JPH0152192B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thin film optical recording medium on which recording is performed by irradiating recording light without using direct heating means such as a thermal recording head. The thermal recording method is a direct recording method that does not require development or fixing, and because of its ease of operation and maintainability, it is the recording method used in simple terminal devices such as printers and facsimile machines. However, since a heating element such as a heating head or a heating pen comes into direct contact with the surface of the medium, a staking phenomenon of the head may occur, resulting in a decrease in resolution and sensitivity. In order to solve these drawbacks, a method has been proposed in which heat-sensitive recording paper is colored with light from a light source such as a Xe-flash and used for recording. An example thereof will be explained based on FIG. 1 of the accompanying drawings. That is, FIG. 1 is a schematic diagram of conventional photothermal recording. In the figure, 10 is a recording medium, 11 is a substrate, 1
2 is a color forming agent layer, 13 is a document for recording and transfer, 14 is a light absorbing portion of the document, 15 is a coloring portion, and 16 is a light source. As shown in FIG. 1, an original 13 is placed below the recording medium 10, irradiated with light from a light source 16, and the coloring agent layer 12 is heated by the heat generated when the light is absorbed by the black part 14 of the original. A method of producing the color developing portion 15 has been considered. However, in this recording method, heat generated in the black portion 14 of the document 13 is largely diffused, and it is not possible to avoid the phenomenon that blurring and blurring occur around the recorded image, resulting in low resolution and low sensitivity. Instead of stacking originals as described above, there is also an attempt to record by dispersing dyes that absorb the wavelength of the exposing light in a thermosensitive coloring agent and converting the absorbed light into heat. . However, since the dyes used for this purpose are visible light absorbing dyes such as methylene blue and rhodamine B, and the absorbing agent (dye) itself is colored, it has the drawback of poor contrast before and after recording. Recently, optical recording media in which near-infrared absorbing dyes are microencapsulated and dispersed as light absorbers are also being considered. Since this medium has weak absorption in the visible light region, it is thought that the above-mentioned drawbacks in recording contrast can be improved. However, uneven color development due to uneven dispersion across both recording media,
Deterioration in resolution due to blurring and blurring is unavoidable. For example, a medium made of dispersion thermal recording paper with a light absorbent added has a maximum resolution of about 20 lines/mm. In addition, in conventional heat-sensitive media systems in which color formers and color developers are colloidal or microcapsulated and non-uniformly dispersed in the binder, the recording area becomes white and opaque, so the light from the recording light source is scattered. etc., there was a large loss in intensity, the resolution decreased in the thickness direction of the recording part, and it was also disadvantageous in terms of recording sensitivity. Therefore, the structure of such an optical recording medium is such that the color forming agent, light absorbing agent, and color developer are uniform in the direction of the recording surface and separated in the thickness direction, and each layer does not cause loss of recording light. It is desirable that the light transmittance is such that the light can reach the light absorber layer without any problems. Based on this idea, an optical recording medium has been proposed in which a heat-sensitive color forming agent, a color developer, and a light absorbing agent are uniformly dissolved in a polymer, and the solution is sequentially spin-coated and laminated. However, in this method, the concentration of the color forming agent and color developer in the thin film layer decreases as the color former and color developer are diluted by the polymer. However, since the coloring reaction relies on contact between both components, a decrease in reaction rate, ie, sensitivity, cannot be avoided. It is easy to increase the concentration of the color forming agent and color developer by reducing the amount of polymer, but increasing the concentration of the color forming component breaks down the uniform dissolution in the polymer matrix, causing crystals of the color forming component to form in the laminated thin film. The problem is that the thin film becomes cloudy and exhibits the same disadvantages as the dispersed binder type media described above. Furthermore, since each thin film layer is sequentially laminated by spin coating, it is very difficult to stack the films without affecting the already coated thin films. For example, the solvent in the spin-coating solution for the upper layer redissolves the coated thin film in the lower layer, and the more layers there are, the more difficult it is to manufacture. Further, it has the disadvantages of spin coating in general, such as the use of a large amount of organic solvent and the difficulty of uniformizing a large area with spin coating. As explained above, there is a method for producing photothermosensitive recording media that maintains a high concentration of color-forming components, as well as a highly translucent thin film, and that allows lamination to be produced using processes such as vacuum evaporation that do not use solvents or spin coating. It was long awaited. A method has been developed in which a coloring agent such as crystal violet lactone is vacuum-deposited, and a mixture of bisphenol A/stearic acid amide is also vacuum-deposited as a color developer to form transparent thin films. However, the color developer layer has problems such as microcrystallization in the thin film when the content of bisphenol A is high, and if possible, it would be easier to fabricate it if it could be replaced by vapor deposition of a single compound. It was thought that it would become. Furthermore, the above vapor deposition method only discloses color development using a color former plus a solid acid. If the vapor deposition method can be applied to a color-forming system in which a color-forming agent plus a base is used, it would be possible to provide color-forming materials with a wider range of color tones. An object of the present invention is to provide a thin film optical recording medium of one or more colors in which a specific color developer layer thin film is formed by vacuum deposition, in order to solve the drawbacks of the conventional optical recording media as described above. It's about doing. Another object of the present invention is to provide a multicolor optical recording medium using different developer layers. That is, to summarize the present invention, the first invention of the present invention consists of a light absorbent layer that absorbs light at the wavelength of a recording light source, a color former layer, and a color developer layer, and each layer is vacuum-deposited. The present invention relates to a thin film optical recording medium laminated by a method in which the color developer layer is constituted by a transparent vacuum-deposited film of a solid acid consisting of a single compound. Also,
The second invention of the present invention is a multicolor thin film consisting of a light absorber layer that absorbs light at the wavelength of a recording light source, a color former layer, and a color developer layer, and each layer is laminated by vacuum deposition. In the optical recording medium, at least one color developer layer is made of a color developer that also has a color forming function, and a layer that also serves as the next color developer layer is used, in which case, as the next color developer layer, The present invention relates to a multicolor thin film optical recording medium characterized in that a layer made of a color developer that develops color is used as the color developer that also has the color development function. The third aspect of the present invention is a thin film light source comprising a light absorber layer that absorbs light of the wavelength of a recording light source, a color former layer, and a color developer layer, and each layer is laminated by vacuum evaporation. The present invention relates to a thin film optical recording medium characterized in that the color developer layer is made of a color developer that also has a light absorption function and also serves as the light absorption layer. Hereinafter, the present invention will be specifically described based on the accompanying drawings. The basic structure of the thin film optical recording medium according to the present invention is explained in the second section.
As shown in the figure. That is, FIG. 2 is a schematic cross-sectional view of the basic structure of the thin film optical recording medium of the present invention. In the figure, 2
0 is a recording medium, 21 is a substrate, 22 is a color forming agent layer or a color developer layer, 23 is a light absorbing agent layer, 24 is a color forming agent layer or a color developer layer, and 25 is a recording light. By stacking one or more sets of these basic structures, a thin film optical recording medium capable of producing a single color or multiple colors can be produced. In FIG. 2, the substrate material of the substrate 21 is glass, polymethyl methacrylate (hereinafter referred to as
Acrylic resin such as PMMA), polycarbonate, and Mylar film can be used. Also, when transparency is not required, use high-quality paper or
Metal materials such as Al can also be used. 2
4 and 22 indicate thin films composed of layers containing coloring components. It consists of a color developer, a color former, or a vacuum-deposited film containing a color developer and a matrix component. Either one of 22 and 24 is a color forming agent layer, and the other is a color developing agent layer, and their order, that is, up and down, does not matter. Representative examples of color formers that can be vacuum deposited are shown below. Crystal violet lactone and benzoyl leucomethylene blue are used as blue color formers, 3-chloro-6-cyclohexylaminofluorane and RED-DCF (manufactured by Hodogaya Chemical Co., Ltd.) are used as red color formers, and TH-107 (Hodogaya Chemical Co., Ltd.) is used as black color formers. (manufactured by Kagakusha), malachite as a green coloring agent.
Leuco Green, used as a yellowish coloring agent by React.
Yellow (manufactured by BASF Japan) can be vacuum deposited. As color developers, phenolphthalein, thymol blue, tetrabromophenol blue, thymolphthalein, pyrogallol red, pyrogallol violet, phenolsulfophthalein, ollin, and eosin yellow powder are used to form a thin film by vacuum evaporation. is possible. Also,
As the basic color developer, a thin film can be formed by depositing a mixture of a base such as 1,3-diphenylguanidine or imidazole and an aliphatic amide such as stearic acid amide or methylolamide. As the material for the light absorber layer 23, almost any material can be used as long as it is a dye that does not overlap the absorption range after coloring of the color former. However, like the color forming agent layer and the color developing agent layer, it is necessary to use a material that can be produced by vacuum deposition. As specific examples, phthalocyanine blue, fluorescein, rhodamine 6G, CI Disperse Yellow 5 (Sumikaron Yellow 5GE manufactured by Sumitomo Chemical Co., Ltd.), etc. can be vacuum deposited. Furthermore, as near-infrared light absorbers, squarylium dyes such as diethylaminonaphthol squarylium, dimethylaminonaphthol squarylium, diethylaminophenol squarylium, and dimethylaminophenol squarylium can be produced as a vacuum-deposited film. Additionally, phthalocyanine ring compounds coordinated with metals other than Cu, such as vanadyl phthalocyanine and aluminum phthalocyanine, which have an absorption range extended to the near-infrared region, can also be vacuum deposited and used as a light absorber layer. Furthermore, bis-(cis-
near-infrared absorbing metal complex salts such as nickel 1,2-tolyl)ethylene-1,2-dithiolate and nickel-bis(1-chloro-3,4-dithiophenolate);
and platinum (Pt) salts can also be used as light absorber layers. As a specific example, NKX-113 (manufactured by Nippon Kanko Shokuryo Co., Ltd.) is the above-mentioned material that can be vacuum deposited. In addition, near-infrared absorber PA is used as the above metal complex salt.
−1001, PA−1002, PA−1003, PA−1005, PA
-1006 (manufactured by Mitsui Toatsu Fine Co., Ltd.) spin-coated film and a thin film obtained by vacuum-depositing the components removed by treating the stable salt from these absorbers can also be used as the light absorbent layer. . In addition, when considering Olin, fluorescein, etc. as a phenolic color developer, since Olin and fluorescein themselves have strong absorption near 480 nm, the color developer and light absorption for recording light near 480 nm such as Ar laser etc. It can also serve as an agent layer. Other examples include vacuum-deposited films of pigments having phenolic hydroxyl groups, such as pyrogallol red, alizarin, morin, quacetin, and cresol red. Similarly, when phenolphthalein is used as a phenol developer, phenolphthalein is crystal violet lactone, RE-D-DCF.
For basic color developers such as diphenylguanidine, it acts as a color developer.
It can be used as a coloring agent that develops an alkali color and turns red. As shown above, when an organic color-forming material is made into a thin-film optical recording medium by vacuum evaporation, uniformity and film thickness can be easily controlled, and the color-forming agent concentration is high.
In other words, a recording medium with high color development speed and high density can be easily obtained. In addition, by forming various materials into a vacuum-deposited film, it is possible to obtain a thin-film optical recording medium with a small number of laminated layers by using both a light absorber and a color developer, or a color developer and a color former. Can be done. By this,
A multi-recordable medium for optical recording can be easily obtained. EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples. Example 1 Each of the following raw materials was placed on a Ta boat and 1x
A thin film thermal recording medium was fabricated by heating and depositing it on a glass substrate in a vacuum chamber at 10 ^-5 Torr or less. (a) Phenolphthalein (film thickness 2.0μm) (b) Crystal violet lactone (film thickness 2.0μm)
m) The thermal recording medium thus obtained was transparent in the visible region and developed a blue color when heated with a thermal pen or thermal head. The color development temperature was lower than that of commercially available thermal recording paper. FIG. 3 shows the coloring properties of the above material when used as a thermosensitive coloring material. In other words, Figure 3 shows the coloring characteristics of the thermosensitive coloring material.
This is a graph showing the relationship between the thermocouple reading of the electrode part (° C.) (horizontal axis) and optical density (reflection, filter; amber) (vertical axis). In FIG. 3, 31 indicates a vapor-deposited film material, and 32 (broken line) indicates a coloring agent for commercially available thermal paper. Further, No. 33 shows an example of a commercially available high-sensitivity thermosensitive recording paper. The fact that each curve shows a tendency for color development to decrease at the tip of the high temperature section indicates the thermochromic nature of the color forming material, and the color contrast can be obtained from the optical density after the temperature decreases. It can be seen that this material develops color at a fairly low temperature. This medium can be colored in the visible region by ultraviolet rays from the medium side, and is also useful as an optical recording medium. Example 2 Under the same conditions as in Example 1, the following raw materials were vacuum-deposited from a Ta boat onto a 1.5 mm thick PMMA substrate to produce an optical recording medium. (a) RED-DCF [Hodogaya Chemical Co., Ltd., film thickness 2.0 μm] (b) NKX-113 [Nippon Kanko Shiki Co., Ltd. film thickness 2000 Å] (c) Phenol phthalein (film thickness 2.0 μm) The optical recording thin film was irradiated with semiconductor laser light with a wavelength of 830 nm from the PMMA substrate side. Under the conditions of laser light output 6mW and 1.6μmφ spot diameter.
It developed a red color with 40nsec pulsed light. It supports a recording sensitivity of approximately 30mJ/ ^cm2 . Example 3 The following raw materials were deposited on a Mo evaporation boat using Mylar.
A thin film optical recording medium was fabricated by vacuum deposition and lamination on a film. FIG. 4 shows the structure of this thin film optical recording medium. That is, FIG. 4 is a schematic cross-sectional view showing one embodiment of the present invention. In FIG. 4, numeral 46 is a substrate, and 41 to 45 are as follows.

[Table] Lactone

[Table] Made by Co., Ltd.
When this recording thin film is exposed to a semiconductor laser with a wavelength of 850 nm, 42 is melted and removed, and 41 and 43 react, producing a blue color. Similarly, when exposed to a semiconductor laser with a wavelength of 1100 nm, the light absorbed by 44 becomes heat. 43 and 45 reacted to produce a red color. The recording sensitivity was approximately 30 mJ/cm ² for each. Example 4 The following raw materials were vacuum deposited and laminated on a PMMA substrate from a W boat. Film thickness (a) TH-107 [manufactured by Hodogaya Chemical Co., Ltd.] 2.0 μm (b) Olin 2.0 μm Figure 5 shows the structure of this medium. That is, the fifth
The figure is a schematic cross-sectional view showing an embodiment of the present invention. In FIG. 5, reference numeral 51 indicates a color former layer on a substrate 52, and reference numeral 53 indicates an Olin layer. This medium has two layers and is colored orange due to the absorption wavelength of Olin (480 nm). When recording on this medium with an Ar laser (wavelength 488nm),
TH-107 and Olin reacted, producing a black color.
The sensitivity was approximately 20 mJ/cm ² . Example 5 A thin film optical recording medium was prepared by vacuum-depositing the following raw materials onto high-quality paper. Film thickness (a) 1,3-diphenylguanidine (3.0μm) (b) Fluorescein (3000Å) (c) Thymolphthalein (2.5μm) 1,3-diphenylguanidine microcrystallizes on paper (substrate) and becomes high-quality paper. The result is a thin film that does not damage the white background. Fluorescein formed a yellow film (λmax 480 nm), and thymol phthalein formed a highly translucent film on each layer (a). When this was recorded with an Ar laser (λ = 488 nm), thymol phthalein reacted with 1,3 diphenylguanidine, resulting in a blue color and recording was possible. The sensitivity corresponded to approximately 50mJ/ ^cm2 . In the above-mentioned recording medium in which fluorescein was omitted, it was also possible to develop a blue color using a thermal head. Example 6 The following raw materials were vacuum deposited on a PMMA substrate to prepare a thin film optical recording medium. Film thickness (a) 1,3 diphenylguanidine/stearamide mixture (weight ratio 1/1) 4.0μm (b) NKX-113 (λmax850nm) 3000Å (c) Phenol phthalein 3.0μm (d) Vanadyl phthalocyanine (λmax780nm) )
3000 Å (e) Crystal violet lactone 2 μm (a) The layer was a highly transparent film in which 1,3 diphenylguanidine was dispersed in stearic acid amide. When recording was performed on this material from the medium side using a semiconductor laser with a wavelength of 780 nm, crystal violet lactone and phenolphthalein reacted, producing a blue color. Furthermore, when recording was performed using a semiconductor laser with a wavelength of 850 nm, phenolphthalein and 1,3-diphenylguanidine reacted, producing a pink color. The color development sensitivity was approximately 50 mJ/cm ² for each. As described above in detail, according to the present invention, a recordable medium with high resolution and high contrast can be produced by irradiation with light from a semiconductor laser or the like. The produced thin film optical recording medium has good transparency in the color forming agent layer and the color developer layer except for the 1,3 diphenylguanidine layer of Example 5, and the color forming agent concentration and color developer concentration are also compared to the binder dispersion system. Since this is extremely high, even in the case of a multicolor coloring system in which thin films are laminated in multiple layers, it has the advantage of little light loss and high coloring sensitivity. In particular, the use of a single vapor-deposited film of a transparent phenolphthalein compound as the color developer layer greatly exceeds conventional methods in terms of ease of production and ensuring transparency. Similarly, the configuration in which the color developer also functions as a light absorber as in Example 4 greatly simplifies the configuration of the optical recording medium.
In combination with the method of configuring the color developer and color former of Example 6, this further expands the range of application of the vapor-deposited film layered optical recording medium. Therefore, it can be said that the structure of the thin film optical recording medium according to the present invention makes it possible to realize high-contrast, high-speed multicolor recording, and is a recording medium suitable for application to wavelength multiplexing optical disk media and color microfilms. Furthermore, if the light absorbent layer is removed, it can be easily used as a heat-sensitive medium, and can also be used to produce a recording medium with high sensitivity characteristics.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of conventional photothermal recording, FIG. 2 is a cross-sectional schematic diagram of the basic structure of the thin film optical recording medium of the present invention, FIG. 3 is a graph showing the coloring characteristics of the thermosensitive coloring material, and FIG. 1 and 5 are schematic cross-sectional views showing an embodiment of the present invention. 10 and 20: recording medium, 21, 46 and 5
1: Substrate, 22: Color former layer (or color developer layer), 2
3, 42 and 44: light absorber layer, 24: color developer layer (or color former layer), 41 and 52: color former layer, 4
3: Color developer and color forming agent layer, 45: Color developer layer, 53:
Color developer and light absorber layer, 31: medium of the present invention, 32 and 33: commercially available products.

Claims (1)

[Scope of Claims] 1. A thin film optical recording medium consisting of a light absorbent layer that absorbs light at the wavelength of a recording light source, a color former layer, and a color developer layer, each of which is laminated by vacuum deposition. . A thin film optical recording medium, wherein the color developer layer is composed of a transparent vacuum-deposited film of a solid acid made of a single compound. 2. The thin film optical recording medium according to claim 1, wherein the solid acid is a phenolphthalein compound. 3. In a multicolor thin film optical recording medium consisting of a light absorber layer that absorbs light at the wavelength of a recording light source, a color former layer, and a color developer layer, each layer being laminated by vacuum deposition, at least one As the color developer layer, a layer consisting of a color developer that also has a coloring function and that also serves as the next coloring agent layer is used, in which case, as the next color developer layer, a color developer that also has the coloring function. A multicolor thin film optical recording medium characterized by using a layer consisting of a color developer that develops color. 4. The multicolor thin film light according to claim 3, wherein the color developer having the color-forming function is phenolphthalein or thymolphthalein, and the color developer that develops the color is a basic color developer. recoding media. 5. In a thin film optical recording medium consisting of a light absorber layer that absorbs light at the wavelength of a recording light source, a color forming agent layer, and a color developer layer, and each layer is laminated by vacuum evaporation, the color developer layer is 1. A thin film optical recording medium comprising a color developer having a light absorption function, the layer also serving as the light absorption layer. 6. The thin film optical recording medium according to claim 5, wherein the color developer having a light absorption function is a dye having a phenolic hydroxyl group.