JPS58101093A - Light information recording medium - Google Patents

Abstract

PURPOSE:To provide a titled medium capable of recording with a high energy beam by forming of a recording layer which is composed of a light absorbing layer of the surface side and a metal reflecting layer of the substrate side on the substrate. CONSTITUTION:Metal compound such as silver nitrate, reducing agent such as reduced sucrose, and colorant are dissolved in aqueous soluble resin with water. Then, the obtained resin solution is coated on a substrate made of plastic or the like, is heated, and drived, a recording layer 2 which is composed of a light absorbing layer 4 which contains colorant at the surface side and a metal reflecting layer 3 which contains colorant at the substrate side in some cases is beared on the substrate 1, thereby obtaining the objective recording medium. The recording of information is performed by contacting the spot of the high energy beam such as laser from the substrate side, and a hole is opened at the reflecting layer by the absorbed heat and is recorded.

Description

[Detailed description of the invention] The present invention relates to a novel optical information recording medium.

In the past, many optical information storage media for laser writing have been developed. Representative examples include d1 metal,
There are recording media with vapor-deposited films of semimetals and non-metals, and recording media with reflective films formed by heating a silver dry plate. However, recording media with vapor-deposited films of metals, semimetals, and non-metals are generally manufactured by vacuum forming methods in the Structural regime rather than in the continuous regime and are therefore expensive (and require more patches). This makes it difficult to achieve uniform quality for mass-producing products. Furthermore, since it is necessary to melt the metal of the recording layer with the energy of the light beam, materials with low melting points are used, which causes problems in oxidation resistance and the like.

In addition, the method of forming a reflective film by heating a silver dry plate is time-consuming because the silver dry plate must be formed in advance by exposure and exposure, and since the reflective film is formed on the surface opposite to the substrate, it is prone to scratches and dust. There is a problem in that a protective film is required in practical use to avoid such effects.

An object of the present invention is to provide an optical information recording medium in which a reflective layer of metal particles is provided on the substrate side of the recording layer through a short process consisting of coating and heating, and the recording sensitivity is improved. Another object of the present invention is to provide an optical information recording medium that does not require a protective film layer. A further object of the present invention is to provide an optical information recording medium in which a metal material can be freely used as a material for a metal reflective layer, and a method such as plating can be used for forming the metal material. Furthermore, the present invention aims at manufacturing optical information recording media in a continuous operation.

According to the present invention, the recording layer is composed of a recording layer supported on a substrate, and the surface of the recording layer is composed of a light absorption layer containing a dye, and the substrate side of the cough recording layer is composed of a metal reflective layer containing a dye as the case may be. An optical information recording medium that can be recorded with a high-energy beam consisting of the following is provided.

The optical information recording medium of the present invention has a recording layer 2 formed on a suitable front substrate 1 as shown in FIG. 1, and the recording layer 2 has a reflective layer 3 of metal particles on the substrate side. It has a light absorbing layer 4 made of metal particles and /l or a metal compound on one surface side. Furthermore, as shown in FIG. 2, an undercoat layer 5 may be provided between the substrate 1 and the recording layer 2.

Both the reflective layer and the light absorbing layer constituting the recording layer of the optical information recording medium of the present invention contain a dye.

Contains. However, depending on the purpose, the dye can be contained only in the light absorption layer.

The substrate materials used in the present invention are well known to those skilled in the art and must be transparent to the high energy beam used.

General recording material substrates such as glass and plastic can be used, and plastic is particularly preferred from the viewpoints of safety, improved recording sensitivity, and flatness. As the plastic, acrylic, polycarbonate, polysulfone, poly'imide, etc. are used. Particularly preferred are polysulfones and polyimides. Further, an undercoat layer using these resins may be provided on the glass substrate. Further, there is no problem even if an undercoat layer is provided on the plastic substrate.

The metal compound used in the present invention can be formed into the following metal particles Ag, Au, and Cu by the action of a reducing agent.

Pd, F61XCo, N1, T1, V, 81, Ge
, Be, ThXMn.

Pt, Rh, Ir, Tc, ReXRu5Os,
MO1'ra, At, Eng1Sn, Be, To
, Cr, Bi, Hf, Y, Nd, ZrXW,
Zn.

M←, Bc, Nb, and LaXPr can be formed.

Specific examples of the metal compounds include silver nitrate, potassium silver cyanide, potassium gold cyanide, Kushi ammine complex, silver cyanide complex, and Kinshiomakusha gold cyanide complex. As a reducing agent, formalin, tartaric acid, tartrate, reducing sugar,
Hyporite.

Sodium borohydride, dimethylamine borane, etc. can be used. The reducing agent has α5 to 10 per mole of metal compound.
It can be used preferably in a mole range of 2 to 4 moles.

Further, the reflective layer of the present invention can be formed by separately forming the metal particles on a substrate by vapor deposition, electroless plating, or the like.

It is sufficient that the dye used in the present invention has absorption near the wavelength of the high-energy beam, and it is particularly preferable that the dye has maximum absorption near the wavelength of the high-energy beam.

Examples of these dyes include the following dyes.

(1) Direct dyes Classified based on chemical structure, there are azo, stilbene, thiazole, dioxazine, phthalocyanine, etc. The representative ones are listed below.

(a) Azo type C, 1, da (L' Takutoi xr: x-12 (C, L 2
4895) Orange 29 (' 29155) Red 2 (' 23500) Violet 7 (' 27855) Blue 4
1 (' 42700) Green 33 (' 34270) ' 59 (' 54040) Brown 25 (
' 36030) Black 22 (1-55455) ' 56 (' 34170) ('b) Stilbene-based C, 1, Direct Yellow 39 C1■, Direct Black 62 (c) Phthalocyanine-based C1, Direct Blue 86 ( C, engineering, 741
80) (2) Acid dye (a) Azo C, 1, Acid Yellow 56CC, Engineering, 13065
) Orange 56 (' 22895) Red 9 (' 15635) Violet 7 (' 18055) Blue 29 (
'20460) Green 35 ('13361) Black 26 ('27070) (b) Anthraquinone C,1, Acid Violet (C,1,61710
, 61800) Blue 23 (' 61125) Green 44 (' 61590) Black 48 (' 65005) (c1 Triphenylmethane C, T, '777 Violet 49 (C, 1, 42
640) Blue 83 ('42660) Green 16 ('44025) (d) Xanthine-based C,1,7 Sid Red 92 (C,1,4541,0
) (e) Azine C4■, Acid Red 59 (C, 1, 50315
) Black 2 (' 50420) (3) Basic dye (a) Cyanine C, 1, Pacific Red 12 (C, ' 1.48
070)-Violet 7 ('48020)
(b) Azo C, 1, Paysic Brown 1 (C1 engineering, 21ooo
) Black 2 (' 11825) (C) Azine C, 1, Pacific Red 2 (C, 1, 5024
0) Red 1 (' 45160) Violet 10 (' 45170) Blue 3 (
' 51005) Blue 25 (' 52025) Button triphenylmethane type C, 1, Pacific Red 9 (C0 engineering, 4250
0) Violet 3 ('42555) Blue
1 (' 42025) Green 4 (142000) (4) Mordant, acidic mordant dye (a) Azo type C0, mordant Φ yellow 1 (c, r, 140
25) Yellow 26 (' 22880) Orange 37 (' 1871) Red 9 (' 16105) Violet 5 (' 15670) C, [, Moment Blue 15 (c, ■, 16680) Green 11 (' 20440) Black 9
(' 16500) (b) Anthraquinone Moment Red 3 (C0, 58005) Blue 8 (' 58805) Black 13 (' 63615) (C) Xanthine Moment Red 15 (C, Eng, 45!+05)
(d) Triphenylmethane Moment Violet 1 (C1■, 43565)
Blue 47 (143855) (5) Vat dye (a) Anthraquinone type C, 1, rose)-E co-2 (C, 1,67300)
Yellow 4 ('59100) Orange 2 ('59705) C, 1, Bat-Red 10 (c, z, 67000
) Violet 13 ('68700) Blue
18 (' 59815) Green 8 (' 71050) Black 9 (' 65230) Green 1 (' 59825) cb) Indigoid C1, bat orange 5 (c, r, 73335)
Orange 7 (#71105) Red 2 (“ 73365) Violet 2 (’ 73385) Blue 1 (
'73000) (6) Disperse dye (a) Azo C,1, Disperse Yellow 7 (C,1,
26090) Orange 5 (' 11100) Red 7 (' 11150) C, 1, Dismace No. 9 Oret 24 (C, L
l 1200) (b) Anthraquinone Orange 11 (C, 1,60700) Red 11 (
' 62015) Violet 4 (' 61105) Blue 27 (# 60767) (7) Oil-soluble dye (al azo C9, Solvent Yellow 6 (C9, 1139)
0) Orange 5 (' 18745) Red 27 (' 26125) Brown 5 (' 12020) (b) Anthraquinone violet 14 (C, ■, 61705) Blue
11 (' 61525) Green (' 6
1565) (c) Phthalocyanine Solvent Blue 25 (C, Engineering, 74350) (d)
The triphenylmethane-based 051 (C, 1, 21260) optical information recording medium of the present invention can be manufactured by various methods, and one of the manufacturing examples will be explained next.

First, the metal compound, the reducing agent, and the dye are dissolved in a water-soluble resin using water or a suitable solvent. As the water-soluble resin, for example, polyvinyl alcohol, polyhinylpyrrolidone, polyacrylic acid, polyacrylamide, etc. can be used. The weight ratio of the metal 41 compound to the water-soluble resin is 0.1 to 10, preferably 0.5 to 1.5.

The amount of dye added is [L'002~1 by weight ratio to resin]
0 preferably [L01 to 1.0. Next, the resin solution is applied onto a suitable substrate to form a recording layer precursor. This recording layer precursor has a film thickness of, for example, 0.1 to 10 μm.
Preferably, the coating film is formed to a thickness of 0.3 to 2 μm on a substrate by a commonly used coating film forming method such as brush coating, roller coating, flow coating, spin coating, or spray coating.

Next, the recording layer precursor obtained in this way was heated to 50 to 1
By heating and drying at 50° C., preferably 60 to 100° C., a reflective layer of metal particles containing a dye is formed on the substrate side. On the other hand, a light absorption layer made of metal particles and/or metal compounds and a dye is formed on the surface side of the recording layer. The heating time varies depending on the heating temperature, etc., but it is necessary to continue heating until a reflective layer of metal particles is formed on the substrate side of the recording layer. The above manufacturing examples are for illustrative purposes only and are not intended to be limiting.

Further, as mentioned above, the reflective layer of the present invention can be separately formed on the substrate by vapor deposition, electroless plating, etc. of the upper i-pi metal particles, but in this case, the thickness of the reflective layer is 0.01~
It is desirable that a05μ is appropriate and that 40-80% of the light is transmitted.

In this case, the light-absorbing layer is constituted by a resin layer containing a light-absorbing substance such as the above-mentioned dye, the above-mentioned metal particles, and the above-mentioned metal compound, and the film thickness is 0.05 to 5 μm, preferably 0.05 μm.
~08 μm. Most existing resins can be used as the resin, but those that are soft and have a low melting point are preferred. For example, polyvinyl alcohol, polyvinyl butyral,
These include vinyl chloride and nidotetracellulose. The concentration of the dye added is such that the light transmittance is 1 in the wavelength range of the laser used.
It is preferable that it be 0 or less.

Information is recorded by applying a spot of a high-energy beam such as a laser beam from the substrate side, and the absorbed heat creates a hole in the reflective layer and records the information. Since the recording surface is on the substrate side, a film retaining layer is not required.

Additionally, information can be read by irradiating a low-power laser beam and detecting changes in the amount of reflected light.

Furthermore, as shown in Figure 3, when a high-energy beam such as a laser is irradiated from the substrate side, the light that has passed through the reflective layer is
It is absorbed in the absorption layer and that part becomes high temperature. Therefore, the resin melts and evaporates, forming holes as shown in FIG. The metal reflective layer remains unchanged. When this is irradiated with a low-energy beam, the reflectance of the metal reflective layer differs by more than 20 points between the part with the hole at the rear and the part without it (the part without the hole is higher), as shown in Figure 4. As shown in the figure, the amount of reflected light changes and information is read.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto.

Example 1 Polyvinyl alcohol 1f Water 9g Silver nitrate α5I28 capsule ammonia water α5-glucose
(L5j A solution having the above composition was coated on an optically polished glass plate by a spin coating method to obtain a recording layer precursor. This was dried at 80° C. for 10 minutes to obtain a 0.8 μm thick O recording layer. .

The reflectance was 35 in the near-infrared region, and the absorption was 60.

The recording medium thus obtained was irradiated with a surface energy of 7 mW using a He-No laser.

When information was recorded from the substrate surface with a beam diameter of 2.4 μm, the irradiation time was 1.0 μs (writing energy 7 nJ/
dot) to form a spot with a diameter of 1.1 μm.

For comparison, we created a sample with the same composition but no dye, and found that it was irradiated for 2.5 μs (writing energy 1).
7.5 nJ/dot), a spot with a diameter of 1 μm was formed.

Example 2 Polyvinylpyrrolidone 3 in water
7t gold potassium cyanide 1f3! l Formalin
0.5- (manufactured by Mitsui Toatsu Chemical Co., Ltd.) A solution consisting of the above components was applied onto an acrylic plate by spin coating to obtain a recording layer precursor. This was surface-dried at 60° C. for 10 minutes to obtain a recording layer with a thickness of 0.4 μm.

The reflectance was 30% in near-infrared light, and the absorption was 60%.

When recording was performed on the recording medium thus obtained in the same manner as in Example 1 using an I (θ-Nθ laser), a7/
A spot with a diameter of 1.0 μm was formed with J seconds of irradiation (4.9 nJ/dot).

For comparison, a sample without the addition of dye No. 11 was prepared, and the writing energy was 19 nJ/dot.

Example 3 Using the same composition as in Example 1 but using the dyes listed in the table below in place of IJiPuru Blue'OBB as the dye, a good recording sensitivity as shown was obtained.

Black B Sumilight Violets 27905 7.0
) BB Direct Blue 2B 22610 7.
0 Hodogaya Chemical Eisen Basic 42025
4.9 Anine 6GH Eisenmethylene Blue 52015 4.9
BH Manufacturer Pigment base C, L level record takeshi (rsuiro ot) Lean GWN Mitsui Toatsu Selmasol Brillia 61200
5.6 Point Plue R Direct Blue Plug” 30235 70 Lac I [fX Mike Lenzl Nib 73002 6.3
Le Blue 0 Nippon Kayaku Kayasil Sky Blue 62045
6.5 kayak loader 45100
7.7 Min BH Orient Water Blue 94.2 Example 4 A solution of nigrosine (manufactured by Sumitomo Chemical) in the same composition as Example 1 was applied to an acrylic plate using Soluble Blue BB, and heated at 90°C, 59°C. A recording medium was obtained by heating and drying for a minute. When recording was performed from the substrate side using a semiconductor laser with a wavelength of 820 nm and a beam diameter of 1.5 μm and an irradiation surface energy of 4 mW, a spot with a diameter of α8 μm was created after irradiation for 1.3 μs (writing energy 5.2 nJ/pit). Well formed.

When no nigrosine was added, the writing energy was 15 n, r/pit.

Example 5 dl y vinyl alcohol 0.7f water 10
fSilver nitrate 1.5f28Rice ammonia water 3-Formand
1-Direct Blue 2B (C, 1
, 22610) (15t (manufactured by Sumitomo Chemical)) A solution having the above composition was applied to a hardened acrylic plate and dried at 80° C. for 10 minutes to obtain a recording medium.

The reflectance was 5016, and the transmittance at 600 to 700 nm was 5. When this recording medium was used with an Hθ-Nθ laser to record a large amount of information on the substrate surface with an irradiation surface energy of 5 mW and a beam diameter of 2.4 μm, 0.6 μsec of irradiation (writing energy of 3 n, T/pit) resulted in There is a hole in the light absorption layer. There was no change in the metal reflective layer. 0 for this.
A continuous beam of 5 mW was irradiated, and a decrease in the amount of reflected light of 20- was observed in the recorded area.

In addition, it takes 7 m to make a hole in the reflective layer of this recording medium.
The energy of W is 2.5 μ5ec (17,5n, Ti
1 t) of energy was required.

Example 6 Nickel sulfate 0.1 mol/l Sodium citrate 0.2# Sodium hypophosphite 0.2# Ammonium sulfate 0.5# A glass plate was nickel plated in a different nickel plating bath to a thickness of 0. A nickel layer of .05 μm was obtained. Furthermore, on top of this, polyvinyl butyral 0.32 ethanol 5WIt water blue 9 (
Orient Chemical Exhibition) A solution called A2F was applied to obtain a light absorption layer with a thickness of α2 μm. Reflectance is 3
5-The transmittance line at 1600 to 700 nm was 3-. When information was recorded on this recording medium in the same manner as in Example 5, irradiation for α8μ seconds (writing energy 4.0
nJ/pit), a hole was formed in the light absorption layer. A similar readout was performed and the amount of reflected light decreased at 229. It was noticed.

[Brief explanation of the drawing]

In the accompanying drawings, FIG. 1 is a cross-sectional view showing the basic structure of the optical information recording medium of the present invention, and FIG. 2 is a cross-sectional view showing another example of the optical information recording medium of the present invention. FIG. 3 is a cross-sectional view showing the writing state of the optical information recording medium of the present invention.
FIG. 4 is a cross-sectional diagram showing the state Wlt of the optical information recording medium of the present invention after recording, and a diagram showing changes in the amount of reflected light. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Brass layer, 6... Metal reflective layer,
4... Light absorption layer, 5... Subbing layer, 6... Condensing lens, 7... Laser beam. Patent applicant: Ricoh Co., Ltd. Patent attorney: Haku Yamashita

Claims (1)

[Scope of Claims] 1) It is supported on a substrate and consists of nine recording layers, and the surface side of the recording layer is composed of a light absorption layer containing a dye, and the substrate side of the recording layer is composed of a metal reflection layer containing a dye as the case may be. An optical information recording medium that can be recorded using a high-energy beam. 2) The optical information recording medium according to claim 1, wherein the substrate side of the recording layer is composed of a metal reflective layer containing a dye. 6) The optical information recording medium according to claim 1, wherein the substrate side of the recording layer is composed of an extremely thin metal reflective layer containing a dye.