JPH07141653A - Magnetic recording medium and its production - Google Patents
Magnetic recording medium and its productionInfo
- Publication number
- JPH07141653A JPH07141653A JP28830893A JP28830893A JPH07141653A JP H07141653 A JPH07141653 A JP H07141653A JP 28830893 A JP28830893 A JP 28830893A JP 28830893 A JP28830893 A JP 28830893A JP H07141653 A JPH07141653 A JP H07141653A
- Authority
- JP
- Japan
- Prior art keywords
- abrasive
- binder
- ferromagnetic powder
- dispersion liquid
- magnetic
- 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.)
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Links
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- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、オーディオ機器，ビデ
オ機器、あるいはコンピューターなどに用いる磁気記録
媒体とその製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium used in audio equipment, video equipment, computers, etc. and a method for manufacturing the same.
【０００２】[0002]
【従来の技術】近年、磁気記録の分野においては、ビデ
オ機器の高画質化の進行あるいはアナログ記録からデジ
タル記録への記録方式の変化などにより、記録波長は益
々短くなっている。そのため、これらに用いられる強磁
性粉末についても電磁変換特性の向上を狙い微粒子化が
進んでいるが、強磁性粉末が微粒子になるほど磁気記録
媒体の磁性層の耐久性(スチル寿命，磁気ヘッドへの粉
付着，磁性層の粉落ち等)が悪化する。このため、磁性
層の耐久性向上のため結合剤樹脂，潤滑剤，研磨剤など
の改良が活発に行われている。2. Description of the Related Art In recent years, in the field of magnetic recording, the recording wavelength has become shorter and shorter due to the progress of higher image quality of video equipment and the change of recording system from analog recording to digital recording. For this reason, the ferromagnetic powders used for these are also becoming finer particles with the aim of improving the electromagnetic conversion characteristics. However, as the ferromagnetic powders become finer particles, the durability of the magnetic layer of the magnetic recording medium (still life, magnetic head (Powder adhesion, powder drop on the magnetic layer, etc.) worsens. Therefore, in order to improve the durability of the magnetic layer, the binder resin, the lubricant, the abrasive and the like are being actively improved.
【０００３】[0003]
【発明が解決しようとする課題】近年の磁気記録媒体の
高密度記録化に伴い、上述したように磁気記録媒体に用
いられる強磁性粉末の微粒子化は更に進み、さらにはヘ
ッド−磁気記録媒体間の相対速度も増加する傾向があ
る。このことによる磁気記録媒体の耐久性低下に対し研
磨剤の影響は大きく、種類，粒子径，添加量等、様々な
検討が行われている。With the recent trend toward higher density recording of magnetic recording media, the finer particles of the ferromagnetic powder used in the magnetic recording media have been further developed, as described above, and further, between the head and the magnetic recording medium. The relative speed of the tends to increase. The influence of the abrasive on the deterioration of the durability of the magnetic recording medium due to this is great, and various studies have been conducted on the type, particle diameter, addition amount and the like.
【０００４】ここで、研磨剤の添加量を増加すれば磁性
塗膜の強度は増加し、スチル寿命，粉落ちなどの耐久性
は向上するが、それに反して磁気ヘッドの磨耗量が大き
くなる。また、この磁気ヘッドの磨耗は、研磨剤の硬
度，粒子径，添加量が大きくなるほど多くなる。Here, if the amount of the abrasive added is increased, the strength of the magnetic coating film is increased and the durability such as the still life and powder falling is improved, but on the contrary, the wear amount of the magnetic head is increased. The wear of the magnetic head increases as the hardness, particle size, and amount of the abrasive increase.
【０００５】一方、高密度記録化に伴い短波長記録時の
間隙損失を少なくし、電磁変換特性が向上するためには
磁性層表面の粗さを小さくする必要があるが、粒子径の
大きな研磨剤や、またその添加量にも上限が生じてく
る。さらに、これら研磨剤粒子は強磁性粉に対して比較
的大きく、強磁性粉末の配向性を阻害し、角型比，飽和
磁束密度等の磁気特性を低下させる。On the other hand, it is necessary to reduce the roughness of the surface of the magnetic layer in order to reduce the gap loss at the time of short wavelength recording and improve the electromagnetic conversion characteristics as the recording density becomes higher. There is an upper limit to the amount of the agent and its addition amount. Further, these abrasive particles are relatively large with respect to the ferromagnetic powder, and hinder the orientation of the ferromagnetic powder, and deteriorate the magnetic properties such as squareness ratio and saturation magnetic flux density.
【０００６】さらに、近年、メタルテープの使用等に対
応するための合金ヘッド(アモルファスヘッドなど)を使
用する割合が多くなり、これらの合金ヘッドとメタルテ
ープの組み合わせで使用した場合、金属−金属の摩擦に
より合金ヘッドに焼き付きが生じ、電磁変換特性が低下
する。Furthermore, in recent years, the proportion of alloy heads (amorphous heads, etc.) used to cope with the use of metal tapes has increased, and when these alloy heads and metal tapes are used in combination, metal-metal Friction causes seizure on the alloy head, which deteriorates electromagnetic conversion characteristics.
【０００７】このヘッドの焼き付きは使用環境に左右さ
れ、低温低湿の環境下でよく起こる現象である。メタル
系磁性粉より研磨性の強い酸化鉄系磁性粉を用いた磁気
記録媒体ではこの現象が起こらないことから磁性層の研
磨性が関係しており、磁性層の研磨性の検討が必要にな
る。The seizure of the head depends on the use environment and is a phenomenon that often occurs in an environment of low temperature and low humidity. This phenomenon does not occur in magnetic recording media using iron oxide-based magnetic powder, which is more abrasive than metal-based magnetic powder, so the abradability of the magnetic layer is related, and the abradability of the magnetic layer needs to be examined. .
【０００８】また、近年のカメラ一体型ビデオテープレ
コーダー，携帯用機器の発展に伴い、機器の使用環境は
低温から高温まで、その範囲が非常に広がっており、大
きな課題となっている。With the recent development of camera-integrated video tape recorders and portable equipment, the range of use environment of the equipment is extremely widened from low temperature to high temperature, which is a big problem.
【０００９】そこで、本発明は磁性層の研磨性を最適に
することによって、磁気ヘッドに対する影響の少ない、
電磁変換特性，走行耐久性などに優れた磁気記録媒体お
よびその製造方法を提供することを目的とする。Therefore, according to the present invention, by optimizing the polishing property of the magnetic layer, the magnetic head is less affected.
An object of the present invention is to provide a magnetic recording medium excellent in electromagnetic conversion characteristics, running durability and the like, and a manufacturing method thereof.
【００１０】[0010]
【課題を解決するための手段】本発明は上記目的を達成
するため、磁気記録媒体の製造方法において、強磁性粉
末と研磨剤を別個に結合剤を用いて分散液を設けた後
に、これらを混合し磁性塗料を設け、さらに、研磨剤分
散液に使用される結合剤として、強磁性粉末分散液に用
いられる結合剤に対して重量比１対１で混合して設けた
膜厚100μmの樹脂膜の波長850nmの吸光度が0.4以下であ
る相溶性の良い結合剤を用いて設けられた研磨剤分散液
と、同様の吸光度が0.5以上である相溶性の悪い結合剤
を用いた研磨剤分散液の２種類を別個に設け、これら研
磨剤分散液を前記強磁性粉末分散液と混合して前記磁性
塗料を設け、この磁性塗料を塗布，乾燥し、磁気記録媒
体を設けることを特徴とする。In order to achieve the above-mentioned object, the present invention provides a method for producing a magnetic recording medium, in which a ferromagnetic powder and an abrasive are separately provided with a binder and then a dispersion is prepared. A resin having a film thickness of 100 μm, which is prepared by mixing and providing a magnetic coating, and further as a binder used in an abrasive dispersion, by mixing the binder used in a ferromagnetic powder dispersion in a weight ratio of 1: 1. Abrasive dispersion prepared using a compatible binder having an absorbance of 0.4 or less at a wavelength of 850 nm, and an abrasive dispersion using a poorly compatible binder having a similar absorbance of 0.5 or more. Are separately provided, the abrasive dispersion is mixed with the ferromagnetic powder dispersion to provide the magnetic paint, and the magnetic paint is applied and dried to provide a magnetic recording medium.
【００１１】[0011]
【作用】本発明によれば、研磨剤を相溶性の良い研磨剤
分散液と相溶性の悪い研磨剤分散液に分割して混合する
ことで、相溶性の悪い研磨剤分散液によって混合された
研磨剤は主結合剤から分離しやすく、最終的に設けられ
た磁性層の表面近傍に浮き上がった状態で存在し、一
方、相溶性の良い研磨剤分散液によって混合された研磨
剤は磁性層塗膜中に存在する。その結果、磁性層塗膜表
面は適度なヘッドクリーニング性を有し、メタルテープ
−合金ヘッド間のヘッドの焼き付きに関しても改善で
き、また、過剰な表面研磨剤が存在しないため、ヘッド
の摩耗にも悪影響を与えない。一方、磁性層塗膜中に存
在する研磨剤は磁性層を向上させ、スチル寿命等の耐久
性の改善ができる。According to the present invention, the abrasive is divided into the abrasive dispersion having good compatibility and the abrasive dispersion having poor compatibility to be mixed, whereby the abrasive dispersion having poor compatibility is mixed. The abrasive is easy to separate from the main binder and exists in a state of floating near the surface of the finally formed magnetic layer.On the other hand, the abrasive mixed by the highly compatible abrasive dispersion has a magnetic layer coating. Present in the membrane. As a result, the surface of the magnetic layer coating film has an appropriate head cleaning property, and it is possible to improve the seizure of the head between the metal tape and the alloy head. Further, since there is no excess surface abrasive, it is possible to prevent head wear. No adverse effect. On the other hand, the abrasive present in the magnetic layer coating film improves the magnetic layer and can improve durability such as still life.
【００１２】また、強磁性粉末より大きく、硬度の高い
研磨剤を強磁性粉末と別個に分散することで、強磁性粉
末の分散性の向上および研磨剤による強磁性粉末の損傷
が低減され、さらに、研磨剤を磁性表面および塗膜中に
適度に分布させることで、その添加総量を減少すること
が可能となり、これらの結果、得られる磁気記録媒体の
電磁変換特性が向上する。Further, by dispersing an abrasive having a hardness larger than that of the ferromagnetic powder and having a high hardness separately from the ferromagnetic powder, the dispersibility of the ferromagnetic powder is improved and the damage of the ferromagnetic powder due to the abrasive is reduced. By properly distributing the abrasive on the magnetic surface and the coating film, it becomes possible to reduce the total addition amount, and as a result, the electromagnetic conversion characteristics of the obtained magnetic recording medium are improved.
【００１３】[0013]
【実施例】以下、本発明の各実施例について述べる。EXAMPLES Examples of the present invention will be described below.
【００１４】(実施例１) 非磁性支持体 ポリエチレンテレフタレートフィルム 厚み 10μm 磁性塗料の最終組成(固形分重量部) 強磁性粉末 100重量部 カーボンブラック (粒子径 0.02μm) １重量部 主結合剤 ポリ塩化ビニル系樹脂 ８重量部 ポリウレタン樹脂１ ８重量部 研磨剤分散液１ 3.5重量部(研磨剤３重量
部，結合剤0.5重量部) 研磨剤分散液２ 3.5重量部(研磨剤３重量
部，結合剤0.5重量部) 潤滑剤 ミリスチン酸 ２重量部 ステアリン酸 １重量部 ｎ−ブチルステアレート １重量部 硬化剤 ポリイソシアネート ５重量部 ここで、強磁性粉末としてＣo付着γ−Ｆe2Ｏ3(比表面
積(BET法)51ｍ2／ｇ，保磁力6.52×104Ａ／ｍ)を用い、
磁性塗料の組成から研磨剤分散液，潤滑剤，硬化剤を除
いた混合物に、メチルエチルケトン／トルエン／シクロ
ヘキサノンの混合溶剤(重量比３対３対１)を添加して適
度な粘度とし、混練機にプラネタリミキサ、分散機にサ
ンドミルを使用して強磁性粉末を充分混練分散し、強磁
性粉末分散液を設ける。Example 1 Non-magnetic support Polyethylene terephthalate film Thickness 10 μm Final composition of magnetic paint (parts by weight of solid content) Ferromagnetic powder 100 parts by weight Carbon black (particle diameter 0.02 μm) 1 part by weight Main binder Polychlorination Vinyl resin 8 parts by weight Polyurethane resin 1 8 parts by weight Abrasive dispersion 1 3.5 parts by weight (abrasive 3 parts by weight, binder 0.5 parts by weight) Abrasive dispersion 2 3.5 parts by weight (abrasive 3 parts by weight, binder) 0.5 parts by weight Lubricant Myristic acid 2 parts by weight Stearic acid 1 part by weight n-Butyl stearate 1 part by weight Curing agent Polyisocyanate 5 parts by weight Here, as a ferromagnetic powder, Co-attached γ-Fe 2 O 3 (specific surface area ( BET method) 51 m 2 / g, coercive force 6.52 × 10 4 A / m),
Add a mixed solvent of methyl ethyl ketone / toluene / cyclohexanone (weight ratio of 3: 3: 1) to the mixture of the magnetic paint composition excluding the abrasive dispersion, the lubricant and the curing agent to obtain an appropriate viscosity, and add it to the kneader. A ferromagnetic powder is sufficiently kneaded and dispersed using a planetary mixer and a sand mill in a disperser to provide a ferromagnetic powder dispersion liquid.
【００１５】一方、研磨剤分散液１は、平均粒子サイズ
0.3μmのα−Ａl2Ｏ3とポリウレタン樹脂２を重量比６
対１で混合し、前記の混合溶剤を添加して適度な粘度と
し、サンドミルを使用して充分に分散を行われた研磨剤
分散液である。ここで、ポリウレタン樹脂２は、主結合
剤の混合物に対して重量比１対１で前述の混合溶剤中に
適度な固形分濃度となるように添加かつ混合後、アプリ
ケータを用いて乾燥膜厚100μmの樹脂膜を設け、その吸
光度(波長850nm)が0.4以下(１μmあたり４×10~3以下)
であるポリウレタン樹脂である。On the other hand, the abrasive dispersion 1 has an average particle size of
0.3 μm α-Al 2 O 3 and polyurethane resin 2 in a weight ratio of 6
It is a polishing agent dispersion liquid which is mixed in a ratio of 1, mixed with the above-mentioned mixed solvent to have an appropriate viscosity, and is sufficiently dispersed using a sand mill. Here, the polyurethane resin 2 is added to the above-mentioned mixed solvent in a weight ratio of 1: 1 with respect to the mixture of the main binder so as to have an appropriate solid content concentration and mixed, and then dried by using an applicator. Provide a resin film of 100 μm and its absorbance (wavelength 850 nm) is 0.4 or less (4 × 10 to 3 or less per 1 μm)
Is a polyurethane resin.
【００１６】一方、研磨剤分散液２は、平均粒子サイズ
0.3μmのα−Ａl2Ｏ3とポリウレタン樹脂３を重量比６
／１で混合し、前記混合溶剤を添加して適度な粘度と
し、サンドミルを使用して充分に分散を行われた研磨剤
分散液である。ここで、ポリウレタン樹脂３は、前述の
ポリウレタン樹脂２と同様の方法で求められた吸光度が
0.5以上(１μmあたり５×10~3以上)であるポリウレタン
樹脂である。On the other hand, the abrasive dispersion 2 has an average particle size of
0.3 μm α-Al 2 O 3 and polyurethane resin 3 in weight ratio 6
It is a polishing agent dispersion liquid which is mixed at a ratio of 1/1, the above mixed solvent is added to have an appropriate viscosity, and the mixture is sufficiently dispersed using a sand mill. Here, the polyurethane resin 3 has an absorbance determined by the same method as the polyurethane resin 2 described above.
It is a polyurethane resin of 0.5 or more (5 × 10 3 or more per 1 μm).
【００１７】これらの強磁性粉末分散液と２種類の研磨
剤分散液を所定の組成比になるように添加し、充分に混
合を行う。その後、濾過精製し、上記の組成になるよう
に潤滑剤，硬化剤を添加し、混合溶剤によって固形分比
率34重量％の塗工用磁性塗料を調整する。These ferromagnetic powder dispersions and two types of abrasive dispersions are added so as to have a predetermined composition ratio, and they are sufficiently mixed. Then, it is filtered and refined, a lubricant and a curing agent are added so as to have the above composition, and a magnetic coating material having a solid content ratio of 34% by weight is prepared by a mixed solvent.
【００１８】この磁性塗料を非磁性支持体上に、乾燥後
膜厚2.5μmになるように、塗布，乾燥後、カレンダー処
理を行う。その後、磁性層と反対面上にカーボンブラッ
クと結合剤樹脂を主体としたバックコート層を膜厚0.6
μmになるように形成し、60℃，36時間のエージング処
理を行う。その後、１／２インチ幅(12.65mm幅)に裁断
し、ＶＨＳ方式カセットとして試作サンプルとした。This magnetic coating material is applied onto a non-magnetic support so as to have a film thickness after drying of 2.5 μm, dried and calendered. After that, a back coat layer mainly composed of carbon black and a binder resin was formed on the surface opposite to the magnetic layer to a thickness of 0.6.
It is formed to have a thickness of μm, and is aged at 60 ° C. for 36 hours. After that, it was cut to a 1/2 inch width (12.65 mm width) and used as a prototype sample as a VHS cassette.
【００１９】(実施例２)(実施例１)において、研磨剤の
添加量として、研磨剤分散液１を4.9重量部(研磨剤4.2
重量部，結合剤0.7重量部)、研磨剤分散液２を2.1重量
部(研磨剤1.8重量部，結合剤0.3重量部)を添加し、その
他は(実施例１)と同様の組成，製造方法で試験サンプル
を作製した。(Example 2) In Example 1, the amount of abrasive added was 4.9 parts by weight of abrasive dispersion 1 (abrasive 4.2.
(Parts by weight, binder 0.7 parts by weight), 2.1 parts by weight of abrasive dispersion 2 (abrasive 1.8 parts by weight, binder 0.3 parts by weight), and the same composition and manufacturing method as in (Example 1) A test sample was prepared in.
【００２０】(比較例１)(実施例１)と比較するために、
研磨剤の添加量として、研磨剤分散液１のみを７重量部
(研磨剤６重量部，結合剤１重量部)を添加し、その他は
(実施例１)と同様の組成で試験サンプルを作製した。Comparative Example 1 In order to compare with (Example 1),
7 parts by weight of only the abrasive dispersion liquid 1 is added as the abrasive amount.
(6 parts by weight of abrasive, 1 part by weight of binder) were added, and others were added.
A test sample was prepared with the same composition as in (Example 1).
【００２１】(比較例２)(実施例１)と比較するために、
研磨剤の添加量として、研磨剤分散液１のみを10.5重量
部(研磨剤９重量部，結合剤1.5重量部)を強磁性粉末分
散液に添加混合し、その他は(実施例１)と同様の組成で
試験サンプルを作製した。(Comparative Example 2) For comparison with (Example 1),
As for the amount of the abrasive added, 10.5 parts by weight of the abrasive dispersion 1 alone (9 parts by weight of the abrasive, 1.5 parts by weight of the binder) were added to and mixed with the ferromagnetic powder dispersion, and the others were the same as in (Example 1). A test sample was prepared with the above composition.
【００２２】(比較例３)(実施例１)と比較するために、
研磨剤の添加量として、研磨剤分散液２のみを７重量部
(研磨剤６重量部，結合剤１重量部)を強磁性粉末分散液
に添加混合し、その他は(実施例１)と同様の組成で試験
サンプルを作製した。(Comparative Example 3) For comparison with (Example 1),
7 parts by weight of only the abrasive dispersion liquid 2 is added as the abrasive amount.
(6 parts by weight of abrasive, 1 part by weight of binder) were added to and mixed with the ferromagnetic powder dispersion, and a test sample was prepared with the same composition as in (Example 1).
【００２３】(実施例３)(実施例１)において、研磨剤分
散液に使用する研磨剤として平均粒子サイズ0.2μmのル
チル型ＴiＯ2を用いて、(実施例１)のポリウレタン樹脂
２を使用し、研磨剤分散液１と同様の組成比，製造方法
で研磨剤分散液３を設ける。さらに、この研磨剤(ルチ
ル型ＴiＯ2)をポリウレタン樹脂３を使用して、研磨剤
分散液２と同様の組成比，製造方法で研磨剤分散液４を
設けた。また、磁性塗料最終組成比は、研磨剤分散液３
および研磨剤分散液４を各々3.5重量部(研磨剤３重量
部，結合剤0.5重量部)とし、それ以外の組成は(実施例
１)と同様である。また、強磁性粉末分散液を始めとす
る製造方法は(実施例１)と同様に行い、試験サンプルを
設けた。(Example 3) In Example 1, the rutile type TiO 2 having an average particle size of 0.2 μm was used as the abrasive used in the abrasive dispersion, and the polyurethane resin 2 of Example 1 was used. Then, the abrasive dispersion liquid 3 is provided with the same composition ratio and manufacturing method as the abrasive dispersion liquid 1. Further, this abrasive (rutile-type TiO 2 ) was used as a polyurethane resin 3 to form an abrasive dispersion 4 with the same composition ratio and manufacturing method as the abrasive dispersion 2. In addition, the final composition ratio of the magnetic coating material is the abrasive dispersion liquid 3
And 3.5 parts by weight of the abrasive dispersion liquid 4 (3 parts by weight of abrasive, 0.5 parts by weight of binder), and the other composition is the same as in (Example 1). A manufacturing method including the ferromagnetic powder dispersion was performed in the same manner as in (Example 1), and a test sample was provided.
【００２４】(実施例４)(実施例３)において、研磨剤の
添加量として、研磨剤分散液１を4.9重量部(研磨剤4.2
重量部，結合剤0.7重量部)、研磨剤分散液２を2.1重量
部(研磨剤1.8重量部，結合剤0.3重量部)を強磁性粉末分
散液に添加混合し、その他は(実施例１)と同様の組成，
製造方法で試験サンプルを作製した。(Example 4) In Example 3, the amount of the abrasive added was 4.9 parts by weight of the abrasive dispersion liquid 1 (abrasive 4.2.
Parts by weight, 0.7 parts by weight of binder), 2.1 parts by weight of abrasive dispersion 2 (1.8 parts by weight of abrasive, 0.3 parts by weight of binder) were added to and mixed with the ferromagnetic powder dispersion, and the others (Example 1). Similar composition to
A test sample was prepared by the manufacturing method.
【００２５】(比較例４)(実施例３)と比較するために、
研磨剤の添加量として、研磨剤分散液３のみを７重量部
(研磨剤６重量部，結合剤１重量部)を強磁性粉末分散液
に添加混合し、その他は(実施例３)と同様の組成で試験
サンプルを作製した。(Comparative Example 4) For comparison with (Example 3),
7 parts by weight of only the abrasive dispersion liquid 3 is added as the abrasive amount.
(Abrasion agent 6 parts by weight, binder 1 part by weight) was added to and mixed with the ferromagnetic powder dispersion, and a test sample was prepared with the same composition as in (Example 3).
【００２６】(比較例５)(実施例３)と比較するために、
研磨剤の添加量として、研磨剤分散液３のみを10.5重量
部(研磨剤９重量部，結合剤1.5重量部)を強磁性粉末分
散液に添加混合し、その他は(実施例３)と同様の組成で
試験サンプルを作製した。(Comparative Example 5) For comparison with (Example 3),
As for the amount of the abrasive added, 10.5 parts by weight of the abrasive dispersion 3 alone (9 parts by weight of the abrasive, 1.5 parts by weight of the binder) were added to and mixed with the ferromagnetic powder dispersion, and the others were the same as in (Example 3). A test sample was prepared with the above composition.
【００２７】(比較例６)(実施例３)と比較するために、
研磨剤の添加量として、研磨剤分散液４のみを７重量部
(研磨剤６重量部，結合剤１重量部)を強磁性粉末分散液
に添加混合し、その他は(実施例３)と同様の組成で試験
サンプルを作製した。(Comparative Example 6) For comparison with (Example 3),
7 parts by weight of the abrasive dispersion liquid 4 alone is added as the abrasive amount.
(Abrasion agent 6 parts by weight, binder 1 part by weight) was added to and mixed with the ferromagnetic powder dispersion, and a test sample was prepared with the same composition as in (Example 3).
【００２８】(実施例５)(実施例１)において、強磁性粉
末として強磁性合金粉末(比表面積(BET法)56ｍ2／ｇ，
保磁力1.21×105Ａ／ｍ)を用いて強磁性粉末分散液を調
整し、研磨剤分散液を始めとする組成および製造方法は
(実施例１)と同様にして試験サンプルを作製した。Example 5 In Example 1, as the ferromagnetic powder, ferromagnetic alloy powder (specific surface area (BET method) 56 m 2 / g,
The coercive force of 1.21 × 10 5 A / m) is used to prepare the ferromagnetic powder dispersion, and the composition including the abrasive dispersion and the manufacturing method are
A test sample was prepared in the same manner as in (Example 1).
【００２９】(実施例６)(実施例５)において、研磨剤の
添加量として、研磨剤分散液１を4.9重量部(研磨剤4.2
重量部，結合剤0.7重量部)、研磨剤分散液２を2.1重量
部(研磨剤1.8重量部，結合剤0.3重量部)を強磁性粉末分
散液に添加混合し、その他は(実施例５)と同様の組成、
製造方法で試験サンプルを作製した。(Example 6) In Example 5, the amount of the abrasive added was 4.9 parts by weight of the abrasive dispersion 1 (abrasive 4.2.
(Parts by weight, binder 0.7 parts by weight), and 2.1 parts by weight of abrasive dispersion 2 (abrasive 1.8 parts by weight, binder 0.3 parts by weight) were added to and mixed with the ferromagnetic powder dispersion. Similar composition to,
A test sample was prepared by the manufacturing method.
【００３０】(比較例７)(実施例５)と比較するために、
研磨剤の添加量として、研磨剤分散液１のみを７重量部
(研磨剤６重量部，結合剤１重量部)を強磁性粉末分散液
に添加混合し、その他は(実施例５)と同様の組成で試験
サンプルを作製した。(Comparative Example 7) For comparison with (Example 5),
7 parts by weight of only the abrasive dispersion liquid 1 is added as the abrasive amount.
(Abrasion agent 6 parts by weight, binder 1 part by weight) was added to and mixed with the ferromagnetic powder dispersion, and a test sample was prepared with the same composition as in (Example 5).
【００３１】(比較例８)(実施例５)と比較するために、
研磨剤の添加量として、研磨剤分散液１のみを10.5重量
部(研磨剤９重量部，結合剤1.5重量部)を強磁性粉末分
散液に添加混合し、その他は(実施例５)と同様の組成で
試験サンプルを作製した。(Comparative Example 8) For comparison with (Example 5),
As for the amount of the abrasive added, 10.5 parts by weight of the abrasive dispersion 1 alone (9 parts by weight of the abrasive, 1.5 parts by weight of the binder) were added to and mixed with the ferromagnetic powder dispersion, and the others were the same as in (Example 5). A test sample was prepared with the above composition.
【００３２】(比較例９)(実施例５)と比較するために、
研磨剤の添加量として、研磨剤分散液２のみを７重量部
(研磨剤６重量部，結合剤１重量部)を強磁性粉末分散液
に添加混合し、その他は(実施例５)と同様の組成で試験
サンプルを作製した。(Comparative Example 9) For comparison with (Example 5),
7 parts by weight of only the abrasive dispersion liquid 2 is added as the abrasive amount.
(Abrasion agent 6 parts by weight, binder 1 part by weight) was added to and mixed with the ferromagnetic powder dispersion, and a test sample was prepared with the same composition as in (Example 5).
【００３３】これらの試作サンプルについて後述する方
法によって、磁性層の静磁気特性，スチル寿命テスト，
電磁変換特性(Ｃ／Ｎ)の評価試験，繰り返し走行テスト
を行った。評価結果について(表１)に示す。These prototype samples were subjected to a method described below to obtain the magnetostatic characteristics of the magnetic layer, a still life test,
An electromagnetic conversion characteristic (C / N) evaluation test and a repeated running test were performed. The evaluation results are shown in (Table 1).
【００３４】[0034]
【表１】 [Table 1]
【００３５】(表１)から明らかなように、本発明の特徴
とする相溶性の良い結合剤樹脂を用いた研磨剤分散液
と、相溶性の悪い結合剤樹脂を用いた研磨剤分散液とを
混合して設けられた(実施例１)、(実施例２)の試験サン
プルは、電磁変換特性(Ｃ／Ｎ)，スチル寿命に優れ、か
つ焼き付きによる出力の低下も少なく、ヘッド摩耗も適
度なものであり、単独の研磨剤分散液を用いた(比較例
１)，(比較例２)，(比較例３)と比較して顕著な効果が
見られる。また、(実施例３)，(実施例４)に示されるよ
うに研磨剤粒子をα−Ａl2Ｏ3からルチル型ＴiＯ2に変
えても、本発明の特徴とする効果は変わっていない。よ
って、モース硬度６以上のその他の研磨剤を用いても同
様の効果が得られる。また、強磁性粉末に強磁性合金粉
末を用いた(実施例５)，(実施例６)においても同様の効
果が確認される。As is clear from (Table 1), an abrasive dispersion containing a binder resin having a good compatibility, which is a feature of the present invention, and an abrasive dispersion containing a binder resin having a poor compatibility. The test samples of (Example 1) and (Example 2) prepared by mixing are excellent in electromagnetic conversion characteristics (C / N), still life, less decrease in output due to seizure, and moderate head wear. However, a remarkable effect can be seen as compared with (Comparative Example 1), (Comparative Example 2) and (Comparative Example 3) using the single abrasive dispersion. Further, as shown in (Example 3) and (Example 4), even if the abrasive particles are changed from α-Al 2 O 3 to rutile type TiO 2 , the effect characteristic of the present invention is not changed. Therefore, the same effect can be obtained even if another abrasive having a Mohs hardness of 6 or more is used. Similar effects are also confirmed in the case where the ferromagnetic alloy powder is used as the ferromagnetic powder (Example 5) and (Example 6).
【００３６】また、(表１)中の評価方法は以下の通りで
ある。The evaluation methods in (Table 1) are as follows.
【００３７】(1)磁性層の静磁気特性 東英工業ｊ製振動試料型磁力計を用いて磁性層の飽和磁
束密度，角形比を測定した。(1) Magnetostatic characteristics of magnetic layer The saturation magnetic flux density and the squareness ratio of the magnetic layer were measured using a vibrating sample magnetometer manufactured by Toei Kogyo j.
【００３８】(2)スチル寿命テスト ＶＨＳ−Ｃ方式ビデオムービー(松下電器産業ｊ製、型
式ＮＶ−Ｍ10)を用い、−10℃の環境下で試験サンプル
のスチル寿命を測定した。寿命は記録したテストパター
ンを再生し、スチル状態としてから計時を開始し映像が
乱れるまでの時間を寿命とした。測定は５回行い、それ
らの平均を寿命とした。また測定の最長は60分までとし
た。ただしビデオムービーのスチル解除機能は削除して
いる。(2) Still Life Test Using a VHS-C type video movie (Matsushita Electric Industrial Co., Ltd., model NV-M10), the still life of the test sample was measured under the environment of -10 ° C. The life was defined as the time from the time when the recorded test pattern was reproduced and the still state was started to the time measurement until the image was disturbed. The measurement was performed 5 times, and the average thereof was used as the life. The maximum measurement time was 60 minutes. However, the still-release function for video movies has been deleted.
【００３９】(3)Ｃ／Ｎの評価試験 ＶＨＳ方式ビデオテープレコーダー(松下電器産業ｊ
製、型式ＮＶ−ＦＳ900)を用いて試験サンプルの７ＭＨ
ｚ±１ＭＨｚのＣ／Ｎの測定を行った。ただし、(実施
例５)，(実施例６)，(比較例７)から(比較例９)で得ら
れた試験サンプルについては、そのサンプルごとの最適
記録電流により信号の書き込みを行った。ここで、(実
施例１)から(実施例４)および(比較例１)から(比較例
６)までは(比較例２)で得られた試験サンプルを、(実施
例５)，(実施例６)および(比較例７)から(比較例９)ま
では(比較例８)を、それぞれ基準(±０dB)として相対比
較を行った。(3) C / N evaluation test VHS system video tape recorder (Matsushita Electric Industrial j
Manufactured by model NV-FS900) and used as test sample 7MH
The C / N of z ± 1 MHz was measured. However, for the test samples obtained in (Example 5), (Example 6), (Comparative Example 7) to (Comparative Example 9), signals were written by the optimum recording current for each sample. Here, the test samples obtained in (Comparative Example 2) from (Example 1) to (Example 4) and (Comparative Example 1) to (Comparative Example 6) were used as (Example 5), (Example From (6) and (Comparative Example 7) to (Comparative Example 9), (Comparative Example 8) was used as a reference (± 0 dB) for relative comparison.
【００４０】(4)繰り返し走行テスト ＶＨＳ方式ビデオテープレコーダー(松下電器産業ｊ
製、型式ＮＶ−ＦＳ900)用い、各試験サンプル(ＶＨＳ
で120分のテープ長)を40℃，80％RHの環境下で100パス
の走行(3.3cm／秒)試験を行い、走行テスト前後のビデ
オテープレコーダーの磁気ヘッドの突き出し量を測定
し、ヘッド摩耗量を算出した。また、磁気ヘッドの汚れ
状態を観察した。(4) Repeated running test VHS video tape recorder (Matsushita Electric Industrial j
Made, model NV-FS900), each test sample (VHS
(120 minutes of tape length) at 40 ° C, 80% RH for 100 passes (3.3 cm / sec) test, and measure the protrusion amount of the magnetic head of the video tape recorder before and after the running test. The amount of wear was calculated. Also, the state of contamination of the magnetic head was observed.
【００４１】また、同様に各試験サンプルを23℃、相対
湿度10％の常温，低湿度環境下で50パスの繰り返し走行
を行った。その前後の７MHz±１MHzのＣ／Ｎ測定結果か
らヘッドの焼き付きによるＣ／Ｎの低下を見た。Similarly, each test sample was repeatedly run for 50 passes under a normal temperature and low humidity environment of 23 ° C. and a relative humidity of 10%. From the C / N measurement results of 7 MHz ± 1 MHz before and after that, it was observed that the C / N decreased due to the burn-in of the head.
【００４２】[0042]
【発明の効果】以上説明したように、本発明の磁気記録
媒体とその製造方法は、ヘッド摩耗，ヘッドの焼き付き
等の磁気ヘッドへの悪影響が非常に少ない上、スチル寿
命，走行耐久性，電磁変換特性に優れた磁気記録媒体を
提供することができる。As described above, the magnetic recording medium of the present invention and the method for manufacturing the same have very little adverse effects on the magnetic head such as head wear and head burn-in, and have a still life, running durability, and electromagnetic resistance. A magnetic recording medium having excellent conversion characteristics can be provided.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 羽根田 匠 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takumi Haneda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.
Claims (2)
研磨剤とを主体とした磁性層を形成してなる磁気記録媒
体の製造方法において、上記強磁性粉末と研磨剤を別個
に結合剤を用いて分散液を設けた後に、これらを混合し
て磁性塗料を設け、さらに研磨剤分散液に使用される結
合剤として、強磁性粉末分散液に用いられる結合剤に対
して重量比１対１で混合して設けられた膜厚100μmの樹
脂膜の波長850nmの吸光度が0.4以下である相溶性の良い
結合剤を用いて設けられた研磨剤分散液と、同様の吸光
度が0.5以上である相溶性の悪い結合剤を用いた研磨剤
分散液の２種類を別個に設け、これら研磨剤分散液を前
記強磁性粉末分散液と混合して前記磁性塗料を設け、こ
の磁性塗料を塗布，乾燥し、磁気記録媒体を設けること
を特徴とする磁気記録媒体の製造方法。1. A method for producing a magnetic recording medium comprising a magnetic layer mainly comprising a ferromagnetic powder, a binder and an abrasive on a non-magnetic support, wherein the ferromagnetic powder and the abrasive are separately prepared. After providing a dispersion liquid with a binder, mixing these to provide a magnetic coating, and as a binder used in the abrasive dispersion liquid, a weight ratio to the binder used in the ferromagnetic powder dispersion liquid. Absorbance of 0.5 or more is the same as that of the abrasive dispersion prepared by using a highly compatible binder in which the absorbance at a wavelength of 850 nm of a resin film having a thickness of 100 μm and prepared in a 1: 1 mixture is 0.4 or less. The two types of abrasive dispersions using a binder having poor compatibility are separately provided, the abrasive dispersions are mixed with the ferromagnetic powder dispersion to provide the magnetic paint, and the magnetic paint is applied. , Magnetic recording medium characterized by being dried and provided with a magnetic recording medium Manufacturing method.
によって製造されたことを特徴とする磁気記録媒体。2. A magnetic recording medium manufactured by the method for manufacturing a magnetic recording medium according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28830893A JPH07141653A (en) | 1993-11-17 | 1993-11-17 | Magnetic recording medium and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28830893A JPH07141653A (en) | 1993-11-17 | 1993-11-17 | Magnetic recording medium and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07141653A true JPH07141653A (en) | 1995-06-02 |
Family
ID=17728497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28830893A Pending JPH07141653A (en) | 1993-11-17 | 1993-11-17 | Magnetic recording medium and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07141653A (en) |
-
1993
- 1993-11-17 JP JP28830893A patent/JPH07141653A/en active Pending
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