JPH06344656A - Infrared photosensitive material - Google Patents

Abstract

PURPOSE:To provide a recording material not causing the deterioration of image quality or trouble during recording and capable of recording detailed data. CONSTITUTION:An IR photosensitive material is obtained by providing one layer together containing an IR absorbing substance (1), a base precursor (2) composed of a salt of an org. base and thermally decomposable carboxylic acid and a dye-stuff (3) having properties erased by the base or two or more layers separately containing those components (1)-(3) on a support.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared-sensitive material capable of forming a negative image by imagewise exposure of infrared rays (including scanning exposure of infrared laser).

[0002]

2. Description of the Related Art A heat-sensitive material having a heat-sensitive color-developing layer provided on a support such as paper or plastic film is widely known and is used in a facsimile or a word processor printer.
The heat-sensitive material has an advantage that it can be recorded in a short time with a compact device.

Separately, when a color head is subjected to thermal scanning with a thermal head, the recording portion is decolored, and negative image type thermal recording materials are disclosed in JP-A-59-229385, JP-A-62-13389 and JP-A-62-249787. It is proposed in Japanese Patent Laid-Open No. 4-90382. Negative-type thermal recording materials are used for overhead projector sheets or X
As a hard copy of a CRT image used in the medical field using a radiographic device, an ultrasonic diagnostic device, or a CT scanner,
It is believed that it can be used to advantage. However, none have been put to practical use. The recording portion of the negative-working heat-sensitive recording material contains a dye and an erasing agent. As the dye, generally, fine particles or a melt of a leuco dye that has been colored in advance are used.
Various compounds such as amides, alcohols, ethers and base precursors have been proposed as decoloring agents. Regarding the arrangement of the dye and the decoloring agent in the recording portion, both a case where they are contained in one layer together and a case where they are contained in two or more layers separately have been proposed.

The recently proposed Japanese Patent Laid-Open No. 4-90382.
In the heat-sensitive recording material described in Japanese Patent Laid-Open Publication No. JP-A-2003-242, a layer of a quaternary ammonium carbonate as a base precursor (decoloring agent) is formed on a layer composed of a mixture (dye) of a fluoran compound and an acidic compound. By the way, in order to perform high-speed recording using a negative-working heat-sensitive recording material, high sensitivity is required. The thermal sensitivity of conventional thermal recording materials has been insufficient for high speed recording. In addition, all the conventional decolorizing agents are hygroscopic and tend to absorb moisture in the air during the storage period. When the decoloring agent absorbs moisture, the decoloring effect is exhibited during storage and the density of the recording material is reduced.

[0005]

PROBLEM TO BE SOLVED BY THE INVENTION Proposed in Japanese Patent Application Nos. 5-11090 and 5-11091 are negative image-type heat-sensitive recording materials having high sensitivity and good storage stability, which solve the above problems. Has been done. Japanese Patent Application No. 5-11090
The specification describes fine particles of a dye obtained by previously reacting a leuco dye with an acidic compound to form a color on a support, and a salt of an organic base and an acid, and a base precursor that produces a base when heated is included in the same layer. A heat-decoloring type heat-sensitive recording material having a heat-sensitive layer has been proposed. On the other hand, Japanese Patent Application No. 5-11091 has a colored continuous layer containing a leuco dye formed by a reaction with a color developer on a support, and a salt of an organic base and an acid in the layer. Therefore, a thermal recording material is proposed in which particles of a base precursor that generates a base when heated are scattered.

However, as another problem that has not been solved by the thermal recording materials described in the above specifications, in the thermal recording method using the thermal head, the image resolution depends on the dot density of the thermal head. I can point out. Therefore, it is generally difficult to record detailed information on the heat-sensitive recording material. Further, in the method of heating the thermal head in contact with the heat-sensitive material, the heat-sensitive material may be scratched by the thermal head and the image quality may be deteriorated. Furthermore, the surface layer of the heat-sensitive recording may adhere to the thermal head, causing trouble during recording. An object of the present invention is to provide a recording material capable of recording detailed information without deterioration of image quality and trouble during recording.

[0007]

Means for Solving the Problems
In the process of improving the heat-erasable type heat-sensitive recording material described in each of the specifications of No. -11090 and No. 4-11091, surprisingly, a completely new infrared-sensitive material was created. The object of the present invention is to combine (1) an infrared absorbing substance, (2) a base precursor composed of a salt of an organic base and a thermally decomposable carboxylic acid, and (3) a dye having a property of decoloring with a base, together or separately. Was achieved by an infrared-sensitive material provided on a support with one or more layers comprising

[0008]

The present invention provides the above-mentioned completely novel infrared-sensitive material. In the present invention, a conventional thermal recording material is modified and used as an infrared-sensitive material. In particular,
By adding the infrared absorbing substance of (1), the input medium for image information is changed from heat to infrared. In the case of infrared rays, the light can be emitted from a light source that is located away from the photosensitive material. Therefore, various problems caused by the contact between the thermal head and the thermal recording material described above are solved. Further, in the present invention, an infrared laser can be preferably used as a light source. The resolution of the laser is so strong that it cannot be compared with the dots of the thermal head. Therefore, by using the infrared-sensitive material and the infrared laser of the present invention, very detailed image information can be recorded.

Infrared photosensitive materials have been proposed in other technical fields such as silver salt photography. Compared with the conventional infrared-sensitive material, the photosensitive material of the present invention has a simple structure and is easy to manufacture. Further, since the image forming process is only the exposure process and does not require pretreatment and posttreatment such as development and transfer, there is an advantage that an image can be formed only by a simple device (exposure device).

[0010]

Detailed Description of the Invention

(1) Infrared absorbing substance As the infrared absorbing substance, a substance that absorbs the wavelength of infrared light (including laser light) used for image recording may be selected and used. Infrared absorbing substances are disclosed in JP-A-2-2074 and 3
-26593, 3-30992, and 3-3489.
No. 1, No. 3-36093, No. 3-36094, No. 3
-36095, 3-42281, 3-6318.
No. 5, No. 3-97589, No. 3-97590, No. 3
-97591, 4-161382, 4-169.
No. 289, No. 4-169290, No. 4-173185.
Nos. 4-173290 and 4-173291, and U.S. Pat. No. 5,019,594. Specific examples of the infrared absorbing substance are shown below.

[0011]

[Chemical 1]

[0012]

[Chemical 2]

[0013]

[Chemical 3]

[0014]

[Chemical 4]

[0015]

[Chemical 5]

[0016]

[Chemical 6]

[0017]

[Chemical 7]

[0018]

[Chemical 8]

[0019]

[Chemical 9]

[0020]

[Chemical 10]

[0021]

[Chemical 11]

[0022]

[Chemical 12]

[0023]

[Chemical 13]

[0024]

[Chemical 14]

[0025]

[Chemical 15]

[0026]

[Chemical 16]

[0027]

[Chemical 17]

[0028]

[Chemical 18]

Two or more infrared absorbing substances may be used in combination. The infrared absorbing substance may be contained in one layer together with the base precursor and the dye. Alternatively, two or more layers may be provided on the support, and the infrared absorbing substance and the base precursor may be contained separately. When two or more layers are provided, there is no particular limitation on when each layer is inserted. For example,
A layer containing an infrared absorbing substance may be provided between the support and the layer containing a dye. Further, a layer containing an infrared absorbing substance can be provided on the layer containing a dye. Infrared absorbing material,
When added to a layer other than the layer containing the base precursor or the dye, it is preferable to use a binder to disperse the infrared absorbing substance. The binder is the same as the binder (described later) used for the layer containing the base precursor or the dye. The infrared absorbing substance may be dissolved or dispersed in a solvent (organic solvent or water) together with a binder and coated on a support to form a layer containing the infrared absorbing substance.

The coating amount of the infrared absorbing substance is set so that the absorbance for infrared light of the specific wavelength used is 0.2 or more, preferably 0.5 or more. Usually 0.01g
It is preferable to apply in the range of 1 / m ² to 1 g / m ² . Further, the weight ratio of the binder to the infrared absorbing substance is 0.
It is preferably from 1 to 5, more preferably from 0.5 to 2.

(2) Base Precursor The base precursor consists of a salt of an organic base and a thermally decomposable carboxylic acid. The base precursor itself is neutral. Upon heating, the carboxylic acid decarboxylates to release the base. Various compounds have already been proposed as base precursors.

The thermally decomposable carboxylic acid must have the property of being decarboxylated above a certain temperature of the carboxyl group.
However, since the carboxyl group generally has the above-mentioned properties, various kinds of carboxylic acids can be used as the base precursor. Examples of the thermally decomposable carboxylic acid include trichloroacetic acid, sulfonylacetic acid and its derivative, and propiolic acid and its derivative. The trichloroacetate base precursor is described in British Patent No. 998949. Regarding the sulfonylacetate-based base precursor, JP-A-5
9-168441, 61-51139, and U.S. Pat. No. 4,060,420. Regarding the propiolic acid salt type base precursor, JP-A-59 / 59
-180537. As the thermally decomposable carboxylic acid, a derivative of sulfonylacetic acid is preferable. As the derivative, a compound in which an aliphatic group, an aromatic group or a heterocyclic group is bound to a sulfonyl group is preferable. Aromatic sulfonylacetic acid is particularly preferably used.

The above publications disclose inventions relating to the improvement of the heat-decomposable carboxylic acid side of the base precursor, but there are various examples of the organic base side. However, as the organic base, those disclosed in JP-A-63-316760 and JP-A-1-687 are more preferable than those exemplified in the above publications.
It is preferable to use a specific amidine or guanidine derivative as in the base precursor described in Japanese Patent No. 46. That is, 2, 3 or 4 (preferably 2)
Compounds having a) amidino or guanidino groups are preferred as organic bases. The linking group of a plurality of amidino groups or guanidino groups may be an aliphatic group, an aromatic group or a heterocyclic group. Part of the amidino group or guanidino group may be bonded to each other to form a heterocycle.

It is preferable that the base precursor satisfies both of rapid decomposition upon heating and no decomposition upon storage at room temperature. For this purpose, it is particularly preferred to combine the above-mentioned sulfonylacetic acid with an amidine or guanidine derivative to form a base precursor. The base precursor preferably releases the base at a temperature of 60 to 200 ° C. The base precursor preferably has extremely low solubility in water. When a hydrophobic base precursor is used, crystals of the base precursor can be finely dispersed in an aqueous medium and used in the form of fine particles. The average particle size of the fine particles is preferably 5 μm or less, and more preferably 0.01 to 1 μm.

The amount of the base precursor used is adjusted so that the released base can sufficiently decolor the dye. For example,
When a leuco dye and an acidic compound are used in combination as the decolorizable dye, the amount of the base released is calculated to be 0.1 to 2 times the molar amount of the acidic compound. When the base precursor is dispersed and used as fine particles, it is preferable to use a water-soluble polymer as a dispersant. The water-soluble polymer is used at a concentration of about 1 to 10%. Examples of water-soluble polymers include polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose,
Ethylene maleic anhydride copolymer, styrene maleic anhydride copolymer, isobutylene maleic anhydride copolymer,
Polyacrylic acid, polyacrylic acid amide, starch derivative,
Mention may be made of casein and gelatin.

(3) Decolorizable dye The dye used in the present invention has the property of being decolorized by a base. As the decolorizable dye, it is preferable to use a leuco dye and an acidic compound in combination. Specifically, the leuco dye is used after being colored in advance with an acidic compound.

The leuco dye is a basic dye precursor which has been conventionally used in pressure-sensitive or heat-sensitive recording materials. Examples of leuco dyes include crystal violet lactone, 3-indolino-3-p-dimethylaminophenyl-6-dimethylaminophthalide, 3-diethylamino-.
7-chlorofluorane, 3-diethylamino-7-cyclohexylaminofluorane, 3-diethylamino-5
-Methyl-7-t-butylfluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-p-butylanilinofluorane, 2- (N-phenyl -N-ethyl) aminofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-cyclohexylamino-6-chlorofluorane, 3-diethylamino-6-methyl-7-xylidinofluorane, 2-anilino -3-Methyl-6- (N
-Ethyl-p-toluidino) fluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-pyrrolidino-7-cyclohexylaminofluorane, 3-piperidino-6-methyl-7-toluidinofluorane , 3-
Pyrrolidino-6-methyl-7- (p-toluidino) fluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3-N-methylcyclohexylamino-6-
Mention may be made of methyl-7-anilinofluorane and 3-diethylamino-7- (m-trifluoromethylanilino) fluorane. The amount of leuco dye used was 0.
It is preferably from 05 to 2 g / m ² , and 0.1 to 1
More preferably, it is g / m ² .

Phenolic compounds, organic acids and metal salts or esters thereof are preferably used as the acidic compound which causes a color reaction with the leuco dye. The melting point of the acidic compound is preferably 50 to 200 ° C, more preferably 60 to 200 ° C. Further, the acidic compound is preferably sparingly soluble in water. Examples of phenolic compounds are 4,4'-isopropylidene-diphenol (bisphenol A), p-tert-butylphenol, 2,4-dinitrophenol, 3,4-dichlorophenol, 4,4'-methylene-bis. (2,6-di-te
rt-butylphenol), p-phenylphenol,
4,4-Cyclohexylidenediphenol, 2,2'-
Methylenebis (4-tert-butylphenol), 2,
2'-methylenebis (α-phenyl-p-cresol)
Thiodiphenol, 4,4'-thiobis (6-tert-butyl-m-cresol), sulfonyldiphenol,
1,1-bis (4-hydroxyphenyl) -n-dodecane, 4,4-bis (4-hydroxyphenyl) -1-pentanoic acid ethyl ester, p-tert-butylphenol-formalin condensate and p-phenylphenol- Formalin condensates are included.

As the organic acid, oxybenzoic acid and its derivative, particularly salicylic acid and its derivative are preferable. Examples of salicylic acid derivatives include 3-tert-butylsalicylic acid, 3,5-tert-butylsalicylic acid, and 5-α.
Mention may be made of -methylbenzylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 3-tert-octylsalicylic acid and 5-α, γ-dimethyl-α-phenyl-γ-phenylpropylsalicylic acid. When organic acids are used as the metal salt, zinc salts, lead salts, aluminum salts, magnesium salts and nickel salts are useful. When organic acids are used as esters, ethyl, butyl, heptyl and benzyl esters are useful. The amount of the acidic compound used is preferably 1 to 20 times, and more preferably 2 to 8 times, the mol of the leuco dye.

The above leuco dye and an acidic compound are reacted in advance and used as a decolorizable dye. The leuco dye and the acidic compound are preferably used by being contained in the fine particles. The fine particles can be prepared by dissolving both in a suitable solvent, then emulsifying and dispersing this in an aqueous medium to form fine oil droplets, and then removing the solvent. Examples of the above solvent include ethyl acetate and isopropyl acetate. In the preparation of the above fine particles, an oil having a high boiling point may coexist. The oil is preferably a hydrocarbon compound that does not inhibit the color development of the leuco dye.
The fine particles of the dye preferably have an average particle diameter of 5 μm or less, more preferably 0.01 μm to 1 μm. As the dispersant used for the preparation of the fine particle dispersion,
The same water-soluble polymer as that used for dispersing the base precursor can be used. Further, a surfactant can be used together in the dispersion of the fine particles. Anionic surfactants such as alkylbenzene sulfonates that do not inhibit the color development of the leuco dye are preferably used.

The above-mentioned base precursor particles and dye particles can be dispersed together in one layer. The water-soluble polymer used when preparing the fine particles also functions as a binder after coating. However, a similar polymer may be additionally added at the time of coating so as to function as a binder. In addition, in order to impart water resistance to the binder, a water resistant agent (eg, gelling agent, crosslinking agent) is added to the coating liquid, or a hydrophobic polymer emulsion (eg, styrene butadiene latex, acrylic resin emulsion) is added. You can also The amount of binder used is 1 to 10g
/ M ² is preferred. When the fine particles of the base precursor and the fine particles of the dye are dispersed together in a hydrophilic binder to be contained in one layer, decolorization at the time of heating progresses efficiently, resulting in high sensitivity.

(4) Support As the support, paper, synthetic paper or plastic film can be used. For applications where a transparent support needs to be used, such as OHP, plastic films are preferred. As an example of plastic film,
Polyester film (eg, polyethylene terephthalate, polyethylene naphthalate), cellulose derivative film (eg, cellulose triacetate), polyolefin film (eg, polystyrene, polyethylene, polypropylene), polyimide film, polyvinyl chloride film,
Examples thereof include polyvinylidene chloride film, polyacrylic film and polycarbonate film. As the support, a polyester film subjected to heat treatment and antistatic treatment is particularly preferably used. Further, for the purpose of preventing the coating layer from peeling off from the support, it is preferable to provide an undercoat layer on the support. The undercoat layer can be formed by coating a polymer. Examples of polymers include gelatin, acrylic acid ester copolymers, polyvinylidene chloride, styrene butadiene latex and aqueous polyesters. The thickness of the undercoat layer is preferably 0.1 to 0.5 μm.

(5) Protective Layer A protective layer may be provided on a layer containing an infrared absorbing substance, a base precursor or a dye to impart water resistance or scratch resistance to the photosensitive material. The protective layer uses a polymer as a binder. Examples of polymers include polyvinyl alcohol, modified polyvinyl alcohol, gelatin, styrene maleic anhydride copolymers and starch. Two or more kinds of polymers may be mixed and used as a binder. A curing agent may be added to cure the binder. Borax, boric acid or colloidal silica may be added to the protective layer. In order to improve the handleability, a slip agent (eg, zinc stearate, paraffin wax) or a pigment (eg, kaolin, calcium carbonate) can be used in the protective layer to the extent that transparency is not impaired. The coating amount of the protective layer is 0.3 to 5 g /
It is preferably m ² .

(6) Image recording By exposing the infrared photosensitive material to infrared rays imagewise,
(1) The infrared absorbing material converts infrared rays into heat, and the exposed portions generate heat. This heat causes the carboxylic acid (2) of the base precursor to decompose, releasing the organic base. Then, the dye (3) is decolored by this base and an image is recorded. The above imagewise exposure is preferably carried out by scanning exposure with an infrared laser. The infrared laser can be obtained by using a known laser device. In practical terms,
Semiconductor lasers are advantageous because of their small size, low cost, stability, reliability, durability and ease of modulation. The wavelength of the laser light is appropriately selected depending on the light absorption wavelength of the infrared absorbing material used. Usually, a laser that oscillates in the wavelength range of 720 nm to 890 nm is effective. The output of the laser light is preferably 10 mW or more, more preferably 50 mW or more.

[0045]

【Example】

[Example 1] "Preparation of solid dispersion of base precursor (KB-1)"
In a 300 ml dispersion container, a 3% aqueous solution of polyvinyl alcohol (PVA205, Kuraray Co., Ltd.) 52.
5 g, 52.5 g of a 3% aqueous solution of carboxymethyl cellulose (Serogen 6A, manufactured by Shin-Etsu Chemical Co., Ltd.), 45 g of the following base precursor (BP-1) and 150 ml of glass beads having a diameter of 0.5 to 0.75 mm were added, and Dynomill. Was dispersed at 3000 rpm for 30 minutes. 2N
The pH was adjusted to 6.5 with sulfuric acid to obtain a base precursor dispersion (KB-1) having a particle size of about 1 μm.

[0046]

[Chemical 19]

"Preparation of Fine Particle Dispersion of Coloring Dye (NB-1)" 2.1 g of the following leuco dye (LD-1) and 45 mg of infrared absorbing substance (19) were dissolved in 30 g of ethyl acetate. 7.5 g of zinc 3,5-di-α-methylbenzylsalicylate was dissolved in this solution to prepare a dye solution. Separately, 2 of polyvinyl alcohol (PVA205)
31 g of 0% aqueous solution, 21 g of water, and 10 g of 5% aqueous solution of sodium dodecylbenzan sulfonate were mixed to obtain 200 m
1 into homogenizer cup. The dye solution was added thereto and stirred at 1000 rpm for 5 minutes to obtain an emulsion of the dye. The emulsion was stirred at 50 ° C. for 2 hours, ethyl acetate was removed, and then the same amount of water as the evaporated amount was added to obtain a fine particle dispersion (NB-1) of a coloring dye having a particle size of about 0.4 μm. It was

[0048]

[Chemical 20]

"Preparation of Infrared Photosensitive Material 101" To 5.1 g of a fine particle dispersion (NB-1) of a color forming dye, 0.5 g of water and 1 g of a 20% aqueous solution of polyvinyl alcohol (PVA205) were added and mixed. To this liquid, 2 g of a solid dispersion of a base precursor (KB-1) was added and mixed. The mixed solution was coated on a 100 μm-thick polyethylene terephthalate film undercoated with gelatin at a coating amount of 10.5 g and dried. Next, 10 of polyvinyl alcohol
% Aqueous solution 4 g, 2% aqueous solution of the following surfactant (WW-1) 1 g, 20% of zinc stearate having a particle size of 0.2 μm
0.5 g of the water dispersion and 4.8 g of water were mixed to prepare a coating liquid for the protective layer. This solution was coated on the above-mentioned sheet at a coating amount of 17.5 g and dried to obtain an infrared photosensitive material 101 of the present invention.

[0050]

[Chemical 21]

"Evaluation of Infrared Photosensitive Material 101" The infrared photosensitive material 101 was irradiated with focused 830 nm laser light. The laser light was generated from a semiconductor laser LN9880 manufactured by Matsushita Electronics Co., Ltd. The spot diameter was 20 μm, the irradiation time was 1 msec to 1 μsec, and the laser power was 40 mW. In this way a clear negative was obtained which became colorless in the high energy part. Further, when the infrared-sensitive material 101 was aged under the conditions of 40 ° C. and 80% relative humidity for 3 days and then similarly laser-printed, no decrease in the maximum image density was observed and it was clear as above. I was able to get an image.

Example 2 Preparation of Fine Particle Dispersion of Coloring Dye (NB-2) In the preparation of fine particle dispersion of color forming dye (NB-1) of Example 1, leuco dye (LD-1) 2 0.1 g of ethyl acetate 30
Instead of dissolving in g, the same leuco dye (LD-1)
2.1 g of the coloring matter was dissolved in a mixture of 10 g of the following oil (Oil) and 20 g of ethyl acetate, and the solution of the infrared absorbing substance (19) was not added in the same manner as described above, but a fine particle dispersion (NB- 2) was prepared.

[0053]

[Chemical formula 22]

"Preparation of Infrared Photosensitive Material 102" Example 1
In the preparation of the infrared-sensitive material 101, the color-forming dye fine particle dispersion (NB-1) was replaced with (NB-
2) Using 5.1 g, add 0.9 g of a 5% aqueous solution of infrared absorbing substance (20) to the coating solution, and apply a coating amount of 21 g.
Infrared photosensitive material 102 of the present invention was obtained in the same manner except that the above was changed to.

"Evaluation of Infrared Photosensitive Material 102" When the infrared photosensitive material 102 was irradiated with laser in the same manner as in Example 1, a negative image was obtained. The sensitivity was about twice as high as that of 101. Moreover, when this sheet was projected by a transmission type OHP projector, a clear negative image could be observed.

[Example 3] "Preparation of solid dispersion of base precursor (KB-2)"
7 g of polyvinyl alcohol (4 g of PVA 117 and 3 g
Of PVA 205) was dissolved in 193 g of water. Three
In a 00 ml dispersion container, add 112.5 of this mixture.
g, the following base precursor (BP-2) 37.5 g and glass beads 150 ml were added and dispersed using Dynomill for 30 minutes at 3000 rpm, pH was adjusted to 6.5 with 2N sulfuric acid, and the particle size was about 1 μm. A base precursor dispersion (KB-2) was obtained.

[0057]

[Chemical formula 23]

"Preparation of Infrared Photosensitive Material 103" Example 1
Microparticle dispersion (NB-1) 5.1 of color forming dye prepared in
g, 0.7 g of water and polyvinyl alcohol (PVA
1) of a 20% aqueous solution of 205) was added and mixed. A solid dispersion (KD-2) 1.8 of a base precursor was added to this liquid.
g was added and mixed. The mixed solution was coated on a 100 μm-thick polyethylene terephthalate film undercoated with gelatin at a coating amount of 10.5 g and dried. A protective layer similar to that of Example 1 was applied onto this and dried to obtain an infrared-sensitive material 103 of the present invention.

[Evaluation of Infrared Photosensitive Material 103] When the infrared photosensitive material 103 was irradiated with laser in the same manner as in Example 1, a negative image could be obtained. Also, an aging test was performed in the same manner, but the image after aging was almost the same as the fresh image.

[Example 4] "Preparation of fine particle dispersion of color forming dye (NB-3)" In the same manner as in Example 1 except that the infrared absorbing substance (19) was omitted, fine particle dispersion of color forming dye (NB) was prepared. -3) was obtained.

[Preparation of Infrared Photosensitive Material 104] An infrared absorbing layer coating solution having the following composition was prepared and applied on the support used in Example 1 so that the thickness after drying would be 0.6 μm. Dried.

──────────────────────────────────── Infrared absorption layer coating liquid ────── ────────────────────────────── Infrared absorbing material (21) 2g Polyvinyl butyral 10g Methyl ethyl ketone 50ml Toluene 50ml Isocyanate (Takenate D110-N) , Takeda Pharmaceutical Co., Ltd. 0.5 ml ─────────────────────────────────────

Then, each layer was coated with the fine particle dispersion (NB-3) of a color forming dye (NB-3) and dried in the same manner as in Example 1 to obtain an infrared-sensitive material 104 according to the present invention. .

"Evaluation of Infrared Photosensitive Material 104" When the infrared photosensitive material 104 was thermally printed in the same manner as in Example 1, a negative image could be obtained. Also, an aging test was performed in the same manner, but the image after aging was almost the same as the fresh image.

Claims (1)

[Claims] 1. A (1) infrared absorbing substance, (2) a base precursor comprising a salt of an organic base and a thermally decomposable carboxylic acid, and (3) a dye having a property of decoloring with a base, together or separately. An infrared-sensitive material comprising one or more layers comprising a support.