JPH08267916A - Recording medium and image recording method - Google Patents

Abstract

PURPOSE: To provide a recording medium having a photothermal conversion layer having sufficient exposure heat resistance even in high luminous intensity exposure, enabling the coating with a general-pourpose solvent, generating no crack and excellent in ink peelability. CONSTITUTION: In a recording medium wherein a photothermal conversion layer and an ink layer are provided on a support, a main binder used in the photothermal conversion layer is characterized by that temp. bringing the wt. reduction ratio of the binder to 50% in a nitrogen gas stream under a condition of a temp. rising speed of 10 deg.C/min in the measurement of thermal decomposition by a TGA method is 360 deg.C or higher. The binder is pref. a water-soluble binder especially selected from polyvinyl alcohol, polyvinyl acetal, nylon, polyacrylamide and polyalkylene oxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermal conversion type recording medium which converts light into heat and transfers the ink layer by the heat.

[0002]

2. Description of the Related Art A thermal transfer recording medium usually transfers a heat-meltable or thermoplastic ink layer to a medium to be transferred by heating, and heating is performed by a thermal head, laser, mask light or the like. Recording using a laser or the like can increase the recording density, and in recent years, since a high-output light source has become available at low cost, research and development for practical use are active.

As a recording medium utilizing light-heat conversion, a structure comprising a light-heat conversion layer and an ink layer on a support is known. However, if the heat-resistance of the light-heat conversion layer is poor, a phenomenon called so-called scattering during exposure and heating occurs. Occur. This is particularly noticeable when the exposure illuminance is large and the arrival sensitivity of the exposed surface is high, and causes serious problems such as color turbidity of a recorded image and obstruction of adhesion due to generated gas.

As measures against this, Japanese Patent Laid-Open No. 62-140884 discloses a photothermal conversion layer containing urea-melamine resin, urea-formalin resin, epoxy resin, urethane resin, acrylic resin, polyester resin, polyimide resin, polyether resin, There is a description of polysulfone resin and the like. Also, Japanese Patent Laid-Open No. 2-
No. 252579 discloses a heat-resistant resin support such as aromatic polyamide or polyimide having a Tg (glass transition point) of 190 ° C. or higher and a thermal decomposition temperature of 450 ° C. or higher in order to improve heat resistance.

On the other hand, Japanese Patent Application Laid-Open No. 5-286257 discloses that polyvinyl alcohol (PVA), water-soluble resin such as cellulose resin, gelatin and the like are binders having good heat resistance. It is described that a cushion layer is provided between the support and the photothermal conversion layer in order to secure the adhesion to the transfer medium and increase the sensitivity.

Since it is necessary to increase the exposure illuminance in order to increase the recording speed and the apparent sensitivity of the recording medium itself, it is necessary to use a resin having good heat resistance. It was hard to say that each of them had sufficient characteristics.

For example, so-called high heat-resistant engineering plastics (functional plastics) lack flexibility even if they have good heat resistance, so that the light-heat conversion layer becomes hard and the recording medium is bent or heat-resistant stored. Then, there arises a problem that the recording surface is cracked. This is particularly remarkable when a cushion layer is provided between the support and the photothermal conversion layer in order to enhance the adhesion to the image receiving medium.

Further, among the functional plastics, most of those disclosed so far have a poor solvent solubility and have a problem in production that coating is difficult with a general-purpose solvent, and actual exposure recording It was not possible to find a concrete useful material such as lack of heat resistance.

In this respect, water-soluble resins such as PVA and cellulosic resins are more flexible than functional plastics, easy to apply, have relatively high heat resistance, and have good ink layer peeling suitability. It is a useful binder.

However, even with useful PVA and cellulosic resins, when the illuminance of the light source is further increased in order to increase the recording speed, the heat resistance cannot be said to be sufficient when the exposure surface illuminance is 0.1 MW / cm ^2. It became clear as a result of the examination. Especially 1 MW
This is noticeable at / cm ² or more.

[0011]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to have sufficient exposure heat resistance even in exposure to high illuminance, and to be able to coat with a general-purpose solvent without cracking.
It is an object of the present invention to provide a recording medium having a photothermal conversion layer which is also excellent in ink peeling property.

[0012]

The above objects of the present invention have been achieved by the following constitutions.

(1) In a recording medium having a photothermal conversion layer and an ink layer on a support, a main binder used in the photothermal conversion layer is subjected to a thermal decomposition measurement by a TGA method, in a nitrogen stream, to a heating rate of 10 ° C. / 50% weight loss rate under minute conditions
A recording medium whose temperature is 360 ° C or higher.

(2) The recording medium according to (1), wherein the binder is a water-soluble binder.

(3) The water-soluble binder is selected from polyvinyl alcohol, polyvinyl acetal, nylon, polyacrylamide and polyalkylene oxide.
The recording medium described in (2).

(4) An image recording method using the recording medium described in (1), (2) or (3) to perform recording with light of 1 MW / cm ² or more.

The present invention will be described in more detail below.

The recording medium of the present invention basically has a structure in which a photothermal conversion layer for converting light radiated imagewise into heat and a heat-fusible ink layer are laminated on a support, but if necessary. An intermediate layer (release layer, barrier layer, cushion layer, etc.) may be provided between the support and the ink layer. In the present invention, it is preferable to provide a cushion layer.

Each structure will be described below.

Any support may be used as long as it has good dimensional stability and withstands heat during image formation. Specifically, it is described in JP-A-63-193886 (2) page, lower left column, lines 12-18. The films or sheets described can be used. If a laser beam for imagewise exposure is irradiated from the recording medium side to form an image, the support is preferably transparent. Further, the support of the recording medium need not be transparent as long as the image is formed by irradiating the laser beam from the image receiving medium side.

The thickness of the support is not particularly limited, but usually 2
˜300 μm, preferably 5-200 μm.

The cushion layer is provided for the purpose of increasing the close contact between the recording medium and the image receiving medium, but the support itself may be provided with cushioning properties.

In order to impart cushioning properties, a material having a low elastic modulus, a material having rubber elasticity, or a thermoplastic material which is easily softened by heating to improve the adhesiveness may be used. Specifically, natural rubber, acrylate rubber, butyl rubber, nitrile rubber, butadiene rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, urethane rubber, silicone rubber, acrylic rubber, fluorine rubber, neoprene rubber, chlorosulfonated polyethylene,
Epichlorohydrin, EPDM (ethylene / propylene / diene rubber), elastomers such as urethane elastomers, polyethylene, polypropylene, polybutadiene,
Polybutene, impact-resistant ABS resin, polyurethane, AB
S resin, acetate, cellulose acetate, amide resin, polytetrafluoroethylene, nitrocellulose,
Polystyrene, epoxy resin, phenol-formaldehyde resin, polyester, impact resistant acrylic resin, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene copolymer, vinyl chloride-vinyl acetate copolymer, poly Among vinyl acetate, vinyl chloride resin containing a plasticizer, vinylidene chloride resin, polyvinyl chloride, polyvinylidene chloride and the like, resins having a small elastic modulus can be mentioned.

As the shape-memory resin usable as the cushion layer, polynorbornene or a styrene hybrid polymer in which a polybutadiene unit and a polystyrene unit are compounded can be cited.

The thickness of the cushion layer depends on various factors such as the type of resin or elastomer used, the suction force when the recording medium / image receiving medium is in close contact, the particle size of the matting material, and the amount of matting material used. I can not decide, but usually 10 ~
It is in the range of 100 μm.

As the method for forming the cushion layer, a material obtained by dissolving the above materials in a solvent or dispersing them in a latex form is applied by a blade coater, a roll coater, a bar coater, a curtain coater, a gravure coater or the like, or is extruded by hot melt. A lamination method, a cushion layer film laminating method or the like can be applied.

The photothermal conversion layer is mainly composed of a photothermal conversion material and a binder.

The photothermal conversion material is preferably a substance that absorbs light and efficiently converts it into heat, although it varies depending on the light source. For example, when a semiconductor laser is used as a light source, a substance having an absorber in the near infrared is preferable. . For example, carbon black, graphite, colloidal silver, phthalocyanine dyes, squarylium dyes, nitroso compounds and metal complex salts thereof, polymethine dyes, thiol nickel salts, triarylmethane dyes, immonium dyes, naphthoquinone dyes, anthracene dyes. A dye or the like can be used. Further, compounds described in JP-A-63-139191, JP-A-3-103476 and the like can be mentioned. Like the binders described below, these photothermal conversion materials are also preferably those having high heat resistance, and colloidal silver, carbon black, graphite and the like are particularly preferable.

The ratio of photothermal conversion material to binder is 7: 3.
˜1: 9, preferably 5: 5 to 2: 8.

The thickness of the photothermal conversion layer is preferably 0.1 to 1 μm, and the content of the photothermal conversion material in the photothermal conversion layer is usually
The absorbance is determined to be 0.3 to 3.0 at the wavelength of the light source used for image recording.

As the binder in the photothermal conversion layer,
TGA ₅₀ resins having a thermal decomposition temperature of 360 ° C. or higher, that is, various functional plastics and water-soluble binders, preferably water-soluble binders such as polyvinyl alcohol, polyvinyl acetal, polyvinyl pyrrolidone, nylon, polyacrylamide, polyalkylene oxide. ,
Gelatin, casein, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxyethyl starch, gum arabic, sucrose octaacetate, ammonium alginate, sodium alginate, polyvinylamine, polyethylene oxide, polyacrylic acid and the like, among them, polyvinyl alcohol, polyvinyl Acetal, nylon, polyacrylamide and polyalkylene oxide are preferred. As the functional plastics, TAG ₅₀ thermal decomposition is selected from the group of resins such as polyacdimide, polyarylate, polyimide, polyetherimide, polyetheretherketone, polycarbonate, polysulfone, polyethersulfone, polyamidesulfone, polyphenylene ether, and polyphenylene sulfide. A resin having a temperature of 360 ° C. or higher can be selected.

Of these, water-soluble binders are particularly preferable.

The photothermal conversion layer has a large absorption per unit film thickness, and it is preferable that it is as thin as possible from the viewpoint of sensitivity, but on the other hand, if the absorption per unit film thickness is too large, the temperature reached during exposure will be high. This setting has an important meaning because it becomes locally high and the heat resistance of the photothermal conversion layer deteriorates. The portion where the ultimate temperature is highest is the light incident surface of the photothermal conversion layer, and when heat resistance is poor, so-called ablation occurs from this light incident interface. When ablation occurs completely when exposed from the support side,
This is the worst case, but the photothermal conversion layer and the ink layer are simultaneously transferred. Further, even if the ablation does not occur clearly, the thermal decomposition gas is generated, so that the close contact between the ink surface and the transfer target is hindered and the transfer unevenness occurs. Therefore, depending on the exposure illuminance, the absorbance at the exposure wavelength is 1 μm
It is preferably 3.0 or less, more preferably 1.5 or less.

In order to avoid such a dilemma of sensitivity and heat resistance, it is preferable to separately provide a photothermal conversion layer having a small absorption per unit film thickness on the incident surface of recording light. That is, by disposing a photothermal conversion layer having an absorbance / μm of 1.5 or less on the light incident surface and further providing a second photothermal conversion layer having an absorbance / μm of 1.5 or more between the ink layer and the ink layer, It is possible to create a recording medium with higher sensitivity and higher heat resistance. Absorbance per unit film thickness of the photothermal conversion layer,
Depending on whether or not there is close contact with the adjacent layer or image receiving medium, the Journal of Imaging Science and Technology (Journal of Imaging Science and Technology)
Technology) 36, 2 (1992) page 180, temperatures as high as 600 ° C or higher are reached. As described above, in the case of heat mode laser recording, the temperature reached by the photothermal conversion layer is extremely high, and since the change is short-term, heat resistance, which is generally said in selecting a binder, can be used as a scale. Our examination has revealed that it is not appropriate. That is, specifically, the exposure is under reduced pressure contact, and the temperature is raised or lowered in a very short time even if the reached temperature is high. We investigated various measuring methods for the heat resistance of the binder and the recording characteristics corresponding to them, and the dynamic thermal decomposition measurement by TGA (thermogravimetric analysis) showed that the thermal decomposition condition was a heating rate of 10 ° C / min. The temperature at which the weight loss rate is 50% under the conditions of nitrogen flow (hereinafter, TG
It was found that the heat resistance suitable for practical use can be determined by measuring the A ₅₀ thermal decomposition temperature).

To the light-heat conversion layer, a surfactant for improving coating properties, a release agent for promoting interfacial peeling from the ink layer, and the like can be added. In particular, it is preferable to add a silicone compound, a fluorine compound, an olefin compound such as wax, or a long-chain alkyl compound as a release agent.

Preferred silicone compounds include polydimethylsiloxane and its modified products such as polyester modified silicone, acrylic modified silicone, urethane modified silicone, alkyd modified silicone, amino modified silicone, epoxy modified silicone and polyether modified silicone. A resin, or a cured product thereof may be used.

Preferred fluorinated compounds include fluorinated olefins and perfluorophosphate ester compounds.

Preferred olefin compounds include dispersions of polyethylene, polypropylene, etc., long-chain alkyl compounds such as polyethyleneimine octadecyl, etc.

Of these releasing agents, those having poor solubility can be used by dispersing them. It is also possible to add it to another polymer like the silicone compound. Further, it is possible to add various crosslinking agents for crosslinking the binder. The amount of additive added to these light-heat conversion layers is 0.01% of the total amount of light-heat conversion material and binder.
-20% by weight is preferred.

The ink layer is mainly composed of coloring material ink and a binder.

As the color material ink, an inorganic or organic pigment or dye is used, and it is composed of a single color, a mixture of two colors, and a mixture of three colors; for example, pigment compounds of yellow, magenta and cyan. As the inorganic pigment, titanium dioxide, carbon black, zinc oxide, Prussian blue, cadmium sulfide,
Examples include iron oxide and chromates of lead, zinc, barium and calcium.

Examples of the organic pigment include azo-based pigments, thioindigo-based pigments, anthraquinone-based pigments, anthanthrone-based pigments, triphendioxazine-based pigments, vat dye pigments, phthalocyanine pigments (copper phthalocyanine and its derivatives), and quinacridone pigments. Also, as an organic dye,
Acid dyes, direct dyes, disperse dyes and the like can be mentioned.

Examples of the binder include vinyl resins such as polyester, polyvinyl acetate, polyacrylamide, styrene resin, styrene copolymer resin, polyacrylic acid ester, polyacrylic acid, and acrylic acid copolymer, rubber resin, ionomer. Resin, olefin resin, rosin resin, polyvinyl alcohol, polyvinyl formal,
Cellulose resins such as polyvinyl butyral, polyvinyl pyrrolidone, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate and the like can be mentioned.

In addition to the binder, rosin or rosin derivative, terpene resin, petroleum resin, phenol resin, xylene resin, etc. can be added as a tackifier.

The weight ratio of the binder to the ink is 1:10 to.
10: 1 is preferable and 3: 7 to 8: 2 is particularly preferable.

Each of the above layers is formed by a known solvent coating method such as air doctor coater method, blade coater method, wire bar method, knife coater method, dip coater method, reverse roll coater method, gravure coater method, cast coating method, curtain coater. Method, an extrusion coater method or the like can be used. Solvents used include water, alcohols (methanol, ethanol, propanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), aromatics (toluene, xylene, chlorobenzene, etc.), ketones (acetone, methyl ethyl ketone, methyl). Isobutyl ketone, cyclohexanone, etc.), ester solvents (ethyl acetate, butyl acetate, etc.), ethers (tetrahydrofuran, dioxane, etc.), chlorine solvents (chloroform, trichloroethylene, etc.), amide solvents (dimethylformamide, N-methylpyrrolidone) Etc.), dimethyl sulfoxide and the like.

As these solvents, one kind or a mixture of two or more kinds is used according to the solution or dispersion. The specific construction method is described in detail in Japanese Patent Application Nos. 5-1237 and 7-8994. In the embodiments described later, the method is used, but of course the invention is not limited to this.

Examples of the image recording laser light source include a semiconductor laser, a YAG laser, a carbon dioxide gas laser, and a helium neon laser. Among the semiconductor lasers, it is preferable to use a so-called single-mode laser diode because it is easy to narrow down the 1 / e ² diameter to several to several tens of μm at the focal point without significantly reducing the optical efficiency.

Light sources other than lasers include light emitting diodes (LEDs). LEDs and semiconductor lasers are easy to use as an array in which a plurality of light emitting elements are integrated.

Laser scanning methods include cylinder outer surface scanning, cylinder inner surface scanning, and plane scanning. In the cylindrical outer surface scanning, laser exposure is performed while rotating the drum wound with the recording material on the outer surface, and the rotation of the drum is the main scanning,
The movement of the laser light is referred to as sub-scanning. When scanning the inner surface of a cylinder,
The recording material is fixed to the inner surface of the drum, the laser beam is irradiated from the inside, and the main scanning is performed in the circumferential direction by rotating part or all of the optical system. Sub-scanning is performed in the axial direction by linearly moving in parallel with. In the plane scanning, a polygon mirror or a galvanometer mirror and an fθ lens are combined to perform main scanning of laser light, and sub-scanning is performed by moving a recording medium. The scanning of the outer surface of the cylinder and the scanning of the inner surface of the cylinder make it easier to increase the accuracy of the optical system and are suitable for high-density recording.

In the case of so-called multi-channel exposure in which a plurality of light emitting elements are used at the same time, cylindrical outer surface scanning is most suitable. Further, when a YAG laser or the like having a large exposure output is used, it is difficult to significantly increase the rotation speed of the drum by scanning the outer surface of the cylinder, and thus inner surface scanning of the cylinder is suitable.

[0052]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. The composition ratio of each component in the examples represents a solid content weight ratio.

Example 1 (Preparation of Recording Medium) 1-1) Preparation of Temporary Support A release layer having the following composition was diluted with water and dried to a coating weight of 0.3 g / m ² of polyethylene terephthalate (25 μm). PE
T) After coating and drying on a film (T-100 made by Diamond Foil Hoechst), heat treatment at 120 ° C for 1 minute, then 60 ° C
・ 36 hours cure.

Polyvinyl alcohol (Nippon Gosei Kagaku: EG-30) 85 parts Crosslinking agent (Sumitomo Chemical: Sumirez Resin-613) 9 parts Crosslinking accelerator (Sumitomo Chemical: ACX-P) 1 part Fluorine compound (Sumitomo Chemical: FP-150) 5 parts 1-2) Ink layer formation On the release layer of the temporary support prepared in 1, dilute the ink layer having the following composition with a mixed solvent of methyl ethyl ketone: cyclohexanone = 8: 2, The coating was applied so that the dry film thickness was 0.5 μm.

Magenta pigment dispersion (Mikuni pigment: MHI-527) 40 parts Styrene acrylic resin (Sanyo Kasei: SBM-73F) 54 parts Ethylene-vinyl acetate resin (Mitsui DuPont Polychemical: EV-40Y) 5 parts Surfactant (Asahi Glass: S-382) 1 part 1-3) Formation of photothermal conversion layer A photothermal conversion layer having the following composition was mixed with a mixed solvent of water: isopropyl alcohol = 8: 2 on the ink layer prepared in 2. It was applied so that the diluted and dried film thickness was 0.5 μm. This time,
The absorbance at 830 nm and 1064 nm is 0.75 and 0.61 respectively.
Met.

Carbon black dispersion (Dainippon Ink: SD-9020) 30 parts Polyvinyl alcohol 70 parts (Nippon Gosei Kagaku: EG-30, PVATGA ₅₀ thermal decomposition temperature 376 ° C.) 1-4) Support backcoat layer The following composition was diluted with water and applied on a PET film of 100 μm (T-100 mentioned above) so that the dry coating amount would be 0.3 g / m ² , and after heat treatment at 120 ° C. for 1 minute, Further, curing was performed at 60 ° C for 36 hours.

Polyvinyl alcohol (EG-30 above) 85 parts Crosslinking agent (Sumiraze Resin-613 above) 9 parts Crosslinking accelerator (ACX-P above) 1 part Fluorine compound (FP-150 above) 5 Part Matting agent (3 μm silica particles) 5 parts 1-5) Cushion layer formation On the back surface of the back coat layer prepared in 4, dissolve the cushion layer of the following composition in a mixed solvent of methyl ethyl ketone: toluene = 1: 4 and dry. It was applied so that the film thickness would be 7 μm.

Styrene-based rubber (Shell: Clayton G1657) 70 parts Tackifier (Arakawa Chemical: Super Ester A100) 70 parts 1-6) Adhesion between cushion layer and light-heat conversion layer The cushion layer surface formed by 5 and 3 The formed photothermal conversion layer surface was laminated at 25 ° C. and a linear pressure of 2 kg / cm.

1-7) Removal of Temporary Support The laminated sheet formed in 6 was removed by removing the temporary support under peeling conditions as shown in FIG. 1, and finally the backcoat layer / support / cushion layer / A recording medium composed of the photothermal conversion layer / ink layer was obtained.

(Preparation of Image Receiving Medium) 2-1) Preparation of Temporary Support 25 The following composition was diluted with water and dried so that the coating amount would be 1 g / m ^2.
A release layer was applied to a μm PET film (T-100 described above).

Methyl cellulose (SM-15, manufactured by Shin-Etsu Chemical) 85 parts Acrylic resin (manufactured by Nippon Pure Chemical Co., Ltd .: Julimer AT-613) 15 parts 2-2) Preparation of support backcoat layer The same back as the support of the recording medium. A coat layer (1-4) was created.

2-3) Formation of Cushion Layer On the back surface of the back coat layer of the support prepared in 2, a cushion layer having the following composition was added with methyl ethyl ketone: toluene =
It was dissolved in a 1: 4 mixed solvent and applied so that the dry film thickness was 30 μm.

Ethylene-vinyl acetate resin (manufactured by Mitsui DuPont Polychemical: EV-40Y) 100 parts 2-4) Adhesion between cushion layer and release layer The cushion layer surface formed in 3 and the release layer surface of the temporary support formed in 1. Was laminated at 25 ° C. and a linear pressure of 2 kg / cm.

2-5) Removal of Temporary Support The temporary support was peeled and removed from the laminate sheet formed in 4 under the peeling condition (1-7) of the recording medium, and the back coat layer / support / cushion layer / A sheet consisting of a release layer was obtained.

2-6) Formation of Image Receiving Layer On the release layer of the sheet prepared in 5, an image receiving layer having the following composition was diluted with a mixed solvent of methyl ethyl ketone: methyl-isobutyl ketone: isopropyl alcohol = 4: 3: 3,
Coating was performed so that the dry film thickness was 1.5 μm, and an image receiving medium was obtained. At this time, the adhesive force between the image receiving layer and the peeling layer was 300 g / cm.

Acrylic resin (BR-113 manufactured by Mitsubishi Rayon) 95 parts Matting agent (T-130, 3 μm particles manufactured by Toshiba Silicone) 5 parts (image formation) The ink layer surface of the recording medium and the image receiving layer surface of the image receiving medium are Face-to-face contact, a vacuum contact (200 mmHg pressure reduction from atmospheric pressure) on a suckable drum, rotation was performed, and exposure recording was performed from the back surface of the ink sheet in the sub-scanning direction with a laser diode with an oscillation wavelength of 830 nm.

Exposure illuminance is 0.15 MW / cm ² , exposure beam diameter is 6
μm.

As a result, when the recording density was 330 mJ / cm ² , the halftone dot shape of 175 lines could be reproduced clearly up to 2 to 98%, and color turbidity and transfer omission were not observed.

Example 2 The light source was oscillated by changing the binder (polyvinyl alcohol, EG-30, manufactured by Nippon Synthetic Chemical Industry) of the photothermal conversion layer in Example 1 to various other binders having different TGA ₅₀ thermal decomposition temperatures. Laser diode with wavelength 830nm, exposure illuminance 0.15MW
/ Exposure energy at the time of the cm ² was evaluated of color turbidity in 330mJ / cm ^2. The results are shown in Table 1.

The TG measuring device is SSC-220 manufactured by Seiko Denshi,
The measurement conditions were a temperature rising rate of 10 ° C./min, a temperature rising start temperature of 30 ° C., a nitrogen stream of 100 cc / min, and a sample amount of 5 to 10 mg.

[0071]

[Table 1]

The transfer using the recording medium having the photothermal conversion layer containing the binder having the TGA ₅₀ thermal decomposition temperature ≧ 360 ° C. was good in all cases.

Example 3 Next, transfer was performed in the same manner as in Example 2 except that the YAG laser having an oscillation wavelength of 1064 nm was used as the light source. The exposure illuminance at this time is 5 MW / cm ² .

All had sufficient sensitivity at an exposure energy of 120 mJ / cm ² , and transfer evaluation was performed at this exposure energy. However, the exposure method was an inner surface scanning type.

[0075]

[Table 2]

The effect of the present invention is clear in this embodiment as well. Among the polyvinyl alcohol, EG-05 and 224C
It is considered that the thermally decomposed gas was accumulated between the ink layer and the image receiving layer and caused adhesion inhibition.

[0077]

According to the present invention, it is possible to obtain a recording medium having a photothermal conversion layer which has sufficient exposure heat resistance, can be coated with a general-purpose solvent, does not crack during transfer, and has excellent ink releasability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing peeling conditions when a recording medium of the present invention is prepared by laminating and peeling.

[Explanation of symbols]

 1 Support 2 Backcoat Layer 3 Cushion Layer 4 Photothermal Conversion Layer 5 Ink Layer 6 Release Layer 7 Temporary Support 8 Roller

Continuation of the front page (72) Inventor Sota Kawakami 1st Sakura-cho, Hino City, Tokyo Konica Stock Association In-house

Claims (4)

[Claims] 1. A recording medium having a photothermal conversion layer and an ink layer on a support, in which a main binder used in the photothermal conversion layer is subjected to a thermal decomposition measurement by a TGA method in a nitrogen stream in a temperature rising rate of 10 ° C./min. The recording medium is characterized in that the temperature at which the weight reduction rate is 50% under the conditions of is 360 ° C or higher. 2. The recording medium according to claim 1, wherein the binder is a water-soluble binder. 3. The recording medium according to claim 2, wherein the water-soluble binder is selected from polyvinyl alcohol, polyvinyl acetal, nylon, polyacrylamide and polyalkylene oxide. 4. An image recording method, wherein the recording medium according to claim 1, 2 or 3 is used to perform recording with light of 1 MW / cm ² or more.