JPH0516540A - Thermal transfer recording image receiving sheet - Google Patents

Abstract

PURPOSE:To provide a thermal transfer recording image receiving sheet in which transfer density, image uniformity and image preservability are improved and trouble due to fusion to a thermal transfer recording ink sheet is prevented at the time of image formation. CONSTITUTION:In a thermal transfer recording image receiving sheet provided, on the support, with a thermally dispersible coloring matter receiving layer containing at least a metal ion containing compound and a layer containing the thermally dispersible coloring matter, which react with the metal ion containing compound to form a chelate, superposed on a thermal transfer ink sheet applied on the basic material and heated according to a recording signal to form an image, an intermediate layer is provided between the support and the thermally dispersible coloring matter receiving layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive transfer recording image-receiving sheet, and more particularly to a heat-sensitive transfer recording image-receiving sheet capable of obtaining a good image at a high transfer density and causing no trouble during image formation.

[0002]

2. Description of the Related Art Conventionally, as a method for obtaining a color hard copy, a color recording technique such as an ink jet method, an electrophotographic method, a thermal transfer method has been studied. Among them, the thermal transfer method is easy to operate and maintain. In addition, it has advantages such as downsizing of the device, cost reduction, and low running cost. In this thermal transfer method,
A transfer sheet having a heat-meltable ink layer on a support (correctly called a heat-sensitive transfer recording material) is heated by a heat-sensitive head to melt-transfer the ink from the heat-meltable ink layer onto an image-receiving sheet for heat-sensitive transfer recording. Method and a transfer sheet having an ink layer containing a heat diffusible dye (sublimable dye) on a support is heated by a thermal head to transfer the heat diffusible dye from the ink layer to an image receiving sheet for thermal transfer recording. There are two types: thermal diffusion transfer method (sublimation transfer method). The thermal diffusion transfer method controls the gradation of the image by changing the transfer amount of the dye according to the change in thermal energy of the thermal head. Therefore, it is advantageous for full-color recording.

By the way, in the thermal transfer recording of the thermal diffusion transfer system, the dye used for the thermal transfer recording material is important, and the stability of the obtained image, that is, the light resistance and the fixing property is not good with the conventional ones. It had a drawback.

In order to improve these points, JP-A-59-7
8893, 59-109394, and 60-2398 use an image-forming method in which a chelatable heat-diffusible dye is used and an image is formed on the image-receiving sheet for thermal transfer recording by the chelated dye. Is disclosed. However, although these image forming methods are excellent as methods for improving heat resistance and fixing property, they form a chelate capable of forming a chelating heat-diffusible dye in the receiving layer of the image-receiving sheet for thermal transfer recording. , If a compound containing a metal ion is included,
There is a problem that fusing tends to occur between the receiving layer of the image receiving sheet for thermal transfer recording and the ink sheet during image formation. Further, when a hard resin film or the like is used as the support of the image receiving sheet, the adhesion with the recording head is deteriorated, which may result in lower sensitivity, uneven transfer, and missing dots.

[0005]

OBJECTS OF THE INVENTION The present invention has been made based on the above circumstances, and the objects of the present invention are: transfer density, image uniformity,
An object of the present invention is to provide an image-receiving sheet for thermal transfer recording which has improved image storability and does not cause troubles due to fusion of the image-receiving sheet and the ink sheet during image formation.

[0006]

The above object of the present invention is achieved by the following configurations. That is, (1) a layer containing a heat-diffusible dye capable of reacting with a metal ion-containing compound to form a chelate is overlaid with a thermal transfer recording ink sheet provided on a substrate, and a recording signal is recorded. A heat-sensitive transfer recording image-receiving sheet comprising a support and a heat-diffusible dye-receiving layer containing at least a metal ion-containing compound, which is heated to form an image, between the support and the heat-diffusible dye-receiving layer. An image-receiving sheet for heat-sensitive transfer recording with an intermediate layer interposed therebetween.

(2) The image-receiving sheet for thermal transfer recording according to (1), wherein at least one of the metal ion-containing compounds is selected from the group of compounds represented by the following general formula (1).

General formula (1) [M (Q ₁ ) _k (Q ₂ ) _m (Q ₃ ) _n ] ^{P +} P (L ⁻ ) In the formula, M is Ni ²⁺ , Cu ²⁺ , Co ²⁺ , Cr ^It represents a metal ion selected from ²⁺ and Zn ²⁺ , and Q ₁ , Q ₂ and Q ₃ each represent a coordination compound capable of forming a coordinate bond with the metal ion represented by M.

(3) The heat diffusible dye capable of reacting with the metal ion-containing compound to form a chelate is selected from the group of compounds represented by the following general formula (2) (1) or (2). An image-receiving sheet for heat-sensitive transfer recording according to item 1.

[0010]

[Chemical 2]

In the formula, X ₁ has at least one ring of 5 to 7
Represents an atomic group necessary for completing an aromatic carbocycle or heterocycle composed of 4 atoms, and at least one of adjacent positions of carbon atoms bonded to an azo bond is substituted with a nitrogen atom or a chelating group. It is a carbon atom. X ₂ represents an aromatic carbocycle in which at least one ring is composed of 5 to 7 atoms, or an atomic group necessary for completing a heterocycle;
Represents a chelating group.

(4) The intermediate layer comprises a plurality of layers (1),
The image-receiving sheet for thermal transfer recording according to (2) or (3).

(5) The image-receiving sheet for thermal transfer recording according to any one of (1) to (4), wherein the surface of the support on which the intermediate layer is provided is surface-treated.

(6) The surface treatment is any one of corona discharge treatment, flame treatment, ozone treatment, primer treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, low temperature plasma and grafting treatment. (5) An image-receiving sheet for thermal transfer recording according to (5).

The present invention will be described in detail below.

(1) Image-Receiving Sheet for Heat-Sensitive Transfer Recording The image-receiving sheet for heat-sensitive transfer recording of the present invention (hereinafter also referred to as an image-receiving sheet) basically has at least one intermediate layer provided on a support and further on it. It is formed by laminating image receiving layers.

As the support, for example, high-quality paper, baryta paper, cast-coated paper, art-coated paper, and synthetic paper (polypropylene-based synthetic paper, polystyrene-based synthetic paper alone or a composite material obtained by laminating them with paper) Various papers such as vinyl chloride resin sheet, ABS resin sheet, polyethylene terephthalate base film, polyethylene naphthalate base film, various plastic films or sheets such as polycarbonate, polyether ether ketone, polyether sulfone, polyether imide, Examples thereof include a film or sheet formed of various metals, a film or sheet formed of various ceramics, and the like.

In the plastic film support for viewing the formed image by reflection, white pigments such as titanium white, magnesium carbonate, zinc oxide, barium sulfate, etc. may be added in order to enhance the sharpness of the formed image. It is preferable that silica, talc, clay, calcium carbonate and the like are added.

Viewing the formed image transparently, especially O
A transparent plastic film or sheet is preferable for use in preparing an HP original, and a polyethylene terephthalate film, a polycarbonate film, or a polysulfone is particularly preferable.

The thickness of the support is usually 20 to 1000 μm, preferably 20 to 800 μm, and is appropriately selected from such a range.

Further, the surface of the support may be surface-treated in advance in order to further enhance the adhesive force with the intermediate layer. Examples of the surface treatment method include corona discharge treatment, flame treatment, ozone treatment, primer treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, low temperature plasma treatment, and grafting treatment. This can dramatically improve the adhesiveness between the intermediate layer and the support. It is particularly effective for a support having a surface of a polyolefin compound. Any method may be used as long as it achieves this purpose. For other details, refer to “Basics and Applications of Polymer Surfaces (below)” Kagaku Dojin, Chapter 2 and / or “Handbook of New Polymer Materials” Maruzen, Chapter 8. Particularly preferred and simple methods include corona discharge treatment and primer treatment.

The compound used in the intermediate layer of the present invention can be used without particular limitation as long as it enhances the adhesive force between the support and the image receiving layer.

Preferred compounds for the intermediate layer are polyethylene resin, polyisobutylene resin and polystyrene.
-Butadiene copolymer resin, polystyrene resin, polychloroprene resin, acrylic copolymer resin, ethylene-
Vinyl acetate copolymer resin, polyvinyl chloride resin, vinylidene chloride resin, polyacrylonitrile-butadiene copolymer resin, polyurethane resin, natural rubber, neoprene resin, vinyl chloride-vinyl acetate copolymer resin, gelatin,
It is preferable that one or more compounds selected from polyester resin, polycarbonate resin, epoxy resin, phenoxy resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyamide resin and the like are contained as a part of the composition.

In addition to these resins, the intermediate layer of the present invention includes
Various additives can be added within a range that does not deteriorate the adhesiveness. Examples thereof include fine particles made of an inorganic or organic compound, a pigment, a hot-melt compound, a plasticizer, and an antistatic agent.

Examples of the inorganic fine particles include silica gel, calcium carbonate, titanium oxide, acid clay, activated clay and alumina. The organic fine particles may be hollow type or internally filled type, for example, fluorine resin particles, Resin particles such as guanamine resin particles, acrylic resin particles, and silicon resin particles can be mentioned. These inorganic / organic resin particles are different depending on the specific gravity, but it is preferably added in an amount of 0 to 30% by weight.

Typical examples of the pigment include titanium white, calcium carbonate, zinc oxide, barium sulfate, silica, talc, clay, kaolin, activated clay and acid clay.

The hot-melting compound is a compound which is solid at room temperature and becomes a liquid which is melted by heating. Generally, higher fatty acid, higher alcohol, wax,
It is called fat and oil. Specifically, it is disclosed in JP-A-61-17978.
The compounds described on page 2, page 7 can be mentioned.

Examples of the plasticizer include phthalic acid esters, trimellitic acid esters, adipic acid esters, other saturated or unsaturated carboxylic acid esters, citric acid esters, epoxidized soybean oil, epoxidized linseed oil, and epoxy. Examples thereof include stearic acid epoxy compounds, orthophosphoric acid esters, phosphorous acid esters, glycol esters and the like.

As the antistatic agent, fine metal powders, fine metal oxide powders, quaternary ammonium salts, cationic surface active agents such as polyamine derivatives, anionic surface active agents such as alkyl phosphates, and betaine type amphoteric agents. Ionic surfactants, nonionic surfactants such as fatty acid esters, polysiloxanes, water-soluble acrylic resins, or electron-conductive inorganic fine powders obtained by doping titanium oxide, zinc oxide, indium oxide, or the like with impurities.

The intermediate layer of the present invention is prepared by dispersing or dissolving the components for forming the intermediate layer in a solvent to prepare a coating solution for forming an intermediate layer, coating the coating solution on the surface of a support, and then drying. Method and melt-extruding a mixture containing the components for forming the intermediate layer,
It can be formed by a laminating method of laminating on the surface of the support. Among these various methods, the coating method is preferable.

As the solvent used in the above coating method, water, alcohols (eg ethanol, propanol), cellosolves (eg methyl cellosolve, ethyl cellosolve), aromatics (eg toluene, xylene, chlorobenzene), ketones ( Examples thereof include acetone, methyl ethyl ketone), ester solvents (eg ethyl acetate, butyl acetate), ethers (eg tetrahydrofuran, dioxane), chlorine solvents (eg chloroform, trichloroethylene) and the like.

For coating, conventionally known gravure roll coating methods, extrusion coating methods, wire bar coating methods, roll coating methods and the like can be employed.

Further, the intermediate layer of the present invention can be made porous. As a method of coating by making it porous,
A method in which a coating liquid in which air bubbles are generated by mechanically stirring the coating liquid is applied and dried on a substrate, a method in which a foaming agent is mixed in the coating liquid, and the mixture is applied and heated to foam. The method of forming microvoids in the layer when the intermediate layer composition is dissolved in a mixed solvent of a good solvent and a poor solvent and applied and dried is preferably applied.

Further, in order to achieve the object of the present invention, a plurality of intermediate layers may be laminated on the support.

The thickness of the intermediate layer of the present invention is 0.1 to 100 μm, preferably 0.5 to 20 μm as the whole intermediate layer.

The image-receiving layer can be formed with a binder for the image-receiving layer, a metal ion-containing compound and various additives.

Generally, the binder for the image-receiving layer is, for example, polyvinyl chloride resin, a copolymer resin of vinyl chloride and another monomer (for example, alkyl vinyl ether, allyl glycidyl ether, vinyl propionate, etc.), polyvinylidene chloride resin. , Polyester resin, acrylic acid ester, methacrylic acid ester, epoxy resin, phenoxy resin, polyvinyl butyral, polyvinylpyrrolidone, polycarbonate, polysulfone, polyarylate, polyparabanic acid, cellulose triacetate, styrene acrylate resin, vinyltoluene acrylate resin,
Examples thereof include polyurethane resin, polyamide resin, urea resin, polycaprolactone resin, styrene-maleic anhydride resin, and polyacrylonitrile resin. Among these, vinyl chloride resins, epoxy resins, phenoxy resins and the like are preferable as the binder for the image receiving layer used in the present invention.

These resins may be used alone or in combination of two or more.

The above various resins may be newly synthesized and used, but commercially available products may also be used. During the formation of the image-receiving layer, the above-mentioned various resins utilize their reaction active points (if there are no reaction active points, they are imparted to the resin) and are exposed to radiation, heat, moisture, a catalyst, etc. It may be crosslinked or cured. In that case, a radiation-active monomer such as epoxy or acrylic, or a crosslinking agent such as isocyanate can be used.

Examples of the metal ion constituting the metal ion-containing compound include divalent and polyvalent metals belonging to Groups I to VIII of the Periodic Table, among which Al, Co, Cr, C
u, Fe, Mg, Mn, Mo, Ni, Sn, Ti and Zn are preferable, and Ni, Cu, Co, Cr and Zn are particularly preferable. The compound containing these metal ions is preferably an inorganic or organic salt of the metal and a complex of the metal. As a specific example, a complex represented by the following general formula and containing Ni ²⁺ , Cu ²⁺ , Co ²⁺ , Cr ²⁺ and Zn ²⁺ is preferably used.

[0041] _{[M (Q 1) k (} Q 2) m (Q 3) n] P + P (L -) wherein, M represents a metal _{ion, Q 1, Q 2, Q} 3 are each, M
Represents a coordination compound capable of forming a coordination bond with a metal ion, and these coordination compounds may be selected from the coordination compounds described in, for example, “Chelate Chemistry (5) (Nankodo)”. it can. Particularly preferably, a coordination compound having at least one amino group that forms a coordinate bond with a metal can be cited, and more specifically, ethylenediamine and its derivatives, glycinamide and its derivatives, picolinamide and its derivatives can be mentioned. To be L is a counter anion capable of forming a complex, and examples thereof include inorganic anions such as Cr, SO ₄ and ClO ₄ and organic anions such as benzenesulfonic acid derivatives and alkylsulfonic acid derivatives, and particularly preferably tetraphenylboron anion [ _{(C 6 H 5) 4 B} -] and derivatives thereof as well as alkyl benzene sulfonate anion and its derivatives. k represents an integer of 1, 2 or 3, m represents 1, 2 or 0, and n represents 1 or 0,
These are determined by whether the complex represented by the general formula is tetradentate or hexadentate, or by the number of ligands of Q ₁ , Q ₂ and Q ₃ . p represents 1, 2 or 3.
Examples of this type of metal ion-containing compound include U.S. Pat.
Those exemplified in No. 7,049 can be mentioned.

The amount of the metal ion-containing compound added is preferably 0.5 to 20 g / m ² , and more preferably 1 to 15 g / m ² with respect to the image receiving layer.

A peeling agent, an antioxidant, a UV absorber, a light stabilizer, a filler (inorganic fine particles, organic resin particles) and a pigment may be added to the image receiving layer. Moreover, you may add a plasticizer, a thermal solvent, etc. as a sensitizer.

The release agent is for improving the releasability between the thermal transfer recording ink sheet and the thermal transfer recording image receiving sheet. Examples of such release agents include silicone oils (including those referred to as silicone resins); solid waxes such as polyethylene wax, amide wax, Teflon powder; fluorine-based and phosphoric acid ester-based surfactants. Among them, silicone oil is preferable. This silicone oil is classified into a type that is simply added (simple addition type) and a type that is cured or reacted (curing reaction type).

In the case of the simple addition type, it is preferable to use a modified silicone oil (for example, polyester modified silicone resin, urethane modified silicone resin, acryl modified silicone resin, etc.) in order to improve the compatibility with the binder. The addition amount of these simple addition type silicone oils cannot be uniformly determined because it changes variously depending on the type, but generally 0.1 to 50% by weight based on the binder for the image receiving layer. And preferably 0.5 to 20% by weight.

As the curing reaction type silicone oil,
Reaction-curable type (for example, one obtained by reaction-curing amino-modified silicone oil and epoxy-modified silicone oil),
Examples include photo-curing type and catalyst-curing type. The amount of these curable silicone oils added is 0.5 of the binder for the image receiving layer.
-30% by weight is preferred.

A release agent layer may be provided on a part of the surface of the image receiving layer by dissolving or dispersing the release agent in an appropriate solvent and applying the solution, followed by drying.

As the above-mentioned antioxidant, JP-A-59-18278
No. 5, No. 60-130735, JP-A No. 1-127387 and the like, and known compounds that improve image durability in photographs and other image recording materials can be mentioned.

UV absorbers and light stabilizers are disclosed in
59-158287, 63-74686, 63-145089, 59-196
No. 292, No. 62-229594, No. 63-122596, No. 61-283595
And the compounds described in JP-A 1-204788, and known compounds that improve image durability in photographs and other image recording materials.

As the filler and pigment, those used in the intermediate layer are preferably used. The addition amount depends on the specific gravity, but the addition amount of 0 to 30% by weight is preferable.

As the plasticizer, those used in the above intermediate layer are also preferably used.

The total amount of the additives in the present invention is usually in the range of 0.1 to 30% by weight based on the binder for the image receiving layer.

An overcoat layer may be laminated on the surface of the image receiving layer for the purpose of improving image storability, and further, antistatic and curl prevention may be provided on the surface opposite to the image receiving layer (support surface). A backing layer may be provided for the purpose.

The thickness of the above-mentioned overcoat layer and backing layer is usually 0.1 to 20 μm. (2) Production of image-receiving sheet for thermal transfer recording The image-receiving sheet is prepared by dispersing or dissolving the components for forming the image-receiving layer in a solvent. Preparation of a coating liquid for forming an image receiving layer, coating of the coating liquid for forming an image receiving layer on an intermediate layer provided on the surface of a support and drying, or a mixture containing the components for forming the image receiving layer. It can be formed by a laminating method of extruding and laminating on the surface of the support. Among these, the coating method is preferable.

As the solvent used in the above coating method, water, alcohols (eg ethanol, propanol), cellosolves (eg methyl cellosolve, ethyl cellosolve), aromatics (eg toluene, xylene, chlorobenzene), ketones ( Examples thereof include acetone, methyl ethyl ketone), ester solvents (eg ethyl acetate, butyl acetate), ethers (eg tetrahydrofuran, dioxane), chlorine solvents (eg chloroform, trichloroethylene) and the like.

For coating, conventionally known gravure roll coating methods, extrusion coating methods, wire bar coating methods, roll coating methods and the like can be employed.

(3) Ink sheet for thermal transfer recording An ink sheet for thermal transfer recording (hereinafter also referred to as an ink sheet) basically comprises an ink layer laminated on a support.

Any material may be used as the support as long as it has good dimensional stability and can withstand the heat at the time of recording with a thermal head. However, thin paper such as condenser paper or glassine paper, polyethylene terephthalate, polyethylene naphthalate,
A heat resistant plastic film such as polyamide, polyimide, polycarbonate, polysulfone, polyvinyl alcohol cellophane, or polystyrene can be used. The thickness of the support is preferably 2 to 10 μm.

The shape of the support is not particularly limited,
For example, there are arbitrary shapes such as a wide sheet or film, a narrow tape or a card.

The ink layer contains a heat diffusing dye and a binder as essential components.

The heat diffusible dye used in the present invention is preferably the dye represented by the general formula (2). Specifically, for example, described in JP-A-59-78893, 59-109349, JP-A-2-213303, 2-214719, 2-203742, at least the above description A cyan image-forming dye (hereinafter, referred to as a cyan dye), a magenta image-forming dye (hereinafter, referred to as a magenta dye) capable of forming a bidentate chelate with a metal ion-containing compound, a yellow image-forming dye (hereinafter, a yellow dye) Can be mentioned).

The heat diffusing dye contained in the ink layer may be any one of a yellow dye, a magenta dye and a cyan dye as long as the image to be formed is a single color. Further, depending on the color tone of the image to be formed, any two or more of the above three types of dyes or other heat diffusible dyes may be contained.

The amount of the heat-diffusible dye used is usually 0.1 to ²⁰ g, preferably 0.2 to 5 g, per 1 m ^{2 of} the support.

As the binder of the ink layer, a cellulose-based compound such as a cellulose addition compound, a cellulose ester or a cellulose ether; a polyvinyl acetal resin such as polyvinyl alcohol, polyvinyl formal, polyvinyl acetoacetal or polyvinyl butyral, polyvinyl pyrrolidone or polyvinyl acetate. Vinyl resins such as polyacrylamide, styrene resin, poly (meth) acrylic acid ester, poly (meth) acrylic acid, and (meth) acrylic acid copolymer, rubber resin, ionomer resin, olefin resin, polyester Resin etc. are mentioned. Among these resins, polyvinyl butyral, polyvinyl acetoacetal, and cellulosic resins, which are excellent in storage stability, are preferable.

One of the various binders may be used alone, or two or more thereof may be used in combination.

The weight ratio of the binder to the heat diffusible dye is preferably from 1:10 to 10: 1, particularly preferably from 2: 8 to 7: 3.

Further, various additives can be appropriately added to the ink layer. As the additive, silicone resin, silicone oil (reaction-curable type is also possible), silicone-modified resin, fluororesin, surface-active agent and peelable compounds such as waxes, fine metal powder, silica gel, metal oxide,
Examples thereof include fillers such as carbon black and resin fine powder, and curing agents capable of reacting with a binder component (for example, radiation-active compounds such as isocyanates, acryls and epoxies). Further, as an additive, a heat-melting substance for promoting transfer, for example, a compound described in JP-A-59-106997 such as wax or higher fatty acid ester can be mentioned.

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 in order to prevent fusion with the image-receiving sheet for thermal transfer recording and settling (blocking) of the heat diffusing dye. Further, the support may have an undercoat layer for the purpose of improving the adhesiveness with the binder and preventing the dye from being transferred to the support or dyeing. Further, a back surface treatment layer may be provided on the back surface of the support (on the side opposite to the ink layer) for the purpose of preventing the head from fusing or sticking to the support and wrinkling of the ink sheet.

The thickness of the overcoat layer, the undercoat layer and the backside treatment layer is usually 0.1 to 1 μm.

(4) Production of Ink Sheet for Thermal Transfer Recording For an ink sheet, an ink layer-forming coating liquid prepared by dispersing or dissolving the various components forming the ink layer in a solvent is prepared and supported. It can be produced by coating on the surface of the body and drying.

The binder may be used alone or in combination of two or more in a solvent or dispersed in a latex form.

Examples of the solvent include water, ethanol, tetrahydrofuran, methyl ethyl ketone, toluene, xylene, chloroform, dioxane, acetone, cyclohexane, and normal butyl acetate.

For the coating, conventionally known surface sequential coating by gravure roll coating method, extrusion coating method, wire bar coating method, roll coating method and the like can be adopted. The ink layer may be formed on the entire surface or a part of the surface of the support as a layer containing a monochromatic heat diffusible dye, or a yellow ink layer containing a binder and a yellow dye, a binder. Even if a magenta ink layer containing a magenta dye and a cyan ink layer containing a binder and a cyan dye is formed on the entire surface or a part of the surface of the support at regular intervals along the plane direction. Good.

Further, in addition to the three ink layers arranged in the plane direction, a black ink layer containing a black image forming substance may be interposed. With respect to the black ink layer, a clear image can be obtained by either the diffusion transfer type or the melt transfer type.

The thickness of the ink layer thus formed is usually 0.2 to 10 μm, preferably 0.3 to 3 μm.

The ink sheet can be conveniently used by forming perforations or providing detection marks for detecting the positions of areas of different hues.

(5) Image Formation (Thermal Transfer Recording) In order to form an image, the ink layer of the ink sheet and the image receiving layer of the image receiving sheet are superposed on each other, and thermal energy is applied to the interface between the ink layer and the image receiving layer in an imagewise manner. give. The heat diffusible dye in the ink layer is vaporized or sublimated by an amount corresponding to the applied heat energy, and is transferred to the image receiving layer side and received, whereby a chelate dye image is formed on the image receiving layer.

As a heat source for giving the above heat energy,
Although a thermal head is generally used, a known one such as a laser beam, an infrared flash, and a heat pen can be used in addition to this.

When a thermal head is used as a heat source for applying heat energy, the applied heat energy can be changed continuously or in multiple steps by modulating the voltage or pulse width applied to the thermal head.

When laser light is used as a heat source for giving heat energy, the heat energy to be given can be changed by changing the light quantity of the laser light or the irradiation area. In this case, to make it easier to absorb the laser light,
A laser light absorbing material (in the case of a semiconductor laser, carbon black, a near infrared absorbing substance, etc.) may be present in the ink layer or in the vicinity of the ink layer. When laser light is used, it is preferable that the ink sheet and the image receiving sheet are sufficiently brought into close contact with each other.

If a dot generator with a built-in acousto-optic element is used, it is possible to give heat energy according to the size of the halftone dot.

When an infrared flash lamp is used as a heat source for providing heat energy, it is preferable to heat through a colored layer such as black as in the case of using laser light. Alternatively, heating may be performed through a pattern or halftone dot pattern in which the shade of the image such as black is continuously expressed, or a negative pattern corresponding to the negative of the above-mentioned pattern and a colored layer such as black on one surface. You may heat by combining. The heat energy may be applied from the ink sheet side, the image receiving sheet side, or both sides. However, if the effective use of heat energy is prioritized, the ink sheet side is used. desirable. By the above thermal transfer recording, 1 is formed on the image receiving layer of the image receiving sheet.
Although a color image can be recorded, it is also possible to obtain a color photographic tone color image composed of a mixture of the respective colors by the following method.

For example, a color image of a color photographic tone can be obtained by sequentially replacing the yellow, magenta, cyan, and if necessary black ink sheets and performing thermal transfer according to each color. Further, instead of using the ink sheet of each color as described above, a method of using an ink sheet having an area formed by separately coating each color is also effective. That is, first, the yellow color separation image is thermally transferred using the yellow area, and then the magenta color separation image is thermally transferred using the magenta area, and thereafter, the yellow, magenta, cyan, and necessary images are sequentially repeated. Then, a method of thermally transferring a black color separation image in order is adopted. With this method, it is possible to obtain a color photograph-like color image, but more advantageously, this method has an advantage that the above-mentioned replacement of the ink sheet is unnecessary.

[0084]

The present invention will be described in more detail with reference to the following examples, but the embodiments of the present invention are not limited thereto. In the following, "part" means "part by weight". Example 1 (Production of Ink Sheet) On a corona-treated surface of a polyethylene terephthalate film [manufactured by Toray Industries, Inc.] having a thickness of 6 μm as a support, a coating liquid for forming an ink layer having the following composition was dried by a wire bar coating method. After coating and drying so that the thickness will be 1 μm, a nitrocellulose solution containing 40% of silicone resin [Dainichi Seika Co., Ltd .: SP-2105] on the back surface not subjected to corona treatment will give a dry film thickness of 0.2. An ink sheet was obtained by applying and drying with a thickness of μm and applying a back treatment.

Coating liquid for forming ink layer Thermal diffusible dye [PCM-1] 3 parts Nitrocellulose 3 parts [Asahi Kasei Co., Ltd .: Cernova BTH1 / 2] Methyl ethyl ketone 44 parts Dioxane 40 parts Cyclohexanone 10 parts

[0086]

[Chemical 3]

(Production of Image Receiving Sheet) As a base material, thickness 150
μm synthetic paper [trade name: YUPO FPG-150: manufactured by Oji Yuka Synthetic Paper Co., Ltd .: Catalog March 1990] was coated with an intermediate layer forming coating solution and an image receiving layer forming coating solution having the following composition. An image receiving sheet was obtained by sequentially applying and drying by a construction method to form a 1.0 μm thick intermediate layer and a 5 μm thick image receiving layer upper layer on a synthetic paper.

Coating liquid for forming intermediate layer Ethylene-vinyl acetate copolymer 6 parts [EV-40Y: manufactured by Mitsui DuPont Polychemical Co., Ltd.] Polyvinyl chloride resin 4 parts [TK-600: manufactured by Shin-Etsu Chemical Co., Ltd. ] Methyl ethyl ketone 80 parts Cyclohexanone 10 parts Coating liquid for forming the image receiving layer upper layer Epoxy resin 6.5 parts [Epotote YD-014 Toto Kasei Co., Ltd.] Metal ion-containing compound [MS-1] 3.0 parts Polyester modified silicone resin 0.5 parts [X- 24-8300: Shin-Etsu chemical Co., Ltd.] Methyl ethyl ketone 80 parts cyclohexanone 10 parts MS-1: [Ni (C 2 H 5 NHCH 2 CH 2 NH 2) 3] 2+ 2 [(C 6 H 5) 4 B] - (Image formation) First, the ink sheet and the image receiving sheet are superposed so that the former ink layer surface and the latter image receiving layer surface are in contact with each other, and heat-sensitive under the following conditions from the support side of the ink sheet. The pad was applied to form an image.

Then, the ink sheet and the image receiving sheet were peeled off, and the image was transferred onto the image receiving sheet.

After recording the image, the transfer density on the surface of the image receiving layer, the image uniformity, the adhesiveness between the image receiving layer and the support, and the degree of fusion between the image receiving sheet and the ink sheet during image formation were evaluated according to the following criteria.

Linear density of main scanning and sub scanning: 8 dots / mm Recording power: 0.6 W / dot Heating time of thermal head: 20 msec (applied energy about 11.2 × 10 ⁻³ J) to 2 msec (applied energy about 1.12 × 10 ^-3 J), the heating time was adjusted stepwise <Transfer density> The reflection density (OD) was measured with an optical densitometer.

◎ ・ ・ ・ OD value is 2.5 or more ○ ・ ・ ・ OD value is 2.0 to 2.5 △ ・ ・ ・ OD value is 1.7 to 2.0 × ・ ・ ・ OD value is 1.7 or less <Image uniformity> Solid on the entire screen An image was formed and the difference between the maximum and minimum optical densities within one screen (120 mm × 80 mm) was measured.

◎ OD difference is 0.05 or less ○ OD difference is 0.1 or less △ OD difference is 0.3 or less × OD difference is 0.3 or more <Adhesiveness between image receiving layer and support>・ ・ ・ No fusion with ink sheet during image formation. No peeling of the image-receiving layer even when the image-receiving sheet is bent.

B: No fusion with the ink sheet during image formation. When the image receiving sheet is bent, there is peeling between the image receiving layer and the support.

Δ: Fusing with the ink sheet during image formation. When the image receiving sheet is bent, there is peeling between the image receiving layer and the support.

X: The image receiving layer was peeled off during printing, and an image could not be formed.

For fusion, the image-receiving sheet and the ink sheet after image formation were visually evaluated.

Example 2 The following intermediate layer forming coating solution and image receiving layer forming coating were formed on a polyethylene layer on one side obtained by laminating a polyethylene layer containing 12% of titanium oxide on both sides of wood free paper to a thickness of 10 μm. The liquid was laminated and applied to 1.0 μm and 5.0 μm to prepare an image receiving sheet. Using the same ink sheet as in Example 1,
An image was formed and evaluated in the same manner as in Example 1.

Coating liquid gelatin for forming intermediate layer [Pigskin: Konica Gelatin Co., Ltd.] 4.5 parts Barium sulfate 0.5 part Water 95 parts Coating liquid for forming upper layer of image receiving layer Polyvinyl chloride resin [TK-300: Shin-Etsu Chemical Co., Ltd. Company-made] 6.5 parts Metal ion-containing compound [MS-1] 3 parts Polyester-modified silicone resin 0.5 part [X-24-8300: Shin-Etsu Chemical Co., Ltd.] Dioxane 80 parts Cyclohexanone 10 parts Example 3 Intermediate layer in Example 2 25W polyethylene layer before
An image-receiving sheet was obtained in the same manner except that the corona discharge treatment was performed at / m ² / min. An image was formed and evaluated in the same manner as in Example 2.

Example 4 White pigment and polyester were mixed and stretched to a thickness of 125 μm.
Of a white polyester film [trade name W-300: manufactured by Dia foil Co., Ltd., Aug. 30, 1986] as a support, the following intermediate layer forming coating liquid and image receiving layer forming coating liquid were respectively prepared. An image-receiving sheet was obtained by stacking and applying the layers to 1.0 μm and 5.0 μm. Using the same ink sheet as in Example 1, an image was formed and evaluated in the same manner as in Example 1.

Coating liquid polyester resin for intermediate layer formation [Byron 200: manufactured by Toyobo Co., Ltd.] 10 parts Methyl ethyl ketone 80 parts Cyclohexanone 10 parts Coating liquid phenoxy resin for image receiving layer formation 7.5 parts [Phenothote YP-50: Toto Kasei Co., Ltd. Company-made] Metal ion-containing compound [MS-1] 2 parts Polyester-modified silicone resin 0.5 part [X-24-8300: Shin-Etsu Chemical Co., Ltd.] Dioxane 80 parts Cyclohexanone 10 parts Example 5 Coating liquid for forming intermediate layer Change to the following composition, dry film thickness 10μ
An image-receiving sheet was prepared in the same manner as in Example 4, except that the intermediate layer having a microporous structure was provided by coating and drying so as to have a thickness of m. An image was formed and evaluated in the same manner as in Example 4.

Polyurethane resin [Takelac T: manufactured by Takeda Pharmaceutical Co., Ltd.] 20 parts Toluene 50 parts Isopropyl alcohol 20 parts Water 10 parts Example 6 The first intermediate layer having the following composition between the intermediate layer of Example 5 and the support. An image receiving sheet was obtained in the same manner as in Example 5 except that the coating liquid was applied so that the dry film thickness was 1.0 μm. An image was formed and evaluated in the same manner as in Example 5.

First Intermediate Layer Coating Liquid Polyester Resin Aqueous Emulsion 30 parts [Vylonal-1200: manufactured by Toyobo Co., Ltd.] Water 70 parts Example 7 A transparent polyester film having a thickness of 125 μm [trade name: Lumirror # 125: manufactured by Toray Industries, Inc.], an ink sheet was prepared in the same manner as in Example 1, and an image was similarly formed and evaluated.

Example 8 A first intermediate layer having the following composition was coated on a 125 μm thick transparent polyester film [trade name: Lumirror # 125: manufactured by Toray Industries, Inc.] so as to have a dry film thickness of 1.0 μm. Further, a second intermediate layer having the following composition is further formed on it to form a dry film thickness.
It was applied to have a thickness of 10 μm. An image receiving layer having the following composition was coated on the second intermediate layer so that the dry film thickness was 5.0 μm to prepare an image receiving sheet. By combining this with the same ink sheet as in Example 1, an image was formed and evaluated in the same manner as in Example 1.

First intermediate layer forming coating liquid polyester resin 20 parts [Peth Resin S-110: manufactured by Takamatsu Yushi Co., Ltd.] Methyl ethyl ketone 40 parts Toluene 40 parts Second intermediate layer forming coating liquid styrene / butadiene co-weight Combined latex 50 parts [Polylac 750: manufactured by Mitsui Toatsu Co., Ltd.] Water 50 parts Coating liquid polycarbonate resin for image forming layer 6.5 parts [Panlite K-1300: manufactured by Teijin Chemicals] Metal ion-containing compound [MS-1] 3 parts Polyester-modified silicone resin 0.5 part [X-24-8300: manufactured by Shin-Etsu Chemical Co., Ltd.] Dioxane 80 parts Cyclohexanone 10 parts Example 9 The same procedure as in Example 8 except that the first intermediate layer was not provided A sheet was prepared, and an image was formed and evaluated in the same manner as in Example 8.

Comparative Examples 1 to 4 Comparative image receiving sheets were prepared in the same manner as in Examples 1 to 4 except that the intermediate layer was not provided, and images were formed and evaluated in the same manner as in Examples 1 to 4.

Comparative Example 5 A comparative image-receiving sheet was prepared in the same manner as in Example 7 except that the intermediate layer was not provided, and images were formed and evaluated in the same manner as in Example 7.

The results of the image formation evaluation in Examples 1 to 5 are summarized in Table 1.

[0109]                                  Table 1     Sample transfer density Image uniformity Image receiving layer and support fusion                                            Adhesiveness    Example 1 ◎ ◎ ◎ None    Example 2 ◎ ◎ ○ None    Example 3 ◎ ◎ ◎ None    Example 4 ◎ ○ ◎ None    Example 5 ◎ ◎ ○ None    Example 6 ◎ ◎ ◎ None    Example 7 ○ ○ ◎ None    Example 8 ◎ ◎ ◎ None    Example 9 ◎ ◎ ○ None    Comparative Example 1 ○ △ × Fusion    Comparative Example 2 △ △ × Fusion    Comparative Example 3 △ × △ Partial fusion    Comparative Example 4 △ × △ Partially fused    Comparative Example 5 △ × △ Partially fused

[0110]

According to the image-receiving sheet for heat-sensitive transfer recording of the present invention, a uniform image can be obtained at a high transfer density, the image storability is excellent, and there is a problem due to fusion of the ink sheet and the image-receiving sheet during image formation. The occurrence of was suppressed.

Claims (6)

[Claims] 1. A thermal transfer recording ink sheet provided on a substrate with a layer containing a heat diffusible dye capable of reacting with a metal ion-containing compound to form a chelate, and the layer is superposed on the substrate. In a heat-sensitive transfer recording image-receiving sheet comprising a support and a heat-diffusible dye receiving layer containing at least a metal ion-containing compound, which is heated to form an image, between the support and the heat-diffusible dye receiving layer. An image-receiving sheet for thermal transfer recording, characterized by having an intermediate layer interposed. 2. The image-receiving sheet for thermal transfer recording according to claim 1, wherein at least one of the metal ion-containing compounds is selected from the group of compounds represented by the following general formula (1). Formula _{(1) [M (Q 1} ) k (Q 2) m (Q 3) n] P + P (L -) wherein, M is ^{Ni 2+, Cu 2+, Co 2+} , Cr 2+ And Zn ^2+, and each of Q ₁ , Q ₂ and Q ₃ represents a coordination compound capable of forming a coordinate bond with the metal ion represented by M. ] 3. Reacting with the metal ion-containing compound,
The heat-sensitive transfer recording image-receiving sheet according to claim 1 or 2, wherein the heat diffusible dye capable of forming a chelate is selected from the group of compounds represented by the following general formula (2). [Chemical 1] [In the formula, X ₁ represents an aromatic carbon ring in which at least one ring is composed of 5 to 7 atoms, or an atomic group necessary for completing a heterocycle, and is a carbon atom bonded to an azo bond. At least one of the adjacent positions is a nitrogen atom or a carbon atom substituted with a chelating group. X ₂ represents an aromatic carbon ring in which at least one ring is composed of 5 to 7 atoms, or an atomic group necessary for completing a heterocycle, and G represents a chelating group. ] 4. The image-receiving sheet for thermal transfer recording according to claim 1, wherein the intermediate layer is composed of a plurality of layers. 5. The image-receiving sheet for thermal transfer recording according to claim 1, wherein the surface of the support on which the intermediate layer is provided is surface-treated. 6. The surface treatment is any one of corona discharge treatment, flame treatment, ozone treatment, primer treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, low temperature plasma, and grafting treatment. Claim 5 characterized by the above-mentioned.
An image-receiving sheet for heat-sensitive transfer recording according to item 1.