JP2001126311A - Optical molding material and optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable molding material having a low rate of change of an optical characteristic (retardation) in a wide wavelength range and suitable for optical use and to obtain an optical disk capable of reading and writing with plural lasers because of good optical characteristics in a wide wavelength range. SOLUTION: The optical molding material is a cyclic polyolefin resin and the width of change of the retardation of the resin when the wavelength of light is varied from 400 nm to 830 nm is <±10% of the retardation at 590 nm wavelength. The optical disk is obtained by molding the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding material suitable for optical use, and more particularly, when an optical disk substrate is molded by injection molding, the range of change in retardation due to the wavelength of light is small and the optical characteristics are low. It relates to an optical molding material and an optical disk which are excellent.

[0002]

BACKGROUND ART Cyclic polyolefin resins have a high glass transition temperature due to the rigidity of the main chain structure, and are amorphous and have high light transmittance due to the presence of bulky groups in the main chain structure.
In addition, it has features such as low birefringence due to small anisotropy of polarizability, and is attracting attention as a transparent thermoplastic resin having excellent heat resistance, transparency, and optical properties. Examples of such a cyclic polyolefin-based resin include, for example, JP-A-1-132625, JP-A-1-132626, JP-A-63-218726, and JP-A-2-13.
No. 3,413, JP-A-61-120816, JP-A-61-115912, and the like.

In recent years, for example, compact discs (CDs)
In the field of optical disks such as CD-ROMs, DVDs, and MOs, and in optical materials such as optical lenses, optical fibers, and light guide plates, amorphous plastics such as polycarbonate and polymethyl methacrylate are used and applied. New applications are being considered. However, polycarbonate and the like have a large wavelength dependence of retardation (birefringence), and even when the retardation at a specific wavelength is a small molded product, the retardation increases when light of a plurality of wavelengths is used, It was difficult to satisfy the required product characteristics. On the other hand, the development of optical devices has been remarkable today. For example, a plurality of types of optical disks (for example, 780 nm for a CD system and 650 n for a DVD system) using different wavelengths of light are used.
Drives for recording and reproducing m) are appearing on the market,
In the next-generation drive, a short wavelength blue laser (40
Since the development for (approximately 0 nm) is being promoted, an optical molding material having stable optical characteristics (retardation) in a wide wavelength range is desired in the market. Also, in the case of an optical disc that reads and writes information using a minute laser beam, changes in optical characteristics greatly affect the product characteristics. Production conditions must be newly set according to the media.On the other hand, the presence of a material that shows a relatively constant retardation over a wide range of wavelengths has a significant advantage, such as an increase in production efficiency. Demands are growing. Further, since the retardation from low wavelength to high wavelength is stabilized, an optical disk that can be read and written by a plurality of lasers can be developed, so that it can be a material and an optical disk that opens up a new technical field.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
When a molding material suitable for optical use, particularly an optical disk substrate is molded by injection molding, the transferability is high, the variation of the retardation on the same radius is small, and the change of the retardation particularly in the light wavelength range of 400 nm to 830 nm. An object of the present invention is to provide an optical molding material and an optical disk having a small width and good optical characteristics in the above-mentioned wide wavelength range.

[0005]

According to the present invention, there is provided a cyclic polyolefin resin having a light wavelength of 400 nm to 83 nm.
An object of the present invention is to provide an optical molding material characterized in that the change width of the resin retardation when changed to 0 nm is within ± 10% of the retardation at a wavelength of 590 nm. Further, the present invention relates to an optical molded product obtained by molding a cyclic polyolefin-based resin, wherein a change width of the retardation of the molded product when the wavelength of light is changed from 400 nm to 830 nm is 59 nm.
An object of the present invention is to provide an optical molded product characterized in that the retardation at 0 nm is within ± 10%.
Further, the present invention relates to an optical disk substrate formed of a cyclic polyolefin resin, wherein the variation width of the retardation of the optical disk substrate when the light wavelength is changed from 400 nm to 830 nm is ± 0.5% of the retardation at a wavelength of 590 nm. An optical disc characterized by being within 10% is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an optical molding material and an optical disk of the present invention will be described in detail. <Cyclic polyolefin resin> Examples of the cyclic polyolefin resin constituting the optical molding material and the optical disk of the present invention include the following polymers. Ring-opening polymer of monomer represented by the following general formula (I) (hereinafter, referred to as “specific monomer”) Ring-opening copolymer of specific monomer and copolymerizable monomer Hydrogenated polymer of ring-opened (co) polymer The above-mentioned ring-opened (co) polymer was cyclized by Friedel-Crafts reaction and then hydrogenated (co) polymer. Specific monomer and unsaturated double bond Saturated copolymer with compound-containing compound Addition polymer of one or more monomers selected from specific monomers, vinyl-based cyclic hydrocarbon-based monomers, and cyclopentadiene-based monomers, and hydrogenated polymers thereof

[0007]

Embedded image ... (I)

[In the formula, R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or another monovalent organic group. You may. R ¹ and R ² or R ³ and R ⁴
May combine to form a divalent hydrocarbon group;
¹ or R ² and R ³ or R ⁴ may combine with each other to form a monocyclic or polycyclic structure. m is 0 or a positive integer, and p is 0 or a positive integer. ]

<Specific monomer> As a preferred specific monomer, in the above general formula (I), R ¹ and R ³ are each a hydrogen atom or a carbon number of 1 to 10, preferably 1 to 4, more preferably 1 to 4. R ² and R ⁴ are a hydrogen atom or a monovalent organic group, at least one of R ² and R ⁴ is a polar group, and m is an integer of 0 to 3, p is an integer of 0 to 3, and m + p is preferably 0 to 4, more preferably 0 to 2, and particularly preferably 1. As the polar group of the specific compound,
Examples thereof include ester groups such as halogen, carboxyl group, hydroxyl group, alkyl ester group and aromatic ester group, amino group, amide group, cyano group, ether group, acyl group, silyl ether group, and thioether group. Among these, a carboxyl group and an ester group are preferable, and an alkyl ester group is particularly preferable. Further, among the specific monomers, the specific monomer having a specific polar group represented by the formula — (CH ₂ ) _n COOR ⁵ in particular is a glass whose cyclic polyolefin-based resin obtained is relatively high. It is preferable because it has a transition temperature, low hygroscopicity, and excellent adhesion to various materials. In the formula according to specific polar group of the, R ⁵ is 1-12 carbon atoms, preferably 1 to 4, more preferably 1 to 2 hydrocarbon groups, preferably alkyl groups. In addition, n is usually from 0 to 5, and a smaller value of n is preferable because the glass transition temperature of the obtained cyclic polyolefin-based resin is higher. This is preferable in that the resulting polymer has a high glass transition temperature. Further, in the general formula (I), R ¹ or R ^1
3 is preferably an alkyl group, and the alkyl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2, and particularly preferably 1. In particular, the alkyl group is the above formula - is preferably coupled to (CH _{2) n} COOR ⁵ in the same carbon atom and the carbon atom to which specific polar group bonded represented. Further, the specific monomer in which m is 1 in the general formula (I) is preferable in that a cyclic polyolefin-based resin having a high glass transition temperature can be obtained.

The specific monomer represented by the above general formula (I)
The following compounds may be mentioned as specific examples. Bi
Cyclo [2.2.1] hept-2-ene, tricyclo
[5.2.1.0^2,6 ] -8-decene, tetracyclo
[4.4.0.1^2,5 . 1^7,10] -3-Dodecene, pen
Tacyclo [6.5.1.1^3,6 . 0^2,7 . 0^9,13] -4
-Pentadecene, pentacyclo [7.4.0.1^2,5 .
1^9,12. 0^8,13] -3-pentadecene, tricyclo
[4.4.0.1^2,5 ] -3-undecene, 5-methyl
Bicyclo [2.2.1] hept-2-ene, 5-ethyl
Bicyclo [2.2.1] hept-2-ene, 5-methoxy
Cycarbonylbicyclo [2.2.1] hept-2-e
5-methyl-5-methoxycarbonylbicyclo
[2.2.1] Hept-2-ene, 5-cyanobicyclo
[2.2.1] Hept-2-ene, 8-methoxycarbo
Nyltetracyclo [4.4.0.1^2,5 . 1^7,10] -3
-Dodecene, 8-ethoxycarbonyltetracyclo
[4.4.0.1^2,5 . 1^7,10] -3-dodecene, 8-
n-propoxycarbonyltetracyclo [4.4.0.
1^2,5 . 1^7,10] -3-dodecene, 8-isopropoxy
Carbonyltetracyclo [4.4.0.1^2,5 .
1^7,10] -3-dodecene, 8-n-butoxycarbonyl
Tetracyclo [4.4.0.1^2,5 . 1^7,10] -3-do
Decene, 8-methyl-8-methoxycarbonyltetracy
Black [4.4.0.1^2,5 . 1 ^7,10-3-dodecene,
8-methyl-8-ethoxycarbonyltetracyclo
[4.4.0.1^2,5 . 1 ^7,10] -3-dodecene, 8-
Methyl-8-n-propoxycarbonyltetracyclo
[4.4.0.1^{2, Five} . 1^7,10] -3-dodecene, 8-
Methyl-8-isopropoxycarbonyltetracyclo
[4.4.0.1^{2, Five} . 1^7,10] -3-dodecene, 8-
Methyl-8-n-butoxycarbonyltetracyclo
[4.4.0.1^2,5. 1^7,10] -3-dodecene, dime
Tanooctahydronaphthalene, ethyl tetracyclodode
Sen, 6-ethylidene-2-tetracyclododecene,
Limethanooctahydronaphthalene, pentacyclo [8.
4.0.1.^2,5 . 1^9,12. 0^8,13] -3-Hexadece
Heptacyclo [8.7.0.1^3,6 . 1^10,17 . 1
^12,15 . 0^2,7 . 0^11,16-4-Eicosene, hepta
Cyclo [8.8.0.1^4,7 . 1^11,18 . 1^13,16 . 0
^3,8 . 0^12,17] -5-Hen-eicosene, 5-ethylidene
Bicyclo [2.2.1] hept-2-ene, 8-ethyl
Lidentetracyclo [4.4.0.1^2,5 . 1^7,10]-
3-dodecene, 5-phenylbicyclo [2.2.1]
Put-2-ene, 8-phenyltetracyclo [4.4.
0.1^2,5 . 1^7,10] -3-dodecene, 5-fluorobi
Cyclo [2.2.1] hept-2-ene, 5-fluoro
Methylbicyclo [2.2.1] hept-2-ene, 5-
Trifluoromethylbicyclo [2.2.1] hept-2
-Ene, 5-pentafluoroethylbicyclo [2.2.
1] Hept-2-ene, 5,5-difluorobicyclo
[2.2.1] Hept-2-ene, 5,6-difluoro
Bicyclo [2.2.1] hept-2-ene, 5,5-bi
(Trifluoromethyl) bicyclo [2.2.1] hep
To-2-ene, 5,6-bis (trifluoromethyl) bi
Cyclo [2.2.1] hept-2-ene, 5-methyl-
5-trifluoromethylbicyclo [2.2.1] hept
-2-ene, 5,5,6-trifluorobicyclo [2.
2.1] Hept-2-ene, 5,5,6-tris (full
Oromethyl) bicyclo [2.2.1] hept-2-e
5,5,6,6-tetrafluorobicyclo [2.
2.1] Hept-2-ene, 5,5,6,6-tetraki
(Trifluoromethyl) bicyclo [2.2.1] hep
To-2-ene, 5,5-difluoro-6,6-bis (to
(Fluoromethyl) bicyclo [2.2.1] hept-2
-Ene, 5,6-difluoro-5,6-bis (trifur
Oromethyl) bicyclo [2.2.1] hept-2-e
, 5,5,6-trifluoro-5-trifluoromethyl
Rubicyclo [2.2.1] hept-2-ene, 5-fur
Oro-5-pentafluoroethyl-6,6-bis (tri
Fluoromethyl) bicyclo [2.2.1] hept-2-
Ene, 5,6-difluoro-5-heptafluoro-is
o-propyl-6-trifluoromethylbicyclo [2.
2.1] Hept-2-ene, 5-chloro-5,6,6-
Trifluorobicyclo [2.2.1] hept-2-e
, 5,6-dichloro-5,6-bis (trifluorome
Tyl) bicyclo [2.2.1] hept-2-ene, 5,
5,6-trifluoro-6-trifluoromethoxybis
Black [2.2.1] hept-2-ene, 5,5,6-to
Trifluoro-6-heptafluoropropoxybicyclo
[2.2.1] Hept-2-ene, 8-fluorotetra
Cyclo [4.4.0.1^2,5 . 1^7,10] -3-Dodece
8-fluoromethyltetracyclo [4.4.0.1
^2,5 . 1^7,10] -3-dodecene, 8-difluoromethyl
Tetracyclo [4.4.0.1^2,5 . 1^7,10] -3-do
Decene, 8-trifluoromethyltetracyclo [4.
4.0.1.^2,5 . 1^7,10] -3-dodecene, 8-pentane
Fluoroethyltetracyclo [4.4.0.1^2,5 . 1
^7,10] -3-dodecene, 8,8-difluorotetracycline
B [4.4.0.1^2,5 . 1^7,10-3-dodecene,
8,9-difluorotetracyclo [4.4.0.1
^2,5 . 1^7,10] -3-dodecene, 8,8-bis (trif
Fluoromethyl) tetracyclo [4.4.0.1^2,5 . 1
^7,10] -3-Dodecene, 8,9-bis (trifluorome
Tyl) tetracyclo [4.4.0.1^2,5 . 1 ^7,10]-
3-dodecene, 8-methyl-8-trifluoromethyl
Toracyclo [4.4.0.1^2,5 . 1 ^7,10] -3-Dode
Sen, 8,8,9-trifluorotetracyclo [4.
4.0.1.^2,5 . 1^7,10] -3-dodecene, 8,8,9
-Tris (trifluoromethyl) tetracyclo [4.
4.0.1.^{2, Five} . 1^7,10-3-dodecene, 8,8,
9,9-tetrafluorotetracyclo [4.4.0.1
^2,5 . 1^7,10] -3-dodecene, 8,8,9,9-tetra
Laquis (trifluoromethyl) tetracyclo [4.4.
0.1^2,5 . 1^7,10] -3-dodecene, 8,8-diflu
Oro-9,9-bis (trifluoromethyl) tetracycl
B [4.4.0.1^2,5 . 1^7,10-3-dodecene,
8,9-difluoro-8,9-bis (trifluoromethyl
Le) tetracyclo [4.4.0.1^2,5 . 1^7,10] -3
-Dodecene, 8,8,9-trifluoro-9-trifur
Oromethyltetracyclo [4.4.0.1^2,5 .
1^7,10] -3-dodecene, 8,8,9-trifluoro-
9-trifluoromethoxytetracyclo [4.4.0.
1^2,5 . 1^7,10] -3-dodecene, 8,8,9-triff
Fluoro-9-pentafluoropropoxytetracyclo
[4.4.0.1^2,5 . 1^7,10] -3-dodecene, 8-
Fluoro-8-pentafluoroethyl-9,9-bis
(Trifluoromethyl) tetracyclo [4.4.0.1
^2,5 . 1^7,10] -3-dodecene, 8,9-difluoro-
8-heptafluoroiso-propyl-9-trifluoro
Romethyltetracyclo [4.4.0.1^2,5 . 1^7,10]
-3-dodecene, 8-chloro-8,9,9-trifluoro
Rotetracyclo [4.4.0.1^2,5 . 1^7,10] -3-
Dodecene, 8,9-dichloro-8,9-bis (triflu
(Oromethyl) tetracyclo [4.4.0.1^2,5 . 1
^7,10] -3-dodecene, 8- (2,2,2-trifluoro)
Roethoxycarbonyl) tetracyclo [4.4.0.1
^2,5 . 1^7,10] -3-dodecene, 8-methyl-8-
(2,2,2-trifluoroethoxycarbonyl) tetra
Lacyclo [4.4.0.1^2,5 . 1^7,10] -3-Dodece
And the like.

Among these specific monomers, 8-methyl-
8-methoxycarbonyltetracyclo [4.4.0.1
^2,5 . 1 ^7,10 ] -3-dodecene, 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1
^7,10 ] -3-dodecene, pentacyclo [7.4.0.1
^{2, 5} . ^19,12 . 0 ^8,13 ] -3-pentadecene (hereinafter, referred to as “specific monomer A”) is a material which is more excellent in optical properties, moldability and heat resistance of an optical molding material and an optical disk finally obtained. This is preferred.

On the other hand, among these specific monomers, bicyclo [2.2.1] hept-2-ene, 5-methylbicyclo [2.2.1] hept-2-ene and 5-ethylbicyclo [ 2.2.1] Hept-2-ene, 5-methoxycarbonylbicyclo [2.2.1] hept-2-ene, 5-
Methyl-5-methoxycarbonylbicyclo [2.2.
1] Hept-2-ene, 5-ethylidenebicyclo [2.
2.1] hept-2-ene, 5-phenylbicyclo [2.2.1] hept-2-ene (hereinafter, referred to as “specific monomer B”) or one or more of the above specific units Those obtained by ring-opening copolymerization with one or more of the monomers A are preferable in that the optical properties and toughness, moldability, and transferability of the finally obtained optical disc are further improved. At this time, the “specific monomer A / specific monomer B (weight ratio)” is preferably 100/0 to 50/50, more preferably 100/0 to 60/40, and most preferably 100/0 to 60/40. / 0 to 70/30.

<Copolymerizable Monomer> In the ring-opening polymerization step for obtaining the cyclic polyolefin-based resin of the present invention, the above-mentioned specific monomer may be subjected to ring-opening polymerization alone. The monomer and the copolymerizable monomer may be subjected to ring-opening copolymerization. Specific examples of the copolymerizable monomer used in this case include cyclobutene, cyclopentene, cycloheptene, cyclooctene, tricyclo [5.2.1.0.
^{2, 6]} -3-decene, 5-ethylidene-2-norbornene, it can be mentioned cycloolefins such as dicyclopentadiene. The carbon number of the cycloolefin is preferably from 4 to 20, and more preferably from 5 to 12. Furthermore, polybutadiene, polyisoprene, styrene
Ring-opening polymerization of a specific monomer in the presence of an unsaturated hydrocarbon-based polymer containing a carbon-carbon double bond in the main chain such as butadiene copolymer, ethylene-non-conjugated diene copolymer, and polynorbornene You may. The ring-opened copolymer obtained in this case can be used as it is, but a hydrogenated product obtained by further hydrogenating the copolymer is useful as a raw material for a resin having high impact resistance. In these copolymerizable monomers, the “specific monomer / copolymerizable monomer (weight ratio)” is preferably from 100/0 to 50/50, and more preferably from 100/0 to 60/50. / 40. The hydrogenated product of the ring-opening polymer obtained in this case is useful as a raw material for a resin having high impact resistance.

<Unsaturated Double Bond-Containing Compound Constituting Saturated Copolymer> Unsaturated double bond-containing compound used together with the above-mentioned specific monomer in order to obtain a cyclic polyolefin resin composed of a saturated copolymer. As, for example, ethylene,
Olefinic compounds having preferably 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms, such as propylene and butene, can be mentioned. These unsaturated double bond-containing compounds are:
"Specific monomer / unsaturated double bond-containing compound (weight ratio)"
However, the ratio is preferably 90/10 to 40/60, and more preferably 85/15 to 50/50.

<Cyclopentadiene-based monomer> Examples of the cyclopentadiene-based monomer used in the addition polymer monomer of the present invention include cyclopentadiene, 1-methylcyclopentadiene, and 2-methylcyclopentadiene. , 2-ethylcyclopentadiene, 5-methylcyclopentadiene, 5,5-methylcyclopentadiene and the like.

<Vinylated Cyclic Hydrocarbon Monomer> Examples of the vinylated cyclic hydrocarbon monomer used for the monomer of the addition polymer of the present invention include, for example, 4-vinylcyclopentene, 2-methyl- 5-membered ring hydrocarbon monomers such as vinylcyclopentene monomers such as 4-isopropenylcyclopentene, and vinylcyclopentane monomers such as 4-vinylcyclopentane and 4-isopropenylcyclopentane; Vinylcyclohexene monomers such as -vinylcyclohexene, 4-isopropenylcyclohexene, 1-methyl-4-isopropenylcyclohexene, 2-methyl-4-vinylcyclohexene, 2-methyl-4-isopropenylcyclohexene, 4-vinyl Bihexane such as cyclohexane and 2-methyl-4-isopropenylcyclohexane Le cyclohexane monomer, styrene, alpha-methyl styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 4-phenyl styrene,
Styrene monomers such as p-methoxystyrene, d-terpene, 1-terpene, diterpene, d-limonene, 1-
Terpene monomers such as limonene and dipentene; vinylcycloheptene monomers such as 4-vinylcycloheptene and 4-isopropenylcycloheptene; 4-vinylcycloheptane and 4-isopropenylcycloheptane; And vinylcycloheptane-based monomers.

<Intrinsic Viscosity> The intrinsic viscosity (ηinh) of the cyclic polyolefin resin used in the present invention measured in chloroform at 30 ° C. is preferably 0.2 to 5.0 dl / g, more preferably. 0.3-3.0dl
/ G, particularly preferably 0.4 to 1.0 dl / g, most preferably 0.4 to 0.7 dl / g. Intrinsic viscosity (η
By setting inh) within this range, a cyclic polyolefin-based resin having more excellent toughness, moldability and retardation characteristics can be obtained.

<Molecular Weight> The molecular weight of the cyclic polyolefin resin of the present invention is preferably a number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) analysis of preferably 10.0 or less.
00 or more and 50,000 or less, more preferably 12.0 or less.
Not less than 00 and not more than 30,000, particularly preferably 15,000.
0 to 25,000 and a weight average molecular weight (M
w) is preferably from 20,000 to 250,000, more preferably from 24,000 to 150,000.
Or less, particularly preferably 30,000 or more and 125,000.
Within the following range, the molecular weight distribution (Mw / Mn) is preferably 2.0 or more and 5.0 or less, more preferably 2.5 or more and 5.0 or less, and particularly preferably more than 2.5 and 4.0. Or less, and the proportion having a molecular weight of 5,000 or less is preferably 15% or less, more preferably 10% or less, particularly preferably 5% or less, and the proportion having a molecular weight of 300,000 or more is preferably 15% or less, more preferably 10% or less.
% Or less, particularly preferably 5% or less. Here, each ratio corresponds to the chart area area (integral value) when the horizontal axis is the molecular weight in the GPC measurement chart. By setting Mn and Mw within the above ranges, it is preferable because an optical disk and an optical component having high toughness and sufficient strength can be obtained, and birefringence (retardation) can be reduced and good optical characteristics can be easily obtained. Further, by setting the molecular weight distribution (Mw / Mn) within this range, an optical disk and an optical component having high toughness and sufficient strength can be easily obtained, and birefringence (retardation) is further reduced, and excellent optical characteristics are obtained. It is preferable because it becomes easy. Further, when the proportion of the component having a molecular weight of 5,000 or less exceeds 15%, the toughness is reduced, and the component is precipitated in a mold during continuous molding to deteriorate the properties of a molded product. Exceeds 15%, the birefringence of the molded article increases, which is not preferable. In particular, in the ring-opening copolymer of the specific monomer A and the specific monomer B, M
By setting n, Mw and Mw / Mn within the above ranges,
It is a good cyclic polyolefin-based resin that provides an optical disk and an optical component having much smaller wavelength dependence of retardation (birefringence).

<Glass Transition Temperature (Tg)> The glass transition temperature (Tg) of the cyclic polyolefin resin of the present invention is 100 ° C. or more and 200 ° C. or less, preferably 120 ° C. or less.
° C to 170 ° C, particularly preferably 130 ° C to 15
It is necessary that the temperature be 0 ° C. or less. If Tg is smaller than the above range, sufficient heat resistance cannot be obtained, while if Tg is larger than this range, moldability will be significantly reduced. In particular, in the ring-opening copolymer of the specific monomer A and the specific monomer B, by changing the composition ratio to keep Tg within the above temperature range, the balance between toughness and moldability is good, It is a good cyclic polyolefin-based resin that provides an optical disk and an optical component whose retardation has a much smaller wavelength dependence on light.

Further, the gel content of the cyclic polyolefin resin of the present invention is preferably 0.1% by weight or less, more preferably 0.05% by weight or less, particularly preferably 0.01% by weight or less.
% By weight, most preferably 0.001% by weight or less. When the gel content is more than the above range, silver streaks tend to occur during molding, and when the gel content is within the above range, occurrence of silver streaks during molding can be suppressed, and a product can be obtained with a high yield. Becomes

The amount of volatile components of the optical molding material of the present invention due to heating is determined by the change in weight before and after heating to 360 ° C., which is a substantial temperature during molding, after drying for molding. Preferably not more than 0.3% by weight, more preferably not more than 0.1% by weight, most preferably 0.05% by weight
It is desirable to make the following. By setting the amount of the volatile component in this range, silver streaks are more unlikely to occur.

The cyclic polyolefin resin of the present invention includes
A hydrocarbon resin, a polystyrene oligomer, or a rosin resin may be contained as a resin component other than the above, and the fluidity of a resin composition obtained with these resin components can be improved. At this time, the content of the other resin component is usually 0.01 to 60 parts by weight, preferably 0.1 to 60 parts by weight, per 100 parts by weight of the cyclic polyolefin resin.
It is 1 to 30 parts by weight.

These other resin components are solid at room temperature and have a weight average molecular weight (Mw) in terms of polystyrene.
Is 20,000 or less, preferably 200 to 20,000
Preferably, it is Here, if the weight average molecular weight in terms of polystyrene is too large, the compatibility with the cyclic polyolefin-based resin becomes poor, and the transparency is undesirably reduced. Use of a hydrocarbon resin that is liquid at room temperature is not preferred because the mechanical strength of the resulting cyclic polyolefin-based resin decreases and bleeds on the surface of the molded article.

Examples of the hydrocarbon resin include a C ₅ resin, a C ₉ resin, a C ₅ / C ₉ mixed resin, a cyclopentadiene resin, a polymer resin of a vinyl-substituted aromatic compound, and an olefin / vinyl substitution resin. Copolymer resins of aromatic compounds, copolymer resins of cyclopentadiene compounds / vinyl-substituted aromatic compounds, hydrogenated products of the resins, and hydrogenated products of the resins can be exemplified.

The rosin resin includes, for example, apietic acid, pimaric acid and the like, and derivatives thereof such as hydrogenated products, disproportionated products, polymers and esterified products.

The cyclic polyolefin resin used in the present invention contains, for the purpose of improving mechanical properties, glass fiber, carbon fiber, metal fiber, metal flake, glass beads, wollastonite, rock filler, calcium carbonate, Fillers such as talc, silica, mica, glass flakes, milled fiber, kaolin, barium sulfate, graphite, molybdenum disulfide, magnesium oxide, zinc oxide whiskers, potassium titanate whiskers can be used alone or in combination of two or more. Can be used even if they are mixed.

The cyclic polyolefin resin used in the present invention includes known flame retardants, antibacterial agents, wood flour, coupling agents, antioxidants, plasticizers, coloring agents, lubricants, silicone oil, foaming agents. Additives such as can be added.

In the case where the other resin components, fillers, additives and the like are blended in the cyclic polyolefin resin of the present invention, a known method is used. For example, a method of obtaining a resin composition in the form of a pellet by mixing using a twin-screw extruder, a roll kneader, or the like, and a method of obtaining a resin by mixing in a solution state and removing the solvent. it can.

In the above-mentioned production method, for example, a melt kneader such as a Banbury mixer, a kneader, a roll, a feeder ruder or the like can be used. The kneading temperature is preferably 100 to 350 ° C., and more preferably 15 to
0-300 ° C. When kneading the components, the components may be kneaded at once or may be kneaded while being added in several portions.

<Optical Disk> The optical disk substrate used for the optical disk of the present invention can be produced from the above-mentioned cyclic polyolefin resin by a known molding method, for example, an injection molding method, a compression molding method, an extrusion molding method or the like. You can,
It is preferable to produce by injection molding, especially injection compression molding.

In order to obtain an optical disk substrate excellent in moldability, transparency, retardation (birefringence), toughness, warpage, transferability, dimensional stability, etc. by injection molding using the optical material of the present invention. The cylinder temperature during molding is preferably 260 to 370 ° C, more preferably 280 ° C.
To 360 ° C, particularly preferably 300 to 360 ° C, and the mold temperature is preferably 80 to 130 ° C, more preferably 9 to
Injection speed at 0 to 130 ° C, particularly preferably 100 to 130 ° C (average value over the entire injection stroke: the same applies hereinafter)
Is preferably from 60 to 300 mm / sec, more preferably from 80 to 300 mm / sec, and particularly preferably from 100 to 300 mm / sec.
It is desirable to combine them in the range of mm / sec.

Here, since the injection speed has a relatively large effect on the melt viscosity of the optical material at the time of molding, it can be a factor largely affecting the optical disk substrate characteristics. The melt viscosity of the optical material during injection molding is determined by the injection speed and the shear rate (γ) given by the shape of the mold / molding machine nozzle.
The shear rate (maximum value on the wall surface) of each part can be calculated by the following equation depending on the shape of the mold / molding machine nozzle. (A) When the shape is rectangular (slit shape): γ = 6Q / WH ² [where Q is the flow rate per unit time (cm ³ / sec),
W represents the width (cm) of the channel portion, and H represents the thickness (cm) of the channel portion.] (B) In the case of a circular (circular tubular) shape: γ = 4Q / πR ³ [where Q is the aforementioned R represents the radius (cm)]

The range of the shear rate (γ) received at the gate portion of the mold and / or the nozzle of the molding machine during injection molding is preferably 1 × 10 ³ to 1 × 10 ^3.
6 (sec- ¹ ), more preferably 5 × 10 ³ to 1 × 10
⁶ (second ^-1 ), particularly preferably 1 × 10 ⁴ to 1 × 10 ⁶ (second
^-1 ). Here, the range of the shear rate (γ) is 1 × 1
0 ³ (s ^-1) than in a an optical disk substrate retardation is not preferable becomes particularly large variation in the retardation on the same radius circle, whereas 1 × 10 ⁶ (s
^-1 ) If it is more than the above, shear heat generation during molding becomes large, and silver streaks tend to occur on the optical disk surface, which is not preferable.

The shear rate (γ) is controlled by the injection speed, the shape of the mold / molding machine nozzle, etc., as described above. In addition to the injection speed, the gate thickness is preferably 50 to 900 μm, more preferably 100 in the circumferential slit shape generally used for the mold gate shape.
The diameter of the nozzle hole of the molding machine is preferably 0.5 to 3.0 mmφ, more preferably 1.0 to 2.0 μm.
It is preferable that the shear rate (γ) is in the range of 5 mmφ, particularly preferably 1.5 to 1.8 mmφ. Here, if the mold gate thickness is less than 50 μm or the nozzle hole diameter is less than 0.5 mmφ, silver streaks easily occur during injection molding, or the injection peak pressure becomes excessively high, making it difficult to perform stable molding. On the other hand, the mold gate thickness exceeds 900 μm or the nozzle hole diameter is 3.0 m.
If the diameter exceeds mφ, the retardation characteristics of the optical disk substrate, particularly the variation on the same circumference, become relatively large, which is not preferable.

Injection molding in the present invention can be carried out in a normal atmospheric atmosphere. However, in order to prevent a decrease in the molecular weight of the optical material, coloring, and generation of a gel, supply of the optical material to a molding machine is prevented. The molding can be carried out by setting the hopper portion of the molding machine under a nitrogen gas atmosphere.

The optical disk substrate obtained by injection molding, particularly preferably injection compression molding, is then formed with a recording layer or a metal layer for reflecting a laser beam by a known method such as a vapor deposition method or a sputtering method. It is completed by further providing a protective layer if necessary. Specifically, an optical disk substrate obtained by injection-molding the optical material in a mold in which a stamper having projections and depressions corresponding to the information pits is set is coated with a metal having a high reflectance, such as Ni, Al, or the like.
Coated with Au or the like, and further applied with a known acrylic-based ultraviolet curable resin or the like to protect the same, and cured, and read-only discs such as CDs and LDs for reading out information using reflection of laser light; 1 μm
Write-once type CD-R, DVD-R, which records by irradiating a laser beam to a substrate coated with an organic dye of cyanine or phthalocyanine type on an optical disk substrate having the following guide grooves.
Further, as a recording medium, as in the case of an As-Te-Ge system, a light reflectance resulting from an amorphous-crystalline phase change by laser light irradiation,
Utilizing a change in light transmittance or using an amorphous rare earth / transition metal alloy film represented by Tb-Fe-Co,
A rewritable disk or the like that uses magnetization reversal by laser light irradiation can be used.

The optical disk of the present invention thus obtained is an optical disk substrate on which a cyclic polyolefin resin is molded as described above, and the wavelength of light is changed from 400 nm to 830 nm by adjusting molding conditions and the like. When made, the change width of the retardation of the resin,
The change in retardation at a wavelength of 590 nm is within ± 10%, preferably within ± 8%, more preferably within ± 5%, and most preferably within ± 3%. It is preferable that the width of the change in the retardation be in the above-mentioned range because the C / N ratio, which is particularly important in optical disc characteristics, is stabilized in a wide wavelength range of light. Here, it is known that the wavelength dependence of the refractive index is generally represented by Cauchy's dispersion formula (formula (1)). n = A + B / λ ² + C / λ ⁴ (1) [where n is the refractive index, λ is the wavelength (nm), A, B, and C]
Is a constant] On the other hand, since the retardation is the difference (phase difference) between the wavefronts of the ordinary ray and the extraordinary ray, the wavelength dependence of the retardation corresponds to the difference in the wavelength dependence of the refractive index of each ray. Can also be expressed by equation (1). When comparing with the specified range of the retardation of the present invention, it is preferable to confirm from the measured values at all wavelengths, but it is actually difficult, and therefore, it is generally arbitrary in the normal dispersion region (here, 400 to 830 nm). From multiple (preferably 4 or more) measurements at a point,
It is possible to easily perform regression and confirmation using the above equation (1).

In the optical disk of the present invention, the variation width of the retardation (birefringence) on the same circumference in the recording area of the disk substrate is preferably 20 nm or less.
More preferably 15 nm or less, particularly preferably 10 n
m, most preferably 5 nm or less. It is preferable that the variation width of the retardation be within this range because the optical disk characteristics are improved and the C / N ratio is particularly improved.

The application of the optical material of the present invention is not particularly limited and can be used over a wide range. For example, eyeglass lenses, general camera lenses, pickup lenses, video camera lenses, telescope lenses, Lenses such as laser beam lens, optical video disk, audio disk such as compact disk (CD), mini disk (MD), DVD disk,
Phase change type disk, magneto-optical disk (MO), CD-R
Optical discs as memory discs such as OM discs, CD-R discs, DVD-RAM discs, video recording discs, optical films such as retardation films, polarizing films, transparent conductive films, and OHP films, light diffusing plates, and conductive films. It can be particularly suitably used as an optical material such as a light plate and a liquid crystal display substrate, a photo-interrupter, a photocoupler, an optical semiconductor encapsulant such as an LED lamp, an IC memory encapsulant such as an IC card, and an optical fiber. Among them, when used as an optical disk, they exhibit particularly excellent characteristics, and thus can be suitably used.

[0040]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited by these. In the following, “parts” indicates “parts by weight”.

[Example 1] 8-- represented by the following formula (1)
Methyl-8-methoxycarbonyltetracyclo [4.
4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene (specific monomer), 250 parts, 1-hexene (molecular weight modifier), 41 parts, and toluene (solvent for ring-opening polymerization reaction), 750 parts, in a reaction vessel in which nitrogen was replaced. And the solution was heated to 60 ° C. Then, 0.62 parts of a toluene solution of triethylaluminum (1.5 mol / l) and tungsten hexachloride modified with t-butanol / methanol (t-butanol: methanol: tungsten = 0.20) were added to the solution in the reaction vessel. (Mol: 35 mol: 0.3 mol: 1 mol) and 3.7 parts of a toluene solution (concentration: 0.05 mol / l), and the system was heated and stirred at 80 ° C. for 3 hours to carry out a ring-opening polymerization reaction. Thus, a ring-opened polymer solution was obtained. The polymerization conversion rate in this polymerization reaction was 97%, and the obtained ring-opened polymer was 30%.
The intrinsic viscosity (ηinh) measured in chloroform at 0.45 ° C. was 0.45 dl / g, and the glass transition temperature (Tg) was 2
04 ° C.

[0042]

Embedded image ... (1)

4,000 parts of the ring-opening polymer solution thus obtained was charged into an autoclave, and RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ was added to the ring-opening polymer solution.
0.48 parts, hydrogen gas pressure 100 kg / cm ² ,
A hydrogenation reaction was performed by heating and stirring for 3 hours at a reaction temperature of 165 ° C. After cooling the resulting reaction solution (hydrogenated polymer solution), the hydrogen gas was released,
After passing through a micro filter having a diameter of μm, the reaction solution was poured into a large amount of methanol to coagulate and separate and collect the hydrogenated polymer. Then, after drying, it was pelletized by an extruder equipped with a 40 mmφ vent. The hydrogenation rate of the hydrogenated polymer thus obtained (hereinafter, referred to as “resin (A-1)”) is substantially 100%, and the number average molecular weight (Mn) in terms of polystyrene measured by GPC is: 1
9,800, the weight average molecular weight (Mw) is 62,000, and the ratios of molecular weight of 5,000 or less and 300,000 or more are 4% and 3%, respectively, and the intrinsic viscosity (ηinh)
Is 0.47, and the amount of volatile components by heating is 0.07.
4%.

Example 2 8-Methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ]
Instead of the 3-dodecene, 8-ethylidene tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] -3-dodecene 200
A ring-opening polymerization reaction, a hydrogenation reaction and a coagulation recovery treatment were carried out in the same manner as in Example (A-1) except for using a part to obtain a hydrogenated polymer, which was then pelletized. The hydrogenated polymer thus obtained (hereinafter referred to as “resin (A-
2) ". ) Has a hydrogenation rate of substantially 100%,
Number average molecular weight in terms of polystyrene measured by GPC (M
n) was 19,200 and the weight average molecular weight (Mw) was 58,
000, molecular weight of 5,000 or less and 30,000
The ratios of 0 or more were 7% and 3%, respectively, the intrinsic viscosity (ηinh) was 0.45, and the amount of volatile components by the heating was 0.06%.

Example 3 8-Methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ]
Example (A-) except that 20 parts of bicyclo [2.2.1] hept-2-ene was used for 230 parts of -3-dodecene.
A ring-opening polymerization reaction, a hydrogenation reaction, and a coagulation recovery treatment were performed in the same manner as in 1) to obtain a hydrogenated polymer, which was then pelletized. The hydrogenation rate of the hydrogenated polymer (hereinafter referred to as “resin (A-3)”) thus obtained was substantially 100%, and the number average molecular weight (Mn) in terms of polystyrene measured by GPC. Is 20,200, the weight average molecular weight (Mw) is 65,000, the proportion of molecular weight of 5,000 or less and 300,000 or more are 3% and 3%, respectively, the intrinsic viscosity (ηinh) is 0.47, Was 0.03%.

Example 4 Stirring blade, gas inlet tube, thermometer
And the reaction vessel equipped with the dropping funnel
Substitute and place molecular sieves in this reaction vessel.
Add 2,000 parts of dehydrated and dried cyclohexane, and add
Under a nitrogen atmosphere, tetracyclo [4.4.0.1^2,5 . 1
^7,10] -3-dodecene (75 parts)
5. n-hexane solution of skichloride (1 mol / l)
6 parts were added. Next, the temperature in the reaction vessel was raised to 10 ° C.
While maintaining the temperature at
Mixed gas of nitrogen and nitrogen (ethylene flow rate: 10 l / H
r, nitrogen flow rate: 40 liter / Hr) for 10 minutes
Was. Then, VO (OC _Two H_Five ) Cl_Two of
23 parts of n-hexane solution (0.07 mol / l) is dropped
The copolymerization reaction was started by dropping from the funnel,
The reaction was continued while passing through. 3 after starting the reaction
After 0 minutes, a small amount of methanol was added to the reaction solution to
The polymerization reaction was stopped, and this polymer solution was
The polymer (saturated copolymer) was solidified by pouring into the mixture. Soshi
After drying, they were pelletized as described above. like this
(Hereinafter referred to as “resin (A-4)”)
U. ) Number average of polystyrene equivalent measured by GPC
Molecular weight (Mn) is 21,000, weight average molecular weight (Mw)
Is 63,000 and the molecular weight is 5,000 or less and 3
The ratios of 00000 or more are 5% and 2%, respectively.
Viscosity (ηinh) is 0.46,
The amount of the generated component was 0.08%.

Example 5 In a glass-made reaction vessel purged with nitrogen, 5-phenylbicyclo [2.2.1] hept-2 was added.
-60 parts of ene and 300 parts of toluene were charged, and 1 part of 1-hexene was added as a molecular weight regulator. Solution at 40 ° C
Then, 10 parts of a 15% by weight solution of triethylaluminum in toluene as a polymerization catalyst,
Parts and a 20% by weight toluene solution of titanium tetrachloride 10
Was added to initiate ring opening polymerization. 40 ° C solution temperature
When the reaction was carried out for 1 hour while maintaining the temperature, 5 parts of methanol was added to stop the reaction. The reaction solution was poured into a mixed solution of 500 parts of acetone and 500 parts of isopropyl alcohol to precipitate a polymer, which was collected by filtration to obtain 50 parts of a ring-opened polymer. 50 parts of this ring-opened polymer and 450 parts of toluene were placed in a new glass reactor purged with nitrogen, and heated to 55 ° C. 5 parts of aluminum chloride was added with stirring, and a cyclization reaction was carried out at a reaction temperature of 55 ° C. for 12 hours. Then, the reaction solution was placed in 1000 parts of isopropyl alcohol, and the precipitated polymer was separated by filtration. Resin was obtained. The intrinsic viscosity of the obtained resin was 0.41 dl / g, Tg was 166 ° C., and the residual ratio of double bonds in the main chain structure was 32%. 30 parts of this resin was dissolved in 70 parts of toluene, and a nickel catalyst supported on alumina (0.3 part nickel in 1 part of catalyst)
Parts, nickel oxide 0.2 parts, pore volume 0.8 cm ³ /
g, specific surface area 300 m ² / g) and 2 parts of isopropyl alcohol, and hydrogenated by reacting in an autoclave at 230 ° C. and 50 kg / cm ² of hydrogen for 5 hours. After completion of the reaction, the catalyst was separated by filtration, the reaction solution was put into 500 parts of isopropyl alcohol, and the precipitated polymer was separated by filtration.
28 parts of a colorless resin were obtained. After drying, they were pelletized as described above. The resin thus obtained (hereinafter referred to as “resin (A-5)”) had an intrinsic viscosity of 0.41 dl / g and a Tg of 150 ° C. The hydrogenation ratio was substantially 100%, the residual ratio of double bonds in the main chain structure was 0%, the aromatic ring structure was saturated and did not remain, and the number average in terms of polystyrene measured by GPC. The molecular weight (Mn) is 28,000, and the weight average molecular weight (Mw) is 7
7,000 and a molecular weight of 5,000 or less and 300
The ratios of 000 or more were 4% and 3%, respectively, the intrinsic viscosity (ηinh) was 0.53, and the amount of volatile components by the heating was 0.07%.

Example 6 The above resin pellets were molded using an injection molding machine “DISK5 MIII” manufactured by Sumitomo Heavy Industries, Ltd. at a cylinder temperature of 330 ° C., a mold temperature of 110 ° C., and an injection speed of 120 mm / sec. 130mmφ and 1.2m thickness
m optical disk substrates were molded. Here, the nozzle diameter of the injection molding machine is 1.5 mmφ (land length 10 mm),
The thickness of the gate portion of the mold is 300 μm. The optical disc substrate was measured for the occurrence of silver streaks, transferability, the variation width of the retardation on the same circumference, and the wavelength dependence of the retardation by visual inspection and microscopic observation. The results are shown in Table 2. Here, with respect to the four types of resins (A-1) to (A-4), no silver streaks occurred at all during molding. In addition, in the case of resin (A-5), 1%
, Silver streaks occurred in a very small percentage.

[Embodiment 7] SiN _x (800 °) / TbFeCo was sputtered on this optical disc substrate.
(200 °) / SiN _x (300 °) / Al (500
Iv) The four-layer film was formed to produce a magneto-optical disk. Various physical property tests were performed on the obtained optical disc, and the results are shown in Tables 1 and 2.

Comparative Example 1 A polycarbonate (PC) “PANLITE AD5503” manufactured by Teijin Chemicals Ltd. was used (hereinafter referred to as “resin (B-1)”).

Comparative Example 2 An optical disk substrate was formed from the resin pellet of the comparative example in the same manner as in Example 6. This optical disk substrate was sputtered in the same manner as in Example 7 to produce a magneto-optical disk. Various physical property tests were performed on the obtained optical disc, and the results are shown in Tables 1 and 2.

<Evaluation of Physical Properties> (1) Glass Transition Temperature (Tg) Under a nitrogen atmosphere by a scanning calorimeter (DSC),
The measurement was performed at a heating rate of 10 ° C./min.

(2) Retardation of optical disc substrate: To determine the variation width (△ Re: nm) of retardation on the same circumference, JEOL Ltd.
, Using a birefringence automatic measurement device, radial position 30, 50m
At m, the retardation (Re: nm) at a wavelength of 633 nm was measured by a double path at normal incidence.

(3) Wavelength dependence of retardation: Automatic birefringence meter (KOBRA: 21A) manufactured by Shin-Oji Paper Co., Ltd.
DH) was used to examine the wavelength dependence of the retardation. Measurements were made at wavelengths of 480, 550, 590, 630, 7
Retardation at a wavelength of 400 to 830 nm was obtained by performing regression using Cauchy's dispersion equation for five wavelengths of 50 nm, and the change width (%) of the retardation at a wavelength of 400 to 830 nm was calculated. The value measured at this time was compared with the wavelength dependence of the retardation calculated from the value using the formula (1) with reference to 590 nm (the ratio was taken), and a representative resin (A-3,
B-1) is shown in FIG. Here, the measurement samples were a transparent optical disk substrate before forming a metal film by sputtering, and an optical disk substrate from which the metal film portion was removed from the optical disk after sputtering. Since it was not possible, the value after sputtering is shown.

(4) C / N ratio: The C / N ratio (dB) of the optical disk was recorded / reproduced using a disk evaluation device and determined for different wavelengths of 650 nm and 830 nm, respectively.

(5) Transferability: Scanning electron microscope (SE
Observe in M), judge from groove depth and formability of edge,
A five-point evaluation was performed, with 5 being good and 1 being bad.

[0057]

[Table 1]

[0058]

[Table 2]

From the results shown in Tables 1 and 2, Examples A-1 to A-1
The optical molding material according to A-5 has a high transferability, a small variation of the retardation on the same radius, and a change width of the retardation in the light wavelength range of 400 nm to 830 nm of ± 5 nm with respect to the wavelength of 590 nm.
It is clear that the change width is within 10% and the optical characteristics are good in a wide wavelength range, and that the optical disks exhibit excellent characteristics, particularly when used as an optical disk.

On the other hand, Comparative Example B-1 is not the cyclic polyolefin resin of the present invention, but has a large variation in retardation on the same radius and a light wavelength range of 400.
It can be seen that the change width of the retardation from nm to 830 nm is large and the C / N ratio is small and inferior.

[0061]

The optical molding material of the present invention is a molding material suitable for optical applications having stable optical characteristics (retardation) over a wide wavelength range. More specifically, an optical disk substrate is molded by injection molding. In this case, the transferability is high, the variation of the retardation on the same radius is small, and especially, the wavelength range of light is from 400 nm to 830.
The change width of the retardation in nm is 590
It is a material having a small change width within ± 10% of the retardation in nm, good optical characteristics over a wide wavelength range, excellent optical disk characteristics, and providing a product having such good characteristics. . By this, when molding optical disc substrates with different working wavelengths,
Since the change width of the retardation due to the wavelength change is small, it is not necessary to newly set the production conditions corresponding to each medium, and it is possible to achieve a large labor saving such as a significant improvement in production efficiency. Furthermore, since the retardation at low to high wavelengths is stabilized, an optical disk that can be read and written by a plurality of lasers can be developed. .

[0062]

[Brief description of the drawings]

FIG. 1 is a graph showing the wavelength dependence of retardation in Examples and Comparative Examples of the present invention.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tatsuya Hirono 2-11-24 Tsukiji, Chuo-ku, Tokyo FSR in JSR Corporation (reference) 4J100 AA02Q AA03Q AA04Q AA15Q AB00Q AB04Q AB07Q AR03Q AR09Q AR11Q AR17Q AR21P AR22Q AS15Q BA02P BA03P BA05Q BA10P BA14P BA16P BA29P BA35P BA40P BA51P BA71P BB00P BB17P BC43Q CA01 CA04 DA61 DA63 HA03 JA36 5D029 KA01 KC07

Claims (3)

[Claims] 1. A cyclic polyolefin-based resin, wherein a variation width of a retardation of the resin when a wavelength of light is changed from 400 nm to 830 nm is 590 nm.
An optical molding material characterized by being within ± 10% of the retardation at m. 2. An optical molded article formed by molding a cyclic polyolefin resin, wherein the light wavelength is from 400 nm to 830.
A molded article for optical use, characterized in that the change width of the retardation of the molded article when changed to nm is within ± 10% of the retardation at a wavelength of 590 nm. 3. An optical disc substrate formed by molding a cyclic polyolefin resin, wherein the wavelength of light is from 400 nm to 83 nm.
An optical disc characterized in that the change width of the retardation of the optical disc substrate when changed to 0 nm is within ± 10% of the retardation at a wavelength of 590 nm.