JPH08258429A - Optical information recording medium - Google Patents

Abstract

PURPOSE: To obtain a recording medium for CD-R which has a high reflection rate and good storage-regeneration stability by incorporating a phthalocyanine compound expressed by a specified formula into a recording layer which is formed on a substrate directly or through an undercoat layer. CONSTITUTION: In an optical information recording medium in which a recording layer is formed on a substrate, which is used for a computer memory, an image and voice filing memory, etc., directly or through an undercoat layer, the recording layer contains a phthalocyanine compound which is expressed by a formula, in which M, a metal atom, can have two hydrogen atoms, halogen atoms, or one oxygen atom; p and q are integers of 0-2; X<1> -X<4> are an oxygen atom or a sulfur atom independently; R<1> -R<4> are substituted or unsubstituted adamantane residue independently; k, l, m, n are integers of 0-4 independently, but all can not be 0 simultaneously, and when k, l, m, n are 3 or less, other substituents of a benzene ring are hydrogen atom or halogen atom.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium (hereinafter also abbreviated as a recording medium) used for a computer memory, a memory for image and audio files, an optical card and the like.

[0002]

2. Description of the Related Art A recording medium having an organic dye thin film as a recording layer is known in which a phthalocyanine compound is used for the organic dye thin film (Japanese Patent Laid-Open No. 183296/1983).
No. 58-37851). Phthalocyanine compounds have the characteristic of being extremely highly stable to heat and light, but have poor solubility in organic solvents, etc., and conventionally they can only be formed into thin films by the vapor deposition method and have difficulty in productivity, and they are easy to associate. However, there is a problem that a high refractive index and a high reflectance cannot be obtained.

On the other hand, in recent years, semiconductor lasers having an oscillation wavelength (up to 680 nm) shorter than the wavelength range used in conventional optical disks have been put into practical use in order to achieve higher recording density. However, there is no conventional organic dye thin film having a light absorption ability and a light reflection ability in a wavelength range of 700 nm or less, and there is a limitation in high density recording property in terms of material.

Further, in a write-once compact disc type (CD-R) recording medium in which an organic dye thin film, a metal reflection layer and a protective layer are sequentially laminated on a substrate, a high reflectance is required to satisfy the CD standard. Therefore, it was necessary to develop an organic dye material having a high refractive index in the reproduction wavelength range (700 to 830 nm) and high stability.

Recently, in order to prevent the association of a phthalocyanine compound and achieve a high refractive index, it has been attempted to introduce a bulky alkoxy group at the α-position of phthalocyanine, and a halogenated phthalocyanine is used for wavelength matching. A measured CD-R type recording medium has been proposed (JP-A-3-
62878, 3-215466, 4-3481.
No. 68, No. 4-226390, No. 4-15263 to 6
No. 5, No. 5-17477, No. 5-86301, No. 5-
No. 25177, No. 5-25179, No. 5-17700.
Nos. 5-1272, etc.).

[0006]

However, although these phthalocyanine compounds certainly bring about an improvement in the refractive index and the like, they are not yet sufficiently satisfied, and further improvement is desired.

Therefore, a first object of the present invention is to record a phthalocyanine compound having a high solubility in an organic solvent, a high productivity and a solvent coatable phthalocyanine compound as a recording material, while utilizing the characteristics of the phthalocyanine compound. To provide the medium. A second object of the present invention is to provide a recording medium applicable to an optical pickup using a 630 to 720 nm semiconductor laser capable of high density recording. Furthermore, a third object of the present invention is to achieve a high reflectance CD-R medium which has a high refractive index in the wavelength range of 770 to 830 nm and is excellent in storage stability and reproduction stability. To provide the medium.

[0008]

[Means for Solving the Problems] A phthalocyanine compound is a macrocyclic planar compound and has an extremely high association property. Therefore, when it is made into a thin film, the absorption spectrum becomes broad and the reflectance (refractive index) also becomes low. are doing. Therefore, the present invention introduces a substituent having a sterically bulky structure as a substituent to the phthalocyanine ring to prevent association.
It realizes high absorption ability and high reflectance (refractive index), and also improves solubility in an organic solvent.

That is, according to the present invention, in the optical information recording medium, a recording layer is provided on a substrate directly or via an undercoating layer, and if necessary, a protective layer is provided on the recording layer. Provided is an optical information recording medium, characterized in that the layer contains a phthalocyanine compound represented by the following general formula (I).

Embedded image ^{Wherein, M, X 1 ~X 4,} R 1 ~R 4 and k~n represent the following, respectively. M: 2 hydrogen atoms, optionally a metal atom which may have a halogen atom or oxygen atom, or - (OR ⁵⁾ p group or ^{- (OSiR 6 R 7 R 8} ) Good metal atom which may have a q group , R ^{5 to} R ⁸ are each independently a hydrogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, or a substituted or unsubstituted 1
Valent aromatic hydrocarbon group, or substituted or unsubstituted monovalent aromatic heterocyclic group, p, q: an integer of 0 to 2, X ^{1 to} X ⁴ : each independently an oxygen atom or a sulfur atom, R ¹ To R ⁴ : each independently a substituted or unsubstituted adamantane residue, k, l, m, n: each independently an integer of 0 to 4, but not all 0 at the same time, k, l, m, When n is 3 or less, the other substituent on the benzene ring is a hydrogen atom or a halogen atom. ]

Further, according to the present invention, a write-once compact disc type recording medium is provided which is provided with a metal reflection layer between the recording layer and the protective layer and records a CD format signal. The optical information recording medium is provided. Furthermore, in the general formula (I), k = 1 = m =
n = 1 or 2, the substitution position is 1 or / and 4 in the formula, and the other substituent is a hydrogen atom or a halogen atom in the optical information recording medium, and the halogen atom is a bromine atom. Optical information recording media are provided respectively.

The present invention will be described in detail below. First, the configuration of the recording medium will be described. FIG. 1 is a diagram showing an example of a layer structure applicable to the recording medium of the present invention, in which a recording layer 2 is provided on a substrate 1 with an undercoat layer 3 interposed if necessary, and further protected if necessary. Layer 4 is provided. FIG. 2 is a diagram showing an example of another type of layer structure applicable to the recording medium of the present invention.
A metal reflective layer 5 is provided on the recording layer 2 having the configuration of FIG.

The recording medium of the present invention may have an air sandwich structure in which the recording layer (organic thin film layer) having the structure shown in FIGS. 1 and 2 is placed inside and sealed with another substrate through a space, Alternatively, a laminated structure in which the protective layer is adhered may be used.

Next, the required characteristics of the constituent layers and the constituent materials thereof will be described. 1) Substrate As a necessary characteristic of the substrate, when recording / reproducing is performed from the substrate side, it must be transparent to the laser light used, but when recording / reproducing is performed from the recording layer side, it is not necessary to be transparent. As the substrate material, for example, polyester,
Acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, plastic such as polyimide, glass, ceramic or metal can be used. In addition, a guide groove or a guide pit for tracking and a preformat such as an address signal may be formed on the surface of the substrate.

2) Recording Layer The recording layer is capable of recording some information by causing some kind of optical change by irradiation of laser light, and the phthalocyanine compound of the general formula (I) is contained in this recording layer. Must be included. In forming the recording layer, the compounds of the present invention may be used alone or in combination of two or more. In addition, the compounds of the invention are other dyes,
For example, polymethine dyes, naphthalocyanine dyes, squarylium dyes, croconium dyes, pyrylium dyes, naphthoquinone dyes, anthraquinone (indanthrene) dyes, xanthene dyes, triphenylmethane dyes, azulene dyes, tetrahydrocholine dyes, phenanthrene dyes, triphenothiazine dyes. Alternatively, it may be used in combination with a metal complex compound or the like. In this case, the above dyes may be used alone or in combination of two or more.

Further, the compound of the present invention is a metal or a metal compound such as In, Al, Te, Bi, Al, Be, Te.
O ₂ , SnO, As, Cd and the like can also be used in the form of dispersion mixing or lamination. Further, various materials such as ionomer resins, polyamide resins, vinyl resins, natural polymers, silicones, liquid rubbers, or silane coupling agents may be dispersed and mixed in the compound of the present invention. Or for the purpose of improving properties, stabilizers (for example, transition metal complexes), dispersants, flame retardants,
It can be used together with a lubricant, an antistatic agent, a surfactant, a plasticizer and the like.

The recording layer is formed by vapor deposition, sputtering, C
It can be done by conventional means such as VD or solvent coating. When the coating method is used, the above compounds and the like are dissolved in an organic solvent, and a conventional coating method such as spraying, roller coating, dipping or spinner coating is used. As the organic solvent, generally, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone,
Amides such as N, N-dimethylacetamide and N, N-dimethylformamide, sulfoxides such as dimethylsulfoxide, ethers such as tetrahydrofuran, dioxane, diethyl ether and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate , Aliphatic halogenated carbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride and trichloroethane, aromatics such as benzene, xylene, monochlorobenzene and dichlorobenzene, or cellsolves such as methylcellosolve and ethylcellosolve, Hydrocarbons such as hexane, pentane, cyclohexane and methylcyclohexane can be used. The film thickness of the recording layer is 100Å in the case of the medium structure shown in FIG.
10 μm, preferably 200 Å to 1000 Å is suitable, and 300 Å to 5 μ in the case of the medium structure shown in FIG.
m, preferably 500Å to 2000Å is suitable.

3) Undercoat layer The undercoat layer has (a) improved adhesion, (b) barrier against water or gas, (c) improved storage stability of the recording layer, and (d) improved reflectance. , (E) protection of the substrate from solvent, (f) formation of guide grooves, guide pits, preformats, etc. For the purpose of (a), it is possible to use various polymers such as ionomer resins, polyamides, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers, and various silane coupling agents. For the purposes of (b) and (c), an inorganic compound such as SiO 2 may be used in addition to the above polymer material.
₂ , MgF ₂ , SiO, TiO ₂ , ZnO, TiN, Si
N, Zn, Cu, Ni, Cr, Ge, Se, Au,
A metal such as Ag or Al or a semi-metal can be used. For the purpose of (b), a metal such as A
l, Ag, or the like, or an organic thin film having a metallic luster, such as a methine dye or a xanthene dye, can be used.
For the purposes of (e) and (f), an ultraviolet curable resin,
A thermosetting resin, a thermoplastic resin or the like can be used.
The thickness of the undercoat layer is 0.01 to 30 μm, preferably 0.1.
05-10 μm is suitable.

4) Metal reflective layer For the metal reflective layer, a metal, a semimetal, or the like, which alone has a high reflectance and is resistant to corrosion, can be used. As a specific material,
Au, Ag, Cu, Al, Cr, Ni, etc. are mentioned,
Au and Al are preferable. These metals and semimetals may be used alone or as an alloy of two or more kinds.
Examples of the film forming method include vapor deposition and sputtering, and the film thickness is 50 to 3000 Å, preferably 100.
It is ~ 1000Å.

5) Protective Layer, Substrate Surface Hard Coat Layer The protective layer or substrate surface hard coat layer (a) protects the recording layer from scratches, dust, dirt, etc. (b) Improves storage stability of the recording layer , (C) used for the purpose of improving the reflectance. For these purposes, the materials shown in the undercoat layer can be used. In addition, as an inorganic material, S
It is also possible to use iO, SiO _2, etc., and as an organic material, acrylic resin, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, natural rubber, styrene-butadiene. Resins, chloroprene rubber, waxes, alkyd resins, drying oils, heat-softening and heat-melting resins such as rosin can also be used. Among the above materials, the most preferable one for the protective layer or the substrate surface hard coat layer is an ultraviolet curable resin having excellent productivity. The thickness of the protective layer or the substrate surface hard coat layer is 0.01 to 30 μm.
m, preferably 0.05 to 10 μm. In the present invention, the undercoat layer and the protective layer may contain a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, etc., as in the case of the recording layer. .

In the present invention, as described above, the recording layer contains the phthalocyanine compound represented by the following general formula (I).

Embedded image ^{Wherein, M, X 1 ~X 4,} R 1 ~R 4 and k~n represent the following, respectively. M: 2 hydrogen atoms, optionally a metal atom which may have a halogen atom or oxygen atom, or - (OR ⁵⁾ p group or ^{- (OSiR 6 R 7 R 8} ) Good metal atom which may have a q group , R ^{5 to} R ⁸ are each independently a hydrogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, or a substituted or unsubstituted 1
Valent aromatic heterocyclic group, p, q: integer of 0 to 2, X ^{1 to} X ⁴ : each independently an oxygen atom or a sulfur atom, R ^{1 to} R ⁴ : independently substituted or unsubstituted adamantane residue , K, l, m, n are each independently an integer of 0 to 4, but all are not 0 at the same time, and when k, l, m, and n are 3 or less, the other substituents on the benzene ring are hydrogen. It is an atom or a halogen atom. ]

In the general formula (I), the metal atom represented by M is Al, Si, Ca, Cd, Ti,
V, Mn, Fe, Co, Ni, Cu, Zn, Ge, M
o, Ru, Rh, Pd, In, Sn, Pt, Pb and the like can be mentioned. In the definition of R ^{5 to} R ⁸ , the monovalent aliphatic hydrocarbon group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, or a sec group.
-Alkyl group such as butyl group, t-butyl group, amyl group, hexyl group, octyl group, decyl group, dodecyl group, octadecyl group, vinyl group, allyl group, isopropenyl group, 1-butenyl group, 2-butenyl group Group, an alkenyl group such as a 2-pentenyl group, and the like. Examples of the monovalent aromatic hydrocarbon group include a phenyl group and a benzyl group. Examples of the substituents include halogen atoms such as fluorine, chlorine and bromine, carbon trifluoride groups, cyano groups and ester groups.

In the general formula (I), R ¹ to
R ⁴ represents a substituted or unsubstituted adamantane residue, and specific examples thereof include the residues shown in Table 1 below.

[Table 1]

Among the phthalocyanine compounds represented by the general formula (I) of the present invention, k = l = m = n
= 1 or 2 and the substitution position is 1 or / and 4 in the formula
And the other substituent is a hydrogen atom or a halogen atom (especially bromine atom), the absorption wavelength can be easily controlled, the association is prevented, and the refractive index of the film is increased. It is particularly excellent in that the reflectance can be improved.

The phthalocyanine compound represented by the general formula (I) can be produced by reacting the corresponding phthalonitrile compound or diiminoisoindoline compound with a metal or metal derivative in an organic solvent. Specifically, the phthalonitrile compound or the diiminoisoindoline compound, Al, Si,
Ca, Cd, Ti, V, Mn, Fe, Co, Ni, C
u, Zn, Ge, Mo, Ru, Rh, Pd, In, S
at least one metal selected from n, Pt, Pb, etc. or their halides, carboxylic acid derivatives, sulfates,
It can be obtained by reacting a derivative selected from nitrates, carbonyl compounds, oxides or complexes in an organic solvent. Further, when M is 2 hydrogen atoms in the above general formula (I), it can be obtained by reacting the corresponding phthalonitrile compound or diiminoisoindoline compound with lithium or sodium in an organic solvent.

Specific examples of the phthalocyanine compound represented by the general formula (I) include those shown in Table 2.

[0026]

[Table 2- (1)]

[0027]

[Table 2- (2)]

[0028]

[Table 2- (3)]

[0029]

The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 A poly (methyl methacrylate) plate having a thickness of 1.2 μm was photopolymerized with a depth of 1000 L and a half width of 0.4 μ.
m and the track pitch of 1.4 μm, the compound No. The 1,2-dichloroethane solution of No. 1 was applied to a spinner, and a recording layer having a thickness of 800Å was provided to obtain a recording medium.

Examples 2 to 6 In Example 1, the compound No. Instead of 1.
Compound No. 6, No. 10, No. 1
2, No. 18, No. Recording media of Examples 2 to 6 were obtained in the same manner as in Example 1 except that No. 20 was used.

Comparative Example 1 In Example 1, the compound No. A recording medium of Comparative Example 1 was obtained in the same manner as in Example 1 except that the compound represented by the following formula (II) was used instead of 1.

Embedded image (However, in the formula, t-Bu is 2 to 2 '''' and 3 to
It is a mixture of 3 '''positions.

Using the recording media of Examples 1 to 6 and Comparative Example 1 described above, recording was performed through the substrate under the following recording conditions, and then the recording position was reproduced by continuous laser light.
/ N was measured. The reflectance was also measured. Table 3 shows the results. Recording conditions: linear velocity 2.1 m / sec recording frequency 1.25 MHz laser oscillation wavelength 680 nm pickup lens N.P. A. 0.5 Playback condition: Scanning filter 30KHz Playback power 0.25-0.3mW

[0034]

[Table 3]

Example 7 On a 1.2 mm thick injection-molded polycarbonate substrate having a guide groove with a depth of 1000 Å, a half width of 0.45 μm and a track pitch of 1.6 μm, the compound No. 2 of 4
-Ethoxyethanol / 1,2-dichloroethane / TH
A mixed solution of F [= 8 / 1.5 / 0.5 (weight ratio)] was applied by spinner, a recording layer having a thickness of 1800Å was provided, and Au was vacuum-deposited on the recording layer having a thickness of 1200Å to form a reflective layer. Further, an acrylic photopolymer was applied onto it by a spinner and UV-cured to form a protective layer, to obtain a CD-R type recording medium.

Examples 8 to 11 In Example 7, the compound Nos. 4 instead of compound No. 4 in the same table. 1, No. 2, No. 9, N
o. Recording media of Examples 8 to 11 were obtained in the same manner as in Example 7 except that No. 21 was used.

Comparative Example 2 In Example 7, the compound No. Example 7 except that the phthalocyanine of Comparative Example 1 was used instead of 4.
A recording medium of Comparative Example 2 was obtained in the same manner as in.

Comparative Example 3 In Example 7, the compound Nos. A recording medium of Comparative Example 3 was obtained in the same manner as in Example 7, except that the compound of the following formula (III) was used instead of 4.

Embedded image

Comparative Example 4 In Comparative Example 3, 1 was added to the compound of the above formula (III).
A recording medium of Comparative Example 4 was obtained in the same manner as Comparative Example 3 except that a mixture containing 0% by weight of the nickel complex compound of the following formula (IV) was used.

[Chemical 4]

Using the recording media of Examples 7 to 11 and Comparative Examples 2 to 4, the laser oscillation wavelength was 790 nm and the linear velocity was 1.4 m.
The EFM signal was recorded under the recording condition of / sec, and the reflectance and the C ₁ error number at the optimum power before recording and after light irradiation were measured. The results are shown in Table 4.

[0041]

[Table 4]

(Evaluation) The optical information recording medium of the present invention has high light absorption and light reflectivity in the wavelength range of 630 to 720 nm.
It can be applied to a pickup using a semiconductor laser with a wavelength of 630 to 720 nm, has a high refractive index at a wavelength of 770 to 830 nm, and has high stability. Therefore, it is a CD having a high reflectance and excellent storage stability and reproduction stability. -R media can be provided.

[0043]

According to the optical information recording medium of the first and second aspects, since the recording layer contains the phthalocyanine compound represented by the general formula (I), the following excellent effects are obtained. Play. B) 630 to 720 capable of high density recording because it has high light absorption and light reflection properties at wavelengths of 630 to 720 nm.
The present invention can be applied to a pickup using a semiconductor laser of 10 nm, and the recording density can be increased by 1.6 to 1.7 times that of the current optical recording medium of 770 to 830 nm. B) Since it has a high refractive index at wavelengths of 770 to 830 nm and high stability, it is possible to provide a CD-R recording medium having a high reflectance and excellent storage stability and reproduction stability.

The optical information recording medium of claim 3 has the general formula (I) in which k = 1 = m = n = 1 or 2 and the substitution position is 1 or / and 4 in the formula, and Since the substituent contains a phthalocyanine compound which is a hydrogen atom or a halogen atom in the recording layer, it is easy to control the absorption wavelength, and the association blocking ability is further improved.
The effect of increasing the refractive index of the film and improving the reflectance is added.

Since the bromine atom is selected as the halogen atom in the optical information recording medium of the fourth aspect, there is an additional effect that the reflectance can be further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a layer structure applicable to a recording medium of the present invention.

FIG. 2 is a diagram showing an example of another type of layer structure applicable to the recording medium of the present invention.

[Explanation of symbols]

 1 substrate 2 recording layer (organic dye layer) 3 undercoat layer 4 protective layer 5 metal reflective layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Noboru Sasa 1-3-3 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Katsuji Maruyama 1-3-6 Nakamagome, Ota-ku, Tokyo In stock company Ricoh (72) Inventor Toshiro Naritsuka 1 Kamitowaue Tonkocho 1 Minami-ku, Kyoto-shi, Kyoto Prefecture Yamada Chemical Industry Co., Ltd. Address 1 Yamada Chemical Industry Co., Ltd.

Claims (4)

[Claims] 1. An optical information recording medium in which a recording layer is provided on a substrate directly or via an undercoating layer, and if necessary, a protective layer is provided on the substrate, the following general formula is contained in the recording layer. An optical information recording medium comprising a phthalocyanine compound represented by (I). Embedded image ^{Wherein, M, X 1 ~X 4,} R 1 ~R 4 and k~n represent the following, respectively. M: 2 hydrogen atoms, optionally a metal atom which may have a halogen atom or oxygen atom, or - (OR ⁵⁾ p group or ^{- (OSiR 6 R 7 R 8} ) Good metal atom which may have a q group , R ^{5 to} R ⁸ are each independently a hydrogen atom, a substituted or unsubstituted monovalent aliphatic hydrocarbon group, or a substituted or unsubstituted 1
Valent aromatic hydrocarbon group, or substituted or unsubstituted monovalent aromatic heterocyclic group, p, q: an integer of 0 to 2, X ^{1 to} X ⁴ : each independently an oxygen atom or a sulfur atom, R ¹ To R ⁴ : each independently a substituted or unsubstituted adamantane residue, k, l, m, n: each independently an integer of 0 to 4, but not all 0 at the same time, k, l, m, When n is 3 or less, the other substituent on the benzene ring is a hydrogen atom or a halogen atom. ] 2. A write-once compact disc type recording medium comprising a metal reflection layer provided between the recording layer and the protective layer and recording a CD format signal. Optical information recording medium. 3. In the general formula (I), k = l = m
= N = 1 or 2 and the substitution position is 1 or / and 4 in the formula.
The optical information recording medium according to claim 1 or 2, wherein the other substituent is a hydrogen atom or a halogen atom. 4. The optical information recording medium according to claim 3, wherein the halogen atom is a bromine atom.