JPS59227045A - Information recording medium - Google Patents

Abstract

PURPOSE:To keep the advantage of a coating agent which is cured by activation energy rays, and to obtain a disk excellent in adhesiveness to metallic surfaces and substrates by coating the coating agent consisting essentially of an epoxy compd. and a photosensitive cationic polymerization catalyst on the surface of a substrate, and irradiating activation energy rays to form a protecting layer. CONSTITUTION:A coating agent consisting essentially of an epoxy compd. and a photosensitive cationic polymerization catalyst is a ring-opening photopolymerization type composition with good wettability to the surface to be coated, and the contraction while curing is small in comparison to (metha) acrylate ester. And the film with good adhesiveness can be obtained from the agent. In addition, the film also has excellent water resistance, hardness, and adhesiveness to printing ink in the aftertreatment. Aromatic, alicylic, and aliphatic epoxy compds. which are already known are used as the epoxy compd. which is selected from a monomer and/or a resin (prepolymer). A compd. for causing the cationic polymerization of the epoxy compd. by the irradiation of activation energy rays is used as the photosensitive cationic polymerization catalyst, and an onium salt of Lewis acid can be cited as an example.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information recording medium (hereinafter referred to as a disk) suitable for video discs, digital audio discs, etc., and in particular to an information recording medium (hereinafter referred to as a disc) suitable for video discs, digital audio discs, etc. The purpose of this invention is to protect the disk from dust and scratches by forming a hard transparent thin film on the surface of the disk in a so-called optical disk system.

Conventionally, recesses are formed using photoresist on a disk substrate made of methacrylic resin, vinyl chloride resin, polycarbonate resin, etc., and then a thin film of Bi (bismuth) or the like is formed on top of the recesses to convey information in the form of geometric changes. 2. Description of the Related Art A so-called optical optical disk system is known in which signals are recorded and read, copied, and erased using a laser beam. After that, metallization treatments such as aluminum vapor deposition began to be applied to the information surface of the disk as a treatment for reflecting laser light. The disc manufactured as described above can be played on only one side of the disc, but it is also known that it can be played on both sides, and after the metallization treatment described above, two discs with the information side inside Glue and paste.

When reproducing the entire disc, the laser beam normally enters the surface of the base material opposite to the information surface, is reflected by the information surface, undergoes modulation, and then exits again from the surface of the base material. At this time, if there are scratches or stains on the information side or the surface of the base material, which is the opposite side, the laser light will be scattered due to the scratches or stains, causing omissions and noise in the reproduced signal. It is also known to record information signals by forming a thin film of a low melting point metal such as Te (tellurium) or B1 on a base material and drilling a hole with a diameter of about 1 μm by irradiating the film with laser light. .

In the above-mentioned disk, there are disadvantages in that it is easily damaged compared to the base material of methacrylic resin, vinyl chloride resin, and polycarbonate resin (d), and it is easy to get dirty due to static electricity, etc. When metals come into direct contact with the air, they have the disadvantage of being oxidized by the effects of oxygen and moisture in the air, and their reflectance decreases. In order to improve these disadvantages, information and It has been proposed to provide a protective layer on the opposite surface of the base material.

Various methods have been proposed for this protective layer. For example, a method in which a thermoplastic resin is applied by spin coating to form a protective layer, a method in which a radiation (active energy ray) curable coating is completely applied, and a method in which a protective layer is formed by applying a thermoplastic resin using active energy rays is applied. A method of curing or a method of bonding a transparent film with an adhesive to form a protective layer are known. However, although a protective layer using a thermoplastic resin has good adhesion to a substrate or a metallized surface such as aluminum vapor deposition and moisture permeability, it has some problems in wear resistance. In the protective layer with radiation-curable coating (C),
Although surface J has excellent abrasion resistance and scratch resistance, adhesion to metal surfaces such as aluminum and metal surfaces is not necessarily good. Generally, (meth)acrylic prepolymers and/or monomers are used as radiation-curable coatings, but coatings based on prepolymers can be coated onto surfaces with minute irregularities to create a smooth film (protective coating). It is difficult to obtain a layer), and furthermore, the shrinkage during curing with active energy rays is large, and the adhesion to metal surfaces and substrates is poor. On the other hand, coating materials mainly composed of monomers may provide a smooth coating film, but have the drawbacks of greater shrinkage upon curing and poorer adhesion.

The present invention provides a disk that retains the advantages of active energy ray-curable coatings and has excellent adhesion to metal surfaces and substrates. That is, an information surface recording information signals in the form of geometric changes on the substrate and/or the surface of the substrate opposite to this information surface is coated with an epoxy compound and a photosensitive cationic polymer. This is an information recording medium that is coated with a catalyst-based coating and irradiated with active energy rays to form a weight layer.

The coating agent (4), which is based on the epoxy compound and the photosensitive cationic polymerization catalyst according to the present invention, is a polymerizable composition of Hikama J1, which has good wettability to the coated surface and shrinkage during curing (
Compared to meth)acrylic esters, it is possible to form a film with good adhesion. Furthermore, it has excellent water resistance, hardness, and adhesion to printing ink used in post-processing.

The epoxy compound according to the present invention is selected from conventionally known aromatic epoxy compounds, alicyclic epoxy compounds, aliphatic epoxy compounds, monomers, and/or resins (prepolymers). In addition, in order to fill in the fine parts of the information surface and generate a smooth surface, it is preferable to use monomer as the main component. The viscosity of the coating material is usually 500 mm or less, preferably 300 mm.
Less than a centiboise.

Examples of monomers include ethylene glycol diglycidyl ether, propylene diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane diglycidyl 7
/L,, trimethylolpropane triglycidyl ether, digly Shichikuchi-lutriglycidyl ether, nlubitol tetraglycidyl ether, alino L glycidyl ether, 2-ethylhexylglyphyl ether, phenylcriglycidyl ether, Vinyl cyclohexene dioxide, 3,4-epoxy/chlorohexylmethyl-3,
4-Epogine chlorohexane lupoxylate, bis(
3,4-Evoquinonecrohequinle) adipate, bis(
These include 3,4-epoxy-6-methyl-cyclohex/lmethyl)adipate, bisphenol-A-diglycidyl ether, cyclohexene oxide, and 2-phenylethylene oxide. Among them, 3,4-epoquinone chlorohexylmethyl-3,4-epoxyhexanecarboxylate is preferred, as it provides a film with excellent physical properties such as weather resistance, boiling water resistance, electrical insulation properties, etc., and a high hardness. It can be done.

As the epoxy resin, for example, grindyl ether, epoxy novola, resin, etc., which are obtained by reacting bisphenol A or its alkylene oxide adduct with epichlorohydrin, are used. It is preferable to use it in combination with the above monomer.

The photosensitive cationic polymerization catalyst is a compound that causes cationic polymerization of an epoxy compound by irradiation with active energy rays, and includes, for example, an onium salt of a Lewis acid. Diazonium salts, halonium salts or aromatic sulfonium salts of Lewis acids are used. Examples of these compounds include phenyl boron tetrafluoride.
Diazonium salt, diphenyliodonium salt of phosphorus hexafluoride, diphenyliodonium salt of antimony hexafluoride, tri-4-methylphenylsulfonium salt of arsenic hexafluoride, tri-4-methylphenylsulfonium salt of antimony tetrafluoride, Examples include a mixture of acetylacetone aluminum salt and orthonitrobenzylsilyl ether, phenylthiopyrylium salt, and the like.

The coloring agent according to the present invention can be either a one-component type or a two-component type, and is usually determined depending on the type of catalyst. Also,
As a coating material, leveling agent, silanka,
Additives such as blinog agents can also be blended. Furthermore, monomers and/or prepolymers other than epoxy compounds can be used in combination within a range that does not impair the effects of the present invention.

The active energy rays include ultraviolet rays emitted by mercury lamps, xenon lamps, tungsten lamps, etc., or electron beams. Sensitizers can also be used, especially when irradiating with ultraviolet light. Examples of sensitizers include:
These include benozophenone, parachlorpe7zophenono, paramethoquinobenzophenone, and the like. The component ratio of the coating agent is usually 100 parts by weight of epoxy/compound to 0.1 to 20 parts by weight of the photosensitive cationic polymerizable catalyst. Other sensitizers, additives, and monomers are usually used in amounts of 30 parts by weight or less.

The present invention will be explained in detail below.

In the examples, "parts" indicate parts by weight.

Example 1 A disk made of polycarbonate resin (thickness 2
Aluminum is evaporated to a thickness of 500A (angstroms) on the uneven surface of the groove to form the entire information surface, and phenylcrisyl ether (Bunacol EX-14) is applied to this information surface.
1. 20 parts of Nagashio Sangyo Co., Ltd.) and 20 parts of 3.4-epoxy/lylohegycylmethyl-3.4-ephoquine cyclohexane/late (Bakeley I-E RL-4221, manufactured by Union Carbide Co., Ltd.) 80 partially diallyliodonium salt type cationic polymerization type photoinitiation catalyst (FC-508,
4 parts of a mixture (coating agent, 138 Senochi Boise) (manufactured by Jusumuriem Co., Ltd.) was applied to a thickness of 5 μm by spin coating. After application, ozone-free ultraviolet lamp 80 W/c
Irradiation was performed once at a speed of 10 m and 7 minutes with an irradiation dose of rn.

The surface of the resulting formed layer has a pencil hardness of 3H, has excellent abrasion, adhesiveness (cross strength using cellophane tape, adhesive), chemical resistance, and solvent resistance, and has a surface resistance of -70°C. 95
No change in the surface was observed even after testing for 48 hours under conditions of humidity of It was similarly spread to a thickness of 5 μm by spin coating. Irradiation was also performed in the same manner as in Example 1.

1.6-hexanediol diacrylate
60 parts trimethylolpropane triacrylate
30 parts ethylene glycol diacrylate
10 parts benzene ethyl ether
The hardness of the 5-part pencil was 2H, but the cured film was peeled off using a cellophane tape, a fr cross force, and a tochistoist.

Example 2 The same coating material as in Example 1 was spin-coated to a thickness of 5 μm.
curtain beam type energy under nitrogen atmosphere.
Using an electron beam irradiation device made by Cy1fufu, 160Kv, 4
As a result of irradiation at a dose of 5 Mrad under mA conditions, a protective layer having excellent performance similar to that of Example 1 was obtained.

Example 3 The same information surface as in Example 1 was coated with a coating agent having the following composition to a thickness of 5 μm by spin coating.

Bunacol EX-14125 parts FC-5081 parts As a result of UV irradiation under the same conditions as in Example 1, an excellent protective layer was obtained.

Example 4 A coating material having the following composition was applied to the same information surface as in Example 1 to a thickness of 5 μm by spin coating.

Bunacol EX-14120 parts FC-5084 parts After irradiation with ultraviolet light twice under the same conditions as in Example 1, a protective layer with excellent properties was obtained.

patent applicant Toyo Ink Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. An information surface formed by recording information signals in the form of geometrical changes on a base material, and/or an epoxy compound and a photosensitive focused thionic polymer on the surface of the base material opposite to this information surface. 1. An information recording medium characterized by being coated with a coating material mainly containing a catalyst and irradiated with active energy rays to form a protective layer. 2. The information recording medium according to claim 1, wherein the epoxy compound is an epoxy monomer.