JPH0221252Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transfer paper that provides a transferred image surface with excellent friction durability.

Conventional transfer paper is made by printing colored ink consisting of a pigment or dye coloring agent and a binder mainly composed of wax or resin to bind them together on a base material such as plastic film or thin paper. ,
This method is used to transfer color onto a transfer object, such as printing paper, by applying heat with a heating element and applying pressure with a printing hammer from the surface of the substrate opposite to the printed surface on which the colored ink has been applied. transfer ink,
Used for the purpose of penetrating and forming images. Therefore, unless the printing paper used as the transfer material has extremely high ink absorption properties, such transferred images generally result from some of the molten colored ink remaining on the surface layer of the printing paper without penetrating. I get tired. The material for this colored ink is selected to have a low softening temperature of about 100°C to 80°C in the case of thermal transfer, for example, in order to improve transferability and transfer speed. The mechanical strength of the ink film itself is weak, and if the transfer ink remains on the surface layer of the printing paper, if a force is applied to the surface, the ink film may be chipped or smudged, resulting in poor image quality. There are drawbacks that can be detrimental.

The present invention is characterized in that the colored ink layer and colorless ink layer of the transfer paper are separated and provided in a layered manner in order to improve these drawbacks and prevent stains caused by transfer ink remaining on the surface of the printing paper. That is.

As shown in Fig. 1, in the conventional transfer paper, a colored ink layer 2 is applied directly onto a base material 1, and the ink 2 is transferred to a transfer target 6 such as printing paper, but the transfer paper of the present invention Explaining according to FIG. 2, in a transfer paper that can be heat-transferred or pressure-transferred at 100°C or less, a colorless ink layer mainly composed of a binder having a softening temperature of about 100°C to 40°C is formed on the base material 1. 3. A transfer paper consisting of a multilayered film of colored ink 2 mainly composed of a binder and a coloring agent having softening temperatures in the same range, and when transferred to an object, the colorless ink layer 3 is transferred to an upper layer than the colored ink layer 2.

In the thermal transfer paper of the present invention, the base material 1 of the transfer paper
This uses thin films such as polyester, cellophane, and capacitor paper, similar to the materials used for conventional thermal transfer paper, but the base material 1
When a thermofusible ink is formed on top as a transfer ink layer, a multilayer structure is used including a colored ink layer 2 containing a pigment or dye as a coloring agent and a colorless ink layer 3 containing no coloring agent. The binder used for each of these two ink layers is, for example, the same material as conventionally used hot melt resin such as ethylene-vinyl acetate copolymer,
Waxes such as carvana wax and paraffin wax are used, but the heat-melting components that serve as the binder for these two ink layers do not have to be exactly the same, but it is better to use waxes with similar heat-softening properties to reduce uneven transfer. This does not occur and stable ink layer transfer can be obtained.

In the transfer ink image formed on the printing paper 6 using the transfer paper of the present invention, as shown in FIG. 4 is overcoated. Therefore, as described above, it is possible to eliminate stains caused by rubbing, etc., which are observed in transfer ink images of conventional thermal transfer paper.

The transfer paper of the present invention can also be used as a pressure-sensitive transfer paper (so-called carbon type ribbon), and even if a transfer ink image is formed by pressure means such as a typewriter, the same effect as above can be obtained. can bring.

The present invention will be explained in detail by way of examples.

Hot melt agent Topco K343 (Toyo Petrolite) was applied to 10μ capacitor paper to a thickness of about 2μ, and colorless ink layer 3 was applied.
A transfer paper coated with was formed. Furthermore, carbon black is applied on the film surface of this colorless ink layer 3.
A colored ink layer 2 having a thickness of about 3μ is obtained by hot-melt coating TOPCO K343 containing 35wt% dispersion. A thermal transfer paper having an ink layer structure separated into two layers was prepared, and the thermal transfer paper was superimposed on a high-quality paper under the conditions described below to form a transfer ink image. Thermal head is 300 msec pulse current
Using a thin film head with a 6 dot/mm heating element that generates a surface temperature of ~400°C, heat is applied from the substrate side of thermal transfer paper with the high quality paper and ink side superimposed, creating a two-layer structure. The ink layer was simultaneously transferred to the high-quality paper. When this transfer ink area is observed under a microscope, the colorless ink is coated and transferred onto the colored ink as a protective film, protecting the surface of the image formed with the colored ink.
The durability of the transferred image can be obtained.

Figure 3 is a graph showing the friction durability of the image surface of a conventional transfer image made with a single-layer ink and a transfer image made with the two-layer structure ink of the present invention, and shows the degree of loss of colored ink due to rubbing with an eraser. There is.

As shown in the graph, the degree of loss of colored ink was measured by the change in light reflection density of the transferred ink image formed on the transfer target using the transferred ink image of the embodiment of the present invention and the conventional thermal transfer paper with only a colored ink layer. In this case, colored ink easily comes off in the transferred ink image that does not have a colorless ink layer, and the density change is large, but compared to this, the density change in the transferred ink image using the thermal transfer paper of the present invention is small; The effectiveness is clear.

Using the transfer paper of this invention, the friction durability of the ink image transferred onto a transfer target such as printing paper is improved, and it is possible to prevent stains caused by the transfer ink on the surface of the printing paper during practical use. It is possible to form a transferred image with good friction durability without impairing the image quality on paper.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional transfer paper, FIG. 2 is a cross-sectional view of the transfer paper of the present invention, and FIG. 3 is a graph showing the friction durability between the transfer paper of the present invention and the conventional transfer paper. 1... Base material, 2... Colored ink layer, 3... Colorless ink layer, 4... Transfer colored ink, 5... Transfer colorless ink.

Claims (1)

[Scope of utility model registration request] In a transfer paper that can be heat-transferred or pressure-transferred at 100°C or less, a colorless ink layer 3 mainly composed of a binder having a softening temperature of about 100°C to 40°C is formed on the base material 1, followed by a colorless ink layer 3 having a softening temperature in the same range. This transfer paper is composed of a multi-layered colored ink layer 2 mainly composed of a binder and a colorant, and when transferred to an object, the colorless ink layer 3 is in an upper layer than the colored ink layer 2. A transfer paper that is characterized by being transferred.