JPH0479056B2 - - Google Patents
Info
- Publication number
- JPH0479056B2 JPH0479056B2 JP57128059A JP12805982A JPH0479056B2 JP H0479056 B2 JPH0479056 B2 JP H0479056B2 JP 57128059 A JP57128059 A JP 57128059A JP 12805982 A JP12805982 A JP 12805982A JP H0479056 B2 JPH0479056 B2 JP H0479056B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- carbon black
- magnetic layer
- sample
- parts
- 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
- 230000005291 magnetic effect Effects 0.000 claims description 28
- 239000006229 carbon black Substances 0.000 claims description 19
- 239000011164 primary particle Substances 0.000 claims description 5
- 239000000463 material Substances 0.000 claims 1
- 235000019241 carbon black Nutrition 0.000 description 17
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 10
- -1 fatty acid esters Chemical class 0.000 description 6
- 239000000696 magnetic material Substances 0.000 description 6
- 238000000034 method Methods 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
- 229910001566 austenite Inorganic materials 0.000 description 3
- 235000014113 dietary fatty acids Nutrition 0.000 description 3
- 239000000194 fatty acid Substances 0.000 description 3
- 229930195729 fatty acid Natural products 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 229910015189 FeOx Inorganic materials 0.000 description 2
- 229920000459 Nitrile rubber Polymers 0.000 description 2
- 239000000020 Nitrocellulose Substances 0.000 description 2
- 239000004952 Polyamide Substances 0.000 description 2
- 241000872198 Serjania polyphylla Species 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- DOIRQSBPFJWKBE-UHFFFAOYSA-N dibutyl phthalate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OCCCC DOIRQSBPFJWKBE-UHFFFAOYSA-N 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- 229920001220 nitrocellulos Polymers 0.000 description 2
- 229920002647 polyamide Polymers 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 229920001228 polyisocyanate Polymers 0.000 description 2
- 239000005056 polyisocyanate Substances 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- 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 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- 229910020630 Co Ni Inorganic materials 0.000 description 1
- 241000557626 Corvus corax Species 0.000 description 1
- 229910002440 Co–Ni Inorganic materials 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- BCKXLBQYZLBQEK-KVVVOXFISA-M Sodium oleate Chemical compound [Na+].CCCCCCCC\C=C/CCCCCCCC([O-])=O BCKXLBQYZLBQEK-KVVVOXFISA-M 0.000 description 1
- YSMRWXYRXBRSND-UHFFFAOYSA-N TOTP Chemical compound CC1=CC=CC=C1OP(=O)(OC=1C(=CC=CC=1)C)OC1=CC=CC=C1C YSMRWXYRXBRSND-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 229920002433 Vinyl chloride-vinyl acetate copolymer Polymers 0.000 description 1
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 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
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- AYOHIQLKSOJJQH-UHFFFAOYSA-N dibutyltin Chemical compound CCCC[Sn]CCCC AYOHIQLKSOJJQH-UHFFFAOYSA-N 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000000635 electron micrograph Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 150000002193 fatty amides Chemical class 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000002223 garnet Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- 239000000787 lecithin Substances 0.000 description 1
- 229940067606 lecithin Drugs 0.000 description 1
- 235000010445 lecithin Nutrition 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229940057995 liquid paraffin Drugs 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 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
- 238000001139 pH measurement Methods 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920003207 poly(ethylene-2,6-naphthalate) Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 239000011112 polyethylene naphthalate Substances 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920002545 silicone oil Polymers 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/708—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by addition of non-magnetic particles to the layer
Landscapes
- Magnetic Record Carriers (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
- Paints Or Removers (AREA)
Description
本発明は磁気記録体に関し、特に改良されたヘ
ツド磨耗性と耐久性を持つた磁気記録体に関す
る。
従来より帯電防止のために磁性層中にカーボン
ブラツクが添加されている。しかし、まだ充分な
カーボンブラツクは見出されていない。
磁気記録体はヘツドを磨耗させない様にするこ
と、即ちヘツド寿命を長くする様に設計されなけ
ればならない。同時に、磁性層の耐久性が大きい
ことも要求される。これらはオーデオテープより
もビデオテープ、メモリーテープの如き精密系テ
ープにおいて強く要求される。
それ故に、本発明の目的は優れたヘツド磨耗性
と耐久性を有する磁気記録体を提供するにある。
上記の特性を満足させるためには、磁性層へ添
加する研磨剤、バインダー組成、磁性体等、或い
は磁性層の表面成形条件を検討する方法がある
が、本発明者達は従来帯電防止用として使用され
ているカーボンブラツクを選択することにより上
記の目的が達成されることを見出した。即ち、本
発明は非磁性支持体とその上に設けられた磁性層
からなり、該磁性層は30mμより大きく且つ90mμ
未満の平均一次粒子サイズと、８より大きいPHと
を有するカーボンブラツクを含有する磁気記録体
に関する。
本発明において重要な点はカーボンブラツクの
平均一次粒子サイズが30mμより大きく、90mμよ
り小さいことであり、特に好ましくは35mμ〜
80mμである。粒子サイズが30mμより小さいと、
磁性層の耐久性が不充分となり、また90mμより
大きいと、ヘツド磨耗が大きくなる。本発明のも
う一つの重要な点はカーボンブラツクのPHが８よ
り大きく、特に好ましくは９又は９より大きいこ
とである。PHが８以下であると、磁性層の耐久性
が劣る。
本発明に使用できるカーボンブラツクとして
は、たとえば、コロンビアンカーボン製
「Raven430」、デグサ（Degussa）製
「Printex200」、「Printex Ｇ」、「Printex Ａ」等
がある。これらのカーボンブラツクは２種以上混
合して使用することができる。カーボンブラツク
の添加量は磁性体100重量部に対して１〜20重量
部、特に３〜15重量部である。添加量が余りに少
ないと帯電防止効果が減少し、余り多いと磁性体
の充填度が低下し、電磁変換特性が劣化する。
磁性体としては、γ−Fe2O3、FeOx（1.33＜ｘ
＜1.5）、CrO2、Co添加γ−Fe2O3、Co添加FeOx
（1.33＜ｘ＜1.5）、平板状バリウムフエライト、
Fe−Co−Ni合金粉末、Fe−Zn合金粉末など通常
の強磁性粉末が使用できる。これらの磁性体は単
独又は混合して使用できる。磁性体の形状は特に
制限されず、粒状、針状、紡錘状などがある。
バインダーとしては、塩化ビニル−酢酸ビニル
共重合体、セルロース誘導体（たとえば、ニトロ
セルロース）、ポリウレタン、ニトリル−ブタジ
エンゴム、スチレン−ブタジエンゴム、ポリエス
テル、ポリアミド、ポリイソシアネート等が使用
できる。
本発明の磁性層には、脂肪酸、脂肪酸エステ
ル、脂肪族アミド、ソルビタン脂肪酸エステル、
流動パラフイン、シリコンオイル、フツ素系オイ
ルの如き液状潤滑剤；Cr2O3、アルミナ、ガーネ
ツト、α−Fe2O3の如き研磨剤；レシチン、オレ
イン酸ナトリウムの如き分散剤；金属石けん、ジ
ブチルスズジカルボキシレートの如き安定剤；ジ
ブチルフタレート、トリクレジルホスフエートの
如き可塑剤；グラフアイト、MoS2の如き固体潤
滑剤などを含有させることができる。
磁性層が塗布される支持体としては、ポリエチ
レンテレフタレート、ポリエチレンナフタレー
ト、ポリアミド、ポリイミド、塩化ビニル系フイ
ルム等がある。支持体には必要によりバツク層が
塗布されてもよい。支持体の両面の平滑性は互に
変えることもできる。更に、支持体の片面（磁性
層と反対側の表面）に、磁性層塗布前又は後に、
潤滑剤又は界面活性剤を塗布することができる。
本発明の磁気記録体を製造するための組成、方
法等については特公昭56−26890号に記載されて
いる。
以下に本発明を実施例に従つて具体的に説明す
る。実施例中「部」は「重量部」を示す。
実施例 １
次の組成をボールミルで分散して磁性塗液を調
製し、15μ厚のポリエチレンテレフタレートフイ
ルムに乾燥厚で5μとなる様に塗布した。磁性層
の表面成形処理後、１／２吋中に裁断しVHS用
ビデオテープ（サンプルNo.１）を得た。
Co添加γ−Fe2O3 100部
カーボンブラツク ７部
Degussa製「Printex Ｇ」
平均一次粒子サイズ51mμ
PH8.5
オレイン酸 １部
ニトロセルロース 15部
ニトリルブタジエンゴム ７部
ポリイソシアネート ８部
α−Fe2O3 ５部
メチルエチルケトン 150部
トルエン 150部
比較例 １
実施例１のカーボンブラツクを下記のカーボン
ブラツクに代える以外は同様にしてサンプルNo.２
〜No.６を得た。
The present invention relates to a magnetic recording medium, and more particularly to a magnetic recording medium having improved head abrasion resistance and durability. Conventionally, carbon black has been added to magnetic layers to prevent static electricity. However, sufficient carbon black has not yet been found. Magnetic recording media must be designed to avoid head wear, ie, to prolong head life. At the same time, the magnetic layer is also required to have high durability. These requirements are more strongly required for precision tapes such as video tapes and memory tapes than for audio tapes. Therefore, an object of the present invention is to provide a magnetic recording medium having excellent head abrasion resistance and durability. In order to satisfy the above characteristics, there is a method of examining the abrasive added to the magnetic layer, the binder composition, the magnetic material, etc., or the surface forming conditions of the magnetic layer. It has been found that the above objectives are achieved by the selection of carbon black used. That is, the present invention consists of a non-magnetic support and a magnetic layer provided thereon, and the magnetic layer is larger than 30 mμ and 90 mμ.
The present invention relates to a magnetic recording medium containing carbon black having an average primary particle size of less than or equal to PH of greater than 8. An important point in the present invention is that the average primary particle size of carbon black is larger than 30 mμ and smaller than 90 mμ, particularly preferably 35 mμ to
It is 80mμ. If the particle size is smaller than 30mμ,
The durability of the magnetic layer will be insufficient, and if it is larger than 90 mμ, head wear will increase. Another important aspect of the invention is that the carbon black has a PH greater than 8, particularly preferably 9 or greater than 9. If the pH is 8 or less, the durability of the magnetic layer will be poor. Examples of carbon blacks that can be used in the present invention include "Raven 430" manufactured by Columbia Carbon, "Printex 200", "Printex G", and "Printex A" manufactured by Degussa. Two or more of these carbon blacks can be used in combination. The amount of carbon black added is 1 to 20 parts by weight, particularly 3 to 15 parts by weight, per 100 parts by weight of the magnetic material. If the amount added is too small, the antistatic effect will be reduced, and if the amount added is too large, the degree of filling of the magnetic material will decrease and the electromagnetic conversion characteristics will deteriorate. Examples of magnetic materials include γ-Fe 2 O 3 and FeOx (1.33<x
<1.5), CrO 2 , Co-added γ-Fe 2 O 3 , Co-added FeOx
(1.33<x<1.5), tabular barium ferrite,
Ordinary ferromagnetic powders such as Fe-Co-Ni alloy powder and Fe-Zn alloy powder can be used. These magnetic materials can be used alone or in combination. The shape of the magnetic material is not particularly limited, and may be granular, acicular, spindle, or the like. As the binder, vinyl chloride-vinyl acetate copolymer, cellulose derivative (for example, nitrocellulose), polyurethane, nitrile-butadiene rubber, styrene-butadiene rubber, polyester, polyamide, polyisocyanate, etc. can be used. The magnetic layer of the present invention includes fatty acids, fatty acid esters, fatty amides, sorbitan fatty acid esters,
Liquid lubricants such as liquid paraffin, silicone oil, and fluorine oil; Abrasives such as Cr 2 O 3 , alumina, garnet, and α-Fe 2 O 3 ; Dispersants such as lecithin and sodium oleate; Metallic soap, dibutyltin Stabilizers such as dicarboxylates; plasticizers such as dibutyl phthalate and tricresyl phosphate; solid lubricants such as graphite and MoS 2 can be included. Examples of the support to which the magnetic layer is applied include polyethylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and vinyl chloride films. A back layer may be applied to the support if necessary. The smoothness of both sides of the support can also be varied. Furthermore, on one side of the support (the surface opposite to the magnetic layer), before or after applying the magnetic layer,
A lubricant or surfactant can be applied. The composition, method, etc. for manufacturing the magnetic recording medium of the present invention are described in Japanese Patent Publication No. 56-26890. The present invention will be specifically explained below based on examples. In the examples, "parts" indicate "parts by weight." Example 1 A magnetic coating liquid was prepared by dispersing the following composition in a ball mill, and coated on a 15μ thick polyethylene terephthalate film to a dry thickness of 5μ. After the surface molding treatment of the magnetic layer, the tape was cut into 1/2 inch pieces to obtain a VHS videotape (sample No. 1). Co-added γ-Fe 2 O 3 100 parts Carbon black 7 parts "Printex G" manufactured by Degussa Average primary particle size 51 mμ PH8.5 Oleic acid 1 part Nitrocellulose 15 parts Nitrile butadiene rubber 7 parts Polyisocyanate 8 parts α-Fe 2 O 3 5 parts Methyl ethyl ketone 150 parts Toluene 150 parts Comparative Example 1 Sample No. 2 was prepared in the same manner except that the carbon black of Example 1 was replaced with the carbon black shown below.
~No.6 was obtained.
【表】
実施例 ２
実施例１に於てカーボンブラツクを
「Printex200」（デグサ製。サイズ56mμ、PH9.5）
に代える以外同様にしてサンプルNo.７を得た。
サンプルNo.１〜No.７の評価結果を第１表に示
す。[Table] Example 2 In Example 1, the carbon black was "Printex 200" (manufactured by Degussa. Size 56 mμ, PH 9.5)
Sample No. 7 was obtained in the same manner except that . The evaluation results for samples No. 1 to No. 7 are shown in Table 1.
【表】
本発明によるサンプルNo.１はVTRでの繰返し
100回走行でも何ら異常が認められず、またヘツ
ド磨耗量も100時間当り1.2μと少なく、良好な結
果を示している。
サンプルNo.１とほぼ同様のPHで粒子サイズの異
なるカーボンブラツクを用いたサンプルNo.２、No.
３、No.４をサンプルNo.１と比較すると、粒子サイ
ズが大きくなるとヘツド磨耗が増大し、一方小さ
くなると耐久性で劣ることがわかる。
また、サンプルNo.１で、ほぼ等しいサイズを持
つが、PHの異なるカーボンブラツクを用いたサン
プルNo.５、No.６をサンプルNo.１と比較すると、サ
ンプルNo.５、No.６は磁性層の平滑性に優れている
為、ヘツド磨耗が極めて少ない。一般にヘツド磨
耗量は少ない方がヘツド寿命を長くし、ヘツド交
換の手間を省き、かつコストダウンにつながるの
で好ましい。しかしながら、100時間当り1μ以下
となるような場合には、磁気テープによるヘツド
表面のクリーニング効果が不足し、ヘツド面の荒
れによりＳ／Ｎが劣化するので好ましくない。サ
ンプルNo.５、No.６は耐久性の点でもサンプルNo.１
より劣つている。
なお、耐久性はVHS方式のVTRに各サンプル
テープを走行させ、テープ鳴き、テープのはりつ
きの如き走行異常が発生する迄のくり返し走行回
数で表わした。また、ヘツド磨耗は100時間当り
のヘツド磨耗量を測定して表わした。
なお、カーボンブラツクのPHの測定はJIS
「K6221」又はこれに準ずる方法で行なうことが
出来る。
カーボンブラツクの平均一次粒子サイズは電子
顕微鏡写真からの算術的測定又はこれに準ずる方
法による直径である。[Table] Sample No. 1 according to the present invention is repeated on VTR
No abnormalities were observed even after 100 runs, and head wear was as low as 1.2 microns per 100 hours, indicating good results. Samples No. 2 and No. 2 used carbon black with approximately the same pH as Sample No. 1 but different particle sizes.
Comparing No. 3 and No. 4 with Sample No. 1, it can be seen that as the particle size increases, head wear increases, while as the particle size decreases, durability deteriorates. Also, when comparing Sample No. 1 with Sample No. 5 and No. 6, which have almost the same size but use carbon black with different PH, Sample No. 5 and No. 6 have magnetic properties. The layer has excellent smoothness, so head wear is extremely low. In general, it is preferable to have a smaller amount of wear on the head because it lengthens the life of the head, saves the effort of replacing the head, and leads to cost reduction. However, if it is less than 1μ per 100 hours, the effectiveness of cleaning the head surface by the magnetic tape will be insufficient and the S/N ratio will deteriorate due to roughness of the head surface, which is not preferable. Sample No. 5 and No. 6 are also sample No. 1 in terms of durability.
It is inferior. The durability was measured by running each sample tape on a VHS VTR and calculating the number of times the tape was run until abnormalities such as tape squealing and tape sticking occurred. Further, head wear was expressed by measuring the amount of head wear per 100 hours. In addition, the PH measurement of carbon black is based on JIS
This can be done using "K6221" or a method similar to this. The average primary particle size of carbon black is the diameter determined by an arithmetic measurement from an electron micrograph or a similar method.
Claims (1)
記録体に於て、該磁性層は、30mμより大きく
90mμより小さい平均一次粒子サイズであつてPH
が８より大きいカーボンブラツクを含有すること
を特徴とする磁気記録体。1. In a magnetic recording medium in which a magnetic layer is coated on a non-magnetic support, the magnetic layer is larger than 30 mμ.
Average primary particle size smaller than 90mμ and PH
A magnetic recording material characterized by containing carbon black having a carbon black of greater than 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57128059A JPS5919232A (en) | 1982-07-22 | 1982-07-22 | Magnetic recording body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57128059A JPS5919232A (en) | 1982-07-22 | 1982-07-22 | Magnetic recording body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5919232A JPS5919232A (en) | 1984-01-31 |
| JPH0479056B2 true JPH0479056B2 (en) | 1992-12-14 |
Family
ID=14975456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57128059A Granted JPS5919232A (en) | 1982-07-22 | 1982-07-22 | Magnetic recording body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5919232A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02122417A (en) * | 1988-10-31 | 1990-05-10 | Sony Corp | Magnetic recording medium |
| JP2869074B2 (en) * | 1988-10-31 | 1999-03-10 | ソニー株式会社 | Magnetic recording media |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5023605A (en) * | 1973-06-29 | 1975-03-13 | ||
| JPS5092101A (en) * | 1973-12-14 | 1975-07-23 | ||
| JPS5238201A (en) * | 1975-09-20 | 1977-03-24 | Hitachi Maxell Ltd | Magnetic recording body |
| JPS5275410A (en) * | 1975-12-20 | 1977-06-24 | Hitachi Maxell | Magnetic recording media |
| JPS5297710A (en) * | 1977-02-18 | 1977-08-16 | Hitachi Maxell | Magnetic recording material |
| JPS5297709A (en) * | 1977-02-18 | 1977-08-16 | Hitachi Maxell | Magnetic recording material |
| JPS53134407A (en) * | 1977-04-28 | 1978-11-24 | Hitachi Maxell | Magnetic recording medium |
| JPS57138037A (en) * | 1981-02-18 | 1982-08-26 | Hitachi Maxell Ltd | Manufacture for magnetic recording medium |
| JPS5864633A (en) * | 1981-10-13 | 1983-04-18 | Hitachi Maxell Ltd | Magnetic recording medium |
-
1982
- 1982-07-22 JP JP57128059A patent/JPS5919232A/en active Granted
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5023605A (en) * | 1973-06-29 | 1975-03-13 | ||
| JPS5092101A (en) * | 1973-12-14 | 1975-07-23 | ||
| JPS5238201A (en) * | 1975-09-20 | 1977-03-24 | Hitachi Maxell Ltd | Magnetic recording body |
| JPS5275410A (en) * | 1975-12-20 | 1977-06-24 | Hitachi Maxell | Magnetic recording media |
| JPS5297710A (en) * | 1977-02-18 | 1977-08-16 | Hitachi Maxell | Magnetic recording material |
| JPS5297709A (en) * | 1977-02-18 | 1977-08-16 | Hitachi Maxell | Magnetic recording material |
| JPS53134407A (en) * | 1977-04-28 | 1978-11-24 | Hitachi Maxell | Magnetic recording medium |
| JPS57138037A (en) * | 1981-02-18 | 1982-08-26 | Hitachi Maxell Ltd | Manufacture for magnetic recording medium |
| JPS5864633A (en) * | 1981-10-13 | 1983-04-18 | Hitachi Maxell Ltd | Magnetic recording medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5919232A (en) | 1984-01-31 |
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