JPH0257029B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thermal transfer recording apparatus that thermally transfers and records monochromatic gradation images, color images, etc. on a recording medium in continuous gradation using a thermal head.

Conventional technology A conventional thermal transfer recording device prints a hot image by mixing a pigment coloring material with a binder material such as hot melt wax on one surface of a heat-resistant base sheet such as capacitor paper or polyethylene terephthalate (PET) film. A so-called melt transfer type thermal transfer recording sheet in which a thermal transfer ink layer is formed using a melt coating method is used.

Thermal transfer using this thermal transfer recording sheet is performed by pressing the thermal transfer recording sheet against a recording medium such as recording paper, and then applying the thermal recording head from the side of the base sheet on which the ink layer is not formed, that is, from the back side of the base sheet. The ink was transferred and adhered to the recording medium by selectively controlling the recording temperature to increase the temperature and utilizing the substantial decrease in viscosity of the ink material as the binder material melted (for example, Japanese Patent Publication No. 49-26245).

Problems to be Solved by the Invention In the case of such conventional melt transfer type thermal transfer recording sheets, so-called ink melting starts from the back side of the ink layer in contact with the base sheet, and as the temperature rises and the writing thermal energy increases, the ink layer thickness increases. It has the characteristic that almost all of the ink material melted in the thickness direction is transferred at once to the recording medium that comes into contact with the ink layer only after the surface portion of the ink layer is melted.

Therefore, thermal transfer recording requires a certain amount of thermal energy to completely melt the ink layer in the thickness direction. Although it is useful for binary density recording, it has the disadvantage that it is difficult to perform so-called continuous gradation recording in which the recording density changes in response to heating energy for writing.

Therefore, digital pseudogradation methods such as the dither method and the density pattern method are being widely considered in order to improve this difficulty. It was rare.

From this point of view, the present inventors have developed a method, also known as a heat penetration method, in which a large number of through holes are arranged in the ink layer to make it porous, and the molten ink immediately penetrates the through holes and is transferred to the recording medium. A thermal transfer recording method (Japanese Patent Application No. 110024/1982) was proposed.

Continuous tone recording is possible with the above recording method, but in order to obtain the desired continuous tone characteristics, the hole diameter and arrangement density of the through holes, as well as the contact conditions between the ink layer surface and the recording medium surface, etc. Careful consideration is required. In order to improve this contact condition, a thermal transfer sheet (patent application 1983-
No. 110023) has also been proposed, but when the particle size of the spacer particles is smaller than the ink layer, there are severe restrictions due to the particle size and arrangement density of the through holes. Therefore, it is not necessarily necessary to use such a heat penetration method;
There is a need for an improved thermal transfer recording sheet that is operationally easy and capable of stable continuous tone recording.

In addition, in the case of melt transfer, in order to obtain the desired transfer recording density, the molten ink must maintain some fluidity after heating and melting, before cooling and returning to its original solid form. It is necessary to quickly separate the recording medium and the thermal transfer recording sheet. Conventionally, the time from heating and melting to peeling was not constant, so
It has been difficult to consistently obtain the desired transfer recording density.

The present invention has been developed in view of the above points, and it is possible to consistently obtain the desired transfer recording density by using a thermal transfer recording sheet that is easy to manufacture and operate, and can perform stable continuous tone recording. The purpose is to provide a thermal transfer recording device that can.

Means for Solving the Problems In order to solve the above problems, the present invention includes an ink material whose viscosity is controlled to be reduced by temperature increase recording control and transferability to a recording medium is imparted. In addition, it has a melting point or pour point higher than that of the binder material, which is a constituent component of this ink material and whose viscosity is controlled to be reduced by increasing the temperature, and particles with a thickness greater than or equal to the thickness of the layer made of this ink material. A thermal transfer layer in which ink transfer auxiliary particles having a diameter are mixed into the ink material is heated and melted with a thermal transfer recording sheet placed on one side of a sheet-like heat-resistant substrate, and then the molten ink cools and returns to its original solid state. Before returning to the state, stabilization is achieved by providing a pressing member that presses and clamps the recording medium and the thermal transfer recording sheet against the platen at a position where the recording medium and the thermal transfer recording sheet can be separated while the molten ink maintains its fluidity to some extent. It is possible to perform gradation recording of monochrome images, full color images, etc.

Ink material here means the intended recording material to be transferred to a recording medium, and it does not matter whether it is colored or non-colored, but in normal transfer recording, pigments, dyes,
Alternatively, it is configured to include a coloring material made of a mixture of these materials. Furthermore, the term binder material collectively refers to materials whose viscosity decreases when the temperature rises and imparts transferability to a recording medium, and these materials are not specified as a single material but may be composed of multiple types of materials. The binder material also includes plasticizers, softeners, surfactants, thixotropic agents, and other auxiliary agents that may be added as necessary.

Further, the particle shape of the ink transfer auxiliary particles is preferably spherical, but sometimes the particle shape does not matter, and in this case, the particle size can be expressed as an average particle size. For the ink transfer auxiliary particles, transparent or opaque materials can be used as required, and colored or non-colored materials can also be selected as appropriate. When the binder material is melted, it may be incompatible, partially compatible or compatible with the binder material, and a plurality of types may be mixed and used as appropriate.

Effects The present invention has the above-mentioned configuration, that is, the melting point (or pour point) of the auxiliary particles is selected to be higher than that of the binder material, so that the increase due to heat conduction from the surface of the heat-resistant substrate and further from the molten ink material. The temperature is continuous up to its melting point. Thus,
In the auxiliary particles, the unmelted ink material that is in contact with the surface of the portion embedded in the ink material layer and the surface of the portion protruding from the layer surface has a melting point temperature, respectively, even at the highest temperature. Therefore, heat of fusion is supplied by heating from the surface of the auxiliary particle having a higher melting point temperature. Therefore, the ink material melts along the surface of the auxiliary particles, and the melted portion expands as the amount of heat is applied, and the viscosity of the melted portion further decreases and fluidity increases.

In this way, the molten ink material is transmitted through the surface of the auxiliary particle due to its thermal expansion, permeates and is pushed out, and since the particle size of the auxiliary particle is larger than the thickness of the ink material layer, the surface of the auxiliary particle and the surface of the recording medium are Through a narrow gap between the auxiliary particles and the auxiliary particles, the auxiliary particles are transferred to the surface of the recording medium by a kind of capillary phenomenon, and are attached to and transferred to the surface of the recording medium.

At this time, by adding the amount of heat applied, the molten ink material to be adhered and transferred can be easily changed, and therefore, continuous tone recording can be easily performed.

Also, at this time, the molten ink cools down after being heated and melted,
Before the molten ink returns to its original solid state, the recording medium and thermal transfer recording sheet are overlapped and pressed against a platen using a pressing member installed at a position where the recording medium and thermal transfer recording sheet can be separated while the molten ink retains some fluidity. Therefore, since the recording medium and the thermal transfer recording sheet are peeled off at the pressing part of the pressing member, the distance at which the recording medium and the thermal transfer recording sheet are in close contact can be kept constant, and therefore the peeling conditions are constant. Therefore, stable continuous tone recording can be performed.

Embodiment FIG. 1 is a schematic diagram of an embodiment of the thermal transfer recording device of the present invention, FIG. 2 is a cross-sectional structure of a thermal transfer recording sheet used in this thermal transfer recording device, and FIG. 3 is a diagram of the thermal transfer layer of the thermal transfer sheet. Surface plan view, Figure 4 a, b
2 is a diagram explaining the principle of transfer using the thermal transfer recording sheet of FIG. 2 as an example.

100 is a thermal transfer recording sheet (transfer body for short),
200 is a recording medium, and in the case of the embodiment shown in FIG.
is wrapped around. Reference numeral 510 denotes an end-face type thermal head (shown as a schematic cross-sectional view in FIG. 1) which has a plurality of heating elements 520 linearly arranged on the end face. The recording medium 200 is stacked so as to face the thermal transfer layer 130 provided on the transfer body 100, and the platen 61
0 with the end face type thermal head 510, the platen 610 is rotated in the direction of arrow 620 (driving means is not shown), the transfer body 100 is wound up in the direction of arrow 630 (driving means is not shown), and heated with heating element 520. and then melt-transferred. 650 is a pressing member, which is at a distance L from the pressing position of the end face type thermal head 510.
The transfer body 100 and the recording medium 200 are placed on the platen 61 from the same side as the edge-type thermal head 510 at the position of
It is pressed and held at 0. The distance L is set to a distance that allows the ink material 120 melted by the heating element 520 to maintain a certain degree of fluidity before being cooled and returning to its original solid state. In this state, the transfer body 100 is wound in a direction such that it is wound around the pressing member 650. Therefore, immediately after the ink material 120 melted by the heating element 520 travels a certain distance L and passes through the pressing part of the pressing member 650, the transfer body 100 is transferred to the recording medium 2 while still maintaining its fluidity to some extent.
It can be stably peeled off from 00. 300 is a heating element 52
The temperature increase recording signal due to heat of 0 is shown, and 400 is the pressing force of the end face type thermal head 510 for pressing the transfer body 100 and the recording medium 200 into contact.

The transfer body 100 has a surface 110 of a thin film or sheet-like substrate 110 that is heat resistant and translucent.
On the a side, there is a mixture of a coloring material 122 containing at least one of pigments or dyes and a binder material 121 whose viscosity decreases as the temperature rises, for example, a hot melt binder material. A thin layer of ink material 120 is formed.

The ink material layer 120 has a temperature increase recording signal 301,
A thermal transfer layer 130 is constructed by disposing a single or a plurality of ink transfer auxiliary particles (hereinafter referred to as auxiliary particles) 123 in correspondence with each recording pixel 310 corresponding to the recording pixel 302, as illustrated in the figure. be done. In this example, the auxiliary particles 123 are spherical, and the particle diameter φ is selected to be equal to or larger than the thickness t of 120 parts of the ink material located between the particles 123. Therefore, the auxiliary particles 123 partially protrude from the ink material layer surface 120a in the area where the particles 123 are not present, and the surface of the thermal transfer layer 130 forms fine irregularities. In this example, the ink material 120' is also located thinly on the protruding surface 123b of the auxiliary particle 123, but this does not necessarily have to be present, and this portion of the auxiliary particle surface 123b may be exposed. can.

By applying the temperature increase recording signal 300, the temperature of the ink material layer 120 is raised from the back surface 120b side, and when the required heat of fusion is supplied even after reaching the melting point, the hot melt binder material is heated under this constant melting point temperature. 121 is melted and liquefied to produce a so-called molten ink material 140a with substantially reduced viscosity.

Further, when the recording signal 300 is applied, the temperature of the molten ink material 140a starts to rise again from the back side of the layer (that is, the front surface 110a of the substrate) beyond the melting point, and in response to the temperature rise, the temperature of the molten ink material 140a starts to rise again.
The viscosity of the ink material 0 further decreases and fluidity is imparted, and at the same time, the melting progresses toward the ink material layer surface 120a side due to heat conduction through the melted ink material 140a.

On the other hand, as the auxiliary particles 123, the binder material 1
If the melting point (or pour point) is selected higher than that of 21, the temperature increase due to heat conduction from the substrate surface 110a and further from the molten ink material 140a is continuous up to the melting point.

In this way, the surface 123 of the portion of the auxiliary particle 123 that is embedded in the ink material layer 120
a, and the unmelted ink materials 120 and 120' in contact with the surface 123b of the portion protruding from the layer surface 120a, respectively, have a melting point temperature even at the highest temperature.
Therefore, the heat of fusion is supplied by heating from the auxiliary particle surfaces 123a and 123b having a higher melting point temperature. Therefore, as shown in FIG. 4a, melted ink materials 140b and 140c are generated along the surfaces 123a and 123b, and a recording signal 300 is generated.
As the applied pulse width increases, the melted area expands,
In addition, the viscosity of the melted zone further decreases and fluidity increases.

Thus, the molten ink material 140a and even 1
Due to its thermal expansion, the auxiliary particle surface 1
23a as shown by the arrow 150, the auxiliary particle surface 123b and the recording medium surface 2 are penetrated and pushed out.
Due to a kind of capillary phenomenon, the particles are transferred to the auxiliary particle surface 123b through a narrow gap with the auxiliary particle surface 123b, and are attached and transferred to the recording medium surface 200a.

In this case, if the recording medium 200 has high ink absorption properties such as porous paper, the above-mentioned adhesion and transfer will be promoted, and if the pressing force 400 is appropriately large, the auxiliary particles 123 and the substrate The molten ink material 140a interposed between the surfaces 110a exerts this pressing force 40
0 through surfaces 123a and 123b,
More effective penetration, it will be pushed out.

The molten ink material adhering to the recording medium surface 200a has heat removed by the recording medium 200, and its viscosity increases or even solidifies.

For example, if the pulse width P _W of the recording signal 300 generated from the pulse width modulated electric signal 500 is appropriately small, the adhesion _and
The amount of transfer is also small, but in Figure 3a, the electrical signal 5
The molten ink material 14 has a suitably large P _W and low viscosity, such that the pulse width P _W corresponding to 01 = P _W1 .
When the auxiliary particles 123 are made mobile by the presence of 0a and 140b, the molten ink materials 140a and 140b are cooled and returned to their original state after the application of the signal 301 is completed, in conjunction with the above-mentioned infiltration and extrusion 150. For example, if the recording medium 200 and the recording sheet are peeled off before returning to a solid state, that is, while they are still in a fluid state and the auxiliary particles 123 have not lost their mobility, they will melt as shown in FIG. 4b. The remainder of the ink materials 140a, 140b, 140c are
The coloring material 12 is attached to the surface of the auxiliary particles and is attached and transferred to the recording medium surface 200a together with the auxiliary particles 123.
A transfer record 161 containing 2 is obtained.

When the pulse width P _W corresponding to the recording signal 300, that is, the electric signal 502, becomes wider as P _W =P _W2 ,
The melting finally reaches the surface 120a of the ink material layer, and the entire thickness of the ink material layer 120 is attached and transferred to the medium surface 200 together with the auxiliary particles 123, and the transfer record 162 in this case is the maximum value of the transfer optical record density. Become.

In the case of the embodiment shown in FIG. 1, as described above, the pressing member 6 peels off the transfer body 100 from the recording medium 200.
50, the melted ink material 140a, 140
Since the distance L is selected so that b cools down and returns to its original state, that is, it still maintains a fluid state and the auxiliary particles 123 do not lose their mobility, a stable peeling state is maintained at all times. can get.

In this way, the ink material layer 120 melts and becomes less viscous in response to the recording signal 300, and in response to this reduction in viscosity, the ink material layer 120 along with the auxiliary particles 123 spreads onto the recording medium surface 2.
Since a transfer record 160 is generated at 00a, the pulse width is
Corresponding to _PW , the optical density of each auxiliary particle 123 can be transferred and recorded in continuous gradation in a form where density modulation and area modulation coexist. In this case, if the density of the auxiliary particles 123 is selected to be appropriately high, there is an advantage that the recorded pixels 310 themselves can be visually controlled by the density gradation.

Above, an example has been described in which the binder material 121 has a clear melting point and the viscosity decreases rapidly when it melts.
21 is made of a mixture of various materials, such as natural wax material, and does not have a clear melting point and its viscosity decreases slowly with increasing temperature, or it has a high penetration rate and is solid or semi-solid at room temperature. It is also possible to record gradation even when Furthermore, even if the binder material 121 has a melting point below room temperature (for example, 25 degrees) and is sticky at room temperature, such as polybutane, fog transfer of the ink material 120 (thermal transfer layer 12
In order to prevent the phenomenon in which the ink material 120 is transferred simply by pressing the recording medium 200 into contact with the recording medium 200, the viscosity at room temperature (for example, 25° C.) is set to, for example, 2×10 ⁴ centipoise or more, preferably 5×10 ⁴ centipoise or more. By selecting a high density and appropriately selecting the arrangement density of the auxiliary particles 123, it is possible to obtain a transfer record 160 with continuous gradations corresponding to the pulse width _PW .

In these cases, the pulse width of the temperature increase recording signal 300
When the viscosity of the ink materials 120, 120' decreases in response to P _W and they become fluid as a whole, a type of capillary phenomenon between the recording medium surface 200a and the particle surface 123b causes the auxiliary particles to The ink materials 120', 120 penetrate and transfer to the recording medium surface 200a via the surface 123b and further through the surface 123a. In addition, the ink material layer 1
When the recording medium 200 and the transfer sheet 100 are separated from each other while the fluidized ink material in Part 20 does not lose its fluid state, the auxiliary particles 123 attached to the surfaces 123a and 123b transfer the ink material having a lower viscosity. As a result, a continuous tone transfer record 160 corresponding to the pulse width P _W is formed on the recording medium surface 200.
obtained in a.

As is clear from the above explanation of the operation, in the recording method using the thermal transfer recording sheet 100 according to the present invention, the auxiliary particle surfaces 123a, 123b and the recording medium surface 20
0a requires good wettability, the wetting angle (contact angle) to these surfaces is at least 90°,
It is set as small as possible.

The particle shape of the auxiliary particles 123 is not necessarily limited to a spherical shape, and may be polygonal or other.
Furthermore, the particle size φ does not necessarily have to be all a single diameter, but may have an appropriate particle size distribution. In this case, auxiliary particles 123 having a particle diameter φ greater than or equal to the thickness t of the ink layer surface 120a and protruding beyond the ink layer surface 120a
contributes to continuous tone transfer recording, and the auxiliary particles 123 having a smaller particle size exhibit behavior similar to the pigment as the coloring material 122.

Therefore, in practical terms, it is convenient to express the particle size φ in terms of the average pore size.

The average particle diameter φ of the auxiliary particles 123 is practically selected within a preferable range based on both the continuous tone transfer characteristics and the maximum density of transfer recording, based on the correlation with the thickness t of the ink material layer 120.

When the average particle diameter φ _n is less than 1.5 μm, the ink material layer 1
If the thickness t of the thermal transfer layer 20 becomes too small, the maximum density of the transfer record 160 cannot be obtained, and it becomes difficult to produce a uniform thermal transfer layer 120, making fog transfer likely to occur. On the other hand, the average particle diameter φ _n of the auxiliary particles 123 is 15μ
If it exceeds m, the heat capacity of the auxiliary particles 123 becomes excessive, making it difficult to raise the temperature as expected, and the path of infiltration and extrusion 150 becomes excessively long, resulting in low sensitivity and a decrease in the maximum recording density.

Therefore, the preferred range of average particle diameter φ _n is 1.5 μm to 15 μm.
It is m. It is sometimes recommended to select the average particle diameter φ _n within the range of 2 μm to 10 μm because fog transfer can be easily prevented and continuous gradation and recording sensitivity can be improved. In this case, the maximum particle size value in the particle size distribution is
It is desirable that the thickness does not exceed 15 μm.

On the other hand, the arrangement density of the auxiliary particles 123 is selected in consideration of the density of the recording pixels 310 and the thermal transfer recording characteristics.

The lowest arrangement density of auxiliary particles 123 is at recording pixel 3.
This is the case where a single piece is located for each of the 10 pieces.

Normally, when a gradation image is recorded using a known linear type thermal recording head, the recording density, that is, the density d of recording pixels 310, is selected to be 4 dots/mm or more from the viewpoint of image quality.

Therefore, the hiding rate (substrate surface 11
Area ratio of particles 123 to unit area of 0a)S
The minimum value of is the preferred minimum value of the grain size φ, φ=
φ _nio (=1.5 μm) is given by (πφ ² _nio d ₂ )/4,
When d=4 dots/mm, it becomes 2.8×10 ^-5 (2.8×10 ^-3 ).

On the other hand, the maximum value of S is the auxiliary particle 123 with φ>t
are arranged most densely on the substrate surface 110a without overlapping each other, and it is given by π/4==0.785 (78.5%). S can be appropriately selected within the above range.

In the above, if the arrangement density of the auxiliary particles 123 is too low, the transfer recording 160 via the particles 123
The density becomes insufficient, and the recorded image also appears rough. To prevent these, the arrangement density of particles 123 is
16 pieces/mm (265 pieces/mm ² φ _nio = 1.5μm and S = 4.5×
10 ^-2 %) or higher. FIG. 2 illustrates a case where four auxiliary particles 123 are arranged in each recording pixel 310.

The auxiliary particles 123 are preferably colorless and transparent or white in view of the color clarity of the transfer record 160, but they may be colored.

The colorless transparent or white particles 123 include, for example, transparent glass powder, fused quartz powder, thermosetting resin particles such as epoxy resin, thermoplastic resin particles such as polyamide and polycarbonate resin, aluminum oxide (Al ₂ O ₃ ), Inorganic powder particles such as titanium oxide, silicon oxide (SiO ₂ ), tin oxide, barium sulfate, etc. are used.

As the auxiliary particles 123, it is also possible to use a hot melt material that is not completely compatible with the binder material 121 or completely soluble in the solvent at room temperature or during the production of the ink material layer 120, such as carnauba wax or Sasol wax particles. In this case, if the material is selected to be compatible with the binder material 121 during thermal transfer, the transfer sensitivity will be improved and a strong transfer record 160 will be obtained.
There are advantages that can be obtained.

These auxiliary particles 123 can also be used in combination of multiple types.

The binder material 121 constituting the ink material layer 120 does not necessarily need to be solid at room temperature (for example, 25° C.), provided that its viscosity is reduced by the ascending recording control and transfer adhesion is imparted. However, in view of the storage stability of the transfer record 160, it is preferable to use a hot melt material that is solid at room temperature.

Hot melt materials include waxes such as carnauba wax, beeswax, paraffin, and microcrystalline wax, low molecular weight polyethylene, low molecular weight polystyrene, polyvinyl stearate, petroleum resins, polyamic acid resins, alicyclic saturated hydrocarbon resins, etc. , rosin-modified maleic acid resin, etc., but the melting point or pour point is selected to be 50 to 170°C, preferably 60 to 120°C, in consideration of transfer sensitivity and fastness of the transferred recorded material. In addition, the softening agent to be mixed in order to impart flexibility to the binder agent may be selected from polyvinyl acetate, cellulose esters, acrylic resins, stearic acid, lanolin, etc., depending on their melting or softening temperature. used. As a binder agent, for example, petroleum resin, which is flexible in itself,
When low molecular weight polystyrene etc. are used,
In particular, sometimes no softener is added. Furthermore, by including an adhesive material in the binder agent, which has a relationship in which the viscosity decreases and the adhesiveness increases as the temperature rises and is fluid at room temperature, it is possible to further reduce the viscosity with respect to temperature rises and increase the transfer efficiency. For example, adhesive materials such as polybutene, polyisobutylene, polybutadiene, and silicone oil can be mixed with the hot melt material to adjust the thermal properties and used as a binder agent.

As the coloring material 122, organic or inorganic pigments and dyes used in ordinary printing inks, paints, etc., or mixtures of these coloring materials can be appropriately selected and used in colored recording.

For example, in black transfer recording, carbon black or diamond black is used as a pigment, and CI Solvent Black 3 is used as a dye.

In addition to the above, for full color transfer recording, C I Pigment Blue 15 (pigment) and C I Solvent Blue 25 (dye) are used for cyan, and C I Pigment Red 57 (pigment) and C I for magenta.
I Soluent Red 49, C I for yellow color
Pigment Yellow 12 (pigment), CI Pigment
Yellow 17 (pigment), CI Solutnt Yellow 16
Thermal transfer layers 130 are sequentially disposed on the same base sheet 110 in frame order using ink materials 120 of three primary colors or four primary colors including black, such as pigments, dyes, or mixtures thereof, and then placed on a platen. 610
Full-color recording is achieved by rotating the images three to four times and sequentially overlapping and transferring them onto the recording medium 200. These coloring materials 122 and binder materials 121
The weight percentage of the mixture is determined in consideration of the transfer recording characteristics.

For example, when a dye is used as the coloring material 122, if the weight percentage in the ink material layer 120 is 2% or less, the transfer recording density will be insufficient;
When is a pigment, if the weight percent exceeds 60%, the viscosity of the ink material 120 as a whole does not decrease sufficiently when melted, making it difficult to transfer to the recording medium surface 200, resulting in insufficient transfer recording density. Therefore, the coloring material 122
The weight percentage of is suitably chosen in the range of 2-60%, so that the binder material 121 is correspondingly 98-40%.
It is desirable to choose within the range of %.

In particular, the ink material 12 contains 10 to 50% of the coloring material 122 and 90 to 50% of the binder material 121.
0 is a recommended range as it provides excellent transfer recording density and continuous gradation. This range is particularly effective when using a pigment as the coloring material 122.

For example, the sheet-like substrate 2 has a thickness of 3.5 to 3.5 mm.
Resin films of about 15 μm such as polyethylene terephthalate, polyimide, cellophane, polycarbonate, triacetyl cellulose, nylon, or high-quality paper, glassine paper, tracing paper,
Heat-resistant paper such as capacitor paper can be used.

As the recording medium 200, high quality paper, coated paper,
Papers such as art paper and synthetic paper, plastic films such as polyethylene terephthalate, polypropylene, and cellophane can be used.

The thermal transfer sheet 100 can be manufactured by applying and layering the thermal transfer layer 130 on the surface 110a of the base sheet by, for example, a hot melt coating method or a solvent coating method by appropriately combining the above configurations.

Note that the ink material layer 120 is configured to be porous,
Furthermore, gradation characteristics can be improved. Such a porous ink material layer 120 can be easily achieved by adjusting the solvent evaporation rate and generating pinholes in a solvent coating method.

Further, in the embodiment shown in FIG.
Although the pressing member 650 is assumed to be non-rotating, it goes without saying that the initial objective can be easily achieved even if a rotating roller made of metal or having rubber or the like on its surface is used as the pressing member 650.

Effects of the Invention As described above, the present invention has an ink material whose viscosity is controlled to be reduced by temperature-raising recording control and transferability to a recording medium is imparted, and this ink material has It has a higher melting point or pour point than the binder material whose viscosity is controlled to decrease as the temperature rises as a constituent component, and
A thermal transfer recording sheet is used in which a thermal transfer layer in which the ink material is mixed with ink transfer auxiliary particles having a particle size equal to or larger than the thickness of the layer made of the ink material is placed on one side of a sheet-shaped heat-resistant substrate. At the same time, the recording medium and the thermal transfer recording sheet are pressed against the platen by a pressing member, the thermal transfer recording sheet is wound around the pressing member, and the thermal transfer recording sheet is peeled from the recording medium, and the pressing member Since the position is set at a position where the molten ink material is still in a fluid state, continuous gradation recording such as stable monochrome images and full color images can be performed, and the industrial effect is extremely large. .

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a thermal transfer recording device according to an embodiment of the present invention, Fig. 2 is a cross-sectional structural diagram of a thermal transfer recording sheet used in this thermal transfer recording device, and Fig. 3 is a surface of the thermal transfer layer of the thermal transfer sheet. Floor plan, 4th
Figures a and b are explanatory diagrams of the principle of transfer, taking the thermal transfer recording sheet of Figure 2 as an example. 100... Thermal transfer memory sheet, 110... Heat resistant substrate, 120... Ink material, 121... Binder material, 122... Coloring material, 123... Ink transfer auxiliary particles, 130... Thermal transfer layer, 200...
Recording medium, 300...Temperature increase recording signal, 310...
Recording pixels, 400... Pressing force, 501, 502...
...electrical signal, 510...end face type thermal head,
520... Heating element, 610... Platen, 650
...Press member.

Claims (1)

[Claims] 1. It has a recording medium and an ink material whose viscosity is controlled to be reduced by temperature-raising recording control and imparts transferability to the recording medium, and from a binder material that is a component of this ink material. The thermal transfer layer includes ink transfer auxiliary particles mixed into the ink material, which have a high melting point or pour point and at least a part of which has a particle size larger than the thickness of the layer made of the ink material. , a thermal transfer recording sheet installed on one side of a sheet-like heat-resistant substrate, a platen, a thermal head equipped with a plurality of heating elements in a straight line, and the above recording medium and the above thermal transfer recording sheet stacked together. It is composed of a pressing member that is held in pressure contact with a platen and placed in a position to separate the recording medium and the thermal transfer recording sheet before the ink material is cooled from a melted state due to heat generated by the thermal head and returns to its original state. A thermal transfer recording apparatus in which the recording medium is opposed to the thermal transfer layer of the thermal transfer recording sheet, and the recording medium and the thermal transfer recording sheet are sandwiched and pressure-contacted by the platen and the thermal head to perform recording.