JPH01190492A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To obtain not only good printing quality excellent in the retentivity of a secret, easy to read and excellent in releasability or sensitivity but also good productivity, by providing an anchor layer containing a resin component and carbon black of a specific ratio between a support and a heat-meltable colorant layer. CONSTITUTION:A support to be used has not only good heat-resistant strength but also high dimensional stability. An anchor layer 2 containing a resin component and carbon black is provided between the support 1 and a heat-meltable colorant layer 3. This anchor layer 2 pref. contains carbon black in an amount of 25wt.% or more, pref., 30wt.% or more per 100wt.% of the anchor layer composition. When this ratio of carbon black is below 25wt.%, the retentivity of a secret, releasability and the easiness to read a printing image are lowered.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal transfer recording medium, and more specifically, after the printed image is transferred, the anchor layer remaining on the support has a shape corresponding to the printed image. It has excellent secrecy as it does not produce so-called blank areas, and the ink layer has good releasability and high sensitivity, and the printed image obtained is not glossy and easy to read, resulting in excellent printing. The present invention relates to a thermal transfer recording medium that achieves high quality, can be produced safely and easily, has a configuration with excellent production stability, and can be suitably used as a thermal recording medium for, for example, facsimiles and printers.

[Prior art and its problems] A thermal transfer recording method usually uses a thermal transfer recording medium having a heat-fusible ink layer formed by dispersing a colorant in a heat-fusible substance on a sheet-like support. The ink layer is superimposed on a transfer medium (generally paper) and heated by a thermal head from the support side of the thermal transfer recording medium, and the molten ink layer is transferred to the transfer medium. It forms an ink image.

However, this transfer type thermal recording method has a problem in that the resulting printed image has a high gloss and is difficult to read.

Therefore, in order to remove the gloss of the printed image in this transfer-type thermal recording method, for example, by subjecting the support to an uneven treatment and providing a heat-melting coloring layer on this support, the image can be transferred to the transfer medium. A resin and a matte pigment are applied to a heat-sensitive transfer recording medium (see Japanese Patent Laid-Open No. 60-212392) or a base film that forms irregularities on the surface of the heat-melting coloring material layer, that is, the surface of the printed image. By providing a matte layer or a gloss control layer (hereinafter both are collectively referred to as the matte layer) containing a heat-melting material and a heat-melting coloring layer adjacent to the matte layer, unevenness can be created on the surface of the printed image. Thermal transfer recording medium to be formed
See JP-A-101083, JP-A-61-84287, etc. ) have been proposed.

However, in these thermal transfer recording media,
Although the glossiness of the printed image decreases, after the heat-fusible ink layer has been transferred to the transfer medium, there is a so-called missing part on the support side that corresponds to the shape of the transferred heat-fusible ink layer and is legible. occurs. There is a possibility that the recorded contents may be leaked to a third party from this blank part.

Therefore, in conventional thermal transfer recording media.

It can be said that no consideration was given to confidentiality at all.

Furthermore, since the unevenness formed on the surface of the printed image is not sufficiently fine, it is difficult to say that the gloss of the printed image is removed sufficiently, and the angle at which the printed image is viewed is affected by the residual gloss. In some cases, it may be difficult to read.

Furthermore, in thermal transfer recording media in which a support is subjected to an uneven treatment (see Japanese Patent Laid-Open No. 60-212392), operations required for the uneven treatment are complicated, and thermal transfer recording media in which a matte layer is provided. Medium (JP-A-60-1010
See Publication No. 83, Japanese Unexamined Patent Publication No. 61-84287, etc. )
However, the problem is that the organic solvent used for coating the matte layer requires careful handling and uneven coating occurs, making it difficult to manufacture easily and safely, and resulting in poor production stability. There is.

Furthermore, there is still room for improvement in print quality and sensitivity.

By the way, in order to obtain a good printed image 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, the ink layer needs to be accurately peeled off from the support depending on the heated portion.

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 for the purpose of improving the releasability of the support.

In general, a release layer is a layer whose main component is a heat-melting substance such as wax, and which also contains a thermoplastic resin. It is formed on a support by applying a coating solution dissolved or dispersed in a solvent.

In order to obtain a printed image with good quality,
It is desirable that the ink layer is transferred from the support side to the transfer medium by interfacial peeling between the release layer and the adjacent ink layer.

However, in conventional release layers, in addition to the above-mentioned interfacial peeling, interfacial peeling occurs at the interface between the release layer adjacent to the support and the support, and cohesive failure peeling occurs within the release layer. However, when such peeling occurs, it is difficult to say that the quality of the printed image obtained is sufficiently good.

In particular, when applying a release layer on a support using an organic solvent, it may worsen the working environment, require special equipment for fire prevention, and increase production costs. There is a problem.

This invention has been made based on the above circumstances.

The object of the present invention is to provide a support with a shape corresponding to the printed image after the printed image is transferred, so that there is no visible so-called missing part, which provides excellent secrecy, and also provides ease of peeling of the ink layer. It has good print quality and high sensitivity, and the resulting printed image is not glossy and easy to read.It has a structure that achieves excellent print quality and is safe and easy to manufacture, with excellent production stability. An object of the present invention is to provide a thermal transfer recording medium having the following properties.

[Means for Solving the Problems] In order to solve the problems described above, the present inventor has made extensive studies and found that a specific resin component is added between the support and the heat-melting coloring material layer. A thermal transfer recording medium provided with an anchor layer containing carbon black in a proportion of This invention was achieved by discovering that it achieves good printing quality and also has excellent production stability.

That is, the structure of the present invention has an anchor layer adjacent to the heat-melting coloring material layer between the support and the heat-melting coloring material layer, and the anchor layer contains a resin component and carbon black. and the carbon black content in the anchor layer is 25% by weight or more.

The thermal transfer recording medium of the present invention, for example, as shown in FIG. 1, comprises at least an anchor layer 2 and a heat-melting coloring material layer 3, which are layered in this order on a support l. .

Single-support support The support in the thermal transfer recording medium of the present invention desirably has good heat-resistant strength and high dimensional stability.

The materials include, for example, papers such as plain 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 foil. All metal sheets such as the above are preferably used.

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

-Anchor layer- One of the important points in this invention is that an anchor containing a resin component and a specific proportion of carbon black is provided between the support and the heat-fusible coloring material layer described in detail next. It consists in providing layers.

The anchor layer in this invention forms fine irregularities on the surface of the heat-fusible coloring material layer, that is, the surface of the printed image, when the heat-melting coloring material layer is peeled off from the support. It has an action or function of removing gloss, and also promotes interfacial peeling between the anchor layer and the heat-melting coloring material layer, improving the peelability of the heat-melting coloring material layer and improving the quality of the printed image. or has a function.

Such action or function of the anchor layer is brought about by the resin component and carbon black contained in the anchor layer.

The resin component mainly has the function of promoting interfacial peeling between the anchor layer and the heat-melting coloring material layer, which will be described in detail next, to achieve good printing quality and high sensitivity.

The resin that can be used as the resin component preferably has good adhesion to the support, and specific examples include unsaturated polyester, glyptal resin, and glyptal-based modified resin.

Unsaturated alcohol-modified phthalic acid resin, isophthalic acid resin, terephthalic acid resin, polyester resin such as aliphatic polyester: polyurethane resin: vinyl chloride resin,
Vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinylidene chloride copolymer resin, vinyl chloride-acrylic acid ester, vinyl chloride-methacrylic acid copolymer resin, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl chloride copolymer , vinyl chloride resins such as propylene-vinyl chloride copolymer; vinylidene chloride resins; polyamide resins such as nylon 6, nylon 66, nylon 610, nylon 8゛, nylon 11; polyacetal: polycarbonate: boris sulfone; phenolic resin , Phenolic resins such as phenol-modified resins: Melamine resins such as melamine resins, urea melamine resins, and phenol melamine resins:
Acrylic resins such as polyacrylic acid ester, polyacrylic acid methyl ester, polyacrylic acid ethyl ester, polyacrylic acid butyl ester; Fluorine thread resin: Polystyrene resin such as epoxy resin, ABS resin, AS resin, ACS resin; Silicone Resins; further examples include water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, gelatin, carboxymethylcellulose, methylcellulose, polyethylene oxide, gum arabic, water-soluble polyester, water-soluble polyurethane, water-soluble polyacrylic, and water-soluble polyamide.

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

Among these, those with a softening point of 100°C or higher are preferred, and those with a softening point of 150°C or higher are particularly preferred. If the softening point is less than 100°C, it may become impossible to stably apply the heat-melting coloring material layer formed on the anchor layer by a hot-melt coating method.

Furthermore, when the material forming the support is polyethylene terephthalate, polyurethane resins, polyester resins, polyacrylic resins, and water-soluble polymers thereof are preferred. This is because these have good adhesion to polyethylene terephthalate.

In addition, when a water-soluble polymer is used, the anchor layer can be applied by a water-based coating method, which is preferable from the viewpoint of production stability.

The content of the resin component in the anchor layer is usually 7.
It is 5% by weight or less, preferably 70% by weight or less. If this content exceeds 75% by weight, the carbon black content in the anchor layer becomes relatively small, and the effects of the present invention may not be fully realized.

One of the important points in this invention is that the anchor layer contains 25% by weight or more based on 100% by weight of the anchor layer composition.
Preferably, carbon black is contained in a proportion of 30% by weight or more. When this proportion is less than 25% by weight, the thermal transfer recording medium of the present invention has excellent confidentiality.
Peelability and legibility of printed images may deteriorate.

That is, the carbon black blackens the anchor layer to prevent so-called missing portions from forming in the anchor layer remaining on the support after the printed image is transferred.
It has the effect of improving the confidentiality of the heat-sensitive transfer recording medium of the present invention, and promotes the interface MllllI between the anchor layer and the heat-melting coloring material layer, which will be described in detail next, to improve the releasability and improve the peelability. It has the effect of realizing high printing quality and the effect of forming fine irregularities on the surface of the printed image to remove gloss from the surface of the printed image.

In particular, the effect of removing gloss on the surface of a printed image is presumed to be achieved as follows.

That is, by containing carbon black in a specific ratio in the anchor layer, the anchor layer becomes in a state where the amount of oil supplied is insufficient.

Then, as shown in FIG. 2(A), for example, a heat-melting coloring material layer 3 adjacent to the anchor layer 2 is formed to supplement the amount of oil supplied to the anchor layer 2 provided on the support 1. A part of the composition transferred to anchor Hj2.

If interfacial peeling occurs between the anchor layer and the heat-melting coloring material layer in this state, fine irregularities 4 will be formed on the interface between the anchor layer 2 and the heat-melting coloring material layer 3. As a result, fine irregularities are formed on the surface of the printed image, as shown in FIG. 2(B), for example. Moreover, the unevenness 4 is similar to the above-mentioned thermal transfer recording medium (Japanese Patent Application Laid-open No.
See JP-A No. 0-212392, JP-A-60-101083, JP-A-61-84287, etc. ) Since the unevenness is finer than the unevenness, no residual gloss is caused in the printed image. In addition, Figure 2 (b)
10 is a transfer medium.

The amount of oil supplied (DBP) of the carbon black to exhibit such an effect is usually 2[1m/100g or more, preferably 40m/7100g or more. Usually 100mJL
The amount is preferably 50 ml or less.

In the thermal transfer recording medium of the present invention, the anchor layer may contain a filler together with the resin component and carbon black.

The filler has the function of adjusting the depth of the unevenness on the surface of the printed image formed by the carbon black, and making the removal of the gloss on the surface of the printed image achieved by the carbon black more sufficient. .

The average particle size of the filler in order to sufficiently exhibit such an effect is usually within a range of Q,2p,m or more and 2.0p,m or less.

Specific examples of the filler include silica, talc, calcium carbonate, alumina, acid clay, clay, magnesium carbonate, tin oxide, titanium white, graphite, curable resin particles, silicone resin particles, fluororesin particles, and melamine resin. particles, urea resin particles, benzoguanamine resin particles, acrylic resin particles, styrene resin particles, boron nitride, copper, iron, aluminum, iron oxide, tin oxide, aluminum oxide, magnesium oxide, titanium nitride, and the like.

When using the filler, the content of the filler in the anchor layer is usually in the range of 3 to 70% by weight, preferably 5 to 40% by weight, based on 100% by weight of the anchor layer composition. is within the range of

The carbon black can be used in the form of an aqueous dispersion to perform aqueous coating of the anchor layer.

The anchor layer includes the resin component and carbon black,
Alternatively, in addition to these and fillers, other components such as wax and surfactants may be contained.

The waxes include, for example, vegetable waxes such as carnauba wax, wood wax, auriculie wax, and Nispar wax, animal waxes such as insect wax, shellac wax, and spermaceti wax; paraffin wax, microcrystal wax, polyethylene wax, ester wax, and acid wax. Petroleum waxes such as wax; mineral waxes such as montan wax, osikerite, and ceresin; and the like.

The wax has the function of adjusting the adhesive force between the anchor layer and the heat-melting coloring material layer, which will be described in detail below.

When using the wax, the content of the wax in the anchor layer is usually 70% by weight or less, preferably 60% by weight or less, based on 100% by weight of the anchor layer composition.
% by weight or less.

The surfactant has the function of adjusting the releasability of the heat-melting coloring material layer.

As the surfactant, various surfactants conventionally used in thermal transfer recording media, such as polyoxyethylene chain-containing compounds, can be used.

When using the surfactant, the content of the surfactant in the anchor layer is usually 30% by weight or less.

In the present invention, the anchor layer containing the above-mentioned components is coated onto the support body safely, easily, and uniformly with excellent production stability, for example, by an aqueous coating method.

The thickness of the anchor layer is usually in the range of 0.05 to 3 pm, preferably in the range of 0.1 to 1.5 pm. If this layer thickness is less than 0.05 gm, there is virtually no point in providing an anchor layer, and the peelability of the heat-melting coloring material layer is improved to improve the quality of the printed image, and the surface of the printed image is The object of the present invention, which is to remove the gloss and obtain an easily legible printed image, is not achieved. On the other hand, even if it exceeds 3 gm, the effect commensurate with the increase in layer thickness will not be achieved.

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

- Heat-melting coloring material layer - The heat-melting coloring material layer usually contains a coloring material, a heat-melting substance, and a thermoplastic resin.

The layer thickness of this heat-melting coloring material layer is usually 0.5 to 8 JLm.
It is preferably within the range of 1.0 to 6.0 #Lm.

Examples of the coloring material include pigments such as inorganic 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-based, thioindigo-based, anthraquinone-based, anthanthrone-based, and triphenedioxazine-based pigments, vat dye pigments, phthalocyanine pigments, such as copper phthalocyanine and its derivatives, and quinacridone pigments.

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

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

Specific examples of the heat-melting substances include vegetable waxes such as carnauba wax, wood wax, auriculie wax, and Nispar wax; animal waxes such as beeswax, insect wax, shellac wax, and spermaceti wax; paraffin wax, microcrystal wax, and polyethylene wax. , petroleum waxes such as ester waxes and acid waxes; and mineral waxes such as montan wax, osichelite and ceresin; and higher fatty acids such as behenic acid; higher alcohols such as palmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol and eicosanol; higher fatty acids such as cetyl balmitate, myricyl valmitate, cetyl stearate and myricyl stearate. Esters: Amides such as acetamide, propionic acid amide, valmitic acid amide, stearic acid amide and amide wax; and higher amines such as stearylamine, behenylamine and palmitylaquine.

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 100''C as measured using a Yanagiki MJP-2 model.

The thermoplastic resins include ethylene copolymers, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, acrylic resins, vinyl chloride resins, cellulose resins, rosin resins, ionomer resins, and petroleum resins. Resins such as natural rubber, styrene-butadiene rubber, inbrene rubber and chloroprene rubber; ester gum, rosin maleic acid resin, rosin derivatives such as rosin phenol resin and hydrogenated rosin; and phenolic resins, terpenes Examples include polymer compounds having a softening point of 50 to 150'C, such as resins, cyclopentadiene resins, and aromatic hydrocarbon resins.

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

In addition to the above-mentioned components, the heat-melting coloring material layer may contain a surfactant such as a polyoxyethylene chain-containing compound in order to adjust releasability.

The content of the heat-fusible substance in the heat-fusible coloring material layer is:
It is usually 50% by weight or more, preferably in the range of 50 to 97% by weight, more preferably 60% by weight, based on the total weight of the thermofusible substance and the thermoplastic resin contained in this layer.
~95% by weight.

If the content of the thermofusible material is less than 50% by weight based on the total weight of the thermofusible material and the thermoplastic resin, releasability may deteriorate.

Furthermore, inorganic or organic fine particles (metal powder, silica gel, etc.) or oils (linseed oil, mineral oil, etc.) can also be added.

The heat-melt coloring material layer can be formed by hot-melt coating method, water-based coating method,
Although it is possible to apply the coating by employing a coating method using an organic solvent or the like, in the present invention, a hot melt coating method is usually employed for coating.

-Others- The heat-sensitive transfer recording medium of the present invention may have a heat-softening layer between the anchor layer and the heat-melting coloring material layer.

The thermosoftening layer is usually a layer made of the above-mentioned thermoplastic resin and a thermofusible substance, and the layer thickness is usually 0.6 to 0.6.
It is within the range of 8.0 p, m, preferably 1.0 to 6.0 p.m.
It is in the range of 0 lm.

The thermosoftening layer is preferably applied by a method of preparing an aqueous emulsion containing a thermofusible substance and a thermoplastic resin, and performing aqueous coating using this aqueous emulsion.

The aqueous emulsion can be applied by employing known methods such as a coating method using a wire bar, a gravure coating method, a kiss coating method, and a calendar coating method.

By removing water from the applied aqueous emulsion, the particles constituting the emulsion (thermally softenable layer-forming component particles) remain as they are or in a similar form (
For example, in the form of crushed spheres), the heat-softening layer is formed, and each particle is bonded to each other at the point or surface where it contacts an adjacent particle. Therefore, during thermal transfer, these spherical or similar particles act independently to some extent to provide good print quality.

Moreover, an overcoat layer can also be laminated on the heat-melting coloring material layer.

After each layer is coated in this manner, it is optionally subjected to a drying process, a surface smoothing process, etc., and then cut into a desired shape to obtain the thermal transfer recording medium of the present invention.

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 A sheet having the same width as the recording paper used in line printers is preferable.

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 using an example in which the most typical thermal head is used as a heat source.

First, the heat-melting coloring material layer of the heat-sensitive transfer recording medium and the medium to be transferred, such as transfer 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 thermal head to locally heat the heat-fusible colorant layer corresponding to the desired print or transfer pattern.

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

[Examples] Next, Examples and Comparative Examples of the present invention will be shown, and the present invention will be explained in more detail. In addition, "r part" used below indicates "part by weight."

(Example 1) The following anchor layer composition was applied onto a polyethylene terephthalate film having a thickness of 4.5 p and 1.5 m over a length corresponding to the width of JIS A4 paper. The anchor layer in the thermal transfer recording medium of the present invention was formed by aqueous coating to give Ogm.

Emushizu L21JDL product Water-soluble polyester 55 parts [manufactured by Toyobo Co., Ltd.: "Pyronal MD-12000.1 Carbon black dispersion 25 parts [carbon black; Average particle size 62ILm, oil supply amount (DBP) 67ml
/100g] Paraffin wax...
・20 parts Next, hot-melt coating the following hot-melt coloring material layer composition onto the anchor layer using a wire bar to a film thickness of 4.2 ILm to form a hot-melting coloring material layer. , a thermal transfer recording medium of the present invention was manufactured.

Paraffin wax: 40 parts Ester wax: 20 parts Carbon black: 25 parts Ethylene-vinyl acetate copolymer ...14 copies of the obtained thermal transfer recording medium were printed on a thermal printer (260 mm width line head, 18G D
PI, platen rubber hardness 40 degrees), use plain paper (
The printed image was recorded (printed) on a 50-second Beck smoothness scale, and the secrecy, glossiness, and print quality of the printed image were evaluated.

The results are shown in Table 1.

Note that confidentiality, glossiness, and print quality were each evaluated as follows.

Confidentiality: Visual observation was performed using reflected light for blanks after printing.

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.

(Examples 2 to 6) In the above Example 1, the anchor layer composition having the blending ratio shown in Table 2 was used instead of the anchor layer composition in the above Example 1. It was carried out in the same manner.

The results are shown in Table 1.

(Example 7) Same as Example 1, but the thickness of the anchor layer was 1.0#L.
The same procedure as in Example 1 was carried out except that m was changed to 0.5 gm.

The results are shown in Table 1.

(Comparative Examples 1 to 3) In Example 1, the anchor layer composition having the blending ratio shown in Table 2 was used instead of the anchor layer composition in Example 1. A thermal transfer recording medium was produced in the same manner as above, and the obtained thermal transfer recording medium was evaluated for confidentiality, glossiness, and print quality.

The results are shown in Table 1.

(Comparative Example 4) In Example 1, an anchor layer composition containing titanium white (average particle size 1.07 JL m ) instead of carbon black was used in place of the anchor layer composition in Example 1. Otherwise, a thermal transfer recording medium was produced in the same manner as in Example 1, and the obtained thermal transfer recording medium was evaluated for confidentiality, glossiness, and print quality.

The results are shown in Table 1.

(Comparative Example 5) A thermal transfer recording medium was manufactured in the same manner as in Example 1, except that the anchor layer was not formed, and the obtained thermal transfer recording medium had secrecy, The glossiness of the printed image and the printing quality were evaluated.

The results are shown in Table 1.

(Gourd, hereafter referred to as margins) Table 1 The symbols for each evaluation item have the following meanings.

Confidentiality: ◎: The portion of the anchor layer corresponding to the printed image is unreadable.

△: Printed image on anchor layer Corresponding parts are legible.

X: Printed image on anchor layer The corresponding part is very easy to read. It's easy.

Print quality; ◎: Both void and sharpness are good.

○: Few voids, but sharpness lack of quality.

×: Both void and sharpness are significant. Inferior.

(Gourd, hereinafter referred to as margin) Table 2 (Evaluation) As is clear from Table 1, the thermal transfer recording medium of the present invention has better confidentiality and In addition to superior printing quality of printed images,
It was confirmed that the glossiness of the printed image was low.

On the other hand, when other fillers were used in place of carbon black in the anchor layer as in Comparative Example 4, coating unevenness occurred in the anchor layer.

[Effects of the Invention] According to the present invention, (1) the anchor layer remaining on the support after the heat-fusible colorant layer is transferred to the transfer medium contains a specific proportion of carbon black; Since it is black, there is no so-called white gap in the anchor layer that corresponds to the shape of the transferred heat-fusible coloring material layer and is readable. Therefore, it has excellent confidentiality, and (2) Since the printed image has low gloss, it is possible to obtain a printed image that is easy to read.

(3) By containing the resin component and carbon black in a specific ratio in the anchor layer, interfacial peeling between the anchor layer and the heat-melting coloring material layer is achieved with good peelability. (4) Furthermore, since the anchor layer can be applied by water-based coating, it is highly safe during manufacturing, and is easy to manufacture, resulting in stable production. It is possible to provide a thermal transfer recording medium that has various advantages such as excellent performance.
.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram showing an example of the thermal transfer recording medium of the present invention, and FIG. FIG. 2(b) is a cross-sectional explanatory view schematically showing the state of the surface, and FIG. 1...Support, 2...Anchor layer, 3...Thermofusible coloring material layer.

Claims (1)

[Claims] (1) having an anchor layer adjacent to the heat-melting coloring material layer between the support and the heat-melting coloring material layer, and the anchor layer containing a resin component and carbon black;
A thermal transfer recording medium characterized in that the content of the carbon black in the anchor layer is 25% by weight or more.