JPH1053710A - Methine compound and optical recording medium containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a methine compound having high reflectivity, solubility and storage stability by reacting a specified tribasic aldehyde derivative with a 1,1-diphenylethene derivative. SOLUTION: A tribasic aldehyde derivative represented by formula I is condensed with a 1,1-diphenylethene derivative represented by formula II at 0-80 deg.C in an acidic medium comprising acetic acid and/or acetic anhydride to obtain a methine compound represented by formula III [wherein R1 is an (un)substituted alkyl; R2 is a halogen, a lower alkyl, an alkyloxy or phenyl, provided that the adjoining groups may be combined to each other to form an aromatic ring; n is 0-2; R3 to R6 are each an (un)substituted alkyl, an (un)substituted alkenyl or an (un)substituted aryl; Y is O, NR7 -, S, selenium, -C(CH3 )2 - or -CH=CH-; R7 is an (un)substituted alkyl; and X is an anion, provided it is null when R1 is a sulfoalkyl].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methine compound and an optical recording medium containing the same, and more particularly to a methine compound useful for information recording, reproduction or image formation by laser light and an optical recording medium containing the same. About.

[0002]

2. Description of the Related Art Hitherto, various dyes such as phthalocyanine derivatives and indolenine-based cyanine dyes have been proposed as recording media for organic dyes, particularly as CD-R dyes that can be recorded only once. However, phthalocyanine dyes are lightfast,
Despite excellent storage resistance, due to restrictions on solvents that do not attack commonly used polycarboxylates, there is not much solubility in solvents, and when applying a dye dissolved in a solvent on a substrate, a desired concentration can be obtained. The cyanine dye, which is another dye, has a certain degree of solvent solubility, but the type of solvent that can be used is also limited, and further, there is a problem in light resistance, storage resistance, and the like.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compound which is excellent in solubility in a solvent, has a high reflectance, and has good storage stability, and an optical recording medium using the compound.

[0004]

Means for Solving the Problems The present inventors have made intensive efforts to solve the above-mentioned problems, and as a result, the following formula (1) has been obtained.
A methine compound having good solvent solubility having a structure as described above is synthesized, and at least one methine compound is further synthesized.
The inventors have found that a stable optical recording material can be produced by incorporating the compound into an optical recording medium, and have completed the present invention. That is, the present invention relates to (1) a methine compound represented by the following formula (1):

[0005]

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(In the formula (1), R ₁ represents a substituted or unsubstituted alkyl group, and R ₂ represents a halogen atom, a lower alkyl group, an alkyloxy group, a phenyl group or an adjacent group linked to form an aromatic ring. N may be 0 to 2
It represents an _{integer, R 3, R 4, R} 5, R 6 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, further, R ₃ And R ₄ and R ₅ and R ₆ may be linked to form a ring. Y is an oxygen atom, -NR ₇ -, sulfur atom,
A selenium _{atom, -C (CH 3) 2 -} , - represents CH = CH-, R ₇ represents a substituted or unsubstituted alkyl group, X
Represents an anion (however, when R ₁ is an alkyl sulfonate group, X does not exist); (2) R ₃ , R ₄ , R ₅ ,
The methine compound according to (1), wherein R ₆ is the same substituted or unsubstituted alkyl group, (3) Y is —C (CH
₃ ) The methine compound according to (1), which is _2- , (4)
R ₁ is a substituted or unsubstituted alkyl group of C1-C6 methine compound described in (1), (5) R 2 is a hydrogen atom or a chlorine _{atom, R 3, R 4, R} 5, R 6 Is C
(1) a methine compound according to (1), which is a substituted or unsubstituted alkyl group of 1 to 6;
(7) An optical recording medium carrying a recording layer containing at least one of the compounds according to (5).
The optical recording medium according to (6), further comprising a singlet oxygen quencher in the recording layer.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the general formula (1), R ₁ , R
_3, as the _{R 4, R 5, R 6} , unsubstituted alkyl groups represented by R _7, for example a methyl group, an ethyl group, a propyl group, an isopropyl group, 2-methylpropyl, butyl, t- butyl group, C1 to C18 alkyl groups such as pentyl group, hexyl group, dodecyl group and octadecyl group, preferably C1 to C4 alkyl groups. Examples of the substituent of the substituted alkyl group include an alkyloxy group, a halogen atom, an alkyloxyalkyloxy group, an aryl group,
A hydroxyl group, etc., specifically, hydroxymethyl group, methoxyethyl group, ethoxyethyl group, butoxyethyl group, phenylethyl group, phenylpropyl group, benzyl group, tetrafluoropropyl group, trifluoroethyl group, methoxyethyl group; C1 to C9 substituted alkyl groups such as an oxyethyl group, a methoxypropyl group, a hydroxypropyl group, a furfuryl group, and an acetyloxyethyl group are preferable, and a C1 to C6 substituted alkyl group is preferable. Examples of the substituted alkyl group for R ₁ include 3
And alkyl sulfonate groups such as -sulfonylpropyl group and 4-sulfonylbutyl group. Examples of the halogen atom for R ₂ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom is preferable. As the lower alkyl group, a C1- such as a methyl group, an ethyl group, a propyl group, and a butyl group is preferred. A C4 alkyl group is mentioned, and the alkyloxy group is a C1-C4 alkoxy group such as a methoxy group, an ethoxy group, a propyloxy group, a butoxy group, and n is preferably 0 or 1. R ₃ , R ₄ , R ₅ ,
Examples of the substituted or unsubstituted alkenyl group for R ₆ include C3-C3 such as an allyl group, a butenyl group and a cinnamyl group.
9 alkenyl groups; and substituted or unsubstituted aryl groups include phenyl, 4-chlorophenyl,
And C6-C7 aryl groups such as 4-methylphenyl group.

Preferred as the ring formed by linking R ₃ and R ₄ and between R ₅ and R ₆ are a 5-membered ring and a 6-membered ring. Specific examples include a pyrrolidine ring, a piperidine ring and a morpholine ring. Preferred examples of Y include an oxygen atom, a sulfur atom, and -CH = CH-.
-C a solubility (CH _{3) 2} - are more preferable. Examples of the anion X include an organic anion such as an organic carboxylic acid and an organic sulfonic acid, an inorganic anion such as a halogen ion, and a transition metal complex anion. Specific examples of the organic acid anion include an acetate ion and a methanesulfonic acid ion. Tetraphenylborate ion, butyltriphenylborate ion, toluenesulfonic acid ion, 4-hydroxynaphthalenesulfonic acid ion, naphthalenesulfonic acid ion, lactate ion, benzenesulfonic acid ion, ethanesulfonic acid ion, trifluoroacetate ion, propionic acid Ion, benzoate ion, oxalate ion, succinate ion, stearic acid ion, trifluoromethanesulfonate ion, and the like. Examples of transition metal complex anions are Ni complex of benzenedithiol derivative and naphthalenedithiol derivative Ni complexes, paintings exhibition thiol derivative N
i complex and the like. Specific examples of inorganic anions include chloride ion, bromine ion, fluorine ion, thiocyanate ion, iodine ion, hexamonate antimonate ion, perchlorate ion, nitrate ion, tetrafluoroborate ion, hexafluorophosphate ion , Molybdate, tungstate, titanate, vanadate, phosphate, borate, etc.
Preferred examples include tetrafluoroborate ion, hexafluorophosphate ion, perchlorate ion and the like.

Specific examples of the compound of the formula (1) of the present invention include, but are not limited to, the following compounds.

[0010]

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[0011]

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[0012]

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[0013]

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[0014]

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[0015]

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[0016]

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[0017]

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[0018]

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[0019]

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[0020]

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The compound represented by the general formula (1) of the present invention comprises a tribase aldehyde derivative represented by the following formula (2) and a 1,1-diphenylethene derivative represented by the following formula (3): In a solvent, preferably in acetic acid or in an acidic medium such as in acetic anhydride or in a mixed solvent of acetic anhydride and acetic acid,
It is obtained by performing a condensation reaction at 0 to 80 ° C, preferably 5 to 30 ° C. When the counter ion is exchanged, the corresponding acid or a salt thereof can be dissolved in a solvent capable of dissolving the same, preferably acetic anhydride or acetic acid, or the dye once removed is added to an alcohol, DMF, acetic acid or the like. It can be synthesized by a method of dissolving in a water-soluble solvent or a mixed solvent thereof and water and adding an acid or salt of a desired anion to carry out salt exchange.

[0022]

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The compound represented by the general formula (1) of the present invention can also be described as the above formula (4) in consideration of resonance.

The recording medium of the present invention comprises a substrate and a recording layer containing a methine compound, and if necessary, a reflective layer and a surface coat layer are provided. The methine compounds in the recording layer may be used alone or in combination of two or more, and may be used in combination with a dye other than the dye of the present invention. Examples of the dye other than the dye of the present invention include a cyanine dye, a squarylium dye, an indoaniline dye, a phthalocyanine dye, and an azo dye. In addition, various antioxidants, ultraviolet absorbers, and singlet oxygen quencher may be used in combination for improving reading durability and light resistance. As the singlet oxygen quencher, a transition metal complex such as a general nickel complex or an aminium-based or diimonium-based compound (for example, IRG-002, IRG-
022, IRG-023, etc.), and various resins may be used in combination. In the present invention, a conjugate of the cation of the compound represented by the general formula (1) and the anion of the quencher can also be used. The quencher is generally used as needed in an amount of 0.01 to 10 mol, preferably 0.03 to 1.2 mol, per 1 mol of the compound of the general formula (1).

As the substrate, any known substrate can be used. For example, glass, metal plates or plastics are mentioned.
Polycarbonate resin, methacrylic resin, polysulfone resin, polyimide resin, amorphous polyolefin resin, polyester resin, polypropylene resin and the like can be mentioned.
Examples of the shape of the substrate include various shapes such as a disk shape, a card shape, a sheet shape, and a roll film shape.

A guide groove may be formed on a glass or plastic substrate to facilitate tracking during recording. A glass or plastic substrate may be provided with an undercoat layer such as a plastic binder or an inorganic oxide or an inorganic sulfide. The undercoat layer preferably has a lower thermal conductivity than the substrate.

The recording layer in the present invention comprises, for example, a methine compound represented by the general formula (1) and, if necessary, an organic solvent such as tetrafluoropropanol, diacetone alcohol, methanol, ethanol or methyl. Cellosolve, ethyl cellosolve, isopropyl alcohol, acetone, methyl ethyl ketone, dichloroethane, dichloromethane, propylene glycol monomethyl ether monoacetate, cyclohexanone,
-Hydroxy-3-methyl-2-butanone
If necessary, it can be obtained by adding an appropriate binder and applying the solution on a substrate by a spin coater or the like. Other methods include a vacuum deposition method, a sputtering method, a doctor blade method, a casting method, and a dipping method in which a substrate is immersed in a solution.

The thickness of the recording layer is 0.01 μm-5 μm,
Preferably, it is 0.02 μm-3 μm, and in the case of reflection reading, it is more preferably an odd multiple of １ ／ of the laser wavelength used for reading.

The optical recording medium of the present invention can be provided with an undercoat layer on the substrate, a protective layer on the recording layer, and a reflective layer on the substrate or the recording layer, if necessary. When a reflective layer is provided, the reflective layer may be formed by a vapor deposition method, a sputtering method, an ion plating method, or a silver mirror reaction by reduction of a metal salt such as gold, silver, or copper or a metal complex salt.

Recording of information on the optical recording medium of the present invention,
Alternatively, the image is formed by a laser, for example, a semiconductor laser, a helium-neon laser, a He-Cd laser,
It is performed by irradiating the recording layer with a focused high-energy beam such as a YAG laser or Ar laser through the substrate or from the opposite side of the substrate. Reading of information or images is performed by irradiating a low-output laser beam. This is performed by detecting the difference between the amount of reflected light or the amount of transmitted light between the pit portion and the portion where no pit is formed.

[0031]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the examples, parts are by weight unless otherwise specified. Example 1 To a mixed solvent of 5 parts of acetic acid and 2 parts of acetic anhydride, 0.72 parts of tribase aldehyde was added, and 1.16 parts of 1,1-bis (p-diethylaminophenyl) ethene was further added. After stirring for 5 minutes, a solution of 0.75 part of 42% borofluoric acid was added to 5.39 parts of acetic anhydride under cooling with care, and the mixture was stirred at room temperature overnight. Then water 25
After stirring at room temperature for 4 hours, the mixture was filtered, washed with 60 parts of water, and dried to obtain dark green crystals of Compound Example (1) (λmax 659 nm (acetone), mp.
218-220 ° C). The crystals were added at 5% to diacetone alcohol at room temperature, stirred, and filtered through a membrane filter. No insoluble matter was recognized on the filter, and a 5% solution was easily obtained. Compound examples (2) to (3) by reacting the corresponding tribase aldehyde derivative with the 1,1-diphenylethene derivative and adding the corresponding anion-forming compound in the same manner as described above.
(33) can be synthesized.

Example 2 (Example of recording medium) 0.2 part of the compound (1) obtained in Example 1 was dissolved in 10 parts of diacetone alcohol and passed through a 0.2 μm filter to obtain a coating solution. Was. 5 ml of this solution was dropped on a 5-inch grooved polycarbonate resin substrate with a pipette, applied by a spin coater, and dried at 50 ° C. for 5 minutes to form a recording layer. The maximum absorption wavelength of the coating film was 689 nm. The reflectance was 79% (780 nm). When the obtained coating film was irradiated with a semiconductor laser beam having a center wavelength of 830 nm at an output of 6 mW, pits with clear contours were formed. Further, the coated substrate was set at 1.3 m /
While rotating at s, the recording frequency is 720 with a semiconductor laser beam having a center wavelength of 780 nm and a laser beam diameter of 1.6 μm.
Irradiation at KHz, C / N ratio 51d at output 8mW
b was obtained. The storage stability of this coating film is 60 ° C x 80% R
Under H conditions, it was good for 25 days or more.

[0033]

The methine compound of the present invention has a high solubility in an organic solvent, and a dye film can be easily obtained by coating. Further, it is characterized by high reflectance and good storage stability, and is useful as a dye for optical recording media.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C07D 235/14 C07D 263/56 263/56 277/64 277/64 293/12 293/12 8721− 5D G11B 7/24 516 G11B 7/24 516 B41M 5/26 Y

Claims (7)

[Claims] A methine compound represented by the following formula (1): (In the formula (1), R ₁ represents a substituted or unsubstituted alkyl group, and R ₂ represents a halogen atom, a lower alkyl group, an alkyloxy group, a phenyl group or an adjacent group linked to form an aromatic ring. N is an integer of 0 to 2, and R ₃ , R ₄ , R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group And R ₃ and R ₄ , or R ₅ and R ₆ may be linked to form a ring, Y is an oxygen atom, —NR ₇ —, a sulfur atom, a selenium atom, —C (CH ₃ ) _2- , -CH = CH-, and R ₇
Represents a substituted or unsubstituted alkyl group, X represents an anion (provided that when R ₁ is an alkyl sulfonate group, X
Does not exist)). 2. The methine compound according to claim 1, wherein R ₃ , R ₄ , R ₅ and R ₆ are the same substituted or unsubstituted alkyl group. 3. The methine compound according to claim 1, wherein Y is —C (CH ₃ ) ₂ —. 4. The methine compound according to claim 1, wherein R ₁ is a C1-C6 substituted or unsubstituted alkyl group. Wherein R ₂ is a hydrogen atom or a chlorine atom, R
_{3, R 4, R 5,} R 6 are methine compound according to claim 1 is a substituted or unsubstituted alkyl group of C1 -C6. 6. An optical recording medium having a recording layer containing at least one of the compounds according to claim 1 on a substrate. 7. The optical recording medium according to claim 6, wherein the recording layer has a singlet oxygen quencher.