JP3102078B2 - Information recording medium element having moisture-proof layer, film for forming moisture-proof layer, coating agent, and spray - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium element having a moisture-proof layer and a spray for forming the moisture-proof layer, and more particularly to an information recording medium element having a moisture-proof layer made of a thermoplastic saturated norbornene-based resin, and the formation of the moisture-proof layer. The present invention relates to a film for film, a coating agent, and a spray.

[0002]

2. Description of the Related Art An information recording medium element includes an optical recording medium disk, an optical recording medium card, and the like. The information recording medium element comprises an information recording medium element substrate and a reflective film, and the information recording medium element substrate and a magnetic film. And the like. In those having a reflective film, information is recorded as unevenness of the reflective film, and the information is read from the reflected light by irradiating a laser.
Information that has a magnetic film is written using the magnetic recording method or magneto-optical recording method, that is, the direction of magnetism is reversed when the temperature of one point of the magnetic film is instantaneously raised by laser irradiation. There is a method of irradiating a weak laser and detecting a portion where the magnetism is inverted from a change in the vibration surface of the reflected light, and reading the information. In addition, there is an electrostatic capacitance type and the like.

Acrylic resins and polycarbonate resins including polymethyl methacrylate have been mainly used as substrates for information recording medium elements. Acrylic resin is inferior in heat resistance and moisture resistance. Polycarbonate resin has excellent heat resistance and moisture resistance, but has insufficient moisture resistance as a substrate of an information recording medium element, and transmits a small amount of moisture. Deterioration or deformation due to moisture absorption may occur. For example, a vapor deposition film of aluminum is usually used as a reflection film, but even in a normal use environment, it is gradually oxidized to aluminum oxide, so that it becomes transparent, and sometimes recorded information cannot be read.

[0004] In addition, in the case of long-term storage or the like, if the amount of water absorption differs between both surfaces, warpage may occur and information may not be read.

[0005]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies with the aim of extending the life of recorded information in an information recording medium element. As a result, the information recording medium element has a moisture-proof layer made of a thermoplastic saturated norbornene resin. It has been found that the above object can be achieved by providing.

[0006]

According to the present invention, there is provided an information recording medium element having a moisture-proof layer made of a thermoplastic saturated norbornene-based resin, a film for forming the moisture-proof layer, a coating agent, and a spray.

(Thermoplastic Saturated Norbornene Resin) As the thermoplastic saturated norbornene resin used in the present invention, for example, (1) a hydrogenated ring-opening (co) polymer of a norbornene monomer may be used, if necessary. Hydrogenated resin after polymer modification such as maleic acid addition and cyclopentadiene addition, (2) resin obtained by addition-type polymerization of norbornene-based monomer, (3) norbornene-based monomer and olefin such as ethylene and α-olefin A resin obtained by addition-type copolymerization with a system monomer can be used. The polymerization method and the hydrogenation method can be performed by a conventional method.

The norbornene-based monomer includes, for example, norbornene and its alkyl and / or alkylidene-substituted products, for example, 5-methyl-2-norbornene, 5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, -Butyl-2-norbornene,
Polar group substituents such as halogens such as 5-ethylidene-2-norbornene; dicyclopentadiene, 2,3-
Dihydrodicyclopentadiene and the like; dimethanooctahydronaphthalene, its alkyl and / or alkylidene-substituted product, and polar group-substituted product such as halogen, for example,
6-methyl-1,4: 5,8-dimethano-1,4,4
a, 5,6,7,8,8a-octahydronaphthalene,
6-ethyl-1,4: 5,8-dimethano-1,4,4
a, 5,6,7,8,8a-octahydronaphthalene,
6-ethylidene-1,4: 5,8-dimethano-1,4,
4a, 5,6,7,8,8a-octahydronaphthalene, 6-chloro-1,4: 5,8-dimethano-1,4
4a, 5,6,7,8,8a-octahydronaphthalene, 6-cyano-1,4: 5,8-dimethano-1,4
4a, 5,6,7,8,8a-octahydronaphthalene, 6-pyridyl-1,4: 5,8-dimetano-1,
4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-methoxycarbonyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octa Hydronaphthalene and the like; adducts of cyclopentadiene with tetrahydroindene and the like; cyclopentadiene trimers and tetramers, for example, 4,9: 5,8-dimethano-3a, 4,4
a, 5,8,8a, 9,9a-octahydro-1H-benzoindene, 4,11: 5,10: 6,9-trimethano-3a, 4,4a, 5,5a, 6,9,9a, 10 ,
10a, 11, 11a-dodecahydro-1H-cyclopentaanthracene;

In the case of the resin (1), other ring-opening polymerizable cycloolefins can be used in combination within a range not to impair the object of the present invention. Specific examples of such a cycloolefin include compounds having one reactive double bond such as cyclopentene, cyclooctene, and 5,6-dihydrodicyclopentadiene.

The thermoplastic saturated norbornene resin used in the present invention generally has a number average molecular weight of 15,000 to 100,000, preferably 2 as measured by gel permeation chromatography (GPC) using a toluene solvent.
000-80,000, more preferably 25,000
It is in the range of 0 to 70,000. If the number average molecular weight is too small, the mechanical strength is inferior, and if it is too large, the operability at the time of synthesizing the resin and forming the protective layer deteriorates.

When the thermoplastic saturated norbornene-based resin is obtained by hydrogenating a ring-opened polymer of a norbornene-based monomer, the hydrogenation rate is usually 90% from the viewpoint of heat deterioration resistance and light deterioration resistance. Above, preferably 95%
Above, more preferably, 99% or more.

The thermoplastic saturated norbornene resin is excellent in transparency, heat resistance, moisture resistance, chemical resistance and the like. In particular,
Hygroscopicity is usually 0.05% or less, preferably 0.01%
The following can be easily obtained. Further, its photoelastic coefficient is as small as 3 to 9 × 10 ⁻¹⁵ cm ² / dyne,
It is a material suitable for forming an optically uniform protective layer.

The thermoplastic saturated norbornene-based resin used in the present invention may optionally contain various additives such as phenol-based and phosphorus-based antioxidants, antistatic agents and ultraviolet stabilizers.

(Molding) In the present invention, various resins and the like are formed into the information recording medium element substrate by an appropriate method. The molding method is not particularly limited. For example, in the case of an acrylic resin or a polycarbonate resin, a usual plastic molding method, for example, a molding method such as an injection molding method, an extrusion molding method, or a compression molding method can be applied.

On the information recording medium element substrate obtained by molding,
By forming an information recording layer, for example, a reflective film or a magnetic film, an information recording medium element, for example, an optical recording medium disk or an optical recording medium card is manufactured. The reflection film is usually formed by depositing a metal having high reflectivity, for example, nickel, aluminum, gold, or the like, and the magnetic film is formed by depositing a Tb-Fe-Co alloy or the like. Will be The method of vapor deposition of the metal film on the optical element substrate is not particularly limited, and a normal vapor deposition method, for example,
A vacuum deposition method, a sputtering method, or the like can be applied.

The information recording layer obtained in this manner is in a bare state, is often a thin layer of 1 μm or less, and has a low mechanical strength, and is easily damaged. In such a case, a protective coat layer or a hard coat layer can be formed on the recording layer as long as it does not impair the function of the information recording medium element. A typical example of the method is a method of applying an ultraviolet curable acrylic paint and irradiating ultraviolet rays.

Such an information recording medium element is used as a single plate after being subjected to processing as required, or is used by bonding two sheets using a hot melt adhesive or an adhesive.

(Method of forming protective layer) As a method of forming the protective layer, a method of attaching a thermoplastic saturated norbornene resin previously processed into a film to the surface of an information recording medium element, and a method of applying a polymer solution to an information recording medium There is a method in which the solvent is applied to the surface of the element and the solvent is dried.

(1) Method of sticking film Film production includes a melt molding method and a solution casting method.

Examples of the melt molding method include a method using a T-die, a melt extrusion method such as an inflation method, a calender method, a hot press method, and an injection molding method. Among them, a melt extrusion method in which the thickness unevenness is small and which can be easily processed to a thickness of about 50 to 500 μm, and an inflation method which is easy to be processed to a thickness of about 10 to 100 μm are preferable.

The conditions of the melt molding method are the same as those used for a polycarbonate resin having a comparable Tg.
For example, in the melt extrusion method using a T die, the resin temperature is about 240 to 300 ° C.
It is preferable to select a relatively high temperature of about 0 to 150 ° C. and conditions under which the resin can be gradually cooled. In addition, in order to reduce surface defects such as die lines, the die needs to have a structure in which the stagnation portion is as small as possible. It is preferable to use a structure in which the inside of the die and the lip have as little scratches as possible.

In the case of the solution casting method, the resin is dissolved in a solvent and cast. The solvent used preferably has a boiling point of 100 ° C. or higher, more preferably 120 ° C. or higher.
If the boiling point is too low, the drying speed will be too fast, foaming will occur, and the surface will be wavy, resulting in a film having poor smoothness. Among them, 2
Even at a solid content of 10% by weight or more at 5 ° C., a solvent capable of uniformly dissolving the thermoplastic saturated norbornene resin is preferable.

Examples of such a solvent include toluene, xylene, ethylbenzene, chlorobenzene, trimethylbenzene, diethylbenzene, isopropylbenzene, chlorobenzene and the like, among which xylene, ethylbenzene and chlorobenzene are preferred.

As long as the thermoplastic saturated norbornene resin is dissolved, these solvents may contain a cyclic ether such as cyclohexane, chloroform, benzene, tetrahydrofuran or dioxane, or n-hexane or n-hexane.
-It may contain a linear hydrocarbon such as octane.

As a material which satisfies these conditions favorably, there is a material which contains 50% or more of an aromatic solvent such as xylene or ethylbenzene having a boiling point of 100 ° C. or more.

The concentration of the resin in the solution used for casting is usually 5
６０60% by weight, preferably 10-50% by weight, more preferably 20-45% by weight. If the concentration of the resin is too low, the viscosity is low and it is difficult to adjust the thickness of the film. If the concentration is too high, the viscosity is high and the operability is poor.

The method for casting the resin solution is not particularly limited, and a general solution casting method used for optical materials such as a polycarbonate resin sheet can be used. Specifically, a resin solution is applied to a bar coater, T die, T
Using a die, a doctor knife, a Meyer bar, a roll coat, a die coat, or the like, a method of casting on a flat plate or a roll such as a heat-resistant material such as polyethylene terephthalate, a steel belt, or a metal foil can be given.

The drying method is not particularly limited, but a drying method with a small amount of residual solvent is preferred. A resin film having a large amount of residual solvent has a problem that the residual solvent gradually evaporates and becomes thin and breaks, and the solvent erodes the information recording medium element substrate and the information recording layer. The residual solvent concentration in the resin film is required to be usually 2% by weight or less, preferably 1% by weight or less, more preferably 0.5% by weight or less. For example, as a drying method for reducing the residual solvent concentration in such a manner, there is the following two-stage drying method.

First, as a first stage of drying, the film on a flat plate or a roll is dried in a temperature range of 100 ° C. or less until the residual solvent concentration becomes 10% by weight or less, preferably 5% by weight or less. In this case, if the drying temperature is too high, the film foams upon evaporation of the solvent.

Next, the film is peeled off from the flat plate or the roll, and the second stage of drying is carried out at room temperature to 80 ° C. or higher.
Preferably from 110 ° C. to the glass transition temperature (Tg) of the resin
And dried until the residual solvent concentration becomes 2% by weight or less, preferably 1% by weight or less, more preferably 0.5% by weight or less.

If the drying temperature is too low, drying does not proceed, and if the temperature is too high, the resin deteriorates due to oxidation in the presence of oxygen. The first step is drying at room temperature, and after completion of the drying, the film is peeled off from the flat plate or roll, and the film is dried in the second step, or after drying by heating in the first step, once cooled, the film is flattened or rolled. And may be dried by reheating.

The heat resistance of the film produced by the solution casting method is determined by the type of the thermoplastic saturated norbornene resin, the type of the solvent used, and the concentration of the residual solvent. The higher the residual solvent concentration, the lower the heat resistance. The glass transition temperature (Tg) of the thermoplastic saturated norbornene resin forming the film for forming a moisture-proof layer of the present invention is usually 90 ° C. or higher, preferably 110 ° C. or higher.

The thickness of the film for forming a moisture-proof layer of the present invention is as follows:
It is 10 μm to 500 μm, preferably 20 to 200 μm. If the thickness of the film is too thin, the strength is reduced and the moisture-proof effect is weak. If the film is too thick, the thickness of the information recording medium element including the moisture-proof layer becomes too thick or too heavy.

The surface of the protective layer forming film of the present invention is preferably as smooth as possible. For this purpose, the film may be polished if necessary. Also, the smaller the thickness unevenness, the better,
For that purpose, both surfaces may be polished as necessary.

By providing an adhesive layer on one side of the film thus obtained, the film for forming a moisture-proof layer of the present invention is obtained. By laminating this film on the information recording element via the adhesive layer, an information recording medium element having the moisture-proof layer of the present invention is obtained. The adhesive layer here is an adhesive,
Or a layer of adhesive.

As the pressure-sensitive adhesive, a pressure-sensitive adhesive which is excellent in transparency, has small birefringence and the like, and can sufficiently adhere even when used as a thin layer is preferable. Examples of such adhesives include natural rubber, synthetic rubber elastomers, vinyl chloride / vinyl acetate copolymers, polyvinyl alkyl ethers, polyacrylates, modified polyolefin resin-based adhesives, and curing agents such as isocyanates. Curable pressure-sensitive adhesives are added, and in particular, curable pressure-sensitive adhesives are preferable among pressure-sensitive adhesives used for bonding a polyolefin foam or a polyester film.

However, when the pressure-sensitive adhesive layer is not laminated on the information recording medium element immediately after lamination, a curable pressure-sensitive adhesive is not preferred. In such a case, a release film such as release paper or a release film may be further laminated on the surface so that the film for forming the moisture-proof layer does not adhere to the surrounding objects by the adhesive layer. preferable. In that case, since the release film and the like can be easily peeled off, lamination on the information recording medium element can be performed with good operability. Usually, the thickness of the adhesive layer is 5 to 40 μm.
m is appropriate.

The adhesive may be any adhesive used for bonding polyethylene, polypropylene or the like. For example, a dry laminating adhesive for mixing a polyurethane resin solution and a polyisocyanate resin solution, a styrene-butadiene rubber-based adhesive, an epoxy-based two-part curable adhesive, for example, an epoxy resin and polythiol two-part adhesive, epoxy A two-component resin and a polyamide can be used. Particularly, a solvent-based adhesive and an epoxy-based two-component curable adhesive are preferable, and a transparent adhesive is preferable. Some adhesives can improve the adhesive strength by using an appropriate adhesive primer. When such an adhesive is used, it is preferable to use an adhesive primer.

When attaching a film for forming a moisture-proof layer,
If dust or the like in the air enters between the film and the information recording medium element, it may cause an information reading error.Therefore, remove the dust with an air gun or the like and paste it. It is preferable to stick them.

(2) Method of Applying Resin Solution In order to form a moisture-proof layer, there is also a method of applying a resin solution to the surface of an information recording medium element and drying it.

The solvent used for preparing the resin solution is preferably a solvent capable of uniformly dissolving the thermoplastic saturated norbornene resin even at a solid content of at least 10% by weight at 25 ° C. However, if the solvent is a solvent that easily dissolves the material of the information recording medium element substrate, the surface may be eroded.

Examples of such a solvent include alicyclic groups such as cyclopentane, cyclohexane and methylcyclohexane, aromatic groups such as toluene, xylene, ethylbenzene, chlorobenzene, trimethylbenzene, diethylbenzene and isopropylbenzene, chloroform and chlorobenzene. A good solvent for a thermoplastic saturated norbornene-based resin such as a halogen-based solvent should be selected in consideration of the effect on the material of the information recording medium element substrate.

In addition, as long as the thermoplastic saturated norbornene resin is dissolved, these solvents may contain a cyclic ether such as cyclohexane, chloroform, benzene, tetrahydrofuran or dioxane, or n-hexane or n-hexane.
-It may contain a linear hydrocarbon such as octane.

Even if the solvent easily dissolves the material of the substrate, if the solvent is easily volatilized, the substrate may be violently eroded and used without clouding depending on the application method and the amount of application. . In such a case, the influence on the reading accuracy of information is small, and the adhesion between the substrate and the moisture-proof layer may be increased. The solvent must be selected in consideration of the information reading accuracy of the recording medium element and the like.

The concentration of the resin solution is usually 5 to 60% by weight, preferably 8 to 50% by weight. If the thickness is too low or too high, it is difficult to adjust the thickness of the moisture-proof layer, and the operability of coating is poor.

If desired, an antioxidant, an antistatic agent, an ultraviolet stabilizer, a leveling agent, and the like may be added to the resin solution.

The coating method may be selected based on the shape of the object to be coated, coating efficiency, etc., such as a spin coating method, a brush coating method, a dip method, a bar coating method, a spray coating method, and the like. Among them, a spray can in which a resin solution is sealed in a can with gas for pressurization, LPG, etc. can easily form a moisture-proof layer on the surface of an already completed information recording medium element according to the needs of the user. It is preferred in that respect.

Dry to remove the solvent. Low-boiling solvents such as chloroform dry well at room temperature, but if relatively high-boiling solvents such as toluene and xylene are used, they should be dried under high-temperature conditions until the residual solvent becomes 5% by weight or less. Is preferred. However, the drying temperature must be selected within a range that does not hinder the material of the information recording layer and the information recording medium element, and it is necessary to dry at 120 ° C. or lower, and sometimes 100 ° C. or lower in some cases.

The thickness of the moisture-proof layer is 5 to 500 μm, preferably 10 to 400 μm, particularly preferably 20 to 300 μm.
It is applied so as to have such a thickness after drying. If the moisture-proof layer is too thin, the moisture-proof effect is small, and if it is too thick, the weight of the information recording medium element increases, and drying becomes difficult.

(Moisture-Proof Layer) In the present invention, the moisture-proof effect depends on the thickness of the moisture-proof layer.
Under an environment of 90% RH, it is 10 g / m ² · 24 hr or less, and depending on the selection of the resin or the like, 5 g / m ² · 24 h
r or less.

The adhesive strength between the moisture-proof layer and the information recording medium element is usually 50% or more in the Goban test, but can be 80% or more, preferably 90% or more depending on the selection of the adhesive layer. is there.

The birefringence of the moisture-proof layer is determined by forming the moisture-proof layer so that the thickness unevenness is small and the surface is smooth, so that the retardation value of the entire surface is 50 nm or less, preferably 30 nm or less.
nm or less.

[0053]

EXAMPLES The present invention will be described in more detail with reference to Reference Examples, Examples and Comparative Examples, but the present invention is not limited to only these Examples. In the following examples, parts and% are based on weight unless otherwise specified.

In the following examples, physical properties are measured as follows. (1) The number average molecular weight was measured by a GPC method using toluene as a solvent. (2) The hydrogenation rate was measured by ¹ H-NMR. (3) The glass transition temperature (Tg) was measured by the DSC method. (4) The retardation is Belek wavelength 550 nm.
It was measured by a compensator. (5) The thickness of the sheet and the film was measured by a dial thickness gauge. (6) The light transmittance is determined by a spectrophotometer at a wavelength of 400 to
Measurement was performed by continuously changing the wavelength in the range of 700 nm, and the minimum transmittance was defined as the light transmittance. (7) The residual solvent concentration of the sheet was measured by gas chromatography at a temperature of 200 ° C.

Reference Example 1 6-methyl-1,4,5,8
-Dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene (hereinafter abbreviated as MTD) was used as a polymerization catalyst in 10 parts of a 15% solution of triethylaluminum in cyclohexane, 5 parts of triethylamine, and Add 10 parts of a 20% solution of titanium chloride in cyclohexane,
Ring-opening polymerization was performed in cyclohexane, and the obtained ring-opened polymer was hydrogenated with a nickel catalyst to obtain a polymer solution. This polymer solution is coagulated in isopropyl alcohol,
After drying, a powdery resin was obtained. This resin had a number average molecular weight of 40,000, a hydrogenation rate of 99.8% or more, and a Tg of 142 ° C.

Reference Example 2 15 g of the resin obtained in Reference Example 1 was dissolved in 85 g of xylene to obtain a resin solution composition. 500 ppm of a leveling agent (Fluorard FC-430, Sumitomo 3M) and an ultraviolet stabilizer (Viosorb)
80, Kyodo Pharmaceutical Co., Ltd.), 300 ppm was added, and the mixture was spread on a glass plate whose surface was polished, and an appropriate amount was cast with a bar coater to a width of about 300 mm and a length of 500 mm. As a first-stage drying, the whole glass plate was heated from 20 ° C. to 50 ° C. for 20 minutes in an air reflux type oven and dried. Next, as a second stage of drying, the resin film was peeled off from the glass plate, dried for 90 minutes in an open at 90 ° C., cooled to room temperature, and cut off around 10 mm wide to obtain a film. The residual solvent concentration of this film was 0.5 % by weight .

When the surface of this film was observed visually and with an optical microscope, no foaming, streaks, or scratches were observed. The Tg was 139 ° C. , the average thickness was 80 μm, the thickness unevenness was at most ± 4 μm or less, the light transmittance was 91.0%, and the absolute value of the retardation value was 3 nm or less on the entire surface. The water vapor permeability of this film is 25 ° C, 90 RH%
Was 3.0 g / m ² · 24 hr under the environment described above.

Example 1 An adhesive (Diabond DA753, manufactured by Nogawa Chemical) was applied to one side of the film obtained in Reference Example 2 to a thickness of 8 μm, and a silicon release paper was laminated thereon to form a moisture-proof layer. A film was made.

Example 2 The film for forming a moisture-proof layer obtained in Example 1 was cut into a compact disk shape.

In an environment having a cleanliness class of 1000, the release paper was peeled off from the film for forming a moisture-proof layer, and the film was attached to both surfaces of a commercially available compact disc (substrate: made of polycarbonate, reflective film: aluminum).

After storage for 24 hours in an environment of 85 ° C. and 90% RH, no corrosion was observed on the aluminum layer of the reflection film. No loss of information or noise was observed on the playback device.

[Comparative Example 1] When the same compact disk used in Example 2 was stored for 24 hours in an environment of 85 ° C and 90% RH, the aluminum layer of the reflective film was corroded and became almost transparent. became. In addition, the information was lost even on the playback device and could not be played back.

Example 3 The resin obtained in Reference Example 1 was dissolved in xylene to obtain a coating solution for forming a moisture-proof layer of the present invention as a resin solution having a concentration of 20% by weight.

Example 4 A chlorinated polypropylene (manufactured by Toyo Kasei Co., Ltd., manufactured by Toyo Kasei Co., Ltd.) was used as a primer on the surface of a commercially available 30 cm laser vision disk (two-layer bonded structure, substrate: polymethyl methacrylate, reflective film: aluminum). A 2 wt% toluene solution of Hardlen 13-MLJ) was added dropwise and spin-coated at 3,000 rpm for 30 seconds, and then dried in an air oven at 50 ° C. for 30 minutes. Subsequently, the same primer treatment was performed on the opposite surface.

The coating agent for forming a moisture-proof layer obtained in Example 3 was
In a nitrogen pressurized spray, both sides of the above-mentioned primer-treated disk were spray-coated so that the surface became smooth, and left at 75 ° C. for 3 hours to dry, thereby forming a moisture-proof layer.

When measured with a thickness gauge, the thickness of the moisture-proof layer was about 100 μm × 2 (front and back). When the disc having the moisture-proof layer was set in a reproducing apparatus, good image quality and sound quality were obtained, and no obvious noise to the image quality and sound quality was recognized.

Further, the disk was heated at 60 ° C. and 90% R
When left on the SUS plate for one month under the environment of H, no obvious noise or warpage was observed for the image quality and sound quality.

Comparative Example 2 The same laser vision disk used in Example 4 was left on a SUS plate for one month in an environment of 60 ° C. and 90% RH without forming a moisture-proof layer.

As a result, the peripheral portion was greatly warped with respect to the central portion, and when viewed from the side on a flat plate, the peripheral portion was warped up to about 5 mm at the maximum. For this reason, it could not be played on a playback device.

[Comparative Example 3] Instead of being left on a SUS plate, three SUS cylindrical rods (a set of two rods) were used.
Comparative Example 2 was performed in the same manner as in Comparative Example 2 except that both sides were pressed with parallel straight lines of the book and left without warping.

When the image was played on a reproducing apparatus, clear deterioration of the screen was recognized, and white dots appeared as countless and irregular noises on the screen and then disappeared. Also, the whole screen was blurry and lacked clarity. The digital voice had some parts that could be heard between noises. About 40
At the time of the second reproduction, the screen was further disturbed and the contents could not be recognized, and the reproduction was stopped in about 45 seconds.

[0072]

According to the present invention, an information recording medium element having a moisture-proof layer made of a thermoplastic saturated norbornene-based resin having excellent water resistance and moisture resistance, a film for forming a moisture-proof layer used for the production thereof, a coating agent, and A spray is provided. Since the information recording medium element having the moisture-proof layer of the present invention has excellent moisture resistance, the recording film on which information is recorded is hardly damaged by moisture, and the life of the recorded information is long.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-42441 (JP, A) JP-A-60-26024 (JP, A) JP-A-5-40973 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 C08J 7/04 G11B 7/24 G11B 11/10

Claims (6)

(57) [Claims] 1. A thermoplastic saturated norbornene resin.
And an information recording medium element having a moisture-proof layer having a retardation value of 50 nm or less . 2. The optical information recording medium element according to claim 1, which is an optical disk. 3. The optical information recording medium element according to claim 1, which is an optical card. 4. A thermoplastic saturated norbornene-based resin film having an adhesive layer provided on one surface thereof and having a retardation value of 5
A film for forming a moisture-proof layer of an optical information recording medium element having a thickness of 0 nm or less . 5. The coating agent for forming a moisture-proof layer of an optical information recording medium element according to claim 1 , comprising a thermoplastic saturated norbornene-based resin solution. 6. A thermoplastic saturated norbornene-based resin solution.
A coating agent consisting of
Play coating to prevent retardation of 50 nm or less
A method for forming a wet layer.