JPH09263065A - Thermal transfer recording material and image forming method - Google Patents

Abstract

(57) Abstract: A thermal transfer recording material comprising a combination of a thermal transfer sheet for sublimation transfer used for many times recording and a thermal transfer image receiving sheet, and a thermal transfer recording material excellent in storage stability of an image obtained in an image forming method. And an image forming method. In a thermal transfer recording material comprising a combination of a thermal transfer sheet and a thermal transfer image receiving sheet, the thermal transfer sheet used for multiple recording in which the moving speed of the thermal transfer sheet is slower than the moving speed of the thermal transfer image receiving sheet, A dye layer comprising a binder resin, a chelatable heat transferable dye, and a lubricant is provided on the material, and the dye receptive portion of the thermal transfer image-receiving sheet contains at least a metal ion-containing compound. Characterize.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording material comprising a combination of a thermal transfer sheet and a thermal transfer image-receiving sheet and an image forming method, and in particular, it is capable of recording many times,
The present invention relates to a thermal transfer recording material for sublimation transfer excellent in image storage stability and an image forming method.

[0002]

2. Description of the Related Art The multi-time recording method is a combination of a thermal transfer sheet provided with a dye layer containing a sublimable dye and a thermal transfer image-receiving sheet for receiving the dye transferred by the heating of a thermal head. In this case, the thermal transfer sheet and the thermal transfer image receiving sheet have different moving speeds, and printing is performed while moving the thermal transfer sheet at a relatively gentle speed as compared with the thermal transfer image receiving sheet. Therefore, this method is excellent in that the printing and recording time can be shortened, the consumption of the thermal transfer sheet can be reduced, and the recording unit can be simplified. By the way, generally, in sublimation transfer recording, a thermal transfer image-receiving sheet used in combination with a thermal transfer sheet has a resin to which a dye is easily dyed,
There is used a base sheet in which particles that adsorb a dye or that react with a dye are dispersed in a resin to form a receptor layer on the base sheet. When such a thermal transfer image-receiving sheet is superposed on the thermal transfer sheet and printing is performed by the thermal head, the temperature of the thermal head instantaneously reaches several hundred degrees, and the temperature of the surfaces of the thermal transfer sheet and the thermal transfer image-receiving sheet also rises. To rise. Therefore, the conventional thermal transfer image forming method has a problem that the thermal transfer sheet and the thermal transfer image receiving sheet are thermally fused during printing. For such problems, conventionally, it has been proposed to prevent the fusion by providing a release layer on the surface of the receiving layer, adding an extender pigment into the receiving layer, or crosslinking the thermoplastic resin. There is.

[0003]

However, in the multi-time recording method as described above, unlike the normal recording method, the thermal transfer image receiving sheet and the thermal transfer sheet have different moving speeds in addition to the heat generated by printing, and therefore the thermal transfer image receiving method is different. There is a drawback that shear stress acts at the overlapping interface between the sheet and the thermal transfer sheet, which makes the surface of the thermal transfer sheet more likely to be damaged. In order to overcome this drawback, JP-A-62-28
No. 2973, in a thermal transfer sheet, a dye layer composed of a resin binder, a dye, and an anti-friction agent is provided on a base material, and thermal fusion of the thermal transfer sheet and the thermal transfer image receiving sheet during printing can be effectively prevented. We proposed a thermal transfer sheet for multi-time recording. However, with this thermal transfer sheet, the storage stability of the obtained image, in particular, light resistance, heat resistance,
There was a problem that it was not sufficient in terms of plasticizer resistance and the like. Therefore, an object of the present invention is to provide a thermal transfer recording material comprising a combination of a thermal transfer sheet for sublimation transfer used for many times recording and a thermal transfer image receiving sheet, and an image forming method, wherein the thermal transfer recording material having excellent storage stability of the obtained image and An object is to provide an image forming method.

[0004]

In order to solve the above problems, as a result of intensive studies by the present inventors, in a thermal transfer recording material comprising a combination of a thermal transfer sheet and a thermal transfer image receiving sheet, the moving speed of the thermal transfer sheet is Regarding the thermal transfer sheet used for recording many times in which printing is performed at a speed slower than the moving speed of the image receiving sheet, a dye layer comprising a binder resin, a chelatable heat transferable dye and a lubricant is provided on a substrate. It has been found that the dye-accepting portion of the thermal transfer image-receiving sheet is characterized by containing at least a metal ion-containing compound, whereby the storage stability of the obtained image can be made excellent. Further, it is characterized in that the lubricant is polyethylene wax and / or silicone resin. Further, in the image recording method, at least in the thermal transfer image receiving sheet and the dye layer of the thermal transfer sheet in which a dye layer comprising a binder resin, a chelatable heat transferable dye and a lubricant is provided on the substrate. While making contact with the dye-receptive portion containing the metal ion-containing compound, and moving the thermal transfer sheet relatively slower than the thermal transfer image-receiving sheet,
It is characterized by printing with a thermal head.

The operation of the present invention is as follows. The thermal transfer sheet of the present invention contains a specific lubricant in the dye layer, so that the frictional force with the thermal transfer image receiving sheet is reduced and thermal fusion with the thermal transfer image receiving sheet is prevented. Further, the dye layer of the thermal transfer sheet of the present invention contains a heat transferable dye capable of chelating, and at least the metal ion-containing compound is contained in the dye-receptive portion of the thermal transfer image-receiving sheet, so that the thermal transfer recording material is printed. Upon heating, the dye and the metal ion-containing compound form a chelate compound and are fixed. Therefore, the storage stability of the obtained image is good.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a thermal transfer sheet showing one embodiment of the present invention. FIG.
As shown in FIG. 3, the thermal transfer sheet 1 of the present invention is provided with the base material 2 and the dye layer 3 on one surface. Further, as a preferred embodiment of the present invention, a heat resistant layer 4 may be provided on the other surface of the base material 2 in order to improve heat resistance and lubricity in contact with a thermal head during printing.

(Substrate) As the substrate 2, the same substrate as that used in the conventional thermal transfer sheet can be used as it is and is not particularly limited. Specific examples of the preferable substrate 2 include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone and other highly heat-resistant polyester film, aramid film, Kapton film, polycarbonate film, Q film (manufactured by Teijin Ltd.), polyparbanic acid film and the like are preferably used. Also,
It is also possible to use thin smooth paper such as glassine paper, condenser paper, and paraffin paper. Moreover, what laminated | stacked these materials etc. is mentioned. The thickness of this substrate can be appropriately selected depending on the material so that the strength, thermal conductivity, heat resistance, etc. are appropriate, but it is usually 1 to 20 μm.
Of these are preferably used. If the thickness is less than 1 μm, the substrate itself lacks in rigidity and the transportability of the printer becomes poor. If the thickness exceeds 20 μm, the sensitivity becomes insufficient during printing. When the substrate as described above has poor adhesion to the dye layer formed on the surface thereof, it is preferable to subject the surface to primer treatment or corona discharge treatment.

(Dye Layer) The dye layer 3 in the present invention is mainly composed of a chelatable heat transferable dye, a lubricant and a binder resin. The heat transferable dye in the present invention may be any chelating dye capable of thermal diffusion transfer, and examples thereof include dyes described in JP-A-59-78893, page 3, and JP-A-60-2398, pages 2-5. Can be used. A particularly preferable dye is a tridentate chelatable dye, and the dye represented by the following general formula (1) can be preferably used.

General formula (1)

Embedded image In the formula, X ₁ represents a group of atoms necessary for completing an aromatic carbocycle or heterocycle in which at least one ring is composed of 5 to 7 atoms, and is a carbon atom bonded to an azo bond. At least one of the adjacent positions is a nitrogen atom or a carbon atom substituted with a chelating group, and X ₂ is an aromatic heterocycle or an aromatic carbocycle in which at least one ring is composed of 5 to 7 atoms. And G represents a chelating group. Also,
It can be produced according to the synthetic methods disclosed in these publications. The amount of the chelatable heat transferable dye used in the present invention is usually 0.0 per 1 m ^{2 of the} substrate.
5g-10g are preferable, and also 0.2g-5g are more preferable. The addition amount of this heat transferable dye is 0.05 g
If it is less than 10 g, the print density is insufficient, and if it exceeds 10 g,
When the thermal transfer sheet is wound, the dye is transferred to the heat-resistant layer on the contact surface, resulting in poor storage stability.

The binder resin used in the dye layer is a cellulose derivative such as ethyl hydroxyethyl cellulose, ethyl cellulose, cellulose acetate, cellulose acetate butyrate, nitrocellulose, polyvinyl butyral, polyvinyl acetal, polyvinyl formal, polyvinyl butyral derivative, polystyrene, acrylic polymer. , Acrylic copolymers and methacrylic copolymers can be preferably used. The amount of the binder resin used is preferably 0.1 g to 50 g per 1 m ² of the base material.

Further, the lubricant used in the dye layer includes a wide range of materials having a function of reducing frictional force and preventing thermal fusion between the dye and the thermal transfer image-receiving sheet, and is a solid particle at room temperature. More specifically, a material that is softened by heat and has neither tackiness nor migration property is used. As such a material, without adversely affecting the dye in the dye layer,
Further, it is important that sensitivity and gradation are not impaired during printing. Specifically, polyethylene wax and / or silicone resin is preferably used. Further, the content of the lubricant in the dye layer is preferably 15 to 30% by weight. When the content is less than 15%, the effect of preventing heat fusion is insufficient, while when it exceeds 30%, the printing sensitivity and the storage stability of the thermal transfer sheet are deteriorated, which is not desirable.

The above dye layer is prepared by adding a heat transferable dye capable of chelating to a binder resin, a lubricant and, if necessary, additives on a substrate, and mixing with water or a solvent such as an organic solvent. , Ball mill, sand mill, etc. are used to apply the dispersed or dissolved ink by the usual methods such as bar coater, gravure printing method, screen printing method, reverse roll coating method using gravure plate, and then dried to form can do. The thickness of the dye layer is preferably 0.1 to 10 μm as a dry film. If it is less than 0.1 μm, the printing density is insufficient, and if it exceeds 10 μm, the printing sensitivity is insufficient, which is not preferable.

(Heat-Resistant Layer) A heat-resistant layer 4 is preferably provided on the surface of the thermal transfer sheet on the side in contact with the thermal head in order to prevent heat fusion to the thermal head. The binder resin used for the heat resistant layer 4 is, for example,
Cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, nitrified cotton, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone and other vinyl resins, polymethacrylic acid. Acrylic resin such as methyl, polyethyl acrylate, polyacrylamide, acrylonitrile / styrene copolymer, polyamide resin, vinyltoluene resin, coumarone indene resin, polyester resin, polyurethane resin,
Examples thereof include silicone-modified urethane resin and fluorine-modified urethane resin.

Further, these resins may be mixed and used. In order to further improve the heat resistance of the heat resistant layer 4, a resin having a reactive group such as a hydroxyl group may be used among the above-mentioned resins, and polyisocyanate or the like may be used in combination as a crosslinking agent to form a crosslinked resin layer. . Not only such a thermosetting resin, but also a UV curable or EB curable resin can be used. Further, in order to improve the slipperiness with a heating device such as a thermal head, a solid or liquid release agent or lubricant may be added to the heat resistant layer 4 so as to have the heat resistant slipperiness. As the release agent or lubricant, for example,
Various waxes such as polyethylene wax and paraffin wax, higher aliphatic alcohol, oreganopolysiloxane, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant, fluorine surfactant, organic Fine particles of an inorganic compound such as carboxylic acid and its derivative, fluorine resin, silicone resin, talc and silica can be used. The amount of the lubricant added to the heat-resistant layer 4 is preferably 5 to 50% by weight, and particularly preferably 10 to 3% by weight based on the total solid content of the heat-resistant layer 4.
0% by weight. The heat-resistant layer 4 can be formed by the same method as that for the dye layer, and its thickness is
It is preferably 0.05 to 5 μm. If the thickness is less than 0.05 μm, the heat resistance will be poor, while if it exceeds 5 μm, the printing sensitivity will be insufficient.

Next, the thermal transfer image receiving sheet used in combination with the thermal transfer sheet of the present invention has a constitution in which a dye receiving layer is provided on the base sheet or a constitution of the base sheet alone made of a material having a dye receiving property. . (Thermal transfer image-receiving sheet) The thermal transfer image-receiving sheet may be any one as long as its recording surface has a dye receptivity for the dye, and as a base sheet having no dye receptive property, paper,
In the case of metal, glass, synthetic resin or the like, the dye receiving layer may be formed on at least one surface thereof. The above paper is, for example, condenser paper, glassine paper,
Sulfuric acid paper, high-sized paper, synthetic paper (polyolefin-based or polystyrene-based), high-quality paper, art paper, coated paper, cast-coated paper, wallpaper, backing paper, synthetic resin or emulsion-impregnated paper, synthetic rubber latex-impregnated paper , Synthetic resin internal paper, paperboard, and cellulose fiber paper.

On the other hand, in the case of a base sheet having dye receptivity (dyeability), the dye receptive layer may not be formed, and the base sheet may be, for example, a polyolefin resin such as polypropylene, Halogenated polymers such as vinyl chloride and polyvinylidene chloride, vinyl polymers such as polyvinyl acetate and polyacrylic ester, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins,
Examples thereof include copolymer resins of olefins such as ethylene and propylene and other vinyl monomers, ionomers, cellulosic resins such as cellulose diacetate, fibers made of polycarbonate, woven fabrics, films, sheets, molded products and the like. As the thermal transfer image-receiving sheet of the present invention, a sheet or film made of polyester or a sheet provided with a polyester layer is particularly preferable. A sheet or film made of a vinyl chloride / vinyl acetate copolymer is also preferable. Even for a thermal transfer image-receiving sheet made of paper, metal, glass or other non-dyeing base material sheet, the recording surface thereof is coated with a solution or dispersion of a resin having the above-mentioned dyeing ability as a receiving layer. Then, a thermal transfer image-receiving sheet can be obtained by drying or laminating these resin films. Further, even in the case of the thermal transfer image-receiving sheet of the above dyeable base sheet, the dye receiving layer may be formed on the surface of the base sheet from a resin having good dyeability.

Further, a laminated body made of any combination of the above-mentioned substrate sheets can also be used. As an example of a typical laminated body, there is a synthetic paper of cellulose fiber paper and synthetic paper or a synthetic paper of cellulose fiber paper and plastic film. The thickness of these substrate sheets may be arbitrary and is usually 10 to 3
It is about 00 μm. When the adhesion between the base sheet and the layer provided thereon is poor, it is preferable to subject the surface of the base sheet to various primer treatments or corona discharge treatments.

The thermal transfer image-receiving sheet of the present invention comprises a dye-receptive portion, that is, a base sheet or a receiving layer,
It is characterized by containing a metal ion-containing compound. Examples of the metal ion-containing compound include inorganic or organic salts of metal ions and metal complexes, of which salts and complexes of organic acids are preferable. As the metal, I to VI of the periodic table
Examples include monovalent and polyvalent metals belonging to Group II, but among them, Al, Co, Cr, Cu, Fe, Mg, Mn, M
o, Ni, Sn, Ti and Zn are preferred, especially Ni,
Cu, Cr, Co and Zn are preferred. Specific examples of the metal ion-containing compound include Ni ²⁺ , Cu ²⁺ , Cr ²⁺ and C.
o ²⁺ and Zn ²⁺ and aliphatic salts such as acetic acid and stearic acid,
Alternatively, a salt of an aromatic carboxylic acid such as benzoic acid or salicylic acid may be used.

Further, the complex represented by the following general formula (2) can be used particularly preferably. Formula (2) _{[M (Q 1) l (Q} 2) m (Q 3) n ] ^p + (Y ^-) _p where in the formula, M is a metal ion, preferably, Ni
^{It represents 2+} , Cu ²⁺ , Cr ²⁺ , Co ²⁺ , Zn ²⁺ . Q ₁ and Q
₂ and Q ₃ each represent a coordination compound capable of forming a coordination bond with the metal ion represented by M, and may be the same as or different from each other. These coordination compounds can be selected, for example, from the coordination compounds described in “Chelate Chemistry (5)” (edited by Nanundou). Y represents an organic anion group, and specific examples thereof include a tetraphenylboron anion and an alkylbenzene sulfonate anion. l
Represents an integer of 1, 2 or 3, m represents 1, 2 or 0, and n represents 1 or 0. These are tetradentate or hexadentate in the complex represented by the general formula. Position, or the number of Q ₁ , Q ₂ , Q ₃ ligands. p represents 1 or 2. Specific examples of the complex represented by the general formula (2) are described in US Pat. No. 4,987,049. The amount of the metal ion-containing compound used in the present invention is usually 0.5 to 1 m ^{2 of} the support.
20 g is preferable, and 1 to 15 g is more preferable.
The metal ion-containing compound in the present invention has the general formula (2)
However, it is not limited thereto, and conventionally known ones can be used.

When a receptive layer is used as a part having a dye receptive property, the dye receptive layer may be formed of a single material or a plurality of materials among the resins having a dyeing property. Of course, various additives may be included as long as they do not interfere with the intended purpose. Such a receiving layer may be of any thickness, but is generally 3-50.
The thickness is μm. Further, the receiving layer is preferably a continuous coating, but it may be formed as a discontinuous coating by using a resin emulsion or a resin dispersion liquid. Further, the base sheet or the receiving layer, which is a part having a dye receptive property, can contain an inorganic powder for preventing heat fusion, and thus, even if the temperature at the time of thermal transfer is further increased, the thermal transfer sheet can be obtained. It is possible to prevent heat fusion between the heat transfer image-receiving sheet and the heat transfer image-receiving sheet and perform more excellent heat transfer. Particularly preferred is finely divided silica.

Further, in place of or in combination with the above-mentioned inorganic powder such as silica, a resin having good releasability as described above may be added. A particularly preferred release polymer is a cured product of a silicone compound, for example, a cured product composed of an epoxy-modified silicone oil and an amino-modified silicone oil. Further, hydroxyl group-modified silicone and addition polymerization type silicone may be used alone or in combination. It is preferable that such a releasing agent accounts for about 0.5 to 30% by weight of the weight of the receiving layer. Further, the thermal transfer image-receiving sheet to be used may have the effect of preventing thermal fusion by adhering the above-mentioned inorganic powder to the surface of the base sheet or the receiving layer, or the release property as described above. You may provide the layer which consists of an excellent mold release agent. Such a release layer has a thickness of about 0.01-5.
With a thickness of μm, a sufficient effect can be exhibited to prevent heat fusion with the receiving layer of the thermal transfer sheet, and further improve dye receptivity. Further, a color pigment, a white pigment, an extender pigment, a filler, an ultraviolet absorber, an antistatic agent, a heat stabilizer, an antioxidant, an optical brightening agent and the like can be optionally used on the dye receiving surface.

In the above-mentioned receiving layer, a metal ion-containing compound and, if necessary, an additive such as a release agent are added to a binder resin on a base sheet, and the solution is dissolved or dispersed in water or a solvent such as an organic solvent. Applied ink by a normal method such as a bar coater, a gravure printing method, a screen printing method, a reverse roll coating method using a gravure plate,
It can be formed by drying. Further, the receiving layer is formed not only by directly applying the ink on the base material sheet and drying as described above, but also by forming the receiving layer on another base material sheet in advance. The receiving layer may be transferred and formed on the material sheet. In addition, as the above-mentioned other base sheet, a material having the same conditions as the base sheet can be used. The thickness of the receiving layer is preferably 0.1 to 10 μm in terms of the film thickness after coating and drying.

Next, an image forming method using a thermal transfer recording material composed of a combination of the thermal transfer sheet and the thermal transfer image receiving sheet having the above-mentioned constitution will be explained. Printing is performed by a thermal head so that the dye layer of the thermal transfer sheet of the present invention and the dye-receptive portion of the thermal transfer image receiving sheet are in contact with each other and the thermal transfer sheet is moved relatively slower than the thermal transfer image receiving sheet. This is an image forming method. Further, heat energy corresponding to image information is applied to the interface between the dye layer and the dye receiving portion by the heating applying means of the thermal head, whereby the dye in the dye layer is transferred to the receiving portion. Since the dye is a chelatable dye, it reacts with the metal ion-containing compound in the transferred dye-accepting portion to form and fix the chelate compound.

[0024]

[Examples] Specific examples will be described below. In the following description, “parts” or “%” is based on weight unless otherwise specified. Synthetic paper (Yupo FPG-110 manufactured by Oji Yuka Co., Ltd.) was used as a base sheet, and a coating solution of the following composition (1) was applied to one surface of the synthetic paper so as to have a dry weight of 5 g / m ² . Further, a coating solution of the following composition (2) was applied thereon so as to have a dry amount of 1 g / m ^2, and the composition was dried at 100 ° C. for 30 minutes.
After drying for a minute, a thermal transfer image-receiving sheet was obtained. Coating solution for composition (1) Polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) 11.5 parts Zinc flower (manufactured by Sakai Chemical Co., Ltd.) 11.5 parts Toluene 33.5 parts Methyl ethyl ketone 33.5 parts Cyclohexanone 10.0 Department

Coating liquid for composition (2) Silicone (KS-772 manufactured by Shin-Etsu Chemical Co., Ltd.) 16.6 parts Curing agent (PL-3 manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03 parts Metal ion-containing compound: 5 parts ^{_{[Ni 2+ (NH 2 CH 2 CONH}} 2) 3 ] 2 _{[(C 6 H 5) 4 B} - ] toluene 78.37 parts

Furthermore, three types of coating liquids for forming a dye layer having the following compositions were prepared, and each of them was provided with a heat-resistant layer on the back surface of 9 μm.
An m-thick polyethylene terephthalate film was coated and dried to a dry coating amount of 1.0 g / m ² to obtain a thermal transfer sheet of the present invention having three dye layers of yellow, magenta and cyan. Dye layer forming coating solution (yellow) Heat transfer yellow dye: Chemical formula 2 below 5.50 parts Polyvinyl butyral resin 4.80 parts Methyl ethyl ketone 55.00 parts Toluene 34.70 parts Polyethylene filler (Microfine MF8F) 2.06 Department

[0027]

Embedded image

Dye layer forming coating solution (magenta) Heat transferable magenta dye: Chemical formula 3 below 5.50 parts Polyvinyl butyral resin 4.80 parts Methyl ethyl ketone 44.85 parts Toluene 44.85 parts Polyethylene filler (Microfine MF8F) 2.06 copies

[0029]

Embedded image

Dye layer forming coating solution (cyan) Heat transfer cyan dye: Chemical formula 4 7.70 parts Polyvinyl butyral resin 5.12 parts Methyl ethyl ketone 29.44 parts Toluene 43.84 parts Methyl isobutyl ketone 10.00 parts Polyethylene filler (Microfine MF8F) 2.56 parts

[0031]

Embedded image

Using the thermal transfer image-receiving sheet and the thermal transfer sheet obtained as described above, printing was carried out by moving the thermal transfer sheet at a speed of 1/2 times or 1/10 times that of the thermal transfer image receiving sheet. Good printing was performed without heat fusion. Further, the storage stability of the obtained image was good.

[0033]

As is clear from the results of the above examples, the thermal transfer sheet of the present invention contains a specific anti-friction agent in the dye layer. It is possible to effectively prevent the occurrence of heat fusion, which is a particular problem. Further, the dye layer of the thermal transfer sheet of the present invention contains a heat transferable dye capable of chelating, and at least the metal ion-containing compound is contained in the dye-receptive portion of the thermal transfer image-receiving sheet, so that the thermal transfer recording material is printed. Upon heating, the dye and the metal ion-containing compound form a chelate compound, and the resulting image has good storage stability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structural example of a thermal transfer sheet of the present invention.

[Explanation of symbols]

 1 Thermal Transfer Sheet 2 Base Material 3 Dye Layer 4 Heat Resistant Layer

Claims (3)

[Claims] 1. A thermal transfer recording material comprising a combination of a thermal transfer sheet and a thermal transfer image-receiving sheet, wherein the thermal transfer sheet is used for multi-time recording in which the moving speed of the thermal transfer sheet is slower than the moving speed of the thermal transfer image receiving sheet. A dye layer composed of a binder resin, a chelatable heat transferable dye and a lubricant is provided on a substrate, and the dye-receptive portion of the thermal transfer image-receiving sheet contains at least a metal ion-containing compound. A thermal transfer recording material characterized by: 2. The thermal transfer recording material according to claim 1, wherein the lubricant is polyethylene wax and / or silicone resin. 3. A dye layer of a thermal transfer sheet, comprising a base material and a dye layer comprising a heat transferable dye capable of chelating with a binder resin and a lubricant, and at least metal ions in the thermal transfer image-receiving sheet. An image forming method, wherein printing is performed by a thermal head while being in contact with a dye-receptive portion containing a contained compound and moving the thermal transfer sheet relatively slower than the thermal transfer image-receiving sheet.