JPS6367187A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To prevent degradation of reproduction, by incorporating a specific cationic compound and a specific anionic compound into an organic coloring matter thin film mainly composed of polymethyn coloring matter provided on a substrate. CONSTITUTION:A recording layer containing cation shown by any one of formulae I-III, anion shown by any one of formulae IV-VI and polymethyn coloring matter is provided on a substrate. Furthermore, an underlying layer 3 and/or a protection layer 4 may be provided. (In the formulae, Z represents atom group, R1, R2 represent alkyl or aryl group, (m) is 0, 1 or 2, A represents formula VII or VIII, R3, R4, R5 and R6 represent hydrogen or alkyl group, X represents dibenzyl amino group or dialkyl amino group, Y is identical with X or hydrogen atom, R7 and R8 represent hydrogen, cyano group, alkyl group or aryl group, M represents nickel, palladium or platinum, R9, R10, R11 and R12 represent hydrogen, halogen, cyano group or hydroxyl group.)

Description

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

[Prior art]

2. Description of the Related Art Conventionally, an information recording and reproducing apparatus is known that records and reproduces information by irradiating a laser beam onto a disk-shaped information recording medium that rotates once. and.

As an information recording medium used in this type of information recording device, one in which a recording layer made of a low melting point metal or a low melting point metal and a dielectric material is provided on a substrate has been proposed. However, these have disadvantages such as poor storage stability, low resolution, low recording density, and high cost.

Therefore, as a result of various studies, the present inventors have found that when a thin organic dye film containing a polymethine dye as a main component is provided on a substrate, a recording medium with improved writing sensitivity and reflectance and a high read S1M ratio can be obtained. The headline already suggests it. However, at present, such recording media still lack sufficient stability against light and heat, and storage stability against reproduction light after recording.

〔the purpose〕

The present invention has been made in view of the above-mentioned current situation, and its main purpose is to improve the readout resistance of an optical information recording medium (preventing playback deterioration).

〔composition〕

In order to achieve the above object, the present inventor conducted extensive research and found that a cation represented by any one of the following general formulas (1) to 3) and any one of the following general formulas (4) to 6) The present inventors have discovered that a compound consisting of an anion represented by one of the following is effective in stabilizing an organic thin film recording layer containing a polymethine dye as a main component.

General formula (1) [In the formula, Z represents an atomic group necessary to complete a substituted or unsubstituted carbocyclic ketone, an aromatic ring may be fused to this cinnabar ring, and R1 and R2 may be the same or different and each represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, 1m represents 0.1 or 2, and A is ÷(
n represents 1 or 2) or (in the case of m=2), and the phenyl group may be substituted with an alkyl group, an alkoxy group, a halogen or a hydroxyl group] General formula (2) (in the formula h R3* R4R5 and R6 may be the same or different and each represents hydrogen or a substituted or unsubstituted alkyl group and A and m have the same meaning as in general formula (1)) General formula (3) (In the formula, X is alkyl or alkoxy depending on the case.

A phenyl group, a cyclohexylamino group, which may be substituted with an alkylthio, halogen or hydroxyl group, a phenyl moiety is optionally alkyl, alkoxy, alkylthio, a dibenzylamino group or an alkyl moiety which may be substituted with an alkylthio, halogen or hydroxyl group. 1
represents a dialkylamino group having ~4 carbon atoms and Y is also the same as or represents a hydrogen atom) General formula (4) (wherein R7 and R8 may be the same or different and Each is hydrogen and cyano group.

represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and M represents nickel, .ξradium or platinum) General formula (5) (wherein R9, ``10s R11 and R12 are the same or different; and each is hydrogen, )・
represents rogene, a cyano group or a hydroxyl group, and the aromatic ring may be fused with another aromatic ring. R7* R8 and M have the same meaning as in general formula (4)) General formula (6 ) (wherein R9 to R12 and R7 to R8 each have the same meaning as in the general formula +5)vc).

The optical information recording medium of the present invention basically consists of a substrate and a recording layer, but if necessary, an intermediate layer such as a subbing layer may be provided between the substrate and the recording layer. A protective layer may be provided on the recording layer. Furthermore, a pair of recording media having such a configuration can be formed into an air sandwich structure or a close-fitting lO-sandwich structure (laminated structure).

The compound consisting of the cation of the above general formula and the anion of the above general formula used in the present invention is novel in itself, and its general manufacturing methods are broadly divided into methods using solubility differences and methods using ion exchange resins. be able to.

t Method using solubility difference a) Salt crystallization A solution of a compound consisting of a cation in the above general formula and its counter ion is mixed with a solution of a compound consisting of an anion in the above general formula and its counter ion. to crystallize the desired salt of cation and anion. On this occasion,
The mixed solution may be concentrated and cooled if necessary. It is preferable to use highly soluble counter ions. As the solvent, a single solvent, a poor solvent for the salt, and a good solvent for the counter ion can be used. Further, for the purpose of promoting crystallization, other salts may be added for salting out.

b) Crystallization of counter ions Contrary to the case of a) above, counter ions can be crystallized to obtain a desired salt of a cation and an anion as a precipitate. In this case, a single solvent, a good solvent for the salt, and a poor solvent for the counter ion can be used as the solvent. Further, for the purpose of promoting crystallization of counter ions, other salts may be added for salting out.

2. Method using an ion exchange resin a) Production using a cation exchange resin A salt can be obtained by adsorbing cations using a cation exchange resin and then ion-exchanging the anion solution.

b) Formation using an anion exchange resin A salt can be obtained by adsorbing anions using an anion exchange resin and then ion-exchanging the cation solution.

Here, specific examples of cations used in the production of the above-mentioned compounds of the present invention are shown below, but the cations are not limited thereto.

Compound Example 3 of General Formula (1) Compound Example 2 of General Formula (2) - I C ((C2I(s)2N&)JIC>-N
-(-/JJ-N (02Hs)2)2)2-2
(:((cHs)2N&”6N・(・・0N(OH3
)2)2)2-3 (((ca3)2n&N+N■”
(”$ N(OH3)2)2]2-4 C((C2H
s)2NCerN■ONe・(=+N(02Hs)2)2
]2-5 CC(C3H7)2Nh〈〉NΦ-E-I
N(03H7)2)2:]2-6 C((n-03H
7) 2N>@ ”■・・(:・e N(n-C3H a)
2) 2) 2, -7 [: ((i-C!3H7)2 to)N''-%C>-N(i-OgH7)2)2-12-
-8 (((n-c4Hp)2Nζhpa)N■...(
・eN(n-c+H9)2)2)2-9 C(CCH
3) 2NOsaMN's -C:・GN(CHs)2)2)2
-10 C ((02Hs) Pa) Dick tips・(・eN(
C2Hs)2)2)2-11 C((03H;+)2
N6N9N''(-)N(C!3H7)2)2') Compound example 16-SCHg of general formula (3) In addition, the following compounds can be mentioned as examples of anions used in combination with the above cations. It is not limited to these only.

Compound example of general formula (4) Compound example of general formula (5) I Compound example 26 of general formula (6) - A cation of any one of general formulas (1) to 3) in the present invention and general formula (4) When a compound consisting of an anion of either of or 6) is included in a recording layer consisting of a polymethine dye, it shows excellent effects in improving the light resistance and heat resistance of an optical information recording medium and preventing reproduction deterioration. It can be added not only to the layer but also to other layers such as the subbing layer or the protective layer or both layers to enhance its effect.

The above compound is contained in the undercoat layer or the protective layer in an amount of 2 to 100% by weight, preferably 20 to 100% by weight, based on the total solid content. In addition, when the above compound is contained in two or more layers, it can be added to each layer in a proportion within the above range for each layer.

Furthermore, the materials constituting the optical information recording medium of the present invention and the necessary characteristics of each layer will be specifically explained.

1) Substrate The required characteristics of the substrate are that it must be transparent to the laser beam used only when recording and reproducing are performed from the substrate side; it does not need to be transparent when recording and reproducing is performed from the recording side. Examples of substrate materials include polyester, acrylic resin, polyamide,
Polyolefin resin, phenolic resin, epoxy resin.

Plastics such as polyimide, glass, ceramics, metals, etc. can be used.

Note that a preformat such as an address signal or a pregroove for a guide groove may be formed on the surface of the substrate.

The substrate can be molded by a photopolymer method (2P method) or an injection method.

2) Recording layer The recording layer causes some kind of optical change when irradiated with laser light and can record information based on the change, and its main components are polymethine dye and the above general formula (1) or 3).
Any one of the cations and the above general formula (4) to 6)
It consists of a compound consisting of any one of the following anions. Typical examples of polymethine dyes include cyanine dyes, merocyanine dyes, croconium dyes, and pyrylium color 2.

The compound according to the present invention may be used in combination with two or more dyes to improve recording properties and stability, and may also be used in combination with other dyes such as phthalocyanine, tetrahydrocholine, dioxazine, triphetchazine, phenanthrene, anthraquinone (indanthrene). Dyes such as xanthine, iJ, phenylmethane, triphenylamine, and azulene may also contain metals such as In, Sn, Te, Bi, Be, Ag, Ou, etc. or metal compounds such as T.
It may be mixed and dispersed with eO2°SnO or the like, or it may be laminated.

In addition, the recording layer also contains polymeric materials and storage stabilizers (for example, metal complexes, phenolic compounds, etc.).

Dispersant% Flame retardant, lubricant, antistatic agent, plasticizer, etc. may be contained.

When the above compound in the present invention is contained in the recording layer, the weight ratio of polymethine dye: the above compound is 30; 70 to 99.
:1 preferably 60:40-95;5.

The recording layer can be formed by conventional means such as vapor deposition, sputtering, OVD or solution coating, with solution coating being preferred. In the case of solution coating, organic solvents such as alcohols are used.

Polymethine dyes are dissolved in ketones, amides, ethers, sulfoxides, esters, aliphatic halogenated hydrocarbons, and aromatics by conventional coating methods such as spray, spinner, dipso, blade, and roller. It is done. The thickness of the recording layer is iooλ~10μ
m is preferably 200~2 μm.

3) Undercoat layer The undercoat layer (a) improves adhesion, (b) serves as a barrier against water or gas, (C) improves storage stability of the recording layer, (d) improves reflectance, and (61 solvent) Protection of the board from
(f) Used for purposes such as forming pregrooves. For the purpose of (a), polymeric materials such as ionomer resins, polyamide resins, vinyl resins, natural polymers,
Various polymeric substances such as silicone and liquid rubber, silane coupling agents, etc. can be used, and for the purposes (b) and (0), inorganic compounds such as 5102, MgF2, Sin , TiO2
, Zn0STiN, SiN, etc. Metals or metalloids such as Zn, Ou, S, Ni, Or, Ge, Be,
Au, Ag, AJ, etc. can be used.

For the purpose (a), metals such as Agh, pigments with metallic luster such as methine dyes, quinanthene dyes, etc. can be used. For the purposes (θ) and (f) above, ultraviolet curing resins, thermosetting resins, thermoplastic resins, etc. can be used. The thickness of the undercoat layer is 0.
．． A suitable thickness is 1 to 3 µm, preferably 0.2 to 10 µm.

4) Protective layer The protective layer is provided for the purpose of protecting the recording layer from scratches, dust, dirt, etc., and improving the storage stability and reflectance of the recording layer, and is made of the same material as the undercoat layer. can do. The thickness of the protective layer is suitably 0.05 μm or more and preferably 5 μm or less.

Note that the undercoat layer and the protective layer may contain stabilizers, dispersants, flame retardants, lubricants, antistatic agents, surfactants, plasticizers, and the like.

Next, the structure of the optical information recording medium according to the present invention will be explained with reference to the drawings.

As shown in FIG. 1, the optical information recording medium of the present invention is basically one in which a recording layer 2 containing a compound according to the present invention and a polymethine dye is provided on a substrate 1. A two-layer structure in which a reflective layer and a light-absorbing layer are combined in any order can also be used.

Furthermore, as shown in FIGS. 2 to 4, the structure shown in FIG. 1 may be further provided with an undercoat layer 3 and/or a protective layer 4.

Furthermore, as another configuration of the optical information recording medium according to the present invention, two recording media having the same configuration as shown in FIGS. It may be arranged in a so-called air sandwich structure in which it is placed inside and sealed, or it may be in a so-called close-contact sandwich structure (laminated structure) in which it is adhered with a protective layer 4 interposed therebetween.

Note that if a semiconductor laser with a wavelength of 750 to 850 nm is used as a laser light source for recording and reproducing information, the device can be made smaller.

〔effect〕

According to the optical information recording medium of the present invention configured as described above, it is possible to obtain a recording medium that has high stability against heat and light, excellent storage stability, and little reproduction deterioration. Furthermore, even if a long wavelength laser (semiconductor laser) is used, recording can be performed with high sensitivity, pits can be formed in a good shape, and high O/N can be obtained.

〔Example〕

The present invention will be further explained below with reference to Examples along with Comparative Examples, but the present invention is not limited to these Examples.

Example 1 A stamper sheet having guide grooves with a pitch of 16 μm, a groove width Q of 3 μm, and a depth of 950 mm was made using an ultraviolet curable resin on a polymethyl methacrylate (m) substrate with a thickness of i, 2 tms and a diameter of 200 m. The groove was transferred.

On top of this, a solution prepared by dissolving the dye of the following formula and the compound of the present invention (a combination of the above exemplary compound 1-1 and the above exemplary compound 4-5) in 1,2-dichloroethane at a weight ratio of 80/20 was applied using a spinner. A recording layer with a thickness of 650 mm was formed to produce a recording medium.

Example 2 The compound of the present invention in Example 1 was converted to the above exemplified compound 2-
A 37-piece recording medium tube was prepared in the same manner as in Example 1, except that Compound No. 8 and Exemplified Compound 4-3 were used in combination.

Example 5 The uninvented compound in Example 1vc was replaced with the above exemplified compound 6.
A recording medium was produced in the same manner as in Example 1 except that Compound -8 was used in combination with Exemplified Compound 4-2.

Example 4 Example 1 except that a combination of the dye of the following formula, the above exemplary compound 1-2, and the above exemplary compound 5-5 was used in the dye and compound substituent 9 in Example 1 at a weight ratio of 90/10. A recording medium was produced in the same manner.

CH343 Example 5 The compound of the present invention in Example 4 was converted to the above exemplified compound 2-
A recording medium was produced in the same manner as in Example 4, except that Example 6 was used in combination with Exemplified Compound 5-6.

Example 6 The compound of the present invention in Example 4 was converted to the above Exemplified Compound 3-
A recording medium was produced in the same manner as in Example 4, except that Compound No. 1 and Exemplified Compound 5-3 were used in combination.

Example 7 On the recording layer formed in Example 2, a silver vapor deposited film with a thickness of 100× was further provided.

Example 8 A tellurium vapor-deposited film having a thickness of 100 mm was provided on a four-face substrate, and the recording layer in Example 2 was provided thereon.

Example 9 On the recording layer formed in Example 2, a dye of the following formula was further vapor-deposited to a thickness of 150×.

Example 10 Example I Recording was carried out in the same manner as in Example 1, except that the dye of the following formula was used instead of the dye and compound in FC, and the combination of the above Exemplified Compound 2-8 and the above Exemplified Compound 5-5 was used. A medium was prepared.

Example 11 A recording medium was produced in the same manner as in Example 10 except that a dye of the following formula was used instead of the dye in Example 10.

Example 12 The compound of the present invention in Example 1 was converted to the above Exemplified Compound 1-
A recording medium was produced in the same manner as in Example 1, except that Example 1 was used in combination with Exemplified Compound 6-1.

Example 16 The compound of the present invention in Example 1 was converted to the above exemplified compound 2-
A recording medium was produced in the same manner as in Example 1, except that Compound 6 was used in combination with Exemplified Compound 6-1.

Example 14 The compound of the present invention in Example 1 was converted to the above exemplified compound 3-
A recording medium was produced in the same manner as in Example 1 except that Compound No. 8 was used in combination with Exemplified Compound 6-5.

Comparative Example 1 A recording medium 4L- was produced in the same manner as in Example 1 except that the recording layer was provided using only the dye.

Comparative Example 2 A recording medium was produced in the same manner as in Example 4 except that the recording layer was provided using only the dye.

Comparative Example 6 A recording medium was produced in the same manner as in Example 10 except that the recording layer was provided using only the dye.

Each recording medium produced in the above Examples and Comparative Examples had a wavelength of 7.
Information was written and reproduced from the substrate side using a 90 nm semiconductor laser beam at a recording frequency of 0.5 WMv and a speed of 1.5 m/sea, and the reproduced waveform was spectral analyzed (scanning filter, bandwidth 30 KHz). Te0/N'! f-traced. Furthermore, the reflectance and 0.7
N was measured. Note that although the 1 reflectance was measured from the substrate side, the value indicates the value on the flat surface, not on the groove portion. The results are summarized in the table below.

Example 1 27.7 55 17.2 462 27.2
52 20.9 483 27.0 54
21.3 494 28.3 54 18.9
485 2&6 54 22.5 496 2
8.0 55 212 497 30.2 48
27.2 448 42.2 49 59.7
459 27.0 52 2Q, 0 471
0 20.3 51 16.6 4611 21
．． 1 51 17.8 4712 27.3
53 18.3 4615 2&2 54 22
．． 0 4914 27.7 53 20.8
48 comparative examples

[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. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Recording layer, 3... Undercoat layer, 4
...Maintenance layer.

Claims (1)

[Scope of Claims] An optical information recording medium comprising an organic thin film recording layer containing a polymethine dye as a main component on a substrate directly or via an intermediate layer, and further providing a protective layer thereon as required. The recording layer has any one of the following general formulas (1) to (3).
A cation represented by the following general formulas (4) to (6)
) An optical information recording medium further comprising a compound consisting of an anion represented by any one of the following. General formula (1) [▲There are mathematical formulas, chemical formulas, tables, etc.▼] (1) [In the formula, Z represents the atomic group necessary to complete the substituted or unsubstituted carbocyclic ketone, and may be a fused aromatic ring, R_1 and R_2 may be the same or different and each represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, m is 0, 1 or 2 and A is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (n indicates 1 or 2) or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (m =
2), and the phenyl group may be substituted with an alkyl group, alkoxy group, halogen or hydroxyl group] General formula (2) (▲There are mathematical formulas, chemical formulas, tables, etc.▼N-A-N▲ There are mathematical formulas, chemical formulas, tables, etc. ▼) (2) (wherein R_3, R_4, R_5 and R_6 may be the same or different and each represents hydrogen or a substituted or unsubstituted alkyl group, and A and m has the same meaning as in general formula (1)) General formula (3) ▲ Numerical formula, chemical formula, table, etc. ▼ (3) (In the formula, a phenyl group, a cyclohexylamino group, which may be substituted, a dibenzylamino group or an alkyl moiety in which the phenyl moiety may optionally be substituted with an alkyl, alkoxy, alkylthio, halogen or hydroxyl group, or 1 to 4 alkyl moieties; represents a dialkylamino group having carbon atoms of Y
is the same as X or represents a hydrogen atom) General formula (4) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (4) (In the formula, R_7 and R_8 may be the same or different, and each represents hydrogen, a cyano group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and M represents nickel, palladium or platinum) General formula (5) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (5) (In the formula, R_9, R_1_0, R_1_1 and R_1
_2 may be the same or different and each represents hydrogen, halogen, cyano group or hydroxyl group, the aromatic ring may be fused with another aromatic ring and R_
7, R_8 and M have the same meaning as in general formula (4)) General formula (6) ▲There are numerical formulas, chemical formulas, tables, etc.▼ (6) (In the formula, R_9 to R_1_2 and R_7 to R
Each of _8 has the same meaning as in general formula (5)).