JPS62124987A - Optical recording material - Google Patents

Abstract

PURPOSE:To obtain an optical recording material having excellent preservation stability and a high sensitivity in writing by a semiconductor laser ray, by providing a recording layer by using a composition comprising a specified squarylium compound and a specified phthalocyanine compound. CONSTITUTION:This optical recording material has a recording layer comprising a squarylium compound of general formula (I), wherein each of R<1>-R<7> and R<11>-R<17> is hydrogen or an organic group and the adjacent organic groups may together form a subst. or unsubst. ring, and a phthalocyanine compound of general formula (II), wherein each of A and B is hydrogen or an organic group, A and B may together form a subst. or unsubst. ring, and M is a metal belonging to Group IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, VB or VIII or an atom group comprising the metal.

Description

[Detailed description of the invention] (,) Purpose of the invention The present invention relates to optical recording bodies.

(Industrial Application Field) The optical recording medium of the present invention can be advantageously used as a recording medium for high-density information recording and storage using radar light and the like, and for recording and reproducing the same.

(Prior Art) Optical recording using radar light or the like is capable of recording and storing information at a high density, and the recording can be easily reproduced and used, and an example thereof is an optical disk.

In general, optical discs record high-density information by irradiating a thin recording layer provided on a circular base with radar light focused to about 1 μm.

The recording is performed by thermal deformation such as decomposition, evaporation, melting, etc. occurring in the recording layer at that location due to absorption of the irradiated radar energy. Further, recorded information is reproduced by reading the difference in reflectance between a portion where deformation has occurred and a portion where deformation has not occurred using radar light.

Therefore, as an optical recording medium, it is necessary to efficiently absorb the energy of the laser beam, so the absorption of the laser beam of a specific wavelength used for recording is large;
In order to accurately reproduce information, it is necessary to have a high reflectance for radar light of a specific wavelength used for reproduction.

Conventionally, various metals, metal compounds, and inorganic compounds such as chalcoglide have been proposed as light-absorbing substances for forming the recording layer of this type of optical recording medium, but all of them are susceptible to air oxidation. Optical recording materials using light-absorbing materials have disadvantages such as being difficult to store for long periods of time, being sensitive to light in the ultraviolet and visible regions, and being sensitive to sunlight and other light.

In addition, cyanine dyes,
Squarylium dyes, phthalocyanine dyes, etc. have been proposed, but both have low solubility in solvents.
It is difficult to use an economically advantageous coating method to form a thin film for the recording layer, a uniform thin film cannot be obtained unless vacuum deposition is used, and the formed thin film has poor storage stability. was there.

(Problems to be Solved by the Invention) The present invention allows easy formation of a recording layer (thin film) by a coating method, has excellent storage stability, and has high writing sensitivity with radar light, especially semiconductor radar light. The present invention aims to provide an optical recording medium.

(b) Structure of the Invention (Means for Solving the Problems) As a result of various studies conducted by the present inventors in order to solve the above-mentioned problem, the present inventors discovered that a specific SQUA IJ+Jium compound and a specific By forming a recording layer using a composition containing a 7-talocyanine compound, this objective could be easily achieved.

That is, the optical recording medium of the present invention has the general formula (wherein R1
-R7 and R11 to R17 each represent a hydrogen atom or an organic group, and the adjacent organic groups may form a substituted or unsubstituted ring with each other. ), and squarylium compounds represented by the general formula (wherein A and B each represent a hydrogen atom or an organic group, and A and B may form a substituted or unsubstituted ring. M is a periodic Belongs to Group 1B, Group 1rA, Group 1IB, Group 1[IA, Group 1[[B, Group 1VA, Group ■B, Group VA, Group VB, and Group [■] of the Table of Laws. It is characterized by having a recording layer containing a phthalocyanine compound represented by (representing a metal or an atomic group containing the metal).

The squarylium compound represented by the general formula (I) in the present invention has the general formula [wherein R1-R7 are R in the general formula (1)]
It is the same as ~R. ] An azulene derivative represented by the general formula [wherein R11
~R17c, the above general formula (1) K okR11~R
It is the same as 17. ] and the azulene derivative represented by the structural formula 3,4-dihydroxy-3
It can be easily produced by reacting with -cyclobutene-1,2-dione, ie, squaric acid, in a solvent.

The organic groups represented by R - R and R to R17 in the general formula (1) include linear or branched alkyl groups having 1 to 26 carbon atoms; substituted alkyl groups (for example, methoxymethyl group, 1- methoxyethyl group, ether bond-containing alkyl group such as methoxyethyl group); alkoxy group (e.g. linear or branched alkoxy group having 1 to 26 carbon atoms); substituted alkoxy group (e.g. methoxyethoxy group, ethoxyethoxy group, butoxyethoxy group, ethoxyethoxyethoxy group, hexyloxyethoxy group, etc.): substituted or unsubstituted aryl group (e.g. phenyl group; linear or branched alkyl group having 1 to 13 carbon atoms) Phenyl group; phenyl group substituted with alkoxy group containing ether bond such as methoxyethoxy group, ethoxyethoxy group, butoxyethoxy group, ethoxyethoxyethoxy group; phenyl group substituted with halodane atom such as fluorine atom, chlorine atom, bromine atom; nitrophenyl group, etc. ); substituted or unsubstituted aralkyl groups (benzyl group, 2-phenylethyl group, etc. which may be substituted with the same substituents as in the above-mentioned aryl group);

In addition, R-R and R-R represent substituted or unsubstituted rings (for example, a linear or branched alkyl group having 1 to 13 carbon atoms, a carbon A benzene ring which may be substituted with a linear or branched alkoxy group of numbers 1 to 13, an alkoxyalkoxy group, etc.; a thiophene ring; a dihydrothiophene ring; a furan ring; an alkoxycardenyl group which may be substituted A pyrrole ring; a pyridine ring; a tetrahydropyri-sine ring which may be substituted with an alkyl group or an alkoxycarinyl group, etc.). The combination of organic groups when forming a ring is particularly preferably a combination of R and R, or a combination of R and R.

The 7-thalocyanine compound represented by the general formula (If) in the present invention has the general formula [wherein A and B are the same as A and B in the general formula (II)]. ] O-dicyano compound represented by and the general formula (n)
from the same metal or metal compound as in the conventional method [for example, Journal of American Chemical Society, Vol. 106, No. 17, 4806-
4711 ('1984)].

The organic group (g) or (B) in the general formula (ID) is an alkyl group (for example, a straight chain or branched alkyl group having 1 to 13 carbon atoms), an alkoxy group (for example, a straight chain or branched alkyl group having 1 to 13 carbon atoms), or branched alkoxy group), substituted alkoxy groups (for example, ether bond-containing alkoxy groups such as methoxyethoxy group, ethoxyethoxy group, butoxyethoxy group, ethoxyethoxyethoxy group, etc.), and aryloxy groups. Examples of the group include the general formula [wherein X represents, for example, a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodo atom, or a nitro group,
is, for example, a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a linear or branched alkyl group having 1 to 13 carbon atoms, an alkoxy group, a substituted alkoxy group (for example, a methoxyethoxy group, an ethoxyethoxy group, It represents an ether bond-containing alkoxy group such as a butoxyethoxy group, an ethoxyethoxyethoxy group, or a nitro group. ] ・ Examples include groups represented by .

Further, A and B may be consecutively formed to form a substituted or unsubstituted ring, and particularly preferred as the ring is a substituted or unsubstituted 7talene ring.

In addition, as a specific example of M in the general formula (IO),
For example, Cu, Mg, Zn, AtX, I
nX, GeX2.5nXz (X in each formula represents a halodane atom), Si, Ge, Sn, Pb%
Tie, Bi, VO, Fe, Go, N1%Pd
, and pt.

The ratio of squarylium compound (1) and 7-thalocyanine compound (IQ) in the recording layer of the optical recording medium of the present invention is preferably in the range of 10/1 to 1/1 as a weight ratio.Squarylium compound (I) or phthalocyanine When a recording layer is formed using each of the compound (n) alone, when only the square IJ compound (I) is used, it tends to crystallize after forming a thin film, and recorded information cannot be stored for a long period of time. Furthermore, when only a phthalocyanine compound (IQ) is used, the recording sensitivity is poor and the reflectance of the thin film is also low, causing problems in reading the recorded information.

Squarylium compound (I) and phthalocyanine compound (If) are soluble in a wide range of various solvents, so a mixed solvent solution using both in an appropriate ratio or a solution in which a binder resin is added, The optical recording medium of the present invention can be easily manufactured by forming a thin film-like recording layer by coating it on a suitable substrate using various coating methods.

Examples of the solvent include halogen-containing carbonated solvents such as chloroform, dichloromethane, dichloroethane, nopromoethane, tetrachloroethane, and chlorobenzene;
diethyl ether, dioxane, tetrahydrofuran,
Ether solvents such as dimethoxyethane; ester solvents such as ethyl acetate; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; acetone, methyl ethyl ketone,
Examples include ketone solvents such as methyl isobutyl ketone; amide solvents such as acetamide, N,N-dimethylacetamide, N,N-dimethylformamide, and N-methylpyrrolidone; and zomethylsulfoxide and methyl cellosolve.

Further, materials for the substrate include glass, plastic, etc., and plastic and plastic are particularly preferred from the viewpoint of safety, lightness, etc. Examples of plastics for the substrate include acrylic resin, methacrylic resin, polycarnate resin, vinyl chloride resin, vinyl acetate resin,
Polyester resin, polyethylene resin, column? Examples include polypropylene resin, polyamide resin, polystyrene resin, and epoxy resin.

6. Formation of Recording Layer on Substrate 6. As a yarn film forming method, a solution in which the above-mentioned squarylium compound (1) and phthalocyanine compound (I[) are dissolved in a suitable solvent, preferably is a solution in which a binder resin is further dissolved in the solvent [in these solutions, compounds (1), (
I[) and the binder resin may be partially dispersed without being dissolved. ] Remove the solvent by evaporation (
The most preferred method is drying. However, it is also possible to use a vacuum evaporation method for the film formation method. Examples of the binder resin include polyimide resin, polyamide resin, polyethylene resin, acrylic resin, polyester resin, polycarnate resin, cellulose resin, and the like.

The concentration of the applied solution is preferably 0.5 to 10% by weight as the total concentration of compound (1) and (IO).

In the optical recording medium of the present invention, the recording layer may be provided on both sides of the substrate or only on one side. The thickness of the recording layer is usually 100 to 10,000×, preferably 400 to 5,000×
It is X.

Recording on the optical recording medium of the present invention is carried out by irradiating the recording layer provided on both sides or one side of the substrate with radar light, preferably semiconductor radar light, focused to about 1 .mu.m. In the area irradiated with the laser beam, thermal deformation of the recording layer such as decomposition, evaporation, and melting occurs due to absorption of the laser beam energy, resulting in recording.

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

The light source used for recording and reproducing is He-N.
Various types of radars are used, such as o-radar-1, ar-rader-1, semiconductor radar, etc., but from the viewpoint of price, size, etc.
Semiconductor radar is particularly interesting.

The center wavelength of the semiconductor radar is 830 nm.

It is possible to use a center wavelength of 780 nm, or a wavelength shorter than that.

(Example) The present invention will be described in more detail below with reference to examples.

Example 1 Synthesis of squarylium compound: 1-n-butyl-5-isoprogylazulene and 3.4-
A mixture with dihydroxy-3-cyclobutene-1,2-dione in a molar ratio of 2:1 is produced in a mixed solvent of n-butyl alcohol and toluene in a volume ratio of 2:1 under heating at 105 to 110°C under reflux. 1 while distilling off the water along with the solvent.
SQUA IJ having the following chemical structure by reacting for a time
An IJium compound was produced. This compound has a melting point of 24
The temperature was 1-243°C.

Synthesis of phthalocyanine compound: 3-(4-ethyl-2-bromphenoxy)-phthalonitrile and lead monoxide were mixed at a molar ratio of 1:1, heated to 210°C to melt, and kept at this temperature for 14 hours. The mixture was stirred and reacted to produce a phthalocyanine compound having the following chemical structural formula. This compound had a melting point of 214-215°C r Squarylium compound (1') produced by the above method
0.2 g, and phthalocyanine compound (■1) 0.
1 g was dissolved in 1,1,2,2-tetrachloroethane 13d, and applied to a methacrylic resin substrate in the form of a thin film with a thickness of 800X by a spin code method (rotation speed: 1000 rpm). The maximum absorption wavelength of the thin film is 750°Cm, and 830°C
The reflectance (5° specular reflection) at °Cm was 26%.

When this thin film was irradiated with semiconductor radar light with a center wavelength of 830 nm and a beam width of about 1 μm at an output mW, the width was about 1 μm.
A pit with a very clear outline and a pit diameter of 2 μm was formed. Its carrier level/noise level (
C/N) ratio was 52 dB.

This thin film was stored for 20 days in a constant temperature and humidity chamber at 70° C. and 85% RE, but no crystals were deposited.

Comparative Example 1 A thin film having a thickness of 800× was formed using the squarylium compound (11) of Example 1, but in the same manner as in Example 1 except for the above. When this thin film was stored in a constant temperature and humidity bath at 70° C. and 85% RH, crystals were precipitated after 2 days.

Comparative Example 2 A thin film having a thickness of 5 oool was formed in the same manner as in Example 1 except that the 7 talocyanine compound (■1) of Example 1 was used. The reflectance of this thin film at 830° C.m was measured and was 17 cm. This thin film has a center wavelength of 83
Example 1: Semiconductor radar light with a wavelength of 0 nm and an output of 5 mW
Irradiation was carried out in the same manner as above, but clear pits were not obtained. , Example 2 According to the synthesis method of the squarylium compound in Example 1, a squarylium compound having the following structural formula was produced. The melting point of this compound was 237-2-7°C.

0.2 g of this squarylium compound (1) and the phthalocyanine compound (II'
) 0.111 and dissolved in dibromoethane 121d,
It was coated on a methacrylic resin substrate by the gin coating method (rotation speed: 100 Orpm). The thickness of the applied thin film is 85
0X, maximum absorption wavelength is 820℃m, 830
The reflectance (5° specular reflection) at °Cm was 24 cm.

In the same manner as in Example 1, this thin film was heated to 830°C.
When holes (pits) were formed using semiconductor radar light and the C ratio was measured, it was 51 dB.

This thin film was stored in a constant temperature and humidity chamber at 70° C. and 85% RH for 20 days, but no crystal precipitation was observed.

Examples 3 to 21 Various squarylium compounds and phthalocyanine compounds shown in Table 1 were synthesized according to each synthesis method in Example 1, and both compounds were mixed at a weight ratio of 2:1. A film was formed by coating on a methacrylic resin plate according to the method in 1. The maximum absorption wavelength and C/N ratio of each thin film obtained were as shown in Table 1. Although each thin film was stored in a constant temperature bath at 70° C. and 85 SRH for 20 days, no crystal precipitation was observed in any of them.

(c) Effects of the invention In the optical recording medium of the present invention, since the light-absorbing substance for the recording layer is soluble in a wide range of solvents, the formation of the recording layer itself is easy, and the recording layer has excellent storage stability. Furthermore, the writing sensitivity by radar light is also extremely high.

Claims (1)

[Claims] 1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1 to R^7, and R^1^1 to R^1^7
Each represents a hydrogen atom or an organic group, and adjacent organic groups may form a substituted or unsubstituted ring with each other. ), and the general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (where A and B each represent a hydrogen atom or an organic group, and A and B represent a substituted or unsubstituted ring. M may be a member of Group IB, Group IIA, Group IIB of the periodic table,
Represents a metal belonging to Group IIIA, Group IIIB, Group IVA, Group IVB, Group VA, Group VB, and Group VIII, or an atomic group containing the metal. ) An optical recording medium characterized by having a recording layer containing a phthalocyanine compound represented by: