JPH03292618A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH03292618A JPH03292618A JP2094346A JP9434690A JPH03292618A JP H03292618 A JPH03292618 A JP H03292618A JP 2094346 A JP2094346 A JP 2094346A JP 9434690 A JP9434690 A JP 9434690A JP H03292618 A JPH03292618 A JP H03292618A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- recording medium
- layer
- coated
- magnetic recording
- 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.)
- Pending
Links
- 239000006247 magnetic powder Substances 0.000 claims abstract description 27
- 229910017052 cobalt Inorganic materials 0.000 claims abstract description 12
- 239000010941 cobalt Substances 0.000 claims abstract description 12
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims abstract description 12
- 230000004907 flux Effects 0.000 claims abstract description 4
- 239000000203 mixture Substances 0.000 claims description 3
- 229910001566 austenite Inorganic materials 0.000 claims 2
- 239000000758 substrate Substances 0.000 claims 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N ferrosoferric oxide Chemical compound O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 abstract description 14
- 239000006229 carbon black Substances 0.000 abstract description 7
- 238000006243 chemical reaction Methods 0.000 abstract description 5
- 230000005415 magnetization Effects 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 28
- 239000003973 paint Substances 0.000 description 18
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 13
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 6
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 6
- 239000000654 additive Substances 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 230000007257 malfunction Effects 0.000 description 3
- 238000002834 transmittance Methods 0.000 description 3
- 239000000428 dust Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000012046 mixed solvent Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 229920005749 polyurethane resin Polymers 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- TWJNQYPJQDRXPH-UHFFFAOYSA-N 2-cyanobenzohydrazide Chemical compound NNC(=O)C1=CC=CC=C1C#N TWJNQYPJQDRXPH-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910002588 FeOOH Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- TUNFSRHWOTWDNC-UHFFFAOYSA-N Myristic acid Natural products CCCCCCCCCCCCCC(O)=O TUNFSRHWOTWDNC-UHFFFAOYSA-N 0.000 description 1
- 235000021360 Myristic acid Nutrition 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
Landscapes
- Magnetic Record Carriers (AREA)
- Paints Or Removers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、磁気記録媒体に係わり、さらに詳しくはその
電磁変換特性の改良に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording medium, and more particularly to improving the electromagnetic conversion characteristics thereof.
最近、ビデオテープなどの高性能化の手段として磁性層
ｔ２層構造とし、各層の粒子径ヤ保磁力を適性化するこ
となどが提案されている（％開平１−１０６３３１号、
特關平１−１０６３３２号、％開平１−１０６３３３号
）。Recently, as a means of improving the performance of video tapes, etc., it has been proposed to create a magnetic layer with a T2 layer structure and to optimize the particle size and coercive force of each layer (%KOKAI Publication No. 1-106331,
Tokukan Hei 1-106332, % Kai Hei 1-106333).
また、磁性粉以外の固形株加剤例えばカーボンブラック
などの添加量を減らし、磁性粉含率を向上させることな
どが行われている。In addition, attempts have been made to reduce the amount of solid additives other than magnetic powder, such as carbon black, to improve the magnetic powder content.
磁性粉含率の向上では、例えばビデオテープでは、ＲＦ
帯域と、リニアオーディオ帯域の両方の出力向上に限界
がある。また、磁性粉の微粒子化に伴い、磁性層のカー
ボンブラック含量を低減し過き゛ると磁性層の遮光性が
小さくなり、ＶＨ８方弐〇ＶＴＲにおいて、光センサー
によるテープ終端検知が誤作動する。この誤作動対策と
して、磁性層厚みτ厚くすると、ＥＰモードでのヘッド
タッチが悪くなシ、エンベローブ不良を生ずる。また磁
性層中のカーボンブラック含有の低減は、テープ表面電
気抵抗が高くなり、使用中の摩擦により、テープ表面が
帯電し、ゴミを吸着し、ドロップアウト増加の原因とな
る。In order to improve the magnetic powder content, for example, in video tape, RF
There are limits to improving the output of both the band and linear audio band. Furthermore, if the carbon black content of the magnetic layer is reduced too much as the magnetic powder becomes finer, the light-shielding properties of the magnetic layer will be reduced, causing the tape end detection by the optical sensor to malfunction in the VH8 VTR. As a countermeasure against this malfunction, if the magnetic layer thickness τ is increased, the head touch in the EP mode will be poor and envelope defects will occur. Further, a reduction in carbon black content in the magnetic layer increases the electrical resistance of the tape surface, and due to friction during use, the tape surface becomes electrically charged and attracts dust, causing an increase in dropouts.
上記の問題は、磁性層を２層としても同様に発生し、広
帯域の出力を同時に飛躍的に向上させるための限界の原
因となっていた。The above-mentioned problem also occurs even when the magnetic layer is two-layered, and is the cause of the limit for dramatically improving broadband output at the same time.
この発明は、上記従来製品が持っていた、高性能磁気配
録機器用磁気記録媒体の電磁変換特性の不足とめう欠点
をｍ決し、以って電磁変換特性に優れ、しかも高信頼性
の磁気記録媒体を提供することを目的とする。This invention solves the drawback of the above-mentioned conventional products, which is the lack of electromagnetic conversion characteristics of the magnetic recording medium for high-performance magnetic recording equipment, and thus provides excellent electromagnetic conversion characteristics and highly reliable magnetic recording media. The purpose is to provide recording media.
上記問題点上解決すべく鋭意研究を重ねた結果、磁性層
を２層構造とし、そりうち少なくとも一層の磁性層に飽
和磁化量の大きく、電気抵抗値も小さい磁性粉であるコ
バルト被着Ｆｅ５Ｏａ磁性粉を用いることにより、電磁
変換特性も優れ、しかもドロップアウトの発生４少ない
磁気記録媒体が得られることを見出した。As a result of intensive research to solve the above problems, the magnetic layer has a two-layer structure, and at least one of the magnetic layers is made of cobalt-coated Fe5Oa magnetic powder, which has a high saturation magnetization and a low electric resistance value. It has been found that by using powder, a magnetic recording medium with excellent electromagnetic characteristics and less occurrence of dropouts can be obtained.
コバルト被着Ｔｈ３０４磁性粉は黒色であり、しかも飽
和磁化量も大きいため、磁性層中のカーボングラツク含
有量を減少させ、磁性層厚を薄くしても磁気記録媒体の
残留磁束密度も１４００Ｇ以上となり、低周波数領域の
出力が向上し、しかも磁気記録媒体の光透過率も増大し
ない。例えば磁性層全厚が３．５μｍ以下でも、テープ
光透過率（光源、タフゲステンランプ色温度２０００に
、受光素子、シリコーンフォトダイオード’Ａｐ＝８７
０ｎｍ）ｔｏ、ｓ％以下に維持させることができ、テー
プ終端検出で誤作動することもなく、ＥＰモードエンベ
ロープで良好にすることができる。Since the cobalt-coated Th304 magnetic powder is black and has a large saturation magnetization, the residual magnetic flux density of the magnetic recording medium is still 1400 G or more even if the carbon grac content in the magnetic layer is reduced and the magnetic layer thickness is thinned. Therefore, the output in the low frequency range is improved, and the optical transmittance of the magnetic recording medium does not increase. For example, even if the total thickness of the magnetic layer is 3.5 μm or less, the tape light transmittance (light source, Toughgesten lamp color temperature 2000, light receiving element, silicone photodiode 'Ap = 87
0nm) to s% or less, there is no malfunction in detecting the end of the tape, and the EP mode envelope can be used satisfactorily.
また、コバルト被着Ｆｅ３Ｏ４磁性粉はＦｅ３Ｏ４と同
様に電気抵抗が小さいので、この磁性粉を用いた磁気記
録媒体の表面電気抵抗１１Ｘ１×１０９Ω／ｓｑ程度に
保持できるので、ゴミ等の付着によるドロップアウトは
ほぼ無くすることができる。In addition, cobalt-coated Fe3O4 magnetic powder has low electrical resistance like Fe3O4, so the surface electrical resistance of a magnetic recording medium using this magnetic powder can be maintained at about 11 x 1 x 109 Ω/sq, so dropouts due to adhesion of dust etc. can be maintained. can be almost eliminated.
コバルト被着ｈ３０４磁性粉は、針状ａ−ＦｅＯＯＨを
水素ガス等を用いて還元するときの条件例えば還元時間
を調節することにより、所望の還元率で止めることによ
りＦｅ”＋量を上記磁性粉の持つ電導性、色などが所期
の値を示す範曲内に納まるようにする。The cobalt-coated h304 magnetic powder can reduce the amount of Fe"+ by adjusting the conditions when reducing acicular a-FeOOH using hydrogen gas, etc., such as by adjusting the reduction time and stopping at a desired reduction rate. Ensure that the conductivity, color, etc. of the object are within the range of desired values.
このようにして得たＦｅ ３０４を核にして、その表面
にコバル）を被着する操作は、コバルト被着ｒ−Ｆｅ２
０Ｂに用められている方法をそのまま利用できる。Using the thus obtained Fe 304 as a core, the operation of depositing cobal) on the surface of the Fe 304 is as follows: cobalt deposited r-Fe2
The method used for 0B can be used as is.
上記コバルト被着Ｆｅ ３０４磁性粉？用いて磁気記録
媒体を作製するには、汎用の結合剤、添加剤、溶剤を用
いた塗料を非磁性支持体上に塗布する方法によって作久
するととカ；できる。The above cobalt-coated Fe 304 magnetic powder? A magnetic recording medium can be produced by applying a paint containing a general-purpose binder, additive, and solvent onto a non-magnetic support.
以下具体的に本発明を実施例に基づき説明する。 The present invention will be specifically described below based on examples.
なお、実施例、比較例中における「部」とあるのは、重
蓋部τ表わす。In addition, "part" in Examples and Comparative Examples represents the heavy lid part τ.
実施例１
塗料Ａ
Ｃｏ被着Ｆｅ２Ｏ３ １００ｉｆＵ”
Ａｌｔｏｓ ６．０部ステア
リン酸亜鉛 Ｑ、５ｔｔ塩化ビニル系
共重合体 ５６．３ ／／シクロヘキサノン
／トルエン：１８０／／１乙混合溶媒
塗料Ｂ
Ｃｏ被着Ｆｅ３Ｏ４（Ｆｅ” １６％含有）１００ 部
カーボンブラック（ギヤボット１，０１１社製ＶＵＬＣ
ＡＮ ＸＣ−７２）
ステアリン酸亜鉛 Ｑ、 ５ ｔｔ塩
塩化ビニル系重重合体 ５６．３ ／／ンクロ
ヘキサノン／トルエン： １５８ ｌ１１／／１混合＃
ｊ媒
上記それぞれの組成物を高速攪拌機で５〜１０時間混合
間部その後サンドグラインダーで分散を行った分散液に
、下記のように上述のｆ料Ａおよび塗料Ｂに応じた添加
物を添卵後、高速撹拌機で混合し、磁性塗料Ａ％Ｂ會得
た。Example 1 Paint A Co coated Fe2O3 100ifU"
Altos 6.0 parts Zinc stearate Q, 5tt Vinyl chloride copolymer 56.3 // Cyclohexanone/Toluene: 180 // 1 O mixed solvent paint B Co-coated Fe3O4 (contains 16% Fe) 100 parts Carbon black (VULC manufactured by Gearbot 1,011
AN
Mix each of the above compositions with a high-speed stirrer for 5 to 10 hours, then add additives corresponding to the above-mentioned Material A and Paint B to the dispersion liquid, which was dispersed with a sand grinder as shown below. Thereafter, the mixture was mixed using a high-speed stirrer to obtain a magnetic paint A%B.
塗料Ａ
ポリウレタン樹脂（２０チ溶液） ４０ｓ三官能性低
分子量インシアネート ４ 部（７５ｍ溶液）
ミリスチン酸 ０．１５ ／／シ
クロヘキサノン／トルエン： ７０ 〃１４混合＃媒
塗料Ｂ
ポリウレタン樹脂（２０％＃液） ４０ 部三官能性低
分子量インシアネート ４ 〃（７５ｓ溶液）
シクロヘキサノン／トルエン＝ ６８ 〃１４混合溶
媒
上記磁性塗料を厚さ１４μｍのポリエステルフィルムの
片面上に、最初塗料Ｂを塗布した後、塗料Ａｋ墜布しカ
レンダ処堆を行ない、全塗布厚が３．４μｍ（上層０．
９μｍ、下層２．５μｍ）なるようにして、さらにバッ
クコート層を塗布後、％インチ幅にスリットしてビデオ
テープを作製した。Paint A Polyurethane resin (20% solution) 40s trifunctional low molecular weight incyanate 4 parts (75m solution) Myristic acid 0.15 //Cyclohexanone/toluene: 70 〃14 mixed #vehicle paint B Polyurethane resin (20% #liquid) 40 parts trifunctional low molecular weight incyanate 4〃(75s solution) Cyclohexanone/toluene = 68〃14 Mixed solvent The above magnetic paint was first coated on one side of a 14 μm thick polyester film, then paint B was applied, and then paint Ak was coated. The total coating thickness was 3.4 μm (the upper layer was 0.5 μm).
A back coat layer was further applied so that the film thickness was 9 μm, and the lower layer was 2.5 μm, and then slit to a width of 1.5 inch was made to prepare a videotape.
実施例２ 実施例１において、塗料Ａの磁性粉としてＣ。Example 2 In Example 1, C was used as the magnetic powder for paint A.
被層Ｆｅ５Ｏａ （Ｆｅ” １６９に含有）１−１また
塗料Ｂの磁性粉としてＣｏ被着ｒ−Ｆｅｔｕｓに東え、
磁性層全厚を３．２μｍ（上層０．８μｍ、下層２．４
μｍ）とした以外は、実施例１と同様にしてビデオテー
プを作製した。The coating layer Fe5Oa (contained in Fe'' 169) 1-1 was also applied to Co-coated r-Fetus as magnetic powder of paint B.
The total thickness of the magnetic layer was 3.2 μm (upper layer 0.8 μm, lower layer 2.4 μm).
A videotape was produced in the same manner as in Example 1, except that the thickness was changed to (μm).
実施例３
実施例１において、塗料Ａの磁性粉をＣＯ被着Ｆｅ５０
４（Ｆｅ” １６９に含有）に宝え、磁性層全厚を３．
５μｍ（上層１．０μｍ、下層２．５μｍ）とした以外
は、実施例１と同様にしてビデオテープを作製した。Example 3 In Example 1, the magnetic powder of paint A was coated with CO-coated Fe50.
4 (contains Fe"169), and the total thickness of the magnetic layer is 3.
A videotape was produced in the same manner as in Example 1, except that the thickness was 5 μm (upper layer: 1.0 μm, lower layer: 2.5 μm).
実施例４
実施例１において塗料Ａの磁性粉としてＣｏ被着Ｆｅ５
０４（Ｆｅ １６−含有）とＣｏ被着ｒ−Ｅｌ；ｘ２
Ｑ３ｔ２＝８の割合に混合した磁性粉によえた以外は実
施例１と同様にしてビデオテープを作製した。Example 4 In Example 1, Co-coated Fe5 was used as the magnetic powder of paint A.
04 (Fe 16-containing) and Co-adhered r-El; x2
A videotape was produced in the same manner as in Example 1 except that magnetic powder was mixed in a ratio of Q3t2=8.
実施例５
実施例１において、塗料Ｂの磁性粉ｔＣＯ被着Ｆｅ５Ｏ
ａ （Ｆｅ” １６ ％含有）とＣＯ被着ｒ −Ｆｅ２
０ｇを５：５の割合に混合した磁性粉に失えた以外は実
施例１と同様にしてビデオテープを作製した。Example 5 In Example 1, Fe5O coated with magnetic powder tCO of paint B
a (containing 16% Fe) and CO adhesion r -Fe2
A videotape was produced in the same manner as in Example 1, except that 0 g was lost to the magnetic powder mixed at a ratio of 5:5.
比較例１
実施例１において、磁性層全厚を３．６μｍ（上層０．
９μｍ、下層２．７μｍ）とした以外は、実施例１と同
様にしてビデオテープを作製した。Comparative Example 1 In Example 1, the total thickness of the magnetic layer was 3.6 μm (upper layer 0.6 μm).
A videotape was produced in the same manner as in Example 1, except that the film thickness was 9 μm and the lower layer was 2.7 μm.
比較例２
実施例１において、塗料Ｂ中のカーボングラツクの添加
を無くした以外は、実施例１と同様にしてビデオテープ
を作製した。Comparative Example 2 A videotape was produced in the same manner as in Example 1, except that the addition of carbon black in paint B was omitted.
比較例３
実施例１において、塗料Ｂ中のカーボングラツクの添加
量を３．０部に変更した以外は、実施例１と同様にして
ビデオテープを作製した。Comparative Example 3 A videotape was produced in the same manner as in Example 1, except that the amount of carbon black added in Paint B was changed to 3.0 parts.
比較例４
実施例１において、塗料Ｂの磁性粉としてＣＯ被着Ｆｅ
２０ｓ Ｋ ’Ｘえた以外は、実施例１と同様にしてビ
デオテープを作製した。Comparative Example 4 In Example 1, CO-adhered Fe was used as the magnetic powder of paint B.
A videotape was produced in the same manner as in Example 1, except that 20s K'X was obtained.
上記各実施例および比較例で得たとデオテーブの表面電
気抵抗、光透過率（光源：タンクズテン２フ１１色温度
２０００に、受光素子：シリコンフォトダイオード（λ
ｐ＝８７０ｎｍ））残留磁束密度、ドロップアウト数、
エンベロープ平坦度、ＲＦ比出力およびリニアオーディ
オ感度を測定した結果を表にして示す。The surface electrical resistance and light transmittance of the phototave obtained in each of the above Examples and Comparative Examples (Light source: Tanksten 2F 11 Color temperature 2000, Light receiving element: Silicon photodiode (λ
p=870nm)) Residual magnetic flux density, number of dropouts,
The results of measuring envelope flatness, RF ratio output, and linear audio sensitivity are shown in a table.
ドロップアウト数はＶＨＳ方式ＶＴＲで標準モードで６
０分走行させたときの、幅１５μｓ、出力域２０ｄＢの
ドロップアウトの数を測定した。The number of dropouts is 6 in standard mode for VHS type VTR.
When running for 0 minutes, the number of dropouts with a width of 15 μs and an output range of 20 dB was measured.
エンベロープ平坦度は、ＶＨ８方式ＶＴＲをＥＰモード
でプレイパックしたさいのＲＦ出力信号をオシロスコー
プで調べ、１つのビデオヘッドの１トレースの中程の蚕
＠τＡ、スイッチング部分の振幅をＢとし、２０ ｌｏ
ｇｌ。丁により算出した。The envelope flatness was determined by examining the RF output signal using an oscilloscope when a VH8 VTR was playpacked in EP mode. The amplitude of the switching part was τA in the middle of one trace of one video head, and B was 20 lo.
gl. Calculated by ding.
ＲＦ（支）力は録画アンプＩｃ ４ Ｍ Ｈｚ ＩＤ無
変調信号を加え、記録電流に！えて記録再生し、最大再
生出力？標準テープと比較して示した。RF (support) power is recorded by adding a recording amplifier Ic 4 MHz ID unmodulated signal to the recording current! Record and play back the maximum playback output? Shown in comparison with standard tape.
リニアオーディオ感度は、入力飽和レベルより１０ｄＢ
低いＩＫＨｚの信号を標準バイアス電流で記録再生し、
再生出力を標準テープと比較して示した。Linear audio sensitivity is 10dB above input saturation level
Record and reproduce low IKHz signals with standard bias current,
The playback output is shown in comparison with a standard tape.
以上説明したように、２層の磁性層を有する磁気記録媒
体で、磁性層の少なくとも一層にコノ（ルト被着Ｆｅ
Ｂ ０ａ−ｚ磁性粉を用いることにより電磁変換特性に
優れ、かつ表面電気抵抗も適正な範囲内に設定でき、高
信頼性の磁気記録媒体が得られることが明らかである。As explained above, in a magnetic recording medium having two magnetic layers, at least one of the magnetic layers is coated with iron-coated Fe.
It is clear that by using the B 0a-z magnetic powder, a highly reliable magnetic recording medium can be obtained which has excellent electromagnetic characteristics and can set the surface electrical resistance within an appropriate range.
Claims (2)
録媒体において、磁性層の少なくとも一層は、コバルト
被着Ｆｅ＿３Ｏ＿４磁性粉あるいは該磁性粉とコバルト
被着γ−Ｆｅ＿２Ｏ＿３磁性粉を混合した磁性粉を含有
した磁性層よりなり、他の一層はコバルト被着γ−Ｆｅ
＿２Ｏ＿３磁性粉を含有した磁性層よりなる磁気記録媒
体の磁性層の表面電気抵抗が１×１０＾９Ω／ｓｑ以下
、残留磁束密度が１４００Ｇ以上、磁性層の全厚が３．
５μｍ以下であることを特徴とする磁気記録媒体。(1) In a magnetic recording medium in which two magnetic layers are coated on a non-magnetic substrate, at least one of the magnetic layers is made of cobalt-coated Fe_3O_4 magnetic powder or a mixture of the magnetic powder and cobalt-coated γ-Fe_2O_3 magnetic powder. The other layer is made of cobalt-coated γ-Fe.
A magnetic recording medium comprising a magnetic layer containing _2O_3 magnetic powder has a surface electrical resistance of 1×10^9 Ω/sq or less, a residual magnetic flux density of 1400G or more, and a total thickness of the magnetic layer of 3.
A magnetic recording medium characterized by having a diameter of 5 μm or less.
ルト被着Ｆｅ＿３Ｏ＿４磁性粉のコバルト被着γ−Ｆｅ
＿２Ｏ＿３への混合比率が２０％以上である磁性層を有
することを特徴とする磁気記録媒体。(2) In the magnetic recording medium according to claim (1), cobalt-coated γ-Fe of cobalt-coated Fe_3O_4 magnetic powder
A magnetic recording medium characterized by having a magnetic layer having a mixing ratio of _2O_3 of 20% or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2094346A JPH03292618A (en) | 1990-04-10 | 1990-04-10 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2094346A JPH03292618A (en) | 1990-04-10 | 1990-04-10 | Magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03292618A true JPH03292618A (en) | 1991-12-24 |
Family
ID=14107724
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2094346A Pending JPH03292618A (en) | 1990-04-10 | 1990-04-10 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03292618A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05242451A (en) * | 1992-02-27 | 1993-09-21 | Victor Co Of Japan Ltd | Magnetic recording medium |
| CN101800125A (en) * | 2010-03-17 | 2010-08-11 | 上海大学 | Pyrolytic synthesis method for carbon-coated magnetic Fe3O4 nano particles |
-
1990
- 1990-04-10 JP JP2094346A patent/JPH03292618A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05242451A (en) * | 1992-02-27 | 1993-09-21 | Victor Co Of Japan Ltd | Magnetic recording medium |
| CN101800125A (en) * | 2010-03-17 | 2010-08-11 | 上海大学 | Pyrolytic synthesis method for carbon-coated magnetic Fe3O4 nano particles |
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