JP3041725B2 - Thermal transfer recording material and thermal transfer recording method - Google Patents

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 and a thermal transfer recording method, and more particularly, to a thermal transfer recording material for obtaining a magenta image having high density and good image stability, and this thermal transfer recording material. The present invention relates to a thermal transfer recording method capable of efficiently recording a magenta image by using the method.

[0002]

BACKGROUND OF THE INVENTION A thermal transfer recording method is easy to operate and maintain, and can be downsized and reduced in cost.
Further, it is useful as a method for obtaining a color hard copy because of its advantages such as low running cost.

However, in the thermal transfer recording of the thermal transfer system, the dye used in the thermal transfer material is important, and the conventional one has a disadvantage that the stability of the obtained image, particularly the fixability and the light resistance, are poor. are doing.

In order to improve the point, Japanese Patent Application Laid-Open No. 59-78893
No. 59-109349, No. 60-2398, etc., an image forming method of forming an image on an image receiving material using a chelatable dye by using a chelatable heat-diffusible dye. Is disclosed.

[0005] These image forming methods are excellent methods for improving fixability and light fastness. However, the dyes disclosed in these known patents are used as a chelating agent for thermal transfer recording materials. The following performances required for possible dyes (hereinafter referred to as post-chelate dyes) are not always satisfied.

1) To provide a chelate dye image having a good color tone by chelate formation. 2) The post-dye dye has good thermal diffusivity. 3) The post-chelating dye does not move to the back of the ink sheet or the like when the ink sheet is stored. 4) The post-dye has good solvent solubility (suitability for ink formation). 5) Good reactivity of the post-chelate dye (reactivity with the metal ion supply compound). 6) Clean
Excellent stability (fixability, light resistance) of the dye image.

[0007] Accordingly, further improvements have been desired for the above-described performance of post-chelate dyes.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method using a post-chelating dye capable of giving a good magenta color tone by chelation. It is an object of the present invention to provide a thermal transfer recording material and a thermal transfer recording method using the recording material.

It is another object of the present invention that the ink suitability, the thermal diffusivity and the chelate reactivity are good, an image can be obtained at a high density with good storability, and the storability of the ink sheet is good. An object of the present invention is to provide a thermal transfer recording material using a post chelate dye and a thermal transfer recording method using this recording material.

[0010]

The above object of the present invention has been attained by the following constitutions. That is, (a) a heat-sensitive transfer recording material having a heat-sensitive transfer layer containing at least a dye represented by the following general formula (1) on a support.

[0011]

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In the formula, R ₁ represents a monovalent organic group, and Y ₁ represents 5
Represents an atomic group necessary for forming a 6-membered heterocyclic ring, and Y ₂
Represents an atomic group necessary for forming an aromatic heterocyclic ring in which at least one of the atoms adjacent to the carbon atom to which the azo group is bonded is a nitrogen atom, an oxygen atom or a sulfur atom (Z ₁ is a nitrogen atom, an oxygen atom, Represents either a sulfur atom or a carbon atom, Z ₂ represents a nitrogen atom or a carbon atom, and at least one of Z ₁ and Z ₂ is a nitrogen atom, an oxygen atom or a sulfur atom).

[0013] The image-receiving material is superimposed on a heat-sensitive transfer recording material having a heat-sensitive transfer layer containing a dye represented by the general formula (1) described in (b) or (a) on a support. Heating,
A thermal transfer recording method in which an image is formed by a chelate dye formed by a reaction between the dye and a metal ion supply compound (hereinafter, referred to as a metal source).

The dye represented by formula (1) of the present invention (hereinafter referred to as the dye of the present invention) will be described in more detail.

In the general formula (1), R ₁ is preferably an alkyl group (eg, ethyl, i-propyl, t-butyl, etc.), an aryl group (eg, phenyl), an alkylamino group (eg, ethylamino, dimethylamino, etc.) An arylamino group (eg, phenylamino), an acylamino group (eg, acetyl), an alkoxy group (eg, methoxy,
Ethoxy), an aryloxy group (eg, phenoxy), an alkylthio group (eg, methylthio, ethylthio, etc.), and an arylthio group (eg, phenylthio).
The atomic group represented by Y ₁ is preferably an atomic group in which a total of 3 to 4 nitrogen atoms form a 5-membered ring, and for example, an alkyl group (methyl, ethyl, trifluoromethyl, etc.) on the ring, Aryl group (phenyl, etc.), alkoxy group (methoxy, ethoxy, etc.), alkylamino group (butylamino, diethylamino, etc.), acylamino group (acetyl, etc.), sulfonyl group (methanesulfonyl, etc.), alkoxycarbonyl group (methoxycarbonyl, etc.) And this group of atoms may form a condensed ring with another ring (for example, a benzene ring). The group of atoms represented by Y ₂ is preferably a group of atoms forming a 5- to 6-membered aromatic heterocyclic ring in which at least one of the atoms adjacent to the azo bond is a nitrogen atom, and the ring further comprises another ring. (Eg, a benzene ring) to form a condensed ring.

The dye of the present invention is excellent in heat diffusivity and chelate reactivity, and a magenta dye having a good color tone is formed by chelation. It is highly soluble. Representative examples of the dye of the present invention are shown below.

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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The dyes of the present invention can be used, for example, in Chemical Review
s, Vol. 75, 241 (1975).

The heat-sensitive transfer recording material of the present invention is provided with a heat-sensitive transfer layer containing the dye of the present invention on a support. The content of the dye in the heat-sensitive transfer layer is per 1 m ² of the support.
0.05 to 10 g is preferred.

The heat-sensitive transfer layer is formed by dissolving one or more of the dyes of the present invention together with a binder in a solvent, or by dispersing the dye in the form of fine particles in the solvent. It can be formed by preparing, applying the ink on a support, and drying it appropriately. The thickness of the thermal transfer layer is 0.1 to 10 in dry film thickness
μm is preferred.

Examples of the binder include acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyethersulfone, and polyvinyl butyral.
Solvent-soluble polymers such as toluene, polyvinyl butyral, polyvinyl acetal, nitrocellulose and ethyl cellulose are preferred. These binders may be used in the form of a latex dispersion, as well as one or two or more of them dissolved in an organic solvent. The amount of the binder used is preferably 0.1 to ²⁰ g per 1 m2 of the support. Examples of the organic solvent include alcohols (for example, ethanol and propanol), cellosolves (for example, methyl cellosolve), aromatics (for example, toluene and xylene), esters (for example, acetate), ketones (for example, acetone and methyl ethyl ketone). ), Ethers (eg, tetrahydrofuran, dioxane) and the like.

The support has good dimensional stability,
Any material that can withstand the heating of the thermal head during recording may be used, but thin paper such as condenser paper or glassine paper, or a heat-resistant plastic film such as polyethylene terephthalate, polyamide, or polycarbonate is preferably used.

The thickness of the support is preferably 2 to 30 μm,
Further, the support preferably has an undercoat layer made of a polymer selected for the purpose of improving the adhesiveness to a binder and preventing transfer and dyeing of the dye to the support. Further, a slipping layer may be provided on the back surface of the support (the side opposite to the thermal transfer layer) for the purpose of preventing the head from sticking to the support.

The heat-sensitive transfer recording material of the present invention is described in JP-A-59-106997 on the heat-sensitive transfer layer for the purpose of using an image-receiving material described later which is not particularly provided with an image-receiving layer such as plain paper. May have a heat-fusible layer containing such a heat-fusible compound. As this heat-fusible compound,
A colorless or white compound that melts at a temperature of 65 to 150 ° C. is preferably used, and examples thereof include waxes such as carnauba wax, beeswax, and candeline wax. In addition, these heat-meltable layers may contain polymers such as polyvinylpyrrolidone, polyvinylbutyral, polyester, and vinyl acetate.

In order to apply the heat-sensitive transfer recording material of the present invention to a heat-sensitive transfer recording material capable of recording a full-color image, a magenta heat-sensitive transfer layer containing the dye of the present invention and a heat-diffusing material capable of forming a cyan image. It is preferable that a total of three layers, a cyan thermal transfer layer containing a dye and a yellow thermal transfer layer containing a heat diffusible dye capable of forming a yellow image, are sequentially and repeatedly coated on the same surface on the support. . Further, if necessary, a total of four heat-sensitive transfer layers containing a black image-forming substance may be successively and repeatedly applied on the same surface.

In the thermal transfer recording method of the present invention, after the thermal transfer layer of the thermal transfer recording material and the image receiving material are overlaid, heat corresponding to the image information is applied to the thermal transfer recording material so that the metal source and An image is formed on the image receiving material by the chelate dye formed by the reaction with the dye of the present invention. In this case, in the present invention, the dye represented by the general formula (1)
Since the dye represented by the formula (1) is used, it is possible to efficiently obtain a magenta image which is high in density, rich in image stability and preferable in color reproduction. The metal source may be present in the image receiving material, or may be present in the heat-meltable layer provided on the heat-sensitive transfer layer.

The above-described thermal transfer recording method will be described with reference to the drawings. In FIG. 1, when a metal source is present in an image receiving layer of an image receiving material 3 comprising a support 1 and an image receiving layer 2, when the support 4 and the thermal transfer The dye in the thermal transfer layer of the thermal transfer material 6 composed of the layer 5 is diffused and transferred to the image receiving material 3 by, for example, heat from the heating resistor 8 of the thermal head 7 and reacts with the metal source in the image receiving layer 2 to chelate. A dye image is formed.

In FIG. 2, when a metal source is present in the heat-meltable layer 9 provided on the heat-sensitive transfer layer 5,
The dye in the thermal transfer layer 5 of the thermal transfer recording material 10 composed of the support 4, the thermal transfer layer 5 and the thermal fusible layer 9 is heated by the heat from the heating resistor 8 of the thermal head 7, for example. , And reacts with the metal source to form a chelate dye. The heat-meltable layer containing the chelate dye transfers to the image receiving material 3 by cohesive failure or interfacial peeling to form an image.

The metal source includes inorganic or organic salts and metal complexes of metal ions, and among them, organic acid salts and complexes are preferable. Metals include I to VI of the periodic table
Examples include monovalent and polyvalent metals belonging to Group II, among which Al, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Sn, Ti and Zn.
Are preferred, and particularly preferred are Ni, Cu, Cr, Co and Zn. Specific examples of the metal source include Ni ²⁺ , Cu ²⁺ , Cr ²⁺ , and Co ²⁺
And Zn ²⁺ and an aliphatic salt such as acetic acid or stearic acid, or a salt of an aromatic carboxylic acid such as benzoic acid or salicylic acid.

The complex represented by the following general formula can be particularly preferably used.

[M (Q₁)_l(Q_Two)_m(Q_Three)_n]^{P +}(Y^-)_P  However, in the above formula, M is a metal ion, preferably N
i²⁺, Cu²⁺, Cr²⁺, Co²⁺, Zn ²⁺Represents Q₁, Q_Two, Q_ThreeIs each
Compound capable of coordinating with metal ions represented by M
And may be the same or different. This
These coordination compounds include, for example, Chelate Science (5)
(Nankodo)
Can be. Y represents an organic anion group, and specifically,
Traphenyl boron anion and alkylbenzene sulfone
Acid anions and the like. l is an integer of 1, 2 or 3
Represents, m represents 1, 2 or 0, and n represents 1 or 0
However, these are those in which the complex represented by the general formula is tetradentate,
Determined by hexadentate coordination or Q₁, Q_Two, Q_Three
Is determined by the number of ligands. p represents 1 or 2
You.

The amount of addition of the metal source is usually preferably 0.5 to 20 g / m ² , and
~15g / m ² is more preferable.

The image receiving material used in the present invention is generally made of paper, a plastic film, or a paper-plastic film composite as a support, and a polyester resin, a polyvinyl chloride resin, or vinyl chloride as an image receiving layer thereon. Copolymer resins with other monomers (eg, vinyl acetate, etc.), polyvinyl butyral, polyvinyl pyrrolidone,
One or two or more polymer layers such as polycarbonate are formed. Further, the support itself may be used as an image receiving material.

[0038]

The present invention will be described in detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 (Preparation of ink) The following raw materials were mixed to obtain an ink in a uniform solution containing the heat diffusible dye according to the present invention.

Thermal diffusible dye M-1 (exemplary compound) 5 g polyvinyl butyral resin (BL-1, manufactured by Sekisui Chemical Co., Ltd.) 5 g methyl ethyl ketone 200 ml (Preparation of thermal transfer recording material) Apply the above ink to a thickness of 4.5μ.
m-sensitive polyethylene terephthalate base, a heat-sensitive transfer recording material having a heat-sensitive transfer layer formed on a polyethylene phthalate base by applying and drying such that the coated amount after drying is 0.8 g / m ² using a wire bar. It was created. A nitrocellulose layer containing a silicon-modified urethane resin (SP-2105, manufactured by Dainichi Seika) is provided as a sticking prevention layer on the back surface of the polyethylene terephthalate base.

(Preparation of image receiving material)
Support (polyester on one side)
White pigment (TiO_Two) And bluing))
Ester modified silicon and metal saw below as image receiving layer
(3.5 g / m^Two) Containing polyvinyl chloride resin
Each amount is 0.15g / m^Two, 5g / m^TwoAnd apply so that
An image receiving material was obtained. Metal sauce: [Ni²⁺(NH_TwoCH_TwoCONH_Two)_Three] [(C₆H_Five)_FourB^-]_Two  (Thermal transfer recording method)
Sheet) and the image receiving material.
Apply the image from the back of the transfer recording material under the following recording conditions.
When recording, a magenta image with excellent gradation was obtained.
Was done.

(Printing conditions) Printing density of main scanning and sub-scanning:
8 dots / mm Recording power: 0.6 W / dot Heating time: Heating time is adjusted stepwise between 20 msec and 0.2 msec Performance of the obtained magenta image (maximum density, chelation reactivity, fixability, light resistance) The ink sheet storage stability was evaluated by the following method. The results are shown in Table 1. <Evaluation of Maximum Density> The maximum reflection density of the image (usually, the portion where the application time was the maximum) was measured by X-rite310TR.

<Chelation Reactivity> ：: Almost sufficiently formed chelate dye image Δ: Insufficient formation of chelate dye ×: Formation of chelate dye of only some dyes <Evaluation of fixability> Image reception of obtained image Layer surface and thickness 18
5 μm thick on 0 μm polyethylene terephthalate film
The coated surface of the sheet coated with a μm nitrocellulose layer was overlapped, heated at 140 ° C. for 2 minutes, and the degree of transfer of the dye from the image receiving layer to the nitrocellulose layer was visually evaluated. The less the dye retransfer, the better the fixability. ：: No retransfer was observed. Δ: Retransfer was slightly observed. X: Retransfer was remarkable. <Evaluation of light fastness>
Time light irradiation, the density before irradiation is D ₀ , the density after irradiation is D
The light fastness was evaluated using (D / D ₀ ) × 100 (%) as the residual ratio of the dye.

<Evaluation of Storage Property of Ink Sheet> The ink surface of the ink sheet and the back surface (sticking prevention layer surface) of the ink sheet were overlapped and left at 55 ° C. for 3 days, and the state of dye transfer to the sticking prevention layer surface Was visually observed to evaluate the storage stability of the ink sheet.

：: Almost no set-off was observed. Δ: Set-off was observed. ×: Set-off was severe. Examples 2 to 10 Dye M-1 in Example 1 was replaced with M-2, M-3, M-
Nine kinds of thermal transfer recording materials-2 to 10 were prepared in the same manner as in Example 1 except that 5, M-6, M-7, M-9, M-11, M-14 and M-18 were used. Then, image recording was performed under the same conditions, and a magenta image excellent in gradation was obtained in each case.

The same evaluation as in Example 1 was performed on these images and the ink sheet. The results are shown in Table 1.

Comparative Examples 1, 2, and 3 Three kinds of comparative heat-sensitive transfer recording materials were prepared in the same manner as in Example 1 except that the dyes were changed to Comparative Dyes A, B and C. Image recording was performed under recording conditions. The same evaluation as in Example 1 was performed on the obtained image and ink sheet. The results are shown in Table 1.

Table 1 Magenta Dye Dmax Chelate Fixing Recording Material Lightfastness Imaging Reactivity Preservation Example 1 M-1 2.04 ○ ○ ○ 89 Example 2 M-2 2.02 ○ ○ ○ 91 Example 3 M-3 1.97 ○ ○ ○ 90 Example 4 M-5 1.95 ○ ○ ○ 86 Example 5 M-6 1.99 ○ ○ ○ 83 Example 6 M-7 2.01 ○ ○ ○ 90 Example 7 M-9 1.92 ○ ○ ○ 88 Example 8 M-11 1.94 ○ ○ ○ 85 Example 9 M-14 1.89 ○ ○ ○ 91 Example 10 M-18 1.85 ○ ○ ○ 89 Comparative Example 1 A 2.13 ○ △ × 87 Comparative Example 2 B 1.75 △ △ ○ 59 Comparative Example 3 C 1.23 × △ ○ 43

[0049]

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As can be seen from the table, in the thermal transfer recording material of the present invention, a magenta image having excellent chelating reactivity, high density and excellent image fixability and light fastness can be obtained. Has good storage stability.

Example 11 On a polyethylene terephthalate film used as a support in Example 1, a heat-sensitive transfer layer containing a dye Y-1 for yellow image formation (amount of 0.5 g / m ² ), a magenta dye M of the present invention Thermal transfer layer containing -1 (weight 0.5 g / m ² ) and a thermal transfer layer containing cyan image forming dye C-1 (weight 0.4 g / m ² ) are sequentially coated. 11 was created. Note that the same binder as in Example 1 was used for the binder of each thermal transfer layer.

Next, when a full-color image was formed using the thermal transfer recording material-11 and the same image-receiving material as in Example 1 using a full-color printer CP3000 manufactured by Nikon Corporation, a full-color image showing good color reproducibility was obtained. was gotten. Further, the stability (fixing property, light resistance) of this image was good.

Example 12 As an intermediate layer, 100 ml of an aqueous solution containing 5 g of a ball mill dispersion of p-toluamide, 7 g of polyvinylpyrrolidone, 3 g of gelatin, and 0.3 g of a hardener H-1 was placed on the heat-sensitive transfer recording material-11 of Example 11. Coating was performed so that the amount of p-toluamide applied was 0.5 g / m ² .

Further, on the intermediate layer, as the heat-fusible layer, the metal source shown in Example 1 (coating amount: 1.0 g / m ² ), the UV inhibitor UV-1 (coating amount: 0.1 g / m ² ), the antioxidant Agent AO-1
(With weight 0.1 g / m ²⁾ and ethylene - vinyl acetate copolymer (20% content of vinyl acetate, with the amount of 0.2 g / m ²⁾ Carnauba wax (with weight 2.0 g / m ²⁾ containing a hot-melt coating Then, a thermal transfer recording material-12 was obtained.

Using this heat-sensitive transfer recording material-12 and the image receiving material, full-color image recording was performed by a full-color printer in the same manner as in Example 11. The image receiving material was white plain paper. The obtained full-color image had good color reproducibility, gradation, and image stability. In addition, the preservability of the recording material-12 was also good.

[0056]

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[0057]

According to the present invention, a heat-sensitive transfer recording material having a high density and a high stability can be obtained by using a dye excellent in thermal diffusivity and chelate reactivity and having good storage stability. And a thermal transfer recording method capable of recording efficiently using the method.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a thermal transfer recording method of the present invention .
FIG.

FIG. 2 is a view showing another example of the thermal transfer recording method of the present invention .
Clear view.

[Explanation of symbols]

1 Support 2 Image receiving layer 3 Image receiving material 4 Support 5 Thermal transfer layer 6 Thermal transfer recording material 7 Thermal head 8 Heating resistor 9 Heat-meltable layer 10 Thermal transfer recording material

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-81195 (JP, A) JP-A 1-275187 (JP, A) JP-A 1-2271468 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B41M 5/38-5/48 REGISTRY (STN) CAPLUS (STN)

Claims (2)

(57) [Claims] 1. The method of claim 1, wherein at least the following general formula (1)
A heat-sensitive transfer recording material having a heat-sensitive transfer layer containing a dye represented by the formula: Embedded image [Wherein, R ₁ represents a monovalent organic group, Y ₁ represents an atomic group necessary for forming a 5- to 6-membered heterocyclic ring, and Y ₂ represents an atom adjacent to a carbon atom to which an azo group is bonded. Represents an atomic group necessary for forming an aromatic heterocyclic ring in which at least one is a nitrogen atom, an oxygen atom or a sulfur atom (Z ₁ represents any _one of a nitrogen atom, an oxygen atom, a sulfur atom and a carbon atom, and ₂ represents a nitrogen atom or a carbon atom, and at least one of Z ₁ and Z ₂ is a nitrogen atom, an oxygen atom or a sulfur atom). ] 2. An image receiving material is superimposed on a thermal transfer recording material having a thermal transfer layer containing a dye represented by the general formula (1) according to claim 1 on a support, and heated in accordance with image information. An image is formed by a chelate dye formed by a reaction between the dye and a metal ion supply compound.