Soft magnetic composite

Abstract

The present invention is a soft magnetic composite containing a flat soft magnetic iron-based alloy powder and a resin, the content of the soft magnetic iron-based alloy powder being 15-55 vol%, the length-width ratio of the soft magnetic iron-based alloy powder in the cross section of the soft magnetic composite being 30-60, the viscosity being 1000-40000 Pa.s, and the magnetic permeability at 100 MHz being 13-200.

Description

TECHNICAL FIELD

[0001] The present application relates to a soft magnetic composite in which a flat soft magnetic iron-based alloy powder is compounded with a resin. BACKGROUND

[0002] In recent years, with the demand for miniaturization and light weight of electronic devices, electronic components used therein are also required to be miniaturized, thinned and high-density packaged. In addition, with the high performance of electronic devices, the working frequency of electronic components is being developed to be high frequency. Due to such high-density and high-frequency, electromagnetic wave noise generated from electronic components becomes a great problem. Therefore, a material capable of suppressing such electromagnetic wave noise is required.

[0003] As a material for suppressing electromagnetic wave noise, a soft magnetic composite in which a filler such as a ferrite powder or a soft magnetic metal powder is compounded with a resin is used. In particular, it is known that a soft magnetic metal powder has a reduced demagnetization coefficient by being flattened, and the permeability in the in-plane direction is improved. Therefore, since a flat soft magnetic metal powder has more excellent magnetic properties such as permeability than a ferrite powder, various soft magnetic composite schemes in which a flat soft magnetic metal powder is compounded are proposed.

[0004] As the soft magnetic composite as described above, for example, Patent Literature 1 discloses a soft magnetic composite in which a flat soft magnetic metal powder having Fe as a base alloy is compounded with a resin. Specifically, in Patent Literature 1, a soft magnetic composite is obtained by compounding a flat soft magnetic metal powder having Fe as a base alloy with a bulk density / true density of 0.04 to 0.15 at 25 to 65% by volume with a resin binder by kneading. Thereby, good permeability can be obtained.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Laid-Open No. 2003-209010 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] As described above, the soft magnetic composite described in Patent Literature 1 is a composite in which a flat soft magnetic metal powder is compounded with a resin, and it is considered to have good permeability and moldability. However, there is still a demand for a soft magnetic composite capable of obtaining high permeability in a high frequency band, particularly in a frequency band of 100 MHz to 3 GHz.

[0010] The present application has been achieved in view of the above problems, and has an object to provide a soft magnetic composite capable of obtaining high permeability in a high frequency band.

[0011] - Solution to the problem -

[0012] To achieve the above object, the present application is configured to increase the filling rate of the flat soft magnetic iron-based alloy powder and to have a desired viscosity.

[0013] Specifically, the soft magnetic composite of the present application is a soft magnetic composite containing a flat soft magnetic iron-based alloy powder and a resin, characterized in that the content of the soft magnetic iron-based alloy powder is 15 to 55 vol%, the aspect ratio of the soft magnetic iron-based alloy powder in the cross section of the soft magnetic composite is 30 to 60, the viscosity of the soft magnetic composite is 1000 to 40000 Pa·s, and the permeability at 100 MHz is 13 to 200.

[0014] The soft magnetic composite of the present application is a molding material obtained by compounding a flat soft magnetic iron-based alloy powder and a resin, and by containing 15 to 55 vol% of the soft magnetic iron-based alloy powder, high permeability can be obtained. In addition, the soft magnetic composite of the present application has an aspect ratio of the soft magnetic iron-based alloy powder in the cross section of the soft magnetic composite of 30 to 60, and thus the filling rate of the soft magnetic iron-based alloy powder can be increased. In addition, the soft magnetic composite of the present application has a viscosity of 1000 to 40000 Pa·s, and has excellent moldability. Therefore, when the soft magnetic composite of the present application is molded, the soft magnetic iron-based alloy powder is easily oriented in a certain direction, and thus the permeability can be increased. Furthermore, the soft magnetic composite of the present application has a permeability at 100 MHz of 13 to 200, and thus when the soft magnetic composite is molded as a cable covering material or the like, a high shielding effect can be exhibited in a high frequency band.

[0015] In the soft magnetic composite of the present application, the soft magnetic iron-based alloy powder can use an Fe-Al alloy, an Fe-Si alloy, an Fe-Si-Al alloy, an Fe-Ni alloy, an Fe-Co alloy, an Fe-Cr alloy, an Fe-Si-Cr alloy, or the like, and is preferably an FeSiAl alloy or an FeSiCr alloy.

[0016] Thus, since the FeSiAl alloy or the FeSiCr alloy having high permeability is contained, the permeability in a high frequency band can be increased.

[0017] - Effects of the invention -

[0018] According to the soft magnetic composite of the present application, high permeability can be obtained in a high frequency band. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a scanning electron microscope (SEM) observation photograph of the flat FeSiAl powder A used in Examples 1 to 4 and Comparative Examples 1 to 3.

[0020] Figure 2 is a scanning electron microscope (SEM) observation photograph of the flat FeSiAl powder B used in Example 5.

[0021] Figure 3 is a scanning electron microscope (SEM) observation photograph of the flat FeSiAl powder C used in Comparative Example 4.

[0022] Figure 4 is a scanning electron microscope (SEM) observation photograph of the flat FeSiAl powder D used in Comparative Example 5.

[0023] Figure 5 is a scanning electron microscope (SEM) observation photograph of the Mn-Zn ferrite used in Comparative Examples 6 and 7.

[0024] Figure 6 is a scanning electron microscope (SEM) observation photograph of a cross section of a test piece made of the soft magnetic composite of Example 1.

[0025] Figure 7 is a graph showing the shielding effect of a cable coated with the soft magnetic composite of Example 1 and Comparative Example 6. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments according to the present application will be described. The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the present application, the application for which this application is made, or the uses of the present application.

[0027] An embodiment of the present application relates to a soft magnetic composite which is a molding material obtained by mixing and compounding a flat soft magnetic iron-based alloy powder and a resin. Since the soft magnetic iron-based alloy powder is flat, as described above, the demagnetization factor is reduced and the permeability in the in-plane direction is improved, so that a soft magnetic composite having high permeability can be obtained. Here, as the resin, there is no particular limitation as long as it is a resin which can be extrusion or injection molded. As the resin for extrusion molding, for example, PVC, SEBS, polyolefin, EEA, etc. can be listed. As the resin for injection molding, for example, polyamide, polyphenylene sulfide, polyolefin, etc. can be listed.

[0028] The soft magnetic composite according to the present embodiment contains the soft magnetic iron-based alloy powder described above at a content of 15 to 55 vol%. If the content of the soft magnetic iron-based alloy powder described above is less than 15 vol%, the content of the soft magnetic iron-based alloy powder is low, and thus the desired magnetic permeability cannot be obtained. On the other hand, if the content is more than 55 vol%, the content of the soft magnetic iron-based alloy powder is too high, and thus the fluidity of the molten soft magnetic composite at the time of molding is reduced, and molding defects are easily generated. The content of the soft magnetic iron-based alloy powder described above is preferably 15 to 50 vol%, and more preferably 15 to 40 vol%. The soft magnetic iron-based alloy powder used in the present embodiment is not particularly limited as long as it is a flat powder.

[0029] The soft magnetic composite according to the present embodiment has an aspect ratio of the soft magnetic iron-based alloy powder in the cross section of the soft magnetic composite of 30 to 60. Note that the aspect ratio referred to here is a value obtained by dividing the length of the long axis of the soft magnetic iron-based alloy powder in the soft magnetic composite by the length of the short axis. If the aspect ratio described above is less than 30, it is difficult to fill the soft magnetic iron-based alloy powder into the resin, and thus it is difficult to increase the content in the soft magnetic composite, and as a result, the magnetic permeability is reduced. On the other hand, in the case where the aspect ratio is high, the soft magnetic iron-based alloy powder is easily filled into the resin, and the increase in viscosity is also small, and thus it is advantageous, but if the aspect ratio is more than 60, adverse situations are easily generated at the time of molding due to steric hindrance within the soft magnetic composite. The aspect ratio described above is preferably 35 to 55, and more preferably 40 to 50.

[0030] The soft magnetic composite according to the present embodiment has a viscosity of 1000 to 40000 Pa s. If the viscosity is less than 1000 Pa s, the solidification is delayed, and adverse situations such as easy deformation are generated at the time of molding. On the other hand, if the viscosity is more than 40000 Pa s, it is difficult to perform industrial production. The viscosity is preferably 1500 to 35000 Pa s, and more preferably 1500 to 20000 Pa s.

[0031] The soft magnetic composite according to the present embodiment has a magnetic permeability of 13 to 200 at 100 MHz. If the magnetic permeability is within the range described above, in the case where the soft magnetic composite according to the present embodiment is molded into a cable covering material or the like, a high shielding effect can be exhibited in the high frequency band.

[0032] In addition, the soft magnetic composite according to the present embodiment has a magnetic permeability of preferably 5 to 30 at 1 GHz. If the magnetic permeability is within the range described above, in the case where the soft magnetic composite according to the present embodiment is molded into a cable covering material or the like, a high shielding effect can be exhibited in the high frequency band.

[0033] The soft magnetic iron-based alloy powder described above can use Fe-Al alloy, Fe-Si alloy, Fe-Si-Al alloy, Fe-Ni alloy, Fe-Co alloy, Fe-Cr alloy, Fe-Si-Cr alloy, or the like, and is preferably FeSiAl alloy or FeSiCr alloy. In the past, it has been known that FeSiAl alloy and FeSiCr alloy exhibit high magnetic permeability. Therefore, by compounding FeSiAl alloy or FeSiCr alloy with a resin, the magnetic permeability of the soft magnetic composite according to the present embodiment can be improved.

[0034] In the soft magnetic composite according to the present embodiment, various additives such as a plasticizer, a stabilizer, a lubricant, or the like can be appropriately added as needed. Here, the plasticizer is not particularly limited, and examples thereof include phthalic acid-based, adipic acid-based, phosphoric acid-based, trimellitic acid-based, and the like. The stabilizer is not particularly limited, and examples thereof include metal soap-based, organic tin-based stabilizers, lead-based stabilizers, and the like. The lubricant is not particularly limited, and examples thereof include hydrocarbons, fatty acid-based, higher alcohol-based, fatty acid amide-based, metal soap-based, ester-based, and the like.

[0035] The method for producing the soft magnetic composite according to the present embodiment is not particularly limited, and various publicly known methods can be employed. For example, a method in which a raw material is dispersed with a universal mixer and then melt-kneaded with a twin-screw extruder, or the like, can be mentioned.

[0036] The flat soft magnetic iron-based alloy powder contained in the soft magnetic composite according to the present embodiment is thin and easily broken, and thus can be broken during the production of the soft magnetic composite. The soft magnetic composite according to the present embodiment can obtain good magnetic permeability while maintaining formability by making the viscosity and the aspect ratio of the soft magnetic iron-based alloy powder broken by kneading within a prescribed range.

[0037] [Examples]

[0038] Hereinafter, examples to which the present application is applied and comparative examples thereof will be described. The present examples are examples of the present application, and do not limit the scope of the application.

[0039] Example 1

[0040] To Figure 10.5 parts by weight of titanate coupling agent (PLENACT TTS, manufactured by Ajinomoto Fine-Techno Co., Inc.) was added to flat FeSiAl powder A (YH-200 manufactured by Yahao MATERIALS & TECHNOLOGY Co., Ltd., with a median diameter D50 of 62 μm on a volume basis). The mixture was stirred for surface treatment. Then, PVC resin (TH-1300, manufactured by TAIYO VINYL CORP) with a degree of polymerization of approximately 1300 and stabilizer (RUP-14, manufactured by ADEKA CORPORATION) were added according to the proportions in Table 1 below. The mixture was stirred using an FM mixer (manufactured by NIPPON COKE & ENGINEERING CO., LTD.) while the temperature was raised to 100°C. Finally, plasticizer (S-10, manufactured by ITOH OIL CHEMICALS CO., LTD.) was added according to the proportions in Table 1 below, and the mixture was stirred. Then, the soft magnetic composite of Example 1 was prepared by mixing at 140-160°C using a biaxial extrusion mixer (JAPAN STEEL WORKS, LTD. TEX-30) and extruding it as a strand, followed by cold cutting.

[0041] Example 2

[0042] Towards Figure 1 0.5 parts by weight of titanate coupling agent (PLENACTTTS, manufactured by Ajinomoto Fine-Techno Co., Inc.) was added to flat FeSiAl powder A (YH-200, manufactured by Yahao MATERIALS & TECHNOLOGY Co., Ltd., with a median diameter D50 of 62 μm on a volume basis). The mixture was stirred for surface treatment. Then, PVC resin (TH-1000, manufactured by TAIYO VINYL CORP) with a degree of polymerization of approximately 1000 and stabilizer (RUP-14, manufactured by ADEKA CORPORATION) were added according to the proportions in Table 1 below. The mixture was stirred using an FM mixer (manufactured by NIPPON COKE & ENGINEERING CO., LTD.) while the temperature was raised to 100°C. Finally, plasticizer (S-10, manufactured by ITOH OIL CHEMICALS CO., LTD.) was added according to the proportions in Table 1 below, and the mixture was stirred. Then, the soft magnetic composite of Example 2 was prepared by mixing at 150-170°C using a biaxial extrusion mixer (JAPAN STEEL WORKS, LTD. TEX-30) and extruding it as a tow, followed by cold cutting.

[0043] Example 3

[0044] TowardsFigure 1 0.5 parts by weight of a titanate coupling agent (PLENACTTTS, manufactured by Ajinomoto Fine-Techno Co., Inc.) was added to flat FeSiAl powder A (YH-200 manufactured by Yahao MATERIALS & TECHNOLOGY Co., Ltd., with a median diameter D50 of 62 μm on a volume basis). The mixture was stirred for surface treatment. PP resin (Welnex, manufactured by JAPAN POLYPROPYLENECORPORATION) and additives (DIACARNA30M, manufactured by Mitsubishi Chemical Corporation) were then mixed in the proportions shown in Table 1 using an FM mixer (NIPPON COKE & ENGINEERING CO., LTD.). The mixture was then compounded at 160–180 °C using a biaxial extrusion mixer (TEX-30, manufactured by JAPAN STEEL WORKS, LTD.), extruded as a tow, and cold-cut to produce the soft magnetic composite of Example 3.

[0045] Example 4

[0046] Towards Figure 1 0.5 parts by weight of silane coupling agent (Dynasylan AMEO, Evonik Industries) were added to flat FeSiAl powder A (YH-200, manufactured by Yahao MATERIALS & TECHNOLOGY Co., Ltd., with a median diameter D50 of 62 μm on a volume basis). The mixture was stirred and surface-treated. Polyamide 12 (ZZ-3000, manufactured by Daicel-Evonik Ltd.), additives (stabilizer (MD1024, manufactured by BASF JAPAN LTD.), and lubricant (WX-1, manufactured by Kawaken Fine Chemicals Co., Ltd.)) were mixed in the proportions shown in Table 1 using an FM mixer (manufactured by NIPPON COKE & ENGINEERING CO.,LTD.). Then, the mixture was compounded at 190–210 °C using a biaxial extrusion mixer (TEX-30, manufactured by JAPAN STEEL WORKS, LTD.), extruded as a tow, and cold-cut to produce the soft magnetic composite of Example 4.

[0047] Example 5

[0048] right Figure 2The flat FeSiAl powder B (average plate surface diameter is about 1.4 times that of the flat FeSiAl powder A) was surface-treated, and was put into a PVC resin (TH-1300 manufactured by TAIYO VINYL CORP.) having a polymerization degree of about 1300 and a stabilizer (RUP-14 manufactured by ADEKA CORPORATION) in the compounding amounts shown in Table 1 below, while stirring with an FM mixer (manufactured by NIPPON COKE & ENGINEERING CO., LTD.) and raising the temperature to 100°C. Then, a plasticizer (S-10 manufactured by ITOH OIL CHEMICALS CO., LTD.) was put in and mixed in the compounding amounts shown in Table 1 below. Then, a biaxial extrusion kneader (TEX-30 manufactured by JAPAN STEELWORKS, LTD.) was used to knead at 140 to 160°C, to extrude as a filament, to cold cut, and to produce the soft magnetic composite of Example 5.

[0049] Comparative Examples 1 and 2

[0050] The compounding amounts of the flat FeSiAl powder A, the PVC resin, the stabilizer, and the plasticizer were changed variously, and otherwise the same as in Example 1 above, to produce the soft magnetic composites of Comparative Examples 1 and 2.

[0051] Comparative Example 3

[0052] The compounding amounts of the flat FeSiAl powder A, the PVC resin, the stabilizer, and the plasticizer were changed variously, and otherwise the same as in Example 2 above, to produce the soft magnetic composite of Comparative Example 3.

[0053] Comparative Examples 4 and 5

[0054] The compounding amounts of the flat FeSiAl powder A, the PVC resin, the stabilizer, and the plasticizer were changed variously, and otherwise the same as in Example 2 above, to produce the soft magnetic composite of Comparative Example 3. Figure 3 , Figure 4The flat FeSiAl powder C (average plate surface diameter is about 0.4 times that of the flat FeSiAl powder A), D (average plate surface diameter is about 0.85 times that of the flat FeSiAl powder A) were surface-treated, and were put into a PVC resin (TH-1300 manufactured by TAIYO VINYL CORP.) having a polymerization degree of about 1300 and a stabilizer (RUP-14 manufactured by ADEKA CORPORATION) in the compounding amounts shown in Table 1 below, while stirring with an FM mixer (manufactured by NIPPON COKE & ENGINEERING CO., LTD.) and raising the temperature to 100°C. Then, a plasticizer (S-10 manufactured by ITOH OIL CHEMICALS CO., LTD.) was put in and mixed in the compounding amounts shown in Table 1 below. Then, a biaxial extrusion kneader (TEX-30 manufactured by JAPAN STEEL WORKS, LTD.) was used to knead at 140 to 160°C, to extrude as a filament, and to cut to produce the soft magnetic composites of Comparative Examples 4 and 5.

[0055] Comparative Examples 6 and 7

[0056] To Figure 5 Mn-Zn ferrite (BSF-547 manufactured by TODA KOGYO CORP.) was surface-treated, and was put into a PVC resin (TH-1300 manufactured by TAIYO VINYL CORP.) having a polymerization degree of about 1300 and a stabilizer (RUP-14 manufactured by ADEKA CORPORATION) in the compounding amounts shown in Table 1 below, while stirring with an FM mixer (manufactured by NIPPON COKE & ENGINEERING CO., LTD.) and raising the temperature to 100°C. Then, a plasticizer (S-10 manufactured by ITOH OIL CHEMICALS CO., LTD.) was put in and mixed in the compounding amounts shown in Table 1 below. Then, a biaxial extrusion kneader (TEX-30 manufactured by JAPAN STEEL WORKS, LTD.) was used to knead at 140 to 160°C, to extrude as a filament, and to cut to produce the soft magnetic composites of Comparative Examples 6 and 7.

[0057] [Table 1]

[0058]

[0059] <Aspect ratio measurement>

[0060] The soft magnetic composites of each of the examples and comparative examples were melted using a desktop mold to produce a test piece having a diameter of 25 mm and a height of about 10 mm. A cutting machine and a grinder were used to cut a fracture surface, and a scanning electron microscope S-4800 manufactured by Hitachi High-Tech Corporation was used to observe the cross section at a magnification of 500 times. Specifically, a plurality of images were captured at an observation magnification of 500 times, the major axis length and the minor axis length of about 300 test bodies were measured from the plurality of images, the aspect ratio was calculated by dividing the major axis length by the minor axis length, and the average value was found.

[0061] <Viscosity Measurement>

[0062] A rheometer CFT-500 manufactured by SHIMADZU CORPORATION was used to measure the viscosity at a mold of 1 mm Φ x 10 mm t and a load of 30 kgf at a temperature increase rate of 5°C / min from 120°C. Note that the measurement temperature of the viscosity (Pa s) was appropriately adjusted according to the resin used. Specifically, in the case of the soft magnetic composite using a crystalline resin, the measurement value at a melting point + 5 to 10°C was used as the viscosity (Pa s), that is, the soft magnetic composite of Example 3 using PP used the measurement value at 180°C as the viscosity (Pa s), and the soft magnetic composite of Example 4 using PA12 used the measurement value at 190°C as the viscosity (Pa s). The soft magnetic composites of Examples 1 to 2, 5 and Comparative Examples 1 to 7 using the non-crystalline resin PVC used the measurement value at 180°C as the viscosity (Pa s).

[0063] <Magnetic Permeability Measurement>

[0064] The soft magnetic composites of each of the examples and comparative examples were melted using a desktop mold to produce a ring having an outer diameter of 20 mm, an inner diameter of 8 mm, and a height of about 6 mm. An impedance analyzer E4991A manufactured by Agilent Technologies Inc. was used to measure the magnetic permeability at 1 MHz to 1 GHz. The square root of the sum of the squares of the real part and the imaginary part of the complex magnetic permeability at 100 MHz and 1 GHz was used as the magnetic permeability.

[0065] Various properties of the soft magnetic composites of each of the examples and comparative examples are shown in Table 2.

[0066] [Table 2]

[0067]

[0068] As shown in Table 2, in the various embodiments containing 15-55 vol% soft magnetic iron-based alloy powder, the aspect ratio of the soft magnetic iron-based alloy powder in the soft magnetic composite was confirmed to be 30-60, the viscosity to be 1000-40000 Pa·s, and the permeability to be 13-200 at 100 MHz. On the other hand, in each comparative example, at least one of the aspect ratio, viscosity, and permeability was outside the aforementioned range. Therefore, the soft magnetic composites of each embodiment can achieve high permeability at high frequencies, and are thus suitable for applications such as cable sheathing materials.

[0069] <Shielding effect>

[0070] The soft magnetic composites of Example 1 and Comparative Example 6 were used in a 32mm extruder coating apparatus manufactured by OHMIYA SEIKI Co., Ltd. to fabricate composite-coated cables at a melt temperature of 160-170°C, a stretching speed of 10 m / min, and a sheath thickness (coating thickness) of 0.5 mm. A 1m section of the fabricated cable was mounted on a Rosenberger Co., Ltd. Tube-in apparatus CoMeT40, and the shielding effect was measured using an Agilent Technologies Inc. N5230 network analyzer from 100 MHz to 5000 MHz (5 GHz). The results are shown below. Figure 7 middle.

[0071] like Figure 7 As shown, the soft magnetic composite of Example 1 exhibits a higher shielding effect than the soft magnetic composite of Comparative Example 6. On the other hand, as shown in Table 2, the permeability of the soft magnetic composites of Comparative Examples 1, 2, 4, and 7 is lower than that of the soft magnetic composite of Example 1. Therefore, it is believed that even if the soft magnetic composites of Comparative Examples 1, 2, 4, and 7 are used, the shielding effect of Example 1 cannot be expected. Furthermore, as shown in Table 2, the soft magnetic composites of Comparative Examples 3, 5, and 6 have high viscosity, making cable coating difficult.

[0072] In summary, the soft magnetic composite material described in this invention can achieve high permeability in the high-frequency band, which is very useful.

Claims

1. A soft magnetic composite, which is a soft magnetic composite containing a flat soft magnetic iron-based alloy powder and a resin, wherein the content of the soft magnetic iron-based alloy powder is 15 to 55 vol%, the content of the soft magnetic iron-based alloy powder is 15 to 55 vol%, the aspect ratio of the soft magnetic iron-based alloy powder in a cross section of the soft magnetic composite is 30 to 60, the viscosity of the soft magnetic composite is 1000 to 40000 Pa-s, the permeability of the soft magnetic composite at 100 MHz is 13 to 200.

2. The soft magnetic composite according to claim 1, wherein the soft magnetic iron-based alloy powder is a FeSiAl alloy or a FeSiCr alloy. ​

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