JPH0825820A - Thermal transfer recording sheet - Google Patents

Abstract

PURPOSE:To record a plurality of colors with one thermal transfer recording sheet by forming a hot-melt ink layer of two or more layers having different ratio of thermoplastic substance to hot-melt substance. CONSTITUTION:Hot-melt ink layers 12, 13 are formed of two or more layers having different hues of coloring materials and formed that the ratio of thermoplastic substance 32 to hot-melt substance is so formed that ratio of the layer 12 of the side near a base material 11 is less than that of the layer 13 of the side farther from the material 11. Thus, in the case of recording with low energy, the layer 13 contains more substance 31, it is thermally transferred, but the layer 12 contains less substance 31, and the ink layer is not transferred. That is, only the layer 13 of the side farther from the material 11 is transferred. On the contrary, in the case of the high energy, not only the layer 13 of the side farther from the material 11 but also the layer 13 of the side near the material 11 becomes melted viscosity capable of transferring to be transferred.

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 sheet used in a thermal transfer recording apparatus using a thermal head or the like, and a thermal transfer recording sheet capable of recording a plurality of colors with one thermal transfer recording sheet. It is about G.

[0002]

2. Description of the Related Art At present, in a recording device such as a word processor, a printer for a terminal of a computer, a facsimile copying machine, etc., a thermal transfer recording method using a heat generating element such as a thermal head is used. It is widely used because it is small, the device is relatively inexpensive and compact, and it is easy and reliable to operate.

In such a thermal transfer recording system, a thermal transfer recording sheet is used in which a thermally fusible ink layer comprising a thermally fusible substance and a coloring material such as a pigment is provided on a substrate such as paper or plastic film. The heat-meltable ink layer is heated and melted by a thermal head and transferred to a recording paper to obtain an image.

In such a heat-melt transfer recording system, generally, a recording sheet of a single color or a heat-melting ink layer having such a single color and a hue different from each other is formed on a substrate in the lateral direction of the recording sheet. A thermal transfer recording sheet of 2 to 4 colors repeatedly provided with a fixed size is used. Also, a single color thermal transfer recording sheet
The sheet is used in word processors, facsimiles, label printers and the like, and the two-color repetitive thermal transfer recording sheet is used in ticket issuing machines and the like. In addition, a thermal transfer recording sheet of three-color and four-color is repeated.
Are used in full color printers.

[0005]

A single color thermal transfer recording sheet.
When recording multiple colors using the
It is very inconvenient to stop the recording and replace the thermal transfer recording sheet. Although there are some recording apparatuses in which a plurality of recording sheets are housed in the recording apparatus and a plurality of thermal heads are used, the apparatus is large and the cost is high.

In addition, a thermal transfer recording sheet for repeating a plurality of colors is used.
Is a compact device that can record multiple colors,
There are many wasteful portions that cannot be used for recording, such as color boundaries and marked portions for sensor detection, and when there is a large deviation in the use of colors, many portions are wasted. Further, the time for transporting the recording sheet is increased, and the recording time is also required.

[0007]

The present invention has been conceived in order to solve the above-mentioned problems, and a heat-melting substance, a thermoplastic property, and a heat-melting substance containing a coloring agent are formed on a substrate made of paper, plastic film, or the like. In a thermal transfer recording sheet provided with a heat-sensitive ink layer, the heat-meltable ink layer is composed of two or more layers having different hues of the colorant, and the ratio of the thermoplastic substance to the heat-meltable substance is higher than that of the substrate. The thermal transfer recording sheet is characterized in that the meltable ink layer on the side closer to the substrate is smaller than the heat-sensitive ink layer.

The thermal transfer recording sheet of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the thermal transfer recording sheet of the present invention comprises a base material (1) made of paper, plastic film or the like.
1) on top of the heat fusible material (31) and the thermoplastic material (3
2), coloring materials (21, 22) such as pigments having different hues,
The heat-fusible ink layers (12, 13) are sequentially provided by dispersing or dissolving in a solvent or water, mixing and coating, to prepare a thermal transfer recording sheet (1). In this case, the heat-meltable ink layer (12) on the side closer to the base material has a higher ratio of the thermoplastic substance (32) to the heat-meltable substance (31) than the heat-meltable ink layer (13) on the side farther from the base material. It is necessary to have many.

When the ratio of the thermoplastic substance (32) to the heat-fusible substance (31) is small, the melt viscosity of the heat-fusible ink layer is low, the transfer sensitivity is increased, and the energy consumption is lower.
The ink layer is melted and transferred. On the contrary, when the proportion of the thermoplastic substance is large, the transfer sensitivity is lowered, and the melt transfer of the ink layer is not performed unless the energy is higher.

In the present invention, the coloring materials (21,
In the thermal transfer recording sheet in which the heat-fusible ink layers (12, 13) having the above (22) are sequentially provided, the hot-melt ink layer (12) on the side closer to the substrate is the heat-melt ink on the side farther from the substrate. From the layer (13), the thermofusible substance (3) of the thermoplastic substance (32)
Increase the ratio to 1). As a result, as shown in FIG. 2, the recording paper (2) is printed using the thermal head (3).
On the other hand, when recording was performed with low energy, the heat-meltable ink layer (13) on the side far from the base material (11) melted because there were more heat-meltable substances (31) as shown in FIG. Viscosity tends to be low, and thermal transfer is performed.

However, the heat-meltable ink layer (12) on the side closer to the substrate has less heat-meltable substance (31) and the proportion of the thermoplastic substance (32) on the side farther from the substrate ( 1
Since it is more than 3), the melt viscosity is low and the ink layer does not transfer. That is, only the heat-meltable ink layer (13) on the side far from the base material is transferred.

On the other hand, when the recording energy becomes high, not only the heat-meltable ink layer (13) on the side far from the base material (11) as shown in FIG. The heat-meltable ink layer (12) also has a transferable melt viscosity and is heat-transferred.

Thus, when the recording energy is low, only the heat-meltable ink layer (13) far from the substrate is transferred, and when the recording energy is high, it is close to the substrate having different hues. Since the heat-meltable ink layer (12) on the side is also transferred, it is possible to record a plurality of colors by changing the recording energy. In this case, because the colors overlap,
Multiple primary colors and multiple dark colors are difficult, but light colors, primary colors, and overlapping colors can be expressed.

Thus, for example, when the colorant on the side closer to the base material is black and the colorant on the side farther from the base material is red, when this is used in a word processor or the like, it is possible to obtain a high energy level at a normal level. When transfer recording is performed, black characters are recorded on the recording paper, but if the recording energy level is lowered at the part where the color is to be partially changed, it is possible to record with red characters.

The substrate used in the present invention is a paper or a plastic film which is usually used in a thermal transfer recording sheet, such as a condenser paper or a polyethylene terephthalate film.
Polyester, polyethylene such as polyethylene naphthalate, polyethylene, polyvinyl chloride, polycarbonate, polystyrene, polysulfone, polyimide, polyvinyl alcohol, aromatic polyamide, plastic film such as aramid film, cellophane, etc. I can.

As the coloring material for the hot-melt ink used in the present invention, known pigments and dyes, for example, disazo ero pigments, monoazo red pigments, phthalocyanine pigments,
Pigments such as carbon black and dyes such as azo dyes, anthraquinone dyes and styryl dyes can be used.

As the heat-melting substance of the heat-melting ink used in the present invention, a heat-melting substance having a low melting point and a low melt viscosity is used. For example, paraffin wax, rice wax, ester wax, oxidation wax, carnauba. Wax, candelilla wax, polyethylene wax,
Waxes such as montan wax and petroleum resin wax can be used. Among them, from the viewpoint of transfer characteristics and storability, the melting point is 50 ° C to 85 ° C and the melt viscosity is 20c at 100 ° C.
Those of ps or less are used. When it exceeds 20 cps, the transfer sensitivity is lowered and a clear image cannot be obtained on the recording paper.

Examples of the thermoplastic material of the hot-melt ink used in the present invention include butyral resin, epoxy resin, polyester resin, urethane resin, acrylic resin, polyethylene resin, polypropylene resin, polybutadiene resin, polyvinyl chloride. Resin, polyvinyl acetate resin, vinyl acetate-vinyl chloride copolymer resin, ethylene-vinyl acetate copolymer resin, polyamide resin, styrene-butadiene copolymer resin, polycarbonate, polycaprolactone, polyacrylonitrile, urea resin, polyamide One or more of various thermoplastic resins such as petroleum resin, polyvinyl acetal, ketone resin, or modified resins or blends thereof can be appropriately selected and used.

Among these thermoplastic substances, those having a softening point of 120 ° C. or less are preferable, although they are not particularly limited in view of thermal sensitivity, and further, the compatibility with a wax mainly used for a heat-melting substance and It is preferable to use an ethylene-vinyl acetate copolymer resin from the viewpoint of adhesiveness to the substrate.

These heat-meltable substances and thermoplastic substances are dissolved or dispersed in a solvent or water to further disperse a coloring material,
After mixing, they are coated on a substrate and dried, and in the same manner, a thermal transfer recording sheet is prepared by coating and drying a mixture having a mixing ratio of a heat-melting substance and a thermoplastic substance and a hue of a coloring material. Alternatively, a mixture of a heat-meltable substance and a thermoplastic substance mixed with a coloring material may be laminated by a hot-melt coat which is applied in a molten state, but water or a solvent such that the respective layers do not mix with each other. It is preferable to prepare a coating liquid from the dispersion, apply the coating liquid, and dry the coating liquid to laminate the hot-melt ink layer.

The mixing ratio of the heat-meltable substance and the thermoplastic substance is such that the ratio of the thermoplastic substance to the heat-meltable substance is 5 to 200.
%, Particularly in the heat-meltable ink layer on the side closer to the substrate, it is preferable to mix at a rate of 50 to 200%, and in the heat-meltable ink layer on the side far from the substrate, it is preferable to mix at a rate of 5 to 100%. In addition, the mixing ratio of the coloring material in these heat-meltable ink layers is 10
-40% is preferable. It is necessary to properly mix them according to the recording energy of the recording device.

Further, in order to stably disperse the colorant in addition to the heat-meltable substance, the thermoplastic substance and the colorant,
Surfactants, oils and fillers for adjusting the melt viscosity, and other additives can also be added.

[0024]

The present invention has the above-mentioned constitution. When the recording energy is low, only the heat-meltable ink layer on the far side is transferred to the substrate, and the thermal transfer recording of the hue of the ink layer can be carried out. When the energy is high, the heat-fusible ink layer on the side closer to the base material having a different hue is also transferred together, so that thermal transfer recording of a mixed hue of the ink layers on the side closer to the base material and the ink layer on the side farther from the base material is performed.

[0025]

EXAMPLES Next, examples of the present invention will be described.

A polyethylene terephthalate film having a thickness of 6 μm was coated with a heat-meltable ink solution having the following composition A by a wire bar and dried to form a heat-meltable ink layer having a thickness of about 3 μm. On this ink layer, the following composition B
The heat-meltable ink solution shown in (4) is applied with a wire bar and dried to form a heat-meltable ink layer having a thickness of about 3 μm, and a total of 6
The thermal transfer recording sheet of the example was prepared as a heat-meltable ink layer having a thickness of μm.

The thermal transfer recording sheet thus prepared was printed on a commercially available copy paper having a thermal head by setting the printing density adjusting scale to the maximum level and increasing the printing energy. As a result, black characters were printed. Next, when the printing density adjustment scale of the word processor was set to the intermediate level and the printing energy was lowered, red characters could be printed.

<Composition A> 155 ° F paraffin wax aqueous emulsion 50 parts by weight (Konishi Co., Ltd .; solid content 40%) Ethylene-vinyl acetate copolymer resin aqueous emulsion 50 parts by weight (Konishi Co., Ltd .; solid content) 40%) Carbon black aqueous dispersion 30 parts by weight (Sanyo Dyestuff Co., Ltd .: Sandye Super Black C, solid content 28%)

<Composition B> 155 ° F paraffin wax aqueous emulsion 75 parts by weight (Konishi Co., Ltd .; solid content 40%) Ethylene-vinyl acetate copolymer resin aqueous emulsion 25 parts by weight (Konishi Co., Ltd .; solid content) 40%) Carbon black water dispersion 40 parts by weight (Sanyo Dye Co., Ltd .: Sandye Super Pink F5B, solid content 19%)

[0030]

When the thermal transfer recording sheet of the present invention is used,
When the recording energy is low, only the heat-fusible ink layer on the far side is transferred to the substrate and thermal transfer recording of the hue of the ink layer is possible, and when the recording energy is high, the side closer to the substrate with a different hue. Since the heat-meltable ink layer of is also transferred together, it is possible to perform heat transfer recording of a mixed hue of the ink layer on the side closer to the substrate and the ink layer on the side farther from the substrate, and with one heat transfer recording sheet,
It is possible to record a plurality of colors by changing the recording energy.

[0031]

[Brief description of drawings]

FIG. 1 is a sectional structural view of a thermal transfer recording sheet of the present invention.

FIG. 2 is a schematic explanatory view of a transfer recording system of a thermal transfer recording sheet of the present invention.

FIG. 3 is an explanatory diagram showing thermal transfer recording at low energy with the thermal transfer recording sheet of the present invention.

FIG. 4 is thermal transfer recording at high energy with the thermal transfer recording sheet of the present invention.

[Explanation of symbols]

 1: Thermal transfer recording sheet of the present invention 11: Substrate 12: Hot-melt ink layer (side closer to the base) 13: Hot-melt ink layer (side far from the base) 21: Coloring material 22: Coloring material 31: Thermofusible substance 32: Thermoplastic substance 2: Recording paper 3: Thermal head 4, 4 '; Transfer recording image (ink)

Claims (3)

[Claims] 1. A thermal transfer recording sheet in which a heat-meltable ink layer comprising a heat-meltable substance, a thermoplastic substance and a colorant is provided on a substrate made of paper, plastic film or the like,
The heat-meltable ink layer is composed of two or more layers having different hues of the colorant, and the ratio of the thermoplastic substance to the heat-meltable substance is closer to the substrate than the heat-meltable ink layer far from the substrate. A thermal transfer recording sheet characterized by having fewer layers. 2. The thermal transfer recording sheet according to claim 1, wherein the heat-meltable ink layer on the side closer to the substrate has a higher melt viscosity than the heat-meltable ink layer on the side farther from the substrate. 3. The thermoplastic material is ethylene-vinyl acetate copolymer resin, and the thermofusible material has a melting point of 50 ° C. to 85 ° C.
2. The thermal transfer recording sheet according to claim 1, wherein the wax has a melt viscosity at 100 [deg.] C. of 20 cps or less.