JP2002146331A - Adhesive composition, adherend, and method for producing optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition capable of retarding corrosion of an aluminum thin film, such as an aluminum vapor deposition layer, caused by decomposition compounds of a photo-induced cationic polymerization initiator even when a protective coat is not applied, and therefore capable of simplifying producing processes of an optical disk, such as a digital video disk, to provide an adherend, and to provide a method for producing the optical disk. SOLUTION: This adhesive composition contains (A) a cationically polymerizing compound, (B) the photo-induced cationic polymerization initiator, and (C) a corrosion inhibitor for the aluminum. The adherend and the method for producing the optical disk are each provided by using the adhesive composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc,
VD (digital versatile disk or digitalvideo d
Adhesive composition suitable for bonding on a thin film surface having a thin film such as an aluminum vapor-deposited film as in isc), and a method for manufacturing an adhesive body and an optical disk

[0002]

2. Description of the Related Art Conventionally, as an adhesive for an optical disk, particularly a DVD, a hot-melt adhesive, a photo-radical-curable adhesive, a photo-cation-curable adhesive, and the like have been studied.

[0003] The hot-melt type adhesive is a method in which a resin melted and liquefied by heat is applied to an aluminum vapor-deposited film on a DVD substrate, and the other DVD substrate is bonded and bonded before the resin solidifies. However, this method has a problem in that the DVD substrate warps or deforms due to heat, which adversely affects signal reading characteristics.

Further, in the case of a photo-radical curing type adhesive, there is a problem that radical curing significantly inhibits curing due to oxygen in the air. Therefore, after the adhesive is applied to an aluminum vapor-deposited film on a DVD substrate, another adhesive is applied. After bonding the DVD substrate, the substrate is irradiated with light and cured. However, in this method, photo-curing is performed through a material having extremely poor light transmittance, such as an aluminum vapor-deposited film. Further, since the curing shrinkage is as large as 5% or more, the DVD substrate may be warped or deformed.

In order to solve the above-mentioned problem, a cationic photocurable adhesive has been proposed (for example, Japanese Patent Laid-Open No. 9-6923).
No. 9). Photocationically curable adhesives do not heat during curing and do not cause curing inhibition by oxygen,
An adhesive is applied to the aluminum vapor-deposited film on the DVD substrate and irradiated with light.
When a substrate is pasted, it has the characteristic of proceeding to final curing by post-curing. In addition, photocationic curing has a small curing shrinkage ratio and a small amount of heat applied during curing, so that the substrate is hardly warped or deformed, and thus has a characteristic of extremely excellent signal reading characteristics from a disk. However, this method has a problem that when exposed for a long time under a high-temperature and high-humidity condition, an aluminum vapor-deposited film is corroded by a chlorine-based impurity derived from a cationic photopolymerization initiator, a decomposition product thereof, and an adhesive. In order to impart long-term durability to a DVD substrate, Japanese Patent Application Laid-Open No. 9-69239 proposes a method of providing a protective layer between an aluminum vapor-deposited film and a cured adhesive layer. However, in this method, the DVD is used only for the production of the protective layer.
There is a problem that the manufacturing process is lengthened and the cost is increased. Japanese Patent Application Laid-Open No. 9-249733 discloses an attempt to capture a corrosive component caused by a cationic photopolymerization initiator by adding an inorganic ion exchanger. However, in this method, since the adhesive becomes white and opaque due to the inorganic ion exchanger, there is a problem that the light transmittance is remarkably reduced and the curing of the adhesive layer is insufficient. Also, JP-A-11-3
In Japanese Patent No. 15132, an attempt is made to prevent corrosion of an aluminum vapor-deposited film as a reflective film by reducing the chlorine content of the glycidyl ether type epoxy resin used to 1% by mass or less. The suppression of corrosion by the decomposition products derived from the agent is not sufficient.

[0006]

According to the present invention, the corrosion of a thin film such as an aluminum vapor-deposited layer due to a decomposition product of a cationic photopolymerization initiator can be suppressed without a protective layer, and the manufacturing process of an optical disk such as a DVD can be simplified. , An adhesive composition, and a method for producing an adhesive body and an optical disk.

[0007]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that an adhesive composition which does not cause corrosion of a thin film such as an aluminum vapor-deposited film without a protective layer.
The present invention has succeeded in providing an adhesive, an adhesive method, and a method for manufacturing an optical disk. That is, the present invention provides the following (1) to
(20).

(1) An adhesive composition containing a cationically polymerizable compound (A), a cationic photopolymerization initiator (B) and an aluminum corrosion inhibitor (C). (2) the cationically polymerizable compound (A) is an epoxy compound,
The adhesive composition according to (1), which is at least one selected from a vinyl ether compound and an oxetane compound. (3) the cationically polymerizable compound (A) is an epoxy compound,
The adhesive composition according to (1), which is at least one selected from oxetane compounds. (4) The epoxy compound is an alicyclic epoxy compound or a novolak type epoxy resin (2).
Or the adhesive composition according to (3).

(5) The adhesive composition according to any one of (1) to (4), wherein the aluminum corrosion inhibitor contains at least one selected from polycarboxylic acids and hydroxycarboxylic acids. (6) The adhesive composition according to any one of (1) to (5), wherein the aluminum corrosion inhibitor (C) is a hydroxycarboxylic acid. (7) The adhesive composition according to any one of (1) to (6), wherein the aluminum corrosion inhibitor (C) is at least one selected from citric acid, tartaric acid, and maleic acid. (8) The addition amount of the aluminum corrosion inhibitor (C) is 0.0 to 100 parts by mass of the cationically polymerizable compound (A).
001 parts by mass to 1 part by mass (1)
The adhesive composition according to any one of (7) to (7).

(9) A compound (D) having at least two hydroxyl groups in the molecule (1).
The adhesive composition according to any one of (8) to (8). (10) The adhesive composition according to (9), wherein the compound (D) having at least two hydroxyl groups in a molecule is a polyether polyol compound and / or a polycaprolactone polyol compound. (11) The adhesive composition according to any one of (1) to (10), further comprising a lactone compound (E). (12) The adhesive composition according to (11), wherein the lactone compound (E) is ε-caprolactone and / or δ-valerolactone.

(13) The adhesive composition according to any one of (1) to (12), further comprising a filler (F). (14) An adhesive having a cured product layer of the adhesive composition according to any one of (1) to (13). (15) The adhesive according to (14), wherein the cured product layer of the adhesive composition according to any one of (1) to (13) is in contact with a thin film. (16) The adhesive according to (14) or (15), which is an optical disk.

(17) The optical disk is a DVD (1)
The adhesive according to 6). (18) At least one surface of the two adherends,
After applying the adhesive composition according to any one of (1) to (13), the applied surface is irradiated with light in such an amount that a cured film is not generated on the applied surface, and then the applied surfaces are applied to each other or to the applied surface. What is claimed is: 1. A method for manufacturing an adhesive body, comprising bonding another adhesive body to which an adhesive is not applied. (19) After applying the adhesive composition according to any one of (1) to (13) to at least one thin film of two optical disk substrates, an amount of light that does not generate a cured film on the application surface is applied to the application surface. Irradiating, and then bonding the coated surfaces or the coated surface and the other optical disk substrate not coated with the adhesive. (20) The method for manufacturing an optical disc according to (19), wherein the thin film is an aluminum vapor-deposited film.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below. The adhesive composition of the present invention is a composition mainly comprising a cationically polymerizable compound (A), a cationic photopolymerization initiator (B), and an aluminum corrosion inhibitor (C).

The cationically polymerizable compound (A) includes an epoxy compound, a vinyl ether compound and an oxetane compound.

The epoxy compound is a compound having an epoxy group in the molecule, and specific examples thereof include 1,2-epoxy-2-butyl-3-phenoxypropane, 1,2
-Epoxy-3-methyl-3-phenoxypropane,
1,3-bis (2,3-epoxypropoxy) benzene, 1,2-epoxy-3-phenoxypropane, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, phenol novolak epoxy resin, cresol novolak epoxy Resin, diglycidyl ether of hydrogenated bisphenol A, cyclohexane-1,4-dimethylol diglycidyl ether,
Butyl glucidyl ether, 1-allyloxy-2,3-
Epoxy propane, 1,4-butanediol diglycidyl ether, glycerin diglycidyl ether, propylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, 4-vinylcyclohexene monooxide, (3,4-epoxycyclohexyl) methyl-3, 4-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexyl)
Adipate, bis (2,3-epoxycyclopentyl)
Ether and bis (2,3-epoxy-6-methylcyclohexylmethyl) adipate.

Among these, preferred epoxy compounds are
In terms of being able to cure in a short time, 4-vinylcyclohexene monoxide, (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexyl)
Adipate, bis (2,3-epoxycyclopentyl)
It is an alicyclic epoxy resin such as ether or bis (2,3-epoxy-6-methylcyclohexylmethyl) adipate, and is a novolak type such as a phenol novolak type epoxy resin and a cresol novolak type epoxy resin in terms of high heat resistance. Epoxy resins are mentioned.

The oxetane compound is a compound having an oxetanyl group in the molecule, and specific examples thereof include 3-methyl-3-hydroxymethyloxetane,
1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene and the like.

The vinyl ether compound is a compound having a vinyl ether group in the molecule. Specific examples thereof include butyl vinyl ether, 2-ethylhexyl vinyl ether, triethylene glycol divinyl ether, divinyl ether of cyclohexanedimethanol,
Examples thereof include 4-hydroxybutyl vinyl ether, and polyurethane resins having a vinyl ether group at a terminal obtained by reacting a diisocyanate compound such as hexamethylene diisocyanate, tolylene diisocyanate, and isophorone diisocyanate with a diol compound and 4-hydroxybutyl vinyl ether.

These epoxy compounds, oxetane compounds and vinyl ether compounds can be used alone or in combination of two or more. Among the above cationically polymerizable compounds, an epoxy compound and / or an oxetane compound are preferable.

Examples of the cationic photopolymerization initiator (B) include compounds capable of generating a Bronsted acid or a Lewis acid upon irradiation with light, such as aromatic iodonium salts and aromatic sulfonium salts. .

Specific examples of the aromatic iodonium salt include:
Diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium triflate, di (4-tert-butylphenyl) iodonium hexafluorophosphate, di (4-nonylphenyl) iodonium Hexafluorophosphate and the like can be mentioned.

Specific examples of the aromatic sulfonium salt include:
Triphenylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, 4,4′-bis (diphenylsulfonio) diphenylsulfide bishexafluorophosphate, 4,4′-bis [Di (β-hydroxyethoxy) phenylsulfonio] diphenylsulfide bishexafluorophosphate, 4,4′-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenylsulfidebishexafluoroantimonate,
7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluoroantimonate, 7
-[Di (p-toluyl) sulfonio] -2-isopropylthioxanthonetetrakis (pentafluorophenyl) borate, 4-phenylcarbonyl-4'-diphenylsulfonio-diphenylsulfidehexafluorophosphate, 4- (p-tert-butylphenyl) Carbonyl) -4′-diphenylsulfoniodiphenylsulfide hexafluoroantimonate, 4- (p-
tert-butylphenylcarbonyl) -4′-diphenylsulfonio-diphenylsulfide hexafluorophosphate, 4- (p-tert-butylphenylcarbonyl) -4′-di (p-toluyl) sulfonio-diphenylsulfidetetrakis (pentafluorophenyl ) Borate and the like. These cationic photopolymerization initiators may be used alone or in combination of two or more.

In the present invention, an aluminum corrosion inhibitor (C) for preventing corrosion of a thin film such as an aluminum vapor deposition film by a decomposition product of a cationic photopolymerization initiator is used. Such a compound is not particularly limited as long as it has an aluminum corrosion preventing ability. For example, a functional group capable of forming a coordination bond or an ionic bond by an acid-base interaction with aluminum is contained in one molecule. Those having two or more and capable of forming a chelate compound with aluminum are exemplified as desirable ones. Examples of such an aluminum corrosion inhibitor include a polycarboxylic acid having two or more carboxylic acid groups in one molecule, and a hydroxycarboxylic acid having one or more hydroxyl and carboxylic acid groups in one molecule. And hydroxycarboxylic acids are particularly preferred as the aluminum corrosion inhibitor of the present invention.

Specific examples of the polycarboxylic acid include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid,
1,10-dodecanedicarboxylic acid, maleic acid, itaconic acid, citraconic acid, 3,3′-thiodipropionic acid,
Alicyclic polycarboxylic acids such as 1,2-cyclohexanediaminetetraacetic acid, endomethylenetetrahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, 1,4-naphthalenedicarboxylic acid, , 6-Naphthalenedicarboxylic acid, 3,3 ', 4
Aromatic polycarboxylic acids such as 4′-benzophenonetetracarboxylic acid and the like can be mentioned.

Specific examples of the hydroxycarboxylic acid include citric acid, isocitric acid, tartaric acid, malic acid, lactic acid, 2-methyllactic acid, hydroxypyruvic acid, dimethylolbutanoic acid, dimethylolpropionic acid, α-hydroxyisobutyric acid. Α, α-diphenylglycolic acid, mandelic acid, gallic acid, 6-hydroxy-2-naphthoic acid,
Examples thereof include p-hydroxybenzoic acid, 5-hydroxyisophthalic acid, p-hydroxyphenylacetic acid, p-hydroxyphenylpropionic acid, citrazic acid, and chelidamic acid.

These aluminum corrosion inhibitors can be used alone or in combination of two or more.
Preferred aluminum corrosion inhibitors are those that readily form aluminum chelates, specifically citric acid, tartaric acid, and maleic acid.

(A) Constituting the Adhesive Composition of the Present Invention
The use ratio of (C) is as follows. (B) is (A) 1
(B) 0.01 to 5 parts by mass with respect to 00 parts by mass,
Preferably it is 0.05 to 3 parts by mass. If the amount is less than 0.01 parts by mass, the curing does not proceed completely, and the final physical properties as an adhesive become insufficient. If the amount is more than 5 parts by mass, the curing proceeds too much at the time of light irradiation, and the tackiness is lost. There is a possibility that the bonding may not be performed sufficiently.

The content of (C) is 0.1 to 100 parts by mass of (A).
0001 parts by mass to 1 part by mass, preferably 0.0005 parts by mass to 0.1 parts by mass, particularly preferably 0.001 parts by mass to 0.05 parts by mass. When the amount is less than 0.0001 part by mass, the effect of preventing corrosion of a thin film such as an aluminum vapor-deposited film is insufficient. When the amount is more than 1 part by mass, the adhesive has a large hygroscopic property. Easily, and the adhesion is reduced. Further, the storage stability of the adhesive composition may be deteriorated.

The adhesive composition of the present invention may contain a compound (D) having at least two hydroxyl groups in a molecule, a lactone compound (E) and / or a filler (F). Among these, the compound (D) and / or the lactone compound (E) having at least two hydroxyl groups in the molecule are mainly used for adjusting the curing speed and increasing the adhesive force, or increasing the flexibility of the cured film. (Improved impact resistance). The filler (F) is mainly used for imparting or improving thixotropic properties.

The compound (D) having at least two hydroxyl groups in the molecule is preferably a compound having no acidic group other than a phenolic hydroxyl group. 20 or less polyol compounds (D1), polyether polyol compounds (D2), polyester polyol compounds (D
3) and polycaprolactone polyol compound (D4)
And the like. By using a compound (D) having at least two hydroxyl groups in these molecules, the formation of a cured film on the surface of the coating film after light irradiation can be strongly suppressed, and the adhesion of the surface is not hindered. It is possible to obtain an adhesive in which the bonding surface does not become uneven. Further, a higher impact resistance can be imparted to an adhesive using the adhesive of the present invention.

Polyol compound having no functional group other than alcoholic hydroxyl group and having 20 or less carbon atoms (D1)
Specific examples of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, tripropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,9-nonanediol, Neopentyl glycol, cyclohexanedimethanol, trimethylolethane, trimethylolpropane, glycerin, 3-cyclohexene-1,1-dimethanol, 6-methyl-3-cyclohexene-1,1-dimethanol and the like can be mentioned.

Specific examples of the polyether polyol compound (D2) include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolpropane polyethoxytriol, bisphenol A polyethoxydiol, and bisphenol F polyethoxydiol.

Specific examples of the polyester polyol compound (D3) include a polyol compound having no functional group other than an alcoholic hydroxyl group and having 20 or less carbon atoms (D3).
1) or polyether polyol (D2) and polybasic acid (for example, maleic acid, fumaric acid, succinic acid, adipic acid, terephthalic acid, isophthalic acid, hydrogenated dimer acid, etc.)
Or a reaction product such as an anhydride thereof.

Polycaprolactone polyol compound (D
4) is a compound containing a unit derived from caprolactone, and specific examples thereof include a reaction between a polyol compound (D1) having no functional group other than an alcoholic hydroxyl group and having 20 or less carbon atoms and ε-caprolactone. , Or a reaction product of a polyol compound (D1) having no more than 20 carbon atoms having no functional group other than an alcoholic hydroxyl group with the polybasic acid or anhydride and ε-caprolactone, polyether polyol, polyester polyol And ε-caprolactone.

Among these compounds (D), more preferred compounds include polyethers which are more excellent in stability over time (pot life) of the adhesive composition and durability of the cured adhesive under high temperature and high humidity. A polyol compound (D2) and a polycaprolactone polyol compound (D4).

Examples of the lactone compound (E) include ε
-Caprolactone, γ-butyrolactone, δ-valerolactone and the like. Of these, ε
-Caprolactone and δ-valerolactone are preferred.

Examples of the filler (F) include silica, titanium oxide, alumina, barium sulfate, kaolin, talc, clay, calcium carbonate, bentonite, glass fiber, carbon fiber, mica, and organic filler (eg, resin beads). Known and commonly used fillers.

In the adhesive composition of the present invention, (D)
The proportions of the components (E) and (F) are as described in the above (A) to (A).
Component (D) with respect to 100 parts by mass of the total amount of component (C),
The component (E) is used in an amount of 0 to 60 parts by mass, preferably 0 to 60 parts by mass.
To 50 parts by mass, and the component (F) is used in an amount of 0 to 60 parts by mass, preferably 0 to 100 parts by mass, based on 100 parts by mass of the components (A) to (E).
40 parts by mass.

The adhesive composition of the present invention may further comprise, if necessary, a (meth) acrylate compound such as an epoxy (meth) acrylate, urethane (meth) acrylate, (meth) acrylate monomer, an ultraviolet absorber, and an antioxidant. , A leveling agent, an antifoaming agent and the like can be used in combination.

The method of mixing the adhesive composition of the present invention is not particularly limited, and is prepared by dissolving, mixing, or dispersing the components (A) to (F) and other components. can do.

The adhesive of the present invention is obtained by bonding two adherends via a cured product layer of the above-mentioned adhesive composition.
The thickness of the cured product layer is preferably about 5 μm to 100 μm. There is no particular limitation on the adherend, but 500 nm
Substrates that do not transmit the following ultraviolet light and visible light are preferable. In particular, the adhesive composition of the present invention is effective even in a wavelength range of 280 nm to 380 nm where a normal photopolymerization initiator cannot be exposed to light to generate cations or radicals, and its function can be fully utilized. An example of such an adherend is an optical disc substrate in which a recording layer made of a thin film such as a sputtered film of a metal such as aluminum is provided on a polycarbonate base material. The two adherends may be the same or different.

An adhesive having a cured layer made of the adhesive composition of the present invention in contact with a thin film can suppress the corrosion of the thin film even without a protective layer of the thin film, and has excellent signal reading characteristics for a long period of time. Aluminum, gold, silver,
Metals such as copper, platinum, cobalt, tin, nickel and the like can be mentioned, and among these metals, aluminum is preferable because the effect of the adhesive composition of the present invention can be best enjoyed. These can be used alone or as alloys.
Of course, it is not limited to these metals, and it is also possible to use an organic high-reflection film. The method for forming the thin film is not particularly limited, and examples thereof include a sputtering method and a vacuum evaporation method. Also, the thickness of the thin film is not particularly limited, and examples thereof include a thin film having a thickness of 20 nm to 200 nm.

To bond two adherends, for example, the following method may be used. That is, the adhesive composition of the present invention is applied to a surface having a thin film of each or any one of two same or different adherends by a spin coater, a screen printer, or the like, to a thickness of 5 μm to 100 μm, preferably 5 μm to 50 μm, more preferably 5 μm to 30 μm
m and irradiate light to such an extent that the adhesive remains tacky. The amount of energy of the irradiation light depends on the amount of the cationic photopolymerization initiator added, but is 50 J / cm2 to 20 J / cm2.
00 mJ / cm2, preferably 100 J / cm2 to 10
00 mJ / cm2, more preferably 200 J / cm2
700 mJ / cm2. When light exceeding 2000 mJ / cm2 is irradiated, the adhesiveness of the adhesive layer is lost, so that another substrate cannot be attached. On the other hand, if the light irradiation amount is less than 50 mJ / cm 2, the curing does not proceed, and the curing of the adhesive layer may be insufficient. The measurement of the amount of energy of light can be performed, for example, using an integrated light meter UIT-
102 (the receiver is UVD-365PD).

After the light irradiation, the light-irradiated surfaces on the two substrates, or one coated surface and the other uncoated surface are brought into close contact with each other, for example, at room temperature (about 20 ° C.) or heated (2 ° C.).
(0 to 50 ° C.) for about 0.5 to 48 hours. Adhesion is possible even if the standing time is 0.5 hour or less.

The optical disk of the present invention is obtained by bonding a substrate for an optical disk to another substrate via a cured layer of the adhesive composition. The thickness of the cured product layer is, for example, 5
１００100 μm is preferred. As an optical disc substrate,
For example, a recording layer made of a vapor-deposited film of a metal such as aluminum is provided on a polycarbonate substrate.
It does not transmit light of up to 380 nm. As another substrate, for example, a substrate for an optical disk can be mentioned. As the optical disk of the present invention, MO (magneto-optical disk), DV
D and the like. Of these, the double-sided reading M
O and DVD and single-sided dual-layer read-type DVDs need to adhere opaque to each other, and are therefore preferable in that the performance of the adhesive composition of the present invention is sufficiently utilized.

To manufacture the optical disk of the present invention, for example, the following method may be used. That is, the adhesive composition is applied to a recording layer of an opaque optical disk having a recording layer formed of a metal vapor-deposited film of aluminum or the like by a spin coater, a screen printer, or the like so as to have a thickness of 5 μm to 100 μm. , 50 mJ / cm2 to 2000 mJ / cm
2, preferably 100 mJ / cm2 to 1000 mJ / c
m2, more preferably 200 mJ / cm2 to 700 mJ
/ Cm 2 to impart tackiness to the adhesive layer. Then, the coated surfaces are bonded to each other, or the coated surface and the other uncoated substrate are bonded, for example, at a normal temperature (about 20 ° C.) or a heated state (about 20 to 50 ° C.). The adhesive hardens within ~ 48 hours, and the optical disk of the present invention can be obtained. When the curing speed of the adhesive composition is high, bonding is possible even when the standing time is 0.5 hour or less.

[0047]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the examples.

Preparation of test pieces (Examples 1 to 3, Comparative Example 1,
2) The adhesive composition of the present invention was prepared according to the composition shown in Table 1. The prepared adhesive composition was coated on a recording layer of an optical disk substrate having an aluminum deposited layer as a recording layer by a bar coater # 16 so as to have a thickness of about 20 μm,
The coated surface was irradiated with ultraviolet rays at 300 mJ / cm2. At this time, a metal halide lamp UVL-6000M2-N1 manufactured by Ushio Inc. was used as a light source for irradiating ultraviolet rays.
The total amount of UV light is integrated by Ushio Inc.
102 (receiver UVD-365PD) was used. Next, the coated surfaces were stuck together and left at about 40 ° C. for 40 hours to obtain a test piece (optical disk). The evaluation was performed according to the following method. Table 1 shows the results.

Curability The substrate on which the test piece was bonded was peeled off, and the state of the surface was observed. ：: No tack was observed. Δ: Tack is slightly observed. ×: Not cured at all.

The state of corrosion of the aluminum-deposited surface The test piece was left for one week at 80 ° C. and 90% RH, and then visually observed. ：: No corrosion was observed on the aluminum deposited film ×: A hole was formed in the aluminum deposited film due to corrosion

[0051]

[Table 1]

The adhesive composition of the present invention is an ultraviolet-curable adhesive, a cationic slow-acting adhesive that gradually cures after irradiation with ultraviolet light, and is a cationic-curable adhesive. Nevertheless, since the thin film such as an aluminum vapor-deposited film does not corrode, the use of the adhesive composition of the present invention makes it possible to produce an optical disk, particularly a DVD, without a protective layer of a thin film such as an aluminum vapor-deposited film. . DVD
This makes it possible to simplify the manufacturing process, which is useful.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 171/00 C09J 171/00 G11B 7/24 538 G11B 7/24 538G 541 541K 541G 7/26 531 7 / 26 531 F-term (reference) 4J040 EC071 EC261 EE002 EE031 FA011 GA05 HA026 HA136 HA196 HA256 HA306 HA346 HA356 HB11 HB26 HB28 HB29 HB45 KA03 KA04 KA11 KA29 KA42 LA07 MA10 MB03 NA17 NA21 PA32 5D029 MA18 RA27FF27 RA18A27FF

Claims (20)

[Claims] 1. A cationic polymerizable compound (A), a cationic photopolymerization initiator (B) and an aluminum corrosion inhibitor (C).
An adhesive composition containing: 2. The adhesive composition according to claim 1, wherein the cationically polymerizable compound (A) is at least one selected from an epoxy compound, a vinyl ether compound and an oxetane compound. 3. The adhesive composition according to claim 1, wherein the cationically polymerizable compound (A) is at least one selected from an epoxy compound and an oxetane compound. 4. The adhesive composition according to claim 2, wherein the epoxy compound is an alicyclic epoxy compound or a novolak type epoxy resin. 5. The adhesive composition according to claim 1, wherein the aluminum corrosion inhibitor (C) contains at least one selected from polycarboxylic acids and hydroxycarboxylic acids. object. 6. The adhesive composition according to claim 1, wherein the aluminum corrosion inhibitor (C) is a hydroxycarboxylic acid. 7. The adhesive composition according to claim 1, wherein the aluminum corrosion inhibitor (C) is at least one selected from citric acid, tartaric acid and maleic acid. . 8. The method according to claim 1, wherein the amount of the aluminum corrosion inhibitor (C) is 0.0001 to 1 part by mass based on 100 parts by mass of the cationically polymerizable compound (A). The adhesive composition according to claim 7. 9. The adhesive composition according to claim 1, further comprising a compound (D) having at least two hydroxyl groups in a molecule. 10. The adhesive composition according to claim 9, wherein the compound (D) having at least two hydroxyl groups in the molecule is a polyether polyol compound and / or a polycaprolactone polyol compound. 11. The adhesive composition according to claim 1, further comprising a lactone compound (E). 12. The adhesive composition according to claim 11, wherein the lactone compound (E) is ε-caprolactone and / or δ-valerolactone. 13. The adhesive composition according to claim 1, further comprising a filler (F). 14. An adhesive having a cured product layer of the adhesive composition according to claim 1. 15. The adhesive according to claim 14, wherein the cured product layer of the adhesive composition according to claim 1 is in contact with a thin film. 16. The adhesive according to claim 14, which is an optical disk. 17. The adhesive according to claim 16, wherein the optical disk is a DVD. 18. After applying the adhesive composition according to any one of claims 1 to 13 to at least one surface of two adherends, an amount of light that does not generate a cured film on the application surface is applied. A method for manufacturing an adhesive body, which comprises irradiating the application surfaces and then bonding the application surfaces to each other or the application surface and the other object to which the adhesive is not applied. 19. After applying the adhesive composition according to any one of claims 1 to 13 to at least one thin film of two optical disk substrates, apply an amount of light that does not generate a cured film on the application surface. A method of manufacturing an optical disk, comprising irradiating the surfaces with each other, and then bonding the coated surfaces or the coated surface and another optical disk substrate not coated with an adhesive. 20. The method according to claim 19, wherein the thin film is a vapor-deposited aluminum film.