JP3503679B2 - Optical information recording medium - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a write-once type optical information recording medium of a heat mode capable of recording and reproducing by laser light in a short wavelength region such as DVD-R.

[0002]

2. Description of the Related Art The CD-R is well known as a means for recording and reproducing data such as images such as characters and figures and video or audio, but the present CD-R has a wavelength of 770-8.
A recording material capable of recording and reproducing corresponding to a laser beam of 30 nm is selected and used on the basis of its absorbance and optical constants (particularly the refractive index n and the extinction coefficient k). As an example, an optical disk having a pentamethine cyanine dye as a dye layer is used. However, recently, a DVD-R (digital disc) capable of high-density recording and reproduction by a red laser beam having a wavelength shorter than the laser beam used for the CD-R, for example, 620 to 690 nm.
Video disc-recordable or digital versatile disc-recordable) has come to be used as a medium for the next era.

[0003]

However, the CD-R and the DVD, which have different wavelength regions for recording and reproduction as described above, are provided.
With -R, the selection criterion of the recording material used for the former cannot be used as it is for the latter, and the selection criterion from the unique viewpoint is required as the recording material for DVD-R.
That is, a CD-R as a write-once type optical information recording medium
Performs recording and reproduction using a semiconductor laser having a wavelength of 770 to 830 nm (λ ₁ ), and therefore, when forming an optical interference layer having a recordable dye layer on a transparent substrate, an appropriate reflectance before and after recording can be obtained. In order to secure (70% or more) and the degree of modulation, the optical constants of the light interference layer at λ ₁ above, particularly the refractive index n and the extinction coefficient k, are 1.6 <n <4.0,
It is considered that 0.01 <k <0.2 is preferable, and the former cannot secure a reflectance of 65% or more after recording in the recording / reproducing wavelength region outside the range, and the latter secures a sufficient reflectance outside the range. As the recording sensitivity becomes too high, the signal cannot be accurately recorded. In order to satisfy the above-mentioned preferable ranges of n and k, it is said that the maximum absorption wavelength λ ₂ of the optical interference layer is preferably in the range of 600 to 750 nm, but the above DVD-R has a wavelength shorter than 770 nm. Since recording and reproduction are performed at 620 to 690 nm (λ ₂ ), the above-mentioned preferable ranges n and k for CD-R are not suitable for DVD-R, and recording and reproduction can be performed with the recording material. First, a recording material having an appropriate optical constant corresponding to the wavelength of λ ₂ must be selected.

A first object of the present invention is to provide an optical information recording medium using a recording material capable of appropriately selecting an optical constant and a maximum absorption wavelength for a short wavelength laser beam for recording and reproducing a DVD. is there. A second object of the present invention is to provide an optical information recording medium in which a recording material having an appropriate optical constant can be selected by selecting a dye structure . A third object of the present invention is to provide an optical information recording medium whose recording sensitivity can be adjusted by selecting or adjusting an optical constant. A fourth object of the present invention is to provide an optical information recording medium which does not require the use of other additives for adjusting the optical constants, and which suppresses heat accumulation during recording and enables recording with lower jitter. is there.

[0005]

Means for Solving the Problems As a result of intensive research for solving the above-mentioned problems, the present inventors have found that a wavelength of 620 nm
When assuming an optical interference layer having a refractive index n of 1.6 to 4.0 and an extinction coefficient k of 0.01 to 0.45 in the range of 690 nm, the reflectance simulations shown in FIGS.
m)), and FIGS. 3 and 4 (wavelength 690 nm) were obtained (calculated according to the method described in "Dyes and Chemicals" Vol. 37, No. 7, 1992). From this result, as a recording material for CD-R, a reflectance of 70% or more for tracking is limited, so that a sufficient reflectance cannot be ensured with an extinction coefficient k = 0.45, but with a DVD-R, the same reflectance is obtained. Rate is 45%
Therefore, for example, the film thickness is not larger than 110 nm,
Preferably, in the range not larger than 90 nm, k = 0.
It can be seen that even 45 can be recorded. Since this simulation was performed on a film for a substrate having no groove, when an actual optical disk has a groove,
The reflectance is slightly lowered, but even when the interference due to these grooves is taken into consideration, there is a margin of the reflectance (reflectance greater than 40%) in the above simulation, which is sufficiently practical. The present inventors have found that when a trimethine cyanine dye is used as a material having these optical constants corresponding to wavelengths of 620 nm to 690 nm, the maximum absorption wavelength and the second largest absorption wavelength are 500 nm to 655 nm.
Therefore, the present invention has been completed. Therefore, the present invention provides (1) an optical information recording medium having an optical interference layer including a dye layer on a substrate, wherein the optical interference layer is 620.
It is possible to record and reproduce with a laser beam selected from the wavelength region of nm to 690 nm, and the refractive index n of the laser beam selected from the wavelength region of the light interference layer is 1.6 to
4.0 and an extinction coefficient k of 0.01 to 0.45, and the optical interference layer has a maximum absorption peak wavelength by a visible ultraviolet spectrophotometer and a second largest absorption peak wavelength of 500 nm.
To 655 nm, the dye layer contains only one kind of trimethine cyanine dye as a dye of a recording material , and the trimethine cyanine dye is represented by the following general formula [Chemical formula 1] The present invention provides an optical information recording medium which is a compound shown and is a single component of a trimethine cyanine dye having an asymmetric ring structure on both sides of a trimethine chain. The present invention also provides (2) the optical information recording medium according to (1) above, wherein the trimethine cyanine dye is an asymmetric trimethine cyanine dye in which the ring structure of A is different from the ring structure of A ′. .

[Chemical 1] [Wherein A represents one of the following general formulas [Chemical Formula 2] to [Chemical Formula 5],

[Chemical 2] ,

[Chemical 3] ,

[Chemical 4] ,

[Chemical 5] , A ′ represents any one of the following general formulas [Chemical formula 6] to [Chemical formula 9],

[Chemical 6] ,

[Chemical 7] ,

[Chemical 8] ,

[Chemical 9] , A and A ′ may be the same or different (provided that D ₁ and D ₂ are each a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, a halogen atom, a carboxyl group,
Alkoxycarbonyl group, alkylcarboxyl group, alkylhydroxyl group, aralkyl group, alkenyl group,
Alkylamide group, alkylamino group, alkylsulfonamide group, alkylcarbamoyl group, alkylsulfamoyl group, alkylsulfonyl group, phenyl group, cyano group, ester group, nitro group, acyl group, allyl group, aryl group, aryloxy Group, alkylthio group, arylthio group, phenylazo group, pyridinoazo group, alkylcarbonylamino group, sulfonamide group, amino group, alkylsulfone group, thiocyano group, mercapto group, chlorosulfone group, alkylazomethine group, alkylaminosulfone group, vinyl Represents a substituent selected from the group consisting of a group and a sulfone group, and may be the same or different, and p and q are the numbers of the substituents and each represents an integer of 1 or more. ), R and R ′ are substituted or unsubstituted alkyl groups, carboxyl groups, alkoxycarbonyl groups,
Alkylcarboxyl group, alkoxyl group, alkylhydroxyl group, aralkyl group, alkenyl group, alkylamide group, alkylamino group, alkylsulfonamide group, alkylcarbamoyl group, alkylsulfamoyl group, hydroxyl group, halogen atom, alkylalkoxyl group,
Represents a substituent selected from the group consisting of a halogenated alkyl group, an alkylsulfonyl group, an alkylcarboxyl group or an alkylsulfonyl group bonded to a metal ion or an alkyl group, a phenyl group, a benzyl group and an alkylphenyl group, which may be the same or different. , X ⁻ is a halogen atom, PF ₆ ⁻ , SbF ₆ ⁻ , H ₃ PO ₄ , perchloric acid, fluoroboric acid, benzenesulfonic acid, toluenesulfonic acid, alkylsulfonic acid, benzenecarboxylic acid, alkylcarboxylic acid, tri fluoromethyl acid, periodic acid and SCN ^- represents an anion selected from among the group of anions. ]

In the present invention, the optical interference layer has a wavelength of 620n.
The optical interference layer is formed so as to be recordable and reproducible by laser light in the wavelength range of m to 690 nm (λ ₂ ). This is to make this optical interference layer usable for DVD-R. In the present invention, the light interference layer is a recording layer including a dye layer made of an organic dye material or a layer made of an organic material or an inorganic material, and containing a single layer or a plurality of dye layers capable of forming pits by laser irradiation. In addition to this recording layer, in the case where the refractive index and the film thickness are adjusted for the purpose of adjusting the optical physical properties of the optical information recording medium, for example, an enhance layer made of a resin material, further the substrate and the dye layer, and the dye layer are plural. Includes an intermediate layer provided between them and is a generic term for them. Further, the refractive index n and the extinction coefficient k as the optical constants at λ ₂ of the light interference layer are 1.6 <n <4.
0, 0.01 <k <0.45 and the maximum absorption peak wavelength and the second largest absorption peak wavelength in the visible ultraviolet spectrophotometer of the light interference layer are set to be in the range of 500 to 655 nm. By contrast with the case of CD-R, the limited range of the optical constant of the former corresponds to the limited range of the optical constant for the laser light having the wavelength of 770 nm to 830 nm (λ ₁ ) for CD-R, and the both overlap. However, the latter limitation of the maximum absorption wavelength region corresponds to the maximum absorption wavelength region of 600 to 750 nm in the case of CD-R, and in this case, it shifts to a lower wavelength region than that of CD-R. ing. If n and k are out of the above ranges, reflectance and push-pull before and after recording cannot be secured, and tracking during recording and reproduction and modulation after recording cannot be secured.

In order to obtain the optical constants required for the above-mentioned optical interference layer and the optical characteristics of the maximum absorption wavelength, one or more dye layers contained in the optical interference layer have different trimethine-based optical constants. It is preferable to contain one or more kinds of cyanine dyes. A dye layer containing a plurality of trimethine dyes can be represented by a composite spectrum of absorption spectra of the respective dyes, and this composite spectrum is suitable for laser light for recording and reproducing of DVD-R. Can be By mixing the dyes having different optical constants in this way, the optical constants can be optimized, and it is preferable to obtain an optical interference layer having the optimized dye layer because the recording sensitivity can be adjusted.

In the trimethine cyanine dye, the molecular main skeleton chain length of the pentamethine cyanine dye used in the recording material for CD-R has 5 carbon atoms, whereas the molecular main skeleton chain length has 5 carbon atoms. Since it is 3, the carbon number is short by 2 carbons, and thus the maximum absorption wavelength of the former pentamethine cyanine dye exists in the range of 600 to 750 nm, while the maximum absorption wavelength and 2 of the short wavelength side are in the range of 500 to 655 nm. The second largest absorption peak can be made to exist.
An appropriate recording material which can be recorded and reproduced by a short wavelength laser beam for DVD-R by selecting a dye having n and k within the preferable range of the optical constants from such trimethine cyanine dyes. Can be Such a trimethine cyanine dye is represented by the above general formula [Chemical formula 1], in which A is arbitrarily selected from the above general formulas [Chemical formula 2] to [Chemical formula 5], and A ' Are arbitrarily selected from the above general formulas [Chemical formula 6] to [Chemical formula 9], and the compounds of all the respective combinations of both selected are included. For example, a combination of the general formula [Chemical formula 2] and each of the general formulas [Chemical formula 6] to [Chemical formula 9] can be mentioned, and the same applies to each of the other general formulas [Chemical formula 3] to [Chemical formula 5]. A,
The substituents (D ₁ ) p and (D ₂ ) q of A ′ have p and q of at least 1, but are plural integers, that is, integers of 2 or more.

In such a trimethine cyanine dye, the left and right ring structures of the cyanine molecule, that is, A on one side of the trimethine chain is represented by any one of the above general formulas [Chemical formula 2] to [Chemical formula 5]. In the ring structure in the formula and the general formula in which A ′ on the other side of the trimethine chain is represented by any one of the above general formulas [Chemical Formula 6] to [Chemical Formula 9], the ring structure of the selected general formula in both is different. It is preferred to use a combination of asymmetric trimethine cyanine dyes. Such a compound has a sharp absorption waveform at λ ₂ and its tail does not have a tail, the absorbance per unit thickness of the dye layer is increased, the recording efficiency is improved, and only the symmetric compound is used. It is possible to use the single component because the appropriate optical constant can be obtained only by the dye without the need for other additives to adjust the lacking optical constant. With this, it is possible to record jitter that is further reduced. Also, the recording sensitivity can be improved. R and R'in the general formula [Chemical Formula 1]
Are preferably different, and the solubility in a solvent can be adjusted. Further, A and A ′ are each a substituent (D
₁ ) By having p and (D ₂ ) q, the moisture resistance and weather resistance of the dye can be controlled. Further X ^- can control the heat decomposability of the dye by a laser beam by changing the type of,
The pit shape during recording can be controlled.

By using the above-mentioned trimethine cyanine dye, the recording sensitivity is improved in the short wavelength range of 620 to 690 nm, particularly 630 to 655 nm, and the DVD-type with good jitter, modulation and asymmetry during reproduction is used. R can be obtained. As a method for synthesizing these dyes, The Chemistry of
The method described in Synthetic Dyes Vol 14 can be used.

To manufacture the optical information recording medium of the present invention,
A dye solution in which the cyanine dye represented by the general formula [Chemical Formula 1] is dissolved is prepared, and this is applied to a translucent substrate. This dye solution contains chloroform, dichloroethane, fluorine-containing solvents such as fluorinated alcohol, methyl ethyl ketone,
Dimethylformamide, methanol, toluene, cyclohexanone, acetylacetone, diacetone alcohol, cellosolves such as methyl cellosolve, dioxane and the like can be used. In this case, the mixing ratio of the cyanine dye is preferably 1% by weight to 10% by weight. Examples of the substrate used in the present invention include glass and plastics such as epoxy resin, methacrylic resin, polycarbonate resin, polyester resin, polyvinyl chloride resin, and polyolefin resin. Track grooves or pits may be formed on this substrate, and may have a signal necessary for an address signal. Further, it is preferable to use a spin coating method to apply the cyanine dye solution to the substrate. In this case, as the thickness of the coating layer after drying, the thickness conventionally used can be applied. The recording layer applied in the present invention has a singlet oxygen quencher,
Other compounds such as a light absorber and a radical scavenger (scavenger) may be included.

A reflective layer may be provided in addition to the above-mentioned light interference layer, and a protective layer may be provided on the reflective layer, and a protective layer may be provided on the substrate surface (laser light incident side).
The reflective layer has a high reflectance such as Au, Al, Ag, Cu, Pt formed by vapor deposition or sputtering, alloys of each of these, and metal films such as alloys to which trace components other than these are added. Examples of the material film include a protective layer, which is coated with a solution of a radiation curable resin such as an ultraviolet curable resin by a spin coating method or the like for the purpose of protecting the optical information recording medium and improving weather resistance, and then dried. Layers.

In this way, an optical disk having a light interference layer including a dye layer, a reflective layer, and a protective layer on the substrate can be obtained. It is also possible to bond optical disks of other similar structure or different structure having at least the light interference layer, or to bond the substrates so that the substrates themselves face each other. Material for this bonding,
As a method, an ultraviolet curable resin, a cationic curable resin,
A double-sided adhesive sheet, a hot melt method, a spin coating method, a dispensing method (extrusion method), a screen printing method, a roll coating method and the like are used.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details will be described with reference to the following embodiments. The track pitch length is 0.74 μm (0.80 μm).
, A polycarbonate substrate having only a wobble signal (which may also have a prepit signal) is used, and the dye layer of the light interference layer is a compound belonging to the above general formula [Chemical formula 1]. [Chemical formula 2] or [Chemical formula 3]
And a dye consisting of a combination of the general formulas [Chemical Formula 6] or [Chemical Formula 7], in which D ₁ and D ₂ are both hydrogen atoms, and D ₁ is a lower alkyl group such as a methyl group,
A dye in which p is 1, D ₂ is a hydrogen atom or a lower alkyl group such as a methyl group, and q is 1 (preferably A,
A'is a benzene ring), especially among
R and R ′ are each lower alkyl such as ethyl group, butyl group and amyl group, and may be the same or different, and in particular, X ⁻ is an anion of perchloric acid or iodine. For each indolenine-based trimethine-based cyanine dye of the dye that is an anion, a solution of the dye belonging to each of these is formed by spin coating, and Au or Al by sputtering is formed.
, A protective layer made of an ultraviolet curable resin is formed thereon by a spin coating method, and a polycarbonate substrate is further adhered by an adhesive layer made of an ultraviolet curable resin by a spin coating method to obtain a bonded optical disk. . Here, the dye used has a maximum absorption wavelength in the range of 500 to 655 nm, particularly 560 to 615 by adding each functional group with a trimethine chain having a main skeleton chain length of the molecule having 3 carbon atoms, In addition, the optical constants thereof are in the range of 1.6 <n <4.0 and 0.01 <k <0.45, particularly 2.1 <n <2.7 and 0.03 <k <0.41.
It is possible to select a dye as a single component that can be made to be, and it is possible to select an optimum optical constant within this range by mixing a plurality of dyes.
The optical constants in the range of up to 690 nm can be adjusted to an appropriate range, and with these, 620 to 690 nm, particularly 630
It is possible to provide a DVD-R capable of recording and reproducing with a laser beam of ˜670 nm. If the optical constants can be optimized, it becomes easy to adjust the sensitivity of the tracking signal represented by push-pull and the reflectance. In addition, by using an asymmetric trimethine dye having a ring structure, the absorption waveform of the laser light of the optical interference layer made of only the dye becomes sharp due to the association state and the tail does not have a tail. When the absorption waveform is sharp as described above, the absorbance per unit film thickness of the dye layer is increased and the recording efficiency is improved. Further, in the case of a trimethine dye having a symmetrical ring structure, the optical constant cannot be adjusted except by mixing two or more kinds thereof, whereas other additives are not necessary for adjusting the optical constant. Since it is possible to use only the dye single component, it is possible to suppress heat accumulation at the time of recording and record with a lower jitter by improving recording efficiency.

[0015]

EXAMPLES Reference Example 1 Width 0.32 μm, depth 100 nm, pitch 0.7 on the surface
4 μm spiral groove formed with a thickness of 0.
A transparent substrate made of polycarbonate and having an outer diameter (diameter) of 6 mm and a diameter of 120 mm was molded by an injection molding method. Next, a trimethine cyanine dye NK-4285 (n = 2.7 at a wavelength of 635 nm) represented by the following [Chemical Formula 10].
0, k = 0.41) (manufactured by Japan Photosensitive Dye Research Institute) and a trimethine cyanine dye NK- represented by the following [Chemical Formula 11].
4270 (n = 2.41 at wavelength 635 nm, k =
0.01) (manufactured by Japan Photosensitive Dye Research Institute) at a weight ratio of 25:75, and this mixture was mixed with 2,2,3,3-tetrafluoro-1-propanol (manufactured by Tokyo Kasei Co., Ltd., hereinafter TF).
(Abbreviated as P) to a concentration of 3% by weight, and the solution is applied to the surface of the substrate by spin coating to give a film thickness of 110
An optical interference layer made of a photosensitive dye film having a thickness of 10 nm was formed.

[0016]

[Chemical 10]

[0017]

[Chemical 11]

Table 1 shows the above results obtained by measuring the optical constants of this optical interference layer with respect to the laser light having the maximum absorption wavelength and the wavelength of 635 nm. From this table, it can be seen that n and k satisfy the conditions of 1.6 <n <4.0 and 0.01 <k <0.45, respectively. Further, when the absorption spectrum [wavelength dependence of absorbance (Abs) of laser light wavelength 400 to 800 nm range] by a visible ultraviolet spectrophotometer / U-4000 (manufactured by Hitachi, Ltd.) was measured for this optical interference layer, This was as shown by the chain line in FIG. From this figure, it can be seen that the optical interference layer has a maximum absorption peak wavelength in the range of 500 to 655 nm and a second largest absorption peak wavelength.

On this optical interference layer, 1 to 44 mmφ of the substrate
An Au film having a film thickness of 80 nm was formed on the entire surface of the area of 17 mmφ by a sputtering method to form a reflective layer. Also,
An ultraviolet curable resin SD-211 (manufactured by Dainippon Ink and Chemicals, Inc.) was spin-coated on the reflective layer, and the coating film was irradiated with ultraviolet rays to be cured to form a protective film having a thickness of 5 μm. Further, a UV curable resin SD-318 is formed on the protective film of the substrate and the light interference layer on which the protective film is not formed.
After dropping (manufactured by Dainippon Ink and Chemicals Co., Ltd.), another substrate formed in the same manner as above was placed on it, and the resin was diffused into the gap by spin coating, and then the substrate side was overlaid with ultraviolet rays. From the beginning to cure and
Thickness 2 made of resin in the area of 2mmφ to 120mmφ
The laminated substrates were bonded together by forming an adhesive layer of 5 μm to produce a bonded optical disk. The NA (aperture ratio (nu
(Mericalaperture)) = 0.6, laser wavelength = 635 nm, DDU-1000 (recorder of Pulstec Co., Ltd.) recorded at a linear velocity of 3.5 m / sec, and Yokogawa Electric Corp. time interval analyzer / TA-32
Jitter was measured at 0. DVD Specificat
According to the ion for Read-Only DISC standard, a Data to Clock Jitter is provided.
(Jitter) means channel bit rate = 26.6
The deviation value σ of the binarized data edge signal is standardized using Mbps (38.23 nsec) as a reference clock. Regarding the evaluation criteria for jitter, the minimum pit length is 0.4 μm, and the EFM at a linear velocity of 3.5 m / sec.
Signal modulation. Furthermore, in order to prevent the signal from being demodulated (decoded) by mistake when standardized with a clock, the limit is 8%, and preferably 8% or less, that is, 8% at the maximum. In addition, a push-pull (Push Pull (PP) is abbreviated as PP) indicating the tracking sensitivity is used for the wavelength 6
It measured using the laser beam of 50 nm, and evaluated. As shown in FIG. 6, the measurement is performed by converting the amount of light reflected by a four-divided detector (four-divided photodetector) when a laser beam (circular shape) is applied to the groove into a voltage (I
₁ + I ₃ )-(I ₂ + I ₄ ) / (I ₁ + I ₂ + I ₃ + I
It is the value expressed in ₄ ). The arrow on the Y-axis is the tangential direction.
edition). If PP is low, tracking becomes impossible and 0.13 or more (not less than 0.13,
That is, it is preferably at least 0.13%). Further, the reflectance, the modulation degree after recording I ₃ / I _top , I ₁₄
/ I _top was measured using a laser beam having a wavelength of 650 nm. Here, I _top substantially matches the maximum reflected light amount of the HF (EFM) signal and the maximum reflected light amount of I ₁₄ . I ₃ is a signal of an optical modulation component that is diffracted in the shortest recorded pit in the recorded groove, reflected by the objective lens and reflected in the non-pit part, and returned by the lens. is there. I ₁₄ is diffracted at the longest recorded pit in the recorded groove,
The amount of light returned to the objective lens and the non-pitted portion are reflected,
It is the signal of the optical modulation component that is the difference in the amount of light returning to the lens. Further, if the reflectance is low, the focus becomes unstable, and it is preferably 45% or more (not less than 45%, that is, at least 45%). The results of each of the above measured values are shown in Table 1. In this example, the dye used is a mixture of two kinds, and both of them are examples of symmetrical ring structures on both sides of the trimethine chain. However, recording with laser light having a wavelength of 635 nm and reproduction with laser light having a wavelength of 650 nm It can be seen that the reflectance is high, the push-pull is high, the degree of modulation is high, and the jitter is not high. The fact that the jitter is not high indicates that the heat storage property is not high, and the fact that the modulation degree and the jitter are good indicates that the reproduction sensitivity is good.

[0020] In Reference Example 2 Reference Example 1, subjected to sputtering using Al instead of Au, except for forming a reflective layer of Al film with a thickness of 80nm was manufactured an optical disk in the same manner, reference is also about this After recording as in Example 1, the measurement results are shown in Table 1. The optical disk of this reference example is different from that of Reference example 1 only in the material of the reflective layer, but recording and wavelength 650n by laser light of wavelength 635nm.
It can be seen that reproduction is possible with a laser beam of m, the jitter is not high, and the performances of push-pull, modulation, and reflectance are inferior to those of Reference Example 1, but not bad.

Example1 reference A substrate prepared in the same manner as in Example 1 was prepared as follows.
Trimethine cyanine dye NK-4321
3% by weight of TFP solvent (manufactured by Japan Photosensitive Dye Research Institute)
So that it dissolves and is applied to the surface of the substrate by spin coating.
And form an optical interference layer consisting of a photosensitive dye film with a thickness of 90 nm.
I made it.

[0022]

[Chemical 12]

Table 1 shows the results of measuring the maximum absorption wavelength (maximum absorption peak wavelength) and the optical constants of laser light having a wavelength of 635 nm for this optical interference layer in the same manner as in Reference Example 1. Moreover, the result of having measured the absorption spectrum similarly to the reference example 1 is shown by a solid line in FIG. From this figure, it can be seen that the above-mentioned optical interference layer has the maximum absorption wavelength in the range of 500 to 655 nm and the second largest absorption peak wavelength.

On this optical interference layer, 1 to 44 mmφ of the substrate
An Au film having a film thickness of 80 nm was formed on the entire surface of the area of 17 mmφ by a sputtering method to form a reflective layer. Also,
The protective layer of the same ultraviolet curable resin as in Reference Example 1 on the reflective layer is formed on the spin coating method, further bonding overlapping substrates by the adhesive layer made of the same ultraviolet curable resin as in Reference Example 1, bonding A mold type optical disc was produced. Table 1 shows the measurement results after recording was performed on the optical disc manufactured in this manner as in Reference Example 1.
This example is an example in which the ring structure on both sides of the trimethine chain of the dye used is asymmetric, but recording can be performed with a laser beam having a wavelength of 635 nm and reproduction can be performed with a laser beam having a wavelength of 650 nm. It can be seen that the jitter is low, the degree of modulation is large, and the reflectance is not low. A low jitter means that the heat storage property is also low, and a good degree of modulation and jitter means that the reproduction sensitivity is good.

ExampleTwo Example1In place of Al in place of Au,
Reflecting layer made of Al film with a thickness of 80 nm
An optical disc was manufactured in the same manner except that
Table 1 shows the results of the same measurement as in Example 1.
You The optical disc of this embodiment is1The opposite of
Only the material of the radiation layer is different, but the wavelength of 635 nm
Recording and laser light with a wavelength of 650 nm
More playable, especially with less jitter and push
Example of various performances such as ripple, modulation, and reflectance1Worse than
I know it's not bad.

[0026]referenceAn exampleThree reference On the substrate prepared in the same manner as in Example 1,
Trimethine cyanine dye NK-4321
And the trimethine cyanine color represented by the above [Chemical Formula 10]
Element NK-4285 is mixed in a weight ratio of 75:25,
Of the TFP solvent to 3% by weight,
The solution is applied to the surface of the substrate by spin coating to give a film thickness.
A light interference layer composed of a 100 nm photosensitive dye film was formed.
The maximum absorption wavelength and the wavelength of 635 nm for this optical interference layer
Optical constants of laser light ofreferenceMeasurement as in Example 1
The results obtained are shown in Table 1. Next, on the optical interference layer of the substrate
Sputtered over the entire area from 44 mmφ to 117 mmφ
A 90 nm thick Au film is formed by the
Formed. Also, on this reflective layerreferencePurple as in Example 1
Form a protective layer of external curing resin by spin coating and then
ToreferenceAs in Example 1, an adhesive layer made of a UV curable resin was used.
Other substrates similar to the above are stacked and bonded together
A set-type optical disc was produced. Made in this way
For optical discsreferenceRecord as in Example 1.
After that, the measurement results are shown in Table 1. thisreferenceExample used
Is a mixture of two types, one of which is trimethyl
The ring structure on both sides of the chain is asymmetric (Example1With
The same), the other has a symmetric ring structure (referenceExample 1
One), the size of k to fine tune the optical constants
This is an example of adjusting the recording characteristics by adding a small amount of the latter to the former.
However, recording and wavelength by laser light of wavelength 635 nm
Reproduction is possible with 650 nm laser light,
Low, reflectivity, push-pull, modulation is not bad
I understand.

[0027]referenceAn exampleFour Reference exampleThreeIn place of Al in place of Au,
And a reflective layer of 80 nm Al film is formed
Except for the above, an optical disc was prepared in the same manner, and
EvenreferenceResults of measurement after recording as in Example 1
Is shown in Table 1. thisreferenceThe example optical disc isreferenceOf example 3
Only the material of the reflective layer is different from that of
Recording with a 5 nm laser beam and recording at a wavelength of 650 nm
It is possible to reproduce by laser light, low jitter,
Emissivity, push-pull, and degree of modulation are inferior to those of Example 5, but worse
I know there isn't.

Reference Example 5 A substrate prepared in the same manner as in Reference Example 1 was prepared using the above [Chemical Formula 10].
The trimethine cyanine dye NK-4285 shown in 1 is dissolved in a cellosolve solvent so as to be 3% by weight, and the solution is applied to the surface of the substrate by spin coating to give a film thickness of 40
An optical interference layer made of a photosensitive dye film having a thickness of 10 nm was formed. The results of measuring the maximum absorption wavelength and the optical constant of the laser beam having a wavelength of 635 nm for this optical interference layer in the same manner as in Reference Example 1 are shown in Table 1. Next, on the optical interference layer, 44 m of the substrate
An Au film having a film thickness of 80 nm was formed on the entire surface of the region of mφ to 117 mmφ by a sputtering method to form a reflective layer. Further, as described above by an adhesive layer a protective layer similarly ultraviolet curable resin as in Reference Example 1 on the reflective layer is formed on the spin coating method, consisting of further reference <br/> the same manner as in Example 1, an ultraviolet curable resin Other substrates were laminated and bonded to each other to produce a bonded optical disk. Recording was performed on the optical disc manufactured in this manner in the same manner as in Reference Example 1, and then the measurement results are shown in Table 1. In this reference example, the ring structure on both sides of the trimethine chain of the dye used is symmetrical, but recording with a laser beam of 635 nm wavelength and 650 nm wavelength
It is possible to reproduce with the laser light of, and the push-pull and reflectance, the modulation factor during reproduction, and the jitter are other examples , reference
Although it cannot be said that it is superior to the examples , it does not have a low reflectance or that the modulation factor and jitter cannot be measured as in the comparative example described later.

[0029]referenceAn example6 reference An example5In place of Al in place of Au,
And a reflective layer of 80 nm Al film is formed
Except for the above, an optical disc was prepared in the same manner, and
EvenreferenceResults of measurement after recording as in Example 1
Is shown in Table 1. thisreferenceThe example optical disc isreferenceAn example5of
Only the material of the reflective layer is different from that of
Recording with a 5 nm laser beam and recording at a wavelength of 650 nm
Playable by laser light, push-pull, modulation
Degree is an example5Less worse but not bad, the reflectance and jitter
It turns out to be the same.

Reference Example 7 An optical disc was prepared in the same manner as in Reference Example 5, except that the trimethine cyanine dye represented by the following [Chemical Formula 13] was used instead of the dye represented by the [Chemical Formula 10]. Table 1 also shows the measurement results after recording in the same manner as in Reference Example 1. The maximum absorption wavelength,
Reference example 1 of optical constants obtained by laser light having a wavelength of 635 nm
Table 1 shows the results of the same measurement. This reference example is an example in which the ring structure on both sides of the trimethine chain of the dye used is symmetrical, and the above [Chemical formula 10] used in Reference example 5 is the same as the general formula [Chemical formula 1] in which the benzene ring of A ′ is methyl. It is possible to record with a laser beam having a wavelength of 635 nm and reproduce it with a laser beam having a wavelength of 650 nm, depending on whether or not it has a group. Push-pull and reflectance are the same as those in Reference Example 5, and modulation during reproduction is performed. The degree is better than that of Reference Example 5 and the jitter is not better than those of the other Examples and Reference Examples , but there is no possibility that measurement cannot be performed as in Comparative Examples described later.

[0031]

[Chemical 13]

It should be noted that substantially the same result can be obtained by using the dye represented by the following [Chemical formula 14] instead of the dye represented by the above-mentioned [Chemical formula 13].

[0033]

[Chemical 14]

[0034] Reference Example 8 Reference Example 7, except for forming a reflective layer of Al film of 80nm Sputtering is carried out using Al instead of Au in the same manner to produce an optical disk, as in Reference Example 1 also this After recording in the same manner, the measurement results are shown in Table 1. The optical disc of this reference example is different from that of Reference example 7 only in the material of the reflective layer, but the wavelength 65
Recording and reproduction is possible with 0 nm laser light,
Push-pull and modulation are inferior to Reference Example 7 , but not bad,
It can be seen that the reflectance and the jitter are the same.

ExampleThree Example1In which the dye represented by the above [Chemical Formula 12] is used
Instead of the trimethine system shown in [Chemical formula 15] below.
Anine dye NK-4370) (manufactured by Japan Photosensitive Dye Research Institute)
An optical disc was prepared in the same manner except that
Even ifreferenceRecording was performed in the same manner as in Example 1 and then measured.
The results are shown in Table 1. The maximum absorption wavelength, wavelength 635n
The optical constant by the laser light of mreferenceMeasurement as in Example 1
The results obtained are shown in Table 1. The maximum absorption wavelength, wavelength 63
The optical constant by 5nm laser lightreferenceSimilar to example 1
The measured results are shown in Table 1. This example shows the colors used
An example of asymmetric ring structures on both sides of the elementary trimethine chain,
Example1The above [Chemical formula 12] used in
X^-Is an anion of perchlorate or anion of iodine
Depending on whether there is a laser beam with a wavelength of 635 nm,
More recording and playback with laser light of 650 nm wavelength
Yes, reflectivity, push-pull, modulation depth and jitter
Is an example1It shows almost the same performance as that of.

[0036]

[Chemical 15]

ExampleFour ExampleThreeIn place of Al in place of Au,
Reflecting layer made of Al film with a thickness of 80 nm
An optical disc was manufactured in the same manner except that
Also aboutComparisonThe results measured in the same manner as in Example 1 are shown in Table 1.
You The optical disc of this embodiment isThreeThe opposite of
Only the material of the radiation layer is different, but the wavelength of 635 nm
Recording and laser light with a wavelength of 650 nm
More playable, especially with less jitter and push
Example of various performances such as ripple, modulation, and reflectanceThreeWorse than
I know it's not bad.

[Table 1]

COMPARATIVE EXAMPLE 1 A substrate prepared in the same manner as in Example 1 was prepared as follows.
Pentamethine cyanine dye NK-3219
(Manufactured by Japan Photosensitive Dye Research Institute) is dissolved in a cellosolve-based solvent so as to be 3% by weight, and the solution is applied onto the surface of the substrate by a spin coating method to form an optical interference layer made of a photoconductive dye film having a thickness of 110 nm. Formed. Table 1 shows the results of measuring the optical constants of the optical interference layer with respect to the laser light having the maximum absorption wavelength and the wavelength of 635 nm in the same manner as in Example 1. Also,
The result of measuring the absorption spectrum in the same manner as in Example 1 is shown in FIG.
Is indicated by a dotted line. From this figure, the above-mentioned optical interference layer is 600-
It can be seen that it has a maximum absorption wavelength at 750 nm and a second largest absorption wavelength. Then, a 90 nm-thick Au film was formed on the entire surface of the region of 44 mmφ to 117 mmφ of the substrate on this optical interference layer by a sputtering method to form a reflective layer. A protective layer of an ultraviolet curable resin was formed on this reflective layer by a spin coating method as in Example 1, and an adhesive layer made of an ultraviolet curable resin was used as in Example 1 to form another substrate similar to the above. Were laminated and bonded to each other to produce a bonded optical disk. Table 1 shows the measurement results of the optical disc manufactured in this manner as in Example 1. In this comparative example, the dye used was pentamethine cyanine, the maximum absorption wavelength thereof was on the long wavelength side, and the optical constant k did not satisfy the condition of 0.01 <k <0.45. As a result, it can be seen that the reflectance is low, the data at the time of reproduction cannot be obtained, and the reproduction is impossible by the laser light having the wavelength of 650 nm.

[0039]

[Chemical 16]

Comparative Example 2 A substrate prepared in the same manner as in Example 1 was prepared by the following reaction.
The phthalocyanine dye represented by
The solution was dissolved in a weight percentage of 10%, and the solution was applied to the surface of the substrate by spin coating to form a light interference layer made of a photosensitive dye film having a film thickness of 90 nm. Table 1 shows the results of measuring the optical constants of the optical interference layer with respect to the laser light having the maximum absorption wavelength and the wavelength of 635 nm in the same manner as in Example 1. Next, on this optical interference layer, from the substrate 44 mmφ to 117 mm
A film thickness of 100 n is formed on the entire surface of the φ region by the sputtering method.
m Au film was formed to form a reflective layer. A protective layer of an ultraviolet curable resin was formed on this reflective layer by a spin coating method as in Example 1, and an adhesive layer made of an ultraviolet curable resin was used as in Example 1 to form another substrate similar to the above. Were laminated and bonded to each other to produce a bonded optical disk. Table 1 shows the measurement results of the optical disc manufactured in this manner as in Example 1. In the case of this comparative example, the reflectance and push-pull were poor, and recording could not be performed. In this comparative example, the dye used was phthalocyanine, not a cyanine dye having a methine chain, and the optical constant k did not satisfy the condition of 0.01 <k <0.45. It is understood that the rate is low, the data at the time of reproduction cannot be obtained, and the reproduction is impossible by the laser light having the wavelength of 650 nm.

[0041]

[Chemical 17]

As a result of these results and the above-mentioned facts, the invention of the present application states that "the reflectance is not less than 45%, and the push-pull is not less than 0.13% (more preferably 0.20) (both sides of the trimethine chain). When the ring structure is asymmetric, or when the ring structures on both sides of the trimethine chain are symmetrical and not more than 0.40 when mixed, the jitter is not more than 8% (when the ring structures on both sides of the trimethine chain are asymmetric) Is not more than 7%), and I ₁₄ / I _top is 60%
At least one limitation, not less than (preferably not less than 70) may be applied. Further, in the invention of the present application, the "general formula [Chemical formula 1]" is limited to a part of various combinations of the general formulas, or limited to a part or all of the cyanine dyes mentioned in Examples and preferred examples. Also, in all of these, restrictions may be added from the above-mentioned other matters.

[0043]

According to the present invention, a recording material having an appropriately selected optical constant and maximum absorption wavelength for short-wavelength laser light for high density recording and reproduction is used. The selection is made by selecting the structure of the dye , that is, the dye layer is used as a dye as a recording material.
Contains only one type of trimethine cyanine dye,
By using a single component of the trimethine cyanine dye, which has asymmetric ring structure on both sides of the trimethine chain, as a methine cyanine dye, the absorption waveform of the laser light of the optical interference layer consisting of only the dye becomes sharp due to the association state, and Does not have a tail, and if the absorption waveform is sharp like this,
The absorbance per unit film thickness of the dye layer increases and recording efficiency improves, and it is not necessary to use other additives to adjust the optical constants of the dye, which suppresses heat accumulation during recording and lowers jitter. Recording becomes possible and recording sensitivity can be improved.

[Brief description of drawings]

FIG. 1 is a graph showing a change in reflectance with respect to film thickness due to a difference in extinction coefficient k when a refractive index n = 4.0 at a wavelength of 620 nm by simulation.

FIG. 2 is a graph showing a change in reflectance with respect to a film thickness due to a difference in refractive index n when an extinction coefficient k = 0.2 at a wavelength of 620 nm by simulation.

FIG. 3 is a graph showing a change in reflectance with respect to film thickness due to a difference in extinction coefficient k when a refractive index n = 4.0 at a wavelength of 690 nm by simulation.

FIG. 4 is a graph showing a change in reflectance with respect to a film thickness due to a difference in a refractive index n when an extinction coefficient k = 0.2 at a wavelength of 690 nm by simulation.

FIG. 5 is a graph showing absorption spectra of photosensitive dye films of Examples , Reference Examples and Comparative Examples of the present invention.

FIG. 6 is an explanatory diagram showing a push-pull calculation method.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-309069 (JP, A) JP-A-7-262604 (JP, A) JP-A-8-99467 (JP, A) JP-A-8- 108625 (JP, A) JP 3-281287 (JP, A) JP 4-28588 (JP, A) JP 9-1934 (JP, A) JP 10-119434 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41M 5/26 G11B 7/24 516 CAPLUS (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. An optical information recording medium having a light interference layer containing a dye layer on a substrate, wherein the light interference layer is 620 nm to 6 nm.
Recording and reproduction are possible with a laser beam selected from the wavelength region of 90 nm, and the refractive index n of the laser beam selected from the wavelength region of the optical interference layer is 1.6 to 4.0 and the extinction coefficient k. Of 0.01 to 0.45, and the optical interference layer has a maximum absorption peak wavelength and a second largest absorption peak wavelength measured by a visible-UV spectrophotometer of 500 nm to 655.
An optical information recording medium in the range of nm, wherein the dye layer contains only one kind of trimethine cyanine dye as a dye as a recording material , and the trimethine cyanine dye is represented by the following general formula [Formula 1]. An optical information recording medium which is a compound shown, which is a single component of a trimethine cyanine dye having an asymmetric ring structure on both sides of a trimethine chain. [Chemical 1] [Wherein A represents any one of the following general formulas [Chemical Formula 2] to [Chemical Formula 5], and , , , , A ′ represents any one of the following general formulas [Chemical Formula 6] to [Chemical Formula 9], and , , , , A and A ′ may be the same or different (provided that D ₁ and D ₂ are each a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group, a halogen atom, a carboxyl group,
Alkoxycarbonyl group, alkylcarboxyl group, alkylhydroxyl group, aralkyl group, alkenyl group,
Alkylamide group, alkylamino group, alkylsulfonamide group, alkylcarbamoyl group, alkylsulfamoyl group, alkylsulfonyl group, phenyl group, cyano group, ester group, nitro group, acyl group, allyl group, aryl group, aryloxy Group, alkylthio group, arylthio group, phenylazo group, pyridinoazo group, alkylcarbonylamino group, sulfonamide group, amino group, alkylsulfone group, thiocyano group, mercapto group, chlorosulfone group, alkylazomethine group, alkylaminosulfone group, vinyl Represents a substituent selected from the group consisting of a group and a sulfone group, and may be the same or different, and p and q are the numbers of the substituents and each represents an integer of 1 or more. ), R and R ′ are substituted or unsubstituted alkyl groups, carboxyl groups, alkoxycarbonyl groups,
Alkylcarboxyl group, alkoxyl group, alkylhydroxyl group, aralkyl group, alkenyl group, alkylamide group, alkylamino group, alkylsulfonamide group, alkylcarbamoyl group, alkylsulfamoyl group, hydroxyl group, halogen atom, alkylalkoxyl group,
Represents a substituent selected from the group consisting of a halogenated alkyl group, an alkylsulfonyl group, an alkylcarboxyl group or an alkylsulfonyl group bonded to a metal ion or an alkyl group, a phenyl group, a benzyl group and an alkylphenyl group, which may be the same or different. , X ⁻ is a halogen atom, PF ₆ ⁻ , SbF ₆ ⁻ , H ₃ PO ₄ , perchloric acid, fluoroboric acid, benzenesulfonic acid, toluenesulfonic acid, alkylsulfonic acid, benzenecarboxylic acid, alkylcarboxylic acid, tri fluoromethyl acid, periodic acid and SCN ^- represents an anion selected from among the group of anions. ] 2. The optical information recording medium according to claim 1 , wherein the trimethine cyanine dye is an asymmetric trimethine cyanine dye having a ring structure of A and a ring structure of A ′ different from each other.