JPH03286420A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH03286420A JPH03286420A JP2086539A JP8653990A JPH03286420A JP H03286420 A JPH03286420 A JP H03286420A JP 2086539 A JP2086539 A JP 2086539A JP 8653990 A JP8653990 A JP 8653990A JP H03286420 A JPH03286420 A JP H03286420A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic recording
- layer
- recording medium
- powder
- 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
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 94
- 239000006247 magnetic powder Substances 0.000 claims abstract description 33
- 230000005415 magnetization Effects 0.000 claims abstract description 17
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 10
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 5
- 239000000758 substrate Substances 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052788 barium Inorganic materials 0.000 claims description 2
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims description 2
- 229910020994 Sn-Zn Inorganic materials 0.000 claims 2
- 229910009069 Sn—Zn Inorganic materials 0.000 claims 2
- 229910052751 metal Inorganic materials 0.000 abstract description 9
- 239000002184 metal Substances 0.000 abstract description 9
- 238000000034 method Methods 0.000 abstract description 9
- 230000000052 comparative effect Effects 0.000 description 7
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 239000003973 paint Substances 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 150000001735 carboxylic acids Chemical class 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 1
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- JJJKYGXVJDTRIF-UHFFFAOYSA-N [Mg].[Sn].[Zn] Chemical compound [Mg].[Sn].[Zn] JJJKYGXVJDTRIF-UHFFFAOYSA-N 0.000 description 1
- OQDDOQFECBFUPY-UHFFFAOYSA-N [Ni].[Sn].[Zn] Chemical compound [Ni].[Sn].[Zn] OQDDOQFECBFUPY-UHFFFAOYSA-N 0.000 description 1
- JGEPRYWSGIOOSM-UHFFFAOYSA-N [Ni].[Ti].[Zn] Chemical compound [Ni].[Ti].[Zn] JGEPRYWSGIOOSM-UHFFFAOYSA-N 0.000 description 1
- YLOGFLJZZLICCB-UHFFFAOYSA-N [Ti].[Sn].[Zn] Chemical compound [Ti].[Sn].[Zn] YLOGFLJZZLICCB-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000003490 calendering Methods 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 description 1
- 229920005749 polyurethane resin Polymers 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 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、短波長域から長波長域にわたる広域において
高出力が得られる磁気テープなどの高記録密度用塗布型
の磁気記録媒体に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a coated magnetic recording medium for high recording density, such as a magnetic tape, which can provide high output over a wide range from short wavelength to long wavelength.
従来の技術
磁気記録は、従来より磁気記録媒体の面内方向の磁化を
用いる長手磁気記録方式によって発展してきた。現在使
われている磁気記録媒体の大部分は、この長手磁気記録
方式によるものである。BACKGROUND OF THE INVENTION Magnetic recording has traditionally been developed using a longitudinal magnetic recording method that uses in-plane magnetization of a magnetic recording medium. Most of the magnetic recording media currently in use are based on this longitudinal magnetic recording method.
塗布型の磁気記録媒体を構成する材料のうち、磁性材料
としては現状では針状形状の酸化鉄やメタル系の磁性粉
体が主流であり、さらに塗布膜の強度と磁気ヘッド表面
の研磨性を上げるためのアルミナや酸化クロムなどを、
電気抵抗を低減し媒体の走行性を向上するためのカーボ
ンブラックを、媒体の走行性と耐久性向上のための潤滑
剤などを有機バインダー中で均一に分散させ磁性塗布膜
を得ている。Among the materials that make up coating-type magnetic recording media, currently the mainstream magnetic materials are acicular-shaped iron oxide and metal-based magnetic powders, and the strength of the coating film and the abrasiveness of the magnetic head surface are being improved. Alumina, chromium oxide, etc. to raise the
A magnetic coating film is obtained by uniformly dispersing carbon black, which reduces electrical resistance and improves the runnability of the medium, and lubricants, which improve the runnability and durability of the medium, in an organic binder.
一般に長手磁気記録では出力の増大を図るために媒体塗
布膜中の磁性粉体粒子はヘッド−媒体の走行方向に配列
されていることが要求される。長手磁気記録方式では、
塗布膜中の磁性粉体の長手方向への配向の程度が高いほ
ど、高記録密度時でのＣ／Ｎは増大することから長手配
向度の増大化が試みられている（例えば、特開昭６２−
１７２５３３号公報、特開昭６２−２１９３３２号公報
などに示されている）。しかしながら、長手磁気記録方
式では高密度記録時に、自己減磁損失に打ち勝って記録
しなければならないため媒体の高保磁力化が高密度記録
のための必須条件であることが知られている。Generally, in longitudinal magnetic recording, in order to increase the output, it is required that the magnetic powder particles in the medium coating film be arranged in the head-medium running direction. In the longitudinal magnetic recording method,
The higher the degree of longitudinal orientation of the magnetic powder in the coating film, the higher the C/N at high recording density. Therefore, attempts have been made to increase the longitudinal orientation (for example, 1986-
172533, Japanese Unexamined Patent Publication No. 62-219332, etc.). However, in the longitudinal magnetic recording method, it is known that a high coercive force of the medium is an essential condition for high-density recording because it is necessary to overcome self-demagnetization loss during high-density recording.
ところが、現行の針状形状の酸化鉄やメタル系磁性粉も
現在以上の高保磁力化は技術的に困難な状況にあり、ま
た高保磁力の媒体に充分に書き込むためには磁気ヘッド
の方にもまだまだ問題があるのが現状である。これら長
手磁気記録のＬｌ’題を解決する方法として、垂直磁気
記録方式が提案されていることはよく知られている（例
えば、文献としては小本・中村・岩崎・日本応用磁気学
会誌１１巻（１９８７）ｐ１０９〜１１４がある）。However, it is technically difficult to increase the coercive force of the current needle-shaped iron oxide and metal magnetic powders even higher than the current level, and in order to write sufficiently on high coercive force media, the magnetic head must also At present, there are still problems. It is well known that the perpendicular magnetic recording method has been proposed as a method to solve the Ll' problem of longitudinal magnetic recording (for example, the literature includes Komoto, Nakamura, Iwasaki, Journal of the Japanese Society of Applied Magnetics, Vol. 11). (1987) p109-114).
垂直記録では、高記録密度になればなるほど自己減磁損
失が小さくなることから究極の磁気記録方式として研究
開発が各方面で行われている（例えば、特開昭６０−１
３２１８３号公報などがある）。In perpendicular recording, the higher the recording density, the smaller the self-demagnetization loss, so research and development are being carried out in various fields as the ultimate magnetic recording method (for example,
32183, etc.).
また一方、六角板状形状のバリウムフェライト磁性粉体
を利用して垂直磁気記録方式に適用した報告もある（例
えば、特開昭６０−１４９１０５号公報、特開昭２１１
６２８号公報、文献として横山他による東芝レビュー４
０巻１３号ｐＨｌｌ〜１１１４がある）。On the other hand, there are also reports on application of hexagonal plate-shaped barium ferrite magnetic powder to perpendicular magnetic recording methods (for example, JP-A-60-149105, JP-A-211
Publication No. 628, Toshiba Review 4 by Yokoyama et al.
Volume 0, No. 13 pHll~1114).
発明が解決しようとする課題
しかしながら、現在塗布型の磁気記録媒体の開発におい
て、先行技術で開示されたように単に板状形状の磁性物
体を塗料化して塗布してもそのメディア特性は必ずしも
良好であるとは言い難い。Problems to be Solved by the Invention However, in the current development of coating-type magnetic recording media, it has been found that simply applying a plate-shaped magnetic substance as a paint does not necessarily provide good media characteristics, as disclosed in the prior art. It's hard to say that there is.
具体的には、市販のメタルテープに対して長波長領域で
は出力の劣化が大きいという課題を有していた。Specifically, compared to commercially available metal tapes, there was a problem in that the output deteriorated significantly in the long wavelength region.
課題を解決するための手段
上記課題を解決するために鋭意研究をすすめた結果、記
録波長１ミクロン以下では媒体に対して垂直方向の磁化
成分が出力に大いに寄与すること、および記録波長１ミ
クロン以上の長波長領域では媒体長尺方向の面内長手磁
化成分が有効に働くことがわかってきた。そして、上記
知見をもとにして磁気記録層を２Ｎ構造とし、下層は媒
体長尺方向に磁化容易軸を有する磁性粉体により構成し
、上層は媒体垂直方向に磁化容易軸を有する磁性粉体に
より構成することにより広域にわたって高出力の磁気記
録媒体が得られることを見出した。故に、本発明の磁気
記録媒体は、非磁性基体と非磁性層および磁気記録層か
ら成る磁気記録媒体において、前記磁気記録層が２層構
成になっており、かつ下層の磁気記録層が磁気記録媒体
長尺方向に磁化容易軸を有し、上層の磁気記録層に異方
性磁界が３０００Ｏｅ以下である板状形状のへキサゴナ
ルフェライト磁性粉体が配設された構成としたものであ
る。Means for Solving the Problems As a result of intensive research to solve the above problems, we found that at recording wavelengths of 1 micron or less, the magnetization component in the direction perpendicular to the medium greatly contributes to the output, and that at recording wavelengths of 1 micron or more, It has been found that in the long wavelength region of the medium, the in-plane longitudinal magnetization component in the longitudinal direction of the medium works effectively. Based on the above knowledge, the magnetic recording layer has a 2N structure, the lower layer is composed of magnetic powder having an axis of easy magnetization in the longitudinal direction of the medium, and the upper layer is composed of magnetic powder having an axis of easy magnetization in the direction perpendicular to the medium. It has been found that a magnetic recording medium with high output over a wide area can be obtained by configuring the following. Therefore, the magnetic recording medium of the present invention is a magnetic recording medium consisting of a nonmagnetic substrate, a nonmagnetic layer, and a magnetic recording layer, in which the magnetic recording layer has a two-layer structure, and the lower magnetic recording layer has a magnetic recording layer. It has a configuration in which plate-shaped hexagonal ferrite magnetic powder having an axis of easy magnetization in the longitudinal direction of the medium and having an anisotropic magnetic field of 3000 Oe or less is disposed in the upper magnetic recording layer.
作用
本発明の磁気記録媒体は前記した構成にすることにより
、長波長領域では下層の磁気記録層により出力を稼ぎ、
短波長Ｍ域では上層に配した異方性磁界の小さい板状形
状磁性粉体の特徴の寄与により広域にわたって高出力の
磁気メディアを得ることができ、市販のメタルテープを
長波長から短波長に至るまでの広域において凌駕するこ
とが可能となる。Operation By having the magnetic recording medium of the present invention configured as described above, the output can be increased in the long wavelength region by the lower magnetic recording layer,
In the short wavelength M range, due to the characteristics of the plate-shaped magnetic powder with a small anisotropic magnetic field placed in the upper layer, it is possible to obtain a magnetic medium with high output over a wide range, and it is possible to convert commercially available metal tapes from long wavelengths to short wavelengths. It becomes possible to outperform in a wide range of areas.
実施例
以下、本発明の一実施例の磁気記録媒体について説明す
る。実施例１に用いた磁性粉体のうち、下層には長軸長
さ０．３ξクロン、針状比１０、保磁力４５０Ｏｅ、飽
和磁化７２ ｅ ｍ ｕ／ ｇ、ＢＥＴ比表面積２８ｎ
ｆ／ｇの磁性粉体を用い、上層にはマグネトプランバイ
ト型構造を有し磁化容易軸が板面に垂直方向である板状
形状のへキサゴナルフェライト磁性粉体で粒子径０．０
５ミクロン、板状比３、保磁力１１００Ｏｅ、飽和磁化
６０ ｅｍｕ／ｇ、ＢＥＴ比表面積３５ボ／ｇ、異方性
磁界２４５０Ｏｅのものを用いた。上記磁性粉体を用い
て、加圧型ニーダ−により硬練り分散後、ダブルプラネ
タリ−ミキサーで希釈し、横型アジテータミルを用いて
分散し磁性塗料を作製した。塗料＆１１ｒｌｉ、は以下
に示したフォーミュレーションで行った。■磁性粉１０
０部、■塩化ビニル系樹脂８部、■ポリウレタン樹脂８
部、■カーボッ１９フ９２部、■アルミナ７部、■潤滑
剤５部、■溶剤・・・・・・メチルエチルケトン１００
部、メチルイソブチルケトン５０部、トルエン１００部
、シクロヘキサノン５０部、■硬化剤４部。ただし、下
層について■、■、■、■の部数を増やして全組成に対
する磁性粉の割合を７３％として行った。得られた磁性
塗料は、下層をグラビアロールを用いて塗工し、ただち
に長手磁場配向処理を施した後、上層をブレードギャッ
プ２柔クロンのブレードを用いて薄層塗工した。塗布膜
が乾燥した後、カレンダー処理を行い６０″Ｃのドライ
オープン中で約２４時間硬化処理を行い、塗布膜の逆側
に非磁性バックコート層を付与し、実施例１の磁気テー
プサンプルを作製した。なお、実施例２には下層の磁性
粉体は実施例１と同様で上層に用いる磁性粉体を鉄とバ
リウム元素の構成比が１５対１であり、粒子径０．０５
ミクロン、板状比３．５、保磁力１０５０Ｏｅ。EXAMPLE A magnetic recording medium according to an example of the present invention will be described below. Among the magnetic powders used in Example 1, the lower layer had a major axis length of 0.3 ξ chron, an acicular ratio of 10, a coercive force of 450 Oe, a saturation magnetization of 72 e mu/g, and a BET specific surface area of 28 n.
f/g magnetic powder, and the upper layer is a plate-shaped hexagonal ferrite magnetic powder with a magnetoplumbite structure and an axis of easy magnetization perpendicular to the plate surface, with a particle size of 0.0.
5 microns, a plate ratio of 3, a coercive force of 1100 Oe, a saturation magnetization of 60 emu/g, a BET specific surface area of 35 vo/g, and an anisotropic magnetic field of 2450 Oe. The above magnetic powder was hard kneaded and dispersed using a pressure kneader, diluted using a double planetary mixer, and dispersed using a horizontal agitator mill to produce a magnetic paint. Paint and 11rli were made using the formulation shown below. ■Magnetic powder 10
0 parts, ■8 parts of vinyl chloride resin, ■8 parts of polyurethane resin
19 parts of carboxylic acid, 92 parts of carboxylic acid, 7 parts of alumina, 5 parts of lubricant, 100 parts of solvent, methyl ethyl ketone
50 parts of methyl isobutyl ketone, 100 parts of toluene, 50 parts of cyclohexanone, 4 parts of curing agent. However, for the lower layer, the number of parts of ■, ■, ■, and ■ was increased so that the ratio of magnetic powder to the total composition was 73%. The obtained magnetic paint was coated as a lower layer using a gravure roll, immediately subjected to a longitudinal magnetic field orientation treatment, and then a thin layer was coated as an upper layer using a blade with a blade gap of 2 soft chrome. After the coating film was dried, it was calendered and cured for about 24 hours in a dry open at 60"C. A nonmagnetic back coat layer was applied to the opposite side of the coating film, and the magnetic tape sample of Example 1 was cured. In Example 2, the magnetic powder in the lower layer was the same as in Example 1, and the magnetic powder used in the upper layer had a composition ratio of iron and barium elements of 15:1, and a particle size of 0.05.
Micron, plate ratio 3.5, coercive force 1050 Oe.
飽和磁化６１ ｅｍｕ／ｇ、ＢＥＴ比表面積４３ｒｌ（
７ｇ、異方性磁界２６００Ｏｅのものを用いて、実施例
１と同様の方法で磁気テープサンプルを作製した。実施
例３．４，５．６は下層は実施例１と同−ｍ性粉体を用
い、上層にはそれぞれニッケルチタン−亜鉛、マグネシ
ウム−錫−亜鉛、ニッケルー錫−亜鉛、錫−チタン−亜
鉛を含む板状形状のへキサゴナルフェライト磁性粉体で
粒子径０．０５０．０６．０．０６．０．０５ミクロン
、板状比３．３．５ 。Saturation magnetization 61 emu/g, BET specific surface area 43 rl (
A magnetic tape sample was prepared in the same manner as in Example 1 using a magnetic tape of 7 g and an anisotropic magnetic field of 2600 Oe. In Examples 3.4 and 5.6, the same powder as in Example 1 was used for the lower layer, and nickel titanium-zinc, magnesium-tin-zinc, nickel-tin-zinc, and tin-titanium-zinc were used for the upper layer, respectively. Plate-shaped hexagonal ferrite magnetic powder containing particle size 0.050.06.0.06.0.05 microns and plate ratio 3.3.5.
３、５、４ 、保磁力１０００，１１００．１０６６゜
１１００Ｏｅ、飽和磁化６Ｌ５９，６０，６０．４ｅｍ
ｕ／ｇ、ＢＥＴ比表面積３３，３１，３６゜３８ボ／ｇ
、異方性磁界２２００．２４００２８００．２５１０Ｏ
ｅのものをそれぞれ用いた。3, 5, 4, coercive force 1000, 1100.1066° 1100 Oe, saturation magnetization 6L 59, 60, 60.4 em
u/g, BET specific surface area 33, 31, 36° 38 bo/g
, anisotropic magnetic field 2200.24002800.2510O
Those of e were used respectively.
実施例１〜６に用いた上層の磁性粉体をそれぞれ用いて
、下層の磁性粉体を長袖長さ０．１５ミクロン、針状比
５、保磁力６２０Ｏｅ、飽和磁化７６ｅｍｕ／ｇ、ＢＥ
Ｔ比表面積４０ｒｒｆ／ｇの磁性粉に固定して作製した
磁気テープを実施例７／１２とした。一方、比較例とし
て、実施例１の上層に用いた磁性粉体で異方性磁界を３
０００Ｏｅ以上となるように調整したものを比較例１〜
３の上層用磁性粉体とした。ここで異方性磁界を用いた
ヘキサゴナルフェライトの組成、置換元素の種類と量を
変化させることにより制御した。また、比較例４として
、実施例１の上層に用いた磁性粉体を用いた磁気記録層
のみを非磁性基体上に塗布した磁気テープを作製した。Using each of the upper layer magnetic powders used in Examples 1 to 6, the lower layer magnetic powders had a long sleeve length of 0.15 microns, an acicular ratio of 5, a coercive force of 620 Oe, a saturation magnetization of 76 emu/g, and a BE of
A magnetic tape prepared by fixing it on magnetic powder having a T specific surface area of 40 rrf/g was designated as Example 7/12. On the other hand, as a comparative example, an anisotropic magnetic field of 3
Comparative Examples 1~
3 was used as the magnetic powder for the upper layer. Here, control was achieved by changing the composition of hexagonal ferrite and the type and amount of substitution elements using an anisotropic magnetic field. Furthermore, as Comparative Example 4, a magnetic tape was produced in which only a magnetic recording layer using the magnetic powder used in the upper layer of Example 1 was coated on a nonmagnetic substrate.
比較例５，６．７として、実施例２〜４の上層に用いた
磁性粉を分散させた塗料のみで非磁性基体上に塗布した
磁気テープを作製した。比較例８，９として、実施例１
および実施例７で下層に用いた磁性粉体を用いて単独で
磁気記録層を形成した磁気テープを作製した。そして、
比較例１０．１１として、市販５ＶＨＳテープ、市販Ｍ
ＩＩ用メツメツメタルテープ。限られた磁気テープサン
プルは、回転シリンダー型ドラムテスターを用いて、電
磁変換特性を評価した。なお、測定にはメタル系の積層
型磁気ヘッドを用いて相対速度５．８ｍ／ｓで行い、測
定記録周波数は１００Ｋ Ｈｚ、 Ｉ ＭＨｚ、 ７
ＭＨｚ、 １５ ＭＨｚの４点とした。なお、出力は
、比較例１０の出力値を各周波数において０デシヘルと
して相対値で示した結果をまとめて第１表に示す。第１
表から明らかなように本発明の磁気記録媒体は、長波長
から短波長に至るまでの広域にわたって高出力となって
いる。特に本発明の磁気記録媒体は、短波長領域で従来
の面内長手方向に磁化容易軸を有する市販の５ＶＨＳテ
ープ、メタルテープを凌く高出力を遠戚することができ
た。これにより、長波長域において低出力であった磁気
テープと短波長域で低出力であった磁気テープとのそれ
ぞれの欠点を補いつつ、より高密度記録に適した磁気記
録媒体が作製できた。As Comparative Examples 5, 6, and 7, magnetic tapes were prepared in which a nonmagnetic substrate was coated with only the paint in which the magnetic powder used in the upper layer of Examples 2 to 4 was dispersed. Example 1 as Comparative Examples 8 and 9
A magnetic tape in which a magnetic recording layer was formed solely using the magnetic powder used for the lower layer in Example 7 was prepared. and,
As Comparative Example 10.11, commercially available 5VHS tape, commercially available M
Metsumetsu metal tape for II. The electromagnetic characteristics of limited magnetic tape samples were evaluated using a rotating cylinder drum tester. The measurements were performed using a metal laminated magnetic head at a relative speed of 5.8 m/s, and the measurement recording frequency was 100 KHz, I MHz, 7 MHz.
There were four points: 15 MHz and 15 MHz. Note that the output is shown in Table 1 as a relative value, with the output value of Comparative Example 10 set to 0 deciher at each frequency. 1st
As is clear from the table, the magnetic recording medium of the present invention has high output over a wide range from long wavelengths to short wavelengths. In particular, the magnetic recording medium of the present invention was able to achieve high output in the short wavelength region, far exceeding that of conventional commercially available 5VHS tapes and metal tapes, which have an axis of easy magnetization in the in-plane longitudinal direction. This made it possible to create a magnetic recording medium that is more suitable for high-density recording while compensating for the respective drawbacks of magnetic tapes that had low output in the long wavelength range and magnetic tapes that had low output in the short wavelength range.
発明の効果
以上述べてきたように、本発明の磁気記録媒体は非磁性
基体と非磁気記録層および磁気記録層から成る磁気記録
媒体において、該磁気記録層が２層構成になっており、
かつ下層の磁気記録層が磁気記録媒体長尺方向に磁化容
易軸を有し、上層の磁気記録層に異方性磁界が３０００
Ｏｅ以下である板状形状のへキサゴナルフェライ）［性
粉体が配設された構成とすることにより、長波長から短
波長領域に至るまで高出力な磁気記録媒体を提供するこ
とができる。これにより、デジタルＶＴＲのような次世
代の高性能ＶＴＲへ寄与するところ大であり、きわめて
有用な発明である。Effects of the Invention As described above, the magnetic recording medium of the present invention is a magnetic recording medium consisting of a non-magnetic substrate, a non-magnetic recording layer, and a magnetic recording layer, in which the magnetic recording layer has a two-layer structure,
and the lower magnetic recording layer has an axis of easy magnetization in the longitudinal direction of the magnetic recording medium, and the upper magnetic recording layer has an anisotropic magnetic field of 3000
By employing a configuration in which a plate-shaped hexagonal ferrite powder having an Oe or less is disposed, a magnetic recording medium with high output from a long wavelength region to a short wavelength region can be provided. This will greatly contribute to next-generation high-performance VTRs such as digital VTRs, and is an extremely useful invention.
Claims (3)
磁気記録媒体において、前記磁気記録層が２層構成にな
っており、かつ下層の磁気記録層が磁気記録媒体長尺方
向に磁化容易軸を有し、上層の磁気記録層に異方性磁界
が３０００Ｏｅ以下である板状形状のヘキサゴナルフェ
ライト磁性粉体が配設されていることを特徴とする磁気
記録媒体。(1) In a magnetic recording medium consisting of a nonmagnetic substrate, a nonmagnetic layer, and a magnetic recording layer, the magnetic recording layer has a two-layer structure, and the lower magnetic recording layer is easily magnetized in the longitudinal direction of the magnetic recording medium. 1. A magnetic recording medium having a shaft and having a plate-shaped hexagonal ferrite magnetic powder having an anisotropic magnetic field of 3000 Oe or less disposed in an upper magnetic recording layer.
ｉ−Ｔｉ−Ｚｎ、Ｍｇ−Ｓｎ−Ｚｎ、Ｎｉ−Ｓｎ−Ｚｎ
、Ｓｎ−Ｔｉ−Ｚｎの中から選ばれる組み合わせの元素
を含むことを特徴とする請求項（１）記載の磁気記録媒
体。(2) Plate-shaped hexagonal ferrite magnetic powder is N
i-Ti-Zn, Mg-Sn-Zn, Ni-Sn-Zn
The magnetic recording medium according to claim 1, characterized in that it contains a combination of elements selected from , Sn-Ti-Zn.
グネトプランバイト型構造を有した磁化容易軸が板面に
垂直方向である磁性粉体であり、かつ前記磁性粉体を構
成する元素のうち鉄元素とバリウム元素の構成比が１２
対１より鉄過剰であることを特徴とする請求項（１）記
載の磁気記録媒体。(3) The plate-shaped hexagonal ferrite magnetic powder is a magnetic powder having a magnetoplumbite structure and the axis of easy magnetization is perpendicular to the plate surface, and among the elements constituting the magnetic powder, iron is The composition ratio of element and barium element is 12
2. The magnetic recording medium according to claim 1, wherein the magnetic recording medium has an iron content greater than 1:1.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2086539A JPH03286420A (en) | 1990-03-30 | 1990-03-30 | Magnetic recording medium |
| KR1019900012871A KR930004444B1 (en) | 1989-08-21 | 1990-08-21 | Magnetic recording medium |
| US07/571,093 US5114801A (en) | 1989-08-21 | 1990-08-21 | Magnetic recording medium having a magnetic layer comprising hexagonal barium ferrite magnetic particles containing tin and magnesium in specified proportions |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2086539A JPH03286420A (en) | 1990-03-30 | 1990-03-30 | Magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03286420A true JPH03286420A (en) | 1991-12-17 |
Family
ID=13889805
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2086539A Pending JPH03286420A (en) | 1989-08-21 | 1990-03-30 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03286420A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0710951A1 (en) | 1994-10-14 | 1996-05-08 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| EP0717396A1 (en) | 1994-12-16 | 1996-06-19 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5717114A (en) * | 1980-07-07 | 1982-01-28 | Seiko Epson Corp | Magnetic medium for vertical magnetic recording |
| JPS60204427A (en) * | 1984-03-22 | 1985-10-16 | 凸版印刷株式会社 | Manufacture of small bag package |
| JPS62204427A (en) * | 1986-03-03 | 1987-09-09 | Victor Co Of Japan Ltd | Magnetic recording medium |
| JPS6479930A (en) * | 1987-09-21 | 1989-03-24 | Matsushita Electric Ind Co Ltd | Magnetic recording medium |
-
1990
- 1990-03-30 JP JP2086539A patent/JPH03286420A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5717114A (en) * | 1980-07-07 | 1982-01-28 | Seiko Epson Corp | Magnetic medium for vertical magnetic recording |
| JPS60204427A (en) * | 1984-03-22 | 1985-10-16 | 凸版印刷株式会社 | Manufacture of small bag package |
| JPS62204427A (en) * | 1986-03-03 | 1987-09-09 | Victor Co Of Japan Ltd | Magnetic recording medium |
| JPS6479930A (en) * | 1987-09-21 | 1989-03-24 | Matsushita Electric Ind Co Ltd | Magnetic recording medium |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0710951A1 (en) | 1994-10-14 | 1996-05-08 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
| EP0717396A1 (en) | 1994-12-16 | 1996-06-19 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
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