JPH0995064A - Ink ribbon and thermal transfer printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink film that the ink adherence is strong and scarcely released. SOLUTION: The ink ribbon 20 is used to thermally transfer print heat meltable ink on a recording sheet by a recording head, and comprises heat meltable binders 12, 16 provided at both sides of the heat meltable inks 13, 14, 15 formed of a plurality of colors on the same flat surface. The binder 12 has coating thickness substantially equal to or more than the surface roughness of the sheet to be printed. The inks of the plurality of colors each has a thickness of 1.8μm or less, and the other binder 16 has a thickness equal to the total sum of the thicknesses of the inks of the plurality of the colors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ribbon and a printing method using the same, and more particularly to an ink ribbon used for thermal transfer printing by transferring a heat-meltable ink to a recording sheet by a recording head. is there.

[0002]

2. Description of the Related Art In thermal transfer printing, as shown in FIG. 1, the principle is as follows: an ink ribbon 2 coated with a heat-melting ink 1 and a recording paper 3, a thermal head 4 and a platen roller 5.
And the ink ribbon 2 and the recording paper 3 are pressed against the platen roller 5 by the thermal head 4, and the heat of the thermal head 4 generated by the electric current flown according to predetermined data is melted by heat. The heat-meltable ink 1 is melted and the melted heat-meltable ink 1 is transferred to the recording paper 3 side.

The printing obtained in this way is as shown in FIG. 2 in the case of one color, and the dots of the hot-melt ink 7 attached to the recording paper 6 by the current flowing according to the data are attached. The area (printing area) is different. When this area is large, the adhesive force of the heat-meltable ink to the recording paper is large, but it is not possible to express detailed data. Conversely, when the area is small, the adhesive force is large. The small heat-meltable ink is easily peeled off.

Color printing of two or more colors, for example, three colors, is as shown in FIG. 3, that is, the case of one color is repeated three times, and the recording paper 8 is melted by heat. The inks 9, 10 and 11 are attached so as to overlap each other.

[0005]

As described above, in the case where the heat-melting inks 9, 10, and 11 are attached to the recording paper 8 so as to overlap with each other, the area (printing area) of the dots of the heat-melting ink is When it is small (the leftmost one in FIG. 3), the adhesive force is still small and the ink is easily peeled off, and when the data of the ink that is overlaid is large like the second one from the left in FIG. Is difficult to adhere to the area below the ink, and if the last ink is to be applied between the dots that overlap three colors, such as the fourth from the left, the ink can be easily applied. There is a drawback that it does not adhere.

As a solution to this drawback, there is an ink ribbon 14 as shown in FIG. 4, for example. That is, a heat-meltable binder layer 12 provided on a base surface (not shown) and having a heat-melting temperature higher than the heat-melting temperature of the heat-melting binder 12, the heat-melting binder and a predetermined coloring material. Hot-melt ink layer 13 containing a mixture of
Using a pair of ink ribbons each of which is provided on the same plane in the longitudinal direction, and by a heat-sensitive transfer printing apparatus as shown in FIG. 1, first, the heat-meltable binder of the heat-meltable binder layer 12 is applied to the recording paper 3. Is melted by the heat of the thermal head 4 to form a heat-meltable binder layer 12 on one surface of the recording paper 3, and then the heat-meltable ink layer 13 is melted by the heat of the thermal head 4 by a predetermined amount of data to heat the same. The hot-melt ink is transferred and printed on the meltable binder layer 12. As a result, the ink adheres firmly after printing and becomes difficult to peel off.
There is an ink ribbon that allows the ink to be fixed accurately according to the data.

However, in the ink ribbon 14 having such a structure, the coating amount (coating thickness) of the hot-melt ink is applied.
In the present situation, no consideration has been given to the above, and no consideration has been given to the coating amount (coating thickness) of the hot-melt binder. The present invention provides a coating amount (coating thickness) of the heat-meltable ink and a coating amount (coating thickness) of the heat-melting binder, which have not been considered until now, in order to obtain a printed image of higher quality. As a result of conducting an experiment focusing on (1), the ink will adhere more strongly than the conventional one and will not come off easily, and the ink ribbon will be fixed accurately according to the data. And so on.

[0008]

That is, the present invention, as the first invention, is used for thermal transfer printing by transferring a heat-melting ink to a recording sheet by a recording head,
An ink ribbon in which a heat-meltable binder is provided on both sides of a heat-meltable ink composed of a plurality of colors on the same plane,
One of the heat-meltable binders has a coating thickness that is approximately equal to or greater than the surface roughness of the recording paper to be printed, and the heat-meltable inks of multiple colors each have a coating thickness of 1.8 μm or less and the other heat-meltable binder. The ink binder is characterized in that the hydrophilic binder is equal to or more than the total coating thickness of the heat-meltable inks of a plurality of colors, and as a second invention, the heat-meltable ink is applied to the recording paper by the recording head. An ink ribbon used for transfer and thermal transfer printing, in which a heat-melting binder composed of a plurality of colors is provided on both sides with a heat-melting binder, and one of the ink ribbons The heat-fusible binder has a coating thickness that is approximately equal to or greater than the surface roughness of the recording paper to be printed. The heat-melting inks of multiple colors each have a coating thickness of 1.8 μm or less. Using an ink ribbon that is equal to or more than the total coating thickness of several heat-meltable inks, first transfer one heat-meltable binder to the surface of the recording paper and The surface is made smooth, the heat-meltable ink is transferred onto the heat-meltable binder of this smooth recording paper, and then the other heat-meltable binder is transferred so as to cover the transferred heat-meltable ink. And a thermal transfer printing method characterized by the above.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION First, the reason why the smoothness of a recording sheet is required will be described with reference to the principle diagram of FIG. 1 and FIG. As described above, generally, when performing thermal transfer printing, the ink ribbon 2 coated with the heat-meltable ink 1 and the recording paper 3 are superposed between the thermal head 4 and the platen roller 5 and fed to the thermal head. Ink ribbon 2 at 4
And the recording paper 3 are pressed against the platen roller 5, and the heat-meltable ink 1 is melted by the heat of the thermal head 4 generated by the electric current applied according to predetermined data.
The recording is performed by transferring the melted heat-meltable ink 1 to the recording paper 3 side.
As shown in FIG. 6, the surface of the ink has unevenness (represented by the width p), and therefore the ink is transferred only to the convex portion and not to the concave portion. Therefore, the adhesive force of the hot-melt ink to the recording paper is weak, and accurate thermal transfer printing cannot be performed.

Here, the unevenness of the surface of the recording paper 3 will be described in detail. Generally, the width p of the unevenness of the surface of the coated paper is 1 to 5 μm, and that of the plain paper is 5 to 10 μm. Therefore, in order to perform accurate thermal transfer printing, it is necessary to first smooth the surface of the recording paper used. Therefore, normally, the heat-meltable ink transfer surface of the recording paper 3 is previously set in advance.
For example, a binder having a heat-melting temperature lower than the heat-melting temperature of the heat-meltable ink is transferred, and heat-sensitive transfer printing is performed on the transferred binder surface. The smoothness of the recording paper is improved by transferring a binder having a heat melting temperature lower than the heat melting temperature of the heat melting ink used.

That is, when heat-sensitive transfer printing is performed with the hot-melt ink, the binder underlying the ink also melts, so the heat-melt ink mixes in the melted binder layer in addition to the adhesive strength of the binder itself. Therefore,
The convex portions on the recording paper due to the transferred hot-melt ink are reduced, and in this case, if the coating amount of the hot-melt ink is reduced, the convex portions are further reduced. This is because even if they are transferred in a superimposed manner, the influence of surface irregularities is significantly reduced, and transfer errors are almost eliminated.

If necessary, a heat-meltable binder that melts at a temperature lower than the heat-melting temperature of the heat-meltable ink on the printing surface after the heat-sensitive transfer printing is low enough that the heat-meltable ink is hardly deformed. If the transfer is performed at a temperature, the printing surface can be covered with the hot-melt binder while the printing state remains almost the same, so that good printing in which the ink does not easily peel off can be performed.

Further, the printed portion is not coated with the ink ribbon at a temperature at which the heat-melting ink hardly melts on the heat-sensitive transfer printing surface and only the previously melted heat-melting binder melts. By heating the ink in the melted binder layer, it is possible to perform good printing in which the ink is hardly peeled off by further mixing the heat-meltable ink.

Here, in consideration of the coating thickness of the heat-meltable binder to be transferred first, the coating thickness is first set to be equal to or more than the surface roughness of the recording paper used. For example, the coating thickness of the heat-melting binder for coated paper is 5 μm or more, and the coating thickness of the heat-melting binder for plain paper is 10 μm or more.

6 and 7 are explanatory views of the ink ribbon 20 according to the present invention. In both figures, 12 is a heat-melting binder layer for undercoat provided on the base surface 17,
Reference numeral 16 is a heat-meltable binder layer for overcoat, which is also provided on the base surface 17. 13, 14, 1
Reference numeral 5 is a heat-meltable ink layer disposed on the base surface 17 between the heat-meltable binder layers 12 and 16. The heat-meltable ink layer has the following structure. That is, the heat-meltable ink layers 13, 14,
15 is set to a heat melting temperature higher than the heat melting temperature of the heat melting binder layers 12 and 16, respectively. In addition,
The heat-meltable ink layer 13 is, for example, yellow (Y), the heat-meltable ink layer 14 is magenta (M), and the heat-meltable ink layer 15 is cyan (C). Further, as described above, when the coating amount of each of the heat-meltable ink layers 13, 14 and 15 is reduced as much as possible, in the case of overlapping transfer, the influence of unevenness due to the presence or absence of transfer of the ink itself is reduced. Therefore, it is advantageous, for example, 1.8 μm or less is preferable.

The ink ribbon 20 according to the present invention will now be described.
Has the above-described structure, and therefore, when heat-sensitive transfer printing is performed using the heat-sensitive transfer printing apparatus as shown in FIG. 1, since the underlying binder layer also melts, it melts in addition to the adhesive force of the binder itself. The hot-melt ink is mixed in the binder layer, so that the adhesive force of the dots of the transfer-printed hot-melt ink becomes greater. If the heat-meltable ink applied to the transfer paper contains the same heat-meltable binder that is formed as the underlayer, the adhesive force of the heat-meltable ink during heat-sensitive transfer printing is better. It will be even bigger. Further, according to the constitution of the ink ribbon 20 according to the present invention, the heat-meltable ink layers 13, 1
In which the heat-melting binder layers 12 and 16 are arranged on both sides of 4, 15, that is, the heat-melting binder similar to the heat-melting binder layer is applied to the printed surface after the heat-sensitive transfer printing. In addition, the ink is more difficult to peel off. FIG. 8 is an explanatory diagram showing a state in which thermal transfer printing is performed in this way.

Here, a heat-meltable binder is transferred onto a publicly available postcard that is commercially available as plain paper as recording paper, and the heat-meltable ink is further transferred onto it to confirm the ink transfer state. The results are shown in Table 1.

[0018]

[Table 1]

From the comparison result of the coating thickness, it is found that the optimum coating thickness of the heat-fusible binder of the postcard manufactured by the government is about 10 μm or more, preferably 10 μm to 15 μm.

On the other hand, the heat melting temperature of the heat melting binder is set as low as possible. Generally, the maximum temperature in Japan is about 40 ° C., and the temperature is set to 60 ° C. or higher in consideration of the temperature rise in the printing device. As described above, the melting temperature of the heat-melting ink is set higher than the melting temperature of the heat-melting binder so that the previously-melted heat-melting binder is easily melted during the transfer of the heat-melting ink. Next, Table 2 shows the results of comparison of the influence of the melting temperature difference of the heat-meltable ink on the heat-meltable binder.

[0021]

[Table 2]

From this comparison result, if the heat-meltable ink is transferred at a temperature higher than the heat-melting temperature of the heat-meltable binder after transferring the heat-meltable binder, the heat-meltable ink is fused with the heat-meltable binder. It can be seen that a conflict transfer error hardly occurs. After this, if a heat-meltable binder is further transferred and covered on the heat-meltable ink transfer portion, a stronger adhesive force can be obtained.

After transferring the heat-meltable binder,
When the first heat-meltable ink is transferred from above, since the surface is smooth, no transfer error occurs even at almost the same heat-melting temperature. After the second color, the effect of unevenness due to the heat-meltable ink occurs, but when the ink coating thickness is reduced,
The influence of this unevenness can be reduced. The results of confirming the influence of this coating thickness by experiments are shown in Table 3.

[0024]

[Table 3]

As a result, the coating thickness of the hot-melt ink is
It is preferable that the thickness is 1.5 μm or less, and the transfer error can be reduced by increasing the temperature of the third color. However, 1.0
When the thickness is set to μm, the density becomes too low, which is not practical. It should be noted that, practically, it can be seen that even with 1.8 μm, there are few transfer errors and there is no problem.

The binder to be finally transferred (the other binder) does not deteriorate the print state of the heat-meltable ink during transfer, and therefore has a heat-melting temperature that does not affect the print state. For manufacturing convenience, it may be the same as the first (one) heat-meltable binder. The coating thickness in this case is
It is not less than the unevenness due to the hot-melt ink. For example, if the coating thickness of the hot-melt ink is 1.5 μm and three colors of Y, M and C are used, the coating thickness of the hot-melt binder in this case is 4.5 μm or more.

As described in detail above, according to the present invention, the surface roughness of the recording paper is eliminated, for example, as shown in FIG.
Heat-fusible binder 1 having a thickness p corresponding to the surface roughness of recording paper
2 is transferred to smooth the surface of the recording paper 8. Next, the heat-meltable inks 13, 14, 15 are heated at a temperature higher than the heat-melting temperature of the heat-meltable binder 12, and the heat-meltable inks 13, 14, 1 are melted while the heat-meltable binder 12 is melted.
5 is sequentially transferred. When using multiple colors of heat-meltable ink, set the coating thickness to 1.8 μm or less to reduce transfer errors due to the first heat-meltable ink stacking and increase the heat-melting temperature of the last heat-meltable ink as high as possible. To do. When color printing is performed by sequentially superposing inks of three colors of Y, M, and C, for example, the first two colors are set to the same heat melting temperature as the heat melting binder, and the third color is increased. By doing so, the first two colors are transferred with low power, and when the last color is transferred, the first two colors, including the first two colors, are fused to the hot-melt binder. Finally, the heat-meltable binder 16 applied to a thickness equal to or larger than the total thickness of the heat-meltable ink is transferred to the printing portion to complete the process.

When a recording paper having good smoothness is used, or when a porous recording medium is used as the recording paper, the first heat-melting binder is omitted, and the heat-melting ink and the heat-melting binder are finally prepared. , For example, when using three colors of hot melt ink, the first two colors are transferred at a low temperature and
The color is transferred at a high temperature. Then, finally, the hot-melt binder is transferred at a low temperature to complete printing.

[0029]

As described in detail above, according to the present invention, since the ink ribbon as the first invention is constructed as described above, the adhesion of the ink by the thermal transfer printing of the heat-meltable ink becomes strong, The heat-sensitive transfer printing method according to the second aspect of the present invention has the advantage that the ink corresponding to the data is accurately fixed and good printing can be performed.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of thermal transfer printing.

FIG. 2 is an explanatory diagram of a conventional printing example.

FIG. 3 is an explanatory diagram of a conventional printing example.

FIG. 4 is an explanatory diagram of an ink ribbon used when performing conventional thermal transfer printing.

FIG. 5 is an explanatory diagram of a surface state of recording paper.

FIG. 6 is an explanatory diagram of an ink ribbon according to the present invention.

FIG. 7 is an explanatory diagram of an ink ribbon according to the present invention.

FIG. 8 is an explanatory diagram of a printing example in which thermal transfer printing is performed using the ink ribbon according to the present invention.

[Explanation of symbols]

 12, 16 Heat-meltable binder layer 13, 14, 15 Heat-meltable ink layer 17 Base surface 20 Ink film

Claims (2)

[Claims] 1. A heat-melting ink is used for heat-sensitive transfer printing by transferring a heat-melting ink to a recording paper by a recording head, and a heat-melting binder is formed on the same plane on both sides of the heat-melting ink composed of a plurality of colors. The ink ribbon provided in
One of the heat-meltable binders has a coating thickness that is approximately equal to or greater than the surface roughness of the recording paper to be printed, and the heat-meltable inks of multiple colors each have a coating thickness of 1.8 μm or less and the other heat-meltable binder. The ink ribbon, wherein the ionic binder is equal to or more than the total coating thickness of the hot-melt inks of plural colors. 2. A heat-meltable ink is used for heat-sensitive transfer printing by transferring a heat-meltable ink to a recording sheet by a recording head, and a heat-meltable binder is formed on the same plane on both sides of the heat-meltable ink composed of a plurality of colors. The ink ribbon provided in
One of the heat-meltable binders of this ink ribbon has a coating thickness that is approximately equal to or greater than the surface roughness of the recording paper to be printed, and heat-meltable inks of multiple colors each have a coating thickness of 1.
8 μm or less, and the other heat-meltable binder is the same as or more than the total coating thickness of heat-meltable inks of multiple colors. The surface of the recording paper is made smooth by transferring a heat-meltable binder, the heat-meltable ink is transferred onto the heat-meltable binder of the smooth recording paper, and then the transferred heat-meltable ink is transferred. A heat-sensitive transfer printing method, characterized in that the other heat-meltable binder is transferred so as to cover the other.