KR20200036596A - Composite Material - Google Patents

Abstract

The present invention relates to a composite material. The composite material has high permeability and is excellent in mechanical properties such as flexibility and the like. The composite material comprises: a first region formed of a metal foam layer having a conductive metal component; a second region formed of a metal foam layer having a soft magnetic metal component; and a conductive material-containing layer.

Description

Composite Material {Composite Material}

This application relates to composite materials.

Materials having a high magnetic permeability can be used for various applications. For example, the above materials may be used as various devices or materials including an EMC core, a low power high inductance resonance circuit, or a broadband transformer, and may also be used as a radio wave absorber.

Typically used as a material having a high magnetic permeability is a material in the form of a polymer composite film produced by rolling a metal with a high magnetic permeability or by using metal particles as a filler.

However, in the method of rolling or the like, a multi-component material is used to increase the permeability of a metal material, or since the crystallization is performed on a film, the process is complicated and the price is high.

In addition, when using metal particles as a filler, the amount of metal particles must be increased in order to secure a high magnetic permeability. In this case, the flexibility of the film is poor.

This application relates to a composite material. One object of the present application is to provide a composite material having high magnetic permeability and excellent mechanical properties such as flexibility. The composite material may be used for various purposes, and may be used, for example, as an electromagnetic wave shielding material.

This application relates to composite materials. The composite material of the present application may include a first region formed of a metal foam having a conductive metal component and a second region formed of a metal foam having a soft magnetic metal component.

The composite material of the present application in the form described above exhibits high magnetic permeability, and is formed of a metal foam, and thus has excellent mechanical properties such as flexibility.

The composite material may be formed of a material having a high magnetic permeability due to the characteristic surface area and porosity characteristics of the metal foam and multiple reflection and absorption by the material of the metal foam. Excellent mechanical strength and flexibility can be ensured in the material.

In this specification, the term metal foam or metal skeleton refers to a porous structure containing metal as a main component. The metal as a main component in the above, based on the total weight of the metal foam or metal skeleton, the proportion of metal is 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80 It means the case of at least 85% by weight, at least 85% by weight, at least 90% by weight, or at least 95% by weight. The upper limit of the proportion of the metal contained as the main component is not particularly limited, and may be, for example, about 100% by weight, 99% by weight, or 98% by weight.

As used herein, the term porosity, when porosity is at least 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 75% or more, or 80% or more Can mean The upper limit of the porosity is not particularly limited, for example, less than about 100%, about 99% or less, about 98% or less, about 95% or less, about 90% or less, about 85% or less, about 80% or less, or It may be about 75% or less. The porosity can be calculated by a known method by calculating the density of a metal foam or the like.

When the measured temperature among the physical properties mentioned in this specification affects the physical property, the physical properties are measured at room temperature unless otherwise specified. The term room temperature is a natural temperature that is not heated or reduced, and may mean, for example, any temperature in the range of about 10 ° C to 30 ° C, or about 23 ° C or about 25 ° C. In addition, unless specifically stated otherwise in this specification, the unit of temperature is ° C.

The shape of the metal foam included in the composite material is not particularly limited, but may be in the form of a film, sheet, or layer in one example. Hereinafter, in the present specification, the metal foam in the form of a film, sheet, or layer may be referred to as a metal foam layer.

For example, the first region and the second region are metal foam layers, and the metal foam layer of the first region and the metal foam layer of the second region may be stacked with each other. 1 is a schematic view of the above structure, showing a case where the metal foam layer 10 of the first region and the metal foam layer 20 of the second region are stacked on each other.

In the composite material, the metal foam may have the following pore characteristics. The pore characteristics described below may be a range for the entire composite material in which the metal foams of the first region and the second region are integrated, or may be a range for the metal foam of any one of the first and second regions. In one example, the metal foam of the first region and the metal foam of the second region may each independently have the porosity characteristics described below, wherein the porosity characteristics of each metal foam may have the same or different pore characteristics. .

In the composite material, the metal foam may have a porosity of about 10% or more. The metal foam having such porosity has a porous metal skeleton forming a suitable network, and thus, it is possible to secure a high permeability even when a small amount of the metal foam is applied. In another example, the porosity is 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more Or more or 70% or more, or 99% or less, 98% or less, about 95% or less, about 90% or less, about 85% or less, about 80% or less, or about 75% or less.

In order to secure an appropriate permeability, the porosity characteristics of the metal foam may be further controlled. For example, the metal foam may include pores of a substantially spherical shape, a needle shape, or a random shape. For example, the metal foam has a maximum pore size of about 100 μm or less, about 90 μm or less, about 80 μm or less, about 70 μm or less, about 60 μm or less, about 50 μm or less, 45 μm or less, 40 μm or less , 35 μm or less or 30 μm or less. In other examples, the maximum pore size is about 2 μm or more, 4 μm or more, 6 μm or more, 8 μm or more, 10 μm or more, 12 μm or more, 14 μm or more, 16 μm or more, 18 μm or more, 20 μm or more, 22 It may be at least μm, at least 24 μm, or at least 26 μm.

Among the total pores of the metal foam, pores of 85% or more may have a pore size of 10 μm or less, and pores of 65% or more of pores may be 5 μm or less. In the above, the lower limit of the pore size of the pore having a pore size of 10 μm or less or 5 μm or less is not particularly limited, but in one example, the pore size is greater than about 0 μm, 0.1 μm or more, 0.2 μm or more, 0.3 μm or more, 0.4 μm or more, 0.5 μm or more, 0.6 μm or more, 0.7 μm or more, 0.8 μm or more, 0.9 μm or more, 1 μm or more, 1.1 μm or more, 1.2 μm or more, 1.3 μm or more, 1.4 μm or more, 1.5 μm or more, 1.6 μm Or more, 1.7 μm or more, 1.8 μm or more, 1.9 μm or more, or 2 μm or more.

In the above, pores having a pore size of 10 μm or less may be 100% or less, 95% or less, or 90% or less of the total pores, and the ratio of pores having a pore size of 5 μm or less is 100% or less of the total pores, 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, or 70% or less.

Due to these pore distributions or characteristics, it may be possible to manufacture a desired composite material. The distribution of the pores may be, for example, determined based on the long axis direction of the film, sheet, or layer when the composite material or metal foam is in the form of a film, sheet, or layer.

The thickness of the metal foam layer in the first and second regions may be adjusted in consideration of characteristics such as desired permeability.

For example, the total thickness of the metal foam layer in the first region and the metal foam layer in the second region may be in the range of approximately 10 μm to 2,000 μm. In other examples, the total thickness is 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, or 100 μm or more, 1,900 μm or less, 1,800 μm 1,700 μm or less, 1,600 μm or less, 1,500 μm or less, 1,400 μm or less, 1,300 μm or less, 1,200 μm or less, 1,100 μm or less, 1,000 μm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, It may be 500 μm or less, 400 μm or less, 300 μm or less, or 200 μm or less.

The ratio (T2 / T1) of the thickness T1 of the metal foam layer in the first region and the thickness T2 of the metal foam layer in the second region may be in the range of 0.2 to 10. The ratio (T2 / T1) may be approximately 0.3 or more, 0.35 or more, or 0.4 or more, or 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, or 3.5 or less in other examples.

In this specification, when the thickness of the object is not constant, the thickness may be a minimum thickness, a maximum thickness, or an average thickness of the object.

Through the thickness control as described above, it may be possible to provide a composite material having desired characteristics.

The metal foam forming the first region among the metal foams may be a metal foam of a conductive metal component. The term conductive metal component may mean a conductive metal or metal alloy. In the present application, the term conductive metal or metal alloy has a conductivity at 20 ° C of about 8 MS / m or higher, 9 MS / m or higher, 10 MS / m or higher, 11 MS / m or higher, 12 MS / m or higher, 13 It may mean a metal or a metal alloy of MS / m or more or 14.5 MS / m or more. The upper limit of the conductivity is not particularly limited, and may be, for example, about 30 MS / m or less, 25 MS / m or less, or 20 MS / m or less.

The metal foam of the conductive metal component may consist of the conductive metal component only, or may mean a metal foam containing the metal component as a main component. Therefore, the metal foam is based on the total weight of the conductive metal component 55 wt% or more, 60 wt% or more, 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more , 90% by weight or more or 95% by weight or more. The upper limit of the proportion of the conductive metal component is not particularly limited, and may be, for example, about 100% by weight, 99% by weight, or 98% by weight.

Examples of specific conductive metal components include nickel, iron, cobalt, silver, copper, gold, aluminum, calcium, tungsten, zinc, lithium, iron, platinum, tin, lead, titanium, manganese, magnesium, or chromium. Although more than one type of alloy may be illustrated, it is not limited thereto. However, in the present application, various materials known to have appropriate conductivity may be applied to the materials.

The metal foam in the first region as described above may be designed to exhibit shielding efficiency of 80 dB or more within a range of 50 kHz to 3 GHz, which is formed by using the material to have the above-described pore characteristics. Can be achieved.

The metal foam of the second region may be a metal foam of a soft magnetic metal component. The term soft magnetic metal component is a soft magnetic metal or a metal alloy, wherein the soft magnetic regulation is as known in the art. In the above, the metal foam of the soft magnetic metal component may consist of only the soft magnetic metal component or may mean a metal foam containing the metal component as a main component. Therefore, the metal foam is based on the total weight of the soft magnetic metal component 55 wt% or more, 60 wt% or more, 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% Or more, 90% by weight or more, or 95% by weight or more. The upper limit of the proportion of the soft magnetic metal component is not particularly limited, and may be, for example, about 100% by weight, 99% by weight, or 98% by weight.

Examples of soft magnetic metal components include Fe / Ni alloys, Fe / Ni / Mo alloys, Fe / Al / Si alloys, Fe / Si / B alloys, Fe / Si / Nb alloys, Fe / Si / Cu alloys, or Fe / Si / B / Nb / Cu alloy may be exemplified, but is not limited thereto. In the above, Fe means iron, Ni means nickel, Mo means molybdenum, Al means aluminum, Si means silicon, B means boron, Nb means niobium, and Cu means copper. However, in the present application, various materials known to exhibit soft magnetic properties may be applied to the materials.

Methods of manufacturing metal foams are well known. In the present application, the metal foams of the first and / or second regions described above can be manufactured and applied in a known manner. At this time, the metal foam in the first region and the metal foam in the second region may be integrally formed, or each may be separately manufactured and then attached thereto to form a composite material. In this case, the adhesion can be performed with an adhesive layer or an adhesive layer. Therefore, when the metal foam layer of the first region and the metal foam layer of the second region are stacked in the above, the pressure-sensitive adhesive layer or the adhesive layer may be present therebetween.

As a method of manufacturing a metal foam, a method of sintering a pore-forming agent such as a salt and a composite material of a metal, a method of coating a metal on a support such as a polymer foam, and sintering in that state or a slurry method are known.

In one example, the method of manufacturing the composite material of the present application comprises: sintering a metal foam precursor containing the soft magnetic metal component to form the second region, and sintering a metal foam precursor containing the conductive metal component to sinter the metal foam precursor. And forming a region. The steps can be performed simultaneously or sequentially, and the order in which they are performed is not limited. The term metal foam precursor in the present application refers to a structure before a process performed to form a metal foam, such as sintering, that is, a structure before the metal foam is generated. The metal foam precursor, even if it is called a porous metal foam precursor, does not necessarily need to be porous by itself, and finally, if it can form a metal foam that is a porous metal structure, it can be called a porous metal foam precursor for convenience.

In one example of the present application, the metal foam precursor may be formed using a slurry containing at least a metal component, a dispersant, and a binder.

Metal powder may be applied as the metal component. The example of the metal powder is not particularly limited to be determined according to the purpose, and a powder of a metal powder or a metal alloy powder or a mixture of metals capable of forming the aforementioned conductive or soft magnetic metal component may be applied.

The size of the metal powder (metal powder) is also not particularly limited to be selected in consideration of the desired porosity or pore size, for example, the average particle diameter of the metal powder is, in the range of about 0.1㎛ to about 200㎛ It can be. In another example, the average particle diameter is about 0.5 μm or more, about 1 μm or more, about 2 μm or more, about 3 μm or more, about 4 μm or more, about 5 μm or more, about 6 μm or more, about 7 μm or more, or about 8 μm. It may be abnormal. In another example, the average particle diameter may be about 150 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, or 20 μm or less. As the metal in the metal particles, those having different average particle diameters may be used. The average particle diameter may be selected in an appropriate range in consideration of the shape of the desired metal foam, for example, the thickness or porosity of the metal foam.

The average particle diameter of the metal powder can be obtained by a known particle size analysis method, and, for example, the average particle diameter may be a so-called D50 particle diameter.

The ratio of the metal component (metal powder) in the slurry is not particularly limited, and may be selected in consideration of a desired viscosity or process efficiency. In one example, the ratio of the metal component in the slurry may be about 0.5 to 95% by weight, but is not limited thereto. In other examples, the ratio is about 1% or more, about 1.5% or more, about 2% or more, about 2.5% or more, about 3% or more, about 5% or more, 10% or more, 15% or more, 20% or more, 25% Above, above 30%, above 35%, above 40%, above 45%, above 50%, above 55%, above 60%, above 65%, above 70%, above 75% or above 80%, or approximately 90% Or less, about 85% or less, about 80% or less, about 75% or less, about 70% or less, about 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less , 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, or 5% or less, but is not limited thereto.

The metal foam precursor may be formed using a slurry containing a dispersant and a binder together with the metal powder.

As the dispersant in the above, for example, alcohol may be applied. As alcohol, methanol, ethanol, propanol, pentanol, octanol, ethylene glycol, propylene glycol, pentanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, glycerol, texanol Or a monohydric alcohol having 1 to 20 carbon atoms such as terpineol or a dihydric alcohol having 1 to 20 carbon atoms such as ethylene glycol, propylene glycol, hexanediol, octanediol or pentanediol or higher polyhydric alcohol or the like can be used. However, the type is not limited to the above.

The slurry may further include a binder. The type of the binder is not particularly limited, and may be appropriately selected according to the type of metal component or dispersant applied at the time of manufacturing the slurry. For example, as the binder, alkyl cellulose having an alkyl group having 1 to 8 carbon atoms such as methyl cellulose or ethyl cellulose, polyalkylene carbonate having an alkylene unit having 1 to 8 carbon atoms such as polypropylene carbonate or polyethylene carbonate, or Polyvinyl alcohol-based binders such as polyvinyl alcohol or polyvinyl acetate (hereinafter, may be referred to as polyvinyl alcohol compounds) may be exemplified, but are not limited thereto.

The proportion of each component in the slurry as described above is not particularly limited. This ratio can be adjusted in consideration of process efficiency such as coating properties and formability during the process using the slurry.

For example, the binder in the slurry may be included in a ratio of about 1 to 500 parts by weight relative to 100 parts by weight of the aforementioned metal component. In other examples, the ratio may be at least about 2 parts by weight, at least about 3 parts by weight, at least about 4 parts by weight, at least about 5 parts by weight, at least about 6 parts by weight, at least about 7 parts by weight, at least about 8 parts by weight, about 9 At least 10 parts by weight, at least about 10 parts by weight, at least about 20 parts by weight, at least about 30 parts by weight, at least about 40 parts by weight, at least about 50 parts by weight, at least about 60 parts by weight, at least about 70 parts by weight, about 80 parts by weight Or more, about 90 parts by weight or more, about 100 parts by weight or more, about 110 parts by weight or more, about 120 parts by weight or more, about 130 parts by weight or more, about 140 parts by weight or more, about 150 parts by weight or more, about 200 parts by weight or more, or It may be about 250 parts by weight or more, about 450 parts by weight or less, about 400 parts by weight or less, about 350 parts by weight or less, about 300 parts by weight or less, about 250 parts by weight or less, about 200 parts by weight or less, about 150 parts by weight or less, About 100 parts by weight or less, about 50 parts by weight or less, about 40 parts by weight or less, about 30 parts by weight or less, about 20 parts by weight or less or about It may be 10 parts by weight or less.

Dispersants in the slurry may be included in a proportion of about 10 to 2,000 parts by weight relative to 100 parts by weight of the binder. In other examples, the ratio may be at least about 20 parts by weight, at least about 30 parts by weight, at least about 40 parts by weight, at least about 50 parts by weight, at least about 60 parts by weight, at least about 70 parts by weight, at least about 80 parts by weight, at least about 90 parts by weight By weight or more, about 100 parts by weight or more, about 200 parts by weight or more, about 300 parts by weight or more, about 400 parts by weight or more, about 500 parts by weight or more, about 550 parts by weight or more, about 600 parts by weight or more or about 650 parts by weight It may be more than about 1,800 parts by weight or less, about 1,600 parts by weight or less, about 1,400 parts by weight or less, about 1,200 parts by weight or less, or about 1,000 parts by weight or less.

In the present specification, the unit weight part means a ratio of weight between each component, unless otherwise specified.

The slurry may further contain a solvent, if necessary. However, according to an example of the present application, the slurry may not include the solvent. As a solvent, an appropriate solvent may be used in consideration of solubility of the components of the slurry, for example, the metal component or the binder. For example, a solvent having a dielectric constant in the range of about 10 to 120 may be used. In another example, the dielectric constant may be about 20 or more, about 30 or more, about 40 or more, about 50 or more, about 60 or more, or about 70 or more, or about 110 or less, about 100 or less, or about 90 or less. Examples of such a solvent include water, ethanol, butanol, or methanol having 1 to 8 carbon atoms such as methanol, dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), or N-methylpyrrolidinone (NMP). no.

When a solvent is applied, it may be present in the slurry at a ratio of about 50 to 400 parts by weight relative to 100 parts by weight of the binder, but is not limited thereto. The proportion of the solvent, in another example, about 60 parts by weight or more, about 70 parts by weight or more, about 80 parts by weight or more, about 90 parts by weight or more, about 100 parts by weight or more, about 110 parts by weight or more, about 120 parts by weight or more , About 130 parts by weight or more, about 140 parts by weight or more, about 150 parts by weight or more, about 160 parts by weight or more, about 170 parts by weight or more, about 180 parts by weight or more, or about 190 parts by weight or more, or about 350 parts by weight or less, It may be 300 parts by weight or less, or 250 parts by weight or less, but is not limited thereto.

The slurry may contain known additives in addition to the components mentioned above. However, the process of the present application may be performed using a slurry containing no blowing agent among known additives.

In another example of the present application, the metal foam precursor may be formed using a slurry containing at least a metal component, an aqueous solvent, an organic solvent, and a surfactant.

The details of the metal component in this type of slurry are as described above.

The slurry may include an aqueous solvent, an organic solvent, and a surfactant together with a metal component. When the ratio and type of the aqueous solvent, organic solvent, and surfactant in the slurry are adjusted, a fine emulsion is formed in the metal foam precursor, and the emulsion can determine the pore characteristics of the metal foam. If necessary, the metal foam precursor may be subjected to a foaming process. For example, due to the difference in vapor pressure between the organic solvent and the aqueous solvent, the pore characteristics of the metal foam can be controlled while a component having a larger vapor pressure is vaporized in the foaming process.

In the above, as the aqueous solvent, water or other polar solvents may be applied, and typically water may be applied. The aqueous solvent may be included in a ratio of 50 to 200 parts by weight based on 100 parts by weight of the metal powder in the slurry. The proportion of the aqueous solvent may be 70 to 100 parts by weight in another example.

As the organic solvent, an appropriate type may be selected without particular limitation. As such an organic solvent, for example, a hydrocarbon-based organic solvent can be used. As the hydrocarbon-based organic solvent, an organic solvent having 4 to 12 carbon atoms may be applied, and specific examples include n-pentane, neopentane, hexane, isohexane, heptane, isoheptane, octane, toluene, benzene, pentine, hexine, Pentene, hexene, heptene, octene, cyclopentane, cycloheptane, cyclooctane, cyclopentene, cyclohexene, cycloheptene, cyclooctene or cyclopentanone may be applied. The organic solvent may be included in a ratio of 0.1 to 3 parts by weight based on 100 parts by weight of the metal powder in the slurry.

The type of surfactant applied to the slurry is not particularly limited, and for example, any one selected from the group consisting of known amphoteric surfactants, nonionic surfactants and anionic surfactants, or mixtures of two or more of the above can be applied. You can. Among the surfactants described above, an appropriate type for forming a desired fine emulsion may be selected, and the type of the aqueous solvent and organic solvent applied in this process may be considered.

Anionic surfactants are surfactants whose anionic surfactants are anionic as known, and examples of the anionic surfactants include carboxylate compounds, sulfate compounds, and isethionate. Compounds, sulfosuccinate compounds, taurate compounds and / or glutamate compounds may be applied, but are not limited thereto.

Nonionic surfactants are surfactants that are not separated into ions as is known, and such surfactants include, for example, alkyl polyglucoside surfactants, fatty acid alkanol amide surfactants, or amine oxide based and higher alcohols. Ethylene oxide is added to the form of the ethylene oxide is added to the surfactant may be used.

An amphoteric surfactant is a surfactant having an anion site and a cation site at the same time, and such surfactants include betaines, for example, cocamidopropyl betaine, lauramidopropyl betaine, cocobetaine, or lauryl beta. Phosphorus, etc., a sultaine type, for example, lauryl hydroxysulfate, lauramidopropyl sultaine, cocamidopropyl hydroxysulfate or cocosulfate, etc. may be applied, but is not limited thereto.

As the surfactant, any one of the above-mentioned anionic, nonionic, or amphoteric surfactants of the above formulas may be used alone, or two or more surfactants may be used in combination.

The surfactant may be included in a ratio of 1 to 10 parts by weight based on 100 parts by weight of the metal powder in the slurry.

The slurry may further include necessary components in addition to the above components. For example, the slurry may further include a binder. As the binder, without particular limitation, for example, a binder applied in the slurry of the first type described above can be applied. The binder may be included in a ratio of 2 to 20 parts by weight based on 100 parts by weight of the metal powder in the slurry. The ratio may be 4 to 10 parts by weight in other examples.

To impart plasticity to the metal foam or its precursor, the slurry may further include a plasticizer. As the plasticizer, an appropriate type capable of imparting plasticity to the above-described slurry system or metal foam may be selected, and for example, polyhydric alcohols, fats and oils, ether compounds or ester compounds may be applied, but are not limited thereto. no.

When a plasticizer is included, the ratio in the slurry is not particularly limited, and can be controlled at an appropriate ratio in consideration of the desired plasticity.

The slurry may contain known additives in addition to the components mentioned above.

The method of forming the metal foam precursor using the slurry as described above is not particularly limited. Various methods for forming a metal foam precursor are known in the field of manufacturing a metal foam, and all of these methods can be applied in the present application. For example, the metal foam precursor may maintain the slurry in an appropriate template or coat the slurry in an appropriate manner to form the metal foam precursor.

In the case of manufacturing a metal foam layer according to one example of the present application, it may be advantageous to apply a coating process. For example, after forming the precursor by coating the slurry on a suitable substrate, a desired metal foam may be formed through a sintering process described later.

In the process of forming the metal foam precursor, an appropriate drying and / or foaming process may be performed. In this case, the conditions of the drying and / or foaming process are not particularly limited, and may be controlled so as to form a desired level of metal foam precursor.

Further, the sintering process can also be performed under appropriate conditions without particular limitation. For example, the sintering may be performed by maintaining the precursor at a temperature in the range of about 500 ° C to 2000 ° C, in the range of 700 ° C to 1500 ° C, or in the range of 800 ° C to 1200 ° C, and the holding time. Can also be arbitrarily selected. The holding time may be in the range of about 1 minute to 10 hours in one example, but is not limited thereto.

Through this sintering process, a desired composite material can be formed. For example, the slurry forming the metal foam in the first region and the slurry forming the metal foam in the second region may be sequentially coated to form an integral metal foam precursor, and then a composite material may be prepared through the sintering. After preparing the metal foams of the first and second regions, the desired composite material may be obtained by laminating them using an adhesive or an adhesive.

In one example, the composite material may include a conductive material-containing layer as a further configuration. In the above, the conductive material-containing layer is a layer containing a conductive material. The conductive material-containing layer may be present on the metal foam layer in the first or second region.

Such a conductive material-containing layer may be particularly useful in forming a composite structure by combining a plurality of the composite materials of the present application.

That is, when necessary in the application process of the composite material, a plurality of single composite materials may be combined. At this time, the permeability may decrease near the interface between the composite materials, or the shielding performance may decrease when applied as an electromagnetic wave shielding material. In addition, in addition to the case of combining a plurality of composite materials, the same phenomenon may also occur at the interface between the metal foam layer in the first region and the metal foam layer in the second region. The above problems can be solved by applying the conductive material-containing layer.

The conductive material-containing layer may be present on the metal foam layer of the first or second region, for example, as shown in FIGS. 2 to 5. 2 to 6, 10 denotes a metal foam layer in the first region, 20 denotes a metal foam layer in the second region, and 30 denotes the conductive material-containing layer.

That is, the conductive material-containing layer is a side opposite to the surface of the metal foam layer of the first region facing the metal foam layer of the second region (FIG. 2), and the metal foam layer of the first region of the metal foam layer of the second region The opposite side to the opposite side (FIG. 3), the opposite side to the opposite side to the second side of the metal foam layer of the first region of the metal foam layer and the second region of the metal foam layer of the first region of the metal foam layer It may be on the opposite side to the opposite surface (FIG. 4) or between the metal foam layer in the first region and the metal foam layer in the second region (FIG. 5).

In particular, the shapes shown in FIGS. 2 to 4 may be useful when combining a plurality of composite materials in the shape shown in FIG. 6.

In another example, in the composite material, the metal foam layer of the first region and the metal foam layer of the second region are stacked in a staggered state, and the conductive particle-containing layer is opposed to the metal foam layer of the second region of the metal foam layer of the first region. The surface may not be overlapped with the metal foam layer in the second region or the surface of the second region may be formed on a surface that does not overlap the metal foam layer in the first region among the surfaces facing the metal foam layer in the first region. have.

In the above, the metal foam layer of the first region and the metal foam layer of the second region are stacked in a staggered state, for example, as shown in FIGS. 7 or 8, the two metal foam layers are disposed to face each other, It may mean a case where at least one metal foam layer among the metal foam layers is stacked to have a portion that does not overlap with the other metal foam layer. In the above, the overlap is based on the observation of the composite material from the top or bottom according to the normal direction of the composite material.

7 or 8, the conductive particle-containing layer 30 is the metal foam layer 20 of the second region among the surfaces facing the metal foam layer 20 of the second region of the metal foam layer 10 of the first region It may be formed on a surface that does not overlap with or a surface that does not overlap with the metal foam layer 10 of the first region among the surfaces facing the metal foam layer of the first region of the metal foam layer 20 of the second region.

Such a structure is useful when combining composites as shown in FIG. 9.

The type of the conductive material included in the conductive material-containing layer is not particularly limited as long as it is selected to exhibit appropriate conductivity. For example, as the conductive material, conductivity at 20 ° C is about 8 MS / m or more, 9 MS / m or more, 10 MS / m or more, 11 MS / m or more, 12 MS / m or more, 13 MS / Materials above m or above 14.5 MS / m can be used. The upper limit of the conductivity is not particularly limited, and may be, for example, about 30 MS / m or less, 25 MS / m or less, or 20 MS / m or less.

As the conductive material, for example, a material in the form of particles can be used. When a conductive material in the form of particles is used, the average particle diameter of the particles may be in the range of about 10 nm to 500 μm. The average particle diameter may be about 100 nm or more or about 1 μm or more in another example. In another example, the average particle diameter is about 450 μm or less, about 400 μm or less, about 350 μm or less, about 300 μm or less, about 250 μm or less, about 200 μm or less, about 150 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 500 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, It may be about 80 nm or less, about 70 nm or less, about 60 nm or less, about 50 nm or less, about 40 nm or less, about 30 nm or less, or about 20 nm or less.

As the conductive material, specifically, metals such as nickel, iron, cobalt, silver, copper, gold, aluminum, calcium, tungsten, zinc, lithium, iron, platinum, tin, lead, titanium, manganese, magnesium or chromium, or any of the above Two or more kinds of alloys, graphite, carbon black, carbon fiber, carbon nanotubes or graphene, and the like may be exemplified, but is not limited thereto.

The specific form of the conductive material-containing layer is not particularly limited, but it may be appropriate to form the conductive material-containing layer with an adhesive layer or an adhesive layer in consideration of the possibility of combination between the aforementioned composite materials.

The specific type of the adhesive or adhesive layer that can be applied is not particularly limited, and for example, as the base resin, the conductive material is introduced into a known adhesive or adhesive including acrylic resin, epoxy resin, silicone resin or urethane resin, etc. To form the layer. The conductive material-containing layer can be formed by applying or transferring such an adhesive or adhesive layer to a desired site.

The proportion of the conductive material in the layer is not particularly limited, for example, the conductive material may be introduced at a ratio of 30 to 200 parts by weight compared to 100 parts by weight of the base resin.

This application also relates to composite structures. The term composite structure may refer to an object in which at least two single composite materials are combined as shown in FIGS. 6 or 9. At this time, as shown in FIG. 6 or 9, the composite material may be combined through a conductive material-containing layer in the composite material.

In addition, as shown in FIG. 9, the composite structure, the metal foam layer of the first region and the metal foam layer of the second region of the single composite material are stacked in a staggered state, the conductive particle-containing layer in the single composite material, the first Among the surfaces facing the metal foam layer of the second region of the metal foam layer of the region, the first surface is not overlapped with the metal foam layer of the second region or the surface of the metal foam layer of the second region facing the metal foam layer of the first region It is formed on a surface that does not overlap with the metal foam layer in the region, and a plurality of composite materials are combined such that the metal foam layer in the first region of one composite material and the metal foam layer in the second region of the other composite material overlap through the conductive material-containing layer. Can have a structure.

In the above combination, when the conductive material-containing layer is an adhesive layer or an adhesive layer as described above, it may mean a case in which the composite material is attached via the adhesive layer or adhesive layer.

The present application can provide a composite material having high magnetic permeability and excellent mechanical properties such as flexibility. The composite material may be used for various purposes, and may be used, for example, as an electromagnetic wave shielding material.

1 to 5, 7 and 8 are schematic diagrams of exemplary forms of the composite material of the present application.
6 and 9 are views showing an exemplary form of a composite structure.

Hereinafter, the present application will be specifically described through examples and comparative examples, but the scope of the present application is not limited to the following examples.

Example 1.

Preparation of metal foam in the first area

Copper (Cu) powder having an average particle size (D50 particle size) of less than about 10 μm was used as a metal component. As a dispersant, the copper powder was added to a mixture of ethylene glycol (EG) and ethyl cellulose (EC) as a binder in a weight ratio of 4: 5 (EG: EC), and the binder and copper powder had a weight ratio of about 10: 1. (Cu: EC) was mixed to prepare a slurry. The slurry was coated in a film form, and dried at about 120 ° C. for about 1 hour to form a metal foam precursor. At this time, the thickness of the coated metal foam precursor was about 90 μm. Sintering was performed by applying an external heat source in an electric furnace so that the precursor was maintained at a temperature of about 1000 ° C. in a hydrogen / argon gas atmosphere for 2 hours to prepare a copper foam having a thickness of about 25 μm. The maximum pore size of the sheet-formed copper foam was approximately less than 25 μm.

Production of metal foam in the second area

A metal foam in a second region was prepared by applying an alloy of iron and nickel (Fe / Ni = 1/4, weight ratio) powder. The average particle diameter (D50) of the alloy powder was approximately 7 μm. The alloy powder and polyvinyl acetate were mixed at a weight ratio of 3: 2 (alloy powder: polyvinyl acetate) to form a slurry. The slurry was coated in a film form and dried at about 1,000 ° C. for about 1 hour to form a metal foam precursor. At this time, the thickness of the coated metal foam precursor was about 200 μm. A metal foam having a thickness of about 80 μm was prepared by applying an external heat source in an electric furnace to sinter the precursor so that the precursor is maintained at a temperature of about 1000 ° C. in a hydrogen / argon gas atmosphere for 2 hours. The maximum pore size of the prepared sheet-form metal foam was approximately 10 μm.

Preparation of conductive adhesive

The conductive pressure-sensitive adhesive was prepared by introducing CNT (Carbon nanotube) powder (DP50-10 µm) as a conductive material into a common acrylic pressure-sensitive adhesive. A conductive pressure-sensitive adhesive was prepared by mixing approximately 100 parts by weight of the conductive material with respect to 100 parts by weight of the acrylic resin as the base resin of the pressure-sensitive adhesive. After forming the conductive pressure-sensitive adhesive layer between the two release films, when applying to the composite material, one release film from the release film is peeled off, and the surface of the pressure-sensitive adhesive layer released by peeling is applied to the surface of the desired composite material. Later, another release film was peeled off and applied.

Preparation of composite materials

After the prepared copper metal foam and the alloy metal foam of iron and nickel were staggered in the form shown in FIG. 7, a composite material was prepared by attaching each other with a general adhesive film. Then, as shown in FIG. 7, the conductive adhesive layer was applied to the surfaces of the metal foam layers 10 and 20 of the first and second regions to prepare a composite material. The shielding efficiency of the composite was greater than approximately 90 dB in the range of 50 kHz to 3 GHz, and the permeability was greater than approximately 100 at 50 kHz to 300 kHz. The shielding efficiency was measured according to the standard of ASTM D4935, and the permeability was measured according to a known relative permeability measurement method.

Example 2

The metal foam was produced in the same manner, except that the thickness of the copper metal foam in the first region was changed to about 70 μm (maximum pore size less than 25 μm). In addition, when manufacturing the metal foam in the second region, ethyl cellulose was applied instead of polyvinyl acetate, and the metal foam was manufactured in the same manner except that the thickness was changed to about 95 μm (maximum pore size 10 μm level). The metal foams of the first and second regions were attached in the same manner as in Example 1, and a conductive adhesive layer was applied in the same manner as in Example to prepare a composite material. The shielding efficiency of the composite was greater than approximately 90 dB in the range of 50 kHz to 3 GHz, and the permeability was greater than approximately 100 at 50 kHz to 300 kHz.

Example 3

The metal foam was produced in the same manner, except that the thickness of the copper metal foam in the first region was changed to about 100 μm (maximum pore size less than 15 μm). In addition, a metal foam was manufactured in the same manner, except that the thickness of the metal foam in the second region was changed to about 40 μm (maximum pore size 10 μm level). The metal foams of the first and second regions were attached in the same manner as in Example 1, and a conductive adhesive layer was applied in the same manner as in Example to prepare a composite material. The shielding efficiency of the composite was greater than approximately 90 dB in the range of 50 kHz to 3 GHz, and the permeability was greater than approximately 100 at 50 kHz to 300 kHz.

Example 4

The metal foam was produced in the same manner, except that the thickness of the copper metal foam in the first region was changed to about 70 μm (maximum pore size less than 25 μm). In addition, as a metal alloy powder in the production of the metal foam in the second region, 1/3 of the iron and nickel (Fe / Ni weight ratio) alloy powder (average particle diameter (D50 particle diameter): 9 µm) was applied, and the thickness was 40. A metal foam was prepared in the same manner, except that it was changed to about μm (maximum pore size 10 μm level). The metal foams of the first and second regions were attached in the same manner as in Example 1, and a conductive adhesive layer was applied in the same manner as in Example to prepare a composite material. The shielding efficiency of the composite was greater than approximately 90 dB in the range of 50 kHz to 3 GHz, and the permeability was greater than approximately 100 at 50 kHz to 300 kHz.

Example 5

The metal foam was produced in the same manner, except that the thickness of the copper metal foam in the first region was changed to about 70 μm (maximum pore size less than 25 μm). In addition, when manufacturing the metal foam in the second region, as a metal alloy powder, 1/4 (Fe / Ni, weight ratio) alloy powder (average particle diameter (D50 particle diameter): 7 µm) of iron and nickel was applied, and the thickness was applied. A metal foam was prepared in the same manner, except that it was changed to about 100 μm (maximum pore size 10 μm level). The metal foams of the first and second regions were attached in the same manner as in Example 1, and a conductive adhesive layer was applied in the same manner as in Example to prepare a composite material. The shielding efficiency of the composite was greater than approximately 90 dB in the range of 50 kHz to 3 GHz, and the permeability was greater than approximately 100 at 50 kHz to 300 kHz.

Example 6

When manufacturing the metal foam in the first region, instead of copper powder, aluminum powder having a similar average particle diameter was applied, and the metal foam was manufactured in the same manner except that the thickness was changed to about 70 μm (maximum pore size less than 10 μm). In addition, when manufacturing the metal foam in the second region, the metal foam was manufactured in the same manner, except that the thickness was changed to about 40 μm (maximum pore size 10 μm level). The metal foams of the first and second regions were attached in the same manner as in Example 1, and a conductive adhesive layer was applied in the same manner as in Example to prepare a composite material. The shielding efficiency of the composite was greater than approximately 90 dB in the range of 50 kHz to 3 GHz, and the permeability was greater than approximately 100 at 50 kHz to 300 kHz.

Claims (15)

A first region formed of a metal foam layer having a conductive metal component having a conductivity of 20 MS or more at 20 ° C; A second region formed of a metal foam layer having a soft magnetic metal component; And a conductive material-containing layer,
The metal foam layer of the first region and the metal foam layer of the second region are stacked with each other, and the conductive material-containing layer is on the metal foam layer of the first or second region. According to claim 1, The metal foam layer of the first region and the metal foam layer of the second region are stacked in a staggered state, the conductive particle-containing layer, the surface facing the metal foam layer of the second region of the metal foam layer of the first region Among them, a composite material formed on a surface that does not overlap with the metal foam layer in the second region or a surface that does not overlap with the metal foam layer in the first region among the surfaces facing the metal foam layer in the first region of the metal foam layer in the second region. According to claim 1, The conductive material is graphite, carbon black, carbon fiber, carbon nanotubes, nickel, iron, cobalt, silver, copper, gold, aluminum, calcium, tungsten, zinc, lithium, iron, platinum, tin, Composites that are lead, titanium, manganese, magnesium or chromium. The composite material according to claim 1, wherein the conductive material-containing layer is an adhesive layer or an adhesive layer. The composite material according to claim 1, wherein the conductive material-containing layer comprises an acrylic resin, an epoxy resin, a silicone resin, or a urethane resin as the base resin. According to claim 5, The conductive material is a composite material contained in the conductive material-containing layer in a proportion of 30 to 200 parts by weight compared to 100 parts by weight of the base resin. The method of claim 1, wherein the conductive metal component is a group consisting of nickel, iron, cobalt, silver, copper, gold, aluminum, calcium, tungsten, zinc, lithium, iron, platinum, tin, lead, titanium, manganese, magnesium or chromium. Composite comprising at least one metal selected from. The method of claim 1, wherein the soft magnetic metal component is Fe / Ni alloy, Fe / Ni / Mo alloy, Fe / Al / Si alloy, Fe / Si / B alloy, Fe / Si / Nb alloy, Fe / Si / Cu alloy. Or a Fe / Si / B / Nb / Cu alloy composite. The composite of claim 1, wherein the metal foam has a porosity in the range of 50% to 95%. The composite material of claim 1, wherein the maximum pore size of the metal foam is 100 μm or less. The composite material according to claim 1, wherein the porosity is 50% or more. The composite material according to claim 1, wherein the total thickness of the metal foam layers in the first and second regions is in the range of 10 μm to 2 mm. The composite material according to claim 12, wherein a ratio (T2 / T1) of the thickness (T1) of the metal foam layer in the first region and the thickness (T2) of the metal foam layer in the second region is in the range of 0.2 to 10. A composite structure in which two or more composite materials of claim 1 are combined through a layer containing a conductive material in the composite material. 15. The method of claim 14, The metal foam layer of the first region of the single composite material and the metal foam layer of the second region are stacked in a staggered state, the conductive particle-containing layer in the single composite material, the second of the metal foam layer of the first region Among the surfaces facing the metal foam layer of the region, do not overlap the metal foam layer of the second region or the surface of the metal foam layer of the second region which does not overlap the metal foam layer of the first region among the surfaces facing the metal foam layer of the first region It is formed on the surface, the plurality of composite material is a composite structure in which the metal foam layer of the first region of one composite material and the metal foam layer of the second region of the other composite material are overlapped via the conductive material-containing layer.

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