Magnet-metal bonded body, rotor, rotating machine, and method for manufacturing magnet-metal bonded body

Abstract

To easily peel off a magnet from an adherend. The magnet-metal bonded body of the present disclosure comprises a magnet having a silicone resin coating layer on at least one surface thereof, and a metal adherend to which the silicone resin coating layer is bonded by an adhesive layer, and the adhesive strength between the silicone resin coating layer and the adhesive layer is smaller than the adhesive strength between the adhesive layer and the metal adherend. The manufacturing method of the magnet-metal bonded body comprises a coating step of applying and curing a silicone resin on at least one surface of the magnet to form a silicone resin coating layer, and an adhesion step of applying an adhesive to either the silicone resin coating layer or the metal adherend, curing the adhesive, and bonding the silicone resin coating layer and the metal adherend such that the adhesive strength between the silicone resin coating layer and the adhesive is smaller than the adhesive strength between the adhesive and the metal adherend. The disassembly method of the magnet-metal bonded body is to separate the silicone resin coating layer and the metal adherend by heating the adhesive layer at 280°C or less.

Description

[Technical field]

[0001] The present disclosure relates to a magnet-metal bonded body, a rotor and a rotating machine using the same, and a method for manufacturing and disassembling the magnet-metal bonded body. [Background technology]

[0002] Many automobiles, industrial equipment, and home appliance motors incorporate rare earth magnets for high performance and efficiency. Concerns have been raised about the medium- to long-term procurement risks of rare earths due to the high dependency on certain producing countries. Furthermore, there are concerns about environmental destruction because the mining and refining of rare earths involves deforestation and the discharge of large amounts of waste liquids (e.g., acids, alkalis, oils, etc.). For this reason, there is a need for the development of resource circulation technologies for the reuse of rare earths.

[0003] By the way, rare earths are sometimes used in magnets of rotors (i.e., motors) of rotating machines, etc. Regarding the reuse of motor magnets, for example, focusing on the components and composition of recovered magnets, reuse methods in which they are molded and magnetized again, that is, recycling methods, are being studied.

[0004] In addition, technology to remove magnets from motors, recover them, and reuse them as is, that is, reuse technology, is also being considered. To reuse magnets, it is necessary to remove them from the adherend and recover them. For example, Patent Document 1 describes a method in which magnets are attached to adherends using an adhesive containing added thermally expandable particles to facilitate removal of magnets when reused. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2003-176459 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the technology of Patent Document 1, thermally expandable particles that peel off at 70 to 240°C are added to the adhesive that fixes the magnet. When recovering the magnet, the magnet is peeled off from the adherend by hot water treatment at that temperature. However, the hot water treatment disclosed in Patent Document 1 may erode the anticorrosive and oxidation layer provided on the surface of the magnet, in which case retreatment is required after peeling. In addition, the thermally expandable particles of Patent Document 1 expand from 70°C, but the operating temperature of the motor may be higher than this, and may be 100°C or higher. Therefore, the particles may expand during operation and the magnet may peel off. Furthermore, during abnormal operation of the motor, such as a short circuit, the temperature may become even higher, and the magnet may easily peel off. In this case, in addition to the insulation short circuit, there is a risk of secondary damage due to the impact caused by the magnet peeling off. In these respects, there is still room for improvement in the magnet adhesive and peeling method of Patent Document 1.

[0007] As another method for recovering magnets fixed with adhesive, for example, it is possible to carbonize and remove the adhesive by heating the adhesive at a temperature higher than the thermal decomposition temperature of the organic polymer adhesive, including epoxy and acrylic adhesives. However, in this case, a heat treatment at a high temperature of, for example, 450°C or higher is required. However, magnets generally used in motors may denature at temperatures above 350°C, causing a decrease in their magnetic properties. For this reason, it is difficult to reuse the recovered magnets as they are.

[0008] The present disclosure has been made to solve the above problems. That is, the objective is to provide an improved magnet-metal adherend that allows the magnet to be easily peeled off and recovered while minimizing denaturation of the magnet and damage to the anticorrosive / oxidation layer that serves as a protective layer, and a manufacturing method and disassembly method thereof. [Means for solving the problem]

[0009] The magnet-metal bonded body of the present disclosure comprises a magnet having a silicone resin coating layer on at least one surface thereof, and a metal adherend to which the silicone resin coating layer is adhered by an adhesive layer, and the adhesive strength between the silicone resin coating layer and the adhesive layer is smaller than the adhesive strength between the adhesive layer and the metal adherend.and the adhesive strength between the silicone resin coating layer and the magnet is stronger than the adhesive strength between the silicone resin coating layer and the adhesive layer, but weaker than the adhesive strength between the adhesive layer and the metal adherend. stomach.

[0010] The rotor or rotating machine of the present disclosure comprises the magnet-metal bond of the present disclosure.

[0011] The method of manufacturing a magnet-metal bonded body disclosed herein includes a coating step of applying and curing a silicone resin on at least one surface of a magnet to form a silicone resin coating layer on at least one surface, and a coating step of applying an adhesive to either the silicone resin coating layer or the metal adherend, curing the adhesive, and causing the adhesive strength between the silicone resin coating layer and the adhesive to be smaller than the adhesive strength between the adhesive and the metal adherend. and the adhesive strength between the silicone resin coating layer and the magnet is stronger than the adhesive strength between the silicone resin coating layer and the adhesive and weaker than the adhesive strength between the adhesive and the metal adherend. and a bonding step of bonding the silicone resin coating layer and the metal adherend so as to form a bond between the silicone resin coating layer and the metal adherend. Effect of the Invention

[0013] According to the present disclosure, magnets can be easily recovered while suppressing changes to the magnetic properties and damage to the surface of a magnet-metal bonded body. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing the configuration of a magnet-metal bonded body according to embodiment 1. FIG. [Diagram 2] FIG. 4 is a diagram showing the evaluation results of examples of the magnet-metal bonded body according to embodiment 1. [Diagram 3] FIG. 4 is a diagram showing an evaluation method for examples of a magnet-metal bonded body according to embodiment 1. [Figure 4] FIG. 11 is a schematic diagram showing a motor for a rotary machine according to a second embodiment. [Diagram 5] FIG. 11 is a schematic diagram showing a motor for a rotary machine according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0016] Embodiment 1 1.Magnet-metal bonded body structure FIG. 1 is a schematic diagram showing the configuration of a magnet-metal bonded body according to the first embodiment. As shown in FIG. 1, the magnet-metal bonded body 1 includes a magnet 10 and a metal adherend 20. A corrosion-resistant / oxidation layer 11 is formed on the surface of the magnet 10. A silicone resin coating layer 13 is formed on one side 12 of the magnet 10. The silicone resin coating layer 13 is bonded to the metal adherend 20 via an adhesive layer 30 on the surface opposite to the surface in contact with the one side 12 of the magnet 10. For the sake of simplicity, the interface between the magnet 10 and the silicone resin coating layer 13 is also referred to as the "magnet / coating layer interface C," the interface between the adhesive layer 30 and the silicone resin coating layer 13 as the "adhesive layer / coating layer interface B," and the interface between the adhesive layer 30 and the metal adherend 20 as the "metal adherend / adhesive layer interface A."

[0017] (1) Magnet The magnet 10 is, for example, a rare earth magnet such as neodymium or samarium. These rare earth magnets are particularly required to be reusable, and from an economical point of view, are suitable as the material for the magnet 10 of this embodiment. However, there is no particular limitation on the material of the magnet 10, and the magnet 10 may be a bonded magnet, a ferrite magnet, a cast magnet, or the like. Also, while FIG. 1 illustrates the magnet 10 in a rectangular parallelepiped shape, there is no particular limitation on the shape of the magnet 10. For example, the magnet 10 may be, for example, a plate shape, a disk shape, a rod shape, or a semi-cylindrical shape.

[0018] (2) Silicone resin coating layer The silicone resin coating layer 13 is formed of a silicone resin. For example, a silicone resin having a siloxane skeleton crosslinked in three or two dimensions is used. More specifically, a skeleton such as triorganosylhemioxane, siloxane, silsesquioxane, or silicate may be included. The silicone resin may have one or more of a methyl group, a phenyl group, and other functional groups as a functional group for imparting heat resistance and strength. Alternatively, the silicone resin coating layer 13 may be formed of a silicone resin modified with epoxy or acrylic. The silicone resin coating layer 13 may be formed by using the above silicone resin alone, or may be formed by using a mixture of two or more silicone resins.

[0019] The curing mechanism of the silicone resin may be either addition polymerization or dehydration condensation, but addition polymerization requires heating. The silicone resin of the silicone resin coating layer 13 is a resin that cures at a temperature below the demagnetization temperature. Specifically, it is desirable to use a silicone resin that has a curing temperature of 280°C or less, preferably 250°C or less, and more preferably 100°C or less.

[0020] There is no particular limit to the thickness of the silicone resin coating layer 13, but it is preferably 100 μm or less, and more preferably in the range of 10 μm to 50 μm. If it is less than 10 μm, sufficient strength cannot be obtained, and it may be damaged when peeled off after heating, making it difficult to protect the surface of the magnet 10. On the other hand, if it is more than 100 μm, the curing reaction may not progress to the inside, particularly when curing by dehydration condensation, and the magnet may remain uncured.

[0021] The adhesive strength between the surface of the magnet 10 and the silicone resin coating layer 13 at the magnet / coating layer interface C is, for example, 15 MPa to 40 MPa, and more preferably 15 MPa to 35 MPa.

[0022] (3) Adhesive layer The adhesive constituting the adhesive layer 30 is mainly composed of a curable resin consisting of at least one of epoxy resin, silicone resin, urethane resin, polyester resin, cyanate ester resin, phenol aldehyde resin, melamine aldehyde resin, urea aldehyde resin, resorcinol aldehyde resin, xylene aldehyde resin, furan resin, and acrylic resin such as thermosetting acrylic resin. However, the adhesive used is one that is oxidized and deteriorated at 280°C or less. There is no particular limitation on the thickness of the adhesive layer 30, but it is preferably 10 μm to 100 μm.

[0023] The adhesive layer 30 may be the above-mentioned adhesive to which an additive such as a foaming material has been added. The addition of an additive can improve the peelability caused by heating, making peeling at the adhesive layer / coating layer interface B easier. An example of an additive is a microcapsule in which a low-boiling point hydrocarbon is encapsulated in a thermoplastic polymer shell. When the microcapsule is heated, the polymer shell softens and the liquid hydrocarbon inside turns into gas, causing the capsule to expand due to the pressure. This mechanism improves the peelability caused by heating between the magnet 10 and the silicone resin coating layer 13, which is the adherend, when the magnet 10 is peeled off.

[0024] The particle size of the microcapsules is not particularly limited, but the average particle size is preferably about 1 μm to 100 μm. If the particle size is 1 μm or less, a sufficient amount of hydrocarbon cannot be encapsulated, and the foaming effect cannot be obtained. On the other hand, if the particle size exceeds 100 μm, the thickness of the adhesive layer 30 becomes excessive.

[0025] The thickness of the polymer shell of the microcapsule is preferably 0.05 μm to 50 μm. If the thickness of the outermost layer is less than 0.05 μm, the strength of the polymer shell is insufficient, and foaming may occur even at a temperature lower than the temperature at which the material is peeled off. Also, sufficient resistance to the low molecular weight organic solvent contained in the adhesive cannot be obtained. On the other hand, if the thickness exceeds 50 μm, foaming is not obtained even if the encapsulated hydrocarbon expands, and the peelability of the adhesive layer 30 decreases.

[0026] The curing temperature of adhesive layer 30 may be within a range in which demagnetization of magnet 10 does not occur, and is 280° C. or less, preferably 250° C. or less, more preferably 100° C. or less, and room temperature is even more preferable.

[0027] The adhesive strength between the adhesive layer 30 and the silicone resin coating layer 13 at the adhesive layer / coating layer interface B is, for example, 10 MPa or less.

[0028] (4) Metal adherend The metal adherend 20 is an adherend to which the magnet 10 is fixed. Specifically, for example, in the case of a motor, a yoke, which is a cylindrical member, or a rotor corresponds to the metal adherend 20. There is no particular limitation on the material of the metal adherend 20, but examples include SUS, iron, and electromagnetic steel plate.

[0029] The metal adherend 20 is subjected to a surface treatment so that the adhesive strength with the adhesive layer 30 is strong on the metal adherend / adhesive layer interface A side and weak on the magnet / coating layer interface B side.

[0030] Specifically, the surface treatment includes atmospheric plasma treatment, UV (ultraviolet) treatment such as deep ultraviolet light treatment, corona discharge treatment, physical treatment such as abrasion treatment, and chemical treatment such as applying a silane coupling agent as a primer, etc. Examples of the abrasion treatment include laser abrasion, polishing, and sandblasting.

[0031] Furthermore, examples of primers for chemical treatment include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(phenylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride.

[0032] The surface treatment of the metal adherend 20 is expected to improve the adhesion or adhesive strength of the metal adherend / adhesive layer interface A. The adhesive strength between the adhesive layer 30 and the metal adherend 20 is 15 MPa to 60 MPa, and more preferably 30 MPa to 50 MPa.

[0033] In the magnet-metal bonded body 1 in Figure 1, the adhesive strength at the adhesive layer / coating layer interface B is the weakest. When peeling off the magnet 10, interfacial peeling at the adhesive layer / coating layer interface B can suppress damage to the surface of the magnet 10. To further reduce the possibility of surface damage, the adhesive strength relationships between the metal adherend / adhesive layer interface A, the adhesive layer / coating layer interface B, and the magnet / coating layer interface C are in the order of interface A > interface C > interface B, with the adhesive strength at the metal adherend / adhesive layer interface A being stronger than the adhesive strength at the magnet / coating layer interface C.

[0034] 2. Manufacturing method of magnet-metal bonded body Next, a manufacturing method of the magnet-metal bonded body will be described. The manufacturing method of the magnet-metal bonded body includes a coating step and a bonding step. In the coating step, a silicone resin is applied to at least one surface 12 of the magnet 10, and the silicone resin coating layer 13 is formed on the magnet surface by leaving it at room temperature or heating it. The coating method here is not particularly limited. Coating methods include brush coating, spraying, and immersion. In order to make the thickness of the silicone resin coating layer 13 uniform, brush coating or spraying is preferable. The coating method can be appropriately selected depending on the viscosity of the silicone resin used, etc.

[0035] In the bonding step, an adhesive is applied to the metal adherend 20. However, the adhesive may also be applied to the silicone resin coating layer 13 side. The silicone resin coating layer 13 of the magnet 10 and the metal adherend 20 are then bonded together with the applied adhesive. This forms the magnet-metal bonded body 1. The manufacturing method for the magnet-metal bonded body may also include a surface treatment step of performing a surface treatment on the metal adherend 20 prior to the bonding step.

[0036] 3. How to recover magnets Next, a method for recovering the magnet 10 from the magnet-metal bonded body 1 will be described. First, to facilitate peeling, it is preferable to demagnetize the magnet 10 beforehand. As the demagnetization method, a method that does not cause demagnetization or denaturation is preferable, since the magnet 10 is to be reused as is. Specifically, for example, demagnetization by applying a magnetic field opposite to that used for magnetization can be mentioned.

[0037] In order to peel off the adhesive layer 30 and recover the magnet 10, the adhesive layer 30 is oxidatively deteriorated. The temperature for this oxidative deterioration is 150°C to 270°C, preferably 180°C to 250°C, and more preferably 180°C to 220°C. Below 150°C, the adhesive does not oxidatively deteriorate, making it difficult to peel off, whereas above 260°C there is a possibility that the magnet 10 will be degenerated.

[0038] The heat treatment time for oxidative degradation is 2 to 24 hours, preferably 2 to 12 hours, and more preferably 4 to 8 hours. If it is less than 2 hours, the oxidative degradation of the adhesive does not progress sufficiently, making it difficult to peel it off. On the other hand, if it exceeds 24 hours, continuous operation of the heating furnace is required, and there is a possibility that the production takt time will be exceeded.

[0039] After the heat treatment, the magnet 10 can be easily peeled off from the metal adherend 20 by manually applying a force in the tensile shear direction, and the magnet 10 and the metal adherend 20 can be separated. There is no particular limitation on the strength of the tensile shear force. The tensile shear force may be of a level that does not damage the magnet 10, and no special device or equipment is required.

[0040] 4.Other As described above, according to the magnet-metal bonded body 1 of the present embodiment, the magnet can be easily collected without damaging the surface of the magnet 10. More specifically, in the magnet-metal bonded body 1 of the first embodiment, the adhesive strength between the metal adherend 20 and the adhesive layer 30 is increased, and the adhesive strength with the adhesive layer 30 is configured to be large on the metal adherend / adhesive layer interface A side and small on the adhesive layer / coating layer interface B. This promotes peeling on the adhesive layer / coating layer interface B side, so the magnet 10 can be collected without damaging the surface of the magnet 10. In addition, since peeling occurs at the adhesive layer / coating layer interface B, the adhesive layer 30 is unlikely to remain on the silicone resin coating layer 13, and the process of removing the oxidized and deteriorated adhesive layer 30 after collection can be omitted.

[0041] Magnet 10 also has a silicone resin coating layer 13 that hardens at a temperature below the demagnetization temperature, for example, below 280°C, on the surface of magnet 10, which is made up of a sintered body and an anticorrosive / oxidation layer 11 on its surface. Silicone resin has a lower adhesive strength with adhesive layer 30 than glass, minerals, or metal oxides, and is therefore prone to peeling at the interface with adhesive layer 30. Furthermore, because silicone resin has a heat resistance of 250°C or higher, even when subjected to a heat treatment at 200°C to 250°C, silicone resin coating layer 13 does not deteriorate, and only adhesive layer 30 deteriorates by oxidation, making it possible to easily peel off at adhesive layer / coating layer interface B.

[0042] Furthermore, the silicone resin coating layer 13 of the magnet-metal bonded body 1 of embodiment 1 cures at low temperatures below the demagnetization temperature or at room temperature. Therefore, denaturation and deterioration of the properties of the magnet 10 during the formation of the silicone resin coating layer 13 can be suppressed.

[0043] Furthermore, in the magnet-metal bonded body 1 of embodiment 1, the silicone resin coating layer 13 provided on the surface of the magnet 10 is more flexible than glass. The silicone resin coating layer 13 can absorb stress caused by the difference in thermal expansion of the constituent materials that occurs during the thermal cycle during operation. That is, in addition to functioning as a protective layer for the magnet 10, the silicone resin coating layer 13 also functions as a stress relaxation layer, and can suppress cracking of the magnet 10.

[0044] 5. Working Example As more specific examples, several types of magnet-metal bonded bodies were produced and evaluated using several types of silicone resins and adhesives. Figure 2 shows the evaluation results of the magnet-metal bonded bodies. However, the magnet-metal bonded body 1 according to the present disclosure is not limited to the following examples.

[0045] (1) Material The following materials are used:

[0046] <Silicone resin coating layer> Silicone resins that can be cured at temperatures below 100°C, including modified silicone resins

[0047] 《Adhesive layer》 Two-part curing epoxy and acrylic adhesives that can be cured at temperatures below 100°C Acrylic adhesive: DP-7810 (3M) Epoxy adhesive: DP-420 (3M)

[0048] "magnet" Neodymium magnets

[0049] <Example 1-10> Using the silicone resin and adhesive shown in FIG. 2, the metal adherend was subjected to acetone degreasing and polishing as a surface roughening treatment (i.e., surface treatment).

[0050] <Comparative Examples 1 and 2> The silicone resin and adhesive used were those shown in Figure 2. The magnet-metal bonded bodies of Comparative Examples 1 and 2 were produced in the same manner as in Examples 1-10, except that the molding temperature for the silicone resin coating layer was different.

[0051] <Comparative Examples 3 and 4> The silicone resin and adhesive used were as shown in Figure 2. The magnet-metal bonds of Comparative Examples 3 and 4 were produced in the same manner as in Examples 1-10, except that the metal adherend was not surface-treated.

[0052] <Comparative Example 5> The magnet-metal bonded body of Comparative Example 5 was produced in the same manner as in Examples 1-10, except that the silicone resin coating layer was not formed.

[0053] <Comparative Example 6> The magnet-metal bonded body of Comparative Example 6 was produced in the same manner as in Examples 1-10, except that an epoxy resin coating layer was formed instead of the silicone resin coating layer.

[0054] <Comparative Examples 7 and 8> In Comparative Examples 7 and 8, the magnet-metal bonded bodies were produced in the same manner as in Examples 1-10, but the heating and peeling temperatures when peeling the magnet were 170°C and 270°C, respectively.

[0055] <Evaluation> The evaluation items and methods are shown below. Peelability The magnet of the magnet-metal bonded assembly heated to the peeling temperature shown in Figure 2 was pressed toward the surface of the metal adherend, and a tensile shear force was applied to check whether peeling occurred. Magnets that did not peel off even after pressing for 10 minutes or more were marked with an "X" in the peeling column in Figure 2. Furthermore, for the magnets that peeled off, the presence or absence of residual adhesive layer on the magnet side and the metal adherend side, and the presence or absence of damage to the silicone resin coating layer were checked.

[0056] <Magnetic properties after peeling> The peeled magnets were magnetized and the coercive force and residual magnetic flux density were measured. If the initial value of the magnet alone is taken as 1, a value less than 0.8 is judged to have been demagnetized, and a value of 0.8 or more is judged to have not been demagnetized. These are indicated by a "○" in the magnetic properties column in Figure 2.

[0057] <Determining whether or not it can be reused> Based on the peelability and magnetic properties after peeling, we determined that those that could be peeled off without damaging the magnet and had 80% or more of their magnetic properties were reusable, and those that were damaged or had less than 80% of their magnetic properties were not reusable. In the reusability column in Figure 2, reusable items are indicated with a "◯" and those that were not reusable are indicated with an "X".

[0058] <<Measurement of adhesive strength at the interface of each layer>> The adhesive strength between the metal adherend and the adhesive layer was measured by a shear strength test. Figure 3 shows the method for preparing the shear test specimen and the shear test. The test specimens were a pair of SPCC (Steel Plate Cold Commercial) plates (i.e., steel plates) 101, 102, and adhesive 103 was applied to the edge of one side of one SPCC plate 101, which was then sandwiched between the two SPCC plates 101, 102. After the test specimens were cured at the temperatures shown in Figure 2, they were pulled up and down to perform a shear test to evaluate the adhesive strength.

[0059] The adhesion between the adhesive layer 30 and the silicone resin coating layer 13 was measured in the same manner as in measuring the adhesion between the adhesive layer and the metal adherend, except that an SPCC plate was used on which the silicone resin shown in Figure 2 had been applied in advance and cured at the temperature shown in Figure 2 to form a silicone resin coating layer.

[0060] <Results and Discussion> As can be seen from FIG. 1, in Example 1-10, the magnet was easier to peel off after heating than in Comparative Example 1-8, and even after peeling, the magnet retained 80% or more of its initial magnetic properties.

[0061] In contrast, the magnetic properties after peeling and recovery were less than 80% of the initial values ​​in Comparative Examples 1 and 2. This is believed to be because the molding temperature of the silicone resin coating layer was 250°C or higher, which causes demagnetization of the magnet.

[0062] In Comparative Examples 3 and 4, the adhesive strength between the adhesive layer and the metal adherend is not improved because the metal adherend side is not subjected to the spalling treatment. As a result, the adhesive strength between the adhesive layer and the silicone resin coating layer is equal to the adhesive strength between the magnet and the silicone resin coating layer, and no significant difference is obtained. For this reason, it is considered that the effect of facilitating magnet peeling, as in Examples 1-10, was not obtained.

[0063] In Comparative Examples 5 and 6, in which the silicone resin coating layer was not provided or the coating layer was replaced with epoxy resin, the adhesive remained on the magnet side after peeling, and it was difficult to peel and collect from the metal adherend without damaging the magnet surface. Comparing Comparative Examples 5 and 6 with Examples 1-10, the effect of the silicone resin coating layer by peeling was confirmed. This is thought to be due to the fact that the adhesive strength between the silicone and the adhesive is lower than that between organic coatings such as epoxy and the metal on the magnet surface and the adhesive, and therefore the silicone resin has relatively excellent releasability, and also due to the high heat resistance of the silicone resin, deterioration due to heating during peeling does not occur.

[0064] Embodiment 2 4 and 5 are schematic diagrams showing an example of a rotor for a rotating machine according to embodiment 2. The rotor for a rotating machine according to embodiment 2 is used as a rotor for a rotating machine. The magnet-metal bonded body 1 according to embodiment 1 is applied to this rotor for a rotating machine. As shown in FIGS. 4 and 5, a motor for a rotating machine includes a magnet 10a or 10b and a rotor core 20a or 20b, and a shaft 40 is installed at the center of the rotor core 20a or 20b. The rotor core 20a or 20b is a metal adherend to which the magnet 10a or 10b is bonded.

[0065] 4 and 5, a rotor for a rotating machine using the magnet-metal bonded body 1 is used as a rotor in a three-phase permanent magnet synchronous motor (i.e., PM motor), which is a rotating machine. A three-phase permanent magnet synchronous motor is a so-called rotating field type synchronous motor in which permanent magnets are provided as magnetic poles in the rotor and the stator, which is the armature, has a stator core and stator windings.

[0066] The rotating machine motor in Fig. 4 is an example of an IPM (Inter Permanent Magnet) motor in which magnet 10a is attached by embedding magnet 10a in rotor core 20a. The rotating machine motor in Fig. 5 is an example of an SPM (Surface Permanent Magnet) motor in which magnet 10b is attached by attaching magnet 10b to the outer periphery of rotor core 20b. In either case of the motor, the magnet-metal bonded body according to embodiment 1 can be used.

[0067] In the second embodiment, an example of a three-phase drive permanent magnet synchronous motor has been described, but the magnet-metal bonded body 1 of the first embodiment can be applied to rotors in other rotating machines.

[0068] In the above embodiments, when the number, quantity, amount, range, etc. of each element is mentioned, the magnet-metal bonded body, rotor, rotating machine, and manufacturing method and disassembly method of the magnet-metal bonded body of the present disclosure are not limited to the mentioned number, unless otherwise specified or clearly specified in principle. Furthermore, the structures, etc. described in the embodiments are not necessarily essential to the magnet-metal bonded body, rotor, rotating machine, and manufacturing method and disassembly method of the magnet-metal bonded body of the present disclosure, unless otherwise specified or clearly specified in principle. [Explanation of symbols]

[0069] 1 magnet-metal bonded body, 10, 10a, 10b magnet, 11 anti-corrosion / oxidation layer, 12 one side, 13 silicone resin coating layer, 20 metal bonded body, 20a, 20b rotor core, 30 adhesive layer, 40 shaft, 101, 102 SPCC plate, 103 adhesive

Claims

1. A magnet having a silicone resin coating layer on at least one surface thereof; a metal adherend to which the silicone resin coating layer is adhered by an adhesive layer; Equipped with the adhesive strength between the silicone resin coating layer and the adhesive layer is smaller than the adhesive strength between the adhesive layer and the metal adherend, and the adhesive strength between the silicone resin coating layer and the magnet is stronger than the adhesive strength between the silicone resin coating layer and the adhesive layer and smaller than the adhesive strength between the adhesive layer and the metal adherend; A magnet-metal bonded body.

2. The magnet-metal bonded body according to claim 1, characterized in that the adhesive layer is formed using an adhesive containing at least one of epoxy resin, silicone resin, urethane resin, polyester resin, cyanate ester resin, phenol aldehyde resin, melamine aldehyde resin, urea aldehyde resin, resorcinol aldehyde resin, xylene aldehyde resin, furan resin, and acrylic resin.

3. 2. The magnet-metal bonded body according to claim 1, wherein the adhesive layer contains a foaming agent as an additive.

4. The adhesive strength between the silicone resin coating layer and the adhesive layer is 10 MPa or less, The adhesive strength between the silicone resin coating layer and the magnet is 15 MPa or more and 40 MPa or less, The adhesive strength between the adhesive layer and the metal adherend is greater than 15 MPa and less than 60 MPa.

2. The magnet-metal bonded body according to claim 1 .

5. A rotor comprising the magnet-metal bonded body according to any one of claims 1 to 4.

6. A rotating machine having a rotor including the magnet-metal bonded body according to any one of claims 1 to 4.

7. a coating step of applying a silicone resin to at least one surface of the magnet and curing the silicone resin to form a silicone resin coating layer on at least the one surface; a bonding step of applying an adhesive to either the silicone resin coating layer or the metal adherend, curing the adhesive, and bonding the silicone resin coating layer to the metal adherend such that the adhesive strength between the silicone resin coating layer and the adhesive is smaller than the adhesive strength between the adhesive and the metal adherend, and the adhesive strength between the silicone resin coating layer and the magnet is stronger than the adhesive strength between the silicone resin coating layer and the adhesive and smaller than the adhesive strength between the adhesive and the metal adherend; A method for producing a magnet-metal bonded body, comprising:

8. The method for producing a magnet-metal bonded body according to claim 7, characterized in that in the coating step, the silicone resin coating layer is formed at a molding temperature below the demagnetization temperature of the magnet.

9. The method for producing a magnet-metal bonded body according to claim 8, characterized in that the molding temperature is 280° C. or less.

10. The method for manufacturing a magnet-metal bonded body according to any one of claims 7 to 9, characterized in that it includes a surface treatment step in which the metal adherend is subjected to one or more of the following surface treatments: application of a coupling agent, roughening, corona discharge treatment, atmospheric plasma treatment, and UV treatment.

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