JP2000235738A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a card-shaped optical recording medium without causing warpage when a transparent substrate and a protective substrate are stuck together. SOLUTION: A hard coat layer 1 is formed on the 1st face of a transparent substrate 2 and an optical recording layer 3 is disposed on the 2nd face of the transparent substrate 2 with a formed preformat. A protective substrate 6 is stuck to the 2nd face of the transparent substrate 2 with the optical recording layer 3 by way of an adhesive 20 to obtain the objective optical recording medium. The transparent substrate 2 and the protective substrate 6 separately comprise mutually different resin materials and the adhesive 20 is formed from two layers of a hot-melt adhesive 4 laminated in direct contact with the optical recording layer 3 and a pressure sensitive adhesive 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an optical recording medium having a card-shaped optical recording section.

[0002]

2. Description of the Related Art In recent years, an optical recording medium for recording and / or reproducing information by light has been proposed as a means for storing a large amount of information. Conventionally, as a method using light, for example, Optical Engineering, Vo
l. 15, No. 2, March-April, 197
6, pp. 99- "Review and Analysis of Optical Recording Media (R
view and Analysis of Opt
As described in “optical recording media)”, when a light beam, for example, a laser beam is applied to a recording layer of an optical recording medium, a type that causes deformation or holes in the recording layer, a type that forms bubbles, and an optical type. There are known types that change the characteristic.

[0003] As a material used for the recording layer,
For example, low melting point metals such as Te, Bi, Sn, Sb, and In, cyanine, squalium, phthalocyanine, tetradehydrocholine, polymethine, naphthoquinone,
Dyeing / pigments (organic dyes) such as benzenedithiol nickel complex, and composite materials of these organic dyes and metals are known.

An organic dye recording medium can be formed as a recording layer on a substrate by a solvent coating method, and is superior in mass productivity to a low melting point metal compound formed by a vacuum evaporation method.

In a recording pit portion of an optical recording medium in which an organic dye is used for a recording layer, the reflectance is reduced by, for example, decolorization due to thermal decomposition of the organic dye, and the recording is performed due to the optical scattering effect due to the deformation of the recording pit portion. Since the reflected light amount of the information reproducing laser light in the pit portion changes, the recorded information can be sensed.

In recent years, optical recording media have been required to be thinner in accordance with the demand for smaller recording / reproducing devices.
0.68 to 0.84 mm according to ISO / IEC standards
Is required.

On the other hand, in order to reduce the influence of dust and scratches on the surface of the substrate of the optical recording medium on recording / reproduction, it is advantageous that the substrate is as thick as possible.
A thickness of about 6 mm is suitable. In addition, the protection substrate is 0.1 mm.
A thickness of about 15 to 0.4 mm is required. Therefore, in order to obtain an optical card having the above thickness, a so-called air gap structure, that is, a hollow portion having a thickness of about 0.5 to 1 mm is provided on a recording layer provided on a substrate, and a protective substrate is laminated thereon. It is difficult to adopt a suitable configuration.

Therefore, in a thin optical recording medium such as an optical card, an adhesive recording structure having a protective substrate laminated on a recording layer via an adhesive layer is employed.

[0009] The applicant of the present invention is Japanese Patent Application Laid-Open No. 1-146144.
In the publication, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer or ethylene-maleic anhydride-acrylic acid terpolymer is mainly used as an adhesive which does not easily damage the organic dye recording layer. An optical recording medium using an adhesive as a component is disclosed. Further, the adhesive is at least one copolymer selected from ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer and ethylene-methacrylic acid ester copolymer. An optical recording medium comprising the adhesive and having a Vicat softening point of the adhesive of 65 ° C. or more and 95 ° C. or less has been proposed.

In any case, it has been proposed to use a hot melt adhesive as the adhesive directly in contact with the organic dye recording layer.

On the other hand, in recent years, various cards have been developed, and further, development and commercialization of hybrid cards such as a card having an optical recording section and an IC recording section, an optical card having an embossing function, and an optical card having a magnetic stripe recording layer. Has been made.

A non-contact IC card having an IC chip, an antenna coil and conductive wiring between at least two polyethylene terephthalates and a total thickness of 250 μm has been developed. Their thickness is 250μ
Non-contact IC card having a thickness of 400 m and an optical recording layer having a thickness of 400
A hybrid card in which a μm transparent substrate is laminated using an adhesive is also being developed.

In these various hybrid cards, the material of the transparent substrate on which the optical recording layer is formed and the material of the protective substrate may not always be the same. Even if the material is the same, to make the card thickness 0.84 mm or less,
When the transparent substrate is 0.4 mm, the thickness of the protective substrate is 0.4
It is often set to less than mm.

[0014]

In particular, an optical / non-contact IC
In order to make a hybrid card satisfying the card thickness of ISO / IEC7810, an optical / non-contact I
The thickness of C hybrid card is 0.68mm ~ 0.84
mm.

An optical / non-contact IC hybrid card is formed from an optical recording section forming sheet (transparent substrate) and a sheet (protective substrate) forming a non-contact IC module (hereinafter referred to as a non-contact IC).
In the case where the optical recording unit forming sheet is formed of a laminate, the thickness of the transparent substrate is ISO / I
It becomes 0.4 mm by EC11693. Further, an adhesive having a thickness of 0.05 mm to 0.15 mm is required for laminating the optical recording portion forming sheet and the non-contact IC sheet.

Therefore, the thickness of the non-contact IC sheet needs to be 0.13 mm to 0.39 mm. IC chips, capacitors, and coils used for non-contact IC sheets have a thickness of 0.05 to 0.1 mm. The contactless IC sheet has a structure in which these IC chips, capacitors, and coils are sandwiched between at least two plastic sheet materials. When the thickness of the non-contact IC sheet is 0.
In order to be 13 mm to 0.39 mm, the thickness of one plastic sheet material needs to be about 0.05 to 0.2 mm.

0. When producing a hybrid card using a plastic sheet material having a thickness of about 1 mm, it is desired that the sheet has a large mechanical strength and a low cost because the sheet is thin. In general, PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) is used as a sheet material that is inexpensive and has high tensile strength. Resins such as polycarbonate and polymethyl methacrylate generally used as a transparent substrate have poor solvent resistance, and may cause cracks on the substrate when forming IC chips, capacitors, coils, etc. . In addition, 0. At a thickness of about 1 mm, there were problems such as easy bending, cracking, and tearing, and it could not be used as a non-contact IC module forming sheet. Therefore, it is essential that the transparent substrate and the protective substrate are made of different materials.

When a transparent substrate and a protective substrate are made of different materials and a hot melt adhesive is used for bonding the transparent substrate and the protective substrate, the thermal expansion coefficient of the transparent substrate and the thermal expansion coefficient of the protective substrate are increased. Are different,
The card is warped by the heat lamination process at 150 ° C.

If the adhesive used for bonding the protective substrate and the transparent substrate is changed to a solvent-applied pressure-sensitive adhesive to solve the above problems, the following problems may occur. Was found. Cracks occurred on the transparent substrate. The recording layer is a metal medium,
Solvent cracks occurred in polycarbonate regardless of the organic dye. The reflectance of the organic dye recording layer was reduced, and optical recording and reproduction could not be performed.

An object of the present invention is to solve the above problems,
Provided is a card-shaped recording medium in which a transparent substrate on which an optical recording layer is formed and a protective substrate are made of different materials and in which no warpage occurs when the transparent substrate and the protective substrate are bonded to each other. The purpose is to do so.

[0021]

That is, the present invention relates to an optical recording medium comprising a transparent substrate on which an optical recording layer is formed and a protective substrate bonded together via an adhesive. Characterized in that the adhesive is formed of two layers of a hot-melt adhesive and a pressure-sensitive adhesive which are laminated so that the adhesive is directly in contact with the optical recording layer. It is a recording medium.

It is preferable that the optical recording layer contains an organic dye. The optical recording layer preferably contains a material selected from a metal, a metal oxide, a silver salt compound and a mixture thereof. Preferably, the transparent substrate is made of a polycarbonate resin, and the protective substrate is made of a resin selected from polyethylene terephthalate, vinyl chloride, polystyrene, an ABS resin and a mixture thereof.

Preferably, the protective substrate includes a non-contact IC module having an IC chip, an antenna coil, and conductive wiring between two polyethylene terephthalate sheets. The hot melt adhesive preferably contains an ethylene-acrylic acid copolymer, an ethylene-acrylic acid ester copolymer, an ethylene-methacrylic acid copolymer, an ethylene-methacrylic acid ester copolymer or a mixture thereof.

The hot melt adhesive preferably has a Vicat softening point of 65 ° C. or higher. Preferably, the pressure sensitive adhesive comprises an acrylic polymer. It is preferable that the optical recording medium has a thickness of 0.84 mm or less. It is preferable that the optical recording medium has a card shape.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to achieve the above object, the present invention provides a transparent substrate and a protective substrate made of different resin materials, respectively. In an optical card medium having a thickness of 0.84 mm or less, the adhesive is directly formed from two layers of a hot melt adhesive and a pressure-sensitive adhesive so as to directly contact the optical recording layer. The present invention is characterized in that a card-shaped recording medium is provided.

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing one embodiment of the optical recording medium of the present invention. FIG. 2 is a schematic cross-sectional view of the optical card in a direction orthogonal to the tracking groove. In FIG. 1, the optical recording medium of the present invention has a hard coat layer 1 formed on a first surface of a transparent substrate 2 and an optical recording medium formed on a second surface of the transparent substrate 2 on which a preformat is formed. A recording layer 3 is provided, and a protective substrate 6 is attached to a surface of the transparent substrate 2 on which the optical recording layer 3 is provided via an adhesive 20. The transparent substrate 2 and the protective substrate 6 are bonded together. A hot-melt adhesive 4 and a pressure-sensitive adhesive 5 each made of a different resin material and laminated so that the adhesive 20 is in direct contact with the optical recording layer 3;
It is characterized by being formed from a layer.

The inventor of the present invention has proposed that when the transparent substrate and the protective substrate are made of different resin materials, and the transparent substrate and the protective substrate have different coefficients of thermal expansion, a conventional adhesive for an optical card is used. It has been found that, when a card is prepared by using, the amount of warpage of the card is significantly larger than the ISO / IEC standard and is insufficient. The present invention is directed to an optical recording medium having an optical recording layer capable of stably recording / reproducing, in particular, a card having a small amount of warpage and particularly an optical / non-contact IC hybrid, as an example of a card in which the materials of the transparent substrate and the protective substrate are different. Important to get the card.

FIG. 2 is an explanatory view showing one embodiment showing a method for manufacturing an optical recording medium of the present invention. FIG. 1 shows an example of a method for manufacturing an optical / non-contact IC hybrid card. In the method for manufacturing an optical recording medium according to the present invention, first, a hard coat layer 1 is formed on one surface of a transparent substrate 2, and a light coat is formed on the other surface of the transparent substrate 2 on which a preformat is formed. The card substrate 13 is obtained by forming the recording layer 3.

Also, a hot melt adhesive 4 having one surface covered with a protective film 7 is prepared. Next, the card substrate 13 and the hot-melt adhesive 4 are passed through the heat laminating roll 8 and the hot-melt adhesive 4 is attached to the side of the card substrate 13 that contacts the optical recording layer 3 so that the reflectance of the optical recording layer 3 is not changed. The substrate 12 with the adhesive is obtained via the hot melt adhesive 4.

Second, the pressure-sensitive adhesive 5 is laminated on the non-contact IC sheet 6a side to obtain the sheet 11 with the adhesive. Third
Then, the protective film 7 covering the surface of the substrate 12 with the adhesive is peeled off, and the hot melt adhesive 4 of the substrate 12 with the adhesive and the pressure-sensitive adhesive 5 of the sheet 11 with the adhesive are overlapped with each other, and the pressing device is used. 9 without pressing, without heating, without contact with the transparent substrate 2 on which the optical recording layer 3 is formed.
The C sheet (protective substrate) 6a is laminated via the hot melt adhesive 4 and the pressure sensitive adhesive 5 to obtain an optical / non-contact IC hybrid card.

In the present invention, by using a hot melt adhesive, optical recording can be performed without forming an air layer between the optical recording layer formed on the uneven preformatted surface of the transparent substrate and the hot melt adhesive. An adhesive layer can be formed on the layer. In addition, using a pressure-sensitive adhesive, at a temperature of 50 ° C. or less, using a pressing or roll laminating method,
By laminating a non-contact IC sheet (protective substrate) on the hot melt adhesive via a pressure-sensitive adhesive, the "transparent substrate on which the optical recording layer is formed" and the "non-contact IC sheet (protective substrate)" The optical / non-contact IC hybrid card can be obtained without causing the warpage of the card due to the difference in the coefficient of thermal expansion.

Further, in the present invention, the presence of the hot melt adhesive between the optical recording layer and the pressure-sensitive adhesive allows
The problem that the hot melt adhesive acts as a barrier layer to cause cracks in the transparent substrate caused by the pressure-sensitive adhesive, and that the reflectivity of the organic dye recording layer is reduced so that optical recording and reproduction cannot be performed. Could be improved.

FIG. 3 is a schematic cross-sectional view of an optical / non-contact IC hybrid card manufactured by the method shown in FIG. 2 as an example of the optical recording medium of the present invention. The light of the present invention
The non-contact IC hybrid card has a structure in which at least respective constituent materials of a hard coat coat layer 1, a transparent substrate 2, an optical recording layer 3, a hot melt adhesive 4, a pressure-sensitive adhesive 5, and a non-contact IC sheet 6a are laminated. have. A feature of the present invention is an optical / non-contact IC hybrid having a configuration in which a transparent substrate on which an optical recording layer is formed and a sheet on which a non-contact IC recording section is formed are bonded via a hot melt adhesive and a pressure-sensitive adhesive. It is to provide a card.

As the hot melt adhesive, an ethylene vinyl acetate resin or a substance mainly composed of a hot melt resin as described below is suitable.

The present invention relates to a transparent substrate, an optical recording layer, and an ethylene-acrylic acid copolymer, an ethylene-acrylic acid ester copolymer, an ethylene-methacrylic acid copolymer and an ethylene-methacrylic acid ester formed on the optical recording layer. A protective substrate is bonded via a hot melt adhesive containing at least one copolymer selected from copolymers and having a Vicat softening point of 65 ° C. or more and 95 ° C. or less, and further a pressure-sensitive adhesive. An optical recording medium that can record information by irradiating a recording light beam to form bits in the optical recording layer.

That is, according to the present invention, by setting the Vicat softening point of the hot melt adhesive to 65 ° C. or higher, the adhesive between the adhesive and the recording layer at high temperature and high humidity or when the intensity of the reproducing light beam is increased. It is considered that as a result of preventing the interaction, an optical recording medium having more excellent durability can be obtained.

In the present invention, the hot melt adhesive 4 is made of ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer and ethylene-methacrylic acid ester copolymer. And at least one copolymer selected from the group consisting of
The Vicat softening point based on STM D1525 is preferably from 65 ° C to 95 ° C, particularly preferably from 70 ° C to 90 ° C. That is, by adjusting the composition and physical properties of the hot melt adhesive 4 as described above, recording by heat generated in the optical recording layer at the time of recording / reproducing under a high temperature / high humidity environment or using a higher power laser beam. It is possible to prevent the interaction between the organic dye in the layer and the adhesive, to suppress the change in the reflectance, and to suppress the decrease in the recording sensitivity and the decrease in the adhesive force when recording information on the recording layer with a laser beam. Can be
An optical recording medium with more excellent durability can be obtained.

In the present invention, the weight average molecular weight of the copolymer contained in the hot melt adhesive is from about 10,000 to 1,
1,000,000, the ethylene-acrylic acid copolymer is, for example, as shown by the following structural formula (I).

[0039]

Embedded image (However, a, b, and n are positive integers) The polyethylene has a structure in which a carboxyl group is randomly included in the structure, and the ethylene-acrylate copolymer is, for example, represented by the following structural formula (II) Is a copolymer of ethylene and acrylate, as shown in

[0040]

Embedded image (Where a, b, and n are positive integers, R: CH ₃ , C ₂ H ₅ ,
C ₃ H ₇ ) The ethylene-methacrylic acid copolymer has a structure in which a carboxyl group is randomly included in the molecular structure of polyethylene as shown by the following structural formula (III), for example.

[0041]

Embedded image (However, a, b, and n are positive integers) Further, the ethylene-methacrylic acid ester copolymer has, for example, a structure as shown by the following structural formula (IV).

[0042]

Embedded image (Where a, b, and n are positive integers, R: CH ₃ , C ₂ H ₅ ,
C ₃ H ₇ )

The hot melt adhesive 4 in the present invention contains at least one of the above-mentioned four types of copolymers, and may contain a mixture of two or more types. Further, in the present invention, the adhesive contains two or more different copolymers of the same kind, for example, a mixture of an ethylene-methyl methacrylate copolymer and an ethylene-ethyl methacrylate copolymer. You may let it.

In the present invention, the Vicat softening temperature of the hot melt adhesive 4 is mainly determined by the following three factors: (1) acrylic acid and acrylic acid in each of the copolymers contained in the adhesive; Content of ester, methacrylic acid, methacrylic acid ester (2) Content of the copolymer in the adhesive (3) Control by appropriately changing the additive in the adhesive alone or in combination of two or more However, in the present invention, it is particularly important to control the element (1) to adjust the softening temperature and to add no additive or to minimize the amount of the additive. It is preferable to prevent the interaction between the layer and the adhesive.

In the present invention, the total content of the copolymer in the hot melt adhesive is 80% of the adhesive.
-100 wt%, especially 90-100 wt%, and even 95
Acrylic acid in the copolymer contained in the hot melt adhesive of the present invention;
The content of acrylic acid ester, methacrylic acid or methacrylic acid ester (in terms of monomer) is 20% by weight or less of the copolymer, particularly 8 to 15% by weight, and more preferably 9 to 1% by weight.
It is preferable to be within the range of 2 wt%.

By adjusting the Vicat softening temperature of the hot melt adhesive to 65 ° C. or more and 95 ° C. or less within the above-mentioned composition range, at the time of high temperature and high humidity or when a higher power reproducing light beam is used. Also, it is possible to obtain an optical recording medium in which the reflectance of the optical recording layer is less reduced and the durability is further improved.

In the present invention, the content of acrylic acid, acrylic acid ester, methacrylic acid or methacrylic acid ester in the copolymer can be calculated by quantifying the absorption of carbonyl in an infrared absorption spectrum.

In the present invention, the hot melt adhesive 4 has a melt flow rate of 2 to 10 g / 10 by a measuring method according to JIS K6730 (ASTM D1238).
When the amount is adjusted so as to be 2 to 5 g / 10 minutes, excessive deformation of the adhesive layer at the time of recording information can be prevented, the pit shape can be made uniform, and the adhesive by reproducing laser light at the time of reproducing recorded information. Is less likely to occur, and the C / N
Can be improved.

The additives to be added to the hot melt adhesive in the present invention include, for example, tackifiers and softeners. Examples of the tackifiers include rosin, polymerized rosin, hydrogenated rosin, and rosin ester. And other modified resins, aliphatic compounds, alicyclic compounds, aromatics, etc.
Petroleum resin, terpene resin, terpene / phenol resin,
Hydrogenated terpene resin, cumarone resin, etc.
Examples of the softener include process oil, paraffin oil, castor oil, polybutene, low molecular weight polyisoprene, and the like. Further, an ultraviolet absorber or the like may be added to the hot melt adhesive of the present invention as needed within a range that does not cause an interaction with the recording layer and does not change the above-described physical properties.

Further, in the present invention, the composition of the hot melt adhesive 4 is a copolymer of acrylic acid,
When the content of acrylic acid ester, methacrylic acid, and methacrylic acid ester is 20 wt% or less, the critical surface tension of the adhesive 4 becomes, for example, 30 to 37 dyn / cm, and polymethyl methacrylate (PMMA) which is usually used as a transparent substrate is used. ) Substrate and polycarbonate (PC)
Although the adhesiveness between the hot melt adhesive 4 and the transparent substrate tends to slightly decrease due to the poor wettability of the adhesive to a resin substrate such as a substrate, the surface modification of the adhesive film or the adhesive as described above. By improving the critical surface tension by improving the quality, it is possible to suppress a decrease in adhesion.

At this time, the method of surface modification is not particularly limited, and examples thereof include a corona discharge treatment, an ozone treatment, an alkali treatment, an argon plasma treatment, an oxygen plasma treatment and the like. When forming an adhesive film 4a of an ethylene-acrylic acid copolymer as a hot melt adhesive film into a sheet by the melt extrusion method shown in FIG. 4, a corona discharge treatment is performed on both surfaces immediately after the extrusion using the corona discharge device 51. Thereby, the critical surface tension of the surface of the adhesive sheet can be improved. Since the surface of both surfaces can be easily modified, the above production method using an adhesive sheet is preferable for producing an optical recording medium having excellent adhesiveness. In the present invention, the critical surface tension is measured according to JIS K-6.
768.

Incidentally, the adhesive force required for the adhesive of the optical recording medium according to the present invention is as follows.
Adhesion strength by a T-type peel test when two resin sheets are adhered with the adhesive is 100 g / 25 mm or more, particularly 400 g
/ 25 mm or more, more preferably 500 g / 25 mm or more.

As the pressure-sensitive adhesive, a rubber-based adhesive or an acrylic-based adhesive is preferable. In particular, when an organic dye is used for the optical recording layer, an acrylic adhesive is preferable for the storage durability of the organic dye recording layer. When an acrylic resin is used for the hot melt adhesive, the pressure sensitive adhesive is also preferably an acrylic resin in order to maintain the adhesion between the hot melt adhesive and the pressure sensitive adhesive.

The acrylic adhesive has a molecular weight of 100,000 to 2
Those having an acrylic polymer of about 100,000 as a main component are preferable. The monomers constituting these polymers are (meth) acrylic acid monomers or alkyl groups having 2 carbon atoms.
About to 12 alkyl (meth) acrylate monomers are suitable. For example, acrylic acid, methacrylic acid, acrylic acid anhydride, methacrylic anhydride, ethyl acrylate, propyl acrylate, butyl acrylate, isopropyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, and the like are used. For adjusting the glass transition temperature, vinyl acetate, methacrylic acid, acrylic acid, methyl methacrylate, acrylonitrile and the like can be added in an amount of 1 to 10% based on the main component.

Examples of the rubber-based adhesive include natural rubber, styrene-butadiene-random copolymer, butyl rubber,
A polyisobutylene-based adhesive is used.

Next, in the present invention, when the wavelength of the light used for recording, for example, the wavelength of a light beam such as a semiconductor laser is in the range of 650 nm or more, particularly in the range of 700 to 900 nm, the optical recording layer 3 is used. It is preferable to have an absorption maximum wavelength in the wavelength region of the beam, and it is preferable that the energy required for an optically detectable change to be caused by irradiation of the light beam is small.

As a material used for the optical recording layer of the present invention, an organic dye, a metal, a metal oxide, a silver salt compound and a mixture thereof are used. For example, Te, Bi, Sn, Sb, I
low melting point metal such as n, cyanine-based, squarium-based, phthalocyanine-based, tetradehydrocholine-based, polymethine-based, naphthoquinone-based, benzenedithiol-nickel complex and other dyes / pigments (organic dyes), and composites of these organic dyes and metals System materials can be used.

The organic dye recording medium can be formed as a recording layer on a substrate by a solvent coating method, and is more excellent in mass productivity than a low melting point metal compound formed by a vacuum evaporation method.

Further, it is preferable that the difference in optical characteristics between the information recording portion and the non-recording portion is large with respect to the light used for reproduction. Examples of the organic dye used in the optical recording layer 3 of the present invention include anthraquinone derivatives (particularly those having an indazulene skeleton), dioxazine compounds and derivatives thereof, triphenodithiazine compounds, phenanthrene derivatives, cyanine compounds, and merocyanine compounds. , Pyrylium compounds, xanthene compounds, triphenylmethane compounds, croconium dyes, azo dyes, crocones, azines, indigoids, polymethine dyes, azulene dyes, squarium dyes, cyanine dyes with polymethine chains And organic dye substances such as tetraphenylcyanine dyes.

In particular, in the present invention, when a polymethine dye represented by the following general formula (1) or a cyanine dye represented by the following general formula (2) is used in a recording layer, optical recording with particularly excellent durability is provided. Medium can be obtained.

[0061]

Embedded image

(Where A, B, D and E represent a hydrogen atom, an alkyl group, an alkenyl group, an aralkyl group, an aryl group,
Shows a group selected from styryl and a heterocyclic group.
r ₁ ′ and r ₂ ′ represent a group selected from a hydrogen atom, an alkyl group, a cyclic alkyl group, an alkenyl group, an aralkyl group and an aryl group, k is 0 or 1, L is 0, 1 or 2
And X ^- represents an anion. A, B, D,
The aralkyl group, aryl group, styryl group and heterocyclic group in E, r ₁ ′ and r ₂ ′ may be substituted. )

The abbreviations in the above general formula will be described in more detail. A, B, D and E represent a hydrogen atom or an alkyl group (for example, a methyl group, an ethyl group, an n-propyl group, an is
o-propyl group, n-butyl group, sec-butyl group, i
so-butyl group, t-butyl group, n-amyl group, t-amyl group, n-hexyl group, n-octyl group, t-octyl group, etc.), and other alkyl groups, for example, substituted alkyl groups ( For example, 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, 2-acetoxyethyl, carboxymethyl, 2-carboxyethyl, 3-carboxypropyl, 2-sulfoethyl, 3-sulfoethyl Propyl group, 4-sulfobutyl group,
3-sulfatepropyl group, 4-sulfatebutyl group, N- (methylsulfonyl) -carbamylmethyl group,
Cyclic alkyl groups (eg, cyclohexyl group) such as 3- (acetylsulfamyl) propyl group and 4- (acetylsulfamyl) butyl group; alkenyl groups (vinyl group, propenyl group, butenyl group, pentenyl group, Hexenyl, heptenyl, octenyl, dodecynyl,
Aralkyl groups (eg, benzyl group, phenethyl group, α-naphthylmethyl group, β-naphthylmethyl group), substituted aralkyl groups (eg, carboxybenzyl group, sulfobenzyl group, hydroxybenzyl group, etc.), Aryl group (for example, phenyl group), substituted aryl group (for example, diethylaminophenyl group)
Is included.

R ₁ ′ and r ₂ ′ represent a hydrogen atom or an alkyl group (for example, methyl group, ethyl group, n-propyl group, is
o-propyl group, n-butyl group, sec-butyl group, i
so-butyl group, t-butyl group, n-amyl group, t-amyl group, n-hexyl group, n-octyl group, t-octyl group, etc.), and other alkyl groups such as substituted alkyl groups. (For example, 2-hydroxyethyl group, 3-
Hydroxypropyl group, 4-hydroxybutyl group, 2-
Acetoxyethyl, carboxymethyl, 2-carboxyethyl, 3-carboxypropyl, 2-sulfoethyl, 3-sulfopropyl, 4-sulfobutyl, 3-sulfopropyl, 4-sulfobutyl, N- (methylsulfonyl) -carbamylmethyl group, 3- (acetylsulfamyl) propyl group, 4-
(Acetylsulfamyl) butyl group, etc., cyclic alkyl group (eg, cyclohexyl group, etc.), alkenyl group (vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, dodecynyl group, Prenyl group), aralkyl group (for example,
Benzyl group, phenethyl group, α-naphthylmethyl group, β
-Naphthylmethyl group) and substituted aralkyl groups (for example, carboxybenzyl group, sulfobenzyl group, hydroxybenzyl group and the like).

[0065]

Embedded image

(Wherein M and M ′ represent an atom group necessary to complete a substituted or unsubstituted nitrogen-containing heterocyclic ring;
r ₁ ′, r ₂ ′, r ₃ ′ and r ₄ ′ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group. k, s
Is 0 or 1, L is 0, 1 or 2,

[0067]

[Outside 1] Represents an anion. )

In the general formula (2), M and M 'are pyridine,
A group of atoms necessary to complete a nitrogen-containing heterocycle such as thiazole, benzothiazole, naphthothiazole, oxazole, benzoxazole, naphthoxazole, imidazole, benzimidazole, naphthymidazole, 2-quinoline, 4-quinoline, isoquinoline or indole. , Halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), alkyl groups (methyl, eryl,
Propyl, butyl, etc.), aryl group (phenyl, tolyl, xylyl, etc.), aralkyl group (benzyl, p-
Tolmethyl).

R ₁ ′ to r ₄ ′ are a hydrogen atom, a substituted or unsubstituted alkyl group (methyl, ethyl, propyl, isopropyl, butyl, t-butyl, amyl, isoamyl, hexyl, octyl, nonyl, dodecyl, methoxyethyl) , Hydroxyethyl, carboxypropyl, etc.), substituted or unsubstituted aryl groups (phenyl, α-naphthyl, β-naphthyl, tolyl, xylyl, biphenyl, ethylphenyl, methoxyphenyl, ethoxyphenyl,
Dimethoxyphenyl, hydroxyphenyl, chlorophenyl, dichlorophenyl, bromophenyl, dibromophenyl, nitrophenyl, diethylaminophenyl, dimethylaminophenyl, dibenzylaminophenyl, etc., and substituted or unsubstituted aralkyl groups (benzyl,
Phenethyl, 3-phenylpropyl, methoxybenzyl, methylbenzyl, chlorobenzyl, etc.).

K and s are 0 or I, and L is 0, 1 or 2.

In the above general formulas (1) and (2),

[0072]

[Outside 2] Is an anion, chloride ion, bromide ion, iodide ion, perchlorate ion, benzenesulfonate ion, p-toluenesulfonate ion, methyl sulfate ion, ethyl sulfate ion, propyl sulfate ion, Tetrafluoroborate ion, tetraphenylborate ion, hexafluorophosphate ion, benzenesulfinate ion, acetate ion, trifluoroacetate ion, propionacetate ion, benzoate ion,
Oxalate ion, succinate ion, malonate ion, oleate ion, stearate ion, citrate ion, monohydrogen diphosphate ion, dihydrogen monophosphate ion, pentachlorostannate Salt, chlorosulfonate, fluorosulfonate, trifluoromethanesulfonate, hexafluoroantimonate, molybdate, tungstate, titanate, zirconate, etc. Express.

The adhesive layer of the present invention can provide an optical recording medium having particularly excellent durability in combination with the following structure among the cyanine dyes.

[0074]

Embedded image

The recording layers containing these organic dyes include:
A stabilizer such as an infrared absorbing compound may be contained for the purpose of improving light resistance. Examples of the material used as the stabilizer include, for example, JP-A-60-1
No. 63245 and JP-A-60-236131, or the following (V) and (VI)
Examples include the substances shown in the formula.

[0076]

Embedded image (Where R is a hydrogen atom, a lower alkyl group, X is an acid ion, and A is

[0077]

Embedded image Is shown. Here, n is an integer of 1 or 2. )

In the above formulas (V) and (VI), the substituent R is an alkoxyalkyl group (for example, methoxyethyl group), an alkenyl group (for example, propenyl group), an alkynyl group (for example, propargyl group). Further, a compound having a cyclic alkyl group (such as a cyclopentyl group) is excellent in the function of stabilizing an organic dye and also excellent in solubility in a solvent. Therefore, when the recording layer 3 is formed by a wet compress, It is a suitable material.

Examples of the quencher having the effect of stabilizing the organic dye include, for example, the following (VII) to (X)
I) The metal complex represented by the formula can also be used.

[0080]

Embedded image

[0081]

Embedded image

(However, R ₁ to R ₄ may be the same or different, each represents a substituted or unsubstituted alkyl group, aryl group or amino group, and R ₅ to R ₈ are the same or different. Each represents a hydrogen atom, a halogen atom or a substituted or unsubstituted alkyl group or an amino group, and M represents Ni, Co,
Represents a transition metal selected from Mn, Cu, Pd and Pt. )

The content of the stabilizer and the quencher contained in the optical recording layer 3 is usually 5 to the content of the dye.
The range is preferably from 50 to 50% by weight, more preferably from 10 to 30% by weight. Further, in the optical recording layer of the present invention, the above-mentioned organic dye, stabilizer and quencher may be contained in a binder in a dispersed state or a dissolved state.

The binder used in the present invention includes:
For example, nitrocellulose, cellulose phosphate, cellulose sulfate, cellulose acetate, cellulose propionate,
Cellulose butyrate, cellulose myristate, cellulose palmitate, cellulose acetate / propionate, acetate
Cellulose esters such as cellulose butyrate, cellulose ethers such as methylcellulose, ethylcellulose, propylcellulose and butylcellulose, polystyrene, polyvinyl chloride and the like can be used.

In the case where an organic dye is formed as an optical recording layer by wet coating, the organic solvent that can be used at the time of coating differs depending on whether the organic dye is in a dispersed state or a dissolved state. Alcohols such as methanol, ethanol, isopropanol and diescent alcohol; ketones such as acetone, methyl ethyl ketone and cyclohesaquinone; N, N-dimethylformamide;
Use of amides such as N, N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, aliphatic halogenated hydrocarbons such as dichloromethane, dichloroethylene and trichloroethylene, and hydrocarbons. Can be.

[0086] These coating solutions can be applied to the transparent substrate by known coating methods, for example, methods such as dip coating, spray coating, spinner coating, bar coating, blade coating, roll coating, and curtain coating. It is formed.

The thickness of the optical recording layer is 400 to 1200.
Although the range of 好 ま し い is preferable, it is usually preferable to set the film thickness so that the surface reflectance becomes maximum by the correlation between the film thickness of the optical recording layer and the reflectance, since an excellent C / N signal can be obtained. When a reflective layer is provided on the surface of the recording layer opposite to the light beam incident surface, it is preferable to set the film thickness so as to minimize the surface reflectance of the optical recording layer because the recording sensitivity is improved.

As the transparent substrate used in the present invention, a transparent plastic plate of polymethyl methacrylate, polycarbonate, polysulfone, polyolefin resin or the like can be used.

The protective substrate used in the present invention is made of a resin material different from that of the transparent substrate. For example, polyethylene terephthalate, vinyl chloride,
Resins selected from polystyrene, ABS resins and mixtures thereof can be used. In addition, a protective substrate is provided between two polyethylene terephthalate sheets.
A device provided with a non-contact IC module including a C chip, an antenna coil, and conductive wiring can be used.

[0090]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 An optical / non-contact IC hybrid card shown in FIG. 3 was manufactured by a method schematically shown in FIG.

A non-contact IC sheet (manufactured by Hitachi, Ltd.) having a thickness of 0.25 mm and a non-contact IC chip, a coil and a capacitor sandwiched between polyethylene terephthalate sheets is coated with a pressure-sensitive adhesive on one surface. To obtain the adhesive-attached sheet 11 of FIG. The thickness of the pressure-sensitive adhesive was 30 μm.

An acrylic pressure-sensitive adhesive (XA602-1, manufactured by Hitachi Chemical Co., Ltd.) was used as the pressure-sensitive adhesive.

On the other hand, a hard coat layer made of an ultraviolet curable resin was provided on a transparent substrate made of a polycarbonate resin having a thickness of 0.4 mm on which a preformat was formed, and 75 parts by weight of a polymethine dye represented by the following structural formula was obtained. An optical recording layer consisting of 25 parts by weight of an aminium salt compound represented by the formula was formed by a solvent coating method. The solvent used for dissolving the dye was sufficiently dried by heating (90 ° C., 10 minutes).

[0095]

Embedded image

Next, a 75 μm-thick hot melt adhesive (O-4121,
The surface of the adhesive (manufactured by Kurashiki Spinning Co., Ltd.) was placed so as to be in contact with the surface of the optical recording layer, and a hot-melt adhesive was laminated on the optical recording layer using a heat lamination at a temperature of 120 ° C. Next, the protective film was peeled off from the hot melt adhesive, and the hot melt adhesive and the sheet with adhesive 11 to which the pressure-sensitive adhesive was applied were bonded. A vacuum laminator was used for bonding. The bonding temperature was 35 ° C.

Next, using a hollow blade cutter, the optical card was cut into a card size based on the recording preformat of the optical card to obtain an optical / non-contact IC hybrid card. The thickness of the card was 0.75 mm.

Example 2 The hot melt adhesive of Example 1 was replaced with hot melt adhesive H
-2500 (manufactured by Kurashiki Spinning Co., Ltd.), and an optical / non-contact IC hybrid card was obtained in the same manner as in Example 1.

Example 3 The optical recording layer of Example 1 was formed as a sputtered TeOx film.
An optical / non-contact IC hybrid card capable of optical recording / reproducing and IC recording / reproducing was obtained by the same method as in Example 1. No solvent cracks occurred on the polycarbonate resin transparent substrate.

Example 4 In place of the pressure-sensitive adhesive of Example 1, a synthetic rubber-based pressure-sensitive adhesive L-751 (manufactured by Panac Co., Ltd.) was used. A contact IC hybrid card was obtained.

Comparative Example 1 In the method shown in FIG. 2, the card substrate 13 on which the optical recording layer was formed and the non-contact IC sheet 6 were laminated with only the hot melt adhesive O-4121 as the adhesive. A contact IC hybrid card was obtained. The temperature of the heat lamination was 120 ° C.

Comparative Example 2 In the method shown in FIG. 2, optical recording was performed by a press method at a temperature of 30 ° C. using only an acrylic adhesive XA602-1 (manufactured by Hitachi Chemical) as a pressure-sensitive adhesive as an adhesive. After bonding the non-contact IC sheet 6 with the card substrate 13 having the layer formed thereon, it was cut into a card size to obtain an optical / non-contact IC hybrid card.

Comparative Example 3 An optical card was obtained by using the adhesive of Example 3 in the same manner as in Comparative Example 2. The light obtained in Examples 1 to 4 and Comparative Examples 1 to 3
ISO / IE warpage of non-contact IC hybrid card
C7810, determined according to ISO / IECl0373. Table 1 shows the results. The reflectivity of the optical recording layer in Table 1 was determined from the amount of reflected light of a 830 nm laser beam.

[0104]

[Table 1]

As shown in Table 1, the optical / non-contact IC hybrid cards of Examples 1 to 4 have a warp of l. 5mm
Therefore, the card was inserted into the optical recording / reproducing apparatus and recording / reproducing was performed. The contact type (communication distance is 1
The recording / reproduction of the non-contact IC portion (about 2 mm) was also possible because the warpage of the card was within 1.5 mm.

In Comparative Example 1, the card could not be inserted into the optical recording / reproducing apparatus because the warpage of the card was 8 mm. Further, since the warp of the card is 8 mm, the distance between the communication coil for recording and reproducing the IC and the electromagnetic coil of the recording and reproducing device is 3 mm or more, and the communication distance is 1 to 2 m.
It was not possible to record / reproduce information of a close contact type non-contact IC card of about m.

[0107]

As described above, according to the present invention, in the optical recording medium in which the transparent substrate on which the optical recording layer is formed and the protective substrate are made of different materials, the reflectance of the optical recording layer is different. The effect of providing a card-shaped recording medium in which warpage does not occur at the time of bonding the transparent substrate and the protective substrate without lowering the image quality was obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of the optical recording medium of the present invention.

FIG. 2 is an explanatory view showing one embodiment showing a method for manufacturing an optical recording medium of the present invention.

FIG. 3 is a schematic sectional view showing another embodiment of the optical recording medium of the present invention.

FIG. 4 is a schematic view of a method for modifying the surface of an adhesive film used in the production method shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hard-coat layer 2 Transparent substrate 3 Optical recording layer 4 Hot-melt adhesive 4a Adhesive film 5 Pressure-sensitive adhesive 6 Protective substrate 6a Non-contact IC sheet 7 Protective film 8 Heat laminating roll 9 Press device 11 Adhesive sheet 12 Adhesion Substrate with agent 13 Card substrate 20 Adhesive 51 Corona discharge device

Claims (10)

[Claims] 1. An optical recording medium comprising a transparent substrate on which an optical recording layer is formed and a protective substrate bonded together via an adhesive, wherein the transparent substrate and the protective substrate are made of different resin materials, respectively. An optical recording medium comprising two layers, a hot-melt adhesive and a pressure-sensitive adhesive, which are laminated so that the adhesive directly contacts the optical recording layer. 2. The optical recording medium according to claim 1, wherein said optical recording layer contains an organic dye. 3. The optical recording layer according to claim 1, wherein the optical recording layer contains a material selected from a metal, a metal oxide, a silver salt compound and a mixture thereof.
An optical recording medium according to claim 1. 4. The method according to claim 1, wherein the transparent substrate is made of a polycarbonate resin, and the protective substrate is made of a resin selected from polyethylene terephthalate, vinyl chloride, polystyrene, ABS resin and a mixture thereof. Optical recording medium. 5. The optical recording medium according to claim 1, wherein said protective substrate comprises a non-contact IC module having an IC chip, an antenna coil and conductive wiring between two polyethylene terephthalate sheets. 6. The hot melt adhesive contains an ethylene-acrylic acid copolymer, an ethylene-acrylic acid ester copolymer, an ethylene-methacrylic acid copolymer, an ethylene-methacrylic acid ester copolymer or a mixture thereof. The optical recording medium according to claim 1. 7. The optical recording medium according to claim 1, wherein the Vicat softening point of the hot melt adhesive is 65 ° C. or higher. 8. The optical recording medium according to claim 1, wherein said pressure-sensitive adhesive contains an acrylic polymer. 9. The optical recording medium according to claim 1, wherein said optical recording medium has a thickness of 0.84 mm or less. 10. The optical recording medium according to claim 1, wherein said optical recording medium has a card shape.