JPH03224792A - Optical recording medium - Google Patents

Abstract

PURPOSE:To improve a pit shape and to perform good recording and reproduction by forming a layer containing the decomposed substance of the material quality of a recording layer and not substantially containing the material quality of a substrate to the interface part of the substrate and recording layer of a pit part. CONSTITUTION:When recording is applied to an optical recording medium 1 or a postscript is added thereto, for example, the recording medium 1 is irradiated with recording light of 780nm in a pulse like state through a substrate 2. By this method, a recording layer 3 absorbs light to generate heat and the substrate 2 is also heated simultaneously. In this case, the decomposed substance layer 61 containing the molten or decomposed substance of the recording layer 3 remains in a shape so as to cover the bottom part and boundary of a usual group 23. In usual, a gap 63 is formed to the interface with a reflecting layer on the decomposed substance layer 61 and the decomposed substance layer 61 and the gap 63 are formed to a pit part 6. By this method, a layer not substantially containing the material quality of the substrate is formed to the interface part of the substrate 2 and recording layer 3 of the pit part 6. As a result, a pit shape becomes well and an S/N ratio is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an optical recording medium, and particularly to a write-once type optical recording disk compatible with a compact disk.

<Prior Art> Optical recording discs capable of additional writing or recording have been proposed in accordance with the compact disc (hereinafter abbreviated as CD) standard (Nikkei Electronics January 23, 1989 issue).

N0.465. P2O3, Functional Pigment Subcommittee, Kinki Chemical Society, March 3, 1989, Osaka Science and Technology Center, 5PIE voL 10780pticalData
Storage Topical Meeti
ng, 80 1989, etc.).

This material is formed by depositing a dye layer, an Au reflective layer, and a protective film in this order on a transparent resin substrate. That is, the reflective layer is provided in close contact with the dye layer.

This proposal is for CD use, and for CD use,
When the dye layer of an optical recording disk is irradiated with a recording laser beam, the dye layer absorbs the light and melts or decomposes, and the substrate also softens, and the dye material and substrate material mix at the interface, and due to the phase difference of the light, It is said that pits with reduced reflectance are formed at the interface between the substrate and the dye layer.

Conventionally, an air layer was provided on the dye layer in order to form pits in the dye layer, but in this proposal, the reflective layer is provided in close contact with the dye M, so the disc metal thickness of the CD standard is achieved. A configuration of 1.2 mm is possible.

<Problems to be Solved by the Invention> The present inventors conducted various additional tests on such optical recording disks.

As a result, when such a reflective layer and a recording layer containing a dye are provided in close contact with each other, the pits formed at the interface between the substrate and the recording layer contain decomposition products of the recording layer material such as the dye. However, if it does not contain any substrate material, the pit shape is good, the noise during recording and playback is small, and the S/N is sufficient.
It was discovered that the ratio can be obtained.

An object of the present invention is to provide a contact type optical recording medium that has a good pit shape and can perform good recording and reproduction.

<Means for Solving the Problems> Such objects are achieved by the following inventions (1) to (17).

(1) A recording layer containing a dye is provided on a substrate, and a reflective layer is laminated in close contact with this recording layer. Recording light is irradiated onto the recording layer to form pits, and playback is performed. An optical recording medium that is reproduced by light, wherein a layer containing a decomposed product of a recording layer material and substantially not containing a substrate material is present at an interface between the substrate and the recording layer in the pit portion. An optical recording medium characterized by:

(2) The pit portion has a void formed therein (
The optical recording medium according to 1).

(3) The optical recording medium according to (1) or (2) above, wherein the recording layer has an extinction coefficient k of 0.03 to 0.25 at the wavelengths of recording light and reproduction light.

(4) The optical recording medium according to (3) above, wherein the recording layer has a refractive index n of 1.8 to 4.0 at the wavelengths of recording light and reproduction light.

(5) The wavelength of recording light and reproduction light is 600 to 900 n
The optical recording medium according to any one of (1) to 4) above, which is m.

(6) The optical recording medium according to any one of (1) to 5) above, wherein the recording layer has a thickness of 500 to 2,000 layers.

(7) When the reproduction light is irradiated from the substrate side, the reflectance of the unrecorded part is 60% or more, and the reflectance of the recorded part is 60% or less of the reflectance of the unrecorded part. 6
).

(8) The above-mentioned (1) or 7, wherein the recording layer is a coating film.
).

(9) The above-mentioned (1) or 7, wherein the recording layer is a vapor deposited film.
).

(10) The above (wherein the recording layer contains two or more types of dyes)
The optical recording medium according to any one of 1) to 9).

(11) The optical recording medium according to any one of (1) to 10 above, wherein a protective film is laminated on the reflective layer.

(12) The optical recording medium according to any one of (1) to 11), wherein the protective film is made by radiation-curing a radiation-curable compound.

(13) The pencil hardness of the protective film at 25°C is H~8
The optical recording medium according to (12) above, which is H.

(14) The optical recording medium according to (12) or (13) above, wherein the protective film has a thickness of 0.1 pm or more.

(15) The amount of oxygen permeation of the substrate at 25°C is 5X
The optical recording medium according to any one of (1) to 14) above, which has a temperature of 10-"cm"cm-"-s-'.(cmHg)-' or less.

(16) The optical recording medium according to any one of (1) to 15 above, comprising an adhesive layer between the recording layer and the reflective layer.

(17) The optical recording medium according to any one of claims 1 to 16, further comprising an anti-jitter film on the reflective layer or between the reflective layer and the recording layer.

<Function> In the optical recording medium of the present invention, the pit portion is formed of a material that contains a decomposed product of the recording layer material and does not contain the substrate material, so the pit shape is good and the S is high during recording and reproduction. /N ratio can be obtained, and good recording and reproduction can be performed.

In addition, CD
Good optical recording that can be reproduced by a player becomes possible.

<Specific configuration> Hereinafter, a specific configuration of the present invention will be explained in detail.

FIG. 1 shows an example of the optical recording medium l of the present invention.

This optical recording medium 1 has a recording layer 3 containing a dye on a substrate 2, and in close contact with the recording layer 3, a reflective layer 4 and a protective film 5.
It is a close-contact type with a

The substrate 2 is made of resin or glass that is substantially transparent (preferably transmittance of 80% or more) to recording light and reproduction light (semiconductor laser light of about 600 to 900 nm, especially about 700 to 800 nm, especially 780 nm). formed from. This allows recording and reproduction from the back side of the substrate.

The substrate 2 has a disk shape of a normal size, and when used as a CD, has a thickness of about 1.2 mm and a diameter of about 80 to 120 mm.

In this case, it is preferable to use resin as the substrate material, and thermoplastic resins such as polycarbonate resin, acrylic resin, amorphous polyolefin, and TPX are suitable.

Of these, the amount of oxygen permeation at 25°C is 5x 10
-"cm3cm-2s-'.(cmHg)-' or less is suitable because it has extremely high light resistance.

In such a case, the amount of oxygen permeation at 25°C is 4 x
10-” cm'・cm-2・s-' (cmHg
) - or less, even more favorable results are obtained. Note that the oxygen permeation amount at 25° C. can be set to various values from almost 0 to the above value.

The amount of oxygen permeation may be measured according to JIS Z 1707.

More specifically, the oxygen permeation amount Q am”・am−”・S
--(cmHg) −' and oxygen permeability coefficient cm”cm
-cm-"-s-1 (cmHg) -' is measured by the following.

P= (273/T)・(V/A)・jll/p)・(
1/760)・(dh/dt)Q= (273/T)
(V/A) −(1/p) −(1/760) ・(d
h/dt) where, T = 298 ■ = Volume on the low pressure side (cm'') A: Sample permeation area (cIn'') i: Substrate thickness (cm, generally O, 12 cm) p: Oxygen pressure (cmHg) dh/dt: slope of the straight line part of the transmission curve (+nmHg-
5-') Various methods can be used to set the oxygen permeation amount Q of the substrate as described above.

The first method is to make the substrate material oxygen-blocking.

In such a case, glass strengthened by various strengthening methods may be used as necessary.

Alternatively, the following resins may be used. In addition,
In the following, 25°C at typical polymerization degrees and compositions.
The oxygen permeability coefficient P at is also written. Therefore, the value obtained by dividing this by the normal thickness of 0.12 cm is the oxygen permeation amount Q of the base.
becomes.

1) Cyclic olefin polymer, which is usually a random copolymer of an amorphous polyolefin cyclic olefin component and optionally an ethylenic double bond component (JP-A No. 63-273655, No. 63-1146)
No. 43, No. 63-218727, No. 63-24310
No. 8, No. 64-31844, etc.) P = 0.05x 10-”cm”-cm-c+n-”
-s-'1cmHg)-'degree 2) High-density polyethylene P=0.4x 10-"c+n"・cnrcm-2s-
” (cmHg) - degree 3) Polyvinyl alcohol type e.g. polyvinyl alcohol P=0.009x 1O-10cn+3・cmcm-2
-s-'1cmHg)-'degree ethylene-vinyl alcohol copolymer P=(10-"-10-')x 10-"cm3cm-
cm-"s (cmHg) -' degree etc. 4) Polyvinyl chloride P = 0.05x 10-"cm3cm-cm-"s-'
-(cmHg)-degree 5) Polyvinylidene chloride P=0.005x 10-"cm"-cm-cm-"
-s-' -(cmHg) -degree 6) Polyamide e.g. nylon 6 P=0.04X 10-"Cm"-cm-cm-"-s
-'-(cmHg)-' degree etc. 7) Polyester e.g. polyethylene terephthalate P=0.04X 10-10cm"-cm-cm-"s
8) Epoxy resin, etc. The oxygen permeability coefficient P of commonly used resin substrate materials is as follows.

Acrylic resin P=1.2X 10-”c+n3・cm・cm-2s-
"(cmHg)-' Degree Polycarbonate P=(1,5-3)X 10-"cm"cm-cm-"
s-"(cmHg)-'Therefore, in these, 1.2 m
m thickness, Q is 10x 10-"cm3cm-"s-'
(cmHg)-', the light resistance deteriorates.

Next, in the second embodiment, an oxygen permeable material such as acrylic resin or polycarbonate is used as the substrate material.

Then, an oxygen-blocking film is formed on at least one of the outer surface, the inner surface, and, if necessary, the inner and outer peripheral surfaces.

Examples of the oxygen-blocking film material include coating films, sputtered films, and plasma polymerized films made of the aforementioned low oxygen permeability coefficient resin materials.

Further, vapor-phase surface films of various glasses, transparent inorganic materials, etc. are also suitable.

These oxygen-barrier films are formed to have a thickness such that the above-mentioned Q can be obtained.

It is preferable that a group for tracking is formed on the surface of the substrate 2 on which the recording 1i3 is formed.

The group is preferably a continuous spiral group, with a depth of 250 to 1800 people and a width of 0.3 to 1,800 people.
1.1 house, especially 0.4 to 0.6-, land (the part between adjacent groups) width is 0.5 to 1.3-1, especially 1
．． It is preferably 0 to 1.2-.

By configuring the group in this way, it is possible to obtain a good tracking signal without lowering the reflection level of the group portion.

Incidentally, the group can also be provided with concavities and convexities for address signals.

In the present invention, when the substrate has groups, it is preferable that the recording light be configured to irradiate the recording layer within the group. That is, the optical recording medium of the present invention is preferably used as an optical recording medium for group recording.
By performing group recording, the effective thickness of the recording layer can be increased.

Further, a resin layer (not shown) may be formed on the substrate 2 by, for example, the 2P method, and the resin layer may be provided with grooves for tracking and irregularities for address signals.

The resin material constituting the resin layer is not particularly limited and may be appropriately selected from known resins used in the so-called 2P method, but radiation-curable compounds are usually used.

The recording layer 3 is formed by mixing one or more types of dyes.

Extinction coefficient (
The imaginary part (k) of the complex refractive index is preferably 0.03 to 0.25.

When k is less than 0.03, the absorption rate of the recording layer decreases, making it difficult to perform recording with normal recording power.

Furthermore, if k exceeds 0.25, the reflectance will fall below 60%, making it difficult to perform reproduction according to the CD standard.

In this case, k is 0.04 to 0.20, especially 0.05 to 0
．． A value of 15 gives extremely favorable results.

Further, the refractive index (real part of the complex refractive index) n is 1.8 to 4.
0, more preferably 2.2 to 3.3.

When n<1.8, the reflectance decreases and reproduction according to the CD standard tends to become difficult. Moreover, in order to make n>4.0, it is difficult to obtain raw material pigments.

The light-absorbing dye used has an absorption maximum of 600 to 9
00nm, preferably 600 to 800nm, more preferably 650 to 750nI11, there are no particular limitations, but cyanine, phthalocyanine, naphthalocyanine, anthraquinone, azo, triphenylmethane, biryllium or thiapyrylium One or more of salt-based, squalinium-based, croconium-based, and metal complex dye-based dyes are preferred.

The cyanine dye is preferably a cyanine dye having an indolenine ring, particularly a benzindolenine ring.

Furthermore, a quencher may be mixed with the light-absorbing dye.
Furthermore, an ionic combination of a dye cation and a quencher anion may be used as a light-absorbing dye.

As the quencher, metal complexes such as acetylacetonate, bisdithiol such as bisdithio-α-diketone and bisphenyldithiol, thiocatechol, salicylaldehyde oxime, and thiobisferrate are preferred.

Also suitable are amine quenchers such as amine compounds having nitrogen radical cations and hindered amines.

The dye constituting the bond is preferably a cyanine dye having an indolenine ring, and the quencher is preferably a metal complex dye such as a bisphenyldithiol metal complex.

For details of preferred dyes and quencher-1 conjugates, see JP-A Nos. 59-24692, 59-55794, 59-55795, 59-81194, and 59-59.
No. 83695, No. 60-18387, No. 60-19
'586, '60-19587, '60-3505
No. 4, No. 60-36190, No. 60-36191,
No. 60-44554, No. 60-44555, No. 60
-44389, 60-44390, 60-47
No. 069, No. 60-20991, No. 60-71294
No. 60-54892, No. 60-71295, No. 60-71296, No. 60-73891, No. 60-
No. 73892, No. 60-73893, No. 60-838
No. 92, No. 60-85449, No. 60-92893, No. 60-159087, No. 60-162691,
No. 60-203488, No. 60-201988, No. 60-234886, No. 60-234892, No. 6
No. 1-16894, No. 61-11292, No. 61-1
No. 1294, No. 61-16891, No. 61-8384
No. 61-14988, No. 61-163243,
No. 61-210539, Japanese Patent Application No. 60-54013,
They are described in JP-A-62-30088, JP-A 62-32132, JP-A 62-31792, and ``Chemistry of Functional Dyes'' published by CMCMC, pages 74 to 76.

The quencher may be added separately from the light-absorbing dye or in the form of a conjugate, but the quencher may be added in an amount of 1 mol or less, particularly 0.05 to 0.05 mol, per 1 mol of the total light-absorbing dye. It is preferable to add about 5 mol.

This further improves light resistance.

In the present invention, a light-absorbing dye, a dye-quencher mixture, and a dye-quencher conjugate having n and k within the above range is selected from the above-mentioned light-absorbing dyes, dye-quencher mixtures, and dye-quencher conjugates, or a new molecular design is performed and synthesized. You can also do that.

Note that the k of dyes for recording light and reproduction light varies widely depending on their skeletons and substituents, ranging from about 0 to 2. For example, when selecting a dye with k of 0.03 to 0.25, it is important to There are restrictions on the skeleton and substituents. For this reason,
There may be restrictions on the coating solvent, or coating may not be possible depending on the substrate material. Alternatively, vapor phase film formation may not be possible. Furthermore, when designing a new molecule, a large amount of effort is required for design and synthesis.

On the other hand, according to the experiments conducted by the present inventors, the value k of a mixed dye layer containing two or more types of dyes corresponds to the k value of a dye layer composed of each dye used alone, and approximately corresponds to the mixing ratio thereof. It turned out to be. Therefore, in the present invention, the recording layer 3
may be formed by dissolving two or more types of dyes.

At this time, in most dye mixing systems, k can be obtained that is approximately proportional to the mixing ratio. That is, when the mixing fraction of one type of dye and k are respectively C1 and ki, k becomes approximately ΣC1ki. Therefore, by mixing dyes with different k values by controlling the mixing ratio, k=
A dye M of 0.03 to 0.25 can be obtained. Therefore, the dye to be used can be selected from a very wide range of dye groups.

This can also be applied to improving wavelength dependence. The wavelength of a semiconductor laser is usually in the range of ±10 nm, and in a commercially available CD player, it is necessary to ensure a reflectance of 70% or more in the range of 770 to 790 nm. In general, the value of dyes often has a strong wavelength dependence, and 7
Even if 80r+m is an appropriate value, 770 or 7
At 90 nm, it is too thick (it often deviates). In such cases, by mixing a second dye, set so that appropriate n and values are always obtained within the range of 780 ± 10 nm. be able to.

As a result, there are no restrictions on film-forming methods such as restrictions on coating solvents, etc., and it is also possible to use dyes that are easy to synthesize and are inexpensive, dyes with good properties, and dyes that are poorly soluble. be able to.

When the recording layer 3 is a mixed dye layer, the dye used is n=
It may be selected from the ranges of 1.6 to 6.5 and k=0 to 2.

In addition, when measuring n and k, a measurement sample is prepared by depositing a recording layer on a predetermined transparent substrate under the conditions of a thickness measurement of, for example, about 400 to 800 people. Next, the reflectance through the substrate or from the recording layer side is measured. The reflectance is measured by specular reflection (
5°). Also, measure the transmittance of the sample. From these measurements, for example, the Valve Chamber Complete Book “
n and k may be calculated according to "Optics" by Kozo Ishiguro, pp. 168-178.

The thickness of such a recording layer 3 is preferably 500 to 2000. Outside this range, the reflectance decreases, making it difficult to perform reproduction in accordance with the CD standard.

Although there is no particular restriction on the method of forming the recording layer 3, in the present invention,
It is preferable to apply the layer by coating, since the flexibility and ease of dye selection, medium design, and manufacturing are expanded.

For coating the recording layer 3, various solvents such as ketone, ester, ether, aromatic, halogenated alkyl, and alcohol solvents can be used, and there is a great degree of freedom in solvent selection. For application, a spin cord or the like may be used.

The recording layer 3 may be formed of a dye deposited film.

In this case, sublimable dyes such as phthalocyanine-based, naphthalocyanine-based, anthraquinone-based, azo-based, triphenylmethane-based, biryllium or thiapyrylium salt-based, squarylium-based, croconium-based, and metal complex dyes are used. In particular, it is preferable to use phthalocyanine-based and naphthalocyanine-based dyes.

By using such a sublimable dye, the pit shape may be improved and jitter may be reduced.

A reflective layer 4 is provided in direct contact with such a recording layer 3.

As the reflective layer 4, Au, A4Mg alloy, A(2N i
Although high reflectance metals such as alloys, Ag, Pt, and Cu may be used, it is preferable to use one of Au, Al2Mg alloy, and Aj2Ni alloy because the reflectance is particularly high among these metals. Note that the Mg content in the Al2Mg alloy is preferably about 3 to 7 wt%. Also,
The Ni content in the AρNi alloy is preferably about 3 to 4 wt%.

The thickness of the reflective layer 4 is preferably 500 Å or more,
The layer may be formed by vapor deposition, sputtering, or the like. There is no particular limit to the upper limit of the thickness, but in consideration of cost, production time, etc., it is preferably about 1000 people or less.

As a result, the reflectance of the unrecorded portion of the medium through the substrate can be changed by 60% or more, particularly 70% or more.

A protective film 5 is provided on the reflective layer 4 .

The protective film 5 may be formed of various resin materials such as ultraviolet curing resin, and usually has a thickness of about 0.1 to 100 μm. The protective film 5 may be in the form of a layer or a sheet.

The protective film 5 is preferably one obtained by radiation-curing a coating film containing a radiation-curable compound and a photopolymerization sensitizer.

The hardness of the protective film 5 is the pencil hardness at 25°C (
JIS K-5400), H~8H, especially 2H~7
Preferably, it is configured such that H.

With this configuration, jitter is significantly reduced.

In addition, the protective film and the reflective layer do not peel off even when stored under high temperature/high temperature or changing temperature/humidity conditions.

More specifically, if the hardness of the protective film is softer than H, the jitter will increase, and if it is harder than 8H, the coating will become brittle (film-forming ability will be reduced, and the adhesive force with the reflective layer will be reduced).

The radiation-curable compound used to form such a protective film preferably contains oligoester acrylate.

Oligoester acrylate is an oligoester compound having multiple acrylate groups or methacrylate groups. The preferred oligoster acrylate has a molecular weight of 1,000 to 10,000, preferably 200
0 to 7000, and the degree of polymerization is 2 to 10, preferably
3 to 5 are listed. Among these, polyfunctional oligoester acrylates having 2 to 6, preferably 3 to 6 acrylate groups or methacrylate groups are preferred.

As polyfunctional oligoester acrylate, Aronix M-7100, M-5400, M-5500, M-5
700, M-6250, M-6500, M-8030,
Commercially available products such as M-8060 and M-8100 (manufactured by Toagosei Kagaku Co., Ltd.) can be used, and these are shown by the following formulas (A) and (B).

(A) (B) A-(-M-N-)-, -M-A A near acrylate group or methacrylate group, M:2
alcohol (e.g., ethylene glycol, diethylene glycol, 1,6-hexane glycol, bisphenol A, etc.) residue, N: dibasic acid (e.g., terephthalic acid, isophthalic acid, adipic acid, succinic acid, etc.) residue, n
:1 to IO1, preferably 2 to 5 Among these, those represented by (A) are preferred.

Such oligoester acrylates may be used alone.

Further, other radiation-curable compounds may be used in combination. In such a case, the oligoester acrylate is preferably present in an amount of 20 wt% or more in the radiation-curable compound.

The above oligoester acrylate can be used in combination with other radiation-curable compounds, such as acrylic acid, methacrylic acid, which has an unsaturated double bond that is sensitive to ionization energy and exhibits radical polymerizability. Acrylic double bonds such as acids or their ester compounds, allylic double bonds such as diallyl phthalate, unsaturated double bonds such as maleic acid and maleic acid derivatives, and groups that can be crosslinked or polymerized by radiation irradiation. Examples include monomers, oligomers, and polymers containing or introducing into the molecule. These are preferably polyfunctional, particularly trifunctional or more functional.

As a radiation-curable monomer, a compound with a molecular weight of less than 2000 is used, and as an oligomer, a compound with a molecular weight of 2000 to 100 is used.
00 is used.

These include styrene, ethyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol methacrylate, 1,6-hexane glycol diacrylate, 1,6-hexane glycol diacrylate, etc., but particularly preferred ones are as pentaerythritol tetraacrylate (methacrylate), pentaerythritol acrylate
(methacrylate), trimethylolpropane triacrylate (methacrylate), trimethylolpropane diacrylate (methacrylate), acrylic modified products of urethane elastomer (Tuboran 4040), or those into which functional groups such as C0OH are introduced,
Acrylate (methacrylate) of phenol ethylene oxide adduct, an acrylic group (methacrylic group) or ε-
Caprolactone - Compound with acrylic group, ■) (CH,=CHC00H2), -CCH,OH (special acrylate A) 2) (CH2=CHCOOH2)s CCH20Hs (special acrylate B) 3) [CH2=CH0C(OC3Ha) , -0CH2]
! -CCH2CH.

(Special acrylate C) (Special acrylate D) (Special acrylate E) ■ CH2CHa COOCH=CH.

(Special acrylate F) In the formula, a compound where m = 1, a = 2, b = 4 (hereinafter referred to as special pentaerythritol condensate A), a compound where m = 1, a = 3, b = 3 (hereinafter referred to as special pentaerythritol condensate A), Pentaerythritol condensate B), m=1, a=6, b=
o compound (hereinafter referred to as special pentaerythritol condensate C
), m = 2, a = 6, b = o (hereinafter referred to as special pentaerythritol condensate), and special acrylates represented by the following general formula.

(16 in n) CH2COOCH=CH2 (Special Acrylate G) 8) CH2=CHCOO-(CH,CH,O) 4COCH
=CH2 (special acrylate H) 9) CH, CH2COOCH=CH.

(Special Acrylate J) 10) (Special Acrylate J) In addition, as radiation-curable oligomers, acrylic modified products of urethane elastomers or C
Examples include those into which a functional group such as 0OH is introduced.

Furthermore, in addition to or in place of the above-mentioned compounds, a radiation-curable compound obtained by radiation-sensitizing a thermoplastic resin may be used.

Specific examples of such radiation-curable resins include acrylic acid, methacrylic acid, or acrylic double bonds such as ester compounds thereof, which have unsaturated double bonds exhibiting radical polymerizability, and diallylphthalate. It is a thermoplastic resin in which groups that can be crosslinked or polymerized by radiation irradiation, such as allylic double bonds and unsaturated bonds such as maleic acid and maleic acid derivatives, are contained or introduced into the molecule of the thermoplastic resin.

Examples of thermoplastic resins that can be modified into radiation-curable resins include vinyl chloride copolymers, saturated polyvinyl sulfate resins,
Examples include polyvinyl alcohol resins, epoxy resins, phenoxy resins, cellulose derivatives, and the like.

Other resins that can be used for radiation sensitivity modification include polyfunctional polyester resins, polyether ester resins, polyvinylpyrrolidone resins, and derivatives (PVP
Also effective are acrylic resins containing at least one of olefin copolymers), polyamide resins, polyimide resins, phenol resins, spiroacetal resins, hydroxyl group-containing acrylic esters, and methacrylic esters as polymerization components.

The thickness of the protective film of such a radiation-curable compound is 0.1
~30 μs, more preferably 1 to 10−.

If the film thickness is less than 0.1, it will be difficult to form a -like film (and the moisture-proofing effect will not be sufficient in a humid atmosphere).
The durability of the recording layer decreases.

Moreover, the jitter prevention effect is reduced.

If it exceeds 30, the recording medium is likely to warp or cracks may occur in the protective film due to shrinkage during curing of the resin film.

Such a coating film may usually be formed by combining various known methods such as spinner coating, gravure coating, spray coating, and dipping. The conditions for forming the coating film at this time may be appropriately determined in consideration of the viscosity of the mixture of coating film composition, the intended coating thickness, etc.

In the present invention, the radiation irradiated onto the coating film includes ultraviolet rays, electron beams, etc., but ultraviolet rays are preferred.

When ultraviolet rays are used, a photopolymerizable sensitizer is usually added to the radiation-curable compound as described above.

The photopolymerization sensitizer used in the present invention has the following general formula (I
) are preferred. By using this material with polyfunctional oligoester acrylate, the above-mentioned hardness can be easily obtained and the film properties can also be improved.

Furthermore, there is less peeling from the adhesive layer, and durability and moisture resistance are also improved.

General formula (I) n In the above general formula (I), R represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group, etc., especially a methyl group. , ethyl group, etc. are preferred.

L represents a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, such as -CH2H3, and H3-H3 is particularly preferred.

Y is a heterocyclic group, such as a morpholino group, a 2-morpholinyl group, a piperidino group, a 4-piperidinyl group, a 2-pyridyl group, a 2-quinolyl group, a -pyrrolidinyl group, a 1-pyrrolyl group, a 2-thienyl group, a 2- Represents a furyl group, etc.
Among these, a morpholino group is preferred.

Although R3- may be bonded to the benzene ring at any substitutable position of the benzene ring in general formula (I), it is preferably the 2-position of 1 -L-Y.

In the present invention, among the compounds represented by general formula (I), the following are most preferred.

Compound A This compound A is commercially available as I RGACURE907 (manufactured by Ciba Geigy, Japan).

The compound represented by the general formula (I) acts as a photopolymerization initiator or photopolymerization sensitizer during radiation curing.

The content of such a compound in the organic protective coating layer is preferably 0.1 to 20 wt%, preferably 1 to 10 wt%.

This is because if it is less than 0.1 wt%, its action as a photopolymerization initiator or photopolymerization sensitizer will not be sufficient, and if it exceeds 20 wt%, the remaining photopolymerization initiator or photopolymerization sensitizer will penetrate into the recording layer. This is because it adversely affects the recording layer.

Further, as the photopolymerization sensitizer, in addition to the compound represented by the above-mentioned general formula (I), the following known ones can be used in combination, if necessary.

For example, benzoin series such as benzoin methyl ether, benzoin ethyl ether, α-methylbenzoin, and α-chlordeoxybenzoin, ketones such as benzophenone, acetophenone, and bisdialkylaminobenzophenone, quinones such as acedraquinone and phenanthraquinone, and benzyl disulfide. and sulfides such as tetramethylthiuram monosulfide.

In order to cure a coating film containing such a photopolymerizable sensitizer and a radiation-curable compound using ultraviolet rays, various known methods may be used.

For example, an ultraviolet light bulb such as a xenon discharge tube or a hydrogen discharge tube may be used.

Moreover, an electron beam can also be used depending on the case.

On such a protective film 5, a layered or sheet-like protective layer made of resin may be further provided.

On the reflective layer 4 and/or between the recording layer 3 and the reflective layer 4,
Furthermore, other anti-jitter films may be provided.

Such anti-jitter films include plasma polymerized films and inorganic thin films, and when provided on the reflective layer 4,
It may function as a protective film itself, or a protective film may be further formed thereon.

The anti-jitter film 5 has a thickness of 0.05- or more, particularly 0.1-1
Preferably, the thickness is 0-.

If the film thickness is too thin, the effect of preventing jitter will be reduced, and if it is too thick, it will deviate from the CD standard or increase the cost, making it impossible to change the effect commensurate with the film thickness.

The plasma polymerized membrane to be used may be any known plasma polymerized membrane (contains C, in addition to H, O
, Cρ, F, and various other elements such as Si and N.

Among these, 1 of C, H and Si and O as necessary.
Those containing more than one species are preferred.

At this time, known source gases, plasma polymerization conditions, etc. may be used.

Since these plasma polymerized films are substantially transparent, they may be provided either above or below the reflective layer.

On the other hand, the inorganic film used may be made of various inorganic compounds, and may contain one or more of oxides, nitrides, carbides, silicides, etc. Alternatively, an adhesive layer may be provided in close contact.

The adhesive layer preferably contains a hydrolyzed condensate of an organic silicate compound, an organic titanate compound, an organic aluminate compound, or an organic zirconate compound, or a hydrolyzed condensate of a halide of Si, Ti, Aj2, or Zr.

Various known compounds can be used as the organic titanate compound, but alkyl titanates, substituted alkyl titanates, alkenyl titanates, and substituted alkenyl titanates are particularly preferred.

Further, as the organic zirconate compound, various known compounds can be used, but particularly preferred are alkylzirconate, substituted alkylzirconate, alkenylzirconate, and substituted alkenylzirconate.

Further, as the organic aluminate compound, aluminum alkoxide and aluminum chelate compound are preferable.

Among these, those having the following structural formula can be particularly preferably used.

M (OR,) (OR,) (OR3) (OR4) AI2
(OR1) (OR2) (OR3) Here, M represents Ti or Zr.

Further, R1, R2, R3 and R4 each represent a hydrogen atom or a substituted or unsubstituted alkyl group or alkenyl group.

However, it is preferable that at least two or more of R5-R4 are not hydrogen atoms but are alkyl groups or alkenyl groups.

Further, the number of carbon atoms in the substituted or unsubstituted alkyl group or alkenyl group is preferably 2 to 18.

In addition, as the group substituting the alkyl group or alkenyl group, a carboxyl group, an alkylcarboxy group, a substituted amino group such as a di(hydroxyalkyl)amino group, a hydroxyl group, an alkyloxycarbonyl group, etc. are suitable.

Specific examples of preferred organic titanate compounds are listed below.

T1 Tetraethyl titanate T2 Tetrapropyl titanate T3 Tetraisopropyl titanate T4 Tetra (n-butyl) titanate T5 Tetra (
Isobutyl titanate T6 Tetra (5ec-butyl) titanate T7 Tetra (tert-butyl) titanate T8 Tetra (2-ethylhexyl) titanate T9 Tetrastearyl titanate TIO Hydroxy titanium stearate Tll Isopropoxy titanium stearate T12 Hydroxy titanium oleate T13
Isopropoxy titanium oleate T14 Di-propoxy bis(acetylacetone) titanate T15 Di-n-butoxy bis(triethanolamine) titanate T16 Dihydroxy bis(raftic acid)
Titanate T17 Tetraoctylene glycol titanate T18 Jimmy propoxy bis(ethyl acetoacetate) titanate Specific examples of preferred organic zirconate compounds are also listed.

Tetra-n-propyl zirconate, tetra-1-propyl zirconate, tetra-n-butyl zirconate, tetra-1-butyl zirconate, zirconium tetraacetylacetonate, zirconium-2-ethylhexoate, zirconium naphthenic acid , diacetate zirconate, etc.

Further, specific examples of preferred organic aluminate compounds will be given.

Aluminum propylate, mono-5ec-butoxyaluminum diisoovirate, aluminum-5
ec-butyrate, ethyl acetoacetate aluminum diisopropylate, aluminum (ethylacetoacetate), etc.

Preferred organic silicate compounds are alkyl silicic acids, particularly tetra-lower alkyl (methyl, ethyl) silicic acids.

In addition, organic titanate compounds, organic zirconate compounds, organic aluminate compounds, and organic silicate compounds are
An oligomer or colloidal condensed oxide may be formed in the coating liquid.

As the halide, silicon halide, particularly silicon tetrachloride, is preferred.

To form an adhesive layer using such an organic silicate compound, organic titanate compound, organic aluminate compound, organic zirconate compound or halide,
These may be diluted with a solvent such as water, alcohol, hexane, benzene, etc., or a mixed solvent thereof, applied onto the dye layer, left to stand, and hydrolyzed to obtain a condensate.

There are no particular restrictions on the method of applying the adhesive layer, and a spin cord or the like may be used.

The thickness of the adhesive layer is preferably 10 to 300, particularly 20 to 100. If the thickness is less than this range, optical non-uniformity will occur and adhesive strength will be insufficient.
Moreover, if this range is exceeded, the optical properties will change and 1
It becomes impossible to increase both reflectance and modulation degree.

To perform recording or additional writing on the optical recording medium 1 having such a configuration, recording light of, for example, 780 nm is irradiated in a pulsed manner through the substrate 2.

As a result, the recording layer 3 absorbs light and generates heat, and the substrate 2 is also heated at the same time. As a result, the recording layer material such as the dye melts or decomposes near the interface between the substrate 2 and the recording layer 3, and pressure is applied to the interface between the recording layer 3 and the substrate 2, deforming the bottom wall and side wall of the group. Sometimes I let it happen.

In this case, the decomposed product M containing the melted product and decomposed product of the recording layer 3
61 generally remains in a shape covering the bottom and border of group 23.

The material of the decomposed product layer 61 is a material that does not substantially contain the substrate material, and is composed of a decomposed product of the recording layer material or a mixture of the decomposed product of the recording layer material and the recording layer material.

The thickness of the decomposed product layer 61 is usually about 30 to 90% of the thickness of the recording layer 3.

Generally, voids 63 are formed on the decomposed product layer 61 at the interface with the reflective layer, and the decomposed product layer 61 and the voids 63 are formed in the pit portions 6 .

The thickness of the void 63 is usually about 10 to 70% of the thickness of the recording layer 3.

Further, in such a recording process, although the substrate 2 may not be deformed, the pit portions 6 of the substrate 2 are usually depressed into a concave shape due to the pressure during heating. The amount of depression in the substrate 2 becomes thicker as the size of the pit portion 6 becomes larger (usually 0
The capacity is approximately 300 people.

Further, the recording layer 3 or its decomposition products may remain on the gap 63 in close contact with the reflective layer 4 with a very small thickness.

In this way, a layer containing substantially no substrate material is formed at the interface between the substrate 2 and the recording layer 3 in the pit portion 6.

The present inventors confirmed as follows that no substrate material was included between the substrate 2 and the recording layer 3 in the pit portion 6.

First, several sample pieces were prepared from one optical recording medium 1 that had been produced and recorded under certain conditions, and the protective film 5 and reflective layer 4 were peeled off from each sample.

Next, the surface of the substrate 2 was cleaned with an alcohol-based solvent.

In this case, two types of cleaning conditions were used: weak cleaning in which the substrate was lightly shaken in an alcohol-based solvent, and strong cleaning in which cleaning was performed while applying ultrasonic waves.

Then, the substrate 2 after cleaning is examined using a scanning tunneling microscope (ST).
M) The thickness within the group of substrate 2 was determined from the output image.

As a result, in the case of the sample subjected to ultrasonic cleaning with strong cleaning power, the pit portion 6 of the substrate 2 was flat or recessed.

In contrast, the pit portions 6 of the substrate 2 of the sample cleaned with weak cleaning power were raised.

From these results, the raised parts of the sample cleaned with weak cleaning power are the result of decomposition of the recording layer material such as dye due to heat, that is, it contains decomposed products of the recording layer material whose solubility has decreased. This layer is considered to be

In fact, liquid chromatography is used to collect the residue after washing.
As a result of measurements using absorption spectra, FTIR, MAS, etc., it has been confirmed that in the case of weak cleaning power, there are decomposed products and no substrate material is included at the bottom of the pit.

Thus, the mechanism of the present invention is described in Nikkei Electronics, January 23, 1989, No.

465, the proposal disclosed in P2O3, namely, ``When the recording laser beam is irradiated, the dye layer melts or decomposes and the substrate also softens, and the dye material and substrate material mix at the interface, causing pits to form. This mechanism is different from that of ``formed.''

As a result, the pit shape becomes good and the S/N ratio improves.

Note that the power of the recording light is approximately 5 to 9 mW, and the linear velocity of rotation of the substrate is approximately 1.2 to 1.4 m/s.

After forming the pit portion 6 in this way, for example, 78
When a reproduction light of 0 nm is irradiated through the substrate 2, a phase difference of the light occurs due to the pit portion 6, and the reflectance decreases to 60% or less, particularly 50% or less, and even 40% or less of the unsaturated portion. .

On the other hand, since the unrecorded portion shows a high reflectance of 60% or more, especially 70% or more, reproduction according to the CD standard is possible.

The power of the reproduction light is approximately 0.1 to 10 mW.

<Examples> Example 1 A recording layer containing a dye was formed on a polycarbonate resin substrate having continuous groups and having a diameter of 120 mm and a thickness of 1.2 mm. On this recording layer, 100% of Au was deposited by vapor deposition.
A reflective layer was formed by forming a layer with a set thickness of 0. Further, an ultraviolet curable resin containing oligoester acrylate was coated and cured with ultraviolet rays to form a protective film having a thickness of 10 mm, thereby obtaining an optical recording disk sample.

The dyes contained in the recording layer of each sample are shown below.

1 1 CH3CH3 The recording layer was formed by spin cord coating while rotating the substrate at 500 rpm.

A 1.5 wt % methanol solution was used as the coating solution. The thickness of the dye layer after drying was 1300.

The dye contained in the recording layer of each sample, its content ratio, the refractive index (n) and extinction coefficient (k) of the recording layer,
It is shown in Table 1 below.

n and k were determined by forming a film containing the above-mentioned dye on a measurement substrate to a dry film thickness of 600 mm to obtain a test record M, and measuring n and k of this test recording layer.
This measurement was carried out in accordance with the description in "Optics" (written by Kozo Ishiguro, Benshiro Zensho), pages 168 to 178.
Furthermore, when measuring the recording layer containing the dyes A1 and A2, methanol was used as the solvent, and a polycarbonate substrate was used as the measurement substrate.

Table 1 No.

■(This invention) Al(90)+A2(10) 2
．． 4 0.10 For each sample obtained, wavelength 78
Compact disc signals were recorded using a 0 nm, 7 mW laser, and then reproduced using a commercially available compact disc player.

As a result, sample No. 1 has a high S/N ratio,
Good playback was possible.

Next, the sample No. 0. One to two sample pieces were obtained.

After peeling off the protective film and the reflective layer, the surface of the substrate was washed with methanol under different conditions for 2 minutes.

In this case, samples that were lightly washed in methanol (like shaking) are called samples No. 0. and 1-1, and samples that were washed strongly while applying ultrasound are called samples No. 0.1 and 1-1.
-2.

After cleaning, an Au film with a thickness of 100 nm was formed on the substrate surface by sputtering, and the surface conditions of both samples were imaged using a scanning tunneling microscope (STM) sold by Toyo Technica.

The 37M image of sample No. 1-1 is shown in FIG. 2, and the 37M image of sample No. 0.1-2 is shown in FIG. 3.

From Figures 2 and 3, sample N was subjected to mild washing.
0.1-1 indicates that the film thickness at the pit portion is thick within the group (it can be confirmed that sample No. 011-2, which was subjected to strong cleaning, has a substantially constant film thickness within the group).

In addition, in order to more accurately confirm the film thickness within a group, a graph showing the surface condition in a cross section along the group was created. Sample no.

The graph of sample No. 1-1 is shown in FIG. 4, and the graph of sample No. 1-2 is shown in FIG.

The vertical axis of the graph is the height in the substrate thickness direction from the reference plane, and the horizontal axis is the distance in the group direction. Further, in the figure, arrow a indicates a pit portion, and arrow s indicates a position outside the pit portion.

As is clear from Figure 4, sample N was lightly washed.
0.1-1 has a raised pit portion as shown by symbol a.

On the other hand, as is clear from FIG. 5, in sample No. 1-2 which was subjected to strong cleaning, the pit portion was slightly depressed as indicated by symbol a.

From these facts, it is thought that the raised portion of sample No. 1-1 is a layer of decomposition products containing decomposed products of the dye whose solubility has decreased, that is, the dye has been decomposed by heat.

Then, after peeling off the recording layer in the pit area and the layer formed at the interface with the substrate using ultrasonic waves, analysis revealed that there were decomposed products and that substantially no substrate material was contained. I was able to confirm that this was not the case.

From these results, the effects of the present invention are clear.

Furthermore, recording layers as shown in Table 2 below were formed using the dyes A1 and A2.

table sample No.

Dye (wt%) 1-3 (comparison) At (100) 2.
4 0.021 Al(90)
+A2 (10) 2.4 0.101-4 (comparison) A2 (100) 2.3 1.
35 For each sample obtained, wavelength 7
A compact disc signal was recorded using an 80 nm, 7 mW laser, and then played back using a commercially available compact disc player.As a result, sample No. In Sample No. 1, good reproduction was possible as described above, but in the other samples No. 1-3, the absorption of the dye layer was insufficient and recording was impossible. Further, in the case of No. 0.1-4, the reflection was small and reproduction was impossible.

Example 2 A recording layer containing the following dye was formed on an amorphous polyolefin resin substrate of 120 mm diameter and 1.2 mm thickness having continuous groups. On this recording layer, Au is deposited to a thickness of 1000 mm by vapor deposition to form a reflective layer, and then an ultraviolet curable resin containing oligoester acrylate is coated and cured by ultraviolet light to form a protective film of 10 scale thickness. An optical recording disk sample was obtained.

The dyes contained in the recording layer of each sample are shown below.
In addition, the transmission and reflection spectra of the dye Bl below are shown in the sixth column.
The figure shows the transmission and reflection spectra of dye B2 below.
As shown in the figure.

2. The recording layer was formed by spin cord coating while rotating the substrate at 50 rpm.

A 1.5 wt % solution of dichloroethane was used as the coating solution. The thickness of the dye layer after drying was 1300.

The dye contained in the recording layer of each sample, its content ratio, the refractive index (n) and extinction coefficient (k) of the recording layer,
It is shown in Table 3 below.

When measuring n of the recording layer, dichloroethane was used as the solvent and a glass substrate was used as the measurement substrate.

table 3 sample No.

Dye (wt%) 2-1 (comparison) Bl (100) 2.
6 0.032-2 Bl(90)
+82 (10) 2.4 0.102-3 (comparison) Bl (50) + B2 (50) 2.0
0.752-4 (comparison) B2 (100)
1.9 1.15 For each sample obtained,
As in Example 1, a compact disc signal was recorded using a laser with a wavelength of 780 nm and a power of 7 mW, and then reproduced using a commercially available compact disc player. As a result, sample No. 0.2-2 was reproduced well. However, in the other sample No. 0.2-1, the absorption of the dye layer was low and the recording sensitivity was lowered. Also,
No.

In samples 2-3 and 2-4, the reflection was small and reproduction was impossible.

Example 3 The following dye layer was formed on a polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm and having continuous groups. The group had a depth of 900 people, a width of 0.5-, and a land width of 1.1-.

The dye layer was a compatible film containing 196 wt% of C and 24 wt% of C as described below.

cI20. - The dye layer was applied by spin cord coating while rotating the substrate at 50 Orpm.

As a coating solution, a 3 wt % solution of cellosolve was used for the dye layer containing the dye CI. The thickness of the dye layer after drying was measured by about 1,000 people. The thickness of the dye layer was measured using a cross-sectional measuring device (PMS-1 manufactured by Elionix ■) using a scanning electron microscope.

The refractive index n of the dye layer at 780 nm was 2.3, and the extinction coefficient was 0.08.

On this dye layer, Au was deposited to a thickness of 1000 nm by vapor deposition to form a reflective layer, and the following coating composition was applied and cured with ultraviolet light to form a protective film, thereby obtaining an optical recording disk sample.

The protective film was formed by spinner coating a coating composition containing the following radiation-curable compound and photopolymerizable sensitizer.

(Coating composition) Multifunctional oligoester acrylate [oligoester acrylate (trifunctional or higher) 30% by weight, trimethylpropane acrylate 70% by weight, trade name Aronix M-
8030; manufactured by Toagosei Co., Ltd.] 100 parts by weight of photopolymerization sensitizer (said compound A: trade name I RGACURE907, manufactured by Nippon Ciba Geigy Co., Ltd.)
After applying 5 parts by weight of such a coating composition, 15 se of 120 W/cm ultraviolet rays were applied.
c irradiation to crosslink and cure the film to form a cured film.

The film thickness at this time was 5-.

This is designated as sample No. 0.11.

100 parts by weight of polyfunctional oligoester acrylate Aroex M-8 used in the protective film of sample No. 11
Sample No. 030 was replaced with 50 parts by weight of Aroex M-400 (monomer with six or more functional functions) and 50 parts by weight of Aroex M-309 (a trifunctional monomer).

Sample No. 12 was prepared in the same manner as No. 11.

In addition, 50 parts by weight of 100 parts by weight of Aloex M-8030 of sample No. 11 was added to Aloex M-1.
Sample No. 11 (monofunctional monomer) was replaced with sample No. 11, except that a synthetic rubber hot-melt adhesive HM-1275 (manufactured by HB Fuller Japan Co., Ltd.) was applied as an adhesive layer to a thickness of 30 mm using a roll coater. Similarly, sample No.
No. 13 was prepared.

Furthermore, sample No. 11 Aloex M-803
0 (100 parts by weight), Aloex M-6100 (2
Sample No. 0.14 was prepared in the same manner as Sample No. 11 except that 50 parts by weight of functional oligoester acrylate) and 150 parts by weight of the above Aloex M-11 were used.

A CD signal (9 types of pulses from 190 to 720 kHz, duty: 50%) was recorded on each sample obtained using a laser having a wavelength of 780 nm. The recording power was 7 mW, and the linear velocity during recording was 1.3 m/s.

Note that recording was done in the group section. Tracking during recording was performed using push-pull track error control.

Then, it was played back on a commercially available compact disc player. The reproduction power was 0.2 mW.

As a result, in each of these samples, a reflectance of 70% or more was obtained in the unrecorded portion, and the reflectance of the recorded portion of the 11T pulse of the CD signal was 40% or less of the reflectance of the unrecorded portion.
Furthermore, pits similar to those in Example 1 were formed in these samples.

Next, jitter was measured for each sample.

Jitter is measured using MEGURO CD Jitter Meter M.
Measured with JM-631.

The results are shown in Table 4.

Table No. Pencil hardness (ns) 11
2H100 124H90 13B >200 14 4B >200 From the results shown in Table 4, it can be seen that as the pencil hardness increases, the jitter decreases significantly.

Note that sample No. 11.12 had good weather resistance, corrosion resistance, and durability.

Example 4 In sample No. 11 of Example 3, the dye was changed as shown in Table 5 below.

The dye D1 quencher Q1 used is as follows.

2 CH3 CH3 Quencher 0 However, a diacetone alcohol solution was used to form the dye layer.

These n and k at 770.780.790 nm are shown in Table 5.

From the results shown in Table 5, 770~
It can be seen that good n and k changes are obtained at 790 nm.

For each sample obtained, 780
Recording was performed at nm, and the reproduction wavelength was set to 770.780.79.
The wavelength was changed to 0 nm and regeneration was performed.

As a result, with samples No. 0.31 and 32, good recording and reproduction could be performed at any wavelength. In these samples, a reflectance of 70% or more was obtained in the unrecorded portion, and the reflectance of the recorded portion of the 11T pulse of the CD signal was 40% or less of the reflectance of the unrecorded portion. In addition, in these samples, pits were formed at the interface between the substrate and the recording layer in the signal recording portion, as in Example 1.

In addition, in sample No.33, 780.790 nm
However, regeneration could not be performed at 770 nm.

Furthermore, recording could not be made with sample No. 0.34.

Next, in each of the above samples, the thickness of the dye layer in the group part was less than 500 and
A sample having a thickness exceeding 0.00 mm was prepared, and a recording/reproducing test similar to that described above was conducted. As a result, in samples with less than 500 people and more than 1500 people, the reflectance of the group portion was less than 60%, and sufficient reflectance and pits required for reproduction could not be obtained.

Example 5 A dye layer was formed on an amorphous polyolefin substrate having continuous groups and having a diameter of 120 mm and a thickness of 1.2 mm. The group has a depth of 1200 people and a width of 0.5μ.
The land width was 1°1)111.

A random copolymer of cyclic olefin and ethylene was used as the amorphous polyolefin.

The oxygen permeation amount Q of this substrate is 0.4X 10-"cm"cIll-"s-(cm
Hg)-.

The pigment layer is E below. 1 was used.

The dye layer was applied by spin cord coating while rotating the substrate at 500 rpm.

As a coating solution, 2W of cyclohexanone was used for the pigment layer.
A t% solution was used. The thickness of the dye layer after drying is 1300
It was about the size of a person. The thickness of the dye layer was measured using a cross-sectional measuring device (Elionix ■) using a scanning electron microscope.
The test was carried out using PMS-1) manufactured by Kogyo Co., Ltd.

The refractive index n of the dye layer at 780 nm was 2.6, and the extinction coefficient was 0.1.

On this dye layer, Au was deposited to a thickness of 1000 nm by vapor deposition to form a reflective layer, and a coating composition of the present invention was applied and cured with ultraviolet light to form a protective film, thereby obtaining an optical recording disk sample. .

The protective film was formed by spinner coating the coating composition of Example 2 containing the radiation-curable compound of N0.11 and a photopolymerizable sensitizer.

After coating such a coating composition, it was cross-linked and cured by irradiation with ultraviolet rays of 120 W/cm for 15 seconds to form a hardened film.

The film thickness at this time was 5-.

This is designated as sample No. 0.41.

Next, Sample No. 0.42 was obtained in exactly the same manner as above except that the substrate material in Sample No. 0.41 was changed to polycarbonate and the coating solution for the dye layer was a 3 wt % solution of ethyl cellosolve.

The oxygen permeability Q of the polycarbonate substrate is 25x 10-
It was 10cm"-cm-"s-'.(cmHg)-'.

Furthermore, sample No. 41. N0. In Sample No. 42, 10% by weight of the following quencher Ql was added to dye D1, and in the same manner as above, sample No. 43,
I got N0.44.

Quencher-Ql Each of these samples No. 41 to 44 was irradiated with a 1.5 kW Xe lamp through the substrate from a distance of 20 cm, and the dye residual rate was plotted against the irradiation time.

The dye residual rate is (100-R)/(100-RO) (where R and Ro are the initial and 7% after irradiation, respectively)
Reflectance at 80 nm).

The results are shown in FIG.

From the results shown in FIG. 8, it can be seen that the light resistance of sample No. 0.41 is significantly improved even without using a quencher.

In addition, in these samples, pits similar to those described above were formed, and good recording and reproduction could be performed.

Example 6 On an amorphous polyolefin substrate of 120 mm diameter and 1.2 mm thickness having continuous groups, a dye layer was formed by vapor deposition using the following dye. The group is 80 deep
0 people, width 0. 4-, and the land width was 1.2μ.

A dye layer was deposited on this substrate using a phthalocyanine having the following central metal.

JYE I Si[03i(CHx)s]zE 2
Cu E3 RuCjt Note that the dye was vapor-deposited by a resistance heating method, and the vapor-deposition conditions were as follows.

■Working pressure: I x 10-'Torr ■Substrate temperature: 20° C. ■Vapor deposition rate: 600 layers/min The thickness of the dye layer deposited in this way within the group was 1,200 layers.

In this case, the thickness of the dye layer was measured using a cross-sectional measuring device (PMS-1 manufactured by Elionix ■) using a scanning electron microscope.
This was done by

Table 6 shows the values of n and k at 780 nm.

A reflective layer and a protective film were formed on this dye layer in exactly the same manner as in Example 4 to obtain an optical recording disk sample.

The film thickness at this time was 5-.

The samples obtained in this manner are referred to as samples No. 0.51, 52, and 53 depending on the dyes used.

CD signals (9 types of pulses from 190 to 720 kHz, duty: 50%) were recorded on these samples using a laser with a wavelength of 780 nm. The recording power was 10 mW, and the linear velocity during recording was 1.3 m/s.
Note that recording was done in the group section. Tracking during recording was performed using push-pull track error control.

Then, it was played back on a commercially available compact disc player. The reproduction power was 0.2 mW.

For each of these samples, the reflectance in the unrecorded area (%
) and 11T of the CD signal with respect to the reflectance of this unrecorded area.
The reflectance ratio (%) of the pulse recording area was determined.

These results are shown in Table 6.

In addition, in each of these samples, pits similar to those in Example 1 were formed, and the jitter was also low.

Example 7 In sample No. 11 of Example 2, an anti-jitter film was formed as shown in Table 7 below.

Table 7 N0. Below reflective layer Above reflective layer 1 2 63　　　　　　C 64D 5 6 67 G 68 H Jitter prevention film A plasma polymerized membrane monomer gas Tetramethoxysilane carrier gas r operating pressure power frequency Film thickness (measured with an ellipsometer) Jitter prevention film B plasma polymerized membrane monomer gas Methyl methacrylate carrier gas r operating pressure power frequency Film thickness 05CCM 5CCM 0.07 Torr 50W 13.56MHz 0.5- 05CCM 5CCM 0.05 Torr 50W 13.56MHz one Jitter prevention film C plasma polymerized membrane monomer gas Tetramethoxysilane carrier gas r operating pressure power frequency Film thickness Jitter prevention film D plasma polymerized membrane monomer gas triethylsilane carrier gas r operating pressure power frequency Film thickness 05CCM CCM 0.05 Torr 50W 13.56MHz 0.3- 05CCM CCM O,06 Torr 50W 13.56MHz 0.5- Jitter prevention film E sputtered film S　i　O2 Film thickness 0.5- Jitter prevention film F sputtered film iOz Film thickness 0.3- Jitter prevention film G sputtered film O3 Film thickness 0.3 units Jitter prevention film H sputtered film 1AnON Film thickness 0.5μ In these samples 61 to 68, A decrease was seen.

Jitter Example 8 In sample No. 11 of Example 2, the following adhesive layer No. 1 was provided between the recording layer 3 and the reflective layer 4. 1 to 4 were installed.

[Adhesive layer N0. l] Ethyl acetate and ethyl alcohol were mixed at a ratio of IQ: 11, and while stirring, 5i (QC2H5) 4 was gradually added at a ratio of 2/25 to ethyl acetate, and the solution was left to stand for 3 to 4 days. - A coating solution was obtained by further diluting 10 times with propatool. This solution was spin-coded onto the dye layer and dried at 60° C. for 30 minutes.

[Adhesive Layer No. 2] Compound T14 was diluted 30 times with a 1:1 mixed solvent of i-propanol and water, spin-coded onto the dye layer, and dried.

[Adhesive Layer No. 3] Ethyl acetoacetate aluminum diisopropylate was diluted 30 times with a 3:1 mixed solvent of i-propatool:water, spin-coded onto the dye layer, and dried.

[Adhesive layer N0.4] Tetraethyl acetoacetate Zr (oxychloride Zr
A 2% n-propertool solution (synthesized by reacting 1 mole of ethyl acetoacetate with 4 moles of ethyl acetoacetate in the presence of sodium carbonate) was spin-coded onto the dye layer and dried.

The thickness of each adhesive layer after drying was 50 people.

When we conducted an experiment on these samples in which adhesive tape was pasted on the protective film and then peeled off, peeling of the reflective layer was observed in the samples without an adhesive layer, but no peeling was observed in the samples with an adhesive layer. It wasn't done.

<Effects of the Invention> According to the present invention, since the reflectance is high and the reflectance is greatly reduced at the pit portion, good optical recording that can be reproduced according to the CD standard is possible.

Then, an optical recording medium with a good pit shape, a high S/N ratio, and which can perform good recording and reproduction is realized.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing the optical recording medium of the present invention. FIGS. 2 and 3 are photographs of output images from a scanning tunneling microscope of the substrate surface after the recording layer of the optical recording medium of the present invention has been washed and removed. FIGS. 4 and 5 are graphs showing the surface condition in a cross section along a group of substrate surfaces of the optical recording medium of the present invention, respectively. FIGS. 6 and 7 are graphs showing the transmission and reflection spectra of the dye used in the present invention, respectively. FIG. 8 is a graph showing the results of light resistance. Explanation of symbols 1... Optical recording medium 2... Substrate 21... Land portion 23... Group 3... Recording layer 4... Reflective layer 5... Protective film 6... Pit portion 61...Degraded product layer 63...Void application Person: TDT-K Co., Ltd., agent Patent attorney, Seika Ishii, patent attorney
Increase 1) Tatsuya F ■ G. Buki fallen? rJ Meunoshima Gornm) Akichou (/nm) ■G. Length (/nm) G- 0 2゜0 4゜0 Irradiation time/hr

Claims (17)

[Claims] (1) A recording layer containing a dye is provided on a substrate, and a reflective layer is laminated in close contact with this recording layer. Recording light is irradiated onto the recording layer to form pits, and playback is performed. An optical recording medium that is reproduced by light, wherein a layer containing a decomposed product of a recording layer material and substantially not containing a substrate material is present at an interface between the substrate and the recording layer in the pit portion. An optical recording medium characterized by: (2) The optical recording medium according to claim 1, wherein a void is formed in the pit portion. (3) The optical recording medium according to claim 1 or 2, wherein the recording layer has an extinction coefficient k of 0.03 to 0.25 at the wavelengths of recording light and reproduction light. (4) The optical recording medium according to claim 3, wherein the recording layer has a refractive index n of 1.8 to 4.0 at the wavelengths of recording light and reproduction light. (5) The wavelength of recording light and reproduction light is 600 to 900 nm.
The optical recording medium according to any one of claims 1 to 4. (6) The optical recording medium according to any one of claims 1 to 5, wherein the recording layer has a thickness of 500 to 2000 Å. (7) When the reproduction light is irradiated from the substrate side, the reflectance of the unrecorded portion is 60% or more, and the reflectance of the recorded portion is 60% or less of the reflectance of the unrecorded portion. The optical recording medium according to any one of the above. (8) The optical recording medium according to any one of claims 1 to 7, wherein the recording layer is a coating film. (9) The optical recording medium according to any one of claims 1 to 7, wherein the recording layer is a vapor deposited film. (10) The optical recording medium according to any one of claims 1 to 9, wherein the recording layer contains two or more types of dyes. (11) The optical recording medium according to any one of claims 1 to 10, further comprising a protective film laminated on the reflective layer. (12) The optical recording medium according to any one of claims 1 to 11, wherein the protective film is made by radiation-curing a radiation-curable compound. (13) The pencil hardness of the protective film at 25°C is H~8
The optical recording medium according to claim 12, which is H. (14) The optical recording medium according to claim 12 or 13, wherein the protective film has a thickness of 0.1 μm or more. (15) The amount of oxygen permeation of the substrate at 25°C is 5×1
0^-^1^0cm^3・cm^-^2・s^-^1・
(cmHg)^-^1 or less. (16) The optical recording medium according to any one of claims 1 to 15, further comprising an adhesive layer between the recording layer and the reflective layer. (17) The optical recording medium according to any one of claims 1 to 16, further comprising an anti-jitter film on the reflective layer or between the reflective layer and the recording layer.