JPS60252343A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To enable recording and regenerating using long wavelength light, such as semiconductor laser beams, and to obtain a record superior in storage stability and recording density and low in deteriorator of regenerating by providing a recording layr incorporated with the specified compd. CONSTITUTION:The recording layer 2 formed on a base plate 1 contains a compd. represented by the formula in which R is each H, halogen, hydroxy, carboxyl, alkyl, acyl, aryl, alkoxy, amino or the like; and l is 1 or 2. Such a recording layer 2 is formed by the vapor deposition, sputtering, CVD, coating with its solvent soln., or the like methods. The use of such a compsn. for the recording layer 2 permits recording to be executed with high sensitivity even by using long wavelength light, such as semiconductor laser beams, a well-shaped pit to be formed, a high S/N ratio to be secured, further, stability to heat and light to be enhanced, and a recording medium good in storage stability and small in deterioration of regeneration to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical information recording medium having a recording layer containing a specific compound. More specifically, the present invention relates to an optical information recording medium used in a method of directly recording with a laser beam and reproducing information by changing reflected light.

[Prior art]

2. Description of the Related Art Conventionally, information recording and reproducing apparatuses are known that record and reproduce information by irradiating a rotating disk-shaped information recording medium with a laser beam. As a recording layer of an information recording medium used in this type of information recording device, a recording layer using a low melting point metal or a low melting point metal and a dielectric material has been proposed.

However, these have drawbacks such as poor storage stability, low resolution, low recording density, and high cost. Therefore, it has recently been proposed to use organic thin films whose physical properties can change with relatively long wavelength light for the recording layer, but organic compounds that have absorption characteristics on the long wavelength side are generally resistant to heat and light. Currently, a recording layer with satisfactory recording properties has not been developed due to problems such as low stability.

〔the purpose〕

The present invention has been made in view of the above-mentioned current situation, and its purpose is to provide an optical information recording medium that is capable of recording and reproducing using long wavelength light such as a semiconductor laser, has excellent storage stability, has little reproduction deterioration, and has a high recording density. It is to be.

〔composition〕

As a result of intensive research to achieve the above object, the present inventors discovered that the compound represented by the following general formula itself is useful as a stable recording material, leading to the completion of the present invention.

That is, an object of the present invention is to provide an optical information recording medium having a recording layer containing a compound represented by the following general formula.

In the general formula, R represents hydrogen, halogen, hydroxy group, carboxyl group, substituted or unsubstituted alkyl, acyl, aryl, alkoxy, acyloxy, aralkyl, alkenyl or amino group, and t represents 1 or 2.

Specific examples of the above compounds of the present invention are shown in the table below, but the present invention is not limited thereto.

1111---------------------Compound name t Ortho position Meta position Para position A I --0CH5 B 1 --- ct C2-CL 0CH3 Di' -, NH2 F, 1 - -' N(CH3)2 F 2 - CH30CH3 G 2 - CH2=CHCH2-NH2H1--N(
C2H5)2z1-0C2H5J2-0COCH3ocH3, 1. -, -Br 1--F Mj--Engineering N i --0C4H9 o 1 - = OH Compound name t Ortho position Meta position Noξ La position R
1--C3H7 1320CH3-0CH5 Tl 2 0CH5-CH5CH=CH-V10C2H
5-w1-0COc2H5-Z2CL-OCOC'H3 The optical information recording medium of the present invention basically consists of a substrate and a recording layer, but may further include an undercoat layer and a storage layer as necessary. A false layer etc. can also be provided. It is also possible to have a so-called air sand inch structure in which two recording media are placed facing each other with their recording layers facing each other.

The recording layer in the present invention is capable of causing some optical change by irradiation with laser light and recording information based on the change, and the recording layer must contain a compound of the above general formula. Further, in forming the recording layer, one kind or a combination of two or more kinds of compounds of the above general formula may be used. Furthermore, the above-mentioned compound of the present invention can be used with other dyes such as phthalocyanine dyes, tetrahydrocholine dyes, dioxazine dyes, triphetchiazine dyes, 7-enanthrene dyes, and cyanine (merocyanine).
dyes, anthraquinone (indanthrene) dyes, xanthine dyes, triphenylmethane dyes, croconiol dyes, biryllium dyes, azulene dyes, etc., or metals, gold and 4 compounds such as In, Sn% Te, B
1. It can also be used in the form of a mixed dispersion or f* layer with At, Be, TeO2, SnO, As, Cd, etc. The above compounds of the present invention can also be used in various materials such as polymeric phase materials such as ionomer resins, polyamide resins, vinyl resins, natural polymers, silicones, liquid rubbers, etc. It may be used by mixing and dispersing it, or it may be used together with stabilizers (for example, transition metal complexes), dispersants, flame retardants, lubricants, antistatic agents, surfactants, plasticizers, etc. for the purpose of improving properties. can.

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 Figure wJ1, the optical information recording medium of the present invention basically comprises a substrate 1 and a recording layer 2 containing a compound of the above general formula. Further, the recording layer can also have a 2N structure in which a light reflecting layer and a light absorbing layer are combined in any order.

The recording layer can be formed by conventional means such as vapor deposition, snobbing, CVD, or solution coating.

When using the coating method, it is dissolved in an organic solvent and sprayed.
It is carried out by conventional coating methods such as roller coating, dipping and spinning. Organic solvents generally include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, N,
Amides such as N-dimethylformamide and N,N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, chloroform, and chloride. Aliphatic chlorogenated hydrocarbons such as methylene, dichloroethane, carbon tetrachloride, trichloroethane, etc., or aromatics such as benzene, toluene, xylene, ligroin, monochlorobenzene, dichlorobenzene, etc. can be used. The thickness of the recording layer is 1001~10μ
m is preferably 200X to 2 μm.

When writing and recording is performed from the substrate side, it must be transparent to the laser beam used, and when writing and recording is performed from the recording layer side, it does not need to be transparent. As the substrate, glass, polyester, polyamide, polyolefin, polycarbonate, epoxy, polyimide, plastics such as polymethyl methacrylate, audio materials, and ceramics are usually used, but any other material used for recording media may be used.

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

At this time, the undercoat layer and/or the protective layer may contain a compound represented by the above general formula of the present invention.

The undercoat layer 3 has the following functions: ←) Improving adhesiveness, (b) acting as a barrier against water or gas, (c) improving storage stability of the recording layer, and (d)
(e) protection of the substrate from solvents and (f)
) Used for purposes such as forming pre-grooves. (
For the purpose of (b), various substances such as the polymer materials and silane coupling agents can be used.
)% For the purpose of (0), inorganic compounds such as 5102, MgF2.810, 102
, ZnO, TiN, Ni-IN, etc. Metals or metalloids such as Zn, Cu, S, N1, Cr%Go, Be.

Cd, Ag, At, etc. can be used. (d
For the purposes of (8) and (f), metals such as At%Ag or organic thin films with metallic luster such as methane dyes and xanthine dyes can be used. , thermosetting resin, thermoplastic resin, etc. can be used.

The thickness of the subbing layer is 0.1 to 30 μm, preferably 0.2 to 1 μm.
0 μm is appropriate. In addition, the insurance layer 4 has scratches, dust,
This layer is provided for the purpose of protecting the recording layer from dirt and improving the chemical stability of the recording layer, and can be made of the same material as the undercoat J-. The film thickness is 0 for protection and no.
．． A suitable thickness is 1 μm or more, preferably 50 μm or more.

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 is also possible to create a so-called air sandwich structure in which the air is placed inside and sealed. A so-called adhesion sandwich structure (bonded structure) in which the I layer 4 is bonded may also be used.

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

, 7/ /Pa [Examples] The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.

Example 1 Polymethyl methacrylate (hereinafter referred to as
[Abbreviated as PMMA J] 1. of the above compound example A on the substrate.
Spin coat 2-dichloroethane solution to a thickness of 0.06
pm recording layer was formed to produce a recording medium.

Example 2 A recording medium was produced in the same manner as in Example 1 except that the recording layer was formed using Compound Example B.

Example 5 A silver vapor deposition film having a thickness of 100λ was further provided on the recording layer formed in Example 1 to produce a recording medium.

Example 4 A 1,2-dichloroethane solution containing the compound example A and the compound of the following general formula (1) mixed at a weight ratio of 1:1 was spin-coated onto a PMMA substrate with a thickness of 1.2 wa to give a thickness of 1.2 wa. Sa0.
A recording layer was formed with a thickness of 0.05 μm to produce a recording medium.

Example 5 The above compound example A was deposited on a PMMA substrate with a thickness of 1.2 wax.
A 1,2-dichloroethane solution containing a compound of general formula (1) below mixed at a weight ratio of 7:3 was spin-coated to a thickness of 1.
A recording layer with a thickness of 05 μm is provided, and the following general formula Cm is formed on it.
) was vacuum-deposited to a thickness of 0.03 μm to produce a recording medium.

0θ Example 6 150λ thick Te on 1.2w thick PMMA substrate
A vapor deposited film is provided on which 1,2- of the compound example A is further applied.
A recording medium was prepared by spin-coating a dichloroethane solution to form a recording layer with a thickness of 0.05 μm.

A write power of 2.25 was applied to the recording medium manufactured in the above example from the substrate side using a semiconductor laser beam with a wavelength of 790 nm.
mW, recording frequency [15MH2, linear velocity 1, 5 m/se
Information was written and reproduced using c, and its spectral analysis (scanning filter, bandwidth 30 KH2) was performed to measure the C/N. Next, C was measured after irradiating the same recording medium with tungsten light of 54,000 lux for 50 hours.

The results are summarized in the table below.

Example 1 53 51 2 53 51 5 52 52 4 56 55 5 55 53 6 54 53 [Effects] The optical information recording medium of the present invention configured as described above can have the following effects.

1. Recording can be performed with high sensitivity even when using a long wavelength laser (semiconductor laser).

2. It is possible to form a bit with a good shape, and a high-quality hole can be obtained.

5. High stability against heat and light, excellent storage stability,
A recording medium with little reproduction deterioration can be obtained.

[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
...protective layer. Patent applicant: Ricoh Co., Ltd., agent: Haku Yamashita, patent attorney

Claims (1)

[Claims] General formula (wherein R represents hydrogen, halogen, hydroxy group, carboxyl group, substituted or unsubstituted alkyl, acyl, aryl, alkoxy, acyloxy, aralkyl, alkenyl or amino group, and t is An optical information recording medium comprising a recording layer containing a compound (representing 1 or 2).