JPH11245520A - Thermal transfer recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form transfer images having the vividness and fastness to friction not depending on a printing method by the use of a specific coloring material and a specific binder combined as a constitutional component of the heat melt type ink layer of a thermal recording medium. SOLUTION: The heat melt ink layer contains a compound A used as a coloring material shown by the formula A-1 or A-2 and a compound B used as a binder having a glass transfer point of 3-100 deg.C, a softening point of 40-120 deg.C, and an endothermic quantity of 10 cal/g or less caused by crystal fusion, and these are used through combination. Each of the compound A is yellow dye, and in the formula, R1 -R3 respectively show independently a hydrogen atom, halogen atom, an amino group, a sulfone group, a hydroxyl atom, a nitro group, a carboxylate group 1-1,000 hydrocarbon group that can be substituted. The R1 -R3 can be the same or different.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a thermal transfer recording medium. More specifically, a transferred image having excellent clarity and fastness to friction can be obtained, and furthermore, a superimposed transferred image of two or more colors and a halftone dot can be printed clearly on a rough surface paper, and a transferred image having excellent gradation. The present invention relates to a thermal transfer recording medium capable of obtaining the following. 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 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 keeping the thermal energy required for printing lower than before, the heating and cooling cycle time of the head is shortened, and the thermal deterioration of the head can be prevented.
In particular, in a line printer, the power supply can be reduced in size. 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 suppress the heat energy required for printing,
When printing on plain paper, background stains due to the low melting point component of the wax occur, and the fixability and robustness of the transferred image decrease. In addition, when the environmental temperature increases during storage, a so-called blocking phenomenon occurs. Has arisen.

[0003] In order to solve these problems, a resin component is conventionally introduced into a binder of a hot-melt ink layer (Japanese Patent Application Laid-Open No. Sho.
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.

[0004] Separately, in order to obtain a color image excellent in gradation by printing two or more colors of a hot-melt ink, especially a full-color reproduction image, 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 capable of obtaining a transferred image excellent in sharpness and friction fastness. It is in. Further, an object of the present invention is to provide a superimposed transfer image of two or more colors and halftone dots on a rough surface paper, and to obtain a transfer image excellent in gradation.
Another object of the present invention is to provide a thermal transfer recording medium suitable for forming a multicolor print image.

[0006]

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). Compound A having a glass transition point of 30 to 100 ° C., a softening point of 40 to 120 ° C., and an endothermic amount due to melting of the crystal of 1
The object has been attained by providing a thermal transfer recording medium characterized by containing a compound B of 0 cal / g or less.

[0008]

Embedded image

[0009]

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.

The thermal transfer recording medium 1 shown in FIG. 1 has a heat-fusible ink layer 3 provided on a base material 2, and a lubrication protection layer 4 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 hot-melt ink layer 3 comprises a compound A represented by the above formula (A-1) or (A-2) and a glass transition point of 3
A compound B having a softening point of 40 to 120 ° C. and an endothermic amount due to melting of the crystal of 10 cal / g or less at 0 to 100 ° C.
And containing. The compound A is used as a coloring material. The compound B is used as a binder.

First, the compound A used as a coloring material
In the description, compound A is a yellow dye, and in each formula, R _{1 to} R ₃ each independently represent a hydrogen atom, a halogen atom, an amino group, a sulfone group, a hydroxyl group, a nitro group, as described above. , 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.

As 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 A is preferably contained in an amount of 5 to 250 parts by weight, more preferably 5 to 230 parts by weight, based on 100 parts by weight of the compound B. If the content of the compound A is less than 5 parts by weight, a sufficient print density may not be obtained and a printed image may be unclear, and if the content exceeds 250 parts by weight,
When the saturation is reduced and the overlay printing of two or more colors is performed, the underlying color is concealed and a desired color may not be obtained.

In the present invention, the above compound A and another coloring material may be used in combination. Examples of such a coloring material include, for example, JP-A-7-223377, column 4, line 49 to fifth column.
The dyes and pigments described in column 18 line 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.

As described above, the compound B has a glass transition point of 30 to 100 ° C. When the glass transition point of the compound B is less than 30 ° C., the rub fastness of a transferred image is not sufficient, and when it is more than 100 ° C., the softening point of the compound B becomes too high and good transferability is obtained. Absent. The preferred range of the glass transition point of the compound B is 40 to 100 ° C.

The compound B has an endothermic amount of 10 cal / g or less due to melting of the crystal. That is, the compound B is a low-crystalline or non-crystalline compound. When the heat absorption is more than 10 cal / g, the so-called solid coverage is poor and the running property of the thermal transfer recording medium may be reduced. The preferable range of the endothermic amount is 0 to 8 cal / g.

Both the glass transition point and the endothermic amount of the compound B are measured by a differential scanning calorimeter (DSC).

The compound B has a softening point of 40
To 120 ° C, preferably 45 to 110 ° C, more preferably 50 to 105 ° C. When the softening point is lower than 40 ° C., so-called solid covering property lowering, background soiling and blocking occur, and when the softening point is higher than 120 ° C., there is a possibility that the transfer sensitivity is lowered, the transfer is poor, and the running property is poor. The softening point is measured by a ring and ball method.

The compound B preferably has the above-mentioned physical properties and usually has a number average molecular weight of 100 to 30,000 calculated from the terminal group. When the number average molecular weight is less than 100, blocking or the like may occur after scumming or high-temperature storage, and when the number average molecular weight is more than 30,000, transfer failure may occur or the releasability may decrease. Is preferred. A more preferred range of the number average molecular weight is from 300 to 10,000, more preferably from 400 to 5,000. The number average molecular weight of the gel
It is measured by permeation chromatography (GPC) using styrene as a standard substance.

The compound A and the compound B preferably contain 5 to 50 parts by weight of the compound A and 20 to 95 parts by weight of the compound B in 100 parts by weight of the hot-melt ink layer. However, in this case, both are contained so that the total does not exceed 100 parts by weight.

Specific examples of the compound B include aromatic epoxy resins, phenol resins, aromatic polyamides, aromatic polyesters, hydrogenated terpene resins and ethylene-
Styrene copolymers and the like can be mentioned. Among them, a polyester resin obtained using benzenedicarboxylic acid as a raw material is preferable.

As the polyester resin, 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. Object is used. The polyester resin 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 heat-meltable ink layer.

As the polyvalent carboxylic acid for preparing the polyester resin, dibasic acid or its anhydride is used. For example, JP-A-25844456, column 3, 37.
Lines to fourth column, line 8, and the like. Particularly preferably used polyvalent carboxylic acids are adipic acid, azelaic acid, sebacic acid, succinic acid, dodecaic acid and anhydrides thereof. More preferred are fumaric acid, adipic acid, maleic anhydride, terephthalic acid, phthalic anhydride, isophthalic acid, and alkyl (C0 to C4) benzene poly (n = 1 to 4) alcohol.

On the other hand, as the polyhydric alcohol for preparing the polyester resin, a dioxy compound or the like is used.
Those described in line 20 are exemplified. Particularly preferably used polyhydric alcohols are ethylene glycol, 1,4
-Butanediol, 1,5-pentenediol, 1,6
-Hexanediol, 1,8-octanediol, 1,
Examples thereof include 9-nonanediol, 1,10-decanediol, neopentyl glycol, bisphenol A, polytetramethylene, ether glycol, and alkylene oxide adducts thereof. More preferably, ethylene glycol, diethylene glycol, bisphenol A, neopentyl glycol, alkyl or alkene (C1-C1)
C46) Poly (n = 1 to 6) alcohol and the like. The polyester resin may be used alone, or may be used as a mixture of two or more of the polyester resins. There is no particular limitation on the method of synthesizing the polyester resin,
Any known method can be used.

The compound B is preferably used in combination with an ethylene-vinyl acetate copolymer. As the ethylene-vinyl acetate copolymer, a melt flow rate (MF
R) is 5 to 2000 dg / min, especially 5 to 1000 d
g / min is particularly preferred. MFR is 5dg / m
If it is less than "in", the resolution may not be good due to poor ink cutting, and if it exceeds 2000 dg / min, ink flow or blocking may occur, and normal uniform thermal transfer recording may not be performed. Is preferred. The ethylene-vinyl acetate copolymer is preferably blended in an amount of 0 to 500 parts by weight, particularly preferably 0 to 200 parts by weight, based on 100 parts by weight of the compound A.

Further, it is preferable to use the compound B in combination with an isocyanate adduct of a higher fatty acid polyhydric alcohol ester. This 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, a fatty acid having a melting point of 20 ° C. or more and a carbon number of 10 to 40 can be suitably used. Of these, lanolin fatty acids and behenic acid are most effective. As the polyhydric alcohol, a saturated aliphatic polyol, an unsaturated aliphatic polyol, an alicyclic polyol, an oxygen-containing aliphatic polyol and the like are used, and particularly preferably used polyhydric alcohols are pentaerythritol, glycerin, glycol and the like. . As the isocyanate compound, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate and the like are particularly preferably used.

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 as long as at least one hydroxyl group capable of reacting with the isocyanate compound remains in the molecule. The addition reaction between the higher fatty acid polyhydric alcohol ester and the isocyanate compound can be carried out according to a conventionally known method. Although the number of moles of the isocyanate compound added is not particularly limited,
Per mole of the higher fatty acid polyhydric alcohol ester,
About 0.1 to 5 mol is preferable. 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 can be used. The isocyanate adduct of the higher fatty acid polyhydric alcohol ester is preferably added in an amount of 0 to 300 parts by weight, particularly preferably 0 to 150 parts by weight, based on 100 parts by weight of the compound A.

If necessary, another binder may be added to the heat-meltable ink layer 3. Examples of the binder that can be added include those described in JP-A-8-80675, column 5, lines 13 to 39. The other binder is 10 parts by weight based on 100 parts by weight of the compound A.
It is preferable to add up to 0 parts by weight.

Further, if necessary, waxes used as binders in conventional thermal transfer recording media,
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 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.
A drop point of 20 to 100 ° C., in particular 30 to 98
C. is preferred. If the dropping point is lower than 20 ° C., blocking may occur. If the dropping point is higher than 100 ° C., the traveling force 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 substrate 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 for improving 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.

The thermal transfer recording medium 1 is excellent in the sharpness of the transferred image and the fastness to friction when used in a single color. In addition to this, the thermal transfer recording medium 1 can print two or more colors of superimposed transfer images and halftone dots clearly on rough surface paper, and has excellent gradation. For example, when the thermal transfer recording medium 1 is used for a recording system for forming a multi-color print image by thermally melting and transferring an arbitrary image on the same recording paper, particularly a recording system for obtaining a full-color reproduction image, the thermal transfer recording medium is used. A configuration in which the heat-fusible ink layer containing the compound A and at least one heat-fusible ink layer colored in a color other than the compound A are provided on the base material 2 as the heat-fusible ink layer in the medium 1. do it. In this case, as the coloring material that can be used, there are known magenta coloring material and cyan coloring material. In particular, a compound represented by the following formula (M-1) is used as a magenta coloring material, and a compound represented by the following formula (C-1), (C-2) or (C-3) as a cyan coloring material. The use of a compound is preferable because the gradation is further improved. Further, it is also preferable that the compound B is contained in the heat-meltable ink layer colored with the magenta-based coloring material and the cyan-based coloring material. Further, a heat-fusible ink layer which is sequentially and repeatedly arranged along the longitudinal direction of the base material 2 may be used.

[0042]

Embedded image

[0043]

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, in order to improve the adhesion between the heat-fusible ink layer and the recording paper, on the heat-fusible ink layer, polyester, ethylene-vinyl acetate copolymer or a modified product thereof, polyamide, petroleum resin, wax, etc. One or more layers may be provided. In order to obtain an image of two or more colors, when providing a heat-fusible ink layer containing the compound A and a heat-fusible ink layer colored in a color other than the color of the compound A, The meltable ink layers may be provided in any order. Further, a black heat-meltable ink layer may be further provided as a heat-meltable ink layer colored other than the color of the compound A.

[0047]

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 coating 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-based back coat using a wire bar coater, and then dried with a hot air drier at 70 ° C. or 80 ° C. for 60 seconds. A lubrication protective layer having a thickness of 1.0 μm was formed. Next, the following components were charged into a mixed solvent, sufficiently dissolved, and further stirred and dispersed to prepare a hot-melt ink layer coating material. This hot-melt ink layer paint is applied on the lubrication protective layer using a wire bar coater,
Drying was performed to obtain only a solid content, and a heat-fusible ink layer having a thickness of 2 μm was formed to obtain an intended thermal transfer recording medium.

[Paint for lubricating protective layer]-80 parts of paraffin wax [HNP-10 (manufactured by Nippon Seiro), melt viscosity at 100 ° C, 8 cp, drop point: 75 ° C, Probutac maximum value: 40 gf]-Ethylene-vinyl acetate 20 parts of polymer [EV-210ET (manufactured by Mitsui DuPont Polychemicals)]-900 parts of solvent (toluene)

[Heat-melting ink layer coating material] 30 parts of compound (A-1) (see Table 1) 40 parts of compound B (polycondensate of terephthalic acid / ethylene glycol / isophthalic acid / neopentyl glycol; glass) Transition point 40 ° C, endothermic amount less than 1 cal / g, softening point 96 ° C, number average molecular weight 1600)-ethylene-vinyl acetate copolymer 30 parts [EV-210ET (manufactured by DuPont Mitsui Polychemicals)]-solvent (methyl ethyl ketone / toluene) ) 900 copies

The thus obtained thermal transfer recording medium 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 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] Vinyl acetate copolymer 20 parts [EV-210ET (manufactured by Mitsui DuPont Polychemicals)]-Solvent (toluene) 900 parts

[Heat-melting ink layer coating material] 10 parts of compound (A-2) (see Table 1) 50 parts of compound B (polycondensate of terephthalic acid / isophthalic acid / bisphenol A, glass transition point 53) ° C, endothermic amount 1.4 cal / g, softening point 85 ° C, number average molecular weight 1700) ・ Ethylene-vinyl acetate copolymer 40 parts [EV-210ET (manufactured by DuPont Mitsui Polychemicals)] ・ Solvent (methyl ethyl ketone / toluene) 900 Department

The same printing as in Example 1 was attempted using the ink ribbon. As a result, the applied voltage required to obtain a transferred image having a density of 1.0 was 33.0 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 paint, and a 2 μm thick hot melt was formed using the following hot-melting ink layer paint. 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 Copolymer 20 parts [EV-210ET (manufactured by Mitsui DuPont Polychemicals)]-Solvent (toluene) 900 parts

[Heat-fusible ink layer paint] 20 parts of compound (A-2) (see Table 1) 50 parts of ethylene-vinyl acetate copolymer [EV-210ET (manufactured by DuPont Mitsui Polychemicals)] Wax 30 parts ・ Solvent (methyl ethyl ketone / toluene) 900 parts

The same printing as in Example 1 was attempted using the above-mentioned ink ribbon. 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 Mitsui DuPont Polychemicals)]-900 parts of solvent (toluene)

[Heat-melting ink layer coating material] 20 parts of compound D (coloring component, see formula D below) 50 parts of binder [styrene-based thermoplastic resin (Hymer SB130 manufactured by Sanyo Chemical), glass transition point 61 ° C. , Endothermic quantity 18 cal / g, softening point 128 ° C, number average molecular weight 46000]-ethylene-vinyl acetate copolymer 30 parts [EV-210ET (manufactured by Mitsui Dupont Polychemical)]-solvent (methyl ethyl ketone / toluene) 900 parts

[0063]

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.

[0065]

[Table 1]

[0066]

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 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 (5)

[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 is a compound A represented by the following formula (A-1) or (A-2): When,
Glass transition point is 30 to 100 ° C, softening point is 40 to 120
And a compound B having an endothermic amount of 10 cal / g or less at 10 ° C. and melting of the crystal. Embedded image 2. The thermal transfer recording medium according to claim 1, wherein the compound A is contained in an amount of 5 to 250 parts by weight based on 100 parts by weight of the compound B. 3. The compound B is contained in an amount of 5 to 50 parts by weight in 100 parts by weight of the hot-melt ink layer.
3. The thermal transfer recording medium according to claim 1, wherein 20 to 95 parts by weight is contained (however, the total thereof does not exceed 100 parts by weight). 4. The thermal transfer according to claim 1, wherein a lubricating protective layer mainly composed of wax is provided between the substrate and the heat-meltable ink layer. recoding media. 5. The heat-fusible ink layer and the compound A
A heat-meltable ink layer colored in a color other than the above is provided on the base material, and is used in a recording system for forming a multicolor print image by heat-melt transfer to an arbitrary image on the same recording paper. The thermal transfer recording medium according to any one of claims 1 to 4, wherein: