JP5124967B2 - Adhesive sheet for permanent magnet and method for adhering permanent magnet - Google Patents

Description

The present invention is a method of bonding the adhesive sheet for that permanent magnets be bonded and the permanent magnets about the adherends permanent magnet.

  Conventionally, a reactive adhesive, an adhesive, or the like is used for bonding a permanent magnet that is bonded to a motor rotor or the like. As the reactive adhesive, a two-component mixed resin, a thermosetting resin, an ultraviolet curable resin, or the like is used. As shown in Patent Document 1, a reactive adhesive applied between a permanent magnet and a rotor is cured by reacting with a curing agent, and both are bonded.

Moreover, the double-sided adhesive sheet etc. which have an acrylic resin, an epoxy resin, etc. in an adhesion layer are used as an adhesive. As shown in Patent Document 2, the adhesive sheet is stuck on a permanent magnet, and the bracket is pressure-bonded after the release paper is peeled off. Thereby, both are adhere | attached.
Japanese Patent Laid-Open No. 2001-115125 (page 3 to page 6, FIG. 1) Japanese Patent Laid-Open No. 6-17011 (pages 3 to 4 and FIG. 7)

  However, when a reactive adhesive is used for adhering the permanent magnet, an application process is required, and the adhesion process becomes complicated. Further, there is a problem that the chemical resistance is low and the strength deteriorates in an environment where the chemical is used. When an adhesive is used for bonding the permanent magnet, there is a problem that the solvent component remains in the adhesive layer and erodes the permanent magnet and the bracket. Further, there is a problem that the water resistance and oil resistance are low, and the strength deteriorates after long-term use.

The present invention has no residual solvent chemical resistance, excellent water resistance and oil resistance, and to provide a method of bonding the adhesive sheet and the permanent magnets for permanent magnet Ru can adhere the permanent magnet by a simple process .

To achieve the above object, the permanent magnet adhesive sheet of the present invention has a permanent magnet adhesive for adhering a permanent magnet to an adherend in an adhesive layer, and the permanent magnet adhesive is made permanent by heat melting. in close contact with the magnet and adherends, Ri consists acid-modified polyolefin to be cured by cooling, the substrate consisting of exfoliated be heat-resistant resin after close contact with the adhesive layer on one of the permanent magnets and adherend adhesion Laminated into layers .

According to this configuration, the adhesive layer made of acid-modified polyolefin is placed on one of the permanent magnet and the adherend, and when the adhesive layer melted by heating comes into close contact with the permanent magnet or the adherend, the substrate is peeled off. Thereby, the adhesive layer is transferred onto the permanent magnet or the adherend. Thereafter, the other is pressure-bonded onto the adhesive layer, and when the adhesive layer is cooled to room temperature, it is cured and the permanent magnet and the adherend are bonded. The permanent magnet may be a rare earth magnet .

  According to the present invention, in the adhesive sheet for a permanent magnet having the above structure, the heat resistant resin is made of polyethylene terephthalate.

  Further, the present invention is characterized in that in the adhesive sheet for a permanent magnet having the above-described configuration, a plurality of the adhesive layers having the same shape are arranged at predetermined intervals on the base material. According to this configuration, the base material is fed at a predetermined interval, and, for example, each adhesive layer is sequentially transferred to a plurality of permanent magnets.

Further, in the method for adhering a permanent magnet of the present invention , in order to adhere the permanent magnet to the adherend, the acid-modified polyolefin is heat-melted and adhered to one adhesive surface of the permanent magnet and the adherend, and the adhesive surface is adhered to the other. the a contact with the bonding method of the permanent magnet Ru curing the acid-modified polyolefin by cooling, the adhesive layer and the adhesive sheet for permanent magnet by laminating a base material made of heat-resistant resin made of acid-modified polyolefin, the adhesive The substrate was placed on the adhesive surface so that the layer was in contact with the adhesive surface, and the adhesive layer was heated to adhere the adhesive layer to the adhesive surface, and then the substrate was peeled off.

  According to the present invention, in the method for adhering a permanent magnet having the above-described configuration, the heat-resistant resin is made of polyethylene terephthalate.

According to the permanent magnet adhesive sheet of the present invention, since the permanent magnet adhesive is made of acid-modified polyolefin, the permanent magnet can be easily bonded to the adherend by heat fusion. In addition, the acid-modified polyolefin has no residual solvent and can prevent erosion of permanent magnets and adherends. Furthermore, since it is excellent in chemical resistance, water resistance and oil resistance, the adhesive strength can be maintained for a long time.

Also, the acid-modified polyolefin has no outflow of chlorine as epoxy resin, it is possible to prevent the rusting of low corrosion resistance rare earth magnet.

Also, since the substrate made of a heat-resistant resin is laminated on the adhesive layer composed of the acid-modified polyolefin, it can be brought into close contact with the permanent magnet and adherend to easily hot-melt adhesive layer.

  Moreover, according to the adhesive sheet for permanent magnets of the present invention, since the heat resistant resin is made of polyethylene terephthalate, the strength is high and the handling in the bonding process is easy.

Also, since a plurality of adhesive layers having the same shape on the substrate and arranged at predetermined intervals, it can be transferred easily adhesive layer to a plurality of permanent magnets or adherends giving feed to a substrate .

  Further, according to the method for adhering a permanent magnet of the present invention, the acid-modified polyolefin is heat-melted and adhered to one of the adhesion surfaces of the permanent magnet and the adherend, and the acid-modified polyolefin is adhered to the other by abutting the adhesion surface to lower the temperature. Since it is cured, the permanent magnet and the adherend can be easily bonded with the acid-modified polyolefin.

  Also, according to the method for adhering a permanent magnet of the present invention, a permanent magnet adhesive sheet in which a base material made of acid-modified polyolefin and a heat-resistant resin is laminated is heated, and the base material is peeled after the acid-modified polyolefin is brought into close contact with the adhesive surface. Therefore, the acid-modified polyolefin can be easily transferred to the adhesive surface.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front sectional view showing a motor on which a permanent magnet is mounted. In the motor 1, a stator 4 is disposed on the outer periphery of a rotor 6 having a shaft portion 6a. FIG. 2 is a perspective view showing the rotor 6. In the rotor 6, a plurality of permanent magnets 2 are bonded with an adhesive 3 in the circumferential direction of the yoke 7. In addition, a coil 5 facing the permanent magnet 2 is provided on the inner peripheral surface of the stator 4.

  The yoke 7 is made of a metal such as iron, and the permanent magnet 2 is made of a rare earth magnet or a ferrite magnet. As the rare earth magnet, an R—Fe—B system such as Nd—Fe—B or an R—Co system such as Sm—Co (R is a rare earth element) is used. The adhesive 3 is made of acid-modified polypropylene (PPa).

  3 and 4 are a plan view and a cross-sectional view showing an adhesive sheet for bonding the permanent magnet 2 to the yoke 7. In the adhesive sheet 10, an adhesive layer 12 made of acid-modified polypropylene (PPa) is laminated on a base material 11 made of polyethylene terephthalate (PET).

  The base material 11 is formed in a tape shape having a thickness of about 50 μm, and positioning holes 10a are formed at a predetermined interval T in the longitudinal direction. A plurality of adhesive layers 12 are arranged on the substrate 11 at intervals T, and each adhesive layer 12 is formed in the same shape. A through hole penetrating the base material 11 and the adhesive layer 12 may be provided. The cylindrical permanent magnet and the adherend can be easily bonded by the through hole.

  The acid-modified polypropylene is melted by heating, and the acid-modified polypropylene melted on the substrate 11 is applied by extrusion with a T-die extruder. The acid-modified polypropylene applied on the base material 11 is sandwiched and fed together with the base material 11 by a roll. Thereby, the adhesive layer 12 having a thickness of about 50 μm can be easily formed.

  The positioning hole 10a can be easily formed by laminating the adhesive layer 12 on the substrate 11 and then punching it out by pressing. Further, the adhesive layer 12 can be formed into a desired shape by half-cutting from the adhesive layer 12 side. Unnecessary portions of the adhesive layer 12 are removed by being wound with a roll or the like.

  FIG. 5 is a diagram showing a bonding process in which the permanent magnet 2 is bonded to the yoke 7 using the adhesive sheet 10. The curved permanent magnet 2 is supported on a jig (not shown) and fed on the conveyor 20. The adhesive sheet 10 is wound around a supply roll 21 and fed by a feed roll 22 and a positioning roll 23. A pin 23 a is projected from the positioning roll 23 and is fitted into the positioning hole 10 a of the adhesive sheet 10 so that the adhesive layer 12 is positioned below the heater 24. At this time, the adhesive layer 12 is disposed below the substrate 11.

  When the permanent magnet 2 is positioned below the heater 24 by the conveyor 20, the heater 24 is lowered and the adhesive sheet 10 is pressed against the permanent magnet 2. The adhesive sheet 10 is heated by the heater 24, and the adhesive layer 12 melts and adheres to the permanent magnet 2. The base material 11 does not melt because it has heat resistance. Alternatively, a heater may be contacted with the permanent magnet 2 and the adhesive layer 12 may be melted by heating the permanent magnet 2.

  The permanent magnet 2 and the adhesive sheet 10 are fed together by a conveyor 20, a feed roll 22 and a positioning roll 23. The substrate 11 is wound upward from the positioning roll 23 by the winding roll 25. Thereby, the base material 11 is peeled from the adhesive layer 12, and the adhesive layer 12 is transferred to the permanent magnet 2.

  The permanent magnet 2 to which the adhesive layer 12 has been transferred is placed on the yoke 7 disposed below the heater 26. The heater 26 is lowered and the permanent magnet 2 is pressed against the yoke 7. As a result, the adhesive layer 12 melts and adheres to the yoke 7. The adhesive layer 12 is cured when cooled, and the permanent magnet 2 and the yoke 7 are bonded.

  A plurality of permanent magnets 2 that are sequentially supplied by rotating the yoke 7 are similarly bonded. Then, the rotor 6 (see FIG. 2) in which the permanent magnet 2 is bonded to the yoke 7 with the adhesive 3 made of acid-modified polypropylene is completed. The permanent magnet 2 may be bonded after the adhesive layer 12 is transferred to the yoke 7.

  The substrate 11 may be any heat-resistant resin having heat resistance, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polymethylpentene (TPX (registered trademark)), polyacetal (POM). Non-stretched or stretched films such as cyclic polyolefin and polypropylene (PP) can be used. Polyethylene terephthalate is more desirable because it is inexpensive and has high strength, so that it can be easily handled in the bonding process. Further, a known release agent may be provided between the base material 11 and the adhesive layer 12 to adjust the peel strength between the base material 11 and the adhesive layer 12.

  Table 1 shows the results of measuring the adhesive strength of acid-modified polypropylene to ferrite magnets. The change with time was measured in (a) a dry state at 60 ° C., (b) a state maintained at 60 ° C. with a humidity of 90%, and (c) a state immersed in machine oil at 60 ° C.

  As shown in FIG. 4, the test piece S was obtained by laminating acid-modified polypropylene (PPa) on a base material obtained by laminating aluminum (AL) on a biaxially stretched nylon film (ONy). Thereby, peeling between a base material and acid-modified polypropylene is prevented. As a measuring method, the test piece S was bonded to the ferrite magnet F, and a tensile test was performed at a speed of 50 mm / min. The bonding condition was heated to 200 ° C. and pressurized with a pressure of 1 MPa for 20 seconds.

  As shown in Table 1, it has a high adhesive strength of about 30 N per 15 mm width under each condition. Further, the adhesive strength hardly changes with time and has water resistance and oil resistance.

  The adhesive layer 12 is not limited to acid-modified polypropylene, and the same adhesive strength can be maintained as long as it is an acid-modified polyolefin. In addition, acid-modified polyolefin has similar adhesive strength to other metals, resins, and ceramics, and also has high chemical resistance. For this reason, the permanent magnet 2 such as a rare earth magnet or a ferrite magnet can be bonded to an adherend made of metal, resin, ceramic or the like with high adhesive strength.

  According to this embodiment, since the adhesive 3 for adhering the permanent magnet 2 is made of acid-modified polyolefin, the permanent magnet 2 can be easily bonded to an adherend made of metal, resin, ceramic or the like by heat fusion. . Further, the acid-modified polyolefin has no residual solvent and can prevent the permanent magnet 2 and the adherend from being eroded. Furthermore, since it is excellent in chemical resistance, water resistance and oil resistance, the adhesive strength can be maintained for a long time. In addition, the acid-modified polyolefin does not flow out of chlorine like an epoxy resin, and can prevent rusting of a rare earth magnet having low corrosion resistance.

  Further, since the base 11 made of heat-resistant resin is formed in a sheet shape laminated on the adhesive layer 12 made of acid-modified polyolefin, the adhesive 3 made of the adhesive layer 12 is simply heat-melted to cover the permanent magnet 2. It can be adhered to the adhesive.

  In addition, since the plurality of adhesive layers 12 having the same shape are arranged on the base material 11 at a predetermined interval T, the adhesive layer 12 can be easily transferred to the plurality of permanent magnets 2 by feeding the base material 11. it can. Further, by providing the positioning holes 11 a in the adhesive sheet 12, the base material 11 can be easily positioned at a predetermined interval T.

  The acid-modified polyolefin may be extruded on one of the permanent magnet 2 and the adherend, and the other may be placed thereon and heated. Thereby, it is not necessary to form the adhesive 3 in a sheet shape, and the base material 11 can also be made unnecessary.

  According to the present invention, the present invention can be used for industrial products such as a motor and a speaker for bonding a permanent magnet to a yoke or the like.

Front sectional drawing which shows the motor provided with the permanent magnet adhere | attached with the adhesive for permanent magnets of embodiment of this invention The perspective view which shows the rotor of the motor provided with the permanent magnet adhere | attached with the adhesive agent for permanent magnets of embodiment of this invention The top view which shows the adhesive sheet for permanent magnets of embodiment of this invention Sectional drawing which shows the adhesive sheet for permanent magnets of embodiment of this invention Schematic which shows the adhesion | attachment process of the to-be-adhered object by the adhesive for permanent magnets of embodiment of this invention. The figure which shows the measuring method of the adhesive strength of the adhesive agent for permanent magnets of embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Permanent magnet 3 Adhesive 4 Stator 5 Coil 6 Rotor 7 Yoke 10 Adhesive sheet 10a Positioning hole 11 Base material 12 Adhesive layer 20 Conveyor 21 Supply roller 22 Feed roller 23 Positioning roller 24 Heater 25 Winding roller

Claims (6)

Has an adhesive permanent magnet bonding the permanent magnet to the adherend to the adhesive layer, the adhesive for the permanent magnets are in close contact with the permanent magnets and the adherend by heat melting the acid-modified polyolefin to be cured by cooling formed Ri from the adhesive sheet for the permanent magnet, characterized in that a substrate consisting of exfoliated be heat-resistant resin was laminated on the adhesive layer after adhesion to one of the adhesive layer of the permanent magnet and adherends. The permanent magnet adhesive sheet according to claim 1, wherein the permanent magnet is a rare earth magnet. 3. The permanent magnet adhesive sheet according to claim 1, wherein the heat resistant resin is made of polyethylene terephthalate. A plurality of adhesive sheets for permanent magnet according to any one of claims 1 to claim 3 wherein characterized in that an adhesive layer is disposed at a predetermined interval of the same shape on the substrate. In order to bond the permanent magnet to the adherend, the acid-modified polyolefin is heat-melted and adhered to one of the permanent magnet and the adherend, and the adhesive surface is brought into contact with the other to cure the acid-modified polyolefin by cooling. a permanent method of bonding the magnet was Ru is, the adhesive sheet a permanent magnet obtained by laminating a base material made of the adhesive layer and the heat-resistant resin made of acid-modified polyolefin, such that the adhesive layer is brought into contact with the adhesive surface A method for adhering a permanent magnet, comprising: placing the substrate on the adhesive surface, heating the adhesive layer to adhere the adhesive layer to the adhesive surface, and then peeling the substrate. 6. The permanent magnet bonding method according to claim 5 , wherein the heat resistant resin is made of polyethylene terephthalate.

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