JPH0422682A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer recording medium having a wide printing condition at the time of thermal transfer by providing a heat-softenable colorant layer containing a colorant, a hot melt substance and a supercooling substance and generating phase separation by the supercooling substance becoming a dispersion medium or dispersoid on a support. CONSTITUTION:A heat-softenable colorant layer contains a colorant, a hot melt substance and a supercooling substance as essential components and generates phase separation. The supercooling substance is characterised by that the temp. difference between the m.p. and solidifying point thereof is 10 deg.C or more, pref., 10-100 deg.C and the m.p. thereof is usually 40-150 deg.C, pref., 50-130 deg.C. When the m.p. is within this range, no background staining is generated at the time of the formation of a printing image and sufficient printing sensitivity is obtained. By providing this supercooling substance in the heat-softenable colorant layer as a dispersion medium or dispersoid, the flocculating force of the heat-softenable colorant layer at the time of relese can be kept constant and, as a result, this thermal transfer recording medium can be subjected to printing under a wide printing condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermal transfer recording medium, and more particularly to a thermal transfer recording medium that can form high-quality images such as prints under a wide range of printing conditions.

[Prior art and inventions or problems to be solved] Conventionally,
As a device that forms images using thermal transfer recording media,
There are printers for word processors, printers for barcode readers, printers for facsimile machines, etc.

Since these printers differ in their machine characteristics and specifications, the time from when the heat-softening coloring material layer is heated to when it is peeled off (peeling timing) in the thermal transfer recording medium used in each printer is different. or are different from each other.

For example, the peeling timing for thermal transfer recording media for word processors ranges from a few millimeters to several tens of millimeters, and the peeling timing for thermal transfer recording media used in barcode reader printers is around 100 millimeters, and is used for facsimile machines. The peeling timing of thermal transfer recording media ranges from 100 milliseconds to several seconds.

In this way, the composition and properties of the heat-softening coloring material layer in the thermal transfer recording medium are appropriately set depending on the properties of the printer.

However, the fact that the composition, etc. of the heat-softening coloring material layer in a thermal transfer recording medium is appropriately adjusted in accordance with the characteristics of the printer poses a new problem.

In other words, it is essential to convert a thermal transfer recording medium adjusted for word processing into a thermal transfer recording medium for facsimile.1. Furthermore, when focusing on word processors, each manufacturer has their own thermal transfer recording media that are compatible with word processor printers, and it is not possible to transfer a thermal transfer recording medium for one manufacturer's word processor to another manufacturer's word processor.

This situation is extremely inconvenient because a thermal transfer recording medium must be prepared for each manufacturer's product or for each type of printer. This new problem is caused by the narrow printing conditions of each thermal transfer recording medium.

On the other hand, in recent years, thermal transfer recording media have progressed from the ability to perform printing only - times to the ability to perform printing multiple times. Various types of heat-softening coloring material layers for thermal transfer recording media that can be printed multiple times have been proposed, such as a porous type, a sponge type, and a cohesive failure type. Among these,
A thermal transfer recording medium having a cohesive failure type heat-softening coloring material,
It is considered promising because of its high printing quality.

However, even with this cohesive failure type thermal transfer recording medium that can be printed many times, the printing conditions are limited to 1.
For example, a heat-softening coloring material layer in a thermal transfer recording medium for word processing cannot be used as a heat-softening coloring material layer in a thermal transfer recording medium for facsimile. Furthermore, even without considering the conversion of thermal transfer recording media from word processors to facsimiles, or vice versa, cohesive failure type thermal transfer recording media have their own printing conditions and are limited by the printing environment. It is easily affected by temperature and printing speed, and it is not always possible to form a high quality printed image.

The present invention has been made based on these circumstances.

That is, an object of the present invention is to provide a thermal transfer recording medium with a wide range of printing conditions during thermal transfer.

Another object of the present invention is to provide a thermal transfer recording medium that can be printed many times under a wide range of printing conditions during thermal transfer.

[Means for Solving Problem W1] The present invention for solving the above problem includes a coloring material, a heat-fusible substance, and a supercooling substance, and the supercooling substance is combined with a dispersion medium or a dispersoid. The present invention is a thermal transfer recording medium characterized by comprising a heat-softening coloring material layer that is phase-separated and provided on a support.

The thermal transfer recording medium of the present invention has a heat-softening coloring material layer on a support.

What is important in the present invention is that this heat-softening coloring material layer contains at least a coloring material, a heat-melting substance, and a supercooling substance as essential components; The thermosoftening coloring material layer undergoes phase separation and becomes either a supercooling substance, a dispersion medium, or a dispersoid.

The supercooling substance referred to in the present invention is defined as the temperature difference between the melting point and the freezing point (the absorption and exothermic behavior of the substance based on the temperature increase rate S and temperature decrease rate of 10°C/min in a differential scanning calorimeter [DSC]). It is characterized by a temperature difference between an endothermic peak and an exothermic peak observed when measuring 10°C or more, preferably 10 to 100°C. The melting point of the supercooling substance in the present invention is usually 40 to 150°C, preferably 50 to 130°C. When the melting point of supercooling property is within the above range, sufficient printing sensitivity can be obtained without causing scumming during printing image formation. The existence of such a supercooling substance as a dispersoid or dispersion medium in the heat-softening coloring material layer causes changes in the peeling time of the heat-softening coloring material layer in the thermal transfer recording medium and the printing environment temperature. Even if this occurs, it becomes possible to maintain a constant cohesive force of the heat-softening coloring material layer before peeling. As a result, this thermal transfer recording medium can be used for printing under a wide range of printing conditions, and can be applied to word processors and facsimiles, for example. Furthermore, even when printing is performed multiple times, it is possible to always print with high print quality.

As the supercooling substance existing as a dispersoid or a dispersion medium, various substances can be exemplified as long as they satisfy the above conditions or do not impede the object of the present invention. Specifically, preferred supercooling substances in the present invention include benzotriazole, pencil, tribenzylamine, vanillin, polyethylene glycol (molecular weight: 6,00
0), polyethylene monostearate (molecular weight of the polyethylene glycol portion; 6,000), ε-polycaprolactone (molecular weight; I, 000), (-polycaprolactone (molecular weight, 10,000), etc.).

In addition to these, hindered phenols, phthalate esters, low molecular weight polyesters, etc. may be mentioned.

The content of this supercooling substance in the heat-softening coloring material layer is usually 5 to 90% by weight, particularly 10 to 60% by weight. When the content of the supercooling substance is within the above range, expansion of the 2nd printing condition is achieved, and when it is less than 5% by weight, the cohesive force of the heat-softening coloring material layer upon peeling is sufficiently reduced. There are times when it is difficult to achieve good repeat printing. Moreover, if it exceeds 90 weight, it is not preferable because background smearing occurs and blocking tends to occur when the thermal transfer recording medium is wound up after printing.

In the present invention, the supercooling substance exists in a phase-separated state as a dispersoid or a dispersion medium in the heat-softening coloring material layer.

In the present invention, when a supercooling substance is present as a dispersion medium, the dispersoid in the heat-softening coloring material layer is a heat-melting substance.

According to research conducted by the present inventors, it has been found whether or not it is possible to print multiple times even with thermal transfer recording media that have a heat-softening coloring material layer made of a mixture of a supercooling substance and a coloring material. There are problems with the occurrence of blocking and poor fixation of printed images. In order to form a thermal transfer recording medium free from such problems, it is important to use a supercooling substance and a heat-melting substance in combination.

Here, in the present invention, the melting point of the heat-melting substance is in the range of 40 to 150°C, preferably 50 to 120°C, and more preferably the temperature difference between the melting point and the solidification temperature is in the range of 40 to 150°C. Compounds that have a temperature of 10°C or less can be mentioned, and more specifically, carnauba wax, wood wax,
Plant waxes such as auriculia wax and nispar wax,
! Animal waxes such as I wax, insect wax, shellac wax and spermaceti wax; Petroleum waxes such as paraffin wax, microcrystal wax, polyethylene wax, ester wax and acid wax; and waxes such as mineral waxes such as montan wax, osichelite and ceresin. In addition to these waxes, higher fatty acids such as palmitic acid, stearic acid, margaric acid, and behenic acid, valmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol, and eicosanol higher alcohols such as cetyl palmitate, myricyl palmitate, cetyl stearate and myricyl stearate, higher fatty acid esters such as cetyl palmitate, myricyl stearate, amides such as acetamide, propionic acid amide, palmitic acid amide, stearic acid amide and amide wax, and stearylamine. , higher amines such as behenylamine and palmitylamine.

The content of this heat-melting substance in the heat-softening coloring material layer is usually 0 to 80% by weight, preferably 20 to 70% by weight. When the content of the heat-fusible substance is within the above range, blocking does not occur, the fixing property is good, and printing can be performed many times. If the content of the heat-fusible substance is less than the above range, scumming occurs during printing, and blocking of the take-up roll is likely to occur, whereas if the content exceeds the above range, sufficient repeated printing is not possible. This is not desirable because it means that you will not be able to have sex.

When this heat-melting substance exists as a dispersoid, it often exists as flat particles in the longitudinal section of the heat-softening coloring material layer, and in such cases, the average major axis of the child particles is usually 1 to 100 μm. It is preferably 5 to 5071 m. If the average major axis is within the above range, when using a thermal transfer recording medium having a heat-softening coloring material layer containing a heat-melting substance having such an average major axis, dot reproducibility will be good, etc. A print quality print image is formed.

Here, when the dispersion medium is a supercooling substance, it becomes a heat-fusible substance or a dispersoid.

The average major axis of the supercooled substance which becomes one dispersoid when the heat-melting substance is used as a dispersion medium is usually 1 to 100 gm, particularly 5 to 50 Bm.

In short, in the present invention, it is desirable that the particle size of the 5-dispersoid particles is adjusted so that it does not become larger than the size of the heating element. The object of the present invention can be well achieved when the polymer is a dispersoid or a dispersoid.

In the present invention, both the dispersoid and the dispersion medium contain a coloring material.

Examples of the coloring material include pigments such as inorganic pigments and organic pigments, and dyes.

Examples of the inorganic pigment include titanium dioxide, carbon black, zinc oxide, Prussian flu, cadmium sulfide, iron oxide, lead, zinc, barium, and calcium chromate.

Examples of the organic pigments include azo, thioindigo, anthraquinone, anthanthrone, and triphenedioxazine pigments, vat dye pigments, phthalocyanine pigments, such as copper phthalocyanine and its derivatives, and quinacridone pigments.

Examples of the organic dye include acid dyes, direct dyes, disperse dyes, oil-soluble dyes, and metal-containing oil-soluble dyes.

The content of the coloring material in the heat-softening coloring material is usually 5 to 5.
The amount is 30% by weight, preferably 10 to 25% by weight.

In the present invention, in particular, if a supercooling substance becomes a molecule and a heat-fusible substance or a dispersoid, or a supercooling substance becomes a dispersoid and a heat-fusible substance becomes a dispersion medium. With this, the separation force of 14 mm during printing can be reduced, and the unevenness of the fractured surface of the heat-softening coloring material layer due to printing is also small, making it possible to form a printed image with good printing quality.

In order to realize a stable phase separation state in which a supercooling substance is used as a dispersion medium and a heat-fusible substance is used as a dispersoid, a phase separation stabilizer may be included in the heat-softening coloring material layer.

There are various types of phase separation stabilizers depending on the type and amount of the dispersion medium and the substance forming the dispersoid, so it is difficult to say with certainty which one is preferable. Mention may be made of silicone (silicone wax) or oily silicone (silicone oil).

Examples of the silicone include dimethylsiloxane,
Alternatively, examples may include other and physical modified forms of these silicones. This organic modified version of silicone has 1
Examples include alcohol-modified products, fluorine-modified products, amino-modified products, Ebogishi-modified products, and higher fatty acid-modified products.

In addition, as a phase separation stabilizer, cyoctylphthale-1-(
DOP), dibutyl phthalate (DBP), fluorosurfactants, liquid paraffin, etc. can also be used.

The content of such a phase separation stabilizer in the heat-softening coloring material layer cannot be determined unconditionally depending on the type and content of the supercooling substance or heat-melting substance, or it is usually 0. ,01-10% by weight, preferably 0.1-5% by weight
It is.

As explained above, the heat-softening color material layer in the present invention is preferably composed of the supercooling substance, the heat-melting substance, and the coloring material, preferably the supercooling substance and the heat-melting substance. It may be formed from a synthetic substance, a coloring material, and a phase separation stabilizer, or it may contain a thermoplastic resin within the scope of the purpose of the present invention.

This thermoplastic resin can improve the adhesion of the thermosoftening coloring material layer to the support, the electrodepositivity of images, and the like.

Thermoplastic resins with such functions or actions include ethylene copolymers, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, acrylic resins, vinyl chloride resins, cellulose resins, and rosin. resins such as ionomer resins and petroleum-based resins, elastomers such as natural rubber, styrene ttadiene rubber, inbrene rubber, chloroprene rubber and diene cobosomer, 2-ester gum, rosin maleic acid resin, rosin phenol shelf and water Examples include rosin derivatives such as added rosin; and polymer compounds having a softening point of 50 to +50°C such as phenol resins, terpene resins, cyclopentadiene resins, and aromatic hydrocarbon resins.

The content of the thermoplastic resin in the thermosoftening coloring material layer is 6
It is usually 0 to 20% by weight, preferably 1 to 15% by weight.

Furthermore, in the present invention, powder or fine particles of a metal with good thermal conductivity such as aluminum, copper, zinc, etc. may be added as a thermally conductive substance in the heat-softening coloring material layer to the extent that the object of the present invention is not impaired. May contain. Such a thermally conductive material promotes a heat conduction effect that causes the colorant layer to melt or soften due to heat. Also castor oil and linseed oil as plasticizers.

It may also contain vegetable oils such as Olly 7 oil, animal oils such as shark oil, mineral oils, and the like.

The thickness of the heat-softening coloring material layer is usually 5 to 50 μm, preferably 7 to 20 gm.

-Support- The support may be any known support, preferably one with high dimensional stability and mechanical strength. Specifically, paper such as plain paper, condenser paper, laminated paper, and coated paper, resins such as polyethylene, polypropylene, polystyrene, polyester (for example, polyethylene terephthalate (hereinafter referred to as PET), polyamide (for example, nylon), and polyimide) Examples include films, paper-resin film composites 3, and metal sheets such as aluminum foil, and PET is particularly preferred. The thickness of the support is usually about 60 uLm or less, especially 2
~204m is preferable.

Note that in the thermal transfer recording medium of the present invention, the structure on the back side of the support may be optional, and a backing layer such as a staking prevention layer may be provided, or a subbing layer may be formed on the surface of the support. It's okay.

-Manufacture of thermal transfer recording medium- As described above, the heat-softening coloring material layer contains a supercooling substance, a heat-melting substance, and a coloring material, and is in a phase-separated state with the supercooling substance as a dispersed phase or a dispersion medium. The heat-softening coloring material layer contained in the material can be formed as follows.

That is, a heat-fusible substance is dispersed in a solvent at a predetermined ratio,
Or dissolve.

Solvents used at this time include, for example, water, acetone, methyl ethyl ketone (MEK), methyl isophthyl ketone (MIBK), ketones such as cyclohexanone, alcohols such as methanol, ethanol, propatool, methyl acetate, acetic acid, etc. Ester systems such as ethyl, phtyl acetate, propyl acetate, ethyl lactate, and ethylene tallycol monoacetate; ether systems such as diethylene glycol dimethyl ether, 2-ethoxyethanol, tetrahydrofuran, and dioxane; aromatic hydrocarbons such as benzene, toluene, and xylene; methylene Halogenated hydrocarbons such as chlorite, ethylene chloride, carbon tetrachloride, chloroform, ethylene chlorohydrin, and dichlorobenzene can be used.

Next, a supercooling substance is added to the resulting mixture and the mixture is stirred and mixed again. At this time, a thermoplastic resin, a phase separation stabilizer, a plasticizer, a filler, etc. may be added as necessary.

Alternatively, a hot melting substance, a supercooling substance, and a phase separation stabilizer may be stirred and mixed, and if necessary, a thermoplastic resin, a phase separation stabilizer, a plasticizer, and a filler may be added at this time. Mix etc.

In this way, the coating solution for the heat-softening coloring material layer can be g*, and the heat-softening coloring material layer can be formed on the support by the method described below.

That is, a coating solution for a heat-softening coloring material layer is applied by a method such as an eight-roll coater method, an extrusion coater method, a gravure coater method, a slide hopper method, or a wire bar coating method, and then, by drying, heat is applied. It is possible to form a softening coloring material layer.

(Hereafter, margin) [Example] Next, the present invention will be explained in more detail with reference to Examples.

(Example 1) By mixing the following components at the following blending ratio,
A coating solution for a heat-softening coloring material layer was prepared.

<Coating liquid for heat-softening coloring material layer> Carbon black-containing solvent solution (3 parts by weight of carbon black in 70 parts by weight of methyl ethyl ketone)
10 parts by weight of paraffin wax-containing dispersion (a solvent solution of 20 parts by weight of paraffin wax dispersed in 80 parts by weight of vinyl acetate, the paraffin wax particle size is 2uLm) 25 parts by weight of a solvent solution containing ethylene-vinyl acetate copolymer (a solvent solution prepared by dissolving 5 parts by weight of the co-merged material in 95 parts by weight of methyl ethyl ketone) 25 parts by weight of a solution containing polyethylene glycol (Molecular weight: 6,000, solvent solution prepared by dissolving 30 parts by weight of polyethylene glycol in 70 parts by weight of methyl ethyl ketone) ...... 30 parts by weight of the obtained coating liquid for the heat-softening coloring material layer. A thermal transfer recording medium was prepared by coating a polyethylene terephthalate (PET) film with a thickness of 6 gm so that the film thickness after drying was 10 μm and drying.

This thermal transfer recording medium was printed using three types of printers (serial type thermal printer, barcode printer, and facsimile) with different peeling timings.

Note that the peeling timing was defined as the interval from when the heat-softening coloring material layer of the thermal transfer recording medium was heated to when the transferred heat-softening coloring material layer was peeled from the paper. Repeatability was evaluated by the number of prints with a reflection density of 1.0 or more. The print quality was evaluated as "good" if there was no trailing or fading, and "poor" if there were voids, fading, or unevenness.

The results are shown in Table 1.

In addition, the cross section of the heat-softening coloring material layer formed on the support using the coating solution for heat-softening coloring material layer prepared in the same manner as above except that no carbon black was used was observed using a llJ microscopic microscope. When observed, it was found that polyethylene glycol had become a dispersoid with an average major axis of 6 gm.

(Example 2) By mixing the following components at the following blending ratio,
A coating solution for a heat-softening coloring material layer was prepared.

Coating liquid for heat-softening color material layer> Carbon black-containing solvent solution (3 parts by weight of carbon black in 70 parts by weight of methyl ethyl ketone)
10 parts by weight of paraffin wax-containing dispersion (a solvent solution of 20 parts by weight of paraffin wax dissolved in 80 parts by weight of ethyl acetate, the paraffin wax particle size is 2 pots m) ...25 parts by weight of a solvent solution containing an ethylene-vinyl acetate copolymer (a solvent solution prepared by dissolving 5 parts by weight of the copolymer in 95 parts by weight of methyl ethyl ketone) ...・・25 parts by weight polyethylene glycol-containing solution (molecular weight: 6,000, solvent solution prepared by dissolving 10 parts by weight of polyethylene glycol in 90 parts by weight of methyl ethyl ketone) ・40 parts by weight 0.01 part by weight of ether-modified silicone oil was obtained A heat-softening coloring material layer coating solution was applied onto a polyethylene terephthalate (PET) film with a thickness of 6 gm to a dry film thickness of 10 μLm, and dried to prepare a thermal transfer recording medium.

Printing was performed on this thermal transfer recording medium in the same manner as in Example 1, and the state of the resulting prints was observed and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

In addition, the cross section of the heat-softening coloring material layer formed on the support using the coating solution for heat-softening coloring material layer prepared in the same manner as above except that no carbon black was used was observed under a microscope. As a result, it was found that the polyethylene glycol had become a dispersoid with an average major axis of 18 pm.

(Example 3) By mixing the following components in the following proportions, 2
A coating solution for a heat-softening coloring material layer was prepared.

<Coating liquid for heat-softening coloring material layer> Carbon black-containing solvent solution (3 parts by weight of carbon black in 70 parts by weight of methyl ethyl ketone)
・100 weight paraffin wax-containing dispersion (solvent solution prepared by dissolving 20 parts by weight of paraffin wax in 80 parts by weight of ethyl acetate, paraffin wax particle size is 2 ILm) 25 parts by weight Solvent solution containing ethylene-vinyl acetate copolymer (solvent solution prepared by dissolving 5 parts by weight of the copolymer in 95 parts by weight of methyl ethyl ketone) 25 parts by weight Poly ε-caprolactam Containing solution (molecular weight, i, ooo, poly ε-caprolactam 10
40 parts by weight of the obtained coating solution for the heat-softening coloring material layer was placed on a 6 gm thick polyethylene terephthalate (PET) film after drying. A thermal transfer recording medium was prepared by coating the film to a thickness of 10 μm and drying it.

Printing was performed on this thermal transfer recording medium in the same manner as in Example 1, and the state of the resulting prints was observed and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

In addition, the cross section of the heat-softening coloring material layer formed on the support using the coating solution for heat-softening coloring material layer prepared in the same manner as above except that no carbon black was used was observed under a microscope. As a result, it was found that polyε-caprolactam was a dispersoid with an average length of 10 gm.

(Example 4) Alcohol-denatured silicone oil was added to 0. A coating solution for a heat-softening coloring material layer obtained in the same manner as in Example 3 except that O1 weight was further added was applied onto a polyethylene terephthalate (PUT) film with a thickness of 6 gm, so that the film thickness after drying was A thermal transfer recording medium was prepared by applying the coating to a thickness of about 10 gm and drying it.

Printing was performed on this thermal transfer recording medium in the same manner as in Example 1, and the state of the resulting prints was observed and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

In addition, the cross section of the heat-softening coloring material layer formed on the support was observed using a microscope using the coating solution for heat-softening coloring material layer prepared in the same manner as above except that no carbon black was used. As a result, it was found that poly ε-caprolactam was in the form of a dispersoid with an average major axis of 30 μm.

(Example 5) By mixing the following components at the following blending ratio,
A coating solution for a heat-softening coloring material layer was prepared.

<Coating liquid for heat-softening coloring material layer> Carbon black-containing solvent solution (3 parts by weight of carbon black in 70 parts by weight of methyl ethyl ketone)
10 parts by weight of paraffin wax-containing dispersion (a solvent solution of 20 parts by weight of paraffin wax dissolved in 80 parts by weight of ethyl acetate, the paraffin wax particle size is 2 μm) ......25 parts by weight of a solvent solution containing an ethylene-vinyl acetate copolymer (a solvent solution prepared by dissolving 5 parts by weight of the copolymer in 95 parts by weight of methyl ethyl ketone)... 25 parts by weight solution containing polyethylene glycol monostearate (solvent solution prepared by dissolving 10 parts by weight of polyethylene glycol monostearate in 90 parts by weight of methyl ethyl ketone)...30 parts by weight benzotriazole (10 parts by weight of benzotriazole dissolved in 90 parts by weight of methyl ethyl ketone) 10
The heat-softening colorant layer coating solution obtained in parts by weight is applied onto a polyethylene terephthalate (PET) film with a thickness of 6 gm to a dry film thickness of 1101 L, and dried to form a thermal transfer recording. Created media.

Printing was performed on this thermal transfer recording medium in the same manner as in Example 1, and the state of the resulting prints was observed and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

In addition, the cross section of the heat-softening coloring material layer formed on the support was observed using a microscope using the coating solution for heat-softening coloring material layer prepared in the same manner as above except that no carbon black was used. As a result, it was found that polyethylene glycol monostearate had become a dispersoid with an average major axis of 15 gm.

(Comparative Example 1.2) The solid contents in Examples 3 and 4 were dispersed and mixed by hot melt, the mixture was dissolved in toluene at a solid concentration of 10i%, and the solid content was mixed on a support in the same manner as in Example 3. It was applied to.

Printing was performed on this thermal transfer recording medium in the same manner as in Example 1, and the state of the resulting prints was observed and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

In addition, the cross section of the heat-softening coloring material layer formed on support 1 using the coating solution for heat-softening coloring material layer prepared in the same manner as above except that no carbon black was used was observed under a microscope. As a result, polyε-caprolactam became a dispersoid, but no phase separation occurred.

(Comparative Example 3) By mixing the following components in the following proportions,
A coating solution for a heat-softening coloring material layer was prepared.

<Coating liquid for heat-softening coloring material layer> Carbon black-containing solvent solution (3 parts by weight of carbon black in 70 parts by weight of methyl ethyl ketone)
Solution containing 0 parts by weight of poly ε-caprolactam (molecular weight: 1,000, 10 parts by weight of poly ε-caprolactam)
80 parts by weight of the resulting coating solution for the heat-softening coloring layer was applied to a 64 m thick polyethylene terephthalate (PET) film. A thermal transfer recording medium was prepared by coating the film on the surface to a film thickness of 104 m after drying and drying.

Printing was performed on this thermal transfer recording medium in the same manner as in Example 1, and the state of the resulting prints was observed and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

(Comparative Example 4) By mixing the following components in the following proportions,
A coating solution for a heat-softening coloring material layer was prepared.

<Coating liquid for heat-softening coloring material layer> Carbon black-containing solvent solution (3 parts by weight of carbon black in 70 parts by weight of methyl ethyl ketone)
A dispersion containing 15 parts by weight of paraffin wax (a solvent solution prepared by dissolving 20 parts by weight of paraffin wax in 80 parts by weight of ethyl acetate, the paraffin wax particle size is 2m) - 57 parts by weight of ethylene-vinyl acetate copolymer-containing solvent solution (solvent solution obtained by dissolving 5 parts by weight of the copolymer in 95 parts by weight of methyl ethyl ketone) 28 parts by weight obtained The resulting heat-softening coloring material layer coating liquid was applied onto a polyethylene terephthalate (PET) film with a thickness of 6 gm to a dry film thickness of 10 grn, and dried to create a thermal transfer recording medium. did.

Printing was performed on this thermal transfer recording medium in the same manner as in Example 1, and the state of the resulting prints was observed and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

[Effect of the invention] The thermal transfer recording medium of the present invention has the following effects.

(1) Wide range of peeling timing for high quality printing.

Therefore, it can be used interchangeably with word processor printers, label printers, and facsimile printers.

(2) Can print multiple times with high print quality.

Claims (4)

[Claims] (1) A heat-softening coloring material layer containing a coloring material, a heat-melting substance, and a supercooling substance, and in which the supercooling substance serves as a dispersion medium or dispersoid and undergoes phase separation, is placed on a support. A thermal transfer recording medium comprising: (2) Claim 1, wherein the heat-softening coloring material layer contains silicone wax and/or silicone oil.
The thermal transfer recording medium described in . (3) The thermal transfer recording medium according to claim 1, wherein the heat-softening coloring material layer is one layer. (4) Claim 1, wherein the heat-softening coloring material layer is a plurality of layers.
The thermal transfer recording medium described in .