JP3473238B2 - Optical recording medium and composition for optical recording medium - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium on / from which information can be written / read by a laser beam, and more specifically, a recording film structure of a write-once compact disc (CD-R) and The present invention relates to a recording film composition.

[0002]

2. Description of the Related Art At present, as a write-once type optical disc having an editing function, a gold reflecting film is provided on an organic dye recording film such as cyanine, and a CD format or CD-ROM format signal is recorded at a wavelength of 780 nm, and a CD or C
A CD-R for reading information from a D-ROM reproducing device has been put into practical use. However, since cyanine dyes generally have poor light stability, there is a possibility that the reliability of recording may be deteriorated under a use condition in which a single-sided structure such as CD is directly exposed to sunlight.

Therefore, an attempt to use a chemically and physically stable phthalocyanine dye as a recording film material in place of the cyanine dye has been studied, and a phthalocyanine compound has been disclosed in Japanese Patent Publication No.
-53713, JP-A-4-214388, JP-A5-1
272, etc., and some compounds have been put to practical use. The characteristics of the CD-R using these materials are the same as those when using the cyanine dye, and the medium is in conformity with the Orange Book, and is far superior to the medium using the cyanine dye. It has excellent light resistance.

[0004]

With the rapid spread of CD-ROMs in recent years, high-speed recording and high-speed reading are required for CD-R media as well. It has become necessary to be able to support quad speed recording. The phthalocyanine dyes described above are generally inferior in recording sensitivity to the cyanine dyes, and thus were insufficient to satisfy all of these requirements. For this reason, in order to improve the recording sensitivity, it is disclosed in JP-A-59-92448, and ingenuity in the dye structure such as introduction of a substituent having good thermal decomposability as disclosed in JP-A-7-20550. As described above, it is necessary to use an additive that accelerates thermal decomposition, and although it was possible to achieve recording sensitivity that can support high-speed recording, durability and light resistance must be sacrificed. It was normal. In addition, JP-A-7-
In 98887, a metal complex compound is presented as a recording pit shape control agent. The addition of these compounds improves the signal characteristics after recording, but it is an important problem that the light resistance is inferior (sacrificed) as compared with the case of the dye-only specification.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the recording layer contains a phthalocyanine dye and a specific metal complex compound, thereby achieving more than double-speed recording. It has been found that an optical recording medium can be realized which stabilizes the signal characteristics after recording and has no problem in reliability such as light resistance and durability while maintaining sufficient recording sensitivity. .

[0006]

DETAILED DESCRIPTION OF THE INVENTION Namely, the present invention includes a transparent substrate, a recording layer, reflective layer, an optical recording medium formed of four layers of the protective layer, a phthalocyanine compound represented by the general formula (1) in the recording layer and the General An optical recording medium characterized by containing an iron complex compound represented by the formula (3). Further, the present invention has been described above, is used in the recording layer, the general formula (1) phthalocyanine compound and one general formula (3) The optical recording medium optical recording material composition of a metal complex compound represented by represented by Also includes.

General formula (1)

[Chemical 4] [Wherein, X1 to X4 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alicyclic residue which may have a substituent, An aralkyl group which may have a substituent, a heterocyclic group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, a substituent which has a substituent. Represents an optionally substituted alkylthio group or an optionally substituted arylthio group. Y1 to Y4 each independently represent a hydrogen atom, a halogen atom, a nitro group, a phthalimidomethyl group which may have a substituent, or a sulfonamide group which may have a substituent. M1 represents Si, Ge, Sn, Al, Ga, In. Z represents -OP (= O) R1 R2, where R1,
R2 is independently a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aryloxy group. n1 to n4 represent the numbers of the substituents X1 to X4, and each independently represent an integer of 1 to 4. m1 to m4 represent the numbers of the substituents Y1 to Y4, and each independently represent an integer of 0 to 4. k represents the number of substituents Z and represents an integer of 1 or 2. ] General formula ( 3 )

[Chemical 5] [Wherein R3 and R4 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, a substituent Represents an aryloxy group which may have. M2 represents a transition metal atom. q represents an integer of 2 to 4 ]

When the phthalocyanine compound is a phthalocyanine compound having a substituent (axial substituent) in a direction perpendicular to the phthalocyanine ring plane from the central metal, a structure having a special axial substituent as represented by the general formula (1) The phthalocyanine compound of No. 1 has good light resistance (Japanese Patent Laid-Open No. 4-214388) (Abstracts of Abstracts 11B-12 of the 1994 Coloring Material Research Conference). It does not act as a stabilizer, but is effective in improving recording characteristics at double speed recording and above.

However, when the central metal is a metal such as Al or Ga that can introduce only one axial substituent, it is generally compared with phthalocyanine compounds such as Si and Ge having two such axial substituents. The light resistance is slightly inferior. In the case of such a phthalocyanine compound, the metal complex compound presented in the present invention acts as a light stabilizer and is effective not only in improving the light resistance but also in improving the recording characteristics in double-speed recording or more. .

As described above, it is the iron dithiocarbamate complex represented by the general formula (3) that has a remarkable effect on both the improvement of the recording characteristics and the improvement of the light resistance, and it is a coating solvent for forming the recording layer. However, these compounds are most preferable because they have good solubility.

The compound represented by the general formula ( 3) in the present invention is added at the time of synthesis or purification of the phthalocyanine compound represented by the general formula (1), or is simply blended into a powder or chemically treated to give phthalocyanine. It may be used by being bound to a compound, or may be used by dissolving it in a coating solvent together with a phthalocyanine compound when forming a recording film by spin coating.
It stabilizers these methods to be used, the kind of the phthalocyanine compound, the best way by the combination different.

The amount of the compound represented by the general formula ( 3) used is 1 to 40% by weight, preferably 1 to 20% by weight based on the phthalocyanine compound represented by the general formula (1).

The structure, substituents and the like in the general formula of the present invention will be described in detail. Examples of the halogen atom include fluorine, chlorine, bromine and iodine. As the alkyl group which may have a substituent, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, tert-
Butyl group, neopentyl group, n-hexyl group, n-octyl group, stearyl group, 2-ethylhexyl group, trichloromethyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, 2,2-dibromoethyl Group, 2,2,3,3-tetrafluoropropyl group, 2-ethoxyethyl group, 2-butoxyethyl group, 2-nitropropyl group and the like. As the aryl group which may have a substituent, a phenyl group, a naphthyl group, an anthranyl group, a p-methylphenyl group, a p-nitrophenyl group, a p-methoxyphenyl group, a 2,4-dichlorophenyl group,
Pentafluorophenyl group, 2-aminophenyl group, 2-methyl-4-chlorophenyl group, 4-hydroxy-1-naphthyl group, 6-methyl-2-naphthyl group, 4,5,8-trichloro-2-naphthyl group , Anthraquinonyl group, 2-aminoanthraquinolyl group and the like. Examples of the alicyclic residue which may have a substituent include a cyclopentyl group, a 2,5-dimethylcyclopentyl group, a cyclohexyl group, a 4-tert-butylcyclohexyl group and an adamantyl group. Examples of the aralkyl group which may have a substituent include a benzyl group, a 4-methylbenzyl group, a 4-tert-butylbenzyl group, a 4-methoxybenzyl group, a 4-nitrobenzyl group and a 2,4-dichlorobenzyl group. There is. The heterocyclic residue which may have a substituent, a pyridinyl group, a 3-methylpyridinyl group, a pyrazinyl group, a pipedinyl group, an N-methylpipedinyl group, a pyranyl group, a morphonyl group, an n-methylpyrrolinyl group, an acridinyl group, Etc. As the alkoxy group which may have a substituent, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, an isobutyloxy group, a tert-butyloxy group, a neopentyloxy group, an n-hexyloxy group. , N-octyloxy group, stearyloxy group, 2-ethylhexyloxy group, trichloromethoxy group, trifluoromethoxy group, 2,2,2-trifluoroethoxy group, 2,2,
There are 3,3-tetrafluoropropyloxy group, 2-ethoxyethoxy group, 2-butoxyethoxy group, 2-nitropropoxy group and the like. As the aryloxy group which may have a substituent, a phenoxy group, a naphthoxy group, an anthranyloxy group, a p-methylphenoxy group, a p-nitrophenoxy group,
p-methoxyphenoxy group, 2,4-dichlorophenoxy group,
There are pentafluorophenoxy group, 2-methyl-4-chlorophenoxy group and the like, and the alkylamino group which may have a substituent includes a methylamino group, an ethylamino group, a dimethylamino group, a dimethylamino group and a diisopropyl group. ,
There is a cyclohexylamino group and the like, and the arylamino group which may have a substituent includes a phenylamino group, a p-nitrophenylamino group, a 4-methylphenylamino group, a diphenylamino group and a di (4-methoxyphenyl) group. There are amino groups and the like, but the present invention is not limited thereto. Examples of transition metals include Ti, V, Cr, Mn, Fe, Co,
There are Ni, Cu, Zn, etc., but not limited to these.

Typical examples of the phthalocyanine compound represented by the general formula (1) in the present invention include phthalocyanine compounds (a) to (d) shown below, but the invention is not limited thereto.

(A)

[Chemical 7]

(B)

[Chemical 8]

(C)

[Chemical 9]

(D)

[Chemical 10]

Typical examples of the metal complex compound represented by the general formula ( 3) in the present invention include the compounds ( VI ) to (IX) shown below, but the present invention is not limited thereto. is not.

[0020]

[0021]

[0022]

[0023]

[0024]

(VI)

[Chemical 16]

(VII)

[Chemical 17]

(VIII)

[Chemical 18]

(IX)

[Chemical 19]

The recording layer may be formed by a dry process such as vacuum deposition or sputtering, but a wet process such as spin coating, dipping, spraying, roll coating, or the like. It is also possible by the LB (Langmuir-Blodgett) method. The recording film material of the present invention is a general-purpose organic solvent,
For example, since it exhibits high solubility in alcohol-based, ketone-based, cellosolve-based, halogen-based, hydrocarbon-based, freon-based solvents, etc., a method of forming a film by spin coating is preferable from the viewpoint of productivity and uniformity of recording film. . Thus, when forming a film by a so-called coating method, a polymer binder may be added as necessary.

Examples of the polymer binder include, but are not limited to, epoxy resin, acrylic resin, polycarbonate resin, polyester resin, polyamide resin, vinyl chloride resin, nitrocellulose resin and phenol resin. The mixing ratio of the polymer binder is not particularly limited, but is preferably 30% or less with respect to the dye. The optimum film thickness of the recording layer of the present invention is not particularly limited because it depends on the type and combination of recording film materials.
0 to 3000 angstroms are preferable, and 800-1500 angstroms are more preferable, and the optimum film thickness range.

The reflective film material of the present invention includes gold, silver,
Metals such as copper, platinum, aluminum, cobalt, and tin, and alloys, oxides, and nitrides containing these as the main components are mentioned, but gold is preferable because it has high absolute reflectance and excellent stability. Optimal. It is also possible to use a highly reflective film of an organic compound depending on the case. As a method for forming such a reflective film, a dry process, for example, a vacuum deposition method or a sputtering method is most preferable, but the method is not limited to these. The optimum film thickness of the reflective film is not particularly limited, but is preferably in the range of 400 to 1600 angstrom.

Further, a protective layer for protecting the disc is provided on the reflective film. As a material for the protective layer, a method of applying a UV effect resin by a spin coating method and curing the UV irradiation resin is preferable, but the material is not limited thereto. For the optimum thickness of the protective layer,
If it is thin, the hardening of protection is lowered, and if it is thick, it causes deterioration of mechanical properties such as warpage of the disk due to shrinkage during hardening of the resin. .

The disk substrate used in the present invention preferably has a light transmittance of 85% or more for writing and reading signals, and a small optical anisotropy. For example, glass, or acrylic resin, polycarbonate resin, polyester resin,
A substrate made of a thermoplastic resin such as a polyamide resin, a polystyrene resin or a polyolefin resin, or a thermosetting resin such as an epoxy resin or an allyl resin can be used. Among these,
From the viewpoint of ease of molding, ATIP wobble signal, and ease of providing guide grooves, etc., a thermoplastic resin is preferable. From the viewpoint of optical characteristics, mechanical characteristics, and cost, acrylic resin or polycarbonate resin is preferable. Are particularly preferred.

The shape of the guide groove of the substrate in the invention is not particularly limited and may be trapezoidal, U-shaped or V-shaped. Further, regarding the size of the guide groove, the optimum value varies depending on the kind of the recording film material, the combination, etc., but the average groove width (width at the position of 1/2 of the groove depth) is 0.4 to
A range of 0.6 micron and a groove depth of 1000-2000 Angstroms is preferred. Since the disc of the present invention needs to function as a CD or a CD-ROM after recording, it must comply with the CD or CD-ROM standard (Red Book) and the CD-R standard (Orange Book). Is preferred.

The present invention will be specifically described by the following examples.

Example 1 Depth of 1600 Å, width of 0.4 μm, thickness of 1.2 mm having guide grooves with a pitch of 1.6 μm,
A 5% wt ethyl cellosolve solution of each of the phthalocyanine compounds (a) to ( c ) was prepared on a polycarbonate substrate having an outer diameter of 120 mm and an inner diameter of 30 mm, and a film having a thickness of 500 angstrom was formed using a spin coater. Next, as a reflective film, gold was deposited on this dye film by sputtering at 800 angstrom. Further, a protective layer was provided on this with a UV curable resin to prepare a CD-R disc. Using a semiconductor laser with a wavelength of 780 nm, this medium was subjected to linear velocities of 1.2 m / sec and 4.8 m / se.
The EFM signal was recorded at c. The recording signal characteristics were evaluated according to the Orange Book. Then, instead of 5% wt ethyl cellosolve solution of the phthalocyanine compound (a) ~ (c), the phthalocyanine compound (a) ~ (c) 0.45g
A disk was prepared in the same manner as above using a solution prepared by dissolving 0.05 g of each of the metal complex compounds ( VI ) to (IX) in 10 ml of ethyl cellosolve. Using a semiconductor laser of 780 nm, this medium has a linear velocity of 1.2 m /
EFM signals were recorded at sec and 4.8 m / sec. The recording signal characteristics were evaluated according to the Orange Book. The results are shown in Tables 1 to 3 .

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

Example 2 Next, with respect to the phthalocyanine compound (c), Example 1
The optical disc prepared in 1. was put into a light resistance tester and taken out after 50,000 lux for 100 hours, and the recording signal characteristics at a linear velocity of 1.2 m / sec were compared before and after the test. The results are shown in Table 5.

[0042]

[Table 5]

From the examples, when both the phthalocyanine compound and the metal complex compound are contained in the recording layer, the recording characteristics such as the error rate and 11T modulation degree are improved, and constant velocity recording (linear velocity 1.2 m / sec). And 4x speed recording characteristics (linear velocity 4.8m / sec)
There is no big difference in the above, and the medium is well balanced from constant speed recording to high speed recording, and there is no practical problem. In addition, no significant change in signal characteristics was observed before and after the light resistance test. From the above, it was confirmed that the inclusion of the phthalocyanine compound and the metal complex compound in the recording layer has the effect of improving the signal characteristics after recording while maintaining high sensitivity sufficient for high-speed recording.

By containing the phthalocyanine dye and the metal complex compound according to the present invention in the recording layer, it is possible to provide an optical recording medium having high recording sensitivity and stable signal characteristics after recording. It has become possible.

─────────────────────────────────────────────────── --- Continuation of front page (56) References JP-A-5-318930 (JP, A) JP-A-6-309696 (JP, A) JP-A-7-186537 (JP, A) JP-A-63- 9577 (JP, A) JP-A-6-8637 (JP, A) JP-A-7-137454 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 5/26 G11B 7 / 24 516

Claims (2)

(57) [Claims] 1. An optical recording medium comprising four layers of a transparent substrate, a recording layer, a reflective layer and a protective layer, wherein the recording layer has the general formula (1).
An optical recording medium comprising a phthalocyanine compound represented by and a compound represented by the general formula ( 3 ). General formula (1) [Wherein, X1 to X4 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alicyclic residue which may have a substituent, An aralkyl group which may have a substituent, a heterocyclic group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, a substituent which has a substituent. Represents an optionally substituted alkylthio group or an optionally substituted arylthio group. Y1 to Y4 each independently represent a hydrogen atom, a halogen atom, a nitro group, a phthalimidomethyl group which may have a substituent, or a sulfonamide group which may have a substituent. M1 represents Si, Ge, Sn, Al, Ga, In. Z represents -OP (= O) R1 R2, where R1,
R2 is independently a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aryloxy group. n1 to n4 represent the numbers of the substituents X1 to X4, and each independently represent an integer of 1 to 4. m1 to m4 represent the numbers of the substituents Y1 to Y4, and each independently represent an integer of 0 to 4. k represents the number of substituents Z and represents an integer of 1 or 2. ] General formula ( 3 ) [Wherein R3 and R4 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, a substituent Represents an aryloxy group which may have. M2 represents a transition metal atom. q represents an integer of 2 to 4] 2. A composition for an optical recording medium used in the recording layer of the optical recording medium according to claim 1 .