JP2623734B2 - Magnetic recording media - Google Patents
Magnetic recording mediaInfo
- Publication number
- JP2623734B2 JP2623734B2 JP19328088A JP19328088A JP2623734B2 JP 2623734 B2 JP2623734 B2 JP 2623734B2 JP 19328088 A JP19328088 A JP 19328088A JP 19328088 A JP19328088 A JP 19328088A JP 2623734 B2 JP2623734 B2 JP 2623734B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic layer
- recording
- coercive force
- recording medium
- 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
Landscapes
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は非磁性支持体上に磁性粉末及び結合剤を含む
磁性層を設けてなる磁気記録媒体に係り、特により高密
度な記録が可能な磁気記録媒体に関する。Description: TECHNICAL FIELD The present invention relates to a magnetic recording medium comprising a nonmagnetic support and a magnetic layer containing a magnetic powder and a binder, and particularly enables higher density recording. Magnetic recording media.
近年、小型の計算機の能力向上に伴い、日常扱われる
プログラムやデータファイルに非常に大容量の記録が必
要となり、磁気ディスク等の磁気記録媒体にも大容量の
記録媒体が要望されている。また、記録媒体の大きさは
取扱い易さや設置又は保管するスペースの問題からより
小さい物が求められている。そこで、これらの要望に答
えるため、同じ大きさの記録媒体により多くの情報を記
録する必要が生じてくる。そのために、記録媒体に記録
される信号の波長を短くし、いわゆる記録密度を高くし
つつある。しかしながら、例えばフレキシブルディスク
においては、直径90mmのディスクに１メガバイトの情報
を記録できる媒体（保磁力500〜700 Oe、塗膜厚さ1.2〜
2.0μｍ）が広く普及しているが、この場合の記録波長
は2.9μｍ（8.7kbpi）が最短であって、記録容量を増す
ためにさらに短波長の記録を行なった場合は、出力が低
下し、S/Nが悪くなる。またデジタル記録の場合には、
長波長の場合の出力と短波長の場合の出力とに大きな差
があると、長波長記録と短波長記録とが隣接した場合に
出力波形が歪み、ピークが本来あるべき位置から大きく
ずれてしまうという問題が生じる。このため、さらに大
容量・高密度の記録媒体として使用するのには適さなか
った。In recent years, with the improvement in the capacity of small computers, very large-capacity recording has been required for programs and data files handled on a daily basis, and magnetic recording media such as magnetic disks are also required to have large-capacity recording media. In addition, the size of the recording medium is required to be smaller due to problems of easy handling and space for installation or storage. Therefore, in order to meet these demands, it becomes necessary to record more information on a recording medium of the same size. For this purpose, the wavelength of a signal recorded on a recording medium has been shortened, and the so-called recording density has been increased. However, for example, in the case of a flexible disk, a medium capable of recording 1 megabyte of information on a disk having a diameter of 90 mm (a coercive force of 500 to 700 Oe, a coating thickness of 1.2 to
2.0 μm) has become widespread, but the shortest recording wavelength in this case is 2.9 μm (8.7 kbpi). If recording with a shorter wavelength is performed to increase the recording capacity, the output decreases. , S / N deteriorates. In the case of digital recording,
If there is a large difference between the output in the case of the long wavelength and the output in the case of the short wavelength, the output waveform is distorted when the long wavelength recording and the short wavelength recording are adjacent to each other, and the peak is largely displaced from the original position. The problem arises. For this reason, it was not suitable for use as a recording medium having a larger capacity and a higher density.
本発明者らはかかる事情に鑑み、種々検討を行なった
結果本発明に到達した。In view of such circumstances, the present inventors have conducted various studies and arrived at the present invention.
即ち、本発明の要旨は、非磁性支持体上に磁性粉末及
び結合剤を含む磁性層に設けてなる磁気記録媒体であっ
て、上記磁性層の残留磁束密度が800ガウス以上、保磁
力が800〜1100 Oe、該磁性層の厚さが0.4〜1.0μｍ、お
よび該磁性層の表面の中心線平均粗さ（Ra）が0.03μｍ
以下、最大高さ（Rmax）が0.15μｍ以下であることを特
徴とする磁気記録媒体に存する。That is, the gist of the present invention is a magnetic recording medium provided on a magnetic layer containing a magnetic powder and a binder on a non-magnetic support, wherein the residual magnetic flux density of the magnetic layer is 800 gauss or more, and the coercive force is 800 11100 Oe, the thickness of the magnetic layer is 0.4 to 1.0 μm, and the center line average roughness (Ra) of the surface of the magnetic layer is 0.03 μm
Hereinafter, there is provided a magnetic recording medium having a maximum height (Rmax) of 0.15 μm or less.
以下、本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
本発明に於いて、磁性層を構成する磁性粉末として使
用される磁性体は、長軸径が0.1〜1.0μｍの範囲にある
針状のコバルト含有磁性酸化鉄粉末が好ましい。さらに
は長軸径が0.2〜0.6μｍの範囲にあるものがより好まし
い。In the present invention, the magnetic substance used as the magnetic powder constituting the magnetic layer is preferably acicular cobalt-containing magnetic iron oxide powder having a major axis diameter in the range of 0.1 to 1.0 μm. Further, those having a major axis diameter in the range of 0.2 to 0.6 μm are more preferable.
磁性体の長軸径が0.1μｍより小さい場合は、結合剤
通に磁性体を均一に分散することが困難であり、また磁
性層の強度が充分でなくなって耐久性が劣化する。1.0
μｍより大きい場合は磁性層中の磁化の分布が不均一に
なり、雑音が大きくなるため、S/Nが劣化する。When the major axis diameter of the magnetic material is smaller than 0.1 μm, it is difficult to uniformly disperse the magnetic material through the binder, and the strength of the magnetic layer is not sufficient, and the durability is deteriorated. 1.0
If it is larger than μm, the distribution of magnetization in the magnetic layer becomes non-uniform and noise increases, so that the S / N deteriorates.
保磁力・残留磁化ともに大きい物が得られる磁性体と
してα−Fe、Fe−Co系合金、Fe−Co−Ni系合金等の金属
磁性粉毎が知られているが、コバルト含有磁性酸化鉄粉
末と較べて酸化劣化の問題から耐環境性が悪くまた、磁
性体自体の硬度が低いため磁性層の強度が不十分とな
り、耐久性に問題がある。従って、磁性体はコバルト含
有磁性酸化鉄粉末であることが好ましい。As a magnetic material capable of obtaining a substance having a large coercive force and a large residual magnetization, metal magnetic powders such as α-Fe, Fe-Co alloys, and Fe-Co-Ni alloys are known. In comparison with this, the environmental resistance is poor due to the problem of oxidative deterioration, and the strength of the magnetic layer becomes insufficient due to the low hardness of the magnetic material itself, and there is a problem in durability. Therefore, the magnetic substance is preferably a cobalt-containing magnetic iron oxide powder.
さらには、保磁力が800〜1100 Oe、好ましくは900〜1
000 Oeの範囲にあり、かつ最大磁化が70emu/g以上でBET
法による比表面積が30〜40m2/gの範囲にあるコバルト含
有磁性酸化鉄であることが特に好ましい。Further, the coercive force is 800-1100 Oe, preferably 900-1
BET in the range of 000 Oe and maximum magnetization of 70 emu / g or more
It is particularly preferable to use a cobalt-containing magnetic iron oxide having a specific surface area of 30 to 40 m 2 / g by the method.
また、磁性層の残留磁束密度が800ガウス以上、磁性
層の厚さが0.4〜1.0μｍ、磁性層の表面の中心線平均粗
さ（Ra）が0.03μｍ以下、最大高さ（Rmax）が0.15μｍ
以下であることが好ましい。The residual magnetic flux density of the magnetic layer is 800 gauss or more, the thickness of the magnetic layer is 0.4 to 1.0 μm, the center line average roughness (Ra) of the surface of the magnetic layer is 0.03 μm or less, and the maximum height (Rmax) is 0.15 μm. μm
The following is preferred.
磁性層の残留磁束密度が800ガウス未満の場合は出力
電圧が小さくなり、正確な記録の読み出しが行なえなく
なる。また磁性層の保磁力が800 Oeより小さい場合は短
波長信号を記録した際の出力が小さく、1100 Oeより大
きい場合は消去特性が悪くなり、重ね書きをした場合に
既に記録されていた信号が残留して再度信号を読み出す
際に後から記録した信号を正しく読取れないといった問
題が生じる。When the residual magnetic flux density of the magnetic layer is less than 800 gauss, the output voltage becomes small, and accurate reading and writing of data cannot be performed. When the coercive force of the magnetic layer is smaller than 800 Oe, the output at the time of recording the short wavelength signal is small, and when the coercive force is larger than 1100 Oe, the erasing characteristic is deteriorated. When the signal remains and the signal is read again, a problem occurs that a signal recorded later cannot be read correctly.
磁性層の厚さが0.4μｍより薄い場合は磁性層の強度
が不十分なために耐久性が劣化する。また、1.0μｍよ
り厚い場合は、長波長記録の場合の出力電圧の増加に対
して、短波長記録の場合には出力電圧が増加しないため
両者の差が大きくなり、前述のピークのずれの問題が生
じる。When the thickness of the magnetic layer is smaller than 0.4 μm, the durability of the magnetic layer is deteriorated due to insufficient strength of the magnetic layer. When the thickness is larger than 1.0 μm, the output voltage does not increase in the case of short wavelength recording, whereas the output voltage does not increase in the case of long wavelength recording. Occurs.
磁性層表面の中心線平均粗さ（Ra）が0.03μｍより大
きい場合は、磁性層中でヘッドに近い部分の磁化に細か
な変動が生じて、雑音が大きくなる。また、磁性層表面
の最大高さが0.15μｍより大きいとヘッドとの距離が実
質的に離れることで、記録／再生の効率が劣化する。高
密度記録であるほどその効果は大きく、短波長信号を記
録した場合の出力電圧が小さくなり、消去特性も悪くな
る。If the center line average roughness (Ra) of the surface of the magnetic layer is larger than 0.03 μm, a small fluctuation occurs in the magnetization of a portion of the magnetic layer near the head, and noise increases. On the other hand, if the maximum height of the magnetic layer surface is larger than 0.15 μm, the distance from the head is substantially increased, and the recording / reproducing efficiency deteriorates. The higher the recording density, the greater the effect, the lower the output voltage when a short wavelength signal is recorded, and the worse the erasing characteristics.
本発明に於いて使用される結合剤成分としては、ポリ
ウレタン系樹脂、塩化ビニル−酢酸ビニル系共重合体、
エポキシ系樹脂、繊維素系樹脂、ポリエステル系樹脂、
アクリル系樹脂、ゴム系樹脂、イソシアネート化合物な
ど、通常磁性粉末の結合剤成分として使用されるもので
あれば使用可能である。As the binder component used in the present invention, a polyurethane resin, a vinyl chloride-vinyl acetate copolymer,
Epoxy resin, cellulose resin, polyester resin,
An acrylic resin, a rubber-based resin, an isocyanate compound, or the like can be used as long as it is generally used as a binder component of a magnetic powder.
非磁性支持体としてはポリエチレンテレフタレートな
どのポリエステル類、ポリエチレン、ポリプロピレンな
どのポリオレフィン類、ポリカーボネート、ポリフェニ
レンサルファイド、ポリイミドなどのプラスチックが通
常用いられ、用途に応じて、非磁性金属、セラミック、
紙などであっても良い。As the non-magnetic support, polyesters such as polyethylene terephthalate, polyethylene, polyolefins such as polypropylene, polycarbonate, polyphenylene sulfide, plastics such as polyimide are commonly used, and depending on the application, non-magnetic metals, ceramics,
It may be paper.
また本発明に於ける磁性層には、必要に応じて、分散
剤、潤滑剤、研磨剤、帯電防止剤等の添加剤を添加して
も良い。Further, additives such as a dispersant, a lubricant, an abrasive, and an antistatic agent may be added to the magnetic layer according to the present invention, if necessary.
以下、本発明を実施例によりさらに詳細に説明する
が、本発明はその要旨を越えない限り実施例によって限
定されるものではない。Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples unless it exceeds the gist thereof.
実施例１ 磁性粉末 200重量部 針状Co−γFe2O3 保磁力 960 Oe 長軸径 0.5μｍ 結合剤樹脂 80重量部 燐酸エステル系分散剤 6重量部 α−アルミナ 3重量部 ステアリン酸エステル 10重量部 導電性カーボンブラック 20重量部 有機溶剤（シクロヘキサノン、メチルエチルケトン等の
混合物） 780重量部 上記組成物を混合分散し、75μｍ厚さのポリエチレン
テレフタレートフィルムに磁性層の厚さが0.64μｍにな
るように均一に塗布し、乾燥後、カレンダー処理を施し
てドーナツ状に打抜き、磁気ディスクを得た。Example 1 Magnetic powder 200 parts by weight Acicular Co-γFe 2 O 3 coercive force 960 Oe Long axis diameter 0.5 μm Binder resin 80 parts by weight Phosphate dispersant 6 parts by weight α-alumina 3 parts by weight Stearic acid ester 10 parts by weight Conductive carbon black 20 parts by weight Organic solvent (mixture of cyclohexanone, methyl ethyl ketone, etc.) 780 parts by weight The magnetic layer was uniformly coated on a polyethylene terephthalate film having a thickness of 0.64 μm, dried, calendered and punched into a donut shape to obtain a magnetic disk.
この試料の保磁力・残留磁束密度を振動試料式磁力計
で測定し、磁性層の厚さを触針式表面粗さ計で測定し
た。また表面粗さは触針式表面粗さ計で、先端がダイヤ
モンドで径が１μmRの測定子を用いて触針荷重0.07gf、
カットオフ0.08mm、走査速度0.03mm/sec、基準長さ0.4m
mでJIS B0601に準じて測定した。The coercive force and residual magnetic flux density of this sample were measured with a vibrating sample magnetometer, and the thickness of the magnetic layer was measured with a stylus type surface roughness meter. The surface roughness was measured with a stylus type surface roughness meter. The stylus load was 0.07 gf using a probe with a diamond tip and a diameter of 1 μmR.
Cutoff 0.08mm, scanning speed 0.03mm / sec, standard length 0.4m
It was measured according to JIS B0601 at m.
実施例２および３ 磁性層の厚さを0.42μｍと0.49μｍにしたこと以外は
実施例１と同様にして磁気ディスクを得た。Examples 2 and 3 Magnetic disks were obtained in the same manner as in Example 1 except that the thicknesses of the magnetic layers were 0.42 μm and 0.49 μm.
比較例１ 磁性粉末を、保磁力670 Oe、長軸径0.7μｍの針状Co
−γFe2O3にし、磁性層の厚さを1.6μｍにしたこと以外
は実施例１と同様にして磁気ディスクを得た。Comparative Example 1 A magnetic powder was prepared from acicular Co having a coercive force of 670 Oe and a major axis diameter of 0.7 μm.
A magnetic disk was obtained in the same manner as in Example 1, except that -γFe 2 O 3 was used and the thickness of the magnetic layer was 1.6 μm.
比較例２ 磁性粉末を、保磁力730 Oe、長軸径0.8μｍの針状Co
−γFe2O3にしたこと以外は実施例１と同様にして磁気
ディスクを得た。Comparative Example 2 A magnetic powder was prepared using needle-shaped Co having a coercive force of 730 Oe and a major axis diameter of 0.8 μm.
A magnetic disk was obtained in the same manner as in Example 1 except that -γFe 2 O 3 was used.
比較例３ 磁性層の厚さを0.54μｍにしたこと以外は比較例２と
同様にして磁気ディスクを得た。Comparative Example 3 A magnetic disk was obtained in the same manner as in Comparative Example 2, except that the thickness of the magnetic layer was changed to 0.54 μm.
比較例４ カレンダー処理を省略したこと以外は実施例１と同様
にして磁気ディスクを得た。Comparative Example 4 A magnetic disk was obtained in the same manner as in Example 1 except that the calendar treatment was omitted.
比較例５ 磁性層の厚さを1.20μｍにしたこと以外は実施例１と
同様にして、磁気ディスクを得た。Comparative Example 5 A magnetic disk was obtained in the same manner as in Example 1 except that the thickness of the magnetic layer was changed to 1.20 μm.
実施例１〜３、比較例１〜５で得られた磁気ディスク
をヘッドギャップ0.9μｍのフェライトヘッドを用い
て、300rpmで回転させて、半径24.7mmの位置で記録・再
生を行なったときのD50と出力電圧を第１表に示す。When the magnetic disks obtained in Examples 1 to 3 and Comparative Examples 1 to 5 were rotated at 300 rpm using a ferrite head with a head gap of 0.9 μm, recording / reproducing was performed at a position with a radius of 24.7 mm. And the output voltage are shown in Table 1.
なお、D50とは出力が長波長信号を記録した際の再生
出力が50％になる記録密度を表わしたもので、装置とし
て実現可能な最大記録密度の目安となる。従ってD50が2
5kbpi以上であれば、従来より高密度な記録を行なうの
に適しているといえる。又、出力電圧はアンプノイズに
比して十分に大きくなければならず、2V以上であること
が望ましい。Note that D50 represents a recording density at which a reproduction output when a long-wavelength signal is recorded becomes 50%, and is a measure of the maximum recording density that can be realized as an apparatus. Therefore D50 is 2
If it is 5 kbpi or more, it can be said that it is suitable for performing higher density recording than before. Also, the output voltage must be sufficiently large compared to the amplifier noise, and is desirably 2 V or more.
比較例１、２および３のように磁性層の保磁力が800
Oeより低い場合は短波長信号を記録した場合の出力電圧
が小さい。また、比較例４のように保磁力やRaが実施例
と同じ程度であっても、Rmaxが大きいと出力電圧が小さ
くなり、特に短波長信号を記録した場合の出力電圧の低
下が激しい為、D50が悪くなる。さらに、比較例５のよ
うに保磁力、Ra、Rmaxともに実施例と同等であっても、
磁性層の厚さが1.0μｍより厚くなると出力電圧は十分
であるが、D50が悪くなる。 As in Comparative Examples 1, 2 and 3, the coercive force of the magnetic layer was 800
When it is lower than Oe, the output voltage when a short wavelength signal is recorded is small. Further, even when the coercive force and Ra are almost the same as those of the embodiment as in Comparative Example 4, the output voltage decreases when Rmax is large, and the output voltage particularly decreases when a short-wavelength signal is recorded. D50 gets worse. Furthermore, even if the coercive force, Ra, and Rmax are the same as in the example as in Comparative Example 5,
When the thickness of the magnetic layer is more than 1.0 μm, the output voltage is sufficient, but D50 is deteriorated.
本発明の磁気記録媒体によれば、従来の磁気記録媒体
より、より短波長での記録が行なえるため、記録密度を
高くし、記録媒体の記録容量を大きくすることができ
る。According to the magnetic recording medium of the present invention, recording at a shorter wavelength can be performed than in the conventional magnetic recording medium, so that the recording density can be increased and the recording capacity of the recording medium can be increased.
Claims (1)
む磁性層を設けてなる磁気記録媒体において、上記磁性
層の残留磁束密度が800ガウス以上、保磁力が800〜1100
Oe、該磁性層の厚さが0.4〜1.0μｍ、および該磁性層
の表面の中心線平均粗さ（Ra）が0.03μｍ以下、最大高
さ（Rmax）が0.15μｍ以下であることを特徴とする磁気
記録媒体。1. A magnetic recording medium comprising a non-magnetic support and a magnetic layer containing a magnetic powder and a binder, wherein the magnetic layer has a residual magnetic flux density of 800 gauss or more and a coercive force of 800 to 1100.
Oe, wherein the thickness of the magnetic layer is 0.4 to 1.0 μm, the center line average roughness (Ra) of the surface of the magnetic layer is 0.03 μm or less, and the maximum height (Rmax) is 0.15 μm or less. Magnetic recording medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19328088A JP2623734B2 (en) | 1988-08-02 | 1988-08-02 | Magnetic recording media |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19328088A JP2623734B2 (en) | 1988-08-02 | 1988-08-02 | Magnetic recording media |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0242626A JPH0242626A (en) | 1990-02-13 |
| JP2623734B2 true JP2623734B2 (en) | 1997-06-25 |
Family
ID=16305304
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19328088A Expired - Lifetime JP2623734B2 (en) | 1988-08-02 | 1988-08-02 | Magnetic recording media |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2623734B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06103562A (en) * | 1992-09-21 | 1994-04-15 | Matsushita Electric Ind Co Ltd | Magnetic tape |
-
1988
- 1988-08-02 JP JP19328088A patent/JP2623734B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0242626A (en) | 1990-02-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2005038579A (en) | Magnetic recording medium | |
| JPH0479046B2 (en) | ||
| JP7512782B2 (en) | Magnetic Recording Media | |
| JPH0650563B2 (en) | Magnetic recording medium | |
| JP2623734B2 (en) | Magnetic recording media | |
| US4699840A (en) | Magnetic recording medium | |
| JP6816851B1 (en) | Magnetic recording medium | |
| JP2701382B2 (en) | Magnetic recording media | |
| JP3170784B2 (en) | Magnetic recording media | |
| JP2004103217A (en) | Magnetic recording medium | |
| WO2021070907A1 (en) | Magnetic recording medium | |
| JP2008059664A (en) | Magnetic recording medium | |
| JPH07114015B2 (en) | Magnetic recording medium | |
| JP2907340B2 (en) | Magnetic recording media | |
| JP2002074649A (en) | Magnetic disk and recording and reproducing device | |
| JP2888488B2 (en) | Magnetic recording media | |
| JPH04248120A (en) | Magnetic recording medium | |
| JP2651749B2 (en) | Magnetic recording media | |
| JP2635596B2 (en) | Magnetic recording media | |
| JP2001325712A (en) | Discoid magnetic recording medium | |
| JP2001325714A (en) | Discoid magnetic recording medium | |
| JPS6173206A (en) | Magnetic recording and reproducing system | |
| JP2006286098A (en) | Magnetic recording medium and manufacturing method therefor | |
| JP2006294078A (en) | Magnetic tape, its recording and reproducing method and magnetic tape cartridge | |
| JP2002092852A (en) | Magnetic recording medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090411 Year of fee payment: 12 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090411 Year of fee payment: 12 |