JPH0744928A - Information recording medium - Google Patents

Abstract

PURPOSE:To obtain an information recording medium having a magnetic function with excellent overwriting characteristics without decreasing output characteristics in an information recording medium having an optical recording/ reproducing function or reproducing function as well as a magnetic recording and reproducing function. CONSTITUTION:This magnetic recording medium has an optical recording surface opposite to the surface of the magnetic recording layer. The magnetic recording layer includes a nonmagnetic substrate 3 and at least a magnetic layer 2 and a nonmagnetic hiding layer 1. An adhesive layer 4 is formed between the nonmagnetic substrate 3 of the magnetic recording layer and the substrate 5 having the optical recording layer. Thus, output characteristics of the magnetic recording medium is improved.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、ディスク等の情報記録
媒体に関するもので、光学的な記録再生または再生機能
と磁気的な記録再生機能を同時に持つ情報記録媒体に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium such as a disk, and more particularly to an information recording medium having an optical recording / reproducing or reproducing function and a magnetic recording / reproducing function at the same time.

【０００２】[0002]

【従来の技術】情報メディアの分野においてメディア記
録容量は年々増加している。その中で光学的な再生を行
うＣＤ−ＲＯＭは記録容量が大きく、安価に製造できる
ことで非常に有用なメディアである。しかしながら、Ｃ
Ｄ−ＲＯＭはそれ自身に記録機能がないため、使用用途
が限定される傾向がある。昨今、ＣＤ−ＲＯＭに磁性層
を付与し記録機能を有するメディアの提案がなされてい
る。このようなメディアの磁性層は、プリペイドカード
のように身の回りにある磁石により記録が消されないよ
うな高いＨｃが必要であり、通常高抗磁力の磁性粉を作
り易いバリウムフェライト磁性粉を用いる。また生活傷
に耐えるような隠蔽層や保護層を必要とする。2. Description of the Related Art In the field of information media, the recording capacity of media is increasing year by year. Among them, a CD-ROM that performs optical reproduction has a large recording capacity and can be manufactured at low cost, and is a very useful medium. However, C
Since the D-ROM itself has no recording function, its intended use tends to be limited. Recently, a medium having a recording function by providing a magnetic layer on a CD-ROM has been proposed. The magnetic layer of such a medium needs to have a high Hc so that the recording is not erased by the magnets around us like a prepaid card, and usually barium ferrite magnetic powder is used which makes it easy to produce magnetic powder with high coercive force. In addition, a concealing layer and a protective layer that can withstand a life wound are required.

【０００３】[0003]

【発明が解決しようとする課題】ディスク状基板に磁性
層を付与する方法として従来スピンコート等の方法が提
案されているが、塗布厚が薄く充分な出力が得られない
という欠点を有している。Although a method such as spin coating has been conventionally proposed as a method for applying a magnetic layer to a disk-shaped substrate, it has a drawback that the coating thickness is thin and sufficient output cannot be obtained. There is.

【０００４】本発明の目的は、出力特性に優た情報記録
媒体を提供するものである。An object of the present invention is to provide an information recording medium having excellent output characteristics.

【０００５】[0005]

【課題を解決するための手段】上記目的を達成するため
に、本発明の磁気記録媒体は磁気記録層に非磁性基体と
少なくとも磁性層、非磁性隠蔽層を含み、磁気記録層の
非磁性基体と光記録面を有する基体の間に接着層を有す
るという構成を備えたものである。In order to achieve the above object, the magnetic recording medium of the present invention includes a non-magnetic substrate in a magnetic recording layer and at least a magnetic layer and a non-magnetic concealing layer. And an adhesive layer between a substrate having an optical recording surface.

【０００６】[0006]

【作用】本発明は上記した構成により磁気記録媒体の出
力特性を向上することになる。The present invention improves the output characteristics of the magnetic recording medium by the above-mentioned structure.

【０００７】[0007]

【実施例】以下、本発明の一実施例について説明する。EXAMPLES An example of the present invention will be described below.

【０００８】（実施例１）磁性層塗料を金属鉄を主成分
とする針状磁性微粉末（Ｈc：１９５０ Oe、σs：１４
３ emu／g、ＢＥＴ比表面積：５６ m²／g）（以下メタ
ル磁性粉と表記）を用い下記の組成によりサンドミルで
３時間混合分散し塗工直前に硬化剤としてデスモジュー
ルＬ（デュポン社製）を６重量部加えて作成した。Example 1 Needle-like magnetic fine powder (Hc: 1950 Oe, σs: 14) containing metallic iron as a main component was used as the magnetic layer coating material.
3 emu / g, BET specific surface area: 56 m ² / g) (hereinafter referred to as metal magnetic powder), and mixed and dispersed by a sand mill for 3 hours with the following composition, and desmodur L (manufactured by DuPont) as a curing agent immediately before coating. ) Was added to prepare 6 parts by weight.

【０００９】 メタル磁性粉 １００重量部 カーボンブラック ６重量部 アルミナ １５重量部 ＭＲ−１１０（日本ゼオン社製） １５重量部 ポリウレタン樹脂 １５重量部 オレイン酸オレイル ５重量部 デスモジュールＬ（デュポン社製） ６重量部 ＭＥＫ １２０重量部 トルエン １２０重量部 シクロヘキサノン ４０重量部 隠蔽層用塗料として酸化チタン粉末（粒系：０．２８μ
ｍ）を用い下記の組成によりボールミルで７０時間混合
分散し塗工直前に硬化剤としてデスモジュールＬ（デュ
ポン社製）を３重量部加えて作成した。Metal magnetic powder 100 parts by weight Carbon black 6 parts by weight Alumina 15 parts by weight MR-110 (manufactured by Zeon Corporation) 15 parts by weight Polyurethane resin 15 parts by weight Oleyl oleate 5 parts by weight Desmodur L (manufactured by DuPont) 6 Parts by weight MEK 120 parts by weight Toluene 120 parts by weight Cyclohexanone 40 parts by weight Titanium oxide powder (grain system: 0.28μ)
m) was mixed and dispersed in a ball mill for 70 hours with the following composition, and 3 parts by weight of Desmodur L (manufactured by DuPont) was added as a curing agent immediately before coating.

【００１０】 酸化チタン粉末 １００重量部 アルミナ ８重量部 ポリウレタン樹脂 １５重量部 オレイン酸 ２重量部 ステアリン酸 ２重量部 デスモジュールＬ（デュポン社製） ３重量部 ＭＥＫ １２０重量部 トルエン １２０重量部 シクロヘキサノン ４０重量部 磁性層塗料と隠蔽層塗料を厚さ６２μｍのポリエチレン
テレフタレート（ＰＥＴ）フィルム上におのおの厚さ２
μｍおよび厚さ３μｍとなるようにダイ塗工法により同
時塗布し交流磁界で磁性体の配向を除去し乾燥後カレン
ダー処理の後、６０℃の雰囲気で２４時間硬化を行っ
た。硬化後、ＰＥＴフィルムの磁性層の塗布していない
面にアクリル系熱可塑樹脂を乾燥厚４μｍで塗布した
後、１２ｃｍＣＤに貼付けられるよう内径４０ｍｍ外径
１１７ｍｍに金型で打ち抜き、レーベル印刷を行ってい
ないＣＤ-ＲＯＭの光読みだし面の反対面に熱融着させ
ディスク状の試料を作成した。Titanium oxide powder 100 parts by weight Alumina 8 parts by weight Polyurethane resin 15 parts by weight Oleic acid 2 parts by weight Stearic acid 2 parts by weight Desmodur L (manufactured by DuPont) 3 parts by weight MEK 120 parts by weight Toluene 120 parts by weight Cyclohexanone 40 parts by weight Part of the magnetic layer coating material and the concealing layer coating material on a polyethylene terephthalate (PET) film having a thickness of 62 μm
The coating was simultaneously applied by a die coating method so as to have a thickness of 3 μm and a thickness of 3 μm, the orientation of the magnetic material was removed by an alternating magnetic field, dried and calendered, and then cured in an atmosphere of 60 ° C. for 24 hours. After curing, an acrylic thermoplastic resin was applied to the surface of the PET film on which the magnetic layer was not applied in a dry thickness of 4 μm, and then stamped with a die to an inner diameter of 40 mm and an outer diameter of 117 mm so as to be attached to a 12 cm CD, and label printing was performed. A disc-shaped sample was prepared by heat-sealing the opposite surface of the unread CD-ROM to the light reading surface.

【００１１】出力はセンダストバルクヘッド（ギャップ
幅３０μｍ、トラック幅１.３ｍｍ）を用い、相対速度
１.３ｍ／ｓｅｃで回転させ５.１ｋＨｚの記録周波数で
矩形波を記録し、再生波形のオシロスコープ上での振幅
により測定した。記録電流は最大出力電圧の８０％の出
力を発生する記録電流の２００％の電流値を用いた。For output, a sendust bulkhead (gap width: 30 μm, track width: 1.3 mm) was used to rotate at a relative speed of 1.3 m / sec to record a rectangular wave at a recording frequency of 5.1 kHz. It was measured by the amplitude at. As the recording current, a current value of 200% of the recording current for generating an output of 80% of the maximum output voltage was used.

【００１２】（比較例１）実施例１と同様の磁性塗料を
予め水溶性ポリエステル樹脂で処理したポリカーボネー
トディスク上に磁性層塗料をスピンコート法により塗布
し、６０℃の雰囲気で２４時間硬化させ、表面研磨をし
た後、隠蔽層塗料をスピンコートし磁気ディスクを作成
した。磁性層の厚さは１μｍ、隠蔽層の厚さは１.２μ
ｍであった。(Comparative Example 1) The same magnetic coating material as in Example 1 was applied by a spin coating method onto a polycarbonate disk which had been previously treated with a water-soluble polyester resin, followed by curing at 60 ° C for 24 hours. After the surface was polished, the concealing layer paint was spin-coated to prepare a magnetic disk. The thickness of the magnetic layer is 1μm and the thickness of the concealing layer is 1.2μ
It was m.

【００１３】以上の実施例の構成とその特性を比較例と
比較して（表１）に示す。The structure and characteristics of the above embodiment are shown in Table 1 in comparison with the comparative example.

【００１４】[0014]

【表１】 [Table 1]

【００１５】（表１）から明らかなように非磁性基体と
光記録面を有する基体の間に接着層を有する磁気ディス
クはスピンコート法による磁気ディスクに比べ出力の向
上が見られる。As is clear from (Table 1), the magnetic disk having the adhesive layer between the non-magnetic substrate and the substrate having the optical recording surface has an improved output as compared with the magnetic disk formed by the spin coating method.

【００１６】なお、本実施例で用いた磁性層の磁性粉体
はメタル純鉄であるが、Ｃｏ−γ酸化鉄、γ酸化鉄、バ
リウムフェライトなどのヘキサゴナルフェライト、窒化
鉄、炭化鉄などでも同様の効果を表す。磁性層とディス
クの間の接着層に用いる樹脂は、本実施例に用いた種類
のみでなく塩化ビニル系、ポリウレタン系、エポキシ系
など一般的な熱可塑性樹脂、熱硬化樹脂を用いても同様
の効果が得られる。接着層は非磁性基板に予め着ける方
法、シート状樹脂を用いる方法によっても同様の効果が
得られる。隠蔽層上に図形の印刷、保護層の塗布を行っ
ても効果は薄れない。The magnetic powder for the magnetic layer used in this embodiment is pure metal iron, but the same applies to hexagonal ferrite such as Co-γ iron oxide, γ iron oxide, barium ferrite, iron nitride, iron carbide, etc. Represents the effect of. The resin used for the adhesive layer between the magnetic layer and the disc is not limited to the type used in this embodiment, but a general thermoplastic resin such as vinyl chloride-based, polyurethane-based, or epoxy-based resin or a thermosetting resin may be used. The effect is obtained. The same effect can be obtained by attaching the adhesive layer to the non-magnetic substrate in advance or by using a sheet resin. The effect is not diminished even if a pattern is printed or a protective layer is applied on the hiding layer.

【００１７】[0017]

【発明の効果】以上のように本発明によれば、磁性磁気
記録層に非磁性基体と少なくとも磁性層、非磁性隠蔽層
を含み、磁気記録層の非磁性基体と光記録面を有する基
体との間に接着層を有することで磁気記録媒体の出力特
性を向上するという効果が得られる。As described above, according to the present invention, the magnetic / magnetic recording layer includes a non-magnetic substrate, at least a magnetic layer, and a non-magnetic shielding layer, and a non-magnetic substrate of the magnetic recording layer and a substrate having an optical recording surface. The effect of improving the output characteristics of the magnetic recording medium is obtained by having an adhesive layer between the two.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の実施例における磁気記録媒体の概念図FIG. 1 is a conceptual diagram of a magnetic recording medium in an embodiment of the present invention.

【符号の説明】[Explanation of symbols]

１ 隠蔽層 ２ 磁性層 ３ 非磁性基体 ４ 接着層 ５ 光記録面を持った基体 1 Concealment Layer 2 Magnetic Layer 3 Nonmagnetic Substrate 4 Adhesive Layer 5 Substrate with Optical Recording Surface

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】磁気記録層の反対面に光記録面を有する情
報記録媒体において、磁気記録層に非磁性基体と少なく
とも磁性層、非磁性隠蔽層を含み、前記磁気記録層の非
磁性基体と光記録面を有する基体の間に接着層を有する
ことを特徴とする情報記録媒体。1. An information recording medium having an optical recording surface opposite to a magnetic recording layer, wherein the magnetic recording layer includes a non-magnetic substrate, at least a magnetic layer and a non-magnetic concealing layer, and the non-magnetic substrate of the magnetic recording layer. An information recording medium having an adhesive layer between substrates having an optical recording surface.