JPH09282709A - Optical information recording medium and its recording, reproducing and erasing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce large spectrum shift by generating an aggregation or dispersion state of dye molecules by the interaction of substituents which are substituted into the dye molecules. SOLUTION: Substituents are introduced into the center metal of a dye molecule in an optical information recording medium comprising a mixture material of dye molecules and a polymer compd. When the substituents are large in the three- dimensional space, the interaction between the basic skeletons of the dye is reduced, which gives the possibility to produce an association or aggregation state of dye molecules by the interaction of intermolecular force of the substituents. However, the distance between the basic skeletons of the dye molecules increases and the interaction between π-conjugate of the basic skeleton is hardly caused. Thereby, during recording, changes in the interaction between dye molecules decrease and reversibility can not be expected. Therefore, in order to obtain reversibility, it is necessary to withdraw dye molecules in a range which enables spectrum shift and also to prevent excessive proximity of dye molecules so as to obtain tunability and reversibility of the spectrum. For this reason, the intermolecular force between the center metal of the dye molecule and the substituents is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rewritable optical information recording medium and a method of recording, reproducing and erasing optical information using the recording medium.

[0002]

2. Description of the Related Art Conventionally, an inorganic material is generally used for a recording layer of a rewritable optical information recording medium. For example, a magneto-optical recording material made of an alloy such as TeFeCo utilizing the Kerr effect or a chalcogenide thin film is used. There is a phase change type optical recording material that utilizes change. These inorganic materials contain a lot of harmful substances, and since the film forming method is limited to vapor deposition, sputtering, etc., there is a demerit that the cost becomes high, so that the organic materials are attracting attention.

As an organic rewritable material, a photochromic compound such as spiropyran (JP-A-59-22)
7972) and a mixture of a liquid crystal polymer and a dye (JP-A-2-136289). However, photochromic compounds such as spiropyran have problems such as stability of recorded state, repeatability of recording / erasing, and read destruction, and many problems have not yet been solved in practical use. On the other hand, the reversible change mechanism of the liquid crystal polymer / dye mixture material is that the interaction between the liquid crystal polymer and the dye changes due to the change of the side chain alignment state of the liquid crystal polymer, resulting in an optical change in the recording layer. It reversibly changes the characteristics. As another rewritable recording material, Japanese Patent Application Laid-Open No. 4-3
There are various proposals such as Japanese Patent No. 39865,
Practically sufficient organic materials are not yet available, and new materials have been awaited.

Further, Japanese Patent Application Laid-Open No. 6-223374 proposes a recording film containing a dye material which forms an association state with a light-transmissive substrate, and rewriting is described in the specification. In addition, the so-called Low in which the reflectance of the portion where the recording mode is irradiated with light increases
It is a to high record. In JP-A-6-251417, good recording is realized by using a phthalocyanine polymer, but like the above description, there is no description of rewriting in the specification, and the recording mode is Lowto h.
In high recording, the recording polarity is opposite to that of a normal optical disc.

Further, in JP-A-6-251418, recording / erasing is achieved by a mixed film of a specific phthalocyanine and an organic compound having a melting point in the range of 140 to 250 ° C. However, in this case as well, Low to hi
In gh recording, the polarity is opposite to that of an ordinary optical disc, and the change level is 42% to 56%, which is not so large.
Further, JP-A-6-279597 proposes a near-infrared absorbing film containing a polyalkyl acrylate resin and a phthalocyanine compound, but there is no description of rewriting in the specification, and the light resistance is improved. Is shown as a method for. Almost all of these recording materials are Low to High recording and 60
It cannot be applied as a CD family media that requires a reflectance of 70% or more. In addition, there are few examples in which the reversible mechanism has been described in detail in the past, and it is only a conceptual explanation, and therefore the guideline for material design cannot be clarified.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a so-called high to lo.
CD can be recorded with the same polarity as a normal w optical disc.
An object of the present invention is to provide an organic reversible optical information recording medium which is compatible with family media, has a large recording contrast, and has a high erasing ratio. In addition, write-once media can be applied to applications that require a high transfer rate such as video playback and signal characteristics improvement such as jitter reduction due to high density, and it is possible to form a recording section with high sensitivity and without shape change. An optical information recording medium is provided. Furthermore, CDs such as CDs, CD-Rs and DVDs
It is an object of the present invention to provide an organic reversible optical information recording medium having compatibility such that information can be read out by a family medium drive.

[0007]

According to the present invention, first of all, a dye material is formed by a mutual action of substituents which are composed of a mixed material containing at least a dye molecule and a polymer compound. In an optical information recording medium that shows different spectra depending on the state of association or aggregation and the state of dispersion due to the interaction between the dye and the polymer compound,
The polymer compound is selected from compounds represented by the following general formula (I) or (II), and any one of the number average molecular weight, the weight average molecular weight, or the viscosity average molecular weight of the polymer compound is 1 × 10 ⁴ or more. An optical information recording medium is provided.

Embedded image

Embedded image (In the formula, R, Z ^{1 to} Z ⁶ and n each represent the following: R: an alkyl group, Z ^{1 to} Z ⁵ : each independently a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkyl group; substituted aryl group, Z ^6: a hydrogen atom, a halogen atom or an alkyl group, n:. polymerization degree) Secondly, in the method for recording optical information recording medium according to claim 1, wherein the substituents are substituted on the dye molecule The spectrum of the unrecorded state, which is the state where the dye molecules are associated or aggregated by the interaction of each other, is irradiated with external energy such as light or heat to cause the dye molecules to interact with each other. A recording method for an optical information recording medium is provided, wherein information is recorded by changing the spectrum of a dispersion state due to an action. Thirdly, in the method of recording the optical information recording medium according to claim 1, light or heat is applied to a spectrum in an unrecorded state due to a dye molecule forming a dispersed state due to an interaction between the dye and a polymer compound. Light that is characterized by recording information by irradiating external energy such as, by changing the spectrum of the state in which the dye molecules are associated or aggregated by the interaction between the substituents substituted in the dye molecule. A recording method of an information recording medium is provided. Fourth,
The method for reproducing an optical information recording medium according to claim 1, wherein a spectrum of an unrecorded portion is formed by forming a state in which dye molecules are associated or aggregated by interaction between substituents substituted in the dye molecule. Information by changing the amount of transmitted light or the reflected light to the laser light of the recording part which is changed into the spectrum of the dispersed state by the interaction between the dye molecule and the polymer compound by the irradiation of external energy such as light or heat. There is provided a method for reproducing an optical information recording medium, which is characterized in that Fifthly, in the method of reproducing the optical information recording medium according to claim 1, light or heat is applied to the spectrum of the unrecorded part due to the dye molecules forming a dispersed state due to the interaction between the dye and the polymer compound. By the irradiation of external energy such as, the reflected light to the laser light of the recording portion, which is changed into a spectrum of a state in which the dye molecules are associated or aggregated by the interaction between the substituents substituted in the dye molecule,
Alternatively, there is provided a reproducing method for an optical information recording medium, which is characterized in that information is reproduced by changing the amount of transmitted light. Sixth, in the method of erasing the optical information recording medium according to claim 1, the recording state is formed by forming a state in which the dye molecules are associated or aggregated by the interaction between the substituents substituted in the dye molecules. Optical information characterized by erasing information by changing the spectrum of a dye molecule into a spectrum in a dispersed state due to the interaction between a dye and a polymer compound by irradiating the spectrum with external energy such as light or heat. A method of erasing a recording medium is provided. Seventh,
The method for erasing an optical information recording medium according to claim 1, wherein a spectrum of a recording state due to a dye molecule forming a dispersed state due to an interaction between a dye and a high molecular compound is compared with external energy such as light or heat. By irradiation,
A method for erasing an optical information recording medium, characterized in that information is erased by changing the spectrum of a state in which dye molecules are associated or aggregated by an interaction between substituents substituted in the dye molecule. To be done.

That is, in the optical information recording medium of the present invention, a mixed material containing at least a dye molecule and a polymer compound is used, and the dye molecules are associated or aggregated by the interaction of the substituents substituted on the dye molecule. It is possible to cause a large spectrum shift by forming a state and a non-association state, a non-aggregation state, or a dispersed state of the dye due to the interaction between the dye and the polymer compound. Not accompanied. Further, although this state change has good reversibility, it is possible to make it irreversible as a write-once type by changing the material. As the polymer compound, a compound represented by the above general formula (I) or (II) is selected, and the degree of polymerization of the polymer compound is 1 in terms of number average molecular weight, weight average molecular weight or viscosity average molecular weight. By setting it to be 10 ⁴ or more, a large spectrum shift and good reversibility can be stably exhibited, and stability with time is also improved.

In the recording method of the optical information recording medium of the present invention, a mixed material containing at least a dye molecule and a polymer compound is used, and a compound having a relatively large association and cohesive force is selected as the dye molecule or an initial annealing treatment is performed. As a non-recorded state, a state in which the dye molecules are associated or aggregated by the interaction between the substituents substituted in the dye molecule is created, and this state is irradiated with external energy such as light or heat. Records the information by destroying the association or aggregation state due to the interaction between the dye molecules and forming the non-association state or the non-aggregation state of the dye due to the interaction between the dye and the polymer compound, that is, the dispersed state. Since this method is used, a large spectrum shift can be generated by this method, and this state change can be caused by the shape of the material. Because without change, highly sensitive,
Higher transfer rate can be achieved. Further, although this state change has good reversibility, it is possible to make it irreversible as a write-once type by changing the material.

In a recording method of another aspect of the optical information recording medium of the present invention, a mixed material containing at least a dye molecule and a polymer compound is used, and a compound having relatively weak association and cohesive force is selected as the dye molecule. As a non-recorded state due to the initial dispersion treatment, etc., the dye molecules interact with the polymer compound to cause non-association and non-aggregation of the dye molecules,
That is, a dispersed state of dye molecules is created, and when this state is irradiated with external energy such as light or heat, the dye molecules are associated or aggregated by the interaction between the substituents substituted on the dye molecules. By doing so, since information is recorded, according to the present method, it is possible to cause a large spectrum shift, and since this state change does not accompany the shape change of the material, high sensitivity and high transfer rate can be achieved. Rate can be achieved. Further, although this state change has good reversibility, it is possible to make it irreversible as a write-once type by changing the material.

The reproducing method of the optical information recording medium of the present invention is carried out by irradiating the recorded portion and the unrecorded portion of the optical information recording medium of the present invention with a laser beam. Using a mixed material containing at least a dye molecule and a polymer compound, as an unrecorded state, a state in which the dye molecules are associated or aggregated by the interaction of the substituents substituted in the dye molecule is created. Irradiation of external energy such as light or heat destroys the association or aggregation state due to the interaction between dye molecules, and the non-association state or dispersion state of the dye due to the interaction between the dye and the polymer compound, that is, the dispersed state. By forming it, information is recorded, and since a large spectrum shift can be caused by this state change of the dye molecule, recording Is irradiated with laser light in the non-recording portion and, depending on the state of both the dye molecules, the reflected light or the transmitted light is greatly changed. Therefore, according to this reproducing method,
It is possible to obtain a large recording contrast signal.

The reproducing method of another aspect of the optical information recording medium of the present invention is also carried out by irradiating the recorded portion and the unrecorded portion of the optical information recording medium of the present invention with a laser beam. The optical information recording medium of No. 1 uses a mixed material containing at least a dye molecule and a polymer compound, and in a non-recorded state, a non-aggregated state or a non-aggregated state of the dye, that is, a dispersed state is formed by the interaction between the dye and the polymer compound Then, by irradiating external energy such as light or heat to this state, the state in which the dye molecules are associated or aggregated by the interaction between the substituents substituted in the dye molecule is created to record information. Of the dye molecule,
Since a large spectrum shift can be caused by this state change, when the recorded portion and the unrecorded portion are irradiated with the laser beam, the reflected light or the transmitted light largely changes depending on the states of the dye molecules of both. Therefore, according to this reproducing method, a large recording contrast signal can be obtained.

The method for erasing an optical information recording medium of the present invention uses a mixed material containing at least a dye molecule and a polymer compound, and causes the dye molecules to associate or aggregate by the interaction of the substituents substituted on the dye molecule. State and the non-aggregated state, that is, the dispersed state of the dye due to the interaction between the dye and the polymer compound, to create the recorded state and the unrecorded / erased state, and therefore, the shape change, the chemical This is a change in the physical binding state that does not involve a physical change, and according to the present method, reversibility can be easily expressed. Further, it is possible to perform erasing with a large erasing ratio and good repetitive characteristics.

The erasing method of another aspect of the optical information recording medium of the present invention uses a mixed material containing at least a dye molecule and a polymer compound, and associates the dye molecules by the interaction between the substituents substituted on the dye molecules, Or in the aggregated state,
Non-association of dye due to interaction between dye and polymer compound,
By forming a non-aggregated state, that is, a dispersed state,
Since an unrecorded / erased state and a recorded state are created, this is a change in the physical binding state without shape change or chemical change. According to this method, reversibility can be easily expressed. Further, it is possible to perform erasing with a large erasing ratio and good repetitive characteristics.

The optical information recording medium of the present invention provides a rewritable optical information recording medium compatible with a CD type medium, but the present invention is not limited to this and the present CD-R is used. It is also applicable to a write-once type optical information recording medium that can be written only once.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below. Phthalocyanine and naphthalocyanine compounds are still one of the most suitable materials for optical information recording media even at present. However, in the CD-R, that is, in the type of medium in which the user can write information only once, the phthalocyanine and naphthalocyanine compounds are simply used for absorbing laser light at the time of recording information, and the recording is phthalocyanine and naphthalocyanine by absorbing laser light. This is carried out by the decomposition of the compound or the deformation of the substrate by the laser light absorption of the phthalocyanine or naphthalocyanine compound. However, in the present invention, the phthalocyanine or naphthalocyanine compound is not used as a mere absorbent as in the conventional case, but the physical property change of the phthalocyanine or naphthalocyanine compound itself is directly utilized to obtain a surface shape such as a substrate deformation. Provided is an optical information recording medium having reversibility which does not change. That is, the present invention provides an optical information recording medium that changes not only the refractive index of the dye (the real part of the complex refractive index) but the absorption coefficient of the dye (the imaginary part of the complex refractive index).

By the way, the reversibility of phthalocyanine and naphthalocyanine compounds is caused by, for example, changes in the crystalline state, the aggregated state, the structure, the electronic state and the like. Although an aggregated state can be formed, it is often not possible to create a dispersed state of dye molecules that eliminates the interaction between dye molecules, or even if a dispersed state can be created, it is not stable (the stability over time is Poor, it gradually returns to the aggregated state. Therefore, in the present invention, a mixture of a dye molecule and one or more polymer compounds is used as a recording material of an optical information recording medium, and an unrecorded or erased state is a dye molecule association / aggregation state, and a recorded state is a dye molecule. The dispersion state of the dye molecules with which the polymer compound interacts, or the unrecorded or erased state is the dispersion state of the dye molecules with which the polymer compound interacts with the dye molecule, and the recording state is the association or aggregation state of the dye molecules. There is a feature in doing it. Therefore,
The present invention requires a dye molecule capable of forming an association or aggregation state and a polymer compound capable of interacting with the dye molecule to form a dispersed state of the dye molecule.

First, the optimum dye structure that can be used in the present invention will be described. The reversibility utilizing the change in the aggregation state is a change in the interaction between dye molecules, and as shown in FIG. 1, a dye molecule does not interact with other dye molecules and exists independently. When the dye molecules aggregate in the dispersed state, the spectrum shifts to a short wavelength or a long wavelength. When two or more dye molecules come close to a molecular order distance or less, a so-called J-association, H-association or other association phenomenon of the dye corresponds to the change of the aggregation state.

Generally speaking, the change of the crystal state is so drastic that the change of the surface state of the film is not suitable for the optical memory. Therefore, it is necessary to search for a dye capable of reversibly changing the aggregation state of the dye. is there. The present invention is not capable of changing the spectrum of the dye molecule, or irreversible, intermolecular force or electrostatic force between the basic skeleton of the dye molecule, to prevent association, aggregation due to forces such as dipole interaction, As a dye molecule that can be aggregated and aggregated to the extent that the spectrum of the dye molecule can be controlled from the outside,
A dye having a substituent on the dye molecule, preferably a dye having a substituent on the central metal, is taken up, and the cohesive force of the substituent causes association and aggregation. Occurs, for the dispersed state of the dye,
It is characterized by changing the spectrum of the dye molecule.

As described above, the dye in the present invention has a substituent on the dye molecule, preferably a substituent on the central metal. When the dye molecules have no substituents (including the substituents substituted on the part other than the central metal) or when the substituents are small, the distance between the dye molecules is narrow and the interaction force between the dye molecules is small. large. Therefore, even if recording by external energy and further erasing are performed, this interaction force cannot be changed and the spectrum cannot be changed. Therefore, since there is no spectral movability, additional writing without shape change is not possible, and of course reversibility does not occur. On the other hand, when the substituent is three-dimensionally very large, the interaction between the dye basic skeletons is weakened, and the dye molecules may associate and form an aggregated state due to the intermolecular force interaction of the substituents. However, the distance between the basic skeletons of the dye molecule becomes large, and the interaction between the π-conjugated systems of the basic dye molecule skeletons is almost eliminated. Therefore, the change in the interaction between dye molecules due to recording is reduced, and reversibility cannot be expected. Therefore, the interaction force between dye molecules can be changed by recording (movement of spectrum), and in order to make the interaction force change reversible, it is necessary to cause sufficient spectrum shift between dye molecules. It is important that the dye molecules are not brought too close to each other in order to bring them into a large distance range and to have spectrum mobility and reversibility.

The preferred dye structure in the present invention is to provide a substituent in the central metal of the dye molecules so as to prevent the dye molecules from coming too close to each other, and to provide a sufficient distance between the dye molecules to cause a spectral shift. The action of pulling into the region is given to the cohesive force (intermolecular force) of the substituent.

The phthalocyanine and naphthalocyanine compounds can be roughly classified according to the place where a substituent is attached. They are classified into a type having a substituent at the α-position and a type having a substituent at the β-position and a type having a substituent on the central metal. Of these, a type having a substituent at the α-position, and a type of phthalocyanine having a substituent at the β-position, naphthalocyanine compounds, the presence of isomers, the presence of an energy level due to the rotation and vibration of the substituent, The spectrum is easy to spread. Therefore, even if there is a spectral change due to a change in the aggregation state such as association, the recording contrast is low unless the change is very large (FIG. 2).

On the other hand, a type having a substituent on the central metal,
The so-called axial ligand type phthalocyanine and naphthalocyanine compounds generally have little effect on the basic skeleton of the phthalocyanine and naphthalocyanine compounds, and therefore the energy state caused by the rotation and vibration of the axial ligand. There is almost no difference between them. Further, unless the α-position or β-position substituent is introduced, there is no isomer, so that the spectrum does not spread and the spectrum shows a sharp peak like a solution state. Therefore, in such an axial ligand type dye, even if the spectrum slightly changes due to a change in the interaction between dye molecules due to a change in the aggregation state,
The original (certain stable state) spectrum is so sharp that the recording contrast is high (FIG. 1).

Further, when the structure is made to be compatible with the CD type medium, that is, when the metal reflection layer is provided on the recording layer, the type having a substituent at the α-position and the type having a substituent at the β-position The phthalocyanine and naphthalocyanine compounds have a broad spectrum and show a spectral shape that originally includes two stable states of reversible changes. The existence of isomers in the wavelength region that should not exist in the main structure dye originally Also, due to the existence of absorption due to the existence of energy levels due to the rotation and vibration of the substituent, there are many cases where there is relatively large absorption at the recording / reproducing wavelength from the initial stage, and the initial stage (when unrecorded or erased) There is a possibility that the reflectance of) will fall. In other words, if you select a recording / reproducing wavelength that raises the reflectivity during unrecorded / erased (there is almost no absorption at that wavelength), it will not be possible to move the spectrum enough to make that wavelength have large absorption. There is a nature.

On the other hand, a type having a substituent on the central metal,
So-called axial ligand type phthalocyanine and naphthalocyanine compounds have a large absorption at the wavelength even if the recording / reproducing wavelength is selected so as to increase the reflectance at the time of unrecorded / erased. , It is possible to move the spectrum (a small spectrum change is enough). This axial ligand plays a role of widening the distance between dye molecules from a state in which the interaction between dye molecules is very large, as in the case of the unsubstituted state, and may have spectrum mobility and reversibility. At the same time, the distance between dye molecules can be controlled by the cohesive force of the axial ligand by appropriately selecting the axial ligand, so that it is possible to provide a recording material with high recording contrast and good reversibility. Becomes

For these reasons, it is very preferable in the present invention to select a so-called axial ligand type phthalocyanine or naphthalocyanine compound having a substituent in the central metal as the organic reversible material. That is, in the present invention, a phthalocyanine compound represented by the following general formula (III) or a naphthalocyanine compound represented by the above general formula (IV) is preferably used.

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Embedded image [In the formula, M, X ^{1 to} X ⁴ , k, l, m, and n each represent the following. M: substituted or unsubstituted alkyl group, aryl group, alkoxy group, aryloxy group, (-OPR ¹ R ² ) t
^{Group, (- OPOR 3 R 4)} t ^{group, (- OSiR 5 R 6 R} 7) t
Group, (-OCOR ⁸ ) t group, (-OR ⁹ ) t group, (-OCO
COOR ¹⁰ ) t group, (-OCOCOR ¹¹ ) t group, or (-
OCONR ¹² N ¹³ ) t group-containing trivalent or tetravalent metal atom, R ^{1 to} R ¹³ are each independently a hydrogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group or a substituted or unsubstituted 1 Valent aromatic hydrocarbon group, t: integer of ^{1 to} 2, X ^{1 to} X ⁴ : each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted Substituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted arylthio group, nitro group, cyano group, sulfonic acid group, sulfonic acid amide group or sulfonic acid ester group, k, l, m, n: each independently an integer of 0 to 4. ]

As the central metal in the above general formulas (III) and (IV), a substituted or unsubstituted alkyl group, aryl group, alkoxy group, aryloxy group, (--OP
R ¹ R ²⁾ t ^{group, (- OPOR 3 R 4)} t group, (- OSiR ⁵
R ⁶ R ⁷⁾ t group, (- OCOR ⁸⁾ t group, (- OR ⁹⁾ t group,
(-OCOCOOR ¹⁰ ) t group, (-OCOCOR ¹¹ ) t group
A trivalent or tetravalent metal atom having a group or a (—OCONR ¹² N ¹³ ) t group is preferable. Where R ^{1 to} R
Each ¹³ independently represents a hydrogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group or a substituted or unsubstituted monovalent aromatic hydrocarbon group, and t is an integer of 1 to 2.

The metals in the central metal M in the general formulas (III) and (IV) are Al, Ga, In,
Tl, Mn, Fe, Ru, Cr, Zr, Ti, Si, G
e, Sn, V and the like. In addition, the general formula (II
In I) and (IV), X ^{1 to} X ⁴ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or Represents an unsubstituted aryloxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted arylthio group, a nitro group, a cyano group, a sulfonic acid group, a sulfonic acid amide group or a sulfonic acid ester group, and k, l, m , N are substituents X ^{1 to} X ⁴
Represents the integer of 0 to 4 each independently.

In order to cause a large spectrum change, first, the dye molecules, that is, the π-conjugated systems of the dye basic skeleton, are made to have a sufficiently large spectrum change by the interaction such as intermolecular force between the substituents. It is necessary to pull in a large range. In this case, if the dye molecules are too close to each other, spectral mobility and reversibility may be lost, which is not preferable, but a type having a substituent on the central metal, so-called axial ligand type phthalocyanine, naphthalocyanine, etc. The compound (1) is convenient because the axial ligand can control the distance at which the dye molecules can approach each other. The present inventors have found that compounds other than phthalocyanine, naphthalocyanine and the like having relatively large axial ligands have poor spectral mobility and reversibility, and that even if they have large axial ligands, they are dye molecules. It has been found that an alkyl group is added as an axial ligand in order to cause them to aggregate with each other, and thereby, large spectral mobility and reversibility can be provided.

By the way, the spectrum due to the interaction between the dyes is as follows:
It can be approximated by including the term of dipole interaction. The dipole-dipole interaction is represented by the following equation.

[Equation 1] E ^(μμ) = − (μ _A · μ _B / r ³ ) {2 cos θ _A cos θ _B
−sin θ _A sin θ _B cos (φ _A −φ _B )} (However, in the formula μ _A , μ
_B is the magnitude of the dipole moment of the dye molecule, r is the distance between the dye molecules, that is, the distance between the dipoles, θ is the angle between the dipole and the line connecting the dipole centers, and φ is the dipole center of the dipole. It shows the rotation angle around the straight line connecting the two axes. This relationship is schematically shown in FIG. )

Now, considering only the term of dipole-dipole interaction and examining the energy change due to this interaction, it becomes as shown in FIG. 4, and the main skeleton ring in the compounds such as phthalocyanine and naphthalocyanine is in the θ direction, It can be seen that the amount of change in the spectrum changes depending on the arrangement in the φ direction, or in the θ direction and the φ direction mixed. As can be seen from the formula of the dipole-dipole interaction, in order to increase the energy change due to this interaction, the magnitudes of the dipole moments μ _A and μ _B are increased and the distance r is increased.
Or it is necessary to optimize φ and θ. Increasing the magnitudes of dipole moments μ _A and μ _B corresponds to changing the main skeleton ring in compounds such as phthalocyanine and naphthalocyanine, and therefore molecular design cannot be easily performed. Further, as described above, it is not preferable to make the distance r extremely small because spectrum mobility and reversibility are lost.

In the present invention, increasing the spectrum shift due to the change in the dipole-dipole interaction force, that is, the change in the interaction force between the dye basic skeleton π-conjugated systems is performed in the θ direction and the φ direction of the main skeleton ring. It is carried out by controlling the arrangement and γ within the range where the spectral mobility is not lost. It has been found that this control can be achieved by choosing the substituents of the central metal, ie the axial ligand. That is, as shown in FIGS. 5- (a) to-(d), by changing the axial ligand [the inclination increases in the order of (a) → (d)], the inclination of the axial ligand, It is possible to control steric hindrance, bulkiness, flexibility, etc., and thus change the arrangement of interaction between dye molecules. An alkyl group is preferable as such an axial ligand. This is because the alkyl group has an appropriate cohesive force, and even if the alkyl group is made larger, the interaction between the dye basic skeleton π-conjugated systems can be given.

For example, when the central metal M is a substituent-containing metal atom having a specific structure, that is, a phthalocyanine compound represented by the following general formula (V) and a naphthalocyanine compound represented by the following general formula (VI) The case of is as follows.

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[Chemical 6] [In the formula, X ^{1 to} X ⁴ , k, l, m, and n each represent the following. X ^{1 to} X ⁴ : each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or Unsubstituted alkylthio group, substituted or unsubstituted arylthio group, nitro group, cyano group, sulfonic acid group, sulfonic acid amide group or sulfonic acid ester group, R ^{14 to} R ¹⁶ : alkyl group, k, l, m, n : Each independently an integer of 0 to 4. ]

The alkyl groups in R ¹⁴ , R ¹⁵ and R ¹⁶ of the compounds represented by the general formulas (V) and (VI) have the following energy changes due to the dipole-dipole interaction. In order to increase the amount of spectral change from the disperse state of so-called non-aggregated and non-aggregated dye molecules, an alkyl group in which the axial ligand is in a relatively standing state is selected,
The dye molecules are in a so-called H-associated state (actually, they are not close to the H-associated distance and there is a considerable intermolecular distance), or the axial ligand is in an extremely sleeping state. It is preferable that the alkyl group is selected and the dye molecules are in a so-called J-association state (actually, there is a considerable intermolecular distance without being close to the J-association distance). There is an optimal combination for taking

This optimum condition is, for example, the above general formula (V).
And in the compounds represented by (VI), R ¹⁴ , R ¹⁵ , R
¹⁶ is an alkyl group, and R ¹⁴ , R ¹⁵ , and R ¹⁶ may have different kinds of alkyl groups, and R ¹⁶ has 5 carbon atoms as compared with the alkyl group having a larger carbon number of R ¹⁴ and R ^15. Alkyl groups having the above differences, or the above general formulas (V) and (VI)
In the compound represented by, R ¹⁴ , R ¹⁵ and R ¹⁶ are alkyl groups, and R ¹⁴ , R ¹⁵ and R ¹⁶ may have different kinds of alkyl groups, and R ¹⁴ and R ¹⁵ have 3 carbon atoms. Of the following alkyl groups, R ¹⁶ is an optimum combination of R ¹⁴ and R ¹⁵ that has a difference in carbon number of 5 or more than an alkyl group having a large number of carbon atoms that can increase the spectrum change.

Specifically, in the compounds represented by the general formulas (V) and (VI), R ¹⁴ , R ¹⁵ and R
^{When 16} are the same and large alkyl groups, they are spatially dense and the dye molecules do not come close to each other (r becomes large), and the interaction of the dye skeleton π-conjugated system decreases, so the amount of spectral shift is small. . In addition, alkyl group 3
If all of them are large alkyl groups, the alkyl group portion is likely to crystallize and cannot be used as an optical information recording medium. Therefore, in the compounds represented by the general formulas (V) and (VI), one of R ^{14 to} R ¹⁶ has a long alkyl group and the other two have a short alkyl group, so that the above problems can be solved. . Furthermore, in the compounds represented by the general formulas (V) and (VI), one alkyl group of R ^{14 to} R ¹⁶ is lengthened, the other two are shortened, and a long alkyl group is converted into a metal. By selecting an alkyl group having a branched structure in the near part, it may be possible to stand an axial ligand, and conversely, by having one extremely long alkyl group having no branched structure, It may be possible to lay down the axial ligand. This provides a reversible recording material that produces large spectral changes.

In the present invention, examples of the alkyl group suitable for the axial ligand of the recording material include the following. Methyl group, ethyl group, n-propyl group, n-butyl group, isobutyl group, n-pentyl group, neopentyl group,
Isoamyl group, 2-methylbutyl group, n-hexyl group,
2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2-ethylbutyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 4
-Methylhexyl group, 5-methylhexyl group, 2-ethylpentyl group, 3-ethylpentyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4
-Methylheptyl group, 5-methylheptyl group, 2-ethylhexyl group, 3-ethylhexyl group, n-nonyl group,
Primary alkyl groups such as n-decyl group and n-dodecyl group; isopropyl group, sec-butyl group, 1-ethylpropyl group, 1-methylbutyl group, 1,2-dimethylpropyl group, 1-methylheptyl group, 1- Ethylbutyl group, 1,
3-dimethylbutyl group, 1,2-dimethylbutyl group, 1
-Ethyl-2-methylpropyl group, 1-methylhexyl group, 1-ethylheptyl group, 1-propylbutyl group, 1
-Isopropyl-2-methylpropyl group, 1-ethyl-
2-methylbutyl group, 1-ethyl-2-methylbutyl group, 1-propyl-2-methylpropyl group, 1-methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, 1- Isopropyl-2-methylbutyl group, 1-isopropyl-3-methylbutyl group, 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-isobutyl-3-
Secondary alkyl group such as methylbutyl group; tert-butyl group, tert-hexyl group, tert-amyl group, te
Tertiary alkyl groups such as rt-octyl group; cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group, 4
A cycloalkyl group such as a-(2-ethylhexyl) cyclohexyl group, a bornyl group, an isobornyl group, an adamantane group and the like.

The definitions of the substituents X ^{1 to} X ⁴ and the substitution numbers k, l, m and n in the general formulas (V) and (VI) are as defined in the general formulas (III) and (IV). Same as the case. However, it is preferable that the number of substituents is small and the number of substituents is small. This is because a sterically large substituent is introduced, and the introduction of a large number of substituents eliminates the spectral characteristics of the axial ligand type dye.

Next, by introducing a polymer compound,
The formation of the dispersed state will be described below. (Reference: INT
ERMOLECULAR AND SURFACE F
ORCES, Second Edition. JACO
BN. ISRAELACHVILI: ACADEMI
C Press. CHAPTER9 P139 ~) two
For any type of interaction between the molecules D and P of
Energy in the intermolecular distance given to the
Is the ratio of the product of some molecular properties of D and some of P
For example. Therefore, let these properties be D and P, respectively. Obedience
Contact each other for various types of interactions.
The electrostatic force between the molecules D and P, the charge-dipole interaction,
Dipole-dipole interaction, charge-induced dipole interaction,
Dipole-induced dipole interaction, dispersion force, etc. (physical coupling)
The interaction energy due to_DD= -D^Two  W_PP= -P^Two W_DP= -DP. However, pure Coulomb interaction between charges
Only in the case, it is necessary to change the negative sign to positive.

Consider a mixture of equal amounts of molecules D and P as shown in FIG. 6- (a). If the molecules are randomly dispersed, both D and P exist on average around one D molecule as the closest molecules. The same applies to the P molecule. However, if the molecules are associated or aggregated, D
Figure 6- shows the molecular composition of the closest molecules around the molecule and the P molecule.
(B). Therefore, the energy difference between the associated clusters and the dispersed clusters is 9 D-D bonds and 9 D-P bonds instead of 18 D-P bonds (which can be called D-P aggregates or D-P aggregates). Since P-P bond is formed, δW = -9 (D-P) ² . In the simplest case where two molecules are associated and aggregated, FIG. 6- (c),-
As shown in (d), δW = − (D−P) ² . Furthermore, in the situation where each central molecule is surrounded by 12 closest molecules, when 6 D molecules and 6 P molecules surround each D and P molecule, 27 DD bonds and 27 ΔW = −27 (DP) ² because the PP bond causes association and aggregation.
Becomes Therefore, in general, it can be written that δW = W (association) −W (dispersion) = − n (DP) ² . Here, n is always equal to the number of molecules involved and the number of bonds (including physical bonds) between the same type of molecules formed in the association and aggregation processes irrespective of their relative sizes. From this, it can be said that a kind of effective attractive force always exists between the same kind of molecules in the binary mixture, and the state of association and aggregation of the same kind of molecules is energetically advantageous as compared with the dispersed state.

In order to form the dispersed state of the dye, another molecule may be introduced so as to stably form the dispersed state of the dye. As described above, if δW is made small, the association and aggregation states can exist stably. That is,
The difference between the association of dye molecules, the aggregation energy and the association of other molecules, and the aggregation energy should be small. It is considered that the polymer compound has a large number of factors that can control the interaction such as modification of the side chain and the degree of polymerization, so that it is easy to form a dispersed state or an aggregated state. From these things, as a mixture to the dye molecule, a polymer compound having a large substituent on the side chain is mentioned as a preferable example.

Specific preferred examples of the polymer compound having a large substituent in the side chain include polymethacrylic acid ester represented by the following general formula (I) and polystyrene substitutes represented by the following general formula (II). .

Embedded image

Embedded image (In the formula, R, Z ^{1 to} Z ⁶ and n each represent the following: R: an alkyl group, Z ^{1 to} Z ⁵ : each independently a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkyl group; Substituted aryl group, Z ⁶ : hydrogen atom, halogen atom or alkyl group, n: degree of polymerization.)

In the polymethacrylic acid ester represented by the general formula (I), R is preferably an optionally branched alkyl group having 3 or more carbon atoms. In the polystyrene substitute represented by the general formula (II), the substituent has 3 or more carbon atoms in at least one position of Z ^{1 to} Z ^6.
It is preferable that the above alkyl group which may have a branch is substituted, and a plurality of substituents may be introduced. The definition of these polymers is that the introduction of an alkyl group into the side chain and the introduction of a bulky substituent that causes steric hindrance to the side chain reduce the interaction between the polymers. It is necessary to enhance intermolecular force, that is, interaction with a substituent of a molecule, specifically, an alkyl group moiety substituted by a central metal, and to achieve formation of a dispersed state of a dye molecule.

The above-mentioned polymer is, so to speak, a polymer that passively changes interaction with external energy such as light or heat. However, in addition to this, an active-type polymer in which the polymer itself changes by external energy is used. Polymers are also suitable for the present invention. This active polymer is a polymer compound that reversibly causes an electronic or structural change by external energy such as light or heat, and for example, there is a polymer material exhibiting photochromism or thermochromism. A polymer compound that reversibly causes an electronic or structural change by external energy such as light or heat utilizes the reversible electronic or structural change of the polymer compound to reversibly change the aggregation state of dye molecules. To change to.

Examples of the polymer compound that reversibly causes an electronic or structural change by external energy such as light or heat include, for example, O, N, S, P, A in the main chain or side chain.
A polymer compound having a coordinating group containing a coordinating atom such as s or Se, or a polymer compound in which the morphology of the molecular chain is changed by external energy is used. Examples of such polymer compounds include compounds represented by the following general formula (VII).

Embedded image In the general formula (VII), R ²¹ and R ²² represent a hydrogen atom or an alkyl group which may have a substituent. However, although they may be the same, both are not hydrogen atoms at the same time, and at least one is an alkyl group which may have a substituent. X is an S atom, an O atom, a Se atom or>
An NR ²³ group is shown, and R ²³ is a hydrogen atom, an alkyl group or an aryl group. In addition, n shows a polymerization degree.

Among the compounds represented by the general formula (VII), a polythiophene derivative in which X is a sulfur atom is preferable, and one of R ²¹ and R ²² is more preferably a hydrogen atom and the other is an alkyl group. It is a poly (3-alkylthiophene). In addition, among the poly (3-alkylthiophenes), from the relationship of solubility in organic solvents, interaction force between polymers, interaction force with dye molecules, and the like,
An alkyl group having n = 6 or more is particularly preferable.

When the external energy is, for example, light, the above-mentioned polymer whose molecular chain morphology changes can be said to be a photoresponsive polymer whose photoinduced molecular chain morphology changes. 1 of high molecular compounds suitable for the invention
As an example: The interaction between the photo-sensitive 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. The light reversibly generates electric charges along the polymer chains and utilizes their electrostatic repulsion.

Further, a thermoplastic polymer compound can also be used in the present invention, but in order to reduce the interaction between the polymers and enhance the interaction force with the dye molecule, a moiety such as an alkyl group in the side chain is used. It is preferred that a substituent having is introduced. As the thermoplastic polymer compound, acrylic resin,
Polycarbonate resin, polyester resin, polyamide resin, vinyl chloride resin, polyvinyl ester resin,
Examples thereof include polystyrene-based resin, polyolefin-based resin (for example, poly-4-methylpentene, etc.), polyether sulfone resin, and the like.

Although the dyes and polymer compounds suitable for the present invention have been described above, the optical information recording medium of the present invention basically utilizes the spectral shift ability or reversibility of the dye itself. However, polymer compounds rather play an auxiliary role. The dye molecule used in the present invention may have a problem with stability such as heat.
At 0 ° C. or higher, the aggregation state of the dye is drastically changed, such as sublimation and dissolution, or crystallization at room temperature.

The polymer compound has an appropriate interaction with the dye and has a function of suppressing this state change. In the present invention, as a result of investigating spectrum mobility, reversibility, stability, etc. in various combinations of dyes and polymer compounds, these properties are greatly influenced by the type of polymer compound and the degree of polymerization of the polymer compound. I was found to be done. Since the magnitude of the interaction between the polymer compounds or the interaction between the polymer compound and the dye largely changes depending on the kind, size, shape, etc. of the side chain of the polymer compound, the interaction of the polymer compound is also used in the present invention. Controlling the force, δW = -n (D-
Appropriate substituents are introduced to reduce P) ² .

In order to reduce δW, it is conceivable to control the degree of polymerization together with the introduction of substituents. In general, the van der Waals force acting between atoms is inversely proportional to the sixth power of the interatomic distance, so the introduction of substituents can increase the interaction distance r between central molecules between polymer compounds, resulting in a sharp decrease in interaction force. It seems, but in reality a gradual change occurs. This is because the dispersive force (van der Waals force) acts not between the centers of molecules but between the centers of electronic polarization of each molecule, and the center of electronic polarization is in a covalent bond. Therefore, for very large molecules, the center distance has no meaning in terms of cohesive energy. That is, the interaction force does not change abruptly in proportion to the so-called r −6th power.

On the other hand, the effect of the degree of polymerization brings about a larger change than the effect of introducing a substituent. For example, in two parallel chain molecules, the non-delayed van der Waals force interaction free energy calculated based on pair additivity is proportional to the length of the chain molecule. Therefore, the degree of polymerization of the polymer compound greatly affects the interaction force between the polymers. From this also, there are two possible methods for controlling the interaction of the polymer compound: introduction of a substituent and control of the degree of polymerization, but in order to carry out more stable and finer control, it is better to modify the substituent. It is advantageous. There is no problem if the degree of polymerization of the polymer compound is very high, but the interaction of the polymer compound with a very low degree of polymerization will decrease sharply, and the interaction force should be adjusted only by modifying the substituents. Is difficult.

In short, the dye used in the present invention alone cannot stably form the dispersed state, and the stability of the aggregated state in a general sense including the dispersed state and the aggregated state of the dye is poor. , By having an interaction with a high molecular compound (this interaction acts not only on the dye molecule itself but also on the dye aggregate. Therefore, it does not matter whether the dye is in the dispersed state or the aggregated state). Has improved. Therefore, the polymer compound in which the aggregation state of the dye changes in the untreated state (for example, allowed to stand naturally) has a large D-P difference and is not suitable as the polymer compound of the present invention. The modification of the substituent is
It is effective for polymer compounds that can control the aggregation state change of the dye in the untreated state (eg, allowed to stand naturally), and this modification controls whether the dispersion state of the dye is stabilized or the aggregation state is stabilized. Of. When the degree of polymerization is low, the interaction force of the polymer compound decreases, and it is not possible to suppress the aggregation change of the dye over time.
It becomes impossible to deal with it by changing the main chain.

In the present invention, in order to ensure the stability, reversibility, and spectral movability of the dye used in the present invention, the polymer compound is generally treated by modifying the main chain or modifying the substituent. Is selected from the compounds represented by the general formulas (I) and (II), and any one of the number average molecular weight, the weight average molecular weight, or the viscosity average molecular weight of the polymer compound is 1 × 10 ⁴ or more. Is experimentally found to be necessary.

Next, the optical information recording medium of the present invention having the recording material contained in the recording layer will be described. In the recording layer of the present invention, other dyes may be added in order to promote changes in energy efficiency, wavelength matching, dye molecular aggregation state, dispersion state, and crystal state. Examples of such dyes include polymethine dyes, naphthalocyanine dyes, phthalocyanine dyes, squarylium dyes, coroconium dyes,
Examples include pyrylium-based, naphthoquinone-based, anthraquinone (indanthrene) -based, xanthene-based, triphenylmethane-based, azulene-based, tetrahydrocholine-based, phenanthrene-based, triphenothiazine-based dyes, and metal complex compounds. May be used alone,
You may make it a combination of 2 or more types. Further, in the above dye, a metal or a metal compound such as In, Te, Bi, Al or B can be used.
It is also possible to use e, TeO ₂ , SnO, As, Cd, etc. in the form of dispersion mixing or lamination. Further, various materials such as ionomer resins, polyamide resins, vinyl resins, natural polymers, silicones, liquid rubbers, or silane coupling agents may be dispersed and mixed in the dye, and used. Alternatively, for the purpose of improving the characteristics, it may be used together with a stabilizer (for example, a transition metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer and the like.

The recording layer is formed by vapor deposition, sputtering,
It can be carried out by ordinary means such as CVD or solvent application. When the coating method is used, the dye or the like is dissolved in an organic solvent, and a conventional coating method such as spraying, roller coating, dipping or spinner coating is used. 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, sulfoxides such as dimethylsulfoxide, ethers such as tetrahydrofuran, dioxane, diethyl ether and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate , Aliphatic halogenated carbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride and trichloroethane, aromatics such as benzene, xylene, monochlorobenzene and dichlorobenzene, or cellosolves such as methoxyethanol and ethoxyethanol, hexane, Hydrocarbons such as pentane, cyclohexane and methylcyclohexane can be used. The film thickness of the recording layer is suitably 100 to 10 μm, preferably 200 to 2000 μm.

The layer structure of an optical information recording medium to which the recording material of the present invention is applied is, for example, a substrate, a recording layer, an undercoat layer, a reflective layer, a hard coat layer, a protective layer (in no particular order), and the like. The properties and materials other than the recording layer are preferably as follows.

<Substrate> A necessary characteristic of the substrate is that it should be transparent to the laser light used when recording / reproducing is performed from the substrate side, but it is transparent when recording / reproducing is performed from the recording layer side. No need. As a substrate material,
For example, polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, plastic such as polyimide, glass, ceramic or metal can be used. Note that a guide groove or guide pit for tracking, and a preformat such as an address signal may be formed on the surface of the substrate.

<Undercoat layer> The undercoat layer comprises (a) improved adhesion, (b) barrier against water or gas, and (c).
Improved storage stability of the recording layer, (d) improved reflectance,
It is used for the purpose of (e) protection of the substrate from solvent, (f) formation of guide grooves, guide pits, preformats, and the like. For the purpose of (a), it is possible to use various polymers such as ionomer resins, polyamides, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers, and various silane coupling agents. You can
For the purposes of (b) and (c), in addition to the above polymeric materials, inorganic compounds such as SiO ₂ , MgF ₂ , SiO, T
iO ₂ , ZnO, TiN, SiN, and Zn, Cu, N
A metal such as i, Cr, Ge, Se, Au, Ag, Al, or a semimetal can be used. For the purpose of (b), a metal such as Al or Ag, or an organic thin film having a metallic luster such as a methine dye or a xanthene dye can be used. For the purpose, an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin or the like can be used. The thickness of the undercoat layer is 0.0
1 to 30 μm, preferably 0.05 to 10 μm is suitable.

<Metal Reflective Layer> As the metal reflective layer, a metal, a semimetal, or the like, which has a high reflectance and is hardly corroded, can be used. Specific materials include Au, Ag, Cu, Al,
Examples thereof include Cr and Ni, and Au and Al are preferable. These metals and metalloids may be used alone.
More than one kind of alloy may be used. Examples of the film forming method include vapor deposition and sputtering, and the film thickness is 50 to 30.
It is 00Å, preferably 100 to 1000Å.

<Protective Layer, Substrate Surface Hard Coat Layer> The protective layer or substrate surface hard coat layer (a) scratches the recording layer,
It is used for the purpose of protecting from dust and dirt, (b) improving storage stability of the recording layer, and (c) improving reflectance. For these purposes, the materials shown in the undercoat layer can be used. In addition, as an inorganic material, Si
O, SiO _{2 and the} like can also be used, and as an organic material, acrylic resin, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, natural rubber, styrene-butadiene. Resins, chloroprene rubber, waxes, alkyd resins, drying oils, heat-softening and heat-melting resins such as rosin can also be used. Among the above materials, the most preferable one for the protective layer or the substrate surface hard coat layer is an ultraviolet curable resin having excellent productivity. The thickness of the protective layer or the substrate surface hard coat layer is 0.01 to 30 μm.
m, preferably 0.05 to 10 μm. In the present invention, the undercoat layer, the protective layer and the substrate surface hard coat layer are the same as in the case of the recording layer, such as a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant and a plasticizer. Can be included.

[0062]

The present invention will be described in detail with reference to the following examples.

In the compound represented by the following general formula (VIII), a phthalocyanine compound in which R ¹⁴ and R ¹⁵ are methyl groups and R ¹⁶ is a dodecyl group was synthesized, and 0.05 g of this dye was dissolved in 3 ml of a toluene solution. A solution was made.

Embedded image

Next, a solution was prepared by completely dissolving a weight corresponding to 1/200 mol of the repeating minimum unit of the polymer compound shown in Table 1 in 50 ml of toluene.

[Table 1] Note) Mw: weight average molecular weight Mn: number average molecular weight

0.1 ml of these polymer solutions and 0.
2 ml was mixed and a recording thin film was formed on a quartz substrate by spin coating. For comparison, a recording thin film containing only a dye was prepared. These recording thin films were spin-coated, heated at 100 ° C. for 10 minutes, and heated at 150 ° C. for 10 minutes, and then their respective absorption spectra were measured. The results are shown in Table 2. The decrease in absorbance means that the spectrum peak value after the heat treatment has decreased to 50% or less with respect to the spectrum peak value after the initial spin coating, x, 50%
When the value decreased to 70%, it was evaluated as Δ, and other than that was evaluated as ◯. Regarding the spectrum shift, ◯ indicates that the spectrum after the heat treatment is shifted with respect to the spectrum after the initial spin coating and reversibility is observed in the spectrum change, and x indicates that the spectrum change does not occur.

[0066]

[Table 2] Note) Mw: weight average molecular weight Mn: number average molecular weight

Next, in the general formula (VIII), R ¹⁴ ,
A phthalocyanine compound in which R ¹⁵ is an isopropyl group and R ¹⁶ is an octyl group was synthesized. 0.05g of this dye is 5m
A solution dissolved in 1 l of toluene was prepared. Next, 0.5 g of polystyrene having different degrees of polymerization (shown in Table 3) was added to 5 g.
A solution dissolved in 0 ml of toluene was prepared. 0.2 ml each of the dye solution and the polystyrene solution were mixed, and a recording thin film was formed on the quartz substrate by spin coating. For comparison, a recording thin film containing only a dye was prepared. With respect to this recording thin film, the absorption spectrum after spin coating and the absorption spectrum after standing for 1 week were measured. As a result, deterioration of the film with time was observed, and the maximum absorbance was reduced to 50% or less of the initial value. Table 3 shows the evaluation of film deterioration based on the rate of decrease in absorbance.

[0068]

[Table 3]

From the results of Table 3, the spectra are almost the same except for the dye single film at the initial stage, but with the passage of time, the aggregation of the dye changes in polystyrene with a low degree of polymerization, and the final Phase separation (deterioration of the membrane accompanied by a rapid decrease in absorbance) is caused. This indicates that the polystyrene having a low degree of polymerization has a weak interaction between the polymer compound and the dye, and the effect of the degree of polymerization does not depend much on the kind of the polymer compound. From the above results, there is a difference in the main chain and substituents of the polymer compound, and the polymer compound in which any of the number average molecular weight, the weight average molecular weight, or the viscosity average molecular weight is less than about 1 × 10 ⁴ is It can be seen that it is not suitable as an optical information recording medium based on the recording / reproducing / erasing method of.

Based on the above results, the above general formula (VII
In I), phthalocyanine in which R ¹⁴ and R ¹⁵ are methyl groups and R ¹⁶ is dodecyl group has Mw of 50,000 to 100,
000 poly-t-butylstyrene mixed film was prepared, and the spectral mobility, reversibility, and repeatability of this recording film were examined. FIG. 7 shows the spectra when unrecorded and when recorded,
FIG. 8 is an evaluation of reversibility and repeatability of absorbance, and it can be seen that good recording contrast, good erasing, and good repeatability have been achieved by the present invention.

Next, in order to confirm compatibility as a CD medium and reversibility in reflectance, a new sample was prepared by depositing gold on the above sample. The spectra of this sample when unrecorded and recorded were measured and found to be as shown in FIG. 9, and it was found that a good spectrum shift was generated as in the case of absorbance. Furthermore, when the reversibility in reflectance was evaluated for this sample, the states shown in FIG. 9 were formed alternately, and good contrast, good erasing, and good repeatability were also confirmed in reflectance.

[0072]

The optical information recording medium according to the present invention comprises, as a recording material, a mixed material containing at least a dye molecule and a polymer compound, and the polymer compound is represented by the general formula (I) or (II). And the number, weight, or viscosity average molecular weight of which is 1 × 10 ⁴ or more, the dye molecules are associated or aggregated by the interaction between the substituents substituted on the dye molecules. It is possible to cause a large spectrum shift by forming a non-association state, a non-aggregation state, or a dispersion state of the dye due to the interaction between the dye and the polymer compound, and good reversibility. Can be stably expressed, and the temporal stability is improved.

The recording method of the optical information recording medium according to claim 2 is:
Using the optical information recording medium according to claim 1, as an unrecorded state,
The dye molecules are associated or aggregated by the interaction of the substituents substituted in the dye molecule, and the interaction of the dye molecules is caused by the irradiation of external energy such as light or heat to this state. Alternatively, by breaking the aggregation state and forming a non-aggregation state or a non-aggregation state, that is, a dispersed state of the dye due to the interaction between the dye and the polymer compound, it is assumed that the information is recorded. Thus, a large spectrum shift can be generated, and since this state change does not accompany the shape change of the material, high sensitivity and high transfer rate can be achieved. Further, although this state change has good reversibility, it is possible to make it irreversible as a write-once type by changing the material.

The recording method of the optical information recording medium according to claim 3 is:
Using the optical information recording medium according to claim 1, as an unrecorded state,
When the dye molecule interacts with the polymer compound, it creates a non-association or non-aggregation state of the dye molecule, that is, a dispersed state, and this state is replaced with the dye molecule by irradiation with external energy such as light or heat. Since the information is recorded by forming a state in which dye molecules are associated or aggregated by the interaction between the substituents, according to this method, it is possible to cause a large spectrum shift, Moreover, since this state change does not accompany the shape change of the material, high sensitivity and high transfer rate can be achieved. Also, this state change has good reversibility,
It is also possible to make an irreversible change for the write-once type by selecting the material.

The reproducing method of the optical information recording medium according to claims 4 and 5 is performed by irradiating the recorded portion and the unrecorded portion of the optical information recording medium according to claim 1 with a laser beam. Since a large spectrum shift can be caused by a change in the state of the molecule, when the recorded portion and the unrecorded portion are irradiated with laser light, the state of the dye molecules of both the
The reflected light or the transmitted light changes greatly. Therefore, according to this reproducing method, a large recording contrast signal can be obtained.

In the erasing method of the optical information recording medium according to claims 6 and 7, the optical information recording medium according to claim 1 associates or aggregates the dye molecules by the interaction of the substituents substituted on the dye molecules. The recording state and the unrecorded / erased state or the unrecorded / erased state and the recorded state are formed by forming a state and a non-aggregated state or a non-aggregated state of the dye due to the interaction between the dye and the polymer compound, that is, a dispersed state. Therefore, it is a change in the physical binding state that is not accompanied by a shape change or a chemical change. According to the present method, reversibility can be easily expressed. Further, it is possible to perform erasing with a large erasing ratio and good repetitive characteristics.

[Brief description of drawings]

FIG. 1 shows an example of an absorption spectrum of an axial ligand type phthalocyanine compound according to a change in aggregation state.

FIG. 2 shows an example of an absorption spectrum of a phthalocyanine compound of a type having a substituent at the α-position depending on a change in aggregation state.

FIG. 3 is a schematic diagram for explaining a relational expression of dipole interaction.

FIG. 4 shows a case where only dipole-dipole interaction is considered,
3 is a graph showing the relationship between the arrangement position of the main skeleton ring of phthalocyanine in the θ direction and the amount of energy.

5 (a) to 5 (d) are schematic diagrams showing the difference in the interaction arrangement between dye molecules depending on the type of axial ligand of the axial ligand type phthalocyanine compound.

6 (a) and 6 (b) are schematic diagrams showing the dispersion and aggregation state of equivalent amounts of dye molecules and polymer compounds, and (c),
(D) is a schematic diagram showing a state in which one molecule of each of a dye molecule and a polymer compound is dispersed and aggregated.

FIG. 7 shows R ¹⁴ = R ¹⁵ = CH ₃ , R ¹⁶ = obtained in the examples.
3 shows the absorption spectra of a C ₁₂ H ₂₅ phthalocyanine compound sample before and after recording.

FIG. 8 shows R ¹⁴ = R ¹⁵ = CH ₃ , R ¹⁶ = obtained in the examples.
It is a graph showing the repetition characteristics measurement results of absorbance of the phthalocyanine compound sample C ₁₂ H _25.

FIG. 9 shows reflection spectra of a gold vapor-deposited sample obtained in an example during non-recording and during recording.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Tsutomu Sato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (7)

[Claims] 1. A state in which a dye molecule is made of a mixed material containing at least a dye molecule and a polymer compound, and the dye molecules are associated or aggregated by the interaction of substituents substituted on the dye molecule, and the dye and the polymer compound. In an optical information recording medium exhibiting different spectra depending on the dispersion state due to the interaction with the polymer, the polymer compound has the following general formula (I) or (II)
An optical information recording medium, which is selected from the compounds represented by the formula (1) and has a number average molecular weight, a weight average molecular weight or a viscosity average molecular weight of 1 × 10 ⁴ or more in the polymer compound. Embedded image Embedded image (In the formula, R, Z ^{1 to} Z ⁶ and n each represent the following: R: an alkyl group, Z ^{1 to} Z ⁵ : each independently a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkyl group; Substituted aryl group, Z ⁶ : hydrogen atom, halogen atom or alkyl group, n: degree of polymerization.) 2. The method for recording on an optical information recording medium according to claim 1, wherein unrecorded by forming a state in which dye molecules are associated or aggregated by the interaction of substituents substituted on the dye molecules. Information is recorded by changing the spectrum of a state into a spectrum of a dispersed state due to the interaction between a dye and a polymer compound by irradiation with external energy such as light or heat. Recording method for optical information recording medium. 3. The method for recording on the optical information recording medium according to claim 1, wherein the dye molecule forms a dispersed state due to the interaction between the dye and the polymer compound, and the spectrum of the unrecorded state is changed to light or Information is recorded by changing the spectrum to the state in which dye molecules are associated or aggregated by the interaction of the substituents substituted in the dye molecule by irradiation with external energy such as heat. Recording method for optical information recording medium. 4. The method for reproducing the optical information recording medium according to claim 1, wherein unrecorded by forming a state in which dye molecules are associated or aggregated by the interaction of substituents substituted in the dye molecules. For some spectra,
When the external energy such as light or heat is applied, the dye molecules are changed into the spectrum of the dispersed state due to the interaction between the dye and the polymer compound. A reproducing method of an optical information recording medium, characterized by reproducing. 5. The method of reproducing the optical information recording medium according to claim 1, wherein the dye molecule forms a dispersed state due to the interaction between the dye and the polymer compound, and the spectrum of the unrecorded portion is changed to light or Reflection of the laser light of the recording part, which is changed to a spectrum in which the dye molecules are associated or aggregated by the interaction of the substituents substituted on the dye molecule by irradiation with external energy such as heat, or transmitted A reproducing method of an optical information recording medium, characterized in that information is reproduced by a change of a light amount. 6. The method for erasing the optical information recording medium according to claim 1, wherein a recording state is formed by forming a state in which dye molecules are associated or aggregated by an interaction between substituents substituted in the dye molecules. For the spectrum of
Erasure of an optical information recording medium characterized by erasing information by changing a dye molecule into a spectrum in a dispersed state due to interaction between a dye and a polymer compound by irradiation of external energy such as light or heat Method. 7. The method for erasing the optical information recording medium according to claim 1, wherein a spectrum of a recording state due to a dye molecule forming a dispersed state due to an interaction between the dye and a high molecular compound is converted into light or heat. By irradiating external energy such as, for example, light that is characterized by erasing information by changing the spectrum of the state in which the dye molecules are associated or aggregated by the interaction between the substituents substituted in the dye molecule. Method of erasing information recording medium.