JP2001273675A - Substrate for information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording medium free of groove deforma tion in the recording and reproduction of a signal and disk vibration and warpage in the read of a signal and excellent also in the transferability of pits and grooves. SOLUTION: The information recording medium uses a substrate obtained by molding an alicyclic structure-containing polymer having 145-170 deg.C glass transition temperature (Tg) and 1-50 g/10 min melt flow rate(MFR) measured according to JIS K-7210 under the conditions of 2.16 kg load and 280 deg.C. The substrate has >=26,000 kgf/cm2 flexural elastic modulus and <=10 nm surface roughness (Rmax) of the specular part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a substrate for an information recording medium obtained by molding a polymer having an alicyclic structure, and more particularly to a substrate for an information recording medium suitable as a digital video disk (DVD) or the like. .

[0002]

2. Description of the Related Art Polymers having an alicyclic structure such as hydrides of norbornene-based polymers are proposed as substrate materials for information recording media such as optical disks because of their excellent transparency, heat resistance and dimensional stability (low water absorption). Have been. However, in recent years, information recording media include higher recording density, higher speed,
A higher degree of reliability is required, and a substrate and a resin material used for the substrate are required to have higher characteristics. More specifically, it can be used for high-density, high-capacity information recording media used in high-speed rotation, has excellent rigidity (flexural modulus), and accurately transfers fine pits and grooves. There is a need for a substrate. In addition, in the case of information recording medium substrates using phase-change type recording films, the substrate surface temperature rises locally during repeated signal writing and signal reading, causing the groove edge to thermally deform and increasing errors. There is also a demand for a substrate made of a material having excellent heat resistance so as not to cause the heat treatment.

On the other hand, a norbornene-based polymer hydride having improved heat resistance and mechanical strength more than ever has been proposed (International Publication WO99 / 09085), and it has been proposed that it can be used as a material for an optical disk substrate and the like. ing. However, even when such a material having high heat resistance and excellent mechanical strength is molded into an optical disc substrate by a conventional method, the transferability of pits and grooves is reduced, the substrate is warped, and the signal reading is difficult. In some cases, the disk vibrates and an error occurs, and in some cases, a disk having sufficient performance cannot be obtained.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an information recording medium which is free from groove deformation during signal recording and reproduction, disk vibration during signal reading and warpage, and has excellent pit and groove transferability. To provide a substrate for use.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the melt flow rate (MFR) measured under a certain condition is 1 to 50 g / 10 min. A specific alicyclic structure-containing polymer having a temperature (Tg) of 145 to 180 ° C. is molded, the flexural modulus is 26,000 kgf / cm ² or more, and the surface roughness (Rmax) of the mirror surface portion is 10 nm or less. It was found that when the substrate was used as an information recording medium, the heat resistance was so high that there was no groove deformation at the time of signal recording and reproduction, and there was no disk vibration at the time of signal reading. Further, such a substrate, using the specific alicyclic structure-containing polymer described above,
The resin temperature is set to 320 to 400 ° C and the mold temperature (Tm)
The relation of the glass transition temperature (Tg) is (Tg−50 ° C.) ≦ T
It was found that m was set to satisfy m ≦ (Tg−10 ° C.) and injection molding was performed. Further, they found that the substrate formed under such conditions did not warp and was excellent in the transferability of pits and grooves, and completed the present invention.

Thus, according to the present invention, the melt flow rate (MFR) measured under the conditions of a glass transition temperature (Tg) of 145 to 180 ° C., a load of 2.16 kg according to JIS K-7210, and a temperature of 280 ° C. is 1 ~ 50g /
An information recording medium substrate formed by molding an alicyclic structure-containing polymer for 10 minutes, having a flexural modulus of 26,000 kgf / cm ² or more and a mirror surface having a surface roughness (Rmax) of 10 nm or less is provided. You. Furthermore, according to the present invention, the glass transition temperature (Tg) is 145 to 180 ° C., and JISK-72
The melt flow rate (MFR) measured under the conditions of a load of 2.16 kg and a temperature of 280 ° C. according to No. 10 is 1 to 5
The alicyclic structure-containing polymer of 0 g / 10 minutes is heated to a resin temperature of 320 to 400 ° C., and the mold temperature (Tm) is set in relation to the glass transition temperature (Tg) of the polymer (Tg−60). ℃)
The present invention provides a method for manufacturing a substrate for an information recording medium, which is set so as to satisfy ≦ Tm ≦ (Tg−10 ° C.) and injection-molded.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Alicyclic Structure-Containing Polymer The alicyclic structure-containing polymer used in the present invention has a main chain and / or
Or, it has an alicyclic structure in the side chain and has a glass transition temperature (T
g) is 145 to 180 ° C, and the melt flow rate (MFR) measured under the conditions of a load of 2.16 kg and a temperature of 280 ° C according to JIS K-7210 is 1 to 50 g / 10.
Is what is the minute. The alicyclic structure is preferably contained in the main chain from the viewpoint of mechanical strength, heat resistance and the like.

Examples of the alicyclic structure include a cycloalkane structure and a cycloalkene structure. From the viewpoints of mechanical strength and heat resistance, a cycloalkane structure is preferred, and the number of carbon atoms constituting the alicyclic structure is as follows. , Mechanical strength,
From the viewpoints of heat resistance and moldability, the number is usually 4 to 30, preferably 5 to 20, and more preferably 5 to 15. The proportion of the repeating unit having an alicyclic structure is appropriately selected depending on the purpose of use, and is usually 50% by weight or more.
Preferably 70% by weight or more, more preferably 90% by weight
That is all. It is preferable from the viewpoint of heat resistance and the like that the proportion of the repeating unit having an alicyclic structure be within this range.

Specific examples of such an alicyclic structure-containing polymer include (1) a norbornene-based polymer, (2) a monocyclic cycloolefin-based polymer, (3) a cyclic conjugated diene-based polymer, and (4) ) Vinyl alicyclic hydrocarbon-based polymers and hydrogenated products thereof. Among these,
A norbornene-based polymer, a cyclic conjugated diene-based polymer and a hydrogenated product thereof are preferable, and a norbornene-based polymer is more preferable in terms of heat resistance and mechanical strength.

(1) Norbornene-based polymer The norbornene-based polymer is disclosed in, for example, JP-A-3-1488.
No. 2, JP-A-3-122137, and the like. Specifically, the polymer is a ring-opened polymer of a norbornene-based monomer, a hydrogenated product thereof, and an addition weight of a norbornene-based monomer. And an addition copolymer of a norbornene-based monomer and a vinyl compound.

Specific examples of the norbornene-based monomer used for the polymerization include bicyclo [2,2,1] -hept-2-.
Ene (common name: norbornene), 5-methyl-bicyclo [2,2,1] -hept-2-ene, 5,5-dimethyl-bicyclo [2,2,1] -hept-2-ene, 5- Ethyl-bicyclo [2,2,1] -hept-2-ene, 5
-Butyl-bicyclo [2,2,1] -hept-2-ene, 5-hexyl-bicyclo [2,2,1] -hept-
2-ene, 5-octyl-bicyclo [2,2,1] -hept-2-ene, 5-octadecyl-bicyclo [2,
2,1] -hept-2-ene, 5-ethylidene-bicyclo [2,2,1] -hept-2-ene, 5-methylidene-bicyclo [2,2,1] -hept-2-ene, 5 -Vinyl-bicyclo [2,2,1] -hept-2-ene, 5
-Propenyl-bicyclo [2,2,1] -hept-2-
En,

5-methoxy-carbonyl-bicyclo [2,2,1] -hept-2-ene, 5-cyano-bicyclo [2,2,1] -hept-2-ene, 5-methyl-
5-methoxycarbonyl-bicyclo [2,2,1] -hept-2-ene, 5-methoxycarbonyl-bicyclo [2,2,1] -hept-2-ene, 5-ethoxycarbonyl-bicyclo [2,2 , 1] -Hept-2-ene,
5-methyl-5-ethoxycarbonyl-bicyclo [2,
2,1] -hept-2-ene, bicyclo [2,2,1]
-Hept-5-enyl-2-methylpropionate, bicyclo [2,2,1] -hept-5-enyl-2-methyloctanoate, bicyclo [2,2,1] -hept-2
-Ene-5,6-dicarboxylic anhydride, 5-hydroxymethyl-bicyclo [2,2,1] -hept-2-ene,
5,6-di (hydroxymethyl) -bicyclo [2,2,
1] -hept-2-ene, 5-hydroxy-i-propyl-bicyclo [2,2,1] -hept-2-ene, bicyclo [2,2,1] -hept-2-ene, 5,6 -Dicarboxy-bicyclo [2,2,1] -hept-2-ene, bicyclo [2,2,1] -hept-2-ene-5.
6-dicarboxylic imide, 5-cyclopentyl-bicyclo [2,2,1] -hept-2-ene, 5-cyclohexyl-bicyclo [2,2,1] -hept-2-ene, 5
-Cyclohexenyl-bicyclo [2,2,1] -hept-2-ene, 5-phenyl-bicyclo [2,2,1]-
Hept-2-ene,

Tricyclo [4,3,1^2,5,
0^1,6] -Deca-3,7-diene (common name is dicyclope
Antadiene), tricyclo [4,3,1^2,5, 0
^1,6] -Dec-3-ene, tricyclo [4,4,1
^2,5, 0^1,6] -Undeca-3,7-diene
Is tricyclo [4,4,1^2,5, 0^1,6]-Unde
C-3,8-diene, tricyclo [4,4,1^2,5,
0^1,6] -Undec-3-ene, tetracyclo [7,
4,1^10,13, 0^1,9, 0^2,7] -Trideca-
2,4,6-11-tetraene (1,4-methano-1,
4,4a, 9a-tetrahydrofluorene),
Tetracyclo [8,4,1^11,14, 0^1,10, 0
^3,8] -Tetradeca-3,5,7,12-11-tet
Raen (1,4-methano-1,4,4a, 5,10,1
0a-hexahydroanthracene)
A norbornene monomer having no bornan ring;

[0014] tetracyclo ^{[4,4,1 2,5,} 1
^7,10,0 ] -dodec-3-ene (also simply referred to as tetracyclododecene), 8-methyl-tetracyclo [4,
4,1 ^{2, 5, 1 7,10,} 0] - dodeca-3-ene,
8-methyl - tetracyclo ^{[4,4,1 2,5,} 1
^7,10, 0] - dodeca-3-ene, 8-ethyl - tetracyclo ^{[4,4,1 2,5, 1 7,10,} 0] - dodeca-3-ene, 8-methylidene - tetracyclo [4,
4,1 ^{2,5, 1 7,10,} 0] - dodeca-3-ene,
8 ethylidene - tetracyclo ^{[4,4,1 2,5,} 1
^7,10, 0] - dodeca-3-ene, 8-vinyl - tetracyclo ^{[4,4,1 2,5, 1 7,10,} 0] - dodeca-3-ene, 8-propenyl - tetracyclo [4,
4,1 ^{2,5, 1 7,} 10, 0] - dodeca-3-ene,
8-methoxycarbonyl-tetracyclo [4,4,1
^{2,5, 1 7,10,} 0] - dodeca-3-ene, 8-methyl-8-methoxycarbonyl - tetracyclo [4,
4,1 ^{2,5, 1 7,10,} 0] - dodeca-3-ene,
8-hydroxymethyl-tetracyclo [4,4,1
^{2,5, 1 7,1} 0, 0] - dodeca-3-ene, 8-carboxy - tetracyclo ^{[4,4,1 2,} 5, 1
^7,10, 0] - dodeca-3-ene, 8-cyclopentyl-- tetracyclo ^{[4,4,1 2,5, 1 7,10,}
0] - dodeca-3-ene, 8-cyclohexyl - tetracyclo ^{[4,4,1 2,5, 1 7,10,} 0] - dodeca-3-ene, 8-cyclohexenyl - tetracyclo [4,4,1 ^{2,5, 1 7,10,} 0] - dodeca-3
Ene, 8-phenyl-tetracyclo [4,4,
1 ^{2,5, 1 7,1} 0, 0] - tetracyclododecene monomers such as dodeca-3-ene; pentacyclo [6,
5,1 ^{1,8, 1 3,6,} 0 ^{2,7, 0 9,13]} - pentadeca-3,10-diene, pentacyclo [7,4,
1 ^{3,6, 1 10,13,} 0 ^{1,9, 0 2,7]} - pentadeca-4,11 norbornene monomer having a norbornane ring such as diene may be mentioned, respectively.

The above norbornene monomers can be used alone or in combination of two or more. In the present invention, in particular, the glass transition temperature is 14%.
In order to increase the temperature to 5 ° C. or higher and to make the resulting substrate excellent in bending elasticity, the above tetracyclo [7,4,1
^{10 and 13, 0 1,9, 0 2,7]} - trideca -2,
4,6-11-tetraene (hereinafter 1,4-methano-
1,4,4a, 9a-tetrahydrofluorene; MTF
Norbornene-based monomers having an aromatic ring represented by 1,4-methano-1,4,4a,
It is preferable to use a norbornene-based monomer having a cyclohexene ring such as 4b, 5,8,8a, 9a-octahydro-9H-fluorene (MOF). As more specific specific examples of such norbornene monomers having an aromatic ring or a cyclohexene ring,
For example, 1,4-methano-1,4,4a, 9a-tetrahydrofluorene, 1,4-methano-8-methyl-1,
4,4a, 9a-tetrahydrofluorene, 1,4-methano-8-chloro-1,4,4a, 9a-tetrahydrofluorene, 1,4-methano-8-bromo-1,4,4
1,4-methano-1,4,4a, 9a-tetrahydrofluorenes such as a, 9a-tetrahydrofluorene;
1,4-methano-1,4,4a, 4b, 5,8,8a,
9a-octahydro-9H-fluorenes; 1,4-methano-1,4,4a, 9a-tetrahydrodibenzofurans; 1,4-methano-1,4,4a, 9a-tetrahydrocarbazole, 1,4-methano- 9-phenyl-
1,4-methano-1,4,4a, 9a-tetrahydrocarbazoles such as 1,4,4a, 9a-tetrahydrocarbazole; 7,10-methano-6b, 7,10,1
0a-tetrahydrofluorancenes; compounds in which cyclopentadiene is further added to 7,10-methano-6b, 7,10,10a-tetrahydrofluorancene; compounds in which cyclopentadiene is added to aceanthrylene; acephenanthrylene To which cyclopentadiene has been added, 11,12-benzo-pentacyclo [6.
5.1.1 ^3,6 . 0 ^2,7 . ^09,13 ] -4-pentadecene, 11,12-benzo-pentacyclo [6.
6.1.1 ^3,6 . 0 ^2,7 . 0 ^9,14] -4-hexadecene, 14,15-benzo - heptacyclo [8.
7.0.1 ^2,9 . 14, ^{7,. 11, 17} .
0 ^3,8 . 0 ^12,16 ] -5-eicosene, and the like.

In the present invention, when a norbornene-based monomer having an aromatic ring typified by the above MTF or a norbornene-based monomer having a cyclohexene ring typified by an MOF is used, As a component of the above tetracyclo [4,4,1
^{2,5, 1 7,10,} 0] - dodeca-3-ene and 8-methyl - tetracyclo ^{[4,4,1 2,5, 1 7,10,}
When a tetracyclododecene-based monomer such as [0] -dode-3-ene is used, the heat resistance and flexural modulus of the obtained polymer are highly balanced.

In the present invention, in addition to the above-mentioned norbornene-based monomer, copolymerizable monomers include, for example,
Ethylene, propylene, 1-butene, 1-pentene, 1
-Hexene, 3-methyl-1-butene, 3-methyl-1
-Pentene, 3-ethyl-1-pentene, 4-methyl-
1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1- Octene, 1-decene, 1-dodecene, 1-
Tetradecene, 1-hexadecene, 1-octadecene,
Α-olefins having 2 to 20 carbon atoms such as 1-eicosene; cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene, cyclooctene; Cycloolefins such as 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene; 1,4-hexadiene, 4-methyl-
Non-conjugated dienes such as 1,4-hexadiene, 5-methyl-1,4-hexadiene and 1,7-octadiene; and the like can be used. These copolymerizable monomers can be used alone or in combination of two or more.

The ring-opening polymer of the above-mentioned monomer is a ring-opening polymerization catalyst comprising a metal halide such as ruthenium, rhodium, palladium, osmium, iridium, platinum or the like, a nitrate or acetylacetone compound, and a reducing agent. Alternatively, titanium, vanadium, zirconium, tungsten, a metal halide such as molybdenum or an acetylacetone compound, using a catalyst system comprising an organoaluminum compound, in a solvent or without a solvent, usually at -50 ℃ ~ 100 ℃ Polymerization temperature, 0-50k
It can be obtained by ring-opening polymerization at a polymerization pressure of g / cm ² .

The hydrogenated norbornene-based polymer can be obtained by hydrogenating a ring-opening (co) polymer in the presence of a hydrogenation catalyst according to a conventional method. In general, the hydrogenation reaction temperature is usually 20
0 ° C or lower, preferably 195 ° C or lower, most preferably 1 ° C or lower.
90 ° C. or less.

As the hydrogenation catalyst, JP-A-58-43
412, JP-A-60-26024, JP-A-64-24826, JP-A-1-138257, JP-A-7-41550 and the like can be used. Alternatively, a homogeneous catalyst or a heterogeneous catalyst may be used. The homogeneous catalyst is easy to disperse in the hydrogenation reaction liquid, so that the addition amount may be small, and since it has high activity, hydrogenation can be performed in a short time with a small amount of catalyst. Heterogeneous catalysts are highly active at high temperatures and pressures, can be hydrogenated in a short time, and are excellent in production efficiency such as being easily removed.

As the homogeneous catalyst, for example, a Wilkinson complex, that is, a catalyst comprising a combination of a chlorotris (triphenylphosphine) rhodium (I); a transition metal compound and an alkyl metal compound, specifically, cobalt acetate / triethylaluminum And combinations of nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium, zirconocene dichloride / sec-butyllithium, tetrabutoxytitanate / dimethylmagnesium and the like.

Examples of the heterogeneous catalyst include Ni, P
Examples thereof include those in which a hydrogenation catalyst metal such as d is supported on a carrier, and it is preferable to use Ni as the metal to be supported from the viewpoint of activity, hydrogenation efficiency, or isomerization ratio. When a Pd catalyst is used, the progress of isomerization is promoted, and the softening point is lowered. In the case where it is preferable that the amount of impurities and the like is small as the carrier, an adsorbent such as alumina and diatomaceous earth is preferably used.

The hydrogenation reaction is usually carried out in an organic solvent. The organic solvent is not particularly limited as long as it is inert to the catalyst. However, a hydrocarbon-based solvent is usually used because of excellent solubility of the generated hydrogenated product.

Examples of the hydrocarbon solvent include aromatic hydrocarbons such as benzene and toluene; aliphatic hydrocarbons such as n-pentane and hexane; alicyclic hydrocarbons such as cyclohexane and decalin; Among them, cyclic aromatic hydrocarbons and alicyclic hydrocarbons are preferable. These organic solvents can be used alone or in combination of two or more.

The hydrogenation reaction can be carried out according to a conventional method, and the hydrogen pressure during the reaction is usually 0.1 to 100 kgf /
cm ² , preferably 0.5 to 60 kgf / cm ² , more preferably 1 to 50 kgf / cm ² .

The addition copolymer of the norbornene-based monomer and the copolymerizable monomer is, for example, a monomer component comprising a titanium compound, a zirconium compound, or a vanadium compound and an organic aluminum compound in a solvent or without a solvent. In the presence of a catalyst system, usually -50 ° C to 1
It can be obtained by a method of copolymerizing at a polymerization temperature of 00 ° C. and a polymerization pressure of 0 to 50 kg / cm ² .

(2) Monocyclic Cyclic Olefin Polymer Examples of the monocyclic cycloolefin polymer include monocyclic cycloolefin polymers such as cyclohexene, cycloheptene and cyclooctene disclosed in JP-A-64-66216. Can be used.

(3) Cyclic conjugated diene-based polymer The cyclic conjugated diene-based polymer is described in, for example,
The cyclic conjugated diene-based monomers such as cyclopentadiene and cyclohexadiene disclosed in JP-A-136057 and JP-A-7-258318 are used as 1,2- or 1,2-
4-Polymerized polymers and hydrogenated products thereof can be used.

(4) Vinyl alicyclic hydrocarbon polymer: Examples of the vinyl alicyclic hydrocarbon polymer include vinyl alicyclic hydrocarbons such as vinyl cyclohexene and vinyl cyclohexane disclosed in JP-A-51-59989. Polymers of alicyclic hydrocarbon monomers and hydrogenated products thereof, vinyls such as styrene and α-methylstyrene disclosed in JP-A-63-43910 and JP-A-64-1706. A hydrogenated product of the aromatic ring portion of the polymer of the aromatic monomer can be used. The configuration of these vinyl alicyclic hydrocarbon-based polymers may be any of atactic, isotactic and syndiotactic. For example, any of 0 to 100% in syndiotacticity by dyad display. Can also be used.

The molecular weight of the alicyclic structure-containing polymer used in the present invention is appropriately selected according to the purpose of use. Gel permeation chromatography of a cyclohexane solution (a toluene solution when the polymer is not dissolved) is used. The weight average molecular weight in terms of polyisoprene measured by a graph method is 5,0
00 to 500,000, preferably 8,000 to 20
0000, more preferably 10,000-100,0
In the above range, the bending elastic modulus and surface accuracy of the obtained substrate are improved. The glass transition temperature (Tg) of the alicyclic structure-containing polymer used in the present invention is 1
45-180 ° C, preferably 150-170 ° C,
2.16 kg load according to JIS K-7210,
MFR measured at a temperature of 280 ° C. is 1 to 50 g /
It is 10 minutes, preferably 2 to 30 g / 10 minutes, more preferably 3 to 25 g / 10 minutes. When Tg and MFR are within the above ranges, pit and groove deformation and vibration during information reproduction and recording of the obtained substrate are significantly reduced.

Ingredients The alicyclic structure-containing polymer may be added , if desired, to an antioxidant such as a phenolic antioxidant or a phosphorus antioxidant, a benzophenone ultraviolet absorber or a benzotriazole ultraviolet absorber. And various additives such as UV absorbers, light stabilizers, antistatic agents, esters of aliphatic alcohols, partial esters of polyhydric alcohols and partial ethers. In addition, other resins, rubbery polymers and the like can be mixed and used as long as the object of the present invention is not impaired.

Information recording medium substrate The information recording medium substrate of the present invention can be obtained by molding the specific alicyclic structure-containing polymer described above. The shape of the substrate is usually a disk having a hole in the center. When the substrate is used as an information recording medium with a recording layer, the disk is used alone or two or more disks are bonded together. be able to.

Examples of the method of bonding the disks include a method using heat fusion, a method using ultrasonic fusion, and a method using an adhesive. From the viewpoint of adhesion and productivity, the method using an adhesive is preferable. . Examples of the type of the adhesive used include a hot melt adhesive, a thermosetting adhesive, a radiation curing adhesive, a solvent volatile drying adhesive, an anaerobic curing adhesive, a pressure-sensitive adhesive sheet, and the like. From the viewpoint of, a thermosetting adhesive or a radiation-curable adhesive, a pressure-sensitive adhesive sheet is preferable, and from the viewpoint of optical properties such as light transmittance,
Radiation-curable adhesives and pressure-sensitive adhesive sheets are more preferred. The radiation-curable adhesive includes an electron beam-irradiated adhesive, an ultraviolet-irradiated adhesive, and the like, and is preferably an ultraviolet-irradiated adhesive from the viewpoint of productivity, equipment, and the like.

Examples of the ultraviolet irradiation type adhesive include a radical polymerization ultraviolet curing adhesive, a cationic polymerization ultraviolet curing adhesive, and a radical / cation combination polymerization ultraviolet curing adhesive.

The specific composition of the radiation-curable adhesive suitable for use in the present invention includes a radical-polymerized ultraviolet-curable adhesive containing an acrylate monomer and a photopolymerization initiator. You can also. Specific examples of suitable acrylate monomers include alicyclic acrylates and linear aliphatic monofunctional acrylates, and these monomers may form oligomers. The alicyclic acrylate is an acrylate monomer composed of an alicyclic structure and an acrylate group directly bonded to the alicyclic structure and / or an oligomer thereof. The alicyclic structure may have a substituent. And those not containing elements other than hydrogen. The alicyclic acrylate is an ester of an alicyclic alcohol and an ester of acrylic acid or methacrylic acid, and may be a monofunctional acrylate or a polyfunctional acrylate such as difunctional or trifunctional, but from the viewpoint of heat resistance and crosslink density. Polyfunctional acrylates are preferred.

The polymer that can be added to the adhesive is not particularly limited as long as it improves the heat resistance and mechanical strength of the adhesive, but the number average molecular weight (Mn) is preferably 10,000 or more, more preferably Is 30,000 or more, particularly preferably 40,000 or more, preferably 400,000 or less, more preferably 300,000 or less,
Particularly preferably, it is 200,000 or less. If Mn is too small, the mechanical strength is inferior, and the solubility is too high, and the production is difficult. Examples of the polymer include styrene-based block copolymers and modified products thereof. Specifically, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene-block copolymer, styrene -Isoprene / pentadiene / styrene block polymers and hydrides of these polymers. Examples of the modified styrene block copolymer include modified dicarboxylic anhydrides, epoxy modified products, and halides of the above copolymers. From the viewpoint of heat resistance, these polymers preferably have a maximum glass transition temperature measured by DSC of 50 ° C.
Or more, more preferably 60 ° C. or more.

The photopolymerization initiator used for the adhesive is not particularly limited, and may be a known one. For example, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1 Acetophenones such as-(4-methylthiophenyl) -2-morpholino-propan-1-one, benzoins such as benzyl, methylorthobenzoyl benzoate, benzoin methyl ether, benzoin ethyl ether, benzyl dimethyl ketals, α-hydroxy ketone And the like.

The adhesive composition used in the present invention has the following composition: (a) an alicyclic acrylate and / or a linear aliphatic monofunctional acrylate, (b) a polymer component, and (c) a photopolymerization initiator. ) Component 100 parts by weight, component (b) component 0.1 parts by weight or more, preferably 1 part by weight or more, more preferably 3 parts by weight or more and 100 parts by weight or less, preferably 5 parts by weight or less.
0 parts by weight or less, more preferably 30 parts by weight or less, (c)
1 part by weight or more of components, preferably 2 parts by weight or more, more preferably 3 parts by weight or more and 30 parts by weight or less, preferably 25 parts by weight or less.
Not more than parts by weight. If the amount of the component (b) is too small, the adhesive after curing has low flexibility, easily peels off from the base material, and has a problem that its physical properties at high temperatures tend to deteriorate,
If it is too large, the viscosity becomes high and the coating workability is poor. If the amount of the component (c) is too small, the curing speed will decrease. If the amount is too large, the number average molecular weight after curing will decrease and the adhesive strength will decrease.

As long as the effects of the present invention can be exerted, the above-mentioned adhesive may contain an acrylate monomer other than the above-mentioned monomers, an acrylate oligomer, etc., an antioxidant, a thermal polymerization inhibitor, a curing accelerator, and an ultraviolet absorber. Further, additives such as an antistatic agent, a leveling agent, an antifoaming agent, and a coloring agent, and inorganic fillers such as talc and silica may be blended.

As a method for forming the adhesive layer, various known methods such as spin coating, gravure coating, spray coating, and dipping may be used, and these methods may be combined. From the viewpoint of film thickness controllability, it is preferable to use a spin coating method. The application conditions in this case may be appropriately determined in consideration of the viscosity of the adhesive, the desired thickness of the coating film, and the like. At the time of curing the adhesive, the intensity of ultraviolet irradiation to be applied is usually 50 mW / cm ² or more, and the amount of ultraviolet irradiation is usually 500 to 2000 mJ / cm ² . As a light source, a high-pressure mercury lamp, a metal halide lamp, or the like may be used.

The thickness of the cured adhesive layer is usually from 10 to 20.
0 μm, more preferably 30 to 100 μm. If the adhesive layer is too thin, it becomes difficult to form an adhesive layer having a uniform thickness, and the durability becomes insufficient. On the other hand, if the thickness is too large, the disk tends to warp due to curing shrinkage.

(Method of Forming Substrate) As a method of forming the substrate, a method of hot-melt molding an alicyclic structure-containing polymer,
Although a method of molding by solution casting can be used, a heat-melt molding method is preferable in order to obtain a substrate having excellent heat resistance and surface accuracy. Specific examples of the heat-melt molding method include injection molding, extrusion molding, and press molding, but in order to obtain a substrate having a small birefringence value (retardation) and warpage and excellent mechanical strength. It is preferable to use an injection molding method. As the injection molding method, a method is generally used in which the alicyclic structure-containing polymer of the present invention is heated and melted by using, for example, a heating cylinder or the like, filled into a mold by an injection device, and then cooled and solidified. A stamper is attached to the inner surface of the mold to be used, and pits, grooves, and the like are transferred. Among the injection molding methods, from filling the mold of the molten resin to cooling and solidification, when the information recording medium substrate of the present invention is molded by the injection compression molding method in which the mold clamping pressure is controlled in multiple stages,
The difference between the retardation at the outer peripheral portion and the retardation at the inner peripheral portion of the substrate is small, which is preferable. In the present invention, in order to obtain a substrate having high flexural elasticity and low surface roughness, the cylinder set temperature of the molding machine, that is, the molten resin temperature is set to 320 to 400 ° C., preferably 325 to 3 ° C.
The mold temperature (Tm) is set in the range of 90 ° C, most preferably 330 to 380 ° C, in relation to the glass transition temperature (Tg) of the alicyclic structure-containing polymer to be used, (Tg−60 ° C) ≦ Tm.
≦ (Tg−10 ° C.), preferably (Tg−50 ° C.) ≦ T
m ≦ (Tg−15 ° C.), more preferably (Tg−40)
C) ≦ Tm ≦ (Tg−20 ° C.). Further, the substrate obtained by molding under the above conditions has excellent pit and groove transferability and small warpage. If the temperature of the molten resin is too low, the transferability is reduced or the birefringence is increased. If the temperature is too high, the strength of the substrate is reduced due to decomposition of the resin or the like, and a problem may occur in the mold releasability.

At the time of injection molding, it is preferable to make the molding environment clean in order to reduce contamination which adversely affects the error rate of the information recording medium. For example, it is more preferable to install the molding machine in a cleanroom class 1000 clean room or to keep the mold part in a cleanroom class 100 environment in a clean booth. Further, it is preferable that the pellets are subjected to a heat treatment before molding, and it is preferred that the pellets be molded within a short time after completion of the heat treatment. Even if the heat treatment is sufficiently performed, if the molding is performed after being left in the air for a long time, there is a possibility that defects such as silver streaks and voids may occur in the molded substrate.

The information recording medium substrate of the present invention obtained by the above method or the like has a flexural modulus of 26,000 kgf /
cm ² or more, preferably 26,500 kgf / cm ²
More preferably, the surface roughness (Rmax) of the mirror portion, that is, the smooth portion where no pits or grooves on the substrate is formed or the bottom portion of the groove is 10 nm or less, more preferably 27,000 kgf / cm ² or more. Preferably it is 8 nm or less, most preferably 5 nm or less.

Information recording medium The information recording medium substrate of the present invention can be used as an information recording medium such as a computer or audio visual (AV) with an information recording layer. The substrate of the present invention is excellent in heat resistance and surface accuracy, and is free from groove deformation during signal recording and reproduction, disk vibration during signal reading, and warpage, and excellent in pits and grooves transferability, so that it can be used for music. An information recording medium such as a CD, a CD-ROM, a laser disk (registered trademark), and a DVD-ROM, which utilizes a change in reflected light due to minute unevenness such as pits;
Functional dyes such as write-once optical disks such as R, rewritable optical disks (magneto-optical disks) such as MOs, MDs (mini disks), rewritable DVDs (digital video disks), and phase change optical disks (PDs); Utilizing a change in reflectance due to a phase change, the present invention can be used for an information recording medium that can be additionally written or rewritten. In particular, it is most suitably used as a substrate for DVDs, MOs, PDs, and the like, which rotate at a high speed with a high density and a large capacity.

(Information Recording Layer) The information recording layer is formed on a substrate surface by a metal reflective film layer of aluminum or nickel, or an organic or organic layer capable of locally changing light reflectance irreversibly or reversibly. An inorganic layer is provided, and its thickness is usually several hundred to several thousand angstroms,
It is not more than 0000 angstroms.

In a compact disc for music (CD), a compact disc for reading (CD-ROM), a read-only digital video disc (DVD-ROM), etc., the information itself is fixed to a stamper portion of a mold at the time of injection molding. Since the grooves are cut as discontinuous grooves (pits), if a reflective film layer such as aluminum or gold is formed on the surface including the pits by a sputtering method or the like, the pits and the reflective film layer form a recording layer. .

Write-once compact disc (CD-R)
And rewritable magneto-optical disks (MO)
A layer of recording film that reversibly or irreversibly changes the reflectance or transmittance of light, a layer of reflective film that reflects light, and a thin inorganic layer that protects them and corrects optical distortion. Alternatively, an organic protective film layer is sequentially formed, and a groove (continuous groove) serving as a guide for reading and writing signals is formed on the substrate. The information recording layer is formed by forming any of the above layers into a single layer or a multilayered structure by a method such as a sputtering method, a gas phase growth method, or a method using a chemical coating. For example, in a magneto-optical disk application, terbium (Tb) -iron (F
e) A recording film made of an alloy of -cobalt (Co) or an alloy to which platinum (Pt) is further added; a reflective film of aluminum, gold, or an alloy thereof; silicon nitride (SiN)
And a thin protective film such as silicon carbide (SiC) or the like. In the case of a phase change type disc, tellurium (Te) -germanium (Ge) -antimony (S
b), indium (In) -Sb-Te, Te-Ge-
Using chromium (Cr), Te-Ge-zinc (Zn) or the like, the following is used by attaching an information recording layer on a substrate in the same manner as the above-mentioned magneto-optical disk.

The thickness and forming method of these information recording layers differ depending on the type of information recording medium, and are formed according to a standard by a known method.

[0050]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Production Examples, Examples, and Comparative Examples. Parts and percentages in these examples are on a weight basis unless otherwise specified. Various physical properties were measured according to the following methods. (1) The molecular weight was measured by GPC using toluene as a solvent, and the weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of standard polystyrene were determined. The molecular weight distribution was determined by Mw and Mn measured by the above method. (Mw / Mn) was calculated. (2) The hydrogenation rate of the aromatic ring was calculated by measuring ¹ H-NMR. (3) The glass transition temperature (Tg) was measured by DSC. (4) The flexural modulus is 120 m in diameter obtained by molding.
m, a disk (single plate) with a thickness of 0.6 mm and a width of 1 in the radial direction
A test piece cut to 5 mm was prepared and measured. (5) Melt flow rate (MFR) is JIS K-7
According to 210, load 2.16kg, temperature 280 ° C
Was measured under the following conditions. (6) The surface roughness of the substrate is measured by using an atomic force microscope (SPM Nanoscope III manufactured by TI Co.)
The measurement was performed in a), and the average surface roughness Rmax was evaluated. (7) The heat resistance of the substrate was measured by using a DVD decoder (DR-3350 manufactured by Kenwood TMI), counting the block errors immediately after molding, and further measuring the substrate
Block errors after standing at 0 ° C. for 8 hours were counted, and the rate of increase (%) in the count was determined and evaluated. (8) The transfer rate of the substrate is determined by measuring the depth of the groove at a radius of 55 mm corresponding to substantially the outermost periphery of the recording layer of the substrate with an atomic force microscope (TI SPM Nanoscope IIIa) and determining the group depth of the stamper. It was evaluated as a percentage of the total. (9) The warpage of the substrate was measured using a laser displacement meter (manufactured by KEYENCE CORPORATION), and the amount of displacement on a circumference having a radius of 55 mm (vertical method) after the substrate was left in an environment of 23 ° C. and 55% humidity for 1 hour That is, how much the substrate is warped in the vertical direction is measured, and the displacement (vertical direction) of the substrate left standing in an environment of 80 ° C. and 85% humidity for 48 hours is measured. It was sought and evaluated. (10) The surface deflection (vibration) of the substrate is obtained by clamping an inner peripheral portion of the substrate and applying a signal recording part having a radius of 50 mm to a signal recording part of Ono Sokki Co., Ltd.
The focus of the pickup lens was narrowed using M-1200, and the amount of vertical displacement of the pickup when the substrate was rotated was measured and evaluated.

[Production Example 1] (Production Example of Polymer A) Tetracyclo [4.4.1 ^2,5 . 1
^7,10 . 0] -dodec-3-ene (1,4: 5,8-
Also referred to as dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene. Hereinafter, abbreviated as TCD) 1
0 parts, and tetracyclo [7.4.1 ^10,13 . 0
^1,9 . 0 ^2,7 ] trideca-2,4,6,11-tetraene (also referred to as 1,4-methano-1,4,4a, 9a-tetrahydrofluorene; hereinafter abbreviated as MTF) 10
200 parts of dehydrated cyclohexane, 2.0 parts of 1-hexene, 15 parts of a 15% toluene solution of triethylaluminum, and 5.0 parts of triethylamine were added to 20 parts of the mixture.
Stirring while maintaining at 40 ° C., 40 parts of TCD and 40 parts of MTF,
And 9.0 parts of a 20% toluene solution of titanium tetrachloride in 60 parts
Added continuously over minutes. Then, after reacting for 1 hour, 5.0 parts of ethyl alcohol and 2.0 parts of water were added to stop the reaction. After heating the reaction solution to 40 ° C. to hydrolyze the catalyst, 3 parts of calcium sulfate and 60 parts of cyclohexane were added to remove excess water. The precipitate containing the deposited metal was removed by filtration to obtain 371 parts of a transparent polymer solution containing a TCD / MTF ring-opening polymer. When the copolymerization ratio of each norbornene in the polymer was calculated from the composition of the residual norbornene in the solution after polymerization (by gas chromatography), TCD / MTF = 50/5.
0 was almost equal to the charge composition. The obtained polymer solution 7
50 parts of Ni-diatomaceous earth catalyst (manufactured by JGC Chemicals, N11
3) 15 parts were added, put in a pressure vessel, hydrogen was introduced, and a hydrogenation reaction was performed at a pressure of 50 kg / cm ² and a temperature of 200 ° C. for 3 hours. After completion of the reaction, 700 parts of cyclohexane was added for dilution, and the catalyst was removed by filtration to obtain 1350 parts of a hydrogenated polymer solution of a ring-opening polymer. This solution 800
3. Part of activated alumina (manufactured by Mizusawa Chemical Co., Neo Bead D)
The mixture was passed through a column having an inner diameter of 10 cm and a length of 100 cm packed with 5 parts so as to have a residence time of 100 seconds, and circulated for 24 hours. 550 parts of this solution is added to isopropanol 15
The mixture was poured into 00 parts with stirring to solidify the hydrogenated TCD / MTF ring-opened polymer. Coagulated TCD / MTF
The hydrogenated ring-opened polymer was recovered by filtration, washed twice with 300 parts of isopropanol, and then dried in a rotary vacuum dryer at 5 torr and 120 ° C. for 48 hours to obtain TCD / MT.
78 parts of hydrogenated F ring-opened polymer were obtained. This TCD / M
The hydrogenated TF ring-opening polymer (Polymer A) has a Mw of 3
1,000, and the molecular weight distribution (Mw / Mn) is 1.8.
Nine. The MFR was 7 g / 10 minutes, the hydrogenation rate was 99.9% or more, and the Tg was 155 ° C.

[Production Example 2] (Production Example of Polymer B) A polymerization reaction and a hydrogenation reaction were carried out under the same conditions as in Production Example 1 except that the amount of 1-hexene used was changed to 1.2 parts. The obtained hydrogenated ring-opened polymer (Polymer B)
Mw is 37,000, molecular weight distribution (Mw / Mn)
Was 1.96. The MFR was 2 g / 10 minutes, the hydrogenation rate was 99.9% or more, and the Tg was 159 ° C.

[Production Example 3] (Production Example of Polymer C) A polymerization reaction and a hydrogenation reaction were carried out under the same conditions as in Production Example 1 except that the amount of 1-hexene used was changed to 0.8 part. The obtained hydrogenated ring-opening polymer (Polymer C)
Mw is 41,000, molecular weight distribution (Mw / Mn)
Was 1.90. The MFR is 0.7 g / 1.
0 minutes, the hydrogenation rate is 99.9% or more, and the Tg is 15 minutes.
6 ° C.

[Production Example 4] (Production Example of Polymer D) In a nitrogen atmosphere, 500 parts of dehydrated cyclohexane was added to 1 part.
-Hexene 0.55 part, dibutyl ether 0.11 part,
And 0.22 parts of triisobutylaluminum were mixed in a reactor at room temperature, and then kept at 45 ° C. while tricyclo [4.3.0.1 ^2,5 ] dec-3-ene (hereinafter D) was added.
200 parts, 0.70 of tungsten hexachloride
A 30% toluene solution was continuously added over 2 hours to carry out polymerization. The obtained polymerization reaction solution was transferred to a pressure-resistant hydrogenation reactor, and 10 parts of a diatomaceous earth-supported nickel catalyst (manufactured by Nissan Gardler Co., Ltd .; G-96D, nickel support rate 58%) and 200 parts of cyclohexane were added. Pressure 45k
The reaction was performed at gf / cm ² for 8 hours. This reaction solution was filtered using a diatomaceous earth as a filter aid using a filter equipped with a stainless steel wire mesh to remove the catalyst. The obtained reaction solution was poured into 300 parts of isopropyl alcohol with stirring to precipitate a hydrogenated product, which was collected by filtration. further,
After washing with 500 parts of acetone, 1 torr or less, 10
The product was dried in a vacuum dryer set at 0 ° C. for 48 hours to obtain 190 parts of a hydrogenated ring-opened polymer (Polymer A). The main-chain hydrogenation rate of the obtained ring-opened polymer hydrogenated product was 99.9.
%, The weight average molecular weight (Mw) was 33,300, the molecular weight distribution (Mw / Mn) was 2.12, the melt flow rate (MFR) was 35 g / 10 min, and the glass transition temperature was 97 ° C. .

[Production Example 5] (Production Example of Polymer E) The amount of 1-hexene used was 0.56 parts, and instead of DCP, 8-methyl-tetracyclo [4.4.0.1 ^2,5 .
[ ^7,10 ] Polymerization was carried out under the same conditions as in Production Example 1 except that 200 parts of dodeca-3-ene was used. The hydrogenation reaction temperature was changed to 180 ° C, and the reaction time was changed to 10 hours. A hydrogenation reaction was performed under the same conditions as in Example 1. The main chain hydrogenation rate of the obtained ring-opened polymer hydrogenated product (polymer E) was 99.9%, and the number average molecular weight (Mn) was 20,40.
0 and the molecular weight distribution (Mw / Mn) was 2.02. The MFR was 20 g / 10 minutes, and the glass transition temperature was 140 ° C.

(Example 1) (Formation of Information Recording Medium Substrate) A soft polymer (manufactured by Asahi Kasei Corporation; Tuftec H1052) was added to 100 parts of the alicyclic structure-containing polymer (polymer A) obtained in Production Example 1. 1 part, and an antioxidant (manufactured by Ciba-Geigy; Irganox 101)
0) and 0.1 part, and a twin-screw kneader (manufactured by Toshiba Machine Co., Ltd .;
TEM-35B: screw diameter 37 mm, L / D = 3
Using 2), kneading at a screw rotation speed of 150 rpm, a resin temperature of 260 ° C., and a feed rate of 15 kg / hour)
Extruded into strands. This was cooled with water, cut with a pelletizer, and pelletized.

Immediately after drying the obtained pellets at 100 ° C. for 5 hours using a hot-air dryer through which air was passed,
Injection molding machine (Sumitomo Heavy Industries, Ltd .; DISK3)
Stamper for DVD (groove depth setting value: 150n)
m, groove pitch: 0.8 μm) using a mold attached to the movable side, injection molding was performed, the injection time was 0.1 second,
Resin temperature 360 ° C, mold temperature 135 ° C, cooling time 7.0
0.6m thickness under the condition of 25 tons of mold clamping pressure
An information recording medium substrate having a diameter of 120 mmφ and an inner hole of 15 mmφ was obtained. Table 1 shows the results of the flexural modulus, surface roughness, transfer rate, and warpage of the obtained substrate.

(Formation of Reflective Film) On the obtained substrate, pits were formed at portions other than the outermost portion having a width of 2 mm and the innermost portion having a width of 12 mm. This pit formation surface is 80n using ILC-3000 manufactured by Nidec Anelva.
m of aluminum reflective film was formed.

(Manufacture of laminated substrate) The above two substrates having the reflection film formed thereon were treated with 90 parts of dicyclopentadienyl acrylate (manufactured by Hitachi Chemical: FA513A) and isobonyl acrylate (manufactured by Kyoeisha Chemical: IB-XA). In 10 copies,
Styrene / ethylene / butadiene / styrene / block copolymer (Asahi Kasei: Tuftec H1052)
5 parts and 8 parts of a photopolymerization initiator (manufactured by Ciba Specialty Chemical Co., Ltd .: Irgacure 184) were added, and an ultraviolet-curable adhesive obtained by mixing was used to obtain 2500 mJ.
After curing at a UV irradiation amount of / cm ² and bonding, a laminated optical disc substrate was manufactured. Table 1 shows the results of the heat resistance of the substrate and the surface deflection of the substrate.

[0060]

[Table 1]

Example 2 An information recording medium substrate was formed and evaluated in the same manner as in Example 1 except that the mold temperature was set to 120 ° C. when forming the substrate. Table 1 shows the results.

Example 3 An information recording medium substrate was molded and evaluated in the same manner as in Example 1 except that the temperature of the mold was 105 ° C. when the substrate was molded. Table 1 shows the results.

Example 4 An information recording medium substrate was molded and evaluated in the same manner as in Example 2 except that the resin temperature was set to 330 ° C. when molding the substrate. Table 1 shows the results.

Example 5 An information recording medium substrate was molded and evaluated in the same manner as in Example 1 except that the resin temperature was changed to 370 ° C. using the polymer B obtained in Production Example 2.
Table 1 shows the results.

(Comparative Example 1) A substrate for an information recording medium was prepared in the same manner as in Example 1 except that the resin temperature was set to 340 ° C and the mold temperature was set to 80 ° C using the polymer D obtained in Production Example 4. It was molded and evaluated. Table 1 shows the results.

Comparative Example 2 An information recording medium substrate was molded and evaluated in the same manner as in Example 1 except that the temperature of the mold was set to 110 ° C. using the polymer E obtained in Production Example 5. Table 1 shows the results.

Comparative Example 3 An information recording medium substrate was molded and evaluated in the same manner as in Example 2 except that the polymer C obtained in Production Example 3 was used. Table 1 shows the results.

(Comparative Example 4) A substrate for an information recording medium was evaluated in the same manner as in Example 1 except that the mold temperature was set to 80 ° C when the substrate was molded. Table 1 shows the results.

Comparative Example 5 An information recording medium substrate was formed and evaluated in the same manner as in Example 2 except that the resin temperature was set to 290 ° C. when the substrate was formed. Table 1 shows the results.

[0070]

According to the present invention, a substrate for an information recording medium having excellent bending elasticity and surface accuracy can be obtained by using an alicyclic structure-containing polymer having a high glass transition temperature under appropriate molding conditions. Thus, the substrate is excellent in the transferability of pits and grooves, and the surface vibration (blur) of the substrate during high-speed rotation is significantly reduced. Also, since the substrate has excellent heat resistance,
As an information recording medium, there is no deformation of pits or grooves due to heat during signal reproduction and recording. According to the substrate of the present invention, a high-density, high-capacity information recording medium such as a digital video disk (DVD) can be provided with high performance.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08J 5/00 CER C08J 5/00 CER 5D075 CEZ CEZ 5D121 G11B 7/26 521 G11B 7/26 521 11/105 521 11 / 105 521A 521C 521D 546 546D // B29K 45:00 B29K 45:00 B29L 17:00 B29L 17:00 C08L 65:00 C08L 65:00 F term (reference) 4F071 AA21 AA69 AA78 AA86 AA88 AF20 AH12 AH14 BC01 BC05 BC BC17 4F206 AA12C AH79 AR064 JA07 JN43 JQ81 4J032 CA34 CA35 CA36 CA43 CA45 CA68 CB04 CC03 CF01 CG00 4J100 AA02Q AA03Q AA04Q AA07Q AA09Q AA15Q AA16Q AA17Q AA18Q AA19Q AA20P AA21Q AB02P AB03P AK31P AM42P AR03P AR03Q AR04Q AR05P AR05Q AR09P AR09Q AR11P AR17P AR18P AR21P AR22P AS11Q AS15P AU21P BA03P BA16P BA20P BA40P BC03P BC04P BC43P CA01 CA04 CA31 HA04 HA05 HB02 JA36 5D029 KA01 KC09 5D075 FG15 FG17 GG07 GG16 5D121 DD05

Claims (4)

[Claims] 1. A glass transition temperature (Tg) of 145-18.
0 ° C, load 2.16 according to JIS K-7210
An alicyclic structure-containing polymer having a melt flow rate (MFR) of 1 to 50 g / 10 minutes measured at 280 ° C. and a temperature of 280 ° C. is molded and has a flexural modulus of 26,000 k.
An information recording medium substrate having a surface roughness (Rmax) of at least gf / cm ² and a mirror surface of at most 10 nm. 2. The information recording medium substrate according to claim 1, wherein the alicyclic structure-containing polymer is a norbornene-based polymer. 3. The information recording medium substrate according to claim 1, wherein the information recording medium substrate is an optical disk substrate. 4. A glass transition temperature (Tg) of 145-18.
0 ° C, load 2.16 according to JIS K-7210
The alicyclic structure-containing polymer having a melt flow rate (MFR) of 1 to 50 g / 10 minutes measured under the conditions of kg and a temperature of 280 ° C. is heated to a resin temperature of 320 to 400 ° C. and a mold temperature (Tm). A method for producing a substrate for an information recording medium, which is set so as to satisfy (Tg−60 ° C.) ≦ Tm ≦ (Tg−10 ° C.) in relation to the glass transition temperature (Tg) of the polymer, and injection molding.