confirmed that T g} is the highest, and the difference is about 4 ° C. . When looking at the results of Comparative Example 2 using ZIF-8 as a curing accelerator, Example 2 using a nanocomposite as a curing accelerator, and Comparative Example 3 using Ag@ZIF-8 as a curing accelerator, the glass transition temperature was considered to have risen.

6, in the case of Example 2, the maximum exothermic temperature is the highest, and the difference between the curing start temperature and the curing end temperature is the smallest. That is, it is judged that the curing speed is increased compared to the conventional curing accelerator due to the high thermal conductivity of fullerene.

In the case of Table 1 and FIG. 7 showing the activation energy calculated by the Kissinger equation, compared with Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 2 in the order of, the graph behavior gradually skewed to the left Confirmed. It can be seen that when 2-MeIM, which is a conventional curing accelerator, is used as a curing accelerator, direct contact with the epoxy resin and curing agent is possible, resulting in high reactivity, whereas ZIF-8 has relatively low reactivity, resulting in better storage stability. .

In Comparative Example 3 containing more silver in Comparative Example 2, the activation energy increased more than in Comparative Example 2, but in Example 2 containing more fullerene oxide, the activation energy increased the most significantly compared to Comparative Example 2. it can be seen that It is judged that the contact between ZIF-8 and the curing reactant is further delayed by the fullerene, resulting in a higher reaction activation energy. For this reason, Example 2 of the present invention is judged to have superior storage stability than other comparative examples.

Heating rate (°C/min) 2 5 10 20 Example 1 153.0 163.5 173.5 182.3 Comparative Example 1 124.4 131.3 144.9 152.5 Comparative Example 2 144.6 155.1 165.4 176.6 Comparative Example 3 145.4 156.9 167.3 176.3

[Experimental Example 2]

The shear strength of the prepared epoxy cured product was measured. The shear strength of the epoxy cured product was measured using a universal testing machine (UTM 5982, INSTRON), and was tested according to ASTM D-1002 standard. 8 is a measurement result of shear strength.

Referring to FIG. 8, the shear strength of Example 1 of the present invention is 18.40 Mpa, which has superior shear strength than the cured epoxy products prepared in Comparative Examples 1 to 3. In particular, it exhibits an effect of about 9.5% higher than the shear strength of Comparative Example 1 using a general curing accelerator.

And, it exhibits superior shear strength compared to Comparative Example 3 in which silver and ZIF are mixed. This is considered to be due to fullerene oxide having a stable structure. That is, it was confirmed that Example 2 had better mechanical strength.

[Experimental Example 3]

In order to investigate the dynamic thermal properties of the epoxy cured material of the present invention, using a dynamics analyzer (DMA Q800, TA Instruments), the amplitude (amplitude) of 10 μm, the temperature increase rate of 5 ℃ per minute was measured while applying heat from room temperature to 200 ℃ Each test piece was processed to a size of 60 mm × 12 mm × 3 mm (length × width × thickness). The results are shown in FIGS. 9 to 11 . 9 is a graph showing the storage modulus, FIG. 10 is tan δ, and FIG. 11 is a graph showing the loss modulus.

9 to 11 , Example 1 of the present invention exhibited the highest values in storage modulus and loss modulus. That is, it was confirmed that the embodiment of the present invention has excellent dynamic thermal properties.

The nanocomposite according to the present invention described above can be used as an epoxy curing accelerator, and it is possible to prepare an epoxy cured product having excellent mechanical properties, thermal properties, and storage stability.

As described above, the present invention has been described with reference to specific matters and limited examples and drawings, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention is not limited to the above embodiments. Various modifications and variations are possible from these descriptions by those of ordinary skill in the art. Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims described below, but also all of the claims and all equivalents or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

Claims (18)

a particulate core containing carbon and metal; and
Nanocomposite comprising; a shell coated with a metal-organic framework (MOF) on the surface of the core. The method of claim 1,
The carbon is a spherical carbon-based compound nanocomposite. The method of claim 1,
The metal-organic framework is a nanocomposite comprising a zeolitic imidazolate framework. The method of claim 1,
The metal is a nanocomposite comprising at least one selected from silver, gold, copper, aluminum, platinum, palladium, nickel, and iron. The method of claim 1,
The nanocomposite wherein the metal content inside the core is higher than the metal content on the surface of the core. The method of claim 1,
The surface of the nanocomposite is a nanocomposite comprising a surface area coated with a particulate metal-organic framework and an exposed surface area of the core. The method of claim 1,
The nanocomposite is a nanocomposite comprising 1 to 350 parts by weight of the metal, 100 to 3000 parts by weight of the metal-organic framework with respect to 100 parts by weight of the fullerene. An epoxy curing accelerator comprising the nanocomposite of any one of claims 1 to 7. A first step of manufacturing a core by coating the carbon particles with a metal; and
A method of manufacturing a nanocomposite comprising; a second step of coating a metal-organic framework (MOF) to form a shell on the surface of the core. 10. The method of claim 9,
In the first step, the carbon particles and the metal precursor are added to and mixed in a solvent in a weight ratio of 1:2 to 1:10 to obtain a first reaction solution;
A method for preparing a nanocomposite comprising adding water to the first reaction solution and then stirring to obtain a core. 10. The method of claim 9,
In the second step, a second solution in which the metal-organic framework is dispersed in a second solvent is mixed with a first solution in which the core is dispersed in a first solvent, and the surface of the core is coated with a metal-organic framework MOF) coating with a nanocomposite manufacturing method. 12. The method of claim 11,
A nanocomposite manufacturing method of mixing 300 to 500 parts by weight of the metal-organic framework with respect to 100 parts by weight of the core. 11. The method of claim 10,
The metal precursor is a water-soluble metal precursor nanocomposite manufacturing method. The epoxy resin curable composition comprising the nanocomposite of any one of claims 1 to 7, an epoxy resin, and a curing agent. 15. The method of claim 14,
An epoxy resin curable composition in which 5 to 15 parts by weight of the curing agent and 0.01 to 3 parts by weight of the nanocomposite are mixed with respect to 100 parts by weight of the epoxy resin. 8. A method comprising: mixing the nanocomposite of any one of claims 1 to 7, an epoxy resin, and a curing agent to obtain an epoxy resin curable composition;
Hardening the epoxy resin composition to obtain a cured epoxy product; Method for producing a cured epoxy product comprising a. 17. The method of claim 16,
The curing step is a method for producing a cured epoxy product is performed at a temperature of 160 to 200 ℃. A cured epoxy product manufactured by the method of claim 16 .

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