JP2866491B2 - Thermal recording material for infrared laser - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material, and more particularly to a non-contact heat-sensitive recording material for recording using an infrared laser beam.

[0002]

2. Description of the Related Art A thermosensitive recording system in which a thermal head is brought into close contact with a surface of a thermosensitive recording material provided with a thermosensitive coloring layer on a support and heat energy is transferred to the thermosensitive coloring layer directly or through a protective layer to record a color image. Is widely known and has been applied to facsimile machines and printers. However, in such a thermal recording method, since the thermal head is brought into close contact with the thermal recording material for scanning, the thermal head may be worn or the components of the thermal recording material may adhere to the surface of the thermal head as scum. As a result, a recorded image may not be obtained correctly, and a problem that the thermal head is broken easily occurs.

Further, the thermal recording method using such a thermal head has limitations in high-speed control of heating / cooling of the heating elements and in increasing the density of the heating elements due to the structural characteristics of the thermal head. There is a disadvantage that high-speed recording, high-density recording, and high-quality recording are limited.

[0004] In order to solve the above-mentioned problems of the thermal recording system using a thermal head, it has been proposed to perform thermal recording at high speed and high density without contact with a thermal recording material using a laser beam. (See, for example,
Nos. 0-23617, JP-A-54-121140, JP-A-57-11090, JP-A-58-56890, JP-A-58-94494, and JP-A-58-134791.
JP-A-58-145493, JP-A-59-891
No. 92, JP-A-60-205182, JP-A-62-5
No. 6195).

However, in such a recording system using a laser beam, the thermosensitive coloring layer generally comprises
Since it is difficult to absorb light in the visible and near-infrared regions, unless the output of the laser is considerably increased, heat energy required for color development cannot be obtained, and it is extremely difficult to create a small and inexpensive device. Was.

Japanese Patent Publication No. 50-774 proposes a method in which a microcapsule containing ink is applied to a base paper, and a strong light is applied to eject the ink in the capsule to record on the base paper. However, the sensitivity is so low that it has not yet been realized.

[0007]

Therefore, there have been many proposals for efficiently absorbing a laser beam in the thermosensitive coloring layer. In general, a light absorption suitable for the wavelength of the laser beam is contained in the thermosensitive coloring layer. Addition of substances has been done.

In this case, if the light absorbing substance to be added is not white, the background of the recording material is colored and the contrast is low.
If the recording results in poor quality and the added light absorbing substance does not exist in a portion requiring direct heating, the recording material has low sensitivity, which is not preferable.

In general, white light-absorbing substances are mostly inorganic compounds, but most of them have low light-absorbing efficiency. Therefore, it has been desired to develop an organic compound having good light-absorbing efficiency and less coloring. .

However, since organic compounds that absorb light in the visible light range are generally colored, they are added to the recording layer as a light-absorbing substance to increase the sensitivity and improve the whiteness of the recording paper. Although it is difficult to do, when using an organic compound that does not absorb light in the visible light region and absorbs a laser beam having a wavelength other than the visible light region, the organic compound is not colored Even when added to the recording layer, the background of the recording material can be made white.

[0011]

However, the mechanism of image recording by a laser beam is to absorb the laser beam irradiated imagewise by the light absorbing substance, convert the energy of the laser beam into thermal energy, and heat the microcapsule wall. By contacting the reaction materials inside and outside the microcapsules with each other, the image is recorded on the thermosensitive recording material. Therefore, if a light absorbing substance is added near or in the microcapsule wall, the microcapsule wall can be directly heated by the laser beam, so that the sensitivity of the thermosensitive recording material can be improved.

Therefore, the present inventors have isolated the two color-forming components contained in the heat-sensitive layer by microcapsules, and provided the microcapsules in the walls of the microcapsules.
The present invention was found to contain an infrared absorbing dye having an active group that reacts with the cell wall material, and that when recording was performed using an infrared laser, extremely good results could be obtained. . Accordingly, an object of the present invention is to provide a heat-sensitive recording material for infrared laser recording, which has high sensitivity and has less coloring of the background and capable of high-quality recording.

[0014]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
What is claimed is: 1. A thermosensitive recording material for infrared laser, comprising: a support, on which a microcapsule containing at least a color former and a thermosensitive layer containing a developer are provided , wherein a wall material of the microcapsule is provided in the wall of the microcapsule. Has an active group that reacts with
That the infrared absorbing dye was achieved by the heat-sensitive recording material for infrared laser, characterized in that it is contained.

The color former and the color developer used in the present invention are components which cause a color development reaction upon contact with a substance. Specifically, an electron-donating dye precursor (color former) and an acidic substance (a color developer) Or a combination of a diazo compound (color former) and a coupling compound (color developer) is preferred.

The electron-donating dye precursor used in the present invention is not particularly limited, but has a property of giving a color by donating electrons or accepting a proton such as an acid, and is usually used. A compound that is substantially colorless and has a partial skeleton such as lactone, lactam, sultone, spiropyran, ester, or amide, and in which these partial skeletons are opened or cleaved upon contact with a developer, is used.

Specifically, crystal violet lactone, benzoyl leucomethylene blue, malachite green lactone, rhodamine B lactam, 1,3,3-
And trimethyl-6'-ethyl-8'-butoxyindolinobenzospiropyran.

As a developer for these color formers,
Acidic substances such as phenol compounds, organic acids or metal salts thereof, and oxybenzoic acid esters are used, and specific examples thereof are described in, for example, JP-A-61-291183.

The diazo compound used in the present invention is a compound which develops a desired hue by reacting with a color developing agent called a coupling component which will be described later. However, it is a photo-decomposable diazo compound that no longer has a color developing ability even when a coupling component acts.

The hue in this color forming system is mainly determined by the diazo dye formed by the reaction between the diazo compound and the coupling component. Therefore, as is well known,
The color hue can be easily changed by changing the chemical structure of the diazo compound or the chemical structure of the coupling component, and a substantially arbitrary color hue can be obtained depending on the combination.

The photo-decomposable diazo compound in the present invention mainly refers to an aromatic diazo compound, and more specifically refers to compounds such as aromatic diazonium salts, diazosulfonate compounds, and diazoamino compounds.

[0022] The diazonium salt of the general formula ArN ₂ ⁺ X ^-
Wherein Ar represents a substituted or unsubstituted aromatic moiety, N ₂ ⁺ represents a diazonium group, and X ⁻ represents an acid anion.

It is generally said that the photolysis wavelength of a diazonium salt is the absorption maximum wavelength. It is also known that the absorption maximum wavelength of a diazonium salt varies from about 200 nm to about 700 nm according to its chemical structure (“Photodecomposition and chemical structure of photosensitive diazonium salts” by Takahiro Tsunoda and Ao Yamaoka, Japan Photography Journal 29 (4) 197-205
P. (1965)). That is, when a diazonium salt is used as a photodecomposable compound, it is decomposed by light having a specific wavelength according to its chemical structure, and when the chemical structure of the diazonium salt is changed, a coupling reaction with the same coupling component occurs. The hue of the dye also changes.

As the light source for photolysis, various light sources emitting light of a desired wavelength can be used. For example, various fluorescent lamps, xenon lamps, xenon flash lamps, mercury lamps of various pressures, photographic flashes, Various light sources such as a strobe can be used. Further, in order to make the light fixing zone compact, the light source unit and the exposure unit may be separated using an optical fiber.

A large number of diazosulfonates that can be used in the present invention are known, and are obtained by treating each diazonium salt with a sulfite. Other diazo compounds that can be used in the present invention include diazoamino compounds. The diazoamino compound is a compound obtained by coupling a diazo group with dicyandiamide, sarcosine, methyltaurine, N-ethylanthranic acid-5-sulfonic acid, monoethanolamine, diethanolamine, guanidine, or the like. Details of these diazo compounds,
For example, it is described in JP-A-2-136286.

Coupling components which form a dye by coupling with a diazo compound (diazonium salt) used in the present invention include, for example, 2-hydroxy-3-naphthoic acid anilide, resorcinol and the like. -14
No. 6678 can be mentioned.

Further, an image of any color tone can be obtained by using two or more of these coupling components in combination. Since the coupling reaction between the diazo compound and the coupling component easily occurs in a basic atmosphere, a basic substance may be added to the layer.

As the basic substance, a water-insoluble or water-insoluble basic substance or a substance which generates an alkali by heating is used. Examples thereof are inorganic and organic ammonium salts, organic amines, amides, ureas and thioureas and their derivatives, thiazoles, pyrroles, pyrimidines,
Piperazines, guanidines, indoles, imidazoles, imidazolines, triazoles, morpholines, piperidines, amidines, formazines,
And nitrogen-containing compounds such as pyridines. Specific examples of these are described in, for example, JP-A-61-291183. Two or more basic substances may be used in combination.

As the infrared absorbing dye used in the present invention, a dye which absorbs a small amount of light having a wavelength in the visible light region but has a particularly high absorption of light having a wavelength in the infrared region is preferable. It is necessary to have an active group that reacts with the material.

[0030] Specific examples of the active group, isocyanate group, hydroxy group, a mercapto group, there may be mentioned an amino group, in particular diisocyanate over preparative group and hydroxy group are preferable. Among the above infrared absorbing dyes, it is particularly preferable to use cationic dyes, complex salt-forming dyes and quinone-based neutral dyes described in detail below.

The cationic dye is a dye represented by the following general formula (1). _{^{D 1 + [X 1 -1 /}} m] m (1) where the D ₁ ⁺ is a cationic dye mother nucleus, X ₁ ^- a counter anion, m represents an integer of 1-4.

As D ₁ + which is a cationic dye nucleus in the general formula (1), polymethine (including cyanine), azurenium, pyrylium, thiopyrylium, squalilium, triarylmethane, immonium, diimmonium and the like are preferable. X ^{−1 / m} is not particularly limited as long as it can form a counter anion, and the active group that reacts with the microcapsule wall may be either D ₁ ⁺ or X ₁ ^{−1 / m} .

Specific examples of the above cationic dyes include:
Dyes represented by the following formula can be mentioned. Polymethine (cyanine) dyes:

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Embedded image However, n = 2 or 3.

Embedded image However, n = 2 or 3.

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Azurenium dyes:

Embedded image Squalilium dyes:

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Triarylmethane dye:

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Immonium and diimmonium dyes:

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As the complex dye, thiol nickel complex salt and phthalocyanine dye are preferable. Specific examples of the complex salt dye include a dye represented by the following formula.

Thiol nickel complex dye:

Embedded image

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Embedded image Here, M is Ni or Pt.

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Phthalocyanine dyes:

Embedded image Here, M is Ni or Pt.

Naphthalocyanine dyes:

Embedded image Here, M is Ni or Pt. As the quinone-based neutral dye, naphthoquinone-based and anthraquinone-based dyes are preferable.

Specific examples of the naphthoquinone-based neutral dye include a dye represented by the following formula.

Embedded image However, R is H or -CH ₂ CH ₂ OH.

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Anthraquinone dyes:

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The color former used in the present invention is used in view of improving the transparency of the recording layer, in view of raw preservability such as preventing contact between the color former and the developer at room temperature (anti-fogging), and at a desired laser energy. A color former is encapsulated and used from the viewpoint of control of the color development sensitivity for producing a color.

For the production of the microcapsules used in the present invention, any of an interfacial polymerization method, an internal polymerization method, and an external polymerization method can be employed. It is preferable to employ an emulsion polymerization method in which after emulsification in an aqueous solution in which a polymer is dissolved, a wall of a polymer substance is formed around the oil droplets.

The reactant forming the polymer substance is added to the inside of the oil droplet and / or to the outside of the oil droplet. Specific examples of the polymer substance include polyurethane, polyurea, polyamide, polyester, polycarbonate, urea-formaldehyde resin, melamine resin, polystyrene, styrene methacrylate copolymer, styrene-acrylate copolymer and the like. Preferred polymeric substances are polyurethanes, polyureas, polyamides, polyesters, polycarbonates, particularly preferably polyurethanes and polyureas. Two or more polymer substances can be used in combination.

Specific examples of the water-soluble polymer include gelatin, polyvinylpyrrolidone, and polyvinyl alcohol. For example, when polyurea is used as the capsule wall material, two polyisocyanates such as diisocyanate, triisocyanate, tetraisocyanate, and polyisocyanate prepolymer, and two polyamines such as diamine, triamine, and tetraamine, and two amino groups are used. The microcapsule wall can be easily formed by reacting the above-mentioned prepolymer, piperazine or a derivative thereof, or a polyol with an interfacial polymerization method in an aqueous solvent.

Further, for example, a composite wall made of polyurea and polyamide or a composite wall made of polyurethane and polyamide is added after adjusting the pH of an emulsifying medium serving as a reaction solution using, for example, polyisocyanate and acid chloride or polyamine and polyol. It can be prepared by heating. For details of the method for producing a composite wall composed of these polyurea and polyamide, see JP-A-58-1986.
No. 6948.

In addition, the microcapsules used in the present invention are added with the infrared absorbing pigment at the time of forming the microcapsule wall, and the infrared absorbing pigment having the active group is reacted with the microcapsule wall material to form the microcapsule wall. To be included.

Further, optional additives such as a metal-containing dye and nigrosine can be added to the microcapsule wall used in the present invention, if necessary. These additives can be incorporated into the capsule wall at the time of wall formation or at any time. Further, a solid sensitizer may be added for swelling the microcapsule wall during laser beam heating.

As the solid sensitizer, those having a melting point of not less than 50 ° C., preferably not more than 120 ° C. and being solid at room temperature can be selected and used from those referred to as polymer plasticizers used as microcapsule walls. . For example, when the wall material is made of polyurea or polyurethane, a hydroxy compound, a carbamate compound, an aromatic alkoxy compound, an organic sulfonamide compound, an aliphatic amide compound, an arylamide compound, or the like is preferably used.

In the present invention, when a diazo compound is used as a color former, a color former may be used. The color-forming auxiliary that can be used in the present invention is a substance that increases the color density at the time of laser heating printing or lowers the minimum color-forming temperature, and lowers the melting point of a coupling component or a diazo compound, or capsules. This is to create a situation in which the diazo compound and the coupling component easily react with each other by the action of lowering the softening point of the wall.

Examples of the coloring aid include phenol compounds, alcoholic compounds, amide compounds, and sulfonamide compounds. Specific examples include p-tert-octylphenol, p-benzyloxyphenol, phenyl p-oxybenzoate, and the like. Examples thereof include compounds such as benzyl carbanilate, phenethyl carbanilate, hydroquinone dihydroxyethyl ether, xylylene diol, N-hydroxyethyl-methanesulfonic acid amide, and N-phenyl-methanesulfonic acid amide. These may be contained in the core substance, or may be added outside the microcapsules as an emulsified dispersion.

In the present invention, the developer is dissolved in an organic solvent which is hardly soluble or insoluble in water, and then mixed with an aqueous phase having a water-soluble polymer containing a surfactant as a protective colloid. Can be used in the form of an emulsified dispersion.

The organic solvent used in this case can be appropriately selected from high-boiling oils. Among them, preferred oils include esters, dimethylnaphthalene, diethylnaphthalene, diisopropylnaphthalene, dimethylbiphenyl, diethylbiphenyl, diisopropylbiphenyl, diisobutylbiphenyl, 1-methyl-1-dimethylphenyl-1-phenylmethane,
-Ethyl-1-dimethylphenyl-1-phenylmethane, 1-propyl-1-dimethylphenyl-1-phenylmethane, triallylmethane (eg, tritolylmethane, toluyldiphenylmethane), terphenyl compound (eg, terphenyl) , Alkyl compounds (for example, terphenyl), alkylated diphenyl ethers (for example, propyldiphenyl ether), hydrogenated terphenyl (for example, hexahydroterphenyl), diphenyl ether and the like. Among these, it is particularly preferable to use esters from the viewpoint of the emulsion stability of the emulsified dispersion.

Examples of the esters include phosphoric esters (eg, triphenyl phosphate, tricresyl phosphate, butyl phosphate, octyl phosphate, cresyl diphenyl phosphate), phthalic esters (dibutyl phthalate, 2-ethylhexyl phthalate, phthalic acid) Ethyl, octyl phthalate, butyl benzyl phthalate), dioctyl tetrahydrophthalate, benzoate (ethyl benzoate, propyl benzoate, butyl benzoate, isopentyl benzoate, benzyl benzoate), abietic acid ester (ethyl abietate, Benzyl abietate), dioctyl adipate, isodecyl succinate, dioctyl azelate, oxalate (dibutyl oxalate, dipentyl oxalate), diethyl malonate, maleate (dimethyl maleate, maleate) Diethyl citrate, dibutyl maleate), tributyl citrate, sorbate (methyl sorbate, ethyl sorbate, butyl sorbate), sebacate (dibutyl sebacate, dioctyl sebacate), ethylene glycol esters (monoformate) And diesters, butyric acid monoesters and diesters, lauric acid monoesters and diesters, palmitic acid monoesters and diesters, stearic acid monoesters and diesters, oleic acid monoesters and diesters), triacetin, diethyl carbonate, diphenyl carbonate, ethylene carbonate, carbonate propylene,
Boric acid esters (tributyl borate, tripentyl borate) and the like. Among them, when tricresyl phosphate is used alone or as a mixture, the emulsification and dispersion stability of the color developer is particularly good, which is preferable.

The above oils can be used together or in combination with other oils. In the present invention, an auxiliary solvent may be further added to the above-mentioned organic solvent as a low boiling point dissolution aid. As such co-solvents, for example, ethyl acetate, isopropyl acetate, butyl acetate, methylene chloride and the like can be mentioned as particularly preferable ones.

The water-soluble polymer to be contained as a protective colloid in the aqueous phase mixed with the oil phase containing these components is appropriately selected from known anionic polymers, nonionic polymers and amphoteric polymers. However, polyvinyl alcohol, gelatin, cellulose derivatives and the like are preferable.

As the surfactant to be contained in the aqueous phase, an anionic or nonionic surfactant which does not cause precipitation or aggregation by acting on the above protective colloid may be appropriately selected and used. it can. Preferred surfactants include sodium alkylbenzenesulfonate, sodium alkylsulfate, dioctyl sodium sulfosuccinate, polyalkylene glycol (eg, polyoxyethylene nonyl phenyl ether), and the like.

The emulsified dispersion of the present invention is prepared by mixing the oil phase containing the above-mentioned components with the aqueous phase containing the protective colloid and the surfactant by means commonly used for ordinary fine particle emulsification, such as high-speed stirring and ultrasonic dispersion. And easily mixed to disperse.

The value of the ratio of the oil phase to the aqueous phase (oil phase weight / water phase weight) is preferably from 0.02 to 0.6, and particularly preferably from 0.1 to 0.4. If it is less than 0.02, the aqueous phase is too much and becomes dilute, so that sufficient color development cannot be obtained.
On the other hand, when the ratio is 0.6 or more, the viscosity of the liquid increases, which causes inconvenience in handling and lowers the stability of the coating liquid.

When the heat-sensitive layer solution prepared as described above is coated on a support, a known aqueous or organic solvent-based coating solution is used. In this case, in order to apply the heat-sensitive layer liquid safely and uniformly and maintain the strength of the coating film, in the present invention, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, starches, gelatin, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, Polyacrylamide, polystyrene and its copolymer, polyester and its copolymer, polyethylene and its copolymer, epoxy resin, acrylate and methacrylate resin and its copolymer, polyurethane resin and polyamide resin are used together with microcapsules You can also.

The support used in the present invention may be transparent or opaque. If a transparent support is used that does not exhibit absorption at the irradiation laser beam wavelength and has dimensional stability without being deformed by heat generated during laser irradiation, the laser beam is passed through the transparent support. Irradiation and recording are also possible. The thickness of the support is 1
Those having a size of 0 μm to 200 μm are used.

As such a transparent support, for example,
Polyester films such as polyethylene terephthalate and polybutylene terephthalate, cellulose derivative films such as cellulose triacetate film, polystyrene films, polypropylene films, polyolefin films such as polyethylene films, polyimide films, polyvinyl chloride films, polyvinylidene chloride films,
Examples thereof include a polyacryl film and a polycarbonate film, and these can be used alone or in combination.

On the other hand, examples of the opaque support of the recording material include paper, synthetic paper, an aluminum vapor-deposited base, and the transparent support coated with a pigment or the like. In this case,
In order to irradiate a laser beam from the heat-sensitive layer side and efficiently absorb the laser beam into the heat-sensitive layer, it is preferable to use a highly reflective laser beam as the opaque support of the recording material.

The support used in the present invention is preferably a polyester film which has been subjected to heat treatment and antistatic treatment. In the present invention, it is desirable to provide an undercoat layer on the support before applying the heat-sensitive layer containing microcapsules or the like on the support in order to prevent the entire heat-sensitive layer from peeling off from the support.

As the undercoat layer, an acrylate copolymer, polyvinylidene chloride, SBR, aqueous polyester or the like can be used.
5 μm is desirable.

The undercoat layer composed of these compositions is coated by a known coating method such as a blade coating method, an air knife coating method, a gravure coating method, a roll coating coating method, a spray coating method, a dip coating method, and a bar coating method. Is done.
The coating amount is preferably 1 to ²⁰ g / m ² , particularly 3 to 10 g.
/ M ² .

Further, a pigment, a wax, a hardener and the like may be added to the heat-sensitive layer, if necessary. The heat-sensitive layer is a color former,
The total amount of the developer and the infrared absorbing dye is 0.1 to 10 g / m.
² and the thickness of the layer is 1 to
It is desirable to apply so that the thickness is 10 μm.

Further, in order to prevent the dye from being physically transferred by adhesion to the heat-sensitive layer, a slipping agent such as wax can be applied. The laser beam used in the present invention has a wavelength in the infrared region. Specific examples thereof include a helium-neon laser, an argon laser, a carbon dioxide laser, a YAG laser, and a semiconductor laser.

Since the heat-sensitive layer of the recording material of the present invention contains an infrared absorbing dye on the microcapsule wall, when irradiated with a laser beam, the infrared absorbing dye contained on the microcapsule wall converts the laser beam. Absorb and convert that energy into heat energy. As a result, the microcapsule wall is directly heated to become material-permeable, and as a result, the reactants inside and outside the microcapsules come into contact with each other to develop color.

In this case, since the heating of the microcapsule wall by the laser beam is more direct than in the case where an infrared absorbing dye is added inside or outside the microcapsule, the sensitivity of thermal recording is greatly improved. . The sensitivity can be further improved by coexisting the infrared absorbing substance not only in the microcapsule wall but also inside or outside the microcapsule.

When a coating solution containing a color developer as an emulsion is applied, the transparency of the heat-sensitive layer can be increased. In addition, since the microcapsule wall contains an infrared-absorbing dye that absorbs infrared light particularly well, while absorbing little light in the visible light region, the recording material has high absorption efficiency of the upper infrared laser with little coloring of the background of the recording material.

[0073]

According to the heat-sensitive recording material of the present invention, the microcapsules contained in the heat-sensitive layer contain an infrared-absorbing dye which absorbs infrared rays particularly well in the microcapsule walls. Since it is directly heated, the thermal sensitivity is good. In addition, by selecting an infrared-absorbing dye that does not have absorption in the visible region, it is possible to prevent coloring of the background of the recording material.

[0074]

The present invention will be described in more detail with reference to the following examples.
The present invention is not limited by this. "Parts" indicating the amount of addition indicates "parts by weight".

Example 1 Preparation of Capsule Solution Crystal Violet Lactone (Leuco Dye) 14
g, Takenate D-110N (trade name of capsule wall material manufactured by Takeda Pharmaceutical Co., Ltd.) 60 g and an infrared absorbing dye 2 g of the following structural formula:

[0076]

Embedded image It was added to and dissolved in a mixed solvent of 55 g of 1-phenyl-1-xylylethane and 55 g of methylene chloride. The obtained solution was treated with an aqueous 8% by weight polyvinyl alcohol solution 100.
g of water and 40 g of water and 1.4 g of a 2% by weight sodium salt of dioctyl sulfosuccinate (dispersant), and then emulsified at 10,000 rpm for 5 minutes using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.). Was. After 150 g of water was further added to the obtained emulsion, an encapsulation reaction was performed at 40 ° C. for 3 hours to prepare a capsule liquid having an average particle diameter of 0.7 μm.

Preparation of a developer emulsified dispersion : 8 g of a developer (a) represented by the following chemical formula:

Embedded image 4 g of a developer (b) represented by the following chemical formula,

Embedded image And 30 g of a developer (c) represented by the following chemical formula:

Embedded image Was dissolved in a mixture of 8.0 g of 1-phenyl-1-xylylethane and 30 g of ethyl acetate.

The obtained solution was mixed with 100 g of an 8% by weight aqueous solution of polyvinyl alcohol, 150 g of water and an aqueous solution of 0.5 g of sodium dodecylbenzenesulfonate, and then mixed with an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.).
Emulsification was carried out at 10,000 rpm for 5 minutes at room temperature so that the average particle size became 0.5 μm, to obtain an emulsified dispersion.

Preparation of heat-sensitive recording material 5.0 g of the above capsule liquid, 10 parts of the above-mentioned developer emulsified dispersion
A solution obtained by stirring and mixing 0 g and 5.0 g of water with a thickness of 70 μ
m on a transparent polyethylene terephthalate (PET) support having a solid content of 15 g / m ² and dried, and then expressed on the heat-sensitive layer formed as described above in Table 1 below. Protective layer solution having a thickness of 2 μm after drying.
m to give a transparent heat-sensitive recording material according to the present invention.

[0080]

TABLE 1 Composition of protective layer liquid 10% by weight Polyvinyl alcohol 20g Water 30 g 2 wt% sodium salt of sulfosuccindioctyl 0.3 g Polyvinyl alcohol 3 g, water 100 g and kaolin 35 g kaolin dispersion 3 g Hydrin Z-7 (manufactured by Chukyo Yushi Co., Ltd.) 0.5 g ────────────────────────────────

A semiconductor laser beam (A) having a wavelength of 780 nm was formed from the heat-sensitive layer side of the heat-sensitive recording material prepared as described above.
(IGaAs junction laser) was irradiated imagewise to obtain a blue recorded image. The output of the laser is 1
The energy was adjusted to 35 mJ / mm ^{2 in} milliseconds. The reflection density of the colored portion of the obtained image was measured using a Macbeth densitometer and was found to be 1.47.

Example 2 Instead of the crystal violet lactone used in Example 1, 2-anilino-3 was used.
A heat-sensitive recording material was prepared and the image was recorded in the same manner as in Example 1 except that -methyl-6-N-ethyl-N-butylaminofluoran was used, and a transparent black image was obtained. The transmission density of the colored portion of the obtained image was measured using a Macbeth densitometer and found to be 1.63.

Example 3 The compositions shown in Table 2 below were dispersed in a ball mill to prepare a developer dispersion having a particle size of 2 μm.

[0084]

[Table 2] Dispersion 5 g of polyvinyl alcohol 4 g of developer (a) having the following chemical formula

Embedded image 2 g of a developer (b) of the following chemical formula

Embedded image 15g of color developer (c) of the following chemical formula

Embedded image 100g of water ───────────────────────

A solution obtained by stirring and mixing 9 g of the obtained developer dispersion, 5 g of the capsule solution prepared in Example 1, and 5 g of water was placed on a 70 μm-thick transparent polyethylene terephthalate (PET) support. A recording material was prepared in the same manner as in Example 1 except that the coating material was applied and dried at 15 g / m ² per minute, and an image was recorded to obtain a transparent blue image.
The transmission density of the colored portion of the obtained image was measured using a Macbeth densitometer and found to be 1.63.

Example 4 An infrared absorbing dye having the following structural formula was used instead of the infrared absorbing dye used in Example 2.

Embedded image A thermosensitive recording material was prepared and the image was recorded in exactly the same manner as in Example 2 except for using, to obtain a transparent black image. The transmission density of the colored portion of the obtained image was measured using a Macbeth densitometer and was found to be 1.57.

Example 5 Preparation of Capsule Solution The following chemical formula

Embedded image Has the following chemical formula

Embedded image 5 parts of an infrared absorbing dye, 150 g of methylene chloride,
50 parts of tricresyl phosphate, 150 parts of trimethylolpropane trimethacrylate, and a 75% by weight ethyl acetate solution of a 3: 1 adduct of m-xylylene diisocyanate with trimethylolpropane (Takenate D110N: trade name of Takeda Pharmaceutical Co., Ltd.) ) 200 parts were uniformly mixed to obtain an oil phase solution.

On the other hand, 7% by weight of polyvinyl alcohol (PVA217E: 88-89% of degree of fighting, degree of polymerization of 1,
700: Kuraray Co., Ltd.) (600 parts) was prepared as a water-soluble polymer aqueous solution.

Next, a dissolver was attached to a 5-liter stainless steel pot equipped with a warm bath, and after adding the polymer aqueous solution, the oil phase solution was added while stirring the dissolver, and the emulsion was observed under a microscope. Was emulsified and dispersed so that the average particle size became about 1.5 μm. After the dispersion was completed, the stirring was loosened and 42 ° C. hot water was passed through a warm bath, and the temperature in the pot was maintained at 40 ° C. to complete the encapsulation reaction in 3 hours. The obtained liquid was mixed with ion-exchange resin MB-3.
After adding 25 ml (trade name, manufactured by Organo Corporation) and stirring, the mixture was filtered to obtain a capsule liquid.

Preparation of Dispersion A The substances shown in Table 3 below were mixed and dispersed in advance with a dissolver, and then Dynomill (Villie A. Bacofen.
Dispersion A was obtained by emulsifying and dispersing with an AG (manufactured by WILLY A. BACHOFEN AG) so as to have an average particle size of 2 μm.

[0091]

[Table 3] １５ 15% by weight polyvinyl alcohol aqueous solution (PVA- 205 Kuraray Co., Ltd. 30 parts Coupler of the compound of the following chemical formula 4.3 parts

Embedded image Coupler of compound of the following chemical formula
0.6 parts

Embedded image Organic basic compound of the following chemical formula
5.0 parts

Embedded image 3.0 parts of a color developing agent of the following chemical formula

Embedded image ────────────────────────────────────

Preparation of Dispersion B The substances shown in Table 4 below were mixed and stirred to obtain Dispersion B.

[0093]

[Table 4] バ ー UNIVER 70 (trade name, manufactured by Shiraishi Industry Co., Ltd.) 20 parts 40% by weight aqueous solution of sodium hexametaphosphate of Kaoblite (trade name of Thiele Kaolin Company Co., Ltd.) 0.5 parts Water 30 parts ──────────────────── ────────────────

Preparation of heat-sensitive recording material 20 parts of the above capsule liquid, 20 parts of dispersion A, 7 parts of dispersion B, and 1.5 parts of a 2% by weight aqueous solution of Nissan Lapisol 13─90 (trade name, manufactured by NOF Corporation) were stirred. Mix,
70 μm thick polyethylene terephthalate (PET)
On the support so that the solid content is 15 g / m ^2.
After drying, a recording layer was provided. Further, a mixture having a composition shown in Table 5 below was applied on the recording layer so as to have a thickness of 2 μm to form a protective layer, thereby producing a recording material.

[0095]

[Table 5] Composition of protective layer １０ 10% by weight polyvinyl alcohol 20 g water 30 g 2 wt% sodium salt of dioctyl sulfosuccinate 0.3 g 3 g of polyvinyl alcohol, 100 g of water and 35 g of kaolin dispersed in a ball mill 3 g Hydrin Z-7 (trade name of Chukyo Yushi Co., Ltd.) 0.5 g ─────────────────────────────────

The obtained recording material was irradiated imagewise with a semiconductor infrared laser beam (AlGaAs junction laser) having a wavelength of 780 nm from the recording layer side to obtain a blue image. The output of the laser beam was adjusted so as to have an energy of 35 mJ / mm ² in 1 millisecond on the surface of the recording layer of the recording material. Next, the recording material was exposed to light over the entire surface using Ricopy Super Dry 100 (manufactured by Ricoh Co., Ltd.) and light-fixed. The reflection density of the obtained blue recorded image was 1.13 as measured with a Macbeth reflection densitometer.

Example 6 Preparation of Capsule Solution 2-anilino-3-methyl-6-N-ethyl-N-butylaminofluoran (leuco dye) 14 g, Takenate D-110N (capsule manufactured by Takeda Pharmaceutical Co., Ltd.) Wall material trade name)) 50 g and infrared absorbing dye 5 of the following chemical formula
g

Embedded image It was added to and dissolved in a mixed solvent of 55 g of 1-phenyl-1-xylylethane and 55 g of methylene chloride.

The obtained solution was treated with 100 g of an 8% by weight aqueous solution of polyvinyl alcohol, 40 g of water and 1.4 g of a 2% by weight sodium salt of dioctyl sulfosuccinate (dispersant).
And then emulsified at 10,000 rpm for 5 minutes using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.). After 150 g of water was further added to the obtained emulsion, an encapsulation reaction was performed at 40 ° C. for 3 hours to prepare a capsule liquid having an average particle diameter of 0.7 μm.

Example 1 was repeated except that the capsule solution obtained above was used in place of the capsule solution used in Example 1.
A recording material was produced in the same manner as described above to obtain a transparent black image.
The color-developed portion of the obtained image was measured with a Macbeth transmission densitometer to be 1.52.

(Comparative Example 1) A recording material was prepared and an image was recorded in the same manner as in Example 1 except that the infrared absorbing dye used in Example 1 was not used, and no image was recorded.

(Comparative Example 2) A recording material was prepared and an image was recorded in exactly the same manner as in Example 1 except that the infrared absorbing dye used in Example 5 was not used, and no image was recorded.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-319182 (JP, A) JP-A-63-193880 (JP, A) JP-A-62-238786 (JP, A) JP-A-4- 331186 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41M 5/28-5/34

Claims (1)

(57) [Claims] To 1. A on a support, a heat-sensitive recording material for infrared laser having a heat-sensitive layer containing microcapsules and color developer containing at least color former, in the wall of the microcapsules, the Reacts with microcapsule wall material
Heat-sensitive recording material for infrared laser, wherein the infrared absorbing dye having a that active group are contained.