JPH0741740B2 - Optical recording medium - Google Patents

Description

TECHNICAL FIELD The present invention relates to an optical recording medium.

The prior art optical recording medium has a characteristic that the recording medium does not wear and deteriorate because the writing and reading optical heads are not in contact with the medium, and therefore various optical recording media have been researched and developed.

Among such optical recording media, heat mode optical recording media have been actively developed because they do not require development processing in a dark room.

This heat mode optical recording medium is an optical recording medium that uses recording light as heat, and as one example thereof, a part of the medium is melted and removed by recording light such as a laser and is called a bit. There is a pit formation type in which a small hole is formed for writing, information is recorded by this pit, and the pit is detected by reading light to perform reading.

Most of the pit-forming type media, especially those having a semiconductor laser as a light source that can downsize the device, have a recording layer mainly made of Te.

However, in recent years, Te-based materials are harmful, need to be more sensitive, and manufacturing costs need to be reduced. The number of proposals and reports on media using the above recording layer is increasing.

For example, for a He-Ne laser, a squarylium dye [VB Jipson and CR Jones, J. Va.
c.Sci.Technol., 18 (1) 105 (1981)] and metal phthalocyanine dyes (JP-A-57-82094 and JP-A-57-82095).

There is also an example in which a metal phthalocyanine dye is used for a semiconductor laser (JP-A-56-86795).

Each of these is a recording layer thin film formed by vapor deposition of a dye, and is not much different from the Te system in terms of manufacturing a medium.

However, the reflectance of the dye vapor deposition film with respect to the laser is generally low, and a large S / N ratio cannot be obtained by a usual method that is currently used to obtain a read signal by changing (decreasing) the amount of reflected light due to pits.

In addition, a transparent substrate carrying a recording layer is integrated so that the recording layers face each other, and a medium having a so-called air sandwich structure is used. When writing and reading are performed through the substrate, the recording sensitivity is not lowered. However, such a recording / reproducing system is not possible with the dye vapor deposition film.

This is because the ordinary transparent resin substrate has a certain degree of refractive index (1.5 for polymethylmethacrylate) and a large surface reflectance (4% for the same), which is reflected through the substrate of the recording layer. This is because the reflectance is, for example, about 60% or less for polymethylmethacrylate and cannot be detected in the recording layer showing only a low reflectance.

In order to improve the read S / N ratio of the recording layer made of a dye vapor deposition film, a vapor deposition reflective film of Al or the like is usually interposed between the substrate and the recording layer.

In this case, the vapor-deposited reflection film is for increasing the reflectance to improve the S / N ratio, and the reflection film is exposed by the formation of pits to increase the reflectance, or in some cases,
Although the reflective film is removed to reduce the reflectance, it goes without saying that recording / reproduction cannot be performed through the substrate.

Similarly, in JP-A-55-161690, a recording layer comprising an IR-132 dye (manufactured by Kodak Co.) and polyvinyl acetate,
JP-A-57-74845 discloses a recording layer composed of 1,1′-diethyl-2,2′-tricarbocyanine iodide and nitrocellulose, and further KY Law, et al., Appl. Phys. Lett.
39 (9) 718 (1981), a recording layer made of a dye and a resin, such as a recording layer made of 3,3'-diethyl-12-acetylthiatetracarbocyanine and polyvinyl acetate, is formed by a coating method. The disclosed medium is disclosed.

However, also in these cases, a reflective film is required between the substrate and the recording layer, and recording and reproduction cannot be performed from the back surface side of the substrate, and thus there are the same drawbacks as in the case of the dye vapor deposition film.

In this way, recording / playback through the substrate is possible,
In order to realize a medium having a recording layer of an organic material, which is compatible with a medium having a recording layer of a Te-based material, the organic material itself needs to exhibit a large reflectance.

However, heretofore, very few examples have shown a high reflectance with a single layer of an organic material without laminating a reflective layer.

Slightly, it was reported that the vapor-deposited film of vanadyl phthalocyanine showed high reflectance [P.Kivits, et al., Appl.Phys.Part A 26
(2) 101 (1981), JP-A-55-97033], the writing sensitivity is low, probably because the sublimation temperature is high.

In addition, it was reported that cyanine dyes such as thiazole and quinoline dyes and merocyanine dyes also show high reflectance [Yamamoto et al., Proceedings of the 27th Japan Society of Applied Physics 1p-p-9 (198
0)], and a proposal based on this has been disclosed in JP-A-58-112.
No. 790, these dyes have a low solubility in a solvent and are easily crystallized, especially when they are formed as a coating film, and further, they are extremely unstable with respect to readout light and are immediately decolorized, It cannot be put to practical use.

In view of such an actual situation, the present inventors previously found an indolenine-based cyanine dye having high solubility in a solvent, little crystallization, and being thermally stable, and having a high reflectance of a coating film. It has been proposed to use it as a single-layer film (Japanese Patent Application No. 57).
-134397, 57-134170).

Also, with other cyanine dyes such as indolenine-based, thiazole-based, quinoline-based, and selenazole-based, a long-chain alkyl group can be introduced into the molecule to improve solubility and prevent crystallization. (Japanese Patent Application Nos. 57-182589 and 57-177776).

Furthermore, in order to improve photostability, and especially to prevent decolorization (reproduction deterioration) due to readout light, a proposal has been made to add a quencher to a cyanine dye (Japanese Patent Application No. 57-16).
6832, 57-168048, etc.).

Furthermore, it has been proposed to add a quencher to styryl-based, indolyl-based, pyrylium-, thiapyrylium-, serenapyrylium- or telluropyrylium-based, polymethylene-based dyes to reduce regeneration deterioration (Japanese Patent Application No.
58-181357, 58-181368, 58-181369, 58
-183454, 58-183455, 58-183456).

Further, as a recording layer having extremely little reproduction deterioration and good moisture resistance, a recording layer containing a combination of a dye cation and a quencher anion is also proposed (Japanese Patent Application No. Sho-200-200).
59-14848 etc.).

Among the various dyes contained in such a recording layer, the naphthalocyanine compound is stable against light, heat, humidity, various reactive gases and the like, and is excellent in the sturdiness.

However, when a naphthalocyanine compound is used as the recording layer, there is no absorption in the near infrared and infrared regions, and it is difficult to write to the recording layer with recording light in such a range.

II Object of the Invention The object of the present invention is that the recording layer constituting the optical recording medium is
(EN) An optical recording medium which is stable to heat, humidity, various gases, etc., has excellent encapsulation properties, high solubility, and can be used with recording light in the near infrared and infrared regions and has good sensitivity. Especially.

III DISCLOSURE OF THE INVENTION Such an object is achieved by the present invention described below.

That is, the present invention is an optical recording medium having a recording layer on a substrate, wherein the recording layer has at least 5 groups represented by the following formula (I) and / or at least 1 group represented by the following formula (II). An optical recording medium containing at least one kind of a naphthalocyanine compound.

Formula (I) -X ₁ R formula (II) -X ₁ QX ₂ - In {the formula (I) and (II), X ₁ and X _2, respectively, represent S or O. R represents a monovalent substituted or unsubstituted aliphatic group, alicyclic group, aromatic group or heterocyclic group, and Q represents a divalent substituted or unsubstituted aliphatic group, alicyclic group, aromatic group Represents a group or a heterocyclic group. } IV Specific Structure of the Invention Hereinafter, the specific structure of the present invention will be described in detail.

The recording layer of the optical recording medium of the present invention comprises at least one naphthalocyanine compound having at least 5 groups represented by the following formula (I) and / or at least one group represented by the following formula (II). Contains.

Formula (I) -X ₁ R formula (II) -X ₁ QX ₂ - in the above formula (I) and (II), X ₁ and X ₂ each represents S or O.

R represents a monovalent group described later, and Q represents a divalent group described later.

In this case, assuming that the number of groups represented by formula (I) is x and the number of groups represented by formula (II) is y, x ≧ 5, y ≧ 1, and x + 2y is 1
~ 24.

Among these, particularly preferred is the following formula (III)
To (IV) are one or more kinds of naphthalocyanine compounds.

Formula (III) M-NcX ₁ R) _n (Y) _24-n Formula (IV) M-NcX ₁ QX ₂ ) _l (X ₁ R) _m (Y) _{24-2l-m The} above formulas (III) and ( In IV), Nc is a naphthalocyanine nucleus represented by the following structural formula (V).

Formula (V) The structural formula (V) with _{-X 1 R, -X 1 QX 2} - or Y is a substituted position is either the 1-position ～24- position.

X ₁ and X ₂ each represent S or O.

M represents the central ion of the naphthalocyanine nucleus.

The central ion includes hydrogen, metal or metalloid, halide, oxide, sulfide and the like.

Examples of the metal or metalloid include Zn, Pb, Cu, Ni, Fe, C
o, Sr, Ca, Yb, Li, Ag, Ru, Sm, Tb, Dy, U, Tl, Cs, Pd, Nd, Ga, In, S
n, Si, Pt, Mn, Ge, Be, Al, V, Sn, Mg, Ti, etc., among which Cu, Ni, Co, Fe, Zn, Al, Pt, V, and hydrogen are preferable.

As the halide, AlCl, AlBr, AlI, GaCl, GaBr, GaI,
There are InCl, InF, InBr, InI, FeCl, SnCl _{2 and the} like.

Further, as the oxide, VO, TiO, ZrO, ThO, HfO, OsO, SiO, G
eO, SnO, VO ₂ As the sulfide, there are TiS, VS and the like.

Further, various ligands may be coordinated above and below the naphthalocyanine ring.

R is a monovalent group and Q is a divalent group, and is a substituted or unsubstituted aliphatic group having 1 to 20 carbon atoms, an alicyclic group such as a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. group, a hexyl group, an ethylene group, a propylene group, butylene group, pentylene group, hexylene group, a benzyl group, a phenethyl group, a cyclohexyl group, an allyl group, a dodecyl _{group, -CH 2 CH 2 CH = CH} -CH 2 -, cyclohexene group , Isopropenyl _{group, -C 2 H 4 -Cl, -CH} 2 -NH 2 and the like; a substituted or unsubstituted aromatic group having 6 to 24 carbon atoms, for example, a phenyl group, a tolyl group, a phenylene group, a naphthylene group, methoxy Phenyl group, naphthyl group, phenyl chloride group, xylyl group, Styryl group, cinnamyl group, phenethyl group, methylphenylene group, A substituted or unsubstituted heterocyclic group, for example, a pyridyl group,
A pyrrolyl group, a quinolyl group, a furyl group, a furfuryl group, a phenyl group, a piperidyl group, a pyrimidyl group and the like;

Y is a hydrogen atom; a halogen atom, for example, Cl, Br, I, F and the like;

X ₁ and X ₂ are each O or, S.

n represents a positive integer of 5 to 24.

l represents a positive integer of 1 to 12 and m represents a positive integer of 0 to 22.

Specific examples of the naphthalocyanine compound of the present invention will be given below.

(1) octa-1,6 (4-methylphenoxy) -CuNc (2) octa - (methoxy) -CuNc (3) octa _{- (- OC 2 H 5)} -CuNc (4) octa - (- OC ₃ H ₇₎ -CuNc (5) octa _{- (- OC 4 H 9)} -H 2 Nc (10) Deca (-OC ₅ H ₁₁ ) -H ₂ Nc (12) pentadeca _{- (- OC 2 H 5)} -H 2 Nc (14) pentadeca _{- (- OC 2 H 7)} -ZnNc (18) pentadeca _{- (- O-C 2 H} 5) -CuNc (19) pentadeca _{- (- O-CH 3)} -CuNc (20) pentadeca _{- (- O-CH 3)} -H 2 Nc (25) hexadeca _{- (- O-CH 3)} -C 0 Nc (26) hexadeca _{- (- O-C 2 H} 5) -CuNc (29) hexadeca _{- (- O-C 3 H} 7) -FeNc (34) octa _{-2,5 - (- OCH 3) -AlClNc} (35) octa _{-1,6 - (- OC 2 H 5} ) -InClNc (37) octa _{-1,4 - (- OC 3 H 7} ) -InBrNc (38) octa _{-1,2 - (- OC 2 H 5} ) -TlClNc (41) Deca _{- (- O-C 2 H} 5) AlINc (46) pentadeca _{- (- O-C 2 H} 5) -InINc (47) pentadeca _{- (- O-C 2 H} 5) -GaINc (50) hexadeca _{- (- OC 2 H 5)} -InBrNc (51) hexadeca _{- (- OC 3 H 7)} -AlClNc (54) undec _{- (- O-C 2 H} 5) -InClNc (58) -heptadec _{- (- O-C 2 H} 5) -CuNc (59) nonadeca _{- (- O-CH 3)} -CoNc (61) Doaikosa _{- (- O-C 2 H} 5) -CoNc (62) Tetoraaikosa _{- (O-C 2 H 5} ) -CuNc (64) hexa _{- (- O-C 5 H} 11) -TiONc (65) octa-1,6 (4-methylphenoxy) -VoNc (66) octa - (methoxy) -TiONc (67) octa - (- _{OC 2 H 5) -VONc (68} ) octa _{- (OC 3 H 7) -TiONc} (69) octa _{- (- OC 4 H 9)} -SiONc (74) Octa-(-OC ₄ H ₉ ) -VONc (76) Deca-(-OC ₅ H ₁₁ ) -SiONc (78) Pentadeca-(-OC ₂ H ₅ ) -VONc (80) pentadeca _{- (- OC 3 H 7)} -TiONc (92) Deca _{- (- O-C 2 H} 5) -SnONc (93) pentadeca _{- (- O-C 2 H} 5) -VONc (94) pentadeca _{- (- O-C 2 H} 5) -SiONc (95 ) hexadeca _{- (- O-C 2 H} 5) -TiONc (97) octa _{-1,6 - (- OCH 3) -AlClNc} (98) octa _{-2,5 - (- O-C 2} H 5) -InClNc (100) octa _{-3,4 - (- OC 2 H 5} ) -AlClNc (101) octa _{-1,2 - (- OC 3 H 7} ) -InClNc (109) hexadeca _{- (- O-C 2 H} 5) -InClNc (111) hexadeca _{- (- (O-C 3} H 7) -CaBrNc (112) hexadeca _{- (- (O-C 3} H 7) -AlBrNc (116) hexadeca _{- (- O-CH 3)} -AlBrNc (121) Octa-(-SCH ₃ ) -CuNc (122) Octa-(-SC ₂ H ₅ ) -CuNc (123) Octa-(-SC ₃ H ₇ ) -CuNc (124) Octa-(-SC ₄ H ₉ ) −H ₂ Nc (129) Deca (-SC ₅ H ₁₁ ) -H ₂ Nc (131) Pentadeca-(-SC ₂ H ₅ ) -H ₂ Nc (133) Pentadeca-(-SC ₃ H ₇ ) -NnNc (137) pentadeca _{- (- S-C 2 H} 5) -CuNc (138) pentadeca _{- (- S-CH 3)} -CuNc (139) pentadeca _{- (- S-CH 3)} -H 2 Nc (144) hexadeca _{- (- S-CH 3)} -CuNc (145) hexadeca _{- (- S-C 2 H} 5) -CuNc (148) Hexadeca-(-SC ₃ H ₇ ) -FeNc (153) octa _{-2,5 - (- SCH 3) -AlClNc} (154) octa _{-1,6 - (- SC 2 H 5} ) -InClNc (156) Octa-1,4-(-SC ₃ H ₇ ) -InBrNc (157) Octa-1,2-(-SC ₂ H ₅ ) -TlClNc (160) Deca _{- (- S-C 2 H} 5) -AlINc (165) pentadeca _{- (- S-C 2 H} 5) -InINc (166) pentadeca _{- (- S-C 2 H} 5) -GaINc (169) hexadeca _{- (- SC 2 H 5)} -InBrNc (170) hexadeca _{- (- SC 3 H 7)} -AlClNc (173) undec _{- (- S-C 2 H} 5) -InClNc (177) -heptadec _{- (- S-C 2 H} 5) -CuNc (178) nonadeca _{- (- S-CH 3)} -CoNc (180) Doaikosa _{- (- S-C 2 H} 5) -CoNc (181) Tetoraaikosa _{- (- S-C 2 H} 5) CuNc (183) hexa _{- (- S-C 5 H} 11) -TiONc (185) Octa-(-SCH ₃ ) -TiONc (186) Octa-(-SC ₂ H ₅ ) -VONc (187) Octa-(-SC ₃₇ ) -TiONc (188) Octa-(-SC ₄ H ₉ ). -SiONc (193) Octa-(-SC ₄ H ₉ ) -UONc (195) Deca-(-SC ₅ H ₁₁ ) -SiONc (197) Pentadeca-(-SC ₂ H ₅ ) -VONc (199) Pentadeca-(-SC ₃ H ₇ ) -TaONc (211) Deca _{- (- S-C 2 H} 5) -SnONc (212) pentadeca _{- (- S-C 2 H} 5) -VONc (213) pentadeca _{- (- S-C 2 H} 5) -SiONc (214 ) hexadeca _{- (- S-C 2 H} 5) -TiONc (216) octa _{-1,6 - (- SCH 3) -AlClNc} (217) octa _{-2,5 - (- SC 2 H 5} ) -InClNc (219) Octa-3,4-(-SC ₂ H ₅ ) -AlClNc (220) Octa-1,2-(-SC ₃ H ₇ ) -InClNc (228) hexadeca _{- (- S-C 2 H} 5) -InClNc (230) hexadeca _{- (- S-C 3 H} 7) -GaBrNc (231) hexadeca _{- (- S-C 3 H} 7) -AlBrNc (235) hexadeca _{- (- S-CH 3)} -AlBrNc The naphthalocyanine compound of the present invention can be generally synthesized by a method according to the following scheme.

Purification of the reaction product using this method is performed as follows.

The reaction product is cooled to 100 ° C., diluted with ethanol, then returned to room temperature and filtered. The filtered product is washed with ethanol, further washed with an ethanol-water solution, and dried. The crude product thus obtained is developed in a silica column with toluene, chloroform or the like, separated and purified.

Purification of the reaction product in this case is performed in the same manner as in Scheme 1.

Purification of the reaction product in this case is performed in the same manner as in Scheme 1.

Next, a synthesis example of the naphthalocyanine compound of the present invention will be given.

Synthesis Example 1. Synthesis of Exemplified Compound (3) 12 g of ethanol and 6 g of KOH in quinoline at 145 ° C.
Reacted for hours. CuNc (Cl) ₁₆ was added to this, 150-180
The reaction was carried out at 0 ° C for 3 hours. The reaction product obtained is 100 ° C.
After cooling to room temperature, it was diluted with ethanol (EtOH), returned to room temperature, and filtered. The filtered product is washed with EtOH, and then Et
_{OH-H 2 O (1:} 1) was washed with a solution, and dried.

The crude product thus obtained was developed with toluene on a silica column, separated and purified. This was repeated twice to obtain the desired product.

The structure was fixed by elemental analysis.

Synthesis Example 2. Synthesis of Exemplified Compound (137) 3 mol of 1 mol and 6 mol of ethanethiol (EtSH) at 135 ° C
React for a time, Got The compound 4 mol ^{_{Li + (OC 5 H 11)}} - by addition of 3 moles, allowed to react for 2.5 hours at 130 ° C., to obtain a Li ₂ NcSEt) _15. Furthermore, 1 mol of this compound is Cu
1 mol of Cl ₂ was added and reacted in amyl alcohol at 125 ° C. for 2 hours to obtain the desired product.

Purification was performed in the same manner as in Synthesis Example 1.

Fixation was performed by elemental analysis.

Two or more kinds of such naphthalocyanine compounds may be used. Further, the recording layer may be formed by combining with other dyes as long as the effect of the present invention is not impaired.

A resin may be contained in the recording layer, if necessary.

The resin used is preferably an auto-oxidizing, depolymerizing or thermoplastic resin.

Among these, the plastic resins that can be particularly preferably used include the following.

i) Polyolefin Polyethylene, polypropylene, poly-4-methylpentene-1, etc.

ii) Polyolefin copolymer For example, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene -Maleic anhydride copolymer,
Ethylene propylene terpolymer (EPT) etc.

In this case, the polymerization ratio of the comonomer can be arbitrary.

iii) Vinyl chloride copolymer For example, vinyl acetate-vinyl chloride copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-maleic anhydride copolymer, acrylic acid ester or methacrylic acid ester and vinyl chloride Copolymer, acrylonitrile-vinyl chloride copolymer, vinyl chloride ether copolymer,
Ethylene or propylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer graft-polymerized with vinyl chloride, etc.

In this case, the copolymerization ratio can be arbitrary.

iv) Vinylidene chloride copolymers Vinylidene chloride-vinyl chloride copolymers, vinylidene chloride-vinyl chloride-acrylonitrile copolymers, vinylidene chloride-butadiene-vinyl halide copolymers and the like.

In this case, the copolymerization ratio can be arbitrary.

v) polystyrene vi) styrene copolymer For example, styrene-acrylonitrile copolymer (AS resin), styrene-acrylonitrile-butadiene copolymer (ABS resin), styrene-maleic anhydride copolymer (S).
MA resin), styrene-acrylic acid ester-acrylamide copolymer, styrene-butadiene copolymer (SB
R), styrene-vinylidene chloride copolymer, styrene-
Methyl methacrylate copolymer etc.

In this case, the copolymerization ratio can be arbitrary.

vii) Styrene type polymer For example, α-methylstyrene, p-methylstyrene, 2,
5-dichlorostyrene, α, β-vinylnaphthalene, α
-Vinylpyridine, acenaphthene, vinylanthracene and the like, or copolymers thereof, for example, a copolymer of α-methylstyrene and methacrylic acid ester.

viii) Chroman-indene resin Chroman-indene-styrene copolymer.

ix) Terpene resin or picolite For example, a terpene resin which is a polymer of limonene obtained from α-pinene, or picolite obtained from β-pinene.

x) Acrylic resin In particular, those containing an atomic group represented by the following formula are preferable.

In the above formula, R ₁₀ represents a hydrogen atom or an alkyl group, and R ₂₀ represents a substituted or unsubstituted alkyl group. In this case, in the above formula, R ₁₀ is preferably a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms, particularly a hydrogen atom or a methyl group.

R ₂₀ may be a substituted or unsubstituted alkyl group, but the alkyl group preferably has 1 to 8 carbon atoms, and when R ₂₀ is a substituted alkyl group, it is an alkyl group. The substituent for substituting the group is preferably a hydroxyl group, a halogen atom or an amino group (particularly a dialkylamino group).

Such an atomic group represented by the above formula may form a copolymer with other repeating atomic groups to form various acrylic resins, but it is usually one kind of the atomic group represented by the above formula. Alternatively, the acrylic resin is constituted by forming a homopolymer or a copolymer containing two or more kinds of repeating units.

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xi) Polyacrylonitrile xii) Acrylonitrile copolymer, for example, acrylonitrile-vinyl acetate copolymer, acrylonitrile-vinyl chloride copolymer, acrylonitrile-styrene copolymer, acrylonitrile-vinylidene chloride copolymer, acrylonitrile-vinylpyridine copolymer , Acrylonitrile-methyl methacrylate copolymer,
Acrylonitrile-butadiene copolymer, acrylonitrile-butyl acrylate copolymer and the like.

In this case, the copolymerization ratio can be arbitrary.

xiii) Diacetone acrylamide polymer A diacetone acrylamide polymer obtained by reacting acrylonitrile with acetone.

xiv) Polyvinyl acetate xv) Vinyl acetate copolymer For example, copolymers with acrylic acid ester, vinyl ether, ethylene, vinyl chloride and the like.

The copolymerization ratio may be arbitrary.

xvi) Polyvinyl ether For example, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl butyl ether and the like.

xvii) Polyamide In this case, as the polyamide, nylon 6, nylon 6-6, nylon 6-10, nylon 6-12, nylon 9, nylon 11, nylon 12, nylon 13 and the like, as well as nylon 6 / 6-6 / 6-10, nylon 6/6
It may be a polymer such as −6/12, nylon 6 / 6−6 / 11, or modified nylon in some cases.

xviii) Polyester For example, aliphatic dibasic acids such as oxalic acid, succinic acid, maleic acid, adipic acid, and sebastenic acid, or various dibasic acids such as aromatic dibasic acids such as isophthalic acid and terephthalic acid, and ethylene glycol. Condensates with glycols such as tetramethylene glycol and hexamethylene glycol, and cocondensates are preferable.

Of these, condensates of aliphatic dibasic acids and glycols and cocondensates of glycols and aliphatic dibasic acids are particularly preferable.

Furthermore, for example, a modified glyptal resin obtained by esterifying a glyptal resin, which is a condensate of phthalic anhydride and glycerin, with an aliphatic or natural resin is also preferably used.

xix) Polyvinyl acetal resin Both polyvinyl formal and polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol are preferably used.

In this case, the degree of acetalization of the polyvinyl acetal resin can be arbitrary.

xx) Polyurethane resin A thermoplastic polyurethane resin having a urethane bond.

In particular, a polyurethane resin obtained by condensation of glycols and diisocyanates, particularly a polyurethane resin obtained by condensation of alkylene glycols and alkylene diisocyanates, is suitable.

xxi) Polyether Styrene formalin resin, ring-opening polymer of cyclic acetal, polyethylene oxide and glycol, polypropylene oxide and glycol, propylene oxide-ethylene oxide copolymer, polyphenylene oxide and the like.

xxii) Cellulose derivative For example, nitrocellulose, acetyl cellulose, ethyl cellulose, acetyl butyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl hydroxyethyl cellulose, various esters of cellulose, ethers or mixtures thereof.

xxiii) Polycarbonate, for example, polydioxydiphenylmethane carbonate,
Various polycarbonates such as dioxydiphenyl propane carbonate.

xxiv) Ionomer Na, Li, Zn, Mg salts such as methacrylic acid and acrylic acid.

xxv) Ketone resin For example, a condensation product of a cyclic ketone such as cyclohexanone or acetophenone and formaldehyde.

xxvi) Xylene resin For example, a condensate of m-xylene or mesitylene and formalin, or a modified product thereof.

xxvii) petroleum resin C ₅ type, C ₉ type, C ₅ -C ₉ copolymer system, dicyclopentadiene-based, or copolymers of the same etc. or modified product.

xxviii) a blend of two or more of the above i) to xxvii),
Or a blend with other thermoplastic resins.

The molecular weight of the resin may be various.

Such a resin and the above dye are usually used in a weight ratio of 1
Layered in a wide range of volume ratio from 0.1 to 100.

In addition, in the recording layer such as, another quencher,
For example, those described in Japanese Patent Application No. 58-181368 may be contained.

In order to form such a recording layer, generally, it may be applied by a conventional method.

The thickness of the recording layer is usually about 0.02 to 10 μm.

In addition, in such a recording layer, other dyes, other polymers or oligomers, various plasticizers, surfactants, antistatic agents, lubricants, flame retardants, stabilizers, dispersants, antioxidants, etc. , And a crosslinking agent and the like may be contained.

In order to form such a recording layer, the substrate may be coated with a predetermined solvent and dried.

As the solvent used for coating, for example, methyl ethyl ketone, methyl isobutyl ketone, ketone-based such as cyclohexanone, butyl acetate, ethyl acetate, carbitol acetate, ester such as butyl carbitol acetate, methyl cellosolve, ether such as ethyl cellosolve A system, an aromatic system such as toluene and xylene, a halogenated alkyl system such as dichloroethane, an alkane system, an alicyclic system, and an alcohol system may be used.

The material of the substrate on which such a recording layer is provided is not particularly limited as long as it is substantially transparent to the writing light and the reading light, and may be any of various resins and glass.

Further, the shape may be a tape, a card drum, a belt or the like depending on the intended use.

The base body usually has a groove for tracking.

Further, as the resin material for the substrate, a grooved or grooveless substrate such as polymethylmethacrylate, acrylic resin, epoxy resin, polycarbonate resin, polysulfone resin, polyether sulfone, methylpentene polymer is suitable.

In order to improve solvent resistance, wettability, surface tension, thermal conductivity and the like, it is preferable to form an underlayer on these substrates. The material of the underlayer is Si, Ti, Al, Zr, I
An oxide formed by applying an organic complex compound such as n, Ni or Ta or an organic polyfunctional compound and heating and drying is preferable.

In addition, it can be used as a base layer of various photosensitive resins.

Further, on the recording layer, if necessary, various uppermost protective layers,
It is also possible to provide a half mirror layer or the like.

The medium of the present invention may have the above-mentioned recording layer on one surface of such a substrate, or may have the recording layer on both surfaces thereof.

Further, two recording layers are provided on one surface of the substrate, and the recording layers are made to face each other and face each other with a predetermined gap, and they are hermetically sealed to prevent dust and scratches. You can also do so.

Further, a silicone resin or the like may be filled in such a predetermined gap to form a close contact type.

V Specific Action of the Invention The medium of the present invention irradiates recording light in a pulsed form while running or rotating. At this time, due to heat generation of the dye in the recording layer, the dye is melted and the pits are formed.

The pits thus formed are read by detecting reflected light or transmitted light of the read light, particularly reflected light while the medium is running or rotating.

In this case, recording and reading are mainly performed from the base side through the base.

Then, the pits once formed in the recording layer can be erased by light or heat and rewritten.

A semiconductor laser or the like can be used as the recording or reading light.

VI Specific Effect of the Invention According to the present invention, reproduction deterioration due to read light is extremely small.

Further, the light resistance is also improved, the characteristic deterioration due to storage in a bright room is small, and the heat resistance, the oxidation resistance, the humidity resistance, and the gas resistance are excellent.

Further, the characteristics are less deteriorated even when erasing and rewriting are performed. Furthermore, storage stability is also improved.

Further, writing can be easily performed by recording light in the near infrared and infrared regions, and the sensitivity is improved. It has a high solubility and a good coating property.

In addition, writing and reading or erasing can be satisfactorily performed through the substrate without laminating the reflective layer.

VII Specific Examples of the Invention Hereinafter, specific examples of the present invention will be shown to explain the present invention in more detail.

Example 1 Using a naphthalocyanine compound shown in Table 1 below, 0.05 g of the naphthalocyanine compound was dissolved in 2.7 g of an organic solvent, ethylcyclohexane, and filtered, and then an acrylic disk substrate with a guide groove having a diameter of 30 cm (Si-based overcoat) was used. Each layer was coated with a spinner to a thickness of 0.07 μm to obtain various media.

The naphthalocyanine compound used was the No. exemplified above. All of these had good coating properties, but the pentaphenoxy VO of Exemplified Compound (63)
When Nc was changed to tetraphenoxy VONc, the solubility decreased and coating film defects occurred.

Writing was performed from the back surface side of the substrate using a semiconductor laser having a wavelength of 83 nm while rotating each medium thus manufactured at 900 rpm. In this case, the condensing unit output is 10
mW, frequency is 2MHz.

Next, the semiconductor laser was used as the reading light, the reflected light through the substrate was detected, and the C / N ratio was measured with a spectrum analyzer manufactured by Hewlett-Packard Company at a bandwidth of 30 KHz.

The results are shown in Table 1.

From the results of Table 1, the effect of the present invention is clear.

Continuation of the front page (56) Reference JP-A-60-23451 (JP, A) JP-A-60-184565 (JP, A) JP-A-61-25886 (JP, A) JP-A-61-163891 (JP , A) JP 61-163892 (JP, A) JP 61-177287 (JP, A) JP 61-177288 (JP, A) JP 62-39286 (JP, A) JP 61-268487 (JP, A) JP 62-122787 (JP, A) JP 62-122788 (JP, A) US Patent 4492750 (US, A)

Claims (1)

[Claims] 1. An optical recording medium having a recording layer on a substrate, the recording layer containing at least 5 groups represented by the following formula (I).
And / or at least one naphthalocyanine compound having at least one group represented by formula (II) below. Formula (I) -X ₁ R formula (II) -X ₁ QX ₂ - In {the formula (I) and (II), X ₁ and X _2, respectively, represent S or O. R represents a monovalent substituted or unsubstituted aliphatic group, alicyclic group, aromatic group or heterocyclic group, and Q represents a divalent substituted or unsubstituted aliphatic group, alicyclic group, aromatic group Represents a group or a heterocyclic group. }