JPS60254038A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To obtain an optical information recording medium capable of recording and reproducing this record using long wavelength light, such as semiconductor laser beams, superior in storage stability, small inreproduction deterioration, and high in recording density by using a recording layer contg. a specified compd. CONSTITUTION:This optical information recording medium is obtained fundamentally only by forming on a base plate a layer contg. a compd. represented by the formula in which each of R1-R3 is independent of each other, and each is H, halogen, OH, COOH, optionally substd. alkyl, alkoxl, aryl, acyl, acyloxy, or alkenyl, and M is Ni, Co, Cu, Mn, Pd, or Pt. The recording layer is formed by vapor deposition, sputtering, CVD or solution coating, etc. Glass, plastics, such as polyester or methyl methacrylate, metals, and ceramics are used for the base plate. As a result, the obtained recording medium has a pit formed in a good shape, and has high S/N ratio and high heat and light stability, superior storage stability, and small reoroduction deterioration.

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 Information recording and reproducing apparatuses have been known that record and reproduce information by irradiating a rotating disc-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 an electric shield 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, R1 to R1 may be the same or different, and each is hydrogen, halogen, hydroxy group, carboxyl group, or substituted or unsubstituted alkyl,
represents an alkoxy, arylζacyl, acyloxy or alkenyl group and M is NiXCoXCu, M
Represents n5Pd or pt.

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

A CH, @ @ Ni ・000 -・ Compound Rj R2R,, M G'HJ-I HNi HCI HHNi I HC1' HNi J HHC1l Ni K CI CI HNi L HCl Ce Ni M CI CI C,e Ni N Br HHNi OHBr HNi P HHBr Ni Q CH3HHNi RHCH3CH3Ni S CH3C'H3CH3Ni T OCH30CH30CH5Ni U COCH3COCH3C'OCH3Ni compound R
I R2R3M W OI■ OHOHNi X Ii' F F Ni 2 Pt 3 y p C.

4 g tt s Cu 5/l Mn 7 # # Pt 8C.

9 Cu 10　Mn Compound RI R2R3M 12 Pt 13　C○ 〃 14 tt tt Cu 15 x p tr Mn 17　s　Pt IB # # tt C.

19 z' tt Cu 2Ott , # # Mn 22 # # Pt 23 s rt C0 24Cu 25, utt s Mn 26 C2H5C2H5C2H5Ni The optical information recording medium of the present invention basically comprises a substrate and a recording layer. However, if necessary, a subbing layer, a waist-retaining layer, etc. can be further provided. It is also possible to form a so-called air sandwich 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 a certain optical change by irradiation with laser light and recording information based on the change, and this recording layer contains a compound of the above general formula. Must be. Further, in forming the recording layer, one type or a combination of two types of compounds having the above general formula may be used. Furthermore, the above compounds of the present invention can be used with other dyes such as phthalocyanine dyes, tetrahydrocholine dyes, dioxazine dyes, triphetchazidi/
dyes, phenanthrene dyes, cyanine (merocyanine) dyes, antho-2-quinone (indanthrene dyes, xanthine dyes, triphenylmethane dyes, croconium dyes, biryllium dyes, azulene dyes, etc.) or metals, Metal compounds such as In, Sns To,
B1, At, Be, 'reo,,, sno, As
, (J, etc.).The above compound of the present invention can also be used in the form of a mixed dispersion or a laminate with polymer materials such as ionomer resins, polyamide resins, vinyl resins, natural polymers, silicones, liquid rubbers, etc. It may be used by mixing and dispersing in various materials or silane coupling agents, or it may be used as a stabilizer (for example, a precipitate pA complex), a dispersant, a flame retardant, a lubricant, or a band for the purpose of improving properties. 't
4 defenses 1).

It can also be used together with agents, surfactants, plasticizers, etc.

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 FIG. 1, the optical information recording medium of the + invention basically comprises a substrate 1 and a recording layer 2 containing the compound of the above general formula. Further, the recording layer can also have a two-layer 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, smottling, 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;
, 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, aliphatic halokenated hydrocarbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride, trichloride, and lolethane, or benzene, toluene, xylene, ligroin, monochlorobenzene, dichlorobenzene, etc. Aromatics and the like can be used. The appropriate thickness of the recording layer is 100λ to 1°/1 m, preferably 2001 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, glass such as polymethyl methacrylate, gold, and ceramics are commonly used, but any other material used for recording media may be used.

Further, as shown in FIGS. 2 to 4, an acidic material having the structure shown in FIG. 1 may be further provided with a subbing layer 3 and/or a protection 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 subbing layer 3 has the following functions: (a) improved adhesiveness, (b) barrier against water or gas, (c) improved storage stability of the recording layer, (
, i) to improve reflectance, (e) to protect the substrate from solvents, and (f) to form pregrooves. For the purpose of (a), various substances such as the above-mentioned polymer materials and silane coupling agents can be used, and for the purposes of (b) and (c), MgF2.5iO
1T102, znOlTiN, 81N, etc., metals or semimetals such as Zn, Cu5S, Ni, Cr%Ge
, Be.

Cd5A(:,, At, etc.) can be used.

For the purpose of (a), it is possible to use metals such as Al, Ag, or organic materials with metallic luster, such as methane dyes, xanthene dyes, etc.; and (e),
For the purpose (f), ultraviolet curing resins, thermosetting resins, thermoplastic resins, 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. Further, the cover layer 4 is provided for the purpose of protecting the recording layer from kisses, dust, dirt, etc. and improving the chemical stability of the recording layer, and the same material as that of the undercoat layer can be used as the material thereof. The film thickness of rm = 0
．． A suitable thickness is 1 μm or more, preferably 50 μm or more.

Furthermore, as another configuration of the original information recording medium according to the present invention, two recording media having the same configuration as shown in FIGS. It may be a so-called air sandwich structure in which the layer 2 is placed inside and picked up, or it may be a so-called folded sandwich structure (bonded structure) in which it is bonded with a protective layer 4 interposed therebetween.

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.

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

Example 1 Polymethyl methacrylate (JJ) with a thickness of 1.2 mm.

A recording medium was prepared by spin-coating a tetrahydrofuran solution of Compound Example A on a substrate (abbreviated as PMMA J) to form a recording layer with a thickness of 0.1 μm.

Example 2 A recording medium was produced in the same manner as in Example 1 except that the recording layer was formed using the example compound described above.

Example 6 A silver vapor deposition film having a thickness of 100 mm was further provided on the recording layer formed in Example 1 to produce a recording medium.

Example 4 On a PMMA substrate with a thickness of about 1.2 mm, the above compound B and a compound of the following general formula (υ) were mixed in a weight ratio of 1=1.
Spin coat the 2-dichloroethane solution to a thickness of 0.1 μm.
A recording layer was formed to produce a recording medium.

Example 5 A 1,2-dichloroethane solution containing the compound example C and the compound of general formula CI+) mixed at a weight ratio of 7:3 was spin-coated onto a 1.2111 pm thick substrate to a thickness of 0. .1
A recording layer of μm is provided on top of the recording layer of the following general formula (III
) was vacuum-deposited to a thickness of 0.05 μm to produce a recording medium.

Example 6 A 150-thick Te vapor-deposited film was provided on a PMMA substrate with a thickness of 1.2 μm, and a 1,2-dichloroethane solution of Compound Example F was spin-coated thereon to give a thickness of 0.1 μm. A layer was formed to produce a recording medium.

A write power of 2.25 was applied to the recording medium produced in the above example from the substrate side using a semiconductor laser beam with a wavelength of 790 nm.
mW, recording frequency 0.5 MHz, linear velocity i, 5 m/
Information was written and reproduced in seconds, and its spectrum analysis (scanning filter, bandwidth 30 KHz) was performed to measure the C/N. Next, 54000 on the same recording medium
C/ after irradiating the tungsten source of Lux for 50 hours
Nf was measured. The results are summarized in the table below.
.

Initial value 50 hours after light irradiation Example 1 48 45 〃 2 50 48 s 3 55 54 #4 56 56 #5 52 52 #6. 19 47 [Effects] The uninvented original information recording medium configured as described above can produce the following effects.

1. Even if a long wavelength laser (semiconductor laser) is used, recording can be performed with high sensitivity.

2. Able to form bits with good shape and high C
/N is obtained.

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

[Brief explanation of drawings]

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: Patent Attorney Haku Tsuchiyamashita'; Figure 1 Figure 2

Claims (1)

[Claims] General formula (wherein R1 to R3 may be the same or different (and each is hydrogen, ], hydroxy group, carboxyl group, or substituted or unsubstituted alkyl, alkoxy, aryl) , represents an acyl, acyloxy or alkenyl group and M is N1, Co, Cu
1. An optical information recording medium, comprising a recording layer enclosing a compound (representing XMn, Pd or pt).