JPH03219477A - Information recording medium - Google Patents

Abstract

PURPOSE:To facilitate mounting operations and to enhance strength of adhesion by mounting hubs having insertion parts, notches and flange parts into the center holes of disk substrates and forming adhesive between these parts. CONSTITUTION:Two sheets of the disk substrates 2a, 2b formed with recording layers 1c, 1d on the surfaces on one side are so stuck to each other that the layers 1c, 1d are positioned on the inner side. The hubs 4 are mounted in the center holes 3 of the substrates 2a, 2b. The substrates 2a, 2b are superposed and stuck on and to each other via spacers 5 and 6. The notches 13 are formed in the outer peripheral parts at the front ends of the insertion parts 8 of the hubs 4. The adhesive layers are formed in the insertion parts 8, between the substrates 2a and 2b, between the flange parts 9 of the hubs 4 and the substrates 2a, 2b, between the insertion parts 8 and in the notches 13, by which the respective parts are fixed and integrated. The information recording medium 1 produced in such a manner is fixed over the entire part via the hubs 4 and the inner peripheral parts is reinforced in this way, by which the sticking strength is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information recording medium used, for example, as an optical disc.

[Conventional technology]

Plastic information recording media, in which information is written and read by focusing light such as a laser beam onto a recording layer, are required to withstand use under harsh conditions due to long-term temperature and humidity cycles. There is. To meet this demand, we created a cured resin (
Information recording medium reinforced by forming an adhesive layer
9-175046). However, although such information recording media are effective against temperature and humidity cycles, they are weak against driving force from the inner periphery, so there is a problem that they tend to peel off from the inner periphery.

Therefore, there is an information recording medium (Japanese Unexamined Patent Publication No. 119747/1989) in which a cage-shaped connecting rod is inserted into a circular hole around the center hole, and metal suction plates are attached above and below the connecting rod, but the structure is It is complicated and requires drilling holes in the disk substrate during installation, which poses problems such as difficult installation work.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide an information recording medium having a laminated structure that is easy to attach and provides high adhesive strength.

[Means to solve the problem]

The present invention provides two disk substrates in which a recording layer is formed on one side of at least one transparent resin substrate and which are bonded together with the recording layer inside, and an insertion portion inserted into a center hole of the disk substrate. , 3, and two hubs that have a flange portion that covers the disk board near the center hole and that are attached to the center hole from both sides, a notch formed on the outer periphery of the hub, and a portion inside the notch. , an information recording medium characterized by having an adhesive layer formed between a disk substrate and a hub, and between two hubs.

In the present invention, two disk substrates are bonded together with the recording layer inside, but they may be bonded directly or may be bonded via an outer spacer and an inner spacer. As a means for bonding, it is preferable to use an active energy ray-curable composition that is cured by irradiation with active energy rays as an adhesive.

The transparent resin substrate, outer spacer, and
Thermoplastic resins such as polycarbonate, polymethyl methacrylate, and amorphous polyolefin are used as materials for forming the inner spacer and the hub. Particularly preferable resins as materials for forming the transparent resin substrate include a cyclic olefin-based random copolymer (a) consisting of a copolymer of ethylene and a cyclic olefin-4-yne represented by the following general formula [1]; Ring-opening polymer of cyclic olefin component represented by general formula [1] or hydrogenated product thereof (b)
If a transparent resin substrate is formed using this resin, no birefringence will occur even if the flange of the hub and the disk substrate are bonded together with an adhesive layer.

(In the formula, R1-R12 are a hydrogen atom, a hydrocarbon group, or a halogen atom, and each may be the same or different. Also, R' and R10, or Hll and R12 are combined to form a divalent hydrocarbon R9 or Hle and R11 or R12 may mutually form a ring. n is 0 or a positive integer, and R5 to R
When 1' is repeated multiple times, these may be the same or different. ) The cyclic olefin as a component of the above-mentioned cyclic olefin-based random copolymer (a) is at least one cyclic olefin selected from the group consisting of unsaturated monomers represented by the above general formula [1]. .

In the cyclic olefin random copolymer (a), the cyclic olefin represented by the general formula [1] above mainly forms repeating units having a structure represented by the following general formula [1-a].

(In the formula, n and R1 to H12 are the same as in the above general formula [1].) R1 to R12 in the above general formula [1] are hydrogen atoms,
An atom or group selected from the group consisting of a halogen atom and a hydrocarbon group.

Examples of R1-Ra in the general formula [1] include a hydrogen atom; a halogen atom such as fluorine, chlorine, and bromine; and a lower alkyl group such as a methyl group, an ethyl group, a propyl group, and a butyl group. , these may be different from each other, may be partially different, or may be entirely the same.

R9-112 in the general formula [1] is, for example, a hydrogen atom; a halogen atom such as fluorine, chlorine, or bromine; a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a hexyl group, or a stearyl group. Alkyl groups such as; cycloalkyl groups such as cyclohexyl; substituted or unsubstituted aromatic hydrocarbon groups such as phenyl, tolyl, ethylphenyl, isopropylphenyl, naphthyl, anthryl; benzyl, phenethyl groups; , and other aralkyl groups in which an alkyl group is substituted with an aryl group, and these may be different from each other or all may be the same.

Further, R9 and RIOl or R11 and R12 may be combined to form a divalent hydrocarbon group, and R9 or HI
O and Hl, 1 or R1,2 may form a ring with each other.

Examples of the divalent hydrocarbon group formed by combining R9 and Hlll or R11 and R12 include alkylidene groups such as an ethylidene group, a propylidene group, and an isopropylidene group.

The ring formed by r+9 or Rio and R11 or R12 may be monocyclic or polycyclic, may be a polycyclic ring having a bridge, or may be a ring having a double bond. The ring may be a combination of rings.

Specific examples of such a ring include the following. These rings may have a substituent such as a methyl group. In the above chemical formula 8, the carbon atoms marked with 1 or 2 represent the carbon atoms to which R9, . . . , R12 are bonded in the general formula [1].

The cyclic olefin represented by the general formula [1] can be easily produced by condensing a cyclopentadiene and a corresponding olefin or cyclic olefin by a Diels-Alder reaction.

Examples of the cyclic olefin represented by the general formula [1] include bicyclo(2,2,1)hept-2-ene or its derivatives, tetracyclo(4,4,0,1"'1"
1o)-3-dodecene or its derivative, hexacyclo(6,6,1,1"", 110113.0"t7
．． 0g114) -4-hebutadecene or its derivative, octacyclo(8,8,0°1!, 9.14,7.1
111IL[1,113,IB,02,11.012,
17) -5-tocosene or its derivative, pentacyclo(6,6,1°13, snO”,7,Q9.
14) -4-hexadecene or its derivative, /<ntashi') o(6,5,1,1", 0217.0911
3) -4-pentadecene or its derivative, heptacyclo [8°7, Q, 12,9 ml', ? , 111
, if , Q3.8 , Q10 +1s)-5-eicosene or its derivatives, heptacyclo(8,8,0,
12-14・7.111・11', 03・a, 012,
17) -5-heneicosene or its derivatives, tricyclo(4,3,0,1'') -3-decene or its derivatives, tricyclo(4,4,0,12+')-3
- undecene or its derivatives, pentacyclo(6,5
, Ll" ls, 0"+7.01111') -4,
10-h:/ tadecasien or its derivative, pentacyclo(6,5,1゜131B, 0217.09.1
3) -4,11-pentadecadiene or its derivatives,
Pentacyclo(4,7,Q,12.s,Qs,1a19
．． 12']-3-pentadecene or its derivative, pentacyclo[4,7,0,121s, 0I1113.19
+12]-3,10-hentadecacyene or its derivative, heptacyclo[7°8.0.13,6.02,7,
110,17.011116.112,151-4-eicosene or its derivatives, nonacyclo(9,10,1
,1' ”03.1+,02,1+1.(p2,21.
11i11ZD, 014119.11G11113-5
- Bentacocene or its derivatives, etc. can be mentioned.

Further, examples of the cyclic olefin represented by the general formula [1] include compounds represented by the following general formula [2].

(In the formula, p is 0 or an integer of 1 or more, q and r are 0.
1 or 2, R1-R4 and H1O to H12 are the same as those in the general formula [1], and R13 to H21 each independently represent a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group,
Indicates an atom or group selected from the group consisting of an aromatic hydrocarbon group and an alkoxy group, and R10 to R12 and R13 to
R2'L may be bonded directly or via an alkylene group having 1 to 3 carbon atoms to form a ring. ) Specific examples of R13 to R21 in the general formula [2] include, for example, a hydrogen atom: a halogen atom such as fluorine, chlorine, or bromine; a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group. , aliphatic hydrocarbon groups such as isobutyl, hexyl, and stearyl groups; cycloalkyl groups such as cyclohexyl; substituted or unsubstituted phenyl, tolyl, ethylphenyl, isopropylphenyl, naphthyl, and anthryl groups; aromatic hydrocarbon groups; aralkyl groups such as benzyl group and phenethyl group; alkoxy groups such as methoxy group, ethoxy group, and propoxy group; these may be different or partially different. or all may be the same.

As for the compound represented by the general formula [2], p is 0
-3 are preferred.

Specific examples of the compound represented by the general formula [1] include those listed in Table 1.

12- Table 1 (Continued 1) 15- Table (Continued 3) 17- Table (Continued 2) 16- Table (Continued 4) 18- Table 1 (Continued 5) 9- Table (Continued 7) 21 Table (dzuki 6) 20- table (dzuki 8) -22= table 1 (dzuki 9) 23- table (continued 11) 5- table (dzuki 10) 24- table (dzuki 12) 6-table 1 (Continued 13) 127 = 29- Table (Continued 14) 28- Table (Continued 16) 30- The cyclic olefin-based random copolymer (a) has the above-mentioned cyclic olefin component and ethylene component as essential components. However, in addition to these two essential components, other copolymerizable unsaturated monomer components may be contained as necessary within a range that does not impair the object of the present invention. Examples of unsaturated monomers that may optionally be copolymerized include those having 3 carbon atoms,
-20 α-olefins, hydrocarbon monomers containing two or more carbon-carbon double bonds in one molecule, and the like. As an α-olefin having 3 to 20 carbon atoms,
Specifically, propylene, 1-butene, 1-pentene, 4
-methyl-1-pentene, 3-methyl-1-pentene,
1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1
-Hexadecene, 1-octadecene, 1-eicosene, etc. can be mentioned. Examples of hydrocarbon monomers containing two or more carbon-carbon double bonds in one molecule include 1,4-hexadiene, 1,6-octadiene, 2
-Methyl-1,5-hexadiene, 4-methyl-1,5
-hexadiene, 5-methyl-1,5-hexadiene,
6-methyl-1,5-hebutadiene, 7-methyl-1,
Chain nonconjugated dienes such as 6-octadiene; cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylene Lyden-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene,
4,9゜5.8-dimethano-3a, 4,4a, 5,8,
Cyclic non-conjugated dienes such as 8a,9,9a-octahydro-IH-benzoindene; 2゜3-diisopropylidene-
Examples include 5-norbornene; 2-ethylidene-3-isopropylidene-5-norbornene; and 2-propenyl-2,2-norbornadiene. Among these, 1,4-hexadiene, 1,6-octadiene, and cyclic nonconjugated dienes, especially dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5-methylene- 2-norbornene, 1,4-hexadiene and 1,6-octadiene are preferred.

In the cyclic olefin random copolymer (a), the structural units derived from the ethylene component range from 40 to 85 mol%, preferably from 50 to 75 mol%, and the structural units derived from the cyclic olefin component range from 15 to 31% by mole. A substantially linear cyclic olefin-based random copolymer in which the structural units derived from the ethylene component and the structural units derived from the cyclic olefin component are randomly arranged in a range of 60 mol%, preferably 25 to 50 mol%. is formed. That the cyclic olefin random copolymer (a) is substantially linear and does not have a gel-like crosslinked structure can be confirmed by completely dissolving the copolymer in decalin at 135°C.

The intrinsic viscosity [η] of the cyclic olefin random copolymer (a) measured in decalin at 135°C is 0.01 to 10.
dl/g, preferably in the range of 0.05 to 5 dl/g.

Further, the cyclic olefin random copolymer (a) has a softening temperature (TMA) of 70°C or higher, preferably 90 to 25°C, as measured by a thermal mechanical analyzer.
0°C, more preferably 100 to 200°C, glass transition temperature (Tg) usually 50 to 230°C, preferably 70°C
~210°C, crystallization measured by X-ray diffraction 32
- Preferably, the degree is in the range of 0 to 10%, preferably 0 to 7%, particularly preferably 0 to 5%.

As the cyclic olebuin-based random copolymer (a), one type of copolymer having physical properties within the above range may be used, but the intrinsic viscosity [η
] is in the range of 0.05 to 10 dI2/g, and the softening temperature (TMA) is 70°C or higher, preferably 90 to 250°C.
The intrinsic viscosity [η] measured in decalin at 135°C is added to 100 parts by weight of a cyclic olefin random copolymer at 135°C.
is in the range of 0.01 to 5 dl/g, and the softening temperature (
It is also possible to use a composition blended with 0.1 to 10 parts by weight of a cyclic olefin random copolymer having a temperature (TMA) of less than 70°C, preferably -10 to 60°C.

The cyclic olefin-based random copolymer (a) comprises an ethylene component, a cyclic olefin component represented by the above-mentioned -Kaburi [1], and other monomer components to be copolymerized if necessary.
It can be produced by polymerization in the presence of a well-known Ziegler catalyst.

Examples of the Ziegler-based catalyst include (a) a catalyst consisting of a composite containing at least magnesium, titanium, and a halogen and an organoaluminum compound, and (b) a catalyst consisting of a vanadium compound and an organoaluminum compound. . Among these, the latter catalyst (a) is preferred, and a catalyst comprising a soluble vanadium compound and an organoaluminum compound is particularly preferred.

A specific method for producing the cyclic olefin random copolymer (a) is described in JP-A-60-168708 and JP-A-6
1-120816, JP-A-61-115912, JP-A-61-115916, JP-A-61-
271308, JP 61-272216, JP 62-252406, JP 62-25
It is disclosed in Publication No. 2407 and the like.

In addition to the cyclic olefin random copolymer (a), preferred resins for the transparent resin substrate for forming the disk substrate include 1 selected from the cyclic olefins represented by the general formula [1] above. A ring-opening polymer consisting of more than one type of cyclic olefin component or its hydrogenated product (b
) (hereinafter referred to as a cyclic olefin ring-opening polymer) can also be used. Such a cyclic olefin-based ring-opening polymer is disclosed, for example, in JP-A-60-26024.

The cyclic olefin constituting the cyclic olefin-based ring-opening polymer (b) is at least one cyclic olefin selected from the group consisting of unsaturated monomers represented by the above general formula [1].

In the ring-opening polymer before hydrogenation of the hydrogenated cyclic olefin-based ring-opening polymer, the cyclic olefin component represented by the general formula [1] is represented by the following general formula (1-b).
In the ring-opened polymer after hydrogenation, repeating units of the following general formula [1-
It mainly forms repeating units with a structure represented by c].

35- (In the formula, n and R1-R12 are the same as in the above general formula [1].) The cyclic olefin-based ring-opening polymer (b) has the above-mentioned cyclic olefin as an essential component, but this If necessary, other copolymerizable unsaturated monomer components may be contained within a range that does not impair the purpose of the invention. Examples of the optionally copolymerized unsaturated monomer include the following general formula [
Examples include cyclic olefins represented by [3].

(In the formula, R22 and R23 are hydrogen atoms, hydrocarbon groups, or halogen atoms, and may be the same or different. Q is an integer of 2 or more, and when R2236-R23 is repeated multiple times, may be the same or different.) Examples of the monomer component represented by the general formula [3] include cyclobutene,
Cyclopentene, cycloheptene, cyclooctene, cyclononene, cyclodecene, methylcyclopentene, methylcycloheptene, methylcyclooctene, methylcyclononene, methylcyclodecene, ethylcyclopentene, ethylcycloheptene, ethylcyclooctene, ethylcyclononene, ethylcyclodecene , dimethylcyclopentene, dimethylcycloheptene, dimethylcyclooctene, trimethylcyclodecene, etc.

Furthermore, examples of heptamer components other than the cyclic olefin represented by the general formula [3] include cyclooctadiene and cyclodecadiene.

The intrinsic viscosity [η] of the cyclic olefin ring-opening polymer (b) measured in decalin at 135°C is 0.01 to 10 dl/
g, preferably 0.05 to 5 dfl/g.

Furthermore, as the cyclic olefin ring-opening polymer (b),
Softening temperature (TMA) is 70°C or higher, preferably 90-2
00℃, crystallinity measured by X-ray diffraction method is 0~
10%, preferably 0-7%, particularly preferably 0-5%
Preferably.

As the cyclic olefin ring-opening polymer (b), a polymer consisting only of those having physical properties within the above range may be used, but a polymer having physical properties outside the above range may be partially included. In this case, it is sufficient that the entire physical property value is within the above range.

In order to produce a ring-opening polymer of a cyclic olefin component represented by the general formula [1] above, a monomer component selected from the general formula [1] above is used as a raw material, and the ring-opening polymer is subjected to ring-opening polymerization using a conventional ring-opening polymerization method for cyclic olefins. Can be polymerized. In this case, examples of the polymerization catalyst include ruthenium, rhodium,
A system consisting of a halide such as palladium, osmium, iridium, platinum, molybdenum, tungsten, nitrate or acetylacetone compound and a reducing agent such as an organic tin compound or alcohol, or a halide such as titanium, vanadium, zirconium, tungsten, molybdenum or acetylacetone A system consisting of a compound and an organic aluminum or the like can be used.

The molecular weight of the ring-opening polymer produced can be adjusted by adding an olefin or the like during ring-opening polymerization.

When hydrogenating the ring-opened polymer obtained above, a conventional hydrogenation method can be used.

As the hydrogenation catalyst, those used in the hydrogenation of olefin compounds can generally be used. Specifically, the heterogeneous catalysts include nickel, palladium,
Solid catalysts include platinum, or these metals supported on carriers such as carbon, silica, diatomaceous earth, alumina, titanium oxide, etc. For example, nickel/silica, nickel/diatomaceous earth, palladium/carbon, palladium/silica, Examples include palladium/diatomaceous earth and palladium/alumina. Homogeneous catalysts include those based on metals from group 1 of the periodic table, such as nickel naphthenate/triethylaluminum, cobalt octenoate/n-butyllithium, nickel acetylacetonate/triethylaluminum. Examples thereof include Ni and Co compounds such as Ni and Co, and organometallic compounds of metals from groups ① to ② of the periodic table, or Rh compounds.

The hydrogenation reaction of the ring-opening polymer is carried out in a homogeneous or heterogeneous system depending on the type of catalyst, under a hydrogen pressure of 1 to 150 atmospheres, and at a temperature range of 0 to 180°C, preferably 20 to 100°C. be exposed. The hydrogenation rate can be adjusted by adjusting the hydrogen pressure, reaction temperature, reaction time, catalyst concentration, etc., but in order for the hydrogenated compound to exhibit excellent heat deterioration resistance and light deterioration resistance, it is necessary to It is preferable that 50% or more of the heavy bonds are hydrogenated, preferably 80% or more, and even more preferably 90% or more.

These resins can be used alone or in combination of two or more.

Further, by molding these resins by a general method such as injection molding, it is possible to obtain a molded article such as a transparent resin substrate or a hub in a desired shape.

40- Also, the recording layer for forming the disk substrate.

Low melting point metal materials such as Te, or Te-C-H, Te
A recording material mainly composed of a low melting point metal material such as -Cr or Te-Cr-C-H film, or a heat mode recording material suitable for the information recording medium of the present invention, such as an organic dye material, or Tb-Fe- Go, Tb-Fe-co with pt or P
A magneto-optical recording material containing a rare earth element and a 3D transition metal, such as those added with d, and an underlayer, antireflection layer, and reflective layer that are laminated on and/or below these recording material layers as necessary. , an interference layer, a protective layer, an enhancement layer, etc., which are suitable for the information recording medium of the present invention.

The hub may be made of, for example, polycarbonate resin, the cyclic olefin random copolymer (a), or the cyclic olefin ring-opening polymer (b), if necessary. A molded product made of a polycarbonate resin, a cyclic olefin random copolymer (a), a cyclic olefin ring-opening polymer (b), etc., with a magnetic metal attached to the resin. can be used. In the present invention, it is particularly preferable to use polycarbonate resin as the hub.

The hub has an insertion portion that is inserted into the center hole of the disk substrate, a flange portion that covers the disk substrate near the center hole, and a notch formed on the outer periphery of the insertion portion. Preferably, the notch is formed on the outer periphery of the distal end of the insertion portion.

In the present invention, adhesives used to form the adhesive layer include amino resins, phenolic resins, resorcinol resins, xylene resins, furan resins, epoxy resins, polyisocyanates, unsaturated polyesters, acrylic resins, etc. Curing adhesive; vinyl acetate, acrylic,
Thermoplastic adhesives such as ethylene copolymer, polyamide, polyester, and polyurethane; Rubber adhesives such as polychloroprene, nitrile rubber, recycled rubber, SBR, and natural rubber; rubber, acrylic, and emulsion type adhesives Pressure-sensitive adhesives such as , oligomer type, hot-melt type, thermosetting type, and moisture-curing type; hot-melt adhesives such as water-soluble type, high-temperature type, reactive type, and pressure-sensitive type; instant adhesives such as cyanoacrylate type; anaerobic adhesives; Examples include adhesives, but ultrasonic or high frequency welding may also be used. Preferred examples include acrylate-based or epoxy-based UV-curable adhesives, but in the present invention, active energy ray-curable compositions that can be cured and bonded by irradiation with active energy rays such as ultraviolet rays are used. It is preferable to use compounds that contain methacrylates, and examples of those that can be used particularly preferably include (A) epoxy resins, (B) compounds selected from the group consisting of sulfonium salts and cyclopentadienyl iron compounds, and (C) acrylates, methacrylates, and their like. Examples thereof include a compound selected from the group consisting of oligomers and an active energy light-curable composition containing (D) an organic peroxide.

The epoxy resin (A) is preferably a compound containing two or more epoxy groups in one molecule, and particularly preferably an aliphatic or alicyclic epoxy compound. Examples of such epoxy resins (A) include bisphenol A, bisphenol F, 1,1,2.2-
Glycidyl ether-based epoxy resins of polyphenol compounds such as tetrakis(4'-hydroxyphenyl)ethane; glycidyl ether-based epoxy resins of polyhydric phenols such as catechol, resorcinol, hydroquinone, and phloroglucin; ethylene glycol, butanediol,
Glycidyl ether-based epoxy resins of polyhydric alcohols such as glycerol, erythritol, and polyoxyalkylene glycol; Novolac-type epoxy resins; Cycloaliphatic epoxy resins such as vinylcyclohexene dioxide, limonene dioxide, and dicyclopentadiene dioxide; Examples include polyglycidyl ester-based epoxy resins which are ester condensates of polycarboxylic acids such as phthalic acid and cyclohexane-1,2-dicarboxylic acid; polyglycidylamine-based epoxy resins. These epoxy trees 4
4- Among the fats, glycidyl ether-based epoxy resins or novolac-type epoxy resins of polyphenol compounds are preferred, and among them, glycidyl ether-based epoxy resins of bisphenol A or bisphenol F are more preferred, and among them, glycidyl ether-based epoxy resins of bisphenol A are preferred. Particularly preferred.

Furthermore, among the sulfonium salts or cyclopentadienyl iron compounds (B), the sulfonium salts are preferably triarylsulfonium salts, and particularly preferably triphenylsulfonium salts. Examples of the anion of such a sulfonium salt include AsF6- or BF4
- etc. are preferred.

Specific examples include triphenylsulfonium salts, tri(4-methylphenyl)sulfonium salts, and tri(4-methoxyphenyl)sulfonium salts.

Cyclopentadienyl iron compounds include compounds containing two cyclopentadienyl groups in the molecule, or compounds containing one cyclopentadienyl group and one aromatic group such as a phenyl group or isopropylphenyl group in the molecule. Compounds that contain Among these, the latter compound containing one cyclopentadienyl group and one aromatic group is more preferable, and furthermore, one containing a cyclopentadienyl group and an isopropylphenyl group is particularly preferable.

Examples of such cyclopentadienyl iron compounds include cyclopentadienyl isoprobylphenyl iron (n) salts.

As the compound (B), a sulfonium salt and a cyclopentadienyl iron compound can be used alone or in combination.

Among these, compound (B) is cyclopentadienyl isopropylphenyl iron (II) represented by the above formula.
Salts are particularly preferred.

Further, as the acrylate or methacrylate of the component (C), an ester of a hydroxy compound or a di or more polyhydroxy compound and acrylic acid or methacrylic acid is used. Such esters include, for example, monovalent aliphatic alcohols having 1 to 20 carbon atoms, alicyclic alcohols having 1 to 30 carbon atoms, and 1 to 30 carbon atoms.
-20 divalent 47-aliphatic alcohol, C1-C20 divalent alicyclic alcohol, C1-2 trivalent aliphatic alcohol, acrylic acid of hydroxy compound such as hydroxyl group-terminated polyester Alternatively, esters with methacrylic acid may be mentioned.

Specific examples of component (C) include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate; cyclohexyl acrylate, norbornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, isobornyl Acrylate, cyclohexyl methacrylate, following formula [4] A→M
-LiM-A... [4] [wherein A is an acrylic acid residue, M is a divalent aliphatic or alicyclic alcohol residue, L is a dibasic acid residue, and P is a positive number. be. ] A polyester whose both ends are blocked with acrylic acid represented by the following formula [5] 48- [wherein B is an acrylic acid residue and X is a trivalent or higher polyvalent aliphatic or alicyclic alcohol residue group, Y is a residue of a divalent or higher polybasic acid, and q is a positive number. Examples include polyesters represented by the following formula in which both ends and the hydroxyl groups in the chain are blocked with acrylic acid.

Further, specific examples of component (C) include the compounds shown in Table 2.

Some of these acrylate or methacrylate compounds are disclosed in JP-A-61-136529. These acrylates or methacrylates can also be used as oligomers produced by prepolymerization according to methods known per se.

Among these components (C), a mixture of an alkyl ester of acrylic acid or methacrylic acid, a compound of the above formula [4], and a compound of the above formula [5] is preferred.

Examples of the organic peroxide (D) include benzoyl peroxide, dichlorobenzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, di-tert-butyl peroxide, and 2,5-dimethyl-
2,5-di(peroxidebenzoate)hexyne-3
, 1,4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-
Butyl peracetate, 2,5-dimethyl-2,5-di(tart-butylperoxy)hexyne-3,2,5
-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylperbenzoate, ta
rt-butyl perphenylacetate, tert-butyl perisobutyrate, tert-butylperu 5ee
-octoate, tert-butyl perpivalate, cumyl perpivalate and tert-butyl perdiethyl acetate.

Among these are dicumyl peroxide, ditert
-butylperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5
Dialkyl peroxides such as -dimethyl-2,5-di(tert-butylperoxy)hexane and 1,4-bis(tert-butylperoxyisopropyl)benzene are preferred.

The composition suitably used as an adhesive in the present invention has the above-mentioned components (A), (B), (C), and (D) as essential components, and is based on 100 parts by weight of component (A). (
B) component 1 to 10 parts by weight, preferably 2 to 5 parts by weight, (
15 to 35 parts by weight of component C), preferably 20 to 30 parts by weight and 1 to 10 parts by weight of component (D), preferably 2 to 5 parts by weight
Preferably, it contains parts by weight.

The composition preferably used as an adhesive in the present invention does not necessarily require a photopolymerization initiation aid, but UV
When using relatively low energy active energy rays such as The photopolymerization initiation aid is
Various known types can be used, such as a decomposition type that decomposes and generates radicals when irradiated with UV or the like, or a hydrogen bow type that generates radicals by extracting hydrogen. Specific examples of such photopolymerization initiation aids include benzoin or its ethers such as benzoin, benzoin methyl ether, benzoin 60-ethyl ether, benzoin isopropyl ether, and benzoin butyl ether; benzophenone, P-chlorobenzophenone, and domethoxybenzophenone; Benzophenone compounds such as non;
Benzyl, benzyl dimethyl ketal and other benzyl compounds; 1-(4-isopropylphenyl)-2-hydroxy-2-methyl-1-propanone, 1-phenyl-2-hydroxy-2-methyl-]-propanone, 1-
Examples include hydroxyalkylphenylketone compounds such as (4-tert-butylphenyl)-2-hydroxy-2-methyl-1-propane.

Furthermore, as a sensitizer, for example, hydrocarbons such as anthracene, naphthalene, chrysene, and phenanthrene; nitro compounds such as p-dinitrobenzene, p-nitroaniline, 1.3.5-trinitrobenzene, and p-nitrodiphenyl; n- Butylamine, di-n-butylamine, triethylamine, diethylaminoethyl methacrylate,
p-nitroaniline, N-acetyl-4-nitro-1-
Amino compounds such as naphthylamine; phenolic compounds such as phenol, P-nitrophenol, 2,4-dinitrophenol, 2,4.6-trinitrophenol; benzaldehyde, 9-anthraaldehyde, acetophenone, benzophenone, diben Ketones such as zalacetone, benzyl, P+P-diaminobenzophenone, P+P-tetramethyldiaminobenzophenone; anthraquinone, 1,2-benzoanthraquinone, benzoquinone, 1,2-naphthoquinone,
Quinones such as 1,4-naphthoquinone; anthrone, 1,
9-Benzanthrone, 6-phenyl-1,9-benzanthrone, 3-phenyl-1,9-benzanthrone, 2-keto-3-aza-1,9-benzanthrone, 3
Examples include an-1-rones such as -methyl-1,3-diaza-1,9-benzaanthrone.

The above-mentioned composition particularly preferably used as an adhesive in the present invention may basically be solvent-free, but a solvent may be added thereto. Components that are included in ordinary solvent-free adhesives, such as additives and plasticizers, may also be included.

In this way, an adhesive made of a composition containing components (A) to (D) and other components as necessary has excellent adhesive properties and moisture-resistant adhesive properties in the initial stage of curing, and also cures in a short time. Therefore, it has advantages such as being able to increase the speed of the production line for information recording media, and is therefore preferably used.

In the information recording medium of the present invention, the disc substrate made of the above material and the hub are bonded together, within the notch of the hub, and between the two hubs using the above adhesive.

The adhesive layer formed between the disk substrate and the hub is formed between the flange portion of the hub and the disk substrate, and between the inner peripheral surface of the center hole of the disk substrate and the outer peripheral surface of the insertion portion of the hub.

In the present invention, since all of the above locations have an adhesive layer, the adhesion between the hub and the disk and/or between the bubbles is extremely strong compared to a case where one of them does not have an adhesive layer. The inner circumferential portion of the disk substrate can be strongly reinforced with a large and simple bonding structure.

If an adhesive layer is formed between the disk substrate made of a resin with high birefringence such as polycarbonate and the flange of the hub, the birefringence will further increase, which will have a negative effect on recording and reproducing information, but the information recording medium of the present invention When the cyclic olefin-based random copolymer (a) and the cyclic olefin-based ring-opening polymer are used as the material of the disk substrate, an adhesive layer may be formed between the disk substrate and the flange portion of the hub. , the increase in birefringence is extremely small, and there is no adverse effect due to the increase in birefringence.

In the present invention, the information recording medium includes all media in which information is recorded in a recording layer, such as an optical disc and a flexible optical disc.

[For production]

In the information recording medium of the present invention, a disk substrate having a recording layer formed on one side of a transparent resin substrate is welded by adhesive or ultrasonic welding directly or through an outer circumferential spacer and an inner circumferential spacer so that the recording layer is on the inside. The insertion portions of the hub are inserted into the center hole from both sides to attach them, and adhesive made of the above composition is applied between the disk substrate and the bar diagram, within the notch of the hub, and between the insertion portions. They are manufactured by filling them with an agent and bonding them by irradiating them with active energy rays such as ultraviolet rays.

In the information recording medium manufactured in this manner, the hub is in contact with the disk substrate through the insertion portion and the flange portion, and the hub and the disk substrate are bonded with the above adhesive, and the hubs are bonded with the above adhesive. In order to
The whole is integrated via the hub, which strengthens the inner circumference of the center hole and increases the bonding strength. Furthermore, since the adhesive is cured while being filled in the notch formed in the hub, the peel resistance of the adhesive is increased.

〔Example〕

Hereinafter, the present invention will be explained with reference to embodiments of the drawings.

FIGS. 1 and 2 are cross-sectional views showing information recording media according to different embodiments, respectively. In the figure, 1 is an information recording medium, and a recording layer IC1 is formed on one side of transparent resin substrates 1a and 1b.
Form 1d1. The two disk substrates 2a and 2b are pasted together 65- with the recording layer IC 11d facing inside, and the hub 4 is attached to the center hole 3 of the two disk substrates 2a and 2b. . Disk board 2a
, 2b are overlapped with each other via an outer circumferential spacer 5 and an inner circumferential spacer 6 in FIG.
In the figure, they are directly bonded together using an adhesive layer 7. hub 4
A metal plate 11 is attached to a hub body 10 having an insertion portion 8 and a flange portion 9, and has a hole 12 in the center. The metal plate 11 is fixed to the hub body 10 by a cut and raised piece, and is driven mechanically or magnetically.
Detailed illustration is omitted. The insertion portion 8 of the hub 4 is inserted into the center hole 3, and the flange portion 9 covers the disk substrates 2a, 2b near the center hole 3. Furthermore, a notch 13 is formed on the outer periphery of the distal end of the insertion portion 8 to improve the retention of the adhesive. The shape of the notch 13 is such that a small diameter part is provided at the tip of the insertion part 8, but there are other shapes such as those shown in FIGS. An easy-to-use shape can be selected as appropriate.

The shape of the notch 13 is as shown in Fig. 1 and Fig. 3 (a).
The one shown in the figure is preferred. An adhesive layer 14 is formed between the insertion portion 8 of the hub 4 and the disk substrates 2a, 2b, between the flange portion 9 of the hub 4 and the disk substrates 2a, 2b, between the insertion portions 8 of the two hubs 4, and in the notch 13. They are then fixed and integrated.

As shown in FIGS. 1 and 2, the information recording medium 1 configured as described above is provided by directly attaching the disk substrates 2a and 2b or using the outer spacer 5 and the inner spacer 6 so that the recording layer IC11d is on the inside. The insertion part 8 of the hub 4 is inserted into the center hole 3 from both sides and attached, and the space between the insertion part 8 of the hub 4 and the disk substrates 2a and 2b is Flange portion 9 of hub 4
and the disk substrates 2a and 2b, the eight insertion portions of the hub 4, and the notch 13 are filled with an adhesive layer 14 made of the composition of the components (A) to (D), and the adhesive layer 14 is bonded by irradiating ultraviolet rays.
Manufactured.

In the thus manufactured information recording medium 1, the hub 4 is connected to the disk substrates 2a, 2b by the insertion portion 8 and the flange portion 9.
is in contact with the insertion section 8 and each disk substrate 2a.
, 2b, between the flange portion 9 and each disk substrate 2a.
, 2b and between the hubs 4 are bonded by the adhesive layer 14, so the whole is fixed via the hub 4,
This reinforces the inner peripheral portion and increases the bonding strength.

Further, since the adhesive is cured with the adhesive filled in the notch 13, the peel resistance strength of the adhesive is increased.

Furthermore, since the above-mentioned active energy beam-curable composition is used as the adhesive, the bonded portion cures quickly and has excellent adhesiveness and moisture-resistant adhesiveness in the initial stage of curing.

Test examples will be explained below.

The evaluation of the test example was determined by determining the hub adhesive strength before and after a humidity test in which the information recording medium 1 was placed in a constant temperature and humidity chamber at a temperature of 70° C. and a humidity of 85% for 200 hours.

The hub adhesive strength (bub-bub and/or hub-disk adhesive strength) was determined as follows.

68- Measuring device No. 2 material testing machine (Intesco 205) Measuring method: Attach a hub plate to the hub of the information recording medium, insert a pin into the hole in the hub, press the pin against the hub plate, and move the bottle at a constant speed ( Find the maximum stress when pressing down at 20mm/m1n).

Unit: kgf Test Example 1 As the transparent resin substrates 1a, 1b and the hub body 10,
The ethylene component measured by C-NMR analysis is 59 mol%,
The intrinsic viscosity [η] measured in decalin at 135°C is 0.
42 dIl/g, ethylene with a glass transition temperature of 136°C and tetracyclo (4,4,0
, 1215) was molded into a desired shape by injection molding. Then, a recording layer 1c is provided on the substrates 1a, 1b and the hub body 10, respectively.
1d and the metal plate 11, the disk substrates 2a, 2
b and hub 4 were created.

On the other hand, 80 parts by weight of bis, phenol A type epoxy resin (manufactured by Mitsui 69-Petrochemical Industries, Ltd., EPOMIKR-140, trademark), and acrylic monomer and oligomer (manufactured by Toagosei Chemical Industry Co., Ltd., Aronix, M −
5700, M-6100, M-6300, M-8030
, trademark), M-5700, M-6100, M-630
0 and M-8030, 7 parts by weight and 5 parts by weight, respectively.
100 parts by weight, 3 parts by weight and 5 parts by weight
To parts by weight, 2 parts by weight of cyclopentagenyl isopropylphenyl iron (II) salt (manufactured by Ciba Geigy), 0.25 parts by weight of anthracene (manufactured by Wako Pharmaceutical Industries, Ltd.),
Cumene hydroperoxide (manufactured by Kayaku Nouri Co., Ltd., 70
% product) was used as an adhesive, and was irradiated with ultraviolet rays for 15 seconds at an illumination intensity of 160 ml/a (160 ml/a) to bond the adhesive layer 14 to the disk substrates 2a, 2b. Between the insertion portions 8, the disk substrate 2a,
2b and the flange portion 9, between the hubs 4 and the notch 13
The information recording medium 1 shown in FIG. 2 was obtained by forming and bonding them together.

The hub adhesion strength of the thus obtained information recording medium was determined by the above measuring method. The results are shown in Table 3.

Test Examples 2 to 3 Next, polycarbonate (manufactured by Ondai Kasei Co., Ltd., AD-5503, trademark) (Test Example 2) and polymethylpentene (Mitsui Petrochemical Industries, Ltd.) were used as the transparent resin substrates 1a and 1b.
Disc substrates 2a and 2b were prepared using TPX RT18 (registered trademark) manufactured by Co., Ltd. (Test Example 3), and the same information recording medium 1 as in Test Example 1 was obtained, and the hub adhesive strength was determined. The results are shown in Table 3.

Test Example 4 “Ethylene content measured by C-NMR: 59 mol%, 1
Intrinsic viscosity [η) measured in decalin at 35°C: 0.42
dU/g, TMA Copolymer (A) of ethylene and TCD at 154°C, and ethylene content 89 mol%, 13
Intrinsic viscosity measured in decalin at 5°C (η30,44dl
/g, TMA A copolymer (B) of ethylene and TCD at 39°C was synthesized.

As the transparent resin substrates 1a and 1b, a blend of the above copolymers (A) and CB) (in weight ratio (A)/(B) =
Information recording medium 1 was prepared in the same manner as Test Example 1 except that 100/1.2) was used, and the hub adhesive strength was determined. The results are shown in Table 3.

Table 3 From the above results, it can be seen that the difference in the hub adhesion strength of the examples of the present invention before and after the moisture resistance test is small, indicating a good value.

〔Effect of the invention〕

According to the present invention, a hub having an insertion portion, a notch, and a flange portion is mounted in the center hole of a disk substrate, and the flange of the hub is placed between the outer peripheral surface of the insertion portion of the hub and the inner peripheral surface of the center hole of the disk substrate Since an adhesive layer is formed between the hub and the disc substrate, within the notch, and between hubs, the simple bonding structure strengthens the bonded area on the inner circumference of the disk substrate, and also facilitates installation work and increases adhesive strength. There is an effect that a large b1 information recording medium can be obtained.

[Brief explanation of drawings]

1 and 2 are sectional views of different embodiments, and FIGS. 3(a) to 3(e) are sectional views of the hub. In each figure, the same reference numerals indicate the same or equivalent parts, 1 is an information recording medium, 2a, 2b are disk substrates, 3 is a center hole, 4 is a hub, 5 is an outer spacer, 6 is an inner spacer,
7.14 is the adhesive layer, 8 is the insertion part, 9 is the flange part, 1
0 is a hub body, and 13 is a notch. 73-

Claims (4)

[Claims] (1) A recording layer is formed on one side of at least one transparent resin substrate, and the two are bonded together with the recording layer inside.
A disc board, an insertion part that is inserted into the center hole of the disc board, and two hubs that have a flange part that covers the disc board near the center hole and are attached to the center hole from both sides. An information recording medium comprising: a notch formed on the outer periphery of a hub; and an adhesive layer formed within the notch, between the disk substrate and the hub, and between the two hubs. (2) The adhesive forming the adhesive layer is (A) an epoxy resin, (B) a compound selected from the group consisting of sulfonium salts and cyclopentadienyl iron compounds, (C) acrylates, methacrylates, and oligomers thereof. 2. The information recording medium according to claim 1, which comprises an active energy beam-curable composition containing a compound selected from the group consisting of: and (D) an organic peroxide. (3) The information recording medium according to claim 1 or 2, wherein the information recording medium is an optical information recording medium. (4) The transparent resin substrate and/or hub have an intrinsic viscosity [η] of 0.01 to 10 when measured in decalin at 135°C.
dl/g (a) A cyclic olefin random copolymer consisting of an ethylene component and a cyclic olefin component represented by the following general formula [1], or (b) a cyclic olefin represented by the following general formula [1] 4. The information recording medium according to claim 1, which is composed of a ring-opened polymer or a hydrogenated product thereof. ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・〔
1] (In the formula, R^1 to R^1^2 are hydrogen atoms, hydrocarbon groups, or halogen atoms, and may be the same or different, respectively. Also, R^9 and R^1^0, or R^1^
1 and R^1^2 may be combined to form a divalent hydrocarbon group, and R^9 or R^1^0 and R^1^1 or R^1^2 may form a ring with each other. may be formed. n is 0 or a positive integer, and when R^5 to R^8 are repeated multiple times, they may be the same or different. )