JPH079696B2 - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH079696B2 JPH079696B2 JP3420685A JP3420685A JPH079696B2 JP H079696 B2 JPH079696 B2 JP H079696B2 JP 3420685 A JP3420685 A JP 3420685A JP 3420685 A JP3420685 A JP 3420685A JP H079696 B2 JPH079696 B2 JP H079696B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- weight
- fluorine
- magnetic layer
- graft copolymer
- 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 - Fee Related
Links
Landscapes
- Graft Or Block Polymers (AREA)
- Paints Or Removers (AREA)
- Macromonomer-Based Addition Polymer (AREA)
- Magnetic Record Carriers (AREA)
Description
【発明の詳細な説明】 ＜産業上の利用分野＞ 本発明は磁気記録媒体に関し、その目的は、磁性層の耐
摩耗性および耐久性が優れ、磁性層表面の平滑性、摩擦
低減性、並びに磁性粉の分散性及び配向性が改善された
磁気記録媒体を提供することにある。DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a magnetic recording medium, and its object is to provide a magnetic layer having excellent wear resistance and durability, smoothness of the magnetic layer surface, friction reducing property, and An object of the present invention is to provide a magnetic recording medium having improved dispersibility and orientation of magnetic powder.
＜従来の技術＞ 磁気テープ、磁気デイスク等の磁気記録媒体は、記録再
生時に磁気ヘツドと大きい相対速度で摺接する為、磁性
層には耐摩耗性が要求され、又磁気表面は平滑で、かつ
摩擦抵抗が小さいことが望まれる。しかしながら、磁性
粉の分散性が良く、ベースとの密着性に優れる汎用に磁
性用バインダー樹脂、例えばポリ（塩化ビニル−塩化ビ
ニリデン）、ポリ（塩化ビニル−酢酸ビニル）、ポリウ
レタン、ポリエステル等は一般に滑性及び非粘着性に乏
しい。このため、磁気ヘツドとの摺接時には摩擦力が増
大する為、磁気記録媒体の走行性は悪化し、又磁性層の
耐久性を著しく損なうという問題があつた。<Prior Art> A magnetic recording medium such as a magnetic tape or a magnetic disk is in sliding contact with a magnetic head at a high relative velocity during recording and reproduction, and therefore the magnetic layer is required to have wear resistance, and the magnetic surface is smooth and Low frictional resistance is desired. However, general-purpose magnetic binder resins, such as poly (vinyl chloride-vinylidene chloride), poly (vinyl chloride-vinyl acetate), polyurethane, and polyester, which have good dispersibility of magnetic powder and excellent adhesion to the base, are generally used. Poor in adhesiveness and non-stickiness. For this reason, the frictional force increases during sliding contact with the magnetic head, which deteriorates the running property of the magnetic recording medium and significantly impairs the durability of the magnetic layer.
また一方、磁性粉とバインダー樹脂から成る磁性塗料を
ベースフイルム上に塗布する際、その表面張力が大きい
ためにレベリング性が悪く、塗布むらないし厚みむらが
生じて、磁気記録媒体としての出力変動が大きくなると
いう欠点があつた。On the other hand, when a magnetic paint composed of magnetic powder and a binder resin is applied to the base film, the leveling property is poor due to the large surface tension, resulting in uneven coating or uneven thickness, and fluctuations in output as a magnetic recording medium. It had the drawback of becoming large.
これらの問題に対し、従来から、磁性塗料中にレシチ
ン等の界面活性剤や、流動パラフイン又はステアリン
酸、シリコンオイル等の各種潤滑剤（以上のものを以後
非フツ素系添加剤と称する）を添加し、磁性層表面の滑
性を向上させる方法、 磁性層表面にフツ素系樹脂粉末を含有せしめ摺動特性
を向上させる方法（特開昭59−162644号）、 パーフロロアルキル基含有界面活性剤を磁性層中に含
有せしめ、磁性層表面の平滑性、耐久性、そして磁性粉
の分散性を改善する方法（特開昭59−167837号、特開昭
59−167838号、特開昭59−167839号、特開昭59−167840
号、特開昭59−167841号、特開昭59−172140号等）、そ
して又ベースフイルム上に磁性塗料を塗布する際のレベ
リング性を改善し、平滑な塗面を得ることにより出力変
動を低下させる方法、（特開昭58−159232号）等の提案
がある。To solve these problems, conventionally, surfactants such as lecithin and various lubricants such as fluid paraffin or stearic acid and silicone oil are added to magnetic paints (these are hereinafter referred to as non-fluorine-based additives). Addition to improve the lubricity of the magnetic layer surface, a method to improve the sliding characteristics by containing fluorine resin powder on the magnetic layer surface (JP-A-59-162644), perfluoroalkyl group-containing surfactant A method of improving the smoothness and durability of the surface of the magnetic layer and the dispersibility of the magnetic powder by containing an agent in the magnetic layer (JP-A-59-167837 and JP-A-59-167837).
59-167838, JP-A-59-167839, JP-A-59-167840
No. 59, No. 59-167841, No. 59-172140, etc.), and by improving the leveling property when applying a magnetic coating on the base film to obtain a smooth coating surface, thereby suppressing the output fluctuation. There is a proposal for a method of lowering it (JP-A-58-159232).
＜発明が解決しようとする問題点＞ しかしながら、従来から使用されてきた上記の非フツ素
系添加剤並びにフツ素系界面活性剤は、磁気ヘツドとの
摺接時に脱落しやすいために、滑性効果が比較的短時間
で消滅し、走行安定性等が損われるという問題があつ
た。また滑性効果の持続性を向上させる目的で、上記非
フツ素系添加剤並びにフツ素系界面活性剤を多量に使用
すると、磁性粉の分散性を悪化させ、磁気特性を低下さ
せたり、又磁性層そのものの機械的特性を悪化させ、耐
久性を損う等の問題があつた。<Problems to be Solved by the Invention> However, the above-mentioned non-fluorine-based additives and fluorine-based surfactants that have been conventionally used are liable to slip off during sliding contact with a magnetic head, and thus have a slipperiness. There is a problem that the effect disappears in a relatively short time and the running stability is impaired. When a large amount of the non-fluorine-based additive and the fluorine-based surfactant is used for the purpose of improving the durability of the lubricity effect, the dispersibility of the magnetic powder is deteriorated and the magnetic properties are deteriorated. There have been problems such as deterioration of mechanical properties of the magnetic layer itself and deterioration of durability.
さらにまた、シリコンオイルの様に磁性層との相溶性に
乏しい滑剤を添加した場合には、適度の表面滲漏が発生
し、これに伴つて磁性層内の分散剤の漏出が誘発され
る。このため、粉落ちに起因した出力変動やテープ鳴き
等が生じるという問題があつた。Furthermore, when a lubricant having poor compatibility with the magnetic layer, such as silicone oil, is added, moderate surface leakage occurs, which causes leakage of the dispersant in the magnetic layer. For this reason, there has been a problem that output fluctuations and tape squeal etc. occur due to powder falling.
これに対して、磁性層との相溶性に優れた添加剤又は界
面活性剤を添加した場合には、これら滑剤の表面滲出量
が少ない為に、所期の滑性効果が得られないことが多か
つた。On the other hand, when an additive or a surfactant having excellent compatibility with the magnetic layer is added, the desired lubrication effect may not be obtained because the surface leaching amount of these lubricants is small. It was many.
以上の様に、少量の添加で十分な表面滑性を発揮し、か
つ磁気ヘツドとの摺接時にも脱落せず、滑性持続性に優
れて非フツ素系添加剤及びフツ素系界面活性剤は見い出
されていないのが現状であつた。As described above, a small amount of additive exerts sufficient surface lubricity, does not fall off during sliding contact with the magnetic head, and has excellent long-lasting lubricity, and is a non-fluorine-based additive and fluorine-based surfactant. The current situation is that no drug has been found.
＜問題点を解決するための手段＞ 本発明者等は、上記問題点を解決すべく鋭意研究を行つ
た結果、主鎖部分が炭素数３〜20のパーフロロアルキル
基含有ビニル化合物の重合体から成り、グラフト鎖部分
が非フツ素系化合物の重合体から成るフツ素系グラフト
共重合体を使用すれば、磁性塗料をベース上に塗布する
際のレベリング性を著しく改善できて平滑な塗面が得ら
れ、かつ従来よりも、磁性粉の分散性及び配向性が向上
し、表面滑性、滑性持続性、さらに耐久性等の点で優れ
た磁性層並びに走行安定性に優れ、出力変動やテープ鳴
きが格段に少ない磁気記録媒体を得られることを見い出
し本発明を完成するに至つた。<Means for Solving the Problems> The inventors of the present invention have conducted earnest research to solve the above problems, and as a result, a polymer of a vinyl compound containing a perfluoroalkyl group having a main chain of 3 to 20 carbon atoms. When a fluorine-based graft copolymer consisting of a polymer of a non-fluorine-based compound is used, the leveling property when applying a magnetic coating to the base can be significantly improved and a smooth coating surface can be obtained. Of the magnetic powder, the dispersibility and orientation of the magnetic powder are improved, and the magnetic layer is excellent in terms of surface lubricity, lubricity sustainability, durability, and running stability. The inventors have found that a magnetic recording medium with significantly less squealing and tape squeal can be obtained, and completed the present invention.
即ち本発明は、磁性層中に、主鎖部分（Ａ）が炭素数３
〜20のパーフロロアルキル基含有ビニル化合物の重合体
からなり、グラフト鎖部分（Ｂ）が分子中に（メタ）ア
クリロイル基を有する化合物を必須成分とする非フッ素
系化合物の重合体から成るグラフト共重合体（Ｇ）を含
有せしめることを特徴とする磁気記録媒体を提供するも
のである。That is, in the present invention, the main chain portion (A) has 3 carbon atoms in the magnetic layer.
To 20 perfluoroalkyl group-containing vinyl compound polymers, and the graft chain part (B) is a non-fluorine-containing compound having a (meth) acryloyl group in the molecule as an essential component. The present invention provides a magnetic recording medium characterized by containing a polymer (G).
本発明に係るグラフト共重合体（Ｇ）の主鎖部分（Ａ）
の構成単位である、炭素数３〜20のパーフロロアルキル
基含有ビニル化合物としては、例えば一般式（Ｉ） 〔式中、Rfは炭素数３〜20好ましくは６〜16のパーフロ
ロアルキル基であつて、 の如き、主鎖中にエーテル酸素を含有するものでも良
く、Ｑは２価の連結基で または （但し、R2は水素原子、または炭素数１〜８のアルキル
基である。）であり、ａは０または１であり、ＸはCH
2 ｍまたは （但し、ｍは１〜６の整数である。）であり、ｂは０ま
たは１であり、R1は水素原子、フツ素原子、塩素原子、
臭素原子、またはメチル基である。〕にて表わされる化
合物が好ましく挙げられる。この化合物によつて得られ
る本願発明の主鎖部分（Ａ）は、 一般式 〔但し、R1、ａ、ｂ、Ｘ、Ｑ、Rfは前期の通りであり、
R3、R4、は水素原子、メチル基、メトキシ基、または−
OSi（CH3）３基であり、R5は水素原子、メチル基または
カルボキシル基であり、Ｂは非フツ素系化合物（後述）
の重合体と連結基（連鎖移動剤残基）から成るグラフト
鎖部分（Ｂ）である。〕で表わされる重合単位である。Main chain portion (A) of graft copolymer (G) according to the present invention
Examples of the perfluoroalkyl group-containing vinyl compound having 3 to 20 carbon atoms, which is a structural unit of [Wherein Rf is a perfluoroalkyl group having 3 to 20 carbon atoms, preferably 6 to 16 carbon atoms, Such as those containing ether oxygen in the main chain, and Q is a divalent linking group. Or (However, R 2 is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.), A is 0 or 1, and X is CH.
2 m or (However, m is an integer of 1 to 6), b is 0 or 1, R 1 is a hydrogen atom, a fluorine atom, a chlorine atom,
It is a bromine atom or a methyl group. ] The compound represented by The main chain portion (A) of the present invention obtained by this compound has the general formula [However, R 1 , a, b, X, Q, and Rf are as described above,
R 3 and R 4 are a hydrogen atom, a methyl group, a methoxy group, or −
OSi (CH 3 ) 3 group, R 5 is a hydrogen atom, a methyl group or a carboxyl group, B is a non-fluorine compound (described later)
It is a graft chain portion (B) consisting of the polymer of (1) and a linking group (chain transfer agent residue). ] It is a polymerized unit represented by.
前記一般式（Ｉ）で表わされるビニル化合物としては、
具体例として、 等が挙げられる。主鎖部分（Ａ）は、パーフロロアルキ
ル基の炭素数の異なる同種化合物もしくは異種化合物、
あるいはこれらの２種以上の混合物から得られる重合体
であつても良い。尚、本発明がこれらの具体的化合物に
よつて何ら限定されるものでないことは勿論である。As the vinyl compound represented by the general formula (I),
As a specific example, Etc. The main chain portion (A) is the same or different compound having different carbon number of perfluoroalkyl group,
Alternatively, it may be a polymer obtained from a mixture of two or more thereof. Needless to say, the present invention is not limited to these specific compounds.
また本発明に係るグラフト共重合体（Ｇ）のグラフト鎖
部分（Ｂ）を構成する化合物は分子中に（メタ）アクリ
ロイル基を有する化合物を必須成分とする非フツ素系化
合物であり、具体例としては、α，β−エチレン性不飽
和単量体、即ちスチレン、核置換スチレン、アクリロニ
トリル、塩化ビニル、塩化ビニリデン、ビニルピリジ
ン、Ｎ−ビニルピロリドン、ビニルスルホン酸、酢酸ビ
ニル等の脂肪酸ビニル、またα，β−エチレン性不飽和
カルボン酸、即ちアクリル酸、メタクリル酸、マレイン
酸、フマール酸、イタコン酸等の一価ないし二価のカル
ボン酸、またα，β−エチレン性不飽和カルボン酸の誘
導体として、アルキル基の炭素数が１〜18の、（メタ）
アクリル酸アルキルエステル（以後この表現はアクリル
酸アルキルエステルとメタクリル酸アルキルエステルの
両方を総称するものとする。）、即ち（メタ）アクリル
酸のメチル、エチル、プロピル、ブチル、オクチル、２
−エチルヘキシル、デシル、ドデシル、ステアリルエス
テル等、また（メタ）アクリル酸の炭素数１〜18のヒド
ロキシアルキルエステル、即ちヒドロキシエチル、エチ
ルエステル、ヒドロキシプロピルエステル、ヒドロキシ
ブチルエステル等、また（メタ）アクリル酸の炭素数１
〜18のアミノアルキルエステル、即ちジメチルアミノエ
チルエステル、ジエチルアミノエチルエステル、ジエチ
ルアミノプロピルエステル等、また（メタ）アクリル酸
の、炭素数が３〜18のエーテル酸素含有アルキルエステ
ル、例えばメトキシエチルエステル、エトキシエチルエ
ステル、メトキシプロピルエステル、メチルカルビルエ
ステル、エチルカルビルエステル、ブチルカルビルエス
テル等、またアルキル炭素数が１〜18のアルキルビニル
エーテル、例えばメチルビニルエーテル、プロピルビニ
ルエーテル、ドデシルビニルエーテル等の単量体から選
ばれた１種ないし２種以上の単量体の重合体もしくは共
重合体、またはポリ（エチレンオキシド）、ポリ（プロ
ピレンオキシド）、ポリ（テトラヒドロフラン）等のポ
リ（アルキレンオキシド）や、エチレンオキシドとプロ
ピレンオキシドの共重合体等のポリ（アルキレンオキシ
ド）、またはポリウレタン、ポリエステル、ポリ（α−
アミノ酸）等が挙げられる。尚、本発明が上記具体例に
よつて何ら制限されるものでないことは勿論のことであ
る。Further, the compound constituting the graft chain portion (B) of the graft copolymer (G) according to the present invention is a non-fluorine-based compound containing a compound having a (meth) acryloyl group in the molecule as an essential component, and specific examples As, α, β-ethylenically unsaturated monomers, that is, styrene, nucleus-substituted styrene, acrylonitrile, vinyl chloride, vinylidene chloride, vinylpyridine, N-vinylpyrrolidone, vinylsulfonic acid, vinyl acetate, and other fatty acid vinyl, α, β-ethylenically unsaturated carboxylic acids, that is, mono- or divalent carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and derivatives of α, β-ethylenically unsaturated carboxylic acids As the alkyl group having 1 to 18 carbon atoms, (meth)
Acrylic acid alkyl ester (hereinafter, this expression generically refers to both acrylic acid alkyl ester and methacrylic acid alkyl ester), that is, (meth) acrylic acid methyl, ethyl, propyl, butyl, octyl, 2
-Ethylhexyl, decyl, dodecyl, stearyl ester, etc., and hydroxyalkyl esters of (meth) acrylic acid having 1 to 18 carbon atoms, that is, hydroxyethyl, ethyl ester, hydroxypropyl ester, hydroxybutyl ester, etc., and (meth) acrylic acid. Carbon number 1
.About.18 aminoalkyl ester, that is, dimethylaminoethyl ester, diethylaminoethyl ester, diethylaminopropyl ester, etc., and (meth) acrylic acid alkyl ether having 3 to 18 carbon atoms, such as methoxyethyl ester and ethoxyethyl. 1 selected from monomers such as ester, methoxypropyl ester, methylcarbyl ester, ethylcarbyl ester, butylcarbyl ester, etc., and alkyl vinyl ether having 1 to 18 carbon atoms such as methyl vinyl ether, propyl vinyl ether, dodecyl vinyl ether, etc. Polymers or copolymers of one or more monomers, or poly (alkylene oxides) such as poly (ethylene oxide), poly (propylene oxide), poly (tetrahydrofuran) De) and, poly (alkylene oxide copolymers of ethylene oxide and propylene oxide), or polyurethane, a polyester, poly (alpha-
Amino acids) and the like. Needless to say, the present invention is not limited to the above specific examples.
上記のとおり具体例の中で本発明に係るグラフト共重合
体のグラフト部分（Ｂ）としては、（メタ）アクリル酸
もしくは（メタ）アクリル酸の誘導体等の単量体から選
ばれた１種ないし２種以上を必須成分とする単量体の重
合体または共重合体である。As described above, in the specific examples, the graft portion (B) of the graft copolymer according to the present invention is one or more selected from monomers such as (meth) acrylic acid or a derivative of (meth) acrylic acid. It is a polymer or copolymer of two or more monomers as essential components.
本発明に係るグラフト共重合体（Ｇ）の製法には何ら制
限はなく、公知の種々方法（例えば、山下雄也、日本接
着協会誌、17、371〜377頁（1981）に記載の方法、又は
川上雄資、山下雄也、表面、22、297〜309頁（1984）に
記載の方法等）に従つて簡便かつ収率良く製造できる。
例えば、その方法の一つにマクロモノマー法が好ましく
挙げられる。これは、本発明に係るグラフト共重合体
（Ｇ）中のグラフト鎖部分（Ｂ）に相当するフツ素不含
の片末端ビニル基含有反応性重合体（これをマクロモノ
マーと称す。）を非フツ素不含ビニル化合物と連鎖移動
剤から予め得、このマクロモノマーと、グラフト共重合
体（Ｇ）中の主鎖部分（Ａ）の構成単位となる前記パー
フロロアルキル基含有ビニル化合物（Ｉ）とを共重合
し、主鎖部分（Ａ）の形成と同時にマクロモノマーをグ
ラフト鎖部分（Ｂ）として導入するというグラフト共重
合体（Ｇ）の製法である。There is no limitation on the method for producing the graft copolymer (G) according to the present invention, and various known methods (for example, the method described in Yuya Yamashita, Journal of Japan Adhesion Society, 17 , 371 to 377 (1981), or Yuji Kawakami, Yuya Yamashita, Surface, 22 , 297 to 309 (1984), etc.) and the like.
For example, one of the methods is preferably a macromonomer method. This is a non-fluorine-containing reactive polymer having one terminal vinyl group (which is referred to as a macromonomer) containing no fluorine, which corresponds to the graft chain portion (B) in the graft copolymer (G) according to the present invention. A vinyl compound (I) containing a perfluoroalkyl group, which is obtained in advance from a fluorine-free vinyl compound and a chain transfer agent and serves as a constitutional unit of the main chain portion (A) in the graft copolymer (G). And a macromonomer is introduced at the same time as the formation of the main chain portion (A), and the macromonomer is introduced as the graft chain portion (B).
前記の本発明に係るマクロモノマーとは、一般式 〔但し、R3、R4、R5、Ｂは前記の通りである。〕 にて表わされるものが良い。The macromonomer according to the present invention has the general formula [However, R 3 , R 4 , R 5 , and B are as described above. ] Is preferable.
マクロモノマーの製法には何ら制限がなく、公知の方
法、即ち、ラジカル重合法、カチオン重合法、アニオン
重合法、重付加法、重縮合法、または開環重合法等が用
いられる。またマクロモノマーとパーフロロアルキル基
含有ビニル化合物（Ｉ）との重合法にも何ら制限はな
く、ラジカル重合法、カチオン重合法、アニオン重合法
等が使用される。There is no limitation on the method for producing the macromonomer, and known methods such as a radical polymerization method, a cationic polymerization method, an anionic polymerization method, a polyaddition method, a polycondensation method, and a ring-opening polymerization method are used. Further, there is no limitation on the polymerization method of the macromonomer and the perfluoroalkyl group-containing vinyl compound (I), and a radical polymerization method, a cationic polymerization method, an anionic polymerization method or the like is used.
マクロモノマーの或るものは市販品を購入して得ること
ができ、例えばスタートマー社製スチレンマクロモノマ
ー4500、新中村化学工業（株）製NKエステルＭ−230G等
がある。Some of the macromonomers can be obtained by purchasing commercially available products, for example, styrene macromonomer 4500 manufactured by Starmer Co., Ltd. and NK ester M-230G manufactured by Shin Nakamura Chemical Co., Ltd.
また本発明に係るグラフト共重合体の或ものは市販品を
購入して得ることもできる。Alternatively, the graft copolymer according to the present invention or a commercial product can be purchased.
本発明に係るグラフト共重合体（Ｇ）において、フツ素
含有量は３〜70重量％が好ましく、５〜40重量％が特に
好ましい。又、グラフト共重合体（Ｇ）の分子量はｎ
＝3,000〜500,000が好ましく、ｎ＝5,000〜100,000が
特に好ましい。In the graft copolymer (G) according to the present invention, the fluorine content is preferably 3 to 70% by weight, particularly preferably 5 to 40% by weight. The molecular weight of the graft copolymer (G) is n
= 3,000 to 500,000 is preferable, and n = 5,000 to 100,000 is particularly preferable.
本発明に係るグラフト共重合体（Ｇ）の使用量は、磁性
層中に磁性粉100重量部に対して、0.001〜20重量部が好
ましく、0.01〜10重量部が特に好ましい。またグラフト
共重合体（Ｇ）を磁性層中に含有させる手段としては、
例えばベンゼン、トルエン等の芳香族系溶剤、フレオン
−113、1,1,1−トリクロロエタン等のハロゲン系溶剤、
メチルエチルケトン、メチルイソブチルケトン等のケト
ン系溶剤、酢酸エチル、酢酸イソブチル等のエステル系
溶剤、またはこれらの溶剤の混合系にグラフト共重合体
（Ｇ）を適宜溶解させ、この溶液を予め形成された磁性
層の表面に塗布もしくは噴霧する方法、または上記溶液
中に磁性層を浸漬する方法、あるいは上記有機溶剤系の
如き磁性塗料中にグラフト共重合体（Ｇ）を混合して磁
性層を形成する方法、さらにまた、予め磁性バインダー
用樹脂に混和しておく方法等がある。The amount of the graft copolymer (G) according to the present invention used is preferably 0.001 to 20 parts by weight, and particularly preferably 0.01 to 10 parts by weight, based on 100 parts by weight of the magnetic powder in the magnetic layer. The means for incorporating the graft copolymer (G) in the magnetic layer is as follows.
For example, benzene, an aromatic solvent such as toluene, Freon-113, a halogen solvent such as 1,1,1-trichloroethane,
The graft copolymer (G) is appropriately dissolved in a ketone-based solvent such as methyl ethyl ketone or methyl isobutyl ketone, an ester-based solvent such as ethyl acetate or isobutyl acetate, or a mixed system of these solvents, and this solution is used to form a preformed magnetic solution. A method of coating or spraying on the surface of the layer, a method of immersing the magnetic layer in the above solution, or a method of forming the magnetic layer by mixing the graft copolymer (G) in a magnetic paint such as the above organic solvent system. Further, there is a method of mixing with a resin for a magnetic binder in advance.
＜作用＞ 本発明に係るグラフト共重合体（Ｇ）が、これまでに開
示されてきた非フツ素系添加剤及びフツ素系界面活性剤
と比較して、何故に摩擦抵抗が少なく、滑性持続性及び
耐久性に優れた磁性層を与えるかについては十分に明確
ではない。しかしながら本発明者等のこれまでの知見に
よれば、従来の高分子量のフツ素系界面活性剤において
は、分子中に滑性効果を発揮するパーフロロアルキル基
がランダムに配置されていたために、滑性部分と、磁性
層の樹脂成分との良い部分が、それぞれ明確なドメイン
を形成し得ず、このために磁性層中の樹脂部分に対する
アンカー効果が不十分なために表面付近のフツ素系界面
活性剤は摺接時に容易に脱落し、充分な滑性効果及び滑
性持続性が得られなかつたものと考えられる。また低分
子量のフツ素界面活性剤についても、アンカー効果並び
にパーフロロアルキル基の磁性層表面での濃縮効果が不
十分なために、充分な滑性効果並びに滑性持続性がなか
つたものと推定される。<Function> The graft copolymer (G) according to the present invention has less frictional resistance and slipperiness than the non-fluorine-based additives and fluorine-based surfactants disclosed so far. It is not clear enough to provide a magnetic layer with excellent durability and durability. However, according to the findings of the inventors of the present invention, in the conventional high molecular weight fluorine-based surfactant, since the perfluoroalkyl group exhibiting the sliding effect is randomly arranged in the molecule, The slippery portion and the good portion of the resin component of the magnetic layer cannot form distinct domains, respectively, and therefore the anchoring effect on the resin portion in the magnetic layer is insufficient, and the fluorine-based material near the surface is It is considered that the surfactant easily fell off during sliding contact, and sufficient lubrication effect and lubricity persistence were not obtained. Also for low-molecular-weight fluorosurfactants, it is presumed that neither sufficient lubrication effect nor lubricity persistence was achieved due to insufficient anchoring effect and concentration effect of perfluoroalkyl group on the magnetic layer surface. To be done.
これに対し、本発明に係るグラフト共重合体（Ｇ）に
は、滑性成分であるパーフロロアルキル基のドメイン、
即ち高分子量の主鎖部分（Ａ）と、磁性層中の樹脂成分
と親和性が良い高分子量のグラフト鎖部分（Ｂ）のドメ
インが存在する。このために磁性層表面に移行したグラ
フト共重合体（Ｇ）は、樹脂に対して充分なアンカー効
果を有していると共に、磁性層表面にパーフロロアルキ
ル基の集合体を形成している為、充分な滑性効果と滑性
持続性を発現しているものと考えられる。On the other hand, in the graft copolymer (G) according to the present invention, the domain of the perfluoroalkyl group which is a slipping component,
That is, there are domains of a high molecular weight main chain portion (A) and a high molecular weight graft chain portion (B) having good affinity with the resin component in the magnetic layer. For this reason, the graft copolymer (G) transferred to the surface of the magnetic layer has a sufficient anchoring effect on the resin and forms an aggregate of perfluoroalkyl groups on the surface of the magnetic layer. It is considered that they exhibit a sufficient lubricity effect and lubricity sustainability.
尚、これらの考察は本発明の内容を理解する上での一助
となるものであり、本発明を何ら限定するものでないこ
とは勿論である。It is needless to say that these considerations are helpful in understanding the content of the present invention and do not limit the present invention in any way.
またアンカー成分である、グラフト共重合体（Ｇ）中の
グラフト鎖部分（Ｂ）が、磁性層中の樹脂成分と全く同
一であることが最適であることは勿論であるが、樹脂成
分と親和性のあるものも同様に有効である。またこのグ
ラフト鎖部分（Ｂ）は磁性層中の樹脂成分と完全に相溶
することは必ずしも必要ではなく、或程度の親和性があ
れば充分である。Of course, it is optimum that the graft chain portion (B) in the graft copolymer (G), which is the anchor component, is exactly the same as the resin component in the magnetic layer, but it is compatible with the resin component. Those that have the same properties are also effective. Further, it is not always necessary that the graft chain portion (B) is completely compatible with the resin component in the magnetic layer, and it is sufficient if it has a certain degree of affinity.
＜発明の効果＞ 本発明に係るグラフト共重合体（Ｇ）は、磁性塗料のレ
ベリング性を向上させるため、磁気テープ及び磁気デイ
スクの生産性向上に大きく寄与し、又、均質性に富んだ
塗面を与えることから、テープの長尺化に伴つて近年特
に要請されている、磁性層の薄層化も可能にすることが
できる。<Effects of the Invention> The graft copolymer (G) according to the present invention improves the leveling property of the magnetic coating material, and thus contributes greatly to the improvement of the productivity of the magnetic tape and the magnetic disk, and the coating material is rich in homogeneity. Since the surface is provided, it is possible to make the magnetic layer thin, which has been particularly required in recent years as the tape becomes longer.
また本発明に係る磁気記録媒体は、滑性及び滑性持続性
に優れていることから、従来よりも磁気テープ又は磁気
デイスク等の走行安定性及び耐久性を向上し、又、出力
変動の少ない再生を可能にすると共に、ビデオテープ等
の長時間のスチル再生も可能にした。Further, since the magnetic recording medium according to the present invention is excellent in slipperiness and slipperiness sustainability, the running stability and durability of the magnetic tape or the magnetic disk etc. are improved as compared with the conventional one, and the output fluctuation is small. In addition to enabling playback, it also enables long-time still playback of video tapes.
次に本発明をより詳細に説明するために、参考例、実施
例並びに比較例を掲げる。Next, in order to explain the present invention in more detail, reference examples, examples and comparative examples will be given.
参考例１ 末端メタクリレート型メチルメタクリレート/i−ブチル
メタクリレート／β−ヒドロキシエチルメタクリレート
型マクロモノマー、 撹拌装置、コンデンサー、滴下ロート、温度計を備えた
ガラスフラスコに、メチルメタクリレート（以後MMAと
称す。）５重量部、ｉ−ブチルメタクリレート（以後iB
MAと称す。）２重量部、β−ヒドロキシエチルメタクリ
レート（以後βHEMAた称す。）３重量部、メチルイソブ
チレケトン90重量部を仕込み、窒素ガス導入後、還流下
に重合開始剤としてアゾビスイソブチロニトリル（以後
AIBNと称す。）0.5重量部と連鎖移動剤としてチオグリ
コール酸0.3重量部を添加し、重合を開始させた。その
後５時間の間にMMA 45重量部、iBMA 18重量部、βHEMA
27重量部の混合液を連続的に滴下し、またチオグリコー
ル酸2.7重量部をメチルイソブチルケトン７重量部に溶
解して、30分毎、９回に分けて添加、同様にAIBH 1.5重
量部を1.5時間毎、３回に分けて添加し、重合を行つ
た。添加終了後、さらに２時間還流して重合を終了し、
末端にチオグリコール酸残基を有するMMA/iBMA/βHEMA
の共重合体（MMA/iBMA/βHEMA−SCH2COOHと略す。）を
得た。反応液の一部をｎ−ヘキサンにて沈澱後、乾燥し
て酸価を測定したところ、0.32kg当量/gであつた。Reference Example 1 Methyl methacrylate (hereinafter referred to as MMA) 5 in a glass flask equipped with terminal methacrylate type methyl methacrylate / i-butyl methacrylate / β-hydroxyethyl methacrylate type macromonomer, a stirrer, a condenser, a dropping funnel, and a thermometer. Parts by weight, i-butyl methacrylate (hereinafter iB
It is called MA. ) 2 parts by weight, β-hydroxyethyl methacrylate (hereinafter referred to as βHEMA) 3 parts by weight, and 90 parts by weight of methylisobutyreketone were charged, and after introducing nitrogen gas, azobisisobutyronitrile was used as a polymerization initiator under reflux. (Since then
It is called AIBN. ) 0.5 part by weight and 0.3 part by weight of thioglycolic acid as a chain transfer agent were added to initiate polymerization. During the next 5 hours, 45 parts by weight of MMA, 18 parts by weight of iBMA, βHEMA
27 parts by weight of the mixed solution was continuously added dropwise, and 2.7 parts by weight of thioglycolic acid was dissolved in 7 parts by weight of methyl isobutyl ketone and added every 30 minutes in 9 batches. Similarly, 1.5 parts by weight of AIBH was added. Polymerization was carried out by adding every 1.5 hours in three batches. After the addition was completed, the mixture was refluxed for 2 hours to complete the polymerization,
MMA / iBMA / βHEMA with thioglycolic acid residue at the end
A copolymer (abbreviated as MMA / iBMA / βHEMA-SCH 2 COOH) was obtained. A part of the reaction solution was precipitated with n-hexane and dried to measure the acid value, which was 0.32 kg equivalent / g.
次に上記反応液に、触媒としてN,N−ジメチルラウリル
アミン１重量部、重合禁止剤としてハイドロキノンモノ
ケチルエーテル0.04重量部を添加し、酸価に対して1.15
倍モルのグリシジルメタクリレートを加え、還流下（約
110℃）に11時間反応させた。酸価から求めた反応率は9
8.7％であつた。次に反応液を15倍量のｈ−ヘキサン中
に投入し、沈澱させた後70℃で減圧乾燥して末端に二重
結合を有するマクロモノマー 95重量部を得た。ゲルパーミエーシヨンクロマトグラフ
（以下GPCと称する。）によるポリスチレン換算分子量
はｎ＝4,200であつた。Next, 1 part by weight of N, N-dimethyllaurylamine as a catalyst and 0.04 part by weight of hydroquinone monoketyl ether as a polymerization inhibitor were added to the above reaction solution to give an acid value of 1.15.
Add twice the molar amount of glycidyl methacrylate and reflux (about
(110 ° C.) for 11 hours. The reaction rate calculated from the acid value is 9
It was 8.7%. Next, the reaction solution was poured into 15 times the volume of h-hexane to precipitate, followed by drying under reduced pressure at 70 ° C. to obtain a macromonomer having a double bond at the end. 95 parts by weight were obtained. The polystyrene reduced molecular weight determined by gel permeation chromatography (hereinafter referred to as GPC) was n = 4,200.
参考例２ 主鎖部分がパーフロロアルキル基含有アクリレートの重
合体から成り、グラフト鎖部分がMMA/iBMA/βHEMAの共
重合体から成るグラフト共重合体の合成撹拌装置、コン
デンサー、温度計を備えたガラスフラスコに、参考例１
で得られたマクロモノマー70重量部、パーフロロアルキ
ル基含有アクリレート 30重量部、そしてメチルイソブチルケトン300重量部、A
IBN0.4重量部を仕込み、100℃、窒素ガス雰囲気下で、
７時間反応した。次に反応液を10倍量のメタノール中に
投入し、沈澱させ、70℃で減圧乾燥してグラフト共重合
体96重量部を得た。このものはGPCにより単一のピーク
を示し、ポリスチレン換算分子量はｎ＝12,400であつ
た。またフツ素含有量は18.6（理論値18.7）重量％であ
つた。Reference Example 2 Synthesis of a graft copolymer in which the main chain portion is made of a perfluoroalkyl group-containing acrylate polymer and the graft chain portion is made of an MMA / iBMA / βHEMA copolymer Stirrer, condenser, thermometer In a glass flask, reference example 1
70 parts by weight of the macromonomer obtained in 1., perfluoroalkyl group-containing acrylate 30 parts by weight, and 300 parts by weight methyl isobutyl ketone, A
Charge 0.4 parts by weight of IBN, 100 ℃, under nitrogen gas atmosphere,
Reacted for 7 hours. Next, the reaction solution was poured into 10 times the amount of methanol to cause precipitation, which was dried under reduced pressure at 70 ° C. to obtain 96 parts by weight of the graft copolymer. This product showed a single peak by GPC and had a polystyrene reduced molecular weight of n = 12,400. The fluorine content was 18.6 (theoretical value 18.7)% by weight.
参考例３〜18 前出パーフロロアルキル基含有ビニル化合物（Ｉ）と非
フツ素系ビニルモノマーを使用し、参考例１、２と同様
にしてグラフト共重合体を得た。それらの性状を表−１
に記す。Reference Examples 3 to 18 Graft copolymers were obtained in the same manner as in Reference Examples 1 and 2 using the above-mentioned perfluoroalkyl group-containing vinyl compound (I) and a non-fluorine-based vinyl monomer. Table 1 shows their properties.
Note.
参考例19〜22 パーフロロアルキル基含有ビニル化合物（Ｉ）と末端ビ
ニル基含有マクロモノマーを使用し、参考例２と同様の
方法にてグラフト共重合体を得た。グラフト共重合体の
性状を表−２に示す。 Reference Examples 19 to 22 Using the perfluoroalkyl group-containing vinyl compound (I) and the terminal vinyl group-containing macromonomer, a graft copolymer was obtained in the same manner as in Reference Example 2. The properties of the graft copolymer are shown in Table 2.
実施例１ 〔配合〕 上記配合組成物をボールミルで60時間混合し、３μフイ
ルターで過した後、11μｍ厚のポリエステルフイル上
に乾燥厚が５μｍになるよう塗布した。スーパーカレン
ダーにて表面処理し、1/2インチ幅に裁断して磁気テー
プを得た。 Example 1 [Formulation] The above blended composition was mixed in a ball mill for 60 hours, passed through a 3 μ filter and then coated on a polyester film having a thickness of 11 μm so that the dry thickness was 5 μm. The surface was treated with a super calendar and cut into 1/2 inch width to obtain a magnetic tape.
実施例２〜16 実施例１に記載した配合組成物中のグラフト共重合体を
下記化合物に代えて、同様にして磁気テープを得た。Examples 2 to 16 Magnetic tapes were obtained in the same manner by substituting the following compounds for the graft copolymer in the compounded composition described in Example 1.
実施例 2 参考例 3の化合物 〃 3 〃 4 〃 〃 4 〃 5 〃 〃 5 〃 6 〃 〃 6 〃 8 〃 〃 7 〃 9 〃 〃 8 〃 10 〃 〃 9 〃 12 〃 〃 10 〃 14 〃 〃 11 〃 16 〃 〃 12 〃 17 〃 〃 13 〃 19 〃 実施例14 参考例20の化合物 〃 15 〃 21 〃 〃 16 〃 22 〃 比較例１〜９ 実施例１に記載した配合組成物中のグラフト共重合体を
下記化合物に代えて、同様にして磁気テープを得た。Example 2 Compound of Reference Example 3 〃 3 〃 4 〃 〃 4 〃 5 〃 〃 5 〃 6 〃 〃 6 〃 8 〃 7 〃 9 〃 〃 8 〃 10 〃 10 〃 16 〃 〃 12 〃 17 〃 〃 13 〃 19 〃 Example 14 Compound of Reference Example 20 〃 15 〃 21 〃 〃 16 〃 22 〃 Comparative Examples 1-9 Graft co-weight of the compounded composition described in Example 1 A magnetic tape was obtained in the same manner by substituting the following compounds for the coalescence.
以上のようにして得られた各例に磁気テープについて、
角形比（即ち磁性粉の分散配向性）、動摩擦係数（即ち
滑性及び滑性持続性）、走行安定性、耐久性（即ち出力
変動）を測定した。その結果を表−３に示す。 Regarding the magnetic tape in each example obtained as described above,
The squareness ratio (that is, the dispersion orientation of the magnetic powder), the coefficient of kinetic friction (that is, the lubricity and the durability of the lubricity), the running stability, and the durability (that is, the output fluctuation) were measured. The results are shown in Table-3.
尚、角形比は、Vibrating Sample Magnetmeterにて測定
した。動摩擦係数は、１回目の走行における磁気ヘツド
との間の動摩擦係数 と600回走行後の動摩擦係数 について求めた。走行安定性は、ビデオデツキにかけた
時の走行むらを画像より判断し、５段階（5;走行むらが
ない、4;走行むらがほんの僅かにある、3;走行むらが僅
かにある、2;走行むらがある、1;走行むらが顕著であ
る）で評価した。耐久性試験は40℃、85％RHの条件下
で、各磁気テープをヘツド荷重10g、走行速度4.8cm/秒
で600回走行させた後再生し、初期出力に対する出力変
動値を測定して評価した。The squareness ratio was measured with a Vibrating Sample Magnetmeter. The coefficient of dynamic friction is the coefficient of dynamic friction with the magnetic head during the first run. And coefficient of dynamic friction after 600 runs Asked about. The running stability is judged from the image of running unevenness when it is applied to a video deck, and it is classified into 5 stages (5; there is no running unevenness, 4; there is only slight running unevenness, 3; there is slight running unevenness, 2; running) There is unevenness; 1; running unevenness is noticeable). The endurance test was performed by running each magnetic tape 600 times at a head load of 10 g and a running speed of 4.8 cm / sec under conditions of 40 ° C. and 85% RH, and then playing it back. did.
表−３の結果から明らかなように、本発明に係るグラフ
ト共重合体を磁性層中に含有させることにより、従来の
添加剤と比較して角形比、動摩擦抵抗低減性、並びに走
行安定性が優れ、又、 の差並びに出力変動値が少ないことから、本発明の磁気
記録媒体は、磁性粉の分散配向性、表面潤滑性、走行安
定性、そして耐久性に優れたものであることが確認され
た。 As is clear from the results in Table 3, by incorporating the graft copolymer according to the present invention in the magnetic layer, the squareness ratio, the dynamic friction resistance reducing property, and the running stability are improved as compared with the conventional additives. Excellent, It was confirmed that the magnetic recording medium of the present invention was excellent in the dispersion orientation of the magnetic powder, surface lubricity, running stability, and durability because of the small difference and the output fluctuation value.
Claims (1)
20のパーフロロアルキル基含有ビニル化合物の重合体か
ら成り、グラフト鎖部分（Ｂ）が分子中に（メタ）アク
リロイル基を有する化合物を必須成分とする非フッ素系
化合物の重合体から成るグラフト共重合体（Ｇ）を含有
せしめることを特徴とする磁気記録媒体。1. The main chain portion (A) in the magnetic layer has 3 to 10 carbon atoms.
Graft copolymerization consisting of a polymer of 20 perfluoroalkyl group-containing vinyl compounds, and a polymer of a non-fluorine-containing compound whose graft chain portion (B) has a (meth) acryloyl group in the molecule as an essential component A magnetic recording medium containing a combination (G).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3420685A JPH079696B2 (en) | 1985-02-22 | 1985-02-22 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3420685A JPH079696B2 (en) | 1985-02-22 | 1985-02-22 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61194627A JPS61194627A (en) | 1986-08-29 |
| JPH079696B2 true JPH079696B2 (en) | 1995-02-01 |
Family
ID=12407679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3420685A Expired - Fee Related JPH079696B2 (en) | 1985-02-22 | 1985-02-22 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH079696B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10048258B4 (en) * | 2000-09-29 | 2004-08-19 | Byk-Chemie Gmbh | Leveling agent for surface coatings |
| US7050227B2 (en) * | 2003-12-11 | 2006-05-23 | 3M Innovative Properties Company | Composition for microstructured screens |
| JP5094578B2 (en) * | 2008-06-17 | 2012-12-12 | 花王株式会社 | Method for producing graft polymer |
| JP5424962B2 (en) * | 2010-03-31 | 2014-02-26 | 富士フイルム株式会社 | Binder for magnetic recording medium, composition for magnetic recording medium, and magnetic recording medium |
| JP5831248B2 (en) * | 2011-02-17 | 2015-12-09 | 東亞合成株式会社 | Fluorine-based graft copolymer and use thereof |
-
1985
- 1985-02-22 JP JP3420685A patent/JPH079696B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61194627A (en) | 1986-08-29 |
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