JPH0449544A - Magneto-optical disk - Google Patents

Abstract

PURPOSE:To improve workability and productivity and to assure high reliability and high strength of adhesion by using a reactive two-part type adhesive for sticking of a pair of substrate to each other. CONSTITUTION:A pair of the substrate 1, 1 consisting of glass, etc., are stuck to each other via the reactive two-part type adhesive 2 having a curing function by a radical reaction and the curing function by photoirradiation. The liquid A of the adhesive is prepd. by using a monomer and oligomer, such as methacrylate, as its essential component and adding a soluble polymer or plasticizer, etc., to prepare the uniform soln. and adding an org. peroxide thereto and the liquid B is prepd. by further adding a curing accelerator to the soln. A photosensitizer is added to either of the liquid A or the liquid B or both thereof and the liquid A and the liquid B are mixed. The mixture is applied on the sticking surfaces and the substrate are stuck to each other. The time is extremely shortened and the substrates are securely joined.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a close bonding type that is constructed by bonding a pair of substrates and is used as a video disc, digital audio disc, or document or data file disc. Regarding magneto-optical disks, in particular, by using a specific adhesive during the above-mentioned bonding, this part is irradiated with light such as ultraviolet rays and rapidly cured, first temporarily fixing the bonded surface, and then the next The material is made to be able to move during the work process, and then completely cured by a radical reaction between the two components.As a result, the bonding time is extremely shortened, the bond is strong, and processes such as heating are not required. The present invention relates to a magneto-optical disk that can be used at low temperatures without the need for information storage, does not erode the information recording layer, and has high reliability.

[Conventional technology]

This type of magneto-optical disk is usually constructed by bonding a pair of substrates together, and an information recording layer is provided on one or both of these bonded surfaces.

Conventionally, various adhesives such as epoxy adhesives, urethane adhesives, ultraviolet curing adhesives, and hot melt adhesives have been used for this bonding.

[Problem that the invention seeks to solve]

However, epoxy adhesives and urethane adhesives have slow curing speeds, which poses productivity problems, and UV-curable adhesives have the risk of the monomer components contained therein corroding the substrate and information recording layer. Furthermore, hot melt adhesives have a problem of low heat resistance and poor adhesive strength.

Especially in recent years, 80℃/85R)1 specified in the ISO standard
Magneto-optical disks are now required to have a durability of 2,000 hours in terms of 2000 hours, and current hot melts cannot meet this requirement.

Therefore, the purpose of the present invention is to use a specific adhesive, irradiate this area with light such as ultraviolet rays, and rapidly harden it, first temporarily fixing the bonded surface, and then use it for the next work. A state in which it can be transferred during the process is achieved, and then the two components are completely cured by a radical reaction. As a result, the bonding time is extremely shortened, the bonding becomes strong, and processes such as heating are not required. It is an object of the present invention to provide a closely bonded magneto-optical disk which can be used at low temperatures without corrosion, does not erode the information recording layer, can ensure high reliability, and has improved the drawbacks of the above-mentioned known techniques.

[Means for solving problems]

In order to achieve the above-mentioned object, according to the present invention, in a magneto-optical disk configured by bonding a pair of substrates together and having an information recording layer on at least one of the bonded surfaces, upon bonding, It is characterized by using a reactive two-component adhesive that polymerizes and cures by a radical reaction, consisting of a liquid A containing an organic peroxide and a liquid B containing a curing accelerator, and which is composed of a liquid A containing an organic peroxide and a liquid B containing a curing accelerator. One or both of them contains a photosensitizer, these A1B solutions are superimposed or mixed and applied to one or both of the bonded surfaces, and then this applied area is irradiated with light. It is characterized by a fixed bond.

Hereinafter, the present invention will be explained in detail using the accompanying drawings.

FIG. 1 is an exploded view of a magneto-optical disk according to the present invention, which includes a pair of substrates l, made of plastic, glass, etc.
1 are bonded together via a reactive two-component adhesive 2 that has both a radical reaction-based curing function and a light irradiation-based curing function. A is a pair of substrates 1.1
1 is an external perspective view of a magneto-optical disk according to the present invention constructed by bonding together.

In the reactive two-component adhesive used in the present invention, component A is mainly composed of monomers and oligomers such as methacrylic acid esters, to which a soluble polymer or plasticizer is added as necessary. A homogeneous solution is prepared by adding 0.1 to 10 parts by weight of an organic peroxide to 100 parts by weight of this solution. Specific examples of such organic peroxides include benzoyl peroxide, di-t-butyl peroxyphthalate, methyl ethyl ketone peroxide, t-butyl hydroperoxide, and cumene hydroperoxide.

Liquid B is mainly composed of monomers and oligomers such as methacrylic acid ester, and if necessary, soluble polymers or plasticizers are added thereto to make a homogeneous solution, and then 100 parts by weight of this solution is added. It is made by adding 0.1 to 5 parts by weight of a curing accelerator.

In the above description, the curing accelerator promotes polymerization and curing of liquid A, and is composed of a liquid mixture of iron salt and linear polyamines. The molar ratio of the iron salt to the linear polyamine is 1:5 to 1:400.

If the ratio of linear polyamines is less than 5, the adhesive strength will be reduced, and if it is more than 400, the curing time will be longer, which is unsuitable.

Examples of the iron salt include inorganic or organic iron salts, such as anhydrous ferric chloride, ferric nitrate, and iron lactate.

Linear polyamines are compounds having the general formula (wherein R+, R2, Ra, and R4 are each hydrogen or an alkyl group having 1 to 8 carbon atoms, and n is an integer of 1 to 5), Specifically, they include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexane.

The aforementioned curing accelerator may also be a liquid mixture of an iron salt and a cyclic polyamine. In this case, the molar ratio of the iron salt to the cyclic polyamine is 1:1 to 1:200.

If the ratio of the cyclic polyamines is less than 1, the adhesive strength will be reduced, and if it is more than 200, the curing time will be longer, which is unsuitable.

As mentioned above, examples of the iron salt include inorganic or organic iron salts, such as anhydrous ferric chloride, ferric nitrate, and iron lactate.

Cyclic polyamines have the general formula (where ml and m2 are each an integer of 2 to 8, nl and n are each an integer of 0 to 6, and n+
+na is 3 or more, and X is 1 or 2. ), specifically, 1.4,7.10-tetraazacyclododecane, 1°5.9.13-tetraazacyclohexadecane, 1°4.8.11-tetraazacyclotetradecane, 1゜4, 7.10.13.16-
Hexaazacyclooctazocane, 1,4,8,12-tetraazacyclopentadecane, and the like.

Further, as the above-mentioned curing accelerator, a substance that forms a redox system with an organic peroxide (redox system accelerator) can also be used. Such redox promoters include, for example, N,N' dimethylaniline, N,N' dimethyltoluidine, tertiary amines such as triethylamine, condensates of aldehydes and amines, cobalt naphthenate,
Metal soaps such as iron propionate, organometallic complexes,
Examples include thiourea or its derivatives.

In addition, the monomers used in the above-mentioned liquids A and B are as follows:
It is a reactive monomer, and as the reactive monomers, acrylic acid ester monomers and methacrylic acid ester monomers such as methyl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropimetal acrylate are used.

As the reactive oligomer, acrylic or methacrylic oligomers such as polyether polyol acrylate, polyether polyol acrylate, and oligoester acrylate are used.Similarly, as the soluble polymers used in liquids A and B, , acrylic elastomer, synthetic rubber such as SBR, NBR, and synthetic resin such as ABS, vinyl chloride, PMMA, alkyd resin, etc.

In the present invention, one or both of the above-mentioned liquids A and B contains a photosensitizer at 0% per 100 parts by weight of liquid A or B.
．． It is characterized by adding 5 to 5 parts by weight. Examples of the photosensitizer include carbonyl compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin octyl ether, α-methylbenzoin, α-phenylbenzoin, acetophenone, and benzophenone; Sulfur compounds such as diphenyl sulfide, diphenyl disulfide, dithiocarbamates,
Examples include azo compounds such as azobisisobutyronitrile and hydrazone, other metal carbonyls, and pigments.

In the present invention, the above-mentioned liquids A and B are applied to the bonding surfaces in an overlapping manner or in a mixed manner, and then the coated areas are irradiated with light to firmly bond and bond the magneto-optical disks.

To describe the above-mentioned bonding more specifically, first, the A liquid and the B liquid are mixed with an applicator, and then applied to the bonding surface and bonded or bonded. At this point, the organic peroxide in Solution A is decomposed by the reaction accelerator in Solution B, and polymerization proceeds by a normal radical reaction. If the exposed part (surface) of the adhesive is irradiated with light while it is still flowing during curing, a radical reaction due to the light will also proceed at the same time in the exposed part, and in particular, the energy of the light irradiation will be reduced. By adjusting the amount, it is possible to harden the area in seconds.
In other words, it is possible to achieve a temporarily fixed state in an extremely short time. Furthermore, as described above, the radical polymerization by the polymerization initiator is also completed, and complete curing and adhesion are achieved.

Liquid A and liquid B do not necessarily need to be mixed and discharged.
Exactly the same effect can be obtained even when the A liquid and the B liquid are overcoated.

Note that the light to be irradiated in the present invention can be, for example, light from a light source, and specifically, a mercury lamp, a xenon lamp, a chemical lamp, a metal halide lamp, or the like is used.

In the present invention, the adhesive used has both a radical reaction-based curing function and a light irradiation-based curing function, so the time required for bonding work is extremely shortened, and each member can be cured easily. The bond is strong.

FIGS. 2 and 3 are cross-sectional views showing the structure of a magneto-optical disk according to the present invention, respectively. Figures 2 and 3
As shown in the figure, a magneto-optical disk A according to the present invention
has an information recording layer 3 on at least one surface, preferably both surfaces, of the bonded surfaces 1a and 1a of a pair of substrates 1.1, and after covering this information recording layer 3 with a protective film 4, this protective layer 3 is formed. A reactive two-component adhesive 2 is interposed on the film 4, and the substrate 1.
1 by pasting them together.

The reactive two-component adhesive 2 may be applied to both bonding surfaces 1a (actually, the upper surface of the protective film 4) of the substrate C1 as shown in FIG. It may be applied to either one side (single side) as shown in .

[Effect]

In the present invention described above, a pair of substrates are bonded together using a reactive two-component adhesive, so due to the characteristics of this reactive two-component adhesive, this area can be irradiated with light such as ultraviolet rays to rapidly cure. At the very least, the bonded surfaces are first temporarily fixed, thereby creating a state in which they can be moved to the next work process, and then completely cured by a radical reaction between the two components.As a result,
The bonding time is extremely shortened, the bond is strong, and it can be used at low temperatures without the need for heating or other processes. Furthermore, the information recording layer does not erode, ensuring high reliability. . Furthermore, heat resistance and high adhesive strength can also be ensured. In other words, the substrate is temporarily fixed in a few seconds by light irradiation with sufficient initial adhesive force to prevent positional displacement, and then the adhesive is completely cured by a radical reaction between the two components, and finally has a heat resistance of 160°C or higher. It exhibits excellent properties and sufficient strength when heated.

〔Effect of the invention〕

As described above, since the present invention uses a reactive two-component adhesive to bond a pair of substrates together, it not only improves workability and productivity, but also ensures high reliability. This is a practically useful invention as it is excellent in adhesive properties and can ensure high adhesive strength.

[Brief explanation of drawings]

FIG. 1 shows an exploded view of a magneto-optical disk according to the invention, and FIGS. 2 and 3 each show a sectional view of the magneto-optical disk according to the invention. 1... Substrate, 1a... Bonding surface, 2...
Reactive two-component adhesive, 3... Information recording layer, 4... Protective film, A... Magneto-optical disk.

Claims (3)

[Claims] (1) In a magneto-optical disk constructed by bonding a pair of substrates and having an information recording layer provided on at least one of the bonded surfaces, during the bonding, a liquid A containing an organic peroxide and a curing It is characterized by using a reactive two-component adhesive that polymerizes and cures by a radical reaction, consisting of a B solution containing an accelerator, and a photosensitizer in either or both of the A solution and B solution. Contains,
A close bonding type characterized in that these A and B liquids are layered or mixed and applied to one or both of the bonded surfaces, and then the coated area is irradiated with light to firmly bond. magneto-optical disk. (2) In the magneto-optical disk according to claim 1,
The curing accelerator contains iron salt and linear polyamine in a molar ratio of 1.
:5 to 1:400, and the linear polyamine is a compound having the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1, R_2, R_3, and R_4 are each hydrogen or an alkyl group having 1 to 8 carbon atoms, and n is an integer of 1 to 5. (3) In the magneto-optical disk according to claim 1,
The curing accelerator is iron salt and cyclic polyamine in a molar ratio of 1:1.
An assembly method in which the cyclic polyamine is a compound having the following general formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, m_1 and m_2 are each an integer from 2 to 8, n_1 and n_2 are each an integer from 0 to 6, and n_1+n_2 is 3 or more, and X is 1 or It is 2.