JPS63299979A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To obtain a high-sensitivity optical information recording medium excellent in stability to reproducing light and thermal stability, by providing an organic thin film comprising a specified compound, on a substrate. CONSTITUTION:A compound of formula (I), wherein each of R<1> and R<2> is hydrogen or a lower alkyl, Ar is a substd. or unsubstd. aromatic heterocyclic ring, and X is an anion, is useful as a stable optical information recording medium, the stability being further enhanced when the compound is used in combination with other organic coloring matter recording material (particularly, a cyanine coloring matter or a merocyanine coloring matter). An organic thin film recording layer 2 comprising the compound of formula (I) as a main constituent is provided on a substrate 1. An undercoat layer 3 may be provided between the substrate 1 and the recording layer 2, or a protective layer 4 may be provided on the recording layer 2. The amount of the compound of formula (I) added, on a total solid component basis, is suitably 2-60 wt.% based on the recording layer, and is suitably 2-90 wt.% based on the undercoat layer 3 or the protective layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical information recording medium, and more particularly to an optical information recording medium suitable for writing, recording, and reproducing using a laser beam.

[Prior art]

2. Description of the Related Art Information recording and reproducing apparatuses that record and reproduce information by irradiating a rotating disk-shaped optical information recording medium with laser light are known and are in practical use. As an optical information recording medium used in this type of information recording device, one is known that is composed of a substrate, a metal reflective film, and a translucent colored layer containing a dye.

In such a recording medium, laser light incident on a semi-transparent colored layer containing a dye reaches a metal reflective film and is reflected so that the reflected light can be easily detected. It is provided to compensate for the amount of reflected light that is insufficient with only the colored layer. However, the presence of the metal reflective film complicates the structure of the information recording medium and causes an increase in cost.

Therefore, it has been proposed to use a monolayer organic dye film with a high reflectance and bronze luster to eliminate the above-mentioned drawbacks. In particular, when a cyanine dye with high light absorption is used as a recording film (recording layer), a light-absorbing and reflective film that exhibits metallic luster (reflectance of 20-30%) can be obtained with a film thickness of 300 to 600 nm. It becomes possible to record and reflect continuously. In addition, as a laser light source, the wavelength is 750 to 850.
The use of a nanometer semiconductor laser has the advantage that the device can be made smaller. However, since organic dyes are generally unstable to light and heat, the reality is that organic thin films with satisfactory properties have not been developed.

〔the purpose〕

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an optical information recording medium that has excellent stability against reproduction light and thermal stability, and is highly sensitive.

〔composition〕

The optical information recording medium of the present invention has the following general formula (I).

R1, Ra represents a hydrogen atom or a lower alkyl group, Ar represents a substituted or unsubstituted aromatic heterocycle, Xe represents an anion. ] It is characterized in that an organic thin film containing a compound represented by these is provided.

Incidentally, the present inventors have discovered that the compound represented by the general formula (T) is useful as a stable optical information recording material, and that this compound can also be used in other organic dye recording materials (especially cyanine dyes and merocyanine dyes). It has been confirmed that the stability of the optical information recording medium becomes even better when used in combination with The present invention has been made based on this.

The invention will be explained in more detail below with reference to the accompanying drawings.

FIG. 1 shows an organic thin film recording layer (hereinafter simply referred to as "recording layer") containing a compound represented by the general formula (I) as a main component on a substrate 1.
(sometimes abbreviated as ) 2) is a type of optical information recording medium. Fig. 2 shows an optical information recording medium in which a subbing layer 3 is provided between the substrate 1 and the recording layer 2, and Fig. 3 shows an optical information recording medium shown in Fig. 1, but in which a protective layer 4 is provided on the recording layer 2. Recording Medium FIG. 4 shows an optical information recording medium shown in FIG. 2 in which a protective layer 4 is provided on the recording layer 2.

As mentioned above, the recording layer 2 in the present invention is an organic thin film containing the compound represented by the general formula (I).

In the general formula (I), specific examples of R1 and R2 include hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, 1so-butyl group, and hexyl group.

Examples of the aromatic heterocycle of Ar include a furan ring, a thiophene ring,
There are pyridine rings, quinoline rings, indole rings, carbazole rings, dibenzothiophene rings, etc. Substituents on these nuclei include alkyl groups such as methyl, ethyl and propyl groups, alkoxy groups such as methoxy and ethoxy groups,
Examples include halogen atoms such as fluorine and chlorine, and hydroxyl groups.

Examples of the anion of Examples include sulfate ion, chloride ion, bromide ion, and iodine ion.

These compounds represented by general formula (I) can be prepared by dissolving the raw material represented by 8 in a solvent such as acetone, diethyl ether, or dimethyl sulfoxide, and then treating this with silver hexafluoroantimonate or silver perchlorate. It can be synthesized by

Typical specific examples of the compound represented by the general formula (I) are as follows.

As mentioned above, the recording layer 2 in the present invention may be formed solely of the compound represented by the general formula (I) that has the ability to absorb the wavelength of the laser beam used;
If the compound (ii) is used in combination with a cyanine dye and/or a merocyanine dye, an even better optical information recording medium can be obtained. Here, the mode of "combining" the cyanine dye and/or merocyanine dye with the compound of general formula (I) is when the cyanine dye and/or merocyanine dye is present in the recording layer 2 together with the compound of general formula (I). In addition, it also includes a case where a cyanine dye and/or a merocyanine dye is added to the undercoat layer 3, the protective layer 4, etc.

Any cyanine dye and merocyanine dye can be used, and representative examples include compounds represented by the following general formulas (n-1) and (II-2), respectively.

(However, R3 and R4 may be the same or different, and are respectively an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an aralkyl group, a carboxyalkyl group, a carboxyalkylate group bonded to an alkali metal cation, a sulfonate group) represents an alkyl group, a sulfoalkyl group, or a sulfonate alkyl group bonded to an alkali metal cation. zl and z2 represent a 5- or 6-membered heterocycle or a fused ring containing a 5- or 6-membered heterocycle (Represents an atomic group. Q represents an integer from 1 to 4. aXe represents an anion.) The substrate 1 must be transparent to the laser beam used when writing and recording from the substrate side, and the recording layer side must be transparent to the laser beam used. If it is done from scratch, it does not need to be transparent. Glass, polycarbonate, and polymethyl methacrylate are commonly used as the substrate, but any other material used for recording media may be used.

Regarding the undercoat layer 3 and the protective layer 4 provided as necessary on the organic dye thin film recording layer 2 in the present invention, the undercoat layer 3 has (i) improved adhesion, (ii) barrier against water or gas, etc. (iii) It is used for the purpose of improving the storage stability of the recording layer, and (m) improving the reflectance. (
For the purpose of (i), various polymeric materials such as ionomer resins, polyamide resins, vinyl resins, natural polymers, silicones, and liquid rubbers can be used; for the purpose of (5), In addition to the above polymer materials, inorganic compounds such as Sin, ? MgF, , Sin.

Metals or metalloids such as TiO2, ZnO, etc.
.

Cu, Sn, Ni, Cr, Oe, Sa, Cd, Ag, A
For the purpose (i) and (n) above, materials such as those exemplified for (i) and (n) can be used, and for the purpose (iv), metals such as AK, AR, etc. can be used.
You can also use something like Further, the protective layer 4 is provided for the purpose of protecting against scratches, dust, dirt, etc. and improving the chemical stability of the protective layer, and the same material as the undercoat layer 3 can be used as the material thereof.

Furthermore, in the present invention, other dyes, low molecular compounds, high molecular compounds, etc. may be combined with the compound of general formula (I) instead of or in combination with the cyanine dye and/or merocyanine dye. May be used. Typical examples of dyes (excluding cyanine dyes and merocyanine dyes) and compounds that can be mixed with the compound of general formula (I) are shown in general formulas (m-i) to (III-14). It is not limited to.

(m-1) Croconium dye (X represents a chromophore, M@ represents a cation,
Although Yo represents an anion, it is assumed that ye does not exist when an anion is contained in the chromophore. ) (III-2) Azulene dye oe □e R5, R@, R1, R@ and R9 represent a hydrogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted aryl group) (III-3) Triphage Thiazine compounds (however,
R'' and R11 may be the same or different,
And each is a hydrogen atom, a halogen, an alkyl group,
It represents a phenyl group and a phenyl group substituted by one or more of alkyl groups, alkoxy groups, carboxyl groups, carboxylic acid groups, halogens, hydroxyl groups, sulfonic acid groups and sulfonic acid groups. ) (III-4) Phenanthrene derivative (However, R1
2 is an alkyl group such as -CI, -C,)I, and BF4. (Represents Cl204,) total 1 (However, R13 is an alkyl group such as -CH, -C, +1., R1,3 X represents BF4.CuO2,) (Ill-5) Phthalocyanine compound (However, M Examples include hydrogen, vanadium oxide, copper, beryllium, magnesium, calcium, zinc, cadmium, barium, aluminum, tin, lead, vanadium, chromium, manganese, iron, cobalt, nickel, tin halide, aluminum halide, etc. Particularly preferred are hydrogen, lead, nickel, cobalt, copper, vanadium oxide, aluminum chloride and tin chloride. X represents hydrogen and halogen such as chlorine, bromine, iodine and fluorine.
n is an integer from 1 to 16. )(III-6) Tetradehydrocholine compound CH3CH.

(However, R" represents an alkyl group, a carbalkoxy group such as -COOC"H', R1" represents a hydrogen atom, an alkyl group, etc. 1M represents H2N1(II), C
o(II), Co(III), etc. X is Br,
Represents COO4 etc. ) (Ill-7) Dioxazine compound and its derivative a
) Ring-condensation reaction products of aromatic amines and fluoranyl, chloranil, bromanyl, iodoanil, etc.

(However, A2 is a residue of an unsubstituted or substituted aromatic amine, X represents -F, -CQ, -Br, -E, etc.) C, R5 (However, Represents Br or -.

R17 is -11, -No2, -jsu112, -0CH,
, -QC,H,, -F, -CQ, -Br, -■ or an aromatic group. l and n are integers of 1 to 4. ) (m −s )Anthraquinone derivatives can be represented by the following structural formulas (8-1) and (8-23).

Structural formula (8-13) (where HLa, R19, Rho and R21 each represent a hydrogen atom, an alkyl group, a hydroxyl group, a nitro group, an amino group, a cyano group, and a halogen. Y represents a hydrogen atom and a sulfonate group. Ar1 represents a hydrogen atom, a phenyl group, a naphthyl group, and their sulfonated products and salts, and the phenyl group is an alkyl group, an alkoxy group, an amino group, an alkylcarbonyl group,
Optionally substituted by methylthio groups, halogens and phenylcarbonyl groups. Ar" represents hydrogen, phenyl group, and sulfonated products and salts thereof, and said phenyl group may be substituted by alkyl group, alkoxy group, amino group, alkylcarbonyl group, phenylcarbonyl group and halogen.) Structural formula (8-2) (However, R", R", R" and R21 have the same meanings as above, R22 represents hydrogen or -NH-Ar". Z3 represents hydrogen, -NH-Ar1 or -5-Ar1, and Ar' has the same meaning as above.) In particular, compounds with an indanthrene skeleton as in structural formula (8-2) have a maximum absorption wavelength around 800 nm, It is ideal as a material for

Examples of the anthraquinone derivatives represented by the above structural formulas (8-1) and (8-2) are as follows.

1-amino-4-(4-sulfonic acid phenylamino)
-6,7-sinitroanthraquinone sodium salt, 1-
Sodium anilino-2-sulfonate-4-(4-methylphenylamino)anthraquinone, 8,17-bis-
(4-methoxyphenylamino)-indanthrene, 1
．． 4-bis(sodium 3-sulfonate-4-methoxyphenylamino)-6,7-dicyazanthraquinone, 1,4-bis(sodium 3-sulfonate-4-chlorophenylamino)-5,8-dichloroanthraquinone, Sodium 1-(2-methylphenylamino)-2-sulfonate-4-(4-aminophenylamino)-6,
7-sinitroanthraquinone, 1,4-bis(sodium 3-sulfonate-4-anilino-1-anthraquinolyl amino)benzene, 1,4-bis(4-(4-sodium sulfonate-phenylamino)- Examples include 1-anthraquinolyl amino)benzene.

(III-9) Xanthine compound (B23 is -OH1;0l-NOR2' (8
2′′ = C-work to C-work.

7 /L/ Ki/L/ group), R24 = N” (R”),
・X- (X-=acid anion, 82'=01-C1a alkyl group), R2H is -11, C1-C2I, alkyl group, -3o, Na, -3O, Hl-3o, N("'
)2 (R"1'=c~C1゜alkyl group), -
Represents COOH5-COONa or -COOK. )(
m-10) Triphenylmethane compound (however,
R”It-Hl-H(R”), (R3o=C,=C1゜alkyl group), 01-C1I, alkyl group or -〇)1
．． R" is -H1"(R")z (P'=c, ~c,.

7 /L/ Ki/L' group), CL ~ Czo furkyl group or -011, R'' is -I), cyo~c2゜alkyl halogen, -3o, H or -N (R3'') 2 (R
"=C1-C1°alkyl group). Xe represents an anion.) (III-11) Bylylium-based compound Z information (wherein, X□ and

Z': [Need to complete pyrylium, thiopyrylium, selenapyrylium, benzopyrylium, benzothiopyrylium, benzoselenapyrylium, def-1-virylium, naphthothiopyrylium or naphthoselenapyrylium, which may be converted into Indicates a hydrocarbon group consisting of a group of atoms.

z': [Represents a hydrocarbon group consisting of an atomic group necessary to complete pyran, thiopyran, selenapyran, benzopyran, benzothiopyran, benzoselenapyran, naphthopyran, naphthothiopyran or naphthoselenapyran, which may be substituted.

R32, R33, R34 and R35: hydrogen atom, substituted or unsubstituted alkyl group, or substituted or unsubstituted aryl group 6R3', R" and R": hydrogen atom, halogen atom, substituted or unsubstituted alkyl group ,
It represents a substituted or unsubstituted furyl group or a substituted or unsubstituted aralkyl group.

A. : Indicates an anion.

Indicates m and Q=1 or 2.

n: Indicates Q, 1 or 2. ) (III-12) Squarylium compound convex e υ8 (However, X represents a chromophore. Representative examples thereof include the following.

n.

(a) R"=CH,, R4Q=R41=H, Z":5
(b) R"=R": CH,, R"=)I, Z'=S
e(b) R”=C2H,, R”=CH,, R”=H
,,Z"=Se(a) R"=C1l.

(b) R”=C2H.

e (a) R”=CH.

(b) R"=C2H5 (III-13) Low molecular compound plasticizer, surfactant, antistatic agent, lubricant, layer retardant, stabilizer, dispersant, antioxidant, light resistance improver, etc.

(m-14) High molecular compounds Various high molecular substances such as ionomer resins, polyamide resins, vinyl resins, natural polymers, silicones, liquid rubbers, and silane coupling agents.

The recording N2 can be formed by conventional means such as vaporization, sputtering, CVD or solution coating.

When a coating method is used, it is dissolved in an organic solvent such as dichloroethane and applied by a conventional coating method such as spraying, roller coating, tipping and spinning. The appropriate thickness of the recording layer is 100-5μ.

Further, as shown in FIGS. 2 to 4, an undercoat layer 3 and/or a protective layer 4 are further provided, and the compound of the general formula (I) is added to at least one of the layers, thereby achieving the present invention. Able to achieve purpose. In this case, the recording layer may or may not contain the above compound. The amount of the compound of general formula (I) added is 2 to 60% by weight for the recording layer, preferably 5 to 40% by weight, based on the total solid content, and 2 to 40% by weight for the undercoat layer 3 or protective layer 4. -90% by weight, preferably 10-50% by weight, as appropriate. Further, the thickness of the undercoat layer 3 is 0.1 to 30 μm, preferably 0.2 to 1 μm.
A range of 0 μm is suitable, and the thickness of the protective layer is 0 μm.
．． A suitable thickness is 1 μm or more, preferably 50 μm or more.

Typical examples of the optical information recording medium of the present invention are shown in FIGS. 1 to 4. In addition, two recording media having the same configuration as shown in FIGS. The organic thin film recording layer 2 may be placed on the inside using a so-called air sandwich structure, or a so-called adhesive sandwich structure (adhesive structure) in which the organic thin film recording layer 2 is bonded via the protective layer 4 may be used. It's okay.

Note that if a semiconductor laser with a wavelength of 750 to 850 nm is used as a laser light source, the device can be miniaturized.

Next, examples and comparative examples will be shown.

Example 1 Polymethyl methacrylate (about 1.2+n+++ thickness)
An acetone solution of the above-mentioned exemplified compound (G) was spin-coated onto the substrate (hereinafter abbreviated as rPMMAJ) to a thickness of about 1.2 μm.
A recording layer was formed to produce an optical information recording medium.

Example 2 On the recording layer formed in Example 1, a silver vapor deposition film having a thickness of approximately 150 mm was further provided to produce an optical information recording medium.

Example 3 The above-mentioned exemplified compound (
A 1,2-dichloroethane solution containing E) and a compound of the following formula (A) mixed at a weight ratio of 1:1 was spin-coated to form a recording layer with a thickness of approximately 700 mm.Optical Information Recording Example 4 Thickness The above-mentioned exemplified compound (B
) and a compound of the following formula (b) at a weight ratio of 6:4, a methyl ethyl ketone solution was spin-coated to a thickness of about 600 mm.
Formed a layer of people. Furthermore, a recording layer is formed by vacuum evaporating a compound of the following formula (c) to a thickness of about 150 m to produce an optical information recording medium.Example 5 On a PMMA substrate with a thickness of about 1.2 m Compound (C) used in Example 4 was vapor-deposited to a thickness of about 100 mm, and a methanol solution of the above-mentioned exemplified compound (J) was further spin-coated thereon to form a recording layer with a total thickness of about 600 mm. An optical information recording medium was produced.

Example 6 An optical information recording medium was produced in the same manner as in Example 2 except that the recording layer was formed using the above-mentioned exemplified compound (H).

The six types of optical information recording media produced in the above example had a wavelength of 83
Information is written and reproduced from the substrate side using a 3 nm semiconductor laser beam at a recording frequency of 0.5 M° and a linear velocity of L5 m/see, and its spectrum analysis (scanning filter, bandwidth 30 KHz) is performed to determine the initial reflectance and C. was measured. Next, the same recording medium was irradiated with 54,000 lux tungsten light for 50 hours, and then the reflectance and C were measured. The results are summarized in Table-1.

Example 7 The dye of the following formula (d) and the above-mentioned exemplary compound (A) were mixed in a weight ratio of 100:1.
5 was dissolved in 1,2-chloroethane, and this was spin-coated onto a PMMA substrate to form a recording layer with a thickness of approximately 500 nm, thereby producing an optical information recording medium.

Example 8 The procedure was the same as in Example 7, except that the dye of the formula below and the exemplified compound (G) shown above were used instead of the dye and compound (A) described in Example 7, and the mixing ratio was 100:30. An optical information recording medium was manufactured using the following steps.

Example 9 An optical information recording medium was produced in the same manner as in Example 7 except that the above-mentioned exemplified compound (C) was used instead of the compound (A) described in Example 7.

Example 10 An optical information recording medium was produced in the same manner as in Example 7, except that the dye of the following formula (% formula %) and the above-mentioned exemplified compound (D) were used instead of the dye and compound (A) described in Example 7. was created.

Example 11 The above-mentioned exemplified compound (D) and polycarbonate were dissolved in 1,2-dichloroethane at a weight ratio of 7:3,
An undercoat layer having a thickness of about 0.2 μm was formed by coating on an MA substrate, and a recording layer containing only the cyanine dye recorded in Example 10 was provided thereon to produce an optical information recording medium.

Example 12 On the recording layer formed in Example 7, the above-mentioned exemplified compound (A
) and polyamide resin dissolved in methanol at a weight ratio of 7:3 was coated to provide a protective layer with a thickness of about 1 μm, thereby producing an optical information recording medium.

Comparative Example 1 An optical information recording medium was produced in the same manner as in Example 7 except that a recording layer consisting only of the dye (d) used in Example 7 was formed.

Comparative Example 2 An optical information recording medium was produced in the same manner as in Example 8 except that a recording layer consisting only of the dye (E) used in Example 8 was formed.

Comparative Example 3 An optical information recording medium was produced in the same manner as in Example 10, except that a recording layer consisting only of the dye used in Example 10 was formed.

Recording and reproduction of semiconductor laser light with a wavelength of 790 nm was performed on the 15 types of optical information recording media produced in this way from the substrate side at a recording frequency of 0.6875 M) Iz and a pit length of 0.9 μm, and the spectrum analysis (scanning filter, band The initial reflectance and C were measured. Next, the same recording medium was exposed to tungsten light of 54,000 lux for 20 hours, and then the reflectance and C were measured. The results are summarized in Table-1.

(The following is a blank space) Table 1 [Effects] The optical information recording medium of the present invention constructed as described above provides excellent optical stability and durability against repeated printing.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views showing the structure of the optical information recording medium of the present invention.

Claims (1)

[Claims] 1. The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) [However, in the formula, R^1, R^2; hydrogen atom or lower alkyl group, Ar
; Represents a substituted or unsubstituted aromatic heterocycle; X; represents an anion. ] An optical information recording medium characterized by being provided with an organic thin film recording layer containing a compound represented by: