EP0482896A1

EP0482896A1 - Heat sensitive transfer recording method

Info

Publication number: EP0482896A1
Application number: EP91309768A
Authority: EP
Inventors: Tawara C/O Konica Corporation Komamura; Katsunori C/O Konica Corporation Katoh; Noritaka c/o Konica Corporation Nakayama
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 1990-10-23
Filing date: 1991-10-22
Publication date: 1992-04-29
Also published as: JPH04158092A

Abstract

Disclosed is a heat-sensitive transfer recording method, which comprises superposing a heat-sensitive transfer recording material having on a support at least an ink layer containing a compound represented by the formula (1) on an image-receiving material, giving a heat corresponding to an image information to said heat-sensitive transfer recording material and forming an image with the chelate dye formed by the reaction between the compound represented by the formula (1) and a compound represented by the formula (2) shown below on the image-receiving material:

Formula (1)

(wherein X¹ represents a group of atoms necessary for formation of an aromatic ring, X₂ represents a group of atoms necessary for formation of thizaole ring or benzothiazole ring, and R¹ an alkyl group);

Formula (2)

[M(Q₁)_l(Q₂)_m(Q₃)_n]^p(Y⁻)_q

(wherein M represents a metal ion, Q1, Q2 and Q3 each represent a coordination compound coordination bonded with the metal ion represented by M, Y represents an anion forming an anion pair with the complex, l represents an integer of 1, 2 or 3, m represents an integer of 1, 2 or 0, n represents 1 or 0, p represents +, 2+ or 3+, and q represents 1, 2 or 3).

Description

BACKGROUND OF THE INVENTION

This invention relates to a heat-sensitive transfer recording method by use of a heat-sensitive recording material, more particularly to a heat-sensitive transfer recording method which forms an image having sufficient image density and also excellent in color reproducibility.
Heretofore, as the method for obtaining color hard copy, there have been investigated color recording techniques by way of ink jet, electrophotography, heat-sensitive transfer, etc.
Among these, particularly the heat-sensitive transfer system has such advantages as easy operation and maintenance, smaller size of device, possible reduction of cost, and further inexpensive running cost, etc.
The heat-sensitive transfer system includes the two kinds, namely the system in which a transfer sheet having a meltable ink layer provided on a support (heat-sensitive transfer recording material) is heated with a heat-sensitive head to have the ink melt transferred onto a transferable sheet (image-receiving material), and the thermal diffusion transfer system (sublimation transfer system) in which a transfer sheet having an ink layer containing a thermally diffusible dye (sublimable dye) on a support is heated with a heat-sensitive head to have the above thermally diffusible dye transferred onto a transferable sheet, but the latter thermally diffusible transfer system is more advantageous for full color recording, because the tone of the image can be controlled by varying the amount of the dye transferred corresponding to the change in thermal energy of the heat-sensitive head.
However, in the heat-sensitive transfer recording of the thermally diffusible transfer system, the dye used for the heat-sensitive transfer recording material is important, and those of the prior art had the drawback that stability, namely light resistance and fixability of the image obtained is not good.
In order to improve that point, Japanese Unexamined Patent Publications Nos. 78893/1984, 109394/1984 and 2398/1985 disclose image forming methods which comprises using a chelatable thermally diffusible dye to form an image with a chelated dye on an image receiving material.
According to these image forming methods, although light resistance and fixability can be improved, still various problems have remained to be solved. More specifically, the cyan dye described in the above published specifications is low in transferability to give no image with sufficient density, or when as the compound to be added for chelation of the dye through the reaction of the dye (hereinafter called metal source), for example, a stearic acid salt, etc. of a transition metal (e.g. nickel, etc.) described in Japanese Unexamined Patent Publication No. 2398/1985 are employed, the reaction efficiency with the dye (hereinafter called chelate formation efficiency) is poor, whereby an image with a dye not chelated is formed on the image and therefore there has been involved such problem as undesirable color reproducibility, etc. Improvement of that point has been deired for a long time.

SUMMARY OF THE INVENTION

The present invention has been accomplished in order to solve the above problem, and an object of the present invention is to provide a heat-sensitive transfer recording method which can obtain a cyan image preferable in color reproduction having high density and excellent image stability (fixability, light resistance) by use of a dye having good diffusibility and a metal source having a high chelate formation efficiency.
The above object of the present invention can be accomplished by a heat-sensitive transfer recording method, which comprises superposing a heat-sensitive transfer recording material having on a support at least an ink layer containing a compound represented by the formula (1) on an image-receiving material, giving a heat corresponding to an image information to said heat-sensitive transfer recording material and forming an image with the chelate dye formed by the reaction between the compound represented by the formula (1) and a compound represented by the formula (2) on the image receiving material:

Formula (1)

[wherein X₁ represents a group of atoms necessary for formation of an aromatic ring, X₂ represents a group of atoms necessary for formation of thizaole ring or benzothiazole ring, and R¹ represents an alkyl group];

Formula (2)

[M(Q₁)_l(Q₂)_m(Q₃)_n]^p(Y⁻)_q

[wherein M represents a metal ion, Q₁, Q₂ and Q₃ each represent a coordination compound coordination bonded with the metal ion represented by M, Y is an anion forming an anion pair with the complex, 1 represents an integer of 1,2 or 3, m represents an integer of 1, 2 or 0, n represents 1 or 0, p represents +, 2+ or 3+, and q represents 1, 2 or 3].

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 and Fig. 2 are illustrations showing the heat-sensitive transfer recording method of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

X₁ in the above formula (1) represents a group of atoms necessary for formation of an aromatic ring, preferably a group of atoms necessary for formation of benzene ring or naphthalene ring. The aromatic ring may also have a substituent. X₂ is a group of atoms necessary for formation of thiazole ring or benzothiazole ring, which may also have a substituent. R₁ represents an alkyl group, preferably a straight or branched alkyl group having 1 to 12 carbon atoms, as exemplified by methyl, ethyl, n-propyl, n-butyl, n-hexyl, n-decyl, i-propyl, 2-ethylhexyl groups and the like. The alkyl group may also have a substituent such as alkoxy group (e.g. a methoxy group, an ethoxy group), halogen atoms (e.g. a fluorine atom, a chlorine atom), carboxyl group, aryl groups (e.g a phenyl group), etc.
As the compound of the formula (1), specifically the compounds represented by the following formulae (3) - (6) are preferable.
In the formulae, R¹ has the same meaning as defined in the formula (1), R² and R³ each represent a hydrogen atom, an alkyl group (e.g. a methyl group, an ethyl group) or a nitro group, R⁴ represents a hydrogen atom, an alkyl group (e.g. a methyl group, an ethyl group), a halogen atom (e.g. a chlorine atom), an alkoxy group (e.g. a methoxy group, an ethoxy group) or an alkoxycarbonyl group (e.g. an ethoxycarbonyl group), R⁵ represents a hydrogen atom, a halogen atom (e.g. a chlorine atom, a fluorine atom), an alkoxy group (e.g. a methoxy group, an ethoxy group), an alkyl group (e.g. a methyl group, an ethyl group) or a nitro group. When R², R³, R⁴ and R⁵ respectively represent alkyl groups, they may also have a substituent, and as the substituent, the same substituents as mentioned for R¹ may be included.
In the following, specific exemplary compounds of the compounds represented by the formula (1) (hereinafter sometimes called also as the compound (1)) are shown, but the present invention is not limited by these at all.

Exemplary compounds

M in the above formula (2) represents a metal ion, including preferably Al²⁺, Co²⁺, Cr²⁺, Cu²⁺, Fe²⁺, Mg²⁺, Mn²⁺, Mo²⁺, Ni²⁺, Sn²⁺, Ti²⁺, Zn²⁺, etc.
Q₁, Q₂ and Q₃ each represent a coordination compound, including, for example, the coordination compounds described in Chelate Chemistry (5) (Nankodo), etc., but particularly preferable in the present invention are ethylenediamine and derivatives thereof, glycineamide and derivatives thereof, picolineamide and derivatives thereof, etc.
Y represents an anion, including inorganic compound anions such as Cl⁻, SO₄⁻ ClO₄⁻, etc. organic compound anions of benzensulfonic acid derivatives, alkylsulfonic acid derivatives, etc., particularly preferably tetraphenylboron anion and its derivatives.
l represents an integer of 1, 2 or 3, m represents 1, 2 or 0, n represents 1 or 0, and these are determined depending on whether the complex represented by the above formula is tetra-dentate coordination or hexa-dentate coordination or depending on the number of the ligands of Q₁, Q₂, Q₃.
In the following, specific exemplary compounds of the compounds represented by the formula (2) preferably used in the present invention (hereinafter sometimes called also as the compound (2)) are shown, but the present invention is not limited by these compounds at all.

Exemplary compounds

MS-1

Ni²⁺(C₂H₅NHCH₂CH₂NH₂)₃[(C₆H₅)₄B⁻]₂

MS-2

Ni²⁺(NH₂CH₂CONH₂)₃[(C₆H₅)₄B⁻]₂

MS-3

MS-4

Cu²⁺(NH₂CH₂CH₂NHC₂H₅)₂[(C₆H₅)₄B⁻]₂

MS-5

Ni²⁺(NH₂CH₂CONHC₃H₇(n))[(C₆H₅)₄B⁻]₂

MS-6

Zn²⁺(NH₂CH₂CH₂NH₂)₃[(C₆H₅)₄B⁻]₂

MS-7

MS-8
The heat-sensitive transfer recording material comprises an ink layer containing the dye represented by the formula (1) (hereinafter sometimes called heat-sensitive layer) provided on a support.
The content of the dye in the above heat-sensitive layer may be preferably 0.1 to 20 g per 1 m² of the support.
The above heat-sensitive layer can be formed by preparing a paint for formation of heat-sensitive layer by dissolving one kind or two or more kinds of the above dyes together with a binder in a solvent or dispersing in fine particles into a solvent, and coating said paint on a support, followed by suitable drying.
The thickness of the heat-sensitive layer may be preferably 0.1 to 5 µm as dry film thickness.
The above binder may include water-soluble polymers such as cellulose type, polyacrylic acid type, polyvinyl alcohol type, polyvinyl pyrrolidone type, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyether sulfone, polyvinyl butyral, polyvinyl acetal, nitrocellulose, ethylcellulose, etc.
These binders, either one kind or two or more kinds, may be used not only as a solution dissolved in an organic solvent, but also in the form of a latex dispersion.
The amount of the binder used may be preferably 0.1 to 50 g per 1 m² of the support.
As the above solvent, there may be included water, alcohols (e.g. ethanol, propanol), cellosolves (e.g. methylcellosolve), esters (e.g. ethyl acetate), aromatics (e.g. toluene, xylene, chlorobenzene), ketones (e.g. acetone, methyl ethyl ketone), ethers (e.g. tetrahydrofuran, dioxane), chlorine type solvents (e.g chloroform, trichloroethylene), etc.
The above support is not particularly limited, provided it has good dimensional stability and can stand the heat of the heat-sensitive head during recording, but may include thin papers such as condenser paper, grassine paper, etc., heat-resistant plastic films such as polyethylene terephthalate, polyamide, polycarbonate, etc.
The thickness of the support may be preferably 2 to 30 µm, and the support may be also provided with a subbing layer for the purpose of improving adhesivness with the binder or preventing transfer, dyeing of the dye onto the support side.
Further, on the back surface of the support (the opposite side to the heat-sensitive layer), a slipping layer may be also provided for the purpose of preventing sticking of the heat-sensitive head to the suport.
The heat-sensitive transfer recording material according to the present invention may also have a heat-meltable layer containing a heat-meltable compound disclosed in Japanese Unexamined Patent Publication No. 106997/1984 provided on the heat-sensitive layer.
As the above heat-meltable compound, colorless or white compounds having melting points of 65 to 130 °C may be preferably used, as exemplified by waxes such as carunauba wax, beeswax, canderilla wax, etc.; higher fatty acids such as stearic acid, behenic acid, etc.; alcohols such as xylitol, etc.; amides such as acetamide, benzamide, etc.; ureas such as phenylurea, diethylurea, etc.
In these heat-meitable layers, for enhancing retentivity of the dye, for example, polymers such as polyvinyl pyrrolidone, polyvinyl butyral, saturated polyesters, etc may be also contained.
The heat-sensitive transfer recording material according to the present invention can obtain a cyan image from one kind of dye, but when applied to full color image recording, it should preferably have at least three layers of a cyan heat-sensitive layer containing a cyan dye, a magenta heat-sensitive layer containing a magenta dye and a yellow heat-sensitive layer containing a thermally diffusible yellow dye provided by coating successively repeatedly on the same surface of the support.
Also, if necessary, in addition to the yellow heat-sensitive layer, the magenta heat-sensitive layer, the cyan heat-sensitive layer, a heat-sensitive layer containing a black image forming substance may be provided by coating successively repeatedly on the same surface of the support.
The compound represented by the formula (2) is used as the metal source, and added into the image-receiving material (preferably the image-receiving layer of the image-receiving material) or the heat-meltable layer as described above. The amount added may be preferably 0.2 to 20 g/m², more preferably 1 to 10 g/m², based on the image-receiving material or the heat-meltable layer.
The image-receiving material to be used in the present invention generally comprises one kind or two or more kinds of polymer layers such as polyester resin, polyvinyl chloride resin, copolymer resin of vinyl chloride with another monomer (e.g. vinyl acetate, etc.), polyvinyl butyral, polyvinyl pyrrolidone, polycarbonate, etc. formed as the image-receiving layer on a support comprising paper, plastic film or paper-plastic film composite.
Alternatively, the above support itself may also sometimes made the image-receiving material.
In the heat-sensitive transfer recording method of the present invention, after the heat-sensitive layer of the above heat-sensitive transfer recording material is superposed on the image-receiving material, the heat corresponding to the image information is given to the heat-sensitive transfer recording material, and the image is formed on the image-receiving material with the chelate dye formed through the reaction between the metal source and the dye.
In the present invention, since the compound (1) is employed as the dye and the compound (2) is employed as the metal source, a cyan image preferable in color reproduction with high density and excellent image stability (fixability, light resistance) can be obtained.
The above heat-sensitive transfer recording method is described by referring to the drawings. In Fig. 1, when a metal source is permitted to exist in the image-receiving layer 2 of the image-receiving material 3 comprising the support 1 and the image-receiving layer 2, the dye in the heat-sensitive layer 5 of the heat-sensitive transfer recording material 6 comprising the support 4 and the heat-sensitive layer 5 is diffused and migrated to the image-receiving material 3 with the heat from, for example, the heat-generating resistor 8 of the heat-sensitive head 7, and reacts with the above metal source in the image-receiving layer 2 to form a chelate dye.
Also, in Fig. 2, when a metal source is permitted to exist in the heat-meltable layer 9 provided on the surface of the heat-sensitive layer 5, the dye in the heat-sensitive layer 5 of the heat-sensitive transfer recording material 10 comprising the support 4, the heat-sensitive layer 5 and the heat-meltable layer 9 is diffused and migrated to the heat-meltable layer 9 with, for example, the heat from the heat-generating resistor 8 of the heat-sensitive head 7, where it reacts with the above metal source to form a chelate dye, and the heat meltable substance 9a containing the chelate dye is migrated to the image-receiving material 3 through agglomeration destruction or surface peel-off, or the heat-meltable layer is migrated to the image-receiving material 11 such as plain paper, etc., followed by diffusion migration of the dye in the light-senstive layer to said heat-meltable layer, where it reacts with the above metal source to form a chelate dye.
As the heating method, heating by means of a heat-sensitive head is generally employed, but current passage heating or heating by use of a laser may be also available.
Referring now to Examples, the present invention is described in more detail, but the present invention is not limited by these Examples at all.

Example 1

Preparation of paint

The starting materials shown below were mixed to obtain a paint of a uniform solution containing the thermally diffusible dye according to the present invention.

Preparation of heat-sensitive transfer recording material

The above paint was coated and dried by use of a wire bar on a polyethylene terephthalate film with a thickness of 4.5 µm to a coated amount after drying of 1.0 g/m² to prepare a heat-sensitive transfer recording material - 1 comprising a heat-sensitive layer formed on the polyethylene terephthalate film.
On the back surface of the above polyethylene terephthalate film is provided as the slipping prevention layer a nitrocellulose layer containing a silicone-modified urethane resin (SP-2105, produced by Dainichi Seika).

Preparation of image-receiving material

On the polyethylene layer on one side of a paper laminated on both sides with polyethylene (containing white pigment (TiO₂), a bluish agent and a compound (2) (Exemplary compound MS-1) (attached amount 5 g/m²) as the metal source) was coated a vinyl chloride resin containing 0.15 g/m² of silicone oil as the image-receiving layer to an attached amount of 10 g/m² to obtain an image-receiving material-1.

Heat-sensitive transfer recording method

The above heat-sensitive transfer recording material and the image-receiving material were superposed so that the heat-sensitive layer surface of the heat-sensitive transfer recording material and the image-receiving surface of the image-receiving material are opposed to each other, and the heat-sensitive head was put against the back of the heat-sensitive transfer recording material to effect image recording under the recording conditions shown below, whereby an image-1 was obtained.
As the result, a cyan image excellent in gradation characteristic was obtained.
The maximum density <Dmax> (reflective density with red light measured by a densitometer PDA-65 produced by Konica K.K.), the hue of image (visial observation) and fixability of the image were evaluated. The results evaluated are shown in Table 1.
However, concerning fixability, evaluation was conducted according to the method shown below.

Recording conditions

Line density of main scanning, sub-scanning: 8 dots/mm
Recording power: 0.6 W/dot
Heating time of heat-sensitive head: heating time was adjusted stepwise between 20 msec. and 0.2 msec.

Evaluation of fixability

With the image-receiving layer surface of the image obtained superposed on the coated surface of the transfer sheet comprising a nitrocellulose layer with a thickness of 5 µm provided by coating on the polyethylene terephthalate film with a thickness of 180 µm, heating was effected at 140 °C for one minute, and the transfer extent of the dye from the image-receiving layer to the above nitrocellulose layer surface was evalauted by visual observation according to the following standards. Fixability is more excellent as retrasfer is less.

Evaluation standards: ⓞ.. no retransfer recognized at all Δ.. substantially no retransfer recognized x... retransfer is marked.

Examples 2 - 8

Heat-sensitive transfer recording materials 2 - 8 were prepared in the same manner as in Example 1 except for changing the dye from the compound (1) (Exemplary compound C-1) to the Exemplary compounds C-2, C-16, C-5, C-17, C-19, C-10 or C-13 in Example 1, and image recording was performed under the same recording conditions to obtain images 2 to 8. For the respective images obtained, the same evaluation as in Example 1 was conducted. The results are shown in Table 1.

Examples 9 - 12

Image receiving materials 2 - 5 were prepared in the same manner as in Example 1 except for changing the metal source from the compound (2) (Exemplary compound MS-1) to MS-2, MS-3, MS-5, MS-7. For the respective image-receiving materials, by use of the heat sensitive transfer recording material 1, image recording was performed by use of the same recording conditions as in Example 1 to obtain images 9 - 12. For the respective images obtained, the same evaluation as in Example 1 was conducted. The results are shown in Table 1.

Comparative examples 1 - 3

Heat-sensitive transfer recording materials 9 - 11 were prepared in the same manner as in Example 1 except for changing the dye to Comparative dyes A, B, C shown below in Example 1, and image recording was performed under the same recording conditions as in Example 1 to obtain images 13 - 15. However, for the image-receiving material, the image-receiving material 1 was employed. For the respective images obtained, the same evaluation as in Example 1 was conducted. The results are shown in Table 1.

Comparative dye A:

Comparative dye B:

Comparative dye C:

Comparative examples 4 - 7

Image-receiving materials 6, 7 were prepared in the same mannerr as in Example 1 except for changing the metal source added in the image-receiving material in Example 1 to nickel stearate or nickel chloride. For the respective image-receiving materials, by use of the heat-sensitive transfer recording material shown in Table 1, image recording was performed under the same recording conditions as in Example 1 to obtain images 16 - 19. For the respective images obtained, the same evaluation as in Example 1 was conducted. The results are shown in Table 1.
As is apparent from Table 1, the images 13 - 15 obtained by use of Comparative dyes A - C are low in diffusibility of the dye, and therefore no image of high density was obtained. On the other hand, since a part of the dye transferred onto the image-receiving material was not chelated, the image obtained by color mixing with the unchelated dye exhibited violet color. Further, in the images by use of Comparative dyes, fixability was also insufficient. This is also caused by retransfer of a part of the unchelated dye.
In the cases when nicel salt for comparison is used (image No. 16 - 19) as the metal source, because of low reactivity of the metal source, color mixing or defective fixabiity occurred due to the unchelated dye similarly as in the iamges 13 - 15. Nickel chloride was added in fine powder, but the luster of the image-receiving layer was lowered, while in the case of nickel stearate, precipitation from the image-receiving layer and the luster deterioration of the image-receiving layer and white ground staining were recognized, whereby the image obtained by use of metal sources for comparison were not desirable in image quality.
On the other hand, the images formed according to the method of the present invention had high density because the transferability of the dye and the reactivity between the dye and the metal source are high, whereby it was found that they are excellent in hue and fixability as cyan. Also, no precipitation of the metal source or white ground staining was recognized.

Example 13

On the heat-sensitive transfer material 1 of Example 1 was provided by coating as the intermediate layer 100 ml of an aqueous solution containing 5 g of a ball mill dispersed product of P-toluamide, 7 g of a polyvinyl pyrrolidone, 3 g of gelatin and 0.3 g of a film hardener shown below to an attached amount of P-toluamide of 0.5 g/m².

Film hardener:

Further, on the intermediate layer was provided by hot melt coating a carunauba wax (attached amount 2.0 g/m²) containing the compound (2) (Exemplary compound MS-1) (attached amount 1.0 g/m²) as the metal source, the UV-ray preventive shown below (attached amount 0.1 g/m²), the antioxidant shown below (attached amount 0.1 g/m²) and an ethylene-vinyl acetate copolymer (content of vinyl acetate 20% by weight, attached amount 0.2 g/m²) to obtain a heat-sensitive transfer material 12 having a heat-meltable layer.
The heat-sensitive transfer material was superposed on an image-receiving material and image recording performed under the same conditions as in Example 1. As the result, a cyan image with Dmax 1.75 could be recorded on the image-receiving material.
However, a white plain paper was employed for the image-receiving material. The image obtained was found to be good in all of stability of image (fixability, light resistance).

Comparative example 8

On the heat-sensitive transfer recording material 9 of Comparative example 1 was provided by coating an intermediate layer and a heat-meltable layer in the same manner as in Example 13 to obtain a heat-sensitive transfer recording material 13. Also, a heat-transfer recording material 14 was obtained in the same manner as in Example 13 except for changing the metal source added in the heat-meltable layer of the heat-sensitive transfer recording material 12 in Example 13 to nickel stearate.
For the heat-transfer recording materials 13, 14 obtained, image recording was performed under the same recording conditions as in Example 13, but because the dye was not sufficiently chelated, image stability was insufficient, and also color mixing was recognized in hue.

Anti-UV agent:

Antioxidant:

As described in detail above, by use of a dye having good diffusibility and a metal source having high chelate formation efficiency according to the present invention, a heat-sensitive recording method capable of obtaining a cyan image preferable in color reproduction with high density and excellent image stability (fixability, light resistance) could be provided.

Claims

A heat-sensitive transfer recording method, which comprises superposing a heat-sensitive transfer recording material having on a support at least an ink layer containing a compound represented by the formula (1) on an image-receiving material, giving a heat corresponding to an image information to said heat-sensitive transfer recording material and forming an image with the chelate dye formed by the reaction between the compound represented by the formula (1) and a compound represented by the formula (2) shown below on the image-receiving material:

Formula (1)
(wherein X₁ represents a group of atoms necessary for formation of an aromatic ring, X₂ represents a group of atoms necessary for formation of thizaole ring or benzothiazole ring, and R¹ an alkyl group);

Formula (2)

[M(Q₁)_l(Q₂)_m(Q₃)_n]^p(Y⁻)_q

(wherein M represents a metal ion, Q1, Q2 and Q3 each represent a coordination compound coordination bonded with the metal ion represented by M, Y represents an anion forming an anion pair with the complex, l represents an integer of 1, 2 or 3, m represents an integer of 1, 2 or 0, n represents 1 or 0, p represents +, 2+ or 3+, and q represents 1, 2 or 3).
The method of Claim 1 wherein X₁ in the formula (1) represents a group of atoms necessary for formation of a benzene ring or a naphthalene ring.
The method of Claim 1 wherein R₁ in the formula (1) represents a straight or branched alkyl group having 1 to 12 carbon atoms.
The method of Claim 3 wherein the alkyl group is the one selected from the group consisting of methyl group, ethyl group, n-propyl group, n-butyl group, n-hexyl group, n-decyl group, i-propyl group and 2-ethylhexyl group.
The method of Claim 1 wherein the compound represented by the formula (1) is the one selected from the group consisting of the compounds represented by the following formula (3) to (6)

in the formulae, R¹ has the same meaning as defined in the formula (1), R² and R³ each represent hydrogen atom, an alkyl group or a nitro group, R⁴ represents a hydrogen atom, an alkyl group, a halogen atom, an alkoxy group or an alkoxycarbonyl group, R⁵ represents a hydrogen atom, a halogen atom, an alkoxy group, an alkyl group or a nitro group.
The method of Claim 1 wherein M in the formula (2) represents a metal ion selected from the groups consisting of Al²⁺, Co²⁺, Cr²⁺, Cu²⁺, Fe²⁺, Mg²⁺, Mn²⁺, Mo²⁺, Ni²⁺, Sn²⁺, Ti²⁺ and Zn²⁺.
The method of Claim 1 wherein Q₁, Q₂ and Q₃ in the formula (2) each represent ethylenediamine and derivatives thereof, glycineamide and derivatives thereof and picolineamide and derivatives thereof.
The method of Claim 1 wherein Y in the formula (2) represents tetraphenylboron anion and derivatives thereof.
The method of Claim 1 wherein the content of the dye represented by the formula (1) in the ink layer is 0.1 to 20 g per 1 m² of the support.
The method of Claim 1 wherein the thickness of the ink layer is 0.1 to 5 µm as dry film thickness.
The method of Claim 1 wherein the added amount of the compound represented by the formula (2) is 0.2 to 20 g/m² based on the image-receiving material.
The method of Claim 11 wherein the added amount of the compound represented by the formula (2) is 1 to 10 g/m² based on the image-receiving material.