JP2008138099A - Squarylium compound-metal complex and optical recording medium using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a squarylium compound/metal complex which is highly able to absorb light in the wavelength region of 300-530 nm, therefore enables recording and reproduction with a blue semiconductor laser, is excellent in thermal decomposition behaviors and solvent solubility, and is also excellent in light resistance and durability and to provide an optical recording medium using the complex. <P>SOLUTION: Disclosed are a squarylium compound/metal complex composed of a squarylium compound represented by formula (A) and a metal ion and an optical recording medium using the same. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squarylium compound metal complex and an optical recording medium using the same, and more specifically, a write-once optical for recording and / or reproducing information using a laser beam having a wavelength in the range of 300 nm to 530 nm. The present invention relates to a squarylium compound metal complex suitable for recording medium applications and an optical recording medium using the same.

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 these, information recording is performed only once by 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. Although the recording capacity is about 0.65 GB, the demand for higher-density and large-capacity optical recording media is increasing with the 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. Near-infrared laser wavelengths (usually 780 nm) are used for CD-R recording and reproduction, but in recent years, high-density, large-capacity recording has been realized using red semiconductor lasers with short wavelengths (630 nm to 680 nm). 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 squarylium compound metal complex suitable for such a DVD-R has been proposed (Patent Document 1).
In the future, higher density recording is required, and the amount of recorded information is expected to reach 15 to 30 GB per sheet.
For this reason, 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 is already required. Was launched.

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 in an optical recording medium capable of high-density recording / reproduction using a blue semiconductor laser, an optical device for the wavelength of the blue laser light used to form and detect good pits on the substrate is used. In particular, there is a demand for a dye having a good absorption property and good decomposition behavior, and particularly a dye having a maximum absorption wavelength in the range of 300 to 530 nm.
In addition, 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 dyes. The absorption wavelength is in the range of 530 to 600 nm, and it is inappropriate because it is not in the wavelength region of blue laser light, similar to that described in Patent Document 1.
Further, although a squarylium dye is proposed in Patent Document 4, it has an absorption peak at the same wavelength as that of the blue laser light, so that there is a problem that the blue laser light is easily broken and the light resistance is insufficient. That is, in a recording method called Low to High type, in which recording is performed by changing the reflectance of the reflective layer from a low state to a high state using the absorption change of the dye due to laser light irradiation, the Patent Document 4 discloses. The dye having the structure described in (1) has high absorption sensitivity at 405 nm, which is the same as that of the blue laser light, and thus has high sensitivity to the blue laser light and lowers light resistance. Accordingly, there is a need for an organic dye and an optical recording medium that have further improved light resistance and are suitable for the recording method.

International Publication No. W02002 / 050190 JP 2004-264805 A JP 2004-258514 A JP 2006-249209 A

  As described above, it is necessary to select an organic dye that is suitable for the optical properties and the decomposition behavior with respect to the blue laser wavelength as the organic dye used in the recording layer. In particular, the organic dye is decomposed to cause a large refractive index change. Therefore, the recording / reproducing wavelength is selected so as to be located on the long wavelength side of the maximum absorption wavelength or on the short wavelength side of the maximum absorption wavelength in order to cause an absorption change.

  In organic dyes, in order to have a maximum absorption wavelength in the vicinity of the blue laser wavelength, it is generally considered that the molecular skeleton is reduced or the conjugated system is shortened. A decrease in refractive index also occurs, making this an undesirable organic dye for use in the recording layer.

  There are also organic dyes having a maximum absorption wavelength of 300 to 530 nm. However, when an organic chelate complex or the like is applied as these organic dyes, the solubility in a solvent is low, and a phenomenon in which crystals precipitate during film formation is observed. Therefore, there is a problem that an appropriate recording layer cannot be formed. When these organic chelate complexes are used, there is a problem that recording and reproduction cannot be performed.

  The object of the present invention is to have high light absorption characteristics and high refractive index in a wavelength range of 300 to 530 nm that can be recorded and reproduced by a blue semiconductor laser, and has excellent solubility in a solvent, and excellent light resistance and durability. An object of the present invention is to provide a squarylium compound metal complex and an optical recording medium using the squarylium compound metal complex.

  As a result of intensive studies to solve the above problems, the present inventors have found that a specific squarylium compound metal complex has high light absorption characteristics and high refractive index in the region of 300 to 530 nm, and is soluble in a solvent. In addition, since it was excellent in light resistance and durability, it was found useful as a recording layer of an optical recording medium, and the present invention was completed.

That is, the present invention
[1] The following general formula (A)

（式中、Ｒ^１、Ｒ^２は、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜１８の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよいアルキル基の炭素数が１〜８の直鎖又は分岐のアルキルフェニル基、又は置換基を有していてもよいアルキル基の炭素数が１〜６の直鎖又は分岐のアルキルスルホン酸基を示し、
Ｒ^３〜Ｒ^８はそれぞれ独立に水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよいヒドロキシ基、置換基を有していてもよいシアノ基、置換基を有していてもよいニトロ基、置換基を有していてもよいアミノ基、置換基を有していてもよいスルホ基、置換基を有していてもよい炭素数２〜２０の直鎖又は分岐鎖のアルケニル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜１８のアリール基、
置換基を有していてもよい炭素数３〜２０のヘテロ環、置換基を有していてもよい炭素数２〜１８の直鎖又は分岐鎖のアシル基、又は置換基を有していてもよい炭素数２〜１８の直鎖又は分岐鎖のアルコキシカルボニル基を示す。尚、Ｒ^１とＲ^２、Ｒ^２とＲ^３及びＲ^３とＲ^４は連結して環を形成してもよい。）
で示されるスクアリリウム化合物と、
金属イオンと、
からなるスクアリリウム化合物金属錯体を提供するものであり、

(In formula, R < ¹ >, R < ² > may have a C1-C20 linear or branched alkyl group which may have a hydrogen atom, a halogen atom, and a substituent, and a substituent. A linear or branched halogenated alkyl group having 1 to 12 carbon atoms, which may have a substituent, a linear or branched cyanoalkyl group having 1 to 20 carbon atoms, or a substituent. A linear or branched alkoxy group having 1 to 18 carbon atoms, a linear or branched alkylphenyl group having 1 to 8 carbon atoms which may have a substituent, or a substituent. A linear or branched alkyl sulfonic acid group having 1 to 6 carbon atoms of the alkyl group that may be present;
R ^{3 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an optionally substituted linear or branched alkyl group having 1 to 20 carbon atoms, or an optionally substituted carbon number. 1-12 linear or branched alkyl halide groups, optionally substituted linear or branched C1-C20 cyanoalkyl groups, optionally substituted hydroxy A group, a cyano group optionally having a substituent, a nitro group optionally having a substituent, an amino group optionally having a substituent, a sulfo group optionally having a substituent, A linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent, a substituent An aryl group having 6 to 18 carbon atoms, which may have
An optionally substituted heterocyclic ring having 3 to 20 carbon atoms, an optionally substituted straight chain or branched chain acyl group having 2 to 18 carbon atoms, or a substituent; Or a C2-C18 linear or branched alkoxycarbonyl group. R ¹ and R ² , R ² and R ^3, and R ³ and R ⁴ may be linked to form a ring. )
A squarylium compound represented by
Metal ions,
A squarylium compound metal complex comprising:

[2] The metal ions are Ni ions, Co ions, Zn ions, Cu ions, Pt ions, Ti ions, Al ions, V ions, Mn ions, Fe ions, Mo ions, W ions, In ions, Sn ions, The squarylium compound metal complex according to the above [1], characterized in that it is at least one selected from the group consisting of Ru ions, Cr ions, Pb ions and Eu ions,

[3] An optical recording medium having a recording layer containing the squarylium compound metal complex according to the above [1] or [2] is provided.

[4] The optical recording medium according to [3] above, wherein the recording layer contains a light stabilizer,

[5] The light stabilizer is represented by the following general formula (B)

（式中、Ｒ^９はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。）、
一般式（Ｄ）

(In the formula, each R ⁹ independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or a carbon atom having 1 to 1 carbon atoms which may have a substituent. 12 straight-chain or branched alkyl halide groups, optionally having 1 to 20 carbon atoms straight or branched cyanoalkyl groups, and optionally having 1 substituent -20 linear or branched alkoxy group, optionally substituted aryl group having 6 to 20 carbon atoms, optionally substituted aralkyl group having 7 to 20 carbon atoms or substituent A C3-C20 heterocyclic ring etc. that may have
Formula (D)

（式中、Ｒ^１１はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。）、
および一般式（Ｆ）

(In the formula, each R ¹¹ independently represents a hydrogen atom, a C 1-20 linear or branched alkyl group which may have a substituent, or a C 1 which may have a substituent. 12 straight-chain or branched alkyl halide groups, optionally having 1 to 20 carbon atoms straight or branched cyanoalkyl groups, and optionally having 1 substituent -20 linear or branched alkoxy group, optionally substituted aryl group having 6 to 20 carbon atoms, optionally substituted aralkyl group having 7 to 20 carbon atoms or substituent A C3-C20 heterocyclic ring etc. that may have
And general formula (F)

（式中、Ｒ^１３はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環を示す。またＸはＳｂＦ_６イオン、ＣｌＯ_４イオン、ＰＦ_６イオン、ＣＦ_３ＳＯ_３イオン、（ＣＦ_３ＳＯ_２）_２Ｎイオン等の異なっていても良いアニオン成分を示す。）
からなる群より選ばれる少なくとも一つであることを特徴とする、上記［４］に記載の光学記録媒体を提供するものであり、

(In the formula, each R ¹³ is independently a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or a carbon number 1 to 1 which may have a substituent. 12 straight-chain or branched alkyl halide groups, optionally having 1 to 20 carbon atoms straight or branched cyanoalkyl groups, and optionally having 1 substituent -20 linear or branched alkoxy group, optionally substituted aryl group having 6 to 20 carbon atoms, optionally substituted aralkyl group having 7 to 20 carbon atoms or substituent X represents a heterocycle having 3 to 20 carbon atoms, which may have an X. X represents SbF ₆ ion, ClO ₄ ion, PF ₆ ion, CF ₃ SO ₃ ion, (CF ₃ SO ₂ ) ₂ N ion, etc. Indicates anion components that may be different.)
The optical recording medium according to the above [4], characterized in that it is at least one selected from the group consisting of:

[6] The optical recording medium according to any one of the above [3] to [5], wherein the recording layer is capable of writing and / or reading information with a laser beam. Yes,

[7] The optical recording medium according to the above [6], wherein writing and / or reading of information by the laser beam is performed by a laser beam having a wavelength in the range of 300 nm to 530 nm. Is.

According to the present invention, it has a high light absorption property and a high refractive index property in a wavelength region of 300 to 530 nm that can be recorded and reproduced by a blue semiconductor laser, and is excellent in solubility in a solvent, and excellent in light resistance and durability. A squarylium compound metal complex and an optical recording medium using the squarylium compound metal complex can be provided.
Moreover, by making the squarylium compound used in the squarylium compound metal complex of the present invention into the structure shown in the above general formula (A), the absorption peak is shifted to the longer wavelength side, and the absorption of blue laser light at a wavelength of 405 nm is reduced. As a result, the sensitivity to blue laser light can be lowered, and the effect that excellent light resistance can be maintained appears. Therefore, it is extremely useful as an optical recording medium used for a Low to High recording method.

  Hereinafter, the squarylium compound metal complex of the present invention will be described in detail.

  The squarylium compound metal complex of the present invention comprises a squarylium compound represented by the general formula (A) and a metal ion.

R ¹ and R ² in the general formula (A) are a hydrogen atom, a halogen atom, a linear or branched alkyl group which may have a substituent, or a linear or branched which may have a substituent. A chain halogenated alkyl group, a linear or branched cyanoalkyl group which may have a substituent, a linear or branched alkoxy group which may have a substituent, or a substituent. A linear or branched alkylphenyl group which may be substituted, or a linear or branched alkylsulfonic acid group which may have a substituent is shown.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom.

  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, sec-butyl group, n A linear or branched alkyl group having 1 to 20 carbon atoms such as a 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 (G).

  General formula (G)

（式中、Ｘはハロゲン原子を示し、ｎは１〜１２の自然数、ｍは１〜２５の自然数を示す。）
上記ハロゲン化アルキル基の炭素数は１〜１２の範囲が好ましい。炭素数が１２個を越えると、スクアリリウム化合物の質量吸光係数が低下してしまう場合がある。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、スクアリリウム化合物の耐熱性、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 the formula, X represents a halogen atom, n represents a natural number of 1 to 12, and m represents a natural number of 1 to 25.)
The halogenated alkyl group preferably has 1 to 12 carbon atoms. If the number of carbon atoms exceeds 12, the mass extinction coefficient of the squarylium compound may decrease. The halogen atom of the halogenated alkyl group is not particularly limited, but a fluorine atom, that is, a fluorinated alkyl group is particularly preferable from the viewpoint of excellent effects of improving the heat resistance and light resistance of the squarylium compound.

  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 above substituent is not particularly limited. For example, a propionitrile group, a butyronitrile group, a pentylnitrile group, a 1-methylpropionitrile group, 1- Examples thereof include a methylbutyronitrile group. A linear or branched cyanoalkyl group having 1 to 20 carbon atoms is preferred, 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, ethoxyethyl group, ethoxyethyl group, ethoxypropyl group, ethoxybutyl group, An ethoxyhexyl group, an ethoxyoctyl group, a propoxymethyl group, a propoxypropyl group, a propoxyhexyl group, and a butoxyethyl group are mentioned, Preferably a C1-C18 linear or branched alkoxy group is mentioned, More preferably C3-C9 linear or branched It is an alkoxy group.

  Examples of the linear or branched alkylphenyl group which may have a substituent include a benzyl group, a phenethyl group, a phenylpropyl group, a phenyl-α-methylpropyl group, a phenyl-β-methylpropyl group, and a phenylbutyl group. And phenylpentyl group. 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.

  Examples of the linear or branched alkylsulfonic acid group that may have a substituent include a methylsulfonic acid group, an ethylsulfonic acid group, and a propylsulfonic acid group. Alkylsulfonic acid groups having a linear or branched alkyl group having 1 to 6 carbon atoms are preferred.

In the general formula (A), R ^{3 to} R ⁸ are each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group which may have a substituent, or a substituent which may have a substituent. A chain- or branched-chain halogenated alkyl group, a linear or branched cyanoalkyl group that may have a substituent, a hydroxy group that may have a substituent, or a substituent. Cyano group, optionally substituted nitro group, optionally substituted amino group, optionally substituted sulfo group, optionally substituted linear Or a branched alkenyl group, a linear or branched alkoxy group which may have a substituent, an aryl group which may have a substituent, a heterocyclic ring which may have a substituent, a substituent A linear or branched acyl group which may have a group, or a substituent And it represents an straight or branched chain alkoxycarbonyl group.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom.

Examples of the linear or branched alkyl group that may have the substituent are the same as the linear or branched alkyl group described above for R ₁ and R ₂ . The same applies to the linear or branched alkyl halide group which may have the substituent and the linear or branched cyanoalkyl group which may have the substituent. .

  Examples of the hydroxy group which may have a substituent include hydroxymethyl group, hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, hydroxyethoxymethyl. Group, 2-hydroxyethoxyethyl group, 3-hydroxyethoxypropyl group, 2-hydroxyethoxypropyl group, 4-hydroxyethoxybutyl group, 3-hydroxyethoxybutyl group, 2-hydroxyethoxybutyl group and the like.

  Examples of the cyano group that may have a substituent include a cyanomethyl group, a cyanoethyl group, a cyanopropyl group, a cyanobutyl group, and a cyanoisopropyl group.

  Examples of the nitro group which may have a substituent include a nitromethyl group, a nitroethyl group, a nitrobutyl group, and a nitropropyl group.

  Examples of the amino group which may have a substituent include alkyl-substituted amino groups such as a methylamino group, an ethylamino group, an n-propylamino group, a dimethylamino group, a diethylamino group, and a di-n-propylamino group, An acylamino group, a sulfoamino group, etc. are mentioned.

  Examples of the sulfo group that may have a substituent include a methylsulfo group, a butylsulfo group, and an arylsulfo group.

  Examples of the alkenyl group which may have a substituent include a vinyl group, an aryl group, a 1-propenyl group, a 2-pentenyl group, a 1,3-butadienyl group, a 2-octenyl group, and a 3-dodecenyl group. It is done. Preferred are linear or branched alkenyl groups having 2 to 20 carbon atoms, and more preferred are linear or branched alkenyl groups having 3 to 6 carbon atoms.

  Examples of the 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, a hexyloxy group, an octyloxy group, and a decyloxy group. Group, methoxymethyl group, methoxyethyl group, methoxypropyl group, methoxybutyl group, methoxyhexyl group, methoxyoctyl group, ethoxyethyl group, ethoxyethyl group, ethoxypropyl group, ethoxybutyl group, ethoxyhexyl group, ethoxyoctyl group, Examples thereof include linear or branched alkoxy groups having 1 to 20 carbon atoms such as propoxymethyl group, propoxypropyl group, propoxyhexyl group and butoxyethyl group, preferably linear or branched alkoxy having 1 to 6 carbon atoms. It is a group.

  Examples of the aryl group which may have a substituent include aryl groups having 6 to 18 carbon atoms such as phenyl group, tolyl group, xylyl group, mesityl group, cumenyl group and naphthyl group, preferably carbon number 6 to 12 substituted or unsubstituted aryl groups.

  Examples of the hetero ring optionally having a substituent include a furan ring, a pyrrole ring, a thiophene ring, a carbazole ring, a pyridine ring, a quinoline ring, an isoquinoline ring, an acridine ring, a pyrimidine ring, a pyrazine ring, and a phenazine ring. Examples include an imidazole ring, a triazole ring, an oxazole ring, a thiazole ring, a thiadiazole ring, and an oxadiazole ring.

  Examples of the acyl group which may have a substituent include linear or branched acyl groups having 2 to 18 carbon atoms such as acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group and isovaleryl group. Preferably, it is a C3-C9 linear or branched acyl group.

  Examples of the alkoxycarbonyl group which may have a substituent include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a butoxycarbonyl group, a 2-methoxyethoxycarbonyl group, a pentyloxycarbonyl group, and hexyl. Examples thereof include linear or branched alkoxycarbonyl groups having 2 to 18 carbon atoms such as oxycarbonyl group, octyloxycarbonyl group, undecyloxycarbonyl group, dodecyloxycarbonyl group, hexadecyloxycarbonyl group, octadecyloxycarbonyl group and the like. , Preferably it is a C2-C8 linear or branched alkoxycarbonyl group.

  For example, in the case of the general formula (A), the squarylium compound included in the metal complex of the squarylium compound of the present invention synthesizes dichlorosquaric acid of the following general formula (H) by a known method. It can be obtained by reacting with a naphthol derivative compound represented by (I).

  General formula (H)

  Formula (I)

上記式中、Ｒ^１〜Ｒ^８は一般式（Ａ）の場合と同様である。

In said formula, R < ¹ > -R < ⁸ > is the same as that of the case of general formula (A).

  Although the specific example (compound (1)-(12)) of the squarylium compound in the squarylium compound metal complex in this invention is given to the following, the said squarylium compound is not limited to these.

  In the present invention, the metal ion that forms a complex with the squarylium compound is not particularly limited as long as it forms a complex with the squarylium compound. For example, Ni ions, Co ions, Zn ions, Cu ions, Various ions such as Pt ion, Ti ion, Al ion, V ion, Mn ion, Fe ion, Mo ion, W ion, Sn ion, Ru ion, Cr ion, Pb ion, Eu ion and Ir ion are preferable, and various solvents Ni ions, Cu ions, Zn ions, Co ions, Ti ions, and Fe ions are particularly preferable in terms of solubility in light, light resistance, and durability.

  The said metal ion can use 1 type, or 2 or more types.

In the squarylium compound metal complex of the present invention, the metal interacts with one or more squarylium molecules as a metal salt even if the metal is present as a complex by binding to one or more squarylium molecules as a metal ion. A weak bond may be formed.
The coordination number in the case of a complex varies depending on the type of metal and the substituent of the squarylium compound.

  The optical recording medium of the present invention has a recording layer containing a squarylium compound metal complex composed of at least one squarylium compound of the general formula (A) and a metal ion.

  Here, the squarylium compound metal complex of the present invention may form one or two of J-type aggregates or H-type aggregates.

  Since the squarylium compound metal complex has an optical constant suitable for recording and reproduction with laser light in a short wavelength region of 300 nm to 530 nm, it is extremely useful as a compound for use in an optical recording medium for recording and reproduction with a short wavelength laser. It is.

  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 pre-groove having a constant track pitch is formed. A configuration in which the two laminated bodies are joined such that the recording layers are inwardly directed. 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 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 these 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 formation method such as a vapor phase method such as a vacuum deposition method, a sputtering method, a CVD method, a liquid phase method such as a doctor blade method, a cast method, a spin coating method, or an immersion method. Although it can be performed, 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, ester ketone solvents such as butyl acetate, ethyl lactate and cellosolve acetate; ketone solvents such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; chlorinated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane and chloroform; dimethylformamide Amide solvents such as: Hydrocarbon solvents such as methylcyclohexane; Ether solvents such as dibutyl ether, diethyl ether, tetrahydrofuran, and dioxane; Alcohol solvents such as ethanol, n-propanol, isopropanol, n-butanol, and diacetone alcohol Fluorine solvents such as 2,2,3,3-tetrafluoropropanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene And the like glycol ethers, such as recall monomethyl ether. The above solvents can be used alone or in combination of two or more in consideration of the solubility of the compound used.

  The 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.

  A light stabilizer may be used for the recording layer in order to improve the light resistance of the recording layer. As light stabilizers, transition metal chelate complexes such as acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone, aromatic nitroso compounds, aminium compounds, iminium compounds, diimonium compounds, bisiminium compounds, etc. Can be mentioned.

  Examples of the light stabilizer include one or more of the following general formulas (B) to (F) and (J) to (K).

  General formula (B)

ここでＲ^９はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。

Here, each R ⁹ is independently a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 20 carbon atoms, or an optionally substituted substituent having 1 to 12 carbon atoms. A linear or branched alkyl halide group, an optionally substituted linear or branched cyanoalkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon atom having 1 to 20 carbon atoms A linear or branched alkoxy group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent or a substituent. An optionally substituted heterocycle having 3 to 20 carbon atoms is shown.

  General formula (C)

ここでＲ^１０はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。またＸはアニオン成分を示す。

Here, each R ¹⁰ is independently a hydrogen atom, a C1-C20 linear or branched alkyl group which may have a substituent, or a C1-C12 which may have a substituent. A linear or branched alkyl halide group, an optionally substituted linear or branched cyanoalkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon atom having 1 to 20 carbon atoms A linear or branched alkoxy group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent or a substituent. An optionally substituted heterocycle having 3 to 20 carbon atoms is shown. X represents an anionic component.

Examples of the anion component of X include SbF ₆ ions, ClO ₄ ions, PF ₆ ions, CF ₃ SO ₃ ions, (CF ₃ SO ₂ ) ₂ N ions, and the like.

  Formula (D)

ここでＲ^１１はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。

Here, each R ¹¹ is independently a hydrogen atom, a C1-C20 linear or branched alkyl group which may have a substituent, or a C1-C12 which may have a substituent. A linear or branched alkyl halide group, an optionally substituted linear or branched cyanoalkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon atom having 1 to 20 carbon atoms A linear or branched alkoxy group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent or a substituent. An optionally substituted heterocycle having 3 to 20 carbon atoms is shown.

  General formula (E)

ここでＲ^１２はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。またＸはアニオン成分を示す。

Here, each R ¹² is independently a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 20 carbon atoms, or an optionally substituted substituent having 1 to 12 carbon atoms. A linear or branched alkyl halide group, an optionally substituted linear or branched cyanoalkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon atom having 1 to 20 carbon atoms A linear or branched alkoxy group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent or a substituent. An optionally substituted heterocycle having 3 to 20 carbon atoms is shown. X represents an anionic component.

Examples of the anion component of X include SbF ₆ ions, ClO ₄ ions, PF ₆ ions, CF ₃ SO ₃ ions, (CF ₃ SO ₂ ) ₂ N ions, and the like.

  Formula (F)

ここでＲ^１３はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。またＸは、アニオン成分を示す。

Here, each R ¹³ is independently a hydrogen atom, a C1-C20 linear or branched alkyl group which may have a substituent, or a C1-C12 which may have a substituent. A linear or branched alkyl halide group, an optionally substituted linear or branched cyanoalkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon atom having 1 to 20 carbon atoms A linear or branched alkoxy group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent or a substituent. An optionally substituted heterocycle having 3 to 20 carbon atoms is shown. X represents an anionic component.

Examples of the anion component of X include SbF ₆ ions, ClO ₄ ions, PF ₆ ions, CF ₃ SO ₃ ions, (CF ₃ SO ₂ ) ₂ N ions, and the like.

  General formula (J)

ここでＲ^１４はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。またＸはアニオン成分を示す。

Here, each R ¹⁴ is independently a hydrogen atom, a C1-C20 linear or branched alkyl group which may have a substituent, or a C1-C12 which may have a substituent. A linear or branched alkyl halide group, an optionally substituted linear or branched cyanoalkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon atom having 1 to 20 carbon atoms A linear or branched alkoxy group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent or a substituent. An optionally substituted heterocycle having 3 to 20 carbon atoms is shown. X represents an anionic component.

  Examples of the anion component of X include tetraethylammonium ion, tetrabutylammonium ion, and tetrahexylphosphonium ion.

  General formula (K)

ここでＮｉイオンに替えて、Ｆｅイオン、Ｐｄイオン等であってもよい。
またＸはＰ（ＯＣＨ_３）_３等を示す。

Here, instead of Ni ions, Fe ions, Pd ions, or the like may be used.
X represents P (OCH ₃ ) ₃ or the like.

  General formula (L)

ここでＲ^１５はそれぞれ独立に水素原子、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルキル基、置換基を有していてもよい炭素数１〜１２の直鎖又は分岐鎖のハロゲン化アルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のシアノアルキル基、置換基を有していてもよい炭素数１〜２０の直鎖又は分岐鎖のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数７〜２０のアラルキル基または置換基を有していてもよい炭素数３〜２０のヘテロ環等を示す。またＸはＳＯ_３基等、ＭはＮｉイオン、Ｃｏイオン等の遷移金属を示す。

Here, each R ¹⁵ is independently a hydrogen atom, a C1-C20 linear or branched alkyl group which may have a substituent, or a C1-C12 which may have a substituent. A linear or branched alkyl halide group, an optionally substituted linear or branched cyanoalkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon atom having 1 to 20 carbon atoms A linear or branched alkoxy group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent or a substituent. An optionally substituted heterocycle having 3 to 20 carbon atoms is shown. X represents a SO ₃ group or the like, and M represents a transition metal such as Ni ion or Co ion.

Among the light stabilizers, the general formulas (B), (D), and (F) are preferable because no precipitate is generated even when they are mixed with the squarylium compound metal complex in an organic solvent.
More preferably, R ^{9 in the} general formula (B) is independently an isobutyl group or a cyanobutyl group.

More preferably, R _{11 in the} general formula (D) is independently an isobutyl group, a cyanobutyl group, an N, N-diisobutylamino group or an N, N-dicyanobutyl group.
It is more preferable that R _{13 in the} general formula (F) is independently an isobutyl group, a cyanobutyl group, an N, N-diisobutylamino group, or an N, N-dicyanobutyl group.

  Although the usage-amount of the said light stabilizer is 0.01-100 mass parts normally with respect to 100 mass parts of said squarylium compound metal complexes, if it is the range of 1-80 mass parts, it is preferable. If the amount used is increased further, the extinction coefficient decreases, and if it is decreased, a sufficient stabilizing effect may not be obtained.

  A light reflecting layer may be formed on the recording layer, and the thickness thereof is preferably 50 to 300 nm. As a material of the light reflecting layer, a material having a sufficiently high reflectance at the wavelength of the reproduction light, for example, Au, Al, Ag, Cu, Ti, Cr, Ni, Pt, Ta, and Pd metal alone or in an alloy is used. It is possible to use. 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 thickness of the light reflection layer is generally in the range of 10 to 300 nm, preferably in the range of 50 to 200 nm.

The material of 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 obtained by dissolving the resin in a suitable solvent to the surface of the substrate on which the recording layer or the light reflecting layer is formed, and drying. Can do.

  A protective layer using a UV curable resin is obtained by applying a coating solution dissolved in the resin alone or in an appropriate solvent to the surface of a substrate on which a recording layer or a light reflecting layer is formed, and then 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 coating method such as a spin coating method and a casting method, a sputtering method, a chemical vapor deposition method, and the like are used as in 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 to 30 μm in the present invention.

  The laser beam used for the optical recording medium of the present invention is selected to have a short wavelength region capable of high-density recording, preferably a blue-violet semiconductor laser beam having an oscillation wavelength of 350 to 430 nm, more preferably 390 to 390 nm. Blue-violet semiconductor laser light having an oscillation wavelength of 420 nm is used.

  Recording on the optical recording medium of the present invention is performed by irradiating a 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. As a result, the optical recording medium of the present invention can write and / or read information by laser light.

  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”.

(Example 1)
(1) In a three-necked flask equipped with a condenser, 23.0 parts of 3,4-dichloro-3-cyclobutene-1,2-dione and 25.0 parts of N, N-dimethyl-1-naphthylamine are added, and toluene is added thereto. 300 parts were added and stirred at room temperature for 10 hours. After completion of the reaction, the precipitated solid was collected by filtration under reduced pressure. After recrystallization from acetone, the residue was dried under reduced pressure to obtain 38.0 parts of a squarylium intermediate. Next, 38.0 parts of the obtained squarylium intermediate and 50.0 parts of acetic acid were placed in a three-necked flask equipped with a condenser, and 100 parts of water was placed therein, followed by heating and stirring at 100 ° C. for 24 hours. After the reaction, the precipitated solid was cooled and collected by filtration under reduced pressure. After washing with water, it was dried under reduced pressure to obtain 29.0 parts of squarylium compound (1).

  (2) In a three-necked flask equipped with a condenser tube, 4.0 parts of squarylium compound (1) and 2.0 parts of nickel acetate tetrahydrate are added, and 50 parts of THF is added thereto, and heated at 60 ° C. for 4 hours. Stir. After the reaction, the reaction mixture was cooled to room temperature, and the precipitated solid was collected by filtration under reduced pressure. After washing with water, drying under reduced pressure yielded 4.5 parts of a squarylium compound (1) -nickel complex.

  The squarylium compound metal complex (1) -nickel complex obtained in Example 1

(Example 2)
A squarylium compound metal complex was obtained in the same manner as in Example 1 except that cobalt acetate was used instead of nickel acetate tetrahydrate. The chemical structure is described below.

  The squarylium compound metal complex (1) -cobalt complex obtained in Example 2

(Example 3)
(1) 33.0 parts of 3,4-dichloro-3-cyclobutene-1,2-dione and 30.0 parts of 4-naphthalene-1-morpholine are placed in a three-necked flask equipped with a condenser, and 300 parts of toluene is added thereto. And stirred at room temperature for 10 hours. After completion of the reaction, the precipitated solid was collected by filtration under reduced pressure. After recrystallization from acetone, drying was performed under reduced pressure to obtain 39.0 parts of a squarylium intermediate. Next, 39.0 parts of the obtained squarylium intermediate and 50.0 parts of acetic acid were added to a three-necked flask equipped with a cooling tube, 100 parts of water and 100 parts of DMF were added, and the mixture was heated and stirred at 100 ° C. for 24 hours. After the reaction, the precipitated solid was cooled and collected by filtration under reduced pressure. After washing with water, it was dried under reduced pressure to obtain 28.0 parts of squarylium compound (8).

  (2) In a three-necked flask equipped with a condenser tube, 4.0 parts of squarylium compound (8) and 2.0 parts of zinc acetate dihydrate are placed, and 50 parts of THF is placed therein, and heated at 60 ° C. for 4 hours. Stir. After the reaction, the reaction mixture was cooled to room temperature, and the precipitated solid was collected by filtration under reduced pressure. After washing with water, drying under reduced pressure yielded 4.5 parts of a squarylium compound (8) -zinc complex.

  The squarylium compound metal complex (8) -zinc complex obtained in Example 3

(Example 2)
A squarylium compound metal complex was obtained in the same manner as in Example 3 except that iron chloride was used instead of zinc acetate dihydrate. The chemical structure is described below.

  The squarylium compound metal complex (8) -iron complex obtained in Example 4

(Comparative Examples 1, 2, 3)
As a comparative example, the characteristics of the following squarylium compound metal complexes described in JP-A-2006-249209 were measured in the same manner as in Examples, and the results are shown in Table 1.

  (Comparative Example 1)

  (Comparative Example 2)

  (Comparative Example 3)

  The results are shown in Table 1.

  The squarylium compound metal complexes of Examples 1 to 4 of the present invention have light absorption at 430 to 450 nm and a high molar extinction coefficient. In the squarylium compound metal complexes of Comparative Examples 1 to 3, the wavelength was 370 to 410 nm, and Examples 1 to 4 resulted in a longer wavelength shift of about 30 to 50 nm.

(Light resistance test of coating film)
Each was formed on a glass substrate by spin coating using a 1: 1 mixed solvent of fluoroalcohol and ethanol under the conditions of 2000 rpm and 10 seconds. The film thickness at this time was 100 nm.

What added the light stabilizer to the squarylium compound metal complex of the above-mentioned Examples 1-2 was made into Examples 5-6, respectively, and what added the light stabilizer to the squarylium compound metal complex of Examples 3-4 Examples 7 to 8 are respectively used, and those obtained by adding a light stabilizer to the squarylium compound metal complexes of Comparative Examples 1 to 3 are referred to as Comparative Examples 4 to 6, respectively. The amount of the light stabilizer used was 25% by mass with respect to the amount of the metal complex.
The light stabilizers shown below were used.

実施例１〜８、比較例１〜６の塗布膜を３２０Ｗキセノンランプ、６３℃雰囲気下で所定時間照射した。λｍａｘにおける初期の吸光度を１００％とし、所定時間後の吸光度の百分率を色素残存率として算出した。これらの結果を表２に示す。
表２に示すように、本発明の実施例１〜４の塗布膜は照射２４時間経過後では色素残存率が８０％程度の耐光性を有し、安定化剤を加えた実施例５〜８は照射２４時間経過後で色素残存率が９３％程度と優れた耐光性を示した。
一方、比較例１〜３では２４時間後の色素残存率が０％とスクアリリウム化合物が変化し、比較例４〜６においても２４時間後の色素残存率が３０％程度と低く、良好な耐光性を維持することができなかった。
吸収ピークを長波長側にシフトさせることにより４０５ｎｍにおける吸光係数を小さくし、また耐光性が向上する結果となった。

The coating films of Examples 1 to 8 and Comparative Examples 1 to 6 were irradiated with a 320 W xenon lamp at 63 ° C. for a predetermined time. The initial absorbance at λmax was taken as 100%, and the percentage of absorbance after a predetermined time was calculated as the dye residual ratio. These results are shown in Table 2.
As shown in Table 2, the coating films of Examples 1 to 4 of the present invention have light resistance with a dye residual ratio of about 80% after 24 hours of irradiation, and Examples 5 to 8 to which a stabilizer is added. Exhibited excellent light resistance with a dye residual ratio of about 93% after 24 hours of irradiation.
On the other hand, in Comparative Examples 1 to 3, the dye residual rate after 24 hours changed to 0% and the squarylium compound changed. In Comparative Examples 4 to 6 as well, the dye residual rate after 24 hours was as low as about 30% and good light resistance. Could not be maintained.
By shifting the absorption peak to the long wavelength side, the extinction coefficient at 405 nm was reduced, and the light resistance was improved.

UV-Vis absorption spectrum of the solution of Example 1 UV-Vis absorption spectrum of the coating film of Example 1

Claims (7)

The following general formula (A)

(In formula, R < ¹ >, R < ² > may have a C1-C20 linear or branched alkyl group which may have a hydrogen atom, a halogen atom, and a substituent, and a substituent. A linear or branched halogenated alkyl group having 1 to 12 carbon atoms, which may have a substituent, a linear or branched cyanoalkyl group having 1 to 20 carbon atoms, or a substituent. A linear or branched alkoxy group having 1 to 18 carbon atoms, a linear or branched alkylphenyl group having 1 to 8 carbon atoms which may have a substituent, or a substituent. A linear or branched alkylsulfonic acid group having 1 to 6 carbon atoms in the alkyl group which may be
R ^{3 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an optionally substituted linear or branched alkyl group having 1 to 20 carbon atoms, or an optionally substituted carbon number. 1-12 linear or branched alkyl halide groups, optionally substituted linear or branched C1-C20 cyanoalkyl groups, optionally substituted hydroxy A group, a cyano group optionally having a substituent, a nitro group optionally having a substituent, an amino group optionally having a substituent, a sulfo group optionally having a substituent, A linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent, a substituent An aryl group having 6 to 18 carbon atoms, which may have
An optionally substituted heterocyclic ring having 3 to 20 carbon atoms, an optionally substituted straight chain or branched chain acyl group having 2 to 18 carbon atoms, or a substituent; Or a C2-C18 linear or branched alkoxycarbonyl group. R ¹ and R ² , R ² and R ^3, and R ³ and R ⁴ may be linked to form a ring. )
A squarylium compound represented by
Metal ions,
A squarylium compound metal complex comprising   The metal ions are Ni ions, Co ions, Zn ions, Cu ions, Pt ions, Ti ions, Al ions, V ions, Mn ions, Fe ions, Mo ions, W ions, In ions, Sn ions, Ru ions, The squarylium compound metal complex according to claim 1, wherein the metal complex is at least one selected from the group consisting of Cr ions, Pb ions, and Eu ions.   The optical recording medium which has a recording layer containing the squarylium compound metal complex of Claim 1 or 2.   The optical recording medium according to claim 3, wherein the recording layer contains a light stabilizer. The light stabilizer is represented by the following general formula (B)

(In the formula, each R ⁹ independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or a carbon atom having 1 to 1 carbon atoms which may have a substituent. 12 straight-chain or branched alkyl halide groups, optionally having 1 to 20 carbon atoms straight or branched cyanoalkyl groups, and optionally having 1 substituent -20 linear or branched alkoxy group, optionally substituted aryl group having 6 to 20 carbon atoms, optionally substituted aralkyl group having 7 to 20 carbon atoms or substituent A C3-C20 heterocyclic ring etc. that may have
Formula (D)

(In formula, R <^11> is respectively independently a hydrogen atom, the C1-C20 linear or branched alkyl group which may have a substituent, and C1-C1 which may have a substituent. 12 straight-chain or branched alkyl halide groups, optionally having 1 to 20 carbon atoms straight or branched cyanoalkyl groups, and optionally having 1 substituent -20 linear or branched alkoxy group, optionally substituted aryl group having 6 to 20 carbon atoms, optionally substituted aralkyl group having 7 to 20 carbon atoms or substituent A C3-C20 heterocyclic ring etc. that may have
And general formula (F)

(In the formula, each R ¹³ is independently a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or a carbon number 1 to 1 which may have a substituent. 12 straight-chain or branched alkyl halide groups, optionally having 1 to 20 carbon atoms straight or branched cyanoalkyl groups, and optionally having 1 substituent -20 linear or branched alkoxy group, optionally substituted aryl group having 6 to 20 carbon atoms, optionally substituted aralkyl group having 7 to 20 carbon atoms or substituent And a heterocycle having 3 to 20 carbon atoms, which may have X. X represents SbF ₆ ion, ClO ₄ ion, PF ₆ ion, CF ₃ SO ₃ ion, (CF ₃ SO ₂ ) ₂ N ion, etc. The anion component which may be different is shown.)
The optical recording medium according to claim 4, wherein the optical recording medium is at least one selected from the group consisting of:   The optical recording medium according to claim 3, wherein the recording layer is capable of writing and / or reading information with a laser beam.   The optical recording medium according to claim 6, wherein the writing and / or reading of information by the laser beam is performed by a laser beam having a wavelength in a range of 300 nm to 530 nm.

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