JPS6377781A - Thermal sensitive transfer material - Google Patents

Abstract

PURPOSE:To preferably separate colors in a 2-color printing by laminating a first ink layer and a second ink layer which contain metal powder on a support, and specifying the bonding strengths between the support and the first layer and the first layer and the second layer. CONSTITUTION:First and second ink layers 3, 4 which contain flaky metal powder are sequentially laminated on a support 2 to form a thermal sensitive transfer material 1. Further, it is necessary that the magnitude relationship between the bonding strength (F2) between the layers 3 and 4 and the bonding strength (F1) between the layer 3 and the support 2 becomes reverse at the times of relatively high and low temperatures. F1>F2 is satisfied at the time of relatively high temperature, and F1<F2 is satisfied at the time of relatively low temperature. Metal powder contained in the layer 3 is preferably acicular or flaky with a maximum diameter of 1-10mum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-color thermal transfer material for transferring two-color recorded images onto a recording medium made of plain paper or the like.
The present invention relates to a thermal transfer material that is capable of bright two-color recording and is particularly suitable for multi-color recording of three or more colors.

■'' L-technique thermal transfer recording method has the general characteristics of thermal recording methods, such as the equipment used is lightweight, compact, noiseless, and has excellent operability and maintainability, as well as eliminating the need for colored processed paper. Moreover, it has been widely used recently because it has lost the characteristic of being excellent in the durability of recorded images.

This heat-sensitive transfer recording method generally uses a heat-sensitive transfer material formed by coating a sheet-like support with a heat-transferable ink made of a heat-melting binder and a colorant dispersed therein. A method of superimposing a thermal transfer material on a recording medium so that its thermally transferable ink layer is in contact with the recording medium, and applying heat from the support side of the thermal transfer material using a thermal head to transfer the molten ink layer onto the recording medium. Accordingly, a transferred recorded image is formed on the recording medium-1- according to the shape of heat supply.

Furthermore, there is a strong market demand for two-color printing while taking advantage of the advantages of the J-type thermal transfer recording method, and various techniques for obtaining two-color printing have been proposed.

Conventionally, as a method for printing in two colors on plain paper-I using a thermal transfer recording method, Japanese Patent Application Laid-open No. 148591/1983 describes
2 in which different colorants are contained in the base material -1-
Two heat-melting high melting point ink layers A and a low melting point ink layer B are laminated sequentially from the substrate side, and in the case of low heat applied energy, only the low melting point ink layer B is transferred to plain paper]2, and in the case of high heat applied energy, In some cases, a two-color thermal transfer recording element is disclosed in which a two-color recorded image is provided by transferring both heat-melting ink layers A and B.

Furthermore, JP-A No. 59-64389 discloses a two-color thermal transfer ink sheet in which an ink layer consisting of an ink that melts and leaches when heated and an ink that melts and peels off at a temperature higher than the melting and leaching temperature is provided on a base material. I. is disclosed.

However, with these methods in which the energy applied to the thermal head is changed in two stages, during high-temperature printing, printing quality is likely to deteriorate, such as "edging" or "tailing" due to the effect of heat. There was a drawback.

As a technique to overcome this drawback, the present applicant previously proposed Japanese Patent Application No. 59-260403 and Japanese Patent Application No. 60-2.
I7 proposed the recording method of No. 98831.

In this recording method, at least first and second
By using a heat-sensitive transfer material provided with an ink layer and applying heat to the heat-sensitive transfer material, the second ink layer can be selectively or , a method in which both the first and second ink layers are transferred to a recording medium.

This recording method makes it possible to solve various problems such as "edging" and "tailing" of printing mentioned above. However, even in such a new two-color recording method, the color tone of the ink layer of the thermal transfer material used for this method (especially the first
In terms of improving the degree of freedom in the color tone of the ink layer, the superiority over conventional two-color printing technology was not necessarily sufficient.

That is, in these recording methods (the conventional two-color recording method described above and the new recording method described above), when using a thermal transfer material formed by disposing the first and second ink layers on the support, During printing, either only the second ink layer is transferred, or the first ink layer is transferred. Both the second ink layer will be transferred to the recording medium. However, when both the first and second ink layers are transferred, it is inevitable that the color of the second ink will be slightly mixed with the color of the first ink layer, so in this case, it is difficult to obtain beautiful colors. It is.

For this reason, conventionally, the hiding power of the first ink has been strengthened by making the second ink a light color and the first ink a dark color. In reality, when the first ink is black, it has a fairly good hiding power, so a nearly black print can be obtained, but when the second ink is red, it becomes a warm black; If the ink is blue, it is inevitable that it will be a cold black color. Also, if the first ink is a dark color other than black, the hiding power will be insufficient, so
It is even more difficult to obtain beautiful colors.

In order to improve this, it is possible to increase the thickness of the first ink layer, but if the first ink layer is too thick,
Not only does the energy required for printing increase, but also the resolution of printing becomes low, making it impossible to obtain good printing. Therefore, in the past, when printing in two colors using an ink film in which the first and second ink layers were laminated, it was actually impossible to obtain a beautiful colored recorded image unless the first ink was black. I couldn't.

Such a limitation on the color tone of the first ink layer is particularly important when applied to an apparatus that uses a plurality of ink films capable of two-color printing and switches between them to obtain multi-color printing.
This is a big drawback. That is, even if two ink films are used, if the first ink in each ink film is black, only three colors can be obtained. or,
Even if the color of the first ink layer is other than black, there will be two dark colors close to black, and the practical advantage of using two ink films will be small.

In addition, when printing in three colors using an ink film capable of two-color printing and a single-color ink film, it is usually possible to print in black, which is the most frequently used color, with a low-cost single-color ink film. It is practically desirable to obtain bright and vivid two-color printing using an ink film capable of two-color printing. However, when using a conventional ink film capable of printing in two colors, beautiful two-color printing (light color-light color) is obtained, both of which have bright tones (because the first ink layer has to be dark). There was no water.

The main purpose of the present invention is to solve the above-mentioned drawbacks of the conventional two-color printing method, to provide two-color printing with good color separation on plain paper in a simple manner, and to An object of the present invention is to provide a heat-sensitive transfer material that allows the use of a light-colored first ink layer.

Jll Uninvented Osamu et al.
As a result of intensive research on thermal transfer materials used in
It has been found that imparting high light reflection properties to the ink layer is extremely effective in achieving the objectives described in -.

The thermal transfer material of the present invention is based on the findings in -1-, and more specifically, at least a first ink layer and a second ink layer are sequentially provided on a support from the support side, ■, ■, ■-The magnitude relationship between the adhesive force between the support and the first ink layer and the adhesive force between the first ink layer and the second ink layer is reversed between high and low temperatures. The thermal transfer material is characterized in that the first ink layer contains metal powder (this is used to include powder made of scale-like particles, etc., which will be described later).

The reason why such an effect is obtained in the present invention is presumed to be as follows.

That is, the thermal transfer material of the present invention having the above structure has (
In order to provide a two-color recorded image by controlling the separation time from the recording material after energy application (not the magnitude of energy application), the first ink layer is transferred to the recording material in a manner that satisfactorily covers the second ink layer. Moreover, it is estimated that the mixing between the first and second ink layers is suppressed to a low level.

Therefore, when using the thermal transfer material of the present invention, the high light reflection property of the first ink layer containing metal powder is effectively utilized, and the recorded image transferred to the recording medium (from the recording medium side to the second The ink layer and the first ink layer are sequentially laminated)
The light incident from the first ink layer side is (substantially)
It is reflected only by the ink layer. Therefore, in the above recorded image, light absorption by the second ink layer is not a substantial problem, and a recorded image that faithfully reproduces (for example, a bright color tone) the color tone of (only) the first ink layer can be obtained. Presumed.

Hereinafter, the present invention will be explained in further detail with reference to the drawings as necessary. In the following description, "
Unless otherwise specified, "%" and "part" are based on weight 11%.

FIG. 1 is a schematic cross-sectional view in the thickness direction showing a basic aspect of the heat-sensitive transfer material of the present invention. Referring to FIG. 1, a thermal transfer material 1 of the present invention is formed by sequentially providing a first ink layer 3 and a second ink layer 4 on a support 2-#-.

In the thermal transfer material 1 used in the present invention, the adhesive force (F2) between the first ink layer 3 and the second ink layer 4 and the adhesive force (Fl) between the first ink layer 3 and the support 2 are different. It is necessary that the relationship can be opposite at relatively high temperatures and at relatively low temperatures, but at relatively high temperatures F > F2 and at relatively low temperatures Fl < F2. It is preferable that there be.

In a thermal transfer material in which the magnitude relationship of adhesive forces F, F2 is in this preferable manner, for example, when heat is applied to the thermal transfer material 1, immediately after heating (preferably J to 20
m sec), the separation between the first ink layer 3 and the second ink layer 4 is better than any separation between the first ink layer 3 and the support 2, and on the other hand, the support 2 is separated from the recording medium after heating. When it takes a long time to separate them, that is, after heat is applied, the heat-sensitive transfer material and the recording medium run while being in close contact with each other (preferably for about 50 to 200 IIl sec after heat application), and the heat-sensitive transfer material is cooled. In some cases, the first ink layer 3 is configured to be easily peeled off from the support 2.

The characteristics of the adhesive force between each of the layers described above will be explained using FIG. 2(a). In the present invention, when evaluating the adhesive force between the second ink layer and the first ink layer (F2) and the adhesive force between the first ink layer and the support (Fl), each ink layer is Second ink layer-first when transferring to body
Only the relative ease of separation between the ink layers and the separation between the first ink layer and the support shall be considered, and the form of separation between the ink layers (for example, if the position of separation is
(Whether or not there is a strict boundary between the ink layers, or how much of the adhesive layer (described later) remains on the heat-sensitive transfer material after transfer, etc.) shall not be considered in the evaluation of adhesive strength.

Referring to FIG. 2(a), the adhesion force (F2) between the first ink layer and the second ink layer and the adhesion force (F+) between the first ink layer and the support are determined by heating or cooling. and change. In the configuration shown in FIG. 1, for example, if the second ink layer 4 is made of a material whose adhesive strength changes greatly depending on temperature, and the first ink layer 3 is made of a material whose adhesive strength changes little with temperature, then the heating by the thermal head When Oni builds an earthen wall,
The adhesive force F2 suddenly decreases. Therefore, in the state immediately after heating (before the temperature drops), as shown in Figure 2 (
As shown in a), F2 becomes smaller than Fl. Therefore, if the recording medium and the thermal transfer material are separated immediately after the second ink layer 4 adheres to the recording medium by heating, that is, at time t in FIG. 2(a), the second ink layer 4 is selectively transferred to the recording medium.

In addition, after heating with a thermal head, when the temperature of the ink layer becomes low F after a while, the adhesive force F2 recovers, and this adhesive force F2
If the thermal transfer material and the recording medium are separated after the adhesive force F1 exceeds the adhesive force F1, that is, at time t2 in FIG. Transfer to.

Therefore, by changing the color tone of the first ink layer 3 and the second ink layer 4 in the thermal transfer method, a clear two-color recorded image can be obtained by the thermal transfer method of the present invention.

FIGS. 3(a) and 3(b) are schematic side sectional views of a typical embodiment of a recorded image formed on a recording medium using the thermal transfer material 1 of the present invention, which has a double continuous structure.

Referring to FIG. 3(a), the recorded image 11a when the second ink layer 41 is selectively transferred to the recording medium 5 is shown in the upper part of the drawing (
When viewed from the surface of the recording medium 5 to which the second ink layer 41 has been transferred, the color tone is that of the second ink layer 41.

On the other hand, with reference to FIG. 3(b), when the recorded image in which both the second ink layer 41 and the first ink layer 31 have been transferred to the recording medium 5 is viewed from above, the first ink layer is substantially 31
Since only the light reflected by the metal fine particles inside enters the eye, the color of the second ink layer 41 below the first ink layer 31 cannot be seen through.

Therefore, in the thermal transfer material 1 of the present invention, a clear two-color recorded image can be obtained even when the second ink layer 4 is dark-colored (unlike conventional two-color thermal transfer materials). As the color tone of the second ink layer 4, substantially all color tones can be used.

In addition, although Fig. 2 (a) describes the case where the adhesive force between one layer recovers to the state before the start of heating as time passes after heating, this adhesive force does not necessarily recover to the state before the start of heating. do not have to. For example, as shown in FIG. 2(b), the magnitude relationship of the adhesive force does not become opposite before heating starts, but it does not matter even if the magnitude relationship of the adhesive force becomes opposite within the cooling period after heating. . In cases where the ink layer is formed by coating an emulsion, the state before heating may be different from the state after a period of time has elapsed after heating.

Furthermore, when peeling the first ink layer 3 from the support 2,
The first ink layer 3 and the support 2 do not necessarily need to be separated at the interface, but may be separated inside the first ink layer.

In the thermal transfer material 1 of the present invention, the adhesive force F1.
Specifically, the magnitude relationship between F2 at a relatively high temperature and a relative low temperature can be easily confirmed, for example, by the following means.

That is, a thermal transfer material 1 and a recording medium 5 made of plain paper (for example, with a Beck de slippage of 200 seconds) are brought into contact with the second ink layer 4 of the thermal transfer material 1. Heat is applied to the thermal transfer material 1 from the second side of the support in a pattern (for example, solid printing) using a thermal head in the same way as in a normal thermal transfer recording method. After applying heat, the thermal transfer material 1 and plain paper are kept at -60 to +270 without being separated.
The sample was loaded into a tensile strength testing machine (Tensilon RTM-100, manufactured by Katachi Baldwin Co., Ltd.) equipped with a constant temperature bath capable of controlling the temperature at °C so that the peel angle was 180 degrees. When peeling the thermal transfer material l and plain paper at a peeling speed of 300 mm/sec using the above test machine, if the environmental temperature (temperature of the constant temperature bath) is set to a relatively high temperature of, for example, 90°C, the recording material The second ink layer 4 is selectively transferred to the barrel paper 5.Confirmation of F2, FIG. 3(a)), On the other hand,
When the environmental temperature at a relatively low temperature is, for example, 40° C., both the first ink layer 3 and the second ink layer 4 are transferred (confirmation that Fl<F2, FIG. 3(b)). At this time, the first
By changing the color tone of the colorant contained in the ink layer and the second ink layer, an image with the color tone of the second ink can be obtained at an environmental temperature of 90'C, and an image with the color tone of the first ink can be obtained at an environmental temperature of 40'C. By doing so, the magnitude relationship between the 4-distribution forces F1 and F2 can be easily confirmed.

In the thermal transfer material of the present invention, the first and second ink layers have a certain relationship of Fl and F2 as described above, but more specifically, it is desirable that each layer satisfy the following physical property conditions.

That is, in order to realize the selective transfer (Fl>F2) of the second ink layer 4 as shown in FIG. 3(a), the cohesive force of the second ink layer 4 must be It is preferable that the cohesive force of the first ink layer 3, a certain l,%, is smaller than the adhesive force (Fl) between the first ink layer 3 and the support 2.

In this case, the second ink layer 4 is likely to be divided, and the second ink layer 4 is easily separated.
Only the ink layer 4 is transferred to the recording medium.

At this time, the adhesive force between the second ink layer 4 and the recording medium (F
3) must be greater than the cohesive force of the second ink layer.

From the above, the relationship between the first ink layer 3 and the second ink layer 4 is such that the cohesive force of the first ink layer at a relatively high temperature is the same as that of the second ink layer.
(larger than that of the ink layer) is desirable. Also,
If the difference in cohesive force between the first and second ink layers is large, the difference in cohesive force between the first and second ink layers will be large, and the mixing of the first ink into the second ink will be small, resulting in a record formed by selective transfer of the second ink. The color tone of the image becomes clearer. Furthermore, in addition to the large difference in cohesive force (l/), the first ink layer 3 and the second ink layer 4 are substantially incompatible, that is, they are composed of different types of materials 4. Desired l/X. In order to satisfy the requirements that there is a large difference in cohesive force and that they are not compatible, for example, the first ink layer 11 may contain resins as exemplified below, and the second ink layer may contain waxes. It is desirable to contain at least 50 parts or more of each binder in 100 parts.

Next, in order to realize the transfer of the first and second ink layers as shown in FIG. 3(b), the cohesive force of the second ink layer 4 is as follows: It is preferable that the adhesive force (Fl) between the support 2 and the first ink layer 3 is larger than the adhesive force (Fl). In this case, if the adhesive force (F3) between the recording medium and the second ink layer 4 is greater than the adhesive force (Fl) between the support 2 and the first ink layer 3, the first ink layer 3, the second ink layer 4 Both layers of the ink layer 4 are transferred to the recording medium.

In order to more easily realize the preferable l and % relationship of adhesive force or cohesive force such as ``double series'', as shown in FIG. A first adhesive layer 6 may also be provided. This first adhesive layer 6 is a layer that controls the adhesive force (Fl) between the first ink layer and the support, and the cohesive force of the first ink layer is higher than that of the second ink layer at a relatively high temperature. It is preferable to provide the first adhesive layer 6 in cases where it is difficult to have both the functions of having a large adhesive strength and a relatively small adhesive force with the support at a relatively low temperature. By providing such a first adhesive layer 6, the first
The material of the ink layer 3 can be selected more widely, which is advantageous in adjusting print quality.

Further, as shown in FIG. 5, a second adhesive layer 7 may be provided between the first ink layer 3 and the second ink layer 4. This second adhesive layer 7 is a layer that controls the adhesive force (F2) between the first ink layer and the second ink layer, and the material of this second adhesive layer 7 is If the second ink layer 4 has similar characteristics to the second ink layer, it is not necessarily necessary for the second ink layer 4 to have the characteristics described in FIG. It is now possible to use materials that can be used, such as Hamura, which is similar to the first ink layer in the embodiment shown in FIG.
It becomes even more advantageous.

Furthermore, as shown in FIG. 6, a third adhesive layer 8 may be provided on the second ink layer 4 (on the surface facing the recording medium).

This third adhesive layer 8 improves the adhesive force of the second ink layer 4 to the recording medium. Since the second ink layer 4 usually contains a certain amount of colorant, it is difficult to significantly increase the adhesive force of the second ink layer 4 to the recording medium. Therefore, providing the third adhesive layer 8 is particularly advantageous, for example, when performing two-color printing on a recording medium with low surface smoothness.

The first adhesive layer 6, the second adhesive layer 7, and the third adhesive layer 8 described above can be provided in a combination of two or more types, if necessary.

By changing the combinations of the layer configurations described above, 28=8 layer configurations are possible (depending on the presence or absence of the three types of adhesive layers described in It can be roughly divided into two depending on the presence or absence of layer 7. That is, the first
Depending on whether the ink layer 3 and the second ink layer 4 are adjacent to each other, the combination of materials constituting these ink layers (or adhesive layer) changes.

As mentioned above, when the first ink layer and the second ink layer are adjacent to each other, it is preferable to use materials that are incompatible with each other as binders. is a resin, and the second ink layer is a wax, at least 50 parts of each binder is contained in 100 parts of the binder.
It is desirable that the content be at least 1 part. Further, the first ink layer 3 may be made of a material that does not soften. Further, when the first ink layer 3 and the second ink layer 4 are adjacent to each other, it is possible that the first ink layer 3 and the second ink layer 4 separate at the interface when they separate at a reciprocal high temperature. , it is difficult to expect that the interface between the first and second ink layers after heat is applied in a pattern will necessarily remain in the state when no heat is applied; Since it is difficult to separate the two, such a mode of separation is undesirable.

On the other hand, when the first ink layer 3 and the second ink layer 4 are not adjacent to each other, that is, when the second adhesive layer 7 (FIG. 5) is provided, there is no restriction that it is preferable to use waxes for the second ink layer. removed. However, in this case, the second adhesive layer 7
Desirably contains 50% or more of waxes.

That is, in the case of such a configuration, when the ink layer is separated at a relatively high temperature, the ink layer is separated in the second adhesive layer 7, which is extremely advantageous for selective transfer of the second ink layer 4.

Therefore, the configuration shown in FIG. 5 is advantageous compared to the case where the second adhesive layer 7 is not provided, since there is substantially no separation in the second ink layer 4, and there is no variation in print density.

Next, the structure of each part of the thermal transfer material 1 of the present invention will be explained in detail.

The support 2 of the thermal transfer material 1 of the present invention has a thickness of 3p.
Plastic films such as polyester, aramid, nylon, polycarbonate, etc., with sizes ranging from m to L2JLm,
Alternatively, paper such as capacitor paper can be used. Excessively thick materials are not preferable because they have poor thermal conductivity. As long as it has high heat resistance and strength, it is also possible to use a thin film with a thickness of 31 LIfi or less.

In the thermal transfer material 1 of the present invention, the total thickness of the ink layer (or adhesive layer) on the support 2 is preferably 20 gm or less. In addition, a first ink layer 3, a second ink layer 4, a first adhesive layer 6, a second adhesive layer 7, a third adhesive layer 8
The thickness of each is preferably in the range of 0.5 to 10 pm.

In addition, it is also effective to provide a layer for supplementing heat resistance on the back surface of the support 2 (the surface opposite to the surface on which the ink layer is formed).

Further, when performing thermal transfer recording using the thermal transfer material 1 of the present invention, in addition to a thermal head, commonly used heating means such as infrared rays, laser beams, etc. can be used as heating means. In addition, in the case of electrical heating, if necessary, a conductive layer (not shown) made of a thin film of aluminum or the like may be provided between the support 2 and the first ink layer 3 to serve as a return electrode. The ink may be electrically conductive.

The first ink layer 3 constituting the thermal transfer layer of the support 2-L is formed by dispersing metal powder in a binder, and the second ink layer 4
is made by dissolving or dispersing a coloring agent in a binder.

In the present invention, it is preferable that the first ink layer 3 and the second ink layer 4 have different tones, but as described above, the combination of these tones is not particularly limited. That is, both the first and second ink layers are brightly colored;
Alternatively, both may be dark colored, or the first ink may be light colored and the second ink may be dark colored.

As the metal powder contained in the first ink layer 3, it is possible to use powder made of conventionally known metals without any particular restriction. It is preferable to use metal powder having a ratio of 50% or more (more preferably 60% or more).

Such metal powders include, for example, powders of single metals such as aluminum, gold, silver, copper, etc., or powders of alloys (brass, etc.) containing these single metals, and two or more types may be used as necessary. Preferably used in combination.

In the present invention, the particle size of the metal powder is usually 1 at its maximum diameter (although it also relates to the thickness of the first ink layer 3).
It is preferable that it is -25gm (furthermore, 1-10gra).

In the present invention, the microscopic shape of the metal powder is not particularly limited;
7p flaky particles) are preferably used. The maximum diameter (major axis) of such scale-like particles can be measured, for example, by direct observation using an electron microscope.

In the first ink layer 3, it is preferable to use 1 to 60 parts (more preferably 1 to 40 parts) of metal powder based on 100 parts of the binder.

Further, the first ink layer 3 may further contain dyes and pigments as described below to form an ink layer having various metallic luster. Such dyes and pigments can be used in an amount of about 1 to 50 parts per 100 parts of the binder.

In the present invention, it is preferable that the first ink layer 3 containing metal powder has a reflectance of 30% or more, more preferably about 50 to 100%, with respect to sodium D rays.

On the other hand, as the colorant contained in the second ink layer 4, dyes and pigments of various colors used in the fields of printing and recording can be used without particular limitation.

Such colorants include carbon black, nigrosine dye, lamp black, sudan black SM, alkali blue, first 2010, benzidine yellow, hikumen l-yellow, indofirst orange, irgazine red, para Nitroaniline Ret, Toluidine Ret, Halanitroaniline Ret, Toluidine φ Red, Carmine FB, Permanent Bordeaux FRR, Higemen L Knee Orange R, Lysol φ Red 20, Lake Fist Red C, Rhodanine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Picment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow GG
, Zaponban First Niro 10GG, Kaya Set Y96
3. Kayaset YG, Sumiplast Yellow GG, Zapon Fast Orange RR, Oil No. Scarlet, Sumiplast Orange G, Orazole Brown G, Zabonfirth I Scarlet CG, Eisensviron
Red BEH, Oil Pink OP, Victoria Blue F
All known dyes and pigments such as 4R, First Gen Blue 5007, Sudan Blue, and Oil Peacock Blue can be used (in combination if necessary). In addition, metal powders such as copper powder and aluminum powder, mineral powders such as mica, etc. can be used. Furthermore, as other additives, surfactants,
Plasticizers, mineral oils, vegetable oils, fillers, etc. may be added as appropriate.

In the second ink layer 4, it is preferable to use 1 to 80 parts (more preferably 10 to 50 parts) of a -1-coloring agent based on 100 parts of the binder.

The binder used for the first ink layer and the second ink layer and the material used for the first and second adhesive layers include natural substances such as spermaceti wax, beeswax, lanolin, carnauba wax, candelilla wax, montan wax, and ceresin wax. Petroleum waxes such as wax, paraffin wax and microcrystalline wax, oxidized waxes, ester waxes, low molecular weight, synthetic waxes such as t'lyethylene and Fischer-Tropsch wax, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, etc. Higher resin acids, higher alcohols such as stearyl alcohol and behenyl alcohol, esters such as sucrose fatty acid ester and fatty acid ester of nrubitan, waxes such as amides such as oleylamide; or poly-17 fin resin, polyamide resin, Polyester resin, epoxy resin, polyurethane resin, polyacrylic resin,
Elastomers such as polyvinyl chloride resin, cellulose resin, polyvinyl alcohol resin, petroleum resin, phenol resin, polystyrene resin, vinyl acetate resin, natural rubber, styrene-butadiene rubber, inbrene rubber, chloroprene rubber, Resins such as polyisobutylene and bolybdenum; and the like may be used in combination of two or more types as required.

In the present invention, -C is a binder described in -1-, which has a softening point of 60 to 200°C (and further 60 to 180°C) by the ring and ball method.
'c) is preferably used.

Adjust the molecular weight, crystallinity, etc. of the above-mentioned materials as appropriate,
Alternatively, an ink layer or adhesive layer having the above characteristics can be obtained by mixing a plurality of the above materials.

However, in the thermal transfer material of the present invention, as described above, the physical properties of each layer, such as softening temperature, melt viscosity, and adhesive strength, or the combination of types of binder materials used are important. Among the binder materials mentioned above, when the first ink layer and the second ink layer are adjacent to each other, a resin-based binder is used for the first ink and a wax-based binder is used for the second ink, in 100 parts of each binder. It is preferable to contain at least 50 parts or more.

On the other hand, when the first ink layer and the second ink layer are not adjacent to each other, that is, when the second adhesive layer 7 is interposed, a resin-based binder is applied to the first ink layer, and a wax-based binder is applied to the second adhesive layer. In 100 parts of binder, at least 50
It is preferable that the resin binder is contained in the first ink and the second ink.
Preferably, the resin of the ink is of a different type.

In the case of a resin-based ink, the binder does not necessarily need to be made of resin only, and it is sufficient that the resin component is contained in an amount of 50 parts or more per 100 parts of the paint. Furthermore, in the case of a wax-based ink, it is sufficient that the wax component is contained in an amount of 50 parts or more in 100 parts of the binder.

In manufacturing the thermal transfer material of the present invention, a coating solution is prepared by mixing the materials constituting each of the layers described above with an organic solvent capable of dissolving the binder, such as methyl ethyl ketone, xylene, and terahydrofuran. It is sufficient to apply them sequentially.

Alternatively, after mixing the materials constituting each layer, they may be heated and melted to perform a so-called hot melt coating in the molten state.

Furthermore, the materials constituting each layer may be mixed and applied as an aqueous emulsion by adding a dispersant such as a surfactant. Furthermore, using these methods, it is also possible to coat each layer by a different method.

Next, a two-color printing method using the thermal transfer method of the present invention will be described.

Specifically, an apparatus such as that shown in FIG. 7, which is a cross-sectional view of the heat-sensitive transfer material in the thickness direction and the force direction, is preferably used. Referring to FIG. 7, the thermal transfer material 1 is unwound from the unwinding core 9a and wound onto the winding core 9b. The platen 12 (opposed to the recording material 5) is brought into pressure contact with the recording material 5, and at the same time, patterned heat is applied from the thermal head 10 to the thermal transfer material l.

Immediately after this heat application, the terminal end 10 of the thermal head 10
When the recording medium 5 and the thermal transfer material 1 are separated at step a, (F
1>F2) Only the second ink layer is transferred to the recording medium 5. On the other hand, the peeling control member 13 is moved in the direction of arrow A and placed at the position 13a (dotted line), the recording medium 5 and the thermal transfer material 1 are brought into pressure contact with each other in the same manner as above, and the thermal head 10 forms a pattern. After applying heat, when the ink is peeled off at the position (13a) of the peeling control member 13, both the first ink layer and the second ink layer are transferred to the recording medium 5 (because F□×F2).

Among the members shown in FIG. 7, the thermal transfer material 1, the unwinding core 9a, the winding core 9b, the thermal head 1
0 and the peeling control member 13 are attached to the carriage 1
4 in the direction of arrow B.

The thermal transfer material of the present invention is also preferably used in an apparatus capable of mounting two thermal transfer materials, as shown in a schematic perspective view in FIG.

Referring to FIG. 8, ribbon cartridges 15a and i each contain one ribbon-shaped thermal transfer material 1.
5b are stacked in two stages and mounted on a movable base 16-1- which can be moved up and down (in the direction shown by arrow C). As shown in the figure, when the movable base 16 is on the lower side (ribbon cartridge 15b side), the ribbon cartridge 15a is used for printing,
On the other hand, when the movable base 16 moves upward (toward the ribbon cartridge 15a side), the ribbon cartridge 15b is used for printing.

When printing, the thermal head 10 is placed on the platen 12.
The thermal transfer material 1 is pressed against the upper recording medium 5 through the thermal transfer material 1, and the thermal transfer material 1 is heated in a pattern, and at the same time, the carriage 14 is moved to the right (in the direction of arrow B). When only the second ink is transferred to the recording medium 5, the peeling control member 13 is kept in a non-contact state with respect to the recording medium 5, whereas when both the first ink and the second ink are transferred, the peeling control member 13 is kept in a non-contact state with respect to the recording medium 5. M material i3 together with thermal head 10 (
(via the thermal transfer material 1) against the recording medium 5.

As described below-4-, the ribbon cartridges 15a, 1
The thermal transfer material 1 contained in each of the 5b
Color printing can be performed, and clear printing can be performed in a total of 4 colors.

In this case, F at a relatively high temperature is >F2,
In addition, although the thermal transfer material 1 (which exhibits changes in adhesive strength as shown in FIG. 2) which is F2 at a relatively low temperature has been described, in the present invention, the first and second ink layers (or adhesive layers) By combining the physical properties such as cohesive force and melt viscosity, it is possible to obtain a thermal transfer material in which F<F2 at a relatively high temperature and Fl>F2 at a relatively low temperature. If a thermal transfer material exhibiting such a change in adhesive strength is used, the thermal transfer material and the recording medium can be peeled off in a relatively short time (tl) after application of thermal energy, and both the first and second ink layers can be bonded together. The second ink layer can be selectively transferred to each recording medium by peeling off for a relatively long time (F2).

Further, in the thermal transfer material 1 described above, the first ink layer 3 made of a binder with metal powder dispersed therein is used, but in the present invention, the first ink layer 3 is (from the side) may be composed of one layer of the first binder, a layer consisting essentially only of metal powder, and one layer of the first or second binder. These first and second binder layers are
It is also possible to serve as the first or second adhesive layer described above.

As described above, according to the present invention, at least the first ink layer and the second ink layer are provided on the support, and the support -
A thermal transfer material in which the magnitude relationship between the adhesive force (Fl) between the first ink layer and the adhesive force (F2) between the first ink layer and the second ink layer is reversed at high temperature and low temperature, and , 1st
A thermal transfer material whose ink layer contains metal powder is provided.

If the thermal transfer material of the present invention is used, beautiful two-color printing can be performed on plain paper, etc. by simply changing the time period between supplying energy in a pattern and separating the thermal transfer material from the recording medium. In addition, when both the first and second ink layers are transferred to the recording medium, the $2 ink layer below (on the recording medium side) is colors can be completely hidden, resulting in clear and complete separation of the two colors. Therefore, since the color of the second ink can be arbitrarily selected, clear two-color recording of, for example, light color-light color is also possible.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Coating liquid A> Polyethylene oxide aqueous dispersion 80 parts (softening point 1
38°C) (In the above and below descriptions, the volume ratio, particle size, and softening point of the dispersion liquid all indicate values for solid content.) -1- Thoroughly mix each component of the recipe. Coating liquid A was prepared. This coating liquid A was applied to a 6 gm thick polyethylene terephthalate film (hereinafter referred to as PET film) and dried at 50°C to form a 17J thick film.

A first adhesive layer of m was formed.

Coating liquid B〉 Coating liquid B obtained by thoroughly mixing the ingredients in the above two formulations was applied to the previously formed first adhesive layer, dried at 70°C, and the thickness was A first ink layer of 2 pLm was formed.

Coating Liquid C> Coating liquid C described above was applied onto the previously formed first ink layer and dried at 50°C to form a second adhesive layer having a thickness of IILm.

Coating liquid D> was applied onto the previously formed second adhesive layer and dried at 70°C to form a second ink layer with a thickness of 2 pLm. I) was obtained.

Next, the above heat-sensitive transfer material (I) was attached to Canon Acid Type Star 6, and printing was performed.

Referring to FIG. 7, the thermal head 10 has a distance of 350 mm from the center of the heat generating part to the thermal head terminal end 10a.
Thermal head 10 using p, m ROHM ■ heads
The carriage 14 carrying the thermal transfer material ribbon 1 was moved in the direction of arrow B at a moving speed of 50 mm/sec.

In this manner, heat is applied in a pattern (pulse width 0, 8 m5) from the thermal head 10 to the thermal transfer material CI).
When the thermal transfer material 1 was peeled off from the recording medium 5 (high-quality paper with a Bekk smoothness of 200 seconds) after 7 m5 ec), a clear image was observed on the recording medium 5 due to the transfer of the second ink. A black recorded image 11a was obtained.

Further, a peeling control member 13 for performing peeling with a delayed time is disposed at a position (position 13a) 5++m (text = 5++m) downstream in the transfer direction of the thermal transfer material l from the terminal end 10a of the thermal head. After applying heat in a pattern to the thermal transfer material 1 from the thermal head 10 in the same manner as described above, the thermal transfer material 1 is transferred to the recording medium 5 at approximately 100 m5ec.
When the film was peeled off, a clear golden recorded image 11b was obtained due to the transfer of the first and second inks.

"Shipping" Coating liquid E> Coating liquid E was prepared by thoroughly mixing the components of the above formulation.

Except for using this coating liquid E in place of coating liquid B in Example 1,
A thermal transfer material (rr) was obtained in the same manner as in Example I.

When printing was carried out in the same manner as in Example 1 using this thermal transfer material (n), clear black printing was obtained at early peeling timing (approximately 7 rnsec), and clear black printing was obtained at late peeling timing (approximately 1 rnsec).
00 m5ec), a clear silver print was obtained.

The quality of all prints was good.

A thermal transfer material (m) was obtained in the same manner as in Example 1, except that in place of Coating Solution B in Example 1, Coating Solution F obtained by sufficiently mixing the components of the following formulation was used.

Coating liquid F> When printing was performed in the same manner as in Example 1 using this thermal transfer material (III), good black printing was obtained as in Example 1 at early peeling timing, but when peeling at late timing, printing was performed in the same manner as in Example 1. , only a muddy color print with a mixture of red and black was obtained, and good color separation was not obtained.

[Brief explanation of the drawing]

1, 3, and 4 to 7 are schematic side sectional views as seen in the thickness direction of the thermal transfer material (or recording medium), and FIG. 8 is a schematic perspective view. Fig. 1 shows an example of the basic layer structure of the thermal transfer material of the present invention, Figs. 4 to 6 show other examples of layer structure, and Figs. FIG. 7 and FIG. 8 show one embodiment of a recorded image formed on a recording medium using the thermal transfer material of the present invention, respectively, and FIGS. 1 shows one embodiment of a thermal transfer recording device. Figure 2(a)
, (b) is a graph showing an example of the change in adhesive force between ink layers with respect to time after heating in the thermal transfer material of the present invention. 1...Thermal transfer material 2...Support 3...First ink layer 4...Second ink layer 5...Recorded body 6...First adhesive layer 7...Second Adhesive layer 8... Third adhesive layer 9a... Unwinding core 9b... Winding core 10... Thermal head 11a, 11b --- Recorded image 12... Platen 13... Peeling control member 14... Carriage 15a, 15b... Ribbon cartridge 16... Movable stand ■J: Figure 1 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] At least a first ink layer and a second ink layer are sequentially provided on a support from the support side, and an adhesive force between the support and the first ink layer; 1st
A thermal transfer material in which the magnitude relationship between the adhesive force between the ink layer and the second ink layer is reversed between high temperature and low temperature, wherein the first ink layer contains metal powder. Thermal transfer material.