JPH11321123A - Heat-transfer recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-transfer recording medium wherein a transferred image which is excellent in visibility and color fastness to rubbing can be obtained, and a superposed transferred image of two colors or more, and half tone dots can be clearly printed especially on a rough surface paper, and also, a transferred image being excellent in gradient can be obtained, and in addition, which is suitable for the formation of a multi-colored printed image. SOLUTION: A heat-melting ink layer contains a magenta based coloring matter which is represented by the formula, and a polyether resin of which the glass transition point is 35-100 deg.C, of which the number average molecular weight is 20,000 or lower, and which has a bisphenol skelton, and also, has a hydroxyl group at the molecular terminal. [In the formula, R1 -R5 each indicates hydrogen atom, halogen atom, a nitro group, and a hydrocarbon radical of which the number of carbon atoms is 1-1,000, or the like, and R6 -R11 each indicates hydrogen atom, halogen atom, an amino group, and a hydrocarbon radical of which the number of carbon atoms is 1-500, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention provides a transfer image excellent in sharpness and abrasion fastness, and furthermore, a superimposed transfer image of two or more colors and halftone dots on a rough surface paper can be printed clearly. The present invention relates to a thermal transfer recording medium capable of obtaining a transferred image having excellent tonality.

[0002]

2. Description of the Related Art As the performance of thermal transfer printers has been improved, it has been desired to reduce the thermal energy required for printing as much as possible. In order to suppress this thermal energy, the melting point of the ink composition is designed to be low. However, in this case, the background stain on plain paper occurs, and the fixability and the robustness of the transferred image are reduced. In addition, there has been a problem that a so-called blocking phenomenon occurs due to a change in environmental temperature during storage.

[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), but those satisfying the requirements are obtained. I didn't. Also,
Attempts have been made to achieve low-energy printing by reducing the thickness of the base material and increasing heat transfer.However, ink coatability on the paper surface is reduced, and ink ribbon running becomes unstable. There was a problem.

[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]

According to the present invention, there is provided a thermal transfer recording medium comprising a substrate having a heat-fusible ink layer provided thereon, wherein the heat-fusible ink layer comprises a compound represented by the following formula (A): And a polyether resin having a glass transition point of 35 to 100 ° C., a number average molecular weight of 20,000 or less, a bisphenol skeleton, and a hydroxyl group at a molecular terminal. Thus, the above object has been achieved.

[0007]

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[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the thermal transfer recording medium of the present invention, a heat-fusible ink layer is provided on a base material, and a lubricating protective layer is provided between the base material and the heat-fusible ink layer. Configuration. Further, a back coat layer is provided on the back surface of the substrate.

The heat-meltable ink layer has a compound represented by the above formula (A), a glass transition point of 35 to 100 ° C., a number average molecular weight of 20,000 or less, and a bisphenol skeleton.
And a polyether resin having a hydroxyl group at a molecular terminal. The compound represented by the formula (A) is used as a coloring material, and the polyether resin is used as a binder.

First, the above formula (A) used as a coloring material
Is a magenta dye, and in each formula, R
_{1 to} R ₅ are each independently a hydrogen atom,
It is a halogen atom, an amino group, a sulfone group, a hydroxyl group, an alkoxy group, a nitro group, a carboxylate group or an optionally substituted hydrocarbon group having 1 to 1000 carbon atoms. R _{1 to} R ₅ may be the same or different.

When R _{1 to} R ₅ are a halogen atom, fluorine, chlorine, bromine and iodine are preferably used. R _{1 to} R
_{When 5} is a hydrocarbon group, an alkyl or alkenyl group having 1 to 200 carbon atoms or 6 to 400 carbon atoms
Are preferably used. As the alkyl group, a linear or branched alkyl group having 1 to 100 carbon atoms is used, and particularly preferably, methyl, ethyl, propyl, butyl, pentyl, hexyl, 2- An ethylhexyl group, a 2-ethyloctyl group and the like are used. As the alkenyl group, alkenyl groups corresponding to these alkyl groups are preferable. Further, the hydrocarbon group may include a triple bond.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, phenanthryl group and the like having 6 carbon atoms.
~ 200 aromatic hydrocarbon groups are preferred. These alkyl group or alkenyl group and aromatic hydrocarbon group,
Some of these hydrogen atoms may be substituted with halogen atoms, amino groups, sulfone groups, nitro groups, hydroxyl groups, alkoxy groups, carboxylate groups, and the like. Also, R _{1 to} R
Among ₅ , R ₅ may be an alkali metal atom or an alkaline earth metal atom in addition to the above examples.

As described above, R _{6 to} R ₁₁ each independently represent a hydrogen atom, a halogen atom, an amino group, a sulfone group, a hydroxyl group, an alkoxy group, a carboxylate group or an optionally substituted carbon atom. 1 to 500 hydrocarbon groups. R _{6 to} R ₁₁ may be the same or different. Examples of the hydrocarbon group include an alkyl group or an alkenyl group and an aromatic hydrocarbon group. Examples of the alkyl group include linear or branched carbon atoms having 1 to 80 carbon atoms.
Of these, an alkyl group is preferably used, and particularly preferably, a methyl group, an ethyl group, a butyl group, a pentyl group, a hexyl group,
-Ethylhexyl group, 2-ethyloctyl group and the like are used. As the alkenyl group, alkenyl groups corresponding to these alkyl groups are preferable. Further, the hydrocarbon group may include a triple bond. As the aromatic hydrocarbon group, an aromatic hydrocarbon group having 6 to 100 carbon atoms such as a phenyl group is preferable. In these alkyl or alkenyl groups and aromatic hydrocarbon groups, even if some of those hydrogen atoms are substituted with halogen atoms, amino groups, sulfone groups, nitro groups, hydroxyl groups, alkoxy groups, carboxylate groups, etc. Good.

Specific examples of preferred compounds represented by the above formula (A) include compounds wherein R ₁ and R ₃ are each an ethyl group and R ₂ , R ₄ and R _{5 to} R ₁₁ are each a hydrogen atom; R _{1 to} R ₄ are each an ethyl group, R _{5 to} R
Compounds in which ₁₁ is each a hydrogen atom, and R ₁ , R ₃
And R ₅ are each an ethyl group, R ₆ and R ₇ are each a methyl group, and R ₂ , R ₄ and R _{8 to} R ₁₁ are each a hydrogen atom.

The compound represented by the formula (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 polyether resin.
If the content of the compound is less than 5 parts by weight, a sufficient print density may not be obtained and a printed image may be unclear,
If the amount is more than 250 parts by weight, the saturation is reduced, and the background color is concealed (opaque) when two or more colors are overprinted, and the desired color may not be obtained.

In the present invention, the compound represented by the formula (A) may be used in combination with another coloring material. Examples of such color materials include those described in JP-A-7-223377, column 4, line 49 to column 5, line 18.
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 polyether resin has a glass transition point (Tg) of 35 to 100 ° C. When the glass transition point of the polyether resin is less than 35 ° C., blocking of the ink is likely to occur, and the stability during storage or use may be lacking. When the temperature exceeds 100 ° C., the thermal stability is good. The use may be limited because the sensitivity is reduced. The preferred range of the glass transition point of the polyether resin is 40 to 100 ° C, and the more preferred range is 55 to 90 ° C. The glass transition point of the polyether resin in the present invention is measured by a differential thermal balance (DSC) method.

The polyether resin has a number average molecular weight (usually a number average molecular weight calculated from a terminal group) of 2
0000 or less, preferably 10,000 or less. A more preferred range is from 300 to 10,000, more preferably from 400 to 5,000. When the number average molecular weight of the polyether resin is within such a range, good transfer and fixing properties can be obtained, and clear transfer to rough surface paper can be achieved. On the other hand, when the number average molecular weight of the polyether resin exceeds 20,000, the sensitivity decreases. The number average molecular weight of the polyether resin in the present invention is a number average molecular weight in terms of polystyrene as measured by gel permeation chromatography (GPC).

The weight average molecular weight of the above polyether resin is preferably in the following range according to the use of the thermal transfer recording medium. That is, when used for the purpose of obtaining a binary transfer image in the same manner as a conventional wax-based hot-melt ink, the weight average molecular weight of the polyether resin is 20,000 or less,
In particular, it is 10,000 or less. Further, it is desirable to make the softening characteristics of the resin more sharp by narrowing the molecular weight distribution. On the other hand, when the resin is used for obtaining a density gradation property or a multi-value transfer image, it is desirable to melt-transfer a resin exhibiting gentle softening characteristics in accordance with the applied energy. The molecular weight does not necessarily need to be reduced, and may be set to 20,000 or more, but is preferably from 400 to 10,000. Of course, even in this case, a binary transfer image can be obtained favorably. The weight average molecular weight of the polyether resin in the present invention is determined by gel permeation chromatography (G
(PC).

Furthermore, the shape of the molecular weight distribution of the weight average molecular weight of the polyether resin does not necessarily need to be a shape having a single molecular weight peak, and may be a distribution shape having a plurality of molecular weight peaks, Alternatively, the distribution shape when a branched polymer component is used in combination may be used. However, the weight average molecular weight is 10,000 or more, especially 40,000
The above case is disadvantageous in sensitivity.

The above polyether resin has a bisphenol skeleton and has a hydroxyl group at a molecular terminal. Examples of the polyether resin include bisphenol compounds represented by the following formula (B) and diols such as propylene oxide adduct and ethylene oxide adduct thereof, and aliphatic epoxy having two epoxy groups in the molecule. Polyethers obtained by addition polymerization with a compound, an alicyclic epoxy compound or an aromatic epoxy compound and reacted so that epoxy groups do not remain at the molecular terminals and having hydroxyl groups at the molecular terminals (both terminals) Resins.

[0021]

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Here, X in the bisphenol compound represented by the above formula (B) is CH ₂ , O, S, CH ₂ C
H ₂ , OCH ₂ CH ₂ O, SCH ₂ CH ₂ S, SO ₂ ,
R ₁ -C-R _2, shows a direct bond, preferably, R ₁
—CR ₂ , a direct bond, CH ₂ CH ₂ , and SO ₂ . R _{1 to} R ₆ are preferably a hydrogen atom or a linear or branched alkyl group having 1 to 28 carbon atoms such as methyl, ethyl, butyl, hexyl, octyl, lauryl group as an alkyl group, and R _{3 to} R ₆ are preferably As a hydrogen atom or a halogen atom, fluorine, chlorine, bromine and iodine are preferred. Examples of the aliphatic epoxy compound having two epoxy groups in the molecule include 1,6-n-hexanediepoxide. Examples of the alicyclic epoxy compound having two epoxy groups in the molecule include 1,4-cyclohexanediepoxide. Examples of the aromatic epoxy compound having two epoxy groups in the molecule include bisphenol A diepoxide.

As another example of the above polyether resin,
Bisphenol epoxy resin and two hydroxyl groups in the molecule
Or more, each obtained by addition polymerization with a compound having one or more hydroxyl groups and one or more amino groups, or a compound having one or more hydroxyl groups and one or more carbonyl groups, and reacted so that no epoxy group remains at the molecular terminal. And polyether resins having hydroxyl groups at molecular terminals (both terminals). Here, examples of the bisphenol-based epoxy resin include a reaction product of an ethylene oxide adduct of bisphenol A and an epoxy compound having two epoxy groups in a molecule. Examples of the compound having two or more hydroxyl groups in the molecule include bisphenol A. Examples of the compound having one or more hydroxyl groups and one or more amino groups in the molecule include ethanolamine and the like. Examples of the compound having one or more hydroxyl groups and one or more carbonyl groups in the molecule include an ester compound of bisphenol A and a fatty acid.

In addition, 1,2,4-
A branched or crosslinked structure prepared by further using an epoxy compound having three or more epoxy groups in the molecule, such as an adduct of benzenetriol and a fatty acid epoxy compound having two epoxy groups in the molecule. May be used. The fact that the polyether resin has a hydroxyl group at the molecular terminal can be identified by infrared absorption or gas chromatography (GPC).

The compound represented by the formula (A) and the polyether resin are prepared by adding 5 to 50 parts by weight of the compound represented by the formula (A) to 100 parts by weight of the hot-melt ink layer.
It is preferable that the polyether resin is contained in an amount of 20 to 95 parts by weight. However, in this case, the total is 10
It is contained so as not to exceed 0 parts by weight.

The above polyether resin has a melt flow rate (MFR) of 5 to 2,000 dg / min, particularly 5 to 2000 dg / min.
It is preferable to use it in combination with a 1000 dg / min ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer is preferably blended in an amount of 0 to 500 parts by weight, particularly preferably 0 to 300 parts by weight, based on 100 parts by weight of the compound represented by the formula (A).

Further, it is preferable to use the above polyether resin in combination with an isocyanate adduct of a higher fatty acid polyhydric alcohol ester. The higher fatty acid used here is preferably a fatty acid having a melting point of at least 20 ° C. and having 10 to 40 carbon atoms. 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 or the like is 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 preferred.

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. still,
As the isocyanate adduct of the higher fatty acid polyhydric alcohol ester, a commercially available product can also be used. 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 a compound 10 represented by the above formula (A).
It is preferable to add 0 to 300 parts by weight, especially 0 to 150 parts by weight, based on 0 parts by weight.

If necessary, a binder described in, for example, JP-A-8-80675, column 5, lines 13 to 39 may be added to the hot-melt ink layer. It is preferable that these binders are blended up to 100 parts by weight based on 100 parts by weight of the compound represented by the formula (A).

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. Also, Japanese Patent Application Laid-Open No. 8-80673 is disclosed.
The various additives described in column 6, lines 35 to 43 of JP-A No. 195/1992 may be added to the hot-melt ink layer or other layers.

The dry thickness of the hot-melt ink layer is 0.1 to 0.1 from the viewpoint of the concealing property of the transferred surface after ink transfer and the halftone dot reproducibility.
It is preferable to set it to 5.0 μm, especially 0.5 to 3.0 μm.

The lubricating protective layer is provided for the purpose of protecting the transferred image and reducing the peeling force of the hot-melt ink layer.
The lubrication protection layer is mainly composed of wax. 100
Preferred are waxes having a melt viscosity at 15 ° C. of less than 15 cp, especially less than 12 cp, especially less than 7 cp. 100
When a wax having a melt viscosity at 15 ° C. of 15 cp or more is used, the running performance 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 also 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 20 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.

As the above wax, for example, JP-A-8
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 may be composed of only the above wax, or may be composed of the wax and other components. Other components include ethylene which can improve the coating strength and flexibility of the lubricating protective layer.
Vinyl acetate copolymer, ethylene-acrylic acid copolymer,
Examples include resins such as polyethylene and petroleum resin. One or more of these resins can be used. These components are 1 to 50% by weight in the lubricating protective layer,
In particular, it is preferable to contain 1 to 20% by weight.

The lubricating protective layer is formed by applying and drying a paint obtained by dissolving or dispersing the wax and other components as required in a predetermined solvent. Dry thickness of the lubrication protective layer is 0.1 μm or more and 5.0 μm
It is preferable that the thickness be less than 0.1 μm, especially 0.1 μm or more, because the transfer sensitivity of the thermal transfer recording medium is further improved, and the releasability and running stability are further improved.

As the base material, paper sheets 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 is about 0.2 to 20 μm, especially 0.5 to
A range of 6.0 μm is preferred.

The back coat layer is provided for improving the heat resistance, slipperiness, running properties, etc. of the thermal transfer recording medium. As a material constituting the back coat layer, a silicone compound, a fluorine compound, a resin, a crosslinked polymer, a metal oil, or the like is used.

The thermal transfer recording medium 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 is capable of superimposedly printing two or more colors of transferred images and halftone dots on rough surface paper, and has excellent gradation. For example, when the thermal transfer recording medium is used for a recording system for forming a multi-color print image by heat-melt transfer into an arbitrary image on the same recording paper, and particularly for a recording system for obtaining a full-color reproduction image, the thermal transfer recording medium is used. The heat-fusible ink layer containing the compound represented by the formula (A) and at least one heat-fusible ink layer colored with a color other than the compound as a heat-fusible ink layer on a substrate. What is necessary is just to provide the structure provided. In this case, as the coloring material that can be used, known yellow coloring materials and cyan coloring materials are used without particular limitation. Particularly, as a yellow-based coloring material, the following formula (Y-1) or (Y-
When the compound represented by the formula (2) is used and the compound represented by the following formula (C-1), (C-2) or (C-3) is used as the cyan coloring material, the gradation is further improved. It is preferable because it improves. In addition, each of the heat-meltable ink layers colored with the yellow-based coloring material and the cyan-based coloring material has a glass transition point of 35 to 100 ° C and a number average molecular weight of 20,000.
Hereinafter, it is also preferable that a polyether resin having a bisphenol skeleton and having a hydroxyl group at a molecular terminal is contained. Further, a heat-fusible ink layer may be used which is arranged repeatedly and sequentially along the longitudinal direction of the base material.

[0041]

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[0042]

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The thermal transfer recording medium of the present invention has been described based on the preferred embodiments. 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. Further, in order to obtain an image of two or more colors, in particular, a full-color image, a heat-fusible ink layer containing the compound represented by the formula (A) and a heat-fusible ink layer colored in a color other than the color of the compound. When the ink layers are provided, the respective heat-fusible ink layers may be provided in any order. Further, as the heat-fusible ink layer colored in a color other than the color of the compound represented by the formula (A), a black heat-fusible ink layer may be further provided.

[0044]

The present invention will be described in more detail with reference to the following examples. 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, stirred and dispersed to prepare a hot-melt ink layer coating material. This hot-melt 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 hot-melt ink layer having a thickness of 2.0 μm. I got the medium.

[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 20 parts of polymer [EV-210ET (manufactured by Mitsui DuPont Polychemicals)]-900 parts of solvent (toluene)

[Coating composition for hot-melt ink layer] 30 parts of compound (A ₁ ) (see Table 1) 40 parts of polyether resin [Epiclone (bisphenol-based epoxy resin, manufactured by Dainippon Ink and Chemicals) and bisphenol Reaction product with A, glass transition point 65 ° C, number average molecular weight 2,000, weight average molecular weight 4,000] ・ Ethylene-vinyl acetate copolymer 30 parts [EV-210ET (manufactured by DuPont Mitsui Polychemicals)] Solvent (methyl ethyl ketone / toluene) 900 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 33.0 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] Vinyl acetate copolymer 20 parts [EV-210ET (manufactured by Mitsui DuPont Polychemicals)]-Solvent (toluene) 900 parts

[Heat-melting ink layer coating] 10 parts of compound (A ₂ ) (see Table 1) 50 parts of polyether resin [Denacol EX-201 (epoxy compound, manufactured by Nagase Kasei Kogyo Co., Ltd.) and screws Reaction product with phenol A, glass transition point 75 ° C, number average molecular weight 3,000, weight average molecular weight 7,000]-40 parts of ethylene-vinyl acetate copolymer [EV-210ET (manufactured by DuPont Mitsui Polychemicals)] Solvent (methyl ethyl ketone / toluene) 900 parts

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 32.0 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.

Example 3 A lubricating protective layer was formed using the lubricating protective layer paint used in Example 2, and a hot-melt ink layer was formed using the following hot-melt ink layer paint. Except for the above, an ink ribbon was obtained in the same manner as in Example 1.

[Coating composition for hot-melt ink layer] 10 parts of compound (A ₃ ) (see Table 1) 50 parts of polyether resin [Reaction of Bisphenol A with Epicoat 828 (epoxy resin, made of oil-based shell epoxy)] Product, glass transition point 83 ° C, number average molecular weight 8,000, weight average molecular weight 15,000] ・ 40 parts of ethylene-vinyl acetate copolymer [EV-210ET (manufactured by Du Pont-Mitsui Polychemicals)] ・ Solvent (methyl ethyl ketone / toluene) ) 900 copies

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 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] An example 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.

[Paint for lubricating protective layer] 80 parts of carnauba wax [Refined No. 1 (manufactured by Cerrica Noda), melt viscosity at 100 ° C 27 cp, drop point 83 ° C, probe tack maximum value 110 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] 20 parts of compound (A ₃ ) (see Table 1) 50 parts of ethylene-vinyl acetate copolymer [EV-210ET (manufactured by Du Pont-Mitsui Polychemicals)] ・ ester 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 hot melt ink layer was formed using the following hot melt ink layer paint. An ink ribbon was obtained in the same manner as in Example 1.

[Coating for lubricating protective layer] 80 parts of polyethylene 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-vinyl acetate Copolymer 20 parts [EV-210ET (manufactured by Mitsui DuPont Polychemicals)]-Solvent (toluene) 900 parts

[Heat-melting ink layer paint] 20 parts of compound D (coloring component, see the following formula D) 50 parts of bisphenol epoxy resin (glass transition point 127 ° C., number average molecular weight 2,600, weight average molecular weight) 3,500) ・ Ethylene-vinyl acetate copolymer 30 parts [EV-210ET (Mitsui DuPont Polychemical)] ・ Solvent (methyl ethyl ketone / toluene) 900 parts

[0063]

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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 in terms of fastness, but poor in chroma, transparency and overlay suitability. The running property of the ink ribbon was unstable immediately after the start of printing.

The polyether resins used in Examples 1 and 2 each had a hydroxyl group at the molecular terminal.

[0066]

[Table 1]

[0067]

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.
Further, a multicolor print image can be formed.

 ──────────────────────────────────────────────────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) and a glass transition point of 35 to
A thermal transfer recording medium comprising: a polyether resin having a bisphenol skeleton, a number average molecular weight of 20,000 or less at 100 ° C., and a hydroxyl group at a molecular terminal. Embedded image 2. The thermal transfer recording medium according to claim 1, wherein the compound represented by the formula (A) is contained in an amount of 5 to 250 parts by weight based on 100 parts by weight of the polyether resin. 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 method according to claim 1, wherein the heat-fusible ink layer is formed of the formula (A)
And a heat-fusible ink layer colored in a color other than the compound represented by the formula: is provided on the base material, and is heat-melt-transferred into an arbitrary image on the same recording paper to form a multicolor print image. The thermal transfer recording medium according to any one of claims 1 to 3, wherein the thermal transfer recording medium is used for: