Resin Composite

Abstract

To provide a resin composite that is low in manufacturing cost, that exhibits high exothermic properties even with induction heating at low frequencies, and that has good formability.SOLUTION: Provided is a resin composite (10) which includes a thermoplastic resin and magnetic fillers (1) that have an average particle size of 100 nm or more and less than 1,000 nm, and which is used to generate heat at a rate of temperature increase of 10°C / s or more with induction heating, or provided is a resin composite (10) which includes a base material (3) and a resin layer (2) located on at least one side of the base material (3), the resin layer (2) including a thermoplastic resin and magnetic fillers (1) that have an average particle size of 100 nm or more and less than 1,000 nm, and which is used to generate heat at a rate of temperature increase of 10°C / s or more with induction heating.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin composite. [Background technology]

[0002] Magnetic fillers are widely used in magnetic fluids, magnetorheological fluids, contrast agents, electromagnetic wave shielding materials, induction heating materials for cancer treatment, etc. For example, Patent Document 1 discloses a thermally conductive electromagnetic wave absorbing sheet obtained by incorporating a metal magnetic oxide into a polymer obtained by polymerizing a monomer containing an acrylic acid ester and molding the polymer into a sheet, the metal magnetic oxides comprising metal magnetic oxides having an average particle size of 1 to 10 μm and metal magnetic oxides having an average particle size of 50 to 100 μm in a volume ratio of 9:13 to 15:7, accounting for 55 to 60 vol% of the entire thermally conductive electromagnetic wave absorbing sheet, and the thermally conductive electromagnetic wave absorbing sheet also contains 8 to 10 vol% of a surface-treated flame-retardant filler.

[0003] It is known that magnetic fillers generate heat through induction heating. This is because magnetic fillers generate heat due to hysteresis loss caused by magnetic field reversal in an AC magnetic field. As shown in Non-Patent Document 1, the heat generation properties of such magnetic fillers are maximized when the particle diameter is 10 to 15 nm.

[0004] Patent Document 2 discloses a planar element including at least one heat-activatable adhesive, at least one induction-heatable material, and at least one thermally conductive filler material, wherein the filler material has a thermal conductivity of at least 0.5 W / (m*K). Patent Document 2 shows a method for generating heat even with low-frequency induction heating by providing a metal layer such as aluminum inside the resin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-092118 [Patent Document 2] Japanese Patent Application Publication No. 2017-222870 [Patent Document 3] Japanese Patent Application Publication No. 2019-094503 [Non-patent literature]

[0006] [Non-Patent Document 1] J. Magn. Soc. Jpn., 33, 391-396 (2009) Summary of the Invention [Problem to be solved by the invention]

[0007] The thermally conductive electromagnetic wave absorbing sheet described in Patent Document 1 focuses on the electromagnetic wave absorption properties of the magnetic filler, and uses small magnetic fillers of 1 to 10 μm (8000 nm in the example) and larger magnetic fillers of 50 to 100 μm. Patent Document 1 does not focus on induction heating, but when the present inventors produced a resin composite sheet using magnetic fillers exceeding 1000 nm, the magnetic fillers settled and it was found that the moldability into a shape in which the magnetic fillers were dispersed and capable of induction heating was poor (see Comparative Example 3 described below). As an example of applying the heat generation phenomenon of magnetic fillers with particle sizes of 10 to 15 nm described in Non-Patent Document 1, there is an inductively heatable adhesive film (HAF) in which magnetic fillers of this size are blended into the adhesive, and Lohmann has commercialized it as DuploCOLL RCD. However, the magnetic fillers of the size used in such products are extremely expensive, and high heat generation cannot be expected. In the planar element described in Patent Document 2, components such as the metal layer are subject to concerns about rust and leaching of the metal material over time, making it difficult to expand its application to electronic device-related components. In addition, the three-layer structure in which the metal layer is laminated with resin is disadvantageous from the viewpoint of manufacturing costs.

[0008] On the other hand, materials that use magnetic fillers for dielectric heating rather than induction heating are known. For example, Patent Document 3 discloses a dielectric heating adhesive film that contains (A) a polypropylene resin and (B) zinc oxide as a dielectric filler, the average particle diameter of which, measured in accordance with JIS Z 8819-2 (2001), is in the range of 2 to 25 μm, and the thickness of the dielectric heating adhesive film is in the range of 100 to 1000 μm. According to Patent Document 3, good bonding can be obtained even with a short dielectric heating treatment of less than 40 seconds, regardless of the type of adherend. However, since an extremely high frequency alternating magnetic field is required to heat the dielectric heating material, huge equipment costs are required, including equipment to protect the human body from radio waves, and from the perspective of the manufacturing cost of the entire dielectric heating system, it is not suitable for mass production.

[0009] In view of the above circumstances, the problem to be solved by the present invention is to provide a resin composite that can be produced at low cost, exhibits high heat generation even with low-frequency induction heating, and has good moldability. [Means for solving the problem]

[0010] According to the present invention, by using a magnetic filler with a specific particle size that has not been used in the technical field of dielectric heating, it has been discovered that a resin composite can be provided that is low in production cost, exhibits high heat generation even with low-frequency induction heating, and has good moldability, thereby solving the above-mentioned problems. The configuration of the present invention, which is a specific means for solving the above-mentioned problems, and preferred configurations of the present invention are described below.

[0011] [1] Contains a thermoplastic resin and a magnetic filler, The average particle size of the magnetic filler is 100 nm or more and less than 1000 nm, Resin composites that are used to generate heat by induction heating at a temperature rise rate of 10°C / s or more. [2] a substrate; A resin layer is provided on at least one surface of a substrate, the resin layer includes a thermoplastic resin and a magnetic filler; The average particle size of the magnetic filler is 100 nm or more and less than 1000 nm, Resin composites that are used to generate heat by induction heating at a temperature rise rate of 10°C / s or more. [3] The resin composite according to [1] or [2], wherein the magnetic filler has a polyhedral shape. [4] The resin composite according to [3], wherein the polyhedron shape is a hexahedron or an octahedron. [5] The resin composite according to any one of [1] to [4], wherein the magnetic filler is magnetite. [6] The resin composite according to any one of [1] to [5], which exhibits heat generation at a temperature rise rate of 10°C / s or more when subjected to induction heating at a frequency of 400 kHz or less. [7] The resin composite according to any one of [1] to [6], wherein the average particle size of the magnetic filler is 200 nm or more and less than 1000 nm. [8] The resin composite according to any one of [1] to [7], which contains 20% by mass or more of a magnetic filler relative to the resin. [9] The resin composite according to any one of [1] to [8], which is a resin composite sheet formed into a sheet shape. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a resin composite that can be produced at low cost, exhibits high heat generation even with low-frequency induction heating, and has good moldability. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing a cross section of an example of the resin composite of the present invention formed into a sheet. [Figure 2] FIG. 2 is a schematic diagram showing a cross section of an example of the resin composite of the present invention formed into a two-layer sheet in which a resin coating layer is provided on a substrate. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0015] [Resin composite] A first aspect of the resin composite of the present invention comprises a thermoplastic resin and a magnetic filler, the average particle size of the magnetic filler being 100 nm or more but less than 1000 nm, and is intended for use in generating heat by induction heating at a temperature rise rate of 10°C / s or more. A second embodiment of the resin composite of the present invention has a substrate and a resin layer located on at least one surface of the substrate, the resin layer containing a thermoplastic resin and a magnetic filler, the magnetic filler having an average particle size of 100 nm or more and less than 1000 nm, and is used for generating heat by induction heating at a temperature rise rate of 10°C / s or more. In the second embodiment of the resin composite of the present invention, it is preferable that the resin layer generates heat by induction heating at a temperature rise rate of 10°C / s or more. Due to these features, the resin composite of the present invention can be produced at low cost, exhibits high heat generation even with low-frequency induction heating, and has good moldability.

[0016] Conventionally, when dielectric heating is performed using a magnetic filler alone, it has been known that the heat generation due to Neel relaxation of magnetic fillers with a small average particle size is higher than the heat generation due to Brownian relaxation of magnetic fillers with a large average particle size (see Non-Patent Document 1: J. Magn. Soc. Jpn., 33, 391-396 (2009)). In fact, when magnetic fillers with an average particle size of 100 nm or more and less than 1000 nm are dielectrically heated alone, they have lower heat generation than magnetic fillers with an average particle size of 10 to 25 nm. In response to this finding, the present invention discovered that when a magnetic filler is incorporated into a thermoplastic resin, the heat generation due to Brownian relaxation of a magnetic filler with a large average particle size is greater than the heat generation due to Neel relaxation of a magnetic filler with a small average particle size. In fact, when a magnetic filler with an average particle size of 100 nm or more but less than 1000 nm is subjected to dielectric heating while incorporated into a thermoplastic resin, it generates more heat than a magnetic filler with an average particle size of 10 to 25 nm. The reason why results different from conventional findings are obtained when a magnetic filler is incorporated into a thermoplastic resin is presumably because, when the magnetic filler is incorporated into a thermoplastic resin, vibrational energy due to Brownian relaxation is converted into frictional energy with the thermoplastic resin. In this specification, high heat generation means that heat is generated by induction heating at a temperature rise rate of 10°C / s or more.

[0017] In this specification, good moldability means that the magnetic filler does not settle in the composition before molding, and as a result, it is preferable that the magnetic filler is highly moldable into a shape that can be induction heated and in which it is dispersed.

[0018] Because the resin composite of the present invention uses a magnetic filler, which is an inorganic material, it is preferable that it is safer than induction heating materials that use organic materials (such as organic fillers) that can be induction heated. Furthermore, compared to high-frequency dielectric heating, which is susceptible to electromagnetic waves affecting the human body, the resin composite of the present invention is also safer in that it can be used for low-frequency induction heating. Preferred embodiments of the present invention are described below.

[0019] <Shape of resin composite> The shape of the resin composite of the present invention is not particularly limited. Hereinafter, the resin composite of the present invention will be described with reference to the drawings, but the shape of the resin composite of the present invention should not be construed as being limited by the drawings. An example of the resin composite of the present invention is shown in FIGS. 1 and 2. Fig. 1 is a schematic diagram showing a cross section of an example of a resin composite of the present invention formed into a sheet. In Fig. 1, resin composite 10 contains a thermoplastic resin (not shown) and magnetic filler 1, and the average particle size of magnetic filler 1 is 100 nm or more and less than 1000 nm. Resin composite 10 of Fig. 1 is used alone as an induction heating sheet. When formed into a sheet by itself, there are no particular restrictions on the thickness of the sheet, but it is preferably 10 to 2000 µm, more preferably 50 to 500 µm, and particularly preferably 100 to 300 µm.

[0020] Figure 2 is a schematic diagram showing a cross section of an example of a resin composite of the present invention formed into a two-layer sheet with a resin coating layer provided on a substrate. In Figure 2, resin composite 10 has substrate 3 and resin layer 2 located on at least one side of substrate 3, resin layer 2 containing a thermoplastic resin (not shown) and magnetic filler 1, the average particle size of which is 100 nm or more and less than 1000 nm. Resin composite 10 of Figure 2 can be used as a two-phase sheet with a resin layer, which is an induction heating exothermic coating, provided on any substrate. When the substrate and the resin coating are formed into a sheet, the thickness of the resin layer is not particularly limited, but is preferably 0.1 to 500 μm, more preferably 1 to 100 μm, and particularly preferably 10 to 50 μm. The thickness of the substrate is not particularly limited, but is preferably 10 to 2000 μm, more preferably 20 to 500 μm, and particularly preferably 30 to 300 μm.

[0021] <Application> The resin composite of the present invention is used in applications where it is heated by induction heating at a temperature rise rate of 10°C / s or more. The resin composite is more preferably used for applications in which it generates heat by induction heating at a temperature rise rate of 15°C / s or more, particularly preferably for applications in which it generates heat at a temperature rise rate of 20°C / s or more, and even particularly preferably for applications in which it generates heat at a temperature rise rate of 30°C / s or more. The resin composite preferably reaches a temperature (maximum temperature) of 180°C or higher by induction heating, more preferably 200°C or higher, particularly preferably 230°C or higher, and even more particularly preferably 270°C or higher. The time required for the resin composite to reach its ultimate temperature (maximum ultimate temperature) by induction heating is preferably 25 seconds or less, more preferably 20 seconds or less, particularly preferably 15 seconds or less, and even more particularly preferably 10 seconds or less.

[0022] The frequency of induction heating is preferably lower than the frequency of dielectric heating in a microwave oven or the like, more preferably 1000 kHz or less, particularly preferably 400 kHz or less, and even more particularly preferably 360 kHz or less. There is no particular lower limit to the frequency of dielectric heating, but it can be, for example, 50 kHz or more, or may be 100 kHz or more. There are no particular restrictions on the power of induction heating, and it can be set to, for example, 1 to 20 kW.

[0023] Specific applications of the resin composite of the present invention include IH-heatable, easily dismantled adhesives or adhesives that can be bonded and peeled using induction heating (IH), IH-heatable sheets that can be wrapped around pipes or the like to prevent freezing, IH-heatable coatings that can be coated on transport films in production lines for resin molded products to reduce energy consumption in the drying or curing process, IH-heatable electromagnetic wave-absorbing sheets that take advantage of the ability of magnetic fillers to absorb electromagnetic waves, IH-heatable thermocrosslinkable polymers that can be blended with magnetic fillers to shorten production takt time, and IH-heatable fibers in which magnetic fillers are blended with fibers. In the case of IH-heatable coatings, the preferred embodiment is one in which a resin coating layer is provided on a substrate, as shown in Figure 2.

[0024] <Thermoplastic resin> The thermoplastic resin used in the resin composite of the present invention will be described below. The thermoplastic resin (matrix resin) is not particularly limited. Examples include polyethylene resin, polypropylene resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, polyurethane resin, styrene-acrylonitrile copolymer (AS) resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, acrylic resin, polyamide resin (nylon 6, nylon 66, etc.), polyacetal resin, polycarbonate resin, polyacetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyphenylene ether resin, polyetherimide resin, and fluororesin. Acrylic resin is preferred from the viewpoints of moldability, safety, and availability. Among acrylic resins, polymethyl methacrylate (PMMA) is more preferred from the viewpoints of moldability (glass transition temperature) and transparency (ease of coloring).

[0025] The glass transition temperature (Tg) of the thermoplastic resin is preferably 200°C or lower, and more preferably 150°C or lower. The weight average molecular weight of the thermoplastic resin is preferably 10,000 to 500,000, and more preferably 15,000 to 200,000, from the viewpoint of viscosity adjustment and solubility.

[0026] Thermoplastic resins are commercially available. Examples of commercially available thermoplastic resins, such as commercially available acrylic resins, include Dianal BR50, BR52, BR60, BR64, BR73, BR75, BR80, BR83, BR87, BR88, BR101, BR105, BR115, BR116, BR117, MB7948, MB7958, and MB7973 (all manufactured by Mitsubishi Chemical Corporation).

[0027] <Magnetic filler> The magnetic filler may be any magnetic material. Examples of the magnetic filler include iron and its oxides (such as magnetite), nickel and its oxides, strontium and its oxides, manganese and its oxides, and magnesium and its oxides. Among these, iron and its oxides, strontium and its oxides, and manganese and its oxides are preferred, and iron and its oxides are more preferred from the viewpoint of heat generation, and magnetite is particularly preferred from the viewpoint of availability. The color of the magnetic filler is not particularly limited, but it is preferable that the magnetic filler be black.

[0028] The shape of the magnetic filler is not particularly limited. For example, it may be spherical, hexahedral, octahedral, or acicular. From the viewpoint of heat generation, a hexahedral or octahedral shape is preferred.

[0029] The average particle size of the magnetic filler is 100 nm or more and less than 1000 nm, and from the viewpoint of heat generation, the average particle size of the magnetic filler is preferably 150 nm or more, and more preferably 200 nm or more. The upper limit of the average particle size of the magnetic filler can be set to 900 nm or less, 700 nm or less, or 500 nm or less, from the viewpoint of moldability (magnetic filler sedimentation).

[0030] The magnetic filler is commercially available. Examples of commercially available magnetic fillers include US3985 (manufactured by US Research Nanomaterials), Magnetite MAT-S, Magnetite MAT-304, Magnetite EPT-1000, and Magnetite MTH-310 (all manufactured by Toda Kogyo Co., Ltd.), and S001 and M001 (both manufactured by Powder Tech Co., Ltd.).

[0031] The amount of magnetic filler added is not particularly limited. In the present invention, the magnetic filler is preferably contained in an amount of 0.1% by mass or more relative to the thermoplastic resin (solid content), more preferably 10% by mass or more from the viewpoint of heat generation, even more preferably 20% by mass or more, and particularly preferably 30% by mass or more. From the viewpoint of moldability, the magnetic filler may be contained in an amount of 90% by mass or less, or may be contained in an amount of 70% by mass or less, or 50% by mass or less, relative to the thermoplastic resin (solid content). By using it in combination with a low-viscosity thermoplastic resin, the viscosity of the material composition can be prevented from increasing too much, and the upper limit of the amount of magnetic filler added can be increased while maintaining good moldability.

[0032] <Material composition> A polymer paste having a dispersed magnetic filler can be used as the material composition. The viscosity of the material composition is preferably 10,000 mPa·s or less, more preferably 3,000 mPa·s or less, and particularly preferably 1,000 mPa·s or less, from the viewpoint of improving the coating properties on the substrate and the moldability (such as magnetic filler settling and smoothness after molding). In addition to the thermoplastic resin and the magnetic filler, any additive may be added to the material composition.

[0033] <Method of manufacturing resin composite> The method for producing the resin composite is not particularly limited. The method for producing a resin composite preferably includes the steps of preparing a solution of a thermoplastic resin, dispersing a magnetic filler in the solution of the thermoplastic resin to prepare a material composition (polymer paste), and molding the material composition.

[0034] In the step of preparing a solution of the thermoplastic resin, the thermoplastic resin is preferably dissolved in a solvent. When dissolving the thermoplastic resin in the solvent, it is preferable to heat and / or stir the solution to completely dissolve the thermoplastic resin.

[0035] In the step of preparing the material composition, a dispersion aid such as glass beads is preferably added to disperse the magnetic filler without causing agglomeration. The dispersion aid is preferably removed from the material composition by a known method.

[0036] The process for molding the material composition is not particularly limited. For example, the process may involve casting the material composition in a mold or applying the material composition to a substrate. During molding, it is preferable to heat and / or dry the material composition to remove the solvent as needed.

[0037] The substrate is not particularly limited. For example, a known thermoplastic resin film can be used as the substrate. Specifically, the substrate can be a film made from any of the materials listed as the thermoplastic resins used in the resin composite of the present invention. [Example]

[0038] The present invention will be explained in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. In the following, Examples 1 to 3 and 6 to 7 will be read as Reference Examples 1 to 3 and 6 to 7, respectively.

[0039] [Example 1] Ethyl acetate was added to an acrylic polymer (Dianal BR80 manufactured by Mitsubishi Chemical Corporation) to adjust the solid content to 20% by mass, and the mixture was stirred using a magnetic stirrer in a water bath at 70°C to prepare an acrylic polymer solution. A magnetic filler (US Research Nanomaterials, US3985) was added to the acrylic polymer solution at a concentration of 40% by mass relative to the acrylic polymer, and 3 mm diameter glass beads were then added and stirred for 20 minutes using a paint shaker. After stirring, the glass beads were removed using a metal mesh to obtain an acrylic polymer paste with dispersed magnetic filler. The viscosity of the acrylic polymer paste was 1000 mPa·s or less. The acrylic polymer paste was cast onto a plastic pad and dried in an oven at 100° C. for 30 minutes to obtain a resin sheet sample having a thickness of 200 μm.

[0040] [Example 2] A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was Magnetite MAT-S manufactured by Toda Kogyo Co., Ltd.

[0041] [Example 3] A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was changed to Magnetite MAT-304 manufactured by Toda Kogyo Co., Ltd.

[0042] [Example 4] A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was Magnetite EPT-1000 manufactured by Toda Kogyo Co., Ltd.

[0043] [Example 5] A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was Magnetite MTH-310 manufactured by Toda Kogyo Co., Ltd.

[0044] [Example 6] A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was S001 manufactured by Powder Tech Co., Ltd.

[0045] [Example 7] A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was M001 manufactured by Powder Tech Co., Ltd.

[0046] [Comparative Example 1] A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was changed to 10 nm magnetite manufactured by Toda Kogyo Co., Ltd.

[0047] Comparative Example 2 A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was US3220 manufactured by US Research Nanomaterials.

[0048] Comparative Example 3 A resin sheet sample was obtained in the same manner as in Example 1, except that the magnetic filler was Magnetite EPT-4L manufactured by Toda Kogyo Co., Ltd.

[0049] [Evaluation method] <Average particle size> A resin sheet sample was cut, and the cross section was smoothed by ion milling, after which osmium tetroxide was vapor-deposited. The obtained product was observed with a scanning electron microscope (Hitachi SU8220). At the location that could be determined to be magnetic filler, the longest distance was measured at 30 or more points, and the average value was taken as the average particle diameter. The results are shown in Table 1. It was confirmed that in the resin composites of each example, most of the magnetic filler was present dispersed as primary particles.

[0050] <Heat generation characteristics by induction heating> A helical coil (diameter 30 mm, 3 turns) was connected to an induction heating device (power supply: Ambrell EASYHEAT8310LI, work head: 800S (301-0294)), and the resin sheet sample was placed vertically above the helical coil, 3 mm away. A current was passed through the helical coil at a frequency of 344 kHz and 7 kW, and the surface temperature of the resin sheet sample was measured using a radiation thermometer (FLIR CPA-T540s). The maximum surface temperature of the resin sheet sample was defined as the ultimate temperature, and the time required to reach the ultimate temperature was defined as the ultimate time. The temperature rise rate was calculated from the ultimate temperature and the ultimate time. The results are shown in Table 1.

[0051] <Magnetic filler sedimentation> In each example and comparative example, the acrylic polymer paste state (a state obtained by blending a magnetic filler into an acrylic polymer solution, dispersing it with a paint shaker, and removing the glass beads) was left to stand in a vial. If the magnetic filler is visually confirmed to have settled within 10 seconds after being left to stand, it is judged as "settling has occurred." If the magnetic filler is not visually observed to sink within 10 seconds after being left to stand, it is determined to be "no settling." The results obtained are shown in Table 1.

[0052] [Table 1]

[0053] From Table 1 above, it was found that the resin composite of the present invention exhibits a high rate of temperature rise even with low frequency induction heating, and has good moldability because no sedimentation of the magnetic filler occurs. On the other hand, in Comparative Examples 1 and 2, in which the average particle size of the magnetic filler was 10 nm or 25 nm, which is below the lower limit specified in the present invention, the rate of temperature rise was low. This result showed a tendency different from the findings in the case of dielectric heating using magnetic filler alone (heat generation due to Neel relaxation of magnetic filler with a small average particle size is higher than heat generation due to Brownian relaxation of magnetic filler with a large average particle size). In the case of Comparative Example 3, in which the average particle size of the magnetic filler was 1500 nm, which exceeded the upper limit specified in the present invention, it was found that the moldability deteriorated due to the occurrence of sedimentation of the magnetic filler.

[0054] Furthermore, the resin composite of the present invention does not require a metal layer as in JP 2017-222870 A, does not require closed space equipment as in dielectric heating, and does not require expensive magnetic fillers with an average particle size of several tens of nanometers, thereby reducing manufacturing costs. As described above, the resin composite of the present invention exhibits high heat generation even with low-frequency induction heating, while being produced at low cost, and has good moldability. [Explanation of symbols]

[0055] 1. Magnetic filler 2 Resin layer 3 Base material 10 Resin composite

Claims

1. A resin composite containing a thermoplastic resin and a magnetic filler, The average particle size of the magnetic filler is 100 nm or more and less than 1000 nm, the magnetic filler has a polyhedral shape, and the polyhedral shape is a hexahedron or an octahedron; The resin composite has a thickness of 200 μm, and when the resin composite is placed 3 mm vertically above the coil of an induction heating device and induction heated by passing a current through the coil at a frequency of 344 kHz and a power of 7 kW, the resin composite generates heat at a temperature rise rate of 30° C. / s or more.

2. A substrate; a resin layer located on at least one surface of the substrate; the resin layer is a resin composite containing a thermoplastic resin and a magnetic filler, The average particle size of the magnetic filler is 100 nm or more and less than 1000 nm, the magnetic filler has a polyhedral shape, and the polyhedral shape is a hexahedron or an octahedron; The resin composite has a thickness of 200 μm, and when the resin composite is placed 3 mm vertically above the coil of an induction heating device and induction heated by passing a current through the coil at a frequency of 344 kHz and a power of 7 kW, the resin composite generates heat at a temperature rise rate of 30° C. / s or more.

3. The resin composite according to claim 1 or 2, wherein the magnetic filler is magnetite.

4. The resin composite according to any one of claims 1 to 3, wherein the magnetic filler has an average particle size of 200 nm or more and less than 1000 nm.

5. The resin composite according to any one of claims 1 to 4, wherein the magnetic filler is contained in an amount of 20% by mass or more relative to the thermoplastic resin.

6. The resin composite according to any one of claims 1 to 5, which is a resin composite sheet formed into a sheet shape.

7. A resin composite described in any one of claims 1 to 6, which is used as an induction-heatable, easily dismantled adhesive or adhesive.

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