JPH0239018B2 - - Google Patents
Info
- Publication number
- JPH0239018B2 JPH0239018B2 JP56071752A JP7175281A JPH0239018B2 JP H0239018 B2 JPH0239018 B2 JP H0239018B2 JP 56071752 A JP56071752 A JP 56071752A JP 7175281 A JP7175281 A JP 7175281A JP H0239018 B2 JPH0239018 B2 JP H0239018B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- metal thin
- magnetic layer
- film
- acyl group
- 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.)
- Expired - Lifetime
Links
- 230000005291 magnetic effect Effects 0.000 claims description 22
- 239000010408 film Substances 0.000 claims description 17
- 239000010409 thin film Substances 0.000 claims description 14
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 12
- 239000010936 titanium Substances 0.000 claims description 12
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 10
- 125000002252 acyl group Chemical group 0.000 claims description 10
- 229910052719 titanium Inorganic materials 0.000 claims description 10
- ODIGIKRIUKFKHP-UHFFFAOYSA-N (n-propan-2-yloxycarbonylanilino) acetate Chemical compound CC(C)OC(=O)N(OC(C)=O)C1=CC=CC=C1 ODIGIKRIUKFKHP-UHFFFAOYSA-N 0.000 claims description 9
- 230000005294 ferromagnetic effect Effects 0.000 claims description 8
- 125000000217 alkyl group Chemical group 0.000 claims description 5
- 239000011248 coating agent Substances 0.000 claims description 4
- 238000000576 coating method Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- 125000004432 carbon atom Chemical group C* 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims 2
- 230000001681 protective effect Effects 0.000 claims 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims 2
- 239000010410 layer Substances 0.000 description 14
- 238000005260 corrosion Methods 0.000 description 10
- 230000007797 corrosion Effects 0.000 description 10
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 229910017052 cobalt Inorganic materials 0.000 description 4
- 239000010941 cobalt Substances 0.000 description 4
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 4
- 238000007738 vacuum evaporation Methods 0.000 description 4
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 229920006267 polyester film Polymers 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- ONIKNECPXCLUHT-UHFFFAOYSA-N 2-chlorobenzoyl chloride Chemical compound ClC(=O)C1=CC=CC=C1Cl ONIKNECPXCLUHT-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- 238000001771 vacuum deposition Methods 0.000 description 2
- UOCLXMDMGBRAIB-UHFFFAOYSA-N 1,1,1-trichloroethane Chemical compound CC(Cl)(Cl)Cl UOCLXMDMGBRAIB-UHFFFAOYSA-N 0.000 description 1
- -1 2-ethylhexyl group Chemical group 0.000 description 1
- KLQSRTKDOLFPQJ-UHFFFAOYSA-M CCCCO[Ti+](OCCCC)OCCCC.CCCCCCCCCCCCCCCCCC([O-])=O Chemical compound CCCCO[Ti+](OCCCC)OCCCC.CCCCCCCCCCCCCCCCCC([O-])=O KLQSRTKDOLFPQJ-UHFFFAOYSA-M 0.000 description 1
- 229910020630 Co Ni Inorganic materials 0.000 description 1
- 229910000531 Co alloy Inorganic materials 0.000 description 1
- 229910002440 Co–Ni Inorganic materials 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000539 dimer Substances 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- CAQIWIAAHXOQOS-UHFFFAOYSA-N octadecanoic acid;propan-2-ol;titanium Chemical compound [Ti].CC(C)O.CCCCCCCCCCCCCCCCCC(O)=O.CCCCCCCCCCCCCCCCCC(O)=O.CCCCCCCCCCCCCCCCCC(O)=O CAQIWIAAHXOQOS-UHFFFAOYSA-N 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- DVQHRBFGRZHMSR-UHFFFAOYSA-N sodium methyl 2,2-dimethyl-4,6-dioxo-5-(N-prop-2-enoxy-C-propylcarbonimidoyl)cyclohexane-1-carboxylate Chemical compound [Na+].C=CCON=C(CCC)[C-]1C(=O)CC(C)(C)C(C(=O)OC)C1=O DVQHRBFGRZHMSR-UHFFFAOYSA-N 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 125000004079 stearyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/72—Protective coatings, e.g. anti-static or antifriction
- G11B5/722—Protective coatings, e.g. anti-static or antifriction containing an anticorrosive material
Landscapes
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Description
本発明は金属薄膜型磁気記録媒体の磁性層表面
の改質を行ない、耐食性、走行性の向上を目ざし
たものである。
一般に真空蒸着またはメツキ法で作成した金属
薄膜型磁気記録媒体は高密度性に優れているとい
われている。特に近年はオーデイオ録音用やビデ
オ録音テープ用しての用途が期待されており、小
型録音テープ用として、プラスチツク基板上に真
空蒸着によつて、コバルト主成分合金の薄膜を形
成したものは、実用化の域に入り、市販されるよ
うになつた。しかし、一般的に強磁性金属は腐食
し易く、これを避けるために磁性体自体の合金化
の方法や磁性層上に高分子化合物の皮膜を形成す
るなどの方法が採用されている。しかしこれらの
方法においては、磁性層の合金化の場合、磁気特
性の観点からは、耐食性の良い合金が必ずしも良
い特性を有するとは言えないのが普通である。ま
た、磁性層表面に耐食性のある被膜を形成する事
は、効果はあるが、電磁変換特性の観点からは、
あまり皮膜層の膜厚が大きすぎるのは好ましいと
は言えない。皮膜層の厚みの許され得る範囲は
高々500Åであり、望ましくは200Å程度である。
この程度の膜厚を持ち、耐食性のある皮膜を安定
にしかも量産性良く形成するのは非常な困難を伴
う。また皮膜が形成されたとしても、この程度の
厚みでは完全に水分の侵入を妨げることは困難で
ある。
本発明では、以上のような従来の困難さを避け
る目的で、チタンアシレートの溶液を塗布した
後、乾燥させることによつて、十分な耐食性を得
るものである。
以下本発明について説明する。
真空蒸着法、電気メツキ法、スパツタリング法
などで作成した、コバルトなどの強磁性金属より
成る磁気記録用薄膜媒体上にチタンアシレート溶
液を塗布する。チタンアシレートは、次式に示す
ような分子式で表わされる。
（R1，R2，R3，R4のうち、少くとも１つ以上が
アシル基であり、他はアルキル基を持つている。）
上式においてＲがアルキル基の場合、微量の水
分によつて加水分解され、次式のような構造をも
つようになる。
また、Ｒがアシル基の場合には、加水分解反応
は起こらず、皮膜中に―ORが残ることになる。
アルキル基によつて加水分解の速度が異なり、
市販品としては、イソプロピル基、ｎ―ブチル
基、２―エチルヘキシル基、ステアリル基が用い
られている。
アシル基は、未反応基として被膜に残るため、
撥水性、滑性の観点から炭素数８から22の長鎖の
アシル基を用いる。
溶媒としては、ｎ―ブタノール、ｎ―ヘキサ
ン、ベンゼン、トルエン、クロロホルム、メチル
クロロホルム、四塩化炭素を用いる。
濃度は10％から0.001％が有効であり、１％か
ら0.01％が望ましい。
濃度が濃い場合には、均一な膜が生成しにくく
チヨーキング現象を起こし、接着性が低下する。
また、濃度が低い場合には、十分な厚みをもつた
皮膜が得られず、金属薄膜が露出する部分が生じ
十分な耐食性が得られない。
チタンアシレートは、金属薄膜上の微量の水分
や水酸基と反応し、錆の原因となる水分、水酸基
を減少させる。また反応後の長鎖のアシル基が残
るため疎水性を示し、水に対する接触角も増大す
るため、錆の原因となる水の浸入を防ぎ、耐食性
が向上する。
また、長鎖のアシル基は、良好な潤滑性を持つ
ていることから、走行性も改善される。
また、チタンアシレートのポリマー（２〜５量
体）でも同様の効果が得られる。
なお後述の実施例では強磁性金属薄膜として
Co―Ni膜を用いているが、Co膜，Co―Cr膜，
Co―Ni―Cr膜、Co―Fe膜等においても類似の効
果が得られた。
次に具体的に実施例の説明を行う。
実施例 １
ポリエステルフイルム上に真空蒸着法で作成し
たコバルト（80％），ニツケル（20％）の強磁性
合金薄膜の磁性層に下記の組成の溶液を塗布し
た。
トリ―ｎ―ブトキシチタンモノステアレート
１部
Ti（ｏ―nC4H9）3（oCOC17H35）〔日本曹達(株)製
チタンアシレート（TBSTA）〕ｎ―ブタノー
ル 100部
塗布後60℃で約30分間乾燥した。処理したもの
は処理前に比較して、磁性層の撥水性が改善され
た。また、鏡面仕上げのSUS304のブロツク上で
10ｇの荷重下での摩擦抵抗を測定したところ処理
前に比較して、約９分の８に低下していた。
第１表に接触角の測定結果と環境試験結果を示
す。
The present invention aims at improving the corrosion resistance and runnability by modifying the surface of the magnetic layer of a metal thin film magnetic recording medium. In general, metal thin film magnetic recording media prepared by vacuum deposition or plating methods are said to have excellent high density properties. Particularly in recent years, applications for audio and video recording tapes have been expected, and thin films of cobalt-based alloys formed by vacuum deposition on plastic substrates have been put into practical use for small-sized recording tapes. It has become commercially available. However, ferromagnetic metals are generally prone to corrosion, and in order to avoid this corrosion, methods such as alloying the magnetic material itself or forming a film of a polymer compound on the magnetic layer are adopted. However, in these methods, when alloying the magnetic layer, it is common that an alloy with good corrosion resistance does not necessarily have good properties from the viewpoint of magnetic properties. Also, forming a corrosion-resistant film on the surface of the magnetic layer is effective, but from the perspective of electromagnetic conversion characteristics,
It cannot be said that it is preferable that the film thickness of the film layer is too large. The allowable range of the thickness of the coating layer is at most 500 Å, preferably about 200 Å.
It is extremely difficult to stably form a corrosion-resistant film with such a thickness and with good mass production. Further, even if a film is formed, it is difficult to completely prevent moisture from entering with such a thickness. In the present invention, in order to avoid the above-mentioned conventional difficulties, sufficient corrosion resistance is obtained by applying a titanium acylate solution and then drying it. The present invention will be explained below. A titanium acylate solution is applied onto a magnetic recording thin film medium made of a ferromagnetic metal such as cobalt and made by vacuum evaporation, electroplating, sputtering, or the like. Titanium acylate is represented by the molecular formula shown in the following formula. (At least one of R 1 , R 2 , R 3 , and R 4 is an acyl group, and the others have an alkyl group.) In the above formula, when R is an alkyl group, it is As a result, it is hydrolyzed and has the structure shown in the following formula. Furthermore, when R is an acyl group, no hydrolysis reaction occurs and --OR remains in the film. The rate of hydrolysis varies depending on the alkyl group,
As commercially available products, isopropyl group, n-butyl group, 2-ethylhexyl group, and stearyl group are used. Since the acyl group remains in the coating as an unreacted group,
From the viewpoint of water repellency and slipperiness, a long chain acyl group with 8 to 22 carbon atoms is used. As the solvent, n-butanol, n-hexane, benzene, toluene, chloroform, methylchloroform, and carbon tetrachloride are used. A concentration of 10% to 0.001% is effective, preferably 1% to 0.01%. If the concentration is high, it will be difficult to form a uniform film, causing a yoking phenomenon and reducing adhesion.
Furthermore, if the concentration is low, a film with sufficient thickness cannot be obtained, and some parts of the thin metal film are exposed, making it impossible to obtain sufficient corrosion resistance. Titanium acylate reacts with trace amounts of moisture and hydroxyl groups on the metal thin film, reducing moisture and hydroxyl groups that cause rust. Furthermore, since long-chain acyl groups remain after the reaction, they exhibit hydrophobicity and increase the contact angle with water, which prevents water from entering which causes rust and improves corrosion resistance. Furthermore, since long-chain acyl groups have good lubricity, running properties are also improved. Similar effects can also be obtained with titanium acylate polymers (dimers to pentamers). In the examples described later, as a ferromagnetic metal thin film.
Co-Ni film is used, but Co film, Co-Cr film,
Similar effects were obtained with Co--Ni--Cr films, Co--Fe films, etc. Next, examples will be specifically explained. Example 1 A solution having the following composition was applied to the magnetic layer of a ferromagnetic alloy thin film of cobalt (80%) and nickel (20%) prepared by vacuum evaporation on a polyester film. tri-n-butoxytitanium monostearate
1 part Ti(onC 4 H 9 ) 3 (oCOC 17 H 35 ) [Titanium acylate (TBSTA) manufactured by Nippon Soda Co., Ltd.] 100 parts n-butanol After coating, it was dried at 60° C. for about 30 minutes. The water repellency of the magnetic layer of the treated magnetic layer was improved compared to that before treatment. In addition, on a mirror-finished SUS304 block,
When the frictional resistance was measured under a load of 10g, it was found to have decreased to about 8/9 compared to before treatment. Table 1 shows the contact angle measurement results and environmental test results.
【表】
実施例 ２
ポリエステルフイルム上に真空蒸着法で作成し
たコバルト（80％），ニツケル（20％）の強磁性
合金薄膜の磁性層に下記の組成の溶液を塗布し
た。
ｉ―プロポキシチタントリ―ステアレート
0.5部
〔Ti（ｏ―ｉ―C3H7）（oCoC17H35）3日本曹達
(株)製チタンアシレート（TTS）〕ベンゼン
100部
塗布後、60℃で約30分間乾燥した。処理したも
のは処理前に比較して磁性層の撥水性が改善され
た。また、鏡面仕上げSUS304のブロツク上で10
ｇの荷重下での摩擦抵抗を測定したところ、処理
前に比較して、約４分の３に低下していた。第２
表の接触角の測定結果と環境試験結果を示す。[Table] Example 2 A solution having the following composition was applied to the magnetic layer of a ferromagnetic alloy thin film of cobalt (80%) and nickel (20%) prepared by vacuum evaporation on a polyester film. i-propoxy titanium tri-stearate
0.5 parts [Ti (o-i-C 3 H 7 ) (oCoC 17 H 35 ) 3 Nippon Soda
Titanium Acylate Co., Ltd. (TTS) Benzene
After applying 100 parts, it was dried at 60°C for about 30 minutes. The water repellency of the magnetic layer of the treated magnetic layer was improved compared to that before treatment. In addition, 10
When the frictional resistance was measured under a load of 100 g, it was found to have decreased to about three-fourths of that before treatment. Second
The contact angle measurement results and environmental test results are shown in the table.
【表】
実施例 ３
ポリエステルフイルム上に真空蒸着法で作成し
たコバルト（80％）、ニツケル（20％）の強磁性
合金薄膜の磁性層に下記の組成の溶液を塗布し
た。
日本曹達(株)製チタンアシレートポリマー ５部
TBSTA―400 ベンゼン 100部
塗布後、60℃で約30分間乾燥した。処理したも
のは処理前に比較して磁性層の撥水性が改善され
た。また鏡面仕上げしたSUS304のブロツク上で
10ｇの荷重下での摩擦抵抗を測定したところ、処
理前に比較して、約５分の４に低下していた。第
３表に接触角の測定結果と環境試験結果を示す。[Table] Example 3 A solution having the following composition was applied to the magnetic layer of a ferromagnetic alloy thin film of cobalt (80%) and nickel (20%) prepared by vacuum evaporation on a polyester film. Titanium acylate polymer manufactured by Nippon Soda Co., Ltd. 5 parts TBSTA-400 Benzene 100 parts After coating, it was dried at 60°C for about 30 minutes. The water repellency of the magnetic layer of the treated magnetic layer was improved compared to that before treatment. Also, on a mirror-finished SUS304 block.
When the frictional resistance was measured under a load of 10g, it was found to have decreased to about 4/5 compared to before treatment. Table 3 shows the contact angle measurement results and environmental test results.
【表】
また、上記実施例１〜３において作成した試料
を、市販のビデオテープレコーダと同等の機能を
有する試験機にて、電磁性変換特性を測定したこ
ろ、未処理品に比較して、チタンアシレート処理
品の出力低下は、1dB以内と十分な特性を示し
た。
以上のように本発明によれば、金属薄膜型磁気
記録媒体の耐蝕性を容易に高めることができると
ともに摩擦抵抗を下げることができる。[Table] In addition, when the electromagnetic conversion characteristics of the samples prepared in Examples 1 to 3 above were measured using a tester having the same function as a commercially available video tape recorder, the results showed that the electromagnetic conversion characteristics were compared with those of the untreated product. The output drop of the titanium acylate treated product was within 1 dB, showing sufficient characteristics. As described above, according to the present invention, the corrosion resistance of a metal thin film magnetic recording medium can be easily increased, and the frictional resistance can be lowered.
Claims (1)
般式 （R1，R2，R3，R4のうち、１つ以上３つ以下が
炭素数８から22のアシル基であり、他はアルキル
基である。） で表わされるチタンアシレートの溶液が塗布、乾
燥されて形成された長鎖のアシル基を有する酸化
チタンの保護皮膜を設けたことを特徴とする金属
薄膜型磁気記録媒体。 ２ 強磁性金属薄膜よりなる磁性層の表面に、一
般式 （R1，R2，R3，R4のうち、１つ以上３つ以下が
炭素数８から22のアシル基であり、他はアルキル
基である。） で表わされるチタンアシレート溶液を塗布し、乾
燥させて、長鎖のアシル基を有する酸化チタンの
保護皮膜を形成することを特徴とする金属薄膜型
磁気記録媒体の製造方法。[Claims] 1. On the surface of a magnetic layer made of a ferromagnetic metal thin film, the general formula (Among R 1 , R 2 , R 3 , and R 4 , one or more and three or less are acyl groups having 8 to 22 carbon atoms, and the others are alkyl groups.) 1. A metal thin film type magnetic recording medium characterized by being provided with a protective film of titanium oxide having a long chain acyl group formed by coating and drying. 2. On the surface of the magnetic layer made of a ferromagnetic metal thin film, the general formula (Among R 1 , R 2 , R 3 , and R 4 , one or more and three or less are acyl groups having 8 to 22 carbon atoms, and the others are alkyl groups.) Apply a titanium acylate solution represented by A method for manufacturing a metal thin film type magnetic recording medium, comprising: forming a protective film of titanium oxide having a long-chain acyl group by drying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56071752A JPS57189339A (en) | 1981-05-13 | 1981-05-13 | Metallic thin film type magnetic recording medium and its manufacture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56071752A JPS57189339A (en) | 1981-05-13 | 1981-05-13 | Metallic thin film type magnetic recording medium and its manufacture |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57189339A JPS57189339A (en) | 1982-11-20 |
| JPH0239018B2 true JPH0239018B2 (en) | 1990-09-03 |
Family
ID=13469571
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56071752A Granted JPS57189339A (en) | 1981-05-13 | 1981-05-13 | Metallic thin film type magnetic recording medium and its manufacture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57189339A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003005659A (en) * | 2001-04-17 | 2003-01-08 | Tokai Rubber Ind Ltd | Transparent electromagnetic wave shield film for plasma display, front surface filter for plasma display panel using it, and plasma display |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5189702A (en) * | 1975-02-05 | 1976-08-06 | JIKIKIOKUTAI | |
| JPS5376013A (en) * | 1976-12-17 | 1978-07-06 | Nec Corp | Magnetic memory medium |
| JPS5441111A (en) * | 1977-09-07 | 1979-04-02 | Nec Corp | Magnetic memory medium |
-
1981
- 1981-05-13 JP JP56071752A patent/JPS57189339A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5189702A (en) * | 1975-02-05 | 1976-08-06 | JIKIKIOKUTAI | |
| JPS5376013A (en) * | 1976-12-17 | 1978-07-06 | Nec Corp | Magnetic memory medium |
| JPS5441111A (en) * | 1977-09-07 | 1979-04-02 | Nec Corp | Magnetic memory medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57189339A (en) | 1982-11-20 |
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