JP2005305839A - Optical recording material and optical recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical recording material, which can realize sensitivity, light fastness and jitter at high level and under good balance, and an optical recording medium employing the same. <P>SOLUTION: This optical recording material is used for an optical recording medium, which can record information by being irradiated with light and includes a chelate compound of an azomethine compound represented by general formula (1), wherein A<SP>1</SP>and A<SP>2</SP>independently and respectively represent a specified monovalent group and R<SP>1</SP>represents a hydrogen atom or the like, and a metal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical recording medium for recording information by light irradiation and an optical recording material used therefor.

As optical recording media, optical recording disks such as CD-R (recordable CD) and DVD-R (recordable DVD) have already been widely used. The wavelength of the reproduction light is being shortened. For example, the current recording / reproducing wavelength of CD-R is 780 nm, but the next-generation CD-R and DVD-R are shortened to 635-680 nm. As a dye used for an optical recording medium for dealing with such short-wavelength light, a dye made of a chelate compound of an azomethine compound and a metal is known (for example, Patent Document 1).
JP-A-10-273484

  In recent years, it has been desired to further increase the recording speed of information on an optical recording medium while increasing the density described above. For this purpose, a higher sensitivity is required for the dye used in the optical recording medium. However, when the sensitivity of the dye is increased, the light resistance tends to decrease. Moreover, in order to increase the recording speed of information, since laser light with higher power is usually used, it is necessary to further improve the light resistance against the laser light, and it is extremely difficult to achieve both sensitivity and light resistance. Furthermore, when the sensitivity of the dye is increased, there is also a problem that the fluctuation in the time direction (jitter) of the reproduction signal tends to increase.

  Therefore, with conventional dyes such as the chelate compounds described in Patent Document 1, it is becoming difficult to achieve levels that simultaneously satisfy sensitivity, light resistance, and jitter for further speed-up of information recording. It was.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical recording material capable of achieving all of sensitivity, light resistance and jitter at a higher level and in a balanced manner than before, and an optical recording medium using the optical recording material. And

  As a result of intensive studies on various dyes in order to solve the above problems, the present inventors have substituted azomethine groups with an aromatic ring having a specific structure as described below as a dye constituting an optical recording material. It has been found that by using an azomethine compound, all of sensitivity, light resistance and jitter can be achieved at a high level and in a balanced manner, and the present invention has been completed.

  That is, the optical recording material of the present invention is an optical recording material used for an optical recording medium capable of recording information by light irradiation, and is a chelate of an azomethine compound represented by the following general formula (1) and a metal. It is characterized by containing a compound.

  The optical recording medium of the present invention is an optical recording material used for an optical recording medium capable of recording information by light irradiation, and is a chelate of an azomethine compound represented by the following general formula (1) and a metal. A recording layer containing the compound is provided.

［式中、Ａ^１及びＡ^２はそれぞれ独立に下記一般式（１１）、（１２）又は（１３）で表される１価の基を示し、Ｒ^１は水素原子、置換基を有していてもよいアルキル基又は置換基を有していてもよいアリール基を示す。

[Wherein, A ¹ and A ² each independently represent a monovalent group represented by the following general formula (11), (12) or (13), and R ¹ has a hydrogen atom or a substituent. The alkyl group which may be substituted or the aryl group which may have a substituent is shown.

Wherein Q ¹ , Q ² and Q ³ each independently represent an atomic group constituting an aromatic ring which may have a substituent, X represents a monovalent group having an active hydrogen atom, and the same molecule A plurality of X may be the same or different, and when A ¹ is a monovalent group represented by the general formula (13), A ² is represented by the general formula (12) or (13). A monovalent group. ]

  In the azomethine compound, X is a hydroxyl group, an amino group which may have a substituent, an amide group which may have a substituent or a sulfonamide group which may have a substituent. The coating solution for forming the recording layer is preferable in that the solubility in a solvent is good.

Q ¹ is preferably an atomic group constituting a benzene ring which may have a substituent, and Q ² and Q ³ are each independently composed of a 5-membered ring and a 6-membered ring. Atoms constituting an aromatic ring selected from the group consisting of a condensed heterocyclic ring which may have a group, a 5-membered ring which may have a substituent and a 6-membered ring which may have a substituent A group is preferred.

  On the other hand, it is preferable that the metal which forms a chelate compound with an azomethine compound is nickel or cobalt.

  The recording layer of the recording material of the present invention and the optical recording medium of the present invention preferably further contains a cyanine dye. The chelate compound has an excellent quencher function, and particularly when used in combination with a cyanine dye, deterioration due to oxidation of the dye can be effectively suppressed.

  According to the present invention, there are provided an optical recording material capable of achieving all of sensitivity, light resistance and jitter at a high level in a balanced manner, and an optical recording medium using the optical recording material.

  In the following, preferred embodiments of the present invention will be described with reference to the drawings as the case may be.

(Optical recording material)
The optical recording material of the present invention contains a chelate compound of an azomethine compound represented by the following general formula (1) and a metal.

In General Formula (1), A ¹ and A ² each independently represent a monovalent group represented by the following General Formula (11), (12) or (13), and R ¹ represents a hydrogen atom or a substituent. The alkyl group which may have or the aryl group which may have a substituent is shown. However, when A ¹ is a monovalent group represented by the general formula (13), A ² is a monovalent group represented by the general formula (12) or (13). A ¹ is preferably a monovalent group represented by the general formula (11) or (12), and A ² is a group represented by the general formula (11), (12) or (13). More preferably, A ¹ and A ² are each independently a monovalent group represented by the general formula (11) or (12).

In the general formulas (11), (12) and (13), Q ¹ , Q ² and Q ³ each independently represent an atomic group constituting an aromatic ring which may have a substituent, and X is 1 represents a monovalent group having an active hydrogen atom, and a plurality of X in the same molecule may be the same or different.

Examples of the aromatic ring constituting Q ¹ include a benzene ring, a naphthalene ring, a pyrazole ring, a pyridine ring, and a quinoline ring, and among these, a benzene ring is preferable.

On the other hand, the aromatic rings constituted by Q ² and Q ³ are each independently composed of a 5-membered ring and a 6-membered ring, and may have a condensed heterocyclic ring or a substituent which may have a substituent. An aromatic ring selected from the group consisting of a good 5-membered ring and an optionally substituted 6-membered ring is preferred. Preferable specific examples of the aromatic ring constituting Q ² include pyrrole ring, pyrazole ring, imidazole ring, 1,2,4-triazole ring, 1,2,3-triazole ring, indole ring, benzimidazole ring and Indazole ring and the like can be mentioned. Preferable specific examples of the aromatic ring constituting Q ³ include a thiadiazole ring, a pyridine ring, a benzothiazole ring, a ring of benzoxazole or a monoaza homologue thereof, and an isoquinoline ring.

  The substituents of the aromatic ring as described above are alkyl groups, aryl groups, acyl groups, alkoxy groups, alkenyl groups, halogen atoms, hydroxy groups, carboxyl groups, carboxylic acid ester groups, sulfone groups, sulfonic acid ester groups, Examples thereof include a monovalent group selected from a sulfamoyl group, a sulfonamido group, a carbamoyl group, an amide group, an amino group, and a nitro group. When there are a plurality of substituents in the same molecule, they may be the same or different. Further, when two or more substituents are bonded to the same aromatic ring, they may be connected to each other to form a ring.

X in the general formula (11) is a functional group having an active hydrogen atom. Examples of the functional group having an active hydrogen atom include a hydroxyl group (—OH), an amino group (—NH ₂ ), an amide group (—CONH ₂ ), a sulfonamide group (—SO ₂ NH ₂ ), and a thiol group (— SH), a carboxy group (—COOH), a sulfo group (—SO ₃ H) and the like, and these may further have a substituent. Among these, X is particularly preferably a hydroxyl group, an amino group which may have a substituent, an amide group which may have a substituent or a sulfonamide group which may have a substituent. preferable.

Examples of the substituent bonded to the functional group having an active hydrogen atom as described above include an alkyl group, an aryl group, an acyl group, an alkoxy group, a halogen group, a hydroxy group, a carboxyl group, a carboxylate group, a sulfone group, and a sulfamoyl group. , Sulfonamido group, carbamoyl group, amide group, amino group, alkenyl group, cyano group, nitro group, mercapto group, thiocyano group, alkylthio group, alkylazomethine group, aralkyl group and the like. Among these, an alkyl group, a sulfone group (—SO ₂ —R; R represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group), an acyl group (—CO—R; R represents a substituted or unsubstituted group) Represents a substituted alkyl group or a substituted or unsubstituted aryl group). When R of a sulfone group and an acyl group is an alkyl group, it is preferable that the carbon number is 1-6.

Among the azomethine compounds as described above, particularly preferable specific examples are Nos. Listed in Tables 1 to 14. The thing represented by the chemical formula of 101-162 is mentioned, These can be used individually or in combination of two or more. Tables 1 to 5 show examples in which A ¹ and A ² are monovalent groups represented by the general formula (11). Tables 6 to 7 show that A ¹ is the general formula (11) and A ² is the general formula. Examples in which the monovalent group represented by (12) is represented, and in Tables 8 to 9, examples in which A ¹ is a monovalent group represented by the general formula (12) and A ² are represented by the general formula (11) Table 10 shows examples in which A ¹ and A ² are monovalent groups represented by the general formula (12). Table 11 shows examples in which A ¹ is a general formula (11) and A ² is a general formula (13 ), Examples in which A ¹ and A ² are monovalent groups represented by the general formula (13) are shown in Table 12, and A ¹ is in general in Table 13 Examples in which Formula (12) and A ² are monovalent groups represented by General Formula (13) are shown. In Table 14, A ¹ is represented by General Formula (13) and A ² is represented by General Formula (12). Examples of monovalent groups are shown.

These azomethine compounds undergo dehydration condensation by reacting an aldehyde compound or ketone compound substituted with an aromatic ring to which a predetermined substituent is bonded and an amine compound substituted with an aromatic ring to which the predetermined substituent is bonded. And so on. For example, as shown in Table 1. The azomethine compound 101 can be synthesized by a reaction represented by the following reaction formula (S). This reaction can be advanced by heating a reaction solution in which an aldehyde compound or a ketone compound and an amine compound are dissolved in a reaction solvent such as methanol in the absence of a catalyst or in the presence of a catalyst. It is preferable that the reaction product is further purified by recrystallization or the like before use in the optical recording material. The structure of the obtained azomethine compound can be identified by ordinary analysis methods such as ¹ H-NMR and mass spectrometry.

  In the chelate compound according to the present invention, when the azomethine compound has an active hydrogen atom, it is usually in a state in which it is eliminated, and a coordination bond is usually formed between the metal as a bidentate or tridentate ligand. Form. For example, when the metal is cobalt (Co), two bidentate or tridentate ligands coordinate per cobalt atom to form a chelate compound.

  As the metal (center metal) constituting the chelate compound, transition metals such as Co, Mn, Cr, Ti, V, Ni, Cu, Zn, Mo, W, Ru, Fe, Pd, Pt, and Al are preferable. Among these, Co or Ni is particularly preferable in combination with the azomethine compound.

When the chelate compound has a negative charge, it forms a salt with a counter cation. As the counter cation, alkali metal ions such as Na ⁺ , Li ⁺ , K ⁺ , ammonium ions, phosphonium ions, and the like are preferably used. Further, a salt may be formed using a light-absorbing dye having a positive charge described later as a counter cation. On the other hand, when the chelate compound has a positive charge, it forms a salt with the counter anion. As this counter anion, PF ₆ ⁻ , SbF ₆ ^{— and the} like are preferably used.

  The method for synthesizing the chelate compound as described above is not particularly limited, and can be synthesized according to a known method. For example, a chelate compound can be obtained by reacting an azomethine compound and a metal salt in a solvent such as water, dioxane, tetrahydrofuran, acetone, or ethanol.

  In the optical recording material of the present invention, this chelate compound may be used alone as a dye, or another light absorbing dye may be used in combination. Since the chelate compound as described above has an excellent quencher function, various characteristics such as light resistance and electric characteristics of the disc can be further improved by using the chelate compound in combination with another light-absorbing dye. Examples of the dye used in combination include a cyanine dye, a hydrazine metal complex, a styryl dye, a porphyrin dye, a rhodamine dye, a triphenylmethane dye, and a formazan metal complex. Among these, a cyanine dye is preferable.

  Moreover, about the pigment | dye which has a positive charge among the pigment | dyes used together, you may form a salt with the said chelate compound. Examples of positively charged dyes include cyanine dyes such as trimethine cyanine dyes and pentamethine cyanine dyes, rhodamine dyes, and triphenylmethane dyes. Among these, cyanine dyes are preferable, and trimethine cyanine dyes are particularly preferable.

  As the trimethine cyanine dye, for example, those having a structure represented by the following general formula (2) can be preferably used.

In general formula (2), R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently an alkyl group which may have a substituent or an aryl which may have a substituent. R ⁷ represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent or an aryl group which may have a substituent, and Q ⁴ and Q ⁵ are each independently Represents an atomic group constituting an aromatic ring which may have a substituent. However, R ² and R ³ , and R ⁴ and R ⁵ may be connected to each other to form a cyclic structure.

In the general formula (2), R ² and R ³ each independently represent an alkyl group or an optionally substituted benzyl group having 1 to 4 carbon atoms, or linked to a 3-6 membered ring; It is preferable that R ⁴ and R ⁵ are each independently an alkyl group having 1 to 4 carbon atoms or a benzyl group optionally having a substituent, or a 3- to 6-membered ring bonded to each other. R ⁶ and R ⁷ are preferably independently an alkyl group having 1 to 4 carbon atoms or an aryl group, and R ⁸ is a hydrogen atom, a halogen atom, or a carbon atom having 1 to 4 carbon atoms. It is preferably an alkyl group, a cyano group, an optionally substituted phenyl group or an optionally substituted benzyl group, and Q ⁴ and Q ⁵ each independently have a substituent. Benzene ring or position It is preferably a group of atoms constituting the naphthalene ring that may have a group. More preferably, at least one of R ² , R ³ , R ^4, and R ⁵ is a group that is not a methyl group, and at least one of R ² , R ³ , R ^4, and R ⁵ has a substituent. The benzyl group which may be present is more preferable in that the sensitivity can be remarkably enhanced.

  Among the cyanine dyes as described above, particularly preferable specific examples include T1 to T91 shown in Tables 15 to 22, and the like, and these can be used alone or in combination. These cyanine dyes can be obtained by synthesis according to a known method.

  In the optical recording material of the present invention, the mixing ratio of the chelate compound and the other light absorbing dye is not particularly limited, but the content ratio of the other light absorbing dye is the total amount of the chelate compound and the other light absorbing dye. It is preferable that it is 20-80 mol% as a reference | standard.

  The optical recording material as described above can be suitably used for forming a recording layer of the optical recording medium of the present invention as described below.

(Optical recording medium)
FIG. 1 is a partial sectional view showing a preferred embodiment of an optical recording disk according to the optical recording medium of the present invention. The optical recording disk 1 shown in FIG. 1 has a laminated structure in which a recording layer 3, a reflective layer 4, a protective layer 5, and a substrate 6 are provided in close contact with each other on a substrate 2. The optical recording disk 1 is a write-once type optical recording disk and can be recorded and reproduced with light having a short wavelength of 630 to 685 nm.

  The substrates 2 and 6 are each disk-shaped having a diameter of about 64 to 200 mm and a thickness of about 0.6 mm, and recording and reproduction are performed from the back side (lower side in the figure) of the substrate 2. Therefore, it is preferable that at least the substrate 2 is substantially transparent to recording light and reproducing light, and more specifically, the transmittance of the substrate 2 with respect to recording light and reproducing light is preferably 88% or more. . As the material of the substrate 2, a resin or glass that satisfies the above-described conditions regarding transmittance is preferable, and among them, a thermoplastic resin such as a polycarbonate resin, an acrylic resin, an amorphous polyolefin, a TPX, and a polystyrene resin is particularly preferable. On the other hand, the material of the substrate 6 is not particularly limited, but for example, the same material as that of the substrate 2 can be used.

  A tracking groove 23 is formed as a concave portion on the recording layer 3 forming surface of the substrate 2. The groove 23 is preferably a spiral continuous groove, and preferably has a depth of 80 to 250 nm, a width of 200 to 500 nm, and a groove pitch of 600 to 1000 nm. By configuring the groove in this way, a good tracking signal can be obtained without reducing the reflection level of the groove. The groove 23 can be formed at the same time when the substrate 2 is formed by injection molding or the like using the above resin. However, after the substrate 2 is manufactured, a resin layer having the groove 23 is formed by the 2P method or the like. A composite substrate with a resin layer may be used.

  The recording layer 3 is formed using the optical recording material of the present invention. The recording layer 3 can be formed by applying a mixed solution obtained by dissolving or dispersing the optical recording material of the present invention in a solvent onto the substrate 2 and removing the solvent from the coating film. As the solvent of the mixed solution, alcohol solvents (including alkoxy alcohol systems such as keto alcohol systems and ethylene glycol monoalkyl ether systems), aliphatic hydrocarbon solvents, ketone solvents, ester solvents, ether solvents, Aromatic solvents, alkyl halide solvents and the like can be mentioned. Among them, alcohol solvents and aliphatic hydrocarbon solvents are preferable.

As the alcohol solvent, an alkoxy alcohol system, a keto alcohol system and the like are preferable. In the alkoxy alcohol solvent, the alkoxy moiety preferably has 1 to 4 carbon atoms, the alcohol moiety preferably has 1 to 5 carbon atoms, more preferably 2 to 5 carbon atoms, and the total number of carbon atoms. It is preferable that it is 3-7. Specifically, ethylene glycol monoalkyl ether (cellosolve) such as ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (also referred to as ethyl cellosolve, ethoxyethanol), butyl cellosolve, 2-isopropoxy-1-ethanol, etc. And 1-methoxy-2-propanol, 1-methoxy-2-butanol, 3-methoxy-1-butanol, 4-methoxy-1-butanol, 1-ethoxy-2-propanol and the like. Examples of keto alcohols include diacetone alcohol. Furthermore, 2,2,
Fluorinated alcohols such as 3,3-tetrafluoropropanol can also be used.

  As the aliphatic hydrocarbon solvent, n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, cyclooctane, dimethylcyclohexane, n-octane, iso-propylcyclohexane, t-butylcyclohexane and the like are preferable. Cyclohexane and the like are preferable.

  Examples of the ketone solvent include cyclohexanone.

  In the present invention, an alkoxy alcohol system such as an ethylene glycol monoalkyl ether system is particularly preferable, and ethylene glycol monoethyl ether, 1-methoxy-2-propanol, 1-methoxy-2-butanol and the like are particularly preferable. A solvent may be used individually by 1 type, or 2 or more types of mixed solvents may be sufficient as it. For example, a mixed solvent of ethylene glycol monoethyl ether and 1-methoxy-2-butanol is preferably used.

  The mixed solution may contain a binder, a dispersant, a stabilizer and the like as appropriate in addition to the above components.

  Examples of the application method of the mixed solution include a spin coating method, a gravure application method, a spray coating method, and a dip coating method, and among these, the spin coating method is preferable.

  The thickness of the recording layer 3 thus formed is preferably 50 to 200 nm. In particular, the thickness of 70 to 150 nm is more preferable because the balance between the degree of modulation and the reflectance is improved. Outside this range, the reflectivity tends to be low, making reproduction difficult. Further, when the thickness of the recording layer 3 in the portion adjacent to the groove 23 is 200 nm or more, the balance between the modulation degree and the reflectance tends to deteriorate.

  The extinction coefficient (imaginary part k of the complex refractive index) of the recording layer 3 with respect to the recording light and the reproduction light is preferably 0 to 0.20. When the extinction coefficient exceeds 0.20, sufficient reflectance tends not to be obtained. The refractive index of the recording layer 3 (real part n of the complex refractive index) is preferably 1.8 or more. When the refractive index is less than 1.8, the degree of signal modulation tends to be small. The upper limit of the refractive index is not particularly limited, but is usually about 2.6 for the convenience of organic dye synthesis.

  The extinction coefficient and refractive index of the recording layer 3 can be obtained according to the following procedure. First, a measurement sample is prepared by providing a recording layer on a predetermined transparent substrate at about 40 to 100 nm, and then the reflectance of the measurement sample through the substrate or the reflectance from the recording layer side is measured. Desired. In this case, the reflectance is measured by specular reflection (about 5 °) using the wavelength of the recording / reproducing light. Further, the transmittance of the sample is measured. From these measured values, the extinction coefficient and the refractive index can be calculated according to the method described in, for example, Kyoritsu Zensho “Optics”, Kozo Ishiguro, pages 168 to 178.

  On the recording layer 3, the reflective layer 4 is provided in close contact with the recording layer 3. The reflective layer 4 can be formed by performing vapor deposition, sputtering, or the like using a highly reflective metal or alloy. Examples of the metal and alloy include gold (Au), copper (Cu), aluminum (Al), silver (Ag), and AgCu. The thickness of the reflective layer 4 thus formed is preferably 10 to 300 nm.

  On the reflective layer 4, a protective layer 5 is provided in close contact with the reflective layer 4. The protective layer 5 may be a layer or a sheet. For example, the protective layer 5 is formed by applying a coating liquid containing a material such as an ultraviolet curable resin on the reflective layer 4 and drying the coating film as necessary. Is possible. In the application, a spin coating method, a gravure coating method, a spray coating method, a dip coating method, or the like can be applied. The thickness of the protective layer 5 thus formed is preferably 0.5 to 100 μm.

  Furthermore, the substrate 6 is provided in close contact with the protective layer 5 on the protective layer 5. The substrate 6 can be made of the same material and thickness as the substrate 2. In addition, when the adhesive strength between the protective layer 5 and the substrate 6 is not sufficient, an adhesive layer may be further provided between the substrate 6 and the protective layer 5.

  When recording or additional recording is performed on the optical recording disk 1 having the above-described configuration, recording light having a predetermined wavelength is irradiated in a pulse form from the back surface of the substrate 2 to change the light reflectance of the irradiation section. At this time, according to the optical recording disk 1 provided with the recording layer 3 containing the azomethine compound, even when information is recorded / reproduced at a high speed with a short wavelength recording / reproducing light, the sensitivity, Light resistance and jitter can be achieved at a high level in a well-balanced manner.

  In the above embodiment, an optical recording disk having one recording layer 3 as a recording layer has been described. However, a plurality of recording layers may be provided, and each layer may contain the same or different dye. Thereby, information can be recorded / reproduced by a plurality of recording / reproducing lights having the same or different wavelengths. In this case, a translucent reflective film that is translucent to recording / reproducing light of each wavelength may be provided on the surface of each recording layer opposite to the light incident surface.

  The optical recording disk 1 obtained in this way is composed of two optical recording disks 1 or a single optical recording disk 1 and another optical recording disk having a different layer structure. It can also be used by bonding the light incident surface (substrate 5 side) outside.

  FIG. 2 is a partial cross-sectional view showing another preferred embodiment of the optical recording disk according to the above-described bonding mode. The optical recording disc 10 shown in FIG. The reflective layer 14, the protective layer 15, the adhesive layer 50, the protective layer 25, the reflective layer 24, the recording layer 23, and the substrate 22 are stacked in this order. That is, the optical recording disk 10 has a configuration in which two optical recording disks having the same structure as the optical recording disk 1 shown in FIG. 1 are bonded so that the respective protective layers face each other with the adhesive layer 50 interposed therebetween. It is what has. This optical recording disk 10 is a write-once digital video disk corresponding to the DVD standard, and performs recording / reproduction with light having a short wavelength of 650 to 670 nm.

  For the adhesive layer 50, a hot melt adhesive, an ultraviolet curable adhesive, a heat curable adhesive, a pressure sensitive adhesive, or the like is used. For example, a roll coater method, a screen printing method, a spin coating method, or the like. It can be formed by a coating method or the like. In the case of DVD-R, it is preferable to form the adhesive layer 50 by a screen printing method or a spin coating method using an ultraviolet curable adhesive from the viewpoint of balance of workability, productivity, disk characteristics and the like. The thickness of the adhesive layer 50 is preferably about 10 to 200 μm.

  The substrates 12 and 22, the recording layers 13 and 23, the reflective layers 14 and 24, and the protective layers 15 and 25 are formed by the same material and method as those of the optical recording disk 1 shown in FIG. The thickness of each of the substrates 12 and 22 is preferably about 0.6 mm. Grooves 123 and 223 are formed on the recording layer 13 forming surface of the substrate 12 and the recording layer 23 forming surface of the substrate 22, respectively. The grooves 123 and 223 preferably have a depth of 60 to 200 nm, a width of 200 to 500 nm, and a groove pitch of 600 to 1000 nm. Further, the thickness of each of the recording layers 13 and 23 is preferably 50 to 300 nm, and the complex refractive index with respect to the light of 650 nm is n = 1.8 to 2.6 and k = 0.00 to 0.10. Preferably there is.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.

(Synthesis Example 1)
2-Amino-4-nitro-phenol 1.54 g (10 mmol) and 4-diethylamino-2-hydroxy-benzaldehyde 1.93 g (10 mmol) were heated to reflux in 50 mL of methanol for 6 hours. The mixture was allowed to cool and then cooled with ice, and the precipitated crystals were filtered off and recrystallized using acetone to obtain 2.76 g of azomethine compound (yield: 84%).

  Subsequently, 0.20 g of sodium hydroxide, 10 g of water and 20 g of methanol were added to 1.32 g (4 mmol) of the obtained azomethine compound, and reacted at 90 ° C. for 16 hours with 0.5 g (2 mmol) of cobalt acetate. After completion of the reaction, suction filtration was performed, and the obtained crystals were dried under vacuum. In this way, no. 1.09 g (1.48 mmol) of a chelate compound (Co complex) of an azomethine compound represented by the chemical formula of 101 and Co was obtained.

By performing mass analysis (ESI method) by ¹ H-NMR and LC-MS on the obtained Co complex of the azomethine compound, this was confirmed as No. 1 in Table 1. It was identified as an azomethine compound having a structure of 101. The data of ¹ H-NMR and mass spectrometry are shown below.
^<1 H-NMR> (acetone _{-d 6, δppm); 1.40 (} t, 12H), 3.7 (q, 8H), 6.2 (s, 2H), 6.7 (d, 2H) 7.1 (d, 2H), 7.4 (d, 2H), 7.4 (d, 2H), 8.1 (d, 2H), 8.3 (s, 2H), 8.5 ( s, 2H).
<Mass Spectrometry> m / z: 713 (negative)

(Synthesis Example 2)
1.80 g (10 mmol) of 2-amino-5-diethylamino-phenol and 1.67 g (10 mmol) of 2-hydroxy-5-nitro-benzaldehyde were heated to reflux in 50 mL of methanol for 6 hours. The mixture was allowed to cool and then cooled with ice, and the precipitated crystals were filtered off and recrystallized using acetone to obtain 2.66 g (yield: 81%) of the azomethine compound (No. 102).

(Synthesis Example 3)
2-Amino-4-nitro-phenol 1.54 g (10 mmol) and 1- (4-dimethylamino-2-hydroxy-phenyl) -ethanone 1.79 g (10 mmol) were heated to reflux in 50 mL of methanol for 6 hours. The mixture was allowed to cool and then cooled with ice, and the precipitated crystals were filtered off and recrystallized using acetone to obtain 2.52 g (yield: 80%) of the azomethine compound (No. 103).

(Synthesis Example 4)
1.54 g (10 mmol) of 2-amino-4-nitro-phenol and 1.78 g (10 mmol) of 4-dimethylamino-2-methylamino-benzaldehyde were heated to reflux in 50 mL of methanol for 6 hours. The mixture was allowed to cool and then cooled with ice, and the precipitated crystals were collected by filtration and recrystallized with acetone to obtain 2.57 g (yield: 82%) of an azomethine compound (N0.104).

(Synthesis Example 5)
1.54 g (10 mmol) of 2-amino-4-nitro-phenol and 2.42 g (10 mmol) of N- (5-dimethylamino-2-formyl-phenyl) -methanesulfonamide were heated to reflux in 50 mL of methanol for 6 hours. . After allowing to cool, the crystals precipitated by further cooling with ice were filtered off and recrystallized using acetone to obtain 2.84 g (yield: 75%) of an azomethine compound (No. 105).

(Synthesis Example 6)
1.54 g (10 mmol) of 2-amino-4-nitro-phenol and 2.32 g (10 mmol) of N- (5-dimethylamino-2-formyl-phenyl) -trifluoromethanesulfonamide were heated to reflux in 50 mL of methanol for 6 hours. did. After standing to cool, the mixture was further cooled with ice, and the precipitated crystals were collected by filtration and recrystallized with acetone to obtain 4.72 g (yield: 78%) of an azomethine compound (No. 106).

(Synthesis Example 7)
2-Amino-4-nitro-phenol 1.54 g (10 mmol) and N- (5-dimethylamino-2-formyl-phenyl) -benzamide 2.68 g (10 mmol) were heated to reflux in 50 mL of methanol for 6 hours. The mixture was allowed to cool and then further cooled with ice, and the precipitated crystals were collected by filtration and recrystallized using acetone to obtain 3.19 g (yield: 79%) of the azomethine compound (No. 107).

(Synthesis Example 8)
2-Amino-4-nitro-phenol 1.54 g (10 mmol) and 4-benzoyl-3-methyl-1-phenyl-5-pyrazolinone 2.78 g (10 mmol) were heated to reflux in 50 mL of methanol for 6 hours. After allowing to cool, the crystals precipitated by further cooling with ice were filtered off and recrystallized using acetone to obtain 3.52 g of azomethine compound (No. 108) (yield: 85%).

(Synthesis Example 9)
1.97 g (10 mmol) of 2-hydroxy-3-methoxy-5-nitro-benzaldehyde and 1.32 g (10 mmol) of 1H-indol-2-ylamine were heated to reflux in 50 mL of methanol for 6 hours. The mixture was allowed to cool and then cooled with ice, and the precipitated crystals were collected by filtration and recrystallized with acetone to obtain 2.33 g (yield: 75%) of the azomethine compound (No. 124).

(Synthesis Example 10)
4-Dimethylamino-2-hydroxy-benzaldehyde 1.65 g (10 mmol) and 2H-pyrazol-3-ylamine 83.1 g (10 mmol) were heated to reflux in 50 mL of methanol for 6 hours. After standing to cool, the mixture was further cooled with ice, and the precipitated crystals were collected by filtration and recrystallized with acetone to obtain 1.59 g (yield 69%) of an azomethine compound (No. 129).

(Synthesis Example 11)
1.46 g (10 mmol) of 1H-benzimidazole-2-carbaldehyde and 1.54 g (10 mmol) of 2-amino-5-nitrophenol were heated to reflux in 50 mL of methanol for 6 hours. After standing to cool, the mixture was further cooled with ice, and the precipitated crystals were collected by filtration and recrystallized with acetone to obtain 2.06 g (yield: 73%) of an azomethine compound (No. 134).

(Synthesis Example 12)
1.63 g (10 mmol) of dimethylamino-5-formyl-1H-pyrrole-2-carbonitrile and 1.59 g (10 mmol) of 1-amino-2-naphthol were heated to reflux in 50 mL of methanol for 6 hours. After standing to cool, the crystals were further cooled with ice, and the precipitated crystals were filtered off and recrystallized with acetone to obtain 2.40 g of azomethine compound (No. 135) (yield: 79%).

(Synthesis Example 13)
0.95 g (10 mmol) of 1H-pyrrole-2-carbaldehyde and 0.83 g (10 mmol) of 1H-imidazol-2-ylamine were heated to reflux in 50 mL of methanol for 6 hours. After standing to cool, the mixture was further cooled with ice, and the precipitated crystals were separated by filtration and recrystallized with acetone to obtain 0.98 g (61%) of an azomethine compound (No. 144).

(Synthesis Example 14)
1.67 g (10 mmol) of 2-hydroxy-4-nitro-benzaldehyde and 2.34 g (10 mmol) of 6-trifluoromethoxy-benzothiazol-2-ylamine were heated to reflux in 50 mL of methanol for 6 hours. After allowing to cool, the crystals precipitated by further cooling with ice were filtered off and recrystallized using acetone to obtain 2.81 g of azomethine compound (No. 149) (yield: 75%).

(Synthesis Example 15)
Chloro-pyridine-2-carbaldehyde 1.41 g (10 mmol) and 5-methanesulfonyl-pyridin-2-ylamine 1.72 g (10 mmol) were heated to reflux in 50 mL of methanol for 6 hours. After allowing to cool, the crystals precipitated by further ice cooling were filtered off and recrystallized using acetone to obtain 2.28 g (yield: 77%) of the azomethine compound (No. 152).

(Example 1)
A chelate compound (No. 116 in Table 4) and its counter cation are formed on a polycarbonate resin substrate having a pregroove (depth 0.16 μm, width 0.30 μm, groove pitch 0.74 μm) formed on one surface. An optical recording material composed of Na ⁺ was applied with a mixed solution in 2,2,3,3-tetrafluoropropanol so that its content was 1.0% by weight, and dried to form a recording layer (thickness). 130 nm). Next, an Ag reflection layer (thickness 85 nm) is formed on the recording layer by sputtering, and a transparent protective layer (thickness 5 μm) made of an ultraviolet curable acrylic resin is further formed on the Ag reflection layer. Thus, a laminated structure was obtained. Further, the two laminated structures were bonded with an adhesive so that the respective protective layers were on the inner side, thereby producing an optical recording disk having the same configuration as the optical recording disk 10 shown in FIG.

  A signal is recorded on the obtained optical recording disk at a linear speed of 3.5 m / s (corresponding to the same speed) or 28.0 m / s (corresponding to 8 times the speed) using a laser beam having a wavelength of 655 nm, and then the wavelength. Jitter was measured when reproduction was performed at a linear velocity of 3.5 m / s using 650 nm laser light. At this time, the lens aperture NA was set to 0.60. Furthermore, the obtained optical disk was irradiated (light exposure) for 40 hours with an 80,000-lux xenon lamp (Xenon Fade Meter, manufactured by Shimadzu Corporation), and jitter was also applied to the optical recording disk after irradiation in the same manner as described above. The light resistance was measured and evaluated. The evaluation results are shown in Table 23.

(Examples 2-16 and Comparative Examples 1-2)
An optical recording disk was prepared and evaluated in the same manner as in Example 1 except that a chelate compound and a trimethine cyanine dye mixed in the combinations and ratios shown in Table 23 were used as the optical recording material. The evaluation results are summarized in Table 23. In Table 23, the chelate compound No. No. in Table 1 to Table 12. No. of trimethine cyanine dye No. in Table 13 to Table 20. The illustrated, counter anion of trimethine cyanine dyes PF ₆ ^- was. No. 101-108, 124, 129, 134, 135, 144, 149 and 152 are the azomethine compounds obtained in the above synthesis examples. The chelate compound 109 was prepared using a commercially available azomethine compound. In Comparative Examples 1 and 2, Comparative Compounds A and B represented by the following chemical formulas (3) and (4) were respectively distributed on cobalt. To prepare a chelate compound.

  The optical recording disks manufactured in Examples 1 to 16 showed good sensitivity enough to withstand practical use even for high-speed recording. Moreover, as shown in Table 21, according to Examples 1-16, it turned out that a jitter is restrained low compared with the comparative examples 1 and 2, and it is excellent also in light resistance. Therefore, according to the present invention, it has been confirmed that an optical recording material capable of achieving all of sensitivity, light resistance and jitter at a high level in a well-balanced manner and an optical recording medium using the optical recording material are provided. It was.

FIG. 1 is a partial sectional view showing an embodiment of an optical recording disk according to the optical recording medium of the present invention. FIG. 2 is a partial sectional view showing another embodiment of the optical recording disk according to the optical recording medium of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,10 ... Optical recording disc, 2, 6, 12, 22 ... Substrate, 3, 13, 23 ... Recording layer, 4, 14, 24 ... Reflective layer, 5, 15, 25 ... Protective layer, 23, 123, 223 ... groove, 50 ... adhesive layer.

Claims (10)

An optical recording material used for an optical recording medium capable of recording information by light irradiation,
An optical recording material containing a chelate compound of an azomethine compound represented by the following general formula (1) and a metal.

[Wherein, A ¹ and A ² each independently represent a monovalent group represented by the following general formula (11), (12) or (13), and R ¹ has a hydrogen atom or a substituent. The alkyl group which may be substituted or the aryl group which may have a substituent is shown.

Wherein Q ¹ , Q ² and Q ³ each independently represent an atomic group constituting an aromatic ring which may have a substituent, X represents a monovalent group having an active hydrogen atom, and the same molecule A plurality of X may be the same or different, and when A ¹ is a monovalent group represented by the general formula (13), A ² is represented by the general formula (12) or (13). A monovalent group. ]   The X is a hydroxyl group, an amino group which may have a substituent, an amide group which may have a substituent or a sulfonamide group which may have a substituent. Optical recording material. Q ¹ is an atomic group constituting a benzene ring which may have a substituent, and Q ² and Q ³ are each independently composed of a 5-membered ring and a 6-membered ring. An atomic group constituting an aromatic ring selected from the group consisting of a condensed heterocyclic ring which may have, a 5-membered ring which may have a substituent, and a 6-membered ring which may have a substituent; The optical recording material according to claim 1 or 2.   The optical recording material according to claim 1, wherein the metal is cobalt or nickel.   The optical recording material according to claim 1, further comprising a cyanine dye. An optical recording medium capable of recording information by light irradiation,
An optical recording medium comprising a recording layer containing a chelate compound of an azomethine compound represented by the following general formula (1) and a metal.

[Wherein, A ¹ and A ² each independently represent a monovalent group represented by the following general formula (11), (12) or (13), and R ¹ has a hydrogen atom or a substituent. The alkyl group which may be substituted or the aryl group which may have a substituent is shown.

Wherein Q ¹ , Q ² and Q ³ each independently represent an atomic group constituting an aromatic ring which may have a substituent, X represents a monovalent group having an active hydrogen atom, and the same molecule A plurality of X may be the same or different, and when A ¹ is a monovalent group represented by the general formula (13), A ² is represented by the general formula (12) or (13). A monovalent group. ]   The X is a hydroxyl group, an amino group which may have a substituent, an amide group which may have a substituent or a sulfonamide group which may have a substituent. Optical recording media. Q ¹ is an atomic group constituting a benzene ring which may have a substituent, and Q ² and Q ³ are each independently composed of a 5-membered ring and a 6-membered ring. An atomic group constituting an aromatic ring selected from the group consisting of a condensed heterocyclic ring which may have, a 5-membered ring which may have a substituent, and a 6-membered ring which may have a substituent; The optical recording medium according to claim 6 or 7.   The optical recording medium according to any one of claims 6 to 8, wherein the metal is cobalt or nickel.   The optical recording medium according to claim 6, further comprising a cyanine dye.

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