JPS62180523A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPS62180523A JPS62180523A JP61021151A JP2115186A JPS62180523A JP S62180523 A JPS62180523 A JP S62180523A JP 61021151 A JP61021151 A JP 61021151A JP 2115186 A JP2115186 A JP 2115186A JP S62180523 A JPS62180523 A JP S62180523A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic film
- carbon black
- contg
- coating type
- 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
- 239000006247 magnetic powder Substances 0.000 claims abstract description 18
- 239000006229 carbon black Substances 0.000 claims abstract description 17
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 12
- 230000035699 permeability Effects 0.000 claims abstract description 8
- 239000011248 coating agent Substances 0.000 abstract description 9
- 238000000576 coating method Methods 0.000 abstract description 9
- 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 abstract description 4
- 229910000889 permalloy Inorganic materials 0.000 abstract description 4
- 230000003746 surface roughness Effects 0.000 abstract description 4
- 229910017518 Cu Zn Inorganic materials 0.000 abstract description 2
- 229910017752 Cu-Zn Inorganic materials 0.000 abstract description 2
- 229910017943 Cu—Zn Inorganic materials 0.000 abstract description 2
- TVZPLCNGKSPOJA-UHFFFAOYSA-N copper zinc Chemical compound [Cu].[Zn] TVZPLCNGKSPOJA-UHFFFAOYSA-N 0.000 abstract description 2
- 229910000702 sendust Inorganic materials 0.000 abstract description 2
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 239000003973 paint Substances 0.000 description 5
- 239000004814 polyurethane Substances 0.000 description 4
- 229920002635 polyurethane Polymers 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- IIZPXYDJLKNOIY-JXPKJXOSSA-N 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine Chemical compound CCCCCCCCCCCCCCCC(=O)OC[C@H](COP([O-])(=O)OCC[N+](C)(C)C)OC(=O)CCC\C=C/C\C=C/C\C=C/C\C=C/CCCCC IIZPXYDJLKNOIY-JXPKJXOSSA-N 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 229940067606 lecithin Drugs 0.000 description 2
- 235000010445 lecithin Nutrition 0.000 description 2
- 239000000787 lecithin Substances 0.000 description 2
- 230000005415 magnetization Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000012046 mixed solvent Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000011282 treatment Methods 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 229920001228 polyisocyanate Polymers 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Abstract
Description
本発明は、例えば磁気テープ又は磁気ディスク等の磁気
記録媒体に関するものである。The present invention relates to a magnetic recording medium such as a magnetic tape or a magnetic disk.
近年、高密度記録の観点から、支持体面上に、市内方向
に磁化容易軸を有するγ−フェライト等の磁性粉を３む
第１の磁性膜を設け、この第１の磁性股上にバリウムフ
ェライト磁性粉を含む第２の磁性膜を設けた２７Ｉ２１
型の垂直磁気記録媒体が提案されている。
このような磁気記録媒体は、単に面内方向に磁化容易軸
を有する第１の磁性膜しか有さない磁気記録媒体よりも
高密度記録に優れている大きな特長を有しているものの
、表面電気抵抗が高く、走行性が悪い欠点があると指摘
されている。
そこで、このような欠点を解決する為に、前記２層型の
垂直磁気記録媒体において、第１の磁性膜を、例えばγ
−フェライト、ＣＯＷ換γ−フェライト又は酸化クロム
等の磁性粉とカーボンブラックとを含む塗布型の磁性膜
で構成することが提案（特開昭５８−２０５９２８号公
報）されている。
しかし、この提案になる磁気記録媒体よりも、さらに高
密度記録を行なう時の電磁変換特性の点においては、未
だ不満足なものであり、さらなる開発研究が望まれてい
る。In recent years, from the viewpoint of high-density recording, a first magnetic film containing magnetic powder such as γ-ferrite having an axis of easy magnetization in the inner direction is provided on the support surface, and barium ferrite is coated on this first magnetic film. 27I21 provided with a second magnetic film containing magnetic powder
A type of perpendicular magnetic recording medium has been proposed. Although such magnetic recording media have the great advantage of being superior to high-density recording than magnetic recording media that simply have a first magnetic film with an axis of easy magnetization in the in-plane direction, surface electrical It has been pointed out that it has high resistance and poor running performance. Therefore, in order to solve such drawbacks, in the two-layer perpendicular magnetic recording medium, the first magnetic film is made of, for example, γ.
- It has been proposed (Japanese Unexamined Patent Publication No. 58-205928) to constitute a coated magnetic film containing magnetic powder such as ferrite, COW-converted γ-ferrite, or chromium oxide and carbon black. However, the proposed magnetic recording medium is still unsatisfactory in terms of electromagnetic conversion characteristics when performing higher density recording, and further research and development is desired.
本発明者は、前記の要望に沿った研究を押し進めた結果
、２層型の垂直磁気記録媒体において、第１の塗布型磁
性膜（以下、第１の磁性膜と称す）を、例えばパーマロ
イ、センダスト、Ｍｎ−Ｚｎフェライト、Ｃｕ−Ｚｎフ
ェライト等の高透磁率磁性粉と、カーボブラックとを含
む塗布型の磁性膜で構成し、かつ、第２の塗布型磁性膜
（以下、第２の磁性膜と称す）を、バリウムフェライト
等の六方晶外フェライト磁性粉を含み、カーボンブラッ
クを実質上含まない塗布型の磁性膜で構成した磁気記録
媒体は、記録密度、再生出力、オーバーライド特性、表
面電気抵抗、表面粗さ等の特性に極めて優れたものであ
ることを見い出した。
尚、第１の磁性膜におけるカーボンブラックの量は、高
透磁率磁性粉１００重量部に対して約１〜１５重量部程
度含まれることが望ましく、そしてこのカーボブラック
させる為には第２の磁性膜の厚みが約３μ−以下の程度
であることが望ましい。As a result of conducting research in line with the above-mentioned demands, the present inventors have discovered that, in a two-layer perpendicular magnetic recording medium, the first coated magnetic film (hereinafter referred to as the first magnetic film) is made of permalloy, for example. It consists of a coated magnetic film containing high permeability magnetic powder such as sendust, Mn-Zn ferrite, Cu-Zn ferrite, and carbo black, and a second coated magnetic film (hereinafter referred to as second magnetic film). A magnetic recording medium composed of a coating-type magnetic film containing hexagonal extraferrite magnetic powder such as barium ferrite and substantially free of carbon black has various characteristics such as recording density, reproduction output, override characteristics, and surface electricity. It has been found that it has extremely excellent properties such as resistance and surface roughness. The amount of carbon black in the first magnetic film is preferably about 1 to 15 parts by weight per 100 parts by weight of the high magnetic permeability magnetic powder. Desirably, the thickness of the membrane is on the order of about 3 microns or less.
【実施例１】
パーマロイ微粉末１００重量部、塩化ビニル−ビニルア
ルコール共重合体とポリウレタンとの混合物２０重量部
、カーボンブラック１０重量部、レシチン１重量部、ト
ルエンとメチルエチルケトンとの等量混合溶剤３００重
量部を、ボールミルで約５時間混線分散し、これにポリ
イソシアネート（日本ポリウレタン工業（株）製のコロ
ネートＬ）５重量部を加え、この第１の磁性塗料を約７
５μｍ厚のポリエステルフィルム等の非磁性支持体面上
にコーター機で約２μｍ厚塗布し、乾燥して第１の磁性
膜を構成した後、バリウムフェライト磁性粉１００重量
部、塩化ビニル−ビニルアルコール共重合体とポリウレ
タンとの混合物２０重量部、レシチン１重量部、アルミ
ナ粉末５重量部、潤滑剤３重量部、トルエンとメチルエ
チルケトンとの等量混合溶剤２００重量部を、ボールミ
ルで約２０時間混線分散し、これにコロネートし５重量
部を加え、この第２の磁性塗料を第１の磁性股上にコー
ター機で約２μ鏑厚塗布し、乾燥して第２の磁性膜を構
成する。
その後、表面処理、硬化処理といった通常の処理を行な
った後、５．２５インチの径で打ち抜いて研磨し、フロ
ッピーディスク等の磁気記録媒体を得る。[Example 1] 100 parts by weight of permalloy fine powder, 20 parts by weight of a mixture of vinyl chloride-vinyl alcohol copolymer and polyurethane, 10 parts by weight of carbon black, 1 part by weight of lecithin, 300 parts by weight of a mixed solvent of equal amounts of toluene and methyl ethyl ketone. Part by weight was mixed and dispersed in a ball mill for about 5 hours, and 5 parts by weight of polyisocyanate (Coronate L manufactured by Nippon Polyurethane Industries Co., Ltd.) was added to this, and this first magnetic paint was dispersed for about 7 hours.
After coating the surface of a non-magnetic support such as a 5-μm-thick polyester film to a thickness of about 2 μm using a coater machine and drying it to form a first magnetic film, 100 parts by weight of barium ferrite magnetic powder and vinyl chloride-vinyl alcohol copolymer were added. 20 parts by weight of a mixture of polyurethane and polyurethane, 1 part by weight of lecithin, 5 parts by weight of alumina powder, 3 parts by weight of a lubricant, and 200 parts by weight of a mixed solvent of equal amounts of toluene and methyl ethyl ketone were mixed and dispersed in a ball mill for about 20 hours. 5 parts by weight of coronate is added to this, and this second magnetic paint is coated on the first magnetic crotch to a thickness of about 2 μm using a coater, and dried to form a second magnetic film. Thereafter, after performing normal treatments such as surface treatment and hardening treatment, it is punched out to a diameter of 5.25 inches and polished to obtain a magnetic recording medium such as a floppy disk.
【比較例１】
実施例１において、第１の磁性塗料におけるパーマロイ
微粉末をγ−フェライトに代えて同様に行ない、磁気記
録媒体を得る。Comparative Example 1 The same procedure as in Example 1 was carried out except that the permalloy fine powder in the first magnetic paint was replaced with γ-ferrite to obtain a magnetic recording medium.
【比較例２】
実施例１において、第１の磁性塗料中にはカーボンブラ
ックを添加しないで同様に、かつ、第２の磁性塗料中に
カーボンブラック１０重量部を添加して同様に行ない、
磁気記録媒体を得る。[Comparative Example 2] The same procedure as in Example 1 was carried out without adding carbon black to the first magnetic paint, and by adding 10 parts by weight of carbon black to the second magnetic paint.
Obtain a magnetic recording medium.
【比較例３】
実施例１において、第１の磁性膜を構成せず、カーボン
ブラック１０重量部をさらに第２の磁性塗料中に添加し
たものを用いて４μ冑厚の磁性膜を構成し、同様に行な
って磁気記録媒体を得る。[Comparative Example 3] In Example 1, the first magnetic film was not formed, but a 4μ thick magnetic film was formed using a second magnetic coating material in which 10 parts by weight of carbon black was further added, A magnetic recording medium is obtained in the same manner.
上記各間で得た磁気記録媒体について、−６ｄＢ時の記
録密度り、。、記録密度が３５ＫＦＲＰＩの時の相対出
力、ｌ０ＫＦＲＰＩ信号書き込み後、２０ＫＦＲＰＩ信
号を書き込み、その時のｌ０ＫＦＲＰＩ信号の残留信号
比（オーバーライド）、表面電気抵抗、表面粗さＲａ等
の特性を調べたので、これらを表に示す。
この表かられかるように、本実施例の磁気記録媒体は、
ｎｓｏ及び相対出力のデータ４゛られかるように電磁変
ｔＡ持性の良いものであり、特に、２層型の垂直磁気記
録媒体における第１の磁性膜を構成する磁性粉が高透磁
率磁性粉であるから、この第１の磁性膜による閉磁路化
によって記録効率が向上しており、しかも、第２の磁性
膜中にはカーボンブラックが含まれていないので出力の
向上は大きく、かつ表面性が大巾に良くなっている。
特に、第１の磁性膜は、カーボンブラックと高透磁率磁
性粉との相乗作用により、表面電気抵抗は小さなもので
あり、又、光透過率は極めて小さなものとなる。For the magnetic recording media obtained between the above, the recording density at -6 dB is as follows. , the relative output when the recording density is 35KFRPI, after writing the 10KFRPI signal, writing the 20KFRPI signal, and examining the characteristics such as the residual signal ratio (override) of the 10KFRPI signal, surface electrical resistance, and surface roughness Ra, etc. are shown in the table. As can be seen from this table, the magnetic recording medium of this example is:
As shown in the nso and relative output data 4, it has a good electromagnetic variation tA property, and in particular, the magnetic powder constituting the first magnetic film in a two-layer perpendicular magnetic recording medium is a high permeability magnetic powder. Therefore, the recording efficiency is improved by creating a closed magnetic circuit with the first magnetic film, and since the second magnetic film does not contain carbon black, the output is greatly improved, and the surface property is also improved. has greatly improved. In particular, the first magnetic film has a small surface electrical resistance and extremely low light transmittance due to the synergistic effect of carbon black and high permeability magnetic powder.
本発明に係る磁気記録媒体は、支持体面上に高透磁率磁
性粉とカーボンブラックとを含む第１の塗布型磁性膜を
設け、この第１の塗布型磁性膜上に六方晶爪フェライト
磁性粉を含みカーボンブラックを実質上音まない第２の
塗布型磁性膜を設けたので、記録効率及び再生出力が良
いものであり、かつ表面電気抵抗が小さく、しかも表面
粗さも小さなものであって走行生が良く、さらには塗布
型のものであるから生産性よく低コストで提供できる等
の特徴を有する。The magnetic recording medium according to the present invention includes a first coated magnetic film containing high magnetic permeability magnetic powder and carbon black on a support surface, and a hexagonal nail ferrite magnetic powder coated on the first coated magnetic film. Since a second coated magnetic film is provided that contains carbon black and makes virtually no noise, it has good recording efficiency and playback output, has low surface electrical resistance, and has low surface roughness, making it easy to run. It has the characteristics of being easy to use, and since it is a coating type, it can be provided with high productivity and at low cost.
Claims (1)
む第１の塗布型磁性膜を設け、この第１の塗布型磁性膜
上に六方晶系フェライト磁性粉を含み、カーボンブラッ
クを実質上含まない第２の塗布型磁性膜を設けたことを
特徴とする磁気記録媒体。A first coated magnetic film containing high magnetic permeability magnetic powder and carbon black is provided on the support surface, and the first coated magnetic film contains hexagonal ferrite magnetic powder and substantially contains carbon black. A magnetic recording medium characterized in that a second coated magnetic film is provided.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61021151A JPH0640381B2 (en) | 1986-02-04 | 1986-02-04 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61021151A JPH0640381B2 (en) | 1986-02-04 | 1986-02-04 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62180523A true JPS62180523A (en) | 1987-08-07 |
| JPH0640381B2 JPH0640381B2 (en) | 1994-05-25 |
Family
ID=12046908
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61021151A Expired - Lifetime JPH0640381B2 (en) | 1986-02-04 | 1986-02-04 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0640381B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02158913A (en) * | 1988-12-12 | 1990-06-19 | Konica Corp | Magnetic recording medium |
-
1986
- 1986-02-04 JP JP61021151A patent/JPH0640381B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02158913A (en) * | 1988-12-12 | 1990-06-19 | Konica Corp | Magnetic recording medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0640381B2 (en) | 1994-05-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |