JPH0210484B2 - - Google Patents
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- Publication number
- JPH0210484B2 JPH0210484B2 JP54134618A JP13461879A JPH0210484B2 JP H0210484 B2 JPH0210484 B2 JP H0210484B2 JP 54134618 A JP54134618 A JP 54134618A JP 13461879 A JP13461879 A JP 13461879A JP H0210484 B2 JPH0210484 B2 JP H0210484B2
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- Prior art keywords
- magnetic
- coercive force
- magnetic powder
- powder
- card
- Prior art date
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Description
本発明は、磁気記録情報が市販されている一般
の磁石類によつて消磁されることのない、所謂、
外部磁界耐性を強化した磁気カードに関するもの
である。
クレジツトカード、バンクカード、定期券など
の磁気カード類は、それに設けられている磁気記
録層に磁気記録を施し、その記録情報に基づいて
自動的に装置を作動すべく使用されている。とこ
ろでこれらのカード類は不特定多数の人によつて
任意の手段で携帯されているので、磁気画鋲やハ
ンドバツグの口金磁石、磁気ネツクレスの磁石等
と接触して磁気記録が消磁される可能性が多く、
ために前記した自動操作が不能になる場合があつ
た。
この一般の磁石類による消磁を防止するために
は、一般の磁石類の影響を受けない高抗磁力磁性
粉を用いた磁気カードを使用すればよいが、現有
の磁気ヘツドには磁化性能に限度があり、あまり
にも高抗磁力の磁性粉を用いた磁気カードでは、
能力オーバーになり、安定した磁気記録ができな
くなる。
磁気ヘツドに於いても磁化能力を強化したヘツ
ドの開発が進んではいるが、一般の磁石類も強力
となり、例えば磁気画鋲で鉄板上に磁気カードを
保持した場合には、約3000ガウス以上の強力な磁
界が働く場合もある。
現在、高い磁化力を容易に実現できるセンダス
トを磁気ヘツドコア材として用いた磁気ヘツドで
安定して磁気記録できる最高は、保磁力3000エル
ステツドの磁性粉を使用した磁気カードが限度で
あるから、上記した磁気画鋲の如き使い方をされ
ると、記録データが消磁されてしまうという事態
を招くことも往々にしてあるわけである。
即ち、現用されている磁気カードは現実に外部
磁界に対する耐性が不足している。
そこで本発明者らは、より高抗磁力磁性粉即ち
現有の高磁化力磁気ヘツドで最大の書込電流を用
いても安定な飽和書込みには至らないが、部分的
に磁化することのできる磁性粉を、基本となる高
抗磁力磁性粉即ち現有ヘツドで飽和書込可能な磁
性粉に配合し、この配合磁性粉を用いて磁気カー
ドの磁気記録層を形成せしめれば、外部磁界耐性
を有する磁気カードとなし得ることを知見し、本
発明を完成するに至つたものである。
即ち、本発明は基本となる保磁力2000〜3000エ
ルステツドの高抗磁力磁性粉に保磁力5000〜6000
エルステツドのより高抗磁力磁性粉を適当量配合
し、該配合磁性粉を用いて磁気記録層を形成せし
めることにより外部磁界耐性を強化したことを特
徴とする磁気カードである。
本発明の磁気カードは、通常の磁気記録には飽
和書込み可能な高抗磁力磁性粉のみから得られる
読取電圧を基準出力として使用し、より高抗磁力
磁性粉が与える読取電圧分は上乗分として包含す
るだけで具体的には利用しないが、この磁気カー
ドが強力な磁石等に起因する外部磁界に触れて消
磁作用を受けたときのみ、より高抗磁力磁性粉が
寄与する残留出力を読取り、磁気記録情報を正し
く判読できるようにしたものである。現有の高抗
磁力用磁気ヘツドで保磁力（以下Hcと略称する）
2000、3000、5000および6000エルステツドの高抗
磁力磁性粉をそれぞれ使用した磁気カードの電磁
変換特性は第１図の通りである。
磁気記録は、記録の信頼性を確保するために、
通常飽和書込み電流値の150％以上の電流値を書
込み電流として使用する。現有の磁気ヘツドで上
記条件において記録できる磁気カードはHc2000
エルステツドの磁性粉を使用したものが限度であ
る。更に飽和書込み電流値そのものを記録条件と
してもHc3000エルステツドの磁性粉を使用した
ものが限度である。従つて、現有磁気ヘツドで磁
気記録できる磁性粉としてはHc2000〜3000エル
ステツドの高抗磁力磁性粉が限度ということにな
る。
一方、市販されている磁石類の磁界の強さは普
通500〜1500ガウスの間に分布するが、鉄板と接
触させると磁界の強さが1000〜3000ガウスにも及
び、Hc3000エルステツドの磁性粉では磁気記録
を確保しきれずに消磁を生ずる。すなわち、
Hc2000〜3000エルステツドの高抗磁力磁性粉を
有する磁気カードは、第２図減磁曲線で明らかな
とおり１回の消磁作用で残留出力が20％以下にま
で減磁されてしまい、情報処理が出来なくなる。
これに対しHc5000〜6000エルステツドの磁性
粉より成る磁気カードは、第１図に示すように充
分な飽和書込みができないので通常の安定した磁
気記録には使用できないが、部分的には書込みが
できて、読取り電圧が得られる。
市販の磁気画鋲（磁界の強さ1500ガウス）と鉄
板との間に、Hc2000、3000、5000および6000エ
ルステツドの磁性粉を用いた磁気カードをそれぞ
れ挿入し、前記磁気画鋲で磁気記録部を所定回数
擦動する。そのときの残留出力を測定し、初期値
に対する残留率（％）で表示する。この場合の記
録条件は3000エルステツドの磁性粉を用いた磁気
カードの飽和記録電流の1.5倍の記録電流で200fci
全ビツト記録した。その結果は第２図のとおりで
ある。この図は、Hc5000および6000エルステツ
ドの磁性粉を用いた磁気カードが外部磁界耐性の
あることを示すものである。つまり、Hc5000エ
ルステツドのものは４回の消磁作用を受けても70
％の出力が残留し、Hc6000エルステツドでは90
％以上も残留する。しかし、Hcが高くなると外
部磁界耐性は充分であるが、第１図に見られると
おり一部が磁化されるにすぎないので、Hc6000
エルステツドを超える磁性粉を使用した磁気カー
ドは、書込みレベル3000エルステツドでは部分的
にも磁気記録できないので、利用不可能となる。
本発明は2000〜3000エルステツドおよび5000〜
6000エルステツドの磁性粉の利点を組合せて外部
磁界耐性のある磁気カードを製造して実用に供す
るよう計つたものである。即ち、通常の磁気記録
読取りに支障のない基準出力が得られるように飽
和書込みのできる高抗磁力磁性粉（例えば
Hc3000エルステツド）を配合し、磁石類に触れ
て消磁されたときに必要最小限の残留出力が得ら
れるように外部磁界耐性のあるより高抗磁力磁性
粉（例えばHc5000エルステツド）を配合した磁
気記録層を有する磁気カードを提供するものであ
る。かようにして通常の磁気記録は高抗磁力磁性
粉分で処理し、より高抗磁力磁性粉分は、通常は
単なる上乗せ分としてしか使用しないが、消磁作
用を受けた場合にのみ働かせることを意図した、
外部磁界耐性の期待できる磁気カードが得られ
る。
このような意図により今後さらに高抗磁力磁気
ヘツドが開発されれば、本発明同様の目的手段で
上記磁気ヘツドの能力以上のさらに抗磁力の大き
いより高抗磁力磁性粉が使用できることになり、
益々外部磁界耐性が向上する。
高抗磁力磁性粉としては、現状ではHcが2000
〜3000エルステツドである磁性粉が適当であり、
バリウムフエライト、ストロンチウムフエライト
等のフエライト系微粉末や各種磁性合金微粉末が
使用できる。
より高抗磁力磁性粉としては、現状ではHcが
5000〜6000エルステツドである磁性粉が適当であ
り、各種のフエライト系微粉末や磁性合金微粉末
が使用できる。
より高抗磁力磁性粉の配合量は、基準出力に対
するノイズ出力レベルが許容できる範囲に限定さ
れるが、好ましくは残留出力が20％以上であるこ
とが望まれる。したがつて配合比は高抗磁力磁性
粉の10〜50％、好ましくは25〜40％である。
配合の方法は、磁気塗料又は磁気インキ中に両
者を混合調整し、カード用紙に一層構造で塗工又
は印刷してもよく、また両者を別々に磁気塗料又
は磁気インキ化して、それぞれ別個に二層構造に
なるよう塗工又は印刷してもよい。この場合、層
の組合せは上下どちらでもかまわないが、より高
抗磁力磁性粉への書込みを容易にするために、よ
り高抗磁力磁性粉層が上層になるよう組合せたも
のの方が良好である。なお第３図に上記それぞれ
の実施態様を示した。
また、別々に調合した磁気塗料又は磁気インキ
を使用時に混合して一層構造になるよう塗工また
は印刷してもかまわない。
従つて本発明により、今まで飽和書込みができ
なくて使用できなかつたより高抗磁力磁性粉の外
部磁界耐性を利用できるようにしたため、市販の
磁石類の発する強力な磁界に触れても磁気記録が
消磁されずに正しく記録情報どおりに操作するこ
とができるようになる。
なお、この処方は磁気通行券のように磁気画鋲
で自動車のボデー（鉄板部）にカードをはさんで
所持される場合の多い磁気カードにおいては特に
有利である。
以下、実施例にもとずいて本発明をさらに詳細
に説明する。
実施例 １
高抗磁力磁性粉としてHc3000エルステツドの
バリウムフエライトを用い、またより高抗磁力磁
性粉としてHc5000エルステツドのバリウムフエ
ライトを用いて、下記の配合によりアトライター
で２時間ミリングを行ない、磁気塗料を調整し
た。
The present invention provides magnetically recorded information that is not demagnetized by commercially available general magnets.
This invention relates to a magnetic card with enhanced resistance to external magnetic fields. Magnetic cards, such as credit cards, bank cards, and commuter passes, are used to have magnetic recording layers provided thereon to perform magnetic recording, and to automatically operate devices based on the recorded information. By the way, since these cards are carried by an unspecified number of people by any means they choose, there is a possibility that their magnetic records may be demagnetized by contact with magnetic thumbtacks, handbag cap magnets, magnetic neckpiece magnets, etc. many,
Therefore, there were cases where the automatic operation described above became impossible. In order to prevent this demagnetization caused by general magnets, it is possible to use a magnetic card that uses high coercive force magnetic powder that is not affected by general magnets, but existing magnetic heads have limited magnetization performance. There is a magnetic card using magnetic powder with too high coercive force,
The capacity will be exceeded and stable magnetic recording will no longer be possible. As for magnetic heads, the development of heads with enhanced magnetization ability is progressing, but general magnets are also becoming stronger; for example, when a magnetic card is held on a steel plate with a magnetic thumbtack, it has a strength of approximately 3000 Gauss or more. In some cases, a strong magnetic field may work. Currently, the maximum that can be stably recorded with a magnetic head using Sendust as the magnetic head core material, which can easily achieve a high magnetizing force, is limited to a magnetic card using magnetic powder with a coercive force of 3000 oersteds. When used like a magnetic thumbtack, recorded data often becomes demagnetized. That is, currently used magnetic cards actually lack resistance to external magnetic fields. Therefore, the present inventors developed a magnetic powder with a higher coercive force, that is, a magnetic powder that can be partially magnetized, although stable saturated writing cannot be achieved even with the maximum write current in the existing high-magnetizing force magnetic head. If the powder is blended with a basic high coercive force magnetic powder, that is, a magnetic powder that can be saturated and written in existing heads, and this blended magnetic powder is used to form the magnetic recording layer of a magnetic card, it will have resistance to external magnetic fields. They found that it could be made into a magnetic card and completed the present invention. That is, the present invention combines a basic high coercive force magnetic powder with a coercive force of 2000 to 3000 oersteds with a coercive force of 5000 to 6000 oersted.
This magnetic card is characterized in that it has enhanced external magnetic field resistance by blending an appropriate amount of Oersted's higher coercive force magnetic powder and forming a magnetic recording layer using the blended magnetic powder. The magnetic card of the present invention uses the read voltage obtained only from the high coercive force magnetic powder that is capable of saturation writing for normal magnetic recording as the reference output, and the read voltage provided by the higher coercive force magnetic powder is the multiplication factor. Although it is not used specifically as it is only included as a magnetic card, only when this magnetic card comes into contact with an external magnetic field caused by a strong magnet etc. and receives a demagnetizing effect, the residual output contributed by the higher coercive force magnetic powder can be read. , which allows magnetically recorded information to be read correctly. Coercive force (hereinafter abbreviated as Hc) with existing magnetic heads for high coercive force
The electromagnetic conversion characteristics of magnetic cards using high coercive force magnetic powders of 2000, 3000, 5000 and 6000 oersted are shown in Figure 1. In magnetic recording, in order to ensure the reliability of recording,
Normally, a current value of 150% or more of the saturated write current value is used as the write current. The magnetic card that can record under the above conditions with the existing magnetic head is Hc2000.
The limit is those using Ørsted magnetic powder. Furthermore, even if the saturation write current value itself is used as the recording condition, the limit is when magnetic powder of Hc3000 oersted is used. Therefore, the limit of the magnetic powder that can be used for magnetic recording with existing magnetic heads is a high coercive force magnetic powder with an Hc of 2,000 to 3,000 oersteds. On the other hand, the magnetic field strength of commercially available magnets is normally distributed between 500 and 1500 gauss, but when it comes into contact with an iron plate, the field strength reaches 1000 to 3000 gauss, and the magnetic powder of Hc3000 Oersted Demagnetization occurs due to inability to secure magnetic recording. That is,
As is clear from the demagnetization curve in Figure 2, a magnetic card containing high coercive force magnetic powder with a Hc of 2000 to 3000 oersted will have its residual output demagnetized to less than 20% with a single demagnetization action, making it impossible to process information. It disappears. On the other hand, magnetic cards made of magnetic powder with a Hc of 5,000 to 6,000 oersted cannot be used for normal stable magnetic recording because they cannot be used for saturation writing, as shown in Figure 1, but they can be partially written. , a read voltage is obtained. A magnetic card using magnetic powder of Hc2000, 3000, 5000, and 6000 oersted is inserted between a commercially available magnetic thumbtack (magnetic field strength 1500 Gauss) and an iron plate, and the magnetic recording area is touched a predetermined number of times with the magnetic thumbtack. Rubbing. The residual output at that time is measured and displayed as a residual rate (%) relative to the initial value. The recording conditions in this case are 200 fci at a recording current 1.5 times the saturation recording current of a magnetic card using 3000 oersted magnetic powder.
All bits were recorded. The results are shown in Figure 2. This figure shows that magnetic cards using Hc5000 and 6000 oersted magnetic powders are resistant to external magnetic fields. In other words, even after being demagnetized four times, Hc5000 Oersted's
% output remains, 90 for Hc6000 Oersted
% or more remains. However, as Hc increases, resistance to external magnetic fields is sufficient, but as shown in Figure 1, only a portion of the magnetic field is magnetized, so Hc6000
Magnetic cards that use magnetic powder exceeding Oersted cannot be used because even a partial magnetic recording cannot be performed at a write level of 3000 Oersted. The invention applies to 2000-3000 Oersted and 5000-
It was designed to combine the advantages of 6000 oersted magnetic powder to produce a magnetic card resistant to external magnetic fields for practical use. In other words, high coercive force magnetic powder (e.g.
A magnetic recording layer containing high coercive force magnetic powder (such as Hc5000 Oersted) that is resistant to external magnetic fields so that the minimum necessary residual output can be obtained when it is demagnetized by contact with a magnet. The present invention provides a magnetic card having the following characteristics. In this way, normal magnetic recording is processed with a high coercive force magnetic powder, and the higher coercive force magnetic powder is normally used only as an additional layer, but it is made to work only when subjected to demagnetization. intended,
A magnetic card that can be expected to withstand external magnetic fields can be obtained. If further high coercive force magnetic heads are developed in the future based on this intention, it will be possible to use higher coercive force magnetic powders that have even greater coercive force than the capabilities of the above-mentioned magnetic heads for the same purpose as the present invention.
External magnetic field resistance is further improved. Currently, Hc is 2000 as a high coercive force magnetic powder.
~3000 oersted magnetic powder is suitable;
Ferrite-based fine powders such as barium ferrite and strontium ferrite, and various magnetic alloy fine powders can be used. Currently, as a magnetic powder with higher coercive force, Hc is
A magnetic powder of 5,000 to 6,000 oersted is suitable, and various ferrite-based fine powders and magnetic alloy fine powders can be used. The blending amount of the higher coercive force magnetic powder is limited to a range that allows the noise output level with respect to the reference output, but it is preferable that the residual output is 20% or more. Therefore, the blending ratio is 10 to 50%, preferably 25 to 40% of the high coercive force magnetic powder. The method of compounding may be to mix the two in a magnetic paint or magnetic ink and coat or print the two in a single layer on card paper, or to form the two separately into a magnetic paint or magnetic ink and apply the two separately. It may be coated or printed in a layered structure. In this case, the layers may be combined either above or below, but in order to make it easier to write on the high coercive force magnetic powder, it is better to combine the layers so that the higher coercive force magnetic powder layer is the upper layer. . Note that FIG. 3 shows each of the above embodiments. Alternatively, separately prepared magnetic paints or magnetic inks may be mixed at the time of use and coated or printed to form a single layer structure. Therefore, the present invention makes it possible to utilize the external magnetic field resistance of higher coercive force magnetic powder, which could not be used until now because saturation writing was not possible. It becomes possible to operate correctly according to the recorded information without being demagnetized. This prescription is particularly advantageous for magnetic cards, such as magnetic passes, which are often held by being attached to the body (iron plate) of a car with a magnetic thumbtack. Hereinafter, the present invention will be explained in more detail based on Examples. Example 1 Using Hc3000 Oersted barium ferrite as a high coercive force magnetic powder and Hc5000 Oersted barium ferrite as an even higher coercive force magnetic powder, milling was carried out for 2 hours with an attritor according to the following composition to form a magnetic paint. It was adjusted.
【表】
磁気塗料は、溶剤（トルエン：MEK＝１：１）
で粘度200CPSになるよう調合し、坪量165ｇ／m2
のカード用紙の所定の位置に塗布厚さ4μになる
よう磁気塗工を行ない、続いて所定の寸法に断截
して磁気カードに仕上げた。
この磁気カードを高抗磁力磁気ヘツドを内蔵す
る高抗磁力磁気測定器を用いて200fci、200ｍＡ
で全ビツト記録を行ない、読取電圧を初期出力と
して記録する。次に、この記録済み磁気カードを
鉄板上に置き、市販の磁気画鋲で磁気ストライブ
部を５回擦動して消磁作用を行なつた後、再び高
抗磁力磁気測定器にかけて残留する読取電圧を測
定し、残留出力として記録する。
このようにして得られた残留出力は初期出力の
20％を有し、正常に磁気記録が読取れた。
実施例 ２
高抗磁力磁性粉とより高抗磁力磁性粉とを別々
に下記配合により三本ロールミルで混練して、高
抗磁力磁気インキ（以下磁気インキＡと略称す
る）とより高抗磁力磁気インキ（以下磁気インキ
Ｂと略称する）を調整した。[Table] Magnetic paint uses solvent (toluene:MEK=1:1)
Mixed to a viscosity of 200 CPS, basis weight 165 g/m 2
Magnetic coating was applied to a predetermined position on the card paper to a coating thickness of 4 μm, and then it was cut to a predetermined size to create a magnetic card. This magnetic card was measured at 200fci, 200mA using a high coercive force magnetic measuring device with a built-in high coercive force magnetic head.
All bits are recorded at , and the read voltage is recorded as the initial output. Next, this recorded magnetic card is placed on an iron plate, and the magnetic stripe section is rubbed five times with a commercially available magnetic thumbtack to perform a demagnetizing action, and then the remaining read voltage is measured by applying it again to a high coercive force magnetic measuring device. is measured and recorded as residual output. The residual output obtained in this way is the initial output
20%, and the magnetic recording could be read normally. Example 2 A high coercive force magnetic powder and a higher coercive force magnetic powder were separately kneaded in a three-roll mill according to the following composition to form a high coercive force magnetic ink (hereinafter abbreviated as magnetic ink A) and a higher coercive force magnetic powder. An ink (hereinafter abbreviated as magnetic ink B) was prepared.
【表】
磁気インキＡを用いて、坪量165ｇ／m2のカー
ド用紙の所定の位置に印刷厚さ3μになるよう磁
気ストライブ印刷を行なう。
次に磁気インキＢを用いて磁気インキＡの磁気
ストライブ上に重ねて印刷厚さ1μになるよう磁
気ストライブ印刷を行なつた。続いて所定の寸法
に断裁して磁気カードに仕上げた。
この磁気カードを用いて実施例１と同様に磁気
記録及び消磁作用を繰返した。その結果22％の残
留出力が認められ、消磁作用後も正常に磁気記録
を読取ることができた。
実施例 ３
実施例２で調整した磁気インキＡと磁気インキ
Ｂを３：１になるよう採取し、よく混合した後に
坪量165ｇ／m2のカード用紙の所定位置に印刷厚
さ4μになるよう磁気ストライブ印刷を行ない、
続いて所定の寸法に断截して磁気カードに仕上げ
た。
この磁気カードを用いて実施例１と同様の磁気
記録及び消磁作用を繰返した。その結果19％の残
留出力が認められ、消磁作用後も正常に磁気記録
を読取ることができた。
比較例 １
実施例２で調整した磁気インキＡのみを用い
て、坪量165ｇ／m2のカード用紙の所定の位置に
塗布厚さ3μになるよう磁気ストライブ印刷を行
なつた後所定の寸法に断截して磁気カードに仕上
げた。
この磁気カードを実施例１と同様に磁気記録及
び消磁作用を繰返した。その結果、残留出力は９
％であり、消磁作用後の磁気記録の読取りは困難
であつた。[Table] Using magnetic ink A, perform magnetic stripe printing on a predetermined position of card paper with a basis weight of 165 g/m 2 to a printing thickness of 3 μm. Next, using magnetic ink B, magnetic stripes were printed over the magnetic stripes of magnetic ink A so that the printing thickness was 1 μm. Next, it was cut to a predetermined size to make a magnetic card. Using this magnetic card, magnetic recording and demagnetization operations were repeated in the same manner as in Example 1. As a result, a residual output of 22% was observed, and the magnetic records could be read normally even after demagnetization. Example 3 Magnetic ink A and magnetic ink B prepared in Example 2 were sampled at a ratio of 3:1, mixed well, and printed at a predetermined position on card paper with a basis weight of 165 g/m 2 to a printing thickness of 4 μm. Perform magnetic stripe printing,
Next, it was cut to a predetermined size and made into a magnetic card. Using this magnetic card, magnetic recording and demagnetization operations similar to those in Example 1 were repeated. As a result, a residual output of 19% was observed, and the magnetic records could be read normally even after demagnetization. Comparative Example 1 Using only the magnetic ink A prepared in Example 2, magnetic stripe printing was performed on a predetermined position of card paper with a basis weight of 165 g/m 2 to a coating thickness of 3 μm, and then the predetermined dimensions were It was cut into pieces and made into magnetic cards. This magnetic card was subjected to repeated magnetic recording and demagnetization operations in the same manner as in Example 1. As a result, the residual output is 9
%, and it was difficult to read the magnetic recording after demagnetization.
第１図は、Hc2000、3000、5000および6000エ
ルステツドの磁性粉を用いた磁気カードの電磁変
換曲線であり、第２図は、上記磁気カードを、市
販の磁気画鋲と鉄板との間にそれぞれ挿入して消
磁させたときの残留出力の推移を示した図であ
る。第３図は、高抗磁力磁性粉とより高抗磁力磁
性粉を配合使用した磁気カードの実施態様を示す
図面で、イは配合磁性粉を一層構造となるよう塗
工又は印刷した磁気カード、ロ，ハは二層構造と
なるよう塗工又は印刷した磁気カードを示すもの
である。
１：高抗磁力磁性粉、２：より高抗磁力磁性
粉、３：カード用紙。
Figure 1 shows the electromagnetic conversion curves of magnetic cards using Hc2000, 3000, 5000 and 6000 oersted magnetic powder, and Figure 2 shows the magnetic cards inserted between a commercially available magnetic thumbtack and an iron plate. FIG. 3 is a diagram showing the transition of residual output when the magnet is demagnetized. Fig. 3 is a drawing showing an embodiment of a magnetic card using a combination of high coercive force magnetic powder and even higher coercive force magnetic powder; B and C indicate magnetic cards coated or printed to have a two-layer structure. 1: High coercive force magnetic powder, 2: Higher coercive force magnetic powder, 3: Card paper.
Claims (1)
とする磁気記録層を設けてなる磁気カードにおい
て、該磁性粉が保磁力2000〜3000エルステツドの
高抗磁力磁性粉と保磁力5000〜6000エルステツド
のより高抗磁力磁性粉との混合系からなることを
特徴とする外部磁界耐性を強化した磁気カード。 ２ 支持体上に、保磁力2000〜3000エルステツド
の高抗磁力磁性粉および結着材樹脂を主成分とす
る磁気記録層と、保磁力5000〜6000エルステツド
のより高抗磁力磁性粉および結着材樹脂を主成分
とする磁気記録層を重ね合わせて磁気記録層を二
重構造とすることを特徴とする外部磁界耐性を強
化した磁気カード。[Scope of Claims] 1. A magnetic card comprising a magnetic recording layer mainly composed of magnetic powder and binder resin on a support, wherein the magnetic powder is a high coercive force magnetic powder with a coercive force of 2000 to 3000 oersteds. A magnetic card with enhanced resistance to external magnetic fields, characterized by being made of a mixed system of magnetic powder with a higher coercive force and a coercive force of 5,000 to 6,000 oersted. 2. On a support, a magnetic recording layer mainly composed of high coercive force magnetic powder with a coercive force of 2000 to 3000 oersteds and a binder resin, and a higher coercive force magnetic powder with a coercive force of 5000 to 6000 oersteds and a binder resin. A magnetic card with enhanced resistance to external magnetic fields, characterized by having a double structure of magnetic recording layers made by overlapping magnetic recording layers whose main component is resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13461879A JPS5658130A (en) | 1979-10-18 | 1979-10-18 | Magnetic card having increased resistance to external magnetic field |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13461879A JPS5658130A (en) | 1979-10-18 | 1979-10-18 | Magnetic card having increased resistance to external magnetic field |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5658130A JPS5658130A (en) | 1981-05-21 |
| JPH0210484B2 true JPH0210484B2 (en) | 1990-03-08 |
Family
ID=15132592
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13461879A Granted JPS5658130A (en) | 1979-10-18 | 1979-10-18 | Magnetic card having increased resistance to external magnetic field |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5658130A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0411215Y2 (en) * | 1986-03-19 | 1992-03-19 | ||
| JPS63127423A (en) * | 1986-11-17 | 1988-05-31 | Hosokawa Katsupanshiyo:Kk | Magnetic recording medium |
| JPH03256218A (en) * | 1990-03-07 | 1991-11-14 | Toshiba Glass Co Ltd | Magnetic card |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5134617Y2 (en) * | 1971-07-28 | 1976-08-26 | ||
| JPS5428502B2 (en) * | 1972-05-19 | 1979-09-17 | ||
| US4237189A (en) * | 1973-10-31 | 1980-12-02 | Robert J. Deffeyes | Polymodal magnetic recording media process for making and verifying the same and compositions useful therein |
| JPS5738963B2 (en) * | 1974-04-05 | 1982-08-18 | ||
| JPS5222247U (en) * | 1975-08-05 | 1977-02-17 |
-
1979
- 1979-10-18 JP JP13461879A patent/JPS5658130A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5658130A (en) | 1981-05-21 |
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