JPH1196591A - Optical information recording material and optical information recording medium, using that - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease wavelength dependence while maintaining a high refractive index by selecting a polymer compd. to optimize the complex refractive index of a dye at the recording and reproducing wavelength and to optimize the wavelength dispersion of the complex refractive index near the recording and reproducing wavelength of the dye at the recording and reproducing wavelength. SOLUTION: A polymer compd. or a second dye to be added to a first dye which substantially contributes to recording and reproducing is selected from compd. having solubility with the first dye. By addition of the second dye or polymer compd., the wavelength dependence is decreased. The effect of addition of the second dye or polymer compd. is evaluated by the changes in the absorption spectrum of dye molecules due to the addition. The wavelength dependence of complex refractive index can be easily judged by the absorption spectrum. The absorption band is controlled to be present in the all measurable wavelength region in order to improve the complex refractive index and wavelength dependence. Therefore, the absorption band of the dye is limited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording material comprising a dye and a high molecular compound, an optical information recording material comprising a first dye and a second dye, and a composition comprising these optical information recording materials. And an optical information recording medium.

[0002]

2. Description of the Related Art Heretofore, recording materials constituting an optical information recording medium are composed of a quencher for improving weather resistance and a specific additive used for preventing association of dyes to achieve a high refractive index. Basically, the dye is used alone, although there may be cases where these are mixed.

In a write-once optical information recording medium such as a CD-R or a DVD-R, a CD, CD-ROM, DVD,
In order to obtain compatibility with VD-R and the like, a reflectance of about 65% or more is specified by standards. However, this reflectance cannot be obtained by the dye film alone. Therefore CD-
Media such as R and DVD-R use a metal reflective layer such as gold having a high reflectivity. In this case, the reflectance from the dye layer alone is not required, but the recording principle using phase change requires a large change in the refractive index of the dye before and after recording, and eventually a large refractive index is required for the dye itself. Will be done.

The refractive index is required to be 2 or more, which cannot be obtained with ordinary organic substances. However, in the case of dyes, since anomalous dispersion based on absorption is used, the dye is locally localized, that is, at the maximum absorption wavelength. 2.0-3 in the wavelength range slightly shifted to long wavelength.
A large refractive index such as 0 can be obtained. On the other hand, it is said that the absorption is preferably small from the viewpoint of securing the reflectance, and specifically, the imaginary part k of the complex refractive index is preferably about 0.03 to 0.05.

The characteristic of the complex refractive index (n-ik) that satisfies both the refractive index and the absorption is obtained at a wavelength slightly shifted from the absorption maximum wavelength to the longer wavelength side. The wavelength slightly deviated from the absorption maximum wavelength to the longer wavelength side, that is, the recording / reproducing wavelength, has both the real part n and the imaginary part k of the complex refractive index,
Since the region exhibits large wavelength dependence, if the recording / reproducing wavelength fluctuates due to individual differences in laser oscillation wavelength (eg, ± 10 nm) or temperature characteristics (eg, 0.15 nm / ° C.), the disk characteristics (recording sensitivity and reflectance) ) Will change greatly. Also, it becomes very difficult to match the dye to the recording / reproducing wavelength. For this reason, dyes cannot respond to changes in recording / reproducing wavelengths (the laser wavelengths continue to change due to the trend toward shorter wavelengths and the productivity of semi-rigid lasers). Have been.

However, in selecting a dye, in the case of many dyes, the disk characteristics with respect to the recording / reproducing wavelength are not so inferior, and are considered to have some problems in terms of reflectance, recording sensitivity, and the like. . In this case, a method of improving the wavelength matching by changing the substituents of the dyes, the central metal, and the like is used. However, this method has a limitation in the wavelength matching (a large adjustment is difficult). In some cases, you lose the characteristics you have.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to achieve the following with respect to an optical information recording medium. (1) Enlargement of wavelength margin: A large disc characteristic change (recording sensitivity, reflectivity, etc.) is prevented from being caused even by a wavelength variation of recording / reproducing light due to an individual difference of a laser or an environmental temperature. (2) Expanding the selection range of the dye: Even if the wavelength matching with respect to the recording / reproducing wavelength is incomplete due to the combination of the substituent, the central metal, etc., the wavelength matching is not greatly impaired, and the inherent characteristics of the dye are not significantly impaired. Improve the performance. (3) Improvement of research and development efficiency by changing the recording / reproducing wavelength, etc. The time required for work (research and development) such as synthesis and evaluation of an enormous amount by introducing a substituent or a metal to the basic skeleton of the dye is reduced. (4) Clarification of the value of the refractive index (the real part of the complex refractive index) and the wavelength dependence.

[0008]

The complex refractive indices n and k are:
The following Kramers-Kronig relationship is given by [Equation 1]:

[0009]

(Equation 1)

(For example, "The 3rd Light Pencil" p.243 New Technology Communications). As is clear from the above equation, on the long wavelength side of the absorption peak wavelength, n is large near a wavelength where k is large, and conversely, n is small near a wavelength where k is small.

From the Kramers-Kronig relationship, the real part n of the complex refractive index at a certain wavelength to be known is not determined only by the imaginary part k of the complex refractive index at the wavelength, but ω ′ is ω
It can be seen that k is also affected in a region that does not greatly depart from (a certain natural frequency). In other words, the sharper the absorption curve and the stronger the absorption, the larger the value of n near the absorption peak, but this n does not involve k at many wavelengths. Therefore, at wavelengths far from the absorption peak, n decreases sharply (wavelength dependence increases) as compared with the vicinity of the absorption peak wavelength.

On the other hand, in the case where the absorption curve is relatively broad, n is related to k at many wavelengths, whether near the absorption peak or at a wavelength far from the absorption peak. Become smaller. However, since the value of n near the absorption peak strongly depends on the value of k at the peak wavelength, the value of n is smaller than that of a sharp absorption curve with strong absorption. In other words, the higher the absorption, the narrower the absorption width, the larger the maximum value of n and the greater the wavelength dependence, and conversely, the wider the absorption width, the smaller the wavelength dependence of n.

In the current write-once optical information recording medium, the control of the complex refractive index n, k is performed by modifying the dye itself, but this modification may completely change the characteristics of the dye itself. In many cases, the relationship between the complex refractive index and the dye structure is not clear, and the improvement of the wavelength dependence of the dye having a high n at the recording / reproducing wavelength and an appropriate k is performed by modifying the substituent or the central metal. Very difficult to do with.

The present invention utilizes the above-mentioned basic phenomena in order to solve this problem. The present invention maintains a high refractive index as a recording layer, has a small wavelength dependence in the refractive index, and furthermore has a certain degree. It is possible to have the absorption of.

The optical information recording material according to claim 1 is an optical information recording material comprising a dye and a polymer compound, wherein the polymer compound has an optimum complex refractive index at the recording / reproducing wavelength of the dye. And to optimize the wavelength dispersion of the complex refractive index near the recording / reproducing wavelength of the dye at the recording / reproducing wavelength.

An optical information recording material according to claim 2 is an optical information recording material comprising a first dye and a second dye, wherein the second dye has a more complex refractive index than the first dye. The wavelength dispersion of the first dye is optimized for the complex refractive index at the recording / reproducing wavelength, and the wavelength dispersion of the complex refractive index near the recording / reproducing wavelength of the optical information recording material at the recording / reproducing wavelength. It is characterized by being for optimization.

The optical information recording material according to claim 3 is the optical information recording material according to claim 2, wherein the second dye is
Of the plurality of absorption bands present in the second dye, 300 n
In the long wavelength region of m or more, an absorption band exists only near the recording / reproduction wavelength, or when there are a plurality of absorption bands other than near the recording / reproduction wavelength and near the recording / reproduction wavelength, the recording / reproduction wavelength It is characterized in that the absorption coefficient of a nearby absorption band is selected from a dye that is sufficiently larger than the absorption coefficients of the other absorption bands.

An optical information recording medium according to claim 4, wherein at least a recording layer and a reflection layer are provided on a substrate, wherein the recording layer comprises a dye and a polymer compound material; The polymer compound material optimizes the complex refractive index at the recording / reproducing wavelength of the dye, and optimizes the wavelength dispersion of the complex refractive index near the recording / reproducing wavelength of the dye at the recording / reproducing wavelength. Characterized in that:

An optical information recording medium according to claim 5, wherein at least a recording layer and a reflective layer are provided on a substrate, wherein the recording layer comprises a first dye and a second dye. The second dye has a smaller wavelength dispersion of the complex refractive index than the first dye, optimizes the complex refractive index at the recording / reproducing wavelength of the first dye, and records / reproduces the recording layer. The wavelength characteristic of the complex refractive index in the vicinity of the wavelength is optimized at the recording / reproducing wavelength.

The optical information recording medium according to claim 6 is the optical information recording medium according to claim 5, wherein the second dye is
Of the plurality of absorption bands present in the second dye, 300n
In the long wavelength region of m or more, an absorption band exists only near the recording / reproduction wavelength, or when there are a plurality of absorption bands other than near the recording / reproduction wavelength and near the recording / reproduction wavelength, the recording / reproduction wavelength It is characterized in that the absorption coefficient of a nearby absorption band is selected from a dye that is sufficiently larger than the absorption coefficients of the other absorption bands.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. As a dye (first dye) on which recording / reproduction is basically performed, a dye based on a molecular design guideline aimed at increasing the refractive index (the real part of the complex refractive index) can be used as in the past.

The high molecular compound or the second dye to be added to the first dye on which the above-mentioned recording / reproduction is basically performed may be any as long as it is compatible with the first dye.
Various things can be used. The term "compatible" as used herein means compatibility within a range that does not cause phase separation or precipitation of a dye, which would significantly reduce disk characteristics immediately after film formation, after a storage test, or after recording. However, this is not the case when the recording is not uniformly performed, and the mixture is uniformly mixed, and phase separation or dye precipitation occurs microscopically only by recording, thereby improving characteristics such as recording contrast and jitter.

Methods for evaluating the complex refractive index and wavelength dispersibility of the dye include, for example, the film surface reflectance, substrate surface reflectance, and transmittance of the dye thin film formed on the substrate;
It is possible to use a method of calculating from the substrate surface reflectance when a gold reflection film is provided on the dye after the transmittance measurement (for example, “Unique reflection properties ofthin”).
films of organic soluble naphthalocyanines ”J. Che
m. Soc. , Perkin Tans. 2, 1996 p. 1219).

[0024] Now, n-ik of the complex refractive index of the recording material containing a dye, a n _s -ik _s complex refractive index of the substrate, the complex refractive index of the air n _air -ik _air, the complex refractive index of gold reflective layer Is n _Au -ik _Au , the film thickness of the recording material containing the dye is d, the wavelength is λ, and the reflectance R _exp measured from the air side and the transmittance measured from the air side of the constituent sample of the substrate / recording layer are _Let T _exp be the reflectivity measured from the substrate side of the constituent sample of substrate / recording layer / gold reflective film as Rm _exp, and calculate the calculated value of the reflectivity from the air side of the constituent sample of substrate / recording layer as R _cal If the calculated value of the transmittance from the air side is T _cal, and the calculated value of the reflectance from the substrate side in the constituent sample of the substrate / recording layer / gold reflective film is Rm _cal , [Equation 2] to [Equation 4]

[0025]

(Equation 2)

[0026]

(Equation 3)

[0027]

(Equation 4)

The values of n and k (curves) satisfying the above conditions are obtained. In this case, the intersection of these three curves becomes the complex refractive index n, k of the recording layer as shown in FIG.

When the second dye or the high molecular compound is added to the first dye which is the basis of recording / reproduction, the effects are as follows: (1) interaction between the first dye molecules; (3) Interaction between high molecular compounds, (4) Interaction between first dye molecules and high molecular compounds, (5) First dye molecules and second dye molecules It depends on the interaction relationship with

For example, when the dye alone forms an aggregate (J-aggregate, etc.) and shows a sharp absorption with a very narrow spectral width (a very high n and a large wavelength dependence near the absorption peak). By adding the second dye or polymer compound, the association state of the dye is disturbed, and the absorption spectrum becomes broad (at the same time, the extinction coefficient decreases). In other words, k becomes blown by the addition of the second dye or the polymer compound, and n near the absorption peak is somewhat reduced, but the wavelength dependence is reduced.

Alternatively, it is conceivable that a dye which has been aggregated randomly by itself may be aggregated with a certain regularity by adding a second dye or a high molecular compound.
In this case, due to the difference in the aggregation state, the absorption spectrum becomes narrower and sharper than the absorption spectrum of the dye alone, or the absorption spectrum becomes broader, or a plurality of peaks are formed in the absorption spectrum. May occur. So n, k
Is not known (because it is not known what kind of change in the aggregation state occurs).

In any case, the effect of the addition of the second dye or the high molecular compound can be determined by observing the change in the absorption spectrum of the dye molecules due to the addition of the second dye or the high molecular compound. This is because the change in the absorption spectrum is almost the same as the change in the imaginary part k of the complex refractive index. If the change in k is known, the complex refractive index real part n can be determined from the Kramers-Kronig relationship.

As described above, since n and k are connected in a dispersive relation, that is, the Kramers-Kronig relation, if n is known, k is known, and if k is known, n is known. However, as is evident from the Kramers-Kronig relation, to know n and k, k,
A value in the wavelength range of 0 to の of n is required.

However, considering that the refractive index n is obtained (the real part of the complex refractive index) from the absorption coefficient k (the imaginary part of the complex refractive index), the integral of the Kramers-Kronig equation is k
The contribution of k is very large in a wavelength region where is large or in the vicinity of the wavelength where the refractive index is to be known. Conversely, the k value in a wavelength region where k is small has a small contribution to the refractive index.

Therefore, when the value of the refractive index and the wavelength dependency are evaluated, even if the above-described method of evaluating the complex refractive index from the transmittance or the reflectance is used, this method does not require the addition of a polymer compound. Also, it is impossible to directly and easily know the change in the refractive index due to the addition of the second dye, but by also utilizing the Kramers-Kronig relationship, it is possible to add a polymer compound and to add the second dye. The change in the refractive index due to the addition can easily be inferred from the change in the absorption spectrum due to the addition of the polymer compound or the addition of the second dye to the wavelength dependence of the refractive index. It is necessary to assume that the coefficient k has substantially the same wavelength dependence as the absorption spectrum).

The fact that the wavelength dependence of the complex refractive index can be easily known from the absorption spectrum is very important in improving the value of the complex refractive index and the wavelength dependence, which are the objects of the present invention. However, in order to make this possible, as described above, all the absorption bands are generally present in a wavelength region that can be measured (excluding absorption in a very short wavelength region, for example, 300 nm or less). ) That is.

Because, for example, the lower limit of measurement is 300
If it has a large absorption band near 300 nm, the influence of the integrated value of 300 nm or less on the overall integrated value becomes large, and the complex refractive index near the recording / reproducing wavelength is absorbed. This is because it cannot be easily determined from the spectrum.

Therefore, in the present invention, the absorption band of the dye is also limited. The limitation on the absorption band of the dye in the present invention is necessary in the sense that the wavelength dependence of the refractive index is easily known from the absorption spectrum, but the recording material by adding a polymer compound or a second dye is necessary. It is not always necessary to compare and evaluate the effect of improving the wavelength dependence of the complex refractive index. This is because ignoring the integrated value outside the measurement range of the absorption spectrum has a large effect on the absolute index of the refractive index and the wavelength dependence, but has no significant effect on the comparison of the wavelength dependence. is there.

<Recording Layer> Examples of dyes include polymethine dyes, naphthalocyanine dyes, phthalocyanine dyes, squarylium dyes, coroconium dyes, pyrylium dyes, naphthoquinone dyes, anthraquinone (indanethrene) dyes, xanthene dyes, triphenylmethane dyes, and the like. Examples include azulene-based, tetrahydrocholine-based, phenanthrene-based, triphenothiazine-based dyes, and metal complex compounds, and the above dyes may be used alone or in combination of two or more.

Metals and metal compounds such as In, Te, Bi, Al, Be, TeO ₂ , SnO,
As, Cd, and the like can be used in the form of dispersion mixing or lamination.

Further, a polymer material such as an ionomer resin, a polyamide resin, a vinyl resin,
Various materials such as natural polymer, silicone, liquid rubber,
Alternatively, a silane coupling agent or the like may be used by dispersing and mixing, or for the purpose of improving properties, a stabilizer (for example, a transition metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plastic, It can be used together with agents and the like.

When the recording layer is formed by using a coating method, the above dye or the like is dissolved in an organic solvent and sprayed,
It is performed by a conventional coating method such as roller coating, dipping, and spin coating, and the spin coating is most preferable due to the characteristics of the present invention.

As the organic solvent, generally, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, amides such as N, N-dimethylacetamide and N, N-dimethylformamide, dimethyl sulfoxide and the like Sulfoxides, ethers such as tetrahydrofuran, dioxane, diethyl ether and ethylene glycol monomethyl ether; esters such as methyl acetate and ethyl acetate; and aliphatic halogenated carbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride and trichloroethane. Or benzene, xylene,
Aromatic substances such as monochlorobenzene and dichlorobenzene, cellosolves such as methoxyethanol and ethoxyethanol, and hydrocarbons such as hexane, pentane, cyclohexane and methylcyclohexane can be used.

The thickness of the recording layer is suitably 100 to 10 μm, preferably 200 to 2000 °.

As the second dye, a dye having the same skeleton as the above-described dye for recording / reproducing (first dye) or a dye having a substituent of the same system is preferable. Thereby, the compatibility with the first dye is enhanced, and a uniform film state can be maintained without phase separation or deposition of one of the dyes in both unrecorded and recorded states.

Other conditions required for the second dye are as follows:
The wavelength dispersion of the complex refractive index of the second dye is smaller than the wavelength dispersion of the complex refractive index of the first dye near the recording / reproducing wavelength. In the present invention, recording and reproduction are basically performed with the first dye, and the purpose is to control this characteristic (complex refractive index), and the mixing ratio of the second dye to the first dye is large. If this happens, the change in the wavelength dependence of the complex refractive index of the first dye may be canceled by the change in the wavelength dependence of the complex refractive index of the second dye.

In addition, by using the second dye having a smaller wavelength dependence of the complex refractive index than the first dye, a wavelength region where the wavelength dependence of the complex refractive index of the first dye is small (the absorption coefficient is smaller). It is possible to adjust the absorption coefficient in a very small wavelength region). In the present invention, there is basically no limitation on the recording / reproducing wavelength, and any one may be selected from a plurality of absorption bands of the dye. Therefore, it is possible to provide an optical information recording material and an optical information recording medium that can flexibly cope with a blue laser or the like that will appear in the future.

Further, a preferred dye in the present invention is 30
In the long wavelength region of 0 nm or more, if an absorption band exists only near the recording / reproducing wavelength, or if there are a plurality of absorption bands other than near the recording / reproducing wavelength, the absorption band near the recording / reproducing wavelength becomes another absorption band. A dye having a sufficiently large absorption coefficient as compared with the absorption band is preferable, or a dye capable of predicting the shape of the absorption band of 300 nm or less to some extent even when having a relatively large absorption band near 300 nm is preferable.

The structural formulas of the various dyes are shown in FIGS.
These absorption spectra (measurement wavelength range 300 to 900
nm) are summarized in FIGS. 50 (a) and (b) to FIGS. 91 (a) and (b). Tables 1 to 5 show (1) classification of each of the above dyes, (2) figure numbers of structural formulas (FIGS. 8 to 49),
(3) Drawing numbers of absorption spectra (FIGS. 50 to 91) and (4) Applicability of the above Kramers-Kronig relational expression are summarized. However, in FIGS.
(A) shows the case where the absorbance was measured by irradiating a solution in which the dye was dissolved in methanol at a predetermined concentration, and (b) shows the case where the solution was applied to a dye layer formed by applying the solution on a glass substrate. The case where the absorbance was measured is shown.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

[Table 4]

[0054]

[Table 5]

An example of a preferred dye in the present invention is, for example, a dye whose structural formula is shown in FIGS. 9 and 10, respectively. In these dyes, the Soret (S) band is much smaller than the Q band, the shape of the S band can be almost specified, and the value of the S band of 300 nm or less can be approximated.

Therefore, based on this absorption spectrum, the value of complex refractive index and wavelength dependency can be relatively easily and visually evaluated from the relationship of Kramers-Kronig. In this case, as described in the detailed description of the invention, n and k are obtained at a certain wavelength from the measurement of the transmittance and the reflectance, and the value of k is used to standardize the entire absorption spectrum. The evaluation can be simplified by using a method in which the normalized absorbance value of each wavelength is set to k. Then, only the integration is performed based on k.

On the other hand, examples of the dyes which are not preferable in the present invention include those having the structural formulas shown in FIGS. 11, 12 and 14 (dyes 4, 5, 7). These dyes have large absorption around 300 nm, and it is difficult to predict the shape of this absorption band.
Even using the Kronig equation, it is difficult to calculate an accurate value due to the large influence of integration with a k value of 300 nm or less.

As described above, Tables 1 to 5 show whether various dyes are classified according to their dye skeletons and whether the Kramers-Kronig relational expression can be used (see these figures). (Based on the spectral data shown in (1)), (△), (、), and (×). However, even if a certain skeleton does not cover all the dyes, even if all the skeletons are (×), the skeleton is It does not mean that the whole is x.

In the present invention, the recording / reproducing wavelength is 500
Since it is assumed that the wavelength is about
When recording / reproducing at a wavelength of 00 nm or more, 300
Even if the absorption near nm is relatively large, or even if the absorption band shape of 300 nm or less cannot be predicted, when the influence of these k values on the whole becomes small, the wavelength around 300 nm or less is used. It is not necessary to care much about the shape of the absorption band in the region.

<Substrate> The required characteristics of the substrate are that it must be transparent to the laser beam used only when recording / reproducing from the substrate side, and transparent when recording / reproducing from the recording layer side. No need. Therefore, in the present invention, when only one substrate is used, the substrate does not need to be transparent. When two substrates are used in a sandwich shape, only the second substrate described in the claims is transparent. , First transparent and opaque.

As the substrate material, for example, polyester,
Plastic such as acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, and polyimide, glass, ceramic, and metal can be used. In addition, 1
When only the layers are used, or when two substrates are used in a sandwich form, a guide groove or guide pit for tracking and a preformat such as an address signal are formed on the surface of the first substrate described in the claims. Need to be.

<Intermediate Layer> The layers provided other than the substrate, the recording layer, the reflective layer, and the protective layer, including the undercoat layer and the like, are herein referred to as intermediate layers. This intermediate layer comprises (a) improved adhesion, (b) a barrier against water or gas, (c) improved storage stability of the recording layer, (d) improved reflectance, and (e) substrate from solvent. And (f) formation of guide grooves, guide pits, preformats, and the like.

For the purpose of the above (a), a polymer material,
For example, various polymer substances such as ionomer resins, polyamide resins, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers, and silane coupling agents can be used. For the purposes (b) and (c), an inorganic compound such as Si
O ₂ , MgF ₂ , SiO, TiO ₂ , ZnO, TiN,
Metals such as SiN, or semi-metals such as Zn, Cu, N
i, Cr, Ge, Se, Au, Ag, Al and the like can be used.

For the purpose of (d), metals such as Al and Ag and organic thin films having metallic luster such as methine dyes and xanthene dyes can be used.
UV curable resin for the purposes of (e) and (f),
A thermosetting resin, a thermoplastic resin, or the like can be used.
The thickness of the undercoat layer is 0.01 to 30 μm, preferably 0.1 to 30 μm.
It is suitably from 05 to 10 μm.

<Protective layer / substrate surface hard coat layer> The protective layer or the substrate surface hard coat layer (a) protects the recording layer (reflection / absorption layer) from scratches, dust, dirt, etc., (b)
It is used for the purpose of improving the storage stability of the recording layer (reflection / absorption layer) and (c) improving the reflectance. For these purposes, the materials shown in the undercoat layer can be used. Further, SiO, SiO ₂ or the like can be used as an inorganic material, and polymethyl acrylate, polycarbonate, epoxy resin, polystyrene,
Heat softening and heat melting resins such as polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, natural rubber, styrene-butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil and rosin Can also be used. Among the above materials, the most preferable substance for the protective layer or the hard coat layer on the substrate surface is an ultraviolet curable resin having excellent productivity. The film thickness of the protective layer or the hard coat layer on the substrate surface is suitably 0.05 to 30 μm, preferably 0.05 to 10 μm. In the present invention, the undercoat layer, the protective layer, and the substrate surface hard coat layer each include a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, and the like as in the case of the recording layer. Can be contained.

<Metal Reflective Layer> The reflective layer may be made of a metal, semi-metal, or the like, which can provide a high reflectance by itself and is hardly corroded.
Examples of the material include Au, Ag, Cu, Cr, Ni, and Al, and preferably Au and Al. These metals and metalloids may be used alone or as two or more alloys. Further, a dielectric multilayer film may be used. Examples of the film forming method include vapor deposition and sputtering, and the film thickness is 50 to 3000 °, preferably 1 to
00 to 1000 °.

<Adhesive Layer> The adhesive layer is used when two substrates of about 0.6 mm are bonded to each other to make a DVD medium.
Required. Particularly preferred in the present invention is a hot-melt type (hot-melt type) adhesive or an ultraviolet curable type adhesive. The ultraviolet curable adhesive is an adhesive which is cured by the initiation of radical polymerization by irradiation with ultraviolet light. The composition is generally composed of (1) an acrylic oligomer, (2) an acrylic monomer, (3) a photopolymerization initiator, and (4) a polymerization inhibitor. The oligomer is a polyester-based, polyurethane-based, or epoxy-based. Benzophenone, benzoin ether and the like can be used as a photopolymerization initiator such as an acrylate ester.

A hot-melt adhesive is one in which a liquid adhesive is cured by solvent volatilization or reaction and develops an adhesive force, whereas a room-temperature solid thermoplastic resin develops an adhesive force by a physical change of heat melting and cooling and solidification. It is. Hot melt adhesive
EVA, polyester, polyamide, polyurethane and the like can be used.

<Polymer Compound> In the present invention, a polymer compound having an alkyl group is mentioned as an example of the polymer compound which easily interacts with the dye. This is because many dyes often have an alkyl substituent introduced as a bulky substituent in order to obtain a high refraction index and ease of synthesis (a technique for increasing monomericity). In order to increase the interaction of the polymer, it is preferable that the alkyl group is also substituted on the side chain of the polymer compound.

Preferred specific examples include polymethacrylic acid esters having the structural formula shown in FIG. 5 or substituted polystyrenes having the structural formula shown in FIG. FIG.
In the polymethacrylate, R is preferably an alkyl group having 3 or more carbon atoms which may have a branch.
In addition, in the substituted polystyrene in FIG. 6, it is preferable that the substituent is substituted at one or more positions of Z1 to Z6 with an alkyl group which may have a branch having 3 or more carbon atoms. However, when one position of the substituent is Z6, an alkyl group having 1 or more carbon atoms which may have a branch is preferably substituted, and a plurality of substituents may be introduced.

The definition of these polymers is intended to reduce the interaction between polymers by introducing an alkyl group into the side chain and introducing a bulky substituent which causes steric hindrance to the side chain. It is necessary to enhance the interaction between the group and the substituent of the dye molecule and change the aggregation state of the dye molecule (change the complex refractive index). The polymer described above is
Although it is a polymer that brings about a change in interaction passively by external energy such as light or heat, an active polymer in which the polymer itself changes by external energy is also suitable for the present invention. .

The active polymer is a polymer compound which reversibly causes an electronic or structural change by external energy such as light or heat, and includes, for example, a polymer material exhibiting photochromism or thermochromism. . light,
Or, a polymer compound that reversibly generates an electronic or structural change by external energy such as heat, and reversibly changes the aggregation state of dye molecules by using the reversible electronic or structural change of the polymer compound Is changed.

Examples of the polymer compound which reversibly causes an electronic or structural change by external energy such as light or heat include, for example, O, N, S,
A polymer compound having a coordinating group containing a coordinating atom such as P, As, Se, or the like, or a polymer compound whose molecular chain form changes with external energy is used.

Examples of such a polymer include those having the structural formula shown in FIG. In FIG. 7, R1
1, R12 represents hydrogen or an alkyl group which may have a substituent. These may be the same, but both are not simultaneously hydrogen, and at least one is an alkyl group which may have a substituent, and X is S, O, Se, or N
Is R ^13, R ¹³ represents hydrogen, an alkyl group or an aryl group.

Of these, preferred are polythiophene derivatives wherein X is a sulfur atom, and more preferred is R1
One is a poly (3-alkylthiophene) in which one of R12 is a hydrogen atom and the other is an alkyl group. Among these poly (3-alkylthiophenes), an alkyl group having n = 6 or more is preferable from the viewpoint of solubility in an organic solvent, interaction between polymers, interaction with a dye molecule, and the like.

Further, as a polymer compound suitable for the present invention,
Examples include a photoresponsive polymer compound in which the external energy is light and the molecular chain form is changed by light. For example, the following types are specific examples of the polymer compound suitable for the present invention. The interaction between the photosensitive groups contained in the main chain or side chain of the polymer is changed by photoisomerization. Changes the structure of the photosensitive group contained in the polymer main chain. Light irradiation reversibly generates charges along the polymer chain, and utilizes their electrostatic repulsion.

Further, a thermoplastic polymer compound can be used in the present invention. However, in order to reduce the interaction between polymers and to increase the interaction force with the dye molecule, a site such as an alkyl group is added to the side chain. Is preferably introduced. As the thermoplastic polymer compound, acrylic resin,
Polycarbonate resin, polyester resin, polyamide resin, vinyl chloride resin, polyvinyl ester resin,
Polystyrene resins, polyolefin resins, polyethersulfone resins and the like can be mentioned.

[0078]

【Example】

<Examples> Example 1 A dye having a structural formula shown in FIG. 8 (however, not exactly the same as in FIG. 8 but having a central metal of Pd) is dissolved in chloroform and spin-coated using this solution. A thin film was formed on a quartz substrate by the method. When the complex refractive index of this sample was evaluated (the method described in detail of the invention), the complex refractive index (n ₁ , n ₁ ) as shown in FIG.
k ₁ ) was obtained.

The wavelength of this thin film is 680 nm, 650 nm,
The value of the complex refractive index at 635 nm is as follows: wavelength 680 nm n-ik = 1.760-I0.0270 wavelength 650 nm n-ik = 2.135-I0.0452 wavelength 635 nm n-ik = 2.375-I0.0676 Using this value, 680 nm, 650 nm, 63
Disc structure at 5 nm (substrate / recording layer / reflection layer)
Of the dependence of the reflectance on the recording layer thickness at the time of FIG.
The following results were obtained.

Example 2 Next, poly (4-tert-butylstyrene) was added to the dye used in Example 1 so that the molar ratio thereof was about 1: 1 (however, the high molecular compound was calculated by repeating basic units). Mixed into
A chloroform solution was obtained. A thin film was formed on a quartz substrate by spin coating using this solution.
When the complex refractive index of this sample was evaluated by the above method, the complex refractive index (n ₂ ,
k ₂ ) was obtained.

The wavelength of this thin film is 680 nm, 650 nm,
The value of the complex refractive index at 635 nm is as follows: wavelength 680 nm n-ik = 1.865-I0.0030 wavelength 650 nm n-ik = 1.920-I0.0396 wavelength 635 nm n-ik = 1.935-I0.1243 Using this value, 680 nm, 650 nm, 63
Disc structure at 5 nm (substrate / recording layer / reflection layer)
When the dependence of the reflectance on the recording layer thickness was calculated, the result shown in FIG. 4 was obtained.

From these results, the dye alone shows a large refractive index in the vicinity of the absorption peak, but the refractive index and the reflectance in the disk structure show a large wavelength dependence (described in the section of "Prior Art"). As described above, when the value of k required for recording is 0.03 to 0.05, the appropriate recording / reproducing wavelength of this dye is about 650 nm.In the vicinity of 650 nm, the change of n is very sharp and 650 nm. The near-wavelength n greatly changes), and the reflectivity of the disk structure has a relatively large dependence on the film thickness. However, the addition of an appropriate polymer compound slightly reduces the refractive index near the absorption peak. Although the wavelength decreases and the wavelength at which a high reflectivity is obtained also shifts to the longer wavelength side, the wavelength dependence of the refractive index and the reflectivity in the disk structure decreases (as described in the section of “Prior Art”, The value of the required k is 0.03 to 0.05
Then, the appropriate recording / reproducing wavelength of this dye is 650 nm.
It is about. The change in n is very gradual near 650 nm, and the wavelength n near 650 nm does not change much. Thus, it has been confirmed that the dependency of the reflectivity of the further disk structure on the film thickness is also improved.

[0083]

As apparent from the above description, according to the present invention, the following remarkable effects can be obtained. (1) Since the value of the complex refractive index and the wavelength dependence of the complex refractive index can be controlled relatively freely within a certain range, the disc characteristics can be easily optimized. (2) Further, since an optical information recording medium with little wavelength dependence can be provided, an organic optical information recording medium which is reliable even with respect to wavelength fluctuation due to manufacturing variations, temperature changes, etc. can be provided. (3) In addition, by using a dye and a method that can easily infer the value of the complex refractive index and the wavelength dependency from the absorption spectrum, the evaluation of the dye that has been unclear in the past can be performed very clearly. Becomes possible. (4) Further, the disc characteristics at the recording / reproducing wavelength can be maximized while effectively utilizing the inherent properties of the dye, so that the development of the optical information recording material can be made more efficient.

[Brief description of the drawings]

FIG. 1 is a graph illustrating a method for determining a complex refractive index (real part n and imaginary part k) of a recording material containing a dye.

FIG. 2 is a graph according to Examples 1 and 2 of the present invention,
4 shows the measurement results of the complex refractive index of a recording layer containing a dye formed on a substrate.

FIG. 3 is a graph according to Example 1, showing a result of examining the relationship between the film thickness of the recording layer and the reflectance of the reflection layer for a disc having a reflection layer formed on the recording layer. It is shown.

FIG. 4 is a graph according to Example 2, showing a result of examining the relationship between the film thickness of the recording layer and the reflectance of the reflection layer for a disk having a reflection layer formed on the recording layer. It is shown.

FIG. 5 is a structural formula showing an example of a preferred polymer compound in the present invention.

FIG. 6 is a structural formula showing another example of a preferable polymer compound.

FIG. 7 is a structural formula showing still another example of a preferable polymer compound.

FIG. 8 is a structural formula showing an example of a dye according to the present invention (dye 1).

FIG. 9 is a structural formula showing another example of a dye (dye 2).

FIG. 10 is a structural formula showing still another example of a dye (dye 3).

FIG. 11 is a structural formula showing still another example of a dye (dye 4).

FIG. 12 is a structural formula showing still another example of a dye (dye 5).

FIG. 13 is a structural formula showing still another example of a dye (dye 6).

FIG. 14 is a structural formula showing still another example of a dye (dye 7).

FIG. 15 is a structural formula showing still another example of a dye (dye 8).

FIG. 16 is a structural formula showing still another example of a dye (dye 9).

FIG. 17 is a structural formula showing still another example of a dye (dye 10).

FIG. 18 is a structural formula showing still another example of a dye (dye 11).

FIG. 19 is a structural formula showing still another example of a dye (dye 12).

FIG. 20 is a structural formula showing still another example of a dye (dye 13).

FIG. 21 is a structural formula showing still another example of a dye (dye 14).

FIG. 22 is a structural formula showing still another example of a dye (dye 15).

FIG. 23 is a structural formula showing still another example of a dye (dye 16).

FIG. 24 is a structural formula showing still another example of a dye (dye 17).

FIG. 25 is a structural formula showing still another example of a dye (dye 18).

FIG. 26 is a structural formula showing still another example of a dye (dye 19).

FIG. 27 is a structural formula showing still another example of a dye (dye 20).

FIG. 28 is a structural formula showing still another example of a dye (dye 21).

FIG. 29 is a structural formula showing still another example of a dye (dye 22).

FIG. 30 is a structural formula showing still another example of a dye (dye 23).

FIG. 31 is a structural formula showing still another example of a dye (dye 24).

FIG. 32 is a structural formula showing still another example of a dye (dye 25).

FIG. 33 is a structural formula showing still another example of a dye (dye 26).

FIG. 34 is a structural formula showing still another example of a dye (dye 27).

FIG. 35 is a structural formula showing still another example of a dye (dye 28).

FIG. 36 is a structural formula showing still another example of a dye (dye 29).

FIG. 37 is a structural formula showing still another example of a dye (dye 30).

FIG. 38 is a structural formula showing still another example of a dye (dye 31).

FIG. 39 is a structural formula showing still another example of a dye (dye 32).

FIG. 40 is a structural formula showing still another example of a dye (dye 33).

FIG. 41 is a structural formula showing still another example of a dye (dye 34).

FIG. 42 is a structural formula showing still another example of a dye (dye 35).

FIG. 43 is a structural formula showing still another example of a dye (dye 36).

FIG. 44 is a structural formula showing still another example of a dye (dye 37).

FIG. 45 is a structural formula showing yet another example of a dye (dye 38).

FIG. 46 is a structural formula showing still another example of a dye (dye 39).

FIG. 47 is a structural formula showing still another example of a dye (dye 40).

FIG. 48 is a structural formula showing still another example of a dye (dye 41).

FIG. 49 is a structural formula showing yet another example of a dye (dye 42).

FIG. 50 is an absorption spectrum of Dye 1.

FIG. 51 is an absorption spectrum of Dye 2.

FIG. 52 is an absorption spectrum of Dye 3.

FIG. 53 is an absorption spectrum of Dye 4.

FIG. 54 is an absorption spectrum of Dye 5.

FIG. 55 is an absorption spectrum of Dye 6.

FIG. 56 is an absorption spectrum of Dye 7.

FIG. 57 is an absorption spectrum of Dye 8.

FIG. 58 is an absorption spectrum of Dye 9.

FIG. 59 is an absorption spectrum of Dye 10.

FIG. 60 is an absorption spectrum of Dye 11.

FIG. 61 is an absorption spectrum of Dye 12.

FIG. 62 is an absorption spectrum of Dye 13.

FIG. 63 is an absorption spectrum of Dye 14.

FIG. 64 is an absorption spectrum of Dye 15.

FIG. 65 is an absorption spectrum of Dye 16.

FIG. 66 is an absorption spectrum of Dye 17.

FIG. 67 is an absorption spectrum of Dye 18.

FIG. 68 is an absorption spectrum of Dye 19.

FIG. 69 is an absorption spectrum of Dye 20.

70 is an absorption spectrum of Dye 21. FIG.

FIG. 71 is an absorption spectrum of Dye 22.

FIG. 72 is an absorption spectrum of Dye 23.

73 is an absorption spectrum of Dye 24. FIG.

74 is an absorption spectrum of Dye 25. FIG.

75 is an absorption spectrum of Dye 26. FIG.

FIG. 76 is an absorption spectrum of Dye 27.

FIG. 77 is an absorption spectrum of Dye 28.

FIG. 78 is an absorption spectrum of Dye 29.

FIG. 79 is an absorption spectrum of Dye 30.

80 is an absorption spectrum of Dye 31. FIG.

81 is an absorption spectrum of Dye 32. FIG.

FIG. 82 is an absorption spectrum of Dye 33.

83 is an absorption spectrum of Dye 34. FIG.

FIG. 84 is an absorption spectrum of Dye 35.

85 is an absorption spectrum of Dye 36. FIG.

FIG. 86 shows an absorption spectrum of Dye 37.

87 is an absorption spectrum of Dye 38. FIG.

FIG. 88 is an absorption spectrum of Dye 39.

89 shows an absorption spectrum of Dye 40. FIG.

90 shows an absorption spectrum of Dye 41. FIG.

91 is an absorption spectrum of Dye 42. FIG.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Higashi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Tsutomu Sato 1-3-6 Nakamagome, Ota-ku, Tokyo Share Inside the company Ricoh

Claims (6)

[Claims] An optical information recording material comprising a dye and a polymer compound, wherein the polymer compound optimizes a complex refractive index at a recording / reproducing wavelength of the dye, and records / reproduces a wavelength of the dye. An optical information recording material for optimizing the wavelength dispersion of a complex refractive index in the vicinity at a recording / reproducing wavelength. 2. An optical information recording material comprising a first dye and a second dye, wherein the second dye has a smaller wavelength dispersion of the complex refractive index than the first dye, and It is necessary to optimize the complex refractive index at the recording / reproducing wavelength of the dye and to optimize the wavelength dispersion of the complex refractive index near the recording / reproducing wavelength of the optical information recording material at the recording / reproducing wavelength. Characteristic optical information recording material. 3. The optical information recording material according to claim 2, wherein the second dye is 300 n of a plurality of absorption bands present in the second dye.
In the long wavelength region of m or more, an absorption band exists only near the recording / reproduction wavelength, or when there are a plurality of absorption bands other than near the recording / reproduction wavelength and near the recording / reproduction wavelength, the recording / reproduction wavelength An optical recording information material, wherein the absorption coefficient of a nearby absorption band is selected from dyes that are sufficiently larger than the absorption coefficients of other absorption bands. 4. In an optical information recording medium having at least a recording layer and a reflective layer provided on a substrate, the recording layer comprises a dye and a polymer compound material, wherein the polymer compound material is Optical information for optimizing the complex refractive index at the recording / reproducing wavelength and optimizing the wavelength dispersion of the complex refractive index near the recording / reproducing wavelength of the dye at the recording / reproducing wavelength. recoding media. 5. An optical information recording medium having at least a recording layer and a reflective layer provided on a substrate, wherein the recording layer comprises a first dye and a second dye, and wherein the second dye is The wavelength dispersibility of the complex refractive index is smaller than that of one dye, the complex refractive index of the first dye at the recording / reproducing wavelength is optimized, and the wavelength dispersibility of the complex refractive index of the recording layer near the recording / reproducing wavelength is reduced. An optical information recording medium for optimizing a recording / reproducing wavelength. 6. The optical information recording medium according to claim 5, wherein the second dye is 300 n of a plurality of absorption bands present in the second dye.
In the long wavelength region of m or more, an absorption band exists only near the recording / reproduction wavelength, or when there are a plurality of absorption bands other than near the recording / reproduction wavelength and near the recording / reproduction wavelength, An optical information recording medium, wherein the absorption coefficient of a nearby absorption band is selected from a dye that is sufficiently large compared to the absorption coefficients of other absorption bands.