JPH0447381B2 - - Google Patents
Info
- Publication number
- JPH0447381B2 JPH0447381B2 JP61056875A JP5687586A JPH0447381B2 JP H0447381 B2 JPH0447381 B2 JP H0447381B2 JP 61056875 A JP61056875 A JP 61056875A JP 5687586 A JP5687586 A JP 5687586A JP H0447381 B2 JPH0447381 B2 JP H0447381B2
- Authority
- JP
- Japan
- Prior art keywords
- protective film
- optical disk
- film
- substrate
- rare earth
- 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
- 239000000758 substrate Substances 0.000 claims description 51
- 230000001681 protective effect Effects 0.000 claims description 42
- 238000010438 heat treatment Methods 0.000 claims description 22
- 239000011347 resin Substances 0.000 claims description 20
- 229920005989 resin Polymers 0.000 claims description 20
- 230000003287 optical effect Effects 0.000 claims description 18
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 18
- 150000002910 rare earth metals Chemical class 0.000 claims description 17
- 238000007740 vapor deposition Methods 0.000 claims description 14
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 13
- 238000004544 sputter deposition Methods 0.000 claims description 6
- 230000006641 stabilisation Effects 0.000 claims description 5
- 238000011105 stabilization Methods 0.000 claims description 5
- 229910016569 AlF 3 Inorganic materials 0.000 claims description 3
- 229910004261 CaF 2 Inorganic materials 0.000 claims description 3
- 150000002222 fluorine compounds Chemical class 0.000 claims description 3
- 229910017768 LaF 3 Inorganic materials 0.000 claims description 2
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Inorganic materials [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 claims description 2
- -1 rare earth metal fluoride Chemical class 0.000 claims description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 10
- 238000000151 deposition Methods 0.000 description 9
- 230000008021 deposition Effects 0.000 description 9
- 229910052731 fluorine Inorganic materials 0.000 description 9
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 8
- 239000011737 fluorine Substances 0.000 description 8
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 5
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 238000007738 vacuum evaporation Methods 0.000 description 3
- 229910052684 Cerium Inorganic materials 0.000 description 2
- 229910052692 Dysprosium Inorganic materials 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 2
- 229910052691 Erbium Inorganic materials 0.000 description 2
- 229910052693 Europium Inorganic materials 0.000 description 2
- 229910052688 Gadolinium Inorganic materials 0.000 description 2
- 229910052689 Holmium Inorganic materials 0.000 description 2
- 229910052765 Lutetium Inorganic materials 0.000 description 2
- 229910052779 Neodymium Inorganic materials 0.000 description 2
- 229910052777 Praseodymium Inorganic materials 0.000 description 2
- 229910052772 Samarium Inorganic materials 0.000 description 2
- 229910052775 Thulium Inorganic materials 0.000 description 2
- 229910052769 Ytterbium Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000004417 polycarbonate Substances 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 229910020156 CeF Inorganic materials 0.000 description 1
- 229910002546 FeCo Inorganic materials 0.000 description 1
- 230000005374 Kerr effect Effects 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
Landscapes
- Optical Record Carriers And Manufacture Thereof (AREA)
Description
【発明の詳細な説明】
〔概要〕
デイスク基板と磁気記録媒体との間に設ける保
護膜がフツ化物−希土類金属の蒸着膜又はスパツ
タ膜で安定化熱処理を施こされており、光デイス
クの長寿命化に寄与するデイスク基板である。[Detailed Description of the Invention] [Summary] The protective film provided between the disk substrate and the magnetic recording medium is a fluoride-rare earth metal evaporated film or sputtered film that has been subjected to stabilizing heat treatment. This is a disk substrate that contributes to longer service life.
本発明は、高密度大容量メモリに用いられる光
デイスクの透明基板に関するものである。
The present invention relates to a transparent substrate for an optical disk used in a high-density, large-capacity memory.
光デイスクには、光磁気デイスク、相変態デイ
スクあるいは追記型光デイスクなどがあり、記録
媒体が劣化しないようにして長寿命化に寄与する
デイスク用基板が求められている。 Optical disks include magneto-optical disks, phase change disks, write-once optical disks, and the like, and there is a need for disk substrates that prevent the recording medium from deteriorating and contribute to a longer service life.
光デイスク用基板としては、(a)アクリル、スチ
レン、エポキシ、ポリカーボネイトなどの樹脂基
板、あるいは(b)ガラス板又はこれらの樹脂板上に
紫外線硬化型樹脂層を形成した基板がある。樹脂
基板の表面部にそして紫外線硬化型樹脂層に案内
溝（光ガイド溝）が形成されている。なお、ガラ
ス板上に紫外線硬化型樹脂層を形成したものも本
明細書では案内溝付き樹脂基板に含める。
Substrates for optical disks include (a) resin substrates such as acrylic, styrene, epoxy, and polycarbonate, or (b) glass plates or substrates in which an ultraviolet curable resin layer is formed on these resin plates. Guide grooves (light guide grooves) are formed on the surface of the resin substrate and on the ultraviolet curable resin layer. In this specification, a resin substrate with a guide groove also includes a glass plate with an ultraviolet curable resin layer formed thereon.
これら案内溝付き樹脂基板上に、例えば、光磁
気デイスク用の磁気記録媒体膜となる希土類金属
−遷移金属（例えば、TbFeCo）を真空蒸着又は
スパツタリングによつて直接に形成すると、磁気
的特性、記録・再生特性などの特性が十分でなく
かつ経時的に劣化する。この原因は、磁気記録媒
体膜の下地の樹脂中に酸素、水分、さらに未硬化
のモノマーなどの活性な成分が含まれており、こ
れらが記録媒体膜成分の希土類金属と反応して酸
化するからである。 If a rare earth metal-transition metal (e.g., TbFeCo), which will become a magnetic recording medium film for a magneto-optical disk, is directly formed on these resin substrates with guide grooves by vacuum evaporation or sputtering, magnetic properties and recording - Characteristics such as playback characteristics are insufficient and deteriorate over time. The reason for this is that the resin underlying the magnetic recording medium film contains active components such as oxygen, moisture, and uncured monomers, and these react with the rare earth metal of the recording medium film and oxidize it. It is.
そこで、従来から、樹脂基板と磁気記録媒体膜
との中間に透明な保護膜を形成して直接接触しな
いようにすることで記録媒体の劣化防止を図つて
いる。この保護膜は、光磁気デイスクであれば、
透明な他に無反射コーテイングと働きカー効果増
大効果をもたらすことなどを考慮して硫化物
（ZnS）膜が提案されている。 Therefore, it has been conventionally attempted to prevent the recording medium from deteriorating by forming a transparent protective film between the resin substrate and the magnetic recording medium film to prevent direct contact between the resin substrate and the magnetic recording medium film. This protective film is used for magneto-optical disks.
In addition to being transparent, a sulfide (ZnS) film has been proposed because it provides a non-reflective coating and enhances the Kerr effect.
硫化物（ZnS）の保護膜によつてかなり特性の
劣化を防ぐことができるが、それでも樹脂基板か
らの酸素および成膜時に保護膜中に取り込まれた
酸素が硫化物の保護膜中を拡散移動して記録媒体
に達するようになつて経時的特性劣化が生じてい
る。
Although a sulfide (ZnS) protective film can prevent property deterioration to a large extent, oxygen from the resin substrate and oxygen incorporated into the protective film during film formation can still diffuse through the sulfide protective film. As a result, characteristics deteriorate over time.
硫化物の代わりにフツ化物を保護膜材料とする
ことが考えられていたが、以下の理由によりその
保護効果が期待できないことがわかつている。そ
れは、フツ化物を蒸着又はスパツタリングによつ
て成膜する際に、一部のフツ素がフツ化物から切
れて遊離フツ素となつて保護膜中に存在し、この
遊離フツ素が記録媒体膜中の希土類金属と反応し
て特性を劣化するからである。 It has been considered to use fluoride as a protective film material instead of sulfide, but it has been found that the protective effect cannot be expected for the following reasons. This is because when fluoride is formed into a film by vapor deposition or sputtering, some fluorine is cut from the fluoride and becomes free fluorine, which exists in the protective film, and this free fluorine is present in the recording medium film. This is because it reacts with rare earth metals and deteriorates their properties.
本発明の目的は、樹脂基板と記録媒体膜との間
の保護膜を上述したフツ化物での欠点が生じない
ようにしてフツ化物を用いて形成し、光デイスク
の長寿命化を図ることのできるデイスク用基板を
提供することである。 An object of the present invention is to form a protective film between a resin substrate and a recording medium film using a fluoride without causing the above-mentioned drawbacks of the fluoride, thereby extending the life of an optical disk. The purpose of the present invention is to provide a disk substrate that can be used.
〔問題点を解決するための手段〕
上述の目的が、案内溝付き樹脂基板上にフツ化
物および希土類金属からなると保護膜が形成さ
れ、この保護膜は加熱による安定化処理が施こさ
れていることを特徴する光デイスク用基板によつ
て達成される。[Means for solving the problem] The above purpose is to form a protective film made of fluoride and rare earth metal on a resin substrate with guide grooves, and this protective film is stabilized by heating. This is achieved by an optical disk substrate having the following characteristics.
保護膜は蒸着又はスパツタリングによつて形成
され、希土類金属のフツ化物に対する蒸着又はス
パツタリング速度の比が0.3〜0.6であることが好
ましく、0.3以下では希土類金属の量が少なく遊
離フツ化物による特性劣化が生じ、一方、0.6以
下では光の吸収が大きくなり反射率が低下する。 The protective film is formed by vapor deposition or sputtering, and it is preferable that the ratio of the vapor deposition or sputtering rate of the rare earth metal to the fluoride is 0.3 to 0.6. If the ratio is less than 0.3, the amount of the rare earth metal is too small to cause property deterioration due to free fluoride. On the other hand, if it is less than 0.6, light absorption increases and the reflectance decreases.
成膜時に希土類金属を含ませることによつて、
多くの遊離フツ素は希土類金属と結合状態にあ
る、一部の遊離フツ素は未結合状態にあると考え
られる。この未結合の遊離フツ素を固定化するた
めに、加熱による安定化処理を45℃ないし樹脂基
板の耐熱性許容温度の温度範囲にて行ない、この
熱処理によつて成膜時に保護膜中に存在する遊離
フツ素と希土類金属原子とを反応させて安定なフ
ツ化物とする。同時に、記録媒体の酸化を防止す
ることもできる。 By incorporating rare earth metals during film formation,
It is believed that most of the free fluorine is in a bonded state with the rare earth metal, and some free fluorine is in an unbonded state. In order to fix this unbound free fluorine, a stabilization treatment by heating is performed at a temperature range of 45℃ or the allowable heat resistance temperature of the resin substrate. Free fluorine is reacted with rare earth metal atoms to form a stable fluoride. At the same time, it is also possible to prevent oxidation of the recording medium.
フツ化物としてはMgF2、CaF2、CeFV、
NdF3、AlF3、LaF3、LiF、NaAlF6、又はThF4
が使用でき、希土類金属としては、Tb、La、
Ce、Pr、Nd、Pm、Sm、Eu、Gd、Dy、Ho、
Er、Tm、YbおよびLuの少くとも一種が用いら
れる。特に、この希土類金属としては記録媒体中
の希土類金属と同じものを用いるのが望ましい。 Fluorides include MgF 2 , CaF 2 , CeFV,
NdF 3 , AlF 3 , LaF 3 , LiF, NaAlF 6 , or ThF 4
can be used, and rare earth metals include Tb, La,
Ce, Pr, Nd, Pm, Sm, Eu, Gd, Dy, Ho,
At least one of Er, Tm, Yb and Lu is used. In particular, it is desirable to use the same rare earth metal as the rare earth metal in the recording medium.
以下、添付図面を参照して本発明の好ましい実
施態様例によつて本発明を詳しく説明する。
DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail by way of preferred embodiments with reference to the accompanying drawings.
例 １
第１図は本発明に係る光デイスク用基板を用い
て製作した光磁気ディスクの部分断面図である。Example 1 FIG. 1 is a partial sectional view of a magneto-optical disk manufactured using the optical disk substrate according to the present invention.
案内溝（図示せず）を有するアクリル基板（例
えば、射出成で作られたPMMA基板）１上にフ
ツ化物としてMgF2を、希土類金属としてTbを用
いて、電子ビーム加熱方式の真空蒸着装置にて蒸
着でMgF2−Tb保護膜２（厚さ200nｍ）を形成
する。保護膜２の蒸着成膜において、MgF2蒸着
速度に対するTb蒸着速度の比（Tb／MgF2）を
０、0.2、0.3、0.4および0.6と変えた条件にて成
膜する。 MgF 2 is used as a fluoride and Tb is used as a rare earth metal on an acrylic substrate (for example, a PMMA substrate made by injection molding) 1 having guide grooves (not shown), and an electron beam heating type vacuum evaporation apparatus is used. A MgF 2 -Tb protective film 2 (thickness: 200 nm) is formed by vapor deposition. In forming the protective film 2 by vapor deposition, the film is formed under conditions where the ratio of the Tb vapor deposition rate to the MgF 2 vapor deposition rate (Tb/MgF 2 ) is changed to 0, 0.2, 0.3, 0.4, and 0.6.
次に、得られた基板を大気中にて60℃、80時間
維持する熱処理（安定化処理）を施こすが、この
熱処理を施こさないでそのままの基板もある。な
お、大気中でなく真空中又は不活性雰囲気中であ
つてもよい。 Next, the obtained substrate is subjected to a heat treatment (stabilization treatment) in which the substrate is maintained at 60° C. for 80 hours in the atmosphere, but some substrates are left as they are without this heat treatment. Note that it may be in a vacuum or in an inert atmosphere instead of in the air.
熱処理した基板および熱処理しない基板の上に
光磁気デイスクの磁気記録媒体膜（例えば、
TbFeCo膜、厚さ100nｍ）３を蒸着にて形成す
る。この成膜条件は、例えば、真空度：1.1×
10-5Pa、蒸着速度：Tbで0.23ｍ／秒およびFeCo
で0.2mm／秒であり、得られた記録媒体膜の特性
はHc（保磁力）＝７〜8kOcおよびθK（カ一回転角）
＝0.35degである。さらに、真空を破ることなく、
磁気記録媒体膜３上に表面保護膜４（厚さ200n
ｍ）をSiの蒸着によつて形成する。この表面保護
膜４は、透明である必要はなく、安定な窒化物
（Si3N4、AlN）あるいは硫化物（ZnS）であつて
もよい。 A magnetic recording medium film of a magneto-optical disk (for example,
A TbFeCo film (thickness: 100 nm) 3 is formed by vapor deposition. This film forming condition is, for example, vacuum degree: 1.1×
10 -5 Pa, deposition rate: 0.23 m/s for Tb and FeCo
The characteristics of the recording medium film obtained are Hc (coercive force) = 7 to 8 kOc and θ K (motor rotation angle).
=0.35deg. Furthermore, without breaking the vacuum,
A surface protective film 4 (thickness 200n) is placed on the magnetic recording medium film 3.
m) is formed by vapor deposition of Si. This surface protection film 4 does not need to be transparent and may be a stable nitride (Si 3 N 4 , AlN) or sulfide (ZnS).
このようにして製作した光磁気デイスクを60
℃、大気中（湿気：90％）にて保持したときの保
磁力（Hc）の経時変化を調べたところ第２図に
示す結果が得られた。第２図中、線ａはTbを含
有しないMgF2保護膜で熱処理なしの場合、線Ｂ
およびｂはTb／MgF2蒸着速度比0.2での保護膜
で熱処理ありの場合となしの場合、線Ｃおよびｃ
はTb／MgF2蒸着速度比0.3での保護膜で熱処理
ありの場合となしの場合、線Ｄおよびｄは蒸着速
度比0.4での保護膜で熱処理ありの場合となしの
場合、および線ｅは蒸着速度比0.6での保護膜で
熱処理なしの場合を示す。なお、破線はMgF2−
Tb保護膜を形成することなくアクリル基板上に
蒸着によつて
TbFeCo膜および保護膜を形成した光磁気デイ
スクの場合を示す。 60 magneto-optical disks produced in this way
℃ and in the atmosphere (humidity: 90%), the change in coercive force (Hc) over time was investigated, and the results shown in FIG. 2 were obtained. In Figure 2, line a is a Tb-free MgF 2 protective film without heat treatment, line B
and b are protective films with Tb/MgF 2 deposition rate ratio of 0.2 with and without heat treatment, lines C and c
are the protective films with and without heat treatment at a Tb/MgF 2 deposition rate ratio of 0.3, lines D and d are the protective films with and without heat treatment at a deposition rate ratio of 0.4, and line e is the protective film with and without heat treatment at a deposition rate ratio of 0.4. The case of a protective film with a deposition rate ratio of 0.6 and no heat treatment is shown. In addition, the broken line is MgF 2 −
The case of a magneto-optical disk in which a TbFeCo film and a protective film are formed by vapor deposition on an acrylic substrate without forming a Tb protective film is shown.
第２図からわかるように、MgF2−Tb保護膜の
ない場合（破線）ではHcが増加しており、これ
はアクリル基板からの活性な成分によるTbFeCo
膜中のTbの酸化に起因していると考えられる。
Tbを含有しない保護膜（線ａ）では保護膜のな
い場合（破線）よりもHcが大きく変化しており、
これはMgF2膜中の遊離フツ素によるTbFeCo膜
中のTbとの反応に起因していると考えられる。
MgF2−Tb保護膜中のTb量が多くなるにしたが
つてHcの変化は小さくなり、さらに熱処理が施
こされることにより小さくなる。 As can be seen from Figure 2, Hc increases in the case without the MgF 2 -Tb protective film (dashed line), and this is due to the active components from the acrylic substrate.
This is thought to be caused by the oxidation of Tb in the film.
With the protective film that does not contain Tb (line a), Hc changes more than when there is no protective film (broken line).
This is considered to be due to the reaction of free fluorine in the MgF 2 film with Tb in the TbFeCo film.
As the amount of Tb in the MgF 2 -Tb protective film increases, the change in Hc becomes smaller, and becomes smaller as heat treatment is performed.
製作した光磁気デイスクを60℃、大気中（湿
度：90％）に保持したときの記録再生特性（CN
比）の経時変化を調べたところ第３図に示す結果
が得られた。線Ｂ、ｂ、Ｄおよびｄは上述した
MgF2−Tb保護膜のある光磁気デイスクの場合で
あり、熱処理を施こすことによつてCN比の減少
をかなり小さくすることがわかる。 Recording and playback characteristics (CN
The results shown in FIG. 3 were obtained by examining the change in ratio) over time. Lines B, b, D and d are as described above.
This is the case of a magneto-optical disk with a MgF 2 -Tb protective film, and it can be seen that the decrease in the CN ratio is considerably reduced by applying heat treatment.
これらの結果から本発明に係るデイスク基板の
採用によつて光磁気デイスクの長寿命化が達成で
きることが明らかである。 From these results, it is clear that by employing the disk substrate according to the present invention, it is possible to extend the life of the magneto-optical disk.
例 ２
例１でアクリル基板の代わりにスチレン、エポ
キシ、ポリカーボネイトを用いた場合にも例１と
同様な結果が得られた。Example 2 Similar results to Example 1 were obtained when styrene, epoxy, or polycarbonate was used instead of the acrylic substrate in Example 1.
例 ３
例１でのアクリル基板の代わりに、ガラス板上
に紫外線硬化型樹脂による案内溝付き樹脂層を形
成した基板を用いる。この基板上に例１の真空蒸
着装置にてMgF2−Tb保護膜（厚さ200nｍ）を
形成する。なお、Ta／MgF2蒸着速度比を0.3お
よび0.6として保護膜を成膜する。Example 3 Instead of the acrylic substrate in Example 1, a substrate is used in which a resin layer with guide grooves made of an ultraviolet curable resin is formed on a glass plate. A MgF 2 -Tb protective film (thickness: 200 nm) is formed on this substrate using the vacuum evaporation apparatus of Example 1. Note that the protective film is formed with a Ta/MgF 2 vapor deposition rate ratio of 0.3 and 0.6.
次に、得られた基板を大気中にて120℃で、１
時間維持する熱処理（安定化処理）を施こすが、
この熱処理を施こさないでそのままの基板もあ
る。 Next, the obtained substrate was heated in the air at 120°C for 1
Heat treatment (stabilization treatment) is applied to maintain the temperature for a long time, but
There are also substrates that are left as they are without this heat treatment.
熱処理した基板および熱処理していない基板の
上に例１と同じに蒸着によつてTbFeCo膜を形成
し、その上にSi表面保護膜を形成して光デイスク
を製作する。 A TbFeCo film is formed by vapor deposition on the heat-treated substrate and the non-heat-treated substrate in the same manner as in Example 1, and a Si surface protection film is formed thereon to produce an optical disk.
製作した光デイスクを120℃、大気中（湿度：
90％）にて保持したときの保磁力（Hc）の経時
変化を調べたところ第４図に示す結果が得られ
た。第４図中、線ＦおよびｆはTb／MgF2蒸着速
度比0.3での保護膜で熱処理ありの場合となしの
場合、および線Ｇおよびｇは蒸着速度比0.6での
保護膜で熱処理ありの場合となしの場合を示す。
保護膜中のTb量が多いほうがHcの変化は小さく
かつ熱処理を施こすことでさらにHc変化は小さ
くなることが第４図からわかる。 The manufactured optical disk was heated at 120℃ in the atmosphere (humidity:
When the change in coercive force (Hc) over time was investigated when the magnetic field was held at 90%), the results shown in Figure 4 were obtained. In Fig. 4, lines F and f represent the protective film with and without heat treatment at a Tb/MgF 2 deposition rate ratio of 0.3, and lines G and g represent the protective film with and without heat treatment at a deposition rate ratio of 0.6. Indicates the case with and without.
It can be seen from FIG. 4 that the larger the amount of Tb in the protective film, the smaller the change in Hc, and the heat treatment further reduces the change in Hc.
また、Tb／MgF2蒸着速度比0.6の保護膜での
光デイスクにおける記録再生特性（CN比）の経
時変化を調べて第５図に示す結果が得られた。熱
処理を施こすこと（線Ｇ）によつてCN比の減少
が小さくなることがわかる。 Further, the change over time in the recording/reproducing characteristics (CN ratio) of an optical disk using a protective film with a Tb/MgF 2 deposition rate ratio of 0.6 was investigated, and the results shown in FIG. 5 were obtained. It can be seen that the decrease in the CN ratio becomes smaller by applying heat treatment (line G).
これらの結果からも本発明に係る基板は光磁気
デイスクの長寿命化に寄与していることが明らか
である。 It is clear from these results that the substrate according to the present invention contributes to extending the life of the magneto-optical disk.
例 ４
例１での保護膜を構成するフツ化物MgF2の代
わりに他のフツ代物AlF3、CaF2、CeF3、LiF、
LaF、NaAlF6、NaF3、又はThF4を用いた場合
にも例１と同様な結果が得られた。Example 4 Instead of the fluoride MgF 2 constituting the protective film in Example 1, other fluorides AlF 3 , CaF 2 , CeF 3 , LiF,
Similar results to Example 1 were obtained using LaF, NaAlF 6 , NaF 3 , or ThF 4 .
例 ５
例１での保護膜を構成する希土類金属Tbの代
わりに他の希土類金属La、Ce、Pr、Nd、Pm、
Sm、Eu、Gd、Dy、Ho、Er、Tm、Yb又はLu
を用いても例１と同様な結果が得られた。Example 5 Instead of the rare earth metal Tb constituting the protective film in Example 1, other rare earth metals La, Ce, Pr, Nd, Pm,
Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb or Lu
The same results as in Example 1 were obtained using .
上述の実施例では光磁気デイスクに適用した例
であるが、相変態比デイスク、追記型光デイスク
にも本発明に係る光デイスク用基板を用いること
ができ、上述したように記録媒体の特性劣化が抑
制できて長寿命化が図れる。
Although the above-mentioned embodiment is an example in which it is applied to a magneto-optical disk, the optical disk substrate according to the present invention can also be used for a phase change ratio disk and a write-once optical disk, and as described above, the optical disk substrate of the present invention can be used to avoid deterioration of the characteristics of the recording medium. can be suppressed and the lifespan can be extended.
第１図は、本発明に係る基板を用いて製作した
光磁気デイスクの部分断面図であり、第２図は、
アクリル基板を用いて製作した光磁気デイスクの
保磁力（Hc）の経時変化を示すグラフであり、
第３図は、アクリル基板を用いて製作した光磁気
デイスクのCN比の経時変化を示すグラフであ
り、第４図は、ガラス板および紫外線硬化型樹脂
層からなる基板を用いて製作した光磁気デイスク
の保磁力の経時変化を示すグラフであり、第５図
は、ガラス板および紫外線硬化型樹脂層からなる
基板を用いて製作した光磁気デイスクのCN比の
経時変化を示すグラフである。
１……アクリル基板、２……保護膜、３……記
録媒体膜、４……表面保護膜。
FIG. 1 is a partial sectional view of a magneto-optical disk manufactured using a substrate according to the present invention, and FIG.
This is a graph showing the change over time in the coercive force (Hc) of a magneto-optical disk manufactured using an acrylic substrate.
Figure 3 is a graph showing the change over time in the CN ratio of a magneto-optical disk manufactured using an acrylic substrate, and Figure 4 is a graph showing the change over time in the CN ratio of a magneto-optical disk manufactured using an acrylic substrate. FIG. 5 is a graph showing the change over time in the coercive force of the disk. FIG. 1... Acrylic substrate, 2... Protective film, 3... Recording medium film, 4... Surface protective film.
Claims (1)
樹脂基板の光デイスク用基板において、前記樹脂
基板上にフツ化物および希土類金属からなる保護
膜が形成され、該保護膜は加熱による安定化処理
が施こされていることを特徴とする光デイスク用
基板。 ２ 前記保護膜は蒸着又はスパツタリングによつ
て形成され、希土類金属のフツ化物に対する蒸着
又はスパツタリング速度の比が0.3〜0.6であるこ
とを特徴とする特許請求の範囲第１項記載の光デ
イスク用基板。 ３ 前記フツ化物はMgF2、CaF2、CeF、NdF3、
AlF3、LaF3、LiF、NaAlF6又はThF4であるこ
とを特徴とする特許請求の範囲第１項記載の光デ
イスク用基板。 ４ 前記加熱による安定化処理は45℃から前記樹
脂基板の許容温度までの範囲の温度にて行われる
ことを特徴とする特許請求の範囲第１項記載の光
デイスク用基板。[Claims] 1. In an optical disk substrate of a resin substrate with guide grooves on which a recording medium film is formed, a protective film made of a fluoride and a rare earth metal is formed on the resin substrate, and the protective film is made of a fluoride and a rare earth metal. An optical disk substrate characterized by being subjected to stabilization treatment by heating. 2. The optical disk substrate according to claim 1, wherein the protective film is formed by vapor deposition or sputtering, and the ratio of the vapor deposition or sputtering rate to the rare earth metal fluoride is 0.3 to 0.6. . 3 The fluorides include MgF 2 , CaF 2 , CeF, NdF 3 ,
The optical disk substrate according to claim 1, characterized in that it is AlF 3 , LaF 3 , LiF, NaAlF 6 or ThF 4 . 4. The optical disk substrate according to claim 1, wherein the stabilization treatment by heating is performed at a temperature in a range from 45° C. to an allowable temperature of the resin substrate.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61056875A JPS62217440A (en) | 1986-03-17 | 1986-03-17 | Substrate for optical disk |
| EP86402530A EP0231672B1 (en) | 1986-01-29 | 1986-11-14 | Optical memory device and process for fabricating same |
| DE8686402530T DE3685649T2 (en) | 1986-01-29 | 1986-11-14 | APPARATUS WITH OPTICAL MEMORY AND METHOD FOR THE PRODUCTION THEREOF. |
| KR1019860009659A KR900003688B1 (en) | 1986-01-29 | 1986-11-15 | Optical memory device and process for fabricating thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61056875A JPS62217440A (en) | 1986-03-17 | 1986-03-17 | Substrate for optical disk |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62217440A JPS62217440A (en) | 1987-09-24 |
| JPH0447381B2 true JPH0447381B2 (en) | 1992-08-03 |
Family
ID=13039593
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61056875A Granted JPS62217440A (en) | 1986-01-29 | 1986-03-17 | Substrate for optical disk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62217440A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2797384B2 (en) * | 1989-03-28 | 1998-09-17 | 日本電気株式会社 | Method for manufacturing magneto-optical recording medium |
-
1986
- 1986-03-17 JP JP61056875A patent/JPS62217440A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62217440A (en) | 1987-09-24 |
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