JPH0479063B2 - - Google Patents
Info
- Publication number
- JPH0479063B2 JPH0479063B2 JP58075398A JP7539883A JPH0479063B2 JP H0479063 B2 JPH0479063 B2 JP H0479063B2 JP 58075398 A JP58075398 A JP 58075398A JP 7539883 A JP7539883 A JP 7539883A JP H0479063 B2 JPH0479063 B2 JP H0479063B2
- Authority
- JP
- Japan
- Prior art keywords
- parts
- magnetic
- silicone oil
- support
- sample
- 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 25
- 229920002545 silicone oil Polymers 0.000 claims description 15
- 239000000696 magnetic material Substances 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 229910001566 austenite Inorganic materials 0.000 description 5
- -1 1.33<x<1.50) Inorganic materials 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 229920001577 copolymer Polymers 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 229920001296 polysiloxane Polymers 0.000 description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
- 229910015189 FeOx Inorganic materials 0.000 description 2
- 229910018104 Ni-P Inorganic materials 0.000 description 2
- 229910018536 Ni—P Inorganic materials 0.000 description 2
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 230000005294 ferromagnetic effect Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920005749 polyurethane resin Polymers 0.000 description 2
- 239000000843 powder 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
- QMMJWQMCMRUYTG-UHFFFAOYSA-N 1,2,4,5-tetrachloro-3-(trifluoromethyl)benzene Chemical compound FC(F)(F)C1=C(Cl)C(Cl)=CC(Cl)=C1Cl QMMJWQMCMRUYTG-UHFFFAOYSA-N 0.000 description 1
- TWJNQYPJQDRXPH-UHFFFAOYSA-N 2-cyanobenzohydrazide Chemical compound NNC(=O)C1=CC=CC=C1C#N TWJNQYPJQDRXPH-UHFFFAOYSA-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
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 229910000521 B alloy Inorganic materials 0.000 description 1
- 229920001747 Cellulose diacetate Polymers 0.000 description 1
- 229920002284 Cellulose triacetate Polymers 0.000 description 1
- 235000021360 Myristic acid Nutrition 0.000 description 1
- TUNFSRHWOTWDNC-UHFFFAOYSA-N Myristic acid Natural products CCCCCCCCCCCCCC(O)=O TUNFSRHWOTWDNC-UHFFFAOYSA-N 0.000 description 1
- 229910017709 Ni Co Inorganic materials 0.000 description 1
- 229910003267 Ni-Co Inorganic materials 0.000 description 1
- 229910003271 Ni-Fe Inorganic materials 0.000 description 1
- 229910003262 Ni‐Co Inorganic materials 0.000 description 1
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- NNLVGZFZQQXQNW-ADJNRHBOSA-N [(2r,3r,4s,5r,6s)-4,5-diacetyloxy-3-[(2s,3r,4s,5r,6r)-3,4,5-triacetyloxy-6-(acetyloxymethyl)oxan-2-yl]oxy-6-[(2r,3r,4s,5r,6s)-4,5,6-triacetyloxy-2-(acetyloxymethyl)oxan-3-yl]oxyoxan-2-yl]methyl acetate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](OC(C)=O)[C@H]1OC(C)=O)O[C@H]1[C@@H]([C@@H](OC(C)=O)[C@H](OC(C)=O)[C@@H](COC(C)=O)O1)OC(C)=O)COC(=O)C)[C@@H]1[C@@H](COC(C)=O)O[C@@H](OC(C)=O)[C@H](OC(C)=O)[C@H]1OC(C)=O NNLVGZFZQQXQNW-ADJNRHBOSA-N 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 239000004205 dimethyl polysiloxane Substances 0.000 description 1
- 235000013870 dimethyl polysiloxane Nutrition 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 229910052571 earthenware Inorganic materials 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 150000004665 fatty acids Chemical group 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- 125000006353 oxyethylene group Chemical group 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920001228 polyisocyanate Polymers 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 238000010186 staining Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 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
- G11B5/7085—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 non-magnetic abrasive particles
Landscapes
- Magnetic Record Carriers (AREA)
- Paints Or Removers (AREA)
Description
本発明は磁気記録体に関し、その主たる目的は
磁気記録体のヘツド摩耗及び耐久性の優れた磁気
記録体に関する。
近年小型ビデオテープレコーダーが著しく普及
し、それに伴ないビデオテープの特性をさらに改
良する要求がある。
この特性の一つはヘツド摩耗量の減少であり、
ヘツド交換頻度を減少することにより、維持費を
低減させることである。他の一つは耐久性の向上
である。
従来磁性層に潤滑性を与えるためシリコーンオ
イルを添加することは知られていた（例えば
USP2654681号明細書）が、ヘツド摩耗及び耐久
性を同時に改良することは出来なかつた。また各
種変性シリコーンについての方法も提案されてい
るが、同様に十分な改良は出来なかつた（例えば
特開昭57−103125号、特開昭57−37724号）。
シリコーンオイルを添加すると潤滑性を付与す
る効果がありヘツド磨耗はある程度低減される
が、まだ十分ではない。また通常磁気記録体に使
用されているバインダーと親和性が悪いので磁性
層表面にのみ浮き出す欠点があり、ヘツドを汚し
特にビデオヘツドの場合目詰りを発生せしめ画面
が消失する場合がある。
また耐久性を向上させる手段として、研磨剤を
磁性層に入れることが知られているが、ヘツド磨
耗量を増大させてしまうという欠点を有する。
本発明の第１の目的はヘツド摩耗を改良した磁
気記録体の提供にある。第２の目的は耐久性を改
良した磁気記録体の提供にある。
すなわち本発明の目的は非磁性支持体上に磁性
層を設けて成る磁気記録体に於て、該磁性層が(1)
シリコーンオイル、(2)モース硬度６以上の研磨剤
及び(3)BET比表面積30m2／ｇ以上の磁性体を含
み、かつ該支持体のRaが0.035μ以下であること
を特徴とする磁気記録体により達成される。
本発明に使用するシリコーンオイルは液状、粘
稠液体、ろう状固形のいずれでも使用する事が出
来、必要に応じて組合せて使用する事も可能であ
る。好ましくは融点が40℃以下のシリコーンオイ
ルでより好ましくは20℃以下のシリコーンオイル
である。常温に於て液体であり25℃での粘度が１
万センチストークス（以下CSという）以下のシ
リコンオイルは本発明の効果をよりよく発揮す
る。
例えばジメチルポリシロキサン、ジフエニルポ
リシロキサン等の他、脂肪酸（例えばミリスチン
酸）やオキシエチレンによる変性シリコーン、エ
ポキシ変性シリコーンなど磁気テープに於て、従
来公知のシリコーンオイルが使用出来る。例えば
特公昭49−14249号、特公昭56−20611号、特公昭
56−26890号、特公昭52−34923号、特公昭56−
71824号、特開昭57−12414号、等に示されるシリ
コンオイルがあげられる。
シリコーンオイルは少量添加することにより効
果があり、磁性体100重量部に対し0.005〜５重量
部が好ましく、より好ましくは0.01〜重量部、一
層好ましい範囲は0.05〜0.5重量部である。
本発明に使用される研磨剤としてはモース硬度
が６以上であればよく、例としては、SiC、α−
Al2O3、Cr2O3、MgO等がある。粒子サイズとし
ては0.05〜5μ、好ましくは0.1〜2μがよい。磁性
体100重量部に対し１〜20重量部添加するのが好
ましい。
本発明に使用する強磁性微粉末としては、粒子
サイズがチツ素ガスによるブルナウアー、エミツ
ト・テーラー（以下BET）比表面積が30m2／ｇ
以上である事が必要である。これより小さいと磁
性層表面の平滑度が劣り、ヘツド磨耗が増大す
る。またシリコーンオイルの磁性層内保持力が小
となり耐久性の点で劣る。
使用される磁性体としては
γ−Fe2O3、Co含有のγ−Fe2O3、Fe3O4、Co
含有のFe3O4、γ−Fe2O3とFe3O4のベルトライ
ド化合物（FeOx、1.33＜ｘ＜1.50）、Co含有のγ
−Fe2O3とFe3O4のベルトライド化合物（FeOx、
1.33＜ｘ＜1.50）、CrO2、平板状Baフエライト、
Co−Ni−Ｐ合金、Co−Ni−Fe合金、Co−Ni−
Fe−Ｂ合金、Fe−Ni−Zn合金、Fe−Mn−Zn合
金、Fe−Co−Ni−Ｐ合金、Ni−Co合金等、公
知の強磁性微粉末が使用できる。
本発明に用いられる支持体の磁性層塗設側の表
面平滑性は中心線平均粗さ（Raという）が
0.035μ以下（cut off0.25mm、触針半径2μR、触針
スピード0.3mm／sec）である事が必要であり、
0.030μ以下がより好ましく、0.02μ以下がより一
層好ましい。これより粗いとヘツド磨耗が大とな
り、ビデオＳ／Ｎ（特にカラー信号）が劣化する。
支持体は素材としてはポリエチレンテレフタレ
ート、ポリエチレン−２，６−ナフタレート等の
ポリエステル類、ポリプロピレン等のポリオレフ
イン類、セルローストリアセテート、セルロース
ダイアセテート等のセルロース誘導体、ポリカー
ボネートなどのプラスチツク、Cu，Al，Znなど
の非磁性金属、ガラス、磁器、陶器等のセラミツ
クなどが使用される。
支持体厚味は2.5〜100μ、好ましくは３〜40μ程
度がよい。
磁性層に含有されるバインダー、分散剤、可塑
剤、安定剤、潤滑剤について、また製法について
は従来公知技術が使用出来、たとえば特公昭56−
26890号に記されている。
以下に本発明を実施例により詳細に説明する。
実施例中「部」は「重量部」を示す。
実施例 １
次の組成物をボールミルで分散した後「デスモ
ジユールＬ−75」（バイエル社製ポリイソシアネ
ート）35部を加え、磁性塗料とした。これを15μ
厚のポリエステルフイルム上に塗布し、磁気テー
プ（サンプルNo.１）を作製した。支持体Raは
0.030μのものを用いた。
Co添加γ−Fe2O3（BET比表面積35m2／ｇ）
300部
シリコーンオイル（ポリジメチルシロキサ1000
CS） １部
研磨剤（Cr2O3、モース硬度8.5、粒子サイズ
0.5μ） 15部
塩化ビニル・酢酸ビニル共重合体（−OH基含
有） 40部
ポリウレタン樹脂 30部
カーボンブラツク 10部
シクロヘキサノン 250部
メチルエチルケトン 250部
比較例 １
実施例１に於てシリコーンオイルを除去したサ
ンプル（No.２）、Cr2O3のかわりに
α−Fe2O3（モース硬度5.5）を用いたサンプル
（No.３）、磁性体をBET比表面積20m2／ｇのもの
に変更したサンプル（No.４）、支持体をRa0.040μ
のものに変更したサンプル（No.５）を作製した。
実施例 ２
実施例１にてCr2O3のかわりにMgO（モース硬
度６）を用いたサンプル（No.６）、磁性体をBET
比表面積30m2／ｇのものに変更したサンプル（No.
７）、支持体をRa0.035μのものに変更したサンプ
ル（No.８）を作製した。
実施例 ３
実施例１における「デスモジユールＬ」以外の
組成を以下に変更したサンプルNo.９を作製した。
但し支持体はRa0.020μのものを用いた。
Co添加γ−Fe2O3（BET比表面積400m2／ｇ）
300部
シリコーンオイルポリジメチルポリシロキサン
10000 CS １部
研磨剤（α−Al2O3、モース硬度９、粒子サイ
ズ0.3μ） 15部
塩化ビニル・酢酸ビニル共重合体（カルボキシ
ル基含有） 45部
ニトリルブタジエン共重合体 ５部
ポリウレタン樹脂 20部
カーボンブラツク 15部
ブチルステアレート １部
オレイン酸 １部
メチルエチルケトン 400部
トルエン 150部
サンプルNo.１〜No.９の評価結果を第１表に示
す。
評価方法の概略は以下の通り。
１／２吋幅にスリツトしたビデオテープをビデ
オカセツトに組込み、VHS方式ビデオテープレ
コーダー（以下VTR）にて繰返し走行させた。
40℃にて100時間走行させた時のヘツドの磨耗量
を〔μ／100h〕単位にて表わし、ヘツド磨耗と
した。
また40℃にて500時間走行させた後のドロツプ
アウト数が、第１回走行時のドロツプアウトに対
し何倍に増加しているかの比率をもつて耐久性と
した。
本発明による実施例１サンプルNo.１は比較例１
サンプルNo.２〜No.５と比較してヘツド磨耗及び耐
久性共に優れており、シリコーンオイル、BET
比表面積30m2／ｇ以上の磁性体、モース硬度６以
上の研磨剤、Ra0.035μ以下の支持体を組合せる
と本効果が認められる。
The present invention relates to a magnetic recording medium, and its main object is to a magnetic recording medium that has excellent head wear and durability. In recent years, small-sized video tape recorders have become extremely popular, and as a result there is a demand for further improvements in the characteristics of video tapes. One of these characteristics is a reduction in head wear,
The objective is to reduce maintenance costs by reducing the frequency of head replacement. Another reason is improved durability. It was previously known to add silicone oil to provide lubricity to the magnetic layer (for example,
No. 2,654,681), it was not possible to simultaneously improve head wear and durability. Also, methods for various modified silicones have been proposed, but similar improvements have not been achieved sufficiently (for example, JP-A-57-103125 and JP-A-57-37724). Adding silicone oil has the effect of imparting lubricity and reduces head wear to some extent, but it is still not sufficient. Furthermore, since it has poor affinity with the binder normally used in magnetic recording media, it has the disadvantage that it stands out only on the surface of the magnetic layer, staining the head and, especially in video heads, causing clogging and causing the screen to disappear. Furthermore, it is known that abrasives are added to the magnetic layer as a means of improving durability, but this has the drawback of increasing the amount of head wear. A first object of the present invention is to provide a magnetic recording medium with improved head wear. The second object is to provide a magnetic recording medium with improved durability. That is, the object of the present invention is to provide a magnetic recording body comprising a magnetic layer on a non-magnetic support, in which the magnetic layer has (1)
Magnetic recording comprising silicone oil, (2) an abrasive with a Mohs hardness of 6 or more, and (3) a magnetic material with a BET specific surface area of 30 m 2 /g or more, and the Ra of the support is 0.035 μ or less. Accomplished by the body. The silicone oil used in the present invention can be used in any of liquid, viscous liquid, and waxy solid forms, and can be used in combination as necessary. Preferably, the silicone oil has a melting point of 40°C or lower, more preferably 20°C or lower. It is liquid at room temperature and has a viscosity of 1 at 25℃.
Silicone oil having a concentration of less than 10,000 centistokes (hereinafter referred to as CS) exhibits the effects of the present invention better. For example, in addition to dimethylpolysiloxane, diphenylpolysiloxane, etc., conventionally known silicone oils can be used in magnetic tapes, such as silicones modified with fatty acids (eg, myristic acid), oxyethylene, and epoxy-modified silicones. For example, Special Publication No. 49-14249, Special Publication No. 56-20611, Special Publication No.
No. 56-26890, Special Publication No. 52-34923, Special Publication No. 56-
Examples include silicone oils disclosed in No. 71824, JP-A-57-12414, and the like. Adding a small amount of silicone oil is effective, and the amount is preferably 0.005 to 5 parts by weight, more preferably 0.01 to 0.5 parts by weight, and even more preferably 0.05 to 0.5 parts by weight based on 100 parts by weight of the magnetic material. The abrasive used in the present invention may have a Mohs hardness of 6 or more, and examples thereof include SiC, α-
Examples include Al 2 O 3 , Cr 2 O 3 and MgO. The particle size is preferably 0.05 to 5μ, preferably 0.1 to 2μ. It is preferable to add 1 to 20 parts by weight per 100 parts by weight of the magnetic material. The ferromagnetic fine powder used in the present invention has a Brunauer-Emmitt-Taylor (hereinafter BET) specific surface area of 30 m 2 /g due to particle size of nitrogen gas.
It is necessary that it is above. If it is smaller than this, the smoothness of the surface of the magnetic layer will be poor and head wear will increase. Furthermore, the retention force of the silicone oil within the magnetic layer is small, resulting in poor durability. The magnetic materials used include γ-Fe 2 O 3 , Co-containing γ-Fe 2 O 3 , Fe 3 O 4 , Co
Containing Fe 3 O 4 , γ-Fe 2 O 3 and Fe 3 O 4 bertolide compound (FeOx, 1.33<x<1.50), Co-containing γ
−Bertride compounds of Fe 2 O 3 and Fe 3 O 4 (FeOx,
1.33<x<1.50), CrO 2 , tabular Ba ferrite,
Co-Ni-P alloy, Co-Ni-Fe alloy, Co-Ni-
Known ferromagnetic fine powders such as Fe-B alloy, Fe-Ni-Zn alloy, Fe-Mn-Zn alloy, Fe-Co-Ni-P alloy, Ni-Co alloy, etc. can be used. The surface smoothness of the magnetic layer coating side of the support used in the present invention is determined by the center line average roughness (referred to as Ra).
It must be 0.035μ or less (cut off 0.25mm, stylus radius 2μR, stylus speed 0.3mm/sec),
It is more preferably 0.030μ or less, even more preferably 0.02μ or less. If it is rougher than this, head wear will increase and video S/N (especially color signals) will deteriorate. Materials for the support include polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polyolefins such as polypropylene, cellulose derivatives such as cellulose triacetate and cellulose diacetate, plastics such as polycarbonate, and materials such as Cu, Al, and Zn. Non-magnetic metals, glass, porcelain, ceramics such as earthenware, etc. are used. The thickness of the support is preferably about 2.5 to 100μ, preferably about 3 to 40μ. Conventionally known techniques can be used for the binder, dispersant, plasticizer, stabilizer, and lubricant contained in the magnetic layer, as well as the manufacturing method.
26890. The present invention will be explained in detail below using examples. In the examples, "parts" indicate "parts by weight." Example 1 The following composition was dispersed in a ball mill, and then 35 parts of "Desmodyur L-75" (polyisocyanate manufactured by Bayer AG) was added to prepare a magnetic paint. Add this to 15μ
A magnetic tape (sample No. 1) was prepared by coating it on a thick polyester film. The support Ra is
A material with a diameter of 0.030μ was used. Co-added γ-Fe 2 O 3 (BET specific surface area 35m 2 /g)
300 parts silicone oil (polydimethylsiloxa 1000
CS) 1 part Abrasive (Cr 2 O 3 , Mohs hardness 8.5, particle size
0.5 μ) 15 parts Vinyl chloride/vinyl acetate copolymer (-OH group-containing) 40 parts Polyurethane resin 30 parts Carbon black 10 parts Cyclohexanone 250 parts Methyl ethyl ketone 250 parts Comparative example 1 Sample from which silicone oil was removed in Example 1 (No. 2), a sample using α-Fe 2 O 3 (Mohs hardness 5.5) instead of Cr 2 O 3 (No. 3), a sample in which the magnetic material was changed to one with a BET specific surface area of 20 m 2 /g. (No. 4), the support is Ra0.040μ
A sample (No. 5) was prepared. Example 2 Sample (No. 6) using MgO (Mohs hardness 6) instead of Cr 2 O 3 in Example 1, BET magnetic material
A sample with a specific surface area of 30m 2 /g (No.
7) A sample (No. 8) was prepared in which the support was changed to one with Ra 0.035μ. Example 3 Sample No. 9 was prepared in which the composition of Example 1 other than "Desmodyur L" was changed as follows. However, the support used had a Ra of 0.020μ. Co-added γ-Fe 2 O 3 (BET specific surface area 400m 2 /g)
300 parts silicone oil polydimethylpolysiloxane
10000 CS 1 part Abrasive (α-Al 2 O 3 , Mohs hardness 9, particle size 0.3μ) 15 parts Vinyl chloride/vinyl acetate copolymer (contains carboxyl group) 45 parts Nitrile-butadiene copolymer 5 parts Polyurethane resin 20 Parts Carbon black 15 parts Butyl stearate 1 part Oleic acid 1 part Methyl ethyl ketone 400 parts Toluene 150 parts The evaluation results of samples No. 1 to No. 9 are shown in Table 1. The outline of the evaluation method is as follows. A video tape slit into 1/2 inch width was inserted into a video cassette and repeatedly run on a VHS video tape recorder (hereinafter referred to as VTR).
The amount of wear on the head after running for 100 hours at 40°C was expressed in units of [μ/100h] and was defined as head wear. Durability was also defined as the ratio of the number of dropouts after 500 hours of running at 40°C compared to the number of dropouts during the first run. Example 1 according to the present invention Sample No. 1 is Comparative Example 1
Compared to samples No. 2 to No. 5, both head wear and durability are superior, and silicone oil, BET
This effect is observed when a magnetic material with a specific surface area of 30 m 2 /g or more, an abrasive with a Mohs hardness of 6 or more, and a support with an Ra of 0.035 μ or less are combined.
【表】【table】
Claims (1)
磁気記録体に於て、該磁性層が(1)シリコンオイ
ル、(2)モース硬度６以上の研磨剤及び(3)BET比
表面積30m2／ｇ以上の磁性体を含み、かつ該支持
体のRaが0.035μ以下であることを特徴とする磁
気記録体。1. In a magnetic recording body comprising a magnetic layer provided on one surface of a non-magnetic support, the magnetic layer contains (1) silicone oil, (2) an abrasive with a Mohs hardness of 6 or more, and (3) a BET specific surface area of 30 m. 1. A magnetic recording material comprising a magnetic material of 2 /g or more and having an Ra of the support of 0.035μ or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58075398A JPS59201218A (en) | 1983-04-28 | 1983-04-28 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58075398A JPS59201218A (en) | 1983-04-28 | 1983-04-28 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59201218A JPS59201218A (en) | 1984-11-14 |
| JPH0479063B2 true JPH0479063B2 (en) | 1992-12-14 |
Family
ID=13575032
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58075398A Granted JPS59201218A (en) | 1983-04-28 | 1983-04-28 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59201218A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0618074B2 (en) * | 1984-10-25 | 1994-03-09 | 住友化学工業株式会社 | Magnetic recording medium |
| JPS62162228A (en) * | 1986-01-08 | 1987-07-18 | Konishiroku Photo Ind Co Ltd | Magnetic recording medium |
| NL8603011A (en) * | 1986-11-27 | 1988-06-16 | P D Magnetics | MAGNETIC REGISTRATION ELEMENT. |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5528562A (en) * | 1978-08-19 | 1980-02-29 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS56143522A (en) * | 1980-04-07 | 1981-11-09 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS56143523A (en) * | 1980-04-07 | 1981-11-09 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS57133519A (en) * | 1981-02-10 | 1982-08-18 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS57135436A (en) * | 1981-02-14 | 1982-08-21 | Sony Corp | Magnetic recording medium |
| JPS57150129A (en) * | 1981-03-12 | 1982-09-16 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS57154618A (en) * | 1981-03-19 | 1982-09-24 | Sony Corp | Magnetic recording medium |
| JPS57162127A (en) * | 1981-03-31 | 1982-10-05 | Fuji Photo Film Co Ltd | Magnetic recording body |
| JPS5870426A (en) * | 1981-10-21 | 1983-04-26 | Sony Corp | Magnetic recording medium |
-
1983
- 1983-04-28 JP JP58075398A patent/JPS59201218A/en active Granted
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5528562A (en) * | 1978-08-19 | 1980-02-29 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS56143522A (en) * | 1980-04-07 | 1981-11-09 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS56143523A (en) * | 1980-04-07 | 1981-11-09 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS57133519A (en) * | 1981-02-10 | 1982-08-18 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS57135436A (en) * | 1981-02-14 | 1982-08-21 | Sony Corp | Magnetic recording medium |
| JPS57150129A (en) * | 1981-03-12 | 1982-09-16 | Fuji Photo Film Co Ltd | Magnetic recording medium |
| JPS57154618A (en) * | 1981-03-19 | 1982-09-24 | Sony Corp | Magnetic recording medium |
| JPS57162127A (en) * | 1981-03-31 | 1982-10-05 | Fuji Photo Film Co Ltd | Magnetic recording body |
| JPS5870426A (en) * | 1981-10-21 | 1983-04-26 | Sony Corp | Magnetic recording medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59201218A (en) | 1984-11-14 |
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