JPS5986637A - Electrically conductive inorganic powder - Google Patents

Abstract

PURPOSE:To provide an electrically conductive inorg. powder which is used as a filler for a plastic material useful as an electromagnetic wave shielding material, by coating the surface of the powder with an electrically conductive material. CONSTITUTION:A coating having a thickness of 100mu to several mm. composed of an electrically conductive material having a volume resistivity of 1OMEGA.cm or below, such as metal (e.g. silver, aluminum or copper), is formed on the surface of a scaly non-metallic inorg. powder such as mica having an aspect ratio of 10 or above. The coating may be conducted by the plating or sputtering of the electrically conductive material, or by coating the powder with said material by using a binder.

Description

【発明の詳細な説明】 本発明は導電性無機粉粒体に関し、さらに詳しくは鱗片
状非金属無機粉粒体をペースとした導電性無機粉粒体に
関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conductive inorganic powder, and more particularly to a conductive inorganic powder having a scale-like nonmetallic inorganic powder as a paste.

近年各種電子機器が発達するにつれて、発生する電磁波
による障害を防ぐための電磁波シールド材が強く望まれ
るようになった。特に電子機器の容器体として多用され
ているプラスチック材料を電磁じゃへいするために有効
な電磁波シールド材（以下シールド材とする）の開発が
望まれている。As various electronic devices have developed in recent years, there has been a strong demand for electromagnetic shielding materials to prevent interference due to generated electromagnetic waves. In particular, it is desired to develop an electromagnetic wave shielding material (hereinafter referred to as "shielding material") that is effective for electromagnetically shielding plastic materials that are often used as containers for electronic devices.

かかる問題に対し、従来提供されてきたシールド材はア
ルミニウム、銅等の金属の粒状粉体、繊維状体および鱗
片状体や炭素繊維、金属被覆ガラヌ繊維等の非金属体を
ベースとした繊維状体がある、さらにプラスチックスと
共に用いられるシールド材としては、電磁じゃへい性能
の他にフィラーとしての機械的および成形性の性能の優
れたものが必要である。かかる観点から上述した従来の
シールド材を見ると、いずれもこれらの性能を満足する
ものは無く、優れたシールド材の開発が望まれていた。To solve this problem, conventionally provided shielding materials are fibrous materials based on granular powders, fibrous materials, and scale-like materials of metals such as aluminum and copper, and non-metallic materials such as carbon fibers and metal-coated galanic fibers. A shielding material that has a body and is used together with plastics must have not only electromagnetic shielding performance but also excellent mechanical and moldability performance as a filler. Looking at the above-mentioned conventional shielding materials from this point of view, none of them satisfy these performance requirements, and there has been a desire to develop an excellent shielding material.

本発明者らは上記問題を解決し、新規なシールド材を開
発すべく鋭意研究の結果、本発明に到達したものである
。すなわち本発明は、鱗片状非金属無機粉粒体の表面が
２０℃における体積抵抗率が１０・Ｑｍ以下の導電性物
質で被覆されてなる導電性無機粉粒体である。The present inventors have arrived at the present invention as a result of intensive research to solve the above problems and develop a new shielding material. That is, the present invention is a conductive inorganic powder in which the surface of a scaly nonmetallic inorganic powder is coated with a conductive substance having a volume resistivity of 10.Qm or less at 20°C.

本発明で用いられる鱗片状非金属無機粉粒体（以下、鱗
片状無機体とする）は白雲母、金雲母などの雲母、ガラ
ス、鉱滓、シラス等の天然または合成された非金属の無
機粉粒体であり、そのアスペクト比（直径の厚さに対す
る比）が１０以上のものが軽重しい。単にシールド材と
しての性能を考慮するだけならば金属の鱗片体は優れた
性能を有しているが、上述したようにプラスチックスの
フィラーとして用いる場合は、その剛性やプラスチック
スとの混練に際しての成形性が優ねでいる点で非金属無
機体の方が好適である。例えば、比弾性率（弾性率（Ｋ
ｇ　／ａｍ’　）の密度（Ｋ９／　ａｍｓ　）に対する
比）で示せば、フレーク状で利用されているアルミニウ
ムの比弾性率は２．５　Ｘ　１０８０ｍであるが、雲母
およびＥガラスの比弾性率は夫々６×１０８ｃｍおよび
３Ｘ１０８ｃｍであシ非金属無機体の方が優れているこ
とは明らかである。さらに実用上の問題と１〜で、金属
フレークは表面積が大きいため易酸化性であり、空気中
で取扱う際には発火、爆発の危険があり、かかる事故の
防止を十分に留意して使用しなければならない。これに
対して本発明の導電性無機粉粒体は非金属体をベースと
しているために上述の問題は全く無い。The scaly nonmetallic inorganic powder used in the present invention (hereinafter referred to as scaly inorganic material) is a natural or synthetic nonmetallic inorganic powder such as mica such as muscovite and phlogopite, glass, slag, and whitebait. It is a granular material, and those with an aspect ratio (ratio of diameter to thickness) of 10 or more are light and heavy. Metal scales have excellent performance if we simply consider their performance as shielding materials, but as mentioned above, when used as fillers for plastics, there are Non-metallic inorganic materials are more suitable because they have better moldability. For example, specific modulus (modulus of elasticity (K
The specific elastic modulus of aluminum used in flake form is 2.5 x 1080 m, but the specific elastic modulus of mica and E-glass is It is clear that the non-metallic inorganic bodies are superior to those of 6×10 8 cm and 3×10 8 cm, respectively. Furthermore, regarding practical issues and points 1 to 1, metal flakes are easily oxidized due to their large surface area, and there is a risk of fire or explosion when handling them in the air. There must be. On the other hand, since the conductive inorganic powder of the present invention is based on a non-metallic material, there is no problem mentioned above.

さらに繊維状導電体、例えば金属繊維、金属被覆ガラス
繊維、炭素繊維等と比較すると、同じくプラスチックス
のフィラーとして考える場合、繊維状体は混練時や成形
加工時にからまりが生じ易く、均一分散が難かしく、面
に対して等方性かつ均質な導電性を与え難い。これらの
性能に対しては鱗片状体がはるかに優れているのである
。Furthermore, when compared with fibrous conductors such as metal fibers, metal-coated glass fibers, carbon fibers, etc., when considered as fillers for plastics, fibrous materials tend to become tangled during kneading and molding processes, making uniform dispersion difficult. It is difficult to provide isotropic and homogeneous conductivity to the surface. Scaly bodies are far superior to these properties.

本発明で用いられる鱗片状無機体としては、白雲母、金
雲母等の雲母フレーク、ガラスフレーク。Examples of the scaly inorganic material used in the present invention include mica flakes such as muscovite and phlogopite, and glass flakes.

タルク、グラファイト、セリサイト、バーミキュライト
、ベントナイト、アタパルジャイト等が挙げられる。鱗
片状無機体の大きさおよび形状は、直径が５μ以上、ア
スペクト比は１０以上婦好ましくは２０以上のものが好
適である。とくに雲母は、高アスペクト比、高剛性、耐
熱性、耐薬品性等の点で最も好ましく用いられる鱗片状
無機体である。Examples include talc, graphite, sericite, vermiculite, bentonite, and attapulgite. The suitable size and shape of the scale-like inorganic body are such that the diameter is 5 μ or more and the aspect ratio is 10 or more, preferably 20 or more. In particular, mica is a scaly inorganic material that is most preferably used in terms of high aspect ratio, high rigidity, heat resistance, chemical resistance, and the like.

上記鱗片状無機体を被覆する導電性物質は２０℃におけ
る体積抵抗率が１オーム・センナメートル以下のものな
ら何でも良く、銀、アルミニウム。The conductive material covering the scale-like inorganic material may be any material having a volume resistivity of 1 ohm/cm or less at 20° C., such as silver or aluminum.

銅、ニッケル、クロム、チタン、スズ、アンチモン、亜
鉛、金、白金から選ばれる少なくとも１種の金属すなわ
ち金属単体、またはこれを含む合金、ならびにこれらの
酸化物、導電性カーボンがある。Examples include at least one metal selected from copper, nickel, chromium, titanium, tin, antimony, zinc, gold, and platinum, that is, an elemental metal, an alloy containing the metal, oxides thereof, and conductive carbon.

特に好ましいのは上述した金属である。該導電性物質は
無電解メッキ、あるいは電解メッキ、真空蒸着、スパッ
タリング、バインダーによるコート法等公知の方法で被
覆することができる。被覆層の厚さは任意に定めること
ができるが、被覆物質の単原子（または分子）層以上の
厚みが必要であり、通常１００オンゲスＦロームから数
ミリメートルの厚みであシ、より好ましくは１０００オ
ングタトローム〜１ミリメートルの厚さである。Particularly preferred are the metals mentioned above. The conductive material can be coated by a known method such as electroless plating, electrolytic plating, vacuum deposition, sputtering, or coating with a binder. The thickness of the coating layer can be determined arbitrarily, but it needs to be at least a monoatomic (or molecular) layer of the coating material, and usually has a thickness of 100 Å to several millimeters, more preferably 1000 Å. ongtatrom ~1 mm thick.

本発明による導電性無機粉粒体はプラスチックスに対す
るフィラーとして用いる場合に最もその効果を発揮でき
るものであるが、他の素材、例えばセラミックス、ガラ
ス等と共に使用してもシールド材として有効である。さ
らにこれら本発明による導電性無機粉粒体を利用した複
合材料の示す導電性は、上述の電磁波シールド材として
のみならず、静電気障害防止材、導電発熱体等各種用途
にも利用されるものである。さらには、本発明の導電性
無機粉粒体は金属との接着性に優れ、複合化によシフレ
ーク強化金属（ＦＲＭ）として有効に利用される。本発
明の導電性無機粉粒体は他の材料との複合材料としての
みならず単体にても非燃焼性の電波散乱材等として利用
されるものである。The conductive inorganic powder according to the present invention is most effective when used as a filler for plastics, but it is also effective as a shielding material when used with other materials such as ceramics and glass. Furthermore, the conductivity exhibited by the composite material using the conductive inorganic powder according to the present invention can be used not only as the above-mentioned electromagnetic shielding material, but also in various applications such as electrostatic interference prevention material and conductive heating element. be. Furthermore, the conductive inorganic powder of the present invention has excellent adhesion to metals, and can be effectively used as a flake-reinforced metal (FRM) by compounding. The conductive inorganic powder of the present invention can be used not only as a composite material with other materials, but also as a non-combustible radio wave scattering material.

以下、実施例をあげて本発明の方法をさらに具体的に説
明するが、本発明はこれらの実施例によシ何ら制限され
るものではない。Hereinafter, the method of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

実施例１ 平均フレーク径２６０μ、平均フレーク厚さ４μ（アス
ペクト比６０）のＥガラスフレークを５０ｆ／ｌのリン
酸ナトリウム水溶液中に浸漬し、１０分間煮沸し、ｒ過
後水洗した。つづいて塩化第一スズ１０　ｆ／ｌおよび
濃塩酸４０ｍＩ！／ｌ：からなる３０〜４０℃の水溶液
中に攪拌しつつ５分間浸漬後ｒ過した。さらにメチルア
ルコ−／Ｌ／３容、４０％ホルムアルデヒド７容の混合
溶液に３分間浸漬後ｒ過水洗し、処理ガラスフレークを
得た。３０ｆの硝酸銀を５００ｍ１の純水に溶かし、つ
ぎにアンモニアを加えると沈殿が生じるが再び溶解する
までアンモニアを加え続け、最後に６００ｍ１：になる
まで純水を加えて銀波を調製した。別に３０ｇのロッセ
ル塩を４００　ｍｌ！の純水に溶解して還元液を調製し
た。Example 1 E-glass flakes having an average flake diameter of 260 μm and an average flake thickness of 4 μm (aspect ratio 60) were immersed in a 50 f/l aqueous sodium phosphate solution, boiled for 10 minutes, filtered with water, and washed with water. Followed by 10 f/l of stannous chloride and 40 mI of concentrated hydrochloric acid! /l: immersed in an aqueous solution at 30 to 40°C with stirring for 5 minutes, and then filtered. Further, the glass flakes were immersed in a mixed solution of 3 volumes of methyl alcohol and 7 volumes of 40% formaldehyde for 3 minutes and washed with water to obtain treated glass flakes. A silver wave was prepared by dissolving 30 f of silver nitrate in 500 ml of pure water, then adding ammonia to form a precipitate, but continuing to add ammonia until it dissolved again, and finally adding pure water until the amount reached 600 ml. Separately, 400 ml of 30 g of Rosselle salt! A reducing solution was prepared by dissolving it in pure water.

銀波および還元液をそれぞれ濾過しだ後全量を混合し、
２０〜２５℃に保持した液中に上述の処理ガラスフレー
ク２５９を加え、１時間攪拌した後フレークを濾過し、
水洗後乾燥して銀被覆ガラスフレークを得た。得られた
銀被覆ガラスフレークは銀色の美麗な光沢を有しており
、走査型電子顕微鏡観察により、銀の被覆厚さはガラス
フレークの片面について約０．３μ程度と推定された。After filtering each silver wave and reducing solution, mix the entire amount,
The above-mentioned treated glass flakes 259 were added to the liquid maintained at 20 to 25°C, and after stirring for 1 hour, the flakes were filtered,
After washing with water and drying, silver-coated glass flakes were obtained. The obtained silver-coated glass flakes had a beautiful silver luster, and the thickness of the silver coating on one side of the glass flakes was estimated to be about 0.3 μm by scanning electron microscopy.

また得られた銀被覆ガラスフレーク粉粒体の５０９７０
ｍ２の加圧下での体積抵抗率は１１０−２Ｏ−ａ以下で
あった。50970 of the obtained silver-coated glass flake powder
The volume resistivity under a pressure of m2 was 110-2 O-a or less.

実施例２ 平均フレーク径２８０μ、平均厚み４μ（アスペクト比
７０）の金雲母フレーク（マリエツタ・リソーシズ・イ
ンターナショナル社製スジライトマイカ６０Ｓ）を６０
％フッ化水素酸溶液にて軽く洗浄した後水洗し、乾燥し
て処理雲母を得た。タング７テンコイルヒーター加熱方
式の真空蒸着装置の基板上に一ヒ記処理雲母を薄く拡げ
、１０　’Ｔｏｒｒの真空下でアルミニウムを蒸着した
。約５分間毎に基板上の雲母フレークをかきまぜ、合計
３０分間蒸着を施した。得られたアルミニウム被覆金雲
母は金属光沢を呈しており、５０ｆ／Ｑｍ２の加圧下で
の体積抵抗率は１１０−２Ｏ−ａ以下であった２実施例
３ 平均フレーク径２８０μ、平均厚み３μ（アスペクト比
９０）の白雲母フレークを５５％フッ化水素酸溶液に約
１分間浸漬し、濾過水洗した。つづいてこのフレークを
塩化第一スズ１０１／／／おヨヒ塩酸５　ｍｌ／ｌから
なる水溶液中に２５〜３５℃にて５分間撹拌しつつ浸漬
した後濾過水洗した。さらにこのフレークを塩化パラジ
ウム０．４　ｆ／ｉおよび塩酸２　ｆｎｌ！　／ｌから
なる水溶液中に３０〜３５℃にて５分間攪拌しつつ浸漬
した後濾過水洗した。これらの処理を施した白雲母フレ
ークを硫酸ニッケ＃２０（／／ｌ　、クエン酸ナトリウ
ム５０　ｆ／ｌ　、次亜リン酸ナトリウム１０１／ｌお
よび乳酸５ｍ１／ｌからなる水溶液中に４０〜４５℃に
て３０分間攪拌しつつ浸漬し、濾過・水洗後乾燥してニ
ッケル被覆雲母を得た。得られたニッケル被覆雲母は美
しい金属光沢を示しており、５０　ｐ／Ｑｍ２の加圧下
での体積抵抗率は１０−２０・ＱＦＦ＋以下であった。Example 2 Phlogopite flakes (Sugilite Mica 60S manufactured by Marietsuta Resources International) with an average flake diameter of 280μ and an average thickness of 4μ (aspect ratio 70) were
% hydrofluoric acid solution, water, and drying to obtain treated mica. The treated mica described above was spread thinly on the substrate of a vacuum evaporation apparatus using a tungsten coil heater heating method, and aluminum was evaporated under a vacuum of 10' Torr. The mica flakes on the substrate were agitated approximately every 5 minutes for a total of 30 minutes of deposition. The obtained aluminum-coated phlogopite had a metallic luster, and the volume resistivity under a pressure of 50 f/Qm2 was 110-2 O-a or less.2 Example 3 Average flake diameter 280μ, average thickness 3μ (aspect Muscovite flakes with a ratio of 90) were immersed in a 55% hydrofluoric acid solution for about 1 minute, filtered and washed with water. Subsequently, the flakes were immersed in an aqueous solution containing 101 stannous chloride and 5 ml/l of hydrochloric acid at 25 to 35° C. with stirring for 5 minutes, and then filtered and washed with water. The flakes were then treated with 0.4 f/i palladium chloride and 2 fnl hydrochloric acid! The sample was immersed in an aqueous solution of 1/1 at 30 to 35°C for 5 minutes with stirring, and then filtered and washed with water. Muscovite flakes subjected to these treatments were placed at 40-45°C in an aqueous solution consisting of nickel sulfate #20 (/l), sodium citrate 50 f/l, sodium hypophosphite 101/l and lactic acid 5 ml/l. The nickel-coated mica was immersed for 30 minutes with stirring, filtered, washed with water, and dried to obtain nickel-coated mica.The obtained nickel-coated mica exhibited a beautiful metallic luster and had a volume resistivity under pressure of 50 p/Qm2. was less than 10-20·QFF+.

実施例４ 実施例１にて得られた銀被覆ガラスフレーク３５重量部
を予め０．２ＰＨＲ（樹脂１００重量部に対する重量部
単位）のナフテン酸コバｐト（００分６％）および１．
５　ＰＨＨの５５％ＭＥＫパーオキサイドを加えた不飽
和ポリエステμ樹脂（日本ユピカ（株）製ュピカ２０７
５　）６５重量部と混合し、シリコンゴム製の２ｍｍ厚
さのスペーサーをはさんだガラス板間に注入し、２０〜
２５℃の室温で５時間、つづいて８０〜１００℃にて１
２時間硬化させ、脱型して２ｍｍ厚、２００　ｍｎｔ角
の銀被覆ガラスフレークと不飽和ポリエステル樹脂との
複合板試料を得た。この複合板試料の体積抵抗率はｌＸ
１０＝Ω・ｃｍであった。Example 4 35 parts by weight of the silver-coated glass flakes obtained in Example 1 were preliminarily mixed with 0.2 PHR (parts by weight relative to 100 parts by weight of resin) of cobapt naphthenate (00 min 6%) and 1.
5 Unsaturated polyester μ resin containing 55% PHH MEK peroxide (Upica 207 manufactured by Nippon Upica Co., Ltd.)
5) Mix with 65 parts by weight and inject between glass plates sandwiching a 2 mm thick spacer made of silicone rubber.
5 hours at room temperature of 25℃, followed by 1 hour at 80-100℃
After curing for 2 hours, the mold was demolded to obtain a 2 mm thick, 200 mnt square composite plate sample of silver-coated glass flakes and unsaturated polyester resin. The volume resistivity of this composite plate sample is lX
10=Ω·cm.

また、一方に窓を開けたアルミニウムおよび鉄製の二重
シールド箱内に電磁波発生器として自動車用点火プラグ
を設置し、開放窓に試料を取付け、窓外に受信部として
ダイポールアンテナおよびヌペクトラムアナライザーを
設置した電磁じゃへい効果測定装置を用い、上記複合板
試料の電磁じゃへい効果を測定した。その効果は５０　
ＭＨｚの周波数の電磁波に対して４２ｄＢ１１５０ＭＥ
（Ｚでは４６ｄＢ。In addition, an automobile spark plug was installed as an electromagnetic wave generator in a double-shielded box made of aluminum and iron with a window open on one side, a sample was attached to the open window, and a dipole antenna and a nupectrum analyzer were installed outside the window as a receiver. The electromagnetic interference effect of the composite plate sample was measured using the installed electromagnetic interference effect measuring device. Its effect is 50
42dB1150ME for electromagnetic waves with a frequency of MHz
(46dB in Z.

また５００ＭＨｚにおいては５０　ｄＢで優れたもので
あった。Furthermore, at 500 MHz, it was excellent at 50 dB.

実施例５ 実施例２にて得られたアルミニウム被覆金雲母フレーク
４０重量部と一般射出成形用ボリプロビレン樹脂６０重
量部との混合物を一軸押出機（スクリュー径４０ｍｍ、
　Ｌ／Ｄ＝　２８、圧縮比３．５）にて溶融混練し、押
出してベレット化した。得られた複合ベレットをフィル
ムゲート平板用金型を取り付けたスクリューインライン
式５オンス創出成形機を用い、シリンダ一温度２３０℃
、金型温度６０℃の条件下で射出成形を行ない、２ｍｍ
厚、１５０ｍｍ角の試料板を成形した。この試料板の表
面は滑らかで光沢を示しておシ、その体積抵抗率け５Ｘ
１０−１０・ａｍであった。実施例４に記した電磁じゃ
へい効果測定装置を用いてこの試料板の電磁じゃへい効
果を測定したところ、５０　ＭＨｚの周波数の電磁波に
対して３４ｄＢ、　１５０ＭＨｚにおいて２８ｄＢ、　
５００ＭＨｚにおいて３２ｄＢであシ優れたものであっ
た。Example 5 A mixture of 40 parts by weight of the aluminum-coated phlogopite flakes obtained in Example 2 and 60 parts by weight of polypropylene resin for general injection molding was heated in a single screw extruder (screw diameter 40 mm,
The mixture was melt-kneaded at L/D=28 and compression ratio 3.5) and extruded to form pellets. The resulting composite pellet was molded using a screw-in-line 5-ounce molding machine equipped with a film gate plate mold, and the cylinder temperature was 230°C.
, injection molding was carried out at a mold temperature of 60°C, and the thickness was 2 mm.
A sample plate with a thickness of 150 mm square was molded. The surface of this sample plate is smooth and glossy, and its volume resistivity is 5X.
It was 10-10 am. When the electromagnetic interference effect of this sample plate was measured using the electromagnetic interference effect measuring device described in Example 4, it was 34 dB for electromagnetic waves with a frequency of 50 MHz, 28 dB at 150 MHz,
It was excellent at 32 dB at 500 MHz.

また試料板よシ切シ出して作製した輻２０　ｍｍ　Ｘ長
さ８０　ｍｍ　Ｘ　２　ｍｍ厚の試験片を用いて測定し
た曲げ強度は７２０　Ｋｇ　／ａｍ’　、曲げ弾性率は
乙３　Ｘ　１０’　Ｋｇ　／ａｍ”であり、電子機器等
の容器体としての用途に対しては優れた特性を示すもの
であった。In addition, the bending strength measured using a test piece with diameter 20 mm x length 80 mm x 2 mm thick prepared by cutting out the sample plate was 720 Kg/am', and the bending elastic modulus was 3 x 10' Kg. /am'', and exhibited excellent properties for use as containers for electronic devices and the like.

比較例１ 実施例５のアルミニウム被覆金雲母フレークにかえて、
処理を施さない原料の金雲母フレーク（スジライトマイ
カ６０Ｓ）を用い、他は実施例５と全く同じ条件によシ
雲母４０重量％とポリプロピレン樹脂６０重量％との複
合試料板を作製し、その物性を測定した。この試料板の
体積抵抗率は１Ｘ１０”Ω・Ｑｍであり、電磁しやへい
効果は５　［Ｉ　ＭＨ’Ｚにおいて約２ｄＢ、　１５０
ＭＨｚにおいて３ｄＢ、　５００　ＭＨｚにおいて５ｄ
Ｂであり、殆んど効果を有していなかった。また曲げ強
度は７５０　Ｋｑ／Ｑｍ２、曲げ弾性率は７、８　Ｘ　
１０’　Ｋｇ　／Ｑｍ２テあった。Comparative Example 1 Instead of the aluminum-coated phlogopite flakes of Example 5,
A composite sample plate of 40% by weight of phlogopite and 60% by weight of polypropylene resin was prepared using untreated raw material phlogopite flakes (sudilite mica 60S) and under the same conditions as in Example 5. Physical properties were measured. The volume resistivity of this sample plate is 1×10”Ω・Qm, and the electromagnetic shielding effect is approximately 2 dB at 5 [I MH'Z, 150
3dB at MHz, 5d at 500MHz
B, and had almost no effect. Also, the bending strength is 750 Kq/Qm2, and the bending modulus is 7.8
It was 10' Kg/Qm2.

比較例２ 実施例５のアルミニウム被覆金雲母フレークにかえて、
平均粒径１．２ｍｙ＋、アスペクト比５０のアルミニウ
ムフレークを用い、他は実施例５と同じ条件によりアル
ミニウムフレーク４０重量％とポリプロピレン樹脂６０
重量％との複合試料板を作製し、その物性を測定した。Comparative Example 2 Instead of the aluminum-coated phlogopite flakes of Example 5,
Using aluminum flakes with an average particle size of 1.2 my+ and an aspect ratio of 50, the other conditions were the same as in Example 5, and 40% by weight of aluminum flakes and 60% by weight of polypropylene resin were used.
A composite sample plate with weight% was prepared and its physical properties were measured.

この試料板の表面平滑性は不良で、光沢は無く、その体
積抵抗率は８Ω−ａｍ−’ｃあり、５０ＭＨｚ、　１５
０ＭＨｚおよび５　ｏ　ｏ　ＭＨｚにおける電磁じゃへ
い効果は夫々２０ｄＢ、１８ｄＢおよび２５ｄＢであり
、曲げ強度は４３０　Ｋｇ　／　０ｍ２、曲げ弾性率は
２．７　Ｘ　１０’　Ｋｑ／Ｑｍ２であって、いずれの
性質も実施例５に劣るものであった。The surface smoothness of this sample plate was poor, there was no gloss, and its volume resistivity was 8Ω-am-'c, 50MHz, 15
The electromagnetic interference effect at 0 MHz and 5 o o MHz is 20 dB, 18 dB and 25 dB, respectively, the bending strength is 430 Kg / 0 m2, the bending modulus is 2.7 X 10' Kq/Qm2, and both properties are It was inferior to Example 5.

比較例６ 実施例５のアルミニウム被覆金雲母フレークにかえて、
処理を施さない金雲母フレーク（スジライトマイカ６０
Ｓ）および平均粒径１．２ｍｍ、アスペクト比５０のア
ルミフレークをそれぞれ２０重量％用い、他は実施例５
と同じ条件により雲母２０重量％とアルミフレーク２０
重量％とポリプロピレン樹脂６０重量％との複合試料板
を作製し、その物性を測定した。この試料板の体積抵抗
率は５×１０４Ω−ＱＩＭであり、５０ＭＨｚ、　１５
０ＭＨｚおよび５００　ＭＨｚにおける電磁じゃへい効
果は夫々１０ｄＢ、１３（ｉＢおよび９ｄＢであった。Comparative Example 6 Instead of the aluminum-coated phlogopite flakes of Example 5,
Untreated phlogopite flakes (Sugilite Mica 60)
S) and aluminum flakes with an average particle size of 1.2 mm and an aspect ratio of 50 were each used in an amount of 20% by weight, and the rest were as in Example 5.
20% by weight of mica and 20% of aluminum flakes under the same conditions as
A composite sample plate of 60% by weight of polypropylene resin was prepared and its physical properties were measured. The volume resistivity of this sample plate is 5 x 104Ω-QIM, 50MHz, 15
The electromagnetic interference effects at 0 MHz and 500 MHz were 10 dB, 13 (iB and 9 dB), respectively.

また曲げ強度は６１０に９　／　０ｍ２、曲げ弾性率は
５．８　Ｘ　１０’　Ｋｇ１０ｍ２テアリ、いずれの性
質も実施例５に劣るものであった。Further, the bending strength was 610.9/0 m2, and the bending elastic modulus was 5.8 x 10' Kg10 m2, both of which were inferior to Example 5.

比較例４ 実施例５のアルミニウム被覆金雲母フレークに１ かえて平均直径１８０μ、平均長さ６ｍｍのアルミニウ
ム繊維を用い、他は実施例５と同じ条件によりアルミニ
ウム繊維４０重量％とポリプロピレン樹脂６０重量％と
の複合試料板を作製しようとしたところ、混練が不可能
であり、作製できなかった。Comparative Example 4 Aluminum fibers with an average diameter of 180μ and an average length of 6 mm were used instead of the aluminum-coated phlogopite flakes of Example 5, and the other conditions were the same as in Example 5, except that 40% by weight of aluminum fibers and 60% by weight of polypropylene resin were used. When I tried to make a composite sample plate with this material, it was impossible to knead it, so I couldn't make it.

そこでアルミニウム繊維の添加量を減少していきようや
く作製できた複合試料板はアルミニウム繊維が約１２重
量％のものであった。この試料板の表面平滑性は不良で
あり、その体積抵抗率は３×１１０４０−ａであシ、５
０ＭＨｚ、　１５０　ＭＨ２および５００ＭＨｚにおけ
る電磁じゃへい効果は夫々１２ｄＢ、２１ｄＢおよび１
３ｄＢであった。また試料板が不良で曲げ試験用の試験
片は切シ出せなかった。いずれの性質も実施例５に劣る
ものであった。Therefore, the amount of aluminum fibers added was reduced, and the composite sample plate that was finally produced contained approximately 12% by weight of aluminum fibers. The surface smoothness of this sample plate was poor, and its volume resistivity was 3 x 11040-a.
The electromagnetic interference effect at 0 MHz, 150 MHz and 500 MHz is 12 dB, 21 dB and 1, respectively.
It was 3dB. In addition, the sample plate was defective and it was not possible to cut out a test piece for the bending test. All properties were inferior to Example 5.

特許出願人　株式会社　り　ラ　し 代理人弁理士本多　堅 ４Patent applicant RiRashi Co., Ltd. Representative Patent Attorney Ken Honda 4

Claims (4)

【特許請求の範囲】[Claims] （１）　＃片状非金属無機粉粒体の表面が２０℃におけ
る体積抵抗率が１０・ＱｔＨ以下の導電性物質で被覆さ
れてなる導電性無機粉粒体。(1) #A conductive inorganic powder in which the surface of a flaky nonmetallic inorganic powder is coated with a conductive substance having a volume resistivity of 10·QtH or less at 20°C. （２）該無機粉粒体がアスペクト比（直径の厚さに対す
る比）１０以上の鱗片体である特許請求の範囲第（１）
項に記載の導電性無機粉粒体。(2) Claim No. 1, wherein the inorganic powder is a scale body with an aspect ratio (ratio of diameter to thickness) of 10 or more.
The conductive inorganic powder described in Section 1. （３）該無機粉粒体が雲母である特許請求の範囲第（１
）項または第（２）項に記載の導電性無機粉粒体。(3) Claim No. 1 in which the inorganic powder is mica
) or (2). （４）該導電性物質が銀、アルミニウム、銅、ニッケル
、クロム、チタン、スズ、アンチモン、亜鉛、金、白金
、鉄から選ばれる少なくとも１種の金属単体またはこれ
を含む合金である特許請求の範囲第（１）項、第（２）
項または第（３）項に記載の導電性無機粉粒体。(4) A patent claim in which the conductive substance is at least one metal selected from silver, aluminum, copper, nickel, chromium, titanium, tin, antimony, zinc, gold, platinum, and iron, or an alloy containing the same. Range items (1) and (2)
The conductive inorganic powder according to item (3) or item (3).