JP2010229374A - Compound having squarylium backbone and optical recording medium using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound having a squarylium backbone which has a good performance of optical absorption in a wavelength region of 330-500 nm, allowing using blue semiconductor laser beam to record/regenerate. <P>SOLUTION: The compound having the squarylium backbone is, for example, a compound represented by formula (J): wherein Bn is benzyl. The compound is excellent in solubility and water resistance, has a good performance of optical absorption in a wavelength region of 330-500 nm, and can be suitably used for an optical recording medium for using laser beam to record and/or regenerate information. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a compound having a squarylium skeleton and an optical recording medium using the compound, and more specifically, a write-once type for recording and / or reproducing information using a laser beam having a wavelength in the range of 300 to 530 nm. The present invention relates to a compound having a squarylium skeleton suitable for use in an optical recording medium, and an optical recording medium using the compound.

  Conventionally, magneto-optical recording media, phase change recording media, chalcogen oxides, and the like have been proposed as recording media for optically recording / reproducing information. Among them, information recording is performed only once by a laser. As a write-once type optical recording medium capable of recording, a CD-R is inexpensive and easy to manufacture, and is mass-produced and widely used. The recording capacity is about 0.65 GB, and the demand for higher-density and large-capacity optical recording media is increasing with a dramatic increase in the amount of information.

  In order to meet the above-mentioned demand, for the purpose of increasing the density of the recording medium, means such as shortening the laser wavelength used for recording / reproducing and reducing the beam spot by increasing the numerical aperture of the objective lens are used. Yes. The wavelength of the near-infrared laser (usually 780 nm) is used for CD-R recording and reproduction, but in recent years, high-density, large-capacity recording using a red semiconductor laser with a short wavelength (630 to 680 nm) has been realized. The organic dye-based optical recording medium (DVD-R) has been put into practical use, and a single-sided 4.7 GB DVD-R medium has been supplied to the market. An optical recording medium using a symmetric squarylium compound metal complex is proposed in Patent Document 1 which is suitable for such a DVD-R.

  Furthermore, at present, higher density recording is required, and the amount of recorded information reaches 15 to 30 GB per sheet. An optical recording medium capable of high-density recording / reproduction using a blue semiconductor laser with a short wavelength (300 to 530 nm) is desired, and an optical recording medium called a Blu-ray system using a blue semiconductor laser with a wavelength of 405 nm has already been sold. ing. In the future, higher density recording is expected.

  By the way, a general write-once optical recording medium has a recording layer made of an organic dye, a light reflecting layer made of a metal such as gold or silver, a protective layer made of a resin, etc. on a transparent disk-shaped substrate in order. It is configured by stacking. Information is written (recorded) by irradiating the recording layer with laser light, the recording layer absorbs the light, and the temperature rises locally, causing a physical or chemical change (for example, generation of pits). Information is recorded using the change in optical characteristics.

On the other hand, reading (reproduction) of information is also performed by irradiating a laser having the same wavelength as the recording laser, and the portion where the optical characteristics of the recording layer have changed (recorded portion) and the portion that has not changed (unrecorded portion) Information is reproduced by detecting the difference in reflectance from the.
Therefore, as a dye used for an optical recording medium capable of high-density recording / reproduction using a blue semiconductor laser, in order to form and detect good pits on the substrate, it corresponds to the wavelength of the blue semiconductor laser light used. Those having good optical properties and decomposition behavior are demanded, and in particular, a dye having a maximum absorption wavelength in the range of 300 to 530 nm is desired.

When a medium is produced by a coating method such as a spin coating method that is simple for forming a recording layer, high solubility is required to dissolve the dye in the coating solvent, and this point needs to be taken into consideration.
In this regard, in an optical recording medium having a recording layer containing an organic dye, in addition to those disclosed in Patent Document 1 as the organic dye, Patent Documents 2 and 3 propose squarylium compounds. The absorption wavelength is in the range of 530 to 600 nm, and it is inappropriate because it is not the wavelength region of the blue semiconductor laser light as described in Patent Document 1.

  Further, although a squarylium compound was proposed in Patent Document 4, since it has an absorption peak at the same wavelength as the blue semiconductor laser light, there is a drawback that it is easily broken by the blue semiconductor laser light.

  Various squarylium compounds having a maximum absorption wavelength at 330 to 500 nm have been proposed so far, but there is a problem that water resistance is poor because of low solubility in solvents, low molecular weight and high polarity.

International Publication No. WO2002 / 050190 JP 2004-264805 A JP 2004-258514 A JP 2006-249209 A

  An object of the present invention is to provide a compound having a squarylium skeleton having higher water-solubility than conventional compounds for optical recording media and having excellent water resistance, and an optical recording medium using the compound.

  As a result of intensive studies to solve the above problems, the present inventors have found that a compound having a specific squarylium skeleton has a maximum absorption wavelength in the region of 330 to 500 nm, and is excellent in solubility and water resistance in a solvent. Thus, the present invention was found to be useful as a recording layer of an optical recording medium and completed the present invention.

  A first invention is a compound having a squarylium skeleton characterized by being represented by the following general formulas (1) to (3).

（式（１）中、Ｒ_１〜Ｒ_４は、それぞれ同一でも異なってもよい水素原子、ハロゲン原子、有機基を表し、環Ａ〜Ｅはハロゲン原子、水酸基、有機基を有してもよいベンゼン環を表し、Ｆは置換基を有してもよい芳香環又は置換基を有してもよい複素環からなる化合物を表す。）

(In Formula (1), R < ₁ > -R < ₄ > represents the hydrogen atom, halogen atom, and organic group which may be same or different, respectively, and ring AE may have a halogen atom, a hydroxyl group, and an organic group. Represents a benzene ring, and F represents a compound comprising an aromatic ring which may have a substituent or a heterocyclic ring which may have a substituent.

（式（２）中、Ｒ_５〜Ｒ_７は、それぞれ同一でも異なってもよい水素原子、ハロゲン原子、有機基を表し、環Ｇ〜Ｉはハロゲン原子、水酸基、有機基を有してもよいベンゼン環を表し、Ｊは置換基を有してもよい芳香環又は置換基を有してもよい複素環からなる化合物を表す。）

(In Formula (2), R _{5 to} R ₇ each represent a hydrogen atom, a halogen atom, or an organic group, which may be the same or different, and rings G to I may have a halogen atom, a hydroxyl group, or an organic group. Represents a benzene ring, and J represents a compound comprising an aromatic ring which may have a substituent or a heterocyclic ring which may have a substituent.

（式（３）中、Ｒ_８、Ｒ_９は、それぞれ同一でも異なってもよい水素原子、ハロゲン原子、有機基を表し、環Ｋはハロゲン原子、水酸基、有機基を有してもよいベンゼン環を表し、Ｌは置換基を有してもよい芳香環又は置換基を有してもよい複素環からなる化合物を表す。）

(In formula (3), R ₈ and R ₉ each represent a hydrogen atom, a halogen atom or an organic group which may be the same or different, and ring K is a benzene ring which may have a halogen atom, a hydroxyl group or an organic group. L represents a compound comprising an aromatic ring which may have a substituent or a heterocyclic ring which may have a substituent.

  The second invention is the compound according to the first invention, wherein the maximum absorption wavelength of the absorption spectrum of the film is in the range of 330 to 500 nm.

  A third invention is the compound according to the first or second invention, wherein the compounds F, J and L are composed of a compound represented by the following general formula (4) or (5).

（式（４）、（５）中、Ｒ_１０〜_１２は、それぞれ同一でも異なってもよい水素原子、有機基を表し、環Ｍ、Ｎはハロゲン原子、水酸基、有機基を有してもよい。）

(In the formula _{(4), (5),} R 10 ~ 12 are good hydrogen atom the same as or different from each other, represent an organic group, ring M, N may have a halogen atom, a hydroxyl group, an organic group .)

  A fourth invention is an optical recording medium comprising at least one compound according to any one of the first to third inventions.

  A fifth invention is an optical recording medium in which a recording layer capable of writing and / or reading information with a laser beam is formed on a substrate, wherein the recording layer is any one of the first to third inventions. An optical recording medium comprising at least one of the above compounds.

  A sixth invention is the optical recording medium according to the fifth invention, wherein information is recorded and / or reproduced by a laser beam selected from a wavelength range of 300 nm to 530 nm.

  The compound having a squarylium skeleton represented by the general formulas (1) to (3) of the present invention has a maximum absorption wavelength in the region of 330 to 500 nm, and is excellent in solubility and water resistance in a solvent. An optical recording medium excellent in reproduction can be provided.

  Hereinafter, the compound having a squarylium skeleton of the present invention will be described in detail.

  The present invention is a compound having a squarylium skeleton represented by the general formulas (1) to (3).

R _{1 to} R ₉ in the general formulas (1) to (3) each represent a hydrogen atom, a halogen atom, or an organic group, which may be the same or different, and rings A to E, G to I, and K are a halogen atom and a hydroxyl group. Represents a benzene ring which may have an organic group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. The organic group has a phenyl group, a linear or branched alkyl group which may have a substituent, a linear or branched halogenated alkyl group which may have a substituent, and a substituent. Linear or branched cyanoalkyl group which may be substituted, linear or branched alkoxy group which may have a substituent, linear or branched alkylphenyl which may have a substituent Groups.

  Examples of the linear or branched alkyl group which may have a substituent include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, iso-butyl group, n A linear or branched alkyl group having 1 to 20 carbon atoms such as -pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, n-dodecyl group, n-octadecyl group, etc. Preferably, it is a C1-C10 linear or branched alkyl group.

  The linear or branched alkyl halide group which may have a substituent is represented by the following general formula (6).

（式（６）中、Ｘはハロゲン原子を示し、ｎは１〜１２の整数、ｍは１〜２５の整数を示す。）
ハロゲン化アルキル基のハロゲン原子としては特に限定はないが、一般式（１）〜（３）の耐光性を向上させる効果に優れる点から、特にフッ素原子、すなわちフッ化アルキル基が好ましい。

(In formula (6), X represents a halogen atom, n represents an integer of 1 to 12, and m represents an integer of 1 to 25.)
Although there is no limitation in particular as a halogen atom of a halogenated alkyl group, a fluorine atom, ie, a fluorinated alkyl group, is especially preferable from the point which is excellent in the effect which improves the light resistance of General formula (1)-(3).

Examples of the fluorinated alkyl group include trifluoromethyl group, 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, 5, 5,5-trifluoropentyl group, 6,6,6-trifluorohexyl group, 8,8,8-trifluorooctyl group, 2-methyl-3,3,3-trifluoropropyl group, perfluoroethyl group, Examples thereof include a perfluoropropyl group, a perfluorobutyl group, a perfluorohexyl group, a perfluorooctyl group, and a 2-trifluoromethyl-perfluoropropyl group.

  The linear or branched cyanoalkyl group which may have the substituent is not particularly limited, and examples thereof include a propionitrile group, a butyronitrile group, a pentylnitrile group, and a 1-methylpropionitrile group. It is done. Preferably, it is a linear or branched cyanonitrile group having 1 to 20 carbon atoms, and the number of substituted cyano groups is preferably 1 to 3.

  Examples of the linear or branched alkoxy group which may have a substituent include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a 2-methoxyethoxy group, a pentyloxy group, and a hexyl group. Oxy group, octyloxy group, decyloxy group, methoxymethyl group, methoxyethyl group, methoxypropyl group, methoxybutyl group, methoxyhexyl group, methoxyoctyl group, ethoxymethyl group, ethoxyethyl group, ethoxypropyl group, ethoxybutyl group, Examples thereof include an ethoxyhexyl group, an ethoxyoctyl group, a propoxymethyl group, a propoxypropyl group, a propoxyhexyl group, and a butoxyethyl group, and a linear or branched alkoxy group having 1 to 10 carbon atoms is preferable.

  Examples of the linear or branched alkylphenyl group that may have a substituent include a methylphenyl group, a benzyl group, a phenethyl group, a phenylpropyl group, a phenyl-α-methylpropyl group, and a phenyl-β-methylpropyl group. , Phenylbutyl group, phenylpentyl group and the like. Those having a linear or branched alkyl group having 1 to 8 carbon atoms are preferred. In addition, an alkyl group, a hydroxyl group, a sulfonic acid group, an alkylsulfonic acid group, a nitro group, an amino group, an alkoxy group, a halogen atom on the phenyl group. It may have at least one substituent selected from the group consisting of an alkyl group and a halogen.

  The compounds F, J, and L in the general formulas (1) to (3) represent an aromatic ring that may have a substituent or a heterocyclic ring that may have a substituent, and may be condensed. Good.

  Examples of the compound comprising an aromatic ring or a heterocyclic ring include benzene compounds, naphthalene compounds, pyridine compounds, quinoline compounds, pyrrole compounds, pyrazole compounds, pyrazoline compounds, imidazole compounds, thiazole compounds, and the like.

  Specific examples of the substituent are independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, an amino group, a carbamoyl group, an alkyl group that may have a substituent, and a substituent. An aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylthio group which may have a substituent, and a substituent An arylthio group which may have a substituent, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, an alkoxycarbonyl group which may have a substituent, and a substituent. An aryloxycarbonyl group that may be substituted, an alkylcarboxamide group that may have a substituent, an arylcarboxamide group that may have a substituent, and a substituent Good alkylcarbamoyl group, which may have a substituent arylcarbamoyl group which may have a substituent alkenyl group include an alkyl sulfamoyl group may have a substituent.

  Examples of the alkyl group include those having 1 to 15 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, and an n-heptyl group. Group, linear alkyl group such as n-octyl group, n-nonyl group, n-decyl group, isobutyl group, isoamyl group, 2-methylbutyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methyl Pentyl 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, 1-methylbutyl, 1,2-dimethylpropyl, 1-methylheptyl, 1-ethylbutyl, 1,3-dimethylbutyl, 1,2-dimethylbutyl, 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-propyl-2-methylpropyl group 1-methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, 1-isopropyl-2-methylbutyl group, 1-isopropyl-3-methylbutyl group, 1-methyloctyl group, 1- Ethyl heptyl group, 1-propylhexyl group, 1-isobutyl-3-methylbutyl group, neopentyl group, te Branched alkyl groups such as t-butyl group, tert-hexyl group, tert-amyl group, tert-octyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group, 4 Examples thereof include cycloalkyl groups such as-(2-ethylhexyl) cyclohexyl group, bornyl group, isobornyl group, adamantyl group, etc. Among them, those having 1 to 8 carbon atoms are preferable.

  Further, these linear and branched alkyl groups may have a hydroxyl group, a halogen atom, a nitro group, a carboxyl group, a cyano group, or a specific substituent (for example, substituted with a halogen atom or a nitro group). It may be substituted with an aryl group, a heterocyclic residue or the like. Further, it may be substituted with the above alkyl group through an atom such as oxygen, sulfur or nitrogen.

  Examples of the alkyl group substituted through oxygen include methoxymethyl group, methoxyethyl group, ethoxymethyl group, ethoxyethyl group, butoxyethyl group, ethoxyethoxyethyl group, methoxypropyl group, ethoxypropyl group, etc. Examples of the alkyl group substituted through a methylthioethyl group, an ethylthioethyl group, and an ethylthiopropyl group include a dimethylaminoethyl group, a diethylaminoethyl group, and a diethylamino group. A propyl group etc. are mentioned.

  Specific examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a phenalenyl group, a phenanthranyl group, a triphenylenyl group, and a pyrenyl group. Further, these aryl groups may have a hydroxyl group, a halogen atom, a nitro group, a carboxyl group, a cyano group, or a specific substituent (for example, an aryl group which may be substituted with a halogen atom or a nitro group). , May be substituted with a heterocyclic residue or the like, or may be substituted with the above alkyl group through an atom such as oxygen, sulfur, nitrogen or the like.

  Specific examples of the alkenyl group include those having 2 to 6 carbon atoms such as vinyl group, aryl group, 1-propenyl group, methacryl group, crotyl group, 1-butenyl group, 3-butenyl group, 2-pentenyl group, 4 -Pentenyl group, 2-hexenyl group, 5-hexenyl group, etc. are mentioned. Examples of the substituent of the alkenyl group include the same substituents as the alkyl group described above.

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

  The alkoxy group which may have a substituent may be any group in which an alkyl group which may have a substituent is directly bonded to an oxygen atom. Specific examples of the alkyl group and the substituent include Specific examples can be given.

  The aryloxy group which may have a substituent may be any as long as the aryl group which may have a substituent is directly bonded to the oxygen atom, and specific examples of the aryl group and the substituent are as follows. Can include the specific examples described above.

  The alkylthio group which may have a substituent is only required to have an alkyl group which may have a substituent directly bonded to a sulfur atom, and specific examples of the alkyl group and the substituent include Specific examples can be given.

  The arylthio group which may have a substituent may be any one in which an aryl group which may have a substituent is directly bonded to a sulfur atom, and specific examples of the aryl group and the substituent include Specific examples can be given.

  The alkylamino group which may have a substituent may be any group in which an alkyl group which may have a substituent is directly bonded to the nitrogen atom, and specific examples of the alkyl group and the substituent are as follows. Can include the specific examples described above. Further, alkyl groups may be bonded to each other to form a ring such as a piperidino group, a morpholino group, a pyrrolidinyl group, a piperazinyl group, an indolinyl group, an isoindolinyl group.

  The arylamino group which may have a substituent may be any one in which an aryl group which may have a substituent is directly bonded to the nitrogen atom, and specific examples of the aryl group and the substituent are as follows. Can include the specific examples described above.

  The alkoxycarbonyl group which may have a substituent may be any group in which an alkyl group which may have a substituent is directly bonded to an oxygen atom, and specific examples of the alkyl group and the substituent are as follows. Can include the specific examples described above.

The aryloxycarbonyl group which may have a substituent may be any group in which an aryl group which may have a substituent is directly bonded to an oxygen atom, and specific examples of the aryl group and the substituent As mentioned above, the above-mentioned specific examples can be given.

  The alkylcarboxamide group which may have a substituent may be any group in which an alkyl group which may have a substituent is directly bonded to a carbon atom. Specific examples of the alkyl group and the substituent are as follows. Can include the specific examples described above.

  The arylcarboxamide group which may have a substituent may be any group in which an aryl group which may have a substituent is directly bonded to a carbon atom, and specific examples of the aryl group and the substituent are as follows. Can include the specific examples described above.

  The alkylcarbamoyl group which may have a substituent may be any group in which an alkyl group which may have a substituent is directly bonded to the nitrogen atom, and specific examples of the alkyl group and the substituent are as follows. Can include the specific examples described above. Further, alkyl groups may be bonded to each other to form a ring such as a piperidino group, a morpholino group, a pyrrolidinyl group, a piperazinyl group, an indolinyl group, an isoindolinyl group.

  The arylcarbamoyl group which may have a substituent may be any group in which an aryl group which may have a substituent is bonded directly to the nitrogen atom, and specific examples of the aryl group and the substituent are as follows. Can include the specific examples described above.

  A specific example of the alkylsulfamoyl group which may have a substituent may be any as long as it contains an alkyl group which may have a substituent directly on the nitrogen atom of the sulfamoyl group. As specific examples of the substituent, the above-described specific examples can be given.

  The compounds F, J, and L in the general formulas (1) to (3) are preferably an aniline compound, anisole compound, indole compound, and naphthylamine compound which may have a substituent. From the viewpoint of water resistance, an aniline compound represented by the general formula (4) and an indole compound represented by (5) are particularly preferred.

R < ₁₀ > -R < ₁₂ > in General formula (4), (5) represents the hydrogen atom and organic group which may be the same or different. Examples of the organic group include a phenyl group, a linear or branched alkyl group that may have a substituent, a linear or branched halogenated alkyl group that may have a substituent, and a substituent. The linear or branched alkylphenyl group which may have is mentioned. Rings M and N represent a benzene ring which may have a halogen atom, a hydroxyl group or an organic group.

  Examples of the linear or branched alkyl group, halogenated alkyl group or alkylphenyl group which may have the substituent include the alkyl groups mentioned as the organic groups of the aforementioned rings A to E, G to I and K. And the same as the halogenated alkyl group or alkylphenyl group.

Examples of the aniline compound include N, N-dimethylaniline, N, N-diethylaniline, N, N-dipropyl, N, N-dibutylaniline, N, N-ditrifluoroaniline and the like.
Examples of the indole compound include N-methylindole, N-ethylindole, N-propylindole, N-butylindole, N-methyl-6-methylindole, N-butyl-6-methylindole, and N-methyl-5. -Hydroxyindole, N-butyl-5-hydroxy-indole, N-methyl-6 fluoroindole, N-butyl-6-fluoroindole, N-methyl-6-chloroindole, N-butyl-6-chloroindole, N -Methyl-5-fluoroindole, N-butyl-5-fluoroindole, N-methyl-5-cyanoindole, N-butyl-5cyanoindole and the like.

  The compound represented by the general formula (1) of the present invention can be produced by, for example, a method according to the method described in the patent document (Japanese Patent Publication No. 43-25335). That is, N, N, N ′, N′-tetrakis (amino) represented by the following general formula (7) is obtained by reducing the product obtained by the Ullmann reaction of p-phenylenediamine and 1-chloro-4-nitrobenzene. Phenyl) -p-phenylenediamine can be obtained.

（式（７）中、環Ａ〜Ｅは前記一般式（１）で定義した通りである。）

(In the formula (7), the rings A to E are as defined in the general formula (1).)

Next, the compound represented by the general formula (7) in an organic solvent, preferably in a water-soluble polar solvent such as dimethylformamide (DMF), dimethylimidazolinone (DMI) or N-methylpyrrolidone (NMP), The halogenated compound corresponding to the desired R _{1 to} R ₄ at 160 ° C., preferably 50 to 140 ° C., is reacted for 4 equivalents to 1 equivalent of the general formula (7), and then the general formula containing the desired compound F A compound represented by the general formula (1) can be obtained by reacting 4 equivalents of the squarylium compound represented by (8).

（式（８）中、Ｆは前記一般式（１）で定義した通りである。）

(In the formula (8), F is as defined in the general formula (1).)

  Since the squarylium part of the squarylium compound is a chloro group, the triphenylamine derivative such as the general formula (7) can be substituted at a right angle with a nitrogen moiety.

  General formula (2), (3) of this invention can also be manufactured by the method similar to general formula (1).

  The optical recording medium of the present invention has a recording layer containing at least one compound having a squarylium skeleton represented by the general formulas (1) to (3) in the present invention on the substrate, and contains two or more different types. You may let them.

Further, the compound having a squarylium skeleton of the present invention may form a J-type aggregate or an H-type aggregate.
The J-type aggregate is a state in which organic dye molecules are aggregated in a self-organized manner to form a one-dimensional chain of the molecule, and the absorption peak shifts to a longer wavelength side and the peak becomes sharp. .
The H-type aggregate is a state in which a minute molecular aggregate is formed in a state where molecules are regularly arranged by intermolecular interaction, and the absorption spectrum is narrower than the case where the half width is narrow and the molecules are random. Also has a feature that the absorbance increases.

  Since the compound having a squarylium skeleton represented by the general formulas (1) to (3) of the present invention has a large molecular weight, it has the characteristics of excellent solubility and water resistance.

  In addition, since the compound having the squarylium skeleton represented by the general formulas (1) to (3) of the present invention is not easily conjugated by substituting the squarylium compound at a right angle with respect to the stabilizing skeleton, the squarylium having a large molecular weight. It is possible to substitute a compound.

  The compounds are also useful for optical recording media, photographic materials, color filter dyes, color conversion filters, thermal transfer recording materials, inks, and the like. In particular, since it has an absorption intensity suitable for recording / reproducing with a laser beam in a short wavelength region of 330 to 500 nm, it is extremely useful as a compound for use in an optical recording medium for recording / reproducing with a short wavelength laser.

  As a preferable configuration of the optical recording medium of the present invention, a recording layer, a light reflection layer, and a protective layer are sequentially formed on a disc-like substrate on which pregrooves having a constant track pitch are formed. The recording layer and the light reflection layer are sequentially formed on the transparent disk-shaped substrate on which the light reflection layer, the recording layer, and the protective layer are sequentially formed, or the pregroove having a constant track pitch is formed. For example, a configuration in which the two laminated bodies are joined such that the recording layers face each other inward. Hereinafter, the optical recording medium will be described in detail.

  The material of the substrate in the optical recording medium of the present invention can be arbitrarily selected from various materials used as a substrate of a conventional optical information recording medium. Examples of the substrate material include glass, polycarbonate resin, acrylic resin such as polymethyl methacrylate, polyvinyl chloride resin such as polyvinyl chloride resin and vinyl chloride copolymer, epoxy resin, amorphous polyolefin resin, and polyester resin. Among the above materials, injection molded polycarbonate is preferable from the viewpoint of moisture resistance, dimensional stability, and price. A resin substrate or a resin layer may be provided in contact with the recording layer, and guide grooves or pits for recording / reproducing light may be provided on the resin substrate or resin layer. When the guide groove has a spiral shape, the groove pitch is preferably about 0.5 to 1.2 μm.

  The recording layer is formed by a generally used thin film forming method such as a vapor phase method such as a vacuum deposition method, a sputtering method, or a CVD method, a liquid phase method such as a doctor blade method, a cast method, a spin coating method, or an immersion method. However, the spin coating method is preferable from the viewpoint of mass productivity and cost.

  The solvent for the liquid phase method is not particularly limited as long as it does not attack the substrate. For example, esters such as butyl acetate, ethyl lactate and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chloroform; amides such as dimethylformamide; Hydrocarbons; ethers such as dibutyl ether, diethyl ether, tetrahydrofuran, dioxane; alcohols such as ethanol, n-propanol, isopropanol, n-butanol, diacetone alcohol; fluorines such as 2,2,3,3-tetrafluoropropanol Solvents: Glycol agents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether And the like Le acids. The above solvents can be used alone or in combination of two or more in consideration of the solubility of the compound used.

  The solubility of the compound for optical recording media is preferably 10 to 100 g / L, more preferably 20 to 100 g / L, and particularly preferably 30 to 100 g / L in order to control the film thickness, reflectance, and the like of the recording layer. .

  The film thickness of the recording layer is generally in the range of 20 to 500 nm, preferably in the range of 30 to 300 nm, and more preferably in the range of 50 to 150 nm.

  In the present invention, a stabilizer that is a singlet oxygen quencher may be used in the recording layer in order to improve the light resistance of the recording layer. Examples of singlet quenchers include transition metal chelate complexes such as acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, and bisdithio-α-diketone, aromatic nitroso compounds, aminium compounds, diimonium compounds, and biiminium compounds.

  The amount of the light stabilizer used is usually in the range of 0.01 to 100 parts by mass with respect to 100 parts by mass of the compound having the squarylium skeleton, but more preferably in the range of 1.0 to 80 parts by mass. preferable. This is because if the amount used is increased further, the absorbance decreases, and if it is decreased, a sufficient stabilizing effect cannot be obtained.

  A light reflecting layer may be formed under the recording layer. As a material of the light reflection layer, a material having a sufficiently high reflectance at the wavelength of the reproduction light, for example, a metal such as Au, Al, Ag, Cu, Ti, Cr, Ni, Pt, Ta, and Pd is used alone or as an alloy. It is possible. Among these, Au, Al, and Ag have high reflectivity and are suitable as the material for the reflective layer. The reflective layer can be formed on the substrate or the recording layer, for example, by vapor deposition, sputtering or ion plating of the light reflective material. The film thickness of the light reflecting layer is generally in the range of 10 to 300 nm, and preferably in the range of 50 to 200 nm.

The material for the protective layer formed on the reflective layer is not particularly limited as long as it protects the reflective layer from external force. Specifically, examples of the organic material include a thermoplastic resin, a thermosetting resin, an electron beam curable resin, and a UV curable resin. Examples of the inorganic material include SiO ₂ , Si ₃ N ₄ , MgF ₂ , SnO _{2 and the} like.

  A protective layer using a thermoplastic resin or a thermosetting resin is formed by applying a coating solution prepared by dissolving the resin in an appropriate solvent to the surface of the substrate on which the recording layer or the light reflecting layer is formed, and then drying. Can do.

  A protective layer using a UV curable resin is formed by applying a coating solution dissolved in the resin alone or in an appropriate solvent to the surface of the substrate on which the recording layer or the light reflection layer is formed, and irradiating and curing the UV light. Can be formed. As the UV curable resin, for example, acrylate resins such as urethane acrylate, epoxy acrylate, and polyester acrylate can be used. These materials may be used alone or in combination, and a single layer or a multilayer film may be formed.

  As a method for forming the protective layer, a spin coating method, a coating method such as a casting method, a sputtering method, a chemical vapor deposition method, or the like is used as in the case of the recording layer. Among these, a spin coating method is preferable. The thickness of the protective layer is generally in the range of 0.1 to 100 μm, but is preferably 3.0 to 30 μm in the present invention.

  The laser light used for the optical recording medium of the present invention is selected in a short wavelength region capable of high-density recording, and is preferably a blue-violet semiconductor laser light having an oscillation wavelength of 300 to 530 nm, and has an oscillation wavelength of 350 to 430 nm. The blue-violet semiconductor laser light is more preferable, and the blue-violet semiconductor laser light having an oscillation wavelength of 390 to 420 nm is particularly preferably used.

  Recording on the optical recording medium of the present invention is performed by irradiating the recording layer provided on both sides or one side of the substrate with laser light focused to about 0.4 to 0.6 μm. In the portion irradiated with laser light, thermal deformation of the recording layer, such as decomposition, heat generation, and dissolution, due to absorption of laser light energy occurs, optical characteristics change, and recording pits are formed. The recorded information is reproduced by irradiating the playback laser beam and detecting the difference in reflectance between the part where the optical characteristics of the recording layer have changed (recorded part) and the part that has not changed (unrecorded part). Is done.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, “part” represents “part by mass”.

  The structural formulas of the compounds (A) to (O) having a squarylium skeleton used in this example are shown below. In the structural formula, TFB represents a trifluorobutyl group, and Bn represents a benzyl group.

Example 1
In a three-necked flask, 6.2 parts of 3,4-chloro-3-cyclobutene-1,2-dione and 7.6 parts of N, N-dimethylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.) are placed. I put it in. Thereto was added 5.9 parts of anhydrous potassium carbonate, and the mixture was stirred at room temperature for 5 hours. After completion of the reaction, the solid was filtered and washed with methanol. To the obtained solid, 200 ml of water and 2.7 parts of potassium carbonate were added, and the mixture was heated and stirred at 50 ° C. for 2 hours. After completion of the reaction, the solid was filtered. After washing with water, it was dried under reduced pressure to obtain 4.3 parts of 3-chloro-4- (N, N-dimethylphenylamine) -cyclobut-3-ene-1,2-dione.
N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine 2.0 parts in 50 parts of N-methylpyrrolidone (NMP), 3-chloro-4- (N, N-dimethylphenylamine) ) -Cyclobut-3-ene-1,2-dione (3.5 parts) was added, and the mixture was stirred at 80 ° C. for 2 hours. Thereafter, 4.6 parts of 4,4,4-trifluorobutyl iodide and 4.6 parts of potassium carbonate were added, and the mixture was stirred at 80 ° C. for 2 hours and reacted at 110 ° C. for 1 hour. After cooling, the mixture is filtered, and 30 parts of methanol is added to the reaction mixture, followed by stirring (10 ° C.) for 3 hours. The produced crystal was filtered, washed with methanol, and then dried to obtain a light brown crystal as compound (A).
Yield 82%, elemental analysis Found (%), C66.05, H4.92, F13.36, N8.15, Calcd for _{C 94 H 84 F 12 N 10} O 8 (%), C66.03, H4.95, F13.33, N8.19

(Example 2)
Compound (B) was obtained in the same manner as in Example 1, except that 4,4,4-trifluorobutyl iodide in Example 1 was replaced with benzyl iodide.
84% yield, elemental analysis Found _{(%), C78.15, H5.47,} N8.55, calcd for _{C 106 H 88 N 10 O 8} (%), C78.11, H5.44, N8. 59

Example 3
Compound (C) was obtained in the same manner as in Example 1 except that N, N-dimethylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.) in Example 1 was replaced with N-methylindole (manufactured by Tokyo Chemical Industry Co., Ltd.).
Yield 79%, elemental analysis Found (%), C67.28, H4.35, F13.02, N8.05, Calcd for _{C 98 H 76 F 12 N 10} O 8 (%), C67.27, H4.38, F13.03, N8.01

Example 4
Except that N, N-dimethylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.) of Example 1 was replaced with N-methylindole (manufactured by Tokyo Chemical Industry Co., Ltd.), and 4,4,4-trifluorobutyl iodide was replaced with benzyl iodide, In the same manner as in Example 1, compound (D) was obtained.
Yield 79%, elemental analysis Found (%), C63.48, H5.95, F11.82, N10.15, calcd for _{C 110 H 80 N 10 O 8} (%), C79.12, H4. 83, N8.39

(Example 5)
Compound (E) was obtained in the same manner as in Example 1, except that N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine in Example 1 was replaced with tris-p-aminophenylamine. It was.
83% yield, elemental analysis Found (%), C65.06, H4.94, F14.01, N8.05, Calcd for _{C 66 H 60 F 9 N 7} O 6 (%), C65.07, H4.96, F14.04, N8.05

(Example 6)
Compound (F) was obtained in the same manner as in Example 2, except that N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine in Example 2 was replaced with tris-p-aminophenylamine. It was.
Yield 85%, elemental analysis Found (%), C77.77, H5.42, F8.41, N12.29, Calcd for _{C 75 H 63 N 7 O 6} (%), C77.77, H5. 48, N8.46

(Example 7)
Compound (G) was obtained in the same manner as in Example 3, except that N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine in Example 3 was replaced with tris-p-aminophenylamine. It was.
83% yield, elemental analysis Found (%), C66.38, H4.35, F13.71, N7.85, Calcd for _{C 69 H 54 F 9 N 7} O 6 (%), C66.39, H4.36, F13.70, N7.86

(Example 8)
Compound (H) was obtained in the same manner as in Example 4 except that N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine in Example 4 was replaced with tris-p-aminophenylamine. It was.
83% yield, elemental analysis Found (%), C578.81, H4.81, N8.25, Calcd for _{C 78 H 57 N 7 O 6} (%), C78.84, H4.83, N8. 25

Example 9
Compound (I) was obtained in the same manner as in Example 1 except that N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine in Example 1 was replaced with p-phenylenediamine.
89% yield, elemental analysis Found (%), C62.80, H4.99, F15.67, N7.75, Calcd for _{C 38 H 36 F 6 N 4} O 4 (%), C62.80, H4.99, F15.69, N7.71

(Example 10)
Compound (J) was obtained in the same manner as in Example 2, except that N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine in Example 2 was replaced with p-phenylenediamine.
87% yield, elemental analysis Found (%), C76.97, H5.55, N8.14, Calcd for _{C 44 H 38 N 4 O 4} (%), C76.95, H5.58, N8. 16

(Example 11)
Compound (K) was obtained in the same manner as in Example 3, except that N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine in Example 3 was replaced with p-phenylenediamine.
89% yield, elemental analysis Found (%), C64.30, H4.35, F15.27, N7.74, Calcd for _{C 40 H 32 F 6 N 4} O 4 (%), C64.34, H4.32, F15.27, N7.50

Example 12
Compound (L) was obtained in the same manner as in Example 4, except that N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine in Example 4 was replaced with p-phenylenediamine.
86% yield, elemental analysis Found (%), C78.17, H4.85, N7.94, Calcd for _{C 46 H 34 N 4 O 4} (%), C78.17, H4.85, N7. 93

(Comparative Example 1)
In a three-necked flask, 6.2 parts of 3,4-dimethoxy-3-cyclobutene-1,2-dione and 7.6 parts of 1,3-dimethyl-5-pyrazolone (manufactured by Lancaster) are placed, and methanol is added thereto. 500 ml was added and stirred at room temperature. Thereto was added 5.9 parts of anhydrous potassium carbonate, and the mixture was stirred at room temperature for 5 hours. After completion of the reaction, the solid was filtered and washed with methanol. To the obtained solid, 200 ml of water and 2.7 parts of potassium carbonate were added, and the mixture was heated and stirred at 50 ° C. for 2 hours. After completion of the reaction, the solution was poured into 500 ml of 1M hydrochloric acid and the precipitated solid was filtered. After washing with water, it was dried under reduced pressure to obtain 4.3 parts of compound (M).

(Comparative Example 2)
In a three-necked flask, put 5.0 parts of 3,4-dichloro-3-cyclobutene-1,2-dione and 4.2 parts of methoxybenzene (manufactured by Tokyo Chemical Industry Co., Ltd.), add 80 parts of dehydrated toluene, Stir at room temperature for 24 hours. After completion of the reaction, the mixture was washed with an aqueous sodium hydrogen carbonate solution, extracted with toluene, and the solvent was distilled off under reduced pressure. 10 parts of acetic acid was added to the obtained solid, and the mixture was collected by filtration, washed with hexane, and dried under reduced pressure to obtain 3.9 parts of compound (N).

(Comparative Example 3)
In a three-necked flask, 5.0 parts of 3,4-dichloro-3-cyclobutene-1,2-dione and 4.6 parts of N, N-dimethylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.) are placed, and dehydrated toluene 80 Part was added and stirred at room temperature for 24 hours. After completion of the reaction, the mixture was washed with an aqueous sodium hydrogen carbonate solution, extracted with toluene, and the solvent was distilled off under reduced pressure. 10 parts of acetic acid was added to the obtained solid, and the mixture was collected by filtration, washed with hexane, and dried under reduced pressure to obtain 5.5 parts of compound (O).

<Measurement of solubility>
0.03 part of each of the compounds (A) to (O) was added to 1.0 part of 2,2,3,3-tetrafluoropropanol (TFP), treated with an ultrasonic cleaner for 15 minutes, and then 0.2 μm. The resulting filtrate was subjected to pressure filtration at room temperature, the solvent was removed from the obtained filtrate, and the solubility was determined by measuring the weight of the compound.

  Table 1 shows the maximum absorption wavelength λmax (nm) in an acetone solvent of the compounds (A) to (O) and the solubility (g / L) in TFP.

  While Comparative Examples 1-3 are less than 1.0 g / L, Examples 1-12 are 30 g / L or more, and it turns out that it is excellent in the solubility with respect to TFP.

(Examples 13-24, Comparative Examples 4-6)
0.02 part of each of the compounds (A) to (O) was dissolved in 1.0 part of TFP, and passed through a 0.2 μm filter to obtain a coating solution. A coating film was prepared by spin coating (2000 rpm, 10 s) using 5 ml of this coating solution on a flat polycarbonate disk. The absorption spectrum of this coating film was measured by the transmission method. When the obtained coating film was immersed in hot water at 70 ° C. for 30 minutes, the dye residual ratio (absorbance after test / initial absorbance) was measured with a spectrophotometer to evaluate water resistance.
Using a reflection spectral film thickness meter (FE-3000 manufactured by Otsuka Electronics Co., Ltd.), the refractive index (n) and extinction coefficient (k) of the film at 405 nm were measured.

  Table 2 shows the measurement results of the maximum absorption wavelength λmax (nm), the refractive index / extinction coefficient (n / k), and the water resistance (%) of the coating films of the compounds (A) to (O).

  The maximum absorption wavelengths of the coating films of Examples 13 to 24 are in the range of 340 to 370 nm, and it can be seen that the coating films are suitable for recording dyes using laser light selected from the wavelength region of wavelengths of 300 to 530 nm. Moreover, it turns out that the direction of Examples 13-24 is excellent in refractive index and water resistance from Comparative Examples 4-6.

  The compounds having a squarylium skeleton of the present invention are useful for optical recording media, photographic materials, color filter dyes, color conversion filters, thermal transfer recording materials, inks and the like. In particular, since the maximum absorption wavelength of the obtained coating film is in the range of 330 to 500 nm and has excellent water resistance, information is recorded and / or reproduced using laser light having a wavelength in the range of 300 to 530 nm. It can be suitably used for optical recording medium applications.

UV-Vis absorption spectrum in acetone solvent and coating film of Example 1

Claims (6)

A compound having a squarylium skeleton represented by the following general formulas (1) to (3).

(In Formula (1), R < ₁ > -R < ₄ > represents the hydrogen atom, halogen atom, and organic group which may be same or different, respectively, and ring AE may have a halogen atom, a hydroxyl group, and an organic group. Represents a benzene ring, and F represents a compound comprising an aromatic ring which may have a substituent or a heterocyclic ring which may have a substituent.

(In Formula (2), R _{5 to} R ₇ each represent a hydrogen atom, a halogen atom, or an organic group, which may be the same or different, and rings G to I may have a halogen atom, a hydroxyl group, or an organic group. Represents a benzene ring, and J represents a compound comprising an aromatic ring which may have a substituent or a heterocyclic ring which may have a substituent.

(In formula (3), R ₈ and R ₉ each represent a hydrogen atom, a halogen atom or an organic group which may be the same or different, and ring K is a benzene ring which may have a halogen atom, a hydroxyl group or an organic group. L represents a compound comprising an aromatic ring which may have a substituent or a heterocyclic ring which may have a substituent.   The compound according to claim 1, wherein the maximum absorption wavelength of the absorption spectrum of the film is in the range of 330 to 500 nm. Compound F, J, L consists of a compound represented by the following general formula (4) or (5), The compound of Claim 1 or 2 characterized by the above-mentioned.

(In formulas (4) and (5), R ₁₀ to ₁₂ each represent a hydrogen atom or an organic group which may be the same or different, and rings M and N may have a halogen atom, a hydroxyl group or an organic group. .)   An optical recording medium comprising at least one compound according to any one of claims 1 to 3.   An optical recording medium in which a recording layer capable of writing and / or reading information with a laser beam is formed on a substrate, the recording layer containing at least one compound according to any one of claims 1 to 3. An optical recording medium characterized by the above.   The optical recording medium according to claim 4 or 5, wherein information is recorded and / or reproduced by a laser beam selected from a wavelength region of a wavelength of 300 nm to 530 nm.

Images