JPH02257451A - Magneto-optical recording medium - Google Patents

Abstract

PURPOSE:To improve an adhesive property and to improve oxidation resistance and the long-term stability of magneto-optical recording characteristics, etc., by composing a substrate from a copolymer of ethylene and specific cyclic olefin and forming the same of cyclic olefin random copolymers having >=70 deg.C and <70 deg.C softening temp. CONSTITUTION:The substrate consists of the copolymer of the ethylene and the cyclic olefin expressed by formula I and consists of the cyclic olefin random copolymer (A) having the ultimate viscosity eta in a 0.05 to 10dl/g range and >=70 deg.C softening temp. TMA and the cyclic olefin random copolymer (B) likewise having <70 deg.C. The weight ratio of the component (A)/component (B) is specified to a 100/0.1 to 100/10 range. The thin film of an amorphous alloy selected from 3d transition metals and rare earths respectively is used as the magneto-optical recording film. In the formula I, n denotes 0 or positive integer; R<1> to R<12> denote a hydrogen atom, halogen atom, etc.; R<9> to R<12> may form a monocyclic or polycyclic group by bonding to each other. The adhesive property between the substrate and the recording medium is improved in this way and the recording medium having the excellent oxidation resistance and the magneto-optical recording characteristics is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magneto-optical recording medium that has excellent adhesion between a substrate and a magneto-optical recording film, as well as excellent oxidation resistance and magneto-optical recording properties.

as well as transition metals such as iron, cobalt, and terbium (Tb).
, magneto-optical recording properties of alloys with rare earth elements such as cadrinium (Gd).The axis of easy magnetization is perpendicular to the film surface, and the film surface is entirely magnetized in one direction, with the direction opposite to this direction of magnetization. It is known that small inverted magnetic domains can be formed.

By associating the presence or absence of this inverted magnetic domain with "1" and "0", it becomes possible to record digital signals on the magneto-optical recording film as described above.

As a magneto-optical recording film made of such a transition metal and a rare earth element, for example, a Tb--Fe based magneto-optical recording film containing 15 to 3 at % of Tb is disclosed in Japanese Patent Publication No. 57-20691. Also, T b-F e-Co, Gd
-Tb-Fe, Dy-Tb-Fe-C.

Magneto-optical recording films, such as those based on magneto-optical systems, are also used.

The power of these magneto-optical recording films IL is that they have excellent recording and reproducing properties. During use, these magneto-optical recording films undergo oxidation and their properties change over time, which is a major practical problem. The mechanism of oxidative deterioration of magneto-optical recording films containing transition metals and rare earth elements is discussed, for example, in Journal of the Japan Society of Applied Magnetics, Vol. 9, NQ, 2, pp. 93-96, and as follows: It has been reported that there are three types:

b) Pitting corrosion Pitting corrosion refers to the formation of pinholes in the magneto-optical recording film.This corrosion mainly progresses in high temperature atmospheres, such as Tb-Fe and Tb-C.

The disease progresses markedly in some systems.

b) Surface oxidation layer is formed on the surface oxidized magneto-optical recording film. Kerr rotation angle θk
changes over time, and eventually the Kerr rotation angle θk decreases.

c) Selective oxidation of rare earth metal The rare earth metal in the magneto-optical recording film is selectively oxidized, and the coercive force Hc changes greatly over time.

In order to prevent the oxidative deterioration of the magneto-optical recording film as described above,
Conventionally, various methods have been tried. For example, a magneto-optical recording film is Si3N, 5iO1Si02, A, (N
A method of creating a three-layer structure sandwiched between various anti-oxidation protective films is being considered.

In addition, in order to improve the oxidation resistance of this thin film, a third
Various methods of adding metals have been attempted.

For example, in the above-mentioned Journal of the Japanese Society of Applied Magnetics, Tb-Fe, Tb-CoE, Co, Ni, and Pt.

Attempts have been made to improve the oxidation resistance of Tb-Fe-based or Tb-Co-based magneto-optical recording films by adding a third metal such as Af7, CrS, Ti, or Pd in an amount of up to 3.5 atomic percent. ing.

Also, the 9th Academic Lecture Summary of the Japanese Society of Applied Magnetics (1985)
(November 2013), page 209, Tb-Fe or Tb-
Fe-Co&=Pt, Al, Cr.

Magneto-optical recording films doped with Ti in amounts up to 1 atomic % have been taught.

Also, in Japanese Patent Application Laid-Open No. 61-255546, a magneto-optical recording film made of rare earth elements and transition elements is described.
A magneto-optical recording film with improved oxidation resistance and properties has been disclosed, in which a noble metal element such as Ir is added within a range that allows the Kerr rotation angle necessary for reproduction to be obtained.

In this way, conventional magneto-optical recording films made of Tb-Fe or Tb-Co doped with a third metal such as C, Al, C, T1, Pd, etc. Magneto-optical recording media in which the recording film is laminated on a normal substrate, such as a substrate made of polycarbonate resin, still do not have sufficient oxidation resistance, the long-term stability of the magneto-optical recording characteristics is insufficient, and the substrate has large complexities. C due to refraction
/N ratio was low, the noise level was high, and the adhesion between the substrate and the film was also insufficient. Therefore, when using polycarbonate resin as the substrate, the process of sufficiently removing moisture from the polycarbonate substrate by heat treatment is also required. In order to improve the adhesion, it was necessary to perform a plasma treatment process on the surface of the substrate.The present inventors conducted intensive research to improve the performance of the magneto-optical recording medium as described above, and found that the magneto-optical recording film The reason for the oxidation and deterioration of the magneto-optical recording film is due to the composition of the magneto-optical recording film as well as the substrate itself that is conventionally used to laminate the magneto-optical recording film. The present inventors discovered that the adhesion with the magnetic recording film was poor, and as a result, the oxidation of the magneto-optical recording film could not be sufficiently prevented. Based on the above findings, further investigation revealed that the substrate If a random copolymer of ethylene and cyclic olefin having the structure is used, and a specific magneto-optical recording film is laminated on the substrate as described above,
A magneto-optical recording medium with excellent adhesion between the substrate and the magneto-optical recording film, excellent oxidation resistance and high C/N ratio in magneto-optical recording properties, and excellent long-term stability of the magneto-optical recording properties can be obtained. The present invention has been completed based on the discovery that the present invention has been completed with the aim of solving the problems associated with the prior art as described above. The object of the present invention is to provide a magneto-optical recording medium which is convenient in terms of performance and has excellent oxidation resistance, magneto-optical recording characteristics, and long-term stability of magneto-optical recording characteristics.

A magneto-optical recording medium according to the present invention is a magneto-optical recording medium in which a magneto-optical film is laminated on a substrate, and comprises a substrate (A) ethylene and the following general formula [I]. The intrinsic viscosity [η] measured in decalin at 135°C is 0.05 to 10 dl/
a cyclic olefin random copolymer having a softening temperature (TMA) of 70° C. or higher, (B) ethylene, and the following general formula [! ] and has an intrinsic viscosity [V] of 0.05 to 5 dl/g as measured in decalin at 135°C.
and a cyclic olefin random copolymer with a softening temperature (TMA) of less than 70°C, and the weight ratio of component (A)/component (B) is 10070.1.
One of its characteristics is that it is formed from a cyclic olefin random copolymer composition in the range of ~100/10.

...[Eco(In formula [I], n is O or a positive integer,
R1 to R12 each represent a hydrogen atom, a nitrogen atom, or a hydrocarbon group, and R9 to R12 may be bonded to each other to form a monocyclic or polycyclic group, and the monocyclic or polycyclic group The group may have a double bond, and R9 and R11 or R11 and R12 may form an alkylidene group).

In such a cyclic olefin random copolymer, the 6-cyclic olefin component forms a structure represented by the general formula [11].

... [II] (In the formula [ul, n is 0 or a positive integer,
R1 to RI2 each represent a hydrogen atom, a halogen atom, or a hydrocarbon group. The group may have a double bond, and Ro and RIM or R11 and RL2 may form an alkylidene group).

In addition, in the present invention, a substrate as described above is used as a magneto-optical recording film, (i) at least one member selected from 3D transition metals.
The present invention is characterized in that it uses an amorphous alloy thin film having an axis of easy magnetization perpendicular to the film surface, which contains at least a species and (1ii) at least one element selected from rare earth elements as essential elements.

The magneto-optical recording medium according to the present invention will be specifically explained below.

The magneto-optical recording medium 1 according to the present invention has an E
, has a structure in which a magneto-optical recording film 3 is laminated on a substrate 2.

Further, the magneto-optical recording medium 1 according to the present invention may have a structure in which a magneto-optical recording film 3 and a reflective film 4 are laminated in this order on a substrate 2, as shown in FIG.

Furthermore, the magneto-optical recording medium 1 according to the present invention may have a structure in which an enhancement film 5 is provided between the substrate 2 and the magneto-optical recording medium 1, as shown in FIG.

Furthermore, the magneto-optical recording medium 1 according to the present invention has an enhancement film 5 provided between the substrate 2 and the magneto-optical recording film 3 as shown in FIG. It may have a structure in which an enhancement film 5 is provided between.

Examples of the enhancement film include SiN, SiN.

Silicon nitride LAjN such as (0<x<473).

Examples include Zn5eS, ZnS, and Si.

In the present invention, the substrate is made of a copolymer of the second generation (A) ethylene as described above and a cyclic olefin represented by the following general formula [I], and has an intrinsic viscosity [V ]Force ζ0, 05~10dl
/g, and a cyclic olefin random copolymer having a softening temperature (TMA) of 70°C or higher; (B) a copolymer of ethylene and a cyclic olefin represented by the following general formula [I]; The intrinsic viscosity measured in decalin at 135°C [η] car〇, 05 to 5 dl/
H range and a cyclic olefin random copolymer having a softening temperature (TMA) of less than 70°C, and the weight ratio of the component (A)/component (B) is 10070.1.
It is formed from a cyclic olefin random copolymer composition in the range of ~100/10.

... [r] (In formula [I], n is O or a positive integer, and
R1 to R12 each represent a hydrogen atom, a halogen atom, or a hydrocarbon group, R9 to Rl 214 may be bonded to each other to form a monocyclic or polycyclic group, and the monocyclic or polycyclic group The group may have a double bond, and R@ and R1. or R11 and RI2 may form an alkylidene group).

To explain in more detail about the cyclic olefin represented by the above general formula [tl], the cyclic olefin represented by the above general formula [r] is the 4L represented by the above formula [I], which is expressed by the following formula [! -a].

In [A] and [B], 14 the cyclic olefin component forms a structure represented by the general formula [nl].

...[I-al However, in the above [■-al, n is O or 1, m is O or a positive integer, and R1-R1@GL
Each independently represents an atom or group selected from the group consisting of a hydrogen atom, a halogen atom, and a hydrocarbon group.

and RI S 4 RI Machi 1 may be bonded to each other to form a monocyclic or polycyclic group, and the monocyclic or polycyclic group may have a double bond.

Furthermore, R15 and RI6 or R1) and RI8 may form an alkylidene group.

Such a cyclic olefin random copolymer...
[nl (In the formula [nl, n is 0 or a positive integer,
・R1 to R12 each represent a hydrogen atom, a halogen atom, or a hydrocarbon group, and may be bonded to each other to form a monocyclic or polycyclic group, and the monocyclic or polycyclic The group may have a double bond, and R11 and R1. or R11 and R12,
(may form an alkylidene group).

Incidentally, the cyclic olefin is expressed as [t-al] in the cyclic olefin-based random copolymers [A] and [B]. forming the structure represented.

... [u -al Tadakitsune In the above [rt-al, n is 0 or 1, m is 0 or a positive integer, and R1 to RIJ4
Each independent! , represents an atom or group selected from the group consisting of a hydrogen atom, a halogen atom, and a hydrocarbon group.

RI S 4 Rl$14 may be bonded to each other to form a monocyclic or polycyclic group, and the monocyclic or polycyclic group may have a double bond.

Further, RIS and RIB or R17 and R1. may form an alkylidene group.

A cyclic olefin, which is a constituent component of the above-mentioned cyclic olefin random copolymer, has the general formula [! ] At least one selected from the group consisting of unsaturated monomers represented by
It is a type of cyclic olefin.

It can be easily produced by condensing the cyclic olefin cyclopentadiene represented by [r] in the general formula with the corresponding olefin or cyclic olefin in a Diels-Alder reaction.

Specifically, the cyclic olefin represented by the general formula [r] includes melon 1.4.5.8-dimethano-1,2,3,4,
4a.

5, 8.8a-octahydronaphthalene and other &:, %
2-methyl-1,4,5,8-dimethano-1,2,3
,4,4a, 5.8.8a-octahydronaphthalene, 2-ethyl-1,4,5,8-dimethano-1,2,3
,4,4a, 5.8.8a-octahydronaphthalene, 2-brobyl-1,4,5,8-dimethano-1,2,
3,4,4a, 5.8.8a-octahydronaphthalene, 2-hexyl-1,4,5,8-dimethano-1,2
, 3,4,4a, 5.8.8a-octahydronaphthalene, 2.3-dimethyl-1,4,5,8-dimethano-
1,2,3,4゜4a, 5.8.8g-octahydronaphthalene, 2-methyl-3-ethyl-1,4,5,8
-dimethano-1,2,3,4,4a, 5.8.8a-
Octahydronaphthalene, 2-chloro-1,4,5,8
-dimethano-1,2,3,4,4a, 5.8.8a-
Octahydronaphthalene, 2-bromo-1,4,5,8
-dimethano-1,2,3,4,4a, 5.8.8a-
Octahydronaphthalene, 2-fluoro-1,4,5,
8-dimethano-1,2,3,4,4a, 5.8.8a
-octahydronaphthalene, 2,3-dichloro-1,4
,5,8-dimethano-1,2,3,4,4a, 5.8
．． 8a-octahydronaphthalene, 2-cyclohexyl-1,4,5,8-dimethano-1,2,3,4,4a,
5.8.8a-Octahydronaphthalene, 2-n-butyl-1,4,5,8-dimethano-1,2,3,4,4
a, 5.8.8a-octahydronaphthalene, 2-isobutyl-1,4,5,8-dimethano-1,2,3,4
, 4a, 5°8.8a-octahydronaphthalenes such as octahydronaphthalene can be exemplified.

Furthermore, examples of the cyclic olefin represented by formula [I] include the compounds described below.

That is, as the cyclic olefin represented by the above formula [l] used in the present invention, specifically, 1-bicyclo[2,2,1]hept-2-ene derivative tetracyclo[4,4,0,1' s, 1〒・Im]-3-
Dodecene-derivatized hexacyclo[5,5,l, ls, s, 11@, +
*, Oa, v, 0*, I41-4-heptadensene-induced mimic octacyclo[g, 3. Q, 12.1, 14. T, 11
1.1., 113.16 Qi, I, Qlli'l]-5
- tococene-induced imitation pentacyclo[6,6,1,1'・6
．． 02.7. Italian 14]-4-hexadecene derivatization heptacyclo-5-icosene derivative Zhu heptacyclo-5-heneicosene derivative,) Lysic O[4,3,0,1''-']-3-thecene derivatization Mimic induction citriciclo 3.0 .1”・6]-3-Undecene derivative book pentacyclo[6,5,1,1m,! , O”
・? , Q・Roku]-4-pentadecene induction imitation, pentacyclopentadecadiene induction & bentashiolo [4,7,0,1”・Ql, 1
3,1@・1m]-3-bentadecene derivative book o [7,8,0,1*,s,Oft, 1
1@, It, QIl, 1·112, Is]-4-eicosene derivative, and nonacyclo[9,10,1,1,4,7,0'·-,Q
2・1・,Of・21113.2@,Qlm,lI,
No. 1111]-5-bentacocene derivatives.

Specific examples of such compounds are shown below.

6-methylbicyclo[2 Bicyclo [2, 2, 11 Hept-2-ene induction conductor: hmm CH.

5.10-dimethyltetra9-isobutyl-11,12 5,8,9,10-tetramethy8-methyl-9-ethylte8-chlorotetrashif8-promotitrashif8-methyltetrashif8-ethyltetrashif1.] -]3-dodecene. [4,4,0, 12 s, 1v, +@]-3 8-isopropylidene-dodecene 8-n-propylidene-9-dodecene+ 1]-]3-dodece-dodecene etc. tetracyclo[4,4,0,12・5.17・+
θ]-3-dodece8-isopropylidene derivative; (blank below) +S, Ql? , Q., +a]-4-hep1z-methylhexacyclo[6,6,1,13・-11113
,Q2. ? ,Q*decene・Ia]-4-hebutadecene derivatives; tococenedecene ■, 1・, 1st, l I+ , (p@, Ql 2・+tl-5-tocosenheptadecene 15-ethyl octashif and other octacyclo[ 8,8,0,11・-914・)
, Ill·1·11+ s , (p ,·,012 1)]-]5-tococene derivative; which pentacyclo[6,6,1,13·e, 02v,
□s, +a) -4-hexadecene derivatives; Hebutacyclo-5-icosene derivatives or Hebutacyclo-5-heneicosene derivatives; Tricyclo[4,3,0,12・S]-3-decene derivatives; 10
-Tricyclo[4,4,0,11s]-3-undecene derivatives such as methyl-tricif; pentacyclo[6,5,1,1-6.02.7 such as 14,15-dimethylben
．． o91 'J] -4-pentadecene derivatives; diene compounds such as 1,6-dimethylbenta; nopentacyclo[4,7,(112,s,Ql,1
3. l11. +2]-3-pentadecene derivatives; nonacyclo[9,10,1,1', ma(p,
@, Ql, I @, Ql 2'”,
1”””, O’ ””, 1”,”] -]5-
Heptacyclo [7, g, Q, 131. Ql, T,
11@, 1. Ql・IlB, 111・+s]-4-eicosene derivative;, 21,112.2@, Ql4.19,
115·l@]-5-bentacocene This cyclic olefin random copolymer [A] and [
B]lL In addition to ethylene and the above-mentioned cyclic olefin, other copolymerizable unsaturated monomer components may be contained as necessary within a range that does not impair the object of the present invention. The unsaturated monomers which may be optionally copolymerized include, for example, propylene, 1-butene, 4-methyl- 1-pentene, 1-hexene, 1-
Octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-
Examples include α-olefins having 3 to 20 carbon atoms such as eicosene.

In the above-mentioned cyclic olefin random copolymer [A] having a softening point (TMA) of 70°C or higher, repeating unit (a) derived from ethylene +L40 to 85 mol%, preferably 50 to 75 mol% %, and the repeating unit derived from the cyclic olefin (b
) is present in a range of 15 to 60 mol%, preferably 25 to 50 mol%, and the repeating units (a) derived from ethylene and the repeating units (b) derived from the cyclic olefin are randomly distributed in a substantially linear manner. They are arranged in a shape. In addition, the ethylene composition and cyclic olefin composition are IC-NM
This cyclic olefin random copolymer is substantially linear and does not have a gel-like crosslinked structure as measured by .

Such a cyclic olefin random copolymer ゛[A]
Intrinsic viscosity [η]tons measured in decalin at 135°C
0.05-10dl/i preferably 0.08-5d
It is in the range of l/g.

In addition, the softening temperature (T
MA) Temperature: 70°C or less, preferably 90-250°C,
More preferably, the temperature is in the range of 100 to 200°C. The softening temperature (TMA) is determined by Thermome manufactured by DuPont.
The thermal deformation behavior of a 11-thick sheet was measured using a chani, cal analyzer.That is, a quartz needle was placed on the sheet, a load of 49 g was applied, and the temperature was raised at a rate of 5°C/min until the needle became 0.635. - The temperature of penetration is TMA and t4 Also, the glass transition temperature (T g) of the cyclic olefin random copolymer [AI] IL usually 50
It is desirable that the temperature is in the range of ~230°C, preferably 70~210°C.

In addition, the crystallinity of this cyclic olefin random copolymer [AI measured by X-ray diffraction method is 0 to 10%,
The range is preferably from 0 to 7%, particularly preferably from 0 to 5%.

Further, in the cyclic olefin random copolymer [B] having a softening point (TMA) of less than 70°C, the repeating unit (a) derived from ethylene is 60 to 98 mol%, preferably 60 to 98 mol%. The repeating unit derived from the cyclic olefin (b
) is present in a range of 2 to 40 mol%, preferably 5 to 40 mol%, and the repeating unit (a) derived from ethylene
and a repeating unit (b) derived from the cyclic olefin
It, randomly arranged substantially in a line. In addition, the ethylene composition and cyclic olefin composition are 13C
-The fact that this cyclic olefin random copolymer [B] is substantially linear and does not have a gel-like crosslinked structure as measured by NMR means that the copolymer completely dissolves in decalin at 135°C. This can be confirmed by

The intrinsic viscosity [η] of such a cyclic olefin random copolymer [B] measured in decalin at 135°C is 0
,05-5dl/g Preferably 0°08-3dl/g
within the range of

In addition, the softening temperature (T
MA) Ik 70℃, preferably -10~60℃
, more preferably in the range of 10 to 55°C. Also,
It is desirable that the glass transition temperature (Tg) of the cyclic olefin random copolymer [B] is usually in the range of -30 to 60°C, preferably in the range of -20 to 50°C.

Further, the crystallization change of the cyclic olefin random copolymer [B] measured by X-ray diffraction is in the range of O to 10%, preferably 0 to 7%, particularly preferably 0 to 5%.

In the present invention, in the cyclic olefin random copolymer composition used as a substrate, the weight ratio of the cyclic olefin random copolymer [A]/the cyclic olefin random copolymer [B] is 10010.1 to 100/10.
, preferably from 10010.3 to 100/7, particularly preferably from 10070.5 to 10015.

[B] Acid component By blending the [A] acid component within this range, the substrate itself can adhere to the magneto-optical recording film used in the present invention under severe conditions while maintaining its excellent transparency and surface smoothness. This cyclic olefin random copolymer composition consisting of a blend of [AI and [B] can be used in the present invention if it is used as a substrate. The excellent adhesion with the magneto-optical recording film is +1. It has the characteristic that it does not change even after being left under high humidity conditions.

Cyclic olefin random copolymer [AI and [B1 generation] constituting the cyclic olefin random copolymer composition used as a substrate in the present invention, both of which were published in Japanese Patent Application Laid-Open No. 60-16
No. 8708 Public/Private JP 61-120816 Public/Private JP 61-115912 Public/Private JP 61-1159
Public and Private Patent Application No. 16, 1982-95905, Public and Private Patent Application, 1982
It can be produced by appropriately selecting conditions according to the method proposed by the present applicant in JP-A-95906, public publication, JP-A-61-271308, public-private publication, and JP-A-61-272216.

A known method can be applied to the production of this cyclic olefin random copolymer composition, in which the cyclic olefin random copolymer [AI and [B] are separately produced, and [
A method of manufacturing by blending AI and [B] with an extruder,
[AI and [B] in a suitable submerged arc, such as heptane,
The solution blending method is carried out by sufficiently dissolving in saturated hydrocarbons such as hexane, decane, and cyclohexane, and aromatic hydrocarbons such as toluene, benzene, and xylene;
One example is a method in which AI and [B] are synthesized in separate polymerization vessels and the resulting polymers are blended in a separate vessel to produce a polymer.

In addition, 135 of the cyclic olefin random copolymer composition
The intrinsic viscosity [V] measured in decalin at °C is 0.05 to 10 dl/&, preferably 0.08 to 5 dl/
The softening temperature (TMA) measured by a thermal mechanical analyzer ranges from 70 to 25 g.
0°C, preferably 80-250°C, particularly preferably 100°C
The glass transition temperature (Tg
) is 70 to 230°C, preferably 90 to 210°C.
in the range of ℃.

In addition, as a resin forming the substrate, in addition to the above-mentioned cyclic olefin random copolymer, the following formula [I11] formed by ring-opening polymerization of the cyclic olefin represented by the above-mentioned formula [r] may be used. It may contain a polymer or copolymer containing the repeating unit represented by A polymer or copolymer containing the unit may also be included.

...[ml ...[rt'] In the above formulas [ml and [■], n and R1 to Rl 214 Same meaning as n and R1-R1ff1 in the cyclic olefin shown in the above formula [1] be.

The cyclic olefin random copolymer composition of the present invention contains the cyclic olefin random copolymer [A] and the cyclic olefin random copolymer [B] as essential components. Weather resistance stable i
1K Antistatic Ship Slip Ship Anti-Blocking Qi L Anti-Fog Ju L Slipboard Dyes, pigments, natural sources, synthesis method Wax, etc. can be blended, and the blending ratio is appropriate.

For example, stabilizers that may be added as optional ingredients include tetrakis[methylene-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate comethane, -t-butyl-4-hydroxyphenyl)propionic acid alkyl esters (especially preferred are alkyl esters having 18 or less carbon atoms).

2.2°-oxamidobis[ethyl-3(3,5-di-
Phenolic antioxidants such as t-butyl-4-hydroxyphenyl propionate) fatty acid metal salts such as zinc stearate, calcium stearate, calcium 12-hydroxystearate, glycerin monostearate, glycerin monolaurate, glycerin distearate , polyhydric alcohol fatty acid esters such as pentaerythritol monostearate, pentaerythritol distearate, and hentaerythritol tristearate. These may be blended alone or in combination, such as tetrakis[methylene-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate comethane and zinc stearate and Examples include combinations with glycerin monostearate.

In the present invention, it is particularly preferable to use a combination of a phenolic antioxidant and a fatty acid ester of a polyhydric alcohol. Preferably, it is an esterified polyhydric alcohol fatty acid ester.

Such fatty acid esters of polyhydric alcohols include:
Specifically 1 glycerin fatty acid esters such as glycerin monostearate, glycerin monolaurate, glycerin monomyristate, glycerin monopalmitate, glycerin distearate, glycerin dilaurate,
Fatty acid esters of pentaerythritol such as pentaerythritol monostearate, pentaerythritol monolaurate, pentaerythritol distearate, pentaerythritol dilaurate, and pentaerythritol tristearate are used.

Such a phenolic antioxidant is 0.0 parts by weight per 100 parts by weight of the cyclic olefin random copolymer composition.
The amount of fatty acid ester of polyhydric alcohol is 0.01 to 100 parts by weight, preferably 0.05 to 3 parts by weight, and more preferably 0.1 to 1 part by weight. -10 parts by weight, preferably 0.05 to 3
Used in parts by weight.

In the present invention, a cyclic olefin-based random copolymer as described above is used as the melon substrate 2, and this cyclic olefin-based random copolymer may be substituted with polycarbonate, poly(meth)acrylate, etc. that have been conventionally used as the substrate 2. Since the water absorption rate is comparatively low, the magneto-optical recording film laminated on the substrate is less likely to be oxidized by moisture. In addition, the substrate made of this cyclic olefin random copolymer composition and the magneto-optical recording film have excellent adhesion, and from this point of view, oxidation of the magneto-optical recording film laminated on the substrate can be effectively prevented. Ru. Therefore, a magneto-optical recording medium formed by laminating a magneto-optical recording film on a substrate made of this cyclic olefin random copolymer composition has excellent durability and long-term stability.

Furthermore, the substrate made of the above-mentioned cyclic olefin random copolymer composition has low birefringence, so the sensitivity when reading the magneto-optical recording film is high, and a non-differential drive device can be used at the time of reading. can.

In the present invention, on the substrate z as described above, a thin film easily magnetized on the film surface containing at least (i) at least one element selected from 3D transition metals and (1ii) at least one element selected from rare earths. A magneto-optical recording film 3 made of an amorphous alloy thin film having an axis is laminated, and in the present invention, in such a magneto-optical recording film 3, (i) at least one selected from 3d transition metals; It is preferable to use a magneto-optical recording film comprising (11) a corrosion-resistant metal and (1ii) at least one element selected from rare earths.

First, this preferred magneto-optical recording film 3 will be explained below.

(i) 3d transition metals such as It, Fe, Co,
Ti, VSCr, Mn, Ni, Cu,
Among these, Fe, Co, or something in between is preferable.

Preferably 20 to 90 at%, more preferably 30 to 85 at%,
It is particularly preferably present in an amount of 35 to 80 atom %.

(11) Corrosion-resistant metal 14 By including it in the magneto-optical recording film 3, the oxidation resistance of the magneto-optical recording film can be improved. +L as such a corrosion-resistant metal
Pt, Pd, Mo, T1, ZrS Ta.

Among these, PtS and Pd are used.

T1 is preferably Pt or Pd or both.

This corrosion-resistant metal is contained in the magneto-optical recording film 3 in an amount of 5 to 30 atomic percent, preferably 5 to 25 N, particularly 10 to 25 atomic percent.
It is present in an amount of atomic %, more preferably 10 to zO atomic %.

If the content of this corrosion-resistant metal is less than 5 at %, the oxidation resistance of the resulting magneto-optical recording film will not be sufficiently improved;
Over time, the coercive force He changes significantly or the Kerr rotation angle θk decreases.

Furthermore, if the amount exceeds 30 atom %, the Curie point of the resulting amorphous alloy thin film tends to be lower than room temperature, which is not preferable. (1ii) Third generation of magneto-optical recording film
In addition to (1) and (ii) above, it is configured to contain at least one rare earth element selected from the following group.

GdS Tb, Dy, Ho, Er, T
m, Yb.

Lu, La, Ce, Pr, Nd,
Pm, Sm.

u Of these, G d s T b SD y, Ho
, NdS Sm, Pr are preferably used.

At least one rare earth element method selected from the above group Remi in the magneto-optical recording film 3 Preferably in an amount of 5 to 50 at%, more preferably 8 to 45 at%, particularly preferably lO to 40 at%. Existing.

In the present invention, it is particularly preferable that the magneto-optical recording material has a composition as described below.

13d transition - The magneto-optical recording film according to the present invention preferably contains Fe or Co or both as the IL(i)3d transition element, and Fe and/or Co 40%
More than 8011 children% or less, preferably 40 children% or more 7
5 atomic% non-polymerized, more preferably 40 atomic% or more 59[
It is desirable that the amount is less than %.

Further, Fe and/or CO have a Co / (Fe + Co ) ratio [cyp particle ratio] Ago or more and 0.3 or less, preferably 0 or more and 0.2 or less, and more preferably 0.01 or more and 0.2 or less. in an amount
It is desirable that it be present in the magneto-optical recording film in an amount of 1%.

80J when the amount of Fe and/or Co is 40% or more
] 1,000% or less has the advantage that a magneto-optical recording film with excellent oxidation resistance and an axis of easy magnetization perpendicular to the film surface can be obtained.

By the way, when CO is added to the magneto-optical recording film, (a)
As the Curie point of the magneto-optical recording film increases and the Kerr rotation angle (θk) increases, the following phenomenon is observed: The recording sensitivity of the magneto-optical recording film is adjusted by adjusting the amount of viscosity and CO added. Moreover, by adding Co, the carrier level of the reproduced signal can be increased. The magneto-optical recording film used in the present invention has a wide noise level, C/
In terms of N ratio, the Co/(Fe + Co) ratio [W, child ratio] is 0 or more and 0.3 or less, preferably 0 or more and 0.2 or less, and more preferably 0.01 or more and 0.2 or less. desirable.

Figure 5 shows that the cyclic olefin copolymer composition substrate is coated with Pt.
Co/(Co + Fe) ratio [yK
Fig. 6 shows the relationship between the Co/(Co + Fe) ratio [atomic ratio] and the noise level in a magneto-optical recording medium in which a Pd Tb Fe Co-based magneto-optical recording film is laminated. (d B m).

Specifically, P tla T b2 s F e5
A magneto-optical recording film (Co
/ (Fe + Co) ratio [m ratio]: 0.15), the noise level is 156 dBm, while the magneto-optical recording film (Co / (Fe + Go) having the composition shown as Pt13Tb2@Fe5sCOa3) )
The noise level is 75'50 dBm, and the noise level tends to increase. Also, Pd+, Tb2vFeB□C
A magneto-optical recording film (Co/(F
e+CO) ratio [atomic ratio]: 0.12) 哄 The noise level is 156 dBm, while Pd+aTbztF
In a magneto-optical recording film having a composition represented by e4+CO+*, the (Co/(Fe +Co) ratio [atomic ratio]: 0.3
1) jL noise has a pel of 151 dBm, and the noise level tends to increase.

Figure 7 shows PtTbFeC0 or PdTbFeC.
Co/(Fe7l-Co) ratio [J
The relationship between J (child ratio) and erasure degradation (ΔC/N ratio (dB)) is shown.

Specifically, a magneto-optical recording film (Co / (Fe + Co
) ratio [/jit ratio]: 0.155) is laminated on the substrate.When erasing recorded information, no film deterioration occurs at all even if the energy irradiated to the film is increased. , new information can also be recorded with the same C/N ratio value as before erasing.

Further, the preferable magneto-optical recording film used in the present invention does not undergo film deterioration even after repeated recording and erasing. For example, in a magneto-optical recording film having a composition of P tl 3 T b2 @F es s COs, no decrease in the C/N ratio is observed even after repeated recording and erasing 100,000 times.

(ii) Corrosion-resistant metal In the preferred magneto-optical recording film used in the present invention ((ii)
The corrosion-resistant metal preferably contains Pt and/or Pd.
is contained in the magneto-optical recording film in an amount of 5 to 30 atomic %, preferably 10
More than 30 atomic %, more preferably 10 atomic %
It is desirable that it is present in an amount of more than 1 atomic % and less than 20 atomic %, most preferably 11 atomic % or more and 19 atomic % or less.

If the amount of PT and/or Pd in the magneto-optical recording film exceeds 5 atomic % or more, especially more than 10 atomic %, it will improve the oxidation resistance of the magneto-optical recording film. First, it has the advantage that the C/N ratio does not deteriorate.

Similar effects are also observed in Ti, MoS, Zr, Ta, Nb, and the like.

Figure 8 shows pt and/or P in the magneto-optical recording film.
d content and the magneto-optical recording medium at 85% relative humidity and 80°C.
The relationship between the ΔC/N ratio and the ΔC/N ratio when maintained for 1000 hours under the following environment is shown.

From this Figure 8, it can be seen that when the amount of PT and/or Pd in the magneto-optical recording film is 5 atomic % or more, especially more than 10 atomic %, the oxidation resistance of the magneto-optical recording film is improved and it can be used for a long period of time. It can be seen that no pitting corrosion occurs even when the C/N ratio is deteriorated.

For example, P tl2 T b2 B Fes @ C
O@ or P C12T bB F ea3 C07
When using a magneto-optical recording film having the composition shown by
The C/N ratio does not change at all even if it is kept in an environment of 85% relative humidity and 80° C. for 1000 hours. On the other hand, T b2s F ea 11 Co which does not contain pt or Pd
When a magneto-optical recording film having the composition shown in No. 7 is used, the C/N ratio decreases significantly when it is kept in an environment of 85% relative humidity and 80° C. for 1000 hours.

In addition, Pt, Pd, Ti,
Zr.

By adding at least one of Nb, Ta, and Mo in an amount within the above range, a sufficiently high C/C ratio can be achieved with a small bias magnetic field when recording information on a magneto-optical recording film or reading information. The N ratio is obtained. If a sufficiently high C/N ratio can be obtained with a small bias magnetic field, the magnet for generating the bias magnetic field can be made smaller, and heat generation from the magnet can also be suppressed, making it possible to drive optical disks with a magneto-optical recording film. The device can be simplified. Moreover, since a sufficiently large C/N ratio can be obtained with a small bias magnetic field, it becomes easy to design a magnet for magnetic field modulation recording that can be overridden.

FIG. 9 shows a magneto-optical recording film having a composition shown as P t+3Tb2sFesscO* and T bes F es
Bias magnetic field dependence and C/N ratio (dB
).

From this figure 9, T b2 s F ee s CO?
When using a magneto-optical recording film shown in 2500e
While the C/N ratio will not be saturated unless a bias magnetic field of the above magnitude is applied, P t+ 3 T b2g F es
It can be seen that sufficient recording is possible even with a small bias magnetic field with the magneto-optical recording film indicated by eCOs, and that the C/N ratio is saturated above 1200e. In the example,
The table shows the value of the minimum bias magnetic field Hsat necessary for saturating the C/N ratio for each magneto-optical recording film. The smaller this value Hsat is, the more the C/N ratio is saturated with a smaller bias magnetic field.

In addition, Fig. 10E shows the relationship between the content of pt and/or Pd in the Pt Tb Fe Co-based magneto-optical recording film and the Pd Tb Fe Co-based magneto-optical recording film and the minimum bias magnetic field (Hsat, (Oe)). show.

From FIG. 10, it can be seen that when the content of Pt and/or Pd exceeds 10i%, the minimum bias magnetic field Hsat becomes sufficiently small.

iii Rare earth -RE The magneto-optical recording film according to the present invention contains a rare earth element (RE).
These rare earth elements include Nd,
SmS Pr, Ce, Eu,
Gd, Tb.

n) y or Ho is used.

Among these, NdS Pr, Gd, Tb.

Dy is preferably used, and Tb is particularly preferred.

Further, two or more kinds of rare earth elements may be used in combination, and in this case, it is preferable that Tb is contained in an amount of 50 at % or more of the rare earth elements.

This rare earth element has the advantage of providing magnetism with an axis of easy magnetization perpendicular to the film surface, so that RE/(RE+Fe +
Co) ratio [atomic ratio] is expressed as X, 0.15≦
It is desirable that the compound be present in the magneto-optical recording film in an amount such that X≦0.45, preferably 0, 20≦X≦0, 4.

In the present invention, small amounts of various elements are added to the IL magneto-optical recording film to adjust the Curie temperature, compensation temperature, or coercive force H.
It is also possible to improve c and Kerr rotation angle θ or to reduce costs. These elements can be used at a rate of, for example, 10 atomic percent of the total number of atoms constituting the recording film.

Examples of other elements that can be used in combination include the following 11 elements.

(1) 3d transition elements other than Fe and Co, specifically Sc, Ti5V, Cr, Mn
.

NiS, Cu, and Zn are used.

Among these, Ti, Ni, Cu, Zn, etc. are preferably used.

(n) 4d transition elements other than Pd Specifically, Ill YSZrSNb, Mo, Tc.

RuS Rh and AgS Cd are used.

Among these, Zr and Nb are preferably used.

(m) 5d transition elements other than Pt Specifically +l Hf5Ta, W, Re,
Os.

Ir, AuS, Hg are used.

Among these, Ta is preferably used.

(rv) mB group elements, specifically: B, AI, Ga, InS Ti
is used.

Among these, B, AI, and Ga are preferably used.

(v) rvB group element Specifically, 11 C, SiS GeX Sn, and Pb are used.

Among these, Si, Ge, Sn, and Pb are preferably used.

(Vl) VB group element Specifically, NSP, As, Sb, and Bi are used.

Among these, sb is preferably used.

(■) VIB group elements Specifically, SS Se, Te, and Po are used.

Among these, Te is preferably used.

Further, in the present invention, as the magneto-optical recording film 3, at least one selected from (i) 3d transition metals as described above;
(1ii) A magneto-optical recording film made of at least one element selected from rare earths can be used. As such a magneto-optical recording film, a magneto-optical recording film based on 1 Tb Fe Co is preferable, and Tb is contained in an amount of 10 to 40 at.
Preferably, e is present in an amount of 30 to 90 atom %, and Co is present in an amount of O to 30 atom %. Furthermore, in the present invention (i
) 3d transition metals and (1ii) rare earth metals such as Tb-
The Fe, Tb-Fe-Co system may further contain other elements (for example, the elements represented by (r) to (■) above).

The magneto-optical recording film 3 having the above composition is an amorphous thin film that has an axis of easy magnetization perpendicular to the film surface and exhibits a rectangular loop with good Kerr hysteresis and is capable of perpendicular magnetic and magneto-optical recording. This can be confirmed by wide-angle X-ray diffraction.

In this specification, a square loop with good Kerr hysteresis means the saturated Kerr rotation angle (θkl), which is the Kerr rotation angle at the maximum external magnetic field, and the residual Kerr rotation angle (θkl), which is the Kerr rotation angle at zero external magnetic field. The ratio θ to 2)
1 means that ka/θ is 0.8 or more.

The film thickness of such a magneto-optical recording film 2 is 100 to 500
0 angstrom, preferably about 100 to 3000 angstrom, more preferably about 150 to 2000 angstrom.

In the magneto-optical recording medium 1 according to the present invention, a reflective film 4 may be provided on the magneto-optical recording film 3 as described above.

The reflective film 4 is desirably made of a metal or alloy having a thermal conductivity of 2 J/cn-sec.K or less, preferably I J /as.sec.K or less.

More preferably, the reflective film 4 has a reflectance of 50% or more, preferably 70% or more, and a thermal conductivity of 2 J
/am-sec -K or less preferably lJ/cffi・
Constructed from metals or alloys below 5ea-.

Specifically, the thermal conductivity of 4 layers of reflective film is 0.71 J/Ql.
Pt whose thermal conductivity is l sec -K and whose thermal conductivity is 0.7
Pd whose thermal conductivity is 6 J/am-sec-0.
T1 whose thermal conductivity is 22 J/cm-sec-, or CO1 whose thermal conductivity is 099 J/cIIl-3eC-. 23 J/al-sec - or an alloy thereof.

The fourth generation of such a reflective film has a reflectance of 50% or more, preferably 70% or more, and a thermal conductivity of 2 J/■-sec -
It is also preferable to use a nickel-based alloy having an I J /cn −5ec − or less.

The nickel-based alloy 1 constituting such a reflective film is mainly composed of nickel, silicon, molybdenum, iron,
At least one selected from the group consisting of chromium and copper
Preferably, it contains seeds. In such nickel-based alloys: nickel is present in an amount of 30 to 99 1,000 %, preferably 50 to 90 atomic %.

The nickel alloy that makes up the above reflective film is as follows:
Specifically, the following alloys can be used.

Ni-Cr alloy (e.g. 30-99 atomic% Ni, 1
~70 at.% Cr, particularly preferably 70-95 at.% Ni, 5-30 at.% Cr) Ni-3i based alloy (e.g. 85 at.% Ni.

10JX%Si, 3atomic%Cu, 2JJK%A
) Ni-Cu alloy (e.g. 63 atomic% Ni, 2
9 to 30 atom% Cu, 0.9 to 2 atom% Fa, 0.
1 to 4 atomic% S da O to 2.75. Jl[child%A)N
i-Mo-Fe alloy (e.g. 60-65ffl%
N1.25-35 at% MO15 at% Fe) Ni-
M o-Fe-Cr alloy (e.g. 55-60 atomic% Ni, 15-20 atomic% Mo, 6 atomic% Fe, 1
2 to 16 atom% Cr, 5 atom% W) N i-Mo-F
e-Cr-Cu alloy (e.g. 60 atomic% N1.5
atomic%Mo, 8atomic%Fe, 21atomic%Cr13JJK
Child% Cu, 1 atom% S1, l atom% Mn, lfi child% W
1 or 44 to 47 atom% Ni, 5. 5~
7.5 at% Mo, 21-23 at% CrS 0. 1
5i% Cu, 1% Si.

1 to 2 atom% Mn, 2,5 atom% Co, 1 atom% W
S1.7-2.5 atomic% Nb, balance Fe) Ni-
Cr-Cu-Mu alloy (e.g. 56-57 atomic%
Ni, 23-24 at% Cr, 8 at% (u, 4y
L % Mo, 2 atomic % W, 1 atomic % S1 or Mn
) Ni-Cr-Fe alloy (e.g. 79.5 atomic% Ni
, 13 atomic% Cu, 6. 5 atom% Fe.

0.2 atom% Cu, or 30-34 atom% Ni
, 19-22yK%Cr, 0. 5 atom% Cu.

l atom %S1.1. 5 atomic % Mn, balance Fe) magneto-optical recording medium Taka aluminum having such a reflective film 4;
It has an excellent C/N ratio compared to a magneto-optical recording medium having a reflective film made of iron or the like.

In other words, when a reflective film such as aluminum with high thermal conductivity is used, pits are formed in the magneto-optical recording film by irradiating the laser beam.Thermal energy given to the magneto-optical recording film by the laser beam is transferred to the reflective film. , which requires a large recording laser power. Furthermore, the shape of the bit formed on the magneto-optical recording film becomes large or irregular. the&
The dependence of recording power on the thickness of the reflective film becomes too large.

In addition, the reflective film 4 as described above has the effect of improving the oxidation resistance of the magneto-optical recording film, so that a magneto-optical recording medium with excellent long-term reliability can be obtained. rate is 2J/aII-8ec・K or less, preferably 1
A reflective film made of the following nickel-based alloy with a diameter of 1/as·5ec- is preferable, particularly a Ni-Cr alloy (e.g. 30
~99 atom% Ni.

1 to 70 atom% Cr) is preferable, and further Ni70 to 9
A reflective film made of a Ni-Cr alloy containing 5yK% and 5 to 30 atomic% of Cr is preferable because a high C/N ratio can be obtained.

On the other hand, by providing a reflective film 4 made of a metal, particularly a nickel-based alloy, that has low thermal conductivity and high reflectance,
Even if the thickness of the magneto-optical recording film is reduced, a high Kerr rotation angle and reflectance can be obtained.

The thickness of such a reflective film 4 is about 100 to 4000 angstroms, preferably about 200 to 2000 angstroms.

The total thickness of the magneto-optical recording film 3 and the reflective film is 300~
4600 angstroms, preferably 350-240
It is approximately 0 angstroms.

In the magneto-optical recording medium 1 according to the present invention, an enhancement film 5 may be provided between the substrate 2 and the magneto-optical recording film 3 as described above, and the magneto-optical recording film 3 and the reflective film 4 may be provided with an enhancement film 5. An enhancement film 5 may be provided between them.This enhancement film 5 serves to increase the sensitivity of the magneto-optical recording medium l according to the present invention, and also acts as a protective film for the magneto-optical recording film 3. As such an enhancement film 5, any transparent film having a refractive index greater than that of the substrate can be used.

As such an enhancement film, Z
nS, Zn5eSCdS.

S i, N,, Si Nx (0<x<4/3), S
i.

AN etc. can be used. The thickness of this enhancement film is about 100 to 1000 angstroms, preferably about 300 to 850 angstroms. Among these, from the viewpoint of crack resistance, Si, N4, SiN
It is particularly preferable to use x (0<x<4/3) as the enhancement film.

Next, a method for manufacturing a magneto-optical recording medium according to the present invention will be explained.

The substrate temperature is maintained at about room temperature, and a composite target in which chips made of each element constituting an amorphous alloy thin film are arranged in a predetermined ratio, or an alloy target with a predetermined composition ratio is used, and the sputtering method or electron beam evaporation method is used. An amorphous alloy thin film of a predetermined composition is deposited on this substrate (the substrate may be fixed or rotating) using conventionally known film forming conditions, and then Accordingly, by depositing a reflective film thereon in the same manner as described above, the magneto-optical recording medium according to the present invention can be manufactured.

As described above, the magneto-optical recording medium 1 according to the present invention is heat treated.
There is no need for pretreatment such as plasma treatment, and the film can be formed at room temperature, and there is no need to perform heat treatment such as annealing after film formation in order to have an axis of easy magnetization perpendicular to the film surface.

Note that, if necessary, the amorphous alloy thin film can be formed on the substrate while heating the substrate to 50 to 100°C or cooling it to -50°C.

Further, during sputtering, the substrate can be biased to a negative potential. In this way, ions of an inert gas such as argon accelerated by an electric field will strike not only the target material but also the perpendicularly magnetized film being formed, resulting in a perpendicularly magnetized film with excellent properties. There is.

In the magneto-optical recording medium according to the present invention, a magneto-optical recording film made of a specific amorphous alloy thin film is laminated on a cyclic olefin random copolymer composition substrate made of ethylene and a cyclic olefin. Because it has such a structure, the adhesiveness between the substrate and the magneto-optical recording film is not damaged, and it also has excellent oxidation resistance, magneto-optical recording characteristics, and long-term stability of the magneto-optical recording characteristics.

The present invention will be explained below by way of examples.
The present invention is not limited to these examples.

The physical properties of the magneto-optical recording medium in the following examples were investigated by the following methods. (1) Composition of the magneto-optical recording film: Performed by ICP analysis (2) Kerr rotation angle was measured from the substrate side. Let's measure the residual Kerr rotation angle with zero magnetic field using the oblique incidence method (λ = 780 nm).The specific measurement method and equipment of the oblique incidence method are described in "Measurement techniques for magnetic materials" supervised by Kazube Yamayo (December 1985). Published by Trikebbs Co., Ltd.) on pages 261 to 263.

(3) The magneto-optical disk is 130 mm in diameter, and the magneto-optical disk is driven by a drive device (Nakamichi 0MS-100).
0), recording frequency IMHz (Duty ratio 50
%), linear velocity 11. In/s, bias magnetic field during writing 2000 eS, read laser power 1. OW
Perform recording and playback under the following conditions (4) Then, Table 6 shows 2.
The signal-to-noise ratio (C/N ratio) and noise level when recording is performed with the recording power that minimizes the level of harmonics (optimum recording power) are also shown.

(5) Then, convert this information to 3.0 from the optimum recording power.
The erasing beast records new information with mW high power. Do this operation 10 times and get the C/N before and after erasing.
The difference in ratio was signed as the ΔC/N ratio.

(6) Concerning the bias magnetic field dependence. Regarding the bias magnetic field dependence under the above conditions. C/N when changing the bias magnetic field from 50 to 5000e under the above conditions.
Hsat was determined from the change in the ratio.
1 during open operation under high temperature conditions of 0°C and 85% relative humidity.
We conducted a life test where we left it for 000 hours, and 1000
The C/N ratio was measured after the elapse of time and is shown in Table 6.

Reference IL (Manufacture of cyclic olefin random copolymer composition substrate) (Synthesis of copolymer (A) with a softening temperature of 70°C or higher) Using a glass polymerization vessel equipped with a stirring blade. Continuous stains
A 1,4,5,8-dimethano-1,2,3° reaction was carried out with ethylene. That is, a cyclohexane solution of DMON was added from the top of the polymerization vessel, and the degree of DMON in the polymerization vessel was 60 g/L.

A cyclohexane solution of VO(OCaHs)C2 was used as a catalyst, and the vanadium concentration in the polymerization vessel was 0°9 mmol.
/ Ethyl aluminum sesquichloride (A l
A cyclohexane solution of (C2Hs) +, s C+, s) was heated to an aluminum concentration of 7 in the polymerization vessel.
．． Continuously feed each into the polymerization vessel so that the amount becomes 2 mmol/L.Meanwhile, continuously draw out the polymer solution in the polymerization vessel from the lower part of the polymerization vessel so that the amount becomes 1. In addition, from the top of the polymerization vessel, 85 kg/h of ethylene and 6.17 kg/h of hydrogen were added.
, nitrogen at a rate of 45 rpm.

Copolymerization reaction The copolymerization is carried out at 10°C by circulating a refrigerant through a jacket attached to the outside of the polymerization. When copolymerization is carried out under the above reaction conditions, ethylene and DMON are produced.
A polymerization reaction mixture containing a random copolymer is obtained. A small amount of isopropyl alcohol was added to the polymerization liquid taken out from the bottom of the polymerization vessel to stop the polymerization reaction.After this, the polymerization liquid was placed in a household mixer containing about three times the amount of acetone as the mixer was being rotated. Pour the polymerization solution
The produced copolymer was precipitated.The precipitated copolymer was filtered,
The copolymer was collected by filtration, dispersed in acetone to a polymer concentration of about 50 g/i, and treated at the boiling point of acetone for about 2 hours. After the above treatment, the copolymer was collected by filtration.1. The ethylene/DMON random copolymer (A) obtained as described above was dried under reduced pressure at 120°C for a day and night. The ethylene composition in the copolymer measured by 11C-NMR analysis was 59 mo1% in decalin at 135°C. The measured intrinsic viscosity [η] is 0, 42 dl/h
The softening temperature (TMA) was 154°C, and DMON, VO(OCaHs)CJl,
The concentrations of ethylaluminum sesquichloride and ethylaluminum sesquichloride in the polymerization vessel were 23 g/IJ, Q, and 7 mmol/, respectively.
and 5. 6 mmol/J was continuously supplied, and ethylene was supplied at 140 J/hour, hydrogen at 13 J/hour, and nitrogen at 25 J/hour from the top of the polymerization vessel, and the polymerization temperature was adjusted to 10 J/hour.
Polymerization was carried out continuously in the same manner except that the temperature was set at 1.degree. ．． Ethylene DMO obtained as above by drying at 180°C for 12 hours under reduced pressure
The ethylene composition in the copolymer measured by ISC-NMR analysis of N copolymer (B) is 89 mo1% S. The intrinsic viscosity measured in decalin at 135°C [η is 0.44 dl/i
The softening temperature (TMA) was 39°C. (1ii) Production of substrate of cyclic olefin random copolymer composition Copolymers (A) and CB synthesized in Polymerization Examples 1 and 2
) respectively 400g and 4g (weight ratio: (A) / (B
) = 10071) was added to cyclohexane 8 and dissolved at about 50°C with thorough stirring.The obtained homogeneous *a was added to acetone zl+=t,, (A)/(B) The blend was precipitated. Tetrakis[methylene-3 (3,5-di-t-butyl-4
-Hydroxyphenyl)propionate comethane, stearic acid monostearate, resin [A
0.5% and 0.1%, respectively, of the total amount of [B].
05%, 0.5% blended fox 20--Extruder (L/D=2
After pelletizing at 23°C using 0), an injection molding machine 15-50 manufactured by Toshiba Machine Co., Ltd. was used to mold a disk plate with a thickness of 1 and a diameter of 30 m (mirror surface on both sides) using Fe as a target. pt and Tb on Co target
A substrate made of a cyclic olefin random copolymer composition (130 mm≠) obtained in Reference Example 1 using a composite target in which chips of and were arranged at a predetermined ratio (hereinafter referred to as PO substrate)
1 was deposited on this substrate without drying (after ultrasonic cleaning with Teflon TE) by magnetron sputtering at 20 to 50°C.
7. Vacuum attainment level 1. under Ar atmosphere. OXI 01
P tl 2T b3 @ F ea @ Co @ f with a film thickness of 1000 angstroms under Torr or less conditions
) The magneto-optical recording film and the obtained magneto-optical recording film were measured by wide-angle X-ray diffraction and were found to be amorphous. The physical properties of the (film) are shown in Table 6.The film formation state was good when observed under a microscope.
% Calm The state of the membrane after the test was observed under a microscope after being left in a constant temperature bath at a temperature of 85℃ for 170 hrs.
There was no change in the appearance of the recording film compared to before the test, and the adhesion of the film was good.''A composite target was used, in which Tb chips were placed at a predetermined ratio on each of Fe and Co targets. , T b2 @ with a film thickness of 1000 angstroms was deposited on the same PO substrate as used in Example 1 under the same conditions as Example 1.
A magneto-optical recording film of Fes*CO〒 was formed.The obtained magneto-optical recording film was amorphous.
Table 6 shows the physical properties of the film 130. , the humidity of the φ disk plate is 8
The film was left in a constant temperature bath at 5% calm for 170 hrs at a temperature of 85°C. When the state of the film was observed after the test using a microscope, there was no change in the appearance of the recording film compared to before the test, and the adhesion of the film was good. Pt and Tb on Fe and Co targets as targets.
A polycarbonate resin substrate (PC board) was dried in a sputtering device at 80°C for 6 hours using a composite target in which chips of A magneto-optical recording film of P tl 2 T b 3 /F ea /Co with a film thickness of 1000 angstroms was formed using the C magnetron sputtering method in an Ar atmosphere with a vacuum attainment of 1,0XIO-F Torr or less. The magneto-optical recording film was found to be amorphous when measured by wide-angle X-ray diffraction.The composition was I.
Comparative Example 2 carried out using the CP analysis method A composite target in which Tb chips were arranged at a predetermined ratio on Fe and Co targets was used as the target, and a film thickness of 10% was deposited on a polycarbonate resin substrate in the same manner as in Comparative Example 1.
00 angstrom Tb2SFe,. A magneto-optical recording film of Cot was formed.The obtained magneto-optical recording film was found to be amorphous as measured by wide-angle X-ray diffraction [Evaluation of adhesion between the substrate and magneto-optical recording film] by the following method. Example 1. 2. Comparative example 1. Table 1 shows the results of evaluating the adhesion between the substrate and the magneto-optical recording film of the magneto-optical recording medium No. 2.

Training Yunu 1 Substrate test (JIS K5400) On the recording film of the sample, draw 11 orthogonal parallel lines at 1 m intervals using a cutter knife. 1 cm
Make incisions in the shape of the base so that 100 squares are formed in 2.

Peeling was evaluated using cellophane tape (manufactured by Chiban).

Evaluation - Immediately After Film Formation ■ 80°C 785% Calm After 100 Hours 1'' Table 2 shows the characteristics of the magneto-optical recording medium obtained by forming the magnetic recording film.

700 angstroms of SiNx (0
<X<4/3, refractive index n=2°3, k (extinction coefficient)=0
．． 014), a magneto-optical recording layer, and a 300 angstrom P t+ *T bs a F es s CO+s
, 700 angstrom Nits as a reflective layer.
A magneto-optical disk was created by sequentially laminating Cr2. The recording and reproducing characteristics of this disk were determined at a recording frequency of 1 MHz (
The optimum recording laser power was 3.5 mW, which was evaluated at a linear velocity of 5.4 m/s.
C/N is 50dB (reproduction laser power is 1, OmW
) was prepared in the same manner as in Example 21 to create a magneto-optical disk having a composition and structure as shown in Table 7 in the magneto-optical recording layer and reflective layer. Table 3 shows the results of evaluation conducted in the same manner.

Table 3

[Brief explanation of drawings]

11. FIG. 3 and FIG. 4 are sectional views of the magneto-optical recording medium according to the present invention. Figure 5.1 Co/magneto-optical recording film containing Pt
FIG. 3 is a diagram showing the relationship between the (Fe + Co 2 ) ratio [JllK ratio] and the noise level (dBm). 6 is a diagram showing the relationship between Co/(Fe+Co) ratio [atomic ratio] and noise level (dBm) in a magneto-optical recording film containing Pd. Fig. 7 Magneto-optical recording film cl)Co/(Fe
+Co) ratio [atomic ratio] and erasure degradation (ΔC/N ratio (d
It is a figure showing the relationship with B)). Figure 8 1. PT and/or Pd in magneto-optical recording film
FIG. 3 is a diagram showing the relationship between the content (yK 1,000%) and oxidation resistance (ΔC/N ratio). FIG. 9 is a diagram showing the relationship between the bias magnetic field (Oe) and the C/N ratio of the magneto-optical recording film. Figure 10 PT and/or P in the magneto-optical recording film
d content (atomic %) and minimum bias magnetic field (Hsat,
(Oe)). The magneto-optical disks shown in FIGS. 4 to 9 all have the configuration shown in FIG. 1, and the substrate is the cyclic olefin random copolymer composition obtained in Reference Example 1.
0.00 angstrom recording films are sequentially laminated. Compiled diagram Figure 3 Agent

Claims (1)

[Scope of Claims] 1) A magneto-optical recording medium in which a magneto-optical recording film is laminated on a substrate, the substrate comprising: (A) a copolymer of ethylene and a cyclic olefin represented by the following general formula [I]; The intrinsic viscosity [η] measured in decalin at 135°C is 0.05 to 10 dl.
/g, and has a softening temperature (TMA) of 70°C or higher; (B) a copolymer of ethylene and a cyclic olefin represented by the following general formula [I]; The intrinsic viscosity [η] measured in decalin at 135°C is 0.05 to 5 dl/
g and a cyclic olefin random copolymer having a softening temperature (TMA) of less than 70°C, and the weight ratio of the component (A)/component (B) is 100/0.1.
The magneto-optical recording film is formed from a cyclic olefin random copolymer composition in the range of 100/10 to 100/10;
) at least one selected from 3d transition metals; and (ii
) A magneto-optical recording medium characterized by being an amorphous alloy thin film containing at least one element selected from rare earths and having an axis of easy magnetization perpendicular to the film surface; Yes▼... [I] (In the formula [I], n is 0 or a positive integer, R^1 to R^1^2 each represent a hydrogen atom, a halogen atom, or a hydrocarbon group, and R^ 9 to R^1^2 may be bonded to each other to form a monocyclic or polycyclic group, and the monocyclic or polycyclic group may have a double bond, and R^9 and R^1^0, or R^1^1 and R^
1^2 may form an alkylidene group). 2) The magneto-optical recording film contains (i) at least one selected from 3D transition metals, (ii) a corrosion-resistant metal, and (iii)
) at least one element selected from rare earths, and the content of the corrosion-resistant metal is 5 to 30 at %;
2. The magneto-optical recording medium according to claim 1, which is an amorphous alloy thin film having an axis of easy magnetization perpendicular to the film surface. 3) (i) 3d transition metal contained in the magneto-optical recording film is F
2. The magneto-optical recording medium according to claim 1, characterized in that it is made of E, Co, or both. 4) Corrosion resistant metal is Ti, Zr, Nb, Ta, Mo, P
2. The magneto-optical recording medium according to claim 1, characterized in that it is at least one of t and Pd. 5) (ii) Corrosion-resistant metal contained in the magneto-optical recording film,
The magneto-optical recording medium according to claim 1, characterized in that it is made of Pt or Pd or both. 6) The rare earth (iii) contained in the magneto-optical recording film is Nd
, Sm, Pr, Ce, Eu, Gd, Tb, Dy or H
2. The magneto-optical recording medium according to claim 1, wherein the magneto-optical recording medium is o. 7) The amount of (i) 3d transition metal contained in the magneto-optical recording film is 40 atomic % or more and 80 atomic % or less, and (ii) the amount of corrosion-resistant metal is more than 10 atomic % and 30 atomic % or less. The magneto-optical recording medium according to claim 1, characterized in that: 8) The magneto-optical recording film is an amorphous film having an axis of easy magnetization perpendicular to the film surface and consisting of (i) at least one element selected from 3D transition metals and (iii) at least one element selected from rare earths. 2. The magneto-optical recording medium according to claim 1, which is a thin alloy film. 9) (i) 3d transition metal contained in the magneto-optical recording film is F
9. The magneto-optical recording medium according to claim 8, characterized in that it is made of E, Co, or both. 10) The rare earth (iii) contained in the magneto-optical recording film is N
9. The magneto-optical recording medium according to claim 8, characterized in that the material is d, Sm, Pr, Ce, Eu, Gd, Tb, Dy or Ho. 11) The magneto-optical recording medium according to claim 1 or 8, wherein a reflective film is laminated on the magneto-optical recording film.