JPH11227341A - Heat-transfer recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an image which is excellent in definition and fastness to rubbing by a method wherein in a heat-melting ink layer, compounds represented by the specified formulas, and an isocyanate adduct of a higher fatty acid polyhydric alcohol ester, are contained. SOLUTION: In this heat-transfer recording medium, on a base material, a heat-melting ink layer is provided with a lubricating protective layer, and on the rear surface of the base material, a back coating layer is provided. In this case, the heat-melting ink layer is prepared by a substance wherein compounds which are represented by formula I or formula II, and an isocyanate adduct of a higher fatty acid polyhydric alcohol ester are contained. In the formulas, R1 -R3 indicate hydrogen atom, halogen atom, an amino group, a sulfone group, hydroxyl group, a nitro group, a carboxylate group or a hydrocarbon group of which the number of carbon atoms is 1-1000. The compounds which are represented by the formulas I, II are used as coloring materials, and the isocyanate adduct of the higher fatty acid polyhydric alcohol ester is used as a binder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a thermal transfer recording medium. More specifically, a transfer image having excellent sharpness and friction fastness can be obtained, a superimposed transfer image of two or more colors and halftone dots can be printed clearly even on rough surface paper, and a transfer image having excellent gradation can be obtained. The present invention relates to a thermal transfer recording medium. The thermal transfer recording medium of the present invention is particularly useful as a thermal transfer recording medium for forming a multicolor print image.

[0002]

2. Description of the Related Art

In order to record a transfer image on plain paper or the like using a thermal transfer recording medium, a thermal transfer printer equipped with a thermal head is generally used. As the performance of thermal transfer printers increases, it is desired that the thermal energy required for printing be kept as low as possible. The reason for this is that by reducing the thermal energy required for printing lower than before, the cycle of heating and cooling of the head can be shortened, and the thermal degradation of the head can be prevented. It is because it becomes. It is also because it can compensate for the lack of heat resistance of the base material. However, if the melting point of the ink composition is designed to be low in order to keep the heat energy required for printing low, background smearing due to the low melting point component of wax occurs when printing on plain paper, and the fixability of the transferred image and the robustness In addition to the decrease in the property, when the environmental temperature rises during storage, there has been a problem that a so-called blocking phenomenon occurs.

[0004] In order to solve these problems, a resin component is conventionally introduced into a binder of a hot-melt ink layer (Japanese Patent Laid-Open No.
JP-A-4-87234, JP-A-54-163044,
JP-A-56-98269 and JP-A-63-130887), or application of a resin-based overcoat layer to wax ink (JP-A-61-242893). Was not obtained enough to satisfy the balance. There are also attempts to achieve low-energy printing by reducing the thickness of the base material and increasing heat transfer. There were problems such as becoming.

[0005] Separately, in order to obtain a color image excellent in gradation by printing two or more colors of a hot-melt ink, in particular, full-color re-development, at least the transparency of a color material superimposed on an upper layer is required. More specifically, the transparency of the binder, the transparency of the coloring material, and the fineness of the colorant of the heat-fusible ink layer are required. However, none of the conventional thermal transfer recording media has achieved such an object by a combination of a coloring material and a binder.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a thermal transfer recording medium capable of transferring a uniform amount of ink without being influenced by a printing method and obtaining a transferred image excellent in sharpness and friction fastness. It is in. Another object of the present invention is to provide a thermal transfer recording medium capable of printing a superimposed transfer image or halftone dots of two or more colors even on rough surface paper and obtaining a transfer image with excellent gradation.

[0007]

The thermal transfer recording medium of the present invention is characterized in that a specific coloring material and a specific binder are used in combination as components of the heat-fusible ink layer.

That is, according to the present invention, in a thermal transfer recording medium having a heat-fusible ink layer provided on a substrate, the heat-fusible ink layer is represented by the following formula (A-1) or (A-2). The object is achieved by providing a thermal transfer recording medium characterized by containing a compound to be obtained and an isocyanate adduct of a higher fatty acid polyhydric alcohol ester.

[0009]

Embedded image

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the thermal transfer recording medium of the present invention will be described below with reference to the drawings. Here, FIG. 1 is a schematic diagram showing the configuration of one embodiment of the thermal transfer recording medium of the present invention.

In the thermal transfer recording medium 1 shown in FIG. 1, a heat-fusible ink layer 3 is provided on a base material 2, and a lubrication protection layer 4 is provided between the base material 2 and the heat-fusible ink layer 3. Have been. Further, a back coat layer 5 is provided on the back surface of the substrate 2. Hereinafter, details of these layers and the substrate will be described.

The heat-fusible ink layer 3 contains the compound represented by the formula (A-1) or (A-2) and an isocyanate adduct of a higher fatty acid polyhydric alcohol ester. The compound represented by the formula (A-1) or (A-2) is used as a coloring material. An isocyanate adduct of a higher fatty acid polyhydric alcohol ester is used as a binder.

First, the above formula (A-
Explaining the compounds represented by 1) and (A-2), these compounds are all yellow dyes, and in each formula, R _{1 to} R ₃ are each independently a hydrogen atom as described above. A halogen atom, an amino group, a sulfone group, a hydroxyl group, a nitro group, a carboxylate group or an optionally substituted hydrocarbon group having 1 to 1000 carbon atoms. R
_{1 to} R ₃ may be the same or different.

When R _{1 to} R ₃ are halogen atoms, F, Cl, Br and I are preferably used as the halogen atoms. When R _{1 to} R ₃ are a hydrocarbon group, an alkyl or alkenyl group having 1 to 200 carbon atoms or an aromatic hydrocarbon group having 6 to 400 carbon atoms is suitably used as the hydrocarbon group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group,
A hexyl group, a 2-ethylhexyl group, a linear or branched alkyl group having 1 to 100 carbon atoms, such as a 2-ethyloctyl group, is particularly preferred. As the aromatic hydrocarbon group,
An aromatic hydrocarbon group having 6 to 200 carbon atoms such as a phenyl group is particularly preferred. These alkyl groups, alkenyl groups, and phenyl groups may have some of their hydrogen atoms replaced with halogen atoms, amino groups, sulfone groups, nitro groups, hydroxyl groups, carboxylate groups, and the like.

The compound represented by the above formula (A-1)
Specific examples of preferable ones include R ₁Is 2-ethylhexyl
A sil group or a 2-ethyloctyl group, R_TwoIs a butyl group,
R_ThreeIs a methyl group. On the other hand,
Preferred compounds as compounds represented by formula (A-2)
As an example, R₁And R_TwoAre each a methyl group
Compound, and R₁And R_TwoAre each an ethyl group
Compounds.

The compound represented by the formula (A-1) or (A-2) is used in an amount of from 20 to 10 based on 100 parts by weight of the isocyanate adduct of the higher fatty acid polyhydric alcohol ester.
It is preferably contained in an amount of 00 parts by weight, particularly 100 to 1000 parts by weight. If the content of these compounds is less than 20 parts by weight, sufficient print density may not be obtained and the printed image may be unclear. If the content exceeds 1000 parts by weight, the saturation is reduced and two or more colors are overlapped. When the overlay printing is performed, the underlying color is hidden, and a desired color may not be obtained.

In the present invention, the compounds represented by the formulas (A-1) and (A-2) may be used in combination with another coloring material. Examples of such a coloring material include, for example, JP-A-7-22
No. 3,377, column 4, line 49 to column 5, line 18 are mentioned. Further, the color tone may be adjusted by mixing with an extender or a white pigment. Further, organic or inorganic fine particles may be added for the purpose of improving the heat stability.

An isocyanate adduct of a higher fatty acid polyhydric alcohol ester is obtained by adding an isocyanate compound to an esterified product of a higher fatty acid and a polyhydric alcohol. As the higher fatty acid used here, for example, JP-A-8-80673, column 3, line 28 to column 4
The ones described in the first row of the column are exemplified, and particularly, fatty acids having a melting point of 20 ° C. or more and a carbon number of 10 to 40 can be suitably used.
Among them, lanolin fatty acid and behenic acid are most suitable.

Examples of the polyhydric alcohol include a saturated aliphatic polyol, an unsaturated aliphatic polyol, an alicyclic polyol,
Oxygen-containing aliphatic polyols and the like are used.
No. 673, column 4, lines 6 to 27 are specifically exemplified. Particularly preferably used polyhydric alcohols are pentaerythritol, glycerin, glycols and the like.

Examples of the isocyanate compound include those described in JP-A-8-80673, column 4, lines 29 to 47. Particularly preferably used isocyanate compounds are tolylene diisocyanate, 4,4
-Diphenylmethane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate and the like.

The esterification reaction between the higher fatty acid and the polyhydric alcohol can be carried out by any conventionally known method. The degree of esterification is not particularly limited. The addition reaction between the higher fatty acid polyhydric alcohol ester and the isocyanate compound can be performed by a conventionally known method. The number of moles of the isocyanate compound added is not particularly limited, but is preferably about 0.1 to 5 moles per mole of the higher fatty acid polyhydric alcohol ester. In addition, a commercial item can also be used as an isocyanate adduct of the higher fatty acid polyhydric alcohol ester, for example, Lanox FPK-210 (manufactured by Nippon Seika) or the like.

The above isocyanate adduct of a higher fatty acid polyhydric alcohol ester may be used in combination with an ester oligomer. In this case, the so-called solid coverage is improved, and two or more colors can be superposed.
As the ester oligomer, a polycondensation reaction product of a polyhydric alcohol and a polycarboxylic acid is used, and preferably a polycondensation reaction product of a dioxy compound and a dibasic acid or an acid anhydride of a dibasic acid is used. Can be The ester oligomer has a lower degree of polymerization than a conventional polyethylene terephthalate-based polyester, and has a relatively low melting point and a narrow temperature range suitable as a binder for a thermal transfer ink layer. The number average molecular weight of the ester oligomer is generally 100 to 3 as calculated from the number of terminal groups.
0000, preferably 300 to 10,000, more preferably 400 to 5,000. The glass transition temperature of the ester oligomer is generally 40 to 160 ° C., preferably 50 to 160 ° C.
１１０110 ° C.

One or more ester oligomers can be used. The method for synthesizing the ester oligomer is not particularly limited, and can be obtained by any known method. The ester oligomer is represented by the formula (A-
It is preferable to add 0 to 500 parts by weight, especially 0 to 300 parts by weight, based on 100 parts by weight of the compound represented by 1) or (A-2).

It is also preferred to use the isocyanate adduct of the higher fatty acid polyhydric alcohol ester in combination with an ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer has a melt flow rate (MFR) of 5 to 2000 dg / min (particularly 5 to 1000 dg / m
In) ones are particularly preferred. MFR is 5dg / min
If it is less than 2000 d, the resolution may be deteriorated due to poor cutting of the ink, and if it exceeds 2000 dg / min, the ink may flow, and normal and uniform thermal transfer recording may not be performed. . The ethylene-vinyl acetate copolymer is used in an amount of 0 to 100 parts by weight of the compound represented by the formula (A-1) or (A-2).
500 parts by weight, particularly preferably 0 to 200 parts by weight, is preferably blended.

If necessary, other binders may be added to the hot-melt ink layer 3. Examples of the binder that can be added include those described in JP-A-8-80675, column 5, lines 13 to 40. It is preferable that the other binder is compounded up to 100 parts by weight based on 100 parts by weight of the compound represented by the formula (A-1) or (A-2).

Further, if necessary, waxes used as a binder in a conventional thermal transfer recording medium,
Oils, (liquid) plasticizers or resins may be added to the hot-melt ink layer 3. Also, JP-A-8-8067
Various additives described in column 6, lines 35 to 43 of JP-A No. 3 may be added to the hot-melt ink layer 3 or other layers.

The hot-melt ink layer 3 is prepared by mixing the above components with a predetermined solvent and mixing and dispersing the mixture with a disper, a homomixer, a dissolver, an ultrasonic mixer, a ball mill, a sand mill, an attritor, a dyno mill, or a three-roll mill. It is formed by applying and printing a coating material obtained by mixing and dispersing with a machine by a solution using a gravure coater or a wire bar or a melt coating method. The dry thickness of the hot-melt ink layer 3 is 0.1 to 5.0 μm, particularly 0.5 to 0.5 μm, from the viewpoint of the concealing property of the transfer surface after ink transfer and the halftone dot reproducibility.
Preferably it is 3.0 μm.

The lubricating protective layer 4 is provided for the purpose of protecting the transferred image and reducing the peeling force of the hot-melt ink layer 3. The lubrication protection layer 4 is mainly composed of wax.
The wax has a melt viscosity at 100 ° C. of 15
It is preferred to use one with less than cp, especially less than 12 cp, especially less than 7 cp. When a wax having a melt viscosity at 100 ° C. of 15 cp or more is used, the running property of the thermal transfer recording medium may be reduced due to insufficient reduction of the peeling force. The melt viscosity of the wax generally depends on its molecular weight and density.

Further, the above wax is ASTM D-3.
It is also preferred that the drop point based on 104 is 100 ° C or less, especially 98 ° C or less. When the dropping point is higher than 100 ° C., the running performance of the thermal transfer recording medium may be reduced due to insufficient reduction of the peeling force.

Further, the wax is JIS-Z-02
The maximum value of the probe tack in the range of 40 to 150 ° C. measured in accordance with No. 37 is 0.1 to 60 gf, particularly 1
It is preferably from 50 to 50 gf, particularly from 1 to 40 gf, from the viewpoint of improving the peelability of the hot-melt ink layer. The maximum value of the probe tack is 5.1 m in diameter of the probe.
m, a contact load of 300 gf / cm ² , a contact time of 0.1 second, and a peeling speed of 120 mm / sec.

Examples of the above wax include, for example,
JP-A-258436, column 4, lines 14 to 18, and the like, and polyethylene wax and paraffin wax are particularly preferably used. Particularly, it is desirable to use polyethylene wax in view of the running property of the thermal transfer recording medium during low energy printing. Examples of the polyethylene wax include those described in JP-A-8-258436, column 4, lines 25 to 43.

The lubricating protective layer 4 may be composed of only the above wax, or may be composed of the wax and other components. Other ingredients include
Resins such as ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, polyethylene, and petroleum resin that can improve the coating strength and flexibility of the lubricating protective layer 4 are exemplified.
One or more of these resins can be used. It is preferable that these components are contained in the lubricating protective layer 4 in an amount of 1 to 50% by weight, particularly 1 to 20% by weight.

The lubricating protective layer 4 is formed by applying and drying a paint obtained by dissolving or dispersing the wax and other components as required in a predetermined solvent. The dry thickness of the lubrication protective layer 4 is 0.1 μm or more and 5.0 μm.
m, and particularly preferably 0.1 to 3.0 μm, because the transfer sensitivity of the thermal transfer recording medium 1 is further improved and the running stability is further improved.

As the base material 2, papers such as condenser paper and glassine paper, and thin sheets and films of plastics such as polyester, polyimide, polycarbonate, polyamide, polyethylene and polypropylene are used. The thickness of the substrate 2 is about 0.2 to 20 μm, particularly 0.5 to 20 μm.
A range of 6.0 μm is preferred. .

The back coat layer 5 is provided to improve the heat resistance, the slipperiness, the running property and the like of the thermal transfer recording medium 1. As a material constituting the back coat layer 5, a silicone compound, a fluorine compound, a resin, a crosslinked polymer, a metal oil, or the like is used.

In the thermal transfer recording medium of the present invention, the above formula (A)
A configuration in which the above-mentioned heat-fusible ink layer containing the compound represented by -1) or (A-2) and at least one heat-fusible ink layer colored in a color other than the compound are provided on the base material 2. By doing so, the thermal transfer recording medium can be used in a recording system for forming a multicolor print image by heat-melting and transferring an arbitrary image onto the same recording paper. In this case, examples of the coloring material that can be used include a magenta coloring material and a cyan coloring material. In particular, the following formula (M
When the compound represented by formula -1) is used and the compound represented by the following formula (C-1), (C-2) or (C-3) is used as a cyan coloring material, the gradation is further improved. It is preferable because it improves. It is also preferable that the hot-melt ink layer colored with the magenta color material and the cyan color material contains an isocyanate adduct of the higher fatty acid polyhydric alcohol ester.

[0037]

Embedded image

[0038]

Embedded image

As the compound represented by the above formula (M-1)
Specific examples of preferable ones include R ₁And R_ThreeEach
Ethyl group, R_Two, R_Four, R_Five~ R₁₁Are each a hydrogen source
A compound that is a child, R₁~ R_FourIs an ethyl group, R_Five
~ R₁₁Is a hydrogen atom, and R₁~ R
_FiveIs an ethyl group, R₆And R₇Is methyl
Group, R₈~ R₁₁Are each a hydrogen atom.
Can be

As the compound represented by the above formula (C-1)
Specific examples of preferable ones include R ₁And R_TwoEach
Hydroxyethyl group, R_Three~ R_FiveAnd R₈Is each
Hydrogen atom, R₆And R₇Are each a hydroxyl group
Is mentioned. A compound represented by the above formula (C-2)
Specific examples of preferred are R₁And R_TwoBut it
A 2-sulfone-4-methylphenyl group, R_Three~ R₇
Is a hydrogen atom, R₈And R₉Is a hydroxyl group
Things. A compound represented by the formula (C-3);
Specific examples of preferred compounds include R₁~ R_FourAnd R
₆~ R₈Is a hydrogen atom, R_FiveAnd R₉Is an amino group
The compound which is is mentioned.

Although the thermal transfer recording medium of the present invention has been described based on the preferred embodiment, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, one or more layers may be provided on the hot-melt ink layer in order to improve the adhesion between the hot-melt ink layer and the recording paper. Further, when a heat-fusible ink layer containing the compound represented by the formula (A-1) or (A-2) and a heat-fusible ink layer colored in a color other than the color of the compound are provided. May be provided in any order. Further, as a hot-melt ink layer colored in a color other than the color of the compound,
A hot-melt ink layer colored black may be further provided.

[0042]

The present invention will be described in more detail with reference to the following examples, and the effectiveness of the present invention will be illustrated. However,
The present invention is not limited to such an embodiment. still,
In the following examples, “parts” means “parts by weight” unless otherwise specified.

Example 1 The following components were dispersed using a ball mill to prepare a paint for a lubricating protective layer. This coating material for a lubricating protective layer was applied on a 2.5 μm PET film coated with a silicone back coat using a wire bar coater, and then dried with a hot air drier at 80 ° C. for 60 seconds to obtain a thickness of 1. A 0 μm lubricating protective layer was formed.
Next, the following formulation was subjected to a dispersion treatment for 12 hours to prepare a hot-melt ink layer paint. This heat-meltable ink layer coating material is applied on the lubricating protective layer using a wire bar coater and dried to a solid content only to form a heat-meltable ink layer having a thickness of 2 μm. Obtained.

[Paint for lubricating protective layer]-80 parts of paraffin wax [HNP-10 (manufactured by Nippon Seiro), melt viscosity at 100 ° C: 8 cp, dropping point: 75 ° C, Probutac maximum value: 40 gf]-Ethylene-vinyl acetate Polymer 20 parts [EV-210ET (manufactured by Mitsui DuPont Polychemicals)] ・ Solvent (toluene) 400 parts

[Coating composition for heat-meltable ink layer] 10 parts of compound (A-1) (see Table 1) 40 parts of isocyanate adduct of lanolin fatty acid polyhydric alcohol [Lannox FPK-210 (manufactured by Nippon Seika)]・ Ethylene-vinyl acetate copolymer 30 parts [EV-210ET (manufactured by DuPont-Mitsui Polychemicals)] ・ Polyester resin 20 parts (bisphenol A glycol-based ester oligomer, number average molecular weight 1675) ・ Solvent (methyl ethyl ketone / toluene) 400 parts

The thermal transfer recording medium thus obtained was slit to a width of 12.7 mm to obtain an ink ribbon.
This ink ribbon was printed on plain paper (BEKK smoothness: 300 seconds) using a serial thermal transfer printer [manufactured by NEC Corporation, Bungo JX70MA Personal Word Processor 400 dpi], and the density of the transferred image was measured. In order to investigate the relationship between the printing energy and the transfer image density, the printing voltage was adjusted to 30.0 to 3 by operating the density adjusting lever.
The transfer density was measured with a Macbeth densitometer (RD514 type) while changing the voltage between 6.5 V. As a result, the applied voltage required to obtain a transferred image having a density of 1.0 was 32.0 V. The transferred image was excellent in chroma and transparency, and had good overlay suitability. No background stain was observed at the time of printing, and the running property of the ink ribbon and the fastness of the transferred image were good.

Example 2 Example 2 was repeated except that a lubricating protective layer was formed using the following lubricating protective layer paint, and a hot melt ink layer was formed using the following hot melt ink layer paint. In the same manner as in Example 1, an ink ribbon was obtained.

[Coating for lubricating protective layer] 80 parts of polyethylene wax [Polywax PW-500 (manufactured by Toyo Petrolite), melt viscosity at 100 ° C 6 cp, dropping point 87 ° C, probe tack maximum value 40 gf] 20 parts of vinyl acetate copolymer [EV-210ET (manufactured by DuPont Mitsui Polychemicals)]-400 parts of solvent (toluene)

[Coating composition for hot-melt ink layer] 10 parts of compound (A-2) (see Table 1) Obtained by subjecting behenic acid and pentaerythritol esterification reaction product to tolylene diisocyanate to an addition reaction. Reacted product 50 parts ・ Ethylene-vinyl acetate copolymer 40 parts [EV-210ET (manufactured by Du Pont-Mitsui Polychemicals)] ・ Solvent (methyl ethyl ketone / toluene) 400 parts

The same printing as in Example 1 was attempted using the above-described ink ribbon. As a result, the applied voltage required to obtain a transferred image having a density of 1.0 was 34.0 V. The transferred image was excellent in chroma and transparency, and had good overlay suitability. No background dirt is recognized at the time of printing,
The running property of the ink ribbon and the fastness of the transferred image were good.

COMPARATIVE EXAMPLE 1 A lubricating protective layer having a thickness of 1.0 μm was formed using the following lubricating protective layer coating material, and a 2 μm-thick lubricating protective layer was formed using the following hot-melting ink layer coating material. An ink ribbon was obtained in the same manner as in Example 1 except that a hydrophilic ink layer was formed.

[Coating for lubricating protective layer]-80 parts of carbana wax [Refined No. 1 (manufactured by Cera Rica Noda), melt viscosity at 100 ° C 27 cp, drop point 83 ° C, probe tack maximum value 110 gf]-Ethylene-vinyl acetate 20 parts of copolymer [EV-210ET (manufactured by Mitsui DuPont Polychemicals)]-400 parts of solvent (toluene)

[Heat-melting ink layer coating] 30 parts of compound (A-1) (see Table 1) 40 parts of ethylene-vinyl acetate copolymer [EV-210ET (manufactured by Du Pont-Mitsui Polychemicals)] Wax 30 parts ・ Solvent (methyl ethyl ketone / toluene) 400 parts

Using the above ink ribbon, the same printing as in Example 1 was attempted. As a result, the applied voltage required to obtain a transferred image having a density of 1.0 was 36.5 V. The transferred image was good in terms of chroma and transparency, but poor in overlay suitability. Further, the running property of the ink ribbon was unstable immediately after the start of printing, and the robustness of the transferred image was poor.

Comparative Example 2 A lubricating protective layer was formed using the following lubricating protective layer paint, and a 2 μm thick heat-fusible ink layer was formed using the following hot-melting ink layer paint. An ink ribbon was obtained in the same manner as in Example 1 except for the above.

[Coating for lubricating protective layer]-80 parts of microcrystalline wax [Polywax PW2000 (manufactured by Toyo Petrolite), melt viscosity at 149 ° C: 48 cp, drop point: 125 ° C, probe tack maximum value: 190 gf] · Ethylene-acetic acid 20 parts of vinyl copolymer [EV-210ET (manufactured by Du Pont-Mitsui Polychemicals)] 400 parts of solvent (toluene)

-Compound D (coloring component, see the following formula D) 10 parts-Isocyanate adduct of lanolinic acid fatty acid polyhydric alcohol 50 parts-Ethylene-vinyl acetate copolymer 30 parts [EV-210ET (manufactured by Du Pont-Mitsui Polychemicals) )] ・ Polyester resin 10 parts [Aromatic dicarboxylic acid ester oligomer, number average molecular weight 16,000] ・ Solvent (methyl ethyl ketone / toluene) 400 parts

[0058]

Embedded image

The same printing as in Example 1 was attempted using the above-mentioned ink ribbon. As a result, a transfer image having a density of 1.0 could not be obtained. The transferred image was good with respect to overlay suitability and fastness, but poor in chroma and transparency. The running property of the ink ribbon was unstable immediately after the start of printing.

[0060]

[Table 1]

[0061]

As described in detail above, according to the thermal transfer recording medium of the present invention, a transferred image excellent in sharpness and friction fastness can be obtained. Further, according to the thermal transfer recording medium of the present invention, a superimposed transfer image of two or more colors and halftone dots can be clearly printed even on rough surface paper, and a transfer image excellent in gradation can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an embodiment of a thermal transfer recording medium of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal transfer recording medium 2 Substrate 3 Thermally fusible ink layer 4 Lubricity protective layer 5 Back coat layer

 ──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Shigeki Takahashi 2606 Akabane, Kaigamachi, Haga-gun, Tochigi Pref.

Claims (4)

[Claims] 1. A thermal transfer recording medium comprising a substrate and a heat-fusible ink layer provided on a substrate, wherein the heat-fusible ink layer comprises a compound represented by the following formula (A-1) or (A-2): A thermal transfer recording medium comprising a higher fatty acid polyhydric alcohol ester and an isocyanate adduct. Embedded image 2. The compound represented by the formula (A-1) or (A-2) is 20 to 1 with respect to 100 parts by weight of the isocyanate adduct of the higher fatty acid polyhydric alcohol ester.
2. The thermal transfer recording medium according to claim 1, wherein the thermal transfer recording medium is contained in an amount of 000 parts by weight. 3. A thermal transfer recording medium according to claim 1, wherein a lubricating protective layer mainly composed of wax is provided between said substrate and said heat-fusible ink layer. 4. The ink composition according to claim 1, wherein
At least one heat-meltable ink layer colored in a color other than the compounds represented by 1) and (A-2) is provided on the base material, and is heat-melt-transferred into an arbitrary image on the same recording paper. The thermal transfer recording medium according to any one of claims 1 to 3, wherein the thermal transfer recording medium is used in a recording system for forming a multicolor print image.