JPS62175930A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPS62175930A JPS62175930A JP61017439A JP1743986A JPS62175930A JP S62175930 A JPS62175930 A JP S62175930A JP 61017439 A JP61017439 A JP 61017439A JP 1743986 A JP1743986 A JP 1743986A JP S62175930 A JPS62175930 A JP S62175930A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- ratio
- surface area
- specific surface
- 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.)
- Granted
Links
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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、高密度磁気記録を行う磁気テープ。[Detailed description of the invention] [Industrial application field] The present invention relates to a magnetic tape that performs high-density magnetic recording.
磁気ディスク等の磁気記録媒体に関するものである。It relates to magnetic recording media such as magnetic disks.
本発明は、非磁性支持体上に六方晶系フェライト磁性粉
末と結合剤とを主成分とする磁性層が形成されてなる磁
気記録媒体において、
使用する六方晶系フェライト磁性粉末の平均粒径を０．
０３〜０．１ μｍ、 ＋Ｉｉ状比を３〜５とし、さら
に比表面積と板状比の積を２０Ｏｎｆ／ｇ以下どするこ
とによって、
特に短波長出力と長波長出力の両者を同時に向上しよう
とするものである。The present invention provides a magnetic recording medium in which a magnetic layer mainly composed of hexagonal ferrite magnetic powder and a binder is formed on a non-magnetic support. 0.
By setting the +II ratio to 03 to 0.1 μm, the +II ratio to 3 to 5, and the product of the specific surface area and the plate ratio to 20 Onf/g or less, we particularly attempted to improve both short wavelength output and long wavelength output at the same time. It is something to do.
従来、磁気記録媒体は、針状磁性粉末を磁性層に水平な
長手方向に配向させる等して磁気特性の向上を図ってい
る。Conventionally, the magnetic properties of magnetic recording media have been improved by orienting acicular magnetic powder in a longitudinal direction parallel to the magnetic layer.
ところが、上述のように磁性層の長手方向の磁化成分を
利用した長手記録においては、低置波帯域（長波長帯域
）では高い再生出力が得られるものの、高周波帯域（短
波長帯域）になるに従って、上記磁性層内部の反磁界が
高まり、自己減磁損失の増加から記録再生特性が劣る欠
点があった。However, as mentioned above, in longitudinal recording that utilizes the magnetization component in the longitudinal direction of the magnetic layer, although high reproduction output can be obtained in the low wave band (long wavelength band), as the frequency band increases (short wavelength band), However, the demagnetizing field inside the magnetic layer increases and self-demagnetization loss increases, resulting in poor recording and reproducing characteristics.
そこで近年、磁化容易軸が板面対、して垂直方向にある
板状の六方晶形フェライト磁性粉末を用い、磁性層面に
対して垂直方向の磁化成分を積極的に利用し、上述の長
手記録の欠点を解消するとともに、高密度記録化を図る
試みが盛んに行われている。Therefore, in recent years, a plate-shaped hexagonal ferrite magnetic powder whose axis of easy magnetization is perpendicular to the plate surface is used, and the magnetization component perpendicular to the magnetic layer surface is actively used to achieve the above-mentioned longitudinal recording. Many attempts are being made to eliminate these drawbacks and achieve higher density recording.
しかしながら、この種の六方晶系フェライＨｆｉ性粉末
を用いた磁気記録媒体では、六方晶系フェライト磁性粉
末の粒径や仮４に比、比表面積等によって磁性層の磁気
特性、特に飽和磁束密度や垂直配向度が大幅に変化する
こと、短波長出力の向上に比較して長波長出力が低いこ
と、等の欠点があって、短波長帯域から長波長帯域に亘
って磁気特性、電磁変換特性を充分に向上することがで
きないという難点があった。However, in a magnetic recording medium using this type of hexagonal ferrite magnetic powder, the magnetic properties of the magnetic layer, especially the saturation magnetic flux density, etc. There are disadvantages such as the degree of vertical orientation changes significantly and the long wavelength output is lower compared to the improvement in short wavelength output, and the magnetic properties and electromagnetic conversion characteristics are not improved from the short wavelength band to the long wavelength band. The problem was that it could not be improved sufficiently.
例えば、ビデオ信号やデジタルオーディオ信号等を磁気
転写しようとする場合には、被転写媒体であるスレーブ
媒体の電磁変換特性は広い周波数帯域に亘り同等である
ことが好ましく、短波長帯域あるいは長波長帯域のいず
れかの再生出力が不足すると、転写効率に偏りを生じ画
質や音質等の記録品質が低下してしまう。For example, when attempting to magnetically transfer a video signal, digital audio signal, etc., it is preferable that the electromagnetic conversion characteristics of the slave medium to be transferred be the same over a wide frequency band, and that If either of the reproduction outputs is insufficient, the transfer efficiency will be biased and recording quality such as image quality and sound quality will deteriorate.
そこで、本発明はかかる実情に鑑みて提案されたもので
あって、短波長出力と長波長出力の両者を同時に向上で
き、これまで提案されている六方晶系フェライ）［気記
録媒体よりも高密度、高品質記録が可能な磁気記録媒体
を提供することを目的とする。The present invention was proposed in view of the above circumstances, and is capable of simultaneously improving both short-wavelength output and long-wavelength output, and is capable of improving both short-wavelength output and long-wavelength output at the same time. The objective is to provide a magnetic recording medium that allows high-density, high-quality recording.
本発明者等は上述の目的を達成せんものと鋭意検討の結
果、六方晶形フェライト磁性粉末の粒径、板状比、比表
面積を所定範囲内に規定した磁気記録媒体が良好な磁気
特性を示すことを見出し本発明を完成するに至ったもの
であって、非磁性支持体上に六方晶系フェライト磁性粉
末と結合剤とを主成分とする磁性層が形成されてなる磁
気記録媒体において、上記六方晶系フェライト磁性粉末
は、平均粒径が０．０３〜Ｏ１１μｍ、板状比が３〜５
で、さらに比表面積と板状比の積が２００ ｒｄ／ｇ以
下であることを特徴とするものである。As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a magnetic recording medium in which the particle size, plate ratio, and specific surface area of hexagonal ferrite magnetic powder is defined within a predetermined range exhibits good magnetic properties. They discovered this and completed the present invention, which provides a magnetic recording medium in which a magnetic layer mainly composed of hexagonal ferrite magnetic powder and a binder is formed on a non-magnetic support. The hexagonal ferrite magnetic powder has an average particle size of 0.03 to 11 μm and a plate ratio of 3 to 5.
The product is further characterized in that the product of specific surface area and platelet ratio is 200 rd/g or less.
本発明の磁気記録媒体において使用される磁性粉末は、
７般式ＭＯ−ｎ（ＦｅｚＯ：＋） （ただし、式中Ｍは
Ｂａ、 Ｓｒ、Ｃａのうち少なくとも一種を表し、ま
た、ｎ＝５〜６である。）で示される六方晶系フェライ
ト磁性粉末である。この場合、抗磁力を制御するために
、Ｃｏ、Ｔｉ、Ｎｉ、Ｍｎ、Ｃｕ。The magnetic powder used in the magnetic recording medium of the present invention is
7 Hexagonal ferrite magnetic powder represented by the general formula MO-n(FezO:+) (wherein M represents at least one of Ba, Sr, and Ca, and n = 5 to 6) It is. In this case, Co, Ti, Ni, Mn, Cu are used to control the coercive force.
Ｚｎ、Ｉｎ、Ｇｅ、Ｎｂのうち少なくとも１種を添加し
、上記六方晶系フェライト磁性粉末のＦｅの一部をこれ
ら元素で置き換えてもよい。例えば、Ｂａ−フェライト
において、上記添加元素によりＦＱの一部を置き換えた
場合には、その組成は、一般式
％式％（１）
（式中Ｘはｃｏ、Ｔｉ、Ｎｉ、Ｍｎ、Ｃｕ、Ｚｎ。At least one of Zn, In, Ge, and Nb may be added to replace a part of Fe in the hexagonal ferrite magnetic powder with these elements. For example, in Ba-ferrite, when a part of FQ is replaced by the above additive element, the composition is expressed by the general formula % (1) (where X is co, Ti, Ni, Mn, Cu, Zn .
Ｉｎ、Ｇｅ、Ｎｂのうち少なくとも一種を表し、ｍはＯ
〜０．２の数、ｎは５〜６の数をそれぞれ表す。）
で表される。Represents at least one of In, Ge, and Nb, and m is O
˜0.2, and n represents a number of 5 to 6, respectively. ).
本発明では、上記六方晶系フェライト磁性粉末の粒径を
０．０３〜０．１μｍ、板状比３〜６とする。In the present invention, the particle size of the hexagonal ferrite magnetic powder is 0.03 to 0.1 μm, and the plate ratio is 3 to 6.
粒径が０．０３μｍよりも小さいと、磁性層の空隙率が
高くなり、磁気記録媒体としたときに飽和磁束密度Ｂｍ
を確保することが難しく、全波長領域において出力が低
下し、不都合を招来する。逆に、粒径が０．１μｍより
も大きい場合には、飽和磁束密度Ｂａ＋はある程度大き
くできるが、表面粗さが増大し、高密度記録を行う上で
不利である。When the particle size is smaller than 0.03 μm, the porosity of the magnetic layer becomes high, and when used as a magnetic recording medium, the saturation magnetic flux density Bm
It is difficult to ensure this, and the output decreases in the entire wavelength range, causing inconvenience. On the other hand, if the particle size is larger than 0.1 μm, the saturation magnetic flux density Ba+ can be increased to some extent, but the surface roughness increases, which is disadvantageous for high-density recording.
一方、板状比が３未満になると、垂直配向処理を行って
も垂直方向の角形比を０．５以上にするこ ・とが困難
となり、垂直成分の磁化が減少し、短波長出力を向上さ
せることができなくなる。板状比が６を越えると、どの
ような粒径のものであっても後述するような板状比Ｘ比
表面積を２００ｒｎ’／ｇとすることができず、全波長
領域における出力を高めることが困難となる。また、粒
子間で凝集し易くなり、分散性が劣化するという欠点も
生ずる。On the other hand, when the plate ratio is less than 3, it becomes difficult to increase the squareness ratio in the vertical direction to 0.5 or more even if vertical alignment treatment is performed, and the magnetization of the perpendicular component decreases, improving short wavelength output. I will not be able to do it. If the plate ratio exceeds 6, no matter what the particle size, the plate ratio becomes difficult. Furthermore, there is also the disadvantage that particles tend to aggregate, resulting in poor dispersibility.
なお、ここで粒径とは、粒子の平均粒径のことで、また
板状比は、粒径をり９粒子の平均厚みをｔとしたときに
Ｄ／ｌで表される値である。Note that the particle size here refers to the average particle size of particles, and the plate ratio is a value expressed as D/l, where t is the particle size and the average thickness of 9 particles.
本発明では、さらに、使用する六方晶系フェライト磁性
粉末の板状比と比表面積の積が重要な要素となる。In the present invention, the plate ratio and specific surface area of the hexagonal ferrite magnetic powder used are further important factors.
すなわち、粒径が０．０３〜０．１μｍ、板状比が３〜
６の磁性粉末を用いる場合においても、板状比と比表面
積（ＢＥＴ法による）の積（板状比Ｘ比表面積）が２０
０ｉ／ｇを越えると、磁性層の空隙率が増大する結果、
飽和磁束密度Ｂｍの低下がみられ、短波長出力、長波長
出力のいずれをも高めることができなくなる。このよう
に、磁性層の飽和磁束密度は、比表面積や板状比９粒径
等の単独の値では決定することができず、磁性層の空隙
率の変化に依存する。That is, the particle size is 0.03 to 0.1 μm, and the plate ratio is 3 to
Even when using magnetic powder No. 6, the product of plate ratio and specific surface area (according to the BET method) (plate ratio x specific surface area) is 20.
When it exceeds 0i/g, the porosity of the magnetic layer increases, resulting in
A decrease in the saturation magnetic flux density Bm is observed, making it impossible to increase either short wavelength output or long wavelength output. As described above, the saturation magnetic flux density of the magnetic layer cannot be determined by independent values such as the specific surface area or the platelet ratio 9 grain size, but depends on the change in the porosity of the magnetic layer.
で示される値であって、第１図に示すように、板状比×
比表面積の値が大きくなるのに比例して増大する。この
（１１式からも、空隙率の増加は得られる磁気記録媒体
の飽和磁束密度Ｂｍの低下をもたらすことがわかる。し
たがって、板状比×比表面積の値と得られる磁気記録媒
体の飽和磁束密度の関係を調べると、第２図に示すよう
に、板状比ｘ比表面積が大きくなるのに伴って、次第に
飽和磁束密度が低下し、短波長帯域、長波長帯域のいず
れの領域にしろ出力を確保するのが難しくなることがわ
かる。上記板状比ｘ比表面積の値が２００ｒｄ／ｇ以下
であれば、飽和磁束密度はおよそ１６００ガウス以上と
なり、実用上問題ない。As shown in FIG.
It increases in proportion to the value of the specific surface area. It can also be seen from this equation (11) that an increase in the porosity brings about a decrease in the saturation magnetic flux density Bm of the obtained magnetic recording medium. Therefore, the value of the plate ratio x specific surface area and the saturation magnetic flux density of the obtained magnetic recording medium As shown in Figure 2, when examining the relationship between It can be seen that it becomes difficult to ensure the above-mentioned plate ratio x specific surface area.If the value of the plate ratio x specific surface area is 200rd/g or less, the saturation magnetic flux density will be approximately 1600 Gauss or more, which poses no problem in practice.
以上のような実験結果より、本発明の磁気記録媒体で用
いられる六方晶系フェライト磁性粉末の好適な範囲を第
３図に図示する。Based on the above experimental results, the preferred range of the hexagonal ferrite magnetic powder used in the magnetic recording medium of the present invention is illustrated in FIG.
第３図は、横軸に板状比、縦軸に比表面積をとり、さら
に粒径りが０．０３ μｍ、 ０．０５ ａｍ、 ０゜
１μｍ、０．２μｍとなる領域をそれぞれ直￥１ｉＤｔ
。In Figure 3, the horizontal axis shows the plate ratio, and the vertical axis shows the specific surface area, and the areas where the grain size is 0.03 μm, 0.05 am, 0°1 μm, and 0.2 μm are expressed as 1iDt, respectively.
.
Ｄ ｚ、 Ｄ ｓ、 Ｄ ４で表したものである。また
、第３図中曲線ａは、板状比ｘ比表面積＝２００ｒｄ／
ｇを表す。したがって、本発明の磁気記録媒体で用いら
れる六方晶系フェライト磁性粉末の範囲は、第３図中斜
線で囲まれる領域となる。They are expressed as D z, D s, and D 4. In addition, curve a in Fig. 3 is plate ratio x specific surface area = 200rd/
represents g. Therefore, the range of the hexagonal ferrite magnetic powder used in the magnetic recording medium of the present invention is the area surrounded by diagonal lines in FIG.
上述の六方晶系フェライ）［性扮末は、六角平板状の粒
子で、この粒子の板面が記録媒体面に平行になり易く、
しかも磁化容易軸が板面に垂直であるために、磁場配向
処理もしくは機械的配向処理によって容易に垂直配向、
無配向（全方向配向）とすることができる、この場合、
垂直方向の角形比（媒体表面に垂直な方向に測定した磁
化曲線を反磁場補正した残留磁化／飽和磁化の比をいう
。）Ｒ５が０．５よりも小さいと、垂直成分の磁化が少
なくなる為、短波長出力が低下するという問題を招来す
る。逆に、垂直方向の角形比Ｒ８が０．７５よりも大き
くなると、短波長出力は高まるものの、長手方向の磁化
成分が減少する結果、長波長出力が著しく低下する欠点
がある。また、表面粗さも増大する為、垂直磁化成分の
増加の割合に比較して、必ずしも短波長出力の向上の割
合が大きくはないという欠点もある。The above-mentioned hexagonal crystal ferrite is a hexagonal plate-shaped particle, and the plate surface of this particle tends to be parallel to the recording medium surface,
Moreover, since the axis of easy magnetization is perpendicular to the plate surface, vertical alignment can be easily achieved by magnetic field alignment treatment or mechanical alignment treatment.
It can be non-oriented (orientated in all directions), in this case,
Vertical squareness ratio (ratio of residual magnetization/saturation magnetization obtained by demagnetizing field correction of the magnetization curve measured in the direction perpendicular to the medium surface) If R5 is smaller than 0.5, the magnetization of the perpendicular component will decrease. Therefore, a problem arises in that the short wavelength output decreases. Conversely, when the vertical squareness ratio R8 is greater than 0.75, although the short wavelength output increases, the long wavelength output decreases significantly as a result of a decrease in the longitudinal magnetization component. Furthermore, since the surface roughness also increases, there is also a drawback that the rate of improvement in short wavelength output is not necessarily large compared to the rate of increase in the perpendicular magnetization component.
したがって、本発明の磁気記録媒体では、垂直方向の角
形比Ｒ５を、０．５≦Ｒ８≦０．７５の範囲内とするこ
とが好ましいと言える。この垂直方向の角形比Ｒ８は、
配向処理条件を変更することにより容易に制御すること
ができる。Therefore, in the magnetic recording medium of the present invention, it is preferable that the squareness ratio R5 in the vertical direction is within the range of 0.5≦R8≦0.75. This vertical squareness ratio R8 is
It can be easily controlled by changing the alignment treatment conditions.
これら六方晶系フェライト磁性粉末は、樹脂結合剤とと
もに有機溶剤に溶解１分散し、磁性塗料としてベースフ
ィルム上に塗布され、磁性層を形成する。磁性層の磁気
特性のうち、垂直方向の抗磁力は６００〜１５００ （
Ｏｅ）とすることが好ましい。These hexagonal ferrite magnetic powders are dissolved and dispersed in an organic solvent together with a resin binder, and applied as a magnetic coating onto a base film to form a magnetic layer. Among the magnetic properties of the magnetic layer, the perpendicular coercive force is 600 to 1500 (
Oe) is preferable.
用いる樹脂結合剤や有ｍ溶剤は、通常この種の磁気記録
媒体に使用されるものであれば如何なるものであっても
よく、さらに磁性層には、分散剤や潤滑剤、研磨剤、帯
電防止剤、防錆剤等を添加してもよい。The resin binder and organic solvent used may be any of those normally used in this type of magnetic recording medium, and the magnetic layer may also contain dispersants, lubricants, abrasives, antistatic agents, etc. Agents, rust preventives, etc. may be added.
使用可能な樹脂結合剤を例示すれば、塩化ビニル−酢酸
ビニル系共重合体、塩化ビニル−塩化ビニリデン共重合
体、塩化ビニル−アクリロニトリル共重合体、アクリル
酸エステルーアクリロニトリル共重合体、熱可塑性ポリ
ウレタンエラストマー、ポリフッ化ビニル、塩化ビニリ
デン−アクリロニトリル共重合体、ブタジェン−アクリ
ロニトリル共重合体、ポリアミド樹脂、ポリビニルブチ
ラール、セルロースｇＢ ４体、ポリエステル樹脂、ポ
リブタジェン等の合成ゴム系樹脂、フェノール樹脂、エ
ポキシ樹脂、ポリウレタン硬化型樹脂、メラミン樹脂、
アルキッド樹脂、シリコーン樹脂、アクリル系反応樹脂
、エポキシ−ポリアミド樹脂、ニトロセルロース−メラ
ミン樹脂、高分子量ポリエステル樹脂とイソシアナート
プレポリマーの混合物、メタクリル酸塩共重合体とジイ
ソシアナートプレポリマーの混合物、ポリエステルポリ
オールとポリイソシアナートとの混合物、尿素ホルムア
ルデヒド樹脂、低分子量グリコール／高分子量ジオール
／トリフェニルメタントリイソシアナートの混合物、ポ
リアミン樹脂及びこれらの混合物等が挙げられる。Examples of usable resin binders include vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinylidene chloride copolymers, vinyl chloride-acrylonitrile copolymers, acrylic ester-acrylonitrile copolymers, and thermoplastic polyurethanes. Elastomer, polyvinyl fluoride, vinylidene chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer, polyamide resin, polyvinyl butyral, cellulose gB 4, polyester resin, synthetic rubber resin such as polybutadiene, phenol resin, epoxy resin, polyurethane Curing resin, melamine resin,
Alkyd resins, silicone resins, acrylic reactive resins, epoxy-polyamide resins, nitrocellulose-melamine resins, mixtures of high molecular weight polyester resins and isocyanate prepolymers, mixtures of methacrylate copolymers and diisocyanate prepolymers, polyesters Examples include mixtures of polyols and polyisocyanates, urea formaldehyde resins, mixtures of low molecular weight glycol/high molecular weight diol/triphenylmethane triisocyanate, polyamine resins, and mixtures thereof.
ベースフィルムの素材としては、ポリエチレンテレフタ
レート等のポリエステル類、ポリエチレン、ポリプロピ
レン等のポリオレフィン類、セルローストリアセテート
、セルロースダイアセテートセルロースアセテートブチ
レート等のセルロース誘導体、ポリ塩化ビニル、ポリ塩
化ビニリデン等のビニル系樹脂、ポリカーボネートポリ
イミド、ポリアミドイミド等のプラスチック、アルミニ
ウム合金、チタン合金等の軽合金、アルミナガラス等の
セラミックス等が挙げられる。このベースフィルムの形
態としては、フィルム、シート。Materials for the base film include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, cellulose derivatives such as cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, Examples include plastics such as polycarbonate polyimide and polyamideimide, light alloys such as aluminum alloys and titanium alloys, and ceramics such as alumina glass. The forms of this base film are film and sheet.
ディスク、カード、ドラム等の何れでもよい。It may be a disk, card, drum, etc.
〔作用〕
六方晶系フェライト磁性粉末の粒径、板状比７板状比Ｘ
比表面積の値を本発明の範囲内に設定することにより、
得られる磁気記録媒体の空隙率が抑えられて飽和磁束密
度が確保され、また六方晶系フェライ＋−ｍ性粉末が垂
直配向性を有することから、短波長域から長波長域に亘
り高い再生出力が達成される。[Function] Particle size of hexagonal ferrite magnetic powder, plate ratio 7 plate ratio X
By setting the value of the specific surface area within the range of the present invention,
The porosity of the resulting magnetic recording medium is suppressed to ensure saturation magnetic flux density, and since the hexagonal ferrite +-m powder has vertical orientation, it has high reproduction output from short wavelength range to long wavelength range. is achieved.
以下、本発明の具体的な実施例について説明するが、本
発明がこれら実施例に限定されるものはない。Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to these examples.
スｌｌ」Ｌ
Ｂａ−フェライト磁性酸化鉄粉末 １００重量部粒径・
・・・・・・・ ０．０７μｍ
板状比・・・・・・・３
比表面積・・・・・・２９ （ｍｍ”／ｇ）板状比ｘ比
表面積・・８７ （ｍｍ”／ｇ）ポリウレタン樹脂
１５重量部塩化ビニル−酢酸ビニル共重
合体 １０重量部研磨剤
５重量部カーボンブラック ５重量
部レシチン １重量部メチ
ルエチルケトン １００重量部トルエン
５０重量部シクロヘキサン
５０重量部上記組成物をボールミ
ル中で２０時間混練し、た後、硬化剤２．５重量部を加
えて平均孔径１μｍのフィルタで濾過し、磁性塗料を調
製した。Sll'L Ba-ferrite magnetic iron oxide powder 100 parts by weight Particle size・
......0.07μm Plate ratio...3 Specific surface area...29 (mm"/g) Plate ratio x specific surface area...87 (mm"/g) ) Polyurethane resin
15 parts by weight Vinyl chloride-vinyl acetate copolymer 10 parts by weight Abrasive
5 parts by weight Carbon black 5 parts by weight Lecithin 1 part by weight Methyl ethyl ketone 100 parts by weight Toluene 50 parts by weight Cyclohexane 50 parts by weight The above composition was kneaded in a ball mill for 20 hours, and then 2.5 parts by weight of a curing agent was added to give an average The mixture was filtered through a filter with a pore size of 1 μm to prepare a magnetic paint.
次いで、この磁性塗料を厚さ１５μｍのポリエステルフ
ィルム上に塗布し、垂直配向処理を行った後、乾燥させ
た。さらに、スーパーカレンダ装置を用いて磁性層表面
を加工処理し、磁性層の膜厚４μｍの広幅のシートを作
製し、これをＡインチ幅に裁断してサンプルテープとし
た。Next, this magnetic paint was applied onto a polyester film having a thickness of 15 μm, subjected to vertical alignment treatment, and then dried. Furthermore, the surface of the magnetic layer was processed using a supercalender device to produce a wide sheet with a magnetic layer thickness of 4 μm, and this was cut into A-inch width to form a sample tape.
得られたサンプルテープの磁気特性は、磁束密度８．１
８００ガウス（Ｇａｕｓｓ）’、磁性層の厚さ方向の角
形比Ｒ，０，６５であった。The magnetic properties of the sample tape obtained were as follows: magnetic flux density 8.1
800 Gauss', and the squareness ratio R in the thickness direction of the magnetic layer was 0.65.
尖崖炭１
磁性粉末として
粒径・・・・・・・・０．０６μｍ
板状比・・・・・・・ ４
比表面積・・・・・・ ３４ （ｍｍ”／ｇ）板状比ｘ
比表面積・・１３６（ｍ１１１２７ｇ）であるＢａ−フ
ェライト磁性酸化鉄粉末を用い、他は実施例１と同様の
手法に従ってサンプルテープを作製した。Spiral coal 1 Particle size as magnetic powder: 0.06 μm Plate ratio: 4 Specific surface area: 34 (mm”/g) Plate ratio x
A sample tape was prepared in the same manner as in Example 1 except for using Ba-ferrite magnetic iron oxide powder having a specific surface area of 136 (m11127 g).
得られたサンプルテープの磁気特性は、磁束密度Ｂ、１
７１０ガウス（Ｇａｕｓｓ） 、 ｍ性層の厚さ方向の
角形比Ｒ，，０，６８であった。The magnetic properties of the obtained sample tape are as follows: magnetic flux density B, 1
710 Gauss, and the squareness ratio R in the thickness direction of the m-layer was 0.68.
比較炎上
磁性粉末として
粒径・・・・・・・・ ０．１μｍ
板状比・・・・・・・ ８
比表面積・・・・・・ ３８ （ｍｍ”／ｇ）板状比×
比表面積・・３０４（１１１１２７ｇ）であるＢａ−フ
ェライト磁性酸化鉄粉末を用い、他は実施例１と同様の
手法に従ってサンプルテープを作製した。Particle size as a comparative flaming magnetic powder: 0.1 μm Plate ratio: 8 Specific surface area: 38 (mm”/g) Plate ratio ×
A sample tape was prepared in the same manner as in Example 1 except that Ba-ferrite magnetic iron oxide powder having a specific surface area of 304 (111,127 g) was used.
得られたサンプルテープの磁気特性は、磁束密度８．１
４００ガウス（Ｇａｕｓｓ） 、 ｍ性層の厚さ方向の
角形比Ｒ，０，７０であった。The magnetic properties of the sample tape obtained were as follows: magnetic flux density 8.1
400 Gauss, and the squareness ratio R in the thickness direction of the m-layer was 0.70.
比較例２
磁性粉末として
粒径・・・・・・・・０，０３μｍ
板状比・・・・・・・ ６
比表面積・・・・・・１０４ （ｍｍ”／ｇ）板状比Ｘ
比表面積・・６２４ （ｍｍ”／ｇ）であるＢａ−フェ
ライトｉｆｉ性酸化鉄粉末を用い、他は実施例１と同様
の手法に従ってサンプルテープを作製した。Comparative Example 2 Particle size as magnetic powder: 0.03 μm Plate ratio: 6 Specific surface area: 104 (mm”/g) Plate ratio: X
A sample tape was prepared in the same manner as in Example 1 except for using Ba-ferrite iron oxide powder having a specific surface area of .624 (mm"/g).
得られたサンプルテープの磁気特性は、磁束密度８．１
０８０ガウス（Ｇａｕｓｓ）＋磁性層の厚さ方向の角形
比Ｒ，０，６５であった。The magnetic properties of the sample tape obtained were as follows: magnetic flux density 8.1
The squareness ratio R in the thickness direction of the magnetic layer was 0.080 Gauss + 0.65.
上述の各サンプルテープについて、それぞれ再 −主
出力の周波数特性を測定した。測定は、トラック幅２０
μｍ、ギャップ長０．２５μｍのメタル系ヘッドを用い
、相対スピード３ｍ／ｓｅｃで２５０ｋ ｔｌｚ〜６Ｍ
Ｈｚの方形波を記録再生し、各周波数の基本波出力レベ
ルをスペクトラムアナライザを用いて測定した。バンド
幅は１０ ｋ Ｉｌｚとした。結果を第４図に示す。The frequency characteristics of the main output were measured for each of the sample tapes mentioned above. The measurement is track width 20
250k tlz ~ 6M at a relative speed of 3m/sec using a metal head with a gap length of 0.25μm and a gap length of 0.25μm.
A square wave of Hz was recorded and reproduced, and the fundamental wave output level of each frequency was measured using a spectrum analyzer. The bandwidth was 10 k Ilz. The results are shown in Figure 4.
この第４図より、板状比Ｘ比表面積が２００ｄ／ｇ以上
である比較例１及び比較例２では、磁性層の磁束密度が
小さく、短波長出力、長波長出力とも実施例１．実施例
２に比較して低いことがわかる。From FIG. 4, it can be seen that in Comparative Examples 1 and 2, in which the plate ratio X specific surface area is 200 d/g or more, the magnetic flux density of the magnetic layer is small, and both short wavelength output and long wavelength output are similar to Example 1. It can be seen that this is lower than in Example 2.
次に、粒径、板状比、比表面積×板状比がそれぞれ本発
明の範囲内のサンプルテープを作製し、角形比Ｒ，の再
生出力に及ぼす影響について調べた。Next, sample tapes were prepared in which the particle size, platelet ratio, and specific surface area x platelet ratio were each within the range of the present invention, and the influence of the squareness ratio R on the reproduction output was investigated.
大止拠主
磁性粉末として
粒径・・・・・・・・０．０９μｍ
板状比・・・・・・・ ４
比表面積・・・・・・２７（ｍ１１１２７ｇ）板状比Ｘ
比表面積・・１０８ （ｍｍｚ／ｇ）であるＢａ−フェ
ライｈ Ｉｆｆ性酸化鉄粉末を用い、他は実施例１と同
様の手法に従ってサンプルテープを作製した。Particle size as main magnetic powder: 0.09μm Plate ratio: 4 Specific surface area: 27 (m11127g) Plate ratio: X
A sample tape was prepared in the same manner as in Example 1 except for using Ba-ferrite iron oxide powder having a specific surface area of 108 (mmz/g).
得られたサンプルテープの磁気特性は、磁束密度８．１
７７０ガウス（Ｇａｕｓｓ）、磁性層の厚さ方向の角形
比Ｒ，０，６５であった。The magnetic properties of the sample tape obtained were as follows: magnetic flux density 8.1
770 Gauss, and the squareness ratio R in the thickness direction of the magnetic layer was 0.65.
大施■工
磁性粉末として
粒径・・・・・・・・ ０．１μｍ
板状比・・・・・・・ ６
比表面積・・・・・・ ３１ （ｍｍ”／ｇ）板状比Ｘ
比表面積・・ｌ ８６ （ｍｍｚ／ｇ）であるＢａ−フ
ェライト磁性酸化鉄粉末を用い、他は実施例１と同様の
手法に従ってサンプルテープを作製した。Particle size as large-scale magnetic powder: 0.1 μm Plate ratio: 6 Specific surface area: 31 (mm”/g) Plate ratio:
A sample tape was prepared in the same manner as in Example 1 except for using Ba-ferrite magnetic iron oxide powder having a specific surface area of l 86 (mmz/g).
得られたサンプルテープの磁気特性は、磁束密度８．１
６２０ガウス（Ｇａｕｓｓ） 、 ｉｆｆ性層の厚さ方
向の角形比Ｒ，０，８２であった。The magnetic properties of the sample tape obtained were as follows: magnetic flux density 8.1
620 Gauss, and the squareness ratio R in the thickness direction of the iff layer was 0.82.
災崖炎盈
磁性粉末として
粒径・・・・・・・・０．０４μｍ
板状比・・・・・・・ ３
比表面積・・・・・・ ５０（ｍｍ”／ｇ）板状比Ｘ比
表面積・・ｌ ５０ （ｍｍ”／ｇ）であるＢａ−フェ
ライト磁性酸化鉄粉末を用い、また配向処理は長手配向
とし、他は実施例１と同様の手法に従ってサンプルテー
プを作製した。Particle size as magnetic powder: 0.04 μm Plate ratio: 3 Specific surface area: 50 (mm”/g) Plate ratio: A sample tape was prepared in the same manner as in Example 1 except that Ba-ferrite magnetic iron oxide powder having a specific surface area of l 50 (mm"/g) was used, and the orientation treatment was performed in a longitudinal direction.
得られたサンプルテープの磁気特性は、磁束密度８．１
６８０ガウス（Ｇａｕｓｓ） 、 Ｔｉｔ性層の厚さ方
向の角形比Ｒ，０，４０であった。The magnetic properties of the sample tape obtained were as follows: magnetic flux density 8.1
680 Gauss, and the squareness ratio R in the thickness direction of the Tit layer was 0.40.
第十図は上記実施例３〜実施例５で作製された各サンプ
ルテープの再生出力の周波数特性を示すものである。な
お、測定方法は前述の方法に従った。FIG. 10 shows the frequency characteristics of the reproduction output of each sample tape produced in Examples 3 to 5 above. Note that the measurement method followed the method described above.
この第奄図から、実施例３で得られたサンプルテープは
短波長帯域から長波長帯域に亘って高い再生出力を示し
ているのに対して、磁性層の厚さ方向の角形比Ｒ３が０
．７５を越えた実施例４のサンプルテープでは、角形比
Ｒ１が高過ぎる為に長手方向の磁化が少なくなり、長波
長出力が若干低下することがわかった。また、実施例５
では、磁性層の厚さ方向の角形比Ｒ，が低過ぎるために
、垂直成分の磁化が減少する結果、短波長出力が低下す
ることが示されている。From this figure, it can be seen that the sample tape obtained in Example 3 shows high reproduction output from the short wavelength band to the long wavelength band, while the squareness ratio R3 in the thickness direction of the magnetic layer is 0.
．． It was found that in the sample tape of Example 4, which exceeded 75, because the squareness ratio R1 was too high, the magnetization in the longitudinal direction decreased, and the long wavelength output decreased slightly. In addition, Example 5
It has been shown that because the squareness ratio R in the thickness direction of the magnetic layer is too low, the perpendicular component magnetization decreases, resulting in a decrease in short wavelength output.
以上の説明からも明らかなように、本発明の磁気記録媒
体は、分散性に優れ、磁性層の飽和磁束密度が高く、垂
直配向度が適度であることから、短波長出力の向上と長
波長出力の向上を同時に可能とした磁気記録媒体であり
、高密度磁気記録用媒体としてその工業的価値は大であ
る。As is clear from the above explanation, the magnetic recording medium of the present invention has excellent dispersibility, a high saturation magnetic flux density of the magnetic layer, and a moderate degree of perpendicular orientation, so that it can improve short wavelength output and long wavelength output. It is a magnetic recording medium that simultaneously enables an improvement in output, and has great industrial value as a medium for high-density magnetic recording.
また、本発明の磁気記録媒体をビデオ信号やデジタルオ
ーディオ信号等の磁気転写媒体として使用すれば、広い
波長領域に亘って効率の良い転写が可能となり、画質や
音質等の品質の良好な磁気転写が可能となる。Furthermore, if the magnetic recording medium of the present invention is used as a magnetic transfer medium for video signals, digital audio signals, etc., efficient transfer over a wide wavelength range is possible, and magnetic transfer with good image quality, sound quality, etc. becomes possible.
第１図は板状比Ｘ比表面積と空隙率の関係を示す特性図
であり、第２図は板状比Ｘ比表面積と磁性層の飽和磁束
密度の関係を示す特性図である。
第３図は本発明で使用する六方晶系フェライト磁性粉末
の好適な範囲を示す特性図である。
第４図は本発明の実施例により作製されたサンプルテー
プの再生出力の周波数特性を比較例のそれと比べて示す
特性図であり、第奄図は垂直方向の角形比が再生出力の
周波数特性へ及ぼす影響を本発明の他の実施例を例にし
て示す特性図である。FIG. 1 is a characteristic diagram showing the relationship between plate ratio X specific surface area and porosity, and FIG. 2 is a characteristic diagram showing the relationship between plate ratio X specific surface area and saturation magnetic flux density of the magnetic layer. FIG. 3 is a characteristic diagram showing the preferred range of the hexagonal ferrite magnetic powder used in the present invention. FIG. 4 is a characteristic diagram showing the frequency characteristics of the playback output of a sample tape produced according to an example of the present invention in comparison with that of a comparative example. FIG. 4 is a characteristic diagram illustrating the influence exerted by using another embodiment of the present invention as an example.
Claims (1)
とを主成分とする磁性層が形成されてなる磁気記録媒体
において、 上記六方晶系フェライト磁性粉末は、平均粒径が０．０
３〜０．１μｍ、板状比が３〜５で、さらに比表面積と
板状比の積が２００ｍ＾２／ｇ以下であることを特徴と
する磁気記録媒体。[Scope of Claims] A magnetic recording medium in which a magnetic layer mainly composed of hexagonal ferrite magnetic powder and a binder is formed on a non-magnetic support, wherein the hexagonal ferrite magnetic powder has an average particle size. Diameter is 0.0
3 to 0.1 μm, a platelet ratio of 3 to 5, and a product of specific surface area and platelet ratio of 200 m^2/g or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61017439A JPH077499B2 (en) | 1986-01-29 | 1986-01-29 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61017439A JPH077499B2 (en) | 1986-01-29 | 1986-01-29 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62175930A true JPS62175930A (en) | 1987-08-01 |
| JPH077499B2 JPH077499B2 (en) | 1995-01-30 |
Family
ID=11944056
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61017439A Expired - Fee Related JPH077499B2 (en) | 1986-01-29 | 1986-01-29 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH077499B2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6069822A (en) * | 1983-08-19 | 1985-04-20 | Toshiba Corp | Magnetic recording medium |
| JPS60119625A (en) * | 1983-12-01 | 1985-06-27 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS60137002A (en) * | 1983-12-26 | 1985-07-20 | Toda Kogyo Corp | Manufacture of tabular ba ferrite fine particle powder for magnetic recording |
| JPS60161341A (en) * | 1984-01-27 | 1985-08-23 | Ube Ind Ltd | Preparation of hexagonal ferrite |
| JPS60223018A (en) * | 1984-04-18 | 1985-11-07 | Fuji Photo Film Co Ltd | Magnetic recording medium |
-
1986
- 1986-01-29 JP JP61017439A patent/JPH077499B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6069822A (en) * | 1983-08-19 | 1985-04-20 | Toshiba Corp | Magnetic recording medium |
| JPS60119625A (en) * | 1983-12-01 | 1985-06-27 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS60137002A (en) * | 1983-12-26 | 1985-07-20 | Toda Kogyo Corp | Manufacture of tabular ba ferrite fine particle powder for magnetic recording |
| JPS60161341A (en) * | 1984-01-27 | 1985-08-23 | Ube Ind Ltd | Preparation of hexagonal ferrite |
| JPS60223018A (en) * | 1984-04-18 | 1985-11-07 | Fuji Photo Film Co Ltd | Magnetic recording medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH077499B2 (en) | 1995-01-30 |
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| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |