JPH04327989A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer material which is high in resolution and excellent in printing quality by a method wherein a peeling control layer is provided between a base material and an ink layer. CONSTITUTION:A peeling control layer 3 having a mixture of heat plastic resin and filler as main component is provided between a base material 1 and an ink layer 2. Only the ink layer 2 of a part heated in transferring is made to be transferred onto a material to be transferred and the ink layer 2 of a non-heated part is made to remain certainly on the base material 1 side by making adhesive strength larger than cohesive force of ink thereby. For example, polyester, polyvinylacetate, polystyrene, etc., are exemplified as the heat platic resin to be used for the peeling control layer 3. As the filler, that of comparatively high transparency is suitable. For example, calcium carbonate, silicon oxide, clay, etc., are used, and its quantity should be preferably 5-50wt.% of the peeling control layer. The base material 1 and the ink layer may be as same as conventionally.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive transfer member, and more particularly to a heat-sensitive transfer member with good print quality.

0002

2. Description of the Related Art Conventional thermal transfer materials, as shown in FIG. (For example, Japanese Patent Laid-Open No. 55-3919).

0003

[Problems to be Solved by the Invention] However, in such a heat-sensitive transfer member, part of the ink layer other than the heated part (non-heated part) is transferred, resulting in low resolution and This tends to result in undesirable print quality.

An object of the present invention is to solve such problems and provide a thermal transfer member with high resolution and good print quality.

[0005]

[Means for Solving the Problems] The present invention achieves the above object by providing a peeling control layer mainly made of a mixture of a thermoplastic resin and a filler between the substrate and the ink layer. be.

That is, by providing a peel control layer mainly made of a mixture of a thermoplastic resin and a filler between the substrate and the ink layer as described above, the adhesive force between the substrate and the ink layer when not heated is improved. was made larger than the cohesive force of the ink layer, thereby ensuring that only the portion of the ink layer that was heated during transfer was transferred onto the transfer target, and the ink layer of the non-heated portion remained on the substrate side. .

[0007] Examples of the thermoplastic resin used in the peel control layer include polyester resin, polyvinyl acetate,
Examples include polystyrene, cellulose esters, cellulose ethers, acrylic resins, and styrene-butadiene copolymers.

[0008] Fillers with relatively high transparency are suitable, such as calcium carbonate, silicon oxide, clay, magnesium carbonate, colloidal silica, kaolin, aerosil, white carbon, and the like.

In the release control layer, the amount of filler is 5
A range of 50% by weight is preferred. When the amount of filler in the release control layer is less than 5% by weight, the adhesive force between the substrate and the release control layer is too strong, resulting in poor transferability of the ink layer, and when the content of filler is more than 50% by weight, The adhesive force between the substrate and the release control layer becomes smaller than the cohesiveness of the ink layer, making it difficult to cut the ink layer.

[0010] The method of forming the above-mentioned peeling control layer is not particularly limited, but a solvent coating method is usually employed.

That is, the thermoplastic resin is dissolved in a solvent,
A filler is uniformly dispersed in the solution to prepare a coating material for forming a peeling control layer, and this coating material for forming a peeling control layer is applied to one side of the substrate and dried to form a peeling control layer. It is formed.

[0012] The thickness of this peeling control layer is 0.3 to 0.
．． The thickness is preferably in the range of 5 μm; if the thickness is less than 0.3 μm, the effect of controlling the peeling of the ink layer in the non-heated portion from the substrate will not be sufficiently exhibited;
If it becomes thicker, heat conduction to the ink layer during heating for transfer will be poor, and there is a risk that defective transfer of the ink layer will occur.

[0013]Thermal transfer material is produced by forming an ink layer on the above-mentioned release control layer. In other words,
In the finished thermal transfer member, the release control layer is provided between the substrate and the ink layer.

[0014] The above-mentioned peeling control layer is composed mainly of a mixture of a thermoplastic resin and a filler, but being composed as a main material means that the peeling control layer is composed only of a mixture of a thermoplastic resin and a filler. This means a case where the release control layer is formed by adding additives to the thermoplastic resin and filler within a range that does not impair the function of the release control layer.

Examples of such additives include dispersants and surfactants for improving the dispersion of the filler into the thermoplastic resin. When these additives are added, the amount thereof is preferably kept at 5% by weight or less in the release control layer.

In the heat-sensitive transfer member of the present invention, the same conventional methods are employed for the substrate and the ink layer. For example, the substrate may be a polyethylene terephthalate film, a polyimide film, or any other material that can be used as a substrate for a heat-sensitive transfer material. Furthermore, in forming the ink layer, various inks that can be used as inks for thermal transfer members can be used.

Furthermore, in order to prevent deterioration of the substrate due to heat, a heat-resistant layer may be formed on the back side of the substrate (that is, the surface opposite to the surface on which the peeling control layer and ink layer are formed). .

[0018]

[Examples] Next, the present invention will be explained in more detail with reference to Examples.

Example 1 35 parts by weight of aromatic ester-containing polyurethane (Vylon UR8200, trade name, manufactured by Toyobo Co., Ltd.), 35 parts by weight of aliphatic polycarbonate (S-8200, trade name, manufactured by Asahi Glass Co., Ltd.), and carbon powder (manufactured by Mitsubishi Kasei Co., Ltd.). 30 parts by weight of MA-8 (trade name) manufactured by Co., Ltd. was dispersed in 150 parts by weight of a solvent (a mixed solvent of methyl isobutyl ketone and toluene in a weight ratio of 1:1) for 100 hours in a ball mill, and then used as a coating for forming an ink layer. It was used as a material.

[0020] Also, 90 parts by weight of a polyester resin (Vylon #103 manufactured by Toyobo Co., Ltd., trade name) was dissolved in 1800 parts by weight of a solvent (a mixed solvent of methyl isobutyl ketone and toluene in a weight ratio of 1:1). The solution has an average particle size of 0.
A coating material for forming a peel control layer was prepared by dispersing 10 parts by weight of 7 μm calcium carbonate powder.

A polyethylene terephthalate film with a thickness of 3.5 μm is used as the base, and one side of the base is coated with a heat-resistant material made of acrylic-silicon copolymer (Cymac 210 manufactured by Toagosei Co., Ltd.) with a hardening agent added. .4 μm thick to form a heat-resistant layer, and on the opposite side, apply the above coating material for forming a peel control layer and dry to a thickness of 0.4 μm.
A peel control layer was formed.

Next, the coating material for forming the ink layer was applied onto the peeling control layer and dried to form an ink layer with a thickness of 2.3 μm, thereby producing the heat-sensitive transfer member shown in FIG. did.

Referring to FIG. 1, 1 is a substrate, 2 is an ink layer, 3 is a release control layer, and 4 is a heat-resistant layer.

The substrate 1 is made of a polyethylene terephthalate film with a thickness of 3.5 μm, and the ink layer 2
Coating the coating material for forming the ink layer on the release control layer 3,
It is formed by drying, and its thickness is 2.3 μm.
It is. However, the solvent in the coating material for forming the ink layer is not contained in the ink layer 2 because it has been removed in the drying process during the formation of the ink layer 2.

The peel control layer 3 is formed by applying the coating material for forming the peel control layer on one side of the substrate 1 and drying it, and has a thickness of 0.4 μm. However, the solvent in the coating material for forming the peel control layer is not contained in the peel control layer 3 because it has been removed in the drying process during the formation of the peel control layer 3.

The heat-resistant layer 4 is formed on the surface of the substrate 1 opposite to the surface on which the ink layer 2 and the like are formed. however,
This heat-resistant layer 4 is not necessarily necessary if the base body 1 has sufficient heat resistance.

Example 2 Thermal transfer material was the same as in Example 1, except that the release control layer 3 was made of a mixture of 80 parts by weight of polyester resin and 20 parts by weight of silicon oxide powder having an average particle size of 0.7 μm. was created.

To explain in detail about the peel control layer 3, the coating material for forming the peel control layer was prepared by mixing 80 parts by weight of the same polyester resin as in Example 1 with 1800 parts by weight of a solvent (weight ratio of methyl isobutyl ketone and toluene). It was prepared by dissolving 20 parts by weight of silicon oxide powder having an average particle size of 0.7 μm in this solution.

The peeling control layer 3 has a thickness of 0.4 μm.
The coating material for forming the peel control layer was applied to one side of the substrate 1 in the same manner as in Example 1, and the coating material was dried.

Comparative Example 1 A thermal transfer member was produced in the same manner as in Example 1, except that the ink layer 2 was directly formed on the substrate 1 without forming the peel control layer 3.

The thermal transfer member of Comparative Example 1 corresponds to a conventional product, and its cross-sectional structure is as shown in FIG.

In FIG. 2, 1 is a substrate, 2 is an ink layer,
4 is a heat-resistant layer, the structure of which is the same as in the first embodiment.

Comparative Example 2 A heat-sensitive transfer member was produced in the same manner as in Example 1, except that a layer made only of polyester resin was formed in place of the peel control layer 3. The polyester resin used was the same as in Example 1.

Using the thermal transfer members of Examples 1 and 2 and Comparative Examples 1 and 2 above, the size of one dot of the thermal head was 120 μm×120 with an applied energy of 35 mj/mm2.
Each dot was transferred onto paper surface-treated with polyester resin using a μm printer, and the transfer area was measured.

The ratio of the measured transfer area to the area of the thermal head (transfer area ratio) is calculated using the following formula,
According to this transfer area ratio, Examples 1 and 2 and Comparative Examples 1 and 2
The resolution of the thermal transfer material No. 2 was evaluated.

[0036] In other words, when the transfer area ratio is close to 100%, it means that the characters to be printed are printed almost as planned, and this indicates that the thermal transfer material has high resolution and good print quality. be judged.

The formula used to calculate the transfer area ratio is as follows. Transfer area ratio (%) = S1 / S0 × 100 S1: Transfer area S0: Area of thermal head

Table 1 shows the transfer area ratios determined for the thermal transfer members of Examples 1 and 2 and Comparative Examples 1 and 2. The transfer area was measured 10 times for each thermal transfer material, and Table 1
shows the range from the minimum value to the maximum value of the transfer area ratio determined based on it. Table 1 also shows the amount of filler and the amount of resin (in both cases, the amount of polyester resin) in the release control layer.

[0039]

[Table 1]

As is clear from the results shown in Table 1, the transfer area ratio of the thermal transfer materials of Examples 1 and 2 remained within an appropriate range close to 100%, and high resolution and good print quality were obtained. It showed that it would be possible. This is Example 1~
This is because in the thermal transfer member No. 2, the peeling of the ink layer in the non-heated portion was controlled by providing a peeling control layer between the base and the ink layer.

On the other hand, the transfer area ratio of the thermal transfer member of Comparative Example 1 varied widely, ranging from 63 to 124%. This is because in the thermal transfer member of Comparative Example 1, the ink layer is formed directly on the substrate, so during transfer, the ink layer in the non-heated area is transferred along with the ink layer in the heated area, resulting in a larger transfer area. It is thought that the transfer area became small because the adhesive force between the substrate and the ink layer was too much greater than the cohesive force of the ink layer and the applied energy was insufficient.

Further, the thermal transfer member of Comparative Example 2 had a low transfer area ratio of 50 to 70%. This is because in the thermal transfer material of Comparative Example 2, a polyester resin layer is provided between the substrate and the ink layer, so the cohesive force of this polyester resin layer is high, and the applied energy as described above is insufficient. This is thought to be due to the fact that transcription was not possible.

In the thermal transfer member of Comparative Example 2, it is considered that when the applied energy is increased, so-called planar peeling occurs and the transfer area ratio greatly exceeds 100%.

[0044]

Effects of the Invention As explained above, in the present invention, by providing a peeling control layer between the substrate and the ink layer,
It was possible to provide a thermal transfer material with high resolution and good print quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a thermal transfer member of the present invention.

FIG. 2 is a sectional view showing a conventional thermal transfer body.

[Explanation of symbols]

1 Base 2 Ink layer 3 Peeling control layer

Claims (2)

[Claims] 1. A heat-sensitive transfer member having at least a base 1 and a heat-fusible ink layer 2, in which a peeling material mainly composed of a mixture of a thermoplastic resin and a filler is provided between the base 1 and the ink layer 2. A heat-sensitive transfer body characterized by providing a control layer 3. [Claim 2] The amount of filler in the peeling control layer 3 is 5 to 5.
The thermal transfer member according to claim 1, wherein the amount is 0% by weight.