JPH057764B2 - - Google Patents
Info
- Publication number
- JPH057764B2 JPH057764B2 JP58075491A JP7549183A JPH057764B2 JP H057764 B2 JPH057764 B2 JP H057764B2 JP 58075491 A JP58075491 A JP 58075491A JP 7549183 A JP7549183 A JP 7549183A JP H057764 B2 JPH057764 B2 JP H057764B2
- Authority
- JP
- Japan
- Prior art keywords
- recording medium
- magnetic recording
- back layer
- inorganic powder
- thin film
- 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
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 12
- 239000000843 powder Substances 0.000 claims description 12
- 239000010409 thin film Substances 0.000 claims description 10
- 239000011230 binding agent Substances 0.000 claims description 9
- 239000006229 carbon black Substances 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 5
- 239000011248 coating agent Substances 0.000 claims description 2
- 238000000576 coating method Methods 0.000 claims description 2
- 239000003973 paint Substances 0.000 description 9
- 238000000034 method Methods 0.000 description 7
- 230000003746 surface roughness Effects 0.000 description 5
- 235000014113 dietary fatty acids Nutrition 0.000 description 4
- 229930195729 fatty acid Natural products 0.000 description 4
- 239000000194 fatty acid Substances 0.000 description 4
- -1 fatty acid esters Chemical class 0.000 description 4
- 239000000020 Nitrocellulose Substances 0.000 description 3
- 229920001971 elastomer Polymers 0.000 description 3
- 239000000806 elastomer Substances 0.000 description 3
- 239000012046 mixed solvent Substances 0.000 description 3
- 229920001220 nitrocellulos Polymers 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 150000004665 fatty acids Chemical class 0.000 description 2
- 239000010408 film Substances 0.000 description 2
- 229920003225 polyurethane elastomer Polymers 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 241000872198 Serjania polyphylla Species 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 238000010008 shearing Methods 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
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/735—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer characterised by the back layer
- G11B5/7356—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer characterised by the back layer comprising non-magnetic particles in the back layer, e.g. particles of TiO2, ZnO or SiO2
Description
【発明の詳細な説明】
産業上の利用分野
本発明は金属薄膜型磁気記録媒体の製造方法に
関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a metal thin film magnetic recording medium.
従来例の構成とその問題点
磁気記録媒体の性能は、磁性層の磁気特性、物
理特性等によつて決定されることが多いが、磁気
記録媒体の非磁性基材の裏面、すなわちバツク面
の性能も優秀な磁気記録媒体を得るのに重要であ
る。特にビデオテープにおいては、ほこりや磁性
粉の脱落粉がバツク面に静電付着し、それがテー
プのリールへの巻き取りにより磁性層側へ移行し
て出力低下の原因となる。この問題を防ぐために
支持体の記録層とは反対側の面にバツク層を設け
る研究がされている。このような状況は、記録層
が金属だけで構成されている金属薄膜型磁気記録
媒体においては、尚一層強調される。また、構成
されたバツク層が、バツク面の走行性を重んじる
あまり、粗面に仕上げられていると、ロール状に
巻き取つた場合にバツク層の形状が磁性層側に写
り、金属薄膜型磁気記録媒体の特徴の一つである
Ｓ／Ｎ特性が低下するという問題が発生する。Structures of conventional examples and their problems The performance of magnetic recording media is often determined by the magnetic properties, physical properties, etc. of the magnetic layer. Performance is also important in obtaining an excellent magnetic recording medium. Particularly in video tapes, dust and fallen magnetic particles electrostatically adhere to the back surface, and as the tape is wound onto a reel, they migrate to the magnetic layer side, causing a decrease in output. In order to prevent this problem, research has been carried out to provide a back layer on the side of the support opposite to the recording layer. This situation is even more emphasized in metal thin film magnetic recording media in which the recording layer is composed only of metal. In addition, if the configured back layer is finished with a rough surface due to the importance placed on running properties of the back surface, the shape of the back layer will be reflected on the magnetic layer side when it is wound into a roll, resulting in metal thin film magnetic A problem arises in that the S/N characteristic, which is one of the characteristics of the recording medium, deteriorates.
発明の目的
本発明はバツク層の表面を平滑に仕上げること
ができる磁気記録媒体の製造方法を提供すること
を目的とする。OBJECTS OF THE INVENTION An object of the present invention is to provide a method for manufacturing a magnetic recording medium that can finish the surface of a back layer to be smooth.
発明の構成
本発明の磁気記録媒体の製造方法は、無機質粉
末を結合剤と共に混合し、この混合物にカーボン
ブラツクを混合して得たバツク層用塗料を、金属
薄膜型磁気記録媒体の裏面に塗布することを特徴
とする。Structure of the Invention The method for manufacturing a magnetic recording medium of the present invention is to mix an inorganic powder with a binder, and apply a back layer paint obtained by mixing carbon black to the mixture on the back surface of a metal thin film magnetic recording medium. It is characterized by
前記無機質粉末は、第一にバツク層の表面を鏡
面にするために平均単一粒子径が0.1（μm）以下
であること。また、無機質粉末自体の硬度が高過
ぎると走行時にバツク層と接触する記録再生装置
側のガイド等の摩耗が大となつてしまうので、モ
ース硬度が7.0以下であること。また、無機質粉
末自体が結合剤に対して重すぎた場合にはバツク
層の表面に適度の突起が生じにくくなるので、そ
の比重が4.0以下であることなどが望ましい。以
上の条件を満足する無機質粉末としては、SiO2，
CaCO3等を挙げることができる。 First, the inorganic powder should have an average single particle diameter of 0.1 (μm) or less in order to make the surface of the back layer mirror-like. In addition, if the hardness of the inorganic powder itself is too high, the wear of the guides on the recording/reproducing device side that come into contact with the backing layer during running will become large, so the Mohs hardness should be 7.0 or less. Further, if the inorganic powder itself is too heavy relative to the binder, appropriate protrusions will be difficult to form on the surface of the back layer, so it is desirable that the specific gravity is 4.0 or less. Inorganic powders that satisfy the above conditions include SiO 2 ,
Examples include CaCO 3 and the like.
上記結合剤としては、ポリウレタンエラストマ
ー、ポリエステルエラストマー、ニトロセルロー
ス、エポキシ樹脂等が使用可能である。 As the binder, polyurethane elastomer, polyester elastomer, nitrocellulose, epoxy resin, etc. can be used.
なお、カーボンブラツクと無機質粉末および結
合剤とを同時に所定時間混合してバツク用塗料と
なす方法では、混合時間、あるいは無機質粉末の
種類や結合剤の種類にもよるが、一般的には、第
１図に示すように表面最大粗さが0.2（μm）以上
のバツクコートしかできない。また、カーボンブ
ラツクと結合剤を十分に混合、分散してから無機
質粉末を加えて所定時間混合してバツク用塗料と
する方法では、後から加えた無機質粉末の分散不
良に基づく粗大粒子が残り、表面粗さはさらに悪
くなる。その状態を第２図に示す。 In addition, in the method of mixing carbon black, inorganic powder, and binder at the same time for a predetermined period of time to form a backing paint, generally speaking, the first step is As shown in Figure 1, only back coats with a maximum surface roughness of 0.2 (μm) or more can be produced. In addition, in the method of making a back paint by thoroughly mixing and dispersing carbon black and a binder, then adding an inorganic powder and mixing for a predetermined time, coarse particles remain due to poor dispersion of the inorganic powder added later. The surface roughness becomes even worse. The state is shown in FIG.
実施例の説明
以下本発明の製造方法を具体的な一実施例に基
づいて説明する。Description of Examples The manufacturing method of the present invention will be described below based on a specific example.
バツク層用塗料は、先ず、無機質粉末結合剤と
を共に十分混合して、その後、これにカーボンブ
ラツクを加えて所定時間分散、混合して作られ、
このバツク層用塗料が金属薄膜型磁気記録媒体の
裏面に塗布される。 The paint for the back layer is made by first thoroughly mixing together an inorganic powder binder, and then adding carbon black to the mixture and dispersing and mixing for a predetermined time.
This back layer paint is applied to the back surface of the metal thin film type magnetic recording medium.
これにより、金属薄膜型磁気記録媒体の場合に
は、バツク面を鏡面状態に近くしたことに基づく
乱巻きは発生しないことがわかつた。なぜなら、
磁性層側の電気抵抗はほとんどゼロに等しいから
である。 As a result, it was found that in the case of a metal thin film type magnetic recording medium, irregular winding due to making the back surface close to a mirror surface does not occur. because,
This is because the electrical resistance on the magnetic layer side is almost equal to zero.
なお、無機質粉末を結合剤と共に混合する第１
の工程において、必要ならば脂肪酸、脂肪酸エス
テル、脂肪酸アミドのような添加剤を少量加えて
もよく、また結合剤としてポリエステルエラスト
マー、ポリウレタンエラストマー、ニトロセルロ
ースを使用したときには、イソシアネート化合物
を、カーボンブラツクを混合する第２の工程で添
加するか、この第２の工程後に加えて塗膜の架橋
反応を促進させることも可能である。 Note that the first step is to mix the inorganic powder with the binder.
In the process, if necessary, small amounts of additives such as fatty acids, fatty acid esters, and fatty acid amides may be added, and when polyester elastomer, polyurethane elastomer, or nitrocellulose is used as a binder, isocyanate compounds and carbon black may be added. It is also possible to add it in the second mixing step or after this second step to accelerate the crosslinking reaction of the coating film.
更に具体的な実施例を説明する。 A more specific example will be described.
（第１の工程）
組 成 重量％
炭酸カルシウム（平均粒度0.07μm） 170ｇ
ポリエステルエラストマー 60ｇ
ニトロセルロース 40ｇ
脂肪酸エステル １ｇ
混合溶剤 1500ｇ
上記の各材料をボールミルで所定時間混合分散
させバツク用塗料の下地とする。(First step) Composition Weight % Calcium carbonate (average particle size 0.07μm) 170g Polyester elastomer 60g Nitrocellulose 40g Fatty acid ester 1g Mixed solvent 1500g The above materials are mixed and dispersed in a ball mill for a predetermined period of time to form the base of the back paint. .
〔第２の工程〕
〔第１の工程〕で作られた下地塗料中に平均粒
径0.08〔μm〕以下のカーボンブラツクを30重量％
添加して所定時間混合し、さらに混合溶剤1500ｇ
を加えて所定時間混合し、所望の粘度のバツク用
塗料とした。こうして得られた塗料を1000〜
1500Aの金属薄膜が形成された厚さ11.5〔μm〕の
ポリエチレンテレフタレートベースの裏面に0.5
〔μm〕の厚さにロールコーターで塗布し、乾燥し
た後、巻き取り、60℃の恒温室に24時間放置し
た。これを８〔mm〕巾に裁断してビデオテープと
した。無機質粉末、およびカーボンブラツクを分
散させる工程では粘度の高い状態でせん断力が大
きくなるようにして混合した。第１の工程は５時
間以上あればよく、第２の工程は10時間程度で十
分である。混合溶剤により粘度を低下させる場合
にも、分散はほとんどこわれない。第３図はこの
実施例によるバツク層の表面粗さを示す。第３図
を第１図および第２図と比べることによりバツク
層の表面がより平滑に仕上げられていることがわ
かる。[Second process] 30% by weight of carbon black with an average particle size of 0.08 [μm] or less is added to the base paint made in [first process].
Add and mix for a specified time, then add 1500g of mixed solvent.
was added and mixed for a predetermined time to obtain a backing paint with a desired viscosity. The paint obtained in this way is 1000~
0.5 μm on the back side of a polyethylene terephthalate base with a thickness of 11.5 μm on which a 1500A thin metal film is formed.
It was applied to a thickness of [μm] using a roll coater, dried, rolled up, and left in a constant temperature room at 60°C for 24 hours. This was cut into 8 mm width pieces and made into video tapes. In the step of dispersing the inorganic powder and carbon black, they were mixed in a high viscosity state with a high shearing force. The first step may take 5 hours or more, and the second step may take about 10 hours. Even when the viscosity is lowered with a mixed solvent, the dispersion is hardly damaged. FIG. 3 shows the surface roughness of the back layer according to this example. Comparing FIG. 3 with FIGS. 1 and 2, it can be seen that the surface of the back layer is finished more smoothly.
発明の効果
以上説明のように本発明の磁気記録媒体の製造
方法によると、金属薄膜型磁気記録媒体に適した
鏡面状態のバツクコートが得られ、バツク層から
磁性面側への形状転写がなく、このようなバツク
層を有する金属薄膜型磁気記録媒体は乱巻きもな
く、本来のＳ／Ｎ特性を十分に発揮でき、従来の
ものに比べてＳ／Ｎ特性を向上させることができ
るものである。Effects of the Invention As explained above, according to the method for manufacturing a magnetic recording medium of the present invention, a mirror-like back coat suitable for a metal thin film type magnetic recording medium can be obtained, and there is no shape transfer from the back layer to the magnetic surface side. A metal thin film magnetic recording medium having such a back layer has no random winding, can fully exhibit its original S/N characteristics, and can improve S/N characteristics compared to conventional media. .
第１図と第２図はそれぞれ従来の磁気記録媒体
のバツク層の表面粗さのパターン図、第３図は本
発明の製造方法による金属薄膜型磁気記録媒体用
バツク層の表面粗さのパターン図である。
1 and 2 are surface roughness patterns of a back layer of a conventional magnetic recording medium, respectively, and FIG. 3 is a surface roughness pattern of a back layer for a metal thin film type magnetic recording medium produced by the manufacturing method of the present invention. It is a diagram.
Claims (1)
物にカーボンブラツクを混合して得たバツク層用
塗料を、金属薄膜型磁気記録媒体の裏面に塗布す
る磁気記録媒体の製造方法。1. A method for producing a magnetic recording medium, in which a back layer coating obtained by mixing inorganic powder with a binder and carbon black in the mixture is applied to the back surface of a metal thin film type magnetic recording medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58075491A JPS59201220A (en) | 1983-04-27 | 1983-04-27 | Production of magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58075491A JPS59201220A (en) | 1983-04-27 | 1983-04-27 | Production of magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59201220A JPS59201220A (en) | 1984-11-14 |
| JPH057764B2 true JPH057764B2 (en) | 1993-01-29 |
Family
ID=13577799
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58075491A Granted JPS59201220A (en) | 1983-04-27 | 1983-04-27 | Production of magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59201220A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59210534A (en) * | 1983-05-16 | 1984-11-29 | Fuji Photo Film Co Ltd | Magnetic recording medium |
-
1983
- 1983-04-27 JP JP58075491A patent/JPS59201220A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59201220A (en) | 1984-11-14 |
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