JPH07101786B2 - Electromagnetic wave absorbing material - Google Patents
Electromagnetic wave absorbing materialInfo
- Publication number
- JPH07101786B2 JPH07101786B2 JP62036239A JP3623987A JPH07101786B2 JP H07101786 B2 JPH07101786 B2 JP H07101786B2 JP 62036239 A JP62036239 A JP 62036239A JP 3623987 A JP3623987 A JP 3623987A JP H07101786 B2 JPH07101786 B2 JP H07101786B2
- Authority
- JP
- Japan
- Prior art keywords
- electromagnetic wave
- wave absorbing
- absorbing material
- titanium
- iron
- 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.)
- Expired - Fee Related
Links
- 239000011358 absorbing material Substances 0.000 title claims description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 19
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 17
- 239000002994 raw material Substances 0.000 claims description 9
- 239000004065 semiconductor Substances 0.000 claims description 8
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 8
- 239000002131 composite material Substances 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 7
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 6
- 238000010304 firing Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- 239000010936 titanium Substances 0.000 claims description 6
- 229910052742 iron Inorganic materials 0.000 claims description 5
- 239000000843 powder Substances 0.000 claims description 5
- 229910052719 titanium Inorganic materials 0.000 claims description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- 238000002844 melting Methods 0.000 claims description 3
- 230000008018 melting Effects 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 229920000620 organic polymer Polymers 0.000 claims description 2
- 239000002952 polymeric resin Substances 0.000 claims description 2
- 229910010413 TiO 2 Inorganic materials 0.000 claims 1
- YDZQQRWRVYGNER-UHFFFAOYSA-N iron;titanium;trihydrate Chemical compound O.O.O.[Ti].[Fe] YDZQQRWRVYGNER-UHFFFAOYSA-N 0.000 claims 1
- 235000013980 iron oxide Nutrition 0.000 description 7
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910000859 α-Fe Inorganic materials 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 3
- 231100000053 low toxicity Toxicity 0.000 description 3
- 238000000465 moulding Methods 0.000 description 3
- NQNBVCBUOCNRFZ-UHFFFAOYSA-N nickel ferrite Chemical compound [Ni]=O.O=[Fe]O[Fe]=O NQNBVCBUOCNRFZ-UHFFFAOYSA-N 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000011449 brick Substances 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 239000012153 distilled water Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 229910001385 heavy metal Inorganic materials 0.000 description 2
- 229910000480 nickel oxide Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 239000000049 pigment Substances 0.000 description 2
- 239000001294 propane Substances 0.000 description 2
- 238000010405 reoxidation reaction Methods 0.000 description 2
- -1 titanium halides Chemical class 0.000 description 2
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical compound OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 229910001308 Zinc ferrite Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 235000014413 iron hydroxide Nutrition 0.000 description 1
- 229910000358 iron sulfate Inorganic materials 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
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 1
- DCKVFVYPWDKYDN-UHFFFAOYSA-L oxygen(2-);titanium(4+);sulfate Chemical compound [O-2].[Ti+4].[O-]S([O-])(=O)=O DCKVFVYPWDKYDN-UHFFFAOYSA-L 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 238000000634 powder X-ray diffraction Methods 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 description 1
- 229910000348 titanium sulfate Inorganic materials 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- WGEATSXPYVGFCC-UHFFFAOYSA-N zinc ferrite Chemical compound O=[Zn].O=[Fe]O[Fe]=O WGEATSXPYVGFCC-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Aerials With Secondary Devices (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は毒性の少ない半導体物質を利用したギガヘルツ
帯電磁波吸収材料を提供することにある。TECHNICAL FIELD The present invention is to provide a gigahertz band electromagnetic wave absorbing material using a semiconductor material having low toxicity.
従来技術及び解決しようとする問題点 現在使用されている電磁波吸収材料はフェライト系を主
体としたものであり、電磁波特にギガヘルツ帯電磁波吸
収能が低いためカーボン等を加えて複合化しなければな
らず、またマンガン，ニッケル，亜鉛等の重金属を含む
ため万一食品に直接触れるような場合などはこれら重金
属が溶出しないよう考慮を払わねばならない。Conventional technology and problems to be solved Electromagnetic wave absorbing materials currently used are mainly based on ferrite, and must be compounded by adding carbon or the like because of their low electromagnetic wave absorbing ability, especially in the GHz band. Also, since heavy metals such as manganese, nickel, and zinc are included, if they come into direct contact with food, care must be taken to prevent these heavy metals from eluting.
問題を解決するための手段 本発明者らは上記問題を解決すべく鋭意努力した結果、
チタン酸化物および鉄の酸化物の混合物、またはチタン
および鉄の複合酸化物を原料の溶融温度以上で焼成し、
急速に冷却し、必要に応じて粉砕することによって得ら
れた半導体物質を用いた電磁波吸収材料が非常に安価
で、毒性が少なく、しかも優れたギガヘルツ帯電磁波吸
収性能を有することを見出し、本発明に至った。Means for Solving the Problems The present inventors have made diligent efforts to solve the above problems,
A mixture of titanium oxide and iron oxide, or a composite oxide of titanium and iron is fired at a melting temperature of the raw material or higher,
According to the present invention, it is found that an electromagnetic wave absorbing material using a semiconductor substance obtained by rapidly cooling and crushing as needed is very inexpensive, has low toxicity, and has excellent gigahertz band electromagnetic wave absorbing performance. Came to.
以下本発明を詳細に説明する。The present invention will be described in detail below.
原料の一つはチタンの酸化物（TiO,TiO3等）と、鉄の酸
化物（FeO,Fe2O3,Fe3O4等）の混合物である。これらの
酸化物は、焼成によって酸化物となる水酸化チタン、硫
酸チタン、ハロゲン化チタン、水酸化鉄、硫酸鉄、ハロ
ゲン化鉄等の前駆物質の焼成によってその場で生成する
酸化物を含んでいる。他の原料は、FeTiO3,Fe2TiO4,Fe2
TiO5等の鉄およびチタンの複合酸化物である。必要に応
じ、原料へ再酸化防止剤（例えばカーボン）、半導化剤
（例えばY2O3）を添加することもできる。One of the raw materials is a mixture of titanium oxides (TiO, TiO 3, etc.) and iron oxides (FeO, Fe 2 O 3 , Fe 3 O 4, etc.). These oxides include oxides formed in situ by firing precursors such as titanium hydroxide, titanium sulfate, titanium halides, iron hydroxide, iron sulfate, iron halides that become oxides by firing. There is. Other raw materials are FeTiO 3 , Fe 2 TiO 4 , Fe 2
It is a composite oxide of iron and titanium such as TiO 5 . If necessary, a reoxidation inhibitor (for example, carbon) and a semiconducting agent (for example, Y 2 O 3 ) can be added to the raw material.
次にこれらの原料は焼成により半導体化される。このた
め原料はその溶融温度以上で焼成され、再酸化を避ける
ため急速に冷却される。このためガス炉、アーク炉、電
気炉、イメージ炉等が用いられる。このようにして得ら
れた物質がなぜ優れた電磁波吸収能を示すのかは明確で
ないが、実施例において得られる物質の粉末Ｘ線回折の
パターンから、FeTiO3,Fe2TiO5,Ti3O5の生成が証明され
ることにより、焼成により高次酸化物の脱酸素によりこ
れら低次酸化物が生成し、半導体物質に変化することに
よるものと推察される。このようにして得られた電磁波
吸収材料の半導化率は10-3Ω・cm〜10+6Ω・cm程度のも
のが使用できる。好ましくは10-2Ω・cm〜10+5Ω・cm程
度がよい。比重は4.5〜5.0g/cm3程度であり、マンガン
フェライト、亜鉛フェライト、ニッケルフェライトの比
重5.0〜5.4g/cm3に比べて軽い。また本発明の半導体物
質はFe,Tiよりなるため、毒性が少なく安全である。Next, these raw materials are made into semiconductors by firing. Therefore, the raw material is fired above its melting temperature and rapidly cooled to avoid reoxidation. Therefore, a gas furnace, an arc furnace, an electric furnace, an image furnace or the like is used. It is not clear why the substance thus obtained exhibits excellent electromagnetic wave absorption ability, but from the powder X-ray diffraction patterns of the substances obtained in Examples, FeTiO 3 , Fe 2 TiO 5 , Ti 3 O 5 It is inferred from the fact that the low-order oxides are generated by the deoxidation of the higher-order oxides by firing, and are converted into a semiconductor material. The electromagnetic conductivity of the electromagnetic wave absorbing material thus obtained can be about 10 −3 Ω · cm to 10 +6 Ω · cm. It is preferably about 10 −2 Ω · cm to 10 +5 Ω · cm. Specific gravity is about 4.5~5.0g / cm 3, manganese ferrite, zinc ferrite, lighter than the specific gravity 5.0~5.4g / cm 3 of nickel ferrite. Since the semiconductor material of the present invention is composed of Fe and Ti, it has low toxicity and is safe.
本発明の半導体物質は次のような形で電磁波吸収材料と
することができる。The semiconductor material of the present invention can be used as an electromagnetic wave absorbing material in the following form.
単独成形使用 単独成形物と合成樹脂と金属板等の複合体 焼成物を粉砕して有機高分子樹脂に練りこんだ複合
体 フェライトとの複合体 実施例１ 二酸化チタン（TiO2）微粉1kgと、酸化鉄（Fe2O3）微粉
1kgをサンプルミルで十分混合し、さらに蒸留水を加え
て粘土状にし、105℃で24時間乾燥脱水後、耐熱煉瓦で
炉を作り、酸素・プロパン炎を熱源として約1900℃で先
に作った二酸化チタン（TiO2）と酸化鉄（Fe2O3）の混
合物を適当な小塊にしたものを炉内に置き、急速加熱溶
解した後水冷し、得られた焼成物を切断し2cm×2cm×0.
5cmとした。Single molding use Single molding, composite of synthetic resin and metal plate, etc. Composite of fired product pulverized and kneaded into organic polymer resin Composite of ferrite Example 1 Titanium dioxide (TiO 2 ) fine powder 1 kg, Fine powder of iron oxide (Fe 2 O 3 )
1 kg was thoroughly mixed with a sample mill, and distilled water was added to make it clay-like. After drying and dehydration at 105 ° C for 24 hours, a furnace was made with heat-resistant bricks, and oxygen / propane flame was used as a heat source at about 1900 ° C to make it first. A mixture of titanium dioxide (TiO 2 ) and iron oxide (Fe 2 O 3 ) made into suitable small lumps was placed in a furnace, rapidly heated and melted, then cooled with water, and the resulting fired product was cut into 2 cm x 2 cm. × 0.
It was 5 cm.
一方酸化ニッケル（NiO）と酸化鉄（Fe2O3）をモル比で
１対１とし、バインダーとしてポバールを重量比で１％
添加し、ボールミルを用いて湿式混合し、ろ過，乾燥，
粉砕後成形し、1350℃で２時間焼成後切断し、2cm×2cm
×0.5cmの大きさのニッケルフェライトを作った。On the other hand, the molar ratio of nickel oxide (NiO) and iron oxide (Fe 2 O 3 ) is 1: 1 and poval as a binder is 1% by weight.
Add, wet mix using a ball mill, filter, dry,
After crushing, molding, firing at 1350 ° C for 2 hours, then cutting, 2cm x 2cm
A nickel ferrite of size 0.5 cm was made.
以上のようにして作った２種類のサンプルを定格出力60
0Wの1.45ギガヘルツ電子レンジで１分30秒間加熱し、サ
ーミスター温度計でこの２種類のサンプルの表面温度を
測定したところ表−１のような結果が得られた。Two types of samples made as described above are rated output 60
When the surface temperature of these two types of samples was measured with a thermistor thermometer after heating for 1 minute 30 seconds in a 0 W 1.45 GHz microwave oven, the results shown in Table 1 were obtained.
実施例２ 二酸化チタン（TiO2）微粉1kgと、酸化鉄（Fe2O3）微粉
1kgをサンプルミルで十分混合し、さらに蒸留水を加え
て粘土状にし、105℃で24時間乾燥脱水後、耐熱煉瓦で
炉を作り、酸素・プロパン炎を熱源として約1900℃で先
に作った二酸化チタン（TiO2）と酸化鉄（Fe2O3）の混
合物を適当な小塊にしたものを炉内に置き、急速加熱溶
解した後水冷し、得られた焼成物を粗粉砕後サンプルミ
ルで粉砕した後、ペイントコンディショナーでエポキシ
樹脂とキシレン溶剤及びハイアルミナビーズを加え２時
間振とうし、得られた塗料にポリアミド樹脂を加え表−
２の顔料対バインダー比率とし、0.5ミリメートル厚で2
0センチ角のアルミ板テストパネルにはけ塗りし、真空
脱気、150℃30分焼付を繰り返し、塗装厚みが2.3ミリメ
ートルに仕上げた。この塗板に9.4ギガヘルツの電磁波
を当てその反射減衰度を測定した。比較として、実施例
１でつくったニッケルフェライトについても同一顔料／
バインダー重量比においてテストした。測定結果を表−
２に示す。 Example 2 1 kg of titanium dioxide (TiO 2 ) fine powder and iron oxide (Fe 2 O 3 ) fine powder
1 kg was thoroughly mixed with a sample mill, and distilled water was added to make it clay-like. After drying and dehydration at 105 ° C for 24 hours, a furnace was made with heat-resistant bricks, and oxygen / propane flame was used as a heat source at about 1900 ° C to make it first. A mixture of titanium dioxide (TiO 2 ) and iron oxide (Fe 2 O 3 ) made into suitable small lumps is placed in a furnace, rapidly heated and melted, then water cooled, and the resulting calcined product is roughly crushed and then sample milled. After pulverizing with, add epoxy resin, xylene solvent and high alumina beads with paint conditioner and shake for 2 hours. Add polyamide resin to the obtained paint and add
2 at 0.5 mm thickness, with a pigment to binder ratio of 2
A 0 cm square aluminum plate test panel was brushed, degassed in vacuum, and baked repeatedly at 150 ° C for 30 minutes to obtain a coating thickness of 2.3 mm. An electromagnetic wave of 9.4 GHz was applied to this coated plate and its return loss was measured. As a comparison, the nickel ferrite prepared in Example 1 also has the same pigment /
Tested in binder weight ratio. Table of measurement results
2 shows.
効果 以上説明したように本発明によって得られた電磁波吸収
材はフェライト系の電磁波吸収材に比べて効果的に電磁
波を減衰せしめることができた。 Effect As described above, the electromagnetic wave absorbing material obtained by the present invention can effectively attenuate the electromagnetic wave as compared with the ferrite type electromagnetic wave absorbing material.
Claims (5)
たはチタンおよび鉄の複合酸化物を、原料の溶融温度以
上で焼成し、急速に冷却して得られる半導体物質よりな
るギガヘルツ帯電磁波吸収材料。1. A gigahertz band electromagnetic wave absorbing material comprising a semiconductor material obtained by firing a mixture of titanium oxide and iron oxide or a composite oxide of titanium and iron at a melting temperature of a raw material or higher and rapidly cooling. .
求項１のギガヘルツ帯電磁波吸収材料。2. The gigahertz band electromagnetic wave absorbing material according to claim 1, wherein the raw material is a mixture of TiO 2 and Fe 2 O 3 .
ヘルツ帯電磁波吸収材料。3. The gigahertz band electromagnetic wave absorbing material according to claim 1, wherein the raw material is ilmenite.
ないし３のいずれかのギガヘルツ帯電磁波吸収材料。4. The semiconductor material in powder form according to claim 1.
To 3 GHz electromagnetic wave absorbing material.
のギガヘルツ帯電磁波吸収材料。5. A composite with an organic polymer resin.
Gigahertz band electromagnetic wave absorbing material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62036239A JPH07101786B2 (en) | 1987-02-18 | 1987-02-18 | Electromagnetic wave absorbing material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62036239A JPH07101786B2 (en) | 1987-02-18 | 1987-02-18 | Electromagnetic wave absorbing material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63202999A JPS63202999A (en) | 1988-08-22 |
| JPH07101786B2 true JPH07101786B2 (en) | 1995-11-01 |
Family
ID=12464223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62036239A Expired - Fee Related JPH07101786B2 (en) | 1987-02-18 | 1987-02-18 | Electromagnetic wave absorbing material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07101786B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002057485A (en) * | 2000-06-01 | 2002-02-22 | Yokohama Rubber Co Ltd:The | Composition of electric wave absorbing body |
| JP4938168B2 (en) * | 2000-10-31 | 2012-05-23 | チタン工業株式会社 | Low magnetic black pigment powder, method for producing the same, and use thereof |
| JP3520470B2 (en) * | 2000-11-07 | 2004-04-19 | 独立行政法人産業技術総合研究所 | Radio wave absorber |
| JP2002151884A (en) * | 2000-11-15 | 2002-05-24 | Yokohama Rubber Co Ltd:The | Radio wave absorbing structure |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57100794A (en) * | 1980-12-16 | 1982-06-23 | Minoru Hayashi | Radio wave absorbing wall material |
| JPS57180206A (en) * | 1981-04-13 | 1982-11-06 | Secr Defence Brit | Improvement in or relative to radio wave absorptive coating |
-
1987
- 1987-02-18 JP JP62036239A patent/JPH07101786B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63202999A (en) | 1988-08-22 |
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