JPS6282080A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To provide an optical information recording medium having high reflectivity and high recording sensitivity, stably performing the writing and reproduction of an optical signal, having high stability to light at the time of regeneration, sun rays and humidity and generating no public nuisance, by providing a recording layer containing a specific org. dye. CONSTITUTION:The titled recording medium has a recording layer containing an org. dye represented by general formula (1). This org. dye is excellent in durability and light resistance and can form a recording layer having a high environmental property and low regeneration deteriorating characteristics. The recording layer containing the dye represented by the general formula is obtained by a method wherein the dye is dissolved in a solvent such as ethyl acetate, toluene, acetone, alcohol or the like and the prepared solution is applied to a substrate by a spinner method or a roll coater method to form a membrane. Recording sensitivity becomes high as the thickness of the recording layer becomes thinner but, because reflectivity is dependent on a binder resin, a range of 10-100nm is proper. Further, by adding 1-40wt% of the binder resin to the dye, a film forming property, heat resistance and humidity resistance can be enhanced.

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]

Generally, optical disks can store high-density information using small (eg, about 1 μm) optically detectable bits formed in a thin film recording layer on a substrate in the form of spiral or circular tracks. To write information on such a y-isk, a focused laser is scanned over the surface of the Radhe-sensitive layer, a bit is formed only on the surface irradiated with the laser beam, and the bit is spread over a spiral or circular track. Formed in the form of. This sensitive layer can absorb laser energy to form an optically detectable bit. 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 (ex reflectance) between the recording layer and the non-irradiated area. , absorption rate, etc.) and read them.

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, sputtering, etc., 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 is low and a high output Raded light source is required. As a result, the disadvantage is that the recording device becomes large and expensive. Thin films of mata, tellurium, bismuth, selenium, etc. have the disadvantage of being toxic.

For these reasons, research proposals have recently been made on optical memory media using the dye NH as a recording layer because it allows selection of absorption properties, high absorption rate, low heat conduction, good productivity, and low toxicity. It is coming. Typical dyes include cyanine dyes (JP 58-112790'), anthraquinone dyes (JP 58-224448), naphthoquinone dyes (JP 58-224793), and phthalocyanine dyes (JP 58-224793). -48396), etc., and is an optical recording medium in which a compound consisting of these alone or in combination with a self-oxidizing resin is formed on a substrate by a spinner coating dipping method, a plasma method, a vacuum evaporation method, or the like. This dye thin film system has the above-mentioned advantages, and in particular, cyanine dyes have been studied a lot because they are structurally capable of having an absorption wavelength in the near-infrared region, and also have advantages such as solubility in solvents and low melting point. 3 However, on the other hand, there are problems such as light deterioration, instability against heat, and humidity deterioration.
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 protective film should be provided on the recording layer (Japanese Unexamined Patent Publication No. 55-22961.
57-66541), mixing a substance that prevents discoloration due to oxygen (JP 59-55795), and forming a metal complex that absorbs light in the long wavelength range (JP 59-215
892) 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, a coating type recording medium using a cyanine dye represented by the following general formula is attracting attention from the viewpoint of recording density and reflectivity.

[However, A in the formula is O, S, Ss, C, and X are Ha0) f
7 anion, BF4''-, ClO2-1R represents alkyl] However, the cyanine dye represented by the above general formula also has the essential problem of lacking film-forming properties and heat-light stability.Film-forming properties It is known that the solvent solubility decreases as the number of methine chains (n) increases, and that the solubility changes depending on the type of heterocycle at both ends and the type of substituent. Regarding thermo-light stability, It is known that as the number of methine chains increases, it becomes more unstable to heat and light, and oxidative deterioration becomes more likely to occur, and that the stability to heat and light differs depending on the type of heterocycle.

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 handling light 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 [wherein R, R2 in formula 1 is a hydrogen atom], a rodene atom, an alkyl group having 1 to 6 carbon atoms, or -N<.

(ph: phenyl group), R3 is an alkyl group having 1 to 6 carbon atoms, an aralkyl group, a phenyl group, and X is selected from no'-chlorate, fluoroborate, iodide, chloride 0, bromide, and p-toluenesulfonate. Anion, Y is an alkyl group having 1 to 18 carbon atoms, -R4-o
, -R40H.

-R4COO)(, -R40R5, -R4COR5, -
R4COOR5゜yl group, R5: alkyl group having 1 to 18 carbon atoms), n-R6CN, -OR,, -OH, -CO
OH, -COR,, 7 alkyl group, preferably an alkyl group having 1 to 10 carbon atoms, R: an alkyl group having 1 to 18 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms or a phenyl group), When n=2, it represents an alkyl group having 1 to 10 carbon atoms or a halogen atom].

Compared to organic dyes whose same structure consists only of methine chains, they have superior durability and light resistance, and can form recording layers with high environmental resistance and playback deterioration characteristics. R1 and R2 of the cyclo ring are as described above, but chlorine, bromine or an alkyl group having 1 to 3 carbon atoms are particularly preferred. However, by introducing a cyclo ring into the methine chain, the solubility of the dye in the solvent is slightly lowered, making it difficult to form a uniform film due to the M concentration of the solvent.

Therefore, the organic dye of the present invention has 10F (10F) as Z in the benzene ring constituting the indole.

By introducing substituents such as -COOH and -COR7, it is possible to improve the solvent solubility and film-forming properties in addition to controlling the dye tip, chemical stability, and maximum absorption wavelength. The above 2 is as described above, but from the viewpoint of improving the light and chemical stability of the dye, 10N, -0CF3. -(C6
) It is desirable to use an electron-withdrawing group such as 2. Further, the substitution position on the benzene ring of 2 is preferably the 5th position because it is the easiest to substitute, and in order to improve solvent solubility and film forming properties, Z is -(R,)2. Although it is desirable to introduce R60Q, -R4COR5, etc., it is preferable to select them in consideration of the substituent (Y) to be introduced into indole.

In addition, the organic dye used in the present invention has a structure in which the above-mentioned substituent (Y) is introduced into indole. It is desirable to introduce a group, R, -@R40R5, and when considering film formability and solvent solubility, -COO as Y
H.

-COOR5, -R4COOR5, -R40R5 are desirable.

As mentioned above, the organic dyes having the structure in which the above-mentioned substituents are introduced are disclosed in Japanese Patent Application Laid-open Nos. 59-150795 and 58-194595.
It has superior light and chemical stability, solvent solubility, and film-forming properties compared to the unsubstituted dye with the following structural formula disclosed in the issue, and as a result,
By forming a recording layer containing this dye, it is possible to reduce noise components in the reproduced signal waveform due to poor film formation properties and to improve environmental resistance.

Specific examples of the dye represented by the above general formula include:
Examples include those shown in Structural Formulas (1) to Reno below.

−−+ (1) −−−<2) 1−−Q) −m−(1′ Lee−−−(+?) −−−(N) −−−(:0) 11−(Yuri Doi A recording layer containing a dye represented by the general formula can be prepared by dissolving the dye in a solvent such as ethyl acetate, toluene, acetone, methyl isobutyl ketone, methylene chloride, alcohol, etc., using a spinner method, a dipping method, a lid-blading method, or a roll method. υ can be obtained by forming a thin film on a substrate by a coater method etc. The thinner the thickness of this recording layer, the higher the recording sensitivity, but since the reflectance depends on the film thickness,
m-11000n, preferably 30nm to 500nm
It is appropriate to keep it within the range of . In addition, commonly used substrates such as glass, plastic, and metal can be used, but acrylic resin, polycarbonate,
Polyolefin? Riester,? A liimide film may also be used.

The recording layer is formed by the method described above. Furthermore, a binder resin is added to the dye in an amount of 1 to 40]i, preferably 3 to 20
By adding % by weight.

It is possible to form a film and improve film formability, heat resistance, and moisture resistance. Examples of binder resins used here include acrylic, ester, nitrocellulose,
Examples include homopolymers of ethylene, propylene, carbonate, ethylene terephthalate, epoxy, butyral, vinyl chloride, vinyl acetate, styrene, and copolymers thereof.

In addition, by mixing other dyes in place of the above binder resin or creating a multilayer structure in which dye layers are stacked, it is possible to improve film formability and improve heat resistance, moisture resistance, and light resistance. It is possible to obtain an optical information recording medium with excellent density, high sensitivity, and excellent durability without reproduction deterioration. 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, xanthine dyes, and phthalocyanine dyes.

For example, amine compounds represented by the following general formulas (A) and (B) or dithiolate metal complexes represented by the following general formula (C) are added to prevent deterioration of the optical properties of the layer due to light, oxygen, and moisture. It is also possible to prevent this. , However, R4'R2' R41R5 in the formula has 1 to 1 carbon atoms.
R 6 represents an alkyl group.

......(B) However, R in the formula is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and X is an anion such as a perchlorate ion, a fluoroborate ion, a hexafluoroate ion, m is 0 or an integer of 1, 2, A is the above m = O +, for example, commercially available IR
Q-002, IRQ-003 (both Nippon Kayaku (
Co., Ltd. product name] etc.

However, R1-R4 in the formula is an alkyl group or a phenyl group,
X and Y are hydrogen, an alkyl group, and a halodane group.

It indicates metals such as M l"j NiT Co + Fer Cr +. Examples of such metal complexes include PA1001 to 1006 (all names of Mitsui Toatsu Fine ■ backwards products), N-bis(0-xylene -4,5,
Nool)tetra(orbutyl)ammonium salts, etc.

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. As the resin, for example, single or copolymers of vinyl chloride, vinyl acetate, acrylic, ester, cellulose, carbonate, epoxy, ethylene, globylene, butyral, etc. can be used, and if necessary, antioxidants can be used. agent,
It is possible to contain an ultraviolet light absorber, a leveling agent, a water repellent, etc. These are formed by a spinner method, a dipping method, or a doctor blade method. Examples of inorganic compounds include 5io2. sto, h2o
3°5n02, MgF2, etc. are used, and a thin film is formed by an ion beam, an electron beam, or a starburst method.

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

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 an optical information recording medium, in which a recording layer 2 containing a general formula dye is provided on a substrate l. Recording and reproduction are performed by focusing the laser beam 3 onto a spot with a size of 0.8 to 1.5 μm on the recording layer 2 through a condensing lens. , recording layer 2
However, if the substrate 1 is made of a transparent material, irradiation from the substrate 1 side can generally reduce the influence of dirt and dust.

FIG. 2 shows a structure in which an intermediate layer 4 is provided between the substrate 1 and the recording layer 20, and a protective layer 5 is provided on the recording layer 2.

In FIG. S, two media having the same configuration are arranged with a spacer 6 in between so that the recording layers 2 face each other.

In addition, 7 in FIG. 3 is an air gear lug, and 8 is a spindle hole. According to this configuration, the characteristics are good,
Furthermore, it has the advantage that the influence of dirt and dust on the recording layer 2 can be controlled.

Furthermore, in the configurations of FIGS. 1 to 3 described above, At
, Ag, or other reflective films 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 coated on a glass substrate with a thickness of 12 using a spinner coater and dried to a thickness of 75 nm.
A recording medium was manufactured by forming a recording layer of m.

Example 2 The dye of structural formula (5) 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 2 m glass substrate and dried to a thickness of 80 nm.
A recording medium was manufactured by forming a recording layer.

Example 3 The dye of structural formula (A) described above was dissolved in methylene chloride to make a 2% solution, which was then coated with a spinner coater to a thickness of 1.5%.
Coated on a 2fi glass substrate and dried to a thickness of 70 nm
A recording layer was formed to produce a recording body.

Example 4 The dye having the above structural formula was dissolved in methylene chloride,
After making it into a 2% solution, it was coated with a spinner coater to a thickness of 1.
On a 2 nm glass substrate (r cloth, dried mulberry to a thickness of 65 mm)
A recording layer of nm thickness was formed, and recording was performed to cover the entire surface of the medium.

Example 5 The above-mentioned structural formula α90 dye was combined with an acrylic resin (manufactured by Mitsubishi L/-Yon Co., Ltd.; Dianal BR) as a binder resin.
-60) was added in an amount of 10 wt. A recording medium was manufactured by forming a recording layer of 95 nm.

Example 6 The dye of structural formula (8) 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 coated on a glass substrate with a thickness of 1.2 ttm using a spinner coater and dried to form a recording layer with a thickness of 80 nm to produce a recording medium.

Example 7 The dye having the structural formula 010 described above and the dye having the following structural formula were mixed at a weight ratio of 2:1, dissolved in the same manner as in Example 1, coated on a substrate, dried, and thickened. A recording layer of 75 nm was formed to produce a recording medium.

U)43CH.

Example 8 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 to produce a recording medium.

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

......(1) Comparative Example 2 A dye of the following structural formula (II), ζO'll, was dissolved in the same manner as in 1, and dried to a thickness of 7 on a glass substrate.
A recording layer with a thickness of 0 nm was formed to produce a recording medium.

Comparative Example 3 A dye having the following structural formula (II) was dissolved in the same manner as in Comparative Example 1 (7. Coated on a glass substrate and dried to a thickness of 70 nm.
Comparative Example 4 A dye having the following structural formula (IV) was dissolved in the same manner as in Comparative Example], coated on a glass substrate, and dried to form a recording layer with a thickness of 70 nm. A layer was formed and a recording medium was manufactured.

For the recording layers of the recording media of Examples 1 to 8 and Comparative Examples 1 to 4, the reflectance of the recording layer side to light having a wavelength of 830 nm was measured using a spectrophotometer. In addition, the absorbance of each recording layer to light with a wavelength of 830 nm was calculated by adding 1. Sara K.

Semiconductor radar light with a wavelength of 830 nm has a medium surface output of 4 mW.
The light was focused on a spot with a diameter of 12 μm so that

This condensed Raded light is written from the substrate side of each recording medium at a moving speed of 9 m/sec, and the same Raded light is used for reproduction at a reproduction output of 0.4 mW to determine the recording sensitivity (recording energy threshold) and reproduction. The CA value of the signal was measured. Furthermore, the recording media of Examples 1 to 8 and Comparative Examples 1 to 4 were heated to 50°C.
A heat-humidity resistance test was carried out in which the sample was left in an atmosphere of . 500°C in an atmosphere of 25°C and 60cm for each recording medium.
W tungsten light 50. Irradiate it for 100 hours,
A light fastness test was conducted to measure the rate of decrease in absorbance and rate of decrease in reflectance 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 recording sensitivity, enables stable writing and reproduction of optical signals, and has low stability against reproduction light, sunlight, and humidity. A highly pollution-free optical information recording medium can be provided.

[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... Spacer. Applicant's representative Patent attorney Atsushi Tsuboi Figure 1 Figure 2 Figure 3 Procedural amendments January 7, 1962 Commissioner of the Patent Office Kuro 1) Akio Tono1, Case indication patent application No. 1988-2231272 , Name of the invention Optical information recording medium 3, Relationship with the person making the amendment Patent applicant (037) Olympus Optical Industry Co., Ltd. 4, Agent UBE Building 7, 3-7-2 Kasumigaseki, Chiyoda-ku, Tokyo;
Contents of amendment (1), Akira 1! ! ! In II, page 3, line 12, “(
(e.g. reflectance, absorption rate, etc.)"
(absorption rate, etc.)”. +21. In the 1st and 2nd lines of page 4 of Akira 1 BW, it says, "On the other hand, it has a large reflectance, high thermal conductivity, and a large specific heat." (3) In the 10th line of page 4 of the specification, the phrase ``high absorption rate, low heat conduction, and good productivity'' is replaced with ``large absorption rate''. Furthermore, it has a low thermal conductivity and is also highly productive.'' (4) In the specification, page 5, line 14, the word "formation" is corrected to "addition." (5) The general formula on page 6, line 3 of the specification is corrected as follows. (6) The general formula on page 11, line 2 of the Ming-A Jiechu Law is corrected as follows. In (7), the general formula on page 21, line 4 of Meikosho Chuho is corrected as follows. Note p. (8), in the first line of page 23 of the specification, rN-
Correct "Ni-bis" to "Ni-bis". (9) The structural formula on page 28, line 1 of the specification is corrected as follows. Record

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [However, R_1 and R_2 in the formula are hydrogen atoms, halogen atoms, alkyl groups having 1 to 6 carbon atoms, or ▲ Numerical formula, chemical formula, table, etc. ▼ (ph; phenyl group), R_3 is an alkyl group having 1 to 6 carbon atoms, an aralkyl group, a phenyl group, and X is selected from perchlorate, fluoroborate, iodide, chloride, bromide, p-toluenesulfonate Anion, Y is an alkyl group with 1 to 18 carbon atoms, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -R_4OH,
-R_4COOH, -R_4OR_5, -R_4COR
_5, -R_4COOR_5, ▲Mathematical formulas, chemical formulas, tables, etc.▼(R_4; Alkyl group with 1 to 20 carbon atoms, R
_5; alkyl group having 1 to 18 carbon atoms), n is an integer of 1 or 2, Z is -R_6OH, -R_6CO when n=1
OH, -R_6OR_7, -R_6COR_7, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -R_6CN, -OR_
7, -OH, -COOH, -COR_7, phenyl group,
-CN, -OCF_3, -OSF_3, -NH_2N(
R_7)_2, -NHCOR_7, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, (R_6: Alkyl group with 1 to 20 carbon atoms, R_7: Alkyl group or phenyl group with 1 to 18 carbon atoms), When n = 2 represents an alkyl group having 1 to 10 carbon atoms or a halogen atom.