JPH11180044A - Thermal transfer recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent scratch resistance and printing quality to a heat transfer recording medium wherein a hot-melt ink layer prepd. by dispersing a coloring material in a binder contg. a wax and thermoplastic oligomers is laminated on a substrate and to form a transfer image with excellent printing quality even when high speed printing is performed. SOLUTION: In a thermal transfer recording medium wherein a hot-melt ink layer 2 prepd. by dispersing a coloring material in a binder contg. a wax and thermoplastic oligomers is laminated on a substrate 1, as the thermoplastic oligomer resin, at least two kinds of thermoplastic oligomer resins are used and as one of two kinds of the thermoplastic oligomer resins, a thermoplastic oligomer resin exhibiting compatibility to the wax is used and as another one, a thermoplastic oligomer resin exhibiting non-compatibility to the wax is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer type thermal transfer recording medium.

[0002]

2. Description of the Related Art Conventionally, a thermal transfer recording medium having a two-layer structure in which a heat-meltable ink layer in which a coloring material is dispersed in a wax-based binder such as carnauba wax on a support such as polyester is widely used. However, when a wax-based binder is used, the abrasion resistance of the formed transferred image is not sufficient, and recently, a part of the wax of the binder has a better cohesive force than the wax and has a good compatibility with the wax. Attempts have been made to replace them with soluble thermoplastic trees.

However, in the case of a thermal transfer recording medium in which a thermoplastic oligomer resin exhibiting compatibility with wax is used in combination with a wax as a binder for the heat-fusible ink layer, a thermal transfer image is not produced as compared with a thermal transfer recording medium using only wax as a binder. Although the abrasion resistance has been improved, the print quality cannot be said to be sufficiently improved in terms of the sharpness of the peripheral portion or details of a transferred image (for example, a bar code pattern).

Therefore, in order to further improve the printing quality of the thermal transfer recording medium, an α-methylstyrene resin, which is a thermoplastic oligomer resin incompatible with the transfer recording wax, is used as a binder for the heat-fusible ink layer. It has been proposed to use them together (JP-A-6-286336). Here, the α-methylstyrene-based resin can form domains in the heat-meltable ink layer, and can maintain the domains even during heating in the thermal transfer operation, so that the details or the peripheral portion of the transferred image can be clearly defined. Thermal transfer can be performed.

As described above, Japanese Patent Application Laid-Open No. 6-2863
In the case of the thermal transfer recording medium described in Japanese Patent Publication No. 36, it can be said that the abrasion resistance and print quality of the thermal transfer image are improved in a better balance than when wax is simply used as a binder.

[0006]

However, in the case of the thermal transfer recording medium described in JP-A-6-286336, the abrasion resistance depends on whether the object to be transferred is ordinary coated paper or gloss coated paper. There is a problem that the balance between the improvement of the print quality and the print quality is lost, and further, when the print speed is increased more than before, the print quality is not sufficiently improved.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a hot-melt ink comprising a support and a coloring material dispersed in a binder containing a wax and a thermoplastic oligomer resin. In the thermal transfer recording medium on which the layers are laminated,
An object of the present invention is to provide excellent abrasion resistance and printing quality, and to form a transferred image having excellent printing quality even in high-speed printing.

[0008]

Means for Solving the Problems The present inventors have developed at least two types of thermoplastic oligomer resins used in combination with a binder: a thermoplastic oligomer resin having compatibility with wax and a thermoplastic oligomer resin having incompatibility with wax. It has been found that the above objects can be achieved by using a resin, and the present invention has been completed.

That is, the present invention relates to a thermal transfer recording medium in which a thermofusible ink layer in which a coloring material is dispersed in a binder containing a wax and a thermoplastic oligomer resin is laminated on a support. Wherein at least two kinds of thermoplastic oligomer resins are used, and one of the two kinds of thermoplastic oligomer resins is compatible with wax and the other is incompatible with wax. I will provide a.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

FIG. 1 is a sectional view of an example of the thermal transfer recording medium of the present invention. This thermal transfer recording medium is provided on a support 1.
It has a structure in which a heat-meltable ink layer 2 in which a coloring material is dispersed in a binder containing a wax and a thermoplastic oligomer resin is formed.

Here, in the heat-meltable ink layer 2, at least two kinds of thermoplastic oligomer resins are used as the thermoplastic oligomer resin used together with the wax, and one of the thermoplastic oligomer resins is compatible with the wax. A resin exhibiting solubility is used, and a thermoplastic oligomer resin exhibiting incompatibility with wax is used. Thereby, regardless of whether the transfer target is normal coated paper or gloss coated paper,
The abrasion resistance and the print quality can be improved in a well-balanced manner, and the print quality can be prevented from lowering even when the print speed is increased.

The at least two types of thermoplastic oligomer resins used in the heat-fusible ink layer 2 include:
Regarding the mutual relationship, it is preferable to use those showing compatibility with each other. Thereby, the abrasion resistance and the printing quality can be improved in a better balance, and furthermore, even when the printing speed is increased, the deterioration of the printing quality can be further suppressed.

In the present invention, two kinds of thermoplastic oligomer resins having different compatibility with the wax are used together with the wax. Here, the oligomer means a polymer having a number average molecular weight or a weight average molecular weight of 10,000 or less. means.

The thermoplastic oligomer resin having compatibility with wax used in the present invention is one which does not separate or become cloudy with the passage of time when left after being mixed with the wax in a heated state. As such a thermoplastic oligomer resin, for example, rosin or an ester thereof, a ketone resin, a coumarone resin, a petroleum resin, a styrene oligomer resin, and particularly an α-alkylstyrene resin can be preferably used. Here, as the α-alkylstyrene resin, a homopolymer of α-alkylstyrene such as α-methylstyrene, α-alkylstyrene,
Copolymers of alkylstyrene and other monomers can be exemplified.

The softening point of a styrene oligomer resin having compatibility with wax is determined by a ring and ball method (JIS K253).
In (1), the temperature is preferably from 70 to 160 ° C. The softening point can be controlled by appropriately adjusting the degree of polymerization of the styrene oligomer resin.

On the other hand, the thermoplastic oligomer resin having incompatibility with the wax is one that separates or becomes cloudy with the passage of time when left after being mixed with the wax in a heated state. As such a thermoplastic transient oligomer resin, for example, a polyester resin, a styrene oligomer resin having a higher molecular weight than the above-mentioned styrene oligomer resin which is compatible with wax, or a copolymer of α-methylstyrene and vinyltoluene is used. Styrene copolymer oligomers such as polymers can be preferably used.

The softening point of a styrene oligomer resin having incompatibility with wax is determined by the ring and ball method (JIS K25).
In 31), the temperature is preferably 90 ° C or more, particularly preferably 100 to 140 ° C. The softening point can be controlled by appropriately adjusting the degree of polymerization of the styrene oligomer resin.

When the two types of thermoplastic oligomer resins are both styrene oligomer resins, they are well compatible with each other after transfer, so that abrasion resistance and printing quality can be further improved in a well-balanced manner. Moreover, even when the printing speed is increased, the deterioration of the printing quality can be further suppressed.

As the wax used in the heat-meltable ink layer 2, those conventionally used in the heat-meltable ink layer of a thermal transfer recording medium can be used. Examples include natural waxes such as candelilla wax, carnauba wax, rice wax, wood wax and beeswax, petroleum waxes such as paraffin wax, petrolatum, ceresin, and synthetic waxes such as montan wax and polyethylene wax. These may be used in combination of two or more.

Further, as these waxes, in order to facilitate application to a printer of ordinary printing energy,
It is preferable to use one having a melting point of 80 ° C. or lower.

In the hot-melt ink layer 2, the wax 1
If the mixing ratio of the thermoplastic oligomer resin with respect to 00 parts by weight is too small, the effect of adding the thermoplastic oligomer resin cannot be sufficiently obtained, and the abrasion resistance will not be improved. Therefore, the amount is preferably 20 to 100 parts by weight, and more preferably 30 to 80 parts by weight.

In the hot-melt ink layer 2, if the proportion of the thermoplastic oligomer resin incompatible with the wax is too small relative to 100 parts by weight of the thermoplastic oligomer resin which is compatible with the wax. Sharp cutting of the hot-melt ink layer 2 at the time of transfer cannot be expected, and if it is too large, voids are likely to occur.

The coloring material used in the heat-fusible ink layer 2 is a coloring material (for example, carbon black,
Various pigments and various dyes).

In addition to the wax, thermoplastic oligomer resin and coloring material, known additives, ultraviolet absorbers, softeners, antibacterial agents and the like can be appropriately added to the heat-meltable ink layer 2.

The thickness of the hot-melt ink layer 2 described above is not particularly limited, but is usually 2.5 to 4.0 μm.

As the support 1 used in the present invention, a support conventionally used in a thermal transfer recording medium can be used, for example, a resin film such as a polyethylene terephthalate film or a polyimide film, or a resin film coated with them. A composite paper material, a metal sheet such as an aluminum foil, or the like can be used.

The thickness of the support 1 is not particularly limited and can be appropriately determined according to the purpose of use.

In the thermal transfer recording medium of the present invention, it is preferable to further provide an adhesive resin layer (primer layer) between the support 1 and the hot-melt ink layer 2. By providing such an adhesive resin layer, unintended peeling of the heat-meltable ink layer 2 can be prevented.

As such an adhesive resin layer, an adhesive resin layer conventionally used in a thermal transfer recording medium can be used, and for example, a urethane resin layer or a polyester resin layer is preferably used. .

The thermal transfer recording medium of the present invention may be provided with a known heat-resistant slide in order to prevent the thermal head from sticking to the back surface of the support 1 and to ensure the heat and running properties of the transfer recording medium, if necessary. A functional layer may be formed.

The thermal transfer recording medium of the present invention can be manufactured according to a conventional method. For example, it can be produced by applying a composition for a heat-fusible ink layer on a support and drying to form a heat-fusible ink layer.

The thermal transfer recording medium of the present invention can be applied to an ordinary thermal transfer printer or the like having a thermal head as a heating means for a transfer target such as a coated sheet, a high gloss coated paper, a resin sheet such as a vinyl chloride sheet, or a paper. A transfer image can be formed using a normal thermal transfer device.

[0034]

The present invention will be described below in more detail with reference to examples.

Table 1 shows information on the types, softening points (° C.), weight average molecular weights and compatibility with waxes of the thermoplastic oligomer resins used in the following Examples and Comparative Examples.

[0036]

[Table 1] Resin name Thermoplastic oligomer Softening point Weight average Type of wax resin (° C) Molecular weight Compatible pentaline K ^{* 1} Polymerized rosin ester 165-185 6000 Compatible Picotex 120 ^{* 2} C9 aromatic hydrocarbon 115-121 3190 Incompatible Entex 155 ^{* 3} C9 aromatic hydrocarbons 150 to 156 6200 Incompatible FTR8100 ^{* 4} C9 aromatic hydrocarbons 95 to 105 1100 Compatible FTR8120 ^{* 5} Alkyl styrene 115 to 125 1490 Compatible Hensel C ^{* 6} Polymerized rosin ester 143 to 148 1720 Compatible YS Hollister T-145 ^{* 7} Phenol-modified terpene 140-150 1120 Compatible Elytel UE-3320 ^{* 8} Polyester resin 79-85 2000 Incompatible * 1, * 2, * 3 Science Hercules * 4, * 5 Mitsui Petrochemical * 6 Arakawa Chemical * 7 Yasuhara Chemical * 8 Unitika

In the following Examples and Comparative Examples,
Examples 1 to 4 are examples in which a styrene oligomer resin was used as both a thermoplastic oligomer resin having compatibility with wax and a thermoplastic oligomer resin having incompatibility with wax.

In Example 5, a styrene oligomer resin was used as a thermoplastic oligomer resin having compatibility with wax, while a thermoplastic oligomer resin having incompatibility with wax other than styrene oligomer resin was used. This is an example.

Examples 6 to 8 used a thermoplastic oligomer resin having compatibility with wax other than styrene oligomer resin, while a thermoplastic oligomer resin having incompatibility with wax used styrene oligomer resin. This is an example using.

Comparative Examples 1 and 2 are examples in which a thermoplastic oligomer resin having compatibility with wax is used but a thermoplastic oligomer resin having incompatibility with wax is not used.

Comparative Example 3 is an example in which a thermoplastic oligomer resin which is incompatible with wax is used, but a thermoplastic oligomer resin which is compatible with wax is not used.

Comparative Example 4 is an example in which a resin other than an oligomer was used as a resin having compatibility with wax.

Example 1 A composition (primer composition) for an adhesive resin layer shown in Table 2 was coated on one surface of a polyester film (4.9 μm thick, manufactured by Teijin Limited) having a heat-resistant lubricating layer on the back surface with a bar coater. It was applied and dried at 110 ° C. for 3 minutes to provide an adhesive resin layer (primer layer) having a thickness of 0.1 μm.

[0044]

Table 2 Component Parts by weight Polyurethane resin solution (solid content 55%) 5 (manufactured by Daicel Chemical Industries, Ltd.) Methyl ethyl ketone 66.5 Toluene 28.5

Next, the composition for a hot-melt ink layer shown in Table 3 was stirred in an oven at 80 ° C. to form a uniform solution, which was coated on the adhesive resin layer using a bar coater. And dried in an oven at 100 ° C. for 2 minutes to 3.3 μm.
By forming a m-thick heat-fusible ink layer, a thermal transfer recording medium was produced.

[0046]

Table 3 Ingredients Parts by weight Carnauba wax 55 Styrene oligomer resin (Picotex 120) 15 Styrene oligomer resin (FTR8100) 10 Carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dye Co., Ltd.) Toluene 160

Example 2 Example 1 was repeated except that the composition for a hot-melt ink layer in Table 4 was used instead of the composition for a hot-melt ink layer in Table 3.
In the same manner as in the above, a thermal transfer recording medium was produced.

[0048]

Ingredients : parts by weight carnauba wax 45 styrene oligomer resin (Endex 155) 15 styrene oligomer resin (FTR8100) 20 carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dyestuffs Co., Ltd.) toluene 160

Example 3 Example 1 was repeated except that the composition for a hot-melt ink layer in Table 5 was used instead of the composition for a hot-melt ink layer in Table 3.
In the same manner as in the above, a thermal transfer recording medium was produced.

[0050]

Table 5 Ingredients Parts by weight Carnauba wax 55 Styrene oligomer resin (ENDEX 155) 15 Styrene oligomer resin (FTR8120) 10 Carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dyestuffs Co., Ltd.) Toluene 160

Example 4 The procedure of Example 1 was repeated except that the composition for an adhesive resin layer (primer composition) shown in Table 6 was used instead of the composition for an adhesive resin layer (primer composition) shown in Table 2. Similarly, a thermal transfer recording medium was produced.

[0052]

[Table 6] Component parts by weight Polyester resin 3 (Vylon # 200, manufactured by Toyobo Co., Ltd.) Methyl ethyl ketone 68 Toluene 29

Example 5 Example 1 was repeated except that the composition for a heat-fusible ink layer in Table 7 was used instead of the composition for a heat-fusible ink layer in Table 3.
In the same manner as in the above, a thermal transfer recording medium was produced.

[0054]

Ingredients : parts by weight carnauba wax 60 polyester resin (UE-3320) 10 styrene oligomer resin (FTR8100) 10 carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dye Co., Ltd.) toluene 160

Example 6 Example 1 was repeated except that the composition for a hot-melt ink layer shown in Table 8 was used instead of the composition for a hot-melt ink layer shown in Table 3.
In the same manner as in the above, a thermal transfer recording medium was produced.

[0056]

[Table 8] Ingredients Parts by weight Carnauba wax 55 Polymerized rosin ester (pentalin K) 10 Styrene oligomer resin (Picotex 120) 15 Carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dye Co., Ltd.) Toluene 160

Example 7 Example 1 was repeated except that the composition for a hot-melt ink layer shown in Table 9 was used instead of the composition for a hot-melt ink layer shown in Table 3.
In the same manner as in the above, a thermal transfer recording medium was produced.

[0058]

Ingredients : parts by weight carnauba wax 55 phenol-modified terpene (T-145) 10 styrene oligomer resin (ENDEX 155) 15 carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dye Co., Ltd.) toluene 160

Example 8 A thermal transfer recording medium was prepared in the same manner as in Example 1 except that the composition for a heat-fusible ink layer in Table 3 was used instead of the composition for a heat-fusible ink layer in Table 3. Produced.

[0060]

[Table 10] Ingredients Parts by weight Carnauba wax 55 Polymerized rosin ester (Pencel C) 10 Styrene oligomer resin (Picotex 120) 15 Carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dyestuffs Co., Ltd.) Toluene 160

Comparative Example 1 A thermal transfer recording medium was prepared in the same manner as in Example 1 except that the composition for a heat-fusible ink layer in Table 3 was used instead of the composition for a heat-fusible ink layer in Table 3. Produced.

[0062]

[Table 11] Ingredients Parts by weight Carnauba wax 55 Styrene oligomer resin (FTR8100) 25 Carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dyestuffs Co., Ltd.) Toluene 160

Comparative Example 2 A thermal transfer recording medium was prepared in the same manner as in Example 1, except that the composition for a heat-fusible ink layer in Table 3 was used instead of the composition for a heat-fusible ink layer in Table 3. Produced.

[0064]

[Table 12] Ingredients by weight Carnauba wax 55 Styrene oligomer resin (FTR8100) 10 Polymerized rosin ester (Pencel C) 15 Carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dye Co., Ltd.) Toluene 160

Comparative Example 3 A thermal transfer recording medium was prepared in the same manner as in Example 1 except that the composition for a heat-fusible ink layer shown in Table 13 was used instead of the composition for a heat-fusible ink layer shown in Table 3. Produced.

[0066]

[Table 13] Ingredients Parts by weight carnauba wax 55 Styrene oligomer resin (Picotex 120) 25 Carbon dispersion (30 wt%) 60 (MHI Perak-209, manufactured by Mikuni Dye Co., Ltd.) Toluene 160

Comparative Example 4 A thermal transfer recording medium was prepared in the same manner as in Example 1 except that the composition for a heat-fusible ink layer shown in Table 14 was used instead of the composition for a heat-fusible ink layer shown in Table 3. Produced.

[0068]

Ingredients : parts by weight carnauba wax 63 ethylene vinyl acetate copolymer 7 (Smitate KA31, molecular weight: about 50,000, manufactured by Sumitomo Chemical Co., Ltd.) Styrene oligomer resin (Endex 155) 10 Carbon dispersion (30 wt%) 60 (MHI Perak) -209, manufactured by Mikuni Dye Co., Ltd.) Toluene 160

(Evaluation) The thermal transfer recording media obtained in Examples 1 to 8 and Comparative Examples 1 to 4 were tested for print quality, print density, high-speed printability and abrasion resistance as described below. ,evaluated. Table 15 shows the obtained results.

The print quality thermal transfer recording medium was converted to a commercially available thermal transfer printer (Z-14).
0, manufactured by ZEBRA) and coated with label coated paper (F
barcode pattern image (print energy 14 mj / mm ² , asson 1C, manufactured by FASSON)
The printing speed was 6 inch / sec). The overall transferability of the resulting transferred image, such as jerk, void and transfer failure, was visually observed and evaluated according to the following criteria.

Print quality evaluation criteria Rank: Standard ◎: Jerky, void, poor transfer, etc. are not observed, and good overall print is obtained ○: Any of jerk, void, poor transfer, etc. Slightly observed, but good printing with no practical problems is obtained. △: Jerky, void, poor transfer, etc. are observed, but overall there is no practical problem. X: When jerk, void, transfer failure, etc. are observed and transfer failure is apparent.

A thermal transfer image was obtained in the same manner as in the evaluation of print quality except that solid printing was performed instead of the print density barcode pattern. The optical density (OD) of the obtained image was measured using a Macbeth densitometer (TR).
-924). The obtained numerical values were evaluated according to the following criteria.

Print Density Evaluation Criteria Rank: Criteria ：: 2.00 <OD △: 1.90 <OD ≦ 2.00 Δ: 1.80 <OD ≦ 1.90 ×: OD ≦ 1.80

High-speed printability Using the same printer as that used in the print evaluation, the print speed (inc) at which the edge portion of the barcode pattern image can be printed with sufficient sharpness can be maintained.
h / sec) was measured visually. In this case, the faster the printing speed, the better.

A bar code pattern was thermally transferred in the same manner as in the evaluation of print quality, except that gloss-coated paper (K8TB, manufactured by TEC) was used instead of the scratch-resistant coated paper (Fasson 1C, manufactured by FASSON). . A rubbing tester (RUBBING TESTER AB-30) was applied to the obtained transferred image.
1, manufactured by Tester Sangyo Co., Ltd.), and a cotton cloth rubbing test was performed in which a load of 800 g was applied and the cotton cloth was rubbed 20 times.
Bar coat 後 after the rubbing test was visually observed and evaluated according to the following evaluation criteria.

The print quality on the gloss-coated paper was evaluated in the same manner as when it was performed on the coated paper.

Evaluation criteria for abrasion resistance Rank criteria ◎: When there is no damage to the image ○: When there is almost no damage △: When there is damage at several places ×: When a considerable number of damage occurs

[0078]

[Table 15] Example Comparative example Evaluation items 1 2 3 4 5 6 7 8 8 1 2 3 4 (FASSON 1C) Print density ○ ○ ○ ○ △ ◎ ○ ◎ × ○ × △ Print quality ◎ ◎ ◎ ◎ ◎ △ ○ ○ ○ △ △ ○ △ High-speed printability 12 12 12 12 10 10 10 9 8 7 10 8 (K8TB) Scratch resistance ◎ ◎ ◎ ◎ ○ ◎ ◎ ◎ ○ ◎ △ × Print quality ◎ ○ ◎ △ ◎ ○ △ ◎ △ × × ×

As is clear from Table 15, Examples 1 to 8
The thermal transfer recording medium uses a thermoplastic oligomer resin compatible with the wax and a thermoplastic oligomer resin incompatible with the wax in addition to the wax as a binder for the heat-meltable ink layer. Good results were obtained for all items regardless of whether the body was coated paper or gloss coated paper. In particular, in the case of Examples 1 to 4 in which the two types of thermoplastic oligomer resins are the same type of resin (styrene oligomer resin), in addition to obtaining good results in a well-balanced manner for all of the evaluation target items,
Excellent high-speed printability.

On the other hand, in addition to the wax, a thermoplastic oligomer resin compatible with the wax is used as the binder of the heat-fusible ink layer, but no thermoplastic oligomer resin incompatible with the wax is used. In the case of Comparative Example 1, in particular, the print density on coated paper (Fasson 1C, manufactured by FASSON) was insufficient. Also,
High-speed printability was also insufficient.

Similarly to Comparative Example 1, in the case of Comparative Example 2 in which a thermoplastic oligomer resin compatible with wax was used, but no incompatible thermoplastic oligomer resin was used, particularly, And the print density on gloss coated paper (K8TB, manufactured by TEC) was insufficient. Also,
High-speed printability was also insufficient.

Further, in Comparative Example 3 in which a thermoplastic oligomer resin incompatible with wax was used, but no compatible thermoplastic oligomer resin was used, coated paper (Fasson 1C, FASSON Co.) Print density on gloss-coated paper (K8T
B, manufactured by TEC).

Further, in the case of Comparative Example 4 in which a thermoplastic oligomer resin incompatible with wax is used, but a resin other than oligomer is used as the resin compatible with wax, especially in the case of gloss coated paper. (K8TB, manufactured by TEC Co., Ltd.) had insufficient scratch resistance and print quality.
In addition, high-speed printability was insufficient.

[0084]

The thermal transfer recording medium of the present invention has excellent abrasion resistance and printing quality, and can form a transferred image having excellent printing quality during high-speed printing.

[Brief description of the drawings]

FIG. 1 is a sectional view of a thermal transfer recording medium of the present invention.

[Brief description of reference numerals]

 1 support 2 heat-meltable ink layer

Claims (8)

[Claims] 1. A thermal transfer recording medium comprising a support and a heat-meltable ink layer in which a coloring material is dispersed in a binder containing a wax and a thermoplastic oligomer resin, wherein at least two types of thermoplastic oligomer resins are used. A thermal transfer recording medium using the thermoplastic oligomer resin of (1), wherein one of the two types of thermoplastic oligomer resins is compatible with wax and the other is incompatible with wax. 2. The thermal transfer recording medium according to claim 1, wherein the two kinds of thermoplastic oligomer resins are compatible with each other. 3. The thermal transfer recording medium according to claim 1, wherein the thermoplastic oligomer resin having compatibility with the wax is a styrene oligomer resin. 4. The thermal transfer recording medium according to claim 3, wherein the styrene oligomer resin is an α-alkylstyrene resin. 5. The thermoplastic oligomer resin having incompatibility with wax is a styrene oligomer resin.
5. The thermal transfer recording medium according to any one of items 1 to 4. 6. The thermal transfer recording medium according to claim 1, wherein the heat-fusible ink layer contains the thermoplastic oligomer resin in a proportion of 20 to 100 parts by weight with respect to 100 parts by weight of the wax. 7. The heat-fusible ink layer contains 30 to 200 parts by weight of a thermoplastic oligomer resin which is incompatible with wax, based on 100 parts by weight of a thermoplastic oligomer resin which is compatible with wax. Claims 1 to 1 containing
7. The thermal transfer recording medium according to any one of 6. 8. The thermal transfer recording medium according to claim 1, wherein an adhesive resin layer is formed between the support and the hot-melt ink layer.