JPH05286257A - Heat mode thermal transfer recording material - Google Patents

Abstract

PURPOSE:To provide a heat mode thermal transfer recording material having sensitivity fitted to laser beam, forming a transfer image free from color turbidity and obtaining an image excellent in color reproducibility. CONSTITUTION:A heat mode thermal transfer recording material is obtained by providing a photothermal conversion layer 4 containing at least a water-soluble colorant and an ink layer on a support 1. The water-soluble colorant is composed of a near infrared absorbing dye dissolved in water in an amount of 0.1wt.% or more and containing a sulfo group and having an absorption peak with respect to light with a long wavelength of 700nm or more. The photothermal conversion layer 4 contains a water-soluble binder and the thickness thereof is 1.0mum or less and the transmissivity thereof at an absorption peak of a wavelength of 700nm or more is 10% or less. The thickness of the ink layer 3 is pref. set to 1.0mum in order to more develop effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat mode thermal transfer recording material, and more particularly to a heat mode thermal transfer recording material capable of obtaining a transferred image with good color reproducibility by a light source such as a laser.

[0002]

BACKGROUND OF THE INVENTION Conventionally, a pressure heating system using a thermal head has been put into practical use as a thermal transfer recording method, but in recent years, as a method capable of recording an image with higher resolution, a laser beam is irradiated onto a thermal transfer recording material, In this recording material, a method of converting a laser beam into heat to perform thermal transfer recording has come to be used. This laser thermal transfer recording method (heat mode thermal transfer recording method) can condense the laser light used for energy supply up to about several μ, so that the resolution is dramatically higher than that of the thermal transfer recording method in which heat is supplied by the thermal head. It is possible to improve.

However, when a color image is to be obtained by using this heat mode thermal transfer recording system, a large amount of local energy given by a laser transfers (scatters) the photothermal conversion material contained in the heat mode thermal transfer recording material. However, there is a problem in that the color image of the transferred image is generated.

JP-A 2-2074, 3-34891, 3-36094
Although the technology relating to the photothermal conversion material is disclosed in the publication etc., all use sublimable dyes, and basically only the dyes are transferred, and there is no clear description about the existence of the photothermal conversion layer. However, the situation and the use of water-soluble coloring materials are not mentioned.

[0005]

It is an object of the present invention to prevent an explosive phenomenon due to thermal decomposition, thermal melting, etc. even when a large amount of local energy is applied, and to prevent the photothermal conversion layer itself from transferring. To provide a thermal transfer recording material.

Another object of the present invention is to provide a heat mode thermal transfer recording material which has a sensitivity suitable for laser light and the like and has no color turbidity of a transferred image and therefore an image excellent in color reproducibility can be obtained. It is in.

[0007]

As a result of intensive studies, the present inventors have completed the present invention by finding that the above object of the present invention can be achieved by making the photothermal conversion layer of the thermal transfer recording material have a high heat resistance.

(1) A heat mode thermal transfer recording material having a photothermal conversion layer containing at least a water-soluble coloring material and an ink layer on a support.

(2) The heat mode thermal transfer recording material according to (1), wherein the water-soluble coloring material is a coloring material which dissolves in water by 0.1% by weight or more.

(3) The water-soluble coloring material contains a sulfo group (1)
The heat mode thermal transfer recording material described.

(4) The heat mode thermal transfer recording material according to (1), wherein the water-soluble coloring material is a near-infrared absorbing dye having an absorption peak for long wavelength light of 700 nm or more.

(5) The heat mode thermal transfer recording material according to (1), wherein the light-heat conversion layer contains a water-soluble binder or an aqueous emulsion resin.

(6) The heat-mode thermal transfer recording material according to (1), wherein the thickness of the photothermal conversion layer is 1.0 μm or less, and the transmittance of the photothermal conversion layer at the absorption peak at a wavelength of 700 nm or more is 10% or less. ..

(7) The thickness of the ink layer is 1.0 μm or less
The heat mode thermal transfer recording material described in (1).

The present invention will be described in more detail below.

The heat mode thermal transfer recording material (hereinafter, also simply referred to as "recording material") is basically a support in which a photothermal conversion layer containing a photothermal conversion substance and an ink layer are laminated in this order. In addition, an intermediate layer (cushion layer, release layer, barrier layer, etc.) may be provided between the light-heat conversion layer and the ink layer.

In the present invention, a water-soluble coloring material is used as the photothermal conversion substance that controls the photothermal conversion action. The water-soluble colorant, a sulfo group (-SO ₃ H), carboxyl (-CO
OH), a phosphono group (—PO ₃ H ₂ ) and other acid groups, and those containing a bond such as sulfonamide and carbonamide are preferable, and those having a sulfo group are particularly preferable.

The coloring material varies depending on the light source,
A substance that absorbs light and efficiently converts it into heat is preferable. For example, when a semiconductor laser is used as a light source, a substance having absorption in the near infrared is preferable. For example, various cyanine dyes, anthraquinone dyes, indoaniline metal complex dyes, azurenium dyes, croconium dyes, squarylium dyes, dithiol metal complex dyes, chelate dyes, naphthalocyanine metal complex dyes, and the like can be used. Among them, the dyes represented by the following general formulas (1) to (12) are preferable.

[0019]

[Chemical 1]

In the general formulas (1) and (2), Z ₁ and Z ₂ are each a substituted or unsubstituted pyridine ring, a substituted or unsubstituted quinoline ring, a substituted or unsubstituted benzene ring or a substituted or unsubstituted Represents a group of atoms necessary to form a naphthalene ring of (in the case where Z ₁ and Z ₂ represent a pyridine ring or a quinoline ring, = N ⁺ (R ₁ ) -bond or -N (R ₆ )-
A bond may be included within Z ₁ or Z ₂ . ).

Z ₃ and Z ₄ each represent an atomic group necessary for forming a substituted or unsubstituted quinoline ring or a substituted or unsubstituted pyridine ring, and ═N ⁺ (in the rings Z ₃ and Z ₄ ( R
₁₎ - bond or -N (R ₆₎ - it may include a bond.

Y ₁ and Y ₂ are each a dialkyl-substituted carbon atom, a vinylene group, an oxygen atom, a sulfur atom, a selenium atom, or a nitrogen atom to which a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group is bonded. Represent

R ₁ and R ₆ each represent a substituted or unsubstituted alkyl group, R ₂ , R ₄ and R ₅ each represent a hydrogen atom or a substituted or unsubstituted alkyl group, and R ₃ represents a hydrogen atom. , A halogen atom, a substituted or unsubstituted alkyl group,
It represents a nitrogen atom to which a substituted or unsubstituted aryl group, or an alkyl group or an aryl group is bonded.

However, at least one of the groups represented by Z _{1 to} Z ₄ and R _{1 to} R ₆ is at least one of acid groups such as sulfo group, carboxyl group and phosphono group (preferably sulfo group). Has been replaced.

[0025] X ^- is an anion, m is 0 or 1, n
Represents an integer of 1 or 2. However, n is 1 when the dye forms an inner salt.

[0026]

[Chemical 2]

In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each a substituted or unsubstituted alkyl group, --N (R ₅ ) (R ₆ ), ═N ⁺ (R ₅ ).
(R ₆ ) or a sulfo group, and R ₅ and R ₆ each represent a substituted or unsubstituted alkyl group. However, at least one of the groups represented by R _{1 to} R ₆ is a sulfo group, a carboxyl group,
It is substituted with at least one acid group such as a phosphono group (preferably a sulfo group). X ^- represents an anion.

[0028]

[Chemical 3]

In the formula, R ₁ , R ₂ , R ₃ and R ₄ each represent a substituted or unsubstituted alkyl group, at least one of which is a sulfo group, a carboxyl group, a phosphono group or the like (preferably a sulfo group). ) Is substituted with at least one of the acid groups.

[0030]

[Chemical 4]

In the formula, R ₁ and R ₂ each represent a substituted or unsubstituted alkyl group, at least one of which is at least one of acid groups such as sulfo group, carboxyl group, phosphono group (preferably sulfo group). Has been replaced. R ₃ and R ₄ each represent a hydrogen atom or an alkyl group, and the alkyl group may be substituted with an acid group such as a sulfo group, a carboxyl group, a phosphono group (preferably a sulfo group).

[0032]

[Chemical 5]

In the formula, R ₁ , R ₂ and R ₃ each represent a substituted or unsubstituted alkyl group, at least one of which is an acid such as a sulfo group, a carboxyl group or a phosphono group (preferably a sulfo group). It is substituted with at least one of the groups. X
^- represents an anion.

[0034]

[Chemical 6]

In the formula, R ₁ and R ₂ each represent a sulfo group, a carboxyl group, a phosphono group or an alkyl group or an aryl group substituted with one of them.

[0036]

[Chemical 7]

In the formula, R ₁ represents a hydrogen atom, an amido group, an amino group, an alkyl group, or a sulfo group, a carboxyl group, a phosphono group or an alkyl group substituted with one of them, and R ₂ and R ₃ are Each represents an alkyl group or an alkyl group substituted with at least one of a sulfo group, a carboxyl group and a phosphono group, and R ₄ is a hydrogen atom, a sulfo group, a carboxyl group, a phosphono group or an alkyl group substituted with one of them. Represents a group.

[0038] M represents a metal atom (Cu, Ni is preferable), X ^- represents an anion.

[0039]

[Chemical 8]

In the formula, R ₁ represents a hydrogen atom or an alkyl group substituted with one of a sulfo group, a carboxyl group and a phosphono group, and R ₂ represents an alkyl group, an amido group, a nitro group, a sulfo group, a carboxyl group. Alternatively, it represents a phosphono group.

[0041]

[Chemical 9]

In the formula, R ₁ and R ₂ each represent a sulfo group, a carboxyl group, a phosphono group or an alkyl group substituted with one of them, and n represents 2 or 3. R ₃ , R ₄ , R
₅ and R ₆ each represent an alkyl group which may be the same or different.

[0043]

[Chemical 10]

In the formula, R ₁ and R ₂ each represent a hydrogen atom, a sulfo group, a carboxyl group, a phosphono group or an alkyl group substituted with one of them. However, R ₁ and R ₂ are not both hydrogen atoms. M represents a divalent or trivalent metal atom, and n represents an integer of 2 or 3.

[0045]

[Chemical 11]

In the formula, R ₁ R ₂ R ₃ and R ₄ each represent a hydrogen atom, a sulfo group, a carboxyl group, a phosphono group or an alkyl group substituted with one of them. However, R ₁ ~
R ₄ is not all hydrogen atoms. M represents a divalent metal atom.

Typical specific examples of the water-soluble coloring materials represented by the general formulas (1) to (12) are shown below, but of course the invention is not limited thereto.

[0048]

[Chemical 12]

[0049]

[Chemical 13]

[0050]

[Chemical 14]

[0051]

[Chemical 15]

In addition, as a near infrared absorbing dye, JP-A-62-62
The compounds described in JP-A-123454, JP-A-3-146565 and the like can be mentioned.

These water-soluble coloring materials are dissolved in water together with a water-soluble binder or an aqueous emulsion resin to prepare a coating solution for the photothermal conversion layer. Examples of the water-soluble binder include polyvinyl alcohol, polyvinylpyrrolidone,
Gelatin, glue, casein, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose,
Hydroxyethyl starch, gum arabic, sucrose octaacetate, ammonium alginate, sodium alginate, polyvinylamine polyethylene oxide, polystyrene sulfonic acid, polyacrylic acid and the like,
Particularly, polyvinyl alcohol and celluloses are preferably used.

A surfactant or the like may be added to the coating liquid in order to improve the coating property, and a substance which increases the adhesion between the photothermal conversion layer and the lower layer or the releasability from the upper ink layer. You may contain the substance which improves. When the water-soluble coloring material and the binder are dissolved, heating and shearing may be added to help the dissolution.

The photothermal conversion substance amount in the photothermal conversion layer is usually 2
It is -80% by weight, preferably 20-70% by weight. The photothermal conversion substance can be added to other layers.

The ink layer is preferably prepared by dissolving or dispersing a necessary coloring material in a solvent together with a binder to prepare a coating liquid.

As the binder, ethyl cellulose,
Cellulosic resins such as hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, and cellulose acetate; polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, polyester, polyvinyl acetate, polyacrylamide, polyvinyl acetoacetal, styrene resin, styrene. Examples thereof include vinyl resins such as copolymer resins, polyacrylic acid esters, polyacrylic acids and acrylic acid copolymers, rubber resins, ionomer resins, olefin resins, rosin resins and the like.
Among these, polyvinyl butyral, polyvinyl acetoacetal, and cellulosic resins having excellent acid resistance are preferable.

As the coloring material, an inorganic or organic pigment,
Although a dye is used, for example, yellow, magenta, and cyan pigment-based compounds are preferable.

Examples of the inorganic pigments include titanium dioxide, carbon black, zinc oxide, Prussian blue, cadmium sulfide, iron oxide and chromates of lead, zinc, barium and calcium. As an organic pigment,
Examples thereof include azo-based, thioindigo-based, anthraquinone-based, anthanthrone-based, triphendioxazine-based pigments, vat dye pigments, phthalocyanine pigments (copper phthalocyanine and its derivatives), and quinacridone pigments.
Examples of organic dyes include acid dyes, direct dyes, disperse dyes, oil-soluble dyes, oil-containing metal-soluble dyes, sublimable dyes (including heat sublimable dyes), and the like.

Examples of the solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate, amyl acetate, dimethyl phthalate and ethyl benzoate, aromatic hydrocarbons such as toluene, xylene and benzene. Halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene and chlorobenzene, ethers such as diethyl ether, methyl cellosolve and tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, bentoxone and the like can be used.

The weight ratio of the binder to the coloring material is 1:10 to 1
0: 1 is preferable and 2: 8 to 8: 2 is particularly preferable.

Various additives can be added to the ink layer as long as the objects of the present invention are not impaired. Specifically, silicone, silicone oil (reaction hardening type is also possible), silicone modified resin, fluororesin, surfactants and peelable compounds such as waxes, metal powder, silica gel, metal oxide, carbon black and resin fine particles. Examples thereof include fillers such as powders, curing agents (eg, isocyanates, acrylics, epoxies) that can react with binder components, waxes, hot solvents, and the like.

Any support may be used as long as it has good dimensional stability and withstands heat during image formation. Specifically, the film described in JP-A-63-193886, page 2, lower left column, lines 12 to 18 is used. Or sheets can be used.

If an image is formed by irradiating a laser beam from the support side, the support is preferably transparent. Further, the support need not be particularly transparent as long as the laser light is emitted from the image receiving layer side.

The thickness of the support is not particularly limited, but usually 2
˜100 μm, preferably 5˜20 μm.

The thinner the photothermal conversion layer and the ink layer, the shorter the time required for the thermal energy obtained in the photothermal conversion layer to reach the interface between the ink layer and the image receiving layer. Since the heat capacity is small, less energy is required to reach the melting temperature. Therefore, both are preferably 1.0 μm or less, and particularly preferably 0.2 to 0.8 μm.

In the present invention, it is preferable to interpose an intermediate layer between the photothermal conversion layer and the ink layer. The intermediate layer can have various functions. For example, a function as a barrier layer that prevents the heat-diffusible coloring material in the ink layer from diffusing into another layer, a function as a cushion layer that increases the adhesion between the recording material and the image receiving material, and an ink layer and an image receiving layer during image formation. The intermediate layer can be provided with a function as a peeling layer that facilitates peeling from the layer. Next, the thermal transfer image receiving material will be described.

The image-receiving material receives the heat-meltable ink layer imagewise peeled from the recording material to form an image. Usually, the image receiving material has a support and an image receiving layer, and may be formed of only the support.

Since the heat-meltable ink layer, which is melted by heat, is transferred to the image-receiving material, it is desirable that the image-receiving material has appropriate heat resistance and is excellent in dimensional stability so that an image is properly formed.

The surface of the image receiving material that comes into contact with the recording material during image formation has good smoothness or is appropriately roughened. More specifically, when the surface of the heat-meltable ink layer of the recording material is roughened by a matte material or the like, it is desirable that the surface of the image-receiving material that contacts the heat-meltable ink layer has good smoothness, Further, when the heat-meltable ink layer is not roughened, it is desirable that the surface of the image-receiving material that comes into contact with the heat-meltable ink layer be roughened by a matte material. Further, both the contact surfaces of the heat-meltable ink layer and the image receiving material may be roughened.

The image-receiving layer can be formed of a binder, various additives added as necessary, and a substance for imparting the cushioning property.

Examples of the binder include ethylene-vinyl chloride copolymer adhesives, polyvinyl acetate emulsion adhesives, chloroprene adhesives, epoxy resin adhesives and other adhesives, natural rubber, chloroprene rubber, butyl rubber adhesives. Adhesives such as polyacrylic acid ester-based, nitrile rubber-based, polysulfide-based, silicon rubber-based, rosin-based resin, vinyl chloride-based resin, petroleum-based resin and ionomer resin, recycled rubber, SBR, polyisoprene, polyvinyl ether, etc. be able to.

The cushion layer interposed between the support and the image receiving layer is the same as the cushion layer described in the recording material.

The thickness of the support in the image receiving material having the support, the cushion layer and the image receiving layer, or the thickness of the support in the image receiving material formed of only the support is not particularly limited. The thickness of the cushion layer is the same as the thickness of the cushion layer in the recording material. The thickness of the image receiving layer is usually 0.1 to 20 μm, but it is not limited to this when the cushion layer is used as the image receiving layer.

[0075]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 (Preparation of Ink Sheet) An ink sheet was prepared by successively coating the following cushion layer, photothermal conversion layer and ink layer on a 100 μm thick PET (polyethylene terephthalate) support. All material amounts in each layer are shown in parts by weight.

<Cushion Layer> A coating solution having the following composition was prepared, coated with a blade coater and dried. The film thickness is about 60 μm.

JSR0617 (Carboxy-modified styrene-butadiene resin 10 parts: made by Japan Synthetic Rubber) Water 90 parts <Photothermal conversion layer> A coating solution having the following composition was prepared, and was coated and dried on the cushion layer using a wire bar. .. The film thickness was controlled in advance by examining the relationship between the absorbance at 830 nm of the photothermal conversion material and the film thickness, and measuring the absorbance.

When using water-soluble photothermal conversion material Water-soluble photothermal conversion material 3.50 parts GL-05 (polyvinyl alcohol: manufactured by Nippon Synthetic Chemical Industry) 3.43 parts FT248 (water-based surfactant: manufactured by BASF) 0.07 parts water 93 parts solvent solubility When using a photothermal conversion material Solvent-soluble photothermal conversion material 3.5 parts S-2000 (polycarbonate: manufactured by Mitsubishi Gas) 3.5 parts MEK (methyl ethyl ketone) 93.0 parts <Ink layer> Prepare a coating solution having the following composition, and apply it on the photothermal conversion layer. Was applied and dried using a wire bar.

DS-90 (manufactured by Harima Kasei) 4.7 parts SD0012 (manufactured by Tokyo Ink) 0.5 parts EV-40Y (manufactured by Mitsui DuPont) 0.5 parts DOP (dioctyl phthalate) 0.3 parts MHI R527 (magenta pigment) 4.0 parts MEK 90.0 parts ( Preparation of Image Receptor) An ink sheet was prepared by successively coating the following cushion layer and image receiving layer on a 100 μm thick PET support. All material amounts in each layer are parts by weight.

<Cushion Layer> A coating solution having the following composition was prepared, coated and dried using a blade coater. The film thickness is about 60 μm.

JSR 0617 (Nippon Synthetic Rubber) 10 parts Water 90 parts <Image Receiving Layer> A coating solution having the following composition was prepared, and was coated on the cushion layer using a wire bar and dried. The film thickness is 1.
0 μm.

RB820 (styrene-butadiene resin: made by Japan Synthetic Rubber) 10 parts Toluene 90 parts (image formation by thermal transfer) On a drum, place the ink sheet on the drum so that the ink layer of the ink sheet and the image receiving layer side of the image receptor are in contact with each other. And then they were stacked. Next, the pressure between the ink sheet and the image receptor was removed by reducing the pressure using a vacuum pump in order to increase the adhesion between the two. At this time, squeeze was applied to further increase the adhesion.

Irradiation from the side of the ink sheet support with a semiconductor laser (830 nm) was carried out, and the transferred image was observed when the number of rotations of the drum was changed, and the sensitivity, color reproducibility, dot reproducibility, etc. were evaluated.

Example 2 Ink sheet (light-heat conversion layer thickness 0.35 μm, ink layer thickness about 0.7 μm, cushion layer thickness about 60 μm) according to Example 1 by changing the photothermal conversion material as follows. Then, an image receptor was prepared, and thermal transfer was performed with a semiconductor laser, and the sensitivity and color reproducibility of the obtained transferred image were evaluated. As a matter of course, S-2000 was used as the binder in the solvent system and GL-05 was used as the binder in the water system.

(Solvent soluble photothermal conversion material) A: IR101 (dithiol metal complex salt) B: IR102 (solvent dispersion type photothermal conversion material) C: IR103 (MEK dispersion of carbon) D: IR104 (MEK dispersion of titanyl phthalocyanine) ) (Water-soluble photothermal conversion material) E: IR105 (cyanine dye) F: IR106 (cyanine dye) G: IR107 (chelate dye)

[0087]

[Chemical 16]

[0088]

[Chemical 17]

The results are as follows.

Photothermal conversion material Sensitivity (mJ / mm ² ) Color reproducibility Remark IR101 5.00 Large color turbidity Comparative example IR102 3.00 Large color turbidity Comparative example IR103 4.00 Large color turbidity Comparative example IR104 4.50 Large color turbidity Comparative example IR105 0.50 Color turbidity No invention IR106 0.50 Color turbidity No invention IR107 1.50 Color turbidity little invention From the above results, it is clear that color turbidity due to the photothermal conversion material can be suppressed by using the water-based photothermal conversion material,
It can be seen that the use of IR106 as a photothermal conversion material is advantageous when sensitivity is also taken into consideration.

Example 3 The sensitivity and color reproducibility were evaluated when the following water-soluble binder and solvent-soluble binder were used as the photothermal conversion layer binder. IR106 is used as the photothermal conversion material when using a water-soluble binder, and I when using a solvent-soluble binder.
R102 was used.

P1800NT11 (Polyethersulfone: Nissan Chemical Industries, Ltd.) Insoluble in water, soluble in MEK U-100 (Polyarylate: Unitika) Insoluble in water, soluble in MEK S-2000 (Polycarbonate: Mitsubishi Gas) Poorly soluble in water, soluble in MEK Pethresin A515G (polyester: made by Takamatsu Yushi) Poorly soluble in water, soluble in MEK Polysol AP2681 (styrene-acrylic: Showa High Polymer) sparingly soluble in water, soluble in MEK UCAR AW850 (Vinyl chloride-Vinyl acetate: made by UCC) Water-insoluble, MEK-soluble TS-625 (gelatin) Water-soluble, MEK-insoluble polyvinylpyrrolidone (K-90) Water-soluble, MEK Slightly soluble GL-05 (Polyvinyl alcohol: manufactured by Nippon Synthetic Chemical Industry) Soluble in water, hardly soluble in MEK The following results were obtained.

Binder Solvent Sensitivity (mJ / mm ² ) Color reproducibility P1800NT11 THF / MEK (6/4) 5.00 Large color turbidity U-100 THF / MEK (6/4) 5.00 Large color turbidity S- 2000 THF / MEK (6/4) 3.00 Large turbidity Pethresin A515G Water (dispersion) 1.00 Small turbidity AP2681 Water (dispersion) 1.50 Small turbidity UCAR AW850 Water (dispersion) 1.00 Small color turbidity TS-625 Water 0.75 No color turbidity K-90 Water 0.75 No color turbidity GL-05 Water 0.50 No color turbidity From these results, it is clear that the color reproducibility can be improved by using an aqueous binder as the binder of the photothermal conversion layer.

Example 4 An ink sheet was prepared by using IR102 as the water-soluble photothermal conversion material and GL-05 as the binder in Example 1. At this time, the film thickness of the photothermal conversion layer was changed to 0.1 to 3.0 μm and the film thickness of the ink layer was changed to 0.3 to 2.0 μm. However, the light-heat conversion layer has a thickness of 830 nm and the ink layer has a thickness of 570 nm.
It was determined by measuring the absorbance at nm. The relationship between the film thickness of the photothermal conversion layer and the sensitivity is shown below.

Binder film thickness (μm) Ink layer film thickness (μm) Sensitivity (mJ / mm ² ) 0.10 0.70 0.40 0.20 0.70 0.40 0.25 0.70 0.40 0.30 0.70 0.50 0.35 0.70 0.50 0.40 0.70 0.61 0.60 0.70 0.75 0.80 0.70 1.00 1.10 0.70 3.25 1.50 0.70 3.50 2.00 0.70 4.00 3.00 0.70 4.50 0.35 0.30 0.50 0.35 0.40 0.50 0.35 0.60 0.50 0.35 0.90 0.75 0.35 1.10 1.25 0.35 1.50 1.25 0.35 2.00 1.25

[0096]

[Table 1]

The degree of heat resistance of the material used for the light-heat conversion layer depends on the applied energy and cannot be generally stated, but a polymer binder having a similar structure or a light-heat conversion dye, or the like. In the additive of
It was confirmed that the heat resistance was improved by using a water-soluble compound.

Further, if the photothermal conversion layer is made water-soluble, the photothermal conversion layer is unlikely to be attacked when the ink layer applied thereon is coated, and a good layer structure can be obtained, so that high sensitivity and color turbidity prevention can be achieved. Is also advantageous.

[0099]

EFFECT OF THE INVENTION The heat mode thermal transfer recording material of the present invention makes it possible to obtain a transferred image having no color turbidity and excellent color reproducibility by using laser beam scanning.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a heat mode thermal transfer recording material of the present invention superimposed on an image receiving material for thermal transfer.

[Explanation of symbols] 1 support 2 image-receiving layer 3 ink layer 4 photothermal conversion layer 5 peeling layer 6 cushion layer

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

Claims (7)

[Claims] 1. A heat mode thermal transfer recording material comprising a photothermal conversion layer containing at least a water-soluble coloring material and an ink layer on a support. 2. The heat mode thermal transfer recording material according to claim 1, wherein the water-soluble coloring material is a coloring material which is dissolved in water by 0.1% by weight or more. 3. The heat mode thermal transfer recording material according to claim 1, wherein the water-soluble coloring material contains a sulfo group. 4. The heat mode thermal transfer recording material according to claim 1, wherein the water-soluble coloring material is a near-infrared absorbing dye having an absorption peak in long wavelength light of 700 nm or more. 5. The heat mode thermal transfer recording material according to claim 1, wherein the photothermal conversion layer contains a water-soluble binder or an aqueous emulsion resin. 6. The photothermal conversion layer has a thickness of 1.0 μm or less,
The heat mode thermal transfer recording material according to claim 1, wherein the transmittance of the photothermal conversion layer at an absorption peak at a wavelength of 700 nm or more is 10% or less. 7. The heat mode thermal transfer recording material according to claim 1, wherein the thickness of the ink layer is 1.0 μm or less.