JPS62103190A - Optical-information recording medium - Google Patents

Abstract

PURPOSE:To provide an optical information-recording medium having high reflectance and recording sensitivity, capable of stably writing and reproducing optical signals, having high stability to light, sunlight and moisture at reproduction time and not generating environmental pollutions, by providing a recording layer comprising a specified organic coloring matter. CONSTITUTION:An organic coloring matter of formula I is incorporated in a recording layer. In formula I, R1 is a 1-6C alkyl, aralkyl or phenyl, A is formula II or III [wherein R2 is hydrogen, an alkyl, a halogen or formula IV (wherein ph is phenyl)], X is an anion selected from perchlorate ion, fluoroborate ion, iodide ion, chloride ion, bromide ion and p-toluenesulfonate ion, Y is -R3OH, -R3COOH, -R3COR4, -CH(R3)ph or formula V or VI (wherein R3 is a 1-20C alkyl and R4 is a 1-18C alkyl), and X is a benzene ring to be added to the benzene ring constituting indole. By this, a recording layer having excellent preservation stability and reproduction deterioration characteristics can be provided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to writing using a radar, particularly a semiconductor radar,
The present invention relates to an optical memory medium on which playback and recording are performed.

[Prior art and problems]

In general, optical disks can store high-density information using optically detectable small (for example, about 1#) pits formed in a thin film recording layer provided on a substrate in the form of spiral or circular tracks. To write information on such a disk, □ scans the surface of the Rade sensitive layer with a focused Radical beam, forms pits only on the surface irradiated with the Radical beam, and shapes these pits into a spiral or circular shape. Formed in the form of This sensitive layer can absorb laser energy to form optically detectable pits. For example, in the heat mode recording method, the recording layer absorbs Radhe energy, and the irradiated area is locally heated, causing physical changes such as melting, evaporation, or aggregation, resulting in an optical difference (X reflection) between the recording layer and the non-irradiated area. absorption rate, absorption rate, etc.).

As such optical recording media, inorganic materials such as metal thin films such as aluminum vapor-deposited films, bismuth thin films, tellurium-based thin films, and chalcoglide-based amorphous glass films have been proposed.

These have the advantage that thin films can be obtained by vapor deposition, Sunoya, and Ta methods, and semiconductor radars can be used because they absorb light even in the near-infrared region, but on the other hand, they have high reflectance, high thermal conductivity, and high specific heat. There is a drawback. In particular, if the reflectance is high, the energy of the Raded light cannot be used effectively, so the optical energy required for recording increases, and a high-output Raded light source is required. As a result, the disadvantage is that the recording device becomes large and expensive. Furthermore, thin films of tellurium, bismuth, selenium, etc. have the disadvantage of being toxic.

For these reasons, research proposals have recently been made on optical memory media that use dye thin films as recording layers because they allow selection of absorption properties, have high absorption rates, low heat conduction, good productivity, and low toxicity. It is coming. Typical dyes include cyanine dyes (Japanese Patent Laid-Open No. 58-112790), anthraquinone dyes (Japanese Patent Laid-Open No. 58-224448), naphthoquinone dyes (Japanese Patent Laid-Open No. 58-224793), and phthalocyanine dyes (4?Sho 6O). -48396), etc., and an optical recording medium in which a compound consisting of these alone or in combination with a self-curing resin is formed on a substrate by a spinner coating method, a ping method, a plasma method, a vacuum evaporation method, etc. It is. This dye thin film system has the above-mentioned advantages; in particular, cyanine dyes are structurally capable of having an absorption wavelength in the near infrared, and also have advantages such as low solubility in solvents and low melting point. Much consideration has been made. On the other hand, it is rough due to light deterioration, instability against heat, humidity deterioration, etc.
It has been said that there are problems with long-term storage stability, reproduction stability (stability against readout light), etc., and various improvement proposals have been proposed to address these problems. Specifically, a peritoneal membrane is provided on the recording layer (Japanese Patent Application Laid-Open No. 55-22961).
.

57-66541), mixing a substance that prevents discoloration by fluorine (JP-A-59-5570.5), and forming a metal complex that absorbs light in the long wavelength range (JP-A-59-21).
5892) etc. have been proposed. However, these proposals do not sufficiently solve the problem, and furthermore, problems arise in that the additives cause a decrease in film formability, reflectance, and absorbance.

For these reasons, coating type recording media using cyanine dyes represented by the following general formula are attracting attention in terms of recording density and reflectivity.

[However, in the formula, A is o, S, Se, C, and X are halogen anions, and BF4- and ClO2-1R are alkyl.] However, the cyanine dye represented by the above general formula also has poor film-forming properties. It has an essential problem of lacking heat and light stability. Regarding film formability, the number of methine chains (n)
It is known that the solubility in solvents decreases as the number increases, and that the solubility changes depending on the types of heterocycles at both ends and the types of substituents. Regarding heat and light stability, as the number of methine chains increases, it becomes unstable to heat and light, and oxidative deterioration becomes more likely to occur.The stability to heat and light varies depending on the type of heterocycle. known to be different.

The present invention was developed in view of the above circumstances, and has high reflectance and high recording sensitivity, enables stable writing and reproduction of optical signals, and is capable of protecting against sunlight and sunlight during reproduction.
The present invention aims to provide a pollution-free optical information recording medium that is highly stable against humidity.

[Means and effects for solving the problems] The present invention has the following features:
General formula (However, in the formula, an alkyl group, an aralkyl group, or a phenyl group having a number of 1 to 6, A is 2R2 [R2; hydrogen atom, alkyl group, 710 Dan atoms, fluoroborate, iodide, chloride, An anion selected from bromide and p-toluenesulfonate, Y is -R30H.

-R, C0OH, -R3COR4, -CH(R3)ph
.

(R3: an alkyl group having 1 to 2 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, R4: an alkyl group having 1 to 18 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms, or a phenyl group, ph : phenyl group), ZJr! It is characterized by having a recording layer containing an organic dye represented by the following formula (indicating a benzene ring added to the benzene ring constituting the compound).

The organic dye used in the present invention is composed only of a methine chain as disclosed in JP-A-59-85791 by introducing a cyclo ring or a penta ring represented by 2R2 into the methine chain. It is possible to form a recording layer with better storage resistance and playback deterioration characteristics than organic dyes. R2 introduced into the cyclo-, chloro-, or penta-ring is as described above, and is particularly preferably a halodane atom or an alkyl group.

Further, the organic dye used in the present invention constitutes an indole such as the one disclosed in JP-A-58-194595 by adding a benzene ring as 2 to the benzene ring constituting the indole. Hydrophobicity is increased compared to organic dyes in which the benzene ring is unsubstituted or substituted with an alkyl group, and moisture resistance, which is one of the elements of environmental resistance, can be improved.

Furthermore, the organic dye used in the present invention has a structure in which Y is introduced into indole, but this Y affects the electron density on the N atom and is associated with heat-humidity and regeneration deterioration characteristics. It is also involved in properties and film formability. as Y-C
H(R4)ph.

When Y is used, the moisture resistance and heat resistance are relatively poor, and when -ROH, -R3COR4, -R, or C0R4 is used as Y, solvent solubility and film formability are good.

Therefore, the substituent for 5y may be selected depending on the configuration and purpose of the recording medium.

Specific examples of the organic dyes represented by the above general formula include those shown in the following structural formulas (1) to αQ.

---(+) ---('I) ---(+O) The recording layer containing the dye represented by the above general formula may contain ethyl acetate, toluene, acetone, methyl isobutyl ketone, methylene chloride, or alcohol. Spinner method by dissolving in a solvent such as r 4 .

It can be obtained by forming a thin film on a substrate by a ping method, a doctor blade method, a roll coater method, or the like. The thinner the thickness of this recording layer is, the higher the recording sensitivity becomes. However, since the reflectance depends on the film thickness, it is appropriate to set the thickness in the range of 10 nm to 101000 nm, preferably 3 Q nm to 500 nm. In addition, the substrate can be glass, plastic,
Generally used materials such as metals can be used, but films of acrylic resin, polycarbonate, polyolefin, polyester, and polyimide may also be used.

The recording layer is formed by the method described above. Further, by adding 1 to 40% by weight, preferably 3 to 20% by weight, of a binder resin to the dye, a film can be formed, and the film formability, heat resistance, and moisture resistance can be improved. Examples of the binder resin used here include homopolymers such as acrylic, ester, nitrocellulose, ethylene, propylene, carnate, ethylene terephthalate, epoxy, butyral, vinyl chloride, vinyl acetate, and styrene;
Copolymers of these can be mentioned.

In addition, by mixing other dyes in place of the binder resin or creating a multilayer structure in which dye layers are stacked, film formability, heat resistance, and moisture resistance can be improved.

The light resistance can be improved, and as a result, an original information recording medium with high density, high sensitivity, and excellent durability without reproduction deterioration etc. can be obtained. In this case, it is also possible to layer other dyes to improve heat resistance, moisture resistance, and light resistance. Examples of the dyes used here include cyanine dyes, merocyanine dyes, anthraquinone dyes, triphenylmethane dyes, quinanthene dyes, and phthalocyanine dyes.

For example, an amine compound represented by the following general formula (Al, (B)) or a dithiolate metal complex represented by the following general formula (C) is added to prevent deterioration of the optical properties of the recording layer caused by light, oxygen, and moisture. It is also possible to do so.

However, R1, R2, R4, and R5 in the formula have 1 to 6 carbon atoms, and R represents an alkyl group having 1 to 6 carbon atoms.

However, R in the formula is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, X is an anion such as perchlorate ion, fluoroborate ion, hexafluoroate ion, etc., and m is an integer of 0 or Fi1.2. , A is the above m=0.1, for example, commercially available I
There are RQ-002, IRQ-003 (both product names of Nippon Shiju Co., Ltd.), etc.

However, R1-R4 in the formula is an alkyl group or a phenyl group,
X, Y are hydrogen, alkyl group, halodane group, M is Ni,
This indicates metals such as Co, Fe, and Cr.

Examples of such metal complexes include PA100I-100
6 (both are product names of Mitsui Toatsu Fine (company)), N
-bis(0-xylene-4,5diol)tetra(t-
butyl) ammonium salt.

In addition to the recording layer containing the dye of the above general formula, an intermediate layer and a protective layer may be provided as necessary. The intermediate layer is provided for the purpose of improving adhesion and protecting from oxygen and moisture, and is mainly formed from a resin or an inorganic compound. Examples of the resin include vinyl chloride, vinyl acetate, acrylic,
Single or copolymers of ester, nitrocellulose, carbon dioxide), epoxy, ethylene, propylene, butyral, etc. can be used, and if necessary, antioxidants, ultraviolet light absorbers, leveling agents, and water repellents can be used. It is possible to contain agents, etc. These are formed by a spinner method, a dipping method, or a doctor blade method. Examples of inorganic compounds include sto□, sto, Az2
o.

SnO□, MgF2, etc. are used, and a thin film is formed by an ion beam, an electron beam, or a sputtering method.

The protective layer has the same structure as the intermediate layer and is used to protect the recording layer from elements, oxygen, moisture, scratches, dust, etc.

Next, a configuration example of the optical information recording medium of the present invention will be described with reference to the drawings.

FIG. 1 shows the basic structure of the original information recording medium, in which a recording layer 2 containing a general formula dye is provided on a substrate 1. Recording and reproduction are performed by condensing Radhe light 3 onto the recording layer 2 into a spot with a size of 0.8 to 1.5 μm using a condensing lens. The laser beam 3 for recording and reproduction may be irradiated from the recording layer 2, but when the substrate 1 is made of a transparent material, the influence of dirt and dust can generally be reduced by irradiating it from the substrate 1 side.

FIG. 2 shows a structure in which an intermediate layer 4 is provided between the substrate 1 and the recording layer 2, and a protective layer 5 is provided on the recording layer 2.

In FIG. 3, two media having the same configuration are arranged across a space 6 so that the recording NIs 2 face each other. In addition, 2 in FIG. 3 is an air gap, and 8 is a spindle hole. According to such a configuration, the characteristics are good.
Furthermore, it has the advantage that the influence of dirt and dust on the recording layer 2 can be suppressed.

Furthermore, in the configurations of FIGS. 1 to 3 described above, AZ
#Ag or other reflective film may be provided between the substrate and the recording layer.

[Embodiments of the invention]

Examples of the present invention will be described in detail below.

Example 1 The above-mentioned dye of structural formula (1) was dissolved in methyl ethyl ketone to form a 2% solution, which was then applied onto a 1.2 tm thick glass substrate using a spinner coater and dried to form a 7 tm thick solution.
A recording medium was manufactured by forming a recording layer of 0 nm.

Example 2 The dye of structural formula (3) described above was dissolved in methylene chloride,
After making a 2% solution, it was coated with a spinner coater to a thickness of 1.
Coated on a 2wm glass substrate and dried to a thickness of 80nm.
A recording medium was manufactured by forming a recording layer of m.

Example 3 An acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd.: Dianal BR-) as a binder resin was added to the dye of structural formula (4) described above.
60) was added at 10wt% and dissolved in methylene chloride to make a 3-triple solution.The solution was coated on a 1.2-thick glass substrate with a spinner coater and dried to a thickness of 80.
A recording medium was manufactured by forming a recording layer with a thickness of 100 nm.

Example 4 The dye of structural formula (7) described above and an infrared absorber (trade name: IRG-003, manufactured by Nihon Kapaku Co., Ltd.) were mixed at a weight ratio of 3:1, and this was dissolved in methyl ethyl ketone. After making a 10% solution, this solution was applied onto a glass substrate with a thickness of 1.2 wg using a spinner coater, and dried to a thickness of 8 wg.
A recording medium was manufactured by forming a recording layer of 0 nm.

Example 5 The dye having the structural formula (1) described above and the dye having the following structural formula αυ were mixed at a Xi ratio of 2:1, dissolved in the same manner as in Example 1, applied onto a substrate, and dried. A recording layer with a thickness of 75 nm was formed in this manner, and a recording medium was manufactured.

・・・・・・aυ Example 6 In the same manner as in Example 1, the structural formula (1
) After forming a recording layer with a thickness of 60 nm consisting of a dye of A reflective protective layer with a thickness of 30 nm was formed using the following steps, and a recording medium was manufactured.

・・・・・・α2 Comparative Example 1 The dye of the following structural formula (I) was dissolved in methylene chloride to 2%
After forming a solution, this solution is coated with a spinner coater to a thickness of 1.
21 on a glass substrate and dried to a thickness of 80 nm.
A recording layer was formed to produce a recording medium.

(1) Comparative Example 2 A dye having the following structural formula (If) was dissolved in the same manner as in Comparative Example 1, applied onto a glass substrate, and dried to form a recording layer with a thickness of 70 nm. and produced a recording medium.

Comparative Example 3 A dye having the following structural formula (Ill) was dissolved in the same manner as in Comparative Example 1, applied onto a glass substrate, and dried to a thickness of 75 nm.
forming a recording layer and manufacturing a recording medium.

For the recording layers of the recording media of Examples 1 to 6 and Comparative Examples 1 to 3, the reflectance at a wavelength of 830 nm from the side to the recording layer was measured using a spectrophotometer. Furthermore, the absorbance of each recording layer to light having a wavelength of 830 nm was measured. Furthermore, a laser conductor laser beam with a wavelength of 830 nm was focused on a spot with a diameter of 1.2 Inn so that the medium surface output was 4rnW, and this focused laser beam was moved from the substrate side of each recording medium at a speed of 9%. Write under the sac condition and reproduce with the same decoder at a reproduction output of 0.4 mW to determine the recording sensitivity (recording energy threshold) and the C'/N of the reproduction signal.
The value was measured. Furthermore, Examples 1 to 6 and Comparative Examples 1 to 3
A heat-humidity resistance test was conducted in which the recording medium was left in a 95% atmosphere at 50° C. for 150 hours, and the absorbance reduction rate and reflectance reduction rate before and after the storage were measured. 25℃, 60℃ for each recording medium
A light emission test was conducted by irradiating 500 W tungsten light at 50 cIrL for 100 hours in the atmosphere of the scratch, and measuring the absorbance reduction rate and reflectance reduction rate before and after irradiation with tungsten light. These results are shown in the table below.

〔Effect of the invention〕

As detailed above, the present invention has high reflectance and high B recording sensitivity, enables stable writing and reproduction of optical signals, and is stable against reproduction light, sunlight, and humidity. It is possible to provide a high pollution-free optical information recording medium.

[Brief explanation of drawings]

1 to 3 are schematic diagrams showing optical information recording media of the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Recording layer, 3... Rade light, 4
. . . Intermediate layer, 5 . . . Protective layer, 6 . . . R-sa. Presenting person's agent Patent attorney Tsuboi Harasha 1vA Figure 3 Figure 2 Procedural amendment 1, Indication of the case Patent application No. 1983-243371 2, Name of the invention optical information recording medium 3, Person making the amendment Case and Relationship Patent applicant (037) Olympus Optical Industry Co., Ltd. 4, Agent 6, υ8E Building 3-7-2 Kasumigaseki, Chiyoda-ku, Tokyo, Subject of amendment 7, Contents of amendment (1), Specification middle page 3 In the 10th line, ``r(ex reflectance, absorption rate, etc.)'' is corrected to ``(for example, reflectance, absorption rate, etc.)''. (2), page 3, lines 19-20 of Mei 1.1, “
On the other hand, it has the drawbacks of high reflectance, high thermal conductivity, and high specific heat. "On the other hand, it has disadvantages such as high reflectance, high thermal conductivity, and high specific heat."
I am corrected. (3), on page 4, line 8 of the specification, the phrase ``high absorption rate, low thermal conductivity, and good productivity'' is replaced with ``high absorption rate, low thermal conductivity, and high productivity.''"That'sgood," he corrected. (4) On page 5, line 12 of the specification, the word "formation" is corrected to "addition." (5) The general formula on page 6, line 1 of the specification is corrected as follows. (6) The general formula on page 18, line 4 of the specification is corrected as follows. Note R1 (3) In the third line from the bottom of page 19 in the specification, the phrase ``N-bis J'' is corrected to ``Ni-bis.'' (8) The structural formula on page 25, line 1 of the specification is corrected as follows.

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ {However, R_1 in the formula is an alkyl group having 1 to 6 carbon atoms, an aralkyl group, or a phenyl group, A is ▲ Numerical formula, chemical formula, table, etc. There is ▼ [R_2; hydrogen atom, alkyl group, halogen atom or ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ (ph; phenyl group)
], X is an anion selected from perchlorate, fluoroborate, iodide, chloride, bromide, p-toluenesulfonate, Y is -R_3OH, -R
_3COOH, -R_3COR_4, -CH(R_3)
There are ph, ▲mathematical formulas, chemical formulas, tables, etc.▼ or ▲mathematical formulas,
There are chemical formulas, tables, etc. ▼ (R_3: alkyl group with 1 to 20 carbon atoms, R_4: alkyl group with 1 to 18 carbon atoms or phenyl group, ph: phenyl group), Z is added to the benzene ring that constitutes indole. 1. An optical information recording medium comprising a recording layer containing an organic dye represented by the following formula.