JPS61286188A - Heat-responsive pressure-sensitive transfer material - Google Patents

Abstract

PURPOSE:To obtain a heat-responsive pressure-sensitive transfer material showing favorable transfer performance under low impact energy, by incorporating an oil having specified properties into an ink layer. CONSTITUTION:The heat-responsive pressure-sensitive transfer material has the ink layer comprising an oil which is a solid or a highly viscous liquid when being heated. In preservation, a base and the ink layer are firmly adhered to each other, and an offset phenomenon is prevented from occurring. At the time of printing, the adhesion between the base and the ink layer is lowered through a lowering in the viscosity of the oil under heating, so that defective transfer such as transfer of broken characters can be obviated even when printing with low impact energy. The oil has an absolute viscosity of 60-300 cp or is a solid at normal temperature, and has an absolute viscosity at a heating temperature of 40-80 deg.C of 5-50 cp.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a novel heat-sensitive ink layer containing oil that is solid or a high viscosity liquid at room temperature and becomes a low viscosity liquid when heated. Concerning pressure-sensitive transfer material. More specifically, at room temperature, the base material and the ink layer firmly adhere to each other.
In addition, the bond between the material and the substrate is weakened during heating, creating a new heat-sensitive pressure-sensitive transfer material that exhibits good transfer performance even with low impact energy.

[Prior Art] Pressure-sensitive transfer materials (for example, ink ribbons for impact printers, etc.) have traditionally used impact energy from a type bar or print ball to transfer and record characters on an adherend such as paper. There is a known C.

Although impact printers that use such ink ribbons can print at higher speeds than, for example, thermal non-impact printers that use thermal energy, they require a large amount of impact energy when printing.
The disadvantage was that it produced a lot of noise during printing.

In recent years, with the development of information equipment, there has been an increasing demand for low-noise printing operations, and impact printers that use daisy wheels instead of the type bars or print balls mentioned above have become widely adopted. . However, even with the impact energy that uses a daisy wheel, an average of about 14 mJ/mm of impact energy is required when printing, and the accompanying noise is not suitable for thermal non-impact printers. The current situation is that it has not been reduced.

In view of these circumstances, recently, with the aim of further reducing the noise of impact printers, it has been proposed to reduce the impact energy during printing in impact printers using the above-mentioned daisy wheel. However, when printing with reduced impact energy, conventional pressure-sensitive transfer materials generally result in transfer defects such as missing characters. When using such pressure-sensitive transfer materials as an ink ribbon, the ink layer of the transfer material wound up into a ribbon is attached to the base material. It sticks to the back side of the paper, causing a so-called set-off phenomenon.

Despite the various attempts mentioned above, so far, no one has been able to solve the conflicting problems of pressure-sensitive transfer materials regarding transfer performance and set-off, which are the adhesion between the base material and the ink layer. The current situation is that it is not possible.

[Problems to be Solved by the Invention] By the way, pressure-sensitive transfer materials such as the above-mentioned ink ribbons for impact printers generally use a film-like base material, and a film-forming resin and a film-forming resin are coated on the base material. The ink layer is composed of laminated ink layers whose main component is oil, which is substantially incompatible with each other. Although there are still many aspects of the printing mechanism of such pressure-sensitive transfer materials that are not yet understood, in general, during printing, impact energy is applied to the ink ribbon to overcome the adhesive force between the base material and the ink layer. Cohesive failure of the oil present at the interface between the material and the ink layer occurs first, followed by destruction of the resin present in the ink layer as a porous film2, and at the same time, oil is deposited on the surface of the ink layer. It is believed that the movement of the ink layer causes the deposition of the ink layer on the adherend, that is, printing is performed.

Therefore, in order to reduce the noise of impact printers that use such pressure-sensitive transfer materials without causing problems such as transfer defects such as missing characters and set-off, it is necessary to reduce the noise between the base material and the ink layer. At the same time, we aim to reduce the adhesive strength to a level that matches the reduction in impact energy to prevent character loss, and at the same time, as a contradictory issue, we try to maintain adhesive strength to the extent that set-off does not occur. It is necessary to consider the balance of adhesive strength between the material and the ink layer.

Now, one of the factors considered to have a large effect on the adhesive force between the base material and the ink layer is the absolute viscosity of the oil contained in the ink layer. In conventional pressure-sensitive transfer materials, the adhesive strength between the base material and the ink layer does not change appreciably depending on temperature, in order to stabilize transfer performance or storage stability under the usage environment.In other words, the viscosity does not change due to temperature changes. The pressure-sensitive transfer material was constructed using a small amount of oil. However, with such oils with little viscosity fluctuation, it is difficult to prevent set-off in the storage environment of pressure-sensitive transfer materials due to weak adhesive strength between the base material and the ink layer, and to prevent the viscosity of the oil from increasing in low-temperature environments. In other words, although it is possible to prevent character chipping due to increased adhesive strength between the base material and the ink layer, when reducing impact energy for the purpose of noise prevention, there are contradictory problems regarding the adhesive strength between the base material and the ink layer. In other words, to prevent deterioration of transfer performance such as missing characters and to prevent set-off,
Both were difficult to resolve.

In view of the above-mentioned problems, the present inventor has made extensive research efforts to provide a transfer medium that exhibits good transfer performance even with low impact energy and is free from set-off, with the premise of reducing the noise of impact printers. However, the ink layer contains oil that is solid or a high viscosity liquid at the current temperature and becomes a low viscosity liquid when heated, and the ink layer is heated during printing to create a base color only during heating. The inventors have discovered that reducing the adhesive force between the material and the In9111 is extremely effective in solving the above problems, and have arrived at the present invention.

That is, in the present invention, the base material and the ink layer are strongly adhered at room temperature, and the adhesive force with the base material is weakened when heated.
The main purpose of the present invention is to provide a new transfer medium that exhibits good transfer performance even with low impact energy, and to solve the problems such as noise, missing characters, and set-off phenomena in the pressure-sensitive transfer materials described above.

[Means for Solving the Problems] The present invention achieves the above object by providing an ink layer on a base material, and the ink layer is solid or a high viscosity liquid at room temperature, and has a low viscosity when heated. This is a heat-sensitive pressure-sensitive transfer material characterized by containing oil that becomes a viscous liquid.

That is, the heat-sensitive pressure-sensitive transfer material of the present invention contains oil in the ink layer that is a solid or a high-viscosity liquid at room temperature and becomes a low-viscosity liquid when heated, so that the ink layer retains its original state in the storage environment. By strongly adhering the material and the ink layer to prevent set-off, and by reducing the adhesion between the base material and the ink layer by utilizing the viscosity reduction of the oil caused by heating during printing, it is possible to print with low impact energy. This is designed to prevent transfer defects such as missing characters from occurring even during printing. As shown in the Examples below, the heat-sensitive pressure-sensitive transfer material of the present invention exhibited good transfer performance even at an impact energy as low as 5 mJ/mm, and no set-off phenomenon occurred. Also,
With the heat-sensitive pressure-sensitive transfer material of the present invention, printing can be performed under desired heating conditions even if the printing environment varies, and the adhesive force between the base material and the ink layer is reduced during heating. Therefore, there is almost no variation in transfer performance.Furthermore, since printing is performed by applying impact energy while the oil viscosity is low, the fluidity of the oil increases and the interface between the ink layer and the adherend increases. The oil became easier to distribute, the ink layer's adhesion to the adherend increased, and the powder falling phenomenon that was often observed in conventional pressure-sensitive transfer materials, especially collector ink ribbons, was not observed.

When constructing such a heat-sensitive pressure-sensitive transfer material of the present invention, a wide variety of base materials of various materials and shapes can be used, such as known plastic films used in conventional pressure-sensitive transfer materials. Preferably, for example, polyethylene,
Examples include plastic films with relatively good heat resistance such as polypropylene, polyethylene terephthalate, and aramid. Considering the heating efficiency, etc., the base material thickness is as follows:
Approximately 4 to 25 − in the lamination direction of the ink layers is suitable.

The ink layer laminated on the above-mentioned base material is, for example, a film-forming resin used in conventional pressure-sensitive transfer materials, which is a solid or a highly viscous liquid at room temperature according to the present invention, and is heated. It is sometimes composed of oil, which is a low-viscosity liquid. Of course, the ink layer may contain various additives used in conventional pressure-sensitive transfer materials, if necessary. The thickness of the ink layer laminated on the base material is preferably about 1 to 3 microns.

The above-mentioned oil to be contained in such an ink layer is
Preferably, the absolute viscosity at room temperature is 60 cp (centivoise) to 300 cp, or it is a solid, and
Absolute viscosity at heating temperature of 0°C to 80°C is 5 cp to 5
It is of 0 cp. Specifically, such oils include polyalkylene glycols [for example, manufactured by NOF Corporation
Polyethylene glycol 400 (trade name) manufactured by Nippon Fine Chemical Co., Ltd., fatty acid monoglyceride (for example, lauric acid monoglyceride (trade name) manufactured by Nippon Fine Chemical Co., Ltd.), liquid paraffin (for example, liquid paraffin 3503 (trade name) manufactured by Chuo Kasei Co., Ltd.)
], halogenated paraffin [for example, manufactured by Nippon Fine Chemical Co., Ltd.
cetyl chloride C (trade name)), aromatic carboxylic acid esters (e.g. Nippon Fine Chemical Co., Ltd., dibutyl phthalate (trade name)), higher fatty acid esters (e.g. Nippon Fine Chemical Co., Ltd., dibutyl phthalate (trade name));
Co., Ltd., butyl stearate S (trade name)), natural oils and fats (for example, Yoken Fine Chemical Co., Ltd., partially hydrogenated castor oil (trade name)), most preferably absolute viscosity at 20 ° C. about 2000+). , and the absolute viscosity at 50° C. is about 10 cp. These oils are preferably contained in the ink layer in an amount of about 4 to 7.5% by weight.In addition to these oils, conventional pressure-sensitive transfer materials (for example, Japanese Patent Publication No. ) Some of the mineral oils, animal and vegetable oils, or higher fatty acid esters used in the above may be used in some cases.

The heat-sensitive transfer material of the present invention can be used in various forms, such as an ink ribbon, but when printing using these heat-sensitive transfer materials, for example, a conventionally known impact printer can be used to print the image. Heating is performed by any method such as installing a film heater of the desired capacity (for example, about IOW) on the back side of the impact area of the ink ribbon cassette installed in the printer (the side opposite to the side facing the adherend). At this time, the heating temperature is, for example, when used as an ink ribbon, the surface temperature of the ink layer of the ribbon on the side in contact with the adherend is 40 to 80.
It is preferable to set it as ℃.

[Example] Examples of the present invention are shown below. In the following description, "1 part" indicating a compounding value is r parts by weight J unless otherwise specified.
It is about.

〔Example]〕

Ink composition Epersamide 725 (manufactured by Nippon Henkel Co., Ltd.) 20 parts Mobil Oil OTE Medium (manufactured by Mobil Oil Co., Ltd.) 16 parts Lauric acid monoglyceride (manufactured by Nippon Sekihi Co., Ltd.) 12 parts Nigrosine Ba5e L (manufactured by BASF) )
7 parts toluene
10 parts isopropyl alcohol 18
2 parts 20 parts of Persamide 725 (resin) was added to 100 parts of isopropyl alcohol and completely dissolved by heating and stirring, and Mobil Oil DTE Medium 16 was added to this solution.
parts, lauric acid monoglyceride 12 parts, oil black N
1qrosine Ba5e L 7 parts, toluene 7
8 parts and 182 parts of isopropyl alcohol were added and dispersed for 30 minutes using a sand grinder to obtain the above ink composition having a uniform composition. This composition was coated on a polyethylene film with a thickness of 15 μm in an amount of approximately 2.59 parts mr after drying.
Apply with a roll coater so that
It was dried in a drying oven at a temperature range of . 8 m of polyethylene film laminated with the ink composition in this way was
A one-time type heat-sensitive pressure-sensitive transfer material of the present invention was obtained by cutting into m-wide pieces and winding them around a core to form an ink ribbon.

(Example 2) Ink composition ■ Polymide S-52 (manufactured by Sanyo Kasei Co., Ltd.) 20 parts Liquid paraffin 350S (manufactured by Chuo Kasei Co., Ltd.) 28 parts Carbon black 3500 (manufactured by Columbia Carbon Co., Ltd.) 9 parts toluene
104 parts ethanol
156 parts Example 1 except that ethanol was used instead of isopropyl alcohol and 9 parts of inorganic pigment was used instead of 7 parts of oil black.
Dispersion was carried out in the same manner as above to obtain the above ink composition II having a uniform composition. This composition was applied on a polypropylene film with a thickness of 15u+ to a coating weight of about 2.5c+/ after drying.
Coat with a roll coater so that
It was dried in a drying oven at a temperature range of 0°C. The polyethylene film laminated with the ink composition in this way was
A collector-type heat-sensitive pressure-sensitive transfer material of the present invention was obtained by cutting into mm width and winding it around a core to form an ink ribbon.

[Example 3] Ink composition ■ Persamide 930 (manufactured by Henkel Japan Co., Ltd.) 20 parts Spindle oil (Mobil Velocity Oil No. 3, manufactured by Mobil Oil Co., Ltd.) 14 parts Chlorinated paraffin (
Cetyl chloride C) manufactured by Nippon Sekihi Co., Ltd. 14 parts Pigment Deep Black A (BAS
F) 10 parts isopropyl alcohol 2
60 parts Dispersion was carried out using the above dispensing table in the same manner as in Example 1 to obtain the above ink composition (2) having a uniform composition. This composition was coated on a polyethylene film with a film thickness of 17u+ using a roll coater so that the coated amount after drying was about 2.59/rrr, and then placed in a drying oven at a temperature of 30°C to 80°C. Dry. The polyethylene film on which the ink composition was laminated in this way was cut into a width of 8 mm, and this was wound around a core to obtain a collector-type heat-sensitive pressure-sensitive transfer material of the present invention, which was formed into an ink ribbon. .

[Comparative example]

The same procedure as in Example 2 was carried out except that 28 parts of liquid paraffin +00S (manufactured by Chuo Kasei Co., Ltd.) was used instead of liquid paraffin 350S in Example 2, so that the coating amount after drying was as follows: Approximately 2.59/r
A conventional collector-type pressure-sensitive transfer material was obtained by laminating ink layers so as to form a .

The ink ribbons of Examples 1 to 3 and Comparative Example obtained as described above were assembled into a cassette equipped with a heating device, and then used as an ink ribbon for a typewriter for a daisy-wheel type electronic typewriter (Canon). AP Co., Ltd.
400), the environmental temperature is 20℃, and the environmental humidity is 50%.
and under two conditions: an environmental temperature of 10°C and an environmental humidity of 50%.
Printing was performed with an impact energy of 3 to 20 mJ/mm. Note that the temperature of the heating device was adjusted, and printing was performed at a surface temperature of the ink ribbon of 50°C.

As a result, in the ink ribbons obtained in Examples 1 to 3,
5 mJ/mn under any environmental conditions
(It showed good transfer performance without missing characters with a low impact energy of
At an impact energy of mJ/mmr, transfer defects such as crushed characters and missing characters occurred. Furthermore, when the ink ribbon of this comparative example was installed in a normal cassette without a heating device and printing was performed under conditions of an environmental temperature of 20°C and an environmental humidity of 50%, it was found that IOmJ/m
n (The following impact energies caused transfer defects due to missing characters. Also, the environmental temperature was 20°C and the environmental humidity was 5.
When printing was carried out under 0% conditions, an impact energy of 14 mJ/mm or more was required to obtain good transfer performance, which is not found in literature.

Separately, each of the ink ribbons of Examples 1 to 3 and Comparative Example above was cut into three pieces each to a length of 10 cm, and after overlapping each of the three ink ribbons, these were overlapped. Each of the ink ribbons was sandwiched between slide glasses, and a load of 3009.5009.7009 was applied, and the ribbons were left at 35° C. for 45 hours in an environment of 95%. As a result, in the ink ribbons of Examples 1 to 3, 700
No set-off phenomenon was observed even under a load of 9, but a set-off phenomenon was observed under a load of 5009.7009 in the ink ribbon of the comparative example.

The above evaluation results are summarized in Table 1.

As is clear from Table 1, the heat-sensitive pressure-sensitive transfer material of the present invention exhibits stable transfer performance with lower impact energy than conventional pressure-sensitive transfer materials, and also has no set-off phenomenon. It is.

Table 1 (Note) ″: Printing is performed without a heating device.

0: Good Δ: Fairly good ×: Bad −: Test not conducted [Effects of the invention] As explained above, the present invention solves problems such as noise, missing characters, and set-off phenomena in conventional pressure-sensitive transfer materials. It has now become possible to provide a new heat-sensitive pressure-sensitive transfer material that solves this problem.

Claims (3)

[Claims] (1) A heat-sensitive sensitizer comprising an ink layer provided on a base material, the ink layer containing oil that is solid or a high-viscosity liquid at room temperature and becomes a low-viscosity liquid when heated. Pressure transfer material. (2) The absolute viscosity of the oil at room temperature is 60 cp or more
300 cp, and has an absolute viscosity of 5 cp to 50 cp at a heating temperature of 40° C. to 80° C. The heat-sensitive pressure-sensitive transfer material according to claim 1. (3) the oil is solid at room temperature, and
Absolute viscosity at heating temperature of 0°C to 80°C is 5 cp to 5
The heat-sensitive pressure-sensitive transfer material according to claim 1, which has a temperature of 0 cp.