JPH01258986A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To form a high-density printing image, by a method wherein a thermal transfer recording medium is formed by successively laminating a heat-softening intermediate layer containing a polyester wax etc. and a heat-softening coloring material layer on a substrate. CONSTITUTION:On a substrate 1, a heat-softening intermediate layer 2 containing one or more compounds selected from among groups made of polyester wax, polyamide wax, and polyurethane wax and a heat-softening coloring material layer 3 are successively laminated to form a thermal transfer recording medium. As the substrate, a material, such as papers and resin films, is preferably used with a thickness of 2-6mum. The thickness of the heat-softening intermediate layer 2 is normally 0.3-5mum and preferably 0.5-3mum. A coloring material, a hot melt compound, and a heat-softening resin are incorporated in the heat- softening coloring material layer with a layer thickness of 0.5-8mum normally and 1.0-5.0mum preferably.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal transfer recording medium, and more specifically, the present invention relates to a thermal transfer recording medium, and more specifically, it is possible to obtain a printed image of high density that is easy to read and has a low gloss level on the surface. In addition, it has excellent film retention properties of the ink layer, and can achieve good printing quality even on so-called rough paper with a low surface smoothness, and is particularly reliable when used for facsimile. This invention relates to a thermal transfer recording medium that is ideal for applications that require high print quality without gloss.

[Prior art and problems to be solved by the invention] A thermal transfer recording medium is generally formed by laminating a heat-softening ink layer containing a softening substance and a colorant on a sheet-like support. It is something.

On the other hand, in recent years, facsimile machines have adopted a thermal transfer recording method, which has improved the storage stability of recorded images compared to the thermal coloring method used in conventional facsimiles, and has also made it possible to print on plain paper. Although some attempts have been made, since facsimile machines are unmanned, there is a need for a thermal transfer recording medium that is highly reliable and provides high print quality without gloss.

However, there is a problem in that printed images obtained from conventional thermal transfer recording media have a high surface gloss and are difficult to read.

Therefore, for example, a matte layer containing a resin and a matte pigment is provided on a base film, and a heat-melting coloring material layer is provided adjacent to this matte layer, thereby removing the gloss of the printed image. Recording media have been proposed (JP-A-60-10108:1, JP-A-61-842).
No. 87 Publication No. 5; see), this thermal transfer recording medium has a problem in that the print quality is degraded. In particular, when printing on plain paper with a low surface smoothness, the print quality deteriorates significantly.

Furthermore, in order to obtain clear printed images for facsimiles and the like, a heat-sensitive transfer recording medium in which the ink layer contains thermosetting polycaprolactone has been proposed (Japanese Unexamined Patent Application Publication No. 1983-1999-1).
(Refer to Japanese Patent No. 230795), even in this thermal transfer recording medium, when printing on paper that passes through the surface, the print quality deteriorates significantly.

In addition, in conventional thermal transfer recording media, the film retention of the ink layer is insufficient, and for example, if there is a slight problem in conveying the ribbon in a low temperature region around 0°C, so-called film peeling may occur. There are also problems. This problem causes a significant loss in reliability, especially when used in unattended applications such as facsimile machines.

However, in order to obtain a printed image with good print quality using the thermal transfer recording method, the ink layer on the thermal transfer recording medium must be accurately transferred to the transfer medium according to the heated portion by the thermal head.

That is, in a thermal transfer recording medium, it is necessary to accurately peel the ink layer from the support depending on the heated portion of the ink layer.

In order to meet this requirement, a technique has long been known in which a layer called a release layer is interposed between the support and the ink layer, and the layer is peeled off from the support together with the ink layer, with the aim of improving the 21fill properties of the ink layer. There is.

This 'A delamination is generally a layer containing a heat-melting compound such as wax as a main component, and further containing a heat-softening resin and a coloring material in some cases.

However, in conventional thermal transfer recording media, improving the releasability of the ink layer means deteriorating the film retention of the ink layer, and thermal transfer that satisfies these contradictory performance requirements The demand for recording media is high.

This invention has been made based on the above circumstances.

The purpose of this invention is to be able to obtain a high-density printed image with low surface gloss and easy to read, and to have excellent film retention of the ink layer, compared to so-called rough paper with low surface smoothness. It is possible to achieve good print quality even when using
In particular, it is an object of the present invention to provide a thermal transfer recording medium that is excellent in reliability even for facsimile use and is optimal for uses that require high print quality without gloss.

[Means for Solving the Problems] In order to solve the problems described above, the inventor has made extensive studies and found that a specific compound group is added between the support and the heat-softening coloring material layer. In a heat-sensitive transfer recording medium provided with a heat-softening intermediate layer containing at least one selected compound, it is possible to obtain a high-density printed image with low surface gloss and easy to read. It has excellent film retention properties of the softening coloring material layer, and can achieve good print quality even on so-called rough paper with a low surface smoothness, and is particularly reliable for facsimile use, with high gloss It was discovered that it can be suitably used in applications that require extremely high print quality.

This shot reached 11.

That is, the structure of the present invention has eight softening intermediate layers between the support and the heat-softening coloring material layer, and the heat-softening intermediate layer is made of a compound selected from Group A below.
This is a thermal transfer recording medium characterized by containing at least one type of compound.

[Group A] Polyester wax, polyamide wax, polyurethane wax.

The heat-sensitive transfer recording medium of the present invention has at least two heat-softening intermediate layers on a support l, as shown in FIG.
and a heat-softening coloring material layer 3 in M layers in this order.

-Support- It is desirable that the support in the thermal transfer recording medium of the present invention has good heat resistance strength and high dimensional stability.

The materials include, for example, paper such as FF paper, condenser paper, laminated paper, and coated paper; resin films such as polyethylene, polyethylene terephthalate, polystyrene, polypropylene, and polyimide; composites of paper and resin films; and aluminum. Any metal sheet such as foil is preferably used.

The thickness of the support is usually 30 Bm or less, preferably 2 to 30 Bm.
It is within the range of 6pm. If the thickness of the support exceeds 307 zm, thermal conductivity may deteriorate, leading to deterioration in printing quality.

In the thermal transfer recording medium of the present invention, the structure on the back side of the support may be arbitrary, and for example, a backing layer such as an anti-sticking layer may be provided.

One of the important points in this invention is that at least one of the compounds selected from Group A is added between the support and the heat-softening coloring material layer, which will be described in detail below. The object of the present invention is to provide a heat-softening intermediate layer containing one type of compound.

The heat-softening intermediate layer in this invention has stable cohesive failure in the vicinity of the interface between the heat-softening intermediate layer and the heat-softening coloring material layer when the heat-softening coloring material layer described in detail next peels off from the support side. It has an action or function of reducing the glossiness of the surface of the printed image by realizing peeling and forming fine irregularities on the peeled surface of the heat-softening coloring material layer, that is, the surface of the printed image, and also has a so-called film. It has the function of preventing peeling and increasing the film retention of the heat-softening coloring material layer and/or the heat-softening intermediate layer.

Such action or function of the heat-softening intermediate layer is mainly brought about by a compound selected from the above-mentioned group A (hereinafter referred to as a group A compound) contained in the heat-softening intermediate layer.

That is, the heat-softening intermediate layer is a layer containing at least one kind of the above-mentioned group A compounds.

By the way, as a result of studies conducted by this inventor, it has been found that when the heat-softening intermediate layer contains only an ordinary wax with low polarity conventionally used in heat-sensitive transfer recording media, the support and the heat-softening intermediate layer are Between the layers.

Alternatively, in some cases, interfacial peeling may occur between the heat-softening intermediate layer and the heat-melting color material layer, resulting in a printed image with high surface gloss, poor film retention, and poor bonding with the support. It was found that the film was prone to peeling between the film and the heat-softening intermediate layer.

On the other hand, is it possible to add a thermoplastic resin to the heat-softening intermediate layer in order to improve film retention?However, this may result in deterioration of print quality.

In this invention, by incorporating the Group A compound into the heat-softening intermediate layer, the adhesive force between the heat-softening intermediate layer and the support is improved while reducing the cohesive force of the heat-softening intermediate layer. I can do it.

The Group A compound is a compound containing three or more polar bonds in its molecule, and the presence of the polar bonds improves the adhesive strength between the support and the heat-softening intermediate layer, and also improves the heat-softening property. This is a compound that does not cause an increase in the cohesive force of the intermediate layer.

The polar bond is an ester bond (-C0NH-)
, amide bond (-CONH-), urethane bond (-NH
COO-).

According to the inventor's research, it has been found that the above-mentioned stable cohesive failure can be realized when a compound having three or more polar bonds in one molecule is contained in the thermosoftening intermediate layer.

For convenience, the Group A compounds in this invention are as follows:
We will classify them into species and explain them in more detail.

(a) Polyester wax (b) Amide wax (c) Polyurethane wax (a) Polyester wax In this invention, polyester wax is one containing three or more ester bonds (-Co-0-) in one molecule. and the weight average molecular weight (Mw) is 300 to 12f.
+00, melting point (m, p, ) or 30~'1
Refers to compounds within the range of 20°C.

The ester bond (-Co-0-) is contained in the main chain.

Such a compound can be obtained, for example, as a polycondensate of a polyhydric alcohol and a polybasic acid or a ring-opened polymer of a lactone compound.

Typical specific examples of polyester wax are shown below.

(1) Polycondensate of adipic acid and 1,4-butanediol (M w = 2000, -, p, 55°C), (2)
ε-caprolactone: ring-opening polymer of (M Fung, 4000, Peng, p, 55°C),
(3) Sebacic acid-decamethylene glycol copolymer (
M stomach = :1000. m, p, 74°C), (4
) Adipic acid-propylene glycol copolymer (M w
= 3000. m, p, 50°C).

(5) ω-hydroxydecanoic acid polymer Mw=4000, llp, 75°C), (6) δ-
Valerolactone polymer (My = 4000, s, p, 54°C), the polyester wax that can be used in this invention is a compound containing such polyester in the molecule in the form of a block or a graft. Furthermore, the terminal may be an alkyl group or an amide group, or may have one or more hydroxyl group, amino group, carboxyl group, or carbonyl group.

Furthermore, it may have a needle bond, an amide bond, or a urethane bond in its main chain or side chain.

Polyesters are not limited to those synthesized using dibasic acids, dihydric alcohols, polybasic acids, and polyhydric alcohols as shown in the examples above, but also those synthesized using other dibasic acids, dihydric alcohols, polybasic acids, and polyhydric alcohols. It may be synthesized using alcohol.

Polyester waxes are also available as commercial products. Specifically, the ``Plaxel'' [product name: manufactured by Daicel Chemical ■] series, the ``Elythil'' [product name;
Unitika III] series, etc.

(b) Amide wax In this invention, amide wax is one that contains three or more amide bonds (-Co-NH-) in one molecule, and has a weight average molecular weight (My) in the range of 00 to 1zooo. It refers to a compound whose melting point (m, p,) is within the range of 30 to 120°C.

The amide bond (-Co-NH-) is contained in the main chain.

Amide waxes are generally produced through polymerization reactions between dibasic acids and diamines, self-condensation reactions between ω-amino acids,
It can be obtained by a ring-opening polymerization reaction of a lactam compound.

In the amide wax, it is particularly preferable to N-alkylate the polyamide moiety to adjust (eg, lower) the melting point.

N-alkylation can be carried out by using a mixture of a diamine polymerized with a dibasic acid and an N-alkyl or N,N'-dialkyldiamine, or by using an ω-N- corresponding to an ω-amino acid.
This is achieved by using an alkyl amino acid.

Specific polymers include, for example, ω-N-methylaminoundecane ugly polymer (M=about 5000, m, p,
+i0°C), but some are also available as commercial products, such as the II T-W series manufactured by Sanso Kagaku Co., Ltd.

The polyamide wax that can be used in the present invention may be a compound containing such polyamide in the molecule in block form or graft form, or may have an alkyl group or an amide group at the end. good. Furthermore, the main chain or side chain may have a part of ether bond, amide bond, or urethane bond.

(C) Polyurethane wax In shellfish, polyurethane wax is one that contains three or more urethane bonds (-NH-CO-〇-) in one molecule, and the weight average molecule N: (Mw) is 30
It refers to a compound whose melting point (m, p, ) is within the range of 30 to 120''C.

The urethane bond (-NH-Co-0-) is contained in the main chain.

Polyurethane waxes can generally be synthesized, for example, by polyaddition reaction between diisocyanates and glycols (11), or by various other methods such as condensation reactions.

Specific polymers include, for example, hexamethylene diisocyanate and hexane-2,5-diol polycondensate (Mw=about 1200, m, p, 86°C).

Further, it may have a part of ether bond, amide bond, or urethane bond in the main chain or side chain.

Note that the polyester wax, polyamide wax, and polyurethane wax may be compounds containing a vinyl bond chain <C-C> in a partially block or graft form in the molecule.

In this invention, the heat-softening intermediate layer contains at least one type of the above-mentioned Group A compound.

The content of the Group A compound in the heat-softening intermediate layer is 3f.
The content is at least 5% by weight, preferably from 5 to 100% by weight, and more preferably from 10 to 50% by weight.

The heat-softening intermediate layer together with the Group A compound.

It is preferable to contain a heat-melting compound, and when the group A compound and the heat-melting compound are used together, compared to the case where the group A compound is used alone.

This is because the cohesive force can be further reduced and the melting point can be easily adjusted.

Examples of the heat-melting compound include carnauba wax,
Vegetable waxes such as wood wax, auriculie wax and Nispar wax; Animal waxes such as beeswax, insect wax, shellac wax and spermaceti wax; Petroleum waxes such as paraffin wax, microcrystalline wax, polyethylene wax, ester wax and acid wax; and Waxes such as mineral waxes such as montan wax, osikerite and ceresin can be mentioned, and in addition to these waxes, higher fatty acids such as valmitic acid, stearic acid, margaric acid and behenic acid; valmityl alcohol, stearyl Higher alcohols such as alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol and eicosanol; Higher fatty acid esters such as cetyl valmitate, myricyl valmitate, cetyl stearate and myricyl stearate: acetamide,
Amides such as propionic acid amide, balmitic acid amide, stearic acid amide and amide wax; and higher amines such as stearylamine, behenylamine and valmitylamine.

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

Among these, preferred is a wax whose melting point is within the range of 50 to 120°C as measured using a Yanagimoto MJP-2 model.

When the heat-melting compound is used, the content of the heat-melting compound in the heat-softening intermediate layer is usually 97.
It is not more than 50% by weight, preferably 50 to 97% by weight.

The heat-softening intermediate layer contains, in addition to the group A compound or the group A compound and the heat-melting compound, other components such as a heat-softening resin, a surfactant, a filler, and a coloring material. Also good.

In particular, it is preferable to include a coloring material in order to improve the confidentiality of the thermal transfer recording medium of the present invention.

The heat-softening resin mainly improves the film retention of the heat-softening intermediate layer and suppresses cohesive failure within the heat-softening intermediate layer. In other words, the print quality does not deteriorate to the same extent as in the case where the group A compound is not contained.

Examples of the thermosoftening resin include polyester resin, ethylene resin, polyolefin resin, acrylic resin, vinyl chloride resin, rosin resin, petroleum resin, ionomer resin, natural rubber, styrene-butadiene rubber, and isoprene. Examples include elastomers such as rubber and chloroprene rubber, ester gums, rosin iris conductors such as rosin maleic acid resins, rosin phenolic resins, and hydrogenated rosins, and phenolic resins, terpene resins, cyclopentadiene resins, and aromatic hydrocarbon resins. It will be done.

These may be used alone or in combination of two or more. In particular, thermoplastic resins, such as polyester polymers, which are preferentially or selectively compatible with the Group A compound, Polyamide polymers, polyurethane polymers, cellulose polymers, etc. may also be added.

Among thermoplastic resins, ethylene copolymers are preferred.

Examples of the ethylene copolymer include ethylene-vinyl acetate, ethylene-ethyl acrylate, ethylene-methyl methacrylate, ethylene-isobutyl acrylate,
Ethylene-acrylic acid.

Examples include ethylene-vinyl alcohol, ethylene-vinyl chloride, and ethylene-acrylic acid metal salts.

In this IJ, the softening point of the thermosetting resin that can be suitably used is usually within the range of 40 to 130°C.

When the thermosoftening resin is used, the content of the resin component in the thermosoftening intermediate layer is usually 30% by weight or less, preferably 20% by weight or less.

The IFi surface agent has the function of adjusting the releasability of the heat-softening coloring material layer.

As the surfactant, various kinds of surfactants conventionally used in thermal transfer recording media can be used, but polyoxyethylene compounds can be suitably used in this invention.

Examples of the polyoxyethylene compounds include polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkylphenyl ether, polyoxyethylene sterol ether, and polyoxyethylene polyoxypropylene block polymer.

Polyoxyethylene polyoxybrobylene block polymer, polyoxyethylene polyoxybrobylene alkyl ether, polyoxyethylene glycerin fatty acid ester, polyoxyethylene castor oil and hydrogenated castor oil,
Examples include polyoxyethylene sorbitan fatty acid ester and polyoxyethylene sorbitol fatty acid ester.

These are l! ! They may be used alone or in combination of two or more.

When the surfactant is used, the content of the surfactant in the heat-softening intermediate layer is usually 30% by weight or less.

The filler is applied to the peeling surface of the heat-softening coloring material layer, which will be described in detail next.
That is, it has the effect of forming fine irregularities on the surface of the printed image to further reduce the low surface gloss of the printed image, which is achieved by stable cohesive failure promoted by the group A compound.

Examples of the filler include silica, talc, calcium carbonate, alumina, acid clay, clay, magnesium carbonate, tin oxide, titanium white, graphite, thermosetting resin particles, fluororesin particles, melamine resin particles, urea resin particles, Benzoguanamine resin particles, acrylic resin particles, styrene resin particles, boron nitride, copper, iron, aluminum,
Examples include iron oxide, tin oxide, aluminum oxide, magnesium oxide, and titanium nitride.

The average particle size of the filler is usually 0.21 Lm or more3
It is within the range of gm or less.

The coloring material has the function of preventing the density of the obtained printed image from decreasing when the stable cohesive failure occurs in the thermosoftening intermediate layer.

Therefore, when the heat-softening intermediate layer contains the coloring material, the color of the coloring material is preferably the same as the color of the coloring material in the heat-softening coloring material layer, which will be described in detail below.

As the coloring material, the same coloring material as the coloring material in the heat-softening coloring material layer described in detail below can be suitably used.

When the coloring material is used, the content of the coloring material in the heat-softening intermediate layer is usually 30% by weight or less.

In this invention, the heat-softening intermediate layer containing the above components can be formed by, for example, a water-based coating method, a coating method using an organic solvent,
It can be coated on the support by a coating method such as a hot melt coating method.

The layer thickness of the heat-softening intermediate layer is usually in the range of 0.3 to 5 gm, preferably in the range of 0.5 to 3 pm.

By setting this layer thickness within the above range, the object of the present invention can be fully achieved.

On this heat-softening intermediate layer, a heat-softening coloring material layer, which will be described next, is usually laminated adjacent thereto.

- Heat Softening Coloring Material Layer - The heat softening coloring material layer usually contains one coloring material, a heat melting compound, and a heat softening resin.

The layer thickness of this heat-softening coloring material layer is usually within the range of 0.5 to 8 pm, preferably within the range of 1.0 to 5.0 #Lm.

Examples of the coloring material include pigments such as S-machine pigments and organic pigments, and dyes.

The inorganic pigments include 1, titanium dioxide, carbon black, zinc oxide, Prussian blue, cadmium sulfide,
These include iron oxides and chromates of lead, zinc, barium and calcium.

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.

The organic dyes include acid dyes and direct dyes.

Examples include disperse dyes, oil-soluble dyes, and metal-containing oil-soluble dyes.

The content of the coloring material in the heat-softening coloring material layer is usually 5.
-35% by weight, preferably 10-25% by weight.

As the heat-melting compound and heat-softening resin, the same heat-melting compounds and heat-softening resins that can be used in the heat-melting intermediate layer can be used, for example.

In addition to the above-mentioned components, the heat-softening coloring material layer may also contain a surfactant such as a polyoxyethylene chain-containing compound.

The content of the heat-melting compound in the heat-softening coloring material layer is usually in the range of 10 to 95% by weight, preferably 60 to 95% by weight.
It is within the range of 90% by weight.

The heat-softening coloring material layer may further contain inorganic or organic fine particles (metal powder, silica gel, etc.) and oils (linseed oil, mineral oil, etc.).

The heat-softening color material layer can be coated on the heat-softening intermediate layer by employing a coating method such as a water-based coating method or a coating method using an organic solvent.

-Others- In the thermal transfer recording medium of the present invention, the heat-softening intermediate layer and the heat-softening coloring material are usually coated on the support in this order, and then, if desired, a drying step and a surface smoothing treatment are performed. It can be manufactured by cutting into a desired shape through various steps.

The thermal transfer recording medium thus obtained can be used in the form of a wide tape or typewriter ribbon generally used in line printers, etc., but the planar shape of the thermal transfer recording medium of the present invention is Preferably, it is in the form of a sheet having substantially the same width as the recording paper used in line printers.

The heat-sensitive transfer method using this heat-sensitive transfer recording medium is not different from a normal heat-sensitive transfer recording method, but will be explained by taking as an example the case where the most typical thermal head is used as the heat source.

First, the heat-softening coloring material layer of the heat-sensitive transfer recording medium and the transfer medium, for example, plain paper, are brought into close contact with each other, and if necessary, a heat pulse is further applied from the back side of the transfer paper using a platen.
A heat pulse is applied by a heat agent to locally heat the heat-softening coloring material layer corresponding to a desired printing or transfer pattern.

The temperature of the heated portion of the heat-softening coloring material layer increases, and the heat-softening coloring material layer is quickly softened and transferred onto the transfer medium.

[Example] Next, Examples and Comparative Examples of the present invention will be shown to further specifically explain the present invention.

(Example 1) The following anchor layer composition was applied onto a polyethylene terephthalate film having a thickness of 4.5 pm according to JIS standard A4.
layer thickness 1. over a length corresponding to the width of the paper. A water-based coating was applied to obtain Ogm to form a heat-softening intermediate layer in the heat-sensitive transfer recording medium of the present invention.

Polyester wax aqueous emulsion [Plaxel 22ON, manufactured by Daicel Chemical ■]...30% by weight Paraffin wax aqueous emulsion...5031% by weight Carbon black aqueous dispersion...20% by weight
A heat-softening coloring material layer was formed by coating the following heat-softening coloring material layer composition on the heat-softening intermediate layer in a water-based manner to a film thickness of 4 OILm, and producing a heat-sensitive transfer recording medium of the present invention. Obtained.

Paraffin wax emulsion...60% by weight Acrylic emulsion...10% by weight Ethylene-vinyl acetate copolymer emulsion...10% by weight Carbon black Water drink...・Record (print) the thermal transfer recording medium obtained at 20% by weight on plain paper (Beck smoothness 20 seconds) using a thermal printer (2601 heavy width line head, 180 DPI, platen rubber hardness 40 degrees), and print. The image gloss, print quality, and film retention were evaluated.

The results are shown in Table 1.

Note that glossiness, print quality, and film retention were evaluated as follows.

Glossiness: Using a glossmeter, the glossiness of the printed image was measured under the condition that both the incident angle and the reflection angle were 60°.

Print quality: Voids and sharpness were visually observed.

Film retention: A peeling test (separation angle 60') using an adhesive tape ("Vostit Tape", manufactured by 3M Co., Ltd.) was carried out to examine the presence or absence of film peeling.

(Examples 2 to 5) In Example 1, a heat-softening intermediate layer composition having the compounding ratio shown in Table 2 was used instead of the heat-softening intermediate layer composition in Example 1. was carried out in the same manner as in Example 1 above.

The results are shown in Table 1.

(Example 6) In Example 1, a heat-softening intermediate layer composition having the compounding ratio shown in Table 2 was used instead of the heat-softening intermediate layer composition in Example 1, and a hot-melt intermediate layer composition was used. Example 1 was carried out in the same manner as in Example 1, except that a heat-softening intermediate layer having a thickness of 1.5 gm was formed by the method.

The results are shown in Table 1.

(Example 7) In Example 1, a heat-softening intermediate layer composition having the compounding ratio shown in Table 2 was used instead of the heat-softening intermediate layer composition in Example 1, and the solvent was Example 1 was carried out in the same manner as in Example 1 except that a heat-softening intermediate layer having a thickness of 2.54 m was formed using toluene.

The results are shown in Table 1.

(Comparative Example 1.2) In Example 1, a heat-softening intermediate layer composition having the compounding ratio shown in Table 2 was used instead of the heat-softening intermediate layer composition in Example 1. A thermal transfer recording medium was produced in the same manner as in Example 1, and the resulting thermal transfer recording medium was evaluated for glossiness of printed images, print quality, and film retention.

The results are shown in Table 1.

(Comparative Example 3) A thermal transfer recording medium was produced in the same manner as in Example 1 except that the heat-softening intermediate layer was not formed. Image gloss, print quality, and film retention were evaluated.

The results are shown in Table 1.

(The following is the margin) Table 1 The symbols for each evaluation item have the following meanings.

Print quality: O: Both voids and sharpness are good.

O: Few voids, but sharpness It lacks quality.

Δ: Both voids and sharpness are poor. Ru.

X: both void and sharpness Inferior.

Film retention; O: No film peeling due to adhesive tape.

X: Film peeling due to adhesive tape. Ru.

(Essence, hereinafter referred to as margin) (Jf value) As is clear from Table 1, the thermal transfer recording medium of the present invention has a higher glossiness of the printed image than the thermal transfer recording media of Comparative Examples 1 to 3. It was confirmed that the printing quality was low and that the printing quality and film retention were excellent.

[Effects of the Invention] According to the present invention, (1) The heat-softening intermediate layer remaining on the support after the heat-softening colorant layer is transferred to the transfer medium contains a specific compound; By realizing stable cohesive failure peeling near the interface between the heat-softening coloring material layer and the heat-softening intermediate layer, it is possible to obtain an easily legible printed image with low surface gloss; (2) Furthermore, because the heat-softening coloring material layer has excellent film retention properties, it is possible to achieve good printing quality with high density and no deformation of characters, not only on plain paper but also on so-called rough paper with low smoothness on one surface. It is possible to provide a thermal transfer recording medium having various advantages such as:

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view showing an example of the thermal transfer recording medium of this invention No. 11. FIG. 1...Support, 2...Thermosoftening intermediate layer, 3...Thermosoftening coloring material layer.

Claims (1)

[Claims] (1) A heat-softening intermediate layer is provided between the support and the heat-softening coloring material layer, and the heat-softening intermediate layer is made of the following A
A thermal transfer recording medium characterized by containing at least one compound selected from the group. [Group A] Polyester wax, polyamide wax, polyurethane wax.