JP7426742B2 - Soft magnetic nanowires, paints containing them, and laminates coated with the same - Google Patents
Soft magnetic nanowires, paints containing them, and laminates coated with the same Download PDFInfo
- Publication number
- JP7426742B2 JP7426742B2 JP2022132877A JP2022132877A JP7426742B2 JP 7426742 B2 JP7426742 B2 JP 7426742B2 JP 2022132877 A JP2022132877 A JP 2022132877A JP 2022132877 A JP2022132877 A JP 2022132877A JP 7426742 B2 JP7426742 B2 JP 7426742B2
- Authority
- JP
- Japan
- Prior art keywords
- soft magnetic
- nanowire
- mass
- iron
- boron
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000002070 nanowire Substances 0.000 title claims description 157
- 239000003973 paint Substances 0.000 title claims description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 137
- 229910052742 iron Inorganic materials 0.000 claims description 79
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 55
- 229910052796 boron Inorganic materials 0.000 claims description 52
- 238000000034 method Methods 0.000 claims description 38
- 230000005415 magnetization Effects 0.000 claims description 35
- 230000035699 permeability Effects 0.000 claims description 32
- 239000000463 material Substances 0.000 claims description 30
- 238000006243 chemical reaction Methods 0.000 claims description 22
- -1 iron ions Chemical class 0.000 claims description 21
- 239000003638 chemical reducing agent Substances 0.000 claims description 20
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 16
- 238000000576 coating method Methods 0.000 claims description 16
- 239000001301 oxygen Substances 0.000 claims description 16
- 229910052760 oxygen Inorganic materials 0.000 claims description 16
- 238000006722 reduction reaction Methods 0.000 claims description 16
- 239000011248 coating agent Substances 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000007810 chemical reaction solvent Substances 0.000 claims description 6
- 239000002994 raw material Substances 0.000 claims description 4
- 239000007791 liquid phase Substances 0.000 claims description 3
- 239000000243 solution Substances 0.000 description 41
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 21
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 15
- 239000000696 magnetic material Substances 0.000 description 15
- 229910052759 nickel Inorganic materials 0.000 description 14
- 229910017052 cobalt Inorganic materials 0.000 description 13
- 239000010941 cobalt Substances 0.000 description 13
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 13
- 229910052710 silicon Inorganic materials 0.000 description 11
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 10
- 239000007864 aqueous solution Substances 0.000 description 10
- 230000005587 bubbling Effects 0.000 description 10
- 239000010703 silicon Substances 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 238000002354 inductively-coupled plasma atomic emission spectroscopy Methods 0.000 description 8
- 239000012279 sodium borohydride Substances 0.000 description 8
- 229910000033 sodium borohydride Inorganic materials 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 238000011156 evaluation Methods 0.000 description 7
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 6
- 239000006096 absorbing agent Substances 0.000 description 6
- 238000011088 calibration curve Methods 0.000 description 6
- 238000001914 filtration Methods 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000011368 organic material Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 239000004810 polytetrafluoroethylene Substances 0.000 description 5
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 5
- 239000011162 core material Substances 0.000 description 4
- 229910001873 dinitrogen Inorganic materials 0.000 description 4
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine hydrate Chemical compound O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 150000002505 iron Chemical class 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000005060 rubber Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 230000000007 visual effect Effects 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 2
- 229940123973 Oxygen scavenger Drugs 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 239000012086 standard solution Substances 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- 229920005992 thermoplastic resin Polymers 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004962 Polyamide-imide Substances 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 238000007754 air knife coating Methods 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- RJTANRZEWTUVMA-UHFFFAOYSA-N boron;n-methylmethanamine Chemical compound [B].CNC RJTANRZEWTUVMA-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000007766 curtain coating Methods 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000007607 die coating method Methods 0.000 description 1
- 238000003618 dip coating Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- FBAFATDZDUQKNH-UHFFFAOYSA-M iron chloride Chemical compound [Cl-].[Fe] FBAFATDZDUQKNH-UHFFFAOYSA-M 0.000 description 1
- 159000000014 iron salts Chemical class 0.000 description 1
- 229910000358 iron sulfate Inorganic materials 0.000 description 1
- NQXWGWZJXJUMQB-UHFFFAOYSA-K iron trichloride hexahydrate Chemical compound O.O.O.O.O.O.[Cl-].Cl[Fe+]Cl NQXWGWZJXJUMQB-UHFFFAOYSA-K 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- MVFCKEFYUDZOCX-UHFFFAOYSA-N iron(2+);dinitrate Chemical compound [Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MVFCKEFYUDZOCX-UHFFFAOYSA-N 0.000 description 1
- PVFSDGKDKFSOTB-UHFFFAOYSA-K iron(3+);triacetate Chemical compound [Fe+3].CC([O-])=O.CC([O-])=O.CC([O-])=O PVFSDGKDKFSOTB-UHFFFAOYSA-K 0.000 description 1
- 229920003049 isoprene rubber Polymers 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 238000007644 letterpress printing Methods 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000005325 percolation Methods 0.000 description 1
- 229920003055 poly(ester-imide) Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920002312 polyamide-imide Polymers 0.000 description 1
- 229920006149 polyester-amide block copolymer Polymers 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 238000007763 reverse roll coating Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000004626 scanning electron microscopy Methods 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229920002725 thermoplastic elastomer Polymers 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
Landscapes
- Soft Magnetic Materials (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
- Powder Metallurgy (AREA)
- Hard Magnetic Materials (AREA)
Description
本発明は、軟磁性ナノワイヤーおよびそれを含む塗料ならびにそれを塗布してなる積層体に関するものである。 The present invention relates to soft magnetic nanowires, paints containing the same, and laminates coated with the same.
軟磁性材料は、モーターのコア、電磁弁、各種センサー、磁界シールドや電磁波吸収材等のさまざまな用途で広く用いられている。一般的に、各用途において良好な性能を得るには、軟磁性材料は、高い透磁率、高い飽和磁化、低い保磁力を有することが好ましい。これらの特性値が良好であるほど、各用途で優れた性能を発揮する。 Soft magnetic materials are widely used in a variety of applications, including motor cores, solenoid valves, various sensors, magnetic field shields, and electromagnetic wave absorbers. Generally, for good performance in each application, it is preferred that soft magnetic materials have high magnetic permeability, high saturation magnetization, and low coercive force. The better these characteristic values, the better the performance in each application.
特に鉄は飽和磁化が高い軟磁性材料であり、センサー、コア材、磁界シールド等に応用されている。さらに、鉄材料の中でも異方性が高い材料は、低い反磁界とパーコレーション閾値を有することから、軟磁性材料として期待されている。 In particular, iron is a soft magnetic material with high saturation magnetization, and is applied to sensors, core materials, magnetic field shields, etc. Furthermore, among iron materials, materials with high anisotropy have low demagnetizing fields and percolation thresholds, so they are expected to be used as soft magnetic materials.
軟磁性材料は異方性を付与することにより、反磁界が抑制でき、透磁率が高くなる。そのため、特許文献１や非特許文献１等の軟磁性のナノワイヤーは軟磁性の粒子と比較し、透磁率が優れた材料になることが知られている。 By imparting anisotropy to soft magnetic materials, demagnetizing fields can be suppressed and magnetic permeability increases. Therefore, it is known that soft magnetic nanowires such as those disclosed in Patent Document 1 and Non-Patent Document 1 are materials with superior magnetic permeability compared to soft magnetic particles.
異方性を有する軟磁性材料としては、例えば、非特許文献２および３に鉄とホウ素を含むナノワイヤーが開示されている。 As a soft magnetic material having anisotropy, nanowires containing iron and boron are disclosed in Non-Patent Documents 2 and 3, for example.
しかしながら、特許文献１のナノワイヤーは十分な保磁力を有していなかった。非特許文献１～３のナノワイヤーは長さが比較的短く異方性に乏しいため、軟磁性材料としての性能、特に比透磁率が不十分であった。 However, the nanowire of Patent Document 1 did not have sufficient coercive force. Since the nanowires of Non-Patent Documents 1 to 3 have relatively short lengths and poor anisotropy, their performance as soft magnetic materials, particularly their relative magnetic permeability, was insufficient.
本発明は、飽和磁化と比透磁率がより十分に高く、かつ保磁力がより十分に低い軟磁性ナノワイヤーを提供することを目的とするものである。 An object of the present invention is to provide a soft magnetic nanowire having sufficiently high saturation magnetization and relative permeability, and sufficiently low coercive force.
本発明はまた、鉄の純度が高く、平均長が長い軟磁性ナノワイヤーを提供することを目的とする。 Another object of the present invention is to provide soft magnetic nanowires with high iron purity and long average length.
本発明者らは、鋭意検討の結果、鉄塩を含む溶液を、ホウ素を含む還元剤を用いて還元する方法において、鉄塩／還元剤のモル比を特定比とすることにより、上記目的が達成されることを見出し、本発明に到達した。 As a result of extensive studies, the present inventors have found that the above objective can be achieved by setting the molar ratio of iron salt/reducing agent to a specific ratio in a method of reducing a solution containing an iron salt using a reducing agent containing boron. The inventors have discovered that this can be achieved, and have arrived at the present invention.
すなわち、本発明の要旨は、以下の通りである。
＜１＞ 鉄とホウ素を含有する軟磁性ナノワイヤーであって、
平均長が５μｍ以上であり、かつＳＥＭ－ＥＤＳ法により測定した該ナノワイヤー中の鉄／ホウ素のモル比が５未満である、軟磁性ナノワイヤー。
＜２＞ 前記ナノワイヤー中の鉄の含有量が７０質量％以上であり、
前記ナノワイヤー中のホウ素の含有量が３．５質量％以上であり、
前記ナノワイヤー中の鉄とホウ素以外の元素の含有量が２５質量％以下である、＜１＞に記載の軟磁性ナノワイヤー。
＜３＞ 前記ナノワイヤー中の鉄の含有量が８５質量％以上である、＜１＞または＜２＞に記載の軟磁性ナノワイヤー。
＜４＞ 前記ナノワイヤー中のホウ素の含有量が３．５質量％以上であり、
前記ナノワイヤー中の鉄とホウ素以外の元素の含有量が１５質量％以下である、＜３＞に記載の軟磁性ナノワイヤー。
＜５＞ 前記ナノワイヤー中の鉄の含有量が８９質量％以上であり、
前記ナノワイヤー中のホウ素の含有量が４質量％以上である、＜１＞または＜２＞に記載の軟磁性ナノワイヤー。
＜６＞ 前記ナノワイヤー中の鉄とホウ素以外の元素の含有量が８質量％以下である、＜５＞に記載の軟磁性ナノワイヤー。
＜７＞ 振動試料型磁力計を用いて測定した飽和磁化を鉄の純度で除算した値が１５０ｅｍｕ／ｇ以上である、＜１＞～＜６＞のいずれかに記載の軟磁性ナノワイヤー。
＜８＞ 振動試料型磁力計を用いて測定した飽和磁化が４０ｅｍｕ／ｇ以上である、＜１＞～＜７＞のいずれかに記載の軟磁性ナノワイヤー。
＜９＞ 振動試料型磁力計を用いて測定した保磁力が５００Ｏｅ未満である、＜１＞～＜８＞のいずれかに記載の軟磁性ナノワイヤー。
＜１０＞ 振動試料型磁力計を用いて測定した比透磁率が５以上である＜１＞～＜９＞のいずれかに記載の軟磁性ナノワイヤー。
＜１１＞ ＜１＞～＜１０＞のいずれかに記載の軟磁性ナノワイヤーを製造する方法であって、
反応開始前の溶存酸素量が０．５～４．０ｍｇ／Ｌである反応溶媒中において、鉄イオンを原料とし、ホウ素原子を含んだ還元剤を用いて、磁場中で液相還元反応をおこなう、軟磁性ナノワイヤーの製造方法。
＜１２＞ ＜１＞～＜１０＞のいずれかに記載の軟磁性ナノワイヤーを含む塗料。
＜１３＞ ＜１２＞に記載の塗料を基材上に塗布してなる塗膜を有する積層体。
＜１４＞ ＜１＞～＜１０＞のいずれかに記載の軟磁性ナノワイヤーを含む成形体。
＜１５＞ ＜１＞～＜１０＞のいずれかに記載の軟磁性ナノワイヤーを含むシート。
＜１６＞ ＜１＞～＜１０＞のいずれかに記載の軟磁性ナノワイヤーを含む電磁波遮蔽材料。
That is, the gist of the present invention is as follows.
<1> A soft magnetic nanowire containing iron and boron,
Soft magnetic nanowires having an average length of 5 μm or more and having an iron/boron molar ratio of less than 5 as measured by SEM-EDS method.
<2> The iron content in the nanowire is 70% by mass or more,
The boron content in the nanowire is 3.5% by mass or more,
The soft magnetic nanowire according to <1>, wherein the content of elements other than iron and boron in the nanowire is 25% by mass or less.
<3> The soft magnetic nanowire according to <1> or <2>, wherein the iron content in the nanowire is 85% by mass or more.
<4> The boron content in the nanowire is 3.5% by mass or more,
The soft magnetic nanowire according to <3>, wherein the content of elements other than iron and boron in the nanowire is 15% by mass or less.
<5> The iron content in the nanowire is 89% by mass or more,
The soft magnetic nanowire according to <1> or <2>, wherein the boron content in the nanowire is 4% by mass or more.
<6> The soft magnetic nanowire according to <5>, wherein the content of elements other than iron and boron in the nanowire is 8% by mass or less.
<7> The soft magnetic nanowire according to any one of <1> to <6>, wherein the value obtained by dividing the saturation magnetization measured using a vibrating sample magnetometer by the purity of iron is 150 emu/g or more.
<8> The soft magnetic nanowire according to any one of <1> to <7>, which has a saturation magnetization of 40 emu/g or more as measured using a vibrating sample magnetometer.
<9> The soft magnetic nanowire according to any one of <1> to <8>, which has a coercive force of less than 500 Oe as measured using a vibrating sample magnetometer.
<10> The soft magnetic nanowire according to any one of <1> to <9>, which has a relative magnetic permeability of 5 or more as measured using a vibrating sample magnetometer.
<11> A method for producing the soft magnetic nanowire according to any one of <1> to <10>, comprising:
In a reaction solvent with a dissolved oxygen content of 0.5 to 4.0 mg/L before the start of the reaction, a liquid phase reduction reaction is carried out in a magnetic field using iron ions as raw materials and a reducing agent containing boron atoms. , a method for producing soft magnetic nanowires.
<12> A paint containing the soft magnetic nanowire according to any one of <1> to <10>.
<13> A laminate having a coating film formed by applying the paint according to <12> onto a base material.
<14> A molded article containing the soft magnetic nanowire according to any one of <1> to <10>.
<15> A sheet containing the soft magnetic nanowires according to any one of <1> to <10>.
<16> An electromagnetic wave shielding material comprising the soft magnetic nanowire according to any one of <1> to <10>.
本発明によれば、飽和磁化と比透磁率がより十分に高く、保磁力がより十分に低い軟磁性ナノワイヤーを提供することができる。 According to the present invention, it is possible to provide soft magnetic nanowires with sufficiently high saturation magnetization and relative magnetic permeability, and sufficiently low coercive force.
［軟磁性ナノワイヤー］
本発明の軟磁性ナノワイヤーは、鉄とホウ素を含む。
[Soft magnetic nanowire]
The soft magnetic nanowire of the present invention contains iron and boron.
本発明の軟磁性ナノワイヤー中の鉄／ホウ素のモル比は、５未満とする必要があり、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、好ましくは４未満、より好ましくは３未満である。当該モル比が５以上である場合、飽和磁化および比透磁率が低下する。当該モル比は通常、０．１以上、特に１以上である。 The iron/boron molar ratio in the soft magnetic nanowires of the present invention must be less than 5, preferably less than 4, and more preferably from the viewpoint of further increasing the saturation magnetization and relative permeability and further reducing the coercive force. Preferably it is less than 3. When the molar ratio is 5 or more, saturation magnetization and relative permeability decrease. The molar ratio is usually 0.1 or more, especially 1 or more.
本明細書中、鉄／ホウ素のモル比は、走査型電子顕微鏡（ＳＥＭ）－ＥＤＳ法により測定された値を用いている。詳しくは、当該モル比は、ＳＥＭによる任意の１０視野において、ＥＤＳ法により各元素の構成比率を測定することにより、算出された平均値を用いている。 In this specification, the iron/boron molar ratio uses a value measured by a scanning electron microscope (SEM)-EDS method. Specifically, the molar ratio is an average value calculated by measuring the composition ratio of each element using the EDS method in ten arbitrary SEM visual fields.
本発明の軟磁性ナノワイヤー中の鉄の含有量は、特に限定されず、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、７０質量％以上とすることが好ましく、８５質量％以上とすることがより好ましく、８８質量％以上とすることがさらに好ましく、８９質量％以上とすることが十分に好ましく、９０質量％以上とすることがより十分に好ましく、９３質量％以上とすることが特に好ましく、９５質量％以上とすることが最も好ましい。鉄の含有量は通常、９８質量％以下、特に９５質量％以下である。 The iron content in the soft magnetic nanowires of the present invention is not particularly limited, and from the viewpoint of further increasing saturation magnetization and relative permeability and further reducing coercive force, it is preferably 70% by mass or more, and 85% by mass or more. It is more preferably at least 88% by mass, even more preferably at least 89% by mass, even more preferably at least 90% by mass, and even more preferably at least 93% by mass. It is particularly preferable that the content be 95% by mass or more, and most preferably 95% by mass or more. The iron content is usually less than 98% by weight, in particular less than 95% by weight.
本発明の軟磁性ナノワイヤー中のホウ素の含有量は、特に限定されず、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、３．５質量％以上とすることが好ましく、４質量％以上とすることがより好ましく、４．８５質量％以上とすることが十分に好ましく、５質量％以上とすることがより十分に好ましい。ホウ素の含有量は通常、１５質量％以下、特に８質量％以下である。 The boron content in the soft magnetic nanowires of the present invention is not particularly limited, and is preferably 3.5% by mass or more from the viewpoint of further increasing saturation magnetization and relative permeability and further reducing coercive force. , more preferably 4% by mass or more, sufficiently preferably 4.85% by mass or more, and even more preferably 5% by mass or more. The boron content is usually 15% by weight or less, especially 8% by weight or less.
本来、鉄の含有量が高いほど飽和磁化等の軟磁性材料としての性能が向上するが、鉄は酸化しやすいため、ナノワイヤー中に酸素等を含み純度が低下する。しかしながら、本発明においてはナノワイヤー中にホウ素を含ませることにより、酸化を抑制しながらナノワイヤーを成長させることができ、鉄の純度が高いナノワイヤーを作製することができる。また、ナノワイヤー中にホウ素を含ませることにより、作製後貯蔵する際にも高い純度を維持することができる。ナノワイヤーが鉄を含まない場合、飽和磁化が低くなるので好ましくない。ナノワイヤーがホウ素を含まない場合、所定の平均長を有するナノワイヤーを作製することができない場合がある。 Originally, the higher the iron content, the better the performance as a soft magnetic material such as saturation magnetization, but since iron is easily oxidized, the nanowires contain oxygen and the like, resulting in a decrease in purity. However, in the present invention, by including boron in the nanowires, the nanowires can be grown while suppressing oxidation, and nanowires with high iron purity can be produced. Furthermore, by including boron in the nanowires, high purity can be maintained even when stored after fabrication. If the nanowires do not contain iron, the saturation magnetization will be low, which is not preferable. If the nanowires do not contain boron, it may not be possible to produce nanowires with a predetermined average length.
本明細書中、鉄およびホウ素の各元素の含有量は、ナノワイヤー全量に対する値（質量％）で表されている。当該各元素の含有量は、ナノワイヤーが溶解された溶液を、ＩＣＰ－ＡＥＳ法に基づく多元素同時分析法および検量線法に供することにより測定された値を用いている。 In this specification, the content of each element of iron and boron is expressed as a value (mass%) based on the total amount of nanowires. The content of each element is a value measured by subjecting a solution in which nanowires are dissolved to a multi-element simultaneous analysis method based on the ICP-AES method and a calibration curve method.
本発明の軟磁性ナノワイヤー中の鉄とホウ素以外の元素の含有量は特に限定されず、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、２５質量％以下とすることが好ましく、１５質量％以下とすることがより好ましく、８質量％以下とすることがさらに好ましく、７質量％以下とすることが十分に好ましく、６質量％以下とすることがより十分に好ましく、５質量％以下とすることがさらに十分に好ましく、３質量％以下とすることがもっと十分に好ましく、１質量％未満とすることが特に好ましく、０．１質量％以下とすることが最も好ましい。鉄とホウ素以外の元素の含有量は、検出限界値（例えば０．１質量％）未満であってもよい。 The content of elements other than iron and boron in the soft magnetic nanowires of the present invention is not particularly limited, and should be 25% by mass or less from the viewpoint of further increasing saturation magnetization and relative permeability, and further reducing coercive force. is preferable, more preferably 15% by mass or less, even more preferably 8% by mass or less, sufficiently preferably 7% by mass or less, even more preferably 6% by mass or less, It is even more preferably 5% by mass or less, even more preferably 3% by mass or less, particularly preferably less than 1% by mass, and most preferably 0.1% by mass or less. The content of elements other than iron and boron may be less than the detection limit value (for example, 0.1% by mass).
鉄とホウ素以外の元素とは、本発明の軟磁性ナノワイヤーに含まれる、鉄でもホウ素でもない元素のことである。鉄とホウ素以外の元素の具体例として、例えば、酸素、炭素、ケイ素等が挙げられる。 Elements other than iron and boron refer to elements that are neither iron nor boron and are included in the soft magnetic nanowire of the present invention. Specific examples of elements other than iron and boron include oxygen, carbon, silicon, and the like.
本明細書中、鉄とホウ素以外の元素の含有量は、それらの元素の合計含有量のことであり、ナノワイヤー全量に対する値（質量％）で表されている。当該元素の含有量は、ナノワイヤーが溶解された溶液を、ＩＣＰ－ＡＥＳ法に基づく多元素同時分析法および検量線法に供することにより測定された値を用いている。詳しくは、ＩＣＰ－ＡＥＳ法に基づく検量線法により測定した鉄およびホウ素の含有量を、ナノワイヤー全量から減ずることにより算出された値を用いている。 In this specification, the content of elements other than iron and boron refers to the total content of those elements, and is expressed as a value (mass%) relative to the total amount of nanowires. The content of the element used is a value measured by subjecting a solution in which nanowires are dissolved to a multi-element simultaneous analysis method based on the ICP-AES method and a calibration curve method. Specifically, values calculated by subtracting the iron and boron contents measured by a calibration curve method based on the ICP-AES method from the total amount of nanowires are used.
本発明の軟磁性ナノワイヤーにおいて、例えば、コバルトおよびニッケルそれぞれの含有量は通常、ナノワイヤー全量に対して０．１質量％以下、特に０質量％である。なお、コバルトおよびニッケルそれぞれの含有量が０質量％であるとは、本発明の軟磁性ナノワイヤーがコバルトおよびニッケルを含まないこと、詳しくは当該コバルトおよびニッケルそれぞれの含有量がＩＣＰ－ＡＥＳ法に基づく測定法による検出限界値未満（例えば０．１質量％未満）であることを意味する。 In the soft magnetic nanowire of the present invention, for example, the content of each of cobalt and nickel is usually 0.1% by mass or less, particularly 0% by mass, based on the total amount of the nanowire. Note that the content of cobalt and nickel of 0% by mass means that the soft magnetic nanowire of the present invention does not contain cobalt and nickel, and more specifically, that the content of cobalt and nickel is 0% by mass according to the ICP-AES method. This means that it is less than the detection limit value (for example, less than 0.1% by mass) by the based measurement method.
本発明の軟磁性ナノワイヤー中の鉄、コバルト、ニッケル、ホウ素およびケイ素の合計含有量（以下、「合計含有量Ｘ」ということがある）は、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、当該ナノワイヤー全量に対して、７５質量％以上が好ましく、８０質量％以上であることがより好ましく、８５質量％以上であることがさらに好ましく、９５質量％以上であることが十分に好ましく、９８質量％以上であることがより十分に好ましい。合計含有量Ｘのナノワイヤー全量に対する割合は通常、１００質量％以下である。 The total content of iron, cobalt, nickel, boron, and silicon (hereinafter sometimes referred to as "total content From the viewpoint of further reduction of the nanowires, it is preferably 75% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and 95% by mass or more, based on the total amount of nanowires. It is fully preferred that the content is 98% by mass or more, and even more preferably 98% by mass or more. The ratio of the total content X to the total amount of nanowires is usually 100% by mass or less.
本明細書中、鉄、コバルト、ニッケル、ホウ素およびケイ素の合計含有量（すなわち「合計含有量Ｘ」）のナノワイヤー全量に対する割合（質量％）は、ＩＣＰ－ＡＥＳ法に基づく検量線法により測定された値を用いている。 In this specification, the ratio (mass%) of the total content of iron, cobalt, nickel, boron, and silicon (i.e., "total content X") to the total amount of nanowires is measured by a calibration curve method based on the ICP-AES method. The calculated value is used.
本発明の軟磁性ナノワイヤーの平均長は、５μｍ以上であることが必要で、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、８～４０μｍであることが好ましく、１０～３５μｍであることがより好ましく、１０～３０μｍであることがさらに好ましい。上記のようにホウ素を特定量含ませることにより、平均長が５μｍ以上のナノワイヤーを作製することができる。ナノワイヤーは、長いほど、異方性が高まり反磁界を低減することができる。ナノワイヤーの平均長が５μｍ未満である場合、飽和磁化および比透磁率が低下する。 The average length of the soft magnetic nanowires of the present invention needs to be 5 μm or more, and from the viewpoint of further increasing saturation magnetization and relative permeability and further reducing coercive force, it is preferably 8 to 40 μm, and 10 μm or more. It is more preferably from 10 to 35 μm, and even more preferably from 10 to 30 μm. By including a specific amount of boron as described above, nanowires having an average length of 5 μm or more can be produced. The longer the nanowire is, the higher the anisotropy becomes and the more the demagnetizing field can be reduced. When the average length of the nanowires is less than 5 μm, the saturation magnetization and relative permeability decrease.
本発明の軟磁性ナノワイヤーの平均径は特に限定されないが、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、２０～３００ｎｍであることが好ましく、５０～２００ｎｍであることがより好ましく、５０～１５０ｎｍであることがさらに好ましい。前記平均径は、反応条件により制御することができ、用途に応じて適宜選択することができる。ナノワイヤーは細いほど、アスペクト比が大きくなり、反磁界が低減される。本発明の軟磁性ナノワイヤーのアスペクト比は特に限定されず、例えば、２０～５００であってもよく、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、好ましくは４０～３００、より好ましくは５０～２００である。 The average diameter of the soft magnetic nanowires of the present invention is not particularly limited, but from the viewpoint of further increasing saturation magnetization and relative magnetic permeability and further reducing coercive force, it is preferably 20 to 300 nm, and preferably 50 to 200 nm. is more preferable, and even more preferably 50 to 150 nm. The average diameter can be controlled by reaction conditions and can be appropriately selected depending on the application. The thinner the nanowire, the higher the aspect ratio and the lower the demagnetizing field. The aspect ratio of the soft magnetic nanowires of the present invention is not particularly limited, and may be, for example, 20 to 500, preferably 40 to 500, from the viewpoint of further increasing saturation magnetization and relative permeability, and further reducing coercive force. 300, more preferably 50-200.
本明細書中、ナノワイヤーの平均長および平均径は、走査型電子顕微鏡（ＳＥＭ）による撮影に基づく、任意の１００点での平均値を用いている。 In this specification, the average length and average diameter of nanowires are average values at 100 arbitrary points based on scanning electron microscopy (SEM) photography.
本発明の軟磁性ナノワイヤーの飽和磁化は、４０ｅｍｕ／ｇ以上であることが好ましく、６０ｅｍｕ／ｇ以上であることがより好ましく、７０ｅｍｕ／ｇ以上であることがさらに好ましく、１５０ｅｍｕ／ｇ以上であることが特に好ましい。飽和磁化が４０ｅｍｕ／ｇ未満の場合、軟磁性材料として性能が不足し扱いにくい。当該飽和磁化は通常、３００ｅｍｕ／ｇ以下、特に２００ｅｍｕ／ｇ以下である。 The saturation magnetization of the soft magnetic nanowire of the present invention is preferably 40 emu/g or more, more preferably 60 emu/g or more, even more preferably 70 emu/g or more, and even more preferably 150 emu/g or more. This is particularly preferred. When the saturation magnetization is less than 40 emu/g, the performance as a soft magnetic material is insufficient and it is difficult to handle. The saturation magnetization is usually 300 emu/g or less, particularly 200 emu/g or less.
本発明の軟磁性ナノワイヤーにおいて、飽和磁化を鉄の純度で除算した値は、４０ｅｍｕ／ｇ以上であることが好ましく、６０ｅｍｕ／ｇ以上であることがより好ましく、７０ｅｍｕ／ｇ以上であることがさらに好ましく、１５０ｅｍｕ／ｇ以上であることが特に好ましい。鉄の純度とは、ナノワイヤー中の鉄の含有量に基づく値であり、ナノワイヤーの全質量を「１」としたときの値である。 In the soft magnetic nanowire of the present invention, the value obtained by dividing the saturation magnetization by the purity of iron is preferably 40 emu/g or more, more preferably 60 emu/g or more, and preferably 70 emu/g or more. More preferably, it is particularly preferably 150 emu/g or more. The purity of iron is a value based on the content of iron in the nanowire, and is a value when the total mass of the nanowire is "1".
本発明の軟磁性ナノワイヤーの比透磁率は、５以上であることが好ましく、１０以上であることがより好ましく、４０以上であることがさらに好ましく、１００以上であることが十分に好ましい。比透磁率が５未満の場合、軟磁性材料として性能が不足し扱いにくい。当該比透磁率は通常、３００以下、特に２００以下である。 The relative magnetic permeability of the soft magnetic nanowires of the present invention is preferably 5 or more, more preferably 10 or more, even more preferably 40 or more, and fully preferably 100 or more. When the relative magnetic permeability is less than 5, the performance as a soft magnetic material is insufficient and it is difficult to handle. The relative magnetic permeability is usually 300 or less, particularly 200 or less.
本発明の軟磁性ナノワイヤーの保磁力は、５００Ｏｅ未満であることが好ましく、４００Ｏｅ未満であることがより好ましく、２００Ｏｅ未満であることがさらに好ましい。保磁力が５００Ｏｅ以上の場合、磁界への反応が鈍く、軟磁性材料として扱いにくい。一般に、異方性が高い材料ほど、保磁力が高くなるが、ホウ素を含有させることにより保磁力の上昇を抑制することができる。当該保磁力は通常、５０Ｏe以上、特に１００Ｏｅ以上である。 The coercive force of the soft magnetic nanowire of the present invention is preferably less than 500 Oe, more preferably less than 400 Oe, and even more preferably less than 200 Oe. When the coercive force is 500 Oe or more, the reaction to a magnetic field is slow and it is difficult to handle as a soft magnetic material. Generally, the higher the anisotropy of a material, the higher the coercive force; however, by containing boron, the increase in coercive force can be suppressed. The coercive force is usually 50 Oe or more, particularly 100 Oe or more.
本明細書中、飽和磁化、比透磁率および保磁力は、２５℃にて振動試料型磁力計（ＶＳＭ）により求めた値（２回の測定値）の平均値を用いている。 In this specification, for saturation magnetization, relative magnetic permeability, and coercive force, the average value of values (measured twice) obtained by a vibrating sample magnetometer (VSM) at 25° C. is used.
［軟磁性ナノワイヤーの製造方法］
本発明の軟磁性ナノワイヤーの製造方法としては、例えば、特定の溶存酸素量の反応溶媒中において、鉄イオンを原料とし、ホウ素原子を含んだ還元剤を用いて、磁場中で液相還元反応をおこなう方法が挙げられる。
[Method for producing soft magnetic nanowires]
The method for producing soft magnetic nanowires of the present invention includes, for example, a liquid phase reduction reaction in a magnetic field using iron ions as raw materials and a reducing agent containing boron atoms in a reaction solvent with a specific amount of dissolved oxygen. There are several ways to do this.
鉄イオンを還元する際、鉄塩を反応溶媒に溶解させて鉄イオンを供給することが好ましい。鉄塩の形態は、用いる反応溶媒に溶解し、還元可能な状態で鉄イオンを供給できるものであれば特に限定されない。鉄塩としては、例えば、塩化鉄、硫酸鉄、硝酸鉄、酢酸鉄等が挙げられる。これらの塩は、水和物でも、無水物でもよい。鉄イオンの価数は特に限定されない。鉄イオンは、飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、鉄（ＩＩ）イオンであることが好ましい。 When reducing iron ions, it is preferable to supply iron ions by dissolving an iron salt in a reaction solvent. The form of the iron salt is not particularly limited as long as it is soluble in the reaction solvent used and can supply iron ions in a reducible state. Examples of iron salts include iron chloride, iron sulfate, iron nitrate, iron acetate, and the like. These salts may be hydrated or anhydrous. The valence of iron ions is not particularly limited. The iron ion is preferably an iron (II) ion from the viewpoint of further increasing the saturation magnetization and relative magnetic permeability and further reducing the coercive force.
鉄イオンの濃度は、１０～１０００ｍｍｏｌ／Ｌとすることが好ましく、ナノワイヤーを形成しやすく、収率が向上しやすいことから、３０～３００ｍｍｏｌ／Ｌとすることがより好ましく、５０～２００ｍｍｏｌ／Ｌとすることがさらに好ましい。 The concentration of iron ions is preferably 10 to 1000 mmol/L, more preferably 30 to 300 mmol/L, and 50 to 200 mmol/L because nanowires are easily formed and the yield is easily improved. It is more preferable that
鉄イオンを含む反応溶液は、反応開始前の溶存酸素量を０．５～４．０ｍｇ／Ｌに制御することが好ましく、１．０～３．０ｍｇ／Ｌに制御することが特に好ましい。前記溶存酸素量が４．０ｍｇ／Ｌを超える場合、ナノワイヤーの平均長が５μｍ以上の長さまで成長しない場合がある。一方、前記溶存酸素量が０．５ｍｇ／Ｌ未満の場合、再イオン化等が起こりやすい不安定なナノワイヤーになる場合がある。溶存酸素量の制御は、不活性ガスによる脱気や脱酸素剤を用いることでおこなうことができる。 In the reaction solution containing iron ions, the amount of dissolved oxygen before the start of the reaction is preferably controlled to 0.5 to 4.0 mg/L, particularly preferably 1.0 to 3.0 mg/L. When the amount of dissolved oxygen exceeds 4.0 mg/L, the nanowires may not grow to an average length of 5 μm or more. On the other hand, if the amount of dissolved oxygen is less than 0.5 mg/L, the nanowires may become unstable and prone to reionization. The amount of dissolved oxygen can be controlled by degassing with an inert gas or by using an oxygen scavenger.
本発明においては、還元剤は、水素化ホウ素ナトリウム、水素化ホウ素カリウム、ジメチルアミンボラン等のホウ素原子を含んだ還元剤である必要があり、中でも、水素化ホウ素ナトリウムが好ましい。ホウ素原子を含まない還元剤を用いる場合、ナノワイヤーを得ることができない場合がある。 In the present invention, the reducing agent needs to be a reducing agent containing a boron atom, such as sodium borohydride, potassium borohydride, dimethylamine borane, etc. Among them, sodium borohydride is preferable. When using a reducing agent that does not contain boron atoms, it may not be possible to obtain nanowires.
還元剤の濃度は特に限定されないが、５０～２０００ｍｍｏｌ／Ｌとすることが好ましく、１００～１０００ｍｍｏｌ／Ｌとすることがより好ましく、１５０～６００ｍｍｏｌ／Ｌとすることがさらに好ましい。還元剤の濃度が５０ｍｍｏｌ／Ｌ未満の場合、還元反応が十分進行しない場合があり、還元剤の濃度が２０００ｍｍｏｌ／Ｌを超える場合、還元反応の進行により急激な発泡が起こる場合がある。 The concentration of the reducing agent is not particularly limited, but it is preferably 50 to 2000 mmol/L, more preferably 100 to 1000 mmol/L, and even more preferably 150 to 600 mmol/L. When the concentration of the reducing agent is less than 50 mmol/L, the reduction reaction may not proceed sufficiently, and when the concentration of the reducing agent exceeds 2000 mmol/L, rapid foaming may occur due to the progress of the reduction reaction.
反応溶媒は、鉄イオンおよび還元剤が溶解できる限り特に限定されないが、溶解性、価格、環境負荷等の観点から、水が好ましい。 The reaction solvent is not particularly limited as long as the iron ions and the reducing agent can be dissolved therein, but from the viewpoints of solubility, cost, environmental impact, etc., water is preferable.
還元反応に際しては、鉄イオン溶液および還元剤溶液について、一方の溶液を他方の溶液に滴下して、反応液を形成することが好ましい。詳しくは、還元剤溶液を鉄イオン溶液に滴下してもよいし、または鉄イオン溶液を還元剤溶液に滴下してもよい。飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、還元剤溶液を鉄イオン溶液に滴下することが好ましい。なお、上記した鉄イオンおよび還元剤の濃度は、反応液（すなわち鉄イオン溶液および還元剤溶液の混合液）中における濃度である。 In the reduction reaction, it is preferable to form a reaction solution by dropping one solution of the iron ion solution and the reducing agent solution into the other solution. Specifically, the reducing agent solution may be dropped into the iron ion solution, or the iron ion solution may be dropped into the reducing agent solution. From the viewpoint of further increasing the saturation magnetization and relative magnetic permeability and further reducing the coercive force, it is preferable to drop the reducing agent solution into the iron ion solution. Note that the concentrations of the iron ions and the reducing agent described above are the concentrations in the reaction solution (ie, the mixed solution of the iron ion solution and the reducing agent solution).
還元反応は、バッチ法で行ってもよいし、フロー法で行ってもよい。 The reduction reaction may be performed by a batch method or a flow method.
鉄イオンを還元する際に印加する磁場は、バッチ法、フロー法いずれの場合であっても、中心磁場を１０～２００ｍＴとすることが好ましい。中心磁場が１０ｍＴ未満の場合、ナノワイヤーが生成しにくい場合がある。２００ｍＴを超える強い磁場は発生させることが困難である。 The magnetic field applied when reducing iron ions preferably has a central magnetic field of 10 to 200 mT, regardless of whether the method is a batch method or a flow method. When the central magnetic field is less than 10 mT, it may be difficult to generate nanowires. Strong magnetic fields exceeding 200 mT are difficult to generate.
還元反応をおこなう温度は特に限定されないが、室温（例えば、２５℃）から溶媒の沸点までの温度が好ましく、簡便性の観点から室温でおこなうことがより好ましい。 The temperature at which the reduction reaction is carried out is not particularly limited, but a temperature from room temperature (for example, 25°C) to the boiling point of the solvent is preferable, and from the viewpoint of simplicity, it is more preferable to carry out the reduction reaction at room temperature.
還元反応の時間は軟磁性ナノワイヤーが作製できれば特に限定されない。バッチ法で行う場合は、１分～１時間が好ましい。フロー法で行う場合、所定の時間が経過すれば反応後の溶液を取り出してもよいし、連続的に反応後の溶液を取り出してもよい。 The time for the reduction reaction is not particularly limited as long as soft magnetic nanowires can be produced. When carried out in a batch method, the time is preferably 1 minute to 1 hour. When using the flow method, the solution after the reaction may be taken out after a predetermined period of time has elapsed, or the solution after the reaction may be taken out continuously.
還元反応に際しては、系中の溶存酸素量を低減させるべく、窒素、アルゴンの不活性ガスによるバブリングを行ってもよいし、または行わなくてもよい。飽和磁化および比透磁率のさらなる増加ならびに保磁力のさらなる低減の観点から、当該バブリングを行うことが好ましい。 During the reduction reaction, bubbling with an inert gas such as nitrogen or argon may or may not be performed in order to reduce the amount of dissolved oxygen in the system. From the viewpoint of further increasing saturation magnetization and relative magnetic permeability and further reducing coercive force, it is preferable to perform the bubbling.
還元反応後、遠心分離、ろ過、磁石による吸着等で軟磁性ナノワイヤーを精製回収することができる。 After the reduction reaction, the soft magnetic nanowires can be purified and recovered by centrifugation, filtration, adsorption with a magnet, etc.
還元反応後、あるいは精製回収後の軟磁性ナノワイヤーについて、水酸化ナトリウム水溶液等の塩基性水溶液を用いて表面処理を行うことで、軟磁性ナノワイヤー表面に酸化層を形成することができる。当該処理を行う場合は、不活性ガスによるバブリングを行わない場合でも、純度が高く、飽和磁化及び比透磁率が高く、保磁力が低いナノワイヤーを得ることができる。塩基性水溶液を用いて表面処理を行うとは、還元反応後、反応液に塩基性水溶液を添加して０．５～３時間保持すること、または精製回収後、軟磁性ナノワイヤーを塩基性水溶液中に分散して０．５～３時間保持することである。 By performing surface treatment on the soft magnetic nanowires after the reduction reaction or after purification and recovery using a basic aqueous solution such as an aqueous sodium hydroxide solution, an oxidized layer can be formed on the surface of the soft magnetic nanowires. When performing this treatment, nanowires with high purity, high saturation magnetization and relative permeability, and low coercive force can be obtained even when bubbling with an inert gas is not performed. Surface treatment using a basic aqueous solution means that after a reduction reaction, a basic aqueous solution is added to the reaction solution and maintained for 0.5 to 3 hours, or after purification and recovery, soft magnetic nanowires are treated in a basic aqueous solution. The method is to disperse the liquid in the liquid and hold it for 0.5 to 3 hours.
［軟磁性ナノワイヤーの使用および用途］
本発明の軟磁性ナノワイヤーは、各種材料と混合し成形加工することで、電磁波遮蔽材料とすることができる。電磁波遮蔽材料は、電界シールド、磁界シールド等の電磁波シールド；および電磁波吸収体等を包含する。電磁波シールドとは、電磁波の透過を抑制し電磁波を反射するものである。電磁波吸収体とは、電磁波の透過や反射を抑制し電磁波を吸収するものである。電磁波遮蔽材料が遮蔽する電磁波の周波数は、例えば、２６．５～４０ＧＨｚ、７０～８０ＧＨｚ、２８７．５～３１２．５ＧＨｚ等の帯域である。前記電磁波遮蔽材料は、モーターのコア、電磁弁、各種センサー等のさまざまな用途に使用できる。
[Uses and applications of soft magnetic nanowires]
The soft magnetic nanowire of the present invention can be made into an electromagnetic wave shielding material by being mixed with various materials and molded. The electromagnetic wave shielding material includes electromagnetic wave shields such as electric field shields and magnetic field shields; electromagnetic wave absorbers, and the like. An electromagnetic wave shield is something that suppresses the transmission of electromagnetic waves and reflects electromagnetic waves. An electromagnetic wave absorber is something that suppresses transmission and reflection of electromagnetic waves and absorbs electromagnetic waves. The frequency of electromagnetic waves shielded by the electromagnetic wave shielding material is, for example, in a band of 26.5 to 40 GHz, 70 to 80 GHz, 287.5 to 312.5 GHz, or the like. The electromagnetic shielding material can be used in various applications such as motor cores, electromagnetic valves, and various sensors.
本発明の軟磁性ナノワイヤーと混合される各種材料は、有機材料、無機材料を問わない。本発明の軟磁性ナノワイヤーは、各種材料として、例えば、エポキシ等の熱硬化性樹脂；ポリオレフィン、ポリエステル、ポリアミド等の熱可塑性樹脂；イソプレンゴムやシリコーンゴム等のゴム；ガラス、セラミックと混合することができる。また、混合の際、揮発性の溶媒等を用いることもできる。有機材料は、熱硬化性樹脂、熱可塑性樹脂、ゴムを包含する。 Various materials to be mixed with the soft magnetic nanowires of the present invention may be organic or inorganic. The soft magnetic nanowires of the present invention can be mixed with various materials such as thermosetting resins such as epoxy; thermoplastic resins such as polyolefin, polyester, and polyamide; rubbers such as isoprene rubber and silicone rubber; glass, and ceramics. I can do it. Further, during mixing, a volatile solvent or the like can also be used. Organic materials include thermosetting resins, thermoplastic resins, and rubber.
本発明の軟磁性ナノワイヤーを含む成形体は、本発明の軟磁性ナノワイヤーおよび上記各種材料（例えば、有機材料）を含み、かつあらゆる形状を有していてもよい成形加工品である。成形加工方法としては、特に限定されず、例えば、キャスト法、溶融混錬法、塗布法、射出成形法、押出成形法等が挙げられる。 The molded article containing the soft magnetic nanowires of the present invention is a molded product that contains the soft magnetic nanowires of the present invention and the above-mentioned various materials (eg, organic materials), and may have any shape. The molding method is not particularly limited, and examples thereof include a casting method, a melt kneading method, a coating method, an injection molding method, an extrusion molding method, and the like.
本発明の軟磁性ナノワイヤーを含む成形体の一例として、例えば、本発明の軟磁性ナノワイヤーを含む塗膜を有する積層体がある。例えば、本発明の軟磁性ナノワイヤーを含む塗料を基材上に塗布（および必要により乾燥）することで本発明の軟磁性ナノワイヤーを含む塗膜を有する積層体を形成することができる。本発明の積層体は特に、磁界シールドや電磁波吸収体等に用いることができる。塗料は、軟磁性ナノワイヤーの他に、上記各種材料（例えば、有機材料）および／または溶媒を含んでもよい。塗料における軟磁性ナノワイヤーの含有量は、特に限定されず、例えば、０．１～７０質量％であってもよく、特に１～５０質量％であることが好ましい。塗料における上記各種材料（特に有機材料）の含有量は、特に限定されず、例えば、１～９９質量％であってもよく、特に１０～９０質量％であることが好ましい。 An example of a molded article containing the soft magnetic nanowires of the present invention is a laminate having a coating film containing the soft magnetic nanowires of the present invention. For example, a laminate having a coating film containing the soft magnetic nanowires of the present invention can be formed by applying a paint containing the soft magnetic nanowires of the present invention onto a base material (and drying if necessary). The laminate of the present invention can be used particularly for magnetic field shields, electromagnetic wave absorbers, and the like. In addition to the soft magnetic nanowires, the coating material may also contain the above-mentioned various materials (eg, organic materials) and/or a solvent. The content of soft magnetic nanowires in the paint is not particularly limited, and may be, for example, 0.1 to 70% by mass, and particularly preferably 1 to 50% by mass. The content of the above-mentioned various materials (particularly organic materials) in the paint is not particularly limited, and may be, for example, 1 to 99% by mass, and particularly preferably 10 to 90% by mass.
積層体を構成する基材としては特に限定されず、塗膜を支持し得るものでれば特に限定されない。基材を構成し得る材料としては、例えば、ポリエステル、ポリアミド、ポリイミド等の有機材料；金属箔、セラミック、ガラス等の無機材料または；それらの複合材料が挙げられる。 The base material constituting the laminate is not particularly limited as long as it can support the coating film. Examples of materials that can constitute the base material include organic materials such as polyester, polyamide, and polyimide; inorganic materials such as metal foil, ceramic, and glass; and composite materials thereof.
積層体を得るための塗布方法は特に限定されないが、例えば、ワイヤーバーコーター塗り、フィルムアプリケーター塗り、スプレー塗り、グラビアロールコーティング法、スクリーン印刷法、リバースロールコーティング法、リップコーティング、エアナイフコーティング法、カーテンフローコーティング法、浸漬コーティング法、ダイコート法、スプレー法、凸版印刷法、凹版印刷法、インクジェット法が挙げられる。 The coating method for obtaining the laminate is not particularly limited, but examples include wire bar coater coating, film applicator coating, spray coating, gravure roll coating method, screen printing method, reverse roll coating method, lip coating, air knife coating method, and curtain coating. Examples include flow coating method, dip coating method, die coating method, spray method, letterpress printing method, intaglio printing method, and inkjet method.
本発明の軟磁性ナノワイヤーを含む成形体の別の一例として、例えば、本発明の軟磁性ナノワイヤーを含むシートがある。例えば、本発明の軟磁性ナノワイヤーを含む塗料を基材上に塗布（および必要により乾燥）して得られたシートを基材から剥離することで形成することができる。本発明のシートは、シート単体で市場にて取引の対象となるものである。本発明のシートは、上記した積層体と同様に、磁界シールドや電磁波吸収体等に用いることができる。塗料は、積層体を得るための塗料と同様に、軟磁性ナノワイヤーの他に、上記各種材料（例えば、有機材料（特に、ポリマーまたはゴム））および／または溶媒を含んでもよい。 Another example of a molded article containing the soft magnetic nanowires of the present invention is, for example, a sheet containing the soft magnetic nanowires of the present invention. For example, it can be formed by applying a paint containing the soft magnetic nanowires of the present invention onto a base material (and drying if necessary) and peeling the obtained sheet from the base material. The sheet of the present invention can be traded in the market as a single sheet. The sheet of the present invention can be used for magnetic field shields, electromagnetic wave absorbers, etc., like the above-described laminate. Similar to the paint for obtaining a laminate, the paint may contain, in addition to the soft magnetic nanowires, the above-mentioned various materials (for example, organic materials (especially polymers or rubbers)) and/or solvents.
シートを得るための基材としては、シートを剥離可能である限り特に限定されず、積層体を構成する基材と同様の範囲内の基材から選択されてもよい。 The base material for obtaining the sheet is not particularly limited as long as the sheet can be peeled off, and may be selected from base materials within the same range as the base materials constituting the laminate.
シートを得るための塗布方法は特に限定されず、積層体を得るための塗布方法と同様の範囲内から選択されてもよい。 The coating method for obtaining the sheet is not particularly limited, and may be selected from within the same range as the coating method for obtaining the laminate.
本発明の軟磁性ナノワイヤーは、飽和磁化と比透磁率がより十分に高く、保磁力がより十分に低く、かつ異方性がより十分に高いため、軟磁性材料として好適に用いることができる。異方性とは、ナノワイヤーのアスペクト比がより十分に大きいことである。本発明の軟磁性ナノワイヤーは、前記したような、より十分に大きいアスペクト比を有することが好ましい。 The soft magnetic nanowire of the present invention has sufficiently high saturation magnetization and relative magnetic permeability, sufficiently low coercive force, and sufficiently high anisotropy, and therefore can be suitably used as a soft magnetic material. . Anisotropy means that the aspect ratio of the nanowires is much larger. The soft magnetic nanowire of the present invention preferably has a sufficiently larger aspect ratio as described above.
以下、本発明を実施例によって具体的に説明するが、本発明はこれらによって限定されるものではない。なお、ナノワイヤーの評価は、以下の方法によりおこなった。 EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto. Note that the evaluation of the nanowires was performed by the following method.
（１）ナノワイヤー化
得られた生成物を真空乾燥したのち、マイクロスコープで観察するとともに、走査型電子顕微鏡（ＳＥＭ）を用いて１０万倍で撮影した。任意の１０視野中における任意の１００点において、ナノワイヤーの長さおよび径を測定し、それぞれ平均値を算出した。また、平均長を平均径で除算することでアスペクト比を算出した。アスペクト比に基づいて、形状を以下の基準で評価した。
○：繊維状（アスペクト比１０以上）；
×：非繊維状（アスペクト比１０未満）；
××：繊維状および非繊維状の生成物いずれも得られなかった。
(1) Nanowire formation After the obtained product was vacuum-dried, it was observed with a microscope and photographed with a scanning electron microscope (SEM) at a magnification of 100,000 times. The length and diameter of the nanowires were measured at arbitrary 100 points in 10 arbitrary visual fields, and the average value was calculated for each. Additionally, the aspect ratio was calculated by dividing the average length by the average diameter. The shape was evaluated based on the aspect ratio using the following criteria.
○: Fibrous (aspect ratio 10 or more);
×: non-fibrous (aspect ratio less than 10);
XX: Neither fibrous nor non-fibrous products were obtained.
（２）ナノワイヤーの平均長、平均径およびアスペクト比
上記項目（１）において、繊維状の生成物が得られた場合、ナノワイヤーの平均長、平均径およびアスペクト比を示した。
(2) Average length, average diameter, and aspect ratio of nanowires In the above item (1), when a fibrous product is obtained, the average length, average diameter, and aspect ratio of nanowires are shown.
ナノワイヤーの平均長は以下の基準で評価した。
◎：１０μｍ以上（優良）；
○：５μｍ以上、１０μｍ未満（良）；
×：５μｍ未満（実用上問題あり）。
The average length of nanowires was evaluated based on the following criteria.
◎: 10 μm or more (excellent);
○: 5 μm or more, less than 10 μm (good);
×: Less than 5 μm (practical problem).
（３）ナノワイヤーのモル比率
得られた生成物を真空乾燥し、走査型電子顕微鏡（ＳＥＭ）を用いて１０万倍で撮影した。任意の１０視野においてＥＤＳ法により各元素の構成比率を測定し、鉄／ホウ素のモル比を算出した。
ナノワイヤー中の鉄／ホウ素のモル比率は以下の基準で評価した。
◎◎：３未満（最良）；
◎：３以上、４未満（優良）；
○：４以上、５未満（良）；
×：５以上（実用上問題あり）。
(3) Molar ratio of nanowires The obtained product was vacuum dried and photographed using a scanning electron microscope (SEM) at a magnification of 100,000 times. The composition ratio of each element was measured by the EDS method in ten arbitrary visual fields, and the iron/boron molar ratio was calculated.
The iron/boron molar ratio in the nanowires was evaluated based on the following criteria.
◎◎: Less than 3 (best);
◎: 3 or more, less than 4 (excellent);
○: 4 or more, less than 5 (good);
×: 5 or more (practical problem).
（４）構成比率（質量比）および合計量
得られた生成物を真空乾燥したのち、希塩酸と希硝酸との混合溶液に溶解した。得られた溶解液を、ＩＣＰ－ＡＥＳ法の多元素同時分析法に供することより、ホウ素、ケイ素およびその他の金属元素の含有の有無を確認した。その他の金属元素としては、鉄、コバルト、ニッケルが挙げられ、これらの金属元素以外の金属元素は確認されなかった。各金属元素の検出限界値は０．１質量％であった。
ケイ素が検出されない場合、ＩＣＰ－ＡＥＳ法により、鉄、コバルト、ニッケル、ホウ素標準液を用いて検量線法により、鉄、コバルト、ニッケル、ホウ素の含有量を定量した。
ケイ素が検出された場合、ＩＣＰ－ＡＥＳ法により、鉄、コバルト、ニッケル、ホウ、ケイ素標準液を用いて検量線法により、鉄、コバルト、ニッケル、ホウ素およびケイ素の含有量を定量した。
定量された各元素の含有量をナノワイヤー全量（１００質量％）に対する割合として示した（表中の（１））。
定量された各元素の含有量から、ナノワイヤー中の「Ｆｅ，Ｃｏ，Ｎｉ，ＢおよびＳｉの合計含有量Ｘに対する各元素の含有量」（表中の（２））および「ナノワイヤー全量に対する合計含有量Ｘの割合」（表中の（３））を算出した。
ナノワイヤー中の鉄、コバルト、ニッケル、ホウ素、ケイ素以外の含有量は、ナノワイヤーの質量から、鉄、コバルト、ニッケル、ホウ素、ケイ素の含有量を差し引いて求めることができる。
(4) Constituent ratio (mass ratio) and total amount The obtained product was vacuum dried and then dissolved in a mixed solution of dilute hydrochloric acid and dilute nitric acid. The resulting solution was subjected to simultaneous multi-element analysis using ICP-AES to confirm the presence or absence of boron, silicon and other metal elements. Other metal elements include iron, cobalt, and nickel, and no metal elements other than these metal elements were confirmed. The detection limit value for each metal element was 0.1% by mass.
If silicon was not detected, the content of iron, cobalt, nickel, and boron was determined by the ICP-AES method using standard solutions of iron, cobalt, nickel, and boron by the calibration curve method.
When silicon was detected, the content of iron, cobalt, nickel, boron, and silicon was determined by the ICP-AES method using standard solutions of iron, cobalt, nickel, boron, and silicon by the calibration curve method.
The content of each quantified element is shown as a percentage of the total amount of nanowires (100% by mass) ((1) in the table).
From the quantified content of each element, the "content of each element relative to the total content X of Fe, Co, Ni, B, and Si" in the nanowire ((2) in the table) and the "content relative to the total amount The ratio of total content X ((3) in the table) was calculated.
The content of substances other than iron, cobalt, nickel, boron, and silicon in the nanowire can be determined by subtracting the content of iron, cobalt, nickel, boron, and silicon from the mass of the nanowire.
（５）磁気特性（飽和磁化、比透磁率および保磁力）
得られた生成物を真空乾燥したのちに、振動試料型磁力計（ＶＳＭ）により求めた。測定は室温（２５℃）でおこなった。なお、測定は生成物を配向させない状態でおこなった。
(5) Magnetic properties (saturation magnetization, relative permeability and coercive force)
After vacuum drying the obtained product, it was determined using a vibrating sample magnetometer (VSM). Measurements were performed at room temperature (25°C). In addition, the measurement was performed in a state where the product was not oriented.
飽和磁化は、以下の基準により評価した。
◎◎：１５０ｅｍｕ／ｇ以上（最良）；
◎：６０ｅｍｕ／ｇ以上、１５０ｅｍｕ／ｇ未満（優良）；
○：４０ｅｍｕ／ｇ以上、６０ｅｍｕ／ｇ未満（良）；
×：４０ｅｍｕ／ｇ未満（実用上問題あり）。
Saturation magnetization was evaluated based on the following criteria.
◎◎: 150 emu/g or more (best);
◎: 60 emu/g or more, less than 150 emu/g (excellent);
○: 40 emu/g or more, less than 60 emu/g (good);
×: Less than 40 emu/g (practical problem).
比透磁率は、以下の基準により評価した。
◎◎：１００以上（最良）；
◎：４０以上１００未満（優良）；
○：１０以上４０未満（良）；
△：５以上１０未満（可：実用上問題なし）；
×：５未満（実用上問題あり）。
Relative magnetic permeability was evaluated based on the following criteria.
◎◎: 100 or more (best);
◎: 40 or more and less than 100 (excellent);
○: 10 or more and less than 40 (good);
△: 5 or more and less than 10 (acceptable: no practical problem);
×: Less than 5 (practical problem).
保磁力は、以下の基準により評価した。
◎◎：２００Ｏｅ未満（最良）；
◎：２００Ｏｅ以上４００Ｏｅ未満（優良）；
○：４００Ｏｅ以上５００Ｏｅ未満（良）；
×：５００Ｏｅ以上（実用上問題あり）。
Coercive force was evaluated based on the following criteria.
◎◎: Less than 200 Oe (best);
◎: 200 Oe or more and less than 400 Oe (excellent);
○: 400 Oe or more and less than 500 Oe (good);
×: 500 Oe or more (practical problems).
（６）磁気特性の総合評価
上記した磁気特性（飽和磁化、比透磁率および保磁力）の評価結果を総合的に評価した。詳しくは、これらの評価結果のうち、最低の評価結果を総合評価の結果として用いた。
◎◎：最良；
◎：優良；
○：良；
△：可（実用上問題なし）；
×：不可（実用上問題あり）。
(6) Comprehensive evaluation of magnetic properties The above evaluation results of magnetic properties (saturation magnetization, relative magnetic permeability, and coercive force) were comprehensively evaluated. Specifically, among these evaluation results, the lowest evaluation result was used as the result of the comprehensive evaluation.
◎◎: Best;
◎: Excellent;
○: Good;
△: Acceptable (no practical problems);
×: Not possible (practical problem).
（７）反応溶液中における溶存酸素濃度
飯島電子工業社製ＤＯメーターＢ－５０６を用いて、大気圧下、２５℃で測定した。
(7) Dissolved oxygen concentration in reaction solution Measured at 25° C. under atmospheric pressure using a DO meter B-506 manufactured by Iijima Electronics Co., Ltd.
実施例１
塩化鉄（ＩＩ）四水和物８．５５質量部（４３モル部）を水３００質量部に溶解し、中心磁場が１３０ｍＴの磁気回路に入れ、窒素ガスのバブリングを開始した。バブリング開始から１０分経過した後、溶存酸素量が２ｍｇ／Ｌであることを確認した後、水素化ホウ素ナトリウム７．００質量部（１８５モル部）を水１７５質量部に溶解した水溶液の滴下を開始した。１５分かけて滴下後、さらに１０分間静置した。反応液中の鉄イオンおよび還元剤の濃度は以下の通りであった：鉄イオン（９１ｍｍｏｌ／Ｌ、還元剤３８９ｍｍｏｌ／Ｌ。）
その後、磁場の印加と窒素ガスのバブリングを停止し、反応液を２００質量部の水に注いで希釈した。生じた黒色のナノワイヤーをＴ１００Ａ０９０ＣのＰＴＦＥ製フィルターを用いてろ過回収後、水、メタノールでそれぞれ３回ずつ洗浄し、室温で２４時間真空乾燥してナノワイヤーを得た。
Example 1
8.55 parts by mass (43 parts by mole) of iron(II) chloride tetrahydrate was dissolved in 300 parts by mass of water, placed in a magnetic circuit with a central magnetic field of 130 mT, and bubbling of nitrogen gas was started. After 10 minutes had passed from the start of bubbling, and after confirming that the amount of dissolved oxygen was 2 mg/L, an aqueous solution of 7.00 parts by mass (185 moles) of sodium borohydride dissolved in 175 parts by mass of water was added dropwise. It started. After the dropwise addition took 15 minutes, the solution was allowed to stand for an additional 10 minutes. The concentrations of iron ions and reducing agent in the reaction solution were as follows: iron ions (91 mmol/L, reducing agent 389 mmol/L).
Thereafter, application of the magnetic field and bubbling of nitrogen gas were stopped, and the reaction solution was diluted by pouring into 200 parts by mass of water. The resulting black nanowires were collected by filtration using a T100A090C PTFE filter, washed three times each with water and methanol, and vacuum-dried at room temperature for 24 hours to obtain nanowires.
実施例２
水素化ホウ素ナトリウム水溶液の滴下にかける時間を１０分とした以外は、実施例１と同様の操作を行って、ナノワイヤーを得た。
Example 2
Nanowires were obtained by performing the same operation as in Example 1, except that the time required for dropping the sodium borohydride aqueous solution was 10 minutes.
実施例３
水素化ホウ素ナトリウム７．００質量部（１８５モル部）を水１７５質量部に溶解し、中心磁場が１３０ｍＴの磁気回路に入れ、窒素ガスのバブリングを開始した。バブリング開始から１０分経過した後、溶存酸素量が２ｍｇ／Ｌであることを確認した後、塩化鉄（ＩＩ）四水和物８．５５質量部（４３モル部）を水３００質量部に溶解した水溶液の滴下を開始した。１０分かけて滴下後、さらに１０分間静置した。
その後、磁場の印加と窒素ガスのバブリングを停止し、反応液を２００質量部の水に注いで希釈した。生じた黒色のナノワイヤーをＴ１００Ａ０９０ＣのＰＴＦＥ製フィルターを用いてろ過回収後、水、メタノールでそれぞれ３回ずつ洗浄し、室温で２４時間真空乾燥してナノワイヤーを得た。
Example 3
7.00 parts by mass (185 moles) of sodium borohydride was dissolved in 175 parts by mass of water, placed in a magnetic circuit with a central magnetic field of 130 mT, and bubbling of nitrogen gas was started. After 10 minutes from the start of bubbling, after confirming that the amount of dissolved oxygen is 2 mg/L, dissolve 8.55 parts by mass (43 parts by mole) of iron(II) chloride tetrahydrate in 300 parts by mass of water. Dropwise addition of the aqueous solution was started. After dropping over 10 minutes, the mixture was allowed to stand still for another 10 minutes.
Thereafter, the application of the magnetic field and the bubbling of nitrogen gas were stopped, and the reaction solution was poured into 200 parts by mass of water to dilute it. The resulting black nanowires were collected by filtration using a T100A090C PTFE filter, washed three times each with water and methanol, and vacuum dried at room temperature for 24 hours to obtain nanowires.
実施例４
原料の塩化鉄（ＩＩ）四水和物を塩化鉄（ＩＩＩ）六水和物に変更した以外は実施例１と同様の操作を行って、ナノワイヤーを得た。
Example 4
Nanowires were obtained by carrying out the same operation as in Example 1, except that the raw material iron (II) chloride tetrahydrate was changed to iron (III) chloride hexahydrate.
実施例５
塩化鉄（ＩＩ）四水和物８．５５質量部（４３モル部）を水３００質量部に溶解し、大気に開放した中心磁場が１３０ｍＴの磁気回路に入れた。溶存酸素量が７ｍｇ／Ｌであることを確認した後、バブリングを行うことなく、水素化ホウ素ナトリウム７．００質量部（１８５モル部）を水１７５質量部に溶解した水溶液の滴下を開始した。１５分かけて滴下後、さらに１０分間静置した。得られた反応液に２０％水酸化ナトリウム水溶液を加えてｐＨを１２ないし１３に調整し、１時間静置した。
その後、磁場の印加を停止し、反応液を２００質量部の水に注いで希釈した。生じた黒色の固体をＴ１００Ａ０９０ＣのＰＴＦＥ製フィルターを用いてろ過回収後、水、メタノールでそれぞれ３回ずつ洗浄し、室温で２４時間真空乾燥してナノワイヤーを得た。
Example 5
8.55 parts by mass (43 parts by mole) of iron(II) chloride tetrahydrate was dissolved in 300 parts by mass of water and placed in a magnetic circuit with a central magnetic field of 130 mT and open to the atmosphere. After confirming that the amount of dissolved oxygen was 7 mg/L, dropping of an aqueous solution in which 7.00 parts by mass (185 moles) of sodium borohydride was dissolved in 175 parts by mass of water was started without bubbling. After the dropwise addition took 15 minutes, the solution was allowed to stand for an additional 10 minutes. A 20% aqueous sodium hydroxide solution was added to the resulting reaction solution to adjust the pH to 12 to 13, and the mixture was allowed to stand for 1 hour.
Thereafter, the application of the magnetic field was stopped, and the reaction solution was diluted by pouring into 200 parts by mass of water. The resulting black solid was collected by filtration using a T100A090C PTFE filter, washed three times each with water and methanol, and vacuum-dried at room temperature for 24 hours to obtain nanowires.
比較例１
塩化鉄（ＩＩ）四水和物８．５５質量部（４３モル部）を水３００質量部に溶解し、大気に開放した中心磁場が１３０ｍＴの磁気回路に入れた。溶存酸素量が７ｍｇ／Ｌであることを確認した後、水素化ホウ素ナトリウム７．００質量部（１８５モル部）を水１７５質量部に溶解した水溶液の滴下を開始した。１５分かけて滴下後、さらに１０分間静置した。
その後、磁場の印加を停止し、反応液を２００質量部の水に注いで希釈した。生じた黒色の固体をＴ１００Ａ０９０ＣのＰＴＦＥ製フィルターを用いてろ過回収後、水、メタノールでそれぞれ３回ずつ洗浄し、室温で２４時間真空乾燥してナノワイヤーを得た。
Comparative example 1
8.55 parts by mass (43 parts by mole) of iron(II) chloride tetrahydrate was dissolved in 300 parts by mass of water and placed in a magnetic circuit with a central magnetic field of 130 mT and open to the atmosphere. After confirming that the amount of dissolved oxygen was 7 mg/L, dropping of an aqueous solution in which 7.00 parts by mass (185 moles) of sodium borohydride was dissolved in 175 parts by mass of water was started. After the dropwise addition took 15 minutes, the solution was allowed to stand for an additional 10 minutes.
Thereafter, the application of the magnetic field was stopped, and the reaction solution was diluted by pouring into 200 parts by mass of water. The resulting black solid was collected by filtration using a T100A090C PTFE filter, washed three times each with water and methanol, and vacuum-dried at room temperature for 24 hours to obtain nanowires.
比較例２
塩化鉄（ＩＩ）四水和物８．５５質量部（４３モル部）を水３００質量部に溶かし、１５０ｍＴの磁場を印加した反応容器中に入れた。脱酸素剤としてヒドラジン一水和物を０．５質量部添加し、溶存酸素量が０．２ｍｇ／Ｌであることを確認した後、水素化ホウ素ナトリウム７．００質量部（１８５モル部）を水１７５質量部に溶解した水溶液の滴下を開始した。１５分かけて滴下後、さらに１０分間静置した。その後、磁場の印加を停止し、反応液を２００質量部の水に注いで希釈した。
生じた黒色の固体をＴ１００Ａ０９０ＣのＰＴＦＥ製フィルターを用いてろ過回収後、水、メタノールでそれぞれ３回ずつ洗浄し、室温で２４時間真空乾燥して黄色の不定形粒子を得た。
Comparative example 2
8.55 parts by mass (43 parts by mole) of iron(II) chloride tetrahydrate was dissolved in 300 parts by mass of water and placed in a reaction vessel to which a magnetic field of 150 mT was applied. After adding 0.5 parts by mass of hydrazine monohydrate as an oxygen scavenger and confirming that the amount of dissolved oxygen was 0.2 mg/L, 7.00 parts by mass (185 parts by mole) of sodium borohydride was added. Dripping of an aqueous solution dissolved in 175 parts by mass of water was started. After the dropwise addition took 15 minutes, the solution was allowed to stand for an additional 10 minutes. Thereafter, the application of the magnetic field was stopped, and the reaction solution was diluted by pouring into 200 parts by mass of water.
The resulting black solid was collected by filtration using a T100A090C PTFE filter, washed three times each with water and methanol, and vacuum-dried at room temperature for 24 hours to obtain yellow amorphous particles.
比較例３
水酸化ナトリウム１．００質量部をエチレングリコール４７２質量部に溶解させて９０℃に加熱した溶液Ａを調製した。塩化鉄（ＩＩ）四水和物３．３４質量部（１６．９モル部）をエチレングリコール９９．３質量部に溶解させた溶液Ｂを調製した。溶液Ａ、２８％アンモニア水２５．０質量部、溶液Ｂおよびヒドラジン一水和物２．５０質量部をこの順で、９０～９５℃に加熱した反応容器に添加した。各液の添加は、撹拌をおこないながら、上記の順序にて１０秒間隔でおこなった。すべてを添加後、１５０ｍＴの磁場を印加し、９０～９５℃を保って９０分間静置したが、反応は進行せず、生成物は得られなかった。
Comparative example 3
Solution A was prepared by dissolving 1.00 parts by mass of sodium hydroxide in 472 parts by mass of ethylene glycol and heating the solution to 90°C. Solution B was prepared by dissolving 3.34 parts by mass (16.9 parts by mole) of iron(II) chloride tetrahydrate in 99.3 parts by mass of ethylene glycol. Solution A, 25.0 parts by mass of 28% aqueous ammonia, solution B and 2.50 parts by mass of hydrazine monohydrate were added in this order to a reaction vessel heated to 90 to 95°C. Each liquid was added in the above order at 10 second intervals while stirring. After adding everything, a magnetic field of 150 mT was applied and the mixture was left standing at 90 to 95° C. for 90 minutes, but the reaction did not proceed and no product was obtained.
実施例および比較例で得られた生成物の評価結果を表１に示す。 Table 1 shows the evaluation results of the products obtained in Examples and Comparative Examples.
実施例１～５の軟磁性ナノワイヤーは、鉄／ホウ素のモル比が５未満であり、平均長が長く、飽和磁化と比透磁率がより十分に高く、保磁力がより十分に低く、軟磁性材料としての性能より十分に優れていた。 The soft magnetic nanowires of Examples 1 to 5 have an iron/boron molar ratio of less than 5, a long average length, a sufficiently high saturation magnetization and a relative permeability, a sufficiently low coercive force, and a soft magnetic nanowire. The performance was sufficiently superior to that of a magnetic material.
比較例１のナノワイヤーは、鉄の純度が低く、平均長が短く、飽和磁化と比透磁率が低く、保磁力が高く、軟磁性材料としての性能が劣っていた。
比較例２は、不定形の劣化物が見られ、鉄／ホウ素のモル比が５以上であり、鉄の純度が低く、飽和磁化と比透磁率が低く、軟磁性材料としての性能が劣っていた。
比較例３では、ホウ素を含んでいなかったため、還元反応が進行せず、生成物が得られなかった。
The nanowires of Comparative Example 1 had low iron purity, short average length, low saturation magnetization and relative permeability, high coercive force, and poor performance as a soft magnetic material.
In Comparative Example 2, amorphous degraded products were observed, the iron/boron molar ratio was 5 or more, the purity of iron was low, the saturation magnetization and relative permeability were low, and the performance as a soft magnetic material was poor. Ta.
In Comparative Example 3, since boron was not included, the reduction reaction did not proceed and no product was obtained.
本発明の軟磁性ナノワイヤーは、軟磁性が要求されるあらゆる用途（例えば、モーターのコア、電磁弁、各種センサー、磁界シールドや電磁波吸収材等）に有用である。 The soft magnetic nanowires of the present invention are useful in all applications requiring soft magnetism (eg, motor cores, solenoid valves, various sensors, magnetic field shields, electromagnetic wave absorbers, etc.).
Claims (14)
前記ナノワイヤー中の鉄の含有量が７０質量％以上であり、
前記ナノワイヤー中のホウ素の含有量が３．５質量％以上であり、
前記ナノワイヤー中の鉄とホウ素以外の元素の含有量が２５質量％以下であり、
平均長が５～４０μｍであり、かつＳＥＭ－ＥＤＳ法により測定した該ナノワイヤー中の鉄／ホウ素のモル比が４未満であり、
振動試料型磁力計を用いて測定した飽和磁化を鉄の純度で除算した値が１５０ｅｍｕ／ｇ以上である、軟磁性ナノワイヤー。 A soft magnetic nanowire containing iron and boron,
The iron content in the nanowire is 70% by mass or more,
The boron content in the nanowire is 3.5% by mass or more,
The content of elements other than iron and boron in the nanowire is 25% by mass or less,
the average length is 5 to 40 μm , and the iron/boron molar ratio in the nanowire measured by SEM-EDS method is less than 4 ;
A soft magnetic nanowire whose saturation magnetization measured using a vibrating sample magnetometer divided by iron purity is 150 emu/g or more.
前記ナノワイヤー中の鉄とホウ素以外の元素の含有量が１５質量％以下である、請求項２に記載の軟磁性ナノワイヤー。 The boron content in the nanowire is 3.5% by mass or more,
The soft magnetic nanowire according to claim 2, wherein the content of elements other than iron and boron in the nanowire is 15% by mass or less.
前記ナノワイヤー中のホウ素の含有量が４質量％以上である、請求項１に記載の軟磁性ナノワイヤー。 The iron content in the nanowire is 89% by mass or more,
The soft magnetic nanowire according to claim 1, wherein the boron content in the nanowire is 4% by mass or more.
反応開始前の溶存酸素量が０．５～４．０ｍｇ／Ｌである反応溶媒中において、鉄イオンを原料とし、ホウ素原子を含んだ還元剤を用いて、磁場中で液相還元反応をおこなう、軟磁性ナノワイヤーの製造方法。 A method for producing a soft magnetic nanowire according to any one of claims 1 to 8, comprising:
In a reaction solvent with a dissolved oxygen content of 0.5 to 4.0 mg/L before the start of the reaction, a liquid phase reduction reaction is carried out in a magnetic field using iron ions as raw materials and a reducing agent containing boron atoms. , a method for producing soft magnetic nanowires.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2023158351A JP2023168423A (en) | 2021-08-25 | 2023-09-22 | Soft magnetic nanowires, coating material containing the same, and multilayer body coated therewith |
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021137422 | 2021-08-25 | ||
| JP2021137422 | 2021-08-25 | ||
| JP2021198606 | 2021-12-07 | ||
| JP2021198606 | 2021-12-07 | ||
| JP2022059546 | 2022-03-31 | ||
| JP2022059546 | 2022-03-31 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2023158351A Division JP2023168423A (en) | 2021-08-25 | 2023-09-22 | Soft magnetic nanowires, coating material containing the same, and multilayer body coated therewith |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2023033191A JP2023033191A (en) | 2023-03-09 |
| JP7426742B2 true JP7426742B2 (en) | 2024-02-02 |
Family
ID=85416018
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2022132877A Active JP7426742B2 (en) | 2021-08-25 | 2022-08-24 | Soft magnetic nanowires, paints containing them, and laminates coated with the same |
| JP2023158351A Pending JP2023168423A (en) | 2021-08-25 | 2023-09-22 | Soft magnetic nanowires, coating material containing the same, and multilayer body coated therewith |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2023158351A Pending JP2023168423A (en) | 2021-08-25 | 2023-09-22 | Soft magnetic nanowires, coating material containing the same, and multilayer body coated therewith |
Country Status (1)
| Country | Link |
|---|---|
| JP (2) | JP7426742B2 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006045660A (en) | 2004-07-05 | 2006-02-16 | Hitachi Metals Ltd | Fe-BASED AMORPHOUS ALLOY THIN STRIP AND MAGNETIC CORE |
| JP2009275269A (en) | 2008-05-16 | 2009-11-26 | Seiko Epson Corp | Production device for acicular metal powder, method for producing acicular metal powder and acicular metal powder |
| JP2010229546A (en) | 2009-03-02 | 2010-10-14 | Tohoku Univ | Metal glass nanowire and method for producing the same |
| WO2019160165A1 (en) | 2018-02-13 | 2019-08-22 | 株式会社村田製作所 | Magnetic structure |
-
2022
- 2022-08-24 JP JP2022132877A patent/JP7426742B2/en active Active
-
2023
- 2023-09-22 JP JP2023158351A patent/JP2023168423A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006045660A (en) | 2004-07-05 | 2006-02-16 | Hitachi Metals Ltd | Fe-BASED AMORPHOUS ALLOY THIN STRIP AND MAGNETIC CORE |
| JP2009275269A (en) | 2008-05-16 | 2009-11-26 | Seiko Epson Corp | Production device for acicular metal powder, method for producing acicular metal powder and acicular metal powder |
| JP2010229546A (en) | 2009-03-02 | 2010-10-14 | Tohoku Univ | Metal glass nanowire and method for producing the same |
| WO2019160165A1 (en) | 2018-02-13 | 2019-08-22 | 株式会社村田製作所 | Magnetic structure |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2023168423A (en) | 2023-11-24 |
| JP2023033191A (en) | 2023-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhang et al. | Synthesis and characterization of monodisperse ultra-thin silica-coated magnetic nanoparticles | |
| Deng et al. | Solvothermal in situ synthesis of Fe3O4-multi-walled carbon nanotubes with enhanced heterogeneous Fenton-like activity | |
| Salavati-Niasari et al. | Synthesis and characterization of Co3O4 nanorods by thermal decomposition of cobalt oxalate | |
| Lai et al. | Iron oxide nanoparticles decorated oleic acid for high colloidal stability | |
| US20190076921A1 (en) | Coated silver particle and manufacturing method therefor, conductive composition, and conductor | |
| US11858196B2 (en) | Iron oxide nanoparticle-based magnetic ink for additive manufacturing | |
| KR20180015175A (en) | Magnetic powder composite, antenna and electronic device and manufacturing method thereof | |
| Huaman et al. | Size-controlled monodispersed nickel nanocrystals using 2-octanol as reducing agent | |
| JP2008081818A (en) | Method for producing precursor powder of nickel-ferroalloy nanoparticle, precursor powder of nickel-ferroalloy nanoparticle, method for producing nickel-ferroalloy nanoparticle, and nickel-ferroalloy nanoparticle | |
| JP7426742B2 (en) | Soft magnetic nanowires, paints containing them, and laminates coated with the same | |
| JP7402557B2 (en) | Soft magnetic nanowires, paints containing them, and laminates coated with the same | |
| Sanles-Sobrido et al. | Tailoring the magnetic properties of nickel nanoshells through controlled chemical growth | |
| Lu et al. | Hierarchical FeNi 3 assemblies with caltrop-like architectures: synthesis, formation mechanism and magnetic properties | |
| Singh et al. | Glycerol mediated low temperature synthesis of nickel nanoparticles by solution reduction method | |
| TW201143941A (en) | Method for preparing copper nanoparticle which is capable of being calcined under atmospheric pressure | |
| Pal et al. | Dipentaerythritol: a novel additive for the precipitation of dispersed Ni particles in polyols | |
| Nandwana et al. | Magnetic properties of FexPtyAu100− x− y nanoparticles | |
| JP2024036139A (en) | Fluid dispersion of soft magnetism nanowire | |
| KR20170121237A (en) | Magnetic compounds, antennas and electronic devices | |
| WO2023027087A1 (en) | Soft magnetic nanowires, coating material containing same, and multilayer body coated with said coating material | |
| Aiswarya et al. | Magnetic nanowires for sensor applications | |
| Nguyen et al. | Solvothermal synthesis of high-performance magnetic cobalt nanowires and bonded anisotropic magnets prepared thereof | |
| JP6295489B2 (en) | Method for producing granulated product for plate-like particles | |
| Azarkharman et al. | A novel method for synthesis of size-controlled L10 FePt nanoparticles | |
| Nica et al. | Synthesis and Characterization of Co-Ni and Fe $ _ {3} $ O $ _ {4} $-Pd Nanocomposites |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20230105 |
|
| A871 | Explanation of circumstances concerning accelerated examination |
Free format text: JAPANESE INTERMEDIATE CODE: A871 Effective date: 20230105 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20230307 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20230424 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20230627 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20230922 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20231004 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20231219 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20240116 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7426742 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |