JP3716856B2 - Optical recording medium - Google Patents

Description

  The present invention relates to an optical recording medium using a porphyrin compound as a recording layer. Specifically, the present invention relates to an optical recording medium corresponding to blue laser light.

In recent years, optical recording using a laser has been especially developed in order to enable high-density information recording storage and reproduction.
An example of the optical recording medium is an optical disk.
In general, an optical disc records high-density information by irradiating a thin recording layer provided on a circular base with a laser beam converged to about 1 μm. Among the optical disks, a writable compact disk (CD-R) is recently attracting attention. The CD-R is usually configured by sequentially laminating a recording layer mainly composed of a dye, a metal reflection film, and a protective film on a plastic substrate having guide grooves. Information was recorded by recording thermal energy such as decomposition, evaporation, and dissolution in the recording layer, reflective layer, or substrate at the location due to absorption of the irradiated laser beam energy. Information reproduction is performed by reading a difference in reflectance between a portion where deformation is caused by a laser beam and a portion where deformation is not caused. Therefore, it is necessary to efficiently absorb the energy of laser light as an optical recording medium, and a laser absorbing dye is used.

  Optical recording media using such organic dyes are expected to become increasingly popular as inexpensive optical recording media because a recording layer can be formed by a simple method by applying an organic dye solution. Densification is demanded. For this reason, it has been studied to shorten the wavelength of laser light used for recording from the conventional semiconductor laser centered at 780 nm to the blue light region.

  An object of the present invention is to provide an optical recording medium using a porphyrin-based compound as an optical recording medium corresponding to blue laser light.

As a result of diligent studies to achieve this object, the present inventors have found that an optical recording medium using a porphyrin compound represented by the following general formula (I) in the recording layer can be satisfactorily recorded with a blue laser.
That is, the present invention provides an optical recording medium in which a recording layer capable of writing and / or reading information with a laser is provided on a substrate, the recording layer having the following general formula (I)

(In the formula, R ^{1 to} R ⁴ each independently represents an aromatic ring or a heterocyclic ring optionally having a substituent ( provided that any one of R ^{1 to} R ⁴ is a pyridine ring). .), X ¹ to X ⁸ represents a hydrogen atom or a halogen atom independently, M represents a hydrogen atom or a metal.) which contains a porphyrin-based compound represented by the writing of information is the recording layer A method of writing an optical recording medium , wherein the absorption spectrum of light of the recording layer is a maximum absorption peak and at least one sub-absorption smaller than the maximum absorption peak
Corresponding to a predetermined sub-absorption peak among a plurality of absorption peaks of the recording layer and a wavelength of recording light for recording information by causing a change in reflectance in the recording layer. In an optical recording medium in which information is written by providing a recording layer on at least a substrate and causing a thermal change by laser irradiation, unless the wavelength is substantially equal) layers above general formula (I) (wherein, R ¹ to R ⁴ are each independently have a substituent represents an even aromatic ring or a heterocyclic ring (provided that among R ¹ to R ⁴ Any of which is a pyridine ring, except when all of R ^{1 to} R ⁴ are pyridine rings.), X ¹ to
X ⁸ each independently represents a hydrogen atom or a halogen atom, and M represents a hydrogen atom or a metal.
Wow. The gist of the present invention is an optical recording medium comprising a porphyrin-based compound represented by the formula:
The porphyrin compound in the present invention has a large molar extinction coefficient in the blue light region of 400 to 500 nm, has a sharp absorption (Soret band), and is suitable for recording with a blue laser. In addition, since the synthesis is relatively easy among porphyrin compounds, an inexpensive optical recording medium can be provided. Furthermore, it has high light stability and heat resistance, and is suitable for an optical recording medium that requires stability.

  The optical recording medium using the porphyrin-based compound of the present invention provides a high-density recording medium that is inexpensive, excellent in light resistance and heat resistance, and is extremely useful industrially.

Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be arbitrarily modified without departing from the gist of the present invention.
In the general formula (I), examples of the optionally substituted aromatic ring represented by R ^{1 to} R ⁴ include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, an indene ring, an azulene ring, and a fluorene ring. As the heterocyclic ring, thiophene ring, furan ring, pyrrole ring, pyrazole ring, imidazole ring, triazole ring, oxazole ring, thiazole ring, thiadiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, pyran ring, Examples include benzofuran ring, indole ring, benzothiophene ring, benzimidazole ring, benzothiazole ring, quinoline ring, coumarin ring, quinoxaline ring, dibenzofuran ring, carbazole ring, acridine ring, phenanthroline ring, phenothiazine ring, etc. , Thiofe Ring is preferable.

The substituent on the aromatic ring or heterocyclic ring is a hydrogen atom; methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, sec-butyl group, n-pentyl group, n -C1-C20 linear or branched alkyl group such as hexyl group; C3-C10 cycloalkyl group such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group; methoxy group, ethoxy group, n -C 1 which may be substituted such as propoxy group, isopropoxy group, n-butoxy group, tert-butoxy group, ethoxycarbonylpropoxy group, sec-butoxy group, n-pentyloxy group, n-hexyloxy group -20 linear or branched alkoxy groups; acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, A linear or branched alkylcarbonyl group having 2 to 21 carbon atoms such as a sovaleryl group, a pivaloyl group, a hexanoyl group, a heptanoyl group; A straight or branched alkenyl group or a corresponding alkenyloxy group, cyclopentenyl group, cyclohexenyl group and other C3-C10 cycloalkenyl group; fluorine atom, chlorine atom, bromine atom and other halogen atom; formyl group; hydroxyl group Group; carboxyl group; hydroxyalkyl group having 1 to 20 carbon atoms such as hydroxymethyl group and hydroxyethyl group; methoxycarbonyl group, trifluoromethoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n -Butoxycarbonyl , A tert-butoxycarbonyl group, a sec-butoxycarbonyl group, an n-pentyloxycarbonyl group, an n-hexyloxycarbonyl group and the like, an optionally substituted linear or branched alkoxycarbonyl group having 2 to 21 carbon atoms; methyl Carbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, trifluoroethylcarbonyloxy group, tert-butylcarbonyloxy group, sec-butylcarbonyloxy group, n A linear or branched alkylcarbonyloxy group having 2 to 21 carbon atoms which may be substituted, such as a pentylcarbonyloxy group, n-hexylcarbonyloxy group; nitro group; cyano group; amino group; methylamino group, ethyl Amino group N-propylamino group, n-butylamino group, dimethylamino group, diethylamino group, di-n-propylamino group, di-iso-propylamino group, di-n-butylamino group, di-sec-butylamino A linear or branched alkylamino group having 1 to 20 carbon atoms such as a group; a diphenylamino group; a trialkylamino group having 3 to 9 carbon atoms such as a trimethylamino group or a triethylamino group; a methoxymethyl group, a methoxyethyl group, A linear or branched alkoxyalkyl group having 2 to 21 carbon atoms such as ethoxymethyl group, ethoxyethyl group, n-propoxyethyl group, n-propoxypropyl group, isopropoxymethyl group, isopropoxyethyl group; methoxycarbonylmethyl group , Methoxycarbonylethyl group, ethoxycarbonylmethyl group, ethoxycarbonyl A linear or branched alkoxycarbonylalkyl group having 3 to 22 carbon atoms such as a til group, n-propoxycarbonylethyl group, n-propoxycarbonylpropyl group, isopropoxycarbonylmethyl group, isopropoxycarbonylethyl group; methylthio group, ethylthio Straight chain or branched alkylthio group having 1 to 20 carbon atoms such as a group, n-propylthio group, isopropylthio group, n-butylthio group, tert-butylthio group, sec-butylthio group, n-pentylthio group, n-hexylthio group Methylsulfonyl group, ethylsulfonyl group, fluoroethylsulfonyl group, n-propylsulfonyl group, isopropylsulfonyl group, n-butylsulfonyl group, tert-butylsulfonyl group, sec-butylsulfonyl group, n-pentylsulfonyl group, n A linear or branched alkylsulfonyl group having 1 to 20 carbon atoms which may be substituted, such as a hexylsulfonyl group; a phenyl group which may have a substituent; a phenoxy group which may have a substituent; Phenylthio group which may have a substituent; —CR ⁵ ═C (CN) R ⁶ (R ⁵ represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms; R ⁶ represents cyano. Or a linear or branched alkoxycarbonyl group having 2 to 7 carbon atoms or a linear or branched alkoxycarbonyl group having 2 to 7 carbon atoms. ); Trifluoromethyl group, pentafluoroethyl group, heptafluoro-n-propyl group, heptafluoroisopropyl group, perfluoro-n-butyl group, perfluoro-tert-butyl group, perfluoro-sec-butyl group, perfluoro group C1-C20 linear or branched fluoroalkyl group such as fluoro-n-pentyl group and perfluoro-n-hexyl group; trifluoromethoxy group, pentafluoroethoxy group, heptafluoro-n-propoxy group, hepta Fluoroisopropoxy group, perfluoro-n-butoxy group, perfluoro-tert-butoxy group, perfluoro-sec-butoxy group, perfluoro-n-pentyloxy group, perfluoro-n-hexyloxy group, bromododecyloxy Straight chain or branched C having 1 to 20 carbon atoms Alkoxy group; trifluoromethylthio group, pentafluoroethylthio group, heptafluoro-n-propylthio group, heptafluoroisopropylthio group, perfluoro-n-butylthio group, perfluoro-tert-butylthio group, perfluoro-sec-butylthio A straight chain or branched haloalkylthio group having 1 to 20 carbon atoms such as a group, a perfluoro-n-pentylthio group, and a perfluoro-n-hexylthio group, and the number of substitutions may be one or more. When the aromatic ring is a pyridine ring or the like, the substitution position of the substituent is preferably the ortho position or the meta position.

The counter ion in the case of the trialkylamino group is not particularly limited as long as it is an anion, but F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , CH ₃ COO—, CF ₃ COO—, BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ ,

Etc.
Further, the R ¹ to R ⁴ is pyrrole ring, if the nitrogen-containing heterocyclic ring such as pyridine ring, may be the above substituents are introduced in the form of quaternized nitrogen atoms. In this case, the counter ion is not particularly limited as long as it is an anion, and examples thereof include the same anions as the counter ion of the trialkylamino group.

In the general formula (I), X ^{1 to} X ⁸ each independently represent a hydrogen atom; a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom, or a nitro group.
In the general formula (I), examples of M include a hydrogen atom or a metal atom. As metal atoms, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Sr, Y, Zr, Nb, Mo, Tc , Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Pr, Eu, Yb, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Th In general, there is no particular limitation as long as it is a metal capable of coordinating with a porphyrin-based compound. In particular, Mg, Al, Si, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Pd, In, Sn, Pb, and the like are preferable. In the case of metals such as Fe, In and Sn, halogen ions such as F ⁻ , Cl ⁻ , B ⁻ and I ⁻ are used as axial ligands; OR ⁻ , NCS ⁻ , N ₃ ⁻ , OH ⁻ and CN ^−. , CH ₃ COO ⁻ , CF ₃ COO ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , tosyloxy, phenoxy and other anions; bases such as pyridine and imidazole; gases such as NO, CO and O ₂ ; You may do it. Here, R has 1 to 10 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, sec-butyl group, n-pentyl group, and n-hexyl group. Represents a linear or branched alkyl group.

  Examples of the porphyrin compound of the present invention include the following structures.

One kind of these porphyrin compounds may be used, or several kinds may be mixed and used.
The metal-free form of the porphyrin compound represented by the general formula (I) includes, for example, an aldehyde derivative represented by the following general formula (II) and a pyrrole derivative represented by the following general formula (III) in an organic solvent such as propionic acid. It can be synthesized by heating. When two or more kinds of aldehyde derivatives are used, a mixture is obtained. Thus, a predetermined substitution product is obtained by separation and purification using a column or the like.

(In the formula, R represents the same meaning as the aromatic ring or heterocyclic ring optionally having the substituent represented by R ^{1 to} R ⁴ , and X and X are the definitions of X ^{1 to} X ⁸ , respectively. It shows the same meaning as
The metal-free porphyrin compound synthesized by the above method can be used in an organic solvent such as acetic acid, N, N-dimethylformamide, benzene, ether, chloroform, pyridine, halides, acetates, metal acetylacetonate complexes, metal carbonyl complexes, etc. A porphyrin compound into which the central metal M is introduced is synthesized by heating with a metal salt.

  Moreover, the introduction of the substituent into the aromatic ring or the heterocyclic ring may be performed either before or after forming the porphyrin ring. For example, introduction of a substituent to a pyridine ring after the formation of a porphyrin ring can be achieved by using a porphyrin compound obtained above in a halide such as alkyl bromide and a base such as potassium carbonate in an organic solvent such as N, N-dimethylformamide. This is done by heating under.

In the general formula (I), a compound in which any ^one of X ^{1 to} X ⁸ is a halogen atom is obtained by halogenating the porphyrin compound obtained by the above method using a halogenating agent. It can also be obtained by nitration using a nitrating agent.
The optical recording medium of the present invention is basically composed of at least a substrate and a recording layer containing the porphyrin-based compound. If necessary, an undercoat layer can be provided on the substrate. .

  The substrate is preferably transparent to the laser beam used, and glass and various plastics are used. Examples of plastic include acrylic resin, methacrylic resin, polycarbonate resin, vinyl chloride resin, vinyl acetate resin, nitrocellulose, polyester resin, polyethylene resin, polypropylene resin, polyimide resin, polystyrene resin, epoxy resin, etc., but high productivity In view of cost and moisture absorption resistance, an injection-molded polycarbonate resin substrate is particularly preferable.

The film thickness of the recording layer containing the porphyrin compound in the optical recording medium of the present invention is 100 to 5 μm, preferably 700 to 3 μm.
As a method for forming the recording layer, it can be formed by a generally used thin film forming method such as a vacuum deposition method, a sputtering method, a doctor blade method, a cast method, a spinner method, an immersion method, etc. From the aspect, the spinner method is preferable.

  The recording layer may be a porphyrin compound alone, but a binder can also be used if necessary. As the binder, known materials such as polyvinyl alcohol, polyvinyl pyrrolidone, ketone resin, nitrocellulose, cellulose acetate, polyvinyl butyral, and polycarbonate are used. In this case, the porphyrin compound of the present invention is preferably contained in the resin in an amount of 10% by weight or more.

In the case of film formation by the spinner method, the rotation speed is preferably 500 to 5000 rpm, and after spin coating, depending on the case, treatment such as heating or solvent vapor may be performed.
In addition, in order to improve the stability and light resistance of the recording layer, a transition metal chelate compound (for example, a chelate of acetylacetonate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone, etc.), etc. In order to improve the recording sensitivity, a recording sensitivity improving agent such as a metal compound may be contained. Here, the metal compound refers to a compound in which a metal such as a transition metal is contained in the compound in the form of atoms, ions, clusters, etc., for example, an ethylenediamine complex, an azomethine complex, a phenylhydroxyamine complex, a phenanthroline complex, Organic metal compounds such as dihydroxyazobenzene complex, dioxime complex, nitrosoaminophenol complex, pyridyltriazine complex, acetylacetonate complex, metallocene complex and porphyrin complex can be mentioned. Although it does not specifically limit as a metal atom, It is preferable that it is a transition metal.

Furthermore, other dyes can be used in combination as required. Other dyes have absorption mainly in the laser wavelength region for recording, and thermal, such as decomposition, evaporation, dissolution, etc., in the recording layer, reflecting layer or substrate at that location by absorption of the irradiated laser light energy There is no particular limitation as long as pits are formed with deformation.
A coating solvent for forming the recording layer by a coating method such as a doctor blade method, a cast method, a spinner method, a dipping method, or a spinner method is not particularly limited as long as it does not attack the substrate. For example, ketone alcohol solvents such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone, cellosolve solvents such as methyl cellosolve and ethyl cellosolve, hydrocarbon solvents such as n-hexane and n-octane, cyclohexane , Hydrocarbon solvents such as methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, n-butylcyclohexane, t-butylcyclohexane, cyclooctane, ether solvents such as diisopropyl ether, dibutyl ether, tetrafluoropropanol, octafluoropentanol, hexa Examples include perfluoroalkyl alcohol solvents such as fluorobutanol, and hydroxyester solvents such as methyl lactate, ethyl lactate, and methyl isobutyrate.

Further, a high reflective medium may be provided by providing a metal reflective layer and a protective layer such as gold, silver, aluminum or alloys thereof on the recording layer. Examples of the reflective layer include gold, silver, and aluminum. In the case of gold or aluminum, the reflectance of the laser beam having a wavelength of 530 nm or less used in the present invention is not sufficient, and silver is preferable.
The metal reflective layer is formed by vapor deposition, sputtering, ion plating, or the like. An intermediate layer may be provided between the metal reflective layer and the recording layer for the purpose of improving the adhesion between the layers or for increasing the reflectance.

Examples of the protective layer include a UV curable resin composition.
Moreover, it may be bonded via an adhesive layer to form a double-sided recording type optical recording medium, or the recording layer may be provided on both sides of the substrate or on one side.
The laser beam used in the optical recording medium of the present invention is preferably as short as possible for high-density recording, but a laser beam of 350 nm to 530 nm is particularly preferable. A typical example of such a laser is a laser having center wavelengths of 410 nm and 545 nm.

  An example of laser light having a wavelength in the range of 350 nm to 530 nm can be obtained by using a high-power semiconductor laser of 410 nm blue or 515 nm blue-green, but for example, (a) the fundamental oscillation wavelength is 740 to 960 nm. By converting the wavelength of either a semiconductor laser capable of continuous oscillation or (b) a solid-state laser excited by a semiconductor laser and capable of continuous oscillation having a fundamental oscillation wavelength of 740 to 960 nm by a second harmonic generation element (SHG) Can also be obtained.

EXAMPLES The present invention will be specifically described below with reference to examples. However, the examples do not limit the present invention as long as the gist thereof is not exceeded.
Example 1
(A) Synthesis of porphyrin compound A solution of 10.7 g (100 mmol) of isonicotinaldehyde in 350 ml of propionic acid was stirred and refluxed, and 6.71 g (100 mmol) of pyrrole was slowly added dropwise thereto. After refluxing for 1 hour, the crystals which are allowed to cool are separated by filtration and purified by an alumina column. When purified by an alumina column, 1.79 g of 5,10,15,20-tetra (4-pyridyl) porphyrin represented by the following structural formula (V) ( Yield 11.6%) was obtained.

This compound had a λmax in chloroform of 417 nm and a molar extinction coefficient of 3.83 × 10 ⁵ . The visible absorption spectrum of this compound in a chloroform solution is shown in FIG.

(B) Production of recording medium A 1 wt% octafluoropentanol solution of the porphyrin compound represented by the structural formula (V) was prepared and filtered to obtain a solution. This solution was dropped on an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm, and was applied by a spinner method. After coating, it was dried at 100 ° C. for 30 minutes. Next, a silver film having a thickness of 1000 mm was formed on the coating film by sputtering to form a reflective layer. Further, an ultraviolet curable resin was spin-coated on this reflective layer, and this was cured by irradiating with ultraviolet rays to form a protective layer having a thickness of 5 μm.

The maximum absorption wavelength of the coating film (recording layer) was 435 nm. The visible part absorption spectrum of the coating film is shown in FIG.
The reflectance of the obtained optical recording medium at 488 nm was 55%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 2
(A) Synthesis of Porphyrin Compound A solution of isonicotinaldehyde 4.07 g (38 mmol) and p-tolualdehyde 13.5 g (112 mmol) in propionic acid 500 ml is stirred and refluxed, and pyrrole 10.1 g (150 mmol) is slowly added thereto. It was dripped. After refluxing for 1 hour, the mixture is allowed to cool and the precipitated crystals are filtered off and purified by a silica gel column, and 5,10,15-tri (4-tolyl) -20- (4-pyridyl) represented by the following structural formula (VI) ) 0.50 g (2.0% yield) of porphyrin was obtained.

  Next, a mixed solution of 0.10 g (0.15 mmol) of compound (VI), 0.25 g (1.52 mmol) of n-hexyl bromide, and 90 ml of N, N-dimethylformamide was heated to reflux for 3 hours in a nitrogen atmosphere. After allowing to cool, the solvent was removed under reduced pressure, and the residue was purified by a silica gel column. 5,10,15-tri (4-tolyl) -20- [4-N- (n-hexyl) represented by the following structural formula (VII) ) Pyridyl] porphyrin, 0.11 g (yield 85.5%) of bromide was obtained.

This compound had a λmax in chloroform of 422 nm and a molar extinction coefficient of 1.50 × 10 ⁵ . The visible absorption spectrum of this compound in a chloroform solution is shown in FIG.

(B) Production of recording medium Using a 1% by weight octafluoropentanol solution of the porphyrin compound represented by the structural formula (VII), it was coated on a polycarbonate resin substrate in the same manner as in Example 1, and then a reflective layer and a protective layer were formed. Formed.
The maximum absorption wavelength of the coating film was 435 nm. The visible part absorption spectrum of the coating film is shown in FIG.
The reflectance of the obtained optical recording medium at 488 nm was 60%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 3
(A) Synthesis of Porphyrin Compound A mixed solution of 0.13 g (0.20 mmol) of the compound represented by the structural formula (VI), 0.48 g (1.68 mmol) of farnesyl bromide and 120 ml of N, N-dimethylformamide was added under a nitrogen atmosphere. And refluxed for 3 hours. After allowing to cool, the solvent was removed under reduced pressure, and the residue was purified with a silica gel column, and 5,10,15-tri (4-tolyl) -20- [4-N-farnesylpyridyl] porphyrin represented by the following structural formula (VIII) , 0.019 g (yield 10.2%) of bromide was obtained.

This compound had a λmax in chloroform of 422 nm and a molar extinction coefficient of 1.33 × 10 ⁵ . The visible absorption spectrum of this compound in a chloroform solution is shown in FIG.

(B) Production of recording medium Using a 1% by weight octafluoropentanol solution of a porphyrin compound represented by the structural formula (VIII), it was applied on a polycarbonate resin substrate in the same manner as in Example 1, and then a reflective layer and a protective layer were formed. Formed.
The maximum absorption wavelength of the coating film was 433 nm. The visible part absorption spectrum of the coating film is shown in FIG.
The reflectivity at 488 nm of the obtained optical recording medium was 62%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 4
(A) Synthesis of Porphyrin Compound A mixed solution of 0.13 g (0.20 mmol) of the compound represented by the structural formula (VI), 0.56 g (2.0 mmol) of methyl 11-bromoundecanoate, and 120 ml of N, N-dimethylformamide Was heated to reflux for 3 hours under a nitrogen atmosphere. After allowing to cool, the solvent was removed under reduced pressure, and the residue was purified by a silica gel column. 5,10,15-tri (4-tolyl) -20- [4- (10-carbomethoxy) represented by the following structural formula (IX) Decylpyridyl] porphyrin, 0.16 g (yield 85.4%) of bromide was obtained.

This compound had a λmax in chloroform of 422 nm and a molar extinction coefficient of 1.46 × 10 ⁵ .

(B) Production of recording medium Using a 1% by weight octafluoropentanol solution of the porphyrin compound represented by the structural formula (IX), it was coated on a polycarbonate resin substrate in the same manner as in Example 1, and then a reflective layer and a protective layer were formed. Formed.
The maximum absorption wavelength of the coating film was 436 nm.
The reflectance of the obtained optical recording medium at 488 nm was 60%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 5
(A) Synthesis of Porphyrin Compound A solution of 10.7 g (100 mmol) of nicotinaldehyde in 350 ml of propionic acid was stirred and refluxed, and 6.71 g (100 mmol) of pyrrole was slowly added dropwise. After refluxing for 1 hour, the crystals which are allowed to cool are separated by filtration, and purified by an alumina column. When purified with an alumina column, 1.85 g of 5,10,15,20-tetra (3-pyridyl) porphyrin represented by the following structural formula (X) ( Yield 12.0%) was obtained.

Λmax of this compound in chloroform was 418 nm, and the molar extinction coefficient was 4.46 × 10 ⁵ .

(B) Production of recording medium A 1 wt% octafluoropentanol solution of the porphyrin compound represented by the structural formula (X) was applied on the polycarbonate resin substrate in the same manner as in Example 1, and then a reflective layer and a protective layer were formed. Formed.
The maximum absorption wavelength of the coating film was 431 nm.
The reflectance of the obtained optical recording medium at 488 nm was 55%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 6
(A) Synthesis of Porphyrin Compound A solution of isonicotinaldehyde 8.14 g (76 mmol) and p-tolualdehyde 9.0 g (76 mmol) in propionic acid 500 ml was stirred and refluxed, and pyrrole 10.1 g (150 mmol) was slowly added dropwise. After refluxing for 1 hour, the mixture is allowed to cool and the precipitated crystals are filtered off and purified by an alumina column, and then 5,10-di (4-tolyl) -15,20-di (4-) represented by the following structural formula (XI). Pyridyl) porphyrin and 1.38 g (yield 5.7%) of 5,15-di (4-tolyl) -10,20-di (4-pyridyl) porphyrin represented by (XII) were obtained.

Λmax of this compound in chloroform was 419 nm, and the molar extinction coefficient was 4.54 × 10 ⁵ .

(B) Production of recording medium Using a 1 wt% octafluoropentanol solution of the porphyrin compound (mixture) represented by the structural formulas (XI) and (XII), it was coated on a polycarbonate resin substrate in the same manner as in Example 1. Next, a reflective layer and a protective layer were formed.
The maximum absorption wavelength of the coating film was 430 nm.
The reflectance of the obtained optical recording medium at 488 nm was 56%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 7
(A) Synthesis of Porphyrin Compound A solution of 4.07 g (38 mmol) of nicotinaldehyde and 13.5 g (112 mmol) of p-tolualdehyde in 500 ml of propionic acid was stirred and refluxed, and 10.1 g (150 mmol) of pyrrole was slowly added dropwise. After refluxing for 1 hour, the mixture is allowed to cool and the precipitated crystals are separated by filtration and purified by a silica gel column to obtain 5,10,15-tri (4-tolyl) -20- (3-pyridyl) represented by the following structural formula (XIII). ) 0.79 g (yield 3.2%) of porphyrin was obtained.

  Next, a mixed solution of 0.20 g (0.3 mmol) of compound (XIII), 4.06 g (12 mmol) of n-octadecyl bromide and 180 ml of N, N-dimethylformamide was heated to reflux for 3 hours in a nitrogen atmosphere. After allowing to cool, the solvent was removed under reduced pressure, and the residue was purified by a silica gel column. 5,10,15-tri (4-tolyl) -20- [3-N- (n-octadecyl) represented by the following structural formula (XIV) ) Pyridyl] porphyrin, 0.18 g (yield 60.5%) of bromide was obtained.

Λmax of this compound in chloroform was 426 nm, and the molar extinction coefficient was 2.40 × 10 ⁵ .

(B) Production of recording medium A 1 wt% octafluoropentanol solution of a porphyrin compound represented by the structural formula (XIV) was used and applied onto a polycarbonate resin substrate in the same manner as in Example 1, and then a reflective layer and a protective layer Formed.
The maximum absorption wavelength of the coating film was 433 nm.
The reflectance of the obtained optical recording medium at 488 nm was 65%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 8
(A) Synthesis of Porphyrin Compound A solution of 4.07 g (38 mmol) of picolinaldehyde and 13.5 g (112 mmol) of p-tolualdehyde was stirred and refluxed, and 10.1 g (150 mmol) of pyrrole was slowly added dropwise. After refluxing for 1 hour, the mixture is allowed to cool and the precipitated crystals are separated by filtration and purified by a silica gel column. 5,10,15-tri (4-tolyl) -20- (2-pyridyl) represented by the following structural formula (XV) ) 0.88 g (yield 3.6%) of porphyrin was obtained.

  Next, a mixed solution of 0.10 g (0.15 mmol) of compound (XV), 2.03 g (6 mmol) of n-octadecyl bromide and 90 ml of N, N-dimethylformamide was heated to reflux for 3 hours in a nitrogen atmosphere. After allowing to cool, the solvent was removed under reduced pressure, and the residue was purified by a silica gel column. 5,10,15-tri (4-tolyl) -20- [2-N- (n-octadecyl) represented by the following structural formula (XVI) ) Pyridyl] porphyrin, 0.075 g (yield 49.8%) of bromide was obtained.

This compound had a λmax in chloroform of 424 nm and a molar extinction coefficient of 2.69 × 10 ⁵ .

(B) Production of recording medium A 1 wt% octafluoropentanol solution of a porphyrin compound represented by the structural formula (XVI) was used and applied onto a polycarbonate resin substrate in the same manner as in Example 1, and then a reflective layer and a protective layer Formed.
The maximum absorption wavelength of the coating film was 430 nm.
The reflectance of the obtained optical recording medium at 488 nm was 64%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 9
(A) Synthesis of porphyrin compound A solution of isonicotinaldehyde 4.07 g (38 mmol) and 2-thiophenecarboxaldehyde 12.6 g (112 mmol) in propionic acid 500 ml was stirred and refluxed, and pyrrole 10.1 g (150 mmol) was slowly added dropwise. . After refluxing for 1 hour, the mixture is allowed to cool and the precipitated crystals are separated by filtration and purified by a silica gel column. 5,10,15-tri (2-thienyl) -20- (4-pyridyl) represented by the following structural formula (XVII) ) 0.37 g (yield 1.5%) of porphyrin was obtained.

  Next, a mixed solution of 0.10 g (0.16 mmol) of compound (XVII), 0.53 g (1.6 mmol) of n-octadecyl bromide, and 90 ml of N, N-dimethylformamide was heated to reflux for 3 hours in a nitrogen atmosphere. After allowing to cool, the solvent was removed under reduced pressure, and the residue was purified by a silica gel column. 5,10,15-tri (2-thienyl) -20- [4-N- (n-octadecyl) represented by the following structural formula (XVIII) ) Pyridyl] porphyrin, 0.049 g (yield 32.0%) of bromide was obtained.

This compound had a λmax in chloroform of 430 nm and a molar extinction coefficient of 1.65 × 10 ⁵ .

(B) Production of recording medium Using a 1% by weight octafluoropentanol solution of a porphyrin compound represented by the structural formula (XVIII), it was coated on a polycarbonate resin substrate in the same manner as in Example 1, and then a reflective layer and a protective layer were formed. Formed.
The maximum absorption wavelength of the coating film was 439 nm.
The reflectivity at 488 nm of the obtained optical recording medium was 62%.
(C) Optical recording method When the optical recording medium was irradiated with an argon laser beam having a central wavelength of 488 nm, good recording pits could be formed.

Example 10-21
The compounds shown in Table 1 were synthesized in the same manner as Example 1. The maximum absorption wavelength and molecular extinction coefficient (ε) are shown.

Further, an optical recording medium was produced by applying these porphyrin compounds on a substrate in the same manner as in Example 1. The maximum absorption wavelength of the coating film is shown in Table-1.
When recording was performed on the obtained optical recording medium using an argon laser having a central wavelength of 488 nm, good recording pits could be formed in all cases.

  Here, the abbreviations in Table-1 are as follows.

The absorption spectrum figure in the chloroform solution of the porphyrin compound obtained in Example 1. FIG. The absorption spectrum figure of the coating film on the polycarbonate substrate of the porphyrin compound obtained in Example 1. FIG. The absorption spectrum figure in the chloroform solution of the porphyrin compound obtained in Example 2. FIG. The absorption spectrum figure of the coating film on the polycarbonate substrate of the porphyrin compound obtained in Example 2. FIG. The absorption spectrum figure in the chloroform solution of the porphyrin compound obtained in Example 3. FIG. The absorption spectrum figure of the coating film on the polycarbonate substrate of the porphyrin compound obtained in Example 3. FIG.

Claims (6)

In a method for writing an optical recording medium in which a recording layer capable of writing and / or reading information with a laser is provided on at least a substrate, the recording layer contains a porphyrin compound represented by the following general formula (I): A method for writing to an optical recording medium , wherein information is written by thermal deformation of the recording layer (however, the light absorption spectrum of the recording layer is smaller than the maximum absorption peak and the maximum absorption peak). At least one sub-absorption pipe
Corresponding to a predetermined sub-absorption peak among a plurality of absorption peaks of the recording layer and a wavelength of recording light for recording information by causing a change in reflectance in the recording layer. Unless the measured wavelength is substantially equal).

(In the formula, R ^{1 to} R ⁴ each independently represents an aromatic ring or a heterocyclic ring optionally having a substituent ( provided that any one of R ^{1 to} R ⁴ is a pyridine ring). .), X ¹ to X ⁸ each independently represent a hydrogen atom or a halogen atom, M represents a hydrogen atom or a metal.) 2. The optical recording medium writing method according to claim 1, wherein both the writing and reading laser wavelengths are 350 nm to 530 nm. A thermal change is caused by laser irradiation, characterized in that a recording layer is formed by applying a coating solution in which a porphyrin compound represented by the following general formula (I) is dissolved to a substrate.
A method of manufacturing an optical recording medium on which more information is written.

(Wherein R ¹ ~ R ^Four Each independently represents an optionally substituted aromatic ring or heterocyclic ring (provided that R represents ¹ ~ R ^Four One of which is a pyridine ring, but R ¹ ~ R ^Four Except when all of the above are pyridine rings. ), X ¹ ~ X ⁸ Each independently represents a hydrogen atom or a halogen atom, and M represents a hydrogen atom or a metal. ) In an optical recording medium in which a recording layer is provided on at least a substrate and information is written by causing a thermal change by laser irradiation , the recording layer is a porphyrin compound represented by the following general formula (I) An optical recording medium comprising:

(In the formula, R ^{1 to} R ⁴ each independently represents an aromatic ring or a heterocyclic ring optionally having a substituent ( provided that any one of R ^{1 to} R ⁴ is a pyridine ring). There, R ¹ all to R ⁴ excluding If a pyridine ring.), X ¹ to X ⁸ each independently represent a hydrogen atom or a halogen atom, M represents a hydrogen atom or a metal. ) In an optical recording medium provided with at least a recording layer capable of writing and / or reading information by a laser on a substrate , a reflective film and a protective film , the recording layer has the following general formula (I)

(In the formula, R ^{1 to} R ⁴ each independently represents an aromatic ring or a heterocyclic ring optionally having a substituent ( provided that any one of R ^{1 to} R ⁴ is a pyridine ring). There, R ¹ all to R ⁴ excluding If a pyridine ring.), X ¹ to X ⁸ each independently represent a hydrogen atom or a halogen atom, M represents a hydrogen atom or a metal. )
An optical recording medium comprising a porphyrin compound represented by the formula: In general formula (I), R ¹ ~ R ^Four Each independently represents an optionally substituted aromatic ring or heterocyclic ring (provided that R represents ¹ ~ R ^Four Any one of them is a pyridine ring. ), X ¹ ~ X ⁸ 6. The optical recording medium according to claim 4, wherein each independently represents a hydrogen atom or a halogen atom, and M represents a hydrogen atom or a metal.

Images