JPH0224822A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH0224822A JPH0224822A JP17463988A JP17463988A JPH0224822A JP H0224822 A JPH0224822 A JP H0224822A JP 17463988 A JP17463988 A JP 17463988A JP 17463988 A JP17463988 A JP 17463988A JP H0224822 A JPH0224822 A JP H0224822A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic recording
- carbon black
- recording medium
- powder
- intermediate layer
- 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
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 32
- 239000006229 carbon black Substances 0.000 claims abstract description 21
- 239000000843 powder Substances 0.000 claims abstract description 18
- 229920005989 resin Polymers 0.000 claims abstract description 10
- 239000011347 resin Substances 0.000 claims abstract description 10
- 239000000020 Nitrocellulose Substances 0.000 claims abstract description 6
- 239000011230 binding agent Substances 0.000 claims abstract description 6
- 229920001220 nitrocellulos Polymers 0.000 claims abstract description 6
- 230000005294 ferromagnetic effect Effects 0.000 claims abstract description 3
- 239000000758 substrate Substances 0.000 claims abstract 6
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 claims description 3
- 229920005749 polyurethane resin Polymers 0.000 claims description 3
- 229920001228 polyisocyanate Polymers 0.000 claims description 2
- 239000005056 polyisocyanate Substances 0.000 claims description 2
- 238000002834 transmittance Methods 0.000 abstract description 11
- 238000006243 chemical reaction Methods 0.000 abstract description 8
- 230000003746 surface roughness Effects 0.000 abstract description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 4
- 239000011248 coating agent Substances 0.000 abstract description 3
- 238000000576 coating method Methods 0.000 abstract description 3
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 abstract description 2
- 239000006231 channel black Substances 0.000 abstract description 2
- 239000006232 furnace black Substances 0.000 abstract description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 abstract description 2
- 239000000463 material Substances 0.000 abstract description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 abstract 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 abstract 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 abstract 2
- FJWGYAHXMCUOOM-QHOUIDNNSA-N [(2s,3r,4s,5r,6r)-2-[(2r,3r,4s,5r,6s)-4,5-dinitrooxy-2-(nitrooxymethyl)-6-[(2r,3r,4s,5r,6s)-4,5,6-trinitrooxy-2-(nitrooxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-3,5-dinitrooxy-6-(nitrooxymethyl)oxan-4-yl] nitrate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O)O[C@H]1[C@@H]([C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@@H](CO[N+]([O-])=O)O1)O[N+]([O-])=O)CO[N+](=O)[O-])[C@@H]1[C@@H](CO[N+]([O-])=O)O[C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O FJWGYAHXMCUOOM-QHOUIDNNSA-N 0.000 abstract 1
- 229910000019 calcium carbonate Inorganic materials 0.000 abstract 1
- 235000010216 calcium carbonate Nutrition 0.000 abstract 1
- 229910052594 sapphire Inorganic materials 0.000 abstract 1
- 239000000543 intermediate Substances 0.000 description 10
- 239000010410 layer Substances 0.000 description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 239000003973 paint Substances 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002156 mixing Methods 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
- 235000021360 Myristic acid Nutrition 0.000 description 1
- TUNFSRHWOTWDNC-UHFFFAOYSA-N Myristic acid Natural products CCCCCCCCCCCCCC(O)=O TUNFSRHWOTWDNC-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- ULBTUVJTXULMLP-UHFFFAOYSA-N butyl octadecanoate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OCCCC ULBTUVJTXULMLP-UHFFFAOYSA-N 0.000 description 1
- 238000003490 calendering Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- QWXYZCJEXYQNEI-OSZHWHEXSA-N intermediate I Chemical compound COC(=O)[C@@]1(C=O)[C@H]2CC=[N+](C\C2=C\C)CCc2c1[nH]c1ccccc21 QWXYZCJEXYQNEI-OSZHWHEXSA-N 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- -1 methyl ether ketone Chemical class 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 125000001273 sulfonato group Chemical group [O-]S(*)(=O)=O 0.000 description 1
Landscapes
- Paints Or Removers (AREA)
- Magnetic Record Carriers (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９．さらに詳しくは電磁変
換特性の優れた元しｆへい性の大きい磁気記録媒体に関
する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording medium. More specifically, the present invention relates to a magnetic recording medium having excellent electromagnetic conversion characteristics and high fragility.
近年、磁気記録媒体は高密度記録および長尺化の検討が
峰んに行なわれてお、９１強磁１８：粉の微粒子化およ
び磁気記録層、ベースフィルム等が薄膜化されるように
な９．磁気テープの光透過率が大きくなる傾向となって
−る。In recent years, there has been a lot of research into high-density recording and longer lengths of magnetic recording media, and 91 ferromagnetic 18: finer particles of powder and thinner magnetic recording layers, base films, etc. ．． There is a tendency for the optical transmittance of magnetic tapes to increase.
磁気テープの光透過率が大きくなるとＶＨ８万式ＶＴＲ
のように光透過量によりテープエンドを検出する方法で
は誤動作を生じｆすくなり問題となるｉこの対策上して
、これまでにカーボンブラックと結合剤樹脂から成る中
間ＪＩＳを設けることが提案されてきた。また、これと
目的は異、なるが。When the light transmittance of the magnetic tape increases, VH80,000 type VTR
The method of detecting the end of the tape based on the amount of light transmission, as in Ta. Also, the purpose is different from this one.
無機質粉末と結合剤樹脂から成る中間ｔｍｔ設け。An intermediate TMT consisting of inorganic powder and binder resin is provided.
テープのヤング率を大きくシ、耐久性の向上ｆ：狙った
方法も提案されている。A method has also been proposed that aims to increase the Young's modulus of the tape and improve its durability.
しかし、Ｌ記の各中間Ｉ−にはそれぞれ欠点が認められ
る。カーボンブラック添加の中ｔｌＲＩ−では。However, each of the intermediates I- in L has its own drawbacks. In tlRI- during carbon black addition.
カーボンブラックの分散性が劣り、この次め得られる中
間層の表面性が悪く、電磁変換特性の低下Ｉｃ）ながる
、１ｔ中間層の望ｌＩＩ率が大きく、その上に磁気紀録
庸を塗布すると、磁気記録ノー用塗料中の溶剤が中間Ｉ
ＩＩの空隙中に＆透するため、磁気記録ｊ−の塗布ムラ
が発生したりする。The dispersibility of carbon black is poor, the surface properties of the subsequently obtained intermediate layer are poor, and the electromagnetic conversion characteristics are reduced. Then, the solvent in the paint for magnetic recording becomes intermediate I.
Since it penetrates into the gap of II, uneven coating of magnetic recording J- may occur.
一方無機’ｉｔ＃末（ＣａＣ０ｈＢａＳＯｎ 、 Ｚｎ
Ｏ，Ｔ１σ１８１（ｈ 、α−Ａｌｚｏｓ等の白色粉末
）と結合剤樹脂よりなる中間ｊ−では、磁気記録媒体の
ヤング率の向上は認められるが光透過率の低減には寄与
しない。On the other hand, inorganic compounds (CaC0hBaSOn, Zn
In the intermediate j-, which is made of O, T1σ181 (h, white powder such as α-Alzos) and a binder resin, an improvement in the Young's modulus of the magnetic recording medium is observed, but it does not contribute to a reduction in light transmittance.
この発明Ｆ′ｉ上記従来製品が持っていた中間層の元透
過率金小さくするとその表面性が低Ｆ−ｒるという欠点
を解決し、以って電磁変換特性が良好でかつ光透過率も
小さい磁気記録媒体を提供することを目的とする。This invention solves the drawback that the above-mentioned conventional products have, that when the original transmittance of the intermediate layer is made smaller, its surface properties become lower F-r, and thus the electromagnetic conversion characteristics are good and the light transmittance is also low. The purpose is to provide a small magnetic recording medium.
上記問題点を解決するため１発明者らはカーボンブラッ
クと無機質粉末を併用し、その配合比および分散方法に
ついて検討した結果、カーボンブラック／無機質粉末を
鷹量比で７０／３０〜４０／６０の範囲で使用するとカ
ーボンブラックの分散性が向上し、中間Ｉ−の表面平滑
性が艮くなり、がつ塗布ムラの発生が防止されるので、
その上に塗布される磁性！−の電磁変換特注が良好とな
る。しかも磁気記録媒体の光透ｉｍ率も十分に小さくな
ることが明らかとなり九。In order to solve the above problems, the inventors used carbon black and inorganic powder in combination and studied the blending ratio and dispersion method. As a result, the inventors found that the carbon black/inorganic powder had a ratio of 70/30 to 40/60. When used within this range, the dispersibility of carbon black improves, the surface smoothness of the intermediate I- improves, and uneven coating is prevented.
Magnetism applied on top of it! - The electromagnetic conversion custom order becomes better. Moreover, it has become clear that the optical transmittance of the magnetic recording medium is also sufficiently small.
カーボンブラックの分＠注が良くなるのは、カーボンブ
ラックと無の質粉末を含む中ｒＩｊＪ層用塗料を分１枚
機を用いて分散するとき、カーボンブラックの盪が無機
質粉末に対し７０％以下になると。The reason why the carbon black ratio is better is that when dispersing a medium layer paint containing carbon black and inorganic powder using a single-layer machine, the ratio of carbon black to the inorganic powder is 70% or less. To become and.
ｊｌに＃４の流動性が飛躍的に同上し、また分散時の治
剤使用産も少なくできるので］料が効率良くせん友ん応
力を受けることができるためと推測している。It is assumed that this is because the fluidity of #4 is dramatically improved compared to #4, and the amount of reagent used during dispersion can be reduced, so that the material can efficiently receive shearing stress.
ま友、カーボンブラックと無機質粉末の比率が５０１５
０〜３０／７０の間で中間層の７！気抵抗は急峻に変化
し５ｔ）１５０の嚇ｆｌｕ−Ω／ｅｊ； ４０／６０で
は１０マΩ／ｃｊ、 ３０／ ７０ テ１０ ” ｎ／
ｃｄとなり。Mayu, the ratio of carbon black and inorganic powder is 5015
A middle class 7 between 0 and 30/70! The air resistance changes sharply, 5t) 150 flu-Ω/ej; 40/60 has 10 maΩ/cj, 30/70 te10”n/
It becomes a CD.
３０／７０となると電気抵抗が高くなシ、＃電気発生が
問題となる。さらに光透過率についても３５／６５より
もカーボンブラックが少なくなると十分に光遣蔽効果が
得られなくなる。When it is 30/70, the electrical resistance is high and electricity generation becomes a problem. Furthermore, regarding the light transmittance, if the amount of carbon black is less than 35/65, a sufficient light-transmitting effect cannot be obtained.
本発明の磁気記録媒体ｔ−製造するには、ファーネスブ
ラック、チャンネルブラック、グラファイト化カーボン
ブラック等のカーボンブラックとＣａＣ０’ｊ、ＢａＳ
Ｏ４，Ｔ１０ｚ 、 ａ−ＡＪｇＯｓ等の無機粉末と、
結合剤樹脂としてニトロセルロース、水酸基。To produce the magnetic recording medium of the present invention, carbon black such as furnace black, channel black, graphitized carbon black, CaC0'j, BaS
Inorganic powder such as O4, T10z, a-AJgOs,
Nitrocellulose, hydroxyl group as binder resin.
カルボキシル基、リン酸エステル基、スルホン酸ンーダ
基等を含む塩化ビニル系樹脂、ボリクレタン樹脂、およ
びポリインシアネート等を用い、１！機醇剤とともに適
宜の配合で混合分散した塗料をまた必要がある場合は、
バックコート層ｔ−設けることもめる。Using vinyl chloride resins, polycrethane resins, polyincyanates, etc. containing carboxyl groups, phosphate ester groups, sulfonate groups, etc., 1! If it is necessary to mix and disperse the paint with the appropriate blending agent,
It is also possible to provide a back coat layer.
次に本発明の実施例２よび比較例を示す。以下の例にお
いて部とあるのは直置部を示す。Next, Example 2 of the present invention and a comparative example will be shown. In the following examples, the word "part" indicates a part that is placed directly.
実施例１〜８．ｊｉＰよび比較例１〜４中間膚塗料組成
として１表１に示す充填剤を用いて、以下の組成の塗料
を作製した。Examples 1-8. jiP and Comparative Examples 1 to 4 Paints with the following compositions were prepared using the fillers shown in Table 1 as intermediate skin paint compositions.
表１に示す充填剤 １００部ニトロ
セルロース（１／２秒／Ｌ’−）”）２７部ポリウレタ
ン樹脂 １９部ポリインシアネー
ト ８９シクロヘキテノン
１００部メチルエチルケトン
２００部トルエン
３００部上記組成物を高速デイスパー、サンドミル
等の分散機を用いて分散した後、平均孔径０．５μ講の
フィルターで濾過しな後、乾燥後の厚みが約０．３〜１
．５μ簿となるように、ポリエステルフィルム（厚さ約
１３μＳ）の一方の面に塗布し、さらにその土に下記に
示す組成の磁気記碌膚を設け、カレンダ処Ｊｌを行った
後１／２インチ幅にスリットしビデオテープを作製した
。Filler shown in Table 1 100 parts Nitrocellulose (1/2 sec/L'-)") 27 parts Polyurethane resin 19 parts Polyincyanate 89 Cyclohextenone
100 parts methyl ethyl ketone
200 parts toluene
After dispersing 300 parts of the above composition using a dispersing machine such as a high-speed disper or a sand mill, and filtering it through a filter with an average pore size of 0.5 microns, the thickness after drying is about 0.3 to 1.
．． It was coated on one side of a polyester film (thickness: about 13 μS) so that it became a 5μ sheet, and then a magnetic recording layer with the composition shown below was applied to the soil, and after calendering, 1/2 inch A videotape was made by slitting the tape widthwise.
実施例および比較例の充填剤（表中数字は重量Ｓを示す
。）
な２．実施例９は中間層の結合剤樹脂のニトロセルロー
スを同量の塩化ビニル系樹脂ＣＵＣＣ社製ＶＡＧＨ）に
代え、有機溶剤の使用量を７クロヘキサノン ８０部、
メチルエテルケトン、１６０ｓ、トルエン、２４０部に
変更した。Fillers of Examples and Comparative Examples (Numbers in the table indicate weight S) 2. In Example 9, the binder resin of the intermediate layer, nitrocellulose, was replaced with the same amount of vinyl chloride resin (VAGH manufactured by CUCC), and the amount of organic solvent used was 80 parts of 7 clohexanone,
The content was changed to methyl ether ketone, 160s, and toluene, 240 parts.
磁気記録層組成
Ｃｏ ｔ＊ ｒ −Ｆａ ｇｏｓ （比表面積３５ｗ１
／Ｉ）１００部
カーボンブラック（平均粒子径０．０２５μｍ）４部
α−人ＪｍＯｓ （平均粒子径０．４μ賜）
４部ステアリン酸亜、＠ Ｏ，Ｓ
部ニトロセルロース（１７２秒グレード） ９１１
ポリウレタン樹脂 ８部ポリイソ
シアネー） ３１１ミリスチン
酸 ２部ステアリン酸ｎ−ブ
チル ｌｓ上記各実施例および比較例で
作製したビデオテープを以下に示す方法で評価した。Magnetic recording layer composition Co t * r −Fa gos (specific surface area 35w1
/I) 100 parts carbon black (average particle size 0.025μm) 4 parts α-JmOs (average particle size 0.4μm)
4 parts stearic acid, @O,S
Nitrocellulose (172 seconds grade) 911
Polyurethane resin 8 parts Polyisocyanate) 311 Myristic acid 2 parts n-Butyl stearate ls The videotapes prepared in each of the above Examples and Comparative Examples were evaluated by the method shown below.
表面粗ｇ：ｍ針式針面表面粗度計いて、磁性層表面の中
心線平均粗さを測定した。Surface roughness g: The center line average roughness of the surface of the magnetic layer was measured using an m-needle surface roughness meter.
ＲＦ出カニ基準ＲＦ記鍮電流でＲＦ信号を記録し、その
再生出力を標準テープとの
相対値で示し九。RF Output Standard RF Recording An RF signal is recorded with a current, and the playback output is expressed as a relative value to the standard tape.9.
光透過率：ビデオテープを日本ビクター■製のオプティ
カルテスターＶＴ−ＩＭ 測
定器にて測定し友。Light transmittance: The videotape was measured using an optical tester VT-IM measuring device manufactured by Victor Japan.
表２に各実施例、比較例でのビデオテープの測定結果を
示す。Table 2 shows the measurement results of the video tapes in each Example and Comparative Example.
表 ２ 実施例１〜９の中間ｒａｔ備えた磁気記録媒体は。Table 2 The magnetic recording media with the intermediate rat of Examples 1 to 9 are as follows.
表面粗さが小さく、シかもＲＦ出力が高い。また光透過
率も低い。Low surface roughness and high RF output. It also has low light transmittance.
以上説明したように、カーボンブラックと無機質粉末を
含む中間Ｊ−ｔ−設けた磁気記録媒体は０表面粗さが小
さく、光透過率も低く、電磁変換特性も優れている。と
くにカーボンブラックと無機質粉末の比率を７０／３０
〜４０７６Ｇの範囲としたものは光適蔽性が大きく、電
磁変換特性に格段に優れた磁気記録媒体が得られること
は明らかである。As explained above, the magnetic recording medium with the intermediate Jt-formation containing carbon black and inorganic powder has low zero surface roughness, low light transmittance, and excellent electromagnetic conversion characteristics. In particular, the ratio of carbon black and inorganic powder is 70/30.
It is clear that a magnetic recording medium in the range of ~4076G has high optical shielding properties and has extremely excellent electromagnetic conversion characteristics.
出願人 日立マクセル株式会社 代表者 氷 井 厚Applicant: Hitachi Maxell, Ltd. Representative: Atsushi Ii
Claims (3)
する磁気記録媒体において、カーボンブラックと無機質
粉末を含む中間層を前記非磁性基体と磁気記録層の間に
設けたことを特徴とする磁気記録媒体。(1) A magnetic recording medium having a magnetic recording layer containing ferromagnetic powder on a non-magnetic substrate, characterized in that an intermediate layer containing carbon black and inorganic powder is provided between the non-magnetic substrate and the magnetic recording layer. magnetic recording media.
の比が重量比で７０／３０〜４０／６０であることを特
徴とする請求項（１）記載の磁気記録媒体。(2) The magnetic recording medium according to claim 1, wherein the ratio of carbon black to inorganic powder contained in the intermediate layer is 70/30 to 40/60 by weight.
ロース、塩化ビニル系樹脂のいずれか、または両者と、
ポリウレタン樹脂、ポリイソシアネートから成ることを
特徴とする請求項（１）または（２）記載の磁気記録媒
体。(3) The binder resin component constituting the intermediate layer is nitrocellulose, vinyl chloride resin, or both,
3. The magnetic recording medium according to claim 1, wherein the magnetic recording medium is made of polyurethane resin or polyisocyanate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63174639A JP2695647B2 (en) | 1988-07-13 | 1988-07-13 | Magnetic recording media |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63174639A JP2695647B2 (en) | 1988-07-13 | 1988-07-13 | Magnetic recording media |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6273897A Division JPH09259421A (en) | 1997-03-17 | 1997-03-17 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0224822A true JPH0224822A (en) | 1990-01-26 |
| JP2695647B2 JP2695647B2 (en) | 1998-01-14 |
Family
ID=15982109
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63174639A Expired - Lifetime JP2695647B2 (en) | 1988-07-13 | 1988-07-13 | Magnetic recording media |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2695647B2 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6020316A (en) * | 1983-07-14 | 1985-02-01 | Sony Corp | Magnetic recording medium |
| JPS6173237A (en) * | 1984-09-18 | 1986-04-15 | Hitachi Maxell Ltd | Magnetic disk |
| JPS62214513A (en) * | 1986-03-14 | 1987-09-21 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS63317926A (en) * | 1987-06-22 | 1988-12-26 | Tokin Corp | Coating type magnetic medium |
-
1988
- 1988-07-13 JP JP63174639A patent/JP2695647B2/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6020316A (en) * | 1983-07-14 | 1985-02-01 | Sony Corp | Magnetic recording medium |
| JPS6173237A (en) * | 1984-09-18 | 1986-04-15 | Hitachi Maxell Ltd | Magnetic disk |
| JPS62214513A (en) * | 1986-03-14 | 1987-09-21 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS63317926A (en) * | 1987-06-22 | 1988-12-26 | Tokin Corp | Coating type magnetic medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2695647B2 (en) | 1998-01-14 |
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