JPH07262604A - Optical recording medium - Google Patents

Abstract

(57) [Summary] [Structure] An optical recording medium having a recording layer and a reflective layer on a substrate, wherein the recording layer comprises a trimethine cyanine dye. The optical recording medium of the present invention is not only capable of recording / reproducing with a red laser having a recording / reproducing wavelength of 680 nm, which has been shifting in recent years, but has also been used conventionally.
Reproduction is possible with a near infrared laser of 30 nm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of recording / reproducing with an optical recording medium, particularly with a red laser having a wavelength of 630 to 690 nm.
The present invention also relates to an optical recording medium that can be reproduced by a near infrared laser having a wavelength of 770 to 830 nm.

[0002]

2. Description of the Related Art As an optical recording medium having a reflective layer on a substrate, a recordable or recordable CD corresponding to the compact disc (hereinafter abbreviated as CD) standard has been proposed [eg Nikkei Electronics, No. 465, P.I. 10
7, January 23, 1989]. This optical recording medium is shown in FIG.
The recording layer 2, the reflective layer 3, and the protective layer 4 are formed on the substrate 1 as shown in FIG.
Are formed in this order. When the recording layer of this optical recording medium is irradiated with a laser beam such as a semiconductor laser with high power, the recording layer undergoes a physical or chemical change,
Record information in the form of pits. Information on the pits can be reproduced by irradiating the formed pits with low-power laser light and detecting the reflected light. Generally, a wavelength of 770 to 830 nm is used for recording / reproducing of such an optical recording medium.
Near infrared semiconductor lasers are used.

Recently, development of a semiconductor laser having a wavelength shorter than 770 nm has progressed, and a red semiconductor laser having a wavelength of 680 nm has been put into practical use [eg Nikkei Electronics, No. 592, P.I. 65, October 11, 1993]. By reducing the beam spot by shortening the wavelength of the recording / reproducing laser, a high-density optical recording medium becomes possible. Large-capacity optical recording media capable of storing moving images have been developed by shortening the wavelength of semiconductor lasers and data compression technology [eg, Nikkei Electronics, No. 5
89, P.I. 55, August 30, 1993]. Such a high-density optical recording medium can record a large amount of data such as a moving image, and is expected to be used for a video CD and the like [eg, Nikkei Electronics, No. 59
4, P.P. 169, November 8, 1993]. Further, JP-A-2-278519 proposes high-sensitivity high-speed recording by a method of recording with high sensitivity by a short wavelength laser of 680 nm and reproducing at 780 nm. However, since it is difficult to increase the density by reproducing at 780 nm, it is desired that the recorded wavelength can be reproduced at 680 nm.

On the other hand, Japanese Patent Laid-Open No. 6-40162 proposes an optical recording medium capable of recording / reproducing with a short wavelength laser. This medium uses an indocarbocyanine dye in the recording layer. The maximum absorption wavelength of this dye is 600 nm
In the first half, 630 nm semiconductor laser and He / N
Although it can be recorded by e-laser, it has almost no absorption at 670 to 690 nm and has been recently put into practical use at 670 to 690.
The red semiconductor laser of nm has insufficient sensitivity. 6
490 nm blue / green semiconductor lasers with wavelengths shorter than 80 nm have also been studied, but have not yet reached the stage of practical application [eg, Applied Physics].
s Letter, P.M. 1272-1274, Vol.
59 (1991) and "Nikkei Electronics" No. 5
52, P.P. 90, April 27, 1992]. From such a background, the recording / reproducing wavelength of the optical recording medium is changing to around 680 nm. Therefore, it is necessary to develop an optical recording medium corresponding to this, and further, a compatible optical recording medium compatible with the conventional 780 nm is also desired.

[0005]

However, in the conventional optical recording medium, the organic dye used in the recording layer has a wavelength of 6
It was found that the absorption was large at 30 to 690 nm and the refractive index was small, so the reflectance was low, and reproduction with a red laser having a wavelength of 680 nm was impossible. The object of the present invention is to provide a wavelength of 6
Recordable and reproducible with 80 nm red laser, and 78
An object of the present invention is to provide an optical recording medium that can be reproduced by a 0 nm near-infrared laser (such as a commercially available CD player).

[0006]

[Means for Solving the Problems] The inventors of the present invention have made extensive studies to solve the above problems, and as a result, have come to propose the present invention. That is, this problem is solved by the following invention. (1) An optical recording medium having a recording layer and a reflective layer on a substrate, wherein the recording layer comprises a trimethine cyanine dye. (2) The trimethine cyanine dye forming the recording layer is
The optical recording medium according to (1), which is a compound represented by the general formula (1) (formula 5).

[0007]

[Chemical 5] [However, P is an atom group consisting of a substituted or unsubstituted 5-membered ring or 6-membered ring containing at least one nitrogen atom as represented by the general formulas (2) to (6) (formula 6).

[0008]

[Chemical 6] Q is an atomic group consisting of a substituted or unsubstituted 5-membered ring or 6-membered ring containing at least one nitrogen atom as represented by the general formulas (7) to (11) (Chemical formula 7).

[0009]

[Chemical 7] A ₁ and A ₁ ′ are atomic groups that form a substituted benzene ring or a naphthalene ring or a substituted naphthalene ring, and may be the same or different. A ₂ ,
A ₃ , A ₄ , A ₅ , A ₂ ′, A ₃ ′, A ₄ ′ and A ₅ ′ are atom groups forming a benzene ring or a substituted benzene ring, or forming a naphthalene ring or a substituted naphthalene ring. The same kind or different kinds may be used. R ₁ and R ′ ₁ are substituted or unsubstituted alkyl groups, alkoxy groups,
Alkylhydroxy group, aralkyl group, alkenyl group,
An alkylcarboxyl group, an alkylsulfonyl group, or an alkylcarboxyl group or an alkylsulfonyl group bonded to an alkali metal ion or an alkyl group, which may be the same or different. R _{2 to} R ₈ are a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a diphenylamino group and the like, and R _{6 to} R ₈ may be a substituted or unsubstituted cyclic side chain having a plurality of carbon atoms. X is a halogen atom, an anion such as perchloric acid, borofluoric acid, benzenesulfonic acid, toluenesulfonic acid, alkylsulfonic acid, benzenecarboxylic acid, alkylcarboxylic acid or trifluoromethylcarboxylic acid, or a general formula (12 )
~ (18) represents the anionic residue of the compound shown in (Chemical formula 8).

[0010]

[Chemical 8] (A and A ′ are an atomic group forming a benzene ring or a substituted benzene ring or forming a naphthalene ring or a substituted naphthalene ring, and may be the same or different. R _{9 to} R ₃₁ are A substituted or unsubstituted alkyl group,
Alkoxy group, hydroxy group, carboxyl group, halogen atom, allyl group, alkylcarboxyl group, alkylalkoxyl group, aralkyl group, alkylcarbonyl group, sulfonate alkyl group bonded to metal ions, nitro group, amino group, alkylamino group, phenyl Group, phenylethylene group and the like. M is Ni, Co, Mn,
Transition metals such as Cu, Pd and Pt are shown. M has an electric charge and may have a cation and a salt structure. a'represents the valence of an ionic body and is a positive integer including 0. Z
Represents a cation, a ′ = b ′ · c ′, and a ′ = 0
In this case, b ′ · c ′ = 0 and Z does not exist, and the compound becomes a neutral body. ) X may not be present when R ₁ and R ′ ₁ have a group to which an alkali metal ion is bonded. Y, Y'is O,
S, Se, NH, -CH = CH- and the like. a is the number of moles and is represented by a positive integer determined by the charge number of X. (3) The reflectance measured from the substrate side with respect to the light selected from the red laser having a wavelength of 630 to 690 nm is 40% or more, recording and reproduction is possible with the red laser having a wavelength of 630 to 690 nm, and the wavelength is 770 to 830 nm. The reflectance measured from the substrate side with respect to the light selected from the near-infrared laser is 65% or more, and it can be reproduced by the near-infrared laser selected from 770 to 830 nm (1) or The optical recording medium according to (2). (4) The optical recording medium according to any one of (1) to (3), in which a recording layer, a reflective layer, and a protective layer are provided in this order on a substrate.

According to the present invention, by using the above-mentioned trimethine cyanine dye in the recording layer, the wavelength of 63
Since the reflectance measured from the substrate side with respect to the light selected from the red laser of 0 to 690 nm is 40% or more, recording and reproduction can be performed by the red laser of wavelength 630 to 690 nm, and the near infrared of wavelength 770 to 830 nm. The reflectance measured from the substrate side for the light selected from the laser is 65.
% Or more, an optical recording medium reproducible with a laser selected from 770 to 830 nm is realized.

A specific configuration of the present invention will be described below. The optical recording medium of the present invention has a reflective layer on the substrate. The optical recording medium refers to both a read-only optical read-only medium in which information is recorded in advance and an optical recording medium in which information can be recorded and reproduced. However, here, as a suitable example, an optical recording medium capable of recording and reproducing the latter information,
Particularly, an optical recording medium in which a recording layer, a reflective layer and a protective layer are formed in this order on a substrate will be described. This optical recording medium has a four-layer structure as shown in FIG. That is, the recording layer 2 is formed on the substrate 1, the reflective layer 3 is provided in close contact therewith, and the protective layer 4 further covers the reflective layer 3 thereon.

The material of the substrate may basically be transparent at the wavelengths of recording light and reproducing light. For example, a polymer material such as a polycarbonate resin, a vinyl chloride resin, an acrylic resin such as polymethylmethacrylate, a polystyrene resin, an epoxy resin, or an inorganic material such as glass is used. These substrate materials are formed into a disc-shaped substrate by an injection molding method or the like. If necessary, grooves may be formed on the surface of the substrate.

A recording layer is formed on the substrate. Currently, a pentamethine cyanine dye having five methine groups is used for a commercially available 770 to 830 nm recording and reproducing device (for example, JP-A-2-292747), which has a large absorption around 700 nm. Yes, 630-690n
Recording at m is possible, but since the refractive index is small and the absorption is large, the reflectance is low, and reproduction at 630 to 690 nm becomes very difficult. Therefore, in the present invention, a trimethine cyanine dye having three methine groups is used. The trimethine cyanine dye has an appropriate absorption at 630 to 690 nm, a large refractive index at 630 to 690 nm, and a large reflectance. Further, since the refractive index at 770 to 830 nm is large and the absorption is small, it is possible to reproduce even on a CD player or a CD-ROM player equipped with a near infrared semiconductor laser of 770 to 830 nm which is currently used.

Specifically, the trimethine cyanine dyes include indocarbocyanine dyes, thiacarbocyanine dyes, quinoxacarbocyanine dyes, quinocarbocyanine dyes, quinothiacarbocyanine dyes, serenacarbocyanine dyes, imida. Examples thereof include carbocyanine dyes and oxacarbocyanine dyes which have a substituent in order to enhance solubility. These substituents may be singular or plural, but an alkyl group,
Alkoxy group, hydroxy group, carboxyl group, halogen atom, allyl group, alkylcarboxyl group, alkylalkoxyl group, aralkyl group, alkylcarbonyl group, sulfonate alkyl group bound to a metal ion, nitro group, amino group, alkylamino group, aryl Group, phenylethylene group and the like.

Among these dyes, 670 to 69 are particularly preferable.
From the viewpoint of improving the recording sensitivity to a 0 nm red semiconductor laser, A ₁ and A ₁ 'in the P and Q of the trimethine cyanine dye represented by the general formula (1) form a naphthalene ring or a substituted naphthalene ring. A group of atoms or A
Atom group in which ₂ , A ₃ , A ₄ , A ₅ , A ₂ ', A ₃ ', A ₄ 'and A ₅ ' form a benzene ring or a substituted benzene ring, or form a naphthalene ring or a substituted naphthalene ring The trimethine cyanine dye which is Above all,
1,3,3,1 ', 3', 3'-hexamethyl-2,
2 '-(4,5,4', 5'-dibenzo) indocarbocyanine perchlorate, 3,3'-diethyl-2,
2 '-(6,7,6', 7'-dibenzo) thiacarbocyanine iodide, 3,3'-diethyl-2,2'-
Thiacarbocyanine iodide, 1,1'-diethyl-2,2'-quinocarbocyanine iodide, 3,
3'-diethyl-2,2'-selenacarbocyanine iodide, 1,3'-diethyl-4,2'-quinoxacarbocyanine iodide, 3,3 ', 9-triethyl-2,2'-( 4,5,4 ', 5'-dibenzo) thiacarbocyanine bromide, 1,1'-diethyl-2,
4'-quinocarbocyanine iodide, 1,3'-diethyl-4,2'-quinothiacarbocyanine iodide and the like are preferable.

In order to further increase the recording sensitivity, pentamethine cyanine dyes, heptamethine cyanine dyes, squarylium dyes, azo dyes, naphthoquinone dyes, anthraquinone dyes, indophenol dyes, phthalocyanine dyes, You may mix and use a naphthalocyanine type dye. If necessary, additives such as a quencher and an ultraviolet absorber can be mixed or introduced as a substituent to this dye. For example, examples of the additives include those represented by the following general formulas (12) to (18) (chemical formula 9).

[0018]

[Chemical 9] (However, A and A ′ are an atomic group forming a benzene ring or a substituted benzene ring or forming a naphthalene ring or a substituted naphthalene ring, and may be the same or different. May be singular or plural, but is an alkyl group, an alkoxy group, a hydroxy group, a carboxyl group, a halogen atom, an allyl group, an alkylcarboxyl group, an alkylalkoxyl group, an aralkyl group, an alkylcarbonyl group, a metal ion. And a sulfonate alkyl group, a nitro group, an amino group, an alkylamino group, a phenyl group, a phenylethylene group, etc. R _{9 to} R ₃₁ are substituted or unsubstituted alkyl groups, alkoxy groups, hydroxy groups, carboxyl groups,
Examples thereof include a halogen atom, an allyl group, an alkylcarboxyl group, an alkylalkoxyl group, an aralkyl group, an alkylcarbonyl group, a sulfonate alkyl group bonded to a metal ion, a nitro group, an amino group, an alkylamino group, a phenyl group and a phenylethylene group. M is Ni, Co,
Transition metals such as Mn, Cu, Pd and Pt are shown. M has an electric charge and may have a cation and a salt structure. a'represents the valence of an ionic body and is a positive integer including 0. Z represents a cation, a ′ = b ′ · c ′, and when a ′ = 0, b ′ · c ′ = 0 and Z does not exist, and the compound becomes a neutral body. These dyes have a thickness of 50 to 500 nm, preferably 100 to 150, on a substrate by a coating method such as a spin coating method or a casting method, a sputtering method, a chemical vapor deposition method, a vacuum vapor deposition method or the like.
to form a recording layer of nm. Particularly in the coating method, a coating solvent in which a dye is dissolved or dispersed is used, and it is preferable to select a solvent that does not damage the substrate. For example, alcohol solvents such as methanol, aliphatic hydrocarbon solvents such as hexane and octane, cyclic hydrocarbon solvents such as cyclohexane, aromatic hydrocarbon solvents such as benzene, halogenated hydrocarbon solvents such as chloroform, An ether solvent such as dioxane, a cellosolve solvent such as methyl cellosolve, a ketone solvent such as acetone, an ester solvent such as ethyl acetate, and the like are used alone or in combination. Further, the recording layer is not limited to one layer, and a plurality of dyes may be formed in multiple layers, or the dyes may be dispersed in a polymer thin film or the like, preferably about 50% or more. When a solvent that does not damage the substrate cannot be selected, sputtering, chemical vapor deposition, vacuum vapor deposition, etc. are effective.

Next, on the recording layer, a thickness of 50 to 300 nm,
Preferably, a reflective layer having a thickness of 100 to 150 nm is formed. The material of the reflective layer has a sufficiently high reflectance at the wavelength of the reproduction light, such as Au, Al, Ag, Cu, Ti, Cr,
Metals of Ni, Pt, Ta, Cr and Pd can be used alone or as an alloy. Among these, Au
And Al have a high reflectance and are suitable as a material for the reflective layer.
Other than the above, the following may be included. For example,
Mg, Se, Hf, V, Nb, Ru, W, Mn, Re,
Fe, Co, Rh, Ir, Cu, Zn, Cd, Ga, I
Metals and semimetals such as n, Si, Ge, Te, Pb, Po, Sn and Bi can be mentioned. Further, a material containing Au as a main component is preferable because a reflective layer having a high reflectance can be easily obtained. Here, the main component means that the content rate is 50% or more. A low refractive index thin film and a high refractive index thin film are alternately stacked with a material other than metal to form a multilayer film,
It can also be used as a reflective layer. Examples of the method of forming the reflective layer include a sputtering method, a chemical vapor deposition method, a vacuum vapor deposition method and the like. Further, a reflection amplification layer or an adhesive layer may be provided between the recording layer and the reflection layer in order to increase the reflectance or improve the adhesion.

The present invention thus obtained is a medium in which a recording layer and a reflective layer are formed on a substrate.
The reflectance from the substrate side to the light of the wavelength selected from the range of 0 nm is 40% or more, preferably 50% or more, and the reflectance from the substrate side to the light of the wavelength selected from the range of 770 nm to 830 nm. Is 65% or more, preferably 70% or more, and satisfies the reflectance of the Red Book (CD) standard and the Orange Book (CD-R) standard. If these standards are satisfied, it can be satisfactorily reproduced even by a CD player that has been commercially available in the past.

Further, a protective layer may be formed on the reflective layer. The material of the protective layer is not particularly limited as long as it protects the reflective layer from external force. Examples of the organic substance include a thermoplastic resin, a thermosetting resin, a UV curable resin, and the like. UV curable resins are preferred. or,
Inorganic substances include SiO ₂ , SiN ₄ , MgF ₂ , S
nO _{2 and the} like can be mentioned. A thermoplastic resin, a thermosetting resin, etc. can be formed by dissolving in a suitable solvent, applying a coating solution, and drying. UV curable resin is
It can be formed by coating the coating liquid as it is or by dissolving it in a suitable solvent and then coating the coating liquid and curing it by irradiating with UV light. As the UV curable resin, for example, an acrylate resin such as urethane acrylate, epoxy acrylate, polyester acrylate can be used. These materials may be used alone or as a mixture, and may be used not only as a single layer but also as a multilayer film. As a method of forming the protective layer, a coating method such as a spin coating method or a casting method, a sputtering method, a chemical vapor deposition method, or the like is used as in the recording layer, and among them, the spin coating method is preferable.

The red laser used in the present invention is 630 to 630.
Any laser having a wavelength of 690 nm may be used. For example, there are dye lasers capable of wavelength selection in a wide range of the visible region, helium neon lasers having a wavelength of 633 nm, and high-power semiconductor lasers having a wavelength of 680 nm that have been recently developed. However, semiconductor lasers are preferable in consideration of mounting on a device. Is. The near infrared laser is 770-8.
Any laser having a wavelength of 30 nm may be used, but a semiconductor laser used in a commercially available CD player or CD recorder is suitable.

[0023]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. [Example 1] Trimethine cyanine dye NK3239
(1,3,3,1 ', 3', 3'-hexamethyl-2,
2 '-(4,5,4', 5'-dibenzo) indocarbocyanine perchlorate) [manufactured by Japan Photosensitive Dye Research Institute]
0.2 g is dissolved in 10 ml of 2,2,3,3-tetrafluoro-1-propanol (Tokyo Kasei) to prepare a dye solution. The substrate is made of polycarbonate resin and has a continuous guide groove (track pitch: 1.6 μm) with a diameter of 1
A disk-shaped product having a diameter of 20 mm and a thickness of 1.2 mm was used.
A dye solution was spin-coated on this substrate at a rotation speed of 1500 rpm and dried at 70 ° C. for 2 hours to form a recording layer.
A Balzers sputtering device (CDI
-900) is used to sputter Au to a thickness of 100 nm.
The reflective layer of was formed. Argon gas was used as the sputtering gas. Sputtering conditions are sputter power 2.5k
W, sputtering gas pressure was 1.0 × 10 ^-2 Torr.
Further, an ultraviolet curable resin SD-17 (manufactured by Dainippon Ink and Chemicals, Inc.) was spin-coated on the reflective layer and then irradiated with ultraviolet rays to form a protective layer having a thickness of 6 μm. Sample 680
nm optical disk evaluation device DDU-1000 and KEN with red semiconductor laser head
Using a WOOD EFM encoder, a linear velocity of 5.6
Recording was performed at m / s and laser power of 10 mW. After recording,
As a result of reproducing the signal using the same evaluation apparatus, a clean eye pattern was observed as shown in FIG. At this time, the reflectance was 62%. Also, as a result of performing reproduction evaluation of the recorded sample with a commercially available CD player having a reproduction wavelength of 780 nm, it is possible to reproduce well with an error rate of 5 cps, and it is possible to reproduce even with a reproducing device using a near infrared semiconductor laser head. Was confirmed.

[Example 2] The trimethine cyanine dye NK467 (3,3'-diethyl-) was used as the dye in Example 1.
An optical recording medium was prepared in the same manner except that 2,2 '-(6,7,6', 7'-dibenzo) thiacarbocyanine iodide) (manufactured by Japan Photosensitive Dye Research Institute) was used. As in Example 1, the manufactured medium was equipped with a 680 nm red semiconductor laser head, and an optical disk evaluation device DDU-1000 manufactured by Pulstec Industrial Co., Ltd. and an EFM manufactured by KENWOOD were used.
Recording was performed at a linear velocity of 5.6 m / s and a laser power of 10 mW using an encoder. After recording, the signal was reproduced using the same evaluation apparatus, and as a result, the reflectance was 58%. The recorded sample was reproduced and evaluated by a commercially available CD player having a reproduction wavelength of 780 nm, and the error rate was 3c.
Good reproduction was possible at ps.

Example 3 The dye used in Example 1 was the trimethine cyanine dye NK176 (3,3'-diethyl-).
2,2'-thiacarbocyanine iodide) (manufactured by Japan Photosensitive Dye Research Institute) was used to prepare an optical recording medium in the same manner. The produced medium was used in the same manner as in Example 1 68
Optical disc evaluation device DDU-1000 and KE manufactured by Pulstec Industrial Co., Ltd. equipped with a 0 nm red semiconductor laser head
A linear velocity of 5. using an EFM encoder manufactured by NWOOD.
Recording was performed at 6 m / s and laser power of 10 mW. After recording, the signal was reproduced using the same evaluation apparatus, and as a result, the reflectance was 63%. Further, the recorded sample was subjected to reproduction evaluation with a commercially available CD player having a reproduction wavelength of 780 nm, and as a result, good reproduction was possible with an error rate of 5 cps.

Example 4 The trimethine cyanine dye NK3 (1,1′-diethyl-2,
An optical recording medium was prepared in the same manner except that 2'-quinocarbocyanine iodide) (manufactured by Japan Photosensitive Dye Research Institute) was used. The manufactured medium was 680n in the same manner as in Example 1.
m Optical disc evaluation system DDU-1000 and KENW manufactured by Pulstec Industrial Co., Ltd. equipped with a red semiconductor laser head
Linear velocity of 5.6m using OFM EFM encoder
/ S, laser power was recorded at 10 mW. After recording, the signal was reproduced using the same evaluation device, and as a result, the reflectance was 55%.
Met. In addition, the recorded sample has a reproduction wavelength of 7
As a result of performing reproduction evaluation with a commercially available CD player of 80 nm, it was possible to reproduce well with an error rate of 2 cps.

Example 5 The trimethine cyanine dye NK616 (3,3′-diethyl-) was used as the dye in Example 1.
An optical recording medium was prepared in the same manner except that 2,2'-selenacarbocyanine iodide) [manufactured by Japan Photosensitive Dye Research Institute] was used. The prepared medium was used in the same manner as in Example 1
Optical disc evaluation device DDU-1000 and K manufactured by Pulstec Industrial Co., Ltd. equipped with an 80 nm red semiconductor laser head
Recording was performed at a linear velocity of 5.6 m / s and a laser power of 10 mW using an EFM encoder manufactured by ENWOOD. After recording, the signal was reproduced using the same evaluation apparatus, and as a result, the reflectance was 60%. Further, the recorded sample was subjected to reproduction evaluation with a commercially available CD player having a reproduction wavelength of 780 nm, and as a result, good reproduction was possible with an error rate of 5 cps.

Example 6 The trimethine cyanine dye NK741 (1,3′-diethyl-) was used as the dye in Example 1.
4,2'-Quinoxacarbocyanine iodide)
An optical recording medium was prepared in the same manner except that [manufactured by Japan Photosensitive Dye Research Institute] was used. The manufactured medium was installed with a 680 nm red semiconductor laser head in the same manner as in Example 1, and an optical disk evaluation device DDU-1000 manufactured by Pulstec Industrial Co., Ltd.
Recording was performed at a linear velocity of 5.6 m / s and a laser power of 10 mW using an EFM encoder manufactured by KENWOOD. After recording, as a result of reproducing the signal using the same evaluation device,
The reflectance was 58%. Further, as a result of performing reproduction evaluation of this recorded sample with a commercially available CD player having a reproduction wavelength of 780 nm, it was possible to favorably reproduce with an error rate of 4 cps.

Example 7 The dye used in Example 1 was the trimethine cyanine dye NK716 (3,3 ′, 9-triethyl-2,2 ′-(4,5,4 ′, 5′-dibenzo) thiacarbocyanine. An optical recording medium was prepared in the same manner except that bromide) (manufactured by Japan Photosensitive Dye Research Institute) was used. The produced medium was recorded at a linear velocity of 5.6 m / s and a laser power of 10 mW by using an optical disc evaluation device DDU-1000 manufactured by Pulstec Industrial Co., Ltd. equipped with a 680 nm red semiconductor laser head and an EFM encoder manufactured by KENWOOD as in Example 1. did. After recording, the signal was reproduced using the same evaluation apparatus, and as a result, the reflectance was 63%. In addition, the recorded sample has a reproduction wavelength of 780n.
As a result of reproduction evaluation with a commercially available CD player of m, it was possible to reproduce well with an error rate of 6 cps.

Example 8 The trimethine cyanine dye NK138 (1,1′-diethyl-) was used as the dye in Example 1.
An optical recording medium was prepared in the same manner except that 2,4′-quinocarbocyanine iodide) (manufactured by Japan Photosensitive Dye Research Institute) was used. The produced medium was used in the same manner as in Example 1 68
Optical disc evaluation device DDU-1000 and KE manufactured by Pulstec Industrial Co., Ltd. equipped with a 0 nm red semiconductor laser head
A linear velocity of 5. using an EFM encoder manufactured by NWOOD.
Recording was performed at 6 m / s and laser power of 10 mW. After recording, the signal was reproduced using the same evaluation apparatus, and as a result, the reflectance was 48%. The recorded sample was subjected to reproduction evaluation with a commercially available CD player having a reproduction wavelength of 780 nm. As a result, the error rate was 8 cps and good reproduction was possible.

[Example 9] The trimethine cyanine dye NK321 (1,3'-diethyl-) was used as the dye in Example 1.
An optical recording medium was prepared in the same manner except that (4,2'-quinothiacarbocyanine iodide) (manufactured by Japan Photosensitive Dye Research Institute) was used. The produced medium was recorded at a linear velocity of 5.6 m / s and a laser power of 10 mW by using an optical disc evaluation device DDU-1000 manufactured by Pulstec Industrial Co., Ltd. equipped with a 680 nm red semiconductor laser head and an EFM encoder manufactured by KENWOOD as in Example 1. did. After recording, the signal was reproduced using the same evaluation apparatus, and as a result, the reflectance was 59%. The recorded sample was subjected to reproduction evaluation with a commercially available CD player having a reproduction wavelength of 780 nm, and as a result, good reproduction was possible with an error rate of 6 cps.

Comparative Example 1 The dye used in Example 1 was the pentamethine cyanine dye NK2929 (1, 3, 3, 3).
1 ', 3', 3'-hexamethyl-2,2 '-(4
An optical recording medium was prepared in the same manner except that 5,4 ′, 5′-dibenzo) indodicarbocyanine perchlorate) (manufactured by Japan Photosensitive Dye Research Institute) was used. An optical disk evaluation device D manufactured by Pulstec Industrial Co., in which the manufactured medium was mounted with a 680 nm red semiconductor laser head as in Example 1
Linear velocity of 5.6 m / s, laser power of 10 using DU-1000 and EFM encoder manufactured by KENWOOD
Recorded in mW. After recording, the signal was reproduced using the same evaluation apparatus. As a result, the signal pattern also had a low reflectance of about 9% and the waveform was distorted as shown in FIG. Moreover, the signal deteriorated when playing for a long time. Moreover, as a result of evaluating the recorded medium with a commercially available CD player having a reproduction wavelength of 780 nm, it was found that the error rate was 2980 cps and the reproduction was defective.

Comparative Example 2 The dye used in Example 1 was the pentamethinecyanine dye NK2627 (3,3′-diethyl-2,2 ′-(6,7,6 ′, 7′-dibenzo) thiadicarbocyanine aio. An optical recording medium was prepared in the same manner except that Dyed) (manufactured by Japan Photosensitive Dye Research Institute) was used. The produced medium was recorded at a linear velocity of 5.6 m / s and a laser power of 10 mW by using an optical disc evaluation device DDU-1000 manufactured by Pulstec Industrial Co., Ltd. equipped with a 680 nm red semiconductor laser head and an EFM encoder manufactured by KENWOOD as in Example 1. did. After recording, the signal was reproduced using the same evaluation apparatus, and as a result, the reflectance was low at 8% and the waveform was distorted. Moreover, the signal deteriorated when playing for a long time. In addition, the recorded medium is reproduced at a reproduction wavelength of 780 nm.
As a result of evaluation with a commercially available CD player, the error rate is 3
The reproduction was defective at 320 cps.

Comparative Example 3 The dye used in Example 1 was pentamethinecyanine dye NK1456 (1,1′-diethyl-2,2′-quinodicarbocyanine iodide).
An optical recording medium was prepared in the same manner except that [manufactured by Japan Photosensitive Dye Research Institute] was used. The manufactured medium was installed with a 680 nm red semiconductor laser head in the same manner as in Example 1, and an optical disk evaluation device DDU-1000 manufactured by Pulstec Industrial Co., Ltd.
Recording was performed at a linear velocity of 5.6 m / s and a laser power of 10 mW using an EFM encoder manufactured by KENWOOD. After recording, as a result of reproducing the signal using the same evaluation device,
The reflectance was low at about 6% and the waveform was distorted. Moreover, the signal deteriorated when playing for a long time. The recorded medium was evaluated by a commercially available CD player having a reproduction wavelength of 780 nm. As a result, the error rate was 3570 cps and the reproduction was defective.

[0035]

According to the present invention, by using a trimethine cyanine dye as a recording layer, not only recording and reproduction can be performed by a red laser having a recording and reproduction wavelength of 680 nm, which is shifting in recent years, but Used 7
It is possible to provide a compatible optical recording medium that can be reproduced even with a near infrared laser of 80 nm.

[Brief description of drawings]

FIG. 1 is a cross-sectional structure diagram of an optical recording medium.

FIG. 2: Reproduction wavelength 680 of trimethine cyanine dye medium
EFM signal pattern in nm

FIG. 3: Regeneration wavelength of pentamethine cyanine dye medium 68
EFM signal pattern at 0 nm

[Explanation of symbols]

 1 substrate 2 recording layer 3 reflective layer 4 protective layer

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[Procedure amendment]

[Submission date] April 6, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Chemical 1] [However, P is an atom group consisting of a substituted or unsubstituted 5-membered ring or 6-membered ring containing at least one nitrogen atom as represented by the general formulas (2) to (6) (Formula 2).

[Chemical 2] Q is an atom group consisting of a substituted or unsubstituted 5-membered ring or 6-membered ring containing at least one nitrogen atom as represented by the general formulas (7) to (11) (Chemical Formula 3).

[Chemical 3]A₁, A₁'Forms a substituted benzene ring or is a naphth
A group of atoms that form a talen ring or a substituted naphthalene ring
Yes, they may be the same or different. A₂，
A₃, A_Four, A_Five, A₂', A₃', A_Four'And A_Five'Is Benz
Form a benzene ring or a substituted benzene ring, or
A group of atoms that form a talen ring or a substituted naphthalene ring
Yes, they may be the same or different. R₁And R
₁'Is a substituted or unsubstituted alkyl group, alkoxy group, or
Alkyl hydroxy group, aralkyl group, alkenyl group,
Alkyl carboxyl group, alkylsulfonyl group or
Alkali bound to a metal ion or an alkyl group
Is a carboxyl group or an alkylsulfonyl group
The same kind or different kinds may be used. R₂~ R₈Is a hydrogen atom, halogen
Atom, alkyl group, alkoxy group, diphenylamino
Selected from the group R₆~ R ₈Is the position across multiple carbons
It may be a substituted or unsubstituted cyclic side chain. X is a halogen
Atom, perchloric acid, borofluoric acid, benzene sulfone
Acid, toluene sulfonic acid, alkyl sulfonic acid, benze
Acid, alkylcarboxylic acid or trifluoro
Anion selected from methylcarboxylic acid, or general
The compounds of formulas (12) to (18) (formula 4)
Represents an on residue.

[Chemical 4] (A and A ′ are an atomic group forming a benzene ring or a substituted benzene ring or forming a naphthalene ring or a substituted naphthalene ring, and may be the same or different. R _{9 to} R ₃₁ are A substituted or unsubstituted alkyl group,
Alkoxy group, hydroxy group, carboxyl group, halogen atom, allyl group, alkylcarboxyl group, alkylalkoxyl group, aralkyl group, alkylcarbonyl group, sulfonate alkyl group bonded to metal ions, nitro group, amino group, alkylamino group, phenyl Group, selected from phenylethylene groups. M is Ni, Co,
It shows a transition metal selected from Mn, Cu, Pd and Pt. M has an electric charge and may have a cation and a salt structure. a'represents the valence of an ionic body and is a positive integer including 0. Z represents a cation, and a ′ = b ′ · c ′
When a ′ = 0, b ′ · c ′ = 0 and Z does not exist, and the compound becomes a neutral body. ) X may not be present when R ₁ and R ₁ 'have a group to which an alkali metal ion is bound. Y, Y'is O,
S, Se, NH, -CH = CH-. a is the number of moles and is represented by a positive integer determined by the charge number of X. ]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

[Chemical 6] Q is an atomic group consisting of a substituted or unsubstituted 5-membered ring or 6-membered ring containing at least one nitrogen atom as represented by the general formulas (7) to (11) (Chemical formula 7).

Claims (4)

[Claims] 1. An optical recording medium having a recording layer and a reflective layer on a substrate, wherein the recording layer comprises a trimethine cyanine dye. 2. A color of trimethine cyanine forming a recording layer.
The element is a compound represented by the general formula (1)
The optical recording medium according to claim 1. [Chemical 1][However, P is represented by general formulas (2) to (6) (chemical formula 2).
Substituted or unsubstituted containing at least one nitrogen atom such as
Is an atomic group consisting of a 5-membered ring or a 6-membered ring. [Chemical 2]Q is represented by general formulas (7) to (11) (Chemical formula 3).
Substituted or unsubstituted containing at least one nitrogen atom such as
Is an atomic group consisting of a 5-membered ring or a 6-membered ring. [Chemical 3]A₁, A₁'Forms a substituted benzene ring or is a naphth
A group of atoms that form a talen ring or a substituted naphthalene ring
Yes, they may be the same or different. A₂，
A₃, A_Four, A_Five, A₂', A₃', A_Four'And A_Five'Is Benz
Form a benzene ring or a substituted benzene ring, or
A group of atoms that form a talen ring or a substituted naphthalene ring
Yes, they may be the same or different. R₁And R
₁'Is a substituted or unsubstituted alkyl group, alkoxy group, or
Alkyl hydroxy group, aralkyl group, alkenyl group,
Alkyl carboxyl group, alkylsulfonyl group or
Alkali bound to a metal ion or an alkyl group
Is a carboxyl group or an alkylsulfonyl group
The same kind or different kinds may be used. R₂~ R₈Is a hydrogen atom, halogen
Atom, alkyl group, alkoxy group, diphenylamino
Selected from the group R₆~ R ₈Is the position across multiple carbons
It may be a substituted or unsubstituted cyclic side chain. X is a halogen
Atom, perchloric acid, borofluoric acid, benzene sulfone
Acid, toluene sulfonic acid, alkyl sulfonic acid, benze
Acid, alkylcarboxylic acid or trifluoro
Anion selected from methylcarboxylic acid, or general
The compounds of formulas (12) to (18) (formula 4)
Represents an on residue. [Chemical 4](A and A'form a benzene ring or a substituted benzene ring
Or naphthalene ring or substituted naphthalene ring
Groups of atoms that form
Is also good. R₉~ R₃₁Is a substituted or unsubstituted alkyl group,
Alkoxy group, hydroxy group, carboxyl group, halogen
Atom, allyl group, alkylcarboxyl group, alkyl
Alkoxyl group, aralkyl group, alkylcarbonyl
Group, a sulfonate alkyl group bonded to a metal ion,
Toro group, amino group, alkylamino group, phenyl group, fluorine group
Selected from a phenylethylene group. M is Ni, Co,
Shows transition metals selected from Mn, Cu, Pd and Pt
is doing. M has an electric charge and forms a cation and a salt structure.
May be. a'represents the charge number of the ionic body, and is positive including zero.
Is an integer. Z represents a cation, and a '= b'.c'
And when a ′ = 0, b ′ · c ′ = 0 and Z exists
Otherwise, the compound becomes neutral. ) R₁And R₁'Has a group to which an alkali metal ion is bound
If X is present, X may not be present. Y, Y'is O,
S, Se, NH, -CH = CH-. a is
It is the number of moles and is represented by a positive integer determined by the charge number of X.
Be done. ] 3. The reflectance measured from the substrate side with respect to light selected from a red laser having a wavelength of 630 to 690 nm is 4.
0% or more, recording and reproduction is possible with a red laser having a wavelength of 630 to 690 nm, and the reflectance measured from the substrate side for light selected from a near infrared laser having a wavelength of 770 to 830 nm is 65% or more, The optical recording medium according to claim 1 or 2, which can be reproduced by a near infrared laser selected from 770 to 830 nm. 4. The optical recording medium according to claim 1, wherein a recording layer, a reflective layer and a protective layer are provided in this order on a substrate.