JPH025596B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a thermal transfer material for obtaining recorded images of two different colors. Furthermore, the present invention relates to a thermal transfer material with good separation of two colors. [Prior art] In addition to the general characteristics of thermal recording methods, such as the equipment used is lightweight, compact, noiseless, and has excellent operability and maintainability, the thermal transfer recording method also eliminates the need for colored processed paper. It is also characterized by excellent durability of recorded images, and has recently begun to be widely used. This thermal transfer recording method generally uses a thermal transfer material made by coating a sheet-like support with a thermal transfer ink made of a heat-melting binder and a colorant dispersed therein. The thermal transferable ink layer is superimposed on the recording medium so as to be in contact with the recording medium, and heat is supplied from the support side of the thermal transfer material by a thermal head to transfer the melted ink layer to the recording medium, thereby transferring heat onto the recording medium. A transfer ink image is formed according to the shape of the supplied ink. Furthermore, there is a strong market demand for two-color printing while taking advantage of the advantages of the thermal transfer recording method, and various techniques for obtaining two-color printing have been proposed. As a conventional two-color printing method using a thermal transfer recording method on plain paper, JP-A-56-148591 discloses two heat-melting high melting point ink layers A and 1 containing different colorants on a base material. Low melting point ink layer B is 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 onto the plain paper, and in the case of high heat applied energy, both the heat melting ink layers A and B are transferred. A two-color thermal transfer recording element is disclosed which provides a two-color record. In this method, if the difference in melting point between layer A and layer B is small,
Since the same material is used for the layer and the B layer, it is difficult to separate the two layers. [Problems to be Solved by the Invention] An object of the present invention is to provide a thermal transfer material that can provide clear two-color recording prints on plain paper while eliminating the above-mentioned drawbacks and maintaining various thermal transfer performances. There is a particular thing. [Means for Solving the Problems] That is, the present invention provides a first heat-fusible ink layer and a second heat-fusible ink layer, which have different color tones and are difficult to mix with each other when heat is applied, on a support. After the second heat-melting ink layer is brought into contact with the recording medium and thermal energy is applied from the support side, when the support is peeled from the recording medium, the heat A heat-sensitive transfer material for performing two-color printing by changing the time from the end of energy application until peeling off the support, wherein the first heat-melting ink layer and the second heat-melting ink layer The present invention relates to a two-color recording heat-sensitive transfer material characterized in that at least one of the meltable ink layers contains silicone oil or a fluorine-based surfactant. The present invention will be described in further detail below with reference to the drawings as necessary. In the following description, "%" and "part" expressing quantitative ratios are based on weight unless otherwise specified. FIG. 1 is a schematic cross-sectional view in the thickness direction of a heat-sensitive transfer material in the most basic embodiment used in the recording method of the present invention. That is, the thermal transfer material 5 is usually formed by forming a thermal transferable ink layer 4 on a sheet-like support 1. Further, the thermal transferable ink layer 4 itself has a multilayer structure, and consists of a first ink layer 2 and a second ink layer 3 provided in this order from the support side. As the support 1, conventionally known films and papers can be used as they are, such as relatively heat-resistant plastic films such as polyester, polycarbonate, triacetyl cellulose, nylon, and polyimide, cellophane or parchment paper, Condenser paper or the like can be suitably used. The thickness of the support is preferably about 1 to 15 μm when considering a thermal head as a heat source during thermal transfer, but it is preferable to use a heat source such as a laser beam that can selectively heat the thermal transferable ink layer. There are no particular restrictions in this case. In addition, when using a thermal head, a heat-resistant protective layer made of silicone resin, fluororesin, polyimide resin, epoxy resin, phenolic resin, melamine resin, nitrocellulose, etc. is applied to the surface of the support that comes into contact with the thermal head. By providing this, the heat resistance of the support can be improved, or it is possible to use a support material that could not be used conventionally. The first ink layer 2 and the second ink layer 3 each consist of a heat-melting binder, a colorant, a silicone oil, or a fluorine-based surfactant, and other plasticizers, dispersants, oils, fillers, etc. may also be used as appropriate. . Colorants having different tones are used for the first ink layer 2 and the second ink layer 3. On the other hand, silicone oil or fluorine-based surfactant only needs to be added to at least one of the first ink layer 2 and the second ink layer, and its function is
This is to completely separate the ink layer 3.
This is to obtain clear two-color printing. Heat-melting binders include spermaceti wax, beeswax, lanolin, natural waxes such as carnauba wax, candelilla wax, Montan wax, and ceresin wax; petroleum waxes such as paraffin wax and microcrystalline wax;
Synthetic waxes such as oxidized waxes, ester waxes, low molecular weight polyethylene, and fiberglass waxes; higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid; higher alcohols such as stearyl alcohol and behenyl alcohol; Esters such as sucrose fatty acid ester, sorbitan fatty acid ester, amides such as oleylamide, other polyolefin resins, polyamide resins, polyester resins, epoxy resins, polyurethane resins, polyacrylic resins, polychloride Vinyl resins, cellulose resins, polyvinyl alcohol resins, petroleum resins, phenolic resins, polystyrene resins, vinyl acetate resins, natural rubber, elastomers such as styrene-butadiene rubber, isoprene rubber, chloroprene rubber, polyisobutylene, An appropriate mixture of polybutene, plasticizer, mineral oil, vegetable oil, etc. is used. In addition, the silicone oil used to improve the separation between the first ink layer 2 and the second ink layer 3 is dimethyl silicone oil called pure silicone oil, methyl phenyl silicone oil, methyl hydrogen silicone oil, and polysilicone oil called modified silicone oil. Examples include organosiloxane diol, chlorophenyl silicone oil, chlorosilicone oil, silicone polyether copolymer, alkyl-modified silicone oil, higher fatty acid-modified silicone oil, amino-modified silicone oil, and epoxy-modified silicone oil. In addition, examples of fluorine-based surfactants include perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, perfluoroalkyl phosphates, perfluoroalkylmethylammonium salts, perfluoroalkylamine oxides,
Examples include perfluoroalkyl E ₀ adduct, perfluoroalkyl quaternary ammonium iodide, perfluoroalkyl polyoxyethylene ethanol, perfluoroalkyl betaine, and fluorinated alkyl ester. Silicone oil or fluorine surfactant is at least 50ppm to 10% in either layer, respectively.
It is better to contain 50ppm to 10%, and less than 50ppm is 2.
The layer separation effect is small, and if it exceeds 10%, the adhesion to the substrate will decrease when used for the first ink layer 2, and the transferability will decrease when used for the second ink layer 3, which is not preferable. Furthermore, when it is added to both the first ink layer and the second ink layer, it is preferably 50 ppm to 10% for each layer as a whole. The thickness of the first ink layer 2 is preferably in the range of 0.5μ to 10μ, and the total thickness of the thermal transferable ink layer 4 is 2μ to 20μ.
is preferred. If you want to obtain the same color tone as the first ink layer 2 and the second ink layer 3, it is recommended to place a dark color such as black in the first ink layer 2 and a light color such as yellow in the second ink layer 3. The color tone of the second ink layer 3 and
If you want to obtain a color mixture of the color tone of the first ink layer 2 and the color tone of the second ink layer 3, for example, if the first ink layer 2 is yellow and the second ink layer 3 is colored magenta, magenta and red can be obtained. It will be done. In addition, by changing the pigment concentration or layer thickness ratio of each layer, various recordings of two different colors can be obtained. Furthermore, if either the first ink layer 2 or the second ink layer 3 is made white, it becomes possible to correct incorrect printing using the same method. As a coloring agent,
Various dyes and pigments widely used in the field of printed records are used. The content of the colorant in each of the first ink layer 2 and the second ink layer 3 is suitably in the range of 1 to 80%. Additionally, additives such as a dispersant or a filler made of fine metal powder, fine inorganic powder, metal oxide, etc. may be added to the first ink layer 2 and the second ink layer 3, respectively, if necessary. In order to obtain the heat-sensitive transfer material 5 of the present invention, the above-described heat-melting binder, colorant, and optionally additives are added to each of the first ink layer 2 and the second ink layer 3 using a dispersion device such as an attritor. After melting and kneading with a suitable solvent or kneading with a suitable solvent to obtain a hot-melt, solution or dispersion ink, silicone oil or fluorine surfactant is added to complete the ink. The timing of adding the oil or fluorine-based surfactant is not particularly limited. Next, the first ink layer 2 and the second ink layer 3 may be formed in this order by sequentially applying the ink onto a support and drying as necessary. The planar shape of the thermal transfer material used in the present invention is not particularly limited, but it is generally used in the form of a typewriter ribbon or a wide tape used in line printers. A thermal transfer recording method for performing two-color printing using the thermal transfer material 5 according to the present invention will be described below. First, thermal transfer recording using the color of the second ink layer 3 is performed by placing the thermal transfer material 5 and the thermal head 6 facing each other and applying thermal energy, as shown in FIGS. For example, by separating the thermal transfer material from the paper immediately after adhering it to the paper, the heated second ink layer 3 is separated from the first ink layer and transferred onto the paper of the recording medium as a recording 3a, resulting in the desired color. get. On the other hand, in thermal transfer recording by color mixing of the first ink layer 2 or the color of the first ink layer 2 and the color of the second ink layer 3, thermal energy is applied to the bithermofusible ink layer 4 as shown in FIGS. is applied to adhere both ink layers to a recording medium, for example, paper, and then through a cooling process l of both thermofusible ink layers 4,
Next, the support 1 and the cooled thermal transferable ink layer 4 are peeled off, and both the first ink layer 2 and the second ink layer 3 are transferred onto paper as a recording medium as a recording 4a. These two types of operations make it possible to obtain two-color recording. That is, in a thermal transfer recording method in which a recording is obtained by attaching the heat-melting ink layer of the heat-sensitive transfer material 5 to the recording medium using thermal energy applied from a thermal head and then peeling off the ink layer from the support, when peeling This is a method of obtaining recorded images of two different colors on a recording medium by changing the timing. In addition to the above-mentioned requirements, the thermal transfer material 5 used in this method has a melting temperature of 50°C of the first ink layer 2.
~150°C, it is desirable for the melt viscosity at 150°C (rotational viscometer) to be 500 cps or less, as will be described later. In addition, the melting temperature referred to in the present invention refers to
This is the temperature at which the outflow starts when the apparent viscosity-temperature curve of the sample ink is determined at a heating rate of 2°C/min. The second ink layer contains at least 50% or more of the resin in the heat-melting binder described above, and in addition, the waxes described above,
The melting temperature of the ink layer is 60℃~150℃, 150℃ by appropriately mixing oil agents such as plasticizer, mineral oil, and vegetable oil.
Melt viscosity (rotational viscometer) of 200cps to 1000000cps
It is best to choose as you see fit. At this time, combined with the effect of silicone oil or fluorine-based surfactant, the first
The effect of separating the ink layer 2 and the second ink layer 3 is remarkable. Furthermore, in order to improve the sharpness of the printing with the second ink layer, the second ink layer may of course be formed into a dot shape or an uneven shape. The case where the most typical heat head is used as a heat source will be explained in more detail below with reference to the drawings.
FIGS. 2 and 3 show an outline of the case where only the second ink layer 3 is transferred. 3 is a schematic cross-sectional view in the thickness direction of a thermal transfer material 5. FIG. FIG. 2 shows the state before recording.
In FIG. 2, 5 indicates a thermal transfer material 6, which is a thermal head 6b.
1 shows a heater section 7 of a thermal head, and a recording medium 8 shows a platen. The case where the first ink layer 2 is black and the second ink layer 3 is red will now be described. Figure 3 shows the state after recording.
The thermal head 6 moves to the right, the tape is wound onto a reel (not shown), and the thermal transfer material 5 is separated from the recording medium 7 immediately after passing through the heater section 6b of the thermal head 6 and placed on the recording medium 7. This indicates that a red record 3a was obtained. 4 and 5 are schematic cross-sectional views in the thickness direction of the heat-sensitive transfer material 5, showing an outline of the case where both the first ink layer 2 and the second ink layer 3 are transferred. FIG. 4 shows the state before recording. The difference from FIG. 2 is that a member 9 is provided for separating the thermal transfer material 5 after it is heated and runs idle for a certain distance l while remaining in close contact with the recording medium 7. heat head 6
They move in conjunction with each other while maintaining a certain distance l and move up and down as necessary to press the thermal transfer material 5 onto the recording medium 7 at the required time and for the required time. That is, FIGS. 2 and 3 show the member 10.
The figure shows the case where is far from the platen side. FIG. 5 shows the state after recording. After the head is heated, the thermal transfer material 5 is moved rightward, and the thermal transfer material 5 is wound up on a reel (not shown) immediately after the member 9. The recording object is separated and the first
This shows that both the ink layer 2 and the second ink layer 3 were transferred and a black recording 4a was obtained on the recording medium 7. FIG. 6 is a thermal transfer material 5 showing an outline of another embodiment.
FIG. 2 is a schematic cross-sectional view in the thickness direction. Figure 6 shows the method for obtaining a black record.
5 is different from the method shown in FIG.
The point is that a member 10 that is removably attached to the thermal head 6 is used as a member to separate the heat head after it runs idle for a certain distance l after coming into close contact with the heat head 6. In this case, a red record is obtained. To obtain a two-color record and a black record, either the head is replaced or only the member 10 is attached and detached to obtain a two-color record. Next, a second method of performing two-color recording using the thermal transfer material 5 of the present invention will be described. The second method is to obtain two-color recording by changing the voltage applied to the thermal head, and the melting temperature of the first ink layer 2 is 70°C.
℃~100℃ The melting temperature of the second ink layer 3 is 50℃~60℃
It is best to keep it at ℃. At this time, the effect of separating the first ink layer 2 and the second ink layer 3 is remarkable together with the effect of the silicone oil or the fluorine-based surfactant. The case where the first ink layer 2 is black and the second ink layer 3 is red will now be described. When the thermal transfer material 5 and the recording medium 7 are stacked facing each other and low printing heating energy is applied by the thermal head 6, only the second ink layer 3 is transferred and a red print is obtained. In addition, when high applied heating energy is applied, both the first ink layer 2 and the second ink layer 3 are melt-transferred, and the red color of the second ink layer 3 is transferred to the first ink layer 3.
As a result, black recording is obtained as a result of the black color of the ink layer 2. [Example] The present invention will be explained in more detail with reference to Examples below. Example 1 Formulation A Terpene-phenol copolymer resin 10 parts Oil-soluble red dye 1 part MEK 89 parts Silicone oil (TSF451-50) manufactured by Toshiba Silicone Co., Ltd. 0.1 part The above resin was dissolved in MEK and the solution was oil-soluble. The red dye was dissolved to form a coating material A' for the second ink layer. Furthermore, what is terpene-phenol copolymer resin?
It is a polycondensate of terpene and bisphenol A whose main components are - and β-pinene. Prescription B Carbon black 12 parts Oxidized wax 30 parts Low molecular weight polyethylene oxide 10 parts Paraffin wax 48 parts Oxidized wax, low molecular weight polyethylene oxide, and paraffin wax were heated and dissolved, carbon black was mixed and stirred, and then sand milled while heating. Carbon black was dispersed for 30 minutes to form a coating material B' for the first ink layer. The above coating material B' was hot-melt coated onto a 6μ polyethylene terephthalate film using a coating bar to obtain a coating film with a thickness of 4μ. Subsequently, coating material A' was solvent coated on the above coating film and heated to 80℃.
It was heated and dried in an oven for 3 minutes to obtain a coating film of 2μ, completing a heat-sensitive transfer material. This was cut into a tape shape with a width of 8m/m, loaded into a thermal transfer printer used in a word processor (Canoward 45S manufactured by Canon Inc.), and printed on copy paper at the maximum print density volume, resulting in a red color. A clear print was obtained. Next, the thermal transfer material to which heat has been applied and the copy paper are separated, and the thermal transfer material is placed adjacent to the thermal head so that the copy paper is separated after the thermal transfer ink layer has cooled down. When a member was attached to press the image on the copy paper and printing was performed in the same manner, a clear black print was obtained on the copy paper. Example 2 Formulation C Permanent red 15 parts oxidized wax 27 parts low molecular weight oxidized polyethylene 9 parts paraffin wax (mp47°C) 49 parts fluorinated surfactant (fluorinated alkyl ester) 0.1 part oxidized wax, low molecular weight oxidized Melt polyethylene and paraffin wax while heating, add permanent red into it, disperse the permanent red in a sand mill for 30 minutes to create ink, and mix 0.1 part of fluorine surfactant with the ink. Coating liquid
I got C′. Formulation D Carbon black 12 parts Oxidized wax 30 parts Low molecular weight polyethylene oxide 58 parts Dissolve the oxidized wax and low molecular weight polyethylene oxide while heating, add the carbon black therein, disperse the carbon black in a sand mill for 30 minutes, and then create the ink. It was prepared and designated as coating liquid D'. Next, apply the coating solution onto a 4μ polyethylene terephthalate film using a mailer bar on a hot plate.
D' was applied to form a first ink layer with a thickness of 4 μm.
Further, the temperature of the hot plate was set to such a level that the first ink layer did not melt, and coating liquid C' was similarly applied on the first ink layer to form a second ink layer of 3 μm. I did it. 8m/m of the thermal transfer material
Cut into widths and use a word processor (Cano Word).
45S (manufactured by Canon Inc.) was used to print on copy paper at the minimum and maximum print density volumes, and the former produced clear red print and the latter produced clear black print.

〔Effect of the invention〕

As is clear from the above, according to the present invention, by including a specific compound in at least one of the ink layers, it is possible to provide a thermal transfer material that provides a two-color recorded image with unprecedented clarity.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view in the thickness direction of the thermal transfer material used in the present invention, and FIGS.
A schematic cross-sectional view in the thickness direction of a thermal transfer material showing an overview of the case where only the ink layer is transferred, and FIGS. FIG. 3 is a schematic cross-sectional view in the thickness direction. FIG. 6 is a schematic sectional view in the thickness direction of a heat-sensitive transfer material showing an outline of another embodiment of the present invention. 1... Support, 2... First ink layer, 3... Second ink layer, 3a... Record when only the first ink layer is transferred, 4... Thermal transfer ink layer, 4a...
Recording when both the first ink layer and the second ink layer are transferred, 5... Thermal transfer material, 6... Thermal head, 6b...
...heater part of thermal head, 7...recorded object, 8...
...Platen, 9...Thermal transfer material pressing member, 10...
...Thermal transfer material pressing member.

Claims (1)

[Scope of Claims] 1. A first heat-fusible ink layer and a second heat-fusible ink layer that have different color tones and are difficult to mix with each other when heat is applied are laminated on a support in order from the support side, After the second heat-melting ink layer is brought into contact with the recording medium and thermal energy is applied from the support side, when the support is peeled off from the recording medium, from the end of the application of the thermal energy to the A thermal transfer material for performing two-color printing by changing the time until peeling off the support,
A two-color recording thermal transfer material, characterized in that at least one of the first heat-melting ink layer and the second heat-melting ink layer contains silicone oil or a fluorine-based surfactant. 2. The two-color recording heat-sensitive transfer material according to claim 1, wherein the content of silicone oil or fluorine-based surfactant in the heat-melting ink layer is 50 ppm to 10%.