JP2001010239A - Thermal transfer recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat resistance and friction resistance of a transferred image recorded by thermal transfer by using a thermal transfer recording medium and to make the image resistant even to pressing by an iron at a high temperature and with a high pressure. SOLUTION: This thermal transfer recording medium has a layered structure wherein a base 1, a release layer 2, an ink layer 3 and an adhesive layer 4 are laminated sequentially, and the ink layer 3 is formed of a coloring agent and a binder resin. As the binder resin, in this case, a copolymer which is constituted of styrene of 20-50 wt.%, methyl methacrylate of 20-80 wt.% and butyl acrylate and/or butyl methacrylate of 10-60 wt.% and of which the flow softening point is 75-170 deg.C is used, and polyamide is used for the adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording medium capable of obtaining a transferred image having excellent friction resistance and heat resistance.

[0002]

2. Description of the Related Art Conventionally, as a thermal transfer recording method, a thermal transfer recording medium in which an ink layer comprising a heat-fusible substance mainly composed of wax and a coloring agent such as a dye or a pigment is provided on a support has been used. In addition, there is known a method in which the ink layer is heated according to print information at the time of transfer, and is thermally melt-transferred to a transfer target such as recording paper. Such a thermal transfer recording method is widely used in various fields in addition to transferring image information and character information to general recording paper. For example, in the label industry and the apparel industry, barcodes, product names, prices, serial numbers, and the like are printed on packaging materials, labels attached, and the like, thereby performing distribution management and product management.

However, when printing is performed on a packing material or a sticking label by thermal transfer recording, the transferred printing is distorted due to friction between the packing materials or friction between the label and the pen scanner, and the printed information becomes unreadable. In some cases, the transferred printing ink softens in a high-temperature atmosphere, and contaminates the product.

In order to solve the above problem, as a technique for improving the transferability of a thermal transfer recording medium, 10 to 40 parts by weight of styrene, 10 to 40 parts by weight of methyl methacrylate, 20
It has been proposed to use a copolymer consisting of .about.80 parts by weight (JP-A-62-23779).

[0005]

However, even when the above-mentioned specific copolymer is used as the binder resin for the ink layer of the thermal transfer recording medium, the printed matter obtained therefrom is used for an apparel tag. However, there is a problem that the ink is softened at the time of the iron press in the finishing process of the apparel product and the product may be stained.

The present invention is intended to solve the above-mentioned problems of the prior art, and can form a clear transfer image on various objects to be transferred such as a coated paper or a resin film. To provide a thermal transfer recording medium capable of improving abrasion resistance and heat resistance, and in particular, to provide a thermal transfer recording medium capable of forming a transfer image that can withstand a high-temperature, high-pressure iron press in an apparel product finishing process. It is an object.

[0007]

In order to achieve the above object, the present invention relates to a binder for forming an ink layer in a thermal transfer recording medium comprising a substrate, a release layer, an ink layer, and an adhesive layer sequentially laminated. The present inventors have found that it is effective to use a resin composed of a copolymer of a specific component and having a flow softening point in a specific range, and have completed the present invention. That is, the present invention provides a thermal transfer recording medium comprising a base material, a release layer, an ink layer, and an adhesive layer, which are sequentially laminated, wherein the ink layer comprises a colorant and a binder resin. %, Methyl methacrylate 20-80% by weight, butyl acrylate and / or butyl methacrylate 10-60% by weight, having a flow softening point of 75-170.
The present invention provides a thermal transfer recording medium characterized in that the recording medium has a temperature of ℃ and the adhesive layer contains a polyamide.

Hereinafter, the thermal transfer recording medium of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a thermal transfer recording medium 10 according to an embodiment of the present invention. As shown in FIG. 1, the thermal transfer recording medium 10 has a release layer 2 and an ink layer 3 sequentially laminated on one surface of a base material 1, and further has an adhesive layer 4 laminated on the ink layer 3. are doing. Further, a protective layer 5 is laminated on the other surface of the substrate 1.

Here, as the substrate 1, a film sheet such as a polyester film, a polyimide film, a polycarbonate film or the like generally used as a substrate for a thermal transfer recording medium, a condenser paper or the like can be used.

The release layer 2 enables the ink layer 3 to be transferred with low energy during transfer, and also allows a heated portion of the ink layer 3 to be uniformly transferred from the substrate 1 to obtain a clear transfer image. It is provided for. As a component of the release layer 2, it is preferable to use a heat-fusible substance having a melting point of 50 to 150 ° C. as a main component. Examples of such a heat-fusible substance include carnauba wax, montan wax, and candelilla. Wax, paraffin wax, oxidized wax, microcrystalline wax, rice wax and the like can be used. Further, as a main component of the release layer 2, a mixture of these waxes and a thermoplastic resin can also be used.

The ink layer 3 is formed from an ink comprising a colorant and a binder resin. In the present invention, the binder resin is composed of 20 to 50% by weight of styrene, 20 to 80% by weight of methyl methacrylate, and 10 to 60% by weight of butyl acrylate. % Of a copolymer having a flow softening point of 75 to 170 ° C. as a main component. Styrene constituting the copolymer is 20
If the amount is less than the weight percentage, the plasticity is reduced, and the friction resistance of the transferred image is reduced. On the other hand, if it exceeds 50% by weight, the melt viscosity increases and the print quality and transferability decrease. On the other hand, if the content of methyl methacrylate is less than 20% by weight, the hardness of the transferred image is insufficient, and sufficient friction resistance cannot be obtained.
If it exceeds, plasticity cannot be obtained, and transferability decreases. Also,
Butyl acrylate is 10 to 60% by weight.
When the content is more than 20% by weight, the heat resistance tends to decrease. When the content exceeds 20% by weight, the melt viscosity is reduced and the heat resistance is easily reduced.

When the flow softening point of the copolymer is less than 75 ° C., the heat resistance and friction resistance of the transferred image are reduced, and when it exceeds 170 ° C., the thermal transfer becomes difficult and the transfer becomes insufficient. And a clear transfer image cannot be obtained. In addition, the flow softening point was measured for the sample 1 in a cylinder (diameter 1 mm).
cm ³ and heated (heating rate 6 ° C / mi
n), when the temperature at which the sample starts to melt is t1, and the temperature at which the sample flows out is t2, (t1 + t2) / 2
Required by

As such a copolymer, those having an average molecular weight in the range of 7 × 10 ^{4 to} 17 × 10 ⁴ are preferable. Incidentally, the above-mentioned Japanese Patent Application Laid-Open No. 62-23779
In the binder resin of the ink layer described in JP
In order to improve the friction resistance and heat resistance, the average molecular weight of the copolymer that can be used there is limited to a narrow range of 1 × 10 ^{4 to} 5 × 10 ^4. Since the release layer 2 is provided on one side and the adhesive layer 4 is provided on the transfer layer side of the ink layer 3, it is possible to use a copolymer having a wider range of molecular weight.

As the coloring agent used in the ink layer, the same coloring agents as those used in the conventional examples can be used. For example, carbon black, organic pigments, inorganic pigments, dyes and the like can be used.

The ink layer may further contain a filler and other additives.

The adhesive layer 4 enables the ink layer 3 to be transferred with low energy during transfer, and transfers the ink layer 3 to various objects to be transferred, such as coated paper or a plastic label, thereby obtaining a strong transfer image. It is provided for the purpose. As a component of the adhesive layer 4, it is preferable to use a thermoplastic resin having a softening point of 80 to 170 ° C., for example, a vinyl acetate resin (Esnil C-2, C-5, etc., manufactured by Sekisui Chemical Co., Ltd.). , Polyester resin (manufactured by Unitika Ltd., UE-3200, manufactured by Toyobo Co., Ltd., Byron # 200, etc.), polyamide resin (Henkel Hakusui Co., Ltd.)
, DPX550, Fuji Kasei Kogyo Co., Ltd., Tomide # 92, etc.), ketone resin, and other hydrocarbon resins (Mitsui Petrochemical Co., Ltd., FTR7100, FTR712)
5) can be used. Further, a wax can be further added to these thermoplastic resins.

The protective layer 5 prevents sticking and allows the thermal transfer recording medium to run smoothly.
Provided as needed. The protective layer 5 is formed of a resin having excellent heat resistance such as a silicone resin, a fluororesin, an acryl-silicone resin, or a nitrocellulose resin, or a resin obtained by adding a lubricant such as a silicone oil or a fluorine powder to these resins. Can be.

The thermal transfer recording medium having the above-described layer structure can be manufactured according to a conventional method. For example, a composition for a protective layer is applied to one surface of the substrate 1 using a gravure coater and dried to form a protective layer 5, and a composition for a release layer is formed on the other surface of the substrate 1 using a gravure coater. The composition can be manufactured by applying a substance and drying to form a release layer 2, applying ink thereon and drying to form an ink layer 3, and further applying and drying the composition for an adhesive layer thereon.

[0020]

In the thermal transfer recording medium of the present invention, a release layer, an ink layer, and an adhesive layer are sequentially laminated on a base material, so that transferability to various objects to be transferred is improved, and a clear transfer image can be obtained. Becomes possible. Further, styrene 20 to 5 is used as a binder resin for forming an ink layer of the thermal transfer recording medium.
0% by weight, 20 to 80% by weight of methyl methacrylate, and 10 to 60% by weight of butyl acrylate having a flow softening point of 75 to 170 ° C. The heat resistance and heat resistance are remarkably improved.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments.

Examples 1 to 7 and Comparative Examples 1 to 5 After drying a coating for a release layer having the following composition on one surface of a polyester film having a thickness of about 5.0 μm and having a protective layer made of an acrylic silicone resin provided on the back surface. 1.0g application weight
/ M ² using a coil bar to apply evenly.
Drying was performed at 100 ° C. to form a release layer. On the other hand, as shown in Table 1, styrene (St), methyl methacrylate (MMA), butyl methacrylate (BMA), and butyl acrylate (BA) were used as binder resins for the ink.
Was used to obtain copolymers of various monomer compositions. Then, the obtained copolymer or carnauba wax is used as a binder resin in a proportion of 24% by weight, carbon black (Monarch 120) in a proportion of 6% by weight, and methyl ethyl ketone (MEK).
An ink was prepared from 70% by weight. This ink was uniformly applied onto the release layer so that the weight after drying was 1.5 g / m ^2, and dried at 100 ° C. to form an ink layer. Further, a coating material for an adhesive layer having the following composition was uniformly applied to the ink layer using a coil bar so that the coating amount was 0.3 g / m ^2, and dried to form an adhesive layer. Obtained. A thermal transfer recording medium without a release layer (Comparative Example 4) or a thermal transfer recording medium without an adhesive layer (Comparative Example 5) was similarly prepared.

(Blending of paint for release layer) Carnauba wax 18 parts by weight Ethylene-vinyl acetate copolymer resin 2 parts by weight (Estate KA-31 manufactured by Sumitomo Chemical Co., Ltd.) Toluene 80 parts by weight (for paint for adhesive layer) Compounding) Polyamide resin (manufactured by Henkel Hakusui Co., Ltd., DPX550) 5 parts by weight Isopropyl alcohol 50 parts by weight Toluene 45 parts by weight The obtained thermal transfer recording medium was mounted on a thermal transfer printer for bar code printing (Autonics, BC8MKII). ,
The printed matter was printed on a surface-coated tag paper, and the printed matter was evaluated for transferability, friction resistance and heat resistance as follows.

That is, the transferability was evaluated by examining the presence or absence of voids, blurring, and ink drop during printing, and evaluated by ○, Δ, and ×. As the rub resistance, based on a dye fastness test of JIS L0823, a dye fastness tester type II was used.
After performing a reciprocating frictional motion 100 times with a load of 0.2 kg / cm ² , the presence or absence of transfer of the ink to the cotton cloth was examined.
It evaluated by x. As for the heat resistance, a tag paper covered with cotton cloth is superimposed on the printing surface with a hot press,
After heating to 50 ° C. and pressing at a pressure of 1 kg / cm ² for 12 seconds, the presence or absence of transfer of the ink to the cotton cloth was examined.
It evaluated by x. The results are shown in Table 1. As shown in Table 1, when the thermal transfer recording media of Examples 1 to 7 of the present invention were used, clear transfer images were obtained, and the rub resistance and heat resistance were excellent. On the other hand, when the flow softening point of the binder resin is as low as 45 ° C. (Comparative Example 1), the friction resistance and heat resistance are inferior. When the flow softening point is as high as 210 ° C. (Comparative Example 2), the transferability is poor. No transfer image was obtained.
When carnauba wax was used as a binder resin (Comparative Example 3), sufficient friction resistance and heat resistance were not obtained. Even when the same copolymer as in Example 5 was used as the binder resin, when a release layer was not provided (Comparative Example 4), voids and blurring occurred, and a good transfer image was not obtained. When not provided (Comparative Example 5)
Similarly, voids and blurring occurred.

[0025]

[Table 1] Example Comparative Example 1 2 3 4 5 6 7 1 1 2 3 4 4 5 Copolymer (Monomer composition: wt%) St 20 40 30 20 50 20 20 20 20-50 50 MMA 20 40 30 70 20 60 20 50 60- 20 20 BMA 40 0 20 0 30 10 30 10 10 −30 30 BA 20 20 20 10 0 10 0 20 10 −0 0 (Average molecular weight: X10-4) 10 10 10 7 15 15 17 5 20 −15 15 (Flow (Softening point: ° C) 75 90 100 130 140 150 170 45 210 − 140 140 Ink composition: wt% copolymer 24 24 24 24 24 24 24 24 24 0 24 24 carnauba wax 0 0 0 0 0 0 0 0 0 24 0 0 carbon 6 6 6 6 6 6 6 6 6 6 6 6 MEK 70 70 70 70 70 70 70 70 70 70 70 70 Layer configuration Release layer Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes Adhesive layer Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No No Evaluation Transferability ○ ○ ○ ○ ○ ○ ○ ○ × ○ × × Friction resistance ○ ○ ○ ○ ○ ○ ○ × − × − − Heat resistance ○ ○ ○ ○ ○ ○ ○ × − × − −

[0026]

According to the thermal transfer recording medium of the present invention, a clear transfer image can be formed on various objects to be transferred such as a coated paper or a resin film, and the transferred image has improved friction resistance and heat resistance. In addition, it will be able to withstand high temperature and high pressure iron press in the finishing process of apparel products.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Release layer 3 Ink layer layer 4 Adhesive layer 5 Protective layer 10 Thermal transfer recording medium

Claims (2)

[Claims] 1. A thermal transfer recording medium comprising a base material, a release layer, an ink layer, and an adhesive layer sequentially laminated, wherein the ink layer comprises a colorant and a binder resin.
Styrene 20 to 50% by weight, methyl methacrylate 20
A copolymer having a flow softening point of 75 to 170 ° C and a bonding layer containing polyamide. A thermal transfer recording medium characterized by the above-mentioned. 2. The copolymer has an average molecular weight of 7 × 10 ⁴ -1.
2. The thermal transfer recording medium according to claim 1, wherein the density is 7 × 10 ⁴ .