JPS6382790A - Optical recording medium - Google Patents

Abstract

PURPOSE:To obtain an optical recording medium using a coloring matter and having high reflectivity, favorable contrast and excellent preservability, by providing a recording layer comprising a 9,19-dioxadinaphtho-pentacene-5,15-dione derivative having a specified coloring matter skeleton on a base. CONSTITUTION:A coloring matter of the formula is heated to about 80-150 deg.C in a vacuum of 1.6X10<-5>Torr, and is vacuum deposited on a methacrylic resin base of 1.2mm thick. When writing into a thin film thus obtained was conducted by using a semiconductor laser with a center wavelength of 780nm and a beam diameter of a about 1mum, uniform and clear-shaped pits could be obtained, and C/N was favorable. This recording medium shows favorable preservability under room light under the conditions of a temperature of 60 deg.C and a humidity of 90%.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an information recording layer made of dioxadinaphtho(J,2,/-4e: J,2
, /-op] Pentacene-! , l! - An optical recording medium containing a dione derivative.

More specifically, the present invention relates to an optical recording medium that performs recording by utilizing changes in the state of matter due to light energy at the oscillation wavelength of a semiconductor laser.

[Conventional technology]

Various configurations of this type of optical recording medium are known.

For example, Japanese Unexamined Patent Publication No. Sho Jr. P7033 discloses a device in which a single layer of a phthalocyanine dye is provided on a substrate. Phthalocyanine dyes have problems such as low sensitivity, high decomposition point, and difficulty in vapor deposition.Furthermore, they have extremely low solubility in organic solvents, making them unsuitable for use in coatings. .

Further, JP-A No. 11-433≠≠ discloses a recording layer in which a phenalene dye is provided, and JP-A-51-2.2 H. 723 discloses a naphthoquinone dye in a recording layer.

However, although such dyes have the advantage of being easy to deposit, they have the problem of low reflectance. If the reflectance is low, the contrast related to the reflectance between the portion recorded by the laser beam and the virgin portion will be low, making it difficult to reproduce the recorded hole information. Furthermore, organic dyes generally have a problem of poor storage stability.

[Problem that the invention seeks to solve]

The present invention provides an optical recording medium using a dye that is easy to vapor deposit, has high solubility in organic solvents, can be coated by coating, has high reflectance, good contrast, and has excellent storage stability. The purpose is to provide

[Means for solving problems]

The present invention is an optical recording medium for recording and reproducing by causing a state change with a laser beam.
,/-de:3,2. ! -op: ] Pentacene-j
,/j-2, t-op)
Pentacene! , l! -Dione derivatives are represented by the following general formula [■] (wherein, R'eR"IR"IR' is a hydrogen i atom,
7 represents an alkyl group, alkoxy group, -.romethyl group, ).rogen atom, and R6 and Ra represent a hydrogen atom or a halogen atom. ) This is an optical recording medium characterized by being provided with a record 1 containing a dye represented by:

In the dye represented by the general formula [■] of the present invention, R1
, R2, Ra, and Ra' include 01-4 alkyl groups such as methyl group, ethyl group, linear or branched propyl group, and linear or branched butyl group. Examples of alkoxy groups include methoxy group, ethoxy group, linear or branched propoxy group,
C! of linear or branched butoxy groups, etc. Examples of the alkoxyl group of -4 include a chloromethyl group and a bromomethyl group. Further, examples of the halogen atom represented by R8 and R6 include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom.

The dye represented by the general formula (11) is 600 to r00
It has absorption in the wavelength band of nm and has a molecular absorption coefficient of 104 to 106 cR.

In the present invention, the dyes used can be synthesized by conventional methods, such as those described by Igen Miller, Otto Baye
r;Methoien Der Organisch
en chemte ((!hinoneten ll
[) P2? ♂(/'P7F)-: Sorry, Abe, Kosoku,
Proposal, Type 3; Chemical Society of Japan Q Q Annual Meeting, 4LR Cococo.

P≠rO: Sorry, Tairayo, Watanabe; 22nd Annual Meeting of the Chemical Society of Japan, 100/ko, P23ri4t: Sorry, Tairayo, Yutsudo;
It can be easily carried out according to the description in Proceedings of the Autumn Conference of the Chemical Society of Japan and the Federation of Chemical Related Societies, JE-/R, /P6.

The optical recording medium of the present invention basically consists of a substrate and a recording layer, but if necessary, an undercoat layer may be provided on the substrate and a protective layer may be provided on the recording circumference. Can be done.

The substrate in the present invention may be either transparent or opaque to the laser beam used. Examples of the substrate material include supports for general recording materials such as glass, plastic, paper, plate-shaped or foil-shaped metal, etc.
Plastic is preferred for various reasons. Examples of the plastic include acrylic resin, methacrylic resin, vinyl acetate resin, vinyl chloride resin, nitrocellulose, polyethylene resin, polypropylene resin, polycarbonate resin, polyimide resin-bolitelphone resin, and the like.

When using the above-mentioned general formula [t'X element as the information recording layer in the optical recording medium of the present invention, the film thickness is 100 ~ μ
m1 is preferably 1000 to 3 μm. The film can be formed by a commonly used thin film forming method such as a vacuum evaporation method, a sputtering method, a doctor blade method, a casting method, a spinner method, or a dipping method.

When forming a recording layer by a coating method such as a doctor grade method, a casting method, a spinner method, or a dipping method, in particular, a spinner method, examples of coating solvents include bromoform, diglomoethane, tetrachloroethane, ethylceronulf, silane, chlorobenzene, m points of cyclohexanone etc./20
~/rO°C is preferably used.

In addition, in the case of film formation using the spinner method, the rotation speed is! 00~
j 000 rpm is preferable, and after the spin code, treatment such as heating or exposure to solvent vapor may be performed as the case requires.

Moreover, a binder can also be used if necessary. Known binders such as PVA, PVP1 nitrocellulose, cellulose acetate, polyvinyl butyral, and polycarbonate can be used, and the amount of dye to resin is preferably 0.0 t or more in weight ratio.

To improve the stability and light resistance of recording media, transition metal chelate compounds (for example,
acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone, etc.). Furthermore, other dyes can be used in combination if necessary. The other pigment may be another type of pigment of the same type, or a pigment of another type such as a triarylmethane dye, an azo dye, a cyanine dye, or a squirt pigment, or it may be provided only on one side. You can.

Recording on the recording medium obtained as described above is performed by shining a laser beam, preferably a semiconductor laser beam, focused to a beam diameter of approximately /Bm on the recording layer provided on both sides or one side of the substrate. . In the portion irradiated with the laser beam, thermal deformation of the recording layer such as decomposition, evaporation, and melting occurs due to absorption of laser energy.

The recorded information is reproduced by using a laser beam to read the difference in reflectance between a portion where thermal deformation has occurred and a portion where no thermal deformation has occurred.

As the laser beam used for the optical recording medium of the present invention, a semiconductor laser is preferable from the viewpoints of lightness, ease of handling, compactness, and the like.

EXAMPLES The present invention will be specifically explained with reference to Examples below, but these Examples are not intended to limit the present invention.

Example/ A dye represented by the following structural formula /j X / 0""'
Under the vacuum of rorr, about ♂O~/! Heat to θ℃,
Methacrylic resin (hereinafter referred to as PM
(denoted as MA) was vacuum deposited on the substrate. The thickness of the vacuum-deposited film was measured using a quartz crystal film thickness meter, and the thickness was found to be very good. The maximum absorption wavelength by spectrophotometer is 700 n
m, and the reflectance is 30 chi at 30 nm.

The shape of the spectrum was broad.

Using a semiconductor laser with a center wavelength of 710 nm as a light source, a beam diameter of approximately 1 was applied to the thin film thus obtained.
When writing was performed in μm, pits with a uniform and clear shape were obtained, and the carrier level/noise level ratio (C/N ratio) was also good.

Furthermore, this recording medium was used in room light at a temperature of 60°C and a humidity of y.
It showed good storage stability under the condition of 0%.

Example 9 When the nine compounds shown in Table 1 below were used instead of the dyes used in Example 1 and vacuum evaporated in the same manner as described in Example 1, the maximum absorption wavelength shown in Table 1 below was obtained. A thin film substrate was obtained. When writing was performed on the thin film thus obtained using a semiconductor laser as a light source, bits with a uniform and clear shape were obtained.OC/N
The ratio was also good, and the storage stability was also good.

Table 1 Example 3 Dye represented by the following structural formula 0. Yo? was dissolved in tetrachloroethane jO2 and filtered through a 0.2λμ filter to obtain a solution. Pour this solution to a depth of 7 o o g
The mixture was dropped onto a PMMA resin substrate (lcoQgonφ) with grooves made of ultraviolet-curing resin having a width of 0.7 μm, and coated using a spinner method at a rotation speed of j 00 rpm. After printing, it was dried at 60° C. for io minutes. When it was applied to a glass plate under the same conditions and the film thickness was measured using Talystep,
It was 7raR. The maximum absorption wavelength of the coating film by spectrophotometry is 70! nm 'C, and the reflectance was 26 cm (I J Onm ). The shape of the spectrum was wide. Figure 1 shows the absorption and reflection spectra.

When this coating film was irradiated with 7rOnmO semiconductor laser light with a center wavelength of 6 mW and a beam diameter of 1 μm,
A pit with a width of approximately 1 μm and a bit length of approximately 1 μm and a very clear outline is formed. The C/N ratio is high and the storage stability (t
o°C, r O% FIH) were also good.

Example ≠ When the compounds shown in Table 2 below were used in place of the dyes used in Example 3 and applied by nine methods according to the method described in Example 3, the maximum absorption wavelength shown in Table 2 below was obtained. A thin film substrate was obtained. When writing was performed on the thin film thus obtained using a semiconductor laser as a light source, bits with a uniform and clear shape were obtained.

The 0/N ratio was also good, and the storage stability was also good.

Table - Table (Effect of the invention).

According to the present invention, vapor deposition is easy, the solubility in organic solvents is high, coating by coating is possible, and, moreover,
It is a pigment with high reflectance, good contrast, and excellent storage stability.
,,2,/-da:3. λ, /-op) pentacene-r
, an optical recording medium using an is-dione derivative can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows the absorption and reflection spectra of the coating film of Example 3, which is an example of the dye of the present invention, measured by a spectrophotometer. The vertical axis shows absorbance and the horizontal axis shows wavelength. (1 other person)

Claims (2)

[Claims] (1) It is an optical recording medium for recording and reproducing by causing a state change with a laser beam, and the substrate has the following pigment skeleton ▲ Numerical formula, chemical formula, table, etc. ▼ 9, 19-dioxazinaphtho-[3,2,
1-de:3,2,1-op]pentacene-5,15-
An optical recording medium comprising a recording layer containing a dione derivative. (2) 9,19-dioxazinaphtho-[3,2,1-d
e: 3, 2, 1-op] pentacene-5, 15-dione derivative has the following general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1, R^2, R^3, R ^4 is a hydrogen atom,
It represents an alkyl group, an alkoxy group, a halomethyl group, or a halogen atom, and R^5 and R^6 represent a hydrogen atom or a halogen atom. ) The optical recording medium according to claim 1, which is a dye represented by: