JPS5841436A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPS5841436A JPS5841436A JP13772881A JP13772881A JPS5841436A JP S5841436 A JPS5841436 A JP S5841436A JP 13772881 A JP13772881 A JP 13772881A JP 13772881 A JP13772881 A JP 13772881A JP S5841436 A JPS5841436 A JP S5841436A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic recording
- recording medium
- magnetic
- vinyl
- acetate 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.)
- Pending
Links
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
- G11B5/702—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 the bonding agent
Landscapes
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は磁気記録媒体に関し、％に磁性塗膜中の磁性粒
子の分散性が良く、塗膜表面の平滑性が優れ、かつ耐久
性の優れた磁気記録媒体に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium, and more particularly, to a magnetic recording medium which has excellent dispersibility of magnetic particles in a magnetic coating film, excellent smoothness of the coating film surface, and excellent durability.
磁気記録テープ、特にビデオ用磁気記録テープは、短波
長での高再生出力を得、Ｓ／ＮＱ向上させるために、磁
性粒子の磁性塗膜への一様な分散性及び磁性塗膜の高度
の表面平滑性が要求され、また信頼性、耐久性等におめ
てもより長時間、より多数回の使用にも耐え得る物性が
要求されて−る。Magnetic recording tapes, especially video magnetic recording tapes, require uniform dispersion of magnetic particles in the magnetic coating film and high degree of magnetic coating film in order to obtain high playback output at short wavelengths and improve S/NQ. Surface smoothness is required, and physical properties such as reliability and durability that can withstand use over a longer period of time and more times are also required.
上記の要求に応えるために、従来磁性塗膜用のバインダ
ーとして種々の樹脂の組合せ組成が提案されている。こ
１れらの提案によって、物性的には一応の成果が得られ
ているが、分散性及び表面平滑性の向上は未だ十分な状
態にあるとは言えない。In order to meet the above requirements, combinations of various resins have been proposed as binders for magnetic coatings. Although these proposals have produced some results in terms of physical properties, improvements in dispersibility and surface smoothness have not yet been achieved sufficiently.
分散性を向上するために提案された技術には、例えば界
面活性剤を分散剤として使用する、或いはバインダー樹
脂の分子内の親水基（たとえばＯＨ基、Ｃ０ＯＨ基等）
の含有量を増す等の方法があるが、前者においては、磁
性１［１１”ｆ’に低分子量の界面活性剤が存在するこ
とによる物性の劣化、経時変化等の不具合があり、又後
者においては若干の向上は見られるがカーボンブラック
勢の分散性の悪い物質を含む場合とか、分散性の悪し樹
脂と組み合せて使用する場合は十分なる分散は得られな
いものであった。又、一般に分散性が良くなれば表面平
滑性も向上するものであるが、分散性の悪い掬脂を使用
しても、軟かい樹脂を大量に使用すればカレンダー等の
表面加工を行なうことにより表面平滑性による変調ノイ
ズを下げることは出来るが、分散不足によるノイズが有
る。又、軟かい樹脂を多用することにより、磁性塗膜の
マサッが上がり、耐久性等においても望ましいものでは
ない。Techniques that have been proposed to improve dispersibility include, for example, using surfactants as dispersants, or adding hydrophilic groups (such as OH groups, COOH groups, etc.) within the molecules of the binder resin.
There are methods such as increasing the content of the Although there was a slight improvement in the dispersibility, sufficient dispersion could not be obtained when carbon black contained substances with poor dispersibility or when used in combination with resins with poor dispersibility. However, even if resin with poor dispersibility is used, if a large amount of soft resin is used, the surface smoothness can be improved by performing surface treatments such as calendering. Although it is possible to reduce modulation noise, there is noise due to insufficient dispersion.Furthermore, by using a large amount of soft resin, the magnetic coating film becomes bulky, which is not desirable in terms of durability.
本発明はこれらの欠点を改良して、分散性、表面平滑性
が優れ、また耐久性にも優れた磁気記録媒体を提供する
ことを目的とする。The object of the present invention is to improve these drawbacks and provide a magnetic recording medium that has excellent dispersibility, surface smoothness, and durability.
本発明者轡は、種々の検討及び実験を重ねた結果、分散
性の非常に優れた特殊のポリウレタン樹脂と、分散性を
改善した塩化ビニル−酢酸ビニル共重合体とをバインダ
ー成分とし且つこれをインシアネート化合物で架橋する
ことにより、分散性、表面平滑性及び耐久性の優れた磁
気記録媒体を提供することができた。As a result of various studies and experiments, the inventor of the present invention has developed a special polyurethane resin with extremely excellent dispersibility and a vinyl chloride-vinyl acetate copolymer with improved dispersibility as a binder component. By crosslinking with an incyanate compound, a magnetic recording medium with excellent dispersibility, surface smoothness, and durability could be provided.
本発明に使用するポリウレタン樹脂は、一般に金属スル
ホン酸塩より成る基、好ましくはスルホン酸ナトリウム
基（以下−８ＯｓＮａ 基）を含有するポリウレタン
樹脂である。−８０５Ｎａ 基を側鎖として有すること
により、分散剤を使用するのと同じ効果を発揮し、かつ
低分子量の分散剤を用いる場合の欠点のないバインダー
が提供できる。The polyurethane resin used in the present invention is generally a polyurethane resin containing a group consisting of a metal sulfonate, preferably a sodium sulfonate group (hereinafter referred to as -8OsNa group). By having an -805Na group as a side chain, a binder can be provided that exhibits the same effect as using a dispersant and does not have the disadvantages of using a low molecular weight dispersant.
本発明者は、特願昭５５−１５２５４５等において、ス
ルホン酸ナトリウム基を含有するポリウレタン樹脂等を
使用した磁気記録媒体を提案した。The present inventor proposed a magnetic recording medium using a polyurethane resin containing a sodium sulfonate group in Japanese Patent Application No. 55-152545 and the like.
これによりポリウレタン樹脂等の分散性は飛躍的に向上
したが、磁気記録媒体の諸物性を向上させるために他の
樹脂と併用すると、折角の分散性がやや阻害される傾向
が見られた。This dramatically improved the dispersibility of polyurethane resins, etc., but when used in combination with other resins to improve the physical properties of magnetic recording media, there was a tendency for the dispersibility to be somewhat inhibited.
従って、本発明は上記の欠点のないバインダー組成を鋭
意探求した結果、上記改良型のポリウレタン樹脂に、ビ
ニルアルコール成分を８ｓ以上含有する塩化ビニル・酢
酸ビニル共重合体を組合せ、さらにこれらをイソシアネ
ート化合物で架橋することにより、分散性、表面平滑性
が非常に優れ、しかも走行耐久性のすぐれた磁気記録媒
体を得ることができた。Therefore, as a result of intensive search for a binder composition free from the above-mentioned drawbacks, the present invention combines the above-mentioned improved polyurethane resin with a vinyl chloride/vinyl acetate copolymer containing a vinyl alcohol component of 8s or more, and further combines these into an isocyanate compound. By crosslinking with , it was possible to obtain a magnetic recording medium with very excellent dispersibility and surface smoothness, as well as excellent running durability.
本発明の実施例に使用したー５ＯｓＮａ 基含有ポリウ
レタン樹脂は、ジカルボン酸成分（プレフタル酸、イソ
フタル酸、セバシン酸）、多価アルコール成分（エチレ
ンクリコール、ネオペンチルクリコ” ） オヨヒ−８
ＵｓＮａ 基を有するジカルボン酸成分（５−ナトリ
ウムスルホイソフタル酸）を重縮合して得たポリエステ
ル樹脂を、ジフェニルメタン４４′ ジイソシアネート
（ＭＤＩ）でウレタン化したものであるが、必要に応じ
てポリエステル樹脂を生成する成分として種々のジカル
ボン酸、多価アルコール成分を組み合せて使用すること
が出来、又、ポリエステル樹脂に反応させるイソシアネ
ート成分としては種々のジイソシアネート化合物、たと
えばヘキサメチレンジインクアネート（ＨＭＤｌ、）、
トルエンジイソシアネー）（ＴＤＩ）、ｔ５−ナフタル
ンジインシアネート（ＮＤＩ）、トリジンジイソシアネ
ー）（ＴＯＤＩ）、 リジンジインシアネートメチル
千ステル（ＬＤＩ）などが使用出来る。The -5OsNa group-containing polyurethane resin used in the examples of the present invention contains a dicarboxylic acid component (prephthalic acid, isophthalic acid, sebacic acid), a polyhydric alcohol component (ethylene glycol, neopentyl glycol) OYOHI-8
A polyester resin obtained by polycondensing a dicarboxylic acid component (5-sodium sulfoisophthalic acid) having a UsNa group is urethanized with diphenylmethane 44' diisocyanate (MDI), but a polyester resin can be produced as needed. Various dicarboxylic acids and polyhydric alcohol components can be used in combination as a component to react with the polyester resin, and various diisocyanate compounds such as hexamethylene diincanate (HMDl),
Toluene diisocyanate (TDI), t5-naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI), lysine diisocyanate methyl 1,000 stel (LDI), etc. can be used.
本実ＩｊＩＫ使用する塩化ビニル酢酸ビニル共重合体は
、従来の塩化ビニル酢酸ビニル共重合体のビニルアルコ
ール成分が０〜４−程度であったものを８−以上にした
ものである。−側基の親水性の為磁性粉表面（親水性）
との濡れが曳くなり分散性が向上する（本発明における
ポリウレタン樹脂の一８Ｏ３Ｎ！ 基はこれの更に優れ
たものである）が、０〜５ｇ＆ではほとんど効果がなく
、６−を越えるとその効果があられれ、約８慢でその効
果が大きく発揮され、それ以上ではその効果は飽和する
。The vinyl chloride/vinyl acetate copolymer used by Honjitsu IjIK is one in which the vinyl alcohol component of the conventional vinyl chloride/vinyl acetate copolymer is about 0 to 4, but is increased to 8 or more. -Magnetic powder surface (hydrophilic) due to hydrophilic side groups
(The polyurethane resin of the present invention, the 8O3N! group, is even better than this), but at 0 to 5g, there is almost no effect, and when it exceeds 6-, the effect is reduced. Hare, its effect is greatly demonstrated at about 8 arrogances, and beyond that the effect saturates.
ビニルアルコール成分を８−以上含有する塩化ビニル酢
酸ビニル共重合体は、塩化ビニル、酢酸ビニル共重合体
としては非常に優れた分散性を有するが、本発明のよう
に優れた分散性を有する樹脂と組み合せて使用すること
により、はじめて従来得られなかった非常に高分散性の
磁気記録媒体用バインダーを提供するものである。A vinyl chloride/vinyl acetate copolymer containing 8 or more vinyl alcohol components has very excellent dispersibility as a vinyl chloride/vinyl acetate copolymer, but resins with excellent dispersibility as in the present invention By using the binder in combination with the present invention, it is possible to provide a binder for magnetic recording media with extremely high dispersibility, which has not been previously available.
ポリウレタン樹脂と塩化ビニル・酢酸ビニル共重合体の
組み合せは、磁気記録媒体用バインダーとしては走行耐
久性等物性の優れたものであるが、磁気記録媒体が使用
される環境のうち高温（４０〜５０℃）では充分な耐用
度を有するとはいえないことが分った。本発明は、イン
シアネート化合物な用いて架橋を行なうことによってこ
の点についても改良を行ない、非常に分散性、表面平滑
性が優れかつ、耐久性の優れた磁気記録媒体を提供する
ものである。本発明に使用出来るイソシアネート化０合
物は、インシアネート基を２個以上有するインクアネー
ト化合物、またはそれらのアダクト体（２１体、５１１
体等のアダクト体、又は２価又は３価の多価アルコール
とのアダクト体等）である。The combination of polyurethane resin and vinyl chloride/vinyl acetate copolymer has excellent physical properties such as running durability as a binder for magnetic recording media. ℃), it was found that it could not be said to have sufficient durability. The present invention improves this point by performing crosslinking using an incyanate compound, and provides a magnetic recording medium with excellent dispersibility, surface smoothness, and durability. The isocyanate compound that can be used in the present invention is an inquanate compound having two or more incyanate groups, or an adduct thereof (21 compound, 511 compound).
or adducts with divalent or trivalent polyhydric alcohols, etc.).
本発明において使用される磁性粉は、γ−酸化鉄、コバ
ルト被着ｒ−酸化鉄、コバルトドープｒ−酸化鉄、Ｃｒ
Ｏ合金磁性粉、メタル磁性粉等 −
である。The magnetic powder used in the present invention includes γ-iron oxide, cobalt-coated r-iron oxide, cobalt-doped r-iron oxide, Cr
O alloy magnetic powder, metal magnetic powder, etc.
又、必要に応じて帯電防止剤、カーボンブラック、調清
剤、非磁性無機顔料等を添加し【使用してもよい。Furthermore, antistatic agents, carbon black, conditioners, non-magnetic inorganic pigments, etc. may be added as necessary.
以下、本発明の詳細な説明する。The present invention will be explained in detail below.
本発明の実施例に使用した樹脂を以下に示す。The resins used in the examples of the present invention are shown below.
ポリウレタン樹脂
塩化ビニル酢酸ビニル共重合体
実施例
重量部
コバルト被着ｒ−Ｆｅ２０． ４００ポリ
クレタン樹脂（表−１による）５゜塩化ビニル・酢酸ビ
ニル共重合体（表−１による）５０カーボンブラツク
５０潤滑剤
１Ｇ非非磁性機顔料 ２０メ
チルエチルケトン ４００トルエン
４００表−１の樹脂の組み合せで上
記組成物を通常用いられる方法により充分分散した後、
ポリエチレンテレフタレートフィルム上に乾燥後５ａｌ
ｌとなるように塗布し乾燥した。Polyurethane resin Vinyl chloride Vinyl acetate copolymer Examples Parts by weight Cobalt coated r-Fe20. 400 Polycrethane resin (according to Table 1) 5° Vinyl chloride/vinyl acetate copolymer (according to Table 1) 50 Carbon black
50 lubricant
1G non-magnetic mechanical pigment 20 methyl ethyl ketone 400 toluene
After sufficiently dispersing the above composition with the combination of resins shown in Table 400 by a commonly used method,
5al after drying on polyethylene terephthalate film
1 and dried.
得られた磁気記録媒体の磁性塗膜の表藺反射本を測定し
たところ、図に示す結果を得た。When the surface reflection of the magnetic coating film of the obtained magnetic recording medium was measured, the results shown in the figure were obtained.
以上の結果から分るように、ポリウレタン樹脂に一８０
ｓＮａ 基を含有させることＫより、磁気記録媒体の
表面平滑性の向上は非常に大きくなる。又、塩化ビニル
・酢酸ビニル共重合体中のビニルアルコール成分の量を
６チ以上Ｋ１ｇ整すると、表面平滑性はさらに向上し、
約ＳＳで非常に改善され、ビニルアルコール成分が約８
−を越えると、表面平滑性に対する効果は飽和する。As can be seen from the above results, polyurethane resin
Inclusion of sNa groups greatly improves the surface smoothness of the magnetic recording medium. In addition, when the amount of vinyl alcohol component in the vinyl chloride/vinyl acetate copolymer is adjusted to 6 g or more, the surface smoothness is further improved.
Very improved with approx. SS, vinyl alcohol content is approx. 8
-, the effect on surface smoothness is saturated.
試料１〜１２の中でも最もすぐれたものの１つである試
料１２の塗料組成物に、イソシアネート化合物としてデ
スモジュールＬ（バイエル社製）を２０重量部添加した
後、試料１〜１２の処理プロセスと同様の方法で塗布・
乾燥し、次いでカレンダー加工をした後、所定の温度で
熱処理して硬化を行い、適宜の幅に切断して磁気記録テ
ープ（以下実施例テープと呼ぶ）を得た。一方、試料１
２の磁気記録媒体にカレンダー加工を施し、同様にテー
プ化したもの（以下比較デーグと呼ぶ）を比較のために
用いた。結果は次表に示す通りであった。After adding 20 parts by weight of Desmodur L (manufactured by Bayer AG) as an isocyanate compound to the coating composition of Sample 12, which is one of the best among Samples 1 to 12, the same treatment process as Samples 1 to 12 was applied. Apply by the method of
After drying and calendering, it was cured by heat treatment at a predetermined temperature and cut into appropriate widths to obtain a magnetic recording tape (hereinafter referred to as Example tape). On the other hand, sample 1
The magnetic recording medium of No. 2 was calendered and made into a tape in the same manner (hereinafter referred to as comparative dagu), which was used for comparison. The results are shown in the table below.
以上の結果より一８ＯｓＮａ 含有ポリウレタン樹脂お
よびビニルアルコール成分を８−以上含有する塩化ビニ
ル・酢酸ビニル共重合体をバインダー成分とし、かつイ
ンシアネート化合物を架橋剤として使用した磁気記録媒
体は、分散性、表面性に優れかつ耐久性も優れたもので
ある。From the above results, a magnetic recording medium using a polyurethane resin containing 18OsNa and a vinyl chloride/vinyl acetate copolymer containing 8 or more vinyl alcohol components as a binder component and an incyanate compound as a crosslinking agent has good dispersibility, It has excellent surface properties and durability.
図面は塩化ビニル・酢酸ビニル共重合体中のビニルアル
コール成分及びポリウレタン樹脂中のスルホン酸す）９
ウム基が、磁気配録媒体の表面反射率に及ぼす影参を示
すグラフである。The drawing shows the vinyl alcohol component in the vinyl chloride/vinyl acetate copolymer and the sulfonic acid component in the polyurethane resin)9
2 is a graph showing the influence of umium groups on the surface reflectance of a magnetic recording medium.
Claims (1)
ビニルアルコール成分を８−以上含有する塩化ビニル・
酢酸ビニル共重合体とより成るバインダーに、インシア
ネート化合物を架橋剤として含有させ、磁性粉末を分散
させた磁性塗膜を支持体上に被着して成る、磁気記録媒
体。 ２ スルホン酸金属塩の基は一８０ｓＮａ である、
特許請求の範囲第１項記載の磁気記録媒体。[Claims] t) A polyurethane resin having a sulfonic acid metal salt group and a vinyl chloride resin containing 8 or more vinyl alcohol components.
A magnetic recording medium comprising a binder made of a vinyl acetate copolymer containing an incyanate compound as a crosslinking agent, and a magnetic coating film in which magnetic powder is dispersed, coated on a support. 2 The group of the sulfonic acid metal salt is -80sNa,
A magnetic recording medium according to claim 1.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13772881A JPS5841436A (en) | 1981-09-03 | 1981-09-03 | Magnetic recording medium |
| US06/412,164 US4411957A (en) | 1981-09-03 | 1982-08-27 | Magnetic recording medium |
| DE19823232008 DE3232008A1 (en) | 1981-09-03 | 1982-08-27 | MAGNETIC RECORDING CARRIER |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13772881A JPS5841436A (en) | 1981-09-03 | 1981-09-03 | Magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5841436A true JPS5841436A (en) | 1983-03-10 |
Family
ID=15205437
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13772881A Pending JPS5841436A (en) | 1981-09-03 | 1981-09-03 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5841436A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61180927A (en) * | 1985-02-06 | 1986-08-13 | Matsushita Electric Ind Co Ltd | Magnetic recording medium |
| JPS62119725A (en) * | 1985-11-19 | 1987-06-01 | Konishiroku Photo Ind Co Ltd | Magnetic recording medium |
| JPS62119728A (en) * | 1985-11-19 | 1987-06-01 | Konishiroku Photo Ind Co Ltd | Magnetic recording medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5674824A (en) * | 1979-11-20 | 1981-06-20 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS5674825A (en) * | 1979-11-20 | 1981-06-20 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS5674826A (en) * | 1979-11-20 | 1981-06-20 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS5674823A (en) * | 1979-11-20 | 1981-06-20 | Hitachi Maxell Ltd | Magnetic recording medium |
-
1981
- 1981-09-03 JP JP13772881A patent/JPS5841436A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5674824A (en) * | 1979-11-20 | 1981-06-20 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS5674825A (en) * | 1979-11-20 | 1981-06-20 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS5674826A (en) * | 1979-11-20 | 1981-06-20 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS5674823A (en) * | 1979-11-20 | 1981-06-20 | Hitachi Maxell Ltd | Magnetic recording medium |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61180927A (en) * | 1985-02-06 | 1986-08-13 | Matsushita Electric Ind Co Ltd | Magnetic recording medium |
| JPH0535483B2 (en) * | 1985-02-06 | 1993-05-26 | Matsushita Electric Ind Co Ltd | |
| JPS62119725A (en) * | 1985-11-19 | 1987-06-01 | Konishiroku Photo Ind Co Ltd | Magnetic recording medium |
| JPS62119728A (en) * | 1985-11-19 | 1987-06-01 | Konishiroku Photo Ind Co Ltd | Magnetic recording medium |
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