JPS6040995B2 - recoding media - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording medium on which recording is performed by irradiating energy beams, and a recording method thereof.

Conventionally, recording media that record by changing physical property constants such as transmittance, refractive index, and reflectance by irradiating them with strong infrared energy, such as laser light, xenon lamps, mercury lamps, and arc lamps, have extremely high The ability to form high-resolution and high-contrast images, the ability to not be exposed to room light and require no darkroom operations, the ability to add information later, the time-series signal that transmits computer output, etc. It has advantages such as being suitable for recording electrical signals such as micro images, C
It is applied to OM, micro facsimile, original plates for phototypesetting, etc.

For example, recording media that perform thermal recording by laser beam irradiation have conventionally been made of thin films of metals, semimetals, derivatives, organic materials, etc., or combinations thereof, on transparent supports such as plastic films. Things have been used as coins. These recording media are particularly required to have excellent sensitivity. This depends on the characteristics of the laser beam. In other words, as a recorded output,
Laser beams, which can be focused non-contact and at high density on the recording medium, demonstrate their advantages in the field of high-speed, high-density recording compared to other recording outputs, so the corresponding high sensitivity is required. This is because the suitability of the recording medium is one of the keys to heat mode recording using a laser beam. Furthermore, if the sensitivity of the recording medium is low, a high-output laser will be required, but this will inevitably require an increase in the size of the recording device, and the consumption of power, cooling water, etc. will also be large. Furthermore, the danger of the laser beam to the human body is significantly increased. The present invention aims to provide a highly sensitive recording medium and a recording method, and its features include a porous layer that is transparent due to its constituent material itself but opaque due to its porous nature, and a highly sensitive recording medium and recording method. The porous layer is filled with a low melting point material layer that melts and flows by applying energy.

Next, it will be explained with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a recording medium according to the present invention.

In the figure, reference numeral 1 denotes a metal or nonmetal support, which is usually an organic resin film such as oxidized cellulose, polyester, triacetate, or polyethylene acetate, paper, glass, or a metal such as N in the form of a plate or foil. 2 is a porous layer,
The material constituting this porous layer, which is opaque because it has a large number of pores 2a, has good translucency and is designed to prevent deformation when thermal energy is applied to melt a low-melting point substance. A material whose softening point is not very low and has a softening point of 10,000 or more, preferably 150oo or more is used. For example, porous organic resins such as polypropylene, polystyrene, polymethyl methacrylate, polyvinyl alcohol, polybutadiene, polyurethane, epoxy resin, and co-condensed polyester, and porous materials such as zeolite, calcium carbonate, and diatoms. There are sea urchins, etc. The porous opaque layer in the present invention may be made by any method and may have pores of any shape.

Examples of methods for forming a porous layer using the organic resin described above include the following. That is, an organic resin is used as a binder, and fine particles (0.1 to several particles) that are soluble in a solution that does not react with the support layer, the low melting point substance layer, and the binder are dispersed, and the particles are dispersed into the low melting point substance. This is a method in which a porous layer is obtained by coating the particles on top and then dissolving and removing only the particles. In this case, it is desirable that the fine particles dispersed in the binder have a size comparable to the thickness of the binder to be applied. If the fine particles are small, the passage for the molten low-melting point substance to infiltrate the pores of the porous layer will not be completely opened, or such
This is because the distribution of passages becomes significantly non-uniform. The thickness of this porous layer can be from 0.5 to 100 mm, preferably from 1 mm to 10 mm.

If this porous layer has sufficient strength, the support described above can be omitted. 3 is a low melting point material layer.

This low melting point substance melts and flows upon application of thermal energy, filling the pores of the porous layer and making the porous layer transparent. Its melting point is preferably 6000 to 1300○,
The thickness thereof is approximately 0.01 to 10 mm, as long as it has a sufficient amount to fill the pores in the porous layer. Examples of transparent low-melting substances used here include organic resins such as polyethylene, polybutene, vinyl acetate, ethylene, vinyl acetate copolymers, polyvinylidene chloride, polymethacrylic acid esters, cellulose nitrate, and cellulose acetate; Examples include organic substances such as melting point paraffin, a mixture of paraffin and ethylene vinyl acetate copolymer, or fatty acids and derivatives thereof. Here, the fatty acids include palmitic acid, heptadecylic acid, stearic acid, montanic acid,
Melisic acid, lactose acid, nonadecanoic acid, arachidic acid,
Behenic acid, lignoceric acid, cerotic acid, heptacanoic acid, etc., and fatty acid derivatives include methyl cerotate, methyl heptacanoate, methyl montanate, methyl melisinate, ethyl montanate, ethyl melisinate, and ethyl lataselate. , stearic acid amide, acetic acid amide, propionic acid amide, butyric acid amide, green acid amide, caproic acid amide, enanthic acid amide, capric acid amide, belargonic acid amide, capric acid amide, undecylic acid amide, lauric acid amide, tridecylic acid amide , myristic acid amide, bentadecylic acid amide, palmitic acid amide, heptadecylic acid amide, stearic acid amide, arachic acid amide, behenic acid amide, cerotic acid amide, montanic acid amide, valeric acid anilide, caproic acid anilide, capric acid anilide , undecylic acid anilide,
Lauric acid anilide, myristic acid anilide, palmitic acid anilide, stearic acid anilide, behenic acid anilide, lauric acid anilide, myristate methylamide, palmitic acid methylamide, stearic acid methylamide, lauric acid dodecylamide, myristic acid dodecylamide, palmitic acid Examples include dodecylamide, stearic acid dodecylamide, and the like. In the configuration shown in FIG. 1, if an energy beam for image recording, such as laser light 5, is irradiated as shown in FIG. Since the pores 2a of the porous layer 2 are filled, the portion of the porous layer corresponding to the irradiated portion is made transparent and the readout light 6 is transmitted therethrough, so that the record can be read out.

This readout method may be a reflective readout method by placing a reflective plate underneath, or a method of detecting the difference in light reflectance of the irradiated portion of the porous layer. Furthermore, in the configuration shown in the first diagram, if the stacking order of the porous layer 2 and the low melting point material layer 3 is reversed, the laser light may be irradiated from the transparent support side. Since recording is performed using the method described above, the amount of energy of the laser beam is sufficient to melt the low-melting point substance, thereby achieving miniaturization of the recording device and high sensitivity of the recording medium.

In the configuration shown in FIG. 1, the low melting point material layer is almost transparent, so the laser light absorption rate is low.

Therefore, an effective method is to disperse, for example, pigments, metal powders, etc. in a low melting point substance to increase the absorption rate of laser light. However, in this case, it is desirable to suppress the coloring of the low melting point material layer as much as possible to avoid deterioration of the contrast of the image. The most desirable method is to use a laser light source with an oscillation wavelength in the infrared range, such as a semiconductor laser, YAG
This method uses a laser, C02 laser, He-Ne laser, etc. to disperse an infrared-absorbing and visible-transmitting substance in a low-melting point substance layer. In this way, it is possible to increase the laser light absorption rate of the low melting point substance, and the contrast of the image is not reduced. As the substance that absorbs infrared light and transmits visible light, salts containing divalent ions of iron, salts containing divalent ions of molybdenum, oxides of ln, Sn, and Cd, and mixtures thereof are preferable.

In addition, in the configuration shown in Figure 1, a recorded image is obtained by filling the holes in the porous layer, but in addition, a thin film of metal or semimetal, which is a conventional laser light absorption layer, is placed on top or bottom. By creating a recording medium with a transparent layer and irradiating it with a laser beam, the laser beam absorption layer in the irradiated area is removed to make it transparent, and the porous layer in the irradiated area is made transparent as described above. If this is done, higher contrast can be obtained by both effects. As for the layer structure, a protective layer of organic resin may be further provided, or a chalcogen or dielectric material may be provided as an anti-reflection film for the irradiated energy beam.

Alternatively, a reflective layer may be provided to reflect the energy beam that has not been absorbed by the energy beam absorption layer and make it enter the energy beam absorption layer again to increase the sensitivity of the recording medium. Alternatively, a heat insulating layer may be provided to prevent heat generated in the energy beam absorption layer from escaping to the substrate. FIG. 3 is a schematic cross-sectional view showing another example of the structure of the recording medium according to the present invention.

In the figure, 1, 2, and 3 are the same layers as described above. 4 is a heat mode recording layer.

When the heat mode recording layer is irradiated with an energy beam such as a laser beam, it melts or evaporates and is removed, changing its physical property constants and recording an image. This layer is composed of a single layer or a stacked layer by vapor deposition or sputtering using a nonmetal, semimetal, metal, metal oxide, or the like as a medium material. Here, the non-metals include thermoplastics,
Paints, dyes, minerals, pigments, chalcogenides, etc. can be applied. Metalloids include Bi, AI, Cu, Ta, and M.
〇, Cr, lr, Pd, Ag, Au, Pt, Zn, Cd
, Co, Pb, Mg, ln, Ge, Rh, Sn, Se,
There are Si and their alloys, and the oxide is ln20
3, Sn02, W02, Pb○, etc. In the case of laminated layers, there are laminated layers of metal and chalcogen, laminated layers of metal and oxide, etc. Recording is performed on the recording medium shown in FIG. 3 as follows.

That is, as shown in FIG. 4a, first, when the laser beam 5 is irradiated, the irradiated portion of the heat mode recording layer is melted or evaporated and removed. At this time, the porous layer acts as a heat insulating layer and reduces heat loss due to heat conduction from the recording layer to the support, resulting in improved sensitivity. Next, thermal energy is applied to the entire surface of the low melting point material layer by means such as infrared irradiation or by bringing it into close contact with a heated roller. When the low melting point substance is melted and infiltrated into the pores of the porous layer, the porous layer becomes transparent and becomes as shown in Figure 4b, revealing the contrast of the heat mode recording layer. . In other words, in conventional recording media, the porous layer provided as a heat insulating layer is generally opaque, and when the written information is read out using transmitted light, the image becomes extremely unclear, which is inconvenient. Ta.

In order to solve this problem, a method has been proposed in which the porous layer is subjected to lacquering as a post-treatment, but this is a wet treatment and is a time-consuming treatment method.
On the other hand, according to the recording method of the present invention, since the porous layer is made transparent, an image with extremely high contrast can be obtained, and the sensitivity of the recording medium is also high. Figure 5 shows
FIG. 7 is a vague cross-sectional view showing still another example of the configuration of the recording medium according to the present invention.

In this configuration, layers 1, 2, 3, and 4 are similar to those described above, and a heat mode recording layer is arranged between the porous layer and the low melting point material layer. Recording is performed on the recording medium shown in FIG. 5 as follows.

By irradiation with a laser beam 5 as shown in FIG. 6a, this layer is melted away and an information-dependent latent image is formed. Thereafter, when this recording medium is heated by another means, the low melting point substance melts and becomes fluidized, as shown in FIG. 6b.
As shown in , since the pores of the porous layer 2 are filled through the removed portion of the heat mode recording layer 4, the portion of the porous layer corresponding to the irradiated area becomes transparent, and the readout light 6 It becomes observable. In such a recording process,
The role of the heat mode recording layer is only to form a submerged group, and it does not have to be involved in image contrast.

Therefore, the thickness of the heat mode recording layer in this configuration can be reduced. Generally, the sensitivity to melting and removal of laser light absorbing layers formed from metals, semimetals, compounds, organic substances such as dyes, or combinations thereof tends to improve as the film thickness decreases. The sensitivity of the heat mode recording layer in this configuration to the laser beam is several orders of magnitude better than that of conventional recording media of this type. Example 1 Co-condensed polyester was dissolved in methyl ethyl ketone and 3
A 0 wt % polyester solution was prepared.

This polyester solution was mixed with toluene in a weight ratio of 0.5, and further mixed with an appropriate amount of Zn○ with an average grain size of about 0.5 mm, and the mixture was thoroughly soaked and coated on a polyester film with a thickness of 75 mm. It was applied to. Soak it in dilute hydrochloric acid solution,
Zn0 was dissolved and removed to form an opaque porous layer (melting point: 160mm) with a thickness of about 1.5mm. Next, add u to the dye.
-3・3″・3…・A vinyl acetate emulsion using DBP (dibutyl phthalate) as a plasticizer mixed with an appropriate amount of tetrazaphthalocyanine was prepared with a viscosity of 53 SI, and the porous material formed earlier was A layer of a low melting point material (melting point: about 90 qo
) was formed. At this time, the wavelength 4 shelf OA of the low melting point material layer
The light absorption rate was approximately 30%. this,
Output on the recording medium surface is approximately 24 hW, oscillation wavelength is 4800
When a △ laser was focused on about 3 spots and irradiated for 25 seconds, the irradiated area became transparent and an image was recorded. At this time, the density difference between the unrecorded area and the transmitted light was 0.6. At this time, the larger the amount of Zn0 mixed during the formation of the porous layer, the better the contrast was observed when the layer became transparent. Example 2 An opaque porous layer similar to that in Example 1 was formed on a polyester film with a thickness of 75 mm, and an ethylene-vinyl acetate copolymer called Evaflex 210 (trade name manufactured by Mitsui Polychemicals) was further added. Paraffin with a softening point of about 70o was dissolved in toluene at a weight ratio of 2:1, and then the dye Cu-3. Coat to a film thickness of 1.
A low melting point material layer of 5 layers was formed.

This was performed for about 8 msec using the same Ar laser beam as in Example 1.
When irradiated with c, the irradiated area became transparent and an image was recorded. The difference in transmission density between this part and the unrecorded part was 0.5. Example 3 A copolymer of vinylidene chloride and acrylic acid ester, called Aron CX-S-Z (manufactured by Toagosei Kagaku Co., Ltd.) by the trade name, was dissolved in monochlorobenzene to create a 50% (Wt) solution, and dipping method was used to prepare a 50% (Wt) solution. , coated on a polyester film with a film thickness of 75 cm, and a low melting point material layer with a film thickness of about 2 cm (
Melting point: about 110°C).

A porous layer was formed thereon by the same method as in Example 1, and a 500 Å thick Bi film was further formed by vacuum evaporation. Furthermore, a 320A WS was applied as an anti-reflection layer on top of this using the same vacuum evaporation method, and a ~laser beam (wavelength 488OA) and a laser beam (wavelength 488OA) focused on 3 spots with an output of 6 hW on the surface of the recording medium. I irradiated the enemy for sec. Thereafter, when it was pressed against a heated roller maintained at about 1100 C, an image with excellent contrast was obtained. At this time, the difference in transmitted light density between the unrecorded area and the unrecorded area was 1.8. Example 4 A polypropylene sheet called DURAGUARD (manufactured by Celanese) has an average thickness of 0.1 through special processing.
It is a porous sheet with pores the size of a Buddha.

A vinyl acetate emulsion prepared by the same method as in Example 1 was applied very thinly onto the hydrophobic surface of this sheet by dipping to close the entrances of the pores in the porous layer. On top of that, a film with a thickness of about 200
A Bi layer of A was provided, and a low melting point material layer similar to that in Example 1 was further applied thereon to a thickness of about 10 mm to obtain a recording medium. An Ar laser beam having an effective output of about 4 W and an oscillation wavelength of 4880 A on the surface of the recording medium was focused on a spot of about 3 mm and was irradiated for about 6 seconds. Then, when this was pressed onto a heated roller kept at a temperature of about 1100C,
The area where Bi was removed by the laser beam became transparent and an image with good contrast was obtained. At this time, the difference in transmission density due to transmitted light between the unrecorded area and the unrecorded area was 1.4.

[Brief explanation of the drawing]

FIG. 1, FIG. 3, and FIG. 5 are schematic cross-sectional views showing configuration examples of a recording medium according to the present invention. Figure 2a, Figure 2b, Figure 4a, Figure 4b, Figure 6a,
FIG. 6b is an explanatory diagram showing the recording method according to the present invention.
2... Porous layer. 2a...Vacancy. 3...Low melting point material layer. 4...Heat mode recording layer. 5...Shiza light. Figure 2 (b) of the group diagram 2 (b) of the younger brother 4 (b) of the 4th diagram (b) of the 5th diagram

Claims (1)

[Scope of Claims] 1. A recording medium comprising a porous layer and a low melting point material layer that can fill the pores of the porous layer when heated and melted. 2. The recording medium according to claim 1, wherein the porous layer has a melting point of 150° C. or higher. 3. The recording medium according to claim 1, wherein the low melting point substance has a melting point of 60°C to 200°C. 4. A recording medium comprising a heat mode recording layer, a porous layer capable of filling the pores of the porous layer when melted by heating, and a low melting point material layer. 5. A recording method characterized by irradiating a recording medium having a porous layer and a low melting point substance layer with an energy beam to fill the pores in the porous layer with the low melting point substance. 6. The recording method according to claim 5, wherein the energy beam is a laser beam. 7. A step of irradiating a recording medium having a porous layer, a low melting point material layer, and an energy beam absorption layer with an energy beam to change the physical property constants of the irradiated portion of the energy beam absorption layer; A recording method comprising the step of heating and melting to fill a porous layer. 8 A step of irradiating an energy beam to a recording medium having an energy beam absorption layer between a porous layer and a low melting point material layer to create a void in the energy beam absorption layer of the irradiated area, and a step of forming a low melting point material layer. A recording method comprising the steps of heating and melting the layer and filling the porous layer through the gaps in the energy beam absorbing layer.