JPH0447632B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium, particularly a heat mode optical recording medium and a recording method thereof. Prior Art Optical recording media have the characteristic that the recording medium does not deteriorate due to wear since the medium and the writing or reading head are not in contact with each other, and for this reason, research and development of various optical recording media are being carried out. Among such optical recording media, heat mode optical recording media are being actively developed because they do not require image processing in a darkroom. This heat mode optical recording medium is an optical recording medium that uses recording light as heat. One example is a heat mode optical recording medium that uses recording light such as a laser to melt or remove a part of the medium, which is called a pitch. There is a pit-forming type in which writing is performed by forming small holes, information is recorded using the pits, and reading is performed by detecting the pits with a readout light. Until now, most of these pit-forming type media, especially those using a semiconductor laser as a light source that can make the device smaller, have a recording layer made of a material mainly composed of Te. However, in recent years, it has become clear that Te-based materials are harmful.
In addition, due to the need for higher sensitivity and lower manufacturing costs, Te
In place of conventional recording media, there are an increasing number of proposals and reports on media that use recording layers made of organic materials mainly containing dyes. For example, for He-Ne lasers, squalirium dye [JP-A No. 56-46221, VBJipson
and CRJones, J.Vac.Sci.Tech-nol., 18(1)
105 (1981)] and metal phthalocyanine dyes (Japanese Unexamined Patent Publication Nos. 57-82094 and 57-82095). There is also an example of using metal phthalocyanine dyes for semiconductor lasers (Japanese Patent Application Laid-Open No. 86795/1986). In both of these, the recording layer is made into a thin film by vapor deposition of dye, and there is no major difference from the Te type in terms of medium production. However, the reflectance of the dye-deposited film to the laser is generally small, and a readout signal is obtained by a change (reduction) in the amount of reflected light due to the pit. A large S/N ratio cannot be obtained with the conventional methods currently in use. In addition, it is possible to use a transparent substrate carrying a recording layer as a medium with a so-called air sandwich structure in which the recording layers are integrated so that they face each other, and write and read data through the substrate without reducing the writing sensitivity. Although it is advantageous in that the recording layer can be protected and the recording density can be increased, such a recording/reproducing method is also not possible with a dye-deposited film. This is because a normal transparent resin substrate has a certain refractive index (1.5 for polymethyl methacrylate) and a certain high surface reflectance (4% for polymethyl methacrylate). This is because, for example, in the case of polymethyl methacrylate, the reflectance is about 60% or less, and therefore it cannot be detected with a recording layer that exhibits only a low reflectance. Readout S/ of recording layer made of dye deposited film
In order to improve the N ratio, a vapor-deposited reflective film of Al or the like is usually interposed between the substrate and the recording layer. In this case, the vapor-deposited reflective film increases the reflectance and increases the S/
The purpose is to improve the N ratio, and the reflective film is exposed by pit formation and the reflectance increases, or in some cases, the reflective film is removed to reduce the reflectance. As a matter of course,
Recording and playback through the substrate is not possible. Similarly, JP-A-55-161690 discloses a recording layer consisting of IR-132 dye (manufactured by Kodatsu) and polyvinyl acetate, and JP-A-57-74845 discloses 1,
A recording layer consisting of 1'-diethyl-2,2'-tricarbocyanine iodide and nitrocellulose, as well as KYLaw, et al., Appl.Phys.Lett. 39 (9)
718 (1981) describes a medium in which a recording layer made of a dye and a resin is formed by a coating method, such as a recording layer made of 3,3'-diethyl-12-acetylthiatetracarbocyanine and polyvinyl acetate. is disclosed. However, these cases also have the same drawback as the dye-deposited film in that a reflective film is required between the substrate and the recording layer, and recording and reproduction cannot be performed from the back side of the substrate. In this way, in order to realize a medium with an organic material-based recording layer that allows recording and reproduction through the substrate and is compatible with a medium that has a recording layer made of Te-based material, it is necessary to use an organic material. It is necessary for it to exhibit a large reflectance. However, conventionally, there are very few examples of a single layer of organic material exhibiting high reflectance without laminating a reflective layer. It has been reported that a vapor-deposited film of vanadyl phthalocyanine exhibits slightly high reflectance [P. Kivits, et al.,
Appl.Phys.Part A 26 (2) 101 (1981), JP-A-55-97033], but the writing sensitivity is low, probably due to the high sublimation temperature. It has also been reported that cyanine dyes and merocyanine dyes such as thiazole and quinoline dyes are used [Yamamoto et al., Proceedings of the 27th Japan Society of Applied Physics, 1p-P-9
(1980)], and a proposal based on this was made in JP-A-58-112790, but these pigments have low solubility in solvents and are easily crystallized, especially when applied as a coating film. Moreover, it is extremely unstable to the readout light and immediately bleaches. It cannot be put to practical use. In view of these actual circumstances, the present inventors first
It is proposed that indolenine cyanine dyes, which have high solubility in solvents, little crystallization, thermal stability, and high reflectance of paint films, be used as a single layer film (Patent Application No. 1983). −134397, 57−
No. 134170). Furthermore, in other cyanine dyes such as indolenine, thiazole, quinoline, and selenazole, long-chain alkyl groups can be introduced into the molecule to improve solubility and prevent crystallization. (Patent Application No. 57-182589, same)
57-177776, etc.). Furthermore, we have proposed adding a quencher to the cyanine dye in order to improve photostability, and in particular to prevent decolorization (reproduction deterioration) caused by readout light (Japanese Patent Application Nos. 1983-166832 and 1983-168048). No. etc.). However, it is desired that each of these media be further improved in terms of recording sensitivity and reproduction S/N ratio. OBJECT OF THE INVENTION An object of the present invention is to improve an optical recording medium having an organic material-based coating film as a recording layer and a recording method thereof.
The object of the present invention is to improve recording sensitivity, improve S/N ratio of reproduction, reduce reproduction deterioration, and improve thermal stability. These objects are achieved by the invention described below. That is, the first invention is an optical recording medium having, on a substrate, a recording layer made of a phthalocyanine polymer formed by crosslinking two or more molecules of phthalocyanine having a vinyl group, or a composition thereof. Further, the second invention provides a method for irradiating writing light in a pulsed manner onto an optical recording medium having a recording layer on a substrate made of a phthalocyanine polymer formed by crosslinking two or more molecules of phthalocyanine having a vinyl group, or a composition thereof. , is a recording method for an optical recording medium characterized by changing the orientation or association state of phthalocyanine molecules in a recording part to form a recording point having a different reflectance or transmittance/absorption rate from the surrounding area. Further, the third invention provides a method of irradiating writing light in a pulsed manner to an optical recording medium having a recording layer on a substrate made of a phthalocyanine polymer formed by crosslinking two or more molecules of phthalocyanine having a vinyl group, or a composition thereof. , is a recording method for an optical recording medium characterized in that recording is performed by forming recording points by forming recesses in a recording layer. Specific Configuration of the Invention The specific configuration of the present invention will be described in detail below. The recording layer of the optical recording medium in the present invention is made of a phthalocyanine polymer obtained by polymerizing or crosslinking two or more molecules of phthalocyanine having a vinyl group, or a composition thereof. In this case, the phthalocyanine polymer refers to a polymer of a phthalocyanine dye having two or more molecules of a phthalocyanine dye having one or more types of vinyl groups, or a copolymer of a phthalocyanine dye having a vinyl group and other components. . Among these phthalocyanine polymers, one or more homopolymers or copolymers of phthalocyanine dyes having a vinyl group, one or more phthalocyanine dyes having a vinyl group, and one Alternatively, it is preferably a copolymer with one or more copolymer components having two or more vinyl groups or the like. The vinyl group-containing phthalocyanine used is represented by the following formula. Pc(-X)n In this case, X is a vinyl group-containing group, particularly preferably -L-CR= _CH2 . In this case, R is hydrogen or a lower alkyl group. Moreover, L is a divalent linking group. As divalent linking groups, -COO-, -OCO-, -
CONH−, −NHCO−, −O−, −SO ₂ −, −SO ₂
Preferably, it is NH-, NHSO ₂ -, an alkylene group, a phenylene group, or a combination thereof. In this case, the end of L on the vinyl group side preferably has OCO- and is acryloyl or methacryloyl. And n is an integer of 1 or more, and generally 1 to
It can be any integer of 8, but is typically 2, 4 or 8. On the other hand, Pc represents a monovalent or higher valence residue of phthalocyanine, and the vinyl-containing group represented by X above is bonded to the benzene ring forming the phthalocyanine ring. In this case, the vinyl-containing group is bonded to any position on the benzene ring of the phthalocyanine, but usually 3
It is bonded at the - to 4-positions. Therefore, when n=2, the bonding positions of the vinyl-containing group are 3,3'-, 3,4'-, 3,3''-, 3,4''-,
4,4'- and is a mixture of these isomers. In addition, when n = 4, 3, 3', 3'', 3- are mainly used, and when n = 8, 3, 4, 3', 4', 3'', 4'', 3,
Mainly 4. Furthermore, there is no particular restriction on the central atom of phthalocyanine, and in addition to Fe, Cu, Co, Ni, etc., V,
Pb, Si, Ge, Sn, Al, Ru, Ti, Zn, Mg,
Mn, VO, AlCl, InBr, GaCl (Cl ₂ ), InBr (Br)
etc., H ₂ is also possible. In this case, one or two other ligands may be further coordinated above and below the phthalocyanine ring. Although other substituents are not usually bonded to the Pc phthalocyanine residue, substituents such as a carboxy group, a sulfo group, and an amino group may be bonded to the benzene ring of Pc in particular. Next, specific examples of phthalocyanine having a vinyl group will be given. In addition, in the following, Mt represents the central metal element of phthalocyanine or hydrogen. [Table] [Table] Such phthalocyanine compounds are synthesized as follows. First, there are usually n pieces, usually 2,4, in the benzene ring.
A phthalocyanine having 8 to 8 carboxy groups is synthesized. These synthesis methods are known, for example, n=2
Proceedings of the Society of Polymer Science, Vol. 32 (1983) No. 3, P505,
n=4 is Makromol.Chem. 182 2429-2438
(1981), n = 8, Makromol.Chem. 181 565
(1980). Alternatively, a phthalocyanine having a functional group such as a hydroxy group or a sulfo group is synthesized according to a conventional method. To these, [Formula] (L and R are the same as above. Y is a functional group such as OH, NH ₂ , COOH, etc.) is added and the reaction is carried out by heating. After the reaction, centrifuge, add water to the supernatant,
A precipitate is obtained, filtered, dried, dissolved in acetone, concentrated, and then purified. The phthalocyanine compound thus obtained has almost the same electronic spectrum as phthalocyanine itself. In addition, the infrared absorption spectrum has ν _C=0 around 1720 cm ⁻¹ and ν _C=C around 1610 to 1650 cm ⁻¹ . As for the melting point, it generally decomposes thermally at about 170 to 200°C. For specific synthesis examples, see
This is shown in the patent application dated March 2, 2017. These vinyl group-containing phthalocyanines are usually polymerized or crosslinked by active radiation such as ultraviolet rays, electron beams, and X-rays after forming a coating film. In this case, the phthalocyanine having a vinyl group may be used alone or may be cured in combination with other compounds curable by actinic radiation. Compounds curable by actinic radiation (polymers,
Examples of oligomers and monomers include the following. 1 Monomer or oligomer 1.1 Monofunctional monomer For example, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, butyl acrylate, cyclohexyl acrylate,
Dimethylaminoethyl methacrylate, benzyl acrylate, carbitol acrylate,
2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl acrylate, 2
-Hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, acrylamide, methacrylamide,
N-methylolacrylamide, N-diacetone acrylamide, N,N'-methylenebisacrylamide, styrene, acrylonitrile,
Vinyl acetate, N-vinylpyrrolidone, phenolethylene oxide adduct acrylate, dicyclobentenyloxyethyl acrylate, etc. 1.2 Polyfunctional acrylic monomers or oligomers For example, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol diacrylate Methacrylate, butylene glycol diacrylate, butylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1 , 6-hexanediol dimethacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, bisphenol S ethylene oxide adduct diacrylate, bisphenol A ethylene oxide Diacrylate of adduct, diacrylate of tris(2-hydroxyethyl)isocyanurate, tris(2-acryloyloxyethyl)
such as isocyanurates. 1.3 Allyl polyfunctional monomers For example, diallyl phthalate, diallyl isophthalate, diallyl maleate, diallyl chlorendate, diallyl adipate, diallyl diglycolate, triallyl cyanurate, diethylene glycol bisallyl carbonate, etc. 1.4 Ring-opening polymerization monomers For example, glycidyl cinnamate, epoxy derivatives of oxychalcone, etc. 1.5 Urethane-type acrylic esters 1.6 Unsaturated esters of polyhydric carboxylic acids 1.7 Unsaturated amides 1.8 Ester metal salts with inorganic acids 1.9 Monomers with acetylenically unsaturated groups 1.10 Monomers with glycidyl groups 1.11 Diazonium salts 1.12 O-quinone azides For example, sulfonic acid esters of o-naphthoquinone diazide. 1.13 Others, such as dihydroxychalcone, divanillalacetone, divanillarusilocpentanone, etc. 1.14 Vinyl monomers with photosensitive groups 1 Cinnamoyl type For example, the following: 2 Cinnamylidene series For example, the following 3 Frilled acryloyl type For example, the following 4 Coumarins, such as the following: 5 Pyrones For example, the following 6 Benzalacetophenones For example, the following: 7 Anthracene series For example, the following 8 Stilbenes such as the following 9 α-Phenylmaleimide series For example, the following 10 Azide type For example, the following CH ₂ ＝CHOCH ₂ CH ₂ N ₃ 11 Unsaturated system For example, the following CH ₂ ＝CHCOOCH ₂ CH＝CH ₂ CH ₂ =CHOCH ₂ CH ₂ O-CO-CH=CH ₂ 12 Benzophenone series For example, the following 13 Benzoin series For example, the following 14 1,3-dioxolane series For example, the following 15 Dithiocarbamate system For example, the following CH ₂ =CH-S-CS=NR 16 Azadioxabicyclo system For example, the following 17 Spiropyrans For example, the following: 2 Polymer or prepolymer A polymer in which, for example, various photosensitive groups exemplified by the following photosensitive groups and/or monomers are chemically bonded to an existing polymer. Examples of polymers include various epoxy resins, polyurethane, polyamide, polyacrylic unsaturated polyester, polyvinyl alcohol, silicone resin, maleic acid copolymer, cellulose derivatives, vinyl chloride-vinyl acetate copolymer, resinous polyol acrylate, etc. In addition to the above, photosensitive groups include olefin, cinnamoyl, cinnamylideneacetyl, benzalacetophenone (chalcone), styrylpyridine,
α-phenylmaleimide, phenyl azide, sulfonyl azide, carbonyl acid, diazo, o-
Examples include quinone diazide (diazo oxide), furyl acryloyl, coumarin, pyrone, anthracene, benzophenone, benzoin, stilbene, dithiocarbamate, xantate, 1,2,3-thiadiazole, cyclopropene, aza-dioxabicyclo, and the like. Furthermore, cyclized rubber, polycon (allyl isocyanate or allyl alcohol is reactively bonded to the end of polyurethane obtained by reacting polyether glycol and tolylene diisocyanate to introduce an allyl group), etc. are also useful. Usually 80wt for phthalocyanine
% or less. Furthermore, a photosensitive crosslinking agent can also be added. The amount of crosslinking agent added is 80wt% of phthalocyanine.
Hereinafter, it is particularly set at about 0.1 to 80 wt%. There are no particular restrictions on the crosslinking agent to be used, but the following are preferred. 1 Dichromate For example, a mixture of a water-soluble polymer compound such as gelatin, glue, egg white, gum arabic, polyvinyl alcohol, etc. and dichromate 2 Organic azide compound For example, 4,4'-diazidostilbene, 4,
3 Sulfur compounds such as 4'-diazide chalcone For example, pentaerythritol tetrakis (β
-mercaptopropionate), etc. 4 Photoduplexing compound, for example, silicic acid, etc. Furthermore, an initiator and a sensitizer can also be added. The amount of the initiator and sensitizer added is approximately 0.001 to 10 wt% of the phthalocyanine. Although there are no particular limitations on the initiator and sensitizer used, the following are preferred. 1 Benzoin ether type For example, isobutyl benzoin ether, isopropyl benzoin ether, benzoin ethyl ether, benzoin methyl ether, etc. 2 α-acyloxime ester type For example, 1-phenyl-1,2-propanedione-2-(-o-ethoxy carbonyl) oxime, etc. 3 Benzyl ketal system, for example, 2,2-dimethoxy, 2-phenylacetophenone, benzyl, hydroxycyclohexyl phenyl ketone, etc. 4 Acetophenone derivative system, for example, diethoxyacetophenone, 2-hydroxy-2. Methyl-1, phenylpropaneacet-1-one, etc. 5 Ketone (ketone-amine) systems For example, benzophenone, chlorothioxanthone, 2-chlorothioxanthone, isopropylthioxanthone, 2-methylthioxanthone, chlorine-substituted benzophenone, halogen-substituted alkyl- Aryl ketones, etc.6 Hydrocarbons such as naphthalene, anthracene, phenanthrene, chrysene, etc.7 Nitrobenzene, p-dinitrobenzene,
1,3,5-trinitrobenzene, p-nitrodiphenyl, m-nitroaniline, 2,4-dinitroaniline picramide, 2-chloro, 4-
Nitroaniline, 2,6-dinitro-4-nitroanilinephenol, p-nitrophenol, 2,4-dinitrophenol, 2,4,6
-Amino, nitro, such as trinitrophenol,
Phenolic compound 8 Benzaldehyde, 9-anthraaldehyde, acetophenone, benzophenone, dibenzalacetone, benzyl, p,p'-diaminobenzophenone, p,p'-dimethylaminobenzophenone, p,p'-tetramethyl Ketones such as diaminobenzophenone (Michler ketone) 9 Benzoquinone, 1,2-naphthoquinone, 1,
4-naphthoquinone, anthraquinone, 1,2-
Quinones such as benzanthraquinone 10 Anthrone, 1,9-benzaanthrone, 6
-phenyl-1,9-benzaanthrone, 3-
Phenyl-1,9-benzanthrone, 2-keto-3-aza-1,9-benzanthrone, 3
-Anthrones such as methyl-1,3-diaza-1,9-benzaanthrone 11 Azo compounds such as azobisisobutyronitrile 12 Organic sulfur compounds such as mercaptans and disulfides 13 Various halogen compounds In addition, various oligomers or various leveling agents such as polymers and silicone acrylics, water repellent,
Oil repellents, light stabilizers, plasticizers, surfactants, antistatic agents, various reaction catalysts, various pigments, fillers, thermal polymerization inhibitors, reducing agents, etc. may be added. Such active radiation, especially ultraviolet rays, electron beams,
The X-ray curable phthalocyanine or its composition is dissolved in a solvent if necessary, coated on a substrate, and then cured by irradiation with actinic radiation. In this case, the solvents used include ketone type (e.g. methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), aromatic type (e.g. toluene, xylene, etc.), halogen type (e.g. dichloroethane, trichlene, etc.), alcohol type (e.g. methanol, ethanol, etc.). , propanol, methyl cellosolve, ethyl cellosolve, etc.), ester systems (for example, butyl acetate, ethyl acetate, carbitol acetate, butyl carbitol acetate, etc.), hydrogen, etc. are possible. The concentration of the phthalocyanine or its composition that can be cured by actinic radiation is 100% or less,
In particular, it is said to be around 20 to 100%. As a coating method, a spinner method, a dip method, a gravure coating method, a spray method, etc. may be used. The wavelength of ultraviolet rays used for curing is mainly 200 ~
It is said to be around 400nm. Further, the light intensity is set such that the lamp input is approximately 1 W/cm to 1 Kw/cm.
Furthermore, the curing time is about 1 μsec to 1 minute, and the curing atmosphere is air, inert gas,
It may be in any environment such as a vacuum. If necessary, the solvent is removed by heating at about 25 to 150° C. before and after curing, preferably before curing. The electron beam used has an acceleration speed of 0.1 to 1000kev,
Preferably, 0.5 to 300 kev is suitable. Further, the electron beam irradiation amount is usually about 0.01 to 100 Mrad. Note that the effects of the present invention are even more excellent when the curing atmosphere is an inert gas atmosphere such as nitrogen, argon, helium, or a mixed gas thereof. Note that there are no restrictions on the electron beam accelerator used. Furthermore, X-rays can also be used. The phthalocyanine polymer after polymerization or crosslinking preferably contains about 1 to 10 million molecules of phthalocyanine dye, particularly about 3 to 1 million molecules. Although the recording layer of the medium of the present invention is made of such a phthalocyanine polymer, the recording layer may contain other resins separately. At this time, coating properties are improved, and recording sensitivity, readout S/N ratio, etc. are improved. Examples of such resins include, for example, Japanese Patent Application No. 1983-
Those described in No. 15229 etc. are suitable. The resin is contained in an amount of about 20% or less by weight based on the phthalocyanine polymer. Furthermore, a quencher can also be included in the recording layer. This reduces reproduction deterioration. The quencher to be used is
Those described in No. 203945 and the like are suitable. In order to form such a recording layer, it is generally necessary to apply it by coating according to a conventional method. And the thickness of the recording layer is usually 0.02~10μm
It is considered to be a degree. There is no particular restriction on the material of the substrate on which such a recording layer is provided, and it may be made of any of various resins, glass, ceramics, metals, etc., but it must be substantially transparent to writing light and reading light. Preferably. Further, its shape may be a tape, a drum, a belt, etc. depending on the intended use. Note that the base body usually has a tracking groove. In addition, resin materials for the base include polymethyl methacrylate, acrylic resin, epoxy resin,
Non-grooved substrates such as polycarbonate resins, polysulfone resins, polyethersulfones, methylpentene polymers, etc. are suitable. These substrates can also be coated with a primer to improve solvent resistance, wettability, surface tension, thermal conductivity, etc. As the primer, for example, titanium-based, silane-based, or aluminum-based coupling agents, various photosensitive resins, and the like can be used. Further, in order to control the orientation, an orientation treatment layer and an orientation control layer may be provided. Further, various uppermost protective layers, half mirror layers, etc. can be provided on the recording layer, if necessary. Further, a reflective layer may be provided under the recording layer. Furthermore, the substrate may be subjected to various treatments, such as corona treatment. The medium of the present invention may have the above-mentioned recording layer on one surface of such a substrate, or may have recording layers on both surfaces thereof. Also,
Two substrates with recording layers coated on one side are used, and the recording layers are placed facing each other with a predetermined gap between them, and they are sealed to prevent dust and scratches. You can also do it like this. Furthermore, since the recording points have substantially no unevenness, it is possible to coat the recording layer with resin or to adhere another resin plate thereon. And with such a close contact structure,
Features such as the ability to make the media more compact, lighter, and thinner can be achieved, and the reliability of the media is also improved. Specific effects of the invention When the medium of the invention is running or rotating,
Recording light is irradiated in a pulsed manner. At this time, the phthalocyanine polymer in the recording layer generates heat and is immediately rapidly cooled, resulting in a change in the orientation or association state of the phthalocyanines in the phthalocyanine polymer, forming a recording point that has a different reflectance or transmittance from its surroundings. In this case, the recording point is usually recorded as a point whose reflectance or absorption rate is different from that of the surrounding area. and,
The recorded points have substantially no unevenness. The recording points formed in this manner are read out by detecting the reflected or transmitted light of the readout light, especially the reflected light, while the medium is running or rotating. In this case, recording and reading may be performed from the substrate side or from the recording layer side, but it is preferable to perform the recording and reading through the substrate. Then, the recording points once formed on the recording layer are heated and slowly cooled using light or heat to restore the original orientation or association state of phthalocyanine, erase the recording points once again with the same reflectance as the surrounding area, and rewrite. You can also do Note that the recording or reading light can be a semiconductor laser, He-Ne laser, Ar laser, He
-Cd laser etc. can be used. Alternatively, if the intensity of the recording light is made higher than in the above case, the recording point will be formed as a pit that is concave with respect to the surroundings. Specific Effects of the Invention According to the present invention, since recording is not performed using pits having irregularities unlike the conventional recording layer made of an organic material, recording sensitivity is improved. Furthermore, the reproduction S/N ratio is also improved. Since phthalocyanine is used, it has extremely high thermal stability and stability against light. Furthermore, compactness can be achieved, improving media performance and reliability. In this case, even when forming uneven bits, when the light intensity of the recording light is increased, the threshold at which recording is possible is clear, its rise is large, and the sensitivity soon saturates, so the recording light intensity is The effect is that the characteristics are stable against fluctuations in. Specific Examples of the Invention Specific examples of the present invention are shown below. Example 1 The base was made of acrylic resin with a diameter of 30 cm and a thickness of 1.5 mm, and one side of the base was made of acrylic resin with a depth of 0.08 mm and a width of 0.08 mm.
0.9 rectangular grooves were formed concentrically. Next, the following composition A was dissolved in 10% dichloroethane, and this solution was spin-coated to a thickness of 0.08 mm, dried, and then irradiated with a high-pressure mercury lamp of 80 W/cm for 10 seconds to effect crosslinking. Phthalocyanine No. 23 Monomer Pentaerythritol tetraacrylate Initiator 2-tert-butylanthraquinone For comparison, a recording layer containing only FnBr-phthalocyanine was similarly prepared. For each sample prepared in this way,
While rotating at 600 rpm, a semiconductor laser (830 nm) was focused by a lens with NA = 0.5 (focusing section output 10 mW), and the writing sensitivity was measured by changing the pulse width. Table 2 shows the sensitivity that allows a reproduction S/N ratio of 40 dB. Next, writing was performed with a pulse width of 100 nsec. As a result, recording points were formed that had no unevenness and had a different reflectance from the surrounding area. After this, 0.6mW semiconductor laser readout light is applied.
The C/N ratio was measured by irradiating as a pulse of 0.2 μsec width and 3 KHz, and detecting the reflected light. Table 1 also shows the reflectance deterioration rate (%) when irradiated with readout light of 0.6 mW, 0.8 μs, and 3 KHz for 5 minutes. [Table] From the results shown in Table 1, the effects of the present invention are clear. Example 2 Using the same substrate as in Example 1, the following composition was dissolved in a 1:1 solution of dichloroethane and cyclohexanone, this solution was spin-coated with 0.09%, dried, and then irradiated with a 60W/cm high-pressure mercury lamp for 1 second. crosslinking was performed. Phthalocyanine No. 14 Pentaerythritol tetraacrylate 2-tert-butylanthraquinone For comparison, a medium with a recording layer made only of Cu-phthalocyanine was prepared. For each sample prepared in this way,
While rotating at 900 rpm, apply He from the back side of the substrate.
-Ne laser is focused on 1φ (focusing part output
10mW) and a pulse width of 100nsec. As a result, in the sample of the present invention, recording points that were substantially concave portions were formed. After this, the same measurements as in Example 1 were performed. The results are shown in Table 2. [Table] From the results shown in Table 2, the effects of the present invention are clear.

Claims (1)

[Scope of Claims] 1. An optical recording medium comprising, on a substrate, a recording layer made of a phthalocyanine polymer obtained by polymerizing or crosslinking two or more molecules of phthalocyanine having a vinyl group, or a composition thereof. 2. An optical recording medium having a recording layer made of a phthalocyanine polymer obtained by polymerizing or crosslinking two or more molecules of phthalocyanine having a vinyl group, or a composition thereof on a substrate is irradiated with pulsed writing light to write the recorded portion. By changing the orientation or association state of phthalocyanine molecules, the reflectance or transmission and
A recording method for an optical recording medium, characterized in that recording is performed by forming recording points with different absorption rates. 3. The recording method for an optical recording medium according to claim 2, wherein the recording points have substantially no unevenness. 4. An optical recording medium having a recording layer on a substrate made of a phthalocyanine polymer obtained by polymerizing or crosslinking two or more molecules of phthalocyanine having a vinyl group, or a composition thereof, is irradiated with pulsed writing light to form a recording layer. A recording method for an optical recording medium, characterized in that recording is performed by forming recording points by forming recesses.