JPH04201493A - Ink sheet for thermal transfer recording and thermal transfer recording method - Google Patents

Abstract

PURPOSE:To enable high-speed printing by low energy by supporting an ink sheet for thermal transfer recording and an image-receiving sheet for thermal transfer recording during a time when electricity is conducted through the conductive layer of the ink sheet for thermal transfer recording, in which the conductive layer and an ink layer containing a thermal diffusive dyestuff are laminated on a supporter in the order, or after electricity is conducted through the conductive layer and forming a picture to the image-receiving sheet for thermal transfer recording through heating. CONSTITUTION:In an ink sheet for thermal transfer recording, a conductive layer 2 and an ink layer 3 are laminated on a support 1 in the order. The ink sheet for thermal transfer recording and an image-receiving sheet for thermal transfer recording are superposed and heated so that the ink layer of the former and the image receiving layer of the latter are brought into contact in order to form a picture to an image-receiving body. Electricity is conducted through the conductive layer and the conductive layer is preheated before heating or during heating at the time. A method, in which the conductive layer 2 exposed to the surface of the ink sheet for thermal transfer recording is brought into contact with a wind-up roll 4 and an unwind roll 5 and electricity is conducted through the conductive layer 2 while using the wind-up roll 4 and the unwind roll 5 as common electrodes, is employed as a method, in which currents are conducted through the conductive layer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ink sheet for thermal transfer recording and a thermal transfer recording method, and more specifically, to perform high-speed printing with low energy on an image-receiving sheet for thermal transfer recording. The present invention relates to an ink sheet for thermal transfer recording and a thermal transfer recording method.

[Assignment that attempts to solve conventional techniques and inventions! i] Conventionally, color recording techniques such as ink sheeting, electrophotography, and thermal transfer recording have been considered as methods for obtaining color hard copies.

Among these, the thermal transfer recording method in particular has advantages such as easy operation and maintenance, miniaturization of the device, and low cost.

There are two types of this thermal transfer recording method:

Specifically, a transfer sheet having a meltable ink layer on a support is heated imagewise with a laser or a thermal head, and the meltable ink layer is melt-transferred onto an image-receiving sheet for thermal transfer recording; Thermal diffusion transfer method uses an ink sheet for thermal transfer recording having an ink layer containing a thermal diffusible dye (sublimable dye) to diffusely transfer the thermal diffusible dye to an image receiving sheet for thermal transfer recording. It is.

Among these, the thermal diffusion transfer method controls the gradation of the image by changing the transfer amount of one dye in response to changes in the thermal energy of the thermal head.
By overlapping magenta and yellow recording,
color! In recent years, this method has attracted attention as a method for obtaining color images with continuous changes in lightness.

However, the conventional thermal diffusion transfer methods have various problems.

For example, as a major example, with the thermal diffusion transfer method that uses ink sheets for thermal transfer recording, it is not necessarily easy to perform high-speed printing with low energy, that is, to achieve high-speed recording with low energy. do not have.

The present invention has been made to improve the above situation.

An object of the present invention is to provide an ink sheet for thermal transfer recording and a thermal transfer recording method that allow high-speed printing with low energy on an image-receiving sheet for thermal transfer recording.

[Means for Solving the Problems] The invention according to claim 1 for achieving the above objects comprises laminating a conductive layer and an ink layer containing a heat-diffusible dye on a support in this order. This is an ink sheet for thermal transfer recording.

In addition, the invention according to claim 2 is such that the ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording are overlapped while or after energization is applied to the conductive layer of the ink sheet for thermal transfer recording according to claim 1. This is a thermal transfer recording method characterized by forming an image on an image receiving sheet for thermal transfer recording by combining and heating.

The present invention will be explained in detail below.

(1.) Ink sheet for thermal transfer recording' The ink sheet for thermal transfer recording of the present invention basically has a conductive layer 2 on a support 1, as shown in FIG.
and an ink layer 3 are laminated in this order.

Conductive Layer: The conductive layer contains a binder and a conductive substance as essential components.

Examples of the binder include polyester resins, polyurethane resins, polyolefin resins, acrylic resins, vinyl chloride resins, cellulose resins, styrene resins, acetal resins, polycarbonates, polysulfones, polyether sulfones, and arylate,
Examples include polyparaban chu.

Further, as the conductive substance, carbon flakes,
Examples include conductive fine powders such as graphite, various metals, metal oxides, and alloys, conductive fibers such as metal fibers, and carbon fibers.

Conductive polymers that have both a binder and a conductive substance, such as polyacetylene, bopparaphenylene, polypyrrole,
Polymers prepared by topping polythiophene, polyaniline, etc. can also be used in the present invention.

In addition, when forming the conductive layer, the various resins mentioned above utilize their reactive active sites (if there are no reactive active sites, they are added to the resin), and are activated by radiation, heat, moisture, catalysts, etc. It may also be crosslinked or cured.

In that case, a radiation active polymer such as epoxy or acrylic or a crosslinking agent such as isocyanate may be used.

The above-mentioned binder and conductive substance each include:
One type can be used alone, or two or more types can be used in combination.

The amount of the conductive substance to be blended is usually 10 to 300 parts by weight, preferably 20 to 100 parts by weight, based on 100 parts by weight of the binder.

If the amount is less than 10 parts by weight, the conductivity may be insufficient, and if the amount exceeds 300 parts by weight, the effect of the binder may be insufficient.

The thickness of this conductive layer is usually 0.01 to 1.0 μm, preferably 0.01 to 1.0 μm. The former value is ~0.5 μm.

This conductive layer includes one or more of the following:
Any optional component that can be included in the ink layer, which will be described later, may be included.

The amount of the optional component to be included can be appropriately determined depending on the type and purpose of the additive.

In the present invention, it is necessary to supply current to the conductive layer.

To this end, it is best to expose the conductive layer on the surface of the ink sheet for thermal transfer recording so that the current-carrying electrode that supplies the current comes into contact with the conductive layer.

Specifically, as shown in FIG. 2(a), in a long ink sheet for thermal transfer recording, the conductive layer 2 is formed into stripes extending in a direction perpendicular to the longitudinal direction. The ink layer 3 is formed on the conductive layer 2 so that the ink layer 3 appears continuously, or as shown in FIG. In this embodiment, an ink layer 3 is formed on the conductive layer 2 so that the conductive layer 2 is exposed between the ink layers.

As a method of passing current through the conductive layer, for example, the third
As shown in the figure, the conductive layer 2 exposed on the surface of the ink sheet for thermal transfer recording is brought into contact with a winding roll 4 and an unwinding roll 5, and the winding roll 4 and unwinding roll 5 are connected to a common electrode. As shown in Fig. 4, a common electrode roll (or brush) 6 is brought into contact with the conductive layer 2 exposed on the surface of both ends of the ink sheet for thermal transfer recording, and the conductive layer 2 is energized. There are ways.

When a part of the conductive layer protrudes from the surface of the ink layer, any of the above methods of applying current can be used.

One Ink Layer - The ink layer basically contains a heat diffusible dye and a binder.

The thickness of the ink layer is usually 0.1 to ]Ogm, preferably 0.3 to 2.0 μm.

1. Heat-diffusible dyes Examples of heat-diffusible dyes include cyan dyes, magenta dyes, and yellow dyes.

As the cyan dye, JP-A-59-78896;
No. 59-227948, No. 60-24966, No. 2, No. 6
〇-5355: No. 1, No. 60-1307: 15, No. 6
No. 0-131292, No. 50-2:19289, No. 5
1-19: No. 196, [il-22993, No. 61]
- : ]] No. 29292 No. 61-31467, No. 61-
: No. l5994, No. 61-49893, No. 61-14
No. 8269, No. 62-191191, No. 63-912
No. 88, No. 63-91287, No. 63-290793
Examples include naphthoquinone dyes, anthraquinone dyes, azomethine dyes, etc., which are described in various publications such as No.

Examples of the magenta dye include JP-A-59-78896, JP-A-60-30392, and JP-A-60-30394.
No., JP-A-60-253595, JP-A-61-262
No. 190, JP-A No. 6:1-5992, JP-A No. 63-2
No. 05288, JP-A-64-159, JP-A-64-6
Examples include anthraquinone dyes, azo dyes, and azomethine dyes described in publications such as No. 31!14.

As a yellow dye, JP-A-59-78896 is used.

JP-A-60-27594, JP-A-60-:1156
No. 0, JP-A-60-53565, JP-A-61-+2
Examples include methine dyes, azo dyes, quinophthalone dyes, and anthrisothiazole dyes described in publications such as No. 194 and JP-A-63-122594.

Also, particularly preferred as the heat-diffusible dye are:

Azomethine dyes and phenol or naphthol derivatives obtained by coupling reaction of a compound having an open-chain or closed-chain active methylene group with an oxidized product of a p-phenylenecyamine derivative or an oxidized product of a p-aminophenol derivative; It is an indoaniline dye obtained by a coupling reaction with an oxidized product of a phenylenecyamine derivative or an oxidized product of a p-aminophenol derivative.

The heat-diffusible dye contained in the ink layer may be any of a yellow dye, a magenta dye, and a cyan dye, as long as the image to be formed is a single color;
Depending on the tone of the image to be formed, it may contain two or more of the three types of dyes or other heat-diffusible dyes.

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

2. Binders for the binder ink layer include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and cellulose acetate, polyvinyl alcohol, polyvinyl rumal, polyvinyl phtyral, polyvinyl pyrrolidone, Vinyl resins such as polyvinyl acetate, polyacrylamide, polyvinyl acetoacetal, styrene resins, styrene copolymer resins, polyacrylic acid esters, polyacrylic acid, acrylic acid copolymers, rubber resins, ionomer resins, olefin resins Examples include resin, polyester resin, etc.

Among these resins, polyvinyl phthyral, polyvinyl acetoacetal, or cellulose resins, which have excellent preservability, are preferred.

The various types of binders mentioned above can be used singly or in combination of two or more.

The weight ratio of the binder and the heat diffusible dye is 1 lO
~lOl is preferred, and a range of 28 to 82 is particularly preferred.

3. Other Optional Components Furthermore, the ink layer may be subjected to various treatments within the range that does not impede the object of the present invention.

As additives, silicone resin, silicone oil (
Reaction curing type is also available), silicone-modified resins, fluororesins, surfactants, and peeling compounds such as waxes, fillers and binder components such as fine metal powders, silica gel, metal oxides, carbon black, and fine resin powders. curing agents (for example, radiation active compounds such as isocyanates, acrylics, and epoxies) that can react with the curing agent.

Furthermore, heat-melting substances for translating transfer in the cutting process, such as waxes and higher fat-resistant esters, may be mentioned, as well as compounds described in JP-A-59-106997.

One-dimensional support The support used in the present invention may be one that is stable in one dimension and can withstand the heat of recording with a thermal head, such as condenser paper or Krashin paper. Tissue paper, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyimide, polycarbonate,
Heat-resistant plastic films such as polysulfone, polyvinyl alcohol cellophane, and polystyrene can be used.

The thickness of the support is preferably 2 to 10 μm.

There are no particular restrictions on the shape of the support, and it may be of any shape, such as a wide sheet or film, a narrow tape, or a cart.

-Other layers- The ink sheet for thermal transfer recording is not limited to a three-layer structure consisting of a support, an ink layer, and a conductive layer, and other layers may be formed as long as they do not impede the purpose of the present invention. It's okay.

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 set-off (flora kink) of the heat-diffusible dye.

Further, the support may have a subbing layer for the purpose of improving stone throwability with the binder and preventing transfer and dyeing of the dye to the support.

Furthermore, on the back side of the support (the side opposite to the ink layer), a sticking prevention layer is provided to prevent the head from adhering to the support, from sticking, and from wrinkling the ink sheet for thermal transfer recording. Good too.

The thickness of this anti-sudikkin layer is normal.

It is 0.1 to 1 m.

(2.) Manufacture of ink sheet for thermal transfer recording Regardless of the embodiment of the ink sheet for thermal transfer recording of the present invention, first, conductive layer forming components are dispersed or dissolved in a melt to form a conductive layer. Prepare a coating solution.

The ink sheet for thermal transfer recording of the present invention is generally prepared by first coating a coating liquid for forming a conductive layer on a support and drying it to form a conductive layer, and then dispersing or dispersing the ink layer forming components in a solvent. It can be manufactured by applying a dissolved coating liquid for forming an ink layer to the surface of a conductive layer and drying it.

In addition, in both the coating liquid Σ for forming a conductive layer and the coating liquid for forming an ink layer, the binder and the binder are used by dissolving one or more types of τ in a solvent or dispersing them in a latex form.

The solvents include water, alcohols (e.g. ethanol, propatool), cellosolves (e.g. methyl cellosolve, ethyl cellosolve), aromatics (e.g. toluene, xylene, chlorobenzene), ketones (e.g. acetone, methyl ethyl ketone), Examples include ester solvents (eg, ethyl acetate, phthyl acetate), ethers (eg, tetrahydrofuran, dioxane), chlorine solvents (eg, chloroform, trichlorethylene), and the like.

The above-mentioned coating method includes a conventionally known surface-sequential rubbing method using a gravure roll, and an extrusion coating method.

Wire bar coating method, roll coating method, etc. can be adopted.

The ink layer contains a monochromatic heat-diffusible dye on the entire surface or a part of the surface of the conductive layer or support depending on the logging state of the ink sheet for thermal transfer recording. Alternatively, it may be formed as a yellow ink layer containing a binder and a yellow dye, a magenta ink layer containing a binder and a magenta dye, a cyan ink layer containing a binder and a cyan dye, or a flat ink layer containing a binder and a cyan dye. They may be formed on the entire surface or a part of the surface of the support body in a constant repeating manner along the direction.

Further, in addition to the three ink layers arranged along the plane direction, a black ink layer containing a black image forming substance may be interposed.

Note that with regard to the black ink layer, clear images can be obtained with either the diffusion transfer type or the melt transfer type.

In addition, by forming perforations on the ink sheet for thermal transfer recording, or providing detection marks for detecting the position t of areas with different hues,
It also makes it easier to use.

(3.) Image-receiving sheet for thermal transfer recording An image-receiving sheet for thermal transfer recording is usually composed of a base material and an image-receiving layer laminated thereon.

Further, when the image-receiving layer has self-supporting properties, the image-receiving layer itself can be used as an image-receiving sheet for thermal transfer recording.

One image-receiving layer One image-receiving layer can be formed by using a binder for the image-receiving layer and various machining processes.

In some cases, the image-receiving layer may be formed using only the image-receiving layer binder.

1. Binters for image-receiving layers Binters for image-receiving layers include, for example, polyvinyl chloride resins, copolymer resins of vinyl chloride and other polymers (such as alkyl vinyl ethers, vinyl acetate, etc.), polyester resins, and acrylic esters. , polyhinylpyrrolitone, polycarbonate, cellulose triacetate, styrene acrylate resin, vinyltoluene acrylate resin, polyurethane resin, polyamide resin, urea resin, polycaprolactone resin, styrene-maleic anhydride resin, polyacrylonitrile resin, etc. I'll come.

The above various resins may be newly synthesized and used, or commercially available products may be used.

In any case, from the viewpoint of physical properties, as a binder for one image-receiving layer, the glass transition point (Tg) is -20 to 15
Resins having a temperature in the range of 0°C, particularly resins in the range of 30 to 120°C are preferable, and from the viewpoint of molecular weight, resins having an Mw in the range of 2,000 to 100,000 are preferable.

In addition, when forming the image-receiving layer, the various resins mentioned above utilize their reactive active sites (if there are no reactive active sites, give them to the resin), and crosslink with radiation, heat, moisture, catalysts, etc. Alternatively, it may be hardened.

In that case, a radiation active monomer such as epoxy or acrylic or a crosslinking agent such as incyanate may be used.

2. Additives The image-receiving layer contains release agents, light stabilizers, fillers (inorganic fine particles,
Organic resin particles) and pigments may also be added. Furthermore, a plasticizer, a hot solvent, etc. may be added as a sensitizer.

The release agent can improve the releasability between the ink sheet for thermal transfer recording and the image receiving sheet for thermal transfer recording.

Such release agents include silicone oil (including what is called silicone resin); solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphoric acid ester-based surfactants, etc. Of these, silicone oil is preferred.

There are two types of silicone oil: a type that simply adds (simple addition type) and a type that cures or reacts (hardening reaction type).

In the case of a simple addition type, it is preferable to use modified silicone oil to improve compatibility with the binder.

As modified silicone oil, polyester modified silicone resin (or silicone modified polyester resin)
, acrylic-modified silicone resin (or silicone-modified acrylic resin), urethane-modified silicone resin (or silicone-modified urethane resin), cellulose-modified silicone resin (or silicone-modified cellulose resin), alkyd-modified silicone resin (or silicone-modified alkyd) resin), epoxy-modified silicone resin (or silicone-modified epoxy resin), etc.

Specifically, polyester-modified silicone resin containing polysiloxane resin in the main chain and copolymerized with polyester in block form, silicone-modified polyester resin having dimethylpolysiloxane moiety as a side chain bonded to the polyester main chain, and dimethylpolyester resin. Block copolymers, alternating copolymers, kraft copolymers, random copolymers, etc. of siloxane and polyester can also be used as modified silicone oils or resins.

In particular, in the present invention, it is preferable to add a polyester-modified silicone resin.

Typical polyester-modified silicone resins include, for example, a copolymer of a diol and a dibasic acid, or a floc copolymer of a polyester, which is a ring-opening polymer of caprolactone, and dimethylpolysiloxane (both ends or one end of dimethylpolysiloxane). Terminals are blocked by the above polyester moieties (or conversely, the above polyesters contain copolymers blocked by dimethylpolysiloxane), or the above polyesters are used as the main chain and (dimethyl)polysiloxane is bonded to the side chains. At least one copolymer can be mentioned.

The amount of these simple addition type silicone oils may vary depending on the type of silicone oil, so it is not possible to uniformly determine the amount. The amount is 0.5 to 50% by weight, preferably 1 to 20% by weight.

As curing reaction type silicone oil, 1 reaction curing type,
Examples include photocuring type and catalyst curing type.

Examples of reaction-curing silicone oils include those obtained by reaction-curing amino-modified silicone oil and epoxy-modified silicone oil.

In addition, as catalyst curing type or photo curing type silicone oil, KS-705F-PS, KS-705F-PS-
1, KS-770-PL-3 [all catalyst curing silicone oils manufactured by Shin-Etsu Chemical Co., Ltd.], KS-72
0, KS-774-PL-3 [all photocurable silicone oils, manufactured by Shin-Etsu Chemical Co., Ltd.], and the like.

The amount of these curable silicone oils added is preferably 0.5 to 30% by weight of the binder for the image-receiving layer.

Note that a release agent layer can also be provided by dissolving or dispersing the above-mentioned release agent in a suitable solvent and applying the solution to a part of the surface of the image-receiving layer, followed by drying.

Next, as the antioxidant, JP-A-59-18278
No. 5, No. 60-1307: IS No. 1-1273
The antioxidants described in No. 87 and the like and compounds known to improve image durability in photographs and other image recording materials may be mentioned.

As the Uv absorber and light stabilizer, JP-A-59-
No. 158287, No. 63-74685, No. 63-14
No. 5089, No. 59-196292, No. 62-229
No. 594, No. 63-122596, No. 61-28?59
Compounds described in No. 5, JP-A-1-204788, etc.
and compounds known to improve image durability in photographs and other image recording materials.

Examples of the filler include inorganic fine particles and organic resin particles.

These inorganic fine particles include silica gel, charcoal calcium,
Examples include titanium oxide, acid clay, activated clay, alumina, etc., and examples of the plated fine particles include resin particles such as fluoride shelving particles, quanamine resin particles, acrylic resin particles, and silicone resin particles.

These inorganic/organic resin particles vary depending on the specific gravity or 0
．． Preferably, it is added in an amount of 1 to 70% by weight.

Typical examples of the pigment include titanium white, calcium carbonate, zinc oxide, barium sulfate, silica, talc, clay, and kaolin 1 activated clay.

Examples include acid clay.

Examples of the plasticizer include phthalate esters (e.g. dimethyl phthalate, dibutyl phthalate, dioctyl phthalate,
didecyl phthalate, etc.), trimellitic acid esters (
For example, trimellitic acid octyl ester, trimellitic acid isononyl ester, trimellitic acid isodesol ester, etc.), pyromellitic acid esters such as octylnisder pyromellitate, adipate esters (dioctyl adipate, methyl adipate, etc.) lauryl, adipine-produced 2-ethylhexyl, ethyl lauryl adipate, etc.), other oleic acid esters, succinic acid esters, maleic acid esters, cehatic acid esters, citric acid esters, epoxidized soybean oil, epoxidized flaxseed oil, epoxy stearic acid epoxy, orthophosphoric esters such as triphenyl phosphate and tricresyl phosphate, triphenyl phosphite, tris.
tridecyl phosphite, dibutyl pytrodiene,
Examples include phosphite esters such as phosphite, and glycol esters such as ethyl phthalyl ethyl cricolate and butylphthalyl phthyl cricolate.

In the present invention, the amount of the catfish machining as a whole is usually in the range of 0.1 to 50% by weight based on the binder for the image-receiving layer.

Examples of base materials include paper, coated paper, synthetic paper (polypropylene, polystyrene, or a composite material made of paper or plastic film), white polyethylene terephthalate base film, transparent polyethylene terephthalate base film. , white vinyl chloride hese film, transparent vinyl chloride hese film, polyolefin coated paper and the like.

The thickness of the base material is usually 20 to 300 μm, preferably 30 μm.
~200 pots m.

-Other layers- An overcoat layer may be laminated on the surface of the image-receiving layer for the purpose of preventing fusion between the ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording, and improving image storage stability. good.

This overcoat layer can be formed by gravure coating, wire bar coating, roll coating or other known coating methods, or by lamination. The thickness of this layer is typically 0.05 to 3 #Lm.

(4.) Manufacture of image-receiving sheet for thermal transfer recording The image-receiving sheet for thermal transfer recording is prepared by dispersing or dissolving the components for forming the image-receiving layer in a solvent to prepare a coating liquid for the image-receiving layer, and applying the coating solution for the image-receiving layer. It can be formed by a coating method in which a liquid is applied to the surface of a substrate and dried, or a lamination method in which a mixture containing the components for forming the image-receiving layer is melt-extruded and laminated on the surface of the substrate.

Examples of the solvent used in the above coating method include tetrahydrofuran, methyl ethyl ketone, toluene, -1r silene, chloroform, dioxane, acetone, cyclohexane, n-phthyl acetate, and the like.

The image receiving layer may be formed over the entire surface of the base material, or may be formed on a part of the surface.

(5,) Image formation (thermal transfer recording) In order to form an image on an image receptor, the ink sheet for thermal transfer recording of the present invention and the image receiving sheet for thermal transfer recording are combined into an ink layer of the former and an image receiving layer of the latter. Lay them on top of each other so that they are in contact and heat them.

When heated in this manner, the heat-diffusible dye in the ink layer is vaporized or sublimated in an amount corresponding to the applied thermal energy, transferred to the image-receiving layer side, and received, thereby forming an image on the image-receiving layer.

In the present invention, it is important to preheat the conductive layer by applying electricity to it before or during the heating.

By heating after preheating or while preheating in this manner, it becomes possible to perform high-speed printing with low energy on the image-receiving sheet for thermal transfer recording, compared to the case where preheating is not performed.

The heat source for heating can be a thermal head or a general one, as well as laser light, infrared flash,
You can use a known device such as a heat vent.

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

When using laser light as a heat source for providing thermal energy, the amount of heat energy provided can be varied by changing the amount of laser light and the irradiation area.

In this case, in order to facilitate the absorption of laser light, a laser light absorbing material (for example, in the case of a semiconductor laser, carbon fluff or an infrared absorbing material) may be present in the ink layer or near the ink layer.

When using a laser beam, it is preferable to bring the ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording into close contact with each other.

If a tod generator with a built-in acousto-optic element is used, thermal energy can be applied depending on the size of the halftone dot.

When using an infrared flash lamp as a heat source that provides thermal energy, as with laser light,
Heating is preferably performed through a colored layer such as black.

Alternatively, heating may be performed through a pattern or halftone dot pattern that continuously expresses the shading of an image, such as black, or a colored layer such as black on the side and a negative pattern corresponding to the negative of the above pattern. Heating may be performed in combination.

Thermal energy can be applied from the ink sheet side for thermal transfer recording, from the image receiving sheet side for thermal transfer recording, or from both sides, if priority is given to effective use of thermal energy. It is preferable to perform this from the ink sheet side for thermal transfer recording.

Is it possible to record a one-color image on the image-receiving layer of an image-receiving sheet for thermal transfer recording by the above thermal transfer recording?According to the method below, it is possible to obtain a color photo-like color image consisting of a combination of layers of each color. I can bring it.

For example, sequentially replace the yellow, magenta, cyan, and, if necessary, black heat-sensitive transfer recording sheets.
By performing thermal transfer according to each color, it is possible to obtain a color photographic-like color image consisting of a combination of each color.

The following method is also effective.

That is, instead of using ink sheets for thermal transfer recording of each color as described above, an ink sheet for thermal transfer recording that has areas formed by painting each color in advance is used.

First, the yellow area is used to thermally transfer a yellow color separation image, then the magenta area is used to thermally transfer a magenta color separation image, and the process is repeated sequentially to create yellow, magenta, cyan, and as needed. A method is adopted in which the image is thermally transferred in order with the black separated color image.

Is it possible to obtain a color photographic-like color image with this method?Moreover, this method has the advantage that there is no need to replace the heat-sensitive sheet for heat-sensitive transfer recording as described above. .

[Example〕 Next, the present invention will be explained in more detail based on Examples.

Note that in the following, "parts" represent "parts by weight."

(Example 1) Production of an ink sheet for thermal transfer recording Formation of conductive layer First, a coating liquid for forming a conductive layer having the following composition was prepared.

Coating liquid for forming conductive layers.

Polyester resin: 2 parts [manufactured by Toyobo Co., Ltd., Vylon 290 conductive material]: 1 part [aluminum average particle l O, 08 g ■] Methyl ethyl ketone... 10 parts toluene...
・・・・・・・・・ 10 parts cyclohexanone・・・・・・
... 2 parts Next, the above coating solution for forming a conductive layer was applied onto a polyethylene terephthalate film (support) having a thickness of 6 gm and dried to form a conductive layer having a thickness of 0.3 gm.

2. Formation of ink layer A coating solution for forming an ink layer having the following composition was prepared.

Coating liquid for forming an ink layer.

Heat-diffusible dye - 4 parts [Nippon Kayaku Co., Ltd., Kayaset True 714] Bosovinyl phthyral 5 parts [Polymerization degree: 170G
, a Manufactured by Mizu Kagaku Kogyo Co., Ltd.

BX-1] Methyl ethyl ketone 90 parts Cyclohexanone 5 parts Next, apply the above coating liquid for forming an ink layer on the conductive layer. was applied and dried to form an ink layer with a thickness of 1.0 μm.

1. Manufacture of image-receiving sheet for thermal transfer recording - The following coating solution for forming an image-receiving layer was mixed to prepare a paint for the image-receiving layer.

Coating liquid for forming image-receiving layer: Vinyl chloride-isobutyl ether copolymer...
・・・・・・・・・・・・9 parts [manufactured by BASF, Raloflex MP25 copolyester modified silicone resin 1 part [manufactured by Shin-Etsu Silicone Co., Ltd., X-24]
-8:l [lO] Methyl ethyl ketone...
...40 parts cyclohexanone...
・10 copies Next, on a synthetic paper with a thickness of 150 gm [Yupo FPG-150, manufactured by Tamago Yuka Synthetic Paper Co., Ltd.] as a base material,
The above coating liquid for forming an image receiving layer is applied and dried to a final thickness of 5 m.
An image-receiving layer was formed.

First, the ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording are overlapped so that the ink layer surface of the former is in contact with the surface of the latter image-receiving layer, and the ink of the ink sheet for thermal transfer recording is On the conductive layer without coating,
A current-carrying electrode was applied, and a current was applied with a DC voltage of 30 V and a pulse width of 150 g sec to perform preheating.

Next, using a thermal head from the support side of the ink sheet for thermal transfer recording, an output of 0.2 W/t, a pulse width of 0.3 to 10 m5ec, and a dot density of 6 tots/mm are applied.
An image was formed by heating under the following conditions.

(Example 2) Example 1 except that the composition of the conductive layer was changed to the following formulation.
I did the same thing.

Coating liquid for forming conductive layer: Vinyl chloride resin 2 parts [manufactured by Nippon Zeon Co., Ltd., MR-120] Conductive substance...
...... Part 1 [5n02 (5b205 to 0.
2 mol% toped): Average particle size 0.08 #L*
] Methyl ethyl ketone 10 parts Toluene 10 parts Cyclohexanone 2 parts (Example 3) Image formation When printing, the semiconductor laser LT9 is used instead of the thermal head from the support side of the ink sheet for thermal transfer recording.
0MD/MF (wavelength 830nm, maximum optical output 10
0■W, manufactured by Sharp Corporation) is focused to approximately 8
The same procedure as in Example 1 was conducted except that a beam with a diameter of 0 was created and an image was formed at a recording speed of 100 Hz.

In Examples 1 to 3, the images formed on the image-receiving layer were clear, and high-speed printing was possible with low energy for image formation.

(Comparative Example 1) The same procedure as in Example 1 was carried out except that the process of preheating by energization was not performed.

(Comparative Example 2) The same procedure as in Example 3 was conducted except that the process of preheating by energization was not performed.

In Comparative Examples 1 and 2, it was not possible to perform low energy, high speed printing in one image formation, and the transfer filtration rate was not sufficient, and a clear image could not be obtained.

[Effects of the Invention] According to the ink sheet for thermal transfer recording and the thermal transfer recording method of the present invention, by applying electricity to the conductive layer to perform preheating,
It is possible to perform high-speed printing with low energy on an image-receiving sheet for thermal transfer recording.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of the ink sheet for thermal transfer recording of the present invention. FIGS. 2(a) and 2(b) are explanatory views showing the formation form of the conductive layer of the ink sheet for thermal transfer recording of the present invention. No.? and FIGS. 4(a) and 4(b) are explanatory diagrams showing how to conduct electricity to the conductive layer of the ink sheet for thermal transfer recording. DESCRIPTION OF SYMBOLS 1... Support body, 2... Conductive layer, 3... Ink layer,
4... Winding-up roll for current-carrying electrode, 5... Unwinding roll for current-carrying electrode, 6... Current-carrying electrode roll (or brush). Figure 1 Figure 2 (a) (b) Figure 3? ;4 Figures (a) (b)

Claims (2)

[Claims] (1) An ink sheet for thermal transfer recording, characterized in that it is formed by laminating a conductive layer and an ink layer containing a heat-diffusible dye on a support. (2) During or after energizing the conductive layer of the ink sheet for thermal transfer recording according to claim 1, the ink sheet for thermal transfer recording and the image receiving sheet for thermal transfer recording are overlapped and heated to record the thermal transfer recording. A thermal transfer recording method characterized by forming an image on an image-receiving sheet.