JP4438397B2 - Azo-substituted quinoline compound, chelate compound and optical recording medium using the same - Google Patents

Description

  The present invention relates to an azo-substituted quinoline compound, a chelate compound, and an optical recording medium using the chelate compound, and more particularly to a high-capacity write-once optical disc for data (a high-capacity write-once compact disc, DVD-R). As an application field of the present invention, for example, a large capacity optical card is cited.

  Currently, DVD + R and DVD-R are commercialized as large-capacity optical disks. In the market, DVD-type optical discs are also expected to require high-speed writing as found in CD-R.

  Regarding optical recording media, the following inventions are known.

A. (For information recording) related to write-once recording medium (WORM) (a) using cyanine dye as recording material (patent documents 1 to 8 below)
(B) Using phthalocyanine dye as a recording material (Patent Documents 9 to 15 below)
B. Recording-type compact disc (CD-R) (a) Cyanine dye + metal reflective layer as recording material (Patent Documents 16 to 19 below)
(B) A phthalocyanine dye + metal reflective layer as a recording material (Patent Documents 20 to 28 below)
(C) An azo metal chelate dye + metal reflective layer as a recording material (Patent Documents 29 to 38 below)
C. Related to large capacity write-once compact disc (DVD-R) (a) Using cyanine dye / metal reflective layer as recording material (Non-patent Document 1 and Patent Document 39 below)
(B) Azomethine dye + metal reflective layer as a recording material (Patent Documents 40 to 43 below)
(C) An azo metal chelate dye + metal reflective layer as a recording material (Patent Documents 44 to 92 below)
(D) Other dyes + metal reflective layer as recording material (Patent Documents 93 to 101 below)
(E) Formazan metal chelate dye + metal reflective layer as recording material (Patent Documents 102 to 110 below)

Here, typical ones of the above patent documents will be described.
The invention described in Japanese Patent Application Laid-Open No. 8-295811 (Patent Document 38 below) finally has an optical property that has high sensitivity and excellent recording / reproducing characteristics, and is particularly excellent in light resistance and storage stability. The object is to provide a recording medium. The structure is first related to a metal chelate compound of an azo compound and a metal represented by a predetermined general formula, and secondly, information can be written and / or read by laser light on a substrate. An optical recording medium provided with a simple recording layer, wherein the recording layer contains the metal chelate compound.

  The inventions described in Japanese Patent Application Laid-Open No. 10-86519 (the following Patent Document 60) and Japanese Patent Application Laid-Open No. 10-181206 (the following Patent Document 69) provide an optical recording medium excellent in light resistance and storage stability. In the constitution, at least one kind of azo metal chelate compound represented by a predetermined general formula is contained in the recording layer, or an organic compound having the maximum absorption wavelength at 680 to 750 nm with the azo metal chelate compound. It is characterized in that a dye is contained in the recording layer.

  The invention described in Japanese Patent Application Laid-Open No. 11-166125 (the following Patent Document 82) relates to a metal chelate compound and an optical recording medium using the compound. The structure is first a metal chelate compound obtained from an azo compound represented by a predetermined general formula and a metal salt (a metal constituting this is, for example, Ni, Co or Cu). . Second, in an optical recording medium in which a recording layer capable of writing and / or reading information with a light beam is provided on a transparent substrate, the recording layer contains the metal chelate compound. It is a recording medium.

JP-A-57-82093 JP 58-56892 A JP 58-1212790 A JP-A-58-114989 JP 59-85791 A JP 60-83236 A JP 60-89842 A Japanese Patent Laid-Open No. 61-25886 JP-A 61-150243 JP-A 61-177287

JP 61-154888 A JP 61-24609 A JP-A-62-39286 JP 63-37991 A JP 63-39888 A JP-A-1-159842 Japanese Patent Laid-Open No. 2-42652 JP-A-2-13656 Japanese Patent Laid-Open No. 2-168446 JP-A-1-176585

Japanese Patent Laid-Open No. 3-215466 JP-A-4-113886 JP-A-4-226390 Japanese Patent Laid-Open No. 5-1272 JP-A-5-171052 Japanese Patent Laid-Open No. 5-116456 Japanese Patent Application Laid-Open No. 5-96860 Japanese Patent Laid-Open No. 5-139044 JP-A-4-46186 Japanese Patent Laid-Open No. 4-141490

Japanese Patent Laid-Open No. 4-361108 JP-A-5-279580 JP-A-7-51673 Japanese Patent Application Laid-Open No. 7-161069 Japanese Unexamined Patent Publication No. 7-37272 JP 7-71867 A JP-A-8-231866 JP-A-8-295811 ISOM / ODS '96: High density of recording on Dye material Disc approach for 4.7G JP-A-10-235999 JP-A-8-198872

Japanese Patent Laid-Open No. 8-209002 JP-A-8-283263 JP-A-10-273484 Japanese Examined Patent Publication No. 5-67438 Japanese Patent Application Laid-Open No. 7-161069 JP-A-8-156408 JP-A-8-231866 JP-A-8-332772 JP-A-9-58123 JP-A-9-175031

JP-A-9-193545 JP-A-9-274732 JP-A-9-277703 Japanese Patent Laid-Open No. 10-6644 Japanese Patent Laid-Open No. 10-6650 Japanese Patent Laid-Open No. 10-6651 JP 10-36693 A JP-A-10-44606 JP-A-10-58828 Japanese Patent Laid-Open No. 10-86519

Japanese Patent Laid-Open No. 10-149484 JP 10-157293 A JP-A-10-157300 JP-A-10-157301 JP-A-10-157302 JP-A-10-181199 Japanese Patent Laid-Open No. 10-18201 Japanese Patent Laid-Open No. 10-181203 JP-A-10-181206 Japanese Patent Laid-Open No. 10-188340

JP-A-10-188341 Japanese Patent Laid-Open No. 10-188358 JP-A-10-208303 Japanese Patent Laid-Open No. 10-214423 JP-A-10-228671 JP 10-36693 A Japanese Patent Laid-Open No. 11-12483 JP 11-28865 A Japanese Patent Laid-Open No. 11-42858 Japanese Patent Laid-Open No. 11-102537

JP-A-11-116834 JP 11-166125 A Japanese Patent Laid-Open No. 11-120616 JP-A-11-130970 JP 11-138999 A JP-A-11-134708 JP 11-138999 A Japanese Patent Laid-Open No. 11-151861 Japanese Patent Laid-Open No. 11-151862 JP-A-11-208111

JP-A-11-213442 JP 2000-36129 A Japanese Patent Laid-Open No. 10-86517 Japanese Patent Laid-Open No. 10-93788 JP-A-10-226172 Japanese Patent Laid-Open No. 10-247452 Japanese Patent Laid-Open No. 10-287819 JP-A-10-297103 Japanese Patent Laid-Open No. 10-309871 JP 10-309872 A

JP 11-129624 A Japanese Patent No. 2791944 JP-A-8-295079 JP 9-193546 A JP-A-10-152623 JP-A-10-154350 JP-A-10-337958 Japanese Patent Laid-Open No. 2001-23235 JP 2002-11950 A JP 2002-11953 A

However, the fact is that a recording material corresponding to high-speed writing has not been developed yet. The present invention has been made in view of the above circumstances of the prior art. A novel azo-substituted quinoline compound, a recording material in an optical recording medium in a write-once DVD disc system compatible with high-speed writing, and an optical recording using this recording material The purpose is to provide each medium.
The object of the invention is as follows for each claim.

Claims 1-2 : To provide a novel azo-substituted quinoline compound.
Claims 3 to 5 : To provide a chelate compound (azo metal chelate compound, the same shall apply hereinafter) comprising the novel azo-substituted quinoline compound and a divalent metal salt.
Claims 6 to 8: To provide an optical recording medium having a recording layer formed using the chelate compound. In particular, an object of claim 8 is to provide an optical recording medium high refractive index is obtained. The object of the inventions of Reference Examples 12 to 14 shown below as reference examples is to provide an optical recording medium capable of performing high density recording with low jitter, and the object of the invention of Reference Example 15 is In other words, the track pitch and guide groove dimensions of a write-once DVD media substrate in which a recording layer is formed using the chelate compound are presented.

  As a result of various investigations, the present inventors have obtained an optical recording medium applicable to a write-once DVD disc system compatible with high-speed writing by providing a recording layer mainly composed of an organic dye having a specific structure. As a result, the present invention has been completed.

  The invention according to claim 1 is an azo-substituted quinoline compound represented by the following general formula (1).

In the general formula (1), R _{1 to} R ₈ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxy group, an amino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group. Group, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylamino group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylcarbonylamino group, substituted or An unsubstituted arylcarbonylamino group, a carbamoyl group, a substituted or unsubstituted alkylcarbamoyl group, a substituted or unsubstituted arylcarbamoyl group, an alkylsulfonylamino group, and an arylsulfonylamino group are represented.
R ₁ and R ₂ , R ₃ and R ₄ , R ₄ and R ₅ , R ₅ and R ₆ , R ₆ and R ₇ , and R ₇ and R ₈ may be linked to form a ring. .
Particularly preferable in the general formula (1) is that R ₁ , R ₄ , R ₆ and R ₈ are hydrogen atoms, R ₂ is a cyano group, R ₃ and R ₅ are each independently a hydrogen atom or an alkyl group, and R ₇ is It represents a hydrogen atom, a halogen atom or an alkyloxy group.

  Specific examples of the halogen atom include fluorine, chlorine, bromine, iodine and the like.

  Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, Primary alkyl group such as n-decyl group, isobutyl group, isoamyl group, 2-methylbutyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2-ethylbutyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2-ethylpentyl group, 3-ethylpentyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5- Methylheptyl group, 2-ethylhexyl group, 3-ethylhexyl group, isopropyl group, sec-butyl group, 1-ethylpropyl group, 1-methylbutyl group, 1,2-dimethylpropyl group, 1-methylheptyl group, 1-ethylbutyl Group, 1,3-dimethylbutyl group 1,2-dimethylbutyl group, 1-ethyl-2-methylpropyl group, 1-methylhexyl group, 1-ethylheptyl group, 1-propylbutyl group, 1-isopropyl-2-methylpropyl group, 1-ethyl 2-methylbutyl group, 1-ethyl-2-methylbutyl group, 1-propyl-2-methylpropyl group, 1-methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, 1- Secondary alkyl groups such as isopropyl-2-methylbutyl group, 1-isopropyl-3-methylbutyl group, 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-isobutyl-3-methylbutyl group, neopentyl Group, tertiary alkyl group such as tert-butyl group, tert-hexyl group, tert-amyl group, tert-octyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group ,Four- Examples thereof include cycloalkyl groups such as (2-ethylhexyl) cyclohexyl group, bornyl group, and isobornyl group (adamantane group).

  These primary and secondary alkyl groups may be substituted with a hydroxyl group, a halogen atom, a nitro group, a carboxy group, a cyano group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic residue, and the like. In addition, the alkyl group may be substituted with an atom such as oxygen, sulfur or nitrogen.

Examples of the alkyl group substituted through oxygen include a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, a butoxyethyl group, an ethoxyethoxyethyl group, a phenoxyethyl group, a methoxypropyl group, and an ethoxypropyl group. Groups, piperidino groups, morpholino groups, etc .;
Examples of the alkyl group substituted through sulfur include a methylthioethyl group, an ethylthioethyl group, an ethylthiopropyl group, and a phenylthioethyl group;
Examples of the alkyl group substituted through nitrogen include a dimethylaminoethyl group, a diethylaminoethyl group, and a diethylaminopropyl group.

  Specific examples of the heterocyclic residue include indolyl group, furyl group, thienyl group, pyridyl group, piperidyl group, quinolyl group, isoquinolyl group, piperidino group, morpholino group, pyrrolyl group and the like.

  Specific examples of the aryl group include a phenyl group, a pentarenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, and a pyrenyl group.

Specific examples of the alkyloxy group may be those in which a substituted or unsubstituted alkyl group is bonded directly to an oxygen atom, and specific examples of the alkyl group may include the above-described specific examples.
Specific examples of the aryloxy group are not particularly limited as long as a directly substituted or unsubstituted aryl group is bonded to an oxygen atom, and specific examples of the aryl group include the above-described specific examples.
Specific examples of the alkylamino group are not particularly limited as long as a directly substituted or unsubstituted alkyl group is bonded to a nitrogen atom, and specific examples of the alkyl group include the above-described specific examples.
Specific examples of the arylamino group are not particularly limited as long as a directly substituted or unsubstituted aryl group is bonded to a nitrogen atom. Specific examples of the aryl group include the specific examples described above.
Specific examples of the alkylcarbonylamino group may be those in which a directly substituted or unsubstituted alkyl group is bonded to a carbon atom of the carbonylamino group. Specific examples of the alkyl group include the above-described specific examples. be able to.
Specific examples of the arylcarbonylamino group may be those in which a directly or unsubstituted aryl group is bonded to a carbon atom of the carbonylamino group, and specific examples of the aryl group include the specific examples described above. Can do.

Specific examples of the alkylcarbamoyl group may be those in which a hydrogen atom or a substituted or unsubstituted alkyl group is directly and independently bonded to the nitrogen atom of the carbamoyl group. Specific examples of the alkyl group include those described above. Specific examples can be given.
Specific examples of the arylcarbamoyl group may be those in which a hydrogen atom or a substituted or unsubstituted aryl group is directly and independently bonded to the nitrogen atom of the carbamoyl group. Specific examples of the aryl group include those described above. Specific examples can be given.
Specific examples of the alkylsulfonylamino group are not particularly limited as long as a directly substituted or unsubstituted alkyl group is bonded to a sulfur atom, and specific examples of the alkyl group include the above-described specific examples.
Specific examples of the arylsulfonylamino group are not particularly limited as long as a directly substituted or unsubstituted aryl group is bonded to a sulfur atom. Specific examples of the aryl include the above-described specific examples.

  The invention according to claim 2 is an azo-substituted quinoline compound represented by the following general formula (2).

The compound represented by the above general formula (2) having a structure in which R ₆ in the above general formula (1) is substituted with an amino group represented by NR ₁₆ R ₁₇ is a simple and inexpensive synthesis of the target azo-substituted quinoline compound. It is important to do. Further, a metal chelate of a compound in which R ₆ is substituted with an amino group represented by NR ₁₆ R ₁₇ has an effect of greatly improving optical characteristics required for use in a write-once DVD system. In particular, the effect of increasing the refractive index n at the DVD recording wavelength was recognized.

In the general formula (2), R _{9 to} R ₁₅ are each independently a hydrogen atom, halogen atom, nitro group, cyano group, hydroxyl group, carboxy group, amino group, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl. Group, substituted or unsubstituted alkyloxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylamino group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylcarbonylamino group, substituted or Represents an unsubstituted arylcarbonylamino group, a carbamoyl group, a substituted or unsubstituted alkylcarbamoyl group, a substituted or unsubstituted arylcarbamoyl group, an alkylsulfonylamino group, an arylsulfonylamino group, and R ₁₆ and R ₁₇ are each independently Hydrogen atom, substituted or unsubstituted alkyl Group, a substituted or unsubstituted aryl group.
R ₉ and R ₁₀ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₃ , R ₁₃ and R ₁₆ , R ₁₆ and R ₁₇ , R ₁₄ and R ₁₇ , R ₁₄ and R ₁₅ are linked to form a ring. It may be formed.
Particularly preferred in the general formula (2) is that R ₉ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ are hydrogen atoms, R ₁₀ is a cyano group, R ₁₆ and R ₁₇ are independently hydrogen atoms, It represents a halogen atom, a benzyl group, or a trifluoromethyl-substituted benzyl group.

  Specific examples of the substituent are the same as those described above (according to the invention of claim 1).

In the present invention, in a range that does not overlap with the azo-substituted quinoline compounds represented by the above general formula (2), an azo-substituted quinoline compound represented by the following general formula (3).

In the general formula (3), R ₁₆ and R ₁₇ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R ₁₈ is a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxy group, an amino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, substituted at any position of the quinoline ring, A substituted or unsubstituted alkyloxy group or a substituted or unsubstituted aryloxy group is represented.
Specific examples of the substituent are the same as those described above (according to the invention of claim 1).

The invention according to claim 3 is a chelate compound comprising the azo-substituted quinoline compound represented by the general formula (1) and a divalent metal salt.
The invention according to claim 4 is a chelate compound comprising the azo-substituted quinoline compound represented by the general formula (2) and a divalent metal salt.
In the present invention, in a range that does not overlap with the azo-substituted quinoline compounds represented by the above general formula (2), and azo substituted quinoline compounds represented by the above following general formula (3), and a divalent metal salt The chelate compound which consists of is mentioned .

The invention according to claim 5 is the chelate compound according to any one of claims 3 to 4 , wherein the metal atom forming the divalent metal salt is nickel or copper.

The invention according to claim 6 is an optical recording medium in which a recording layer is provided on a substrate, wherein the recording layer contains at least one chelate compound according to claim 3. .
The invention according to claim 7 is an optical recording medium in which a recording layer is provided on a substrate, wherein the recording layer contains at least one chelate compound according to claim 4. .
The invention according to claim 8 is an optical recording medium in which a recording layer is provided on a substrate, wherein the recording layer contains at least one chelate compound according to claim 5. .

Invention of Reference Example 12, the optical recording medium according to any one of claims 6-8, the refractive index n is 1.5 ≦ n ≦ the single recording layer for light having a wavelength region of record reproduction wavelength ± 10 nm 3.0 and the extinction coefficient k is 0.02 ≦ k ≦ 0.2 .
The invention of Reference Example 13 is the optical recording medium according to any one of claims 6 to 8 and Reference Example 12, wherein the chelate compound has a weight loss gradient of 2% / with respect to temperature in the main weight loss process in thermogravimetric analysis. It is characterized by being at or above ° C.
Invention of Example 14, claims 6 to 8, in the optical recording medium according to any of Reference Example 12 and 13, before Symbol chelate compound, the total weight reduction in the main weight reduction process in the thermogravimetric analysis 30% or more And the weight loss starting temperature is 350 ° C. or lower .

The invention of Example 15, in the optical recording medium according to any one of claims 6-8, Reference Examples 12 to 14, the track pitch on the base plate is 0.7～0.8Myuemu, groove width half The value range is 0.18 to 0.36 μm .

The azo-substituted quinoline compound according to claims 1 and 2 easily forms a chelate compound by acting with a divalent metal salt or the like. These chelate compounds have been found to have physical properties that can be used as recording materials for write-once DVDs and can accommodate high linear velocity recording.

According to the present invention, the following effects can be obtained.
According to the first and second aspects of the invention, a novel azo-substituted quinoline compound can be provided. In particular, the invention of claim 2 can provide an azo-substituted quinoline compound that can be synthesized inexpensively and easily and has excellent optical properties. Further, according to the invention of claim 2, an azo-substituted quinoline compound having excellent thermal decomposition behavior can be provided.

According to the inventions of claims 3 to 5 , it is possible to provide an azo-substituted quinoline chelate compound that can be used as a recording material for a write-once DVD system. These azo metal chelate compounds have been found to have physical properties that can be used as recording materials for write-once DVDs and that can handle high linear velocity recording.

According to the inventions of claims 6 to 8 , it is possible to provide an optical recording medium which can be recorded and reproduced with a laser beam having a wavelength region of 690 nm or less and is excellent in light resistance and storage stability. In particular, the invention of claim 8 can provide an optical recording medium capable of stable recording and reproduction with a high reflectance and a high degree of modulation.
According to the inventions of Reference Examples 12 to 14, it was possible to provide an optical recording medium capable of recording high density with low jitter.
According to the invention of Reference Example 15, an optical recording medium capable of stable recording and reproduction could be provided.

  Embodiments of the present invention will be described below.

[Regarding the layer structure of optical recording media]
According to the present invention, for example, an optical recording medium having the structure shown in FIGS. 1 to 3 is provided. In other words, FIGS. 1A to 1D are schematic cross-sectional views showing a laminated structure of a normal write-once type optical recording medium. In this case, a so-called air sandwich in which two optical recording media are bonded together, or a close bonding structure may be used. 2A to 2C are schematic cross-sectional views showing a laminated structure of an optical recording medium for CD-R. 3A to 3C are schematic cross-sectional views showing a laminated structure of an optical recording medium for DVD-R.

  1-3, 1 is a substrate, 2 is a recording layer, 3 is an undercoat layer, 4 is a protective layer, 5 is a hard coat layer, 6 is a metal reflective layer, and 7 is a protective substrate. , 8 is an adhesive layer. A preferable configuration of the optical recording medium according to the present invention is basically a structure in which the first substrate and the second substrate are bonded with an adhesive via a recording layer. The recording layer may be a single organic dye layer, or a laminate of an organic dye layer and a metal reflective layer in order to increase the reflectance. The most typical one is a structure comprising a first substrate / organic dye layer / metal reflective layer / protective layer / adhesive layer / second substrate, which can be shown in FIG. 3 (b).

  In order to produce the chelate compound according to the present invention, the azo-substituted quinoline compound shown in claims 1 to 3 and a divalent metal salt are added to a solvent such as alcohol, DMF, or glycerin. In some cases, an alkali component such as sodium hydroxide solution or aqueous ammonia is added, or the mixture is heated to a temperature ranging from room temperature to the boiling point of the solvent.

  Specific examples of the divalent metal atom include manganese, iron, cobalt, nickel, copper, and zinc. Particularly, a chelate compound of nickel or copper is excellent in optical characteristics such as light resistance and refractive index as an optical recording material.

  Next, regarding the configuration of the optical recording medium of the present invention, optical characteristics and thermal characteristics are listed as items necessary for configuring the recording layer. The necessary condition for the optical characteristics is that the recording / reproducing wavelength has a large absorption band on the short wavelength side with respect to 630 nm to 690 nm, and the recording / reproducing wavelength is in the vicinity of the long wavelength end of the absorption band. This means that it has a large refractive index and extinction coefficient at a recording / reproducing wavelength of 630 nm to 690 nm.

  Specifically, the refractive index n of the single recording layer with respect to light in the wavelength range near the long wavelength near the recording / reproducing wavelength is 1.5 or more and 3.0 or less, and the extinction coefficient k is 0.02 or more and 0.2. It is preferable to be in the following range. When n is less than 1.5, it is difficult to obtain a sufficient optical change and the recording modulation degree is lowered, which is not preferable. When n is more than 3.0, the wavelength dependency becomes too high. Even in the recording / reproducing wavelength region, an error occurs, which is not preferable. Further, when k is less than 0.02, it is not preferable because the recording sensitivity is deteriorated, and when k exceeds 0.2, it is difficult to obtain a reflectance of 50% or more.

  Thermally necessary conditions are that weight loss in the main weight loss process in thermogravimetric analysis is steep with respect to temperature. This is because the organic material film is decomposed by the main weight reduction process, causing a decrease in film thickness and a change in optical constant, thereby forming a recording portion in an optical sense. Accordingly, when the weight loss in the main weight loss process is moderate with respect to the temperature, this is formed over a wide temperature range, which is extremely disadvantageous when forming a high-density recording portion. For the same reason, when a material having a plurality of weight loss processes is used, it is disadvantageous for high density.

  In the present specification, among several weight loss processes, the one with the largest weight loss rate is called a main weight loss process. The slope of weight loss is determined as follows.

  As shown in FIG. 4, the organic material having a weight of m0 is heated at 10 ° C./min in a nitrogen atmosphere. As the temperature rises, the weight of the organic material decreases by a small amount, indicating a weight loss line (almost straight line ab). When a certain temperature is reached, the organic material undergoes a rapid weight loss, causing a weight loss substantially along a straight line cd. This is the main weight loss process. If the temperature is further raised, the rapid weight loss ends, and the weight is reduced substantially along the straight line ef.

Now, the temperature at the intersection of the straight line ab and the straight line cd is T1 (° C.), the residual weight loss rate with respect to the initial weight m0 is m1 (%), and the temperature at the intersection of the straight line cd and the straight line ef Is T2 (° C.), and the residual weight loss rate with respect to the initial weight m0 is m2 (%). The rapid weight loss start temperature is T1, the rapid weight loss end temperature is T2, and the slope of weight loss when rapid weight loss is manifested is:
(M1-m2) (%) / (T2-T1) (° C.)
The weight loss rate with respect to the initial weight is represented by (m1-m2) (%). In FIG. 4, “TG%” represents the weight loss rate of the organic compound to be measured. The weight m0 of the organic compound before the temperature rise is expressed as 100%, and the state where there is no substance in the measuring instrument is 0%.

  Based on the above definition, the recording material used for the optical recording medium preferably has a weight loss gradient of 2% / ° C. or more in the main weight loss process. If a recording material having a weight loss gradient of less than 2% / ° C. is used, the recording area becomes large and it becomes difficult to form a short recording area, which is not suitable for an optical recording medium.

  Further, the weight reduction rate in the main weight loss process is preferably 30% or more. If it is less than 30%, a good recording modulation degree and recording sensitivity may not be obtained. Further, the necessary condition for the thermal characteristics is that the weight loss starting temperature T1 is in a certain temperature range. Specifically, the weight loss starting temperature is 350 ° C. or lower, and it is desirable that it is in the range of 200 to 350 ° C. If the weight loss starting temperature exceeds 350 ° C., the required recording laser light power becomes high and is not practical, and if it is less than 200 ° C., the recording stability deteriorates, such as causing deterioration in reproduction.

  The necessary conditions for the substrate shape are that the track pitch on the substrate is 0.7 to 0.8 μm, the groove width is a half width, and is in the range of 0.18 to 0.36 μm. The substrate usually has guide grooves with a depth of 1000 to 2500 mm. The track pitch is usually 0.7 to 1.0 μm, but 0.7 to 0.8 μm is preferable for high capacity use. The groove width is preferably a full width at half maximum of 0.18 to 0.36 μm. If it is less than 0.18 μm, it may be difficult to obtain a sufficient tracking error signal intensity. On the other hand, if it exceeds 0.36 μm, the recording part tends to spread laterally when recording is not preferable.

[Required characteristics of each layer and examples of constituent materials]
<Board>
The necessary characteristic of the substrate is that it is transparent to the laser beam used only when recording / reproducing is performed from the substrate side, and the substrate is not necessarily transparent when recording / reproducing is performed from the recording layer side.

  As the substrate material, for example, plastic such as polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, polyimide, glass, ceramic, metal, or the like can be used. When only one layer is used, or when two substrates are used in a sandwich shape, a tracking guide groove or guide pit and a preformat such as an address signal are formed on the surface of the first substrate. There is a need.

<Intermediate layer>
A layer provided other than the substrate, the recording layer, the reflective layer, and the protective layer including the undercoat layer is referred to as an intermediate layer herein. This intermediate layer has (a) improved adhesion, (b) a barrier such as water or gas, (c) improved storage stability of the recording layer, (d) improved reflectivity, (e) a substrate from a solvent. And (f) formation of guide grooves, guide pits, preformats, and the like.

For the purpose of (a) above, polymeric materials such as ionomer resins, polyamide resins, vinyl resins, natural resins, natural polymers, silicone resins, liquid rubbers, and various polymeric substances, and silane coupling agents Etc. can be used. For the purposes (b) and (c) above, other than the polymer material, inorganic compounds such as SiO ₂ , MgF ₂ , SiO, TiO ₂ , ZnO, TiN, SiN, etc., metals or semimetals such as Zn, Cu, Ni, Cr, Ge, Se, Au, Ag, Al, or the like can be used. For the purpose of (d), metals such as Al and Ag, and organic thin films having metallic luster such as methine dyes and xanthene dyes can be used. For the purposes (e) and (f), an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used.
The thickness of the undercoat layer is 0.01 to 30 μm, preferably 0.05 to 10 μm.

<Recording layer>
The recording layer is capable of causing some optical change upon irradiation with laser light and recording information by the change. The organic dye of the present invention (hereinafter sometimes referred to as a dye) is contained in this recording layer. That is, it is necessary that a chelate compound comprising a predetermined azo-substituted quinoline compound and a divalent metal salt is contained, but in forming the recording layer, one or more of the dyes of the present invention are used. May be used in combination. Furthermore, the dye of the present invention may be used by mixing or laminating with other organic dyes, metals or metal compounds for the purpose of improving optical characteristics, recording sensitivity, signal characteristics and the like.

  Specific examples of the above-mentioned other organic dyes include polymethine dyes, naphthalocyanine series, phthalocyanine series, squarylium series, croconium series, pyrylium series, naphthoquinone series, anthrequinone (indanthrene) series, xanthene series, triphenylmethane series , Azulene-based, tetrehydrocholine-based, phenanthrene-based, triphenothiazine-based dyes, metal chelate compounds, and the like. It can also be used in combination.

Examples of the metal or metal compound for forming the recording layer by laminating the layer made of the dye of the present invention include In, Te, Bi, Se, Sb, Ge, Sn, Al, Be, TeO ₂ , SnO, Examples include As and Cd. These substances may form an alloy. Furthermore, various materials such as ionomer resins, polyamide resins, vinyl resins, natural polymers, silicone resins, liquid rubber, or silane coupling agents are dispersed and mixed in the dye of the present invention. May be. Alternatively, for the purpose of improving the characteristics, a recording layer can be formed by using a stabilizer (for example, a transition metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer and the like in combination.

  The recording layer can be formed by ordinary means such as vapor deposition, sputtering, CVD or solution coating. In the case of using a coating method, the dye is dissolved in an organic solvent or the like, and a conventional coating method such as spraying, roller coating, dipping, or spin coating is performed.

Examples of the organic solvent generally include alcohols such as methanol, ethanol and isopropanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; amides such as N, N-dimethylformamide and N, N-dimethylacetamide; sulfoxides such as dimethyl sulfoxide Ethers such as tetrahydrofuran, dioxane, diethyl ether and ethylene glycol monomethyl ether; esters such as methyl acetate and ethyl acetate; aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride and trichloroethane; or Aromatics such as benzene, xylene, monochlorobenzene and dichlorobenzene; cellosolves such as methoxyethanol and ethoxyethanol; hexane, pentane, cyclohexane, Hydrocarbons such as tilcyclohexane can be used.
The thickness of the recording layer is 100 to 10 μm, preferably 200 to 2000 μm.

<Metal reflective layer>
Examples of the material for forming the metal reflective layer include metals, semi-metals, and the like, which can obtain high reflectivity by themselves and are not easily corroded. Specific examples include Au, Ag, Cr, Ni, Al, Fe, Sn, and the like. However, Au, Ag, and Al are most preferable from the viewpoint of reflectivity and productivity, and these metals and metalloids may be used alone or as two kinds of alloys.

  Examples of the method for forming the metal reflective layer include vapor deposition and sputtering, and the film thickness is 50 to 5000 mm, preferably 100 to 3000 mm.

<Protective layer, substrate surface hard coat layer>
The protective layer and the substrate surface hard coat layer (a) protect the recording layer (reflection / absorption layer) from scratches, dust, dirt, etc. (b) improve the storage stability of the recording layer (reflection / absorption layer), (c ) Used for the purpose of improving the reflectance.

For these purposes, the materials shown for the intermediate layer can be used. Also, SiO, SiO ₂ or the like can be used as the inorganic material. In addition, polymethyl acrylate, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, natural rubber, styrene butadiene resin, chloroprene rubber, wax, alkyd resin as organic materials Also, heat softening and heat melting resins such as drying oil and rosin can be used.

  Among the materials described above, the most preferable example for the protective layer or the substrate surface hard coat layer is an ultraviolet curable resin excellent in productivity. The film thickness of the protective layer or the substrate surface hard coat layer is 0.01 to 30 μm, preferably 0.05 to 10 μm. In the present invention, the intermediate layer (undercoat layer), the protective layer, and the substrate surface hard coat layer have the same stabilizers, dispersants, flame retardants, lubricants, antistatic agents, surfactants as in the recording layer. A plasticizer or the like can be contained.

Examples are shown below, but the present invention is not limited to these examples.
In addition, examples of the azo-substituted quinoline compound according to the present invention include compounds A-1 to A-8 represented by the following chemical formulas, respectively. Here, synthesis examples of compounds A-1 to A-4 are included. Indicates.

Example 1 (Synthesis Example 1 of an azo-substituted quinoline compound)
An aqueous hydrochloric acid solution (3-fold molar ratio) of 3-amino-4-cyanopyrazole (1.08 g) was maintained at a temperature of 0 ° C., and a nitrous acid aqueous solution having a 1.1-fold molar ratio was added dropwise thereto for diazotization. . After confirming nitrite positive with iodine starch paper, stirring was continued for 1 hour. Excess nitrous acid was decomposed with amidosulfuric acid, and negative was confirmed with iodine starch paper. To this solution, a cooled saturated solution of zinc chloride was added dropwise. The precipitated zinc chloride of diazonium salt was collected by filtration and air-dried. Next, Grignard reagent was prepared by reacting 1.07 g of 8-chloroquinoline and 0.16 g of magnesium pieces in dry ether. The zinc chloride adduct of the diazonium salt obtained previously was put into ether, and the above Grignard reagent was allowed to act on this. After completion of the reaction, dilute hydrochloric acid and then water were added, and the ether layer was extracted. After distilling off ether, the crude product was recrystallized from ethanol to obtain 0.65 g of the desired compound A-1 represented by the above chemical formula.

The results of elemental analysis of Compound A-1 are as follows.
Carbon C: measured value is 62.71%, calculated value is 62.90%
Hydrogen H: measured value 3.49%, calculated value 3.25%
Nitrogen N: measured value is 33.80%, calculated value is 33.58%

Example 2 (Synthesis Example 2 of an azo-substituted quinoline compound)
1.08 g of 3-amino-4-cyanopyrazole was dissolved in heated glacial acetic acid. After cooling the solution to room temperature, 1.88 g of 6-methoxy-8-nitrosoquinoline was added and allowed to act. After stirring for 1 day, the precipitated crude product was collected by filtration. The crude product was recrystallized from ethanol to obtain 1.14 g of the target compound A-2 represented by the above chemical formula.

The results of elemental analysis of Compound A-2 are as follows.
Carbon C: measured value is 60.33%, calculated value is 60.3%
Hydrogen H: measured value is 3.57%, calculated value is 3.62%
Nitrogen N: measured value is 30.42%, calculated value is 30.20%

Example 3 (Synthesis example 3 of azo-substituted quinoline compound)
An acidic aqueous solution (3-fold molar ratio) of 3-amino-4-cyanopyrazole (1.08 g) was kept at 0 ° C., and a 1.1-fold molar ratio of nitrous acid aqueous solution was added dropwise thereto for diazotization. Excess nitrous acid was decomposed with amidosulfuric acid to prepare a diazo solution. Next, 1.44 g of 5-aminoquinoline was dissolved in ethanol, and the above diazo solution was added thereto to act. The precipitated crude crystals were collected by filtration and recrystallized from ethanol to obtain 2.06 g of the target compound A-3 represented by the above chemical formula.

The results of elemental analysis of Compound A-3 are as follows.
Carbon C: measured value is 59.19%, calculated value is 59.31%
Hydrogen H: measured value is 3.32%, calculated value is 3.45%
Nitrogen N: measured value is 37.37%, calculated value is 37.24%

Example 4 (Synthesis example 4 of azo-substituted quinoline compound)
After adding 1.44 g of 5-aminoquinoline and 1.06 g of benzaldehyde to an acetic acid-sodium acetate aqueous solution, a 1.5 times molar ratio sodium cyanoborohydride aqueous solution was allowed to act while maintaining the temperature below 0 ° C. Got. Next, 1.08 g of 3-amino-4-cyanopyrazole hydrochloric acid aqueous solution (3 times molar ratio) is kept at 0 ° C., and 1.1 times molar ratio of nitrous acid aqueous solution is added dropwise to diazotize. went. Excess nitrous acid was decomposed with amidosulfuric acid to prepare a diazo solution. The above diazo solution was added to the ethanol solution of the coupler synthesized earlier and allowed to act. The precipitated crude crystals were collected by filtration and recrystallized from ethanol to obtain 3.10 g of the target compound A-4 represented by the above chemical formula.

The results of elemental analysis of Compound A-4 are as follows.
Carbon C: measured value is 68.02%, calculated value is 67.98%
Hydrogen H: measured value is 4.07%, calculated value is 4.28%
Nitrogen N: measured value 27.91%, calculated value 27.75%

  Next, examples of the chelate compound comprising the azo-substituted quinoline compound and the divalent metal salt according to the present invention include compounds C-1 to C-14 represented by the following chemical formulas, respectively, Among them, synthesis examples of compounds C-1 and C-2 are shown.

Example 5 (Synthesis Example 1 of a chelate compound comprising an azo-substituted quinoline compound and a divalent metal salt)
1.88 g of compound A-5 represented by the above chemical formula was dissolved in ethanol, and a dilute aqueous sodium hydroxide solution was added to make the reaction system weakly basic. To this solution, an ethanol solution of 0.62 g of nickel acetate (II) tetrahydrate was added, the temperature was raised to 60 ° C., and the mixture was stirred for 1 hour. The reaction solution was concentrated and dried, washed with water, and recrystallized from MEK to obtain 1.67 g of the target compound C-1 represented by the above chemical formula.

The results of elemental analysis of Compound C-1 are as follows.
Carbon C: measured value is 62.39%, calculated value is 62.46%
Hydrogen H: measured value is 5.94%, calculated value is 5.99%
Nitrogen N: measured value is 24.40%, calculated value is 24.28%

Example 6 (Synthesis Example 2 of a chelate compound comprising an azo-substituted quinoline compound and a divalent metal salt)
2.90 g of compound A-6 represented by the above chemical formula and 0.50 g of copper (II) acetate monohydrate were suspended in DMF (dimethylformamide). This was heated up to 100 degreeC and stirred for 1 hour. The reaction solution was poured into water, and the precipitated crude product was recrystallized from MEK (methyl ethyl ketone) to obtain 2.64 g of the target compound C-2 represented by the above chemical formula.

The results of elemental analysis of Compound C-2 are as follows.
Carbon C: measured value is 57.02%, calculated value is 57.08%
Hydrogen H: measured value is 3.13%, calculated value is 3.14%
Nitrogen N: measured value is 16.14%, calculated value is 16.07%

Next, an example of producing an optical recording medium using a chelate compound comprising the azo-substituted quinoline compound according to the present invention and a divalent metal salt as a recording layer material will be described.
Example 7 (Production Example 1 of optical recording medium)
A guide groove having a depth of 1750 mm, a half width of 0.25 μm, and a track pitch of 0.74 μm is formed on an injection-molded polycarbonate substrate having a thickness of 0.6 mm. A solution dissolved in 2-tetrafluoropropanol was applied with a spinner to form a recording layer having a thickness of 900 mm. Next, a gold 1200 mm reflective layer is formed by sputtering, and a protective layer of 7 μm is formed thereon with an acrylic photopolymer, and then an injection-molded polycarbonate flat substrate having a thickness of 0.6 mm is bonded with the acrylic photopolymer. Thus, an optical recording medium was obtained.

Examples 8 to 20 (Production Examples 2 to 14 of an optical recording medium)
An optical recording medium was produced in exactly the same manner as in Example 7 except that each of the above compounds C-2 to C-14 was used alone in place of the above compound C-1.

<Recording / playback test>
Each optical recording medium manufactured as described above uses a semiconductor laser beam having a laser oscillation wavelength of 658 nm and a beam diameter of 1.0 μm to record an EFM signal (linear speed: 14 m / sec) while tracking, and a semiconductor having an oscillation wavelength of 670 nm. Reproduction was performed with continuous laser light (reproduction power 0.7 mW), and the reproduction waveform was observed.

Further, a weather resistance test and a storage test were performed on the above optical recording media under the following conditions.
<Weather resistance test and storage test>
Light resistance test condition: 50,000 LuX, Xe light, continuous irradiation for 20 hours Storage test condition: left at 60 ° C. and 90% RH for 600 hours

<Evaluation results>
The results of the recording / reproduction test, light resistance test and storage test are shown in Table 1 below.

It is a figure which shows the example of a layer structure of a normal write-once type optical recording medium, (a) is the basic composition which consists of a board | substrate and a recording layer, (b) is the structure which provided the undercoat layer between the board | substrate and the recording layer. (C) shows a configuration in which a protective layer is further provided on the recording layer, and (d) shows a configuration in which a hard coat layer is further provided on the back surface of the substrate. It is a figure which shows the layer structural example of the optical recording medium for CD-R, (a) is what provided the recording layer, the metal reflection layer, and the protective layer in order on the board | substrate, (b) is further a board | substrate and a recording layer. (C) shows the structure which provided the hard-coat layer in the back surface of the board | substrate further, respectively. It is a figure which shows the layer structural example of the optical recording medium for DVD-R, (a) is what provided the recording layer, the metal reflective layer, and the protective layer in order on the board | substrate, (b) is further on a protective layer. (C) shows a configuration in which a subbing layer is further provided between the substrate and the recording layer, and a hard coat layer is provided on the back surface of the substrate. It is explanatory drawing of the method of calculating | requiring the main weight loss process and weight loss rate of an organic material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Recording layer 3 ... Undercoat layer 4 ... Protective layer 5 ... Hard coat layer 6 ... Metal reflective layer 7 ... Protective substrate 8 ... Adhesive layer

Claims (8)

An azo-substituted quinoline compound represented by the following general formula (1):

(In General Formula (1), R ₁ , R ₄ , R ₆ and R ₈ are hydrogen atoms, R ₂ is a cyano group, R ₃ and R ₅ are each independently a hydrogen atom or an alkyl group, R ₇ is a hydrogen atom, Represents a halogen atom or an alkyloxy group. An azo-substituted quinoline compound represented by the following general formula (2):

(In the general formula (2), R ₉ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ are hydrogen atoms, R ₁₀ is a cyano group, R ₁₆ and R ₁₇ are each independently a hydrogen atom, a halogen atom, Represents a benzyl group or a trifluoromethyl-substituted benzyl group. A chelate compound comprising an azo-substituted quinoline compound represented by the following general formula (1) and a divalent metal salt.

(In General Formula (1), R ₁ , R ₄ , R ₆ and R ₈ are hydrogen atoms, R ₂ is a cyano group, R ₃ and R ₅ are each independently a hydrogen atom or an alkyl group, R ₇ is a hydrogen atom, Represents a halogen atom or an alkyloxy group. A chelate compound comprising an azo-substituted quinoline compound represented by the following general formula (2) and a divalent metal salt.

(In the general formula (2), R ₉ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ are hydrogen atoms, R 10 is a cyano group, R ₁₆ and R 17 are each independently a hydrogen atom, a halogen atom, an alkyl group, Represents a benzyl group, trifluoromethyl or an alkyloxy-substituted benzyl group. ) The chelate compound according to claim 3 or 4 , wherein the metal atom forming the divalent metal salt is nickel or copper. An optical recording medium comprising a recording layer provided on a substrate, wherein the recording layer contains at least one chelate compound according to claim 3 . An optical recording medium comprising a recording layer on a substrate, wherein the recording layer contains at least one chelate compound according to claim 4 . An optical recording medium comprising a recording layer provided on a substrate, wherein the recording layer contains at least one type of the chelate compound according to claim 5 .

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