JP2007283500A - Optical information recording medium and information recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information recording medium which has the favorable high-density recording and reproduction of information, and has also favorable preservabilities against light and against wet heat, and also to provide the optimum information recording method for the optical information recording medium. <P>SOLUTION: In the optical information recording medium having a recording layer recordable with information by being irradiated with laser beam having a wavelength of ≤440 nm on a board, the recording layer includes a coloring matter consisting of a cationic portion and an anionic portion under the condition that the coloring matter consists of a cationic chromophore and an anionic counter-ion, or of an anionic chromophore and a cationic counter-ion, and each counter-ion is an organic counter-ion and contains ≥1 substituent having its A value as a steric parameter of ≥2.0 (kcal/mol). Information recording method is to irradiate the laser beam having the wavelength of ≤440 nm on the optical information recording medium for recording information. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical information recording medium and an information recording method capable of recording and reproducing information using a laser beam. In particular, the present invention relates to a heat mode type optical information recording medium and information recording method suitable for recording information using a short wavelength laser beam having a wavelength of 440 nm or less.

  Conventionally, an optical information recording medium (optical disc) capable of recording information only once by laser light is known. This optical disk is also called a recordable CD (so-called CD-R), and its typical structure is a recording layer made of an organic dye on a transparent disk-shaped substrate, a light reflecting layer made of a metal such as gold, and a resin. A protective layer made of a metal is provided in this order in a laminated state. Information recording on this CD-R is performed by irradiating the CD-R with a near-infrared laser beam (usually a laser beam having a wavelength near 780 nm), and the irradiated portion of the recording layer emits the light. Information is recorded by absorbing and locally raising the temperature, causing a physical or chemical change (eg, pit generation) and changing its optical properties. On the other hand, reading (reproduction) of information is also performed by irradiating laser light having the same wavelength as the recording laser light, and the part where the optical characteristics of the recording layer have changed (recorded part) and the part not changed (unrecorded) Information is reproduced by detecting the difference in reflectance from (part).

  Recently, networks such as the Internet and high-definition TV are rapidly spreading. Also, due to the broadcast of HDTV (High Definition Television), there is an increasing demand for a large-capacity recording medium for easily and inexpensively recording image information. The above-mentioned CD-R and a write-once digital vasatile disc (so-called DVD-R) capable of high-density recording using a visible laser beam (630 nm to 680 nm) as a recording laser are positioned as large-capacity recording media. However, it cannot be said that the recording capacity is sufficiently large to meet future demands. Therefore, development of an optical disc having a higher recording capacity by using a laser beam having a shorter wavelength than that of a DVD-R has been developed. For example, a Blu-ray method using a blue laser of 405 nm An optical recording disk called “Launch” was launched.

In an optical information recording medium having a recording layer containing an organic dye, a recording / reproducing method for recording / reproducing information by irradiating a laser beam having a wavelength of 530 nm or less from the recording layer side toward the light reflecting layer side is disclosed. Yes. Specifically, an information recording / reproducing method has been proposed in which information is recorded / reproduced by irradiating a laser beam having a wavelength of 550 nm or less onto an optical disk using a cyanine dye as a dye of the recording layer (for example, Patent Documents 1 to 3). 5). In addition, an information recording / reproducing method has been proposed in which information is recorded / reproduced by irradiating an optical disk using an oxonol dye as a dye of a recording layer with a laser beam of 550 nm or less (see, for example, Patent Documents 1 to 22). .
JP 2001-287460 A JP 2001-287465 A JP 2001-253171 A JP 2001-39034 A JP 2000-318313 A JP 2000-318312 A JP 2000-280621 A JP 2000-280620 A JP 2000-263939 A JP 2000-222772 A JP 2000-222771 A JP 2000-218940 A JP 2000-158818 A JP 2000-149320 A JP 2000-108513 A JP 2000-113504 A JP 2002-301870 A JP 2001-287465 A US Patent 2002 / 76648A1 JP 2003-94828 A JP 2001-71638 A JP 2004-188968 A

  However, according to the study of the present inventor, the known cyanine dyes described in Patent Documents 1 to 21 use a halogen atom or an organometallic ion as a counter anion, and environmental considerations are not sufficient. Further, optical resistance using a known oxonol dye was not at a level where the light resistance was satisfactory. The oxonol dye described in Patent Document 22 has sufficient light preservability, but does not describe a dye capable of recording information with a laser having a wavelength of 440 nm or less. Further, the optical disk using the known oxonol dye described in the above patent document has a satisfactory level of reproduction durability, and is unsatisfactory in practice.

  In view of the above, an object of the present invention is to solve the above conventional problems. In other words, the present invention is an optical information recording medium that can perform high-density recording and reproduction of information performed by irradiation with a laser beam of 440 nm or less, and has good light storage properties and wet heat storage properties in consideration of the environment. And an information recording method optimum for the optical information recording medium.

  The present inventors have found that the light preservability is caused by the association state of the methine dye, improves the light preservability by introducing a bulky substituent that suppresses the association, and further introduces a bulky substituent. An environmentally friendly dye with improved wet heat storage was developed and the following invention was completed.

  That is, the optical information recording medium of the present invention has on a substrate a recording layer capable of recording information by irradiation with laser light having a wavelength of 440 nm or less, and the recording layer contains a dye composed of a cation portion and an anion portion. The dye comprises a cationic chromophore and an anionic counterion, or an anionic chromophore and a cationic counterion, and each of the counterions is an organic counterion and has a steric parameter. It contains at least one substituent having a certain A value of 2.0 (kcal / mol) or more.

  The dye as described above has a long lifetime in the excited state due to the association of the dye, and generates singlet oxygen therefrom, leading to dye decomposition. Therefore, since the organic counter ion contains one or more substituents having an A value of 2.0 (kcal / mol) or more, a bulky substituent that suppresses association is introduced, so that the light preservation property is improved. It is possible to improve wet heat storage.

  Here, the organic counter ion refers to a counter ion excluding an inorganic ion such as a halogen ion or an organometallic complex ion. Preferably, “C” and “H” are essential components, and “O” ”,“ N ”, and“ S ”as appropriate refers to a counter ion.

  It is preferable that at least one of the following first to fifth aspects is applied to the optical information recording medium of the present invention.

(1) A 1st aspect is an aspect in which the said pigment | dye contains the cyanine chromophore represented by the following general formula (1), or the styryl chromophore represented by the following general formula (2).

[In the above general formulas (1) and (2), each X independently represents an oxygen atom, a sulfur atom or N—R, and R, R ^a and R ^b each independently represent an alkyl group, an aryl group or a heterocyclic ring. Represents a group, and R ^a and R ^b may be linked to each other to form a ring. Z ^a represents an atomic group necessary for completing ^a 5-membered or 6-membered heterocyclic ring, and L ¹ , L ² , and L ³ each independently represents a substituted or unsubstituted methine group (provided that L ^{1 to} L ³ may be linked to each other to form a ring), j represents 0 or 1, Q represents an ion that neutralizes charge, and y represents neutralization of charge. Represents the number required for. In this case, Q is an organic counter anion as the organic counter ion. ]

  The cyanine chromophore represented by the general formula (1) and the styryl chromophore represented by the general formula (2) each have high counterions and can suppress dye association, thereby improving light fastness. Can be made.

  (2) In the second aspect, the compounds represented by the general formula (1) and the general formula (2) are represented by the following general formula (1-1), the following general formula (2-1), and the following general formula. It is an aspect which is a compound represented by either (1-2), the following general formula (2-2), the following general formula (1-3), or the following general formula (2-3). Each of these compounds has a large counter ion and can suppress dye association. Further, the methine chain is shortened, so that it is difficult to receive the addition of singlet oxygen, and the light fastness can be further improved.

In the general formula (1-1), the general formula (2-1), the general formula (1-2), and the general formula (2-2), Z ^b is each independently an indolenine nucleus, a benzoindo. A group of atoms necessary for forming a renin nucleus, a benzimidazole nucleus, a benzoxazole nucleus or a benzothiazole nucleus. X ^a represents an oxygen atom, a sulfur atom, C (R ₃ ) (R ₄ ) or N—R ₅ . R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represents an alkyl group or an aryl group. L ⁴ and L ⁵ represent a substituted or unsubstituted methine group. Q represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge. In this case, Q is an organic counter anion. R ^a and R ^b each independently represents an alkyl group or an aryl group, and may be linked to each other to form a ring. In the general formula (1-3) and the general formula (2-3), X ^b and X ^c each independently represent an oxygen atom, a sulfur atom, or N—R ¹⁴ . R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. . L ⁶ , L ⁷ and L ⁸ each independently represent a substituted or unsubstituted methine group. However, when there are substituents on L ^{6 to} L ⁸ , these substituents may be connected to each other to form a ring. k represents 0 or 1; Similarly to the above, Q represents an ion for neutralizing electric charge, and y represents a number necessary for neutralizing electric charge.

(3) A third aspect is an aspect in which the cationic chromophore in the general formula (1) is monomethinecyanine (j = 0 in the general formula (1)).

  Each of the monomethinecyanines has a large counter ion and can suppress dye association. Further, when the methine chain is shortened, it is difficult to receive the addition of singlet oxygen, and the light fastness can be further improved.

(4) In a fourth aspect, the dye is an oxonol represented by the following general formula (3).

[In the above general formula (3), A, B, C and D are electron attractive properties in which the sum of the Hammett σp values of A and B and the sum of the Hammett σp values of C and D are each 0.6 or more. And “A and B” or “C and D” may be linked to form a ring, R represents a substituent on the methine carbon, m represents an integer of 0 to 3, and n Represents an integer of 0 to 2m + 1, and when n is an integer of 2 or more, a plurality of R may be the same or different from each other, and may be connected to each other to form a ring. Q represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge. In this case, Q is an organic counter cation as the organic counter ion. Further, two or more of the dyes represented by the general formula (3) (they may be the same or different) may be connected to each other through any one of A, B, C, and D. Also, two or more oxonol dyes connected in this manner are also included in the general formula (3). ]

  Since the oxonol dye represented by the general formula (3) has a bulky counter ion and can suppress dye association, light fastness can be improved.

(5) A fifth aspect is an aspect in which the anionic chromophore in the general formula (3) is monomethine oxonol (m = 0 in the general formula (3)).

  The monomethine oxonol has a bulky counter ion and can suppress dye association. Further, when the methine chain is shortened, it is difficult to receive the addition of singlet oxygen, and the light fastness can be further improved.

(6) A sixth aspect is an aspect in which the organic counter cation as the organic counter ion is represented by the following general formula (E).

In the general formula ^{(E), R l, R} m, R n, and R ^o each independently represent an alkyl group or a cyclic hydrocarbon group having 3 to 10 carbon atoms having 1 to 20 carbon atoms, R ^l and R ^m or R ⁿ and R ^o may be linked to each other as a methylene chain. The number of methylene chains in that case is an integer of 2 to 15 carbon atoms, and l, m, and n are each independently an integer of 0 to 10. Since the organic counter cation represented by the general formula (E) is bulky and can suppress dye association, it can improve light fastness and wet heat fastness.

(7) In the seventh aspect, the substituent whose A value is 2.0 (kcal / mol) or more is a tertiary alkyl group, a secondary alkyl group, a trifluoromethyl group, an aliphatic cyclic hydrocarbon It is an embodiment that is a group, a substituted phenyl group, a substituted heterocyclic group, or a heteroatom-containing group. Since the above substituent is bulky and suppresses dye association, the light fastness of the dye can be improved.

  The substituent is more preferably a tertiary alkyl group, a secondary alkyl group, a trifluoromethyl group, an aliphatic cyclic hydrocarbon group, or a substituted phenyl group, and more preferably a tertiary alkyl group, A secondary alkyl group, an aliphatic cyclic hydrocarbon group, and a substituted phenyl group.

  The information recording method of the present invention is characterized in that information is recorded by irradiating an optical information recording medium with a laser beam having a wavelength of 440 nm or less. Since the above-described optical information recording medium of the present invention is used in the information recording method of the present invention, high-density recording and reproduction of information can be performed satisfactorily.

  According to the present invention, an optical information recording medium capable of satisfactorily recording and reproducing information performed by irradiating a laser beam of 440 nm or less, and having good environment-friendly light storage properties and wet heat storage properties, and An information recording method optimum for the optical information recording medium can be provided.

<Optical information recording medium>
The present invention is described in detail below. In the present invention, when a specific portion is referred to as “group”, unless otherwise specified, it may be substituted with one or more substituents (up to the maximum possible number). It means that it is not necessary. For example, “alkyl group” means a substituted or unsubstituted alkyl group. In addition, the substituent that can be used in the compound in the present invention may be any substituent. Furthermore, in the present invention, when a specific moiety is referred to as “ring”, or when “ring” is included in “group”, it may be monocyclic or condensed unless otherwise specified. May not be substituted. For example, the “aryl group” may be a phenyl group, a naphthyl group, or a substituted phenyl group.

  The optical information recording medium of the present invention has, on a substrate, a recording layer capable of recording information by irradiation with laser light having a wavelength of 440 nm or less, the recording layer containing a dye composed of a cation portion and an anion portion, The dye comprises a cationic chromophore and an anionic counterion, or an anionic chromophore and a cationic counterion, each of the counterions being an organic counterion and a steric parameter A 1 or more substituents having a value of 2.0 (kcal / mol) or more are contained.

The steric parameters representing the size of the substituent can be broadly divided into those derived from chemical reactions and those that are not (for example, “Chemical Supplement 107 Structure-Activity Relationship and Drug Design, edited by Fujio Ikuo”, “ MacPhee, JA; Panaye, A .; Dubois, JE; Tetrahedron, 1978, 34, 3553 "," JP 2005-313632 A "," Eliel, EL; Wilen, S .; H .; Mander, L. N. Stereochemistry of Organic Compounds: John Wiley and Sons: New York, 1994; p695, etc.). Examples of the former include E _{s of} Taft obtained from the acid hydrolysis reaction rate of ester and E _s ^C related thereto. The latter is further related to the volume of the whole molecule, such as the van der Waals radius representing the molecular size and the associated STERIMOL parameter.

  The former parameter is considered to be an effective constant in the case of dynamic behavior such as during a chemical reaction, but a static constant is more preferable as a parameter used in the present invention.

  On the other hand, the steric parameter A value is a value resulting from the free energy difference in the axial-equatorial conformational equilibrium of the cyclohexane ring, and can be said to be a more static parameter than the Taft value. There are also documents that use this to discuss the stereoelectronic effect (for example, “Shimizu, M .; Nakaki, C .; Shimono, K .; Schelper, M .; Kurahashi, T .; Hiyama, T .; J Am. Chem. Soc., 2005, 127, 12506 ", etc.).

  Although the present invention is defined using the A value as a three-dimensional parameter, even if it is defined using a parameter described in Japanese Patent Laid-Open No. 2005-313632 or a parameter derived from the Taft value, the content of the present invention is essentially changed. There is no.

  When the A value, which is a steric parameter, is less than 2.0 (kcal / mol), the dyes associate and light fastness is lowered. Preferably, it is 2.0-6.0 (kcal / mol), More preferably, it is 2.0-5.0 (kcal / mol). In addition, the number of the substituents is required to be 1 or more, but considering that the refractive index decreases and recording performance is impaired as a large number of bulky substituents are introduced into the molecule, 1 to 1 10 is preferable, and 1 to 4 is more preferable.

  The dye contained in the recording layer is preferably a dye represented by the following general formula (1) and the following general formula (2). When a bulky substituent is introduced into the counter anion, a dye containing a cyanine chromophore represented by the following general formula (1) and a styryl chromophore represented by the following general formula (2) is preferable.

In the general formulas (1) and (2), each X independently represents an oxygen atom, a sulfur atom or N—R, R represents an alkyl group, an aryl group, or a heterocyclic group, and Z ^a each independently L ¹ , L ² and L ³ each independently represents a substituted or unsubstituted methine group (provided that L ¹ to If there is a substituent on L ³ , they may be linked to each other to form a ring), j represents 0 or 1, Q represents an ion that neutralizes charge, and y is necessary for charge neutralization Represents a number. In this case, Q is not an inorganic cation such as halogen, or a cation such as an organometallic complex. R ^a and R ^b each represents an alkyl group or an aryl group, and may be linked to each other to form a ring.

Hereinafter, the polymethine dyes represented by the general formulas (1) and (2) will be described in detail. In the formula, the methine group represented by L ¹ , L ² and L ³ may have a substituent, and when the substituent is V, the substituent represented by V is not particularly limited, For example, a halogen atom (eg, chlorine, bromine, iodine, fluorine), mercapto group, cyano group, carboxyl group, phosphate group, sulfo group, hydroxy group, 1 to 10 carbon atoms, preferably 2 to 8 carbon atoms, more preferably Is a carbamoyl group having 2 to 5 carbon atoms (for example, methylcarbamoyl, ethylcarbamoyl, morpholinocarbonyl, sulfamoyl group having 0 to 10, preferably 2 to 8, more preferably 2 to 5 carbon atoms (for example, methylsulfamoyl group). Moyl, ethylsulfamoyl, piperidinosulfonyl, nitro group, 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably charcoal An alkoxy group having a prime number of 1 to 8 (for example, methoxy, ethoxy, 2-methoxyethoxy, 2-phenylethoxy), an aryloxy group having a carbon number of 6 to 20, preferably a carbon number of 6 to 12, and more preferably a carbon number of 6 to 10. (For example, phenoxy, p-methylphenoxy, p-chlorophenoxy, naphthoxy),

An acyl group having 1 to 20 carbon atoms, preferably 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms (eg, acetyl, benzoyl, trichloroacetyl), 1 to 20 carbon atoms, preferably 2 to 12 carbon atoms, Preferably an acyloxy group having 2 to 8 carbon atoms (for example, acetyloxy, benzoyloxy), an acylamino group having 1 to 20, preferably 2 to 12, more preferably 2 to 8 carbon atoms (for example, acetylamino), A sulfonyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms (for example, methanesulfonyl, ethanesulfonyl, benzenesulfonyl, etc.), carbon 1 to 20, preferably 1 to 10 carbon atoms, More preferably, the sulfinyl group having 1 to 8 carbon atoms (for example, methanesulfinyl group) Benzene sulfinyl), carbon 1 to 20, preferably 1 to 10 carbon atoms, more preferably a sulfonylamino group (e.g., methanesulfonylamino 1 to 8 carbon atoms, ethanesulfonylamino, etc. benzenesulfonylamino)

An amino group, a substituted amino group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms (for example, methylamino, dimethylamino, benzylamino, anilino, diphenylamino), 0 to 15 carbon atoms Preferably an ammonium group having 3 to 10 carbon atoms, more preferably 3 to 6 carbon atoms (eg trimethylammonium group, triethylammonium group), 0 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably carbon number 1 to 6 hydrazino groups (eg trimethylhydrazino group), 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms ureido groups (eg ureido groups, N, N-dimethylureido) Group), carbon number 1 to 15, preferably carbon number 1 to 10, and more preferably carbon number To 6 imide groups (eg succinimide groups), alkyl or arylthio groups having 1 to 20, preferably 1 to 12, more preferably 1 to 8 carbon atoms (eg methylthio, ethylthio, carboxyethylthio, sulfobutyl) Thio, phenylthio, etc.), carbon 2 to 20, preferably 2 to 12, more preferably 2 to 8 alkoxycarbonyl groups (eg methoxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl), carbon 6 to 20, preferably Is an aryloxycarbonyl group having 6 to 12 carbon atoms, more preferably 6 to 8 carbon atoms (for example, phenoxycarbonyl),

An unsubstituted alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg, methyl, ethyl, propyl, butyl), 1 to 18 carbon atoms, preferably 1 carbon atom To 10 and more preferably a substituted alkyl group having 1 to 5 carbon atoms (hydroxymethyl, trifluoromethyl, benzyl, carboxyethyl, ethoxycarbonylmethyl, acetylaminomethyl, and preferably 2 to 18 carbon atoms, more preferably In the substituted alkyl group, an unsaturated hydrocarbon group having 3 to 10 carbon atoms, particularly preferably 3 to 5 carbon atoms (for example, vinyl group, ethynyl group, 1-cyclohexenyl group, benzylidine group, benzylidene group) is also included in the substituted alkyl group. 6), preferably 6 to 15, and more preferably 6 to 15 carbon atoms. 10 substituted or unsubstituted aryl group (e.g. phenyl, naphthyl, p- carboxyphenyl, p- nitrophenyl, 3,5-dichlorophenyl, p- cyanophenyl, m- fluorophenyl, p- tolyl)

Heterocyclic group having 1 to 20 carbon atoms, preferably 2 to 10 carbon atoms, more preferably 4 to 6 carbon atoms, which may be substituted (eg, pyridyl, 5-methylpyridyl, thienyl, furyl, morpholino, tetrahydrofurfuryl) Is mentioned.

Preferred as the substituent are the above-mentioned alkyl group, aryl group, alkoxy group, halogen atom, acyl group, cyano group, sulfonyl group, and benzene ring condensation, more preferably alkyl group, aryl group, halogen atom, acyl group. And a sulfonyl group. L _{1 to} L ₃ are preferably unsubstituted methine groups. j is 0 or 1, and when j is 1, the methine group is repeated but need not be identical.

As the alkyl group, for example, an unsubstituted alkyl group having 1 to 18, preferably 1 to 7, particularly preferably 1 to 4 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, octyl, dodecyl, Octadecyl), a substituted alkyl group having 1 to 18, preferably 1 to 7, and particularly preferably 1 to 4 carbon atoms (for example, an alkyl group substituted with V mentioned as a substituent such as L ¹ described above).

  Preferably, an aralkyl group (for example, benzyl, 2-phenylethyl), an unsaturated hydrocarbon group (for example, allyl group), a hydroxyalkyl group (for example, 2-hydroxyethyl, 3-hydroxypropyl), a carboxyalkyl group (for example, 2- Carboxyethyl, 3-carboxypropyl, 4-carboxybutyl, carboxymethyl), an alkoxyalkyl group (for example, 2-methoxyethyl, 2- (2-methoxyethoxy) ethyl), an aryloxyalkyl group (for example, 2-phenoxyethyl, 2- (1-naphthoxy) ethyl),

An alkoxycarbonylalkyl group (for example, ethoxycarbonylmethyl, 2-benzyloxycarbonylethyl), an aryloxycarbonylalkyl group (for example, 3-phenoxycarbonylpropyl), an acyloxyalkyl group (for example, 2-acetyloxyethyl), an acylalkyl group (for example, 2 -Acetylethyl), a carbamoylalkyl group (for example, 2-morpholinocarbonylethyl), a sulfamoylalkyl group (for example, N, N-dimethylcarbamoylmethyl), a sulfoalkyl group (for example, 2-sulfoethyl, 3-sulfopropyl, 3- Sulfobutyl, 4-sulfobutyl, 2- [3-sulfopropoxy] ethyl, 2-hydroxy-3-sulfopropyl, 3-sulfopropoxyethoxyethyl), sulfoalkenyl groups (for example, sulfoprop Sulfatoalkyl group (for example, 2-sulfatoethyl group, 3-sulfatopropyl, 4-sulfatobutyl), heterocyclic-substituted alkyl group (for example, 2- (pyrrolidin-2-one-1-yl) ) Ethyl, tetrahydrofurfuryl), alkylsulfonylcarbamoylmethyl group (for example, methanesulfonylcarbamoylmethyl group)}.

As the aryl group, for example, an unsubstituted aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms (for example, phenyl group, 1-naphthyl group), 6 to 20 carbon atoms, Preferably, it is a substituted aryl group having 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms (for example, an aryl group substituted with V mentioned as a substituent such as L ¹ described above. Specifically, p-methoxy is mentioned. A phenyl group, a p-methylphenyl group, a p-chlorophenyl group, etc.).

Examples of the heterocyclic group include unsubstituted heterocyclic groups having 1 to 20 carbon atoms, preferably 3 to 10 carbon atoms, and more preferably 4 to 8 carbon atoms (for example, 2-furyl group, 2-thienyl group, 2-pyridyl group). Group, 3-pyrazolyl, 3-isoxazolyl, 3-isothiazolyl, 2-imidazolyl, 2-oxazolyl, 2-thiazolyl, 2-pyridazyl, 2-pyrimidyl, 3-pyrazyl, 2- (1,3,5-triazolyl), 3- (1,2,4-triazolyl), 5-tetrazolyl), a substituted heterocyclic group having 1 to 20 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 4 to 8 carbon atoms (for example, the aforementioned L ¹ And a heterocyclic group substituted by V as a substituent such as 5-methyl-2-thienyl group, 4-methoxy-2-pyridyl group and the like. And the like.

In the general formulas (1) and (2), Za independently represents an atomic group necessary for completing a 5-membered or 6-membered heterocyclic ring. Examples of the 5- or 6-membered heterocyclic ring (nucleus) containing Za include a thiazole nucleus, benzothiazole nucleus, naphthothiazole nucleus, thiazoline nucleus, oxazole nucleus, benzoxazole nucleus, naphthoxazole nucleus, oxazoline nucleus, selenazole nucleus, Benzoselenazole nucleus, naphthoselenazole nucleus, selenazoline nucleus, tellurazole nucleus, benzotelrazole nucleus, naphthotelrazole nucleus, tellurazoline nucleus, imidazole nucleus, benzimidazole nucleus, naphthimidazole nucleus, pyridine nucleus, quinoline nucleus, isoquinoline nucleus, imidazo [4,5-b] quinoxaline nucleus, oxadiazole nucleus, thiadiazole nucleus, tetrazole nucleus, pyrimidine nucleus, pyrrole nucleus, indolenine nucleus, benzoindolenine nucleus, 1,3-dioxolane nucleus, and 1,3-dithiolane nucleus , Etc. It can gel. Among these, thiazole nucleus, thiazoline nucleus, benzothiazole nucleus, oxazole nucleus, oxazoline nucleus, benzoxazole nucleus, imidazole nucleus, benzimidazole nucleus, naphthimidazole nucleus, quinoline nucleus, isoquinoline nucleus, imidazo [4,5-b] A quinoxaline nucleus, thiadiazole nucleus, tetrazole nucleus, pyrimidine nucleus, pyrrole nucleus, indolenine nucleus, benzoindolenin nucleus, 1,3-dioxolane nucleus, and 1,3-dithiolane nucleus are preferred. These rings may be further condensed with a benzene ring, a dioxolane ring, or a naphthoquinone ring. However, when j is 1, i.e., when the number of methine groups of coupling 3, a heterocyclic ring containing Z ^a do not constitute the indolenine nucleus.

  The 5-membered or 6-membered nitrogen-containing heterocycle may have a substituent. Examples of preferable substituents (atoms) include halogen atoms, substituted or unsubstituted alkyl groups, aryl groups, alkoxy groups, and alkoxycarbonyl groups. As the halogen atom, a chlorine atom is preferable. The alkyl group is preferably a linear alkyl group having 1 to 6 carbon atoms. Examples of the substituent for the alkyl group include an alkoxy group (eg, methoxy) and an alkylthio group (eg, methylthio). As the aryl group, phenyl is preferable. As the alkoxy group, a methoxy group is preferable. As the alkoxycarbonyl group, a methoxycarbonyl group is preferable. Particularly preferred examples of the substituent are a halogen atom, an unsubstituted alkyl group, an alkoxy group, and an alkoxycarbonyl group.

  The compounds represented by the general formula (1) and the general formula (2) are further represented by the following general formula (1-1), the following general formula (2-1), the following general formula (1-2), the following general formula ( It is preferable that it is a compound represented by the following general formula (1-3) or the following general formula (2-3).

In the general formula (1-1), the general formula (2-1), the general formula (1-2), and the general formula (2-2), Z ^b is each independently an indolenine nucleus, a benzoindo. A group of atoms necessary for forming a renin nucleus, a benzimidazole nucleus, a benzoxazole nucleus or a benzothiazole nucleus. X ^a each independently represents an oxygen atom, a sulfur atom, C (R ₃ ) (R ₄ ) or N—R ₅ . R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represents an alkyl group or an aryl group. L ⁴ and L ⁵ represent a substituted or unsubstituted methine group. Q represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge. In this case, Q is an organic counter anion. R ^a and R ^b each independently represents an alkyl group or an aryl group, and may be linked to each other to form a ring.

Indolenine nucleus containing the Z ^b, a benzindolenine nucleus, benzimidazole nucleus, a benzoxazole nucleus or a benzothiazole nucleus may have a substituent. Examples of the substituent (which may be an atom) include the examples of the substituent on the 5-membered or 6-membered heterocyclic ring described above, and the preferred ranges thereof are also the same.

R ₁ and R ₂ are synonymous with R in the general formula (1), and their preferred ranges are also the same.

R ₃ , R ₄ and R ₅ are preferably an alkyl group, more preferably a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms which may have a substituent. . The alkyl group represented by R ₃ , R ₄ and R ₅ is particularly preferably a linear unsubstituted alkyl group having 1 to 6 carbon atoms (for example, methyl, ethyl).

In the general formula (1-3) and the general formula (2-3), X ^b and X ^c each independently represent an oxygen atom, a sulfur atom, or N—R ¹⁴ . R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. . L ⁶ , L ⁷ and L ⁸ each independently represent a substituted or unsubstituted methine group. However, when there are substituents on L ^{6 to} L ⁸ , these substituents may be connected to each other to form a ring. k represents 0 or 1; Q represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge. In this case, Q is an organic counter anion. R ^a and R ^b each independently represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and may be linked to each other to form a ring.

X ^b and X ^c are preferably an oxygen atom, a sulfur atom, N—R ¹⁴ , an oxygen atom and N—R ^14, or a combination of a sulfur atom and N—R ^{14 at} the same time. R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a substituent. A good linear, branched or cyclic alkyl group having 1 to 18 carbon atoms. The alkyl groups represented by R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each a linear unsubstituted alkyl having 1 to 6 carbon atoms. Particularly preferred are groups (eg methyl, ethyl).

In the above general formula (1-3), L ⁶ , L ⁷ and L ⁸ have the same meanings as L ¹ , L ² and L ³ described in the general formula (1), respectively, and their preferred ranges are also the same.

Preferred examples of the compound represented by the general formula (1) according to the present invention (including the compound represented by the general formula (1-1), the general formula (1-2), or (1-3)) are as follows. Specific examples are given below with the counter anion Qy removed.

  The compound represented by the general formula (1) is, for example, from HM Harmer, “The Cyanine Soybean and Related Compounds 5 (Interscience Publishers, NY 1964)” p. Nikolai Chuturkov, Jurgen Fabian, Akim Merhorn, Philitz Dietz, Aria Tazier University Press, Sofia (St. Klimn Ohridki University Press, Sophia), pages 23-38; (D.M. Sturmer), “Heterocyclic Compounds in Special Cyclics in Heterocyclic Chemistry”, Chapters 18, Sections 48, 48. 515, John Wiley & Sons, New York, London, (1977); “Rod's Chemistry of Carbon Compounds”, (2nd.Ed.). Vol. IV, part B, 1977), Chapter 15, pp. 369-422, (2nd. Ed. Vol. IV, part B, published in 1985), Chapter 15, pp. 267-296, Elsvier Science Public Company Inc., New York, and the like.

  Preferred examples of the compound represented by the general formula (2) according to the present invention (including the compound represented by the general formula (2-1), the general formula (2-2), or (2-3)) are as follows. Specific examples are given below with the counter anion Qy removed.

  Q in the general formulas (1), (2), (1-1) to (1-3), and (2-1) to (2-3) represents an ion that neutralizes the charge, and y represents a charge. This represents the number required for neutralization. In this case, Q is an organic counter anion and contains at least one substituent having an A value of 2.0 (kcal / mol) or more.

Examples of the organic counter anion include substituted aryl sulfonate ions (for example, p-toluene sulfonate ion, p-chlorobenzene sulfonate ion), aryl disulfonate ions (for example, 1,3-benzene sulfonate ion, 1,5-naphthalene). Disulfonate ion, 2,6-naphthalenedisulfonate ion), alkyl sulfate ion, alkyl or aryl carboxylate ion, and trifluoromethanesulfonate ion. Furthermore, an anionic polymer may be used. In the present invention, the sulfo group is represented as “SO ₃ ⁻ ”.

  Further, the substituent is specifically a tertiary alkyl group (preferably a substituted or unsubstituted tertiary alkyl group having 4 to 30 carbon atoms, more preferably a t-butyl group, a 2-methylbutyl group, a neopentyl group. , 3-methylpentyl group), secondary alkyl group (preferably a substituted or unsubstituted secondary alkyl group having 3 to 30 carbon atoms, more preferably isopropyl group, 3-methylbutyl group, 2-ethylhexyl group), Trifluoromethyl group, aliphatic cyclic hydrocarbon group, cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), bicycloalkyl A group (preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, ie carbon Monovalent groups obtained by removing one hydrogen atom from 5 to 30 bicycloalkanes (for example, bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl) In addition, a tricyclo structure having more ring structures is also included. Moreover, a substituted phenyl group, a substituted heterocyclic group, a hetero atom containing group, etc. are mentioned.

An alkyl group [for example, an alkyl group of an alkylthio group] in a substituent described below also represents an alkyl group having such a concept. ], Substituted aryl groups (preferably substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, such as phenyl, o-tolyl, naphthyl, o-chlorophenyl, o-hexadecanoylaminophenyl), substituted heterocyclic groups (preferably Is a monovalent group obtained by removing one hydrogen atom from a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, more preferably 5 or 6 having 3 to 30 carbon atoms. Member heteroaromatic group), hetero atom-containing group (for example, methylsulfonyl group SO ₂ Me (2.50), diphenylphosphinooxy group O═P (C ₆ H ₅ ) ₂ (2.46) , diphenylphosphino sulfide _{S = P (C 6 H 5} ) 2 (3.13), trimethylsilyl group SiMe ₃ (2.5), trimethylgermyl group GeMe ₃ (2.1) A triphenyl germyl group GePh ₃ (2.9)), more preferably a tertiary alkyl group, secondary alkyl group, a trifluoromethyl group, an aliphatic cyclic hydrocarbon group, a substituted phenyl group, a substituted heterocyclic Group, hetero atom-containing group, more preferably a tertiary alkyl group, a secondary alkyl group, a trifluoromethyl group, an aliphatic cyclic hydrocarbon group or a substituted phenyl group, most preferably a tertiary alkyl group. An alkyl group, a secondary alkyl group, an aliphatic cyclic hydrocarbon group, and a substituted phenyl group; The numerical value in the parentheses is an A value that is a three-dimensional parameter.

Below, the preferable specific example of the organic counter anion which concerns on this invention is given to the following.

  In the method of introducing a polyvalent anion as a counter ion, first, a dye having a counter ion is dissolved in an appropriate solvent, a polyvalent acid or a salt solution is added thereto, and the dye is further dissolved if necessary. A method of adding a difficult solvent to precipitate a dye crystal having a polyvalent ion as a counter ion is the simplest and suitable for a large amount of synthesis. Other methods include a method of exchanging counter ions using an ion exchange resin.

  The dye compounds represented by the general formulas (1) and (2) according to the present invention may be used alone or in combination of two or more. Alternatively, the dye compound according to the present invention may be used in combination with a dye compound for optical information recording media conventionally used other than these. Examples of these include cyanine dyes other than those used in the present invention, oxonol dyes, azo metal complexes, phthalocyanine dyes, pyrylium dyes, thiopyrylium dyes, azurenium dyes, squarylium dyes, naphthoquinone dyes Examples thereof include a dye, a triphenylmethane dye, and a triallylmethane dye.

  Next, the polymethine dye represented by the following general formula (3) will be described in detail. In the present invention, the oxonol dye is defined as a polymethine dye having an anionic dye. In view of excellent recording characteristics, an oxonol dye represented by the following general formula (3) is particularly preferably used.

  In the general formula (3), A, B, C and D are electron withdrawing groups in which the sum of the Hammett σp values of A and B and the sum of the Hammett σp values of C and D are each 0.6 or more. A and B or C and D may be linked to form a ring, R represents a substituent on the methine carbon, m represents an integer of 0 to 3, and n represents an integer of 0 to 2m + 1 And when n is an integer of 2 or more, a plurality of R may be the same or different from each other, and may be linked to each other to form a ring, and Q represents an ion that neutralizes the charge. , Y represents a number necessary for charge neutralization. In this case, Q is a quaternary alkyl ammonium cation or a quaternary anilinium cation. Two or more of the molecules represented by the general formula (3) (which may be the same or different) may be linked to each other via any one of A, B, C, and D. Such two or more linked oxonol dyes are also included in the general formula (3).

  The general formula (3) includes a plurality of tautomers depending on the notation of the local position of the anion, and in particular, any one of A, B, C, and D is “—CO—E (E is a substituent). In general, a negative charge is localized on an oxygen atom. For example, when D is “—CO-E”, the following general formula (3-1) is common as the notation, and such notation is also included in the general formula (3).

  The definitions of A, B, C, R, m, n, Q, and y in the general formula (3-1) are the same as those in the general formula (3). E is a substituent.

  Hereinafter, the oxonol dye represented by the general formula (3) will be described. In the general formula (3-1), A, B, C, and D each have a sum of Hammett's substituent constants σp values of A and B and a sum of Hammett's substituent constants σp values of C and D of 0.6, respectively. This represents the electron-withdrawing group. A, B, C and D may be the same or different. A and B or C and D may be linked to form a ring. The Hammett substituent constant σp value of the electron-withdrawing group represented by A, B, C and D is preferably independently in the range of 0.30 to 0.85, more preferably 0.35. It is in the range of ~ 0.80.

  Hammett's substituent constant σp value (hereinafter referred to as σp value) is described in, for example, Chem. Rev. 91, 165 (1991) and references cited therein, and those not described can be obtained by the method described in the same document. When A and B (C and D) are linked to form a ring, the σp value of A (C) means the σp value of the group -A-B-H (-C-10D-H). , B (D) σp value means the σp value of the group -BAH (-DCH). In this case, both have different σp values because of different coupling directions.

  Preferable specific examples of the electron-withdrawing group represented by A, B, C and D include a cyano group, a nitro group, and an acyl group having 1 to 10 carbon atoms (eg, acetyl, propionyl, butyryl, pivaloyl, benzoyl). An alkoxycarbonyl group having 2 to 12 carbon atoms (eg, methoxycarbonyl, ethoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, decyloxycarbonyl), an aryloxycarbonyl group having 7 to 11 carbon atoms (eg, phenoxycarbonyl), A carbamoyl group having 1 to 10 carbon atoms (eg, methylcarbamoyl, ethylcarbamoyl, phenylcarbamoyl), an alkylsulfonyl group having 1 to 10 carbon atoms (eg, methanesulfonyl), an arylsulfonyl group having 6 to 10 carbon atoms ( Example: benzenesulfonyl), charcoal An alkoxysulfonyl group having 1 to 10 atoms (eg, methoxysulfonyl), a sulfamoyl group having 1 to 10 carbon atoms (eg, ethylsulfamoyl, phenylsulfamoyl), an alkylsulfinyl group having 1 to 10 carbon atoms ( Examples, methanesulfinyl, ethanesulfinyl), arylsulfinyl groups having 6 to 10 carbon atoms (eg, benzenesulfinyl), alkylsulfenyl groups having 1 to 10 carbon atoms (eg, methanesulfenyl, ethanesulfenyl), carbon Arylsulfenyl group having 6 to 10 atoms (eg, benzenesulfenyl), halogen atom, alkynyl group having 2 to 10 carbon atoms (eg, ethynyl), diacylamino group having 2 to 10 carbon atoms (eg, diacetyl) Amino), phosphoryl group, carboxyl group, 5-membered or Membered heterocyclic group (for example, 2-benzothiazolyl, 2-benzoxazolyl, 3-pyridyl, 5- (1H) -tetrazolyl, 4-pyrimidyl), preferably cyano group, alkoxycarbonyl group, alkylsulfonyl group And an arylsulfonyl group.

  In the general formula (3), examples of the substituent on the methine carbon represented by R include those described below. A linear or cyclic alkyl group having 1 to 20 carbon atoms (for example, methyl, ethyl, n-propyl, isopropyl, n-butyl), a substituted or unsubstituted aryl group having 6 to 18 carbon atoms (for example, phenyl) , Chlorophenyl, anisyl, toluyl, 2,4-di-t-amyl, 1-naphthyl), alkenyl group (for example, vinyl, 2-methylvinyl), alkynyl group (for example, ethynyl, 2-methylethynyl, 2-phenyl) Ethynyl), halogen atom (eg, F, Cl, Br, I), cyano group, hydroxyl group, carboxyl group, acyl group (eg, acetyl, benzoyl, salicyloyl, pivaloyl), alkoxy group (eg, methoxy, butoxy, cyclohexyl) Oxy), aryloxy groups (eg, phenoxy, 1-naphthoxy), alkylthio Group (e.g., methylthio, butylthio, benzylthio, 3-methoxypropylthio), an arylthio group (e.g., phenylthio, 4-chlorophenylthio)

An alkylsulfonyl group (for example, methanesulfonyl, butanesulfonyl), an arylsulfonyl group (for example, benzenesulfonyl, paratoluenesulfonyl), a carbamoyl group having 1 to 10 carbon atoms, an amide group having 1 to 10 carbon atoms, and the number of carbon atoms 2-12 imide groups, C2-C10 acyloxy groups, C2-C10 alkoxycarbonyl groups, heterocyclic groups (e.g., pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrazolyl and other heteroaromatics) Ring, pyrrolidine ring, piperidine ring, morpholine ring, pyran ring, thiopyran ring, dioxane ring, dithiolane ring and other aliphatic heterocycles).

  R is preferably a halogen atom, a linear or cyclic alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or 6 to 10 carbon atoms. An aryloxy group, a heterocyclic group having 3 to 10 carbon atoms, particularly a chlorine atom, an alkyl group having 1 to 4 carbon atoms (eg, methyl, ethyl, isopropyl), phenyl, 1 to 4 carbon atoms Alkoxy groups (eg, methoxy, ethoxy), phenoxy, and nitrogen-containing heterocyclic groups having 4 to 8 carbon atoms (eg, 4-pyridyl, benzoxazol-2-yl, benzothiazol-2-yl) are preferable.

  n represents an integer of 0 to 2m + 1. When n is an integer of 2 or more, a plurality of Rs may be the same as or different from each other, and may be connected to each other to form a ring. At this time, the number of ring members is preferably 4 to 8, particularly preferably 5 or 6, and the constituent atoms of the ring are preferably carbon atoms, oxygen atoms or nitrogen atoms, and particularly preferably carbon atoms.

  A, B, C, D and R may further have a substituent, and examples of the substituent include those mentioned above as examples of the monovalent substituent represented by R in the general formula (3). The same thing can be mentioned.

As the dye used for the optical disk, it is preferable that A and B or C and D are connected to form a ring from the viewpoint of thermal decomposability. Examples of such a ring include the following. In the examples, R ^a , R ^b and R ^c each independently represents a hydrogen atom or a substituent.

  Preferred rings are AO-2, AO-8, AO-9, AO-10, AO-13, AO-14, AO-16, AO-17, AO-36, AO-39, AO-42, AO-. 54, AO-57, AO-59, AO-61, AO-65, AO-66, AO-67 and AO-68. More preferably, AO-2, AO-9, AO-10, AO-13, AO-17, AO-42, AO-54, AO-57, AO-59, AO-61, AO-65, AO- 66, AO-67 and AO-68. Most preferred are those represented by AO-13, AO-17, AO-54, AO-57, AO-59, AO-61, AO-65, AO-66, AO-67 and AO-68.

The substituents represented by R ^a , R ^b and R ^c have the same meanings as those exemplified as the substituent represented by R. R ^a , R ^b and R ^c may be connected to each other to form a carbocyclic or heterocyclic ring. Examples of the carbocycle include saturated or unsaturated 4- to 7-membered carbocycles such as a cyclohexyl ring, cyclopentyl ring, cyclohexene ring, and benzene ring. Examples of the heterocyclic ring include saturated or unsaturated 4- to 7-membered heterocyclic rings such as piperidine ring, piperazine ring, morpholine ring, tetrahydrofuran ring, furan ring, thiophene ring, pyridine ring, and pyrazine ring. it can. These carbocycles or heterocycles may be further substituted. Further, the group that can be substituted has the same meaning as the substituents represented by R.

  In the general formula (3), m is an integer from 0 to 3, and the absorption wavelength of the oxonol dye varies greatly depending on the value of m. Although it is necessary to design a dye having an optimum absorption wavelength according to the oscillation wavelength of the laser used for recording and reproduction, the selection of the value of m is important in this respect. When the central oscillation wavelength of the laser used for recording / reproduction is 780 nm (semiconductor laser for CD-R recording), in the general formula (3), m is preferably 2 or 3, and when the central oscillation wavelength is 635 nm or 650 nm (DVD- R is a semiconductor laser for recording, and m is preferably 1 or 2, and m is preferably 0 or 1 when the center oscillation wavelength is 550 nm or less (for example, a blue-violet semiconductor laser having a center oscillation wavelength of 405 nm).

  The oxonol chromophore represented by the general formula (3) may be bonded at an arbitrary position to form a multimer. In this case, each unit may be the same as or different from each other. You may couple | bond with polymer chains, such as a methacrylate, polyvinyl alcohol, and a cellulose.

  Among the dyes represented by the general formula (3), an optical information recording medium containing a dye having a structure represented by the following general formula (4) is preferable.

In the general formula (4), Za ^5, Za ⁶ is a primitive group forming an acidic nucleus, definition of L ¹¹ is the same as L ¹¹ in the general formula (1), also A, B, C, D , R, m, n, Q, and y are the same as A, B, C, D, R, m, n, Q, and y in the general formula (1).

In the general formula (4), any of the hydrogen atoms constituting Za ⁵ and Za ⁶ can be removed and bonded to the linking groups L ¹¹ and L ^2k as the dye residue of the general formula (1). .

Za ¹ , Za ² and Za ³ are oxazole nuclei having 3 to 25 carbon atoms (for example, 2-3-methyloxazolyl, 2-3-ethyloxazolyl, 2-3,4-diethyloxazolyl, 2-3-methylbenzoxazolyl, 2-3-ethylbenzoxazolyl, 2-3-sulfoethylbenzoxazolyl, 2-3-sulfopropylbenzoxazolyl, 2-3-methylthioethylbenzox Zolyl, 2-3-methoxyethylbenzoxazolyl, 2-3-sulfobutylbenzoxazolyl, 2-3-methyl-β-naphthoxazolyl, 2-3-methyl-α-naphthoxazolyl 2-3-sulfopropyl-β-naphthoxazolyl, 2-3-sulfopropyl-β-naphthoxazolyl, 2-3- (3-naphthoxyethyl) benzoxazolyl, 2- , 5-Dimethylbenzoxazolyl, 2-6-chloro-3-methylbenzoxazolyl, 2-5-bromo-3-methylbenzoxazolyl, 2-3-ethyl-5-methoxybenzoxazolyl , 2-5-phenyl-3-sulfopropylbenzoxazolyl, 2-5- (4-bromophenyl) -3-sulfobutylbenzoxazolyl, 2-3-dimethyl-5,6-dimethylthiobenzoxa Zoril),

A thiazole nucleus having 3 to 25 carbon atoms (for example, 2-3-methylthiazolyl, 2-3-ethylthiazolyl, 2-3-sulfopropylthiazolyl, 2-3-sulfobutylthiazolyl, 2-3,4-dimethyl) Thiazolyl, 2-3,4,4-trimethylthiazolyl, 2-3-carboxyethylthiazolyl, 2-3-methylbenzothiazolyl, 2-3-ethylbenzothiazolyl, 2-3 -Butylbenzothiazolyl, 2-3-sulfopropylbenzothiazolyl, 2-3-sulfobutylbenzothiazolyl, 2-3-methyl-β-naphthothiazolyl, 2-3-sulfopropyl-γ-naphthothiazolyl, 2-3- (1-naphthoxyethyl) benzothiazolyl, 2-3,5-dimethylbenzothiazolyl, 2-6-chloro-3-methylbenzothiazolyl, 2-6-iodo- 3-ethylbenzothiazolyl, 2-5-bromo-3-methylbenzothiazolyl, 2-3-ethyl-5-methoxybenzothiazolyl, 2-5-phenyl-3-sulfopropylbenzothiazolyl 2-5- (4-bromophenyl) -3-sulfobutylbenzothiazolyl, 2-3-dimethyl-5,6-dimethylthiobenzothiazolyl, etc.)

C 3-25 imidazole nucleus (for example, 2-1,3-diethylimidazolyl, 2-1,3-dimethylimidazolyl, 2-1-methylbenzimidazolyl, 2-1,3,4-triethylimidazolyl, 2-1 , 3-diethylbenzimidazolyl, 2-1,3,5-trimethylbenzimidazolyl, 2-6-chloro-1,3-dimethylbenzimidazolyl, 2-5,6-dichloro-1,3-diethylbenzimidazolyl, 2-1,3 -Disulfopropyl-5-cyano-6-chlorobenzimidazolyl and the like), an indolenine nucleus having 10 to 30 carbon atoms (for example, 3,3-dimethylindolenine), a quinoline nucleus having 9 to 25 carbon atoms (for example, 2-1-methylquinolyl, 2-1-ethylquinolyl, 2-1-methyl-6-chloroquinolyl, 2-1 3-diethylquinolyl, 2-1-methyl-6-methylthioquinolyl, 2-1-sulfopropylquinolyl, 4-1-methylquinolyl, 4-1-sulfoethylquinolyl, 4-1-methyl-7- Chloroquinolyl, 4-1,8-diethylquinolyl, 4-1-methyl-6-methylthioquinolyl, 4-1-sulfopropylquinolyl, etc.), C 3-25 selenazole nucleus (for example, 2 -3-methylbenzoselenazolyl),

Examples thereof include pyridine nuclei having 5 to 25 carbon atoms (for example, 2-pyridyl and the like), and further thiazoline nuclei, oxazoline nuclei, selenazoline nuclei, tellurazoline nuclei, tellurazole nuclei, benzotelrazole nuclei, imidazoline nuclei, Examples include imidazo [4,5-quinoxaline] nucleus, oxadiazole nucleus, thiadiazole nucleus, tetrazole nucleus, and pyrimidine nucleus. These may be substituted. As the substituent, for example, an alkyl group (for example, methyl, ethyl, propyl), a halogen atom (for example, chlorine, bromine, iodine, fluorine), a nitro group, an alkoxy group (for example, methoxy, ethoxy) ), An aryl group (eg, phenyl), a heterocyclic group (eg, 2-pyridyl, 3-pyridyl, 1-pyrrolyl, 2-thienyl), an aryloxy group (eg, phenoxy), an acylamino group (eg, acetylamino, benzoylamino) ), Carbamoyl group (for example, N, N-dimethylcarbamoyl), sulfo group, sulfonamide group (for example, methanesulfonamide), sulfamoyl group (for example, N-methylsulfamoyl), hydroxy group, carboxy group, alkylthio group (for example, methylthio group) ), Cyano group, etc. Details, oxazole nucleus, an imidazole nucleus, a thiazole nucleus. These heterocycles may be further condensed. Examples of the condensed ring include a benzene ring, a benzofuran ring, a pyridine ring, a pyrrole ring, an indole ring, and a thiophene ring.

Za ⁵ , Za ⁵ and Za ⁶ each represent an atomic group necessary for forming an acidic nucleus, and are defined by James, The Theory of the Photographic Process, 4th edition, Macmillan, 1977, p. 198. The Specifically, 2-pyrazolone-5-one, pyrazolidine-3,5-dione, imidazolin-5-one, hydantoin, 2 or 4-thiohydantoin, 2-iminooxazolidine-4-one, 2-oxazoline-5 -One, 2-thiooxazoline-2,4-dione, isorhodanine, rhodanine, indan-1,3-dione, thiophen-3-one, thiophen-3-one-1,1-dioxide, indoline-2-one, Indoline-3-one, 2-oxoindazolium, 5,7-dioxo-6,7-dihydrothiazolo [3,2-a] pyrimidine, 3,4-dihydroisoquinolin-4-one, 1,3- Dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, coumarin-2,4-dione, indazolin-2-one, pyrido Nuclei such as 1,2-a] pyrimidine-1,3-dione, pyrazolo [1,5-b] quinazolone, pyrazolopyridone, 3-dicyanomethylidenyl-3-phenylpropionitrile, oxathiolanone dioxide, meldrum acid, etc. Preferred are 2-pyrazolone-5-one, barbituric acid, 2-thiobarbituric acid, oxathiolanone dioxide, meldrum acid, and pyrazolidine-3,5-dione.

In the general formula (1), L ¹¹ and L ^2k each independently represent a divalent linking group, and there is no particular limitation except that a π-conjugated system is not formed between the chromophores to which they are bonded. A group (having 1 to 20 carbon atoms such as methylene, ethylene, propylene, butylene, pentylene), an arylene group (having 6 to 26 carbon atoms such as phenylene or naphthylene), an alkenylene group (having 2 to 20 carbon atoms such as ethenylene or propenylene), Alkyninlene group (having 2 to 20 carbon atoms, for example, ethynylene, propynylene), metallocenylene group (for example, ferrocene), —CO—N (R ¹⁰¹ ) —, —CO—O—, —SO ₂ —N (R ¹⁰² ) —, — SO ₂ —O—, —N (R ¹⁰³ ) —CO—N (R ¹⁰⁴ ) —, —SO ₂ —, —SO—, —S—, —O—, —CO—, —N (R ¹⁰⁵ ) — , Heterylene group ( 1 to 26 carbon atoms, for example, 6-chloro-1,3,5-triazyl-2,4-diyl group, pyrimidine-2,4-diyl group) or a combination of one or more carbon atoms of 0 to It represents 100 or less, preferably 1 or more and 20 or less linking groups. R ¹⁰¹ , R ¹⁰² , R ¹⁰³ , R ¹⁰⁴ , and R ¹⁰⁵ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. One or more linking groups represented by L ¹¹ and L ^2k may be present between two chromophores to which they are linked, and a plurality (preferably two) are bonded to form a ring. It may be formed. Each of L ¹¹ and L ^2k is preferably one in which two alkylene groups (preferably ethylene) are bonded to form a ring. Among them, the case where a 5- or 6-membered ring (preferably cyclohexyl) is formed is more preferable.

  In the general formula (1), n represents an integer of 0 or more and 10 or less, preferably an integer of 0 to 5, more preferably an integer of 0 to 3, and particularly preferably an integer of 0 to 2.

In the general formula (1), k represents all integers of 0 or more and n or less. For example, when n is 2, k represents three integers of 0, 1, and ^2, and Dye ^2k and L ^2k are independently Dye ²⁰ , Dye ²¹ , and Dye ²² chromophores, and L ²⁰ , L ²¹ , L ²² linking groups are represented. When n represents an integer of 2 or more, the plurality of Dye ^2k may be the same or different from each other. When n represents an integer of 2 or more, the plurality of L2k may be the same or different from each other.

  Among the dyes represented by the general formula (4), an optical information recording medium containing a dye having a structure represented by the following general formula (5) is most preferable.

  In general formula (5), A, B, C, D, R, m, n, Q, and y are defined as A, B, C, D, R, m, n, Q, and y in general formula (3). Is the same.

  Specific examples of the anion moiety of the oxonol dye represented by the general formula (3) of the present invention include the anion moiety of the oxonol dye described in JP-A-10-297103. Although the following is given in the state where the anion Qy is removed, the present invention is not limited to these.

  Q in the general formula (3) represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge.

  In this case, Q represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge. In this case, Q is an organic counter cation and contains at least one substituent having an A value of 2.0 (kcal / mol) or more. Specific examples include a quaternary alkyl ammonium cation, a quaternary alkyl phosphonium cation, a quaternary anilinium cation, and a quaternary aryl phosphonium cation.

  Further, as the substituent, specifically, a tertiary alkyl group (preferably a substituted or unsubstituted tertiary alkyl group having 4 to 30 carbon atoms, more preferably a t-butyl group, a 2-methylbutyl group, a neopentyl group, 3-methylpentyl group), secondary alkyl group (preferably a substituted or unsubstituted secondary alkyl group having 3 to 30 carbon atoms, more preferably isopropyl group, 3-methylbutyl group, 2-ethylhexyl group), tri A fluoromethyl group, a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably a carbon number of 5 To a substituted or unsubstituted bicycloalkyl group having from 1 to 30 carbon atoms, A monovalent group obtained by removing one hydrogen atom from a can, for example, bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl), and a ring structure It includes many tricyclo structures. An alkyl group (for example, an alkyl group of an alkylthio group) in the substituents described below also represents such an alkyl group. ],

A substituted aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms such as phenyl, o-tolyl, naphthyl, o-chlorophenyl, o-hexadecanoylaminophenyl), a substituted heterocyclic group (preferably 5 Or a monovalent group obtained by removing one hydrogen atom from a 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and more preferably a 5- or 6-membered group having 3 to 30 carbon atoms. An aromatic heterocyclic group), a hetero atom-containing group (for example, a methylsulfonyl group SO ₂ Me (2.50), a diphenylphosphinooxy group O═P (C ₆ H ₅ ) ₂ (2.46), diphenyl phosphino sulfide _{S = P (C 6 H 5} ) 2 (3.13), trimethylsilyl group SiMe ₃ (2.5), trimethylgermyl group GeMe ₃ (2.1), bets Phenyl germyl group GePh ₃ (2.9)), more preferably a tertiary alkyl group, secondary alkyl group, a trifluoromethyl group, an aliphatic cyclic hydrocarbon group, a substituted phenyl group, a substituted heterocyclic group A heteroatom-containing group, more preferably a tertiary alkyl group, a secondary alkyl group, an aliphatic cyclic hydrocarbon group, or a substituted phenyl group. The numerical value in the parentheses is an A value that is a three-dimensional parameter.

As an organic counter cation as an organic counter ion, what is represented by the following general formula (E) is preferable.

In the general formula (E), R ¹ , R ^m , R ⁿ and R ^o each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a cyclic hydrocarbon group having 3 to 10 carbon atoms, R ¹ and R ^m or R ⁿ and R ^o may form a methylene chain and may be linked to each other. The number of methylene chains in that case is an integer of 2 to 15 carbon atoms, and l, m, and n are each independently an integer of 0 to 10. When n = 0, two N atoms may be connected via R ¹ , R ^m , R ⁿ , and R ^o , and they may form an alicyclic heterocycle. Specific preferred examples of the organic counter cation according to the present invention are listed below. In addition, among the following organic counter cations, E-1 to E-4 are preferred specific examples of the general formula (E).

  Examples of preferred specific compounds used in the present invention are shown in Table 23 below. The “maximum A value” in the table is the largest A value among the substituents contained in the counter ion structure.

  The recording layer of the information recording medium of the present invention can contain various anti-fading agents in order to improve the light resistance of the recording layer. Examples of the antifading agent include organic oxidants and singlet oxygen quenchers. As the organic oxidizing agent used as the anti-fading agent, compounds described in JP-A-10-151861 are preferable. As the singlet oxygen quencher, those described in publications such as known patent specifications can be used. Specific examples thereof include JP-A Nos. 58-175893, 59-81194, 60-18387, 60-19586, 60-19586, 60-35054, 60-36190, 60-36191, 60-44554, 60-44555, 60-44389, 60-44390, 60-54892, 60-47069, 63-20995, JP Listed in publications such as Nos. 4-25492, 1-38680, and 6-26028, German Patent No. 350399, and the Chemical Society of Japan, October 1992, page 1141 Can do. Preferred examples of the singlet oxygen quencher include compounds represented by the following general formula.

Where R ²¹ represents an alkyl group which may have a substituent, and Q ⁻ represents an anion.

In the above general formula, R ²¹ is generally an optionally substituted alkyl group having 1 to 8 carbon atoms, and is preferably an unsubstituted alkyl group having 1 to 6 carbon atoms. Examples of the substituent for the alkyl group include a halogen atom (eg, F, Cl), an alkoxy group (eg, methoxy, ethoxy), an alkylthio group (eg, methylthio, ethylthio), an acyl group (eg, acetyl, propionyl), an acyloxy group (Eg, acetoxy, propionyloxy), hydroxy group, alkoxycarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl), alkenyl group (eg, vinyl), aryl group (eg, phenyl, naphthyl). Among these, a halogen atom, an alkoxy group, an alkylthio group, and an alkoxycarbonyl group are preferable. Preferred examples of the Q ⁻ anion include ClO ₄ ⁻ , AsF ₆ ⁻ , BF ₄ ⁻ , and SbF ₆ ⁻ . Examples of compounds represented by the general formula (II) are shown in Table 24 below.

  The amount of the antifading agent such as the singlet oxygen quencher used is usually in the range of 0.1 to 50% by weight, preferably in the range of 0.5 to 45% by weight, based on the amount of the dye. Preferably, it is in the range of 3 to 40% by weight, particularly preferably in the range of 5 to 25% by weight.

<Optical information recording media>
The optical information recording medium of the present invention has a mode (1): a write-once recording layer containing a dye on a substrate having a thickness of 0.7 to 2 mm, a cover layer having a thickness of 0.01 to 0.5 mm, Information recording medium or embodiment having the above in order: (2): a write-once recording layer containing a dye on a substrate having a thickness of 0.1 to 1.0 mm, and a protective substrate having a thickness of 0.1 to 1.0 mm And an optical information recording medium having the above in this order. In aspect (1), it is preferable that the track pitch of the pregroove formed on the substrate is 50 to 500 nm, the groove width is 25 to 250 nm, and the groove depth is 5 to 150 nm. In aspect (2), the substrate It is preferable that the track pitch of the pregroove formed is 200 to 600 nm, the groove width is 50 to 300 nm, the groove depth is 30 to 200 nm, and the wobble amplitude is 10 to 50 nm. The optical information recording medium of aspect (1) has at least a substrate, a write-once recording layer, and a cover layer. First, components essential to these will be described in order.

[Substrate (1)]
In the substrate of the preferred mode (1), a pregroove (guide groove) having a shape in which all of the track pitch, groove width (half width), groove depth, and wobble amplitude are in the following ranges is formed. It is essential. This pre-groove is provided to achieve a higher recording density than CD-R and DVD-R. For example, the optical information recording medium of the present invention is used as a medium corresponding to a blue-violet laser. It is suitable for use.

  The track pitch of the pregroove is essential to be in the range of 50 to 500 nm, the upper limit value is preferably 420 nm or less, more preferably 370 nm or less, and further preferably 330 nm or less. Further, the lower limit is preferably 100 nm or more, more preferably 200 nm or more, and further preferably 260 nm or more. If the track pitch is less than 50 nm, it becomes difficult to form the pregroove accurately, and a crosstalk problem may occur. If the track pitch exceeds 500 nm, the recording density may decrease.

  The groove width (half width) of the pregroove is essential to be in the range of 25 to 250 nm, the upper limit is preferably 200 nm or less, more preferably 170 nm or less, and 150 nm or less. Further preferred. Further, the lower limit is preferably 50 nm or more, more preferably 80 nm or more, and further preferably 100 nm or more. If the groove width of the pregroove is less than 25 nm, the groove may not be sufficiently transferred at the time of molding, or the recording error rate may increase. If it exceeds 250 nm, the pits formed during recording will spread, It may cause crosstalk or a sufficient degree of modulation may not be obtained.

  The groove depth of the pregroove is essential to be in the range of 5 to 150 nm, the upper limit is preferably 100 nm or less, more preferably 70 nm or less, and further preferably 50 nm or less. Further, the lower limit is preferably 10 nm or more, more preferably 20 nm or more, and further preferably 28 nm or more. If the groove depth of the pregroove is less than 5 nm, a sufficient recording modulation degree may not be obtained, and if it exceeds 150 nm, the reflectivity may be significantly lowered.

  In addition, the groove inclination angle of the pregroove is preferably 80 ° or less, more preferably 70 ° or less, still more preferably 60 ° or less, and particularly preferably 50 ° or less. preferable. Further, the lower limit value is preferably 20 ° or more, more preferably 30 ° or more, and further preferably 40 ° or more. If the groove inclination angle of the pregroove is less than 20 °, a sufficient tracking error signal amplitude may not be obtained, and if it exceeds 80 °, molding becomes difficult.

  As the substrate used in the present invention, various materials used as substrate materials for conventional optical information recording media can be arbitrarily selected and used. Specifically, glass; acrylic resin such as polycarbonate and polymethyl methacrylate; vinyl chloride resin such as polyvinyl chloride and vinyl chloride copolymer; epoxy resin; amorphous polyolefin; polyester; metal such as aluminum; These may be used together if desired.

  Among the above materials, thermoplastic resins such as amorphous polyolefin and polycarbonate are preferable, and polycarbonate is particularly preferable from the viewpoints of moisture resistance, dimensional stability, and low price. When these resins are used, the substrate can be manufactured by injection molding. Further, the thickness of the substrate needs to be in the range of 0.7 to 2 mm, preferably in the range of 0.9 to 1.6 mm, and more preferably 1.0 to 1.3 mm. .

  In addition, it is preferable to form an undercoat layer on the substrate surface on the side where a light reflecting layer described later is provided for the purpose of improving the flatness and the adhesive force. Examples of the material for the undercoat layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene / vinyl toluene copolymer, and chloro. Polymer materials such as sulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate, etc .; silane coupling Surface modifiers such as agents; The undercoat layer is formed by dissolving or dispersing the above materials in an appropriate solvent to prepare a coating solution, and then applying this coating solution to the substrate surface by a coating method such as spin coating, dip coating, or extrusion coating. can do. The thickness of the undercoat layer is generally in the range of 0.005 to 20 μm, and preferably in the range of 0.01 to 10 μm.

[Write-once recording layer of aspect (1)]
In the write-once recording layer of the preferred embodiment (1), the aforementioned dye is dissolved in a suitable solvent together with a binder or the like to prepare a coating solution, and then this coating solution is applied to the substrate or a light reflecting layer described later. It is formed by applying a coating film on the top and then drying. Here, the write-once recording layer may be a single layer or a multilayer. In the case of a multilayer structure, the step of applying the coating liquid is performed a plurality of times. The concentration of the dye in the coating solution is generally in the range of 0.01 to 15% by mass, preferably in the range of 0.1 to 10% by mass, more preferably in the range of 0.5 to 5% by mass, most preferably. It is the range of 0.5-3 mass%.

  Examples of the solvent for the coating solution include 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; dimethylformamide and the like Amides; Hydrocarbons such as methylcyclohexane; Ethers such as tetrahydrofuran, ethyl ether, dioxane; Alcohols such as ethanol, n-propanol, isopropanol, n-butanol diacetone alcohol; 2,2,3,3-tetrafluoropropanol, etc. Fluorinated solvents; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether; That. The above solvents can be used alone or in combination of two or more in consideration of the solubility of the dye used. In the coating solution, various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be added according to the purpose.

  Examples of the coating method include a spray method, a spin coating method, a dip method, a roll coating method, a blade coating method, a doctor roll method, and a screen printing method. At the time of application, the temperature of the coating solution is preferably in the range of 23 to 50 ° C, more preferably in the range of 24 to 40 ° C, and particularly preferably in the range of 23 to 50 ° C.

  The thickness of the write-once recording layer formed in this way is preferably 300 nm or less, more preferably 250 nm or less, and more preferably 200 nm or less on the groove (convex portion in the substrate). More preferably, it is particularly preferably 180 nm or less. The lower limit is preferably 30 nm or more, more preferably 50 nm or more, still more preferably 70 nm or more, and particularly preferably 90 nm or more. Further, the thickness of the write-once recording layer is preferably 400 nm or less, more preferably 300 nm or less, and further preferably 250 nm or less on the land (the concave portion in the substrate). The lower limit is preferably 70 nm or more, more preferably 90 nm or more, and further preferably 110 nm or more. Further, the ratio of the thickness of the write-once recording layer on the groove / the thickness of the write-once recording layer on the land is preferably 0.4 or more, more preferably 0.5 or more, and 6 or more is more preferable, and 0.7 or more is particularly preferable. The upper limit is preferably less than 1, more preferably 0.9 or less, still more preferably 0.85 or less, and particularly preferably 0.8 or less.

  When the coating solution contains a binder, examples of the binder include natural organic polymer materials such as gelatin, cellulose derivatives, dextran, rosin, and rubber; hydrocarbon resins such as polyethylene, polypropylene, polystyrene, and polyisobutylene. , Polyvinyl chloride, polyvinylidene chloride, vinyl resins such as polyvinyl chloride / polyvinyl acetate copolymer, acrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resin, butyral And synthetic organic polymers such as resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins. When a binder is used in combination as a material for the write-once recording layer, the amount of binder used is generally in the range of 0.01 to 50 times (mass ratio) with respect to the dye, preferably 0.1. It exists in the range of double amount-5 times amount (mass ratio).

[Cover layer of aspect (1)]
The cover layer of the preferred embodiment (1) is bonded to the above-described write-once recording layer or a barrier layer described later via an adhesive or an adhesive material. The cover layer used in the present invention is not particularly limited as long as it is a transparent material film; however, an acrylic resin such as polycarbonate and polymethyl methacrylate; a vinyl chloride resin such as polyvinyl chloride and a vinyl chloride copolymer; It is preferable to use epoxy resin; amorphous polyolefin; polyester; cellulose triacetate and the like. Among them, it is more preferable to use polycarbonate or cellulose triacetate. Note that “transparent” means that the transmittance is 80% or more with respect to light used for recording and reproduction.

  Further, the cover layer may contain various additives as long as the effects of the present invention are not hindered. For example, a UV absorber for cutting light having a wavelength of 400 nm or less and / or a pigment for cutting light having a wavelength of 500 nm or more may be contained. Further, as the surface physical properties of the cover layer, it is preferable that both the two-dimensional roughness parameter and the three-dimensional roughness parameter have a surface roughness of 5 nm or less. Further, from the viewpoint of the concentration of light used for recording and reproduction, the birefringence of the cover layer is preferably 10 nm or less.

  The thickness of the cover layer is appropriately defined by the wavelength and NA of the laser light irradiated for recording and reproduction. In the present invention, the thickness is in the range of 0.01 to 0.5 mm, and 0 More preferably, it is in the range of 0.05 to 0.12 mm. The total thickness of the cover layer and the layer made of an adhesive or a pressure-sensitive adhesive is preferably 0.09 to 0.11 mm, and more preferably 0.095 to 0.105 mm. The light incident surface of the cover layer may be provided with a protective layer (hard coat layer) for preventing the light incident surface from being damaged when the optical information recording medium is manufactured.

  For example, a UV curable resin, an EB curable resin, a thermosetting resin, or the like is preferably used as the adhesive used to bond the cover layer, and it is particularly preferable to use a UV curable resin. When a UV curable resin is used as an adhesive, the UV curable resin may be used as it is or dissolved in an appropriate solvent such as methyl ethyl ketone or ethyl acetate to prepare a coating solution, which may be supplied from the dispenser to the barrier layer surface. . Further, in order to prevent warpage of the produced optical information recording medium, it is preferable that the UV curable resin constituting the adhesive layer has a small curing shrinkage rate. Examples of such UV curable resins include UV curable resins such as “SD-640” manufactured by Dainippon Ink and Chemicals, Inc.

  The adhesive is applied, for example, on a surface to be bonded composed of a barrier layer, and after a cover layer is placed thereon, the adhesive is applied by spin coating to the surface to be bonded and the cover layer. It is preferable that the film is cured after being spread so as to be uniform. The thickness of the adhesive layer made of such an adhesive is preferably in the range of 0.1 to 100 μm, more preferably in the range of 0.5 to 50 μm, and still more preferably in the range of 10 to 30 μm.

  As the pressure-sensitive adhesive used for laminating the cover layer, acrylic, rubber-based, and silicon-based pressure-sensitive adhesives can be used. From the viewpoint of transparency and durability, acrylic pressure-sensitive adhesive is used. preferable. As such an acrylic pressure-sensitive adhesive, 2-ethylhexyl acrylate, n-butyl acrylate and the like are the main components, and in order to improve cohesion, short-chain alkyl acrylates and methacrylates such as methyl acrylate, ethyl acrylate, and methyl methacrylate are used. And acrylic acid, methacrylic acid, acrylamide derivatives, maleic acid, hydroxylethyl acrylate, glycidyl acrylate, and the like, which can be crosslinking points with the crosslinking agent, are preferably used. The glass transition temperature (Tg) and the crosslinking density can be changed by appropriately adjusting the mixing ratio and type of the main component, the short chain component, and the component for adding a crosslinking point.

  As a crosslinking agent used together with the said adhesive, an isocyanate type crosslinking agent is mentioned, for example. Such isocyanate-based crosslinking agents include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluidine isocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, and the like. Isocyanates, products of these isocyanates with polyalcohols, and polyisocyanates formed by condensation of isocyanates can be used. Commercially available products of these isocyanates include Coronate L, Coronate HL, Coronate 2030, Coronate 2031, Millionate MR, Millionate HTL manufactured by Nippon Polyurethane; Takenate D-102 and Takenate D-110N manufactured by Takeda Pharmaceutical Co., Ltd. , Takenate D-200, Takenate D-202; Death Module L, Death Module IL, Death Module N, Death Module HL;

  The pressure-sensitive adhesive may be uniformly applied on the surface to be bonded made of the barrier layer, and may be cured after placing the cover layer thereon, or in advance on one side of the cover layer, A predetermined amount may be uniformly applied to form a pressure-sensitive adhesive coating film, the coating film may be bonded to the surface to be bonded, and then cured. Moreover, you may use the commercially available adhesive film in which the adhesive layer was previously provided for the cover layer. The thickness of the pressure-sensitive adhesive layer made of such a pressure-sensitive adhesive is preferably in the range of 0.1 to 100 μm, more preferably in the range of 0.5 to 50 μm, and still more preferably in the range of 10 to 30 μm.

[Other layers in aspect (1)]
The optical information recording medium of the preferred embodiment (1) may have other optional layers in addition to the above essential layers as long as the effects of the present invention are not impaired. As such other optional layers, for example, a label layer having a desired image formed on the back surface of the substrate (the back surface with respect to the write-once recording layer forming surface), or between the substrate and the write-once recording layer is provided. And a barrier layer (described later) provided between the write-once recording layer and the cover layer, an interface layer provided between the light reflective layer and the write-once recording layer, and the like. Here, the label layer is formed using an ultraviolet curable resin, a thermosetting resin, a heat drying resin, or the like. These essential and optional layers may be a single layer or may have a multilayer structure.

[Light Reflecting Layer in Mode (1)]
In the optical information recording medium of the preferred mode (1), a light reflecting layer is formed between the substrate and the write-once recording layer in order to increase the reflectivity for laser light and to give the function of improving the recording / reproducing characteristics. It is preferable to do. The light reflecting layer can be formed on the substrate by vacuum-depositing, sputtering, or ion plating a light-reflecting material having a high reflectance with respect to laser light. The 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 reflectance is preferably 70% or more.

  As a light reflective material having a high reflectance, Mg, Se, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Ru, Rh, Pd , Ir, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi, and other metals and semi-metals or stainless steel. These light reflecting materials may be used alone or in combination of two or more or as an alloy. Among these, Cr, Ni, Pt, Cu, Ag, Au, Al, and stainless steel are preferable. Particularly preferred is Au, Ag, Al or an alloy thereof, and most preferred is Au, Ag or an alloy thereof.

[Formation process of barrier layer (intermediate layer) in aspect (1)]
In the optical information recording medium of the preferred mode (1), it is preferable to form a barrier layer between the write-once recording layer and the cover layer. The barrier layer is provided for improving the storage stability of the write-once recording layer, improving the adhesion between the write-once recording layer and the cover layer, adjusting the reflectance, adjusting the thermal conductivity, and the like. The material used for the barrier layer is not particularly limited as long as it is a material that transmits light used for recording and reproduction, and can express the above functions. Is a material with low gas and moisture permeability and is preferably a dielectric. Specifically, materials made of nitrides, oxides, carbides, sulfides such as Zn, Si, Ti, Te, Sn, Mo, Ge are preferable. ZnS, MoO ₂ , GeO ₂ , TeO, SiO ₂ , TiO ₂ , ZuO, ZnS—SiO ₂ , SnO ₂ and ZnO—Ga ₂ O ₃ are preferable, and ZnS—SiO ₂ , SnO ₂ and ZnO—Ga ₂ O ₃ are more preferable.

  The barrier layer can be formed by a vacuum film forming method such as vacuum deposition, DC sputtering, RF sputtering, or ion plating. Among these, it is more preferable to use sputtering, and it is more preferable to use RF sputtering. The thickness of the barrier layer in the present invention is preferably in the range of 1 to 200 nm, more preferably in the range of 2 to 100 nm, and still more preferably in the range of 3 to 50 nm.

  Next, an optical information recording medium having a preferable mode (2) will be described. Here, the optical information recording medium of the mode (2) is an optical information recording medium having a laminated type layer structure, and a typical layer structure is as follows.

(1) The first layer configuration is a configuration in which a write-once recording layer, a light reflection layer, and an adhesive layer are sequentially formed on a substrate, and a protective substrate is provided on the adhesive layer.
(2) The second layer configuration is a configuration in which a write-once recording layer, a light reflection layer, a protective layer, and an adhesive layer are sequentially formed on a substrate, and a protective substrate is provided on the adhesive layer.
(3) The third layer configuration is a configuration in which a write-once recording layer, a light reflection layer, a protective layer, an adhesive layer, and a protective layer are sequentially formed on a substrate, and a protective substrate is provided on the protective layer.
(4) In the fourth layer configuration, a write-once recording layer, a light reflecting layer, a protective layer, an adhesive layer, a protective layer, and a light reflecting layer are sequentially formed on a substrate, and a protective substrate is provided on the light reflecting layer. It is a configuration.
(5) The fifth layer configuration is a configuration in which a write-once recording layer, a light reflecting layer, an adhesive layer, and a light reflecting layer are sequentially formed on a substrate, and a protective substrate is provided on the light reflecting layer.

  Note that the layer configurations (1) to (5) are merely examples, and the layer configuration is not limited to the order described above, and a part of the layer configuration may be replaced or a part of the layer configuration may be omitted. The write-once recording layer may also be formed on the protective substrate side. In this case, an optical information recording medium capable of recording and reproducing from both sides is obtained. Furthermore, each layer may be composed of one layer or a plurality of layers. As an example of the optical information recording medium of the present invention, a recording medium having a write-once recording layer, a light reflecting layer, an adhesive layer, and a protective substrate in this order will be described below.

[Substrate (2)]
In the preferred embodiment (2), a pregroove (guide groove) having a shape in which all of the track pitch, groove width (half width), groove depth, and wobble amplitude are in the following ranges is formed. It is essential. This pre-groove is provided to achieve a higher recording density than CD-R and DVD-R. For example, the optical information recording medium of the present invention is used as a medium corresponding to a blue-violet laser. It is suitable for use.

  The track pitch of the pregroove is essential to be in the range of 200 to 600 nm, and the upper limit is preferably 500 nm or less, more preferably 450 nm or less, and further preferably 430 nm or less. The lower limit is preferably 300 nm or more, more preferably 330 nm or more, and still more preferably 370 nm or more. If the track pitch is less than 200 nm, it is difficult to form the pregroove accurately, and a crosstalk problem may occur. If the track pitch exceeds 600 nm, the recording density may decrease.

  The groove width (half width) of the pregroove is in the range of 50 to 300 nm, the upper limit is preferably 250 nm or less, more preferably 200 nm or less, and 180 nm or less. Further preferred. Further, the lower limit value is preferably 100 nm or more, more preferably 120 nm or more, and further preferably 140 nm or more. If the groove width of the pregroove is less than 50 nm, the groove may not be sufficiently transferred at the time of molding or the recording error rate may be high. If it exceeds 300 nm, the pits formed at the time of recording spread. It may cause crosstalk or a sufficient degree of modulation may not be obtained.

  The groove depth of the pregroove is essential to be in the range of 30 to 200 nm, the upper limit is preferably 170 nm or less, more preferably 140 nm or less, and further preferably 120 nm or less. The lower limit is preferably 40 nm or more, more preferably 50 nm or more, and further preferably 60 nm or more. When the groove depth of the pregroove is less than 30 nm, a sufficient recording modulation degree may not be obtained, and when it exceeds 200 nm, the reflectivity may be significantly lowered.

  As the substrate used in the preferable mode (2), various materials used as the substrate material of the conventional optical information recording medium can be arbitrarily selected and used. Specific examples and preferable examples are described in the mode (1). ). Further, the thickness of the substrate needs to be in the range of 0.1 to 1.0 mm, preferably in the range of 0.2 to 0.8 mm, and in the range of 0.3 to 0.7 mm. It is more preferable.

  In addition, it is preferable to form an undercoat layer on the substrate surface on the side on which the write-once recording layer described later is provided for the purpose of improving flatness and adhesion, and the material of the undercoat layer and the coating method Specific examples and preferred examples of the layer thickness are the same as those of the undercoat layer of the aspect (1).

[Write-once recording layer of aspect (2)]
The detailed description of the write-once recording layer of the preferred mode (2) is the same as that of the write-once recording layer of the mode (1).

[Light reflecting layer of mode (2)]
In a preferred mode (2), a light reflecting layer may be formed on the write-once recording layer in order to increase the reflectance with respect to the laser beam or to provide a function for improving the recording / reproducing characteristics. Details regarding the light reflecting layer of the aspect (2) are the same as those of the light reflecting layer of the aspect (1).

[Adhesive layer of aspect (2)]
The adhesive layer in the preferred embodiment (2) is an arbitrary layer formed in order to improve the adhesion between the light reflecting layer and the protective substrate. As a material constituting the adhesive layer, a photo-curing resin is preferable, and in particular, a material having a small curing shrinkage rate is preferable in order to prevent the disk from warping. Examples of such a photocurable resin include UV curable resins (UV curable adhesives) such as “SD-640” and “SD-347” manufactured by Dainippon Ink, Inc. Further, the thickness of the adhesive layer is preferably in the range of 1 to 1000 μm in order to give elasticity.

[Protective board of mode (2)]
The protective substrate (dummy substrate) in the preferred mode (2) can be made of the same material and the same shape as the above-described substrate. The thickness of the protective substrate requires a thickness in the range of 0.1 to 1.0 mm, preferably in the range of 0.2 to 0.8 mm, and in the range of 0.3 to 0.7 mm. It is more preferable that

[Protective layer of aspect (2)]
In the optical information recording medium of the preferred mode (2), a protective layer may be provided for the purpose of physically and chemically protecting the light reflecting layer and the write-once recording layer depending on the layer structure. Examples of materials used for the protective layer include inorganic substances such as ZnS, ZnS—SiO ₂ , SiO, SiO ₂ , MgF ₂ , SnO ₂ , and Si ₃ N ₄ , thermoplastic resins, thermosetting resins, and UV curable materials. Organic substances such as resins can be mentioned. The protective layer can be formed, for example, by bonding a film obtained by plastic extrusion onto the light reflecting layer via an adhesive. Moreover, you may provide by methods, such as vacuum evaporation, sputtering, and application | coating.

  Further, when a thermoplastic resin or a thermosetting resin is used as the protective layer, it is also formed by dissolving these in an appropriate solvent to prepare a coating solution, and then applying and drying the coating solution. be able to. In the case of a UV curable resin, it can also be formed by preparing a coating solution as it is or by dissolving it in a suitable solvent, and then applying the coating solution and curing it by irradiation with UV light. In these coating liquids, various additives such as an antistatic agent, an antioxidant, and a UV absorber may be added according to the purpose. The thickness of the protective layer is generally in the range of 0.1 μm to 1 mm.

[Other layers of aspect (2)]
The optical information recording medium of the preferred embodiment (2) may have other arbitrary layers in addition to the above-mentioned layers as long as the effects of the present invention are not impaired. The detailed description of the other optional layers is the same as that of the other layers in the aspect (1).

<Information recording method>
The information recording method of the present invention is characterized in that information is recorded by irradiating an optical information recording medium with a laser beam having a wavelength of 440 nm or less. Since the above-described optical information recording medium of the present invention is used in the information recording method of the present invention, high-density recording and reproduction of information can be performed favorably.

  Specifically, the information recording method of the present invention is performed as follows using the optical information recording medium of the preferred mode (1) or (2).

  First, while rotating the optical information recording medium at a constant linear velocity (0.5 to 10 m / sec) or a constant angular velocity, recording light such as semiconductor laser light is irradiated from the substrate side or the protective layer side. By this light irradiation, the recording layer absorbs the light and the temperature rises locally, causing a physical or chemical change (for example, generation of pits) and changing its optical characteristics, thereby recording information. It is thought that it is done. In the present invention, semiconductor laser light having an oscillation wavelength in the range of 390 to 440 nm is used as recording light. As a preferred light source, a blue-violet semiconductor laser beam having an oscillation wavelength in the range of 390 to 415 nm, and a blue-violet SHG having a central oscillation wavelength of 425 nm obtained by halving an infrared semiconductor laser beam having a central oscillation wavelength of 850 nm using an optical waveguide device. A laser beam can be mentioned. In particular, it is preferable to use a blue-violet semiconductor laser beam having an oscillation wavelength in the range of 390 to 415 nm in terms of recording density. The information recorded as described above is reproduced by irradiating a semiconductor laser beam from the substrate side or the protective layer side while rotating the optical information recording medium at the same constant linear velocity as above and detecting the reflected light. Can be performed.

  Hereinafter, synthesis examples of the dye according to the present invention will be shown. Other compounds of the present invention can be synthesized by similar methods.

[Synthesis of Dye S-7]
(1) Scheme (A)

6.28 g of compound “2” was added to 110 ml of N, N′-dimethylformamide, and after cooling to 0 ° C., 18.6 ml of triethylamine was added with stirring, and then 10.5 g of compound “1” was added. Then, after reacting at 0 ° C. for 4 hours, 400 ml of ethyl acetate was added to form crystals and filtered to obtain 14.7 g of compound “H-1”. The structure was confirmed by NMR. ¹ HNMR (DMSO-d ⁶ )): δ = 1.15 (t, 18H), 2.05 (s,
8H), 2.6 (t, 4H), 3.05 to 3.20 (m, 16H), 7.80 (s, 2H), 8.80 (s, 2H)

(2) Scheme B

14.0 g of compound “3” was added to 140 ml of isopropyl alcohol, 10.0 g of compound “4” was added with stirring, and the mixture was heated to reflux. Thereafter, the mixture was cooled to room temperature and then concentrated with an evaporator. Thereafter, 400 ml of ethyl acetate was added to form crystals, followed by filtration to obtain 23.4 g of compound “5”. The structure was confirmed by NMR. ¹ HNMR (DMSO-d ⁶ ): δ = 1.30 to 1.90 (m, 26H), 2.15 (m, 6H), 3.03 (s, 12
H)

(2) Scheme B

0.388 g of compound “H-1” was added to 10 ml of methanol, 0.202 g of compound “5” was added, and the mixture was stirred for a while. Thereafter, yellow crystals were precipitated and heated to reflux for 1 hour. After cooling to room temperature, filtration was performed to obtain 0.30 g of dye S-7. The structure was confirmed by NMR. ¹ HNMR (DMSO-d ⁶ )): δ = 1.15 (t, 18H), 1.30 to 1.90 (m, 26H), 2.05 (s, 8H), 2.15 (m, 6H) ), 2.6 (t, 4H), 3.03 (s, 12H), 3.05 to 3.20 (m, 16H), 7.80 (s, 2H)

[Other synthesis examples]
Synthesis of Compound “H-2”:

Compound "H-1" 0.60g was added to methanol 10ml, Compound "6" 5.00g was added, and it stirred for a while. Then, 10 ml of water was added and heated to reflux for 1 hour. After cooling to room temperature, filtration was performed to obtain 0.40 g of compound “H-2”. The structure was confirmed by NMR. ¹ HNMR (CDCl ₃ )): δ = 1.00 (t, 24H), 1.35 to 1.75 (m,
32H), 2.20 (s, 8H), 2.75 (t, 4H), 3.20 (s, 16H), 8.20 (s, 2H)

  The present invention will be specifically described below with reference to the following examples.

[Examples 1 to 4]
<Manufacture of optical information recording media>
(Production of substrate)
Thickness 1.1 mm, outer diameter 120 mm, inner diameter 15 mm, spiral pre-groove (track pitch: 320 nm, groove width: on-groove width 120 nm, groove depth: 35 nm, groove inclination angle: 65 °, wobble amplitude: 20 nm) An injection-molded substrate made of a polycarbonate resin was prepared. Mastering of the stamper used at the time of injection molding was performed using laser cutting (351 nm).

(Formation of light reflection layer)
APC light reflecting layer (Ag: 98.1 mass%, Pd: 0.9 mass) as a vacuum film-forming layer having a film thickness of 100 nm by DC sputtering in an Ar atmosphere using a Cube manufactured by Unaxis Co. %, Cu: 1.0 mass%). The film thickness of the light reflecting layer was adjusted by the sputtering time.

(Formation of write-once recording layer)
2 g of each of the compounds (S-7), (S-8), (S-9), and (S-11) in Table 23 was added to 100 ml of 2,2,3,3-tetrafluoropropanol and dissolved. A dye-containing coating solution was prepared. And the prepared pigment | dye containing coating liquid was apply | coated on the conditions of 23 degreeC and 50% RH, changing the rotation speed to 300-4000 rpm with a spin coat method on the light reflection layer. Then, it was stored at 23 ° C. and 50% RH for 1 hour to form a write-once recording layer (thickness on the groove 120 nm, thickness on the land 170 nm).

  After the write-once recording layer was formed, annealing treatment was performed in a clean oven. The annealing treatment was performed by supporting the substrate on a vertical stack pole while leaving a gap with a spacer, and holding at 80 ° C. for 1 hour.

(Formation of barrier layer)
Thereafter, on the write-once recording layer, a Cubes made by Unaxis is used and made of ZnO—Ga ₂ O ₃ (ZnO: Ga ₂ O ₃ = 3: 7 (mass ratio)) by RF sputtering in an Ar atmosphere. A barrier layer having a thickness of 5 nm was formed.

(Covering the cover layer)
As the cover layer, a polycarbonate film (Teijin Pure Ace, thickness: 80 μm) having an inner diameter of 15 mm and an outer diameter of 120 mm and coated with an adhesive on one side, the thickness of the adhesive layer and the polycarbonate film is used. The total thickness was set to 100 μm. Then, the cover layer was placed on the barrier layer so that the barrier layer and the pressure-sensitive adhesive layer were in contact with each other, and the cover layer was pressed and pressed with a pressing member.

(Comparative Examples 1-4)
Examples were used except that the compounds (S-7), (S-8), (S-9), and (S-11) were used instead of the comparative compounds (A) to (D) represented by the following chemical formulas. Disks were produced in exactly the same way as in 1-4.

  Thus, optical information recording media of Examples 1 to 4 and Comparative Examples 1 to 4 were produced.

<Evaluation of optical information recording media>
C / N (carrier-to-noise ratio) evaluation The produced optical information recording medium was recorded using a recording / reproduction evaluation machine (PDUTEC: DDU1000) loaded with a 403 nm laser and NA 0.85 pickup, with a clock frequency of 66 MHz and a linear velocity of 5 A 0.16 μm signal (2T) was recorded and reproduced at .28 m / s, and C / N (after recording) was measured with a spectrum analyzer (manufactured by Advantest Corporation: TR4171). This evaluation was performed using the optical information recording method of the present invention, and recording was performed on a groove. The recording power was 5.2 mW and the reproducing power was 0.3 mW.

[Examples 5 to 8]
<Manufacture of optical information recording media>
(Production of substrate)
Thickness 0.6 mm, outer diameter 120 mm, inner diameter 15 mm and spiral pregroove (track pitch: 400 nm, groove width: 170 nm, groove depth: 100 nm, groove inclination angle: 65 °, wobble amplitude: 20 nm), An injection molded substrate made of polycarbonate resin was produced. Mastering of the stamper used at the time of injection molding was performed using laser cutting (351 nm).

(Formation of write-once recording layer)
2 g of each of the compounds (S-7), (S-8), (S-9), and (S-11) shown in Table 1 is added to 100 ml of 2,2,3,3-tetrafluoropropanol and dissolved. Then, a dye-containing coating solution was prepared. And the prepared pigment | dye containing coating liquid was apply | coated on the conditions of 23 degreeC and 50% RH, changing the rotation speed to 300-4000 rpm by a spin coat method. Then, it was stored at 23 ° C. and 50% RH for 1 hour to form a write-once recording layer (thickness on groove: 170 nm, thickness on land: 120 nm).

  After the write-once recording layer was formed, annealing treatment was performed in a clean oven. The annealing treatment was performed by supporting the substrate on a vertical stack pole while leaving a gap with a spacer, and holding at 80 ° C. for 1 hour.

(Formation of light reflection layer)
An APC light reflecting layer (Ag: 98.1% by mass, Pd: 0) as a vacuum film-forming layer having a film thickness of 100 nm was formed on the write-once recording layer using a Cube manufactured by Unaxis, and DC sputtering in an Ar atmosphere. .9 mass%, Cu: 1.0 mass%) was formed. The film thickness of the light reflecting layer was adjusted by the sputtering time.

(Lamination of protective substrate)
On the light reflection layer, an ultraviolet curable resin (SD640, manufactured by Dainippon Ink) is applied by spin coating, and a protective substrate made of polycarbonate (same as the above substrate except that no pregroove is formed) is bonded. And cured by irradiating with ultraviolet rays. The thickness of the adhesive layer made of the ultraviolet curable resin in the produced optical information recording medium was 25 μm.

(Comparative Examples 5 to 8)
Examples were used except that the compounds (S-7), (S-8), (S-9), and (S-11) were used instead of the comparative compounds (A) to (D) represented by the following chemical formulas. Disks were produced in exactly the same way as in 5-8.

  Thereby, optical information recording media of Examples 5 to 8 and Comparative Examples 5 to 8 were produced.

<Evaluation of optical information recording media>
(1) C / N (carrier-to-noise ratio) evaluation The produced optical information recording medium was recorded using a recording / reproduction evaluation machine (DDU1000 manufactured by Pulstec Corp.) loaded with a 405 nm laser and NA 0.65 pickup. A 0.204 μm signal (2T) was recorded and reproduced at 8 MHz and a linear velocity of 6.61 m / s, and C / N (after recording) was measured with a spectrum analyzer (manufactured by Advantest Corporation: TR4171).

  This evaluation was performed using the optical information recording method of the present invention, and recording was performed on a groove. The recording power was 12 mW and the reproducing power was 0.5 mW.

  Further, the produced optical information recording medium was stored in an environment of a temperature of 60 ° C. and a humidity of 80% for 24 hours, and the same measurement was performed. The results are shown in Table 3. Here, when the C / N (after recording) is 25 dB or more, the reproduction signal intensity is sufficient and the recording characteristics are preferable. Further, when the C / N after being stored for 24 hours in an environment of a temperature of 60 ° C. and a humidity of 80% is 25 dB or more, the storage stability is sufficient, which means that it is practically preferable.

  From the results of Table 3 above, the recording media 1 to 8 comprising the recording layer containing the compound of the present invention have a higher reproduction signal intensity than those of Comparative Examples 1 to 8, and also have high storage stability under high temperature and high humidity. It turns out that it is favorable.

<Evaluation of light fastness>
(Production of glass substrate)
20 mg of each of the above-mentioned dye S-7 and comparative compounds “H-1” and “H-2” were added and dissolved in 1 ml of 2,2,3,3-tetrafluoropropanol, and the dye-containing coating was applied. A liquid was prepared. And the prepared pigment | dye containing coating liquid was apply | coated on the conditions of 23 degreeC and 50% RH, changing the rotation speed to 300-4000 rpm by a spin coat method on the glass substrate.

(Evaluation)
Then, after storing for 1 day under light shielding at room temperature, the glass substrate was filtered on a xenon lamp (XL-500D-O 500W manufactured by USHIO DISCHARGE LAMPS) using a merry-go-round light resistance tester (customized by Eagle Engineering Co., Ltd.) (HOYA). HA-A-50) manufactured by the company was mounted, and a glass substrate coated with a pigment was placed at a distance of 8 cm from the light source and irradiated with light. Thereafter, the absorbance was measured with SHIMADZU UV-1600.

  The dye S-7 was compared with “H-1” and “H-2” as comparative compounds. The change in absorbance due to the above measurement is shown in Table 26 below.

  From the above table, it can be seen that the dye S-7 has higher light preservability than the comparative compounds “H-1” and “H-2”. This shows the usefulness of the present invention.

  As described above, by using the coloring matter according to the present invention, it is possible to obtain an optical information recording medium exhibiting good recording characteristics and good light / wet heat storage properties while considering the environment. In particular, since the above effect can be obtained by using a laser having a shorter wavelength than in the case of CD-R and DVD-R, a higher-density information recording medium and a recording / reproducing method can be provided.

Claims (9)

An optical information recording medium having a recording layer capable of recording information on a substrate by irradiation with laser light having a wavelength of 440 nm or less,
The recording layer contains a dye composed of a cation moiety and an anion moiety, and the dye comprises a cationic chromophore and an anionic counterion, or an anionic chromophore and a cationic counterion;
Each of the counter ions is an organic counter ion, and contains one or more substituents having an A value of 2.0 (kcal / mol) or more as a steric parameter. . The optical information recording medium according to claim 1, wherein the dye contains a cyanine chromophore represented by the following general formula (1) or a styryl chromophore represented by the following general formula (2). .

[In the above general formulas (1) and (2), each X independently represents an oxygen atom, a sulfur atom or N—R, and R, R ^a and R ^b each independently represent an alkyl group, an aryl group or a heterocyclic ring. Represents a group, and R ^a and R ^b may be linked to each other to form a ring. Z ^a represents an atomic group necessary for completing ^a 5-membered or 6-membered heterocyclic ring, and L ¹ , L ² , and L ³ each independently represents a substituted or unsubstituted methine group (provided that L ^{1 to} L ³ may be linked to each other to form a ring), j represents 0 or 1, Q represents an ion that neutralizes charge, and y represents neutralization of charge. Represents the number required for. In this case, Q is an organic counter anion as the organic counter ion. ] The compounds represented by the general formula (1) and the general formula (2) are represented by the following general formula (1-1), the following general formula (2-1), the following general formula (1-2), and the following general formula. The optical information recording medium according to claim 2, wherein the optical information recording medium is a compound represented by any one of (2-2), the following general formula (1-3), and the following general formula (2-3).

(In the above general formula (1-1), the above general formula (2-1), the above general formula (1-2), and the above general formula (2-2), Z ^b each independently represents an indolenine nucleus, a benzo X ^a represents an atomic group necessary for forming an indolenine nucleus, a benzimidazole nucleus, a benzoxazole nucleus or a benzothiazole nucleus, where X ^a is an oxygen atom, a sulfur atom, C (R ₃ ) (R ₄ ) or N—R .R ₁ representing the _{5, R 2, R 3,} R 4 and R ₅ .L ⁴ representing each independently an alkyl group or an aryl group, L ⁵ is .Q to represent a substituted or unsubstituted methine group charge Represents an ion to be neutralized, and y represents a number necessary for neutralizing the charge, wherein Q is an organic counter anion, R ^a and R ^b each independently represents an alkyl group or an aryl group, and It may be linked to form a ring, and the above general formula (1-3) And the general formula (2-3), X ^b and X ^c are independently an oxygen atom, a sulfur atom .R ⁶ to or representing the ^{N-R 14,, R 7} , R 8, R 9, R 10, R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and L ⁶ , L ⁷ and L ⁸ are each independently substituted or Represents an unsubstituted methine group, provided that when there are substituents on L ^{6 to} L ⁸ , these substituents may be linked to each other to form a ring, and k represents 0 or 1; (Similar to the above, Q represents an ion for neutralizing electric charge, and y represents a number necessary for neutralizing electric charge.)   3. The optical information recording medium according to claim 2, wherein the cationic chromophore in the general formula (1) is monomethinecyanine (j = 0 in the general formula (1)). The optical information recording medium according to claim 1, wherein the dye is an oxonol represented by the following general formula (3).

[In the above general formula (3), A, B, C and D are electron attractive properties in which the sum of the Hammett σp values of A and B and the sum of the Hammett σp values of C and D are each 0.6 or more. And “A and B” or “C and D” may be linked to form a ring, R represents a substituent on the methine carbon, m represents an integer of 0 to 3, and n Represents an integer of 0 to 2m + 1, and when n is an integer of 2 or more, a plurality of R may be the same or different from each other, and may be connected to each other to form a ring. Q represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge. In this case, Q is an organic counter cation as the organic counter ion. Further, two or more of the dyes represented by the general formula (3) (they may be the same or different) may be connected to each other through any one of A, B, C, and D. Also, two or more oxonol dyes connected in this manner are also included in the general formula (3). ]   6. The optical information recording medium according to claim 5, wherein the anionic chromophore in the general formula (3) is monomethine oxonol (m = 0 in the general formula (3)). 6. The optical information recording medium according to claim 1, wherein the organic counter cation as the organic counter ion is represented by the following general formula (E).

(In the above general formula (E), R ¹ , R ^m , R ⁿ and R ^o each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a cyclic hydrocarbon group having 3 to 10 carbon atoms. , R ^l and R ^m or R ⁿ and R ^o may be linked to each other in the form of a methylene chain, wherein the number of methylene chains is an integer of 2 to 15 carbon atoms, It is an integer of 0-10 independently.)   The substituent whose A value is 2.0 (kcal / mol) or more is a tertiary alkyl group, a secondary alkyl group, a trifluoromethyl group, an aliphatic cyclic hydrocarbon group, a substituted phenyl group, or a substituted heterocyclic ring. The optical information recording medium according to claim 1, wherein the optical information recording medium is a group or a heteroatom-containing group.   An information recording method for recording information by irradiating the optical information recording medium according to any one of claims 1 to 8 with a laser beam having a wavelength of 440 nm or less.