JPH01232528A - Magnetic recording medium - Google Patents

Magnetic recording medium

Info

Publication number
JPH01232528A
JPH01232528A JP63058883A JP5888388A JPH01232528A JP H01232528 A JPH01232528 A JP H01232528A JP 63058883 A JP63058883 A JP 63058883A JP 5888388 A JP5888388 A JP 5888388A JP H01232528 A JPH01232528 A JP H01232528A
Authority
JP
Japan
Prior art keywords
magnetic
benzyl acetate
powder
magnetic powder
acetate
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
Application number
JP63058883A
Other languages
Japanese (ja)
Inventor
Mikio Kishimoto
幹雄 岸本
Yoshinori Yamamoto
山本 芳典
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Maxell Ltd
Original Assignee
Hitachi Maxell Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Maxell Ltd filed Critical Hitachi Maxell Ltd
Priority to JP63058883A priority Critical patent/JPH01232528A/en
Publication of JPH01232528A publication Critical patent/JPH01232528A/en
Pending legal-status Critical Current

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Landscapes

  • Paints Or Removers (AREA)
  • Magnetic Record Carriers (AREA)

Abstract

PURPOSE:To enhance the dispersibility of magnetic powder in a binder resin and to improve the magnetic characteristics of the magnetic recording medium by incorporating benzyl acetate into the magnetic powder to form the magnetic layer of the magnetic recording medium. CONSTITUTION:The benzyl acetate is relatively small in mol.wt. and has a hydrophilic acetic acid group and lipophilic arom. ring. The surface of the benzyl acetate is securely bonded to the hydrophilic magnetic powder by the hydrophilic acetate group possessed in the molecule and since the benzyl acetate has an arom. ring as a lipophilic property, the benzyl acetate has the good affinity to the lipophilic binder resin. The benzyl acetate is, therefore, well deposited on the surface of the magnetic powder if the benzyl acetate is incorporated into the magnetic layer. The dispersibility of the magnetic powder in the binder resin is thereby sufficiently enhanced and the magnetic characteristics are greatly improved.

Description

【発明の詳細な説明】 〔産業上の利用分野] この発明は磁気記録媒体に関し、さらに詳しくは、磁性
粉末の分散性が良好で磁気特性に優れた磁気記録媒体に
関する。
DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a magnetic recording medium, and more particularly to a magnetic recording medium in which magnetic powder has good dispersibility and excellent magnetic properties.

〔従来の技術〕[Conventional technology]

磁気記録媒体は、通常、磁性粉末、結合剤成分、有機溶
剤およびその他の必要成分からなる磁性塗料をポリエス
テルフィルムなどの基体上に塗布、乾燥してつくられ、
磁気特性に優れたものが要求される。
Magnetic recording media are usually made by applying a magnetic paint consisting of magnetic powder, a binder component, an organic solvent, and other necessary components onto a substrate such as a polyester film, and drying the coating.
A material with excellent magnetic properties is required.

そのため、使用される磁性粉末は分散性に優れ、磁気記
録媒体に優れた磁気特性を付与できるものであることが
望ましいが、磁性粉末の表面ば通常親水性であるため、
そのままでは親油性の結合剤樹脂中に良好に分散するこ
とが難しい。
Therefore, it is desirable that the magnetic powder used has excellent dispersibility and can impart excellent magnetic properties to the magnetic recording medium, but since the surface of the magnetic powder is usually hydrophilic,
As it is, it is difficult to disperse it well in the lipophilic binder resin.

そこで、磁性粉末の分散性を良好にするため、分子の一
端に親水基、他端に親油基を有する脂肪酸などを分散剤
として磁性塗料中に混入させることが提案されている。
Therefore, in order to improve the dispersibility of the magnetic powder, it has been proposed to mix a fatty acid having a hydrophilic group at one end of the molecule and a lipophilic group at the other end into the magnetic paint as a dispersant.

(特開昭51−33703号) (発明が解決しようとする課題〕 ところが、これらの脂肪酸等の分散剤は、未だ磁性粉末
との結合力が弱くて結合剤樹脂とのなじみもそれほど良
好でなく、磁性粉末の結合剤樹脂中における分散性を未
だ充分に改善することができない。
(Unexamined Japanese Patent Publication No. 51-33703) (Problems to be Solved by the Invention) However, these dispersants such as fatty acids still have a weak bonding force with magnetic powder and are not so compatible with the binder resin. However, it is still not possible to sufficiently improve the dispersibility of magnetic powder in a binder resin.

〔課題を解決するための手段] この発明は、かかる現状から磁性粉末の結合剤樹脂中へ
の分散にさらに有効なものを見出すべく、親油基と親水
基をともに有する化合物群について種々検討を行った結
果、酢酸ベンジルが特に優れた分散能力を有することが
わかりなされたもので、酢酸ベンジルを使用することに
よって、磁性粉末の分散性を充分に改善し、得られる磁
気記録媒体の磁気特性を充分に向上させたものである。
[Means for Solving the Problems] In view of the current situation, the present invention conducts various studies on a group of compounds having both a lipophilic group and a hydrophilic group in order to find something more effective for dispersing magnetic powder into a binder resin. As a result, it was found that benzyl acetate has particularly excellent dispersion ability. By using benzyl acetate, the dispersibility of magnetic powder can be sufficiently improved, and the magnetic properties of the resulting magnetic recording medium can be improved. This is a sufficient improvement.

かかる酢酸ヘンシルが、如何なる理由で優れた分散能力
を有するかについては、未だ明確には解明されていない
が、その固有の化学構造につき考察すると、親水基であ
る酢酸基と、親油基である芳香環を併せもつため、磁性
粉末との結合力が強化されるとともに、結合剤樹脂との
なじみが良好になることが考えられる。
It has not yet been clearly elucidated why Hensyl acetate has such excellent dispersion ability, but considering its unique chemical structure, it consists of an acetate group, which is a hydrophilic group, and a lipophilic group. Since it also has an aromatic ring, it is thought that the bonding force with the magnetic powder is strengthened and the compatibility with the binder resin is improved.

この発明において使用される酢酸ベンジルは、化学式 %式% で表される化合物で、分子量が比較的小さく、親水性の
酢M基と、親油性の芳香環を有する。しかして、この酢
酸ベンジルは、分子中に有する親水性の酢酸基により表
面が親水性の磁性粉末と強固に結合し、また親油基とし
て芳香環を有するため、親油性の結合剤樹脂となじみや
すい。従って、この酢酸ベンジルが磁性層中に含有され
ると、磁性粉末表面に良好に被着して、磁性粉末の結合
剤樹脂中における分散性が充分に改善され、磁気特性が
充分に向上される。
Benzyl acetate used in the present invention is a compound represented by the chemical formula %, which has a relatively small molecular weight and has a hydrophilic acetic acid M group and a lipophilic aromatic ring. However, this benzyl acetate has a hydrophilic acetate group in its molecule that firmly bonds to the magnetic powder whose surface is hydrophilic, and since it has an aromatic ring as a lipophilic group, it is compatible with the lipophilic binder resin. Cheap. Therefore, when this benzyl acetate is contained in the magnetic layer, it adheres well to the surface of the magnetic powder, sufficiently improving the dispersibility of the magnetic powder in the binder resin, and sufficiently improving the magnetic properties. .

このような酢酸ベンジルは、これを磁性塗料調製時に直
接添加するか、またはこれをアルコール、エーテル等の
適当な溶剤に溶解させ、この溶解によって得られた溶液
を磁性塗料の調製時に添加するか、あるいはこの溶液中
に磁性粉末を浸漬して、予め磁性粉末の表面処理を行い
、この磁性粉末を使用して磁性塗料を調製し、これを基
体上に塗布、乾燥するなどの方法で磁性層中に含有され
る。
Such benzyl acetate can be added directly when preparing a magnetic paint, or it can be dissolved in a suitable solvent such as alcohol or ether, and the solution obtained by this dissolution can be added when preparing a magnetic paint. Alternatively, the magnetic powder is immersed in this solution, the surface of the magnetic powder is treated in advance, the magnetic powder is used to prepare a magnetic paint, and this is applied onto the substrate and dried to form a magnetic layer. Contained in

このようにして磁性層中に含有される酢酸ヘンシルの含
有量は、磁性粉末に対して0.1〜10重量%の範囲内
にするのが好ましい。また、この酢酸ベンジルは他の分
散剤、たとえば、飽和脂肪酸類、不飽和脂肪酸類、脂肪
酸エステル類、リン酸エステル類、レシチン、金属石鹸
類、アルコール類等と併用してもよい。なお、この酢酸
ヘンシルは、独特の匂いを発するが人体に全く無害であ
り、むしろ快適な匂いである。
The content of Hensyl acetate thus contained in the magnetic layer is preferably within the range of 0.1 to 10% by weight based on the magnetic powder. Furthermore, this benzyl acetate may be used in combination with other dispersants such as saturated fatty acids, unsaturated fatty acids, fatty acid esters, phosphoric acid esters, lecithin, metal soaps, alcohols, and the like. Although Hensyl acetate emits a unique odor, it is completely harmless to the human body and is rather a pleasant odor.

この発明に使用する磁性粉末としては、たとえば、7−
Fe201粉末、Fe30a粉末、T−FezOi粉末
とFe3O4粉末の中間化合物粉末、Co含有7Fez
C1+粉末、Co含有Fe3O4粉末、Cry、粉末の
他、α−Fe粉末、Cc粉末、Fe−Ni粉末、Fe、
N粉末、Fe−Co粉末、Ba−フェライト粉末など従
来公知の各種磁性粉末が広く包含される。
Examples of the magnetic powder used in this invention include 7-
Fe201 powder, Fe30a powder, intermediate compound powder between T-FezOi powder and Fe3O4 powder, Co-containing 7Fez
In addition to C1+ powder, Co-containing Fe3O4 powder, Cry powder, α-Fe powder, Cc powder, Fe-Ni powder, Fe,
Various conventionally known magnetic powders such as N powder, Fe--Co powder, and Ba-ferrite powder are widely included.

また、結合剤樹脂としては、塩化ビニル−酢酸ビニル系
共重合体、繊維素系樹脂、ポリビニルブチラール系樹脂
、ポリウレタン系樹脂、ポリエステル系樹脂、エポキシ
系樹脂、ポリエーテル系樹脂、イソシアネート化合物、
放射線硬化型樹脂など従来から汎用されている結合剤樹
脂がいずれも用いられる。
Examples of binder resins include vinyl chloride-vinyl acetate copolymers, cellulose resins, polyvinyl butyral resins, polyurethane resins, polyester resins, epoxy resins, polyether resins, isocyanate compounds,
Any of the binder resins that have been widely used in the past, such as radiation-curable resins, can be used.

有機溶剤としては、シクロヘキサノン、メチルエチルケ
トン、メチルイソブチルケトンなどのケトン系溶剤、酢
酸エチル、酢酸ブチルなどのエステル系溶剤、ベンゼン
、トルエン、キシレンなどの芳香族炭化水素系溶剤、ジ
メチルスルホキシドなどのスルホキシド系溶剤、テトラ
ヒドロフラン、ジオキサンなどのエーテル系溶剤など、
使用する結合剤樹脂を溶解するのに通した溶剤が、特に
制限されることなく単独または二種以上混合して使用さ
れる。
Examples of organic solvents include ketone solvents such as cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, aromatic hydrocarbon solvents such as benzene, toluene, and xylene, and sulfoxide solvents such as dimethyl sulfoxide. , ether solvents such as tetrahydrofuran, dioxane, etc.
The solvent used to dissolve the binder resin is not particularly limited and may be used alone or in combination of two or more.

なお、磁性塗料中には通常使用されている各種添加剤、
たとえば、潤滑剤、研磨剤、帯電防止剤などを適宜に添
加使用してもよい。
In addition, various additives commonly used in magnetic paints,
For example, a lubricant, an abrasive, an antistatic agent, etc. may be added as appropriate.

また、この発明の磁気記録媒体は、磁気テープ、磁気デ
ィスク、磁気カード等、従来公知の各種の形状の磁気記
録媒体を包含する。
Furthermore, the magnetic recording medium of the present invention includes magnetic recording media of various conventionally known shapes, such as magnetic tapes, magnetic disks, and magnetic cards.

〔実施例〕〔Example〕

次に、この発明の実施例について説明する。 Next, embodiments of the invention will be described.

実施例I Co含有r  FezO3800重計部VAGH(米国
U、C,C,社製、塩 120〃化ビニル−酢酸ビニル
−ビニ ルアルコール共重合体) 酢酸ベンジル          16〃メチルイソブ
チルケトン    400〃トルエン        
       400  ノ!この組成物をボールミル
中で72時間混合分散したのち、 クケラノクE−551T (武田薬  65重量部品工
業社製、ポリウレタン樹 脂) コロ2−トL(日本ボリウレタ  15〃ン工業社製、
三官能性低分子 量イソシアネート化合物) を添加し、さらに1時間混合分散して磁性塗料を調製し
た。この磁性塗料を厚さ11μmのポリエステルフィル
ム上に乾燥厚が約4μmとなるように塗布、乾燥し、カ
レンダー処理を行ったのち、所定の巾に裁断して磁気テ
ープをつくった。
Example I Co-containing r FezO3800 weighing unit VAGH (manufactured by U.C.C., USA, salt 120 vinylide-vinyl acetate-vinyl alcohol copolymer) benzyl acetate 16 methyl isobutyl ketone 400 toluene
400 no! After mixing and dispersing this composition in a ball mill for 72 hours, Kukeranoku E-551T (manufactured by Takeda Yakuhin 65 Heavy Parts Industry Co., Ltd., polyurethane resin), Coro 2-T L (manufactured by Nippon Polyurethane Industry Co., Ltd., polyurethane resin),
A trifunctional low molecular weight isocyanate compound) was added and mixed and dispersed for an additional hour to prepare a magnetic paint. This magnetic paint was applied onto a polyester film with a thickness of 11 μm to a dry thickness of about 4 μm, dried, calendered, and then cut into a predetermined width to produce a magnetic tape.

実施例2 実施例1における磁性塗料の組成において、酢酸ベンジ
ルの使用量を16重量部から8重量部に変更した以外は
、実施例1と同様にして磁気テープをつくった。
Example 2 A magnetic tape was produced in the same manner as in Example 1, except that in the composition of the magnetic paint in Example 1, the amount of benzyl acetate used was changed from 16 parts by weight to 8 parts by weight.

比較例1 実施例1における磁性塗料の組成において、酢酸ヘンシ
ルを省いた以外は、実施例1と同様にして磁気テープを
つくった。
Comparative Example 1 A magnetic tape was produced in the same manner as in Example 1 except that Hensyl acetate was omitted from the composition of the magnetic paint in Example 1.

比較例2 実施例1における磁性塗料の組成において、酢酸ベンジ
ルに代えてラウリン酸を同量使用した以外は、実施例1
と同様にして磁気テープをつくった。
Comparative Example 2 Example 1 except that the same amount of lauric acid was used in place of benzyl acetate in the composition of the magnetic paint in Example 1.
I made magnetic tape in the same way.

各実施例および比較例で得られた磁気テープについて、
保磁力、角型、残留磁束密度及び飽和磁束密度を測定し
た。
Regarding the magnetic tapes obtained in each example and comparative example,
Coercive force, squareness, residual magnetic flux density, and saturation magnetic flux density were measured.

下記第1表はその結果である。Table 1 below shows the results.

第1表 [発明の効果] 上記第1表から明らかなように、この発明で得られた磁
気テープ(実施例1および2)は従来の磁気テープ(比
較例1および2)に比べて、角型、残留磁束密度および
飽和磁束密度がいずれも高く、このことからこの発明に
よって得られる磁気記録媒体は、磁性粉末の分散性が良
好で、磁気特性が一段と向上されていることがわかる。
Table 1 [Effects of the Invention] As is clear from Table 1 above, the magnetic tapes obtained by the present invention (Examples 1 and 2) have a higher angle than the conventional magnetic tapes (Comparative Examples 1 and 2). The type, residual magnetic flux density, and saturation magnetic flux density are all high, which indicates that the magnetic recording medium obtained by the present invention has good dispersibility of magnetic powder and further improved magnetic properties.

Claims (1)

【特許請求の範囲】[Claims] 1、磁性粉末と、酢酸ベンジルとが含まれてなる磁性層
を有する磁気記録媒体
1. Magnetic recording medium having a magnetic layer containing magnetic powder and benzyl acetate
JP63058883A 1988-03-11 1988-03-11 Magnetic recording medium Pending JPH01232528A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP63058883A JPH01232528A (en) 1988-03-11 1988-03-11 Magnetic recording medium

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63058883A JPH01232528A (en) 1988-03-11 1988-03-11 Magnetic recording medium

Publications (1)

Publication Number Publication Date
JPH01232528A true JPH01232528A (en) 1989-09-18

Family

ID=13097169

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63058883A Pending JPH01232528A (en) 1988-03-11 1988-03-11 Magnetic recording medium

Country Status (1)

Country Link
JP (1) JPH01232528A (en)

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