JPH07118089B2 - Magneto-optical recording medium having a plastic disk substrate - Google Patents
Magneto-optical recording medium having a plastic disk substrateInfo
- Publication number
- JPH07118089B2 JPH07118089B2 JP58037759A JP3775983A JPH07118089B2 JP H07118089 B2 JPH07118089 B2 JP H07118089B2 JP 58037759 A JP58037759 A JP 58037759A JP 3775983 A JP3775983 A JP 3775983A JP H07118089 B2 JPH07118089 B2 JP H07118089B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- recording medium
- magneto
- substrate
- optical recording
- 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 - Lifetime
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
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/7368—Non-polymeric layer under the lowermost magnetic recording layer
-
- 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
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/739—Magnetic recording media substrates
- G11B5/73923—Organic polymer substrates
Landscapes
- Thin Magnetic Films (AREA)
Description
【発明の詳細な説明】 （発明の技術分野） 本発明はポリメチルメタクリレート、ポリスチレン、ポ
リカーボネート等のプラスチックディスク基板を有する
光磁気記録媒体に関する。TECHNICAL FIELD OF THE INVENTION The present invention relates to a magneto-optical recording medium having a plastic disk substrate such as polymethylmethacrylate, polystyrene, or polycarbonate.
（発明の背景） 高度な記録密度が期待されることから、Gd−Co、Tb−Fe
等の垂直磁化膜を真空蒸着、スパッタリングのような薄
膜形成技術により基板上に積層された光磁気記録媒体が
盛んに研究されている。この記録媒体は例えば予め垂直
磁化膜を一方向に磁化させておき、記録したい部分にレ
ーザー光の微小スポットを照射し、それと同時に逆向き
の弱い外部磁場を印加する。そうすると照射部分は温度
が上昇してキュリー点又は補償温度を越え、容易に逆向
きの外部磁場に従って磁化するので照射を止めると、照
射部分は他とは磁化の向きが異なることから0.1のデジ
タル信号の１が記録される。一方、記録された部分に偏
光（レーザー光）を照射し、その反射光又は透過光の偏
光面を測定すると、偏光面は磁化の向きによって異なる
回転をする。従って、偏光面の回転角を測定して行け
ば、記録のある部分と、ない部分を区別することがで
き、結局再生（読み出し）を行なうことができる。(Background of the Invention) Since high recording density is expected, Gd-Co and Tb-Fe are expected.
Magneto-optical recording media in which perpendicularly magnetized films such as the above are laminated on a substrate by a thin film forming technique such as vacuum deposition and sputtering have been actively studied. In this recording medium, for example, a perpendicular magnetization film is magnetized in one direction in advance, and a portion to be recorded is irradiated with a minute spot of laser light, and at the same time, a weak external magnetic field in the opposite direction is applied. Then, the temperature of the irradiated part rises above the Curie point or the compensation temperature, and it easily magnetizes in accordance with the opposite external magnetic field. 1 is recorded. On the other hand, when the recorded portion is irradiated with polarized light (laser light) and the polarization plane of the reflected light or the transmitted light is measured, the polarization plane rotates differently depending on the magnetization direction. Therefore, by measuring the rotation angle of the plane of polarization, it is possible to distinguish between a recorded portion and a non-recorded portion, so that reproduction (reading) can be performed.
ところでこのような磁性薄膜自身は非常に薄くて済むこ
と、あるいは強度、コストなどを考えると、何らかの基
板例えばガラス、プラスチック、金属などの基板の上に
磁性薄膜を形成することが現実的である。なかでも、ポ
リメチルメタクリレート、ポリスチレン、ポリカーボネ
ート等のプラスチックディスク基板（以下プラスチック
基板と略す）は、安価で軽く、耐衝撃性、強度等にも秀
れていることから、ガラスや金属基板に比べて最も実用
的である。By the way, it is realistic to form the magnetic thin film on some substrate such as a substrate made of glass, plastic, metal, or the like, considering that the magnetic thin film itself is very thin, or considering strength and cost. Among them, plastic disk substrates made of polymethylmethacrylate, polystyrene, polycarbonate, etc. (abbreviated as plastic substrates below) are cheap and light, and have excellent impact resistance and strength, etc., so they are superior to glass and metal substrates. Most practical.
しかしながら、本発明者の研究によると、これらのプラ
スチック基板上に、直接に磁性薄膜を、蒸着又はスパッ
タリングすると、基板に対する付着力は弱く、磁性薄膜
が剥れ易いことが判った。However, according to the research by the present inventor, it has been found that when a magnetic thin film is directly vapor-deposited or sputtered on these plastic substrates, the adhesion to the substrate is weak and the magnetic thin film is easily peeled off.
（発明の目的） 従って、本発明の目的は、プラスチック基板の持つ利点
を保持又は大きく損なうことなく、薄膜形成技術による
磁性薄膜の基板に対する付着力が向上した光磁気記録媒
体を提供することにある。(Object of the Invention) Accordingly, an object of the present invention is to provide a magneto-optical recording medium in which the adhesion of a magnetic thin film to a substrate by a thin film forming technique is improved without retaining or greatly impairing the advantages of a plastic substrate. .
（発明の概要） そこで本発明者は、磁性薄膜のプラスチック基板に対す
る付着力を向上させるためにアンダコートについて研究
した。その結果、蒸着用ガラスが磁性薄膜のプラスチッ
ク基板に対する付着力を著しく向上させることを見い出
し、本発明を成すに至った。(Summary of Invention) Therefore, the present inventor has studied an undercoat in order to improve the adhesion of the magnetic thin film to the plastic substrate. As a result, they have found that the glass for vapor deposition significantly enhances the adhesion of the magnetic thin film to the plastic substrate, and have completed the present invention.
プラスチックディスク基板の上に、真空薄膜形成技術に
より形成した、Naの含有率がNa2O換算で10重量％以下の
ガラス層を介して重希土類−遷移金属からなる磁性薄膜
を形成したことを特徴とする光磁気記録媒体を提供す
る。A magnetic thin film composed of heavy rare earth-transition metal is formed on a plastic disk substrate through a glass layer having a Na content of 10% by weight or less in terms of Na 2 O formed by a vacuum thin film forming technique. The present invention provides a magneto-optical recording medium.
本発明に於いて、プラスチック基板としては例えばポリ
メチルメタクリレート、ポリスチレン、ポリカーボネー
ト等が使用される。In the present invention, as the plastic substrate, for example, polymethylmethacrylate, polystyrene, polycarbonate or the like is used.
この基板の上に蒸着用ガラスの薄膜を形成する訳である
が蒸発源として使用する「蒸着用ガラス」それ自身は、
既に知られており、例えばSiO280〜90重量％、B2O35〜1
5重量％、Al2O3１〜10重量％、Na2O１〜10重量％からな
る組成を有するものである。このような組成の蒸着用ガ
ラスを通常の真空薄膜形成技術例えば真空蒸着、イオン
プレーティング、スパッタリング等によりプラスチック
基板の上に例えば200Å〜20μｍ好ましくは0.1〜１μｍ
の厚さに積層する。一般に、形成された薄膜と蒸発源と
の組成は互いに異なるが、本発明に於いてもこれを否定
することはできない。Although a thin film of vapor deposition glass is formed on this substrate, the "vapor deposition glass" used as an evaporation source itself is
It is already known, for example, 80 to 90% by weight of SiO 2 , B 2 O 3 5 to 1
5 wt%, Al 2 O 3 1 to 10% by weight, and has a composition consisting of Na 2 O1~10 wt%. A glass for vapor deposition having such a composition is formed on a plastic substrate by a conventional vacuum thin film forming technique such as vacuum vapor deposition, ion plating, and sputtering, for example, 200Å to 20 μm, preferably 0.1 to 1 μm.
To the thickness of. Generally, the composition of the formed thin film and the composition of the evaporation source are different from each other, but this cannot be denied in the present invention.
なお、場合によっては、蒸着用ガラス層の上に磁性薄膜
を形成する前に目的に応じて（透明）熱拡散層、（透
明）導電層例えばIn2O3、SnO2、ITO（SnO2とIn2O3との
混合物）、TiO2、ZrO2、Al2O3等を同様に真空薄膜形成
技術により積層してもよい。但し、これらの中間層は蒸
着用ガラス層及び磁性薄膜に対する付着力が良好なもの
でなければならない。In some cases, a (transparent) thermal diffusion layer, a (transparent) conductive layer such as In 2 O 3 , SnO 2 , ITO (SnO 2 and A mixture with In 2 O 3 ), TiO 2 , ZrO 2 , Al 2 O 3 and the like may be similarly laminated by a vacuum thin film forming technique. However, these intermediate layers must have good adhesion to the vapor deposition glass layer and the magnetic thin film.
その後、引続いて磁性薄膜を形成する。磁性材料として
は、既に知られているように重希土類一遷移金属系のTb
−Fe、Gd−Fe、Dy−Fe、Gd−Co、Ho−Co、GdTbFe、GdDy
Fe、TbDyFE、GdFeCo等のアモルファスが使用される。こ
れらの磁性薄膜は例えば200Å〜数μｍの膜厚に形成さ
れる。After that, a magnetic thin film is subsequently formed. As a magnetic material, as already known, heavy rare earth-transition metal based Tb
-Fe, Gd-Fe, Dy-Fe, Gd-Co, Ho-Co, GdTbFe, GdDy
Amorphous materials such as Fe, TbDyFE and GdFeCo are used. These magnetic thin films are formed to have a film thickness of, for example, 200 Å to several μm.
磁性薄膜が空気中に露出していると、酸化作用を受けて
磁気特性が低下したり、傷を受けたりするので、その上
に保護層を設けることが好ましい。保護層の材料として
例えばSiO、SiO2、TiO2、ZrO2、Ta2O5、Al2O3、ZnS、Mg
F2、ITOが挙げられる。これらの材料は通常の真空薄膜
形成技術例えば真空蒸着、イオンプレーティング、スパ
ッタリング等により例えば1000Å〜5000Åの厚さに形成
される。If the magnetic thin film is exposed to the air, it is subjected to an oxidative action to deteriorate the magnetic properties and is damaged. Therefore, it is preferable to provide a protective layer on the magnetic thin film. Examples of materials for the protective layer include SiO, SiO 2 , TiO 2 , ZrO 2 , Ta 2 O 5 , Al 2 O 3 , ZnS, and Mg.
F 2 and ITO are examples. These materials are formed to have a thickness of, for example, 1000Å to 5000Å by an ordinary vacuum thin film forming technique such as vacuum deposition, ion plating, and sputtering.
次に実施例により本発明をより具体的に説明する。Next, the present invention will be described more specifically by way of examples.
（実施例） 第１図は本発明にかかる記録媒体の部分縦断面図であ
り、引用数字（１）は直径12Cm厚さ0.12Cmの透明なポリ
メチルメタクリレート製基板である。(Embodiment) FIG. 1 is a partial longitudinal sectional view of a recording medium according to the present invention. Reference numeral (1) is a transparent polymethylmethacrylate substrate having a diameter of 12 Cm and a thickness of 0.12 Cm.
この基板（１）の上に真空蒸着装置を用い、基板温度：
室温、蒸着物質：《SiO284重量％、B2O310重量％、Al2O
3重量％、Na2O３重量％からなる蒸着用ガラス》、真空
度６〜10×10-6Torr.の条件下で５分間蒸着を行ない、
厚さ1000Åのガラス層（２）を形成させた。Using a vacuum vapor deposition apparatus on this substrate (1), the substrate temperature:
Room temperature, deposition material: << SiO 2 84% by weight, B 2 O 3 10% by weight, Al 2 O
Glass for vapor deposition consisting of 3 wt% and Na 2 O 3 wt% >>, vapor deposition was performed for 5 minutes under the conditions of a vacuum degree of 6 to 10 × 10 −6 Torr.
A glass layer (2) having a thickness of 1000Å was formed.
その後、２元蒸着法により基板温度：室温、真空度３×
10-6Torr.の条件下で３分間蒸着を行ない、ガラス層
（２）の上に厚さ5000ÅのTb−Fe系磁性薄膜（３）を形
成させた。After that, substrate temperature: room temperature, vacuum degree 3 ×
Evaporation was performed for 3 minutes under the condition of 10 -6 Torr. To form a 5000 Å-thick Tb-Fe magnetic thin film (3) on the glass layer (2).
実際には、この後保護のために厚さ2000ÅのSiO2薄膜を
蒸着するが付着力の測定のために次の試験に供した。Actually, after this, a 2000 Å thick SiO 2 thin film was evaporated for protection, but the film was subjected to the next test for measuring the adhesive force.
磁性薄膜（３）の上に住友スリーエム社のメンディング
テープNo.810を密着させ、テープの一端を手で持って素
速く剥したところ、テープ自体が磁性薄膜（３）から剥
れ、磁性薄膜（３）が下地から剥れることはなかった。When the Sumitomo 3M Mending Tape No. 810 was brought into close contact with the magnetic thin film (3) and one end of the tape was quickly peeled off by holding it by hand, the tape itself peeled off from the magnetic thin film (3). (3) did not peel off from the base.
比較例として（イ）ガラス層（２）を設けなかったもの
及び（ロ）ガラス層（２）に代えて同じ膜厚のSiO2層
（２′）を設けたものを同様に作製したが、上述の粘着
テープ剥離試験を供すると、いずれも磁性薄膜（３）が
剥れてしまった。後者（ロ）の場合には、SiO2（２′）
と基板（１）との間で剥れていた。As comparative examples, (a) the glass layer (2) was not provided and (b) the glass layer (2) was replaced by an SiO 2 layer (2 ′) having the same thickness, but the same production was carried out. When the above-mentioned adhesive tape peeling test was performed, the magnetic thin film (3) peeled off in all cases. In the latter case (b), SiO 2 (2 ')
It was peeled off between the substrate and the substrate (1).
（発明の効果） 以上の通り、本発明によれば、蒸着用ガラス層を設ける
ことにより、磁性薄膜のプラスチック基板への付着力が
格段に向上するほか、ガラス層が透明であることから、
透明な基板を使用すれば、基板側からレーザー光による
記録及び再生が可能となる。(Effect of the invention) As described above, according to the present invention, by providing the glass layer for vapor deposition, the adhesion of the magnetic thin film to the plastic substrate is significantly improved, and since the glass layer is transparent,
If a transparent substrate is used, recording and reproduction with a laser beam can be performed from the substrate side.
また、ガラス層のNaの含有率を、Na2Oの換算で10重量％
以下としたことで、記録再生時の加熱により下地として
の基板から磁性薄膜中へ拡散するNa量を抑制することが
でき、その結果、Naが磁性薄膜中の重希土類を酸化して
S/n比を悪化させるという問題を解決することができ
る。In addition, the Na content of the glass layer is 10% by weight in terms of Na 2 O.
By the following, it is possible to suppress the amount of Na diffused from the substrate as an underlayer into the magnetic thin film due to heating during recording and reproduction, and as a result, Na oxidizes the heavy rare earth in the magnetic thin film.
It is possible to solve the problem of deteriorating the S / n ratio.
【図面の簡単な説明】 第１図は本発明の一実施例を示す光磁気記録媒体の部分
縦断面図である。 （主要部分の符号の説明） １……プラスチックディスク基板 ２……蒸着用ガラス層 ３……磁性薄膜BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial vertical sectional view of a magneto-optical recording medium showing an embodiment of the present invention. (Explanation of symbols of main parts) 1 ... Plastic disk substrate 2 ... Evaporation glass layer 3 ... Magnetic thin film
Claims (2)
膜形成技術により形成した、Naの含有率がNa2O換算で10
重量％以下のガラス層を介して重希土類−遷移金属から
なる磁性薄膜を形成したことを特徴とする光磁気記録媒
体。1. The content of Na formed on a plastic disk substrate by a vacuum thin film forming technique is 10 in terms of Na 2 O.
A magneto-optical recording medium, wherein a magnetic thin film made of a heavy rare earth-transition metal is formed through a glass layer of not more than wt%.
3:5〜15重量％、Al2O3:1〜10重量％及びNa2O:1〜10重量
％からなることを特徴とする特許請求の範囲第１項記載
の光磁気記録媒体。2. The glass layer comprises SiO 2 : 80 to 90% by weight, B 2 O
3: 5-15 wt%, Al 2 O 3: 1 to 10 wt% and Na 2 O: 1 to 10 magneto-optical recording medium of the claims paragraph 1, wherein the consisting wt%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58037759A JPH07118089B2 (en) | 1983-03-08 | 1983-03-08 | Magneto-optical recording medium having a plastic disk substrate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58037759A JPH07118089B2 (en) | 1983-03-08 | 1983-03-08 | Magneto-optical recording medium having a plastic disk substrate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59162621A JPS59162621A (en) | 1984-09-13 |
| JPH07118089B2 true JPH07118089B2 (en) | 1995-12-18 |
Family
ID=12506392
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58037759A Expired - Lifetime JPH07118089B2 (en) | 1983-03-08 | 1983-03-08 | Magneto-optical recording medium having a plastic disk substrate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07118089B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63313322A (en) * | 1987-06-17 | 1988-12-21 | Toshiba Corp | Production of magnetic recording medium |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5515647U (en) * | 1978-07-14 | 1980-01-31 | ||
| JPS5668924A (en) * | 1979-11-07 | 1981-06-09 | Hitachi Maxell Ltd | Magnetic recording medium |
| JPS57164454A (en) * | 1981-03-31 | 1982-10-09 | Fujitsu Ltd | Treating method for surface of glass substrate for optical recording medium |
-
1983
- 1983-03-08 JP JP58037759A patent/JPH07118089B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59162621A (en) | 1984-09-13 |
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