JPS61216116A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPS61216116A JPS61216116A JP5691285A JP5691285A JPS61216116A JP S61216116 A JPS61216116 A JP S61216116A JP 5691285 A JP5691285 A JP 5691285A JP 5691285 A JP5691285 A JP 5691285A JP S61216116 A JPS61216116 A JP S61216116A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- magnetic layer
- magnetic
- conductive layer
- carbon black
- 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.)
- Granted
Links
Landscapes
- Magnetic Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は磁気記録媒体に関し、さらに詳しくは磁性層
の表面電気抵抗が小さくかつ表面平滑性が良好で電磁変
換特性に優れた磁気記録媒体に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording medium, and more particularly to a magnetic recording medium whose magnetic layer has low surface electrical resistance, good surface smoothness, and excellent electromagnetic conversion characteristics. .
磁気記録媒体の磁性層は、通常、磁性粉末、結合剤成分
、有機溶剤およびその他の必要成分からなる磁性塗料を
ポリエステルフィルムなどの基体上に塗布、乾燥してつ
くられる。ところが、このようにしてつくられる磁性層
は表面電気抵抗が高いため帯電しやずく、記録再生時に
放電によるノイズを発生したり塵埃が付着してドロノプ
アウ１゜の原因になったりする。The magnetic layer of a magnetic recording medium is usually made by applying a magnetic paint consisting of magnetic powder, a binder component, an organic solvent, and other necessary components onto a substrate such as a polyester film, and drying the coating. However, the magnetic layer formed in this way has a high surface electrical resistance and is easily charged, causing noise due to discharge during recording and reproduction, and dust adhering to it, causing a dropout of 1°.
そこで、その対策として、磁性層中にカーボンブラック
などの導電性粉末を含有させたり（特公昭５Ｂ−３１６
５４号）、あるいは基体と磁性層との間に導電性粉末を
均一に分散させた導電体層を設ける（特開昭５０−１０
４００３号）などして、磁性層の表面電気抵抗を低減す
ることが行われている。Therefore, as a countermeasure, conductive powder such as carbon black was included in the magnetic layer (Japanese Patent Publication No. 5B-316
No. 54), or a conductive layer in which conductive powder is uniformly dispersed is provided between the substrate and the magnetic layer (Japanese Unexamined Patent Publication No. 50-10
4003) to reduce the surface electrical resistance of the magnetic layer.
ところが、磁性層中にカーボンブラックなどの導電性粉
末を含有させると、非磁性のカーボンブラック等の磁性
層中に占める割合が増加し、磁性粉末の充填密度が低下
するため、出力が低下したり、ノイズが増大したりし、
また、基体と磁性）−との間に導電体層を設ける方法で
は、カーボンブラックなどの導電性粉末を、多ケ導電体
層に含有させなければ磁性層の表面電気抵抗を充分に小
さくすることができず、この導電体層に使用される従来
のカーボンブラックは嵩高くてしかも導電体層を構成す
る結合剤樹脂に対する分散性が悪いため、このカーボン
ブラックなどの導電性粉末を多量に含有させた導電体層
の表面平滑性が悪くなり、これが導電体層上に形成され
る磁性層に影響を及ぼして磁性層の表面平滑性を悪くし
、出力の低下やノイズの増大を招来して、電磁変換特性
が劣化するという難点がある。However, when conductive powder such as carbon black is included in the magnetic layer, the proportion of non-magnetic carbon black etc. in the magnetic layer increases and the packing density of the magnetic powder decreases, resulting in a decrease in output. , the noise may increase,
In addition, in the method of providing a conductive layer between the substrate and the magnetic layer, the surface electrical resistance of the magnetic layer cannot be sufficiently reduced unless conductive powder such as carbon black is included in the multiple conductive layers. Conventional carbon black used for this conductive layer is bulky and has poor dispersibility in the binder resin that makes up the conductive layer, so it is necessary to contain a large amount of conductive powder such as carbon black. The surface smoothness of the conductive layer deteriorates, which affects the magnetic layer formed on the conductive layer, worsening the surface smoothness of the magnetic layer, resulting in a decrease in output and an increase in noise. There is a drawback that the electromagnetic conversion characteristics deteriorate.
この発明は、かかる現状に鑑み、種々検ｉ４を行った結
果なされたもので、基体と磁性層との間に、ＤＢＰ吸油
量が５０〜Ｉ Ｏ’Ｏｍ１／ ｌＯＯｇで、粒子径が０
．０１３〜０．０４０μｍのカーボンブラックを含む表
面粗度が中心線平均粗さで０．０１０μｍ以下の導電体
層を設けることによって、導電体層の表面平滑性を良好
にして磁性層の表面平滑性を充分に向上させ、磁性層の
表面電気抵抗を充分に低減するとともに出力低下やノイ
ズの増大を良好に抑制して電磁変換特性を充分に向上さ
せたちのである。This invention was made as a result of conducting various tests in view of the current situation, and found that the DBP oil absorption between the base and the magnetic layer is 50 to IO'Om1/lOOg and the particle size is 0.
．． By providing a conductive layer containing carbon black of 0.013 to 0.040 μm and having a center line average roughness of 0.010 μm or less, the surface smoothness of the conductive layer is improved and the surface smoothness of the magnetic layer is improved. This sufficiently improves the surface electrical resistance of the magnetic layer, satisfactorily suppresses the decrease in output and the increase in noise, and sufficiently improves the electromagnetic conversion characteristics.
この発明において、基体と磁性層との間に設Ｊｌる導電
体層中に含有さゼるカーホンブラ、り目、Ｄ Ｂ Ｐ吸
油量が５０〜１００ ｍ ｌ！ ／ １００ ｇで、粒
子径が０．０１３〜０．０４０μｍのものであることが
好ましく、吸浦星が５０ｍｎ／１００ｇより少なくなる
と分散性し１良好になるが、ス１ラクチャ配列構造がと
りに（くなるため電気抵抗が大きくなり、１００ｍ７！
／１００ｇより多くなるとスｌラクチャ配列構造をとり
易くなる反面、導電体層に使用する結合剤樹脂に対する
分散性が悪くなり、導電体層の表面平滑性を劣化して導
電体層上に形成される磁性層の表面平滑性を悪くし、出
力の低下やノイズの増大を招く。また粒子径は、０．０
１３〜０．０４０μｍの範囲内のものが好ましく使用さ
れ、このような粒子径が０．０１３〜Ｏ，０４０μｍの
範囲内でＤＢＰ吸油量が５０〜１００ｍ１／１００ｇの
カーボンブラックを使用すると、表面Ｉｎ度が中心線平
均粗さで０．０１０μｍ以下の導電体層が容易に形成さ
れる。使用量は、導電体層の全固形成分との合計量に対
して重量比で、２０〜８０重量％□１ の
範囲内で使用するのが好ましく、少なすぎると］
磁性層の表面電気抵抗を充分に小さくすること
が、 ７ｆｆ′＃”ｌｈｉＭｆｉ４＊Ｎ（ＤＴ
ｓ４＊Ｌ”４０１性が低下する。In this invention, the oil absorption amount of the carbon fiber, rim, and DBP contained in the conductive layer provided between the base and the magnetic layer is 50 to 100 ml! / 100 g, the particle size is preferably 0.013 to 0.040 μm, and if the Ukuura star is less than 50 m/100 g, the dispersibility will be good. (The electrical resistance increases because it becomes 100m7!
If the amount exceeds /100g, it becomes easier to form a sloughed arrangement structure, but on the other hand, the dispersibility in the binder resin used for the conductor layer deteriorates, the surface smoothness of the conductor layer deteriorates, and it becomes difficult to form on the conductor layer. This impairs the surface smoothness of the magnetic layer, leading to a decrease in output and an increase in noise. Also, the particle size is 0.0
Carbon black having a particle diameter of 0.013 to 0.040 μm and a DBP oil absorption of 50 to 100 m1/100 g is preferably used, and the surface In A conductive layer having a center line average roughness of 0.010 μm or less can be easily formed. The amount used is preferably within the range of 20 to 80% by weight □1 based on the total amount of all solid components of the conductor layer, and if it is too small]
Making the surface electrical resistance of the magnetic layer sufficiently small is 7ff'#"lhiMfi4*N(DT
s4*L”401 property is decreased.
」 このようなカーボンブラックを用い
て基体と磁性層との間に設ける導電体層は、表面粗度が
中心ｉ 線平均粗さで０．０１０μ−以下
であることが好ましく、このような表面粗度が中心線平
均粗さで０．０１０μｍ以下の導電体層が形成されると
、導電体層の表面平滑性が極めて良好なためこの上に形
成される磁性層の表面平滑性が充分に良好になり、従ｊ
９７、磁性Ｎ（Ｄ表面気抵抗ヵ、充分０．
低減あわお１ とともに出力低下やノイズ
の増大が良好に抑制さ］ れ、電磁変換特性
ヵ９充分、３向よあ、、、。It is preferable that the conductive layer formed between the substrate and the magnetic layer using such carbon black has a surface roughness of 0.010μ or less in center i-line average roughness. When a conductive layer with a center line average roughness of 0.010 μm or less is formed, the surface smoothness of the conductive layer is extremely good, and the surface smoothness of the magnetic layer formed thereon is sufficiently good. Become a submissive
97, magnetic N (D surface resistance, sufficient 0.
The output drop and noise increase are well suppressed along with the reduction of bubbles (1).
ｊ このようなりＢＰ吸油量が５０〜１０
０ｍ１／１００ｇで粒子径が０．０１３〜０．０４０
ｐ ｍのカーボンブラックを含む、表面粗度が中心線平
均粗さで” ０．０１０，１７ｍＪａ工（Ｄ＊
＊４＊Ｍ！よ１．や、ＣｔＬ ６０）／’Ｊ−ボンブラ
ックを結合剤樹脂および有機溶剤とともに混合分散して
導電体層用塗料を調製し、これをポリエステルフィルム
などの基体−Ｉニに塗布し、乾燥して形成される。この
ようにして形成される導電体層の厚さは０．２μｍより
薄くすると所期の効果が得られ難り、２．０μｍより厚
くすると磁性層を内側にしたカールが発生しやすいため
、０．２〜２．０μｍの範囲内にするのが好ましく 、
０．３〜１．３ μｍの範囲内の厚みにするのがより好
ましい。j Like this, the BP oil absorption is 50 to 10
Particle size is 0.013 to 0.040 at 0m1/100g
The surface roughness is 0.010,17 mJa (D*
*4*M! Yo1. A conductive layer coating material is prepared by mixing and dispersing CtL 60)/'J-bon black with a binder resin and an organic solvent, and this is applied to a substrate such as a polyester film and dried to form a conductive layer coating. be done. If the thickness of the conductive layer formed in this way is less than 0.2 μm, it is difficult to obtain the desired effect, and if it is thicker than 2.0 μm, curling with the magnetic layer inside tends to occur. It is preferably within the range of .2 to 2.0 μm,
More preferably, the thickness is within the range of 0.3 to 1.3 μm.
また使用される結合剤樹脂としては、塩化ビニル−酉酸
ビニル系共重合体、ポリビニルブチラール樹脂、繊維素
系樹脂、ポリうレタン系樹脂、アクリル系樹脂、イソシ
アネート化合物、エポキシ樹脂、フェノール系樹脂、放
射線硬化型樹脂等など従来一般に使用されるものがいず
れも好適なものとして使用され、有機溶剤としては、メ
チルイソブチルケトン、メチルエチルケＩ・ン、シクロ
ヘキザノン、ｌ・ルエン、酢酸エチル、テトラヒドロフ
ラン、ジメチルポルムアミＦなど従来一般に使用される
有ＩＩ！溶剤がいずれも単独で、或いは二種以上混合し
て使用される。The binder resins used include vinyl chloride-vinyl toroate copolymers, polyvinyl butyral resins, cellulose resins, polyurethane resins, acrylic resins, isocyanate compounds, epoxy resins, phenolic resins, All conventionally used materials such as radiation-curable resins are suitable. Examples of organic solvents include methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, l-luene, ethyl acetate, tetrahydrofuran, and dimethyl porpoise. A II that is commonly used in the past such as Muami F! Each of the solvents may be used alone or in combination of two or more.
このようにして導電体層を形成する場合、さらに必要で
あれば、前記の導電性微粉末および非磁性無機質微粉末
の分１１に性向上のために、脂肪酸、レシチン、エチレ
ンオキサイド−プロピレンオキサイド共重合体等の分散
剤、およびその他の界面活性剤等を併用してもよい。When forming the conductive layer in this way, if necessary, fatty acids, lecithin, ethylene oxide-propylene oxide may be added to the conductive fine powder and non-magnetic inorganic fine powder to improve the properties. Dispersants such as polymers, other surfactants, etc. may be used in combination.
導電体層上の磁性層の形成は、ｒ−Ｆｅ２０３粉末、Ｆ
ｅ３Ｏ４粉末、Ｃｏ含有ｒＦｅ２Ｏ３粉末、ＣＯ含有Ｆ
ｅ３Ｏ４粉末、Ｆｅ粉末、ＣＯ鉛粉末Ｆｅ−Ｎｉ粉末お
よびハリウムフェライ１−などの従来公知の各種磁性粉
末を結合剤樹脂および有機溶剤等とともに混合分散して
調製した磁性塗料を、基体」−に形成した導電体１５
Ｊ：に塗布、乾燥するなどの方法で形成される他、Ｃ０
１Ｎｉ、Ｆ ｅ −、Ｃｏ Ｎ ｉ合金、Ｃｏ−Ｃｒ
合金、Ｃｏ −Ｐ、Ｃｏ−Ｎ１−Ｐなどの強磁性材を、
真空蒸着、イオンブレーティング、スパツタリング、メ
ッキ等の手段によって導電体層」二に被着するなどの方
法でも形成される。The magnetic layer on the conductor layer is formed using r-Fe203 powder, F
e3O4 powder, Co-containing rFe2O3 powder, CO-containing F
A magnetic paint prepared by mixing and dispersing various conventionally known magnetic powders such as e3O4 powder, Fe powder, CO lead powder, Fe-Ni powder, and halium ferrite 1- with a binder resin, an organic solvent, etc., is applied to the base material. Formed conductor 15
In addition to being formed by coating and drying on J:, C0
1Ni, Fe-, CoNi alloy, Co-Cr
Ferromagnetic materials such as alloy, Co-P, Co-N1-P,
It can also be formed by depositing the conductive layer on the conductor layer by vacuum deposition, ion blating, sputtering, plating, or the like.
以りのように、基体とｖｔ磁性層の間に、ｌ） １３１
）吸油Ｍが５０〜１００ｍ７！／１００ｇで、粒子径が
０．０１３〜０．０４０ ｐ ｍのカーボンブラ’７り
を含む表面粗度が中心線平均粗さで０．０１０μｍ以下
の導電体）ｉを設し〕ると、導電体層の表面平ｌｈ性が
良好となり、この導電体層」−に形成されるＴＪｉＩ性
層の表面平滑性も良好になるため、出力低下やノイズの
増大が効果的に抑制され、磁性層の表面電気抵抗が小さ
くて電磁変換特性に（夏れた磁気記録媒体が得られる。As shown below, between the substrate and the vt magnetic layer, l) 131
) Oil absorption M is 50-100m7! /100g, and the surface roughness including carbon brazing with a particle size of 0.013 to 0.040 pm is 0.010 μm or less in terms of center line average roughness. The surface smoothness of the conductive layer becomes good, and the surface smoothness of the TJiI layer formed on this conductive layer also becomes good, so that output reduction and noise increase are effectively suppressed, and the magnetic layer A magnetic recording medium with low surface electrical resistance and excellent electromagnetic conversion characteristics can be obtained.
次に、この発明の実施例について説明−」−る。 Next, embodiments of this invention will be explained.
実施例１
ラーヘン１２５５ （コロンヒヤ ｔｏｏ 市ｍｔｈｓ
ンカーボン社製、カーホンブ
ランク、Ｄ Ｉ３ Ｐ吸／１１１置５６ ｍ ｌ／１０
０ｇ、粒子径Ｑ、０２３／１ｍ）エスレノクＡ（漬水化
学］−業社 ５０・・製、塩化ヒニルー酢酸ビニル
一ビニルアルコール共ｔｍ合体）
パンデノクスＴ−５２５０（大 ３５〃日本インキ化学
工業社製、ウ
レタンエラストマー）
シクロへキサノン ３５０〃トルエン
３５０〃の組成物をザンドミルで２時
間混合分散した後、これにさらにコロネ−１・Ｌ（日本
ポリウレタン工業社製、三官能性低分子量イソシアネー
１〜化合物）を１５重量部添加し、０．５時間混合分散
して導電体層用塗料をｍ製した。この導電体層用塗料を
厚さ１３μｍのポリエステルフィルム」二に乾燥厚が約
１．０μｍとなるように塗布、乾燥して導電体層を形成
した。次いで、これをさらに６０℃で４８時間キュアー
した後、この導電体層上に、下記組成の磁性塗料を乾燥
厚が約３．０ｐｍとなるように塗布、乾燥し、鏡面処理
を行って磁性層を形成した。しかる後、これを所定の巾
に裁断してビデオテープをつくった。Example 1 Lachen 1255 (Koronhia too city mths
Manufactured by Carbon Carbon Co., Ltd., car phone blank, D I3 P absorption/111 position, 56 ml/10
0g, particle size Q, 023/1m) Eslenoku A (Zukesui Kagaku) - manufactured by Gyosha 50..., hinyl chloride-vinyl acetate-vinyl alcohol co-TM combination) Pandenox T-5250 (large 35〃manufactured by Nippon Ink Chemical Industry Co., Ltd.) , urethane elastomer) Cyclohexanone 350〃Toluene
After mixing and dispersing the composition of No. 350 for 2 hours in a sand mill, 15 parts by weight of Corone-1 L (manufactured by Nippon Polyurethane Industries, Ltd., trifunctional low molecular weight isocyanate 1 to compound) was further added to give 0.5 parts by weight. The mixture was mixed and dispersed for a period of time to prepare a conductor layer paint. This paint for a conductive layer was applied to a 13 μm thick polyester film to a dry thickness of about 1.0 μm, and dried to form a conductive layer. Next, this was further cured at 60°C for 48 hours, and then a magnetic paint having the following composition was applied to the conductive layer to a dry thickness of approximately 3.0 pm, dried, and mirror-finished to form a magnetic layer. was formed. Afterwards, this was cut to a specified width and a videotape was made.
磁性塗料
α−Ｆｅ磁性粉末 １００重量部コニスレ
ツクＡ １０．（ｉ 〃バンデソク
ス’Ｉ’ ５２５０ ８．２ ”コＩ：Ｊ不
−１・Ｉ−４，７〃
低分子星ニトロセルロース １ １／Ａ＋２０３
粉末 ４ ・・ステアリン酸
２ 〃ステアリン酸−ｎ−ブチル
１ ／／シクロへキサノン ９５１１ト
ルエン ９５〃実施例２
実施例１における導電体ｙｍｌ用塗粗の組成において、
ラーヘン１２５５に代えてラーヘン２０００（コヤンビ
ャンカーボン社製、カーホンブラ、り、吸油量６５ｍｎ
／１００ｇ、粒子径０．旧を３μｍ）を同車使用し、さ
らに新たにエチレンオキ９−イド−プロピレンオキサイ
１−共重合体を５重Ｉ部加えた以外は、実施例１と同様
にして１ＪＪＶｌｉ体層を形成し、ビデオテープをつく
った。Magnetic paint α-Fe magnetic powder 100 parts by weight Konislec A 10. (i 〃Vandesox'I' 5250 8.2 ``Ko I:JF-1・I-4,7〃 Low molecular weight star nitrocellulose 1 1/A+203
Powder 4 Stearic acid
2 n-butyl stearate
1 //Cyclohexanone 9511Toluene 95〃Example 2 In the composition of the rough coating for conductor yml in Example 1,
Rahen 2000 (manufactured by Koyanbyang Carbon Co., Ltd., Carhon Bra, Ri, oil absorption 65mm) instead of Rahen 1255
/100g, particle size 0. A 1JJVli body layer was formed in the same manner as in Example 1, except that the old 3 μm) was used in the same car, and 5 parts of ethylene oxide 9-ide-propylene oxide 1-copolymer was newly added. I made a videotape.
比較例１
実施例１におりる導電体層用塗料の組成において、ラー
ベン１２５５に代えてパルカンＸＣ−７２Ｒ（キャボッ
１−礼製、カーボンブラック、ＤＢＰ吸油量１８５ｍｊ
！／１００ｇ、粒子径０．０３０，１７ｍ）を同量使用
した以外は実施例１と同様にして導電体層を形成し、ビ
デオテープをつくった。Comparative Example 1 In the composition of the paint for the conductive layer in Example 1, Palcan
! A conductor layer was formed in the same manner as in Example 1, except that the same amount of 100 g, particle size 0.030, 17 m) was used, and a videotape was produced.
各実施例および各比較例で得られた各磁気テープについ
て、導電体層および磁性層の表面電気抵抗、および表面
粗さを測定し、ＲＦ比出力クロマ出力、ビデオＳ／Ｎ、
カラーＳ／Ｎ等のビデオ特性を測定した。またドロップ
アウトも測定した。For each magnetic tape obtained in each example and each comparative example, the surface electrical resistance and surface roughness of the conductor layer and magnetic layer were measured, and the RF specific output chroma output, video S/N,
Video characteristics such as color S/N were measured. Dropout was also measured.
導電体層および磁性層の表面粗さは、触針式表面粗度計
（東京精密社製サーフコム）を用い、力・ノドオフ０．
０８ｍｍ１． ）ラハース長さ８ｍｍ、トラバース：
速度０．０６・・／・・・で、導電体層お
よび磁性層の中） 心線平均粗さを算出し
て、測定した。なお、ビデ１ オ特性は比
較例１を基準とした相対値で表した。The surface roughness of the conductor layer and magnetic layer was measured using a stylus surface roughness meter (Surfcom, manufactured by Tokyo Seimitsu Co., Ltd.), and measured by force and throat-off of 0.
08mm1. ) Lahase length 8mm, traverse:
The average roughness of the conductive layer and the magnetic layer was calculated and measured at a speed of 0.06.../.... Note that the video characteristics are expressed as relative values based on Comparative Example 1.
１ 下表はその結果である。1. The table below shows the results.
） 〔発明の効果〕
上表から明らかなように、この発明で得られた磁気テー
プ（実施例１および２）は、導電体層および磁性層の表
面電気抵抗が充分に小さく、また従来の磁気テープ（比
較例１）に比べて、導電体層の表面粗さおよび磁性層の
表面粗さが小さく、ｊ さら′”ＲＦ比出
力″。″？比出力３デ１８／ゞ・”□ｊ
ラーＳ／Ｎ等のビデオ特性がいずれも高く、また皇
ドロップアウトも少なく、このことからこ
の発明ＩＩ 、よ、７（い、、、お３．
、□およ、□。０よ′１ カ□、□、ヵ、
ワ、□□、よ、イ４、。よ□４゜１ が向
上され、表面電気抵抗を劣化させることなく）
電磁変換特性が向上されていることがわかる。) [Effects of the Invention] As is clear from the above table, the magnetic tapes obtained by the present invention (Examples 1 and 2) have sufficiently small surface electrical resistances of the conductor layer and magnetic layer, and are superior to conventional magnetic tapes. Compared to the tape (Comparative Example 1), the surface roughness of the conductive layer and the surface roughness of the magnetic layer are smaller, and the RF specific output is lower. ″?Specific output 3 de 18/ゞ・”□j
The video characteristics such as color S/N are high, and
Dropouts are also small, which is why this invention II.
, □ and □. 0yo'1 Ka □, □, Ka,
Wa, □□, yo, i4. 4゜1 has been improved without deteriorating the surface electrical resistance)
It can be seen that the electromagnetic conversion characteristics are improved.
丹Tan
Claims (1)
０ｍｌ／１００ｇで、粒子径が０．０１３〜０．０４０
μｍのカーボンブラックを含む表面粗度が中心線平均粗
さで０．０１０μｍ以下の導電体層を設けたことを特徴
とする磁気記録媒体1. DBP oil absorption between the substrate and the magnetic layer is 50 to 10
0ml/100g, particle size 0.013-0.040
A magnetic recording medium characterized by being provided with a conductive layer containing micrometer carbon black and having a center line average roughness of 0.010 micrometers or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60056912A JPH0724101B2 (en) | 1985-03-20 | 1985-03-20 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60056912A JPH0724101B2 (en) | 1985-03-20 | 1985-03-20 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61216116A true JPS61216116A (en) | 1986-09-25 |
| JPH0724101B2 JPH0724101B2 (en) | 1995-03-15 |
Family
ID=13040670
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60056912A Expired - Lifetime JPH0724101B2 (en) | 1985-03-20 | 1985-03-20 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0724101B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62214514A (en) * | 1986-03-14 | 1987-09-21 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| EP0388731A2 (en) * | 1989-03-22 | 1990-09-26 | BASF Magnetics GmbH | Magnetic information carrier |
| US5763046A (en) * | 1991-01-21 | 1998-06-09 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5827600A (en) * | 1991-01-21 | 1998-10-27 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US6096406A (en) * | 1997-07-15 | 2000-08-01 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US6203934B1 (en) | 1997-10-14 | 2001-03-20 | Fui Photo Film Co., Ltd. | Magnetic recording medium |
| US6316077B1 (en) | 1998-06-22 | 2001-11-13 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US6444290B1 (en) | 1998-06-11 | 2002-09-03 | Fuji Photo Film Co., Ltd. | Magnetic recording medium comprising a support containing a specific size filler and having a specific concentration of surface protrusions |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5698719A (en) * | 1980-01-10 | 1981-08-08 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS6020316A (en) * | 1983-07-14 | 1985-02-01 | Sony Corp | Magnetic recording medium |
| JPS60164926A (en) * | 1984-02-08 | 1985-08-28 | Hitachi Maxell Ltd | Magnetic disk |
| JPS6173236A (en) * | 1984-09-18 | 1986-04-15 | Fuji Photo Film Co Ltd | Magnetic recording medium |
-
1985
- 1985-03-20 JP JP60056912A patent/JPH0724101B2/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5698719A (en) * | 1980-01-10 | 1981-08-08 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS6020316A (en) * | 1983-07-14 | 1985-02-01 | Sony Corp | Magnetic recording medium |
| JPS60164926A (en) * | 1984-02-08 | 1985-08-28 | Hitachi Maxell Ltd | Magnetic disk |
| JPS6173236A (en) * | 1984-09-18 | 1986-04-15 | Fuji Photo Film Co Ltd | Magnetic recording medium |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62214514A (en) * | 1986-03-14 | 1987-09-21 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| EP0388731A2 (en) * | 1989-03-22 | 1990-09-26 | BASF Magnetics GmbH | Magnetic information carrier |
| US6025082A (en) * | 1991-01-21 | 2000-02-15 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5985408A (en) * | 1991-01-21 | 1999-11-16 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5763046A (en) * | 1991-01-21 | 1998-06-09 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5811166A (en) * | 1991-01-21 | 1998-09-22 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5811172A (en) * | 1991-01-21 | 1998-09-22 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5827600A (en) * | 1991-01-21 | 1998-10-27 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5851622A (en) * | 1991-01-21 | 1998-12-22 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US6020022A (en) * | 1991-01-21 | 2000-02-01 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US6015602A (en) * | 1991-01-21 | 2000-01-18 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5780141A (en) * | 1991-04-25 | 1998-07-14 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US5792543A (en) * | 1991-04-25 | 1998-08-11 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US6096406A (en) * | 1997-07-15 | 2000-08-01 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| US6203934B1 (en) | 1997-10-14 | 2001-03-20 | Fui Photo Film Co., Ltd. | Magnetic recording medium |
| US6444290B1 (en) | 1998-06-11 | 2002-09-03 | Fuji Photo Film Co., Ltd. | Magnetic recording medium comprising a support containing a specific size filler and having a specific concentration of surface protrusions |
| US6316077B1 (en) | 1998-06-22 | 2001-11-13 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0724101B2 (en) | 1995-03-15 |
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