JPH0424771B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel optical information recording medium comprising a combination of a reflective layer and an absorbing layer. Conventionally, optical information recording media include Te and Bi.
It is known to use a single layer of a low melting point metal such as, a single layer of a pigment with bronze luster, and a laminate of a silver mirror and a pigment as a recording layer. However, although a recording layer made only of Te, Bi, etc. has a low melting point, the energy required for recording is somewhat large. Furthermore, since a recording medium using a pigment with bronze luster is sensitive only to light near the absorption wavelength of the pigment, the use of a semiconductor laser has the drawback of slightly low sensitivity. Furthermore, the type with a layered silver mirror and dye requires recording energy of about Te or Bi. The present invention has been made in view of the above problems, and uses a low melting point metal or a pigment with bronze luster as a reflective layer, and a specific light absorption layer is laminated thereon to increase the recording sensitivity, especially the recording sensitivity in semiconductor lasers. The present invention has been completed by successfully improving the following properties. An object of the present invention is to lower the recording threshold value by combining a light-reflecting layer and a light-absorbing layer compared to a conventional recording medium having only a light-absorbing layer. Another object of the present invention is to obtain even higher recording sensitivity by using a low melting point metal or a dye with bronze luster in the reflective layer. According to the present invention, in an optical information recording medium comprising a reflective layer and an absorbing layer laminated in an arbitrary order on a substrate, the reflective layer is made of a low melting point metal or a pigment with bronze luster; An optical information recording medium is provided, which is characterized by comprising an anthraquinone compound represented by the following general formula () or an indanthrene compound represented by the following general formula (). (In the formula, X ₁ , X ₂ , X ₃ and X ₄ are each hydrogen,
represents an alkyl group, a hydroxyl group, a nitro group, an aino group, a cyano group, and a halogen; Y represents hydrogen and a sulfonate group; Ar ₁ represents hydrogen, a phenyl group, a naphthyl group, and their sulfonates and salts; The phenyl group may be substituted by an alkyl group, an alkoxy group, an amino group, an alkylcarbonyl group, a methylthio group, a halogen and a phenylcarbonyl group, and Ar ₂ is hydrogen, a phenyl group, and sulfonated products and salts thereof, and the phenyl group may be substituted with an alkyl group, an alkoxy group, an amino group, an alkylcarbonyl group, a phenylcarbonyl group, and a halogen) (In the formula, X ₁ , X ₂ , X ₃ and X ₄ have the same meanings as above, X ₅ represents hydrogen -NH-Ar ₁ and -S-Ar, Z represents hydrogen, -NH-Ar ₁ and -S-Ar ₁
and Ar ₁ has the same meaning as above).
The optical information recording medium of the present invention basically includes a substrate,
Although it is composed of a reflective layer and an absorbing layer, other layers such as a protective layer and an undercoat layer may be provided depending on the purpose. The low melting point metals used in the present invention include Bi,
Examples include metals exhibiting relatively low melting points, such as Te, Se, Sn, Ge, In, As, Pb, and Zn, or alloys thereof. The metals or alloys thereof are deposited on the substrate by, for example, a vapor deposition method or a sputtering method.
It can be applied at a thickness of 1000 nm. Also,
Pigments with bronze luster include cyanine or merocyanine dyes, triphenylmethane dyes, xanthene dyes, naphthoquinone dyes,
Squarenium dyes, phthalocyanine dyes, perylene pigments, dioxazine compounds, and the like can be selected and used as appropriate. Examples include 2-[7
-(3-ethyl-2-benzothiazolinylidene)-
1,3,5-heptatrienyl]-3-ethylbenzothiazolium chloride, 2,4-bis-(2,
4,6-Trihydroxyphenyl)-1,3-cyclobutadienedaleium-1,3-dithiolate, 1,3-bis-[3-ethyl-benzthiazolinylidene-(2)-methyl] -phenalenium tetrafluoroborate, N,N'-dianisole-substituted perylene, CI Solvent Blue, Magenta Base, Lead Phthalocyanine, CI Direct Blue 108 (CI51320), 6-Amino-3-hydroxy-9-(2-carboxylphate) enyl)-xanthylium chloride, CI Watt Blue 1 (CI7300), and methylene blue. In the present invention, a plurality of the above dyes may be combined. In addition, the pigment with bronze luster in the present invention can be applied to the substrate by vapor deposition or solvent coating, for example.
Applied in a thickness of 1000nm. The compounds used as the absorption layer in the present invention have various substituents on the anthraquinone skeleton or indanthrene skeleton represented by the above general formulas () and (). In particular, compounds with an indanthrene skeleton as shown in the general formula () have a maximum absorption wavelength of around 800 nm, and are therefore optimal as materials for semiconductor lasers. Examples of the anthraquinone compounds or indanthrene compounds represented by the above general formulas () and () are shown below. 1-amino-4-(4-sulfonic acid phenylamino)-6,7-dinitroanthraquinone sodium salt, 1-anilino-2-sulfonic acid sodium salt -4-(4-methylphenylamino)anthraquinone, 8,17- Bis-(4-methoxyphenylamino)-indanthrene, 1,4-bis(3
-sodium sulfonate-4-methoxyphenylamino)-6,7-dicyanoanthraquinone, 1,
4-bis(sodium 3-sulfonate-4-chlorophenylamino)-5,8-dichloroanthraquinone, 1-(2-methylphenylamino)-2-
Sodium sulfonate-4-(4-aminophenylamino)-6,7-dinitroanthraquinone,
Sodium 1,4-bis(3-sulfonate-4-
Anilino-1-anthraquinolyl amino)benzene, 1,4-bis(4-(4-sodium sulfonate-phenylamino)-1-anthraquinolyl amino)benzene, 1,4-bisanilinoanthraquinone, 1,4 -bis(4-methylphenylamino)anthraquinone, 1,4-bis(4-methoxyphenylamino)anthraquinone, 1,4-
Bis(4-aminophenylamino)anthraquinone, 1,4-bis(4-benzoylphenylamino)anthraquinone, 1,4-bis(4-chlorophenylamino)anthraquinone, 1,4-bis(4-acetylphenylamino)anthraquinone enylamino) anthraquinone,
1,4-bis(naphthylamino)anthraquinone, 1,4-bis(sodium 4-sulfonate-4-methylphenylamino)anthraquinone, 1,4-bis(sodium 3-sulfonate-4-methylphenylamino)anthraquinone, 1 ,4-bis(3-
Sulfonic acid-4-methoxyphenylamino)anthraquinone, 1,4-bisanilino-6,7-dinitroanthraquinone, 1-anilino-4-(4
-methylphenylamino)-6,7-dinitroanthraquinone, 1,4-bis(sodium 4-sulfonatephenylamino)-6,7-dicyanoanthraquinone, 1-anilino-4-(4-nitrophenylamino) ) anthraquinone, 1-(4-methoxyphenylamino)-4-(4-nitrophenylamino)anthraquinone, terephthalamide,
N,N'-bis-{2-bromo-4-(2-methylthioanilino)-1-anthraquinolyl}, 1-
(4-sodium sulfonate phenylamino)-4
-(sodium 4-methyl-3-sulfonate phenylamino)-5,8-cyanoanthraquinone,
1,4-bis(4-methylphenylamino)-6,
7-dichloroanthraquinone, 1,4-bis(4
-ethoxyphenylamino)-6,7-dinitroanthraquinone, 8,17-bis(4-methylphenylamino)indanthrene, 8,17-bis(4
-chlorophenylamino)indanthrene, 2,
3,11,12-tetranitro-8,17-bisanilinoindanthrene, 6,15-bis(2-methylthiophenylamino)indanthrene, 6,15-bis-(3,5-dimethoxyphenylamino) ) indanthrene, 8,17-bis(anilino)indanthrene, 8,17-bis(sodium 4-sulfonate phenylamino)indanthrene, 8,17-bisphenylthioindanthrene, 8, 17-bis(2-methoxyphenylamino)indanthrene,
8,17-bis(3-methoxyphenylamino)indanthrene, 8,17-bis(2-methylphenylamino)indanthrene, 8,17-bis(3-
Methylphenylamino) indanthrene, 8,17
-bis(2-chlorophenylamino)indanthrene, 8,17-bis(3-chlorophenylamino)indanthrene, 8,17-bis(2-methylthiophenylamino)indanthrene, 8,17-
Bis(3-methylthiophenylamino)indanthrene, 8,17-bis(4-methylthiophenylamino)indanthrene, 8,17-bis(4-phenylthiophenylamino)indanthrene,
8,17-bis(2,5-dimethoxyphenylamino)indanthrene, 8,17-bis(4-methyl-2-chlorophenylamino)indanthrene,
8,17-bis(2,4,6-trimethylphenylamino)indanthrene, 8,17-bis(1-naphthylamino)indanthrene, 8,17-bis(2-naphthylamino)indanthrene , 8, 17
-Bis(2-methoxyphenylthio)indanthrene, 8,17-bis(4-phenylphenylamino)indanthrene, 8,17-bis(2-methoxy-4-sulfonic acid sodium phenylamino) )
Indanthrene, 8,17-bis(3-methoxy-
Sodium 4-sulfonate phenylamino)indanthrene, 8,17-bis(4-methoxy-2-
Sodium sulfonate phenylamino)indanthrene, 8,17-bis(2-methyl-sulfonate sodium phenylamino)indanthrene,
8,17-bis(3-methyl-4-sulfonic acid sodium phenylamino)indanthrene, 8,17
-bis(sodium 4-methyl-2-sulfonate phenylamino)indanthrene, 8,17-bis(2-methylthio-4-sulfonate sodium phenylamino)indanthrene, 8,17-bis(3 -Methylthio-4-sulfonic acid sodium phenylamino)indanthrene, 8,17-bis(4-methylthio-2-sulfonic acid sodium phenylamino)indanthrene, 8,17-bis[4-(4- sodium sulfonate)
phenylamino]indanthrene, 8,17-bis(2,5-dimethoxy-4-sulfonate sodium phenylamino)indanthrene, 8,17-bis[1-(4-sulfonate sodium naphthyl)
Amino] indanthrene, 8,17-bis[2-
(4-sulfonate sodium naphthyl)amino]
Indanthrene, 8,17-bis(4-hydroxyphenylamino)indanthrene, 8,17-bis(3-hydroxyphenylamino)indanthrene, 8,17-bis(2-hydroxyphenylamino) ) indanthrene, 6,15-bis(2-chlorophenylamino)indanthrene, 6,15-bis(3-chlorophenylamino)indanthrene,
6,15-bis(4-chlorophenylamino)indanthrene, 6,15-bis(2-methylphenylamino)indanthrene, 6,15-bis(3-methylphenylamino)indanthrene, 6,15−
Bis(4-methylphenylamino)indanthrene, 6,15-bis(4-chloro-2-methylphenylamino)indanthrene, 6,15-bis[3
-(Methylthio)phenylamino]indanthrene, 6,15-bis[2-(methylthio)phenylamino]indanthrene, 6,15-bis(2-methoxyphenylamino)indanthrene, 6,15
-bis(3-methoxyphenylamino)indanthrene, 6,15-bis(4-methoxyphenylamino)indanthrene, 6,15-bis(4-ethoxyphenylamino)indanthrene, 6, 15−
bis(1-naphthylamino)indanthrene,
6,15-bis(2-naphthylamino)indanthrene, 6,15-bis[4-(phenylthio)phenylamino]indanthrene, 6,15-bis(2
-Sodium chloro-4-sulfonate phenylamino)indanthrene, 6,15-bis(sodium 3-chloro-4-sulfonate phenylamino)
Indanthrene, 6,15-bis(4-chloro-2
-Sodium sulfonate phenylamino)indanthrene, 6,15-bis(2-methyl-4-sodium sulfonate-phenylamino)indanthrene, 6,15-bis(3-methyl-4-sodium sulfonate) phenylamino)indanthrene, 6,15-bis(4-methyl-3-sulfonic acid sodium-phenylamino)indanthrene,
6,15-bis(2-methoxy-4-sulfonic acid sodium-phenylamino)indanthrene,
6,15-bis(3-methoxy-4-sulfonic acid sodium-phenylamino)indanthrene,
6,15-bis(4-methoxy-2-sulfonic acid sodium-phenylamino)indanthrene,
6,15-bis(4-aminophenylthio)indanthrene, 6,15-bis(4-methylphenylthio)indanthrene, 6,15-bis(4-sodium sulfonate-phenylthio)indanthrene Len. The absorbing layer in the present invention has the above-mentioned general formula ()
Or, it is composed of a compound having an anthraquinone structure or an indanthrene structure represented by () alone or in combination with other components (including other dyes). The absorption layer can be formed by dissolving the above compound in a solvent and applying it, by vapor deposition, by mixing it with a resin solution, by co-evaporating it with other dyes, or by applying a mixed solution with other dyes. It is formed by dissolving it in a resin solution together with other pigments and applying it. In this case, known resins such as PVA, PVA, polyvinyl butyral, and polycarbonate are used, and the amount of the above compound to the resin is 0.01% by weight.
It is desirable that there be at least one. In addition, other types of anthraquinone derivatives may be used as other pigments,
It is preferable to use a dye such as a triarylmethane dye or an azo dye that absorbs in a wavelength range other than that of a semiconductor laser, since a medium that can be recorded not only with a semiconductor laser but also with a He-Ne laser or the like can be obtained. The thickness of the absorption layer is preferably 0.01 to 1 μm.
It is in the range of 0.05 to 0.5 μm. Next, an example of the structure of the optical information recording medium of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing the basic structure of the recording medium of the present invention, in which a reflective layer 2 is provided on a substrate 1, and an absorbing layer 3 is further provided thereon. As the substrate, transparent materials such as glass and plastics such as acrylic and polycarbonate are used. Furthermore, there is no problem in providing the undercoat layer 4 and/or the protective layer 5. FIG. 2 shows an example in which both of these are provided. Recording of information takes place through the substrate. Further, a configuration as shown in FIG. 3 is also possible, in which an absorbing layer 3 is provided on the substrate 1, and a reflective layer 2 is further provided thereon. In this case, in addition to glass and plastics such as acrylic and polycarbonate, metals such as iron and aluminum can also be used as the substrate. Moreover, there is no problem even if the undercoat layer 4 and/or the protective layer 5 are provided. FIG. 4 shows an example in which both of these are provided. Information is recorded from the reflective layer side. When the reflective layer is on the substrate side, a configuration in which two reflective layers are placed back to back as shown in FIG. 5 is also possible. Information is recorded by irradiating a spot of a high-energy beam such as a laser from the side of the reflective layer, and the absorbed heat creates holes in the recording layer and records are recorded. Of course, recording from the absorption layer side is also possible. Furthermore, information can be read by irradiating a low-power laser beam and detecting changes in the amount of reflected light. The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited thereto. Example 1 A reflective layer was obtained by depositing Te to a thickness of 100 nm on an acrylic plate. Furthermore, add 8,17-bis (4
- phenylphenylamino) indanthrene was vapor-deposited to a thickness of 150 nm to form a light absorption layer. The reflectance and transmittance of the recording medium thus obtained at 800 nm were 43% and 2%, respectively. This recording medium was irradiated with semiconductor laser light with an irradiation surface energy of 3 mW and a beam diameter of 1.6 μm.
A 1MHz signal was recorded. The recording threshold per pit was 0.6 nJ/pit and the pit diameter was 1.3 μm. Example 2 A glass plate was coated with polyvinyl butyral to a thickness of 1.5 μm to form an undercoat layer. On this board,
Se and Sn were co-deposited at a ratio of 2:1 to obtain a reflective layer with a thickness of 100 nm. Furthermore, a solution consisting of 0.5 g of polyvinyl alcohol, 10 g of water, and 0.3 g of 8,17-bis(2-methoxy-4-sulfonic acid phenylamino)indanthrene was spin-coated to obtain a light absorption layer. The reflectance and transmittance of the recording medium thus obtained at 800 nm were 37% and 1%, respectively. When information was recorded on this recording medium in the same manner as in Example 1, the recording threshold was 0.7 nJ/pit and the diameter
A pit of 1.4 μm was formed. Example 3 A 70 nm thick As ₁₀ Se ₃₀ Te ₆₀ vapor deposited film was provided on an acrylic plate to serve as a reflective layer. Furthermore, 1,4-bis-(4-methoxyphenylamino)-
A light absorption layer was obtained by spin coating a solution consisting of 1 g of 6,7-dicyanoanthraquinone and 10 g of dichloroethane. The reflectance and transmittance of the recording medium thus obtained at 800 nm were 33% and 12%, respectively.
It was hot. When information was recorded on this recording medium in the same manner as in Example 1, the recording threshold was 1.2 nJ/pit and the diameter
A pit of 1.2 μm was formed. Example 4 2 g of 2-[7-(3-ethyl-2-benzothiazolinylidene)-1,3,5-heptatrienyl]-3-ethylbenzothiazolium chloride was placed on a 1.5 mm thick polysulfone resin plate. A reflective layer of bronze pigment was obtained by spin coating a solution consisting of 10 g of dichloroethane. Furthermore, on top of this 8,17−
A light absorption layer was obtained by depositing bisanilinoindanthrene to a thickness of 70 nm. The reflectance and transmittance of the recording medium thus obtained were 27% and 13%. When information was recorded on this recording medium in the same manner as in Example 1, the recording threshold was 0.7 nJ/pit and the diameter
A pit of 1.2 μm was formed. Example 5 2,4-bis-(2,4,6-
50nm of trihydroxyphenyl-1,3-cyclobutadienedaleium-1,3-diolate
A reflective layer was obtained by vapor deposition to a thickness of . Further, 8,17-bis(4-chlorophenylamino)indanthrene was vapor-deposited thereon to a thickness of 100 nm to obtain a light absorption layer. The reflectance and transmittance of the recording medium thus obtained were 31% and 6%, respectively. When information was recorded on this recording medium in the same manner as in Example 1, the recording threshold was 0.7 nJ/pit diameter 1.3 μm.
m pits were formed. Examples 6 to 14 Recording media were obtained by forming a reflective layer and a light absorbing layer on an acrylic substrate using the materials shown in the table below. When information was recorded on these in the same manner as in Example 1, the recording threshold values shown in the table were obtained.

[Table] Example 15 8,17-bis (4-
(phenylamino) indanthrene with a thickness of 100 nm
A light absorption layer was obtained by vapor deposition. Furthermore, on top of this
was vapor-deposited to a thickness of 50 nm to form a light-reflecting layer. The reflectance and transmittance of the recording medium thus obtained at 800 nm were 38% and 3%, respectively. When a signal was recorded on this recording medium in the same manner as in Example 1, the recording threshold was 0.4 nJ/pit diameter.
A pit of 1.4 μm was formed. Example 16 A photopolymerizable methyl methacrylate monomer was applied to a glass substrate and cured by ultraviolet irradiation to obtain an undercoat layer. On this substrate, 6,15-bis(4-aminophenylthio)indanthrene was deposited to a thickness of 100 nm to obtain a light absorption layer. Furthermore, on top of this, Te is added to the thickness
It was vapor deposited to a thickness of 50 nm to form a light reflecting layer. The reflectance and transmittance of the recording medium thus obtained at 800 nm were 42% and 4%, respectively. When information was recorded on this recording medium in the same manner as in Example 1, the recording threshold was 0.4 nJ/pit and the diameter
A pit of 1.4 μm was formed. Example 17 SiO was deposited to a thickness on the recording medium obtained in Example 16.
A protective layer was formed by vapor deposition at a thickness of 500 nm. When the signal was recorded in the same manner as in Example 1,
A pit with a diameter of 1.2 μm was formed at a recording threshold of 0.7 nJ/pit. When optical recording media were prepared and information was recorded using the same method as described in the above examples for other low melting point metals, pigments with bronze luster, or anthraquinone derivatives used in the present invention, similar characteristics were obtained. Ta. The optical recording medium of the present invention constructed as described above has absorption in the wavelength range of a semiconductor laser, is highly stable, and has an excellent effect on long-term information storage.

[Brief explanation of drawings]

1 to 5 are conceptual diagrams showing the structure of the optical information recording medium of the present invention. 1...Substrate, 2...Reflection layer, 3...Absorption layer, 4
...undercoating layer, 5...protective layer, 6...spacer.

Claims (1)

[Scope of Claims] 1. An optical information recording medium comprising a reflective layer and an absorbing layer laminated in any order on a substrate, wherein the reflective layer is made of a low melting point metal or a pigment with bronze luster, and the absorbing layer is the following general formula ()
An optical information recording medium comprising an anthraquinone compound represented by the formula () or an indanthrene compound represented by the following general formula (). (In the formula, X ₁ , X ₂ , X ₃ and X ₄ are each hydrogen,
represents an alkyl group, a hydroxyl group, a nitro group, an amino group, a cyano group, and a halogen; Y represents hydrogen and a sulfonate group; Ar ₁ represents hydrogen, a phenyl group, a naphthyl group, and their sulfonates and salts; The phenyl group may be substituted by an alkyl group, an alkoxy group, an amino group, an alkylcarbonyl group, a methylthio group, a halogen and a phenylcarbonyl group, and Ar ₂ is hydrogen, a phenyl group, and sulfonated products and salts thereof, and the phenyl group may be substituted with an alkyl group, an alkoxy group, an amino group, an alkylcarbonyl group, a phenylcarbonyl group and a halogen) (In the formula, X ₁ , X ₂ , X ₃ and X ₄ have the same meanings as above, X ₅ represents hydrogen -NH-Ar ₁ and -S-Ar, Z represents hydrogen, -NH-Ar ₁ and -S-Ar ₁
and Ar ₁ has the same meaning as above).