JP2000071627A - Thermal transfer image receiving sheet and method for thermal transferring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image receiving sheet having high image quality and excellent image storage stability in a system for forming the image by a reactive sublimable thermal transferring method and a method for forming the thermal transfer image for obtaining an image having the high image quality and the excellent image storage stability. SOLUTION: The thermal transfer image receiving sheet for forming an image by oppositely superposing an ink layer of an ink sheet having a dye precursor and an image receiving layer of the sheet, heating in an image-like state by a heating means to receive the precursor by the image receiving layer having a dye fixing material, and forming a dye by reaction of the precursor with a fixing material to form the image. In this case, the fixing material is non-thermal diffusible in the receiving layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer image-receiving sheet and a thermal transfer method, and more particularly to a sublimation thermal transfer image-receiving sheet having high image quality and high image storability.

[0002]

2. Description of the Related Art Hitherto, as a technique for forming a color or monochrome image, a sublimation thermal transfer using a sublimable dye having a property of diffusing and transferring by heating has been known, and a digital image comparable to silver halide photography with high image quality has been known. A dry full-color image can be output. In this transfer method, an ink sheet containing a sublimable dye is made to face an image receiving layer of an image receiving sheet, and the image is transferred by imagewise transferring the sublimable dye to the image receiving layer using a heating means such as a thermal head or a laser. To form. In such thermal transfer recording,
The sublimable dye used in the ink sheet plays an important role, but the conventional sublimable dye is diffused and transferred by heat.
It is very sensitive to heat, and even after transfer to the image receiving layer, it continues to diffuse due to heat, causing image bleeding, and also has the disadvantage of insufficient image preservability such as dark fading and light fading of the obtained image. Have.

In order to improve this point, an image forming method using a so-called reactive dye (reactive sublimation thermal transfer method), in which an image is formed by reacting a dye precursor with a dye fixing body, is proposed. Have been. For example, JP
JP-A-9-78893, JP-A-59-109394, JP-A-60-2398, etc., use a heat-diffusable compound capable of chelation (hereinafter also referred to as a post-chelating dye) as a dye precursor, and fix the dye. There is disclosed a method of forming an image by reacting with a metal ion-containing compound (hereinafter, also referred to as a metal source) as a body to form a metal chelate. According to this method, image bleeding is improved as compared with a general sublimation thermal transfer image, but it is still insufficient as compared with a normal printed image.

[0004] With respect to image storability such as dark fading and light fading, it is conceivable to make the formed dye itself resistant to the influence of light, oxygen, moisture and the like, but there is a limit. In the reactive sublimation thermal transfer method, since the post-chelating dye is transferred and diffused from the image receiving layer surface side, the formed dye tends to be biased near the surface of the image receiving layer, and it is difficult to uniformly distribute the dye in the image receiving layer. Met. Therefore, the dye near the surface is direct light,
There is a problem that the discoloration is accelerated due to the influence of oxygen, moisture and the like. On the other hand, there is a report on a technique of providing a protective layer on the surface of an image receiving layer by using a heating means together with the reactive sublimation thermal transfer method. As a result, mechanical abrasion was improved, but there was a problem that if the dye was localized on the surface of the image receiving layer, the dye would diffuse into the protective layer and the image durability would deteriorate.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide high image quality (improved image bleeding) and excellent image storability (improved dark fading and light fading). An object of the present invention is to provide an image receiving sheet having the following characteristics and a thermal transfer image forming method capable of obtaining an image having high image quality and excellent image storability.

[0006]

The above object of the present invention is attained by the following constitutions.

[0007] 1. The dye precursor is received by the image receiving layer having the dye fixing body by overlapping the ink layer having the dye precursor so as to face the ink layer and heating imagewise with a heating means, and the dye precursor and the dye fixing are performed. A thermal transfer image-receiving sheet capable of forming an image by forming a dye by reaction with a body, wherein the dye-fixed body is non-thermally diffusible in an image-receiving layer.

[0008] 2. 2. The heat transfer image-receiving sheet according to claim 1, wherein the dye fixing body is uniformly distributed in the image receiving layer.

3. The ink layer of the ink sheet having the dye precursor is superimposed on the image receiving layer of the thermal transfer image receiving sheet having the dye fixing body so as to face each other, and the dye precursor is transferred to the image receiving layer by imagewise heating with a heating means. A thermal transfer method for forming an image, wherein the dye fixing body in the image receiving layer of the thermal transfer image receiving sheet is non-thermally diffusible in the image receiving layer.

[0010] 4. The ink layer of the ink sheet having the dye precursor is superimposed on the image receiving layer of the thermal transfer image receiving sheet having the dye fixing body so as to face each other, and the dye precursor is transferred to the image receiving layer by imagewise heating with a heating means. 4. The thermal transfer method according to claim 3, wherein the thin film material is transferred to the image forming surface of the image receiving sheet again by using the heating means.

5. The ink layer of the ink sheet having the dye precursor is superimposed on the image receiving layer of the thermal transfer image receiving sheet having the dye fixing body so as to face each other, and the dye precursor is transferred to the image receiving layer by imagewise heating with a heating means. 4. The thermal transfer method according to claim 3, wherein the image forming surface of the image receiving sheet is subjected to a heat treatment again using a heating unit after the heat transfer.

The present inventors have conducted intensive studies to improve the image quality and image storability of an image obtained by the reactive thermal transfer method. As a result, the dyes produced by the reaction are prevented from being localized on the surface of the image receiving layer. If the dye fixing body is non-thermally diffusible in the image receiving layer, the reactive dye formed can be uniformly distributed in the image receiving layer. The present invention was found to be hardly attacked by light, oxygen, and moisture surrounded by a binder, and to improve image storability, leading to the present invention. Further, the sensitivity can be improved because a high density can be obtained with a smaller amount of dye, and further, the mechanical resistance of the image receiving layer surface can be improved and retransfer to other materials can be reduced.

In the reactive sublimation thermal transfer method, the dye precursor is transferred from the ink layer to the upper surface of the image receiving layer and is localized on the surface of the image receiving layer. Is also formed and fixed on the surface of the image receiving layer, which causes problems of dark fading, light fading, and deterioration of mechanical resistance of an image, and causes insufficient image storability to be obtained. I have. In contrast, in the present invention, the dye fixing body does not thermally diffuse in the image receiving layer, but captures and reacts with the diffused dye precursor, and is fixed at that position as a reactive dye. The same pigment distribution is obtained. When the dye fixing body is distributed so as not to be localized on the surface of the image receiving layer, it is possible to prevent the dye formed by the reaction on the surface of the image receiving layer from being localized. Further, by forming a protective layer, mechanical durability can be particularly improved.

Hereinafter, the present invention will be described in more detail.

[1] Thermal Transfer Image-Receiving Sheet In the method of forming a reactive thermal transfer image in the present invention, a conventionally known technique, for example, a post-chelate sublimation thermal transfer method described in Japanese Patent Application No. 59-78893, Japanese Patent Application No. 5-221151, and the like.
And the reactive dye described in JP-A-6-64343.
Iels-alder reaction type method, 6-344678
The above-mentioned ion-bonding type cationic mordants can be used publicly.

The image receiving layer of the thermal transfer image receiving sheet (hereinafter simply referred to as an image receiving sheet) contains a metal source capable of forming a metal chelate, for example, as a dye fixing body. The image receiving sheet of the present invention comprises at least a support and an image receiving layer formed on the surface of the support.

The image receiving sheet of the present invention is characterized in that the dye fixing body is non-thermally diffusible in the image receiving layer, and the dye fixing body is present in the image receiving layer without being thermally diffused, and is transferred and diffused. The reactive dye formed by the reaction with the dye precursor is fixed at a position where the dye fixing body is dispersed in advance, so that the same dye distribution as that of the dye fixing body can be obtained. Therefore, the image storability of the obtained reactive dye is remarkably improved as compared with the related art, and the reactive dye formed can be prevented from being localized on the surface of the image receiving layer even in the image quality. Image quality is expected.

In the sublimation thermal transfer, a thermal head is generally used as a heat source. However, when heating is performed by the thermal head, the ink layer of the ink sheet and the image receiving layer of the image receiving sheet are overlapped so as to face each other, and from the ink sheet side. The dye precursor in the ink layer is transferred to the image receiving layer by pressing the heating element of the thermal head and heating it imagewise. At this time, not only the ink layer but also the image receiving layer is heated to about 50 to 150 degrees.

"The dye fixing body is non-thermally diffusible in the image receiving layer" means that the dye fixing body does not move in the image receiving layer compared to the film thickness even when the image receiving layer is heated by the thermal head. That means. As a method for specifically measuring the non-thermal diffusion property of the dye fixing body in the image receiving layer, a method of scanning the cross section of the image receiving layer by SIMS and measuring the distribution amount of the dye fixing body in the cross section is exemplified. In the case of post-chelate sublimation thermal transfer, the distribution of the metal is measured by scanning the cross section of the image receiving layer by SIMS using the metal of the metal source as the dye fixing body as a measurement object.

In the present invention, a case where the distribution of the dye fixing body in the cross section of the image receiving layer hardly changes before and after heating by a heating device such as a thermal head is referred to as non-thermal diffusion. To form the image receiving layer so that the dye fixing body is non-thermally diffusible in the image receiving layer, for example, a method of fixing the dye fixing body using a material in which the dye fixing body is attached to a polymer (that is, the method of fixing the dye fixing body). (A very large molecular weight), a method of adding a curing agent such as coronate to the image receiving layer to make the dye-fixed body difficult to move, or a method of selecting a binder having very good compatibility with the dye-fixed body to move the dye-fixed body. And the like. When a curing agent such as coronate is added to the image receiving layer, the molecular weight of the dye fixing body is made larger than the molecular weight of the dye precursor, and the curing agent keeps the dye precursor thermally diffusible in the image receiving layer. Is important.

In the present invention, it is preferable that the dye fixing body is uniformly distributed in the image receiving layer. Specifically, the dye fixing body is distributed so as not to be localized on the surface of the image receiving layer. is there. Thereby, localization of the dye formed by the reaction on the surface of the image receiving layer can be prevented. Further, by forming a protective layer on the image receiving layer, particularly mechanical durability can be enhanced.

"Dye fixing body is not localized on the surface of image receiving layer"
Means that the dye fixing body is not denser than the other parts on the image receiving layer surface in the measurement method as shown in the method for specifically measuring the non-thermal diffusion property of the dye fixing body described above. . Specifically, it refers to a state in which the amount of the dye fixing body is contained in an amount of の or less, preferably １ ／ or less, in the range of 0.5 μm or less of the image receiving layer surface.

In the present invention, the specific amount that indicates that the dye fixing body is non-thermally diffusible in the image receiving layer is, for example, a distribution amount of the dye fixing body every 0.5 μm before and after imagewise heating. Is less than ± 30%, preferably ±
Less than 20%.

As the support of the image receiving sheet, for example, paper,
Coated paper and synthetic paper (polyethylene, polypropylene,
Various kinds of papers such as a composite material obtained by laminating polystyrene and paper), a vinyl chloride resin sheet, an ABS resin sheet, a polyethylene terephthalate (PET) base film,
Examples include various plastic films and sheets such as a polyethylene naphthalate (PEN) base film, films and sheets formed of various metals, and films and sheets formed of various ceramics.

When the support is made of a material other than metals and ceramics, especially when the support is made of the synthetic paper, the support may have a structure for enhancing the sharpness of an image formed in a later step. And white pigments (for example, titanium white, magnesium carbonate, zinc oxide, barium sulfate, silica, talc, clay, calcium carbonate, etc.). The thickness of the support is usually 20 to 1000 μm.
m is appropriate, and preferably 20 to 800 μm.

In the present invention, a post chelate sublimation thermal transfer method will be described as an example. When the image receiving layer of the image receiving sheet contains a metal source, and a post-chelating dye is used as the dye contained in the dye-containing region of the ink sheet, the formed dye image has high transfer density, high image storability, and particularly, prevention of bleeding. Excellent effect can be exhibited. Examples of the metal source include inorganic or organic salts and metal complexes of metal ions, and among them, organic acid salts and complexes are preferable. Examples of the metal include monovalent and polyvalent metals belonging to Groups I to VIII of the periodic table. Among them, Al, Co, Cr, C
u, Fe, Mg, Mn, Mo, Ni, Sn, Ti and Z
n is preferable, and Ni, Cu, Cr, Co and Zn are particularly preferable. Specific examples of the metal source include Ni ²⁺ , C
Examples thereof include salts of u ²⁺ , Cr ²⁺ , Co ²⁺ and Zn ²⁺ with aliphatic salts such as acetic acid and stearic acid, and salts of aromatic carboxylic acids such as benzoic acid and salicylic acid. Further, a complex represented by the following general formula (1) is mentioned as a preferable example.

The general formula (1) [M (Q1) X (Q2) Y (Q3) Z] P + (L -) in _P-type, M is a metal ion, preferably Ni ^2+, Cu ^2+, C
represents r ²⁺ , Co ²⁺ or Zn ²⁺ . Q1, Q2 and Q3 each represent a coordination compound capable of coordinating with the metal ion represented by M, and may be the same or different.
These coordination compounds can be selected, for example, from the coordination compounds described in Chelate Science (5) (Nankodo). L ⁻ represents an organic anion group, and specific examples include a tetraphenylboron anion and an alkylbenzenesulfonic acid anion. X represents 1, 2 or 3, Y represents 1, 2 or 0, and Z represents 1
Or 0, which is determined by whether the complex represented by the general formula (1) is tetradentate or hexadentate,
Alternatively, it is determined by the number of ligands of Q1, Q2 and Q3. P represents 1 or 2. Specific examples of this type of metal source include those exemplified in U.S. Pat. No. 4,987,049 and the compounds exemplified in JP-A-6-127156.

The addition amount of the metal source is usually preferably 5 to 80% by weight based on the binder of the image receiving layer.
70% by weight is more preferred.

As the binder for the image receiving layer, various binders such as a vinyl chloride resin, a polyester resin, a polycarbonate resin, an acrylic resin, a polyvinyl acetal resin and various heat resistant resins can be used.

In addition to the polyvinyl acetal resin and the vinyl chloride resin, a polyester resin can also be suitably used as the image receiving layer for thermal transfer. Examples of polyester-based resins include JP-A-58-188695 and JP-A-6-18869.
The compound described in 2-244696 can be mentioned. As the polycarbonate resin, for example, various compounds described in JP-A-62-169694 can be used.

In the present invention, the binder preferably has a glass transition point (Tg) of 50 to 150 ° C.

As a method of making the metal source non-thermally diffusible in the image receiving layer in the post-chelate sublimation thermal transfer, there is, for example, a) a method using an organometallic binding polymer as the metal source. By combining the organic metal and the polymer, the polymer becomes a long chain, becomes immobile in the image receiving layer, and tends to become non-diffusible to heat. Also, b) a method of adding a curing agent to make the metal source difficult to move.
According to this, not only the degree of freedom in selecting a metal source is improved, but also non-thermal diffusion can be surely achieved in the layer.
Further, c) a method of using a binder having good compatibility with the metal source to make it hard to move thermally can be used. According to this, since the binder surrounding the metal source shows compatibility with the metal source, it is expected that the binder will be immobile and uniformly non-diffusible in a uniformly distributed state in the layer. .

[2] Ink sheet The ink sheet is formed at least from a support and an ink layer provided thereon, and the ink layer contains at least a dye precursor.

The support for the ink sheet is not particularly limited as long as it has good dimensional stability and can withstand heat during recording with a thermal head, and any known support can be used.

Examples of the binder for the ink layer include cellulose adducts, cellulose resins such as cellulose esters and cellulose ethers, polyvinyl acetal resins such as polyvinyl alcohol, polyvinyl formal, polyvinyl acetoacetal and polyvinyl butyral, polyvinyl pyrrolidone, and polyvinyl acetate. , Polyacrylamide, styrene resin, poly (meth) acrylic acid ester, poly (meth) acrylic acid, vinyl resin such as (meth) acrylic acid copolymer, rubber resin, ionomer resin, olefin resin, polyester Resins and the like can be mentioned. One of the above various binders can be used alone, or two or more of them can be used in combination.

The ink sheet may have a structure of “ink layer and reheating layer” in which a combination of a region containing a dye and a region containing a reheating layer is repeated next. The dye-containing region can be one or more dye-containing regions differing in hue, for example, the dye-containing region comprises a region containing a yellow dye, a region containing a magenta dye, and a region containing a cyan dye, and these The embodiment in which the reheating layer region is formed next to the dye-containing region, the embodiment in which the dye-containing region is composed of an ink layer containing a black dye, and the region in which the reheating layer region is formed next to the region, and the dye-containing region Is composed of a region containing a yellow dye, a region containing a magenta dye, a region containing a cyan dye, and a region containing a black dye, such as an embodiment in which a reheating layer region is formed next to these dye-containing regions. No. When the post-heating is performed by another heating means, the region of the reheating layer is not formed on the ink sheet.

In the present specification, the term “black dye” means, for example, a dye having a black hue,
An embodiment in which two or more dyes are combined to obtain a black hue by mixing a yellow dye, a magenta dye, and a cyan dye, for example, an embodiment in which black is obtained by combining two or more dyes is included.

Next, an example of the arrangement of the ink layers of the ink sheet will be described with reference to the drawings. FIG. 1 shows that the dye-containing region is composed of a region containing a yellow dye, a region containing a magenta dye, and a region containing a cyan dye, and a reheating layer region or a protective layer is formed after these dye-containing regions. One example of an embodiment having a region is shown. In FIG. 1, an ink sheet 1 has an area 1 containing a yellow dye.
The ink layers of Y, a region 1M containing a magenta dye, and a region 1C containing a cyan dye are provided in this order, and after these dye-containing regions, a reheating layer region containing no heat transferable dye or a protective layer. A region 1a on which a layer is formed is provided, and this combination of arrangements is repeated.
The order shown in FIG. 1 is hereinafter referred to as “frame sequential”.

The post-chelate sublimation thermal transfer method will be described as an example. For example, a post-chelate dye is used as a dye precursor to be contained in the ink layer in the dye-containing region.
The post-chelating dye is not particularly limited as long as thermal transfer is possible, and various known compounds can be appropriately selected and used. Specifically, see, for example,
No. 78893, No. 59-109349, Japanese Patent Application No. 2-2
For example, cyan dyes, magenta dyes, and yellow dyes described in JP-A Nos. 13303, 2-214719, and 2-203742 can be used. Examples of such a dye include a dye represented by the following general formula (2).

Formula (2) X ₁ -N = N-X ₂ -G In the formula, X ₁ represents an aromatic carbocyclic or heterocyclic ring in which at least one ring is composed of 5 to 7 atoms. Represents a collection of atoms necessary for completion, wherein at least one of the carbon atoms attached to the azo bond is a nitrogen atom or a carbon atom substituted with a chelating group. X ₂ represents an aromatic heterocyclic ring or an aromatic carbocyclic ring in which at least one ring is composed of 5 to 7 atoms. G represents a chelating group.
The amount of the dye used is usually the amount of the ink layer 1 of the ink sheet.
0.1 to ²⁰ g per m ² , preferably 0.2 to ²⁰ g
5 g.

The weight ratio between the binder and the dye is 1:10.
10 to 10: 1, more preferably 2: 8 to 7: 3.
Range.

In the present invention, the ink sheet is not limited to the two-layer structure composed of the support and the ink layer, and other layers may be formed. For example, an overcoat layer may be provided on the surface of the ink layer for the purpose of preventing fusion with the image receiving layer and offset (blocking) of the dye.

Examples of preferred resins constituting the binder used in the reheating layer include silicone resin, polyethylene, polypropylene, fluororesin, polyvinyl acetoacetal, polyvinyl butyral, polyvinyl alcohol, cellulose ester, ethyl cellulose, polyvinyl formal, polyvinyl pyrrolidone, and the like. Examples include vinyl resins such as polyacrylamide, poly (meth) acrylic acid ester, poly (meth) acrylic acid, and (meth) acrylic acid copolymer, and olefin resins.

In the present invention, the reheating layer may contain a metal source. As the metal source, the compounds described as the metal source contained in the image receiving layer can be used. The content of the metal source is preferably in the range of 0 to 20% by weight, and more preferably in the range of 0 to 5% by weight.

In the present invention, various additives can be appropriately added to the reheating layer and the ink layer in addition to the above components. Additives include silicone resin, silicone oil (reaction curing type is also possible), silicone modified resin, fluororesin, surfactant, release compounds such as waxes, metal fine powder, silica gel, metal oxide, carbon Fillers such as black and fine resin powder, and curing agents (e.g., radiation-active compounds such as isocyanates, acryls, and epoxies) that can react with a binder component can be used.

Further, as an additive, a heat-fusible substance for promoting transfer, for example, compounds described in JP-A-59-106997, such as waxes and higher fatty acid esters, may be mentioned.

As the support for the reheating layer, those similar to those used for the ink sheet can be used. An undercoat layer may be provided between the reheating layer and the support. Further, an anti-sticking layer may be provided on the back surface (the side opposite to the ink layer) of the support for the purpose of preventing the heating device from fusing to the support, sticking, and wrinkling of the sheet. The thickness of the overcoat layer, the undercoat layer and the anti-sticking layer is usually 0.1 to 1 μm.

[3] Thermal Transfer Method In the thermal transfer method of the present invention, as a heating means, a known heating apparatus such as a thermal head, a heat roller, a hot press using a metal plate or heat-resistant silicone rubber, a hot stamping method, or the like is used. Or, a thermal transfer recording device) can be used. As the heating device, it is preferable to use a thermal head or a heat roller in view of the size and simplicity of the device.

As the thermal transfer recording apparatus, for example, an apparatus as shown in FIG. 2 can be used. In FIG. 2, 1
0 is an ink sheet supply roll, 1 is an ink sheet, 11
Is a take-up roll for winding the used ink sheet 1;
Reference numeral 2 denotes a thermal head, 13 denotes a platen roller, and 14 denotes an image receiving sheet inserted between the thermal head 12 and the platen roller 13.

In order to form a transfer image using the thermal transfer recording apparatus shown in FIG. 2 and, for example, the ink sheet shown in FIG. 1 as the ink sheet, first, the yellow dye precursor of the ink sheet 1 (the precursor is A 1Y) containing
And the image receiving layer of the image receiving sheet are overlapped, and the yellow dye A in the ink layer in the area is transferred to the image receiving sheet according to the image data by applying heat from the thermal head to form a yellow image, and then the yellow image is formed on the yellow image. Similarly, the magenta dye A is transferred imagewise from the ink layer of the area 1M containing the magenta dye A, and then the cyan dye A is similarly formed on the transferred image from the ink layer of the area 1C containing the cyan dye A. Is transferred imagewise, and reheating is performed via the reheating layer so that the reheating layer is in contact with the image forming surface of the image receiving sheet, thereby terminating the reaction with the dye fixing body in the image receiving layer.

The image may be formed by a multi-head type printer. In this case, unlike the printer shown in FIG. 2, heating devices such as thermal heads are arranged in the number of colors to be printed. Generally, there are three heads of yellow, magenta and cyan, or four heads of yellow, magenta, cyan and black. Further, a thermal head or a heat roller is added for reheating. A single color ink sheet is used. For example, the first thermal head and the yellow ink sheet transfer the yellow dye A onto the image receiving layer, then the second thermal head and the magenta ink sheet transfer the magenta dye A, and the third thermal head and the cyan ink sheet transfer the cyan dye. Dye A is transferred to each of the image receiving layers, and finally, the image receiving layer surface on which an image has been formed with the fourth thermal head and the reheating layer is heated, whereby a dye precursor is obtained.
The reaction of the dye fixing body is terminated.

[0052]

EXAMPLES The present invention will now be described specifically with reference to examples, but the embodiments of the present invention are not limited thereto. The following “parts” represent “parts by weight”.

Example 1 <Preparation of Ink Sheet 1> An ink sheet was prepared as follows.

A PET film (Lumirror 6CF531, manufactured by Toray Industries, Inc.) having a 6 μm-thick anti-sticking layer as a support was coated on the opposite side of the anti-sticking layer with each of the yellow, magenta and cyan ink layers of the following formulation. The coating liquid and the reheating layer coating liquid were applied by a gravure method (thickness after drying was 1 μm) to obtain an ink sheet 1 in which yellow, magenta, and cyan ink layers and a reheating layer were formed in a plane-sequential manner. The ink sheet 1 has Y, M, C
This is an ink sheet having a layer + reheating layer area and a plane sequential.

(Preparation of Yellow Ink Layer) 20 parts of post-chelating dye Y-1 below Polyvinyl acetal (KY-24, manufactured by Denki Kagaku Kogyo KK) 80 parts (prescription of magenta ink layer) 20 parts of post-chelating dye M-1 below 80 parts of polyvinyl acetal (KY-24, manufactured by Denki Kagaku Kogyo Co., Ltd.) (prescription of cyan ink layer) 20 parts of post-chelating dye C-1 described below 20 parts of polyvinyl acetal (KY-24, manufactured by Denki Kagaku Kogyo Co., Ltd.) 80 parts ( Reheating layer area formulation) Securing the same area as one color ink layer without applying anything <Preparation of ink sheet 2> PE used in ink sheet 1
On the opposite side of the T film from the anti-sticking layer,
The yellow, magenta, and cyan ink layer coating solutions and the protective layer having the following formulation are applied by a gravure method (coating thickness after drying is 1 μm), and the yellow, magenta, and cyan ink layers and the protective layer are sequentially formed. Ink sheet 2 was obtained. The ink sheet 2 has a Y, M, C layer and a protective layer, and is a surface-sequential ink sheet.

(Preparation of Yellow Ink Layer) 20 parts of post-chelating dye Y-1 shown below Polyvinyl acetal (KY-24, manufactured by Denki Kagaku Kogyo KK) 80 parts (prescription of magenta ink layer) 20 parts of following post-chelating dye M-1 80 parts of polyvinyl acetal (KY-24, manufactured by Denki Kagaku Kogyo Co., Ltd.) (prescription of cyan ink layer) 20 parts of the following post-chelating dye C-1: 80 parts of polyvinyl acetal (KY-24, manufactured by Denki Kagaku Kogyo Co., Ltd.) Protective Layer Forming Formula) A release layer coating solution and an adhesive layer coating solution having the following formulations have a film thickness of 0.7 μm, respectively. Coating and drying were performed to a thickness of 0 μm to form a protective layer.

Formulation of protective layer 90 parts acrylic resin (manufactured by Mitsubishi Rayon, Dianal BR-87) 90 parts Silicone resin fine particles (manufactured by Toshiba Silicone Co., Ltd., Tospearl 120) 10 parts adhesive layer formulation Styrene resin (manufactured by Shell Chemical Co., Ltd.) , Clayton G-1726) 90 parts Hydrogenated petroleum resin (Escorts 5320HC, manufactured by Toneck Co., Ltd.) 10 parts

[0058]

Embedded image

<Preparation of Image Receiving Sheet 1> Next, an image receiving sheet was prepared as follows.

An anchor layer and an image receiving layer having the following formulation were applied in this order on the surface of a synthetic paper having a thickness of 188 μm (Crisper 2312, manufactured by Toyobo Co., Ltd.) as a support, and the thickness was 2 μm.
An anchor layer of m and an image receiving layer of 4 μm were formed to obtain an image receiving sheet 1.

(Anchor Layer Formulation) Polyol-Modified Chlorinated Polyolefin (Toyo Kasei Co., Ltd., Hardlen B-13) 75 parts Isocyanate (Nippon Polyurethane Industry Co., Ltd., Coronate HX) 25 parts (Image-receiving layer formulation) Metal source MS-1 60 parts Polyvinyl butyral (Eslek BX-1 manufactured by Sekisui Chemical Co., Ltd.) 35 parts Polyester modified silicone (X-24-8300 manufactured by Shin-Etsu Chemical Co., Ltd.) 5 parts <Preparation of image receiving sheet 2> Image receiving sheet 2 was obtained in the same manner as image receiving sheet 1 except that the layers were changed as follows.

[0062] (image receiving layer formulation) metal source ^{MS-2 (Ni 2+ (NH} 2 COCH 2 NH 2) 3 · 2B (C 6 H 5) 4) 30 parts Polyvinyl butyral (Sekisui Chemical Co., Ltd., S-LEC BX-1) 65 parts Polyester-modified silicone (X-24-8300, manufactured by Shin-Etsu Chemical Co., Ltd.) 5 parts

[0063]

Embedded image

<Formation of Image> Using an A4 sublimation thermal transfer line printer, a solid image of yellow, magenta, and cyan is formed, and the same head is used to reheat through a reheating layer area or to form a protective layer. And yellow, magenta, and cyan images having a final image density of 1.0. Then, the following evaluation was performed.

(Evaluation) The light-fading image-receiving sheet was subjected to 1 x 70000 Lx using a xenon lamp.
Exposure / exposure was performed for a month, and the result was shown by the color retention rate.

The results are shown by the residual ratio of the color after storage for one month under the condition of 85 ° and 60% RH.

Eraser resistance The image area was rubbed 10 times with a sand eraser, and the condition of the surface was visually evaluated according to the following evaluation criteria.

A: No change is observed in the image. The surface of the image is scratched, but the image is hardly deteriorated. X: The surface of the image is scratched, and the image is significantly deteriorated.

The distribution of the non-thermally diffusible dye-fixed body was measured by scanning with SIMS before printing. The change in the distribution of the dye fixing body was measured after printing, and the change before and after printing was compared. Here, the dye fixing body corresponds to Ni.

The results obtained are shown in Table 1 below.

[0071]

[Table 1]

Existence: The distribution of the dye fixing body having a depth of 5 μm from the image receiving layer surface is increased by 20% or more.

None: The change in the distribution of the dye-fixed body every 0.5 μm in the image receiving layer is less than 20%.

As is evident from Table 1, the image receiving sheet of the present invention has improved image storability, that is, light fading and dark fading, and can provide a high quality image. Further, it can be seen that when the protective layer was formed, mechanical abrasion was sufficiently improved. These are attributable to the fact that the dye fixing body has a non-thermal diffusion property in the image receiving layer, which is supported by the above evaluation of the non-thermal diffusion property.

[0075]

According to the present invention, in a system for forming an image by the reactive sublimation thermal transfer method, high image quality and excellent image storability can be obtained, and furthermore, sufficient mechanical abrasion can be prevented. It has a remarkably excellent effect of being improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an embodiment having a dye-containing region provided on an ink sheet and a region where a reheating layer region or a protective layer is formed.

FIG. 2 is a conceptual diagram of an example of a thermal transfer recording device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ink sheet 1Y area containing yellow dye 1M area containing magenta dye 1C area containing cyan dye 1a area where reheating layer or protective layer is formed 10 ink sheet supply roll 11 take-up roll 12 thermal head 13 Platen roller 14 Image receiving sheet

Claims (5)

[Claims] An image receiving layer having a dye fixing body receives the dye precursor by overlapping the ink sheet having the dye precursor so as to face the ink layer and heating the image precursor imagewise with a heating means. A thermal transfer image receiving sheet capable of forming an image by forming a dye by a reaction between a precursor and a dye fixing body, wherein the dye fixing body is non-thermally diffusible in an image receiving layer. . 2. The thermal transfer image-receiving sheet according to claim 1, wherein the dye fixing body is uniformly distributed in the image receiving layer. 3. An ink layer of an ink sheet having a dye precursor and an image receiving layer of a thermal transfer image receiving sheet having a dye fixing body are superposed on each other and heated imagewise by a heating means. In a thermal transfer method for transferring an image to the image receiving layer to form an image, wherein the dye fixing body in the image receiving layer of the thermal transfer image receiving sheet is non-thermally diffusible in the image receiving layer. 4. An ink layer of an ink sheet having a dye precursor and an image receiving layer of a thermal transfer image receiving sheet having a dye fixing body are superposed on each other and heated imagewise by a heating means. 4. The thermal transfer method according to claim 3, wherein, after transferring the thin film material to the image receiving layer, the thin film material is transferred to the image forming surface of the image receiving sheet by using the heating means again. 5. An ink layer of an ink sheet having a dye precursor and an image receiving layer of a thermal transfer image receiving sheet having a dye fixing body are superimposed on each other and heated imagewise by a heating means. 4. The thermal transfer method according to claim 3, wherein, after transferring to the image receiving layer, the image forming surface of the image receiving sheet is subjected to heat treatment again using a heating means.