Thermal transfer recording medium, transfer film and method for manufacturing transfer film

Abstract

The thermal transfer recording medium is transferred to a transparent film, and includes a base material layer, and a first ink layer and a second ink layer laminated in this order on the base material layer, the second ink layer having light transmittance such that the first ink layer can be visually recognized, and the L value of the color difference of reflected light from the second ink layer being 20 or less. Furthermore, the transfer-completed film is obtained by sequentially laminating a first ink layer, a second ink layer having light transmittance such that the first ink layer is visible, and a transparent film, the total light transmittance of the second ink layer being 16% or more, and the total light transmittance of the transparent film being 80% or more.

Description

[0001] Related Application

[0002] This application corresponds to Japanese Patent Application No. 2022-125295 filed with the Japan Patent Office on August 5, 2022, and all disclosed contents of the application are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a thermal transfer recording medium, a transferred film, and a method for producing the transferred film. Background Art

[0004] Patent document 1 discloses a two-color recording thermal transfer material, wherein a first heat-melt ink layer and a second heat-melt ink layer having different tones and being difficult to mix with each other when heat is applied are stacked in sequence on a support body from the support body side, and after the second heat-melt ink layer is brought into contact with a recording body and heat energy is applied from the support body side, when the support body is peeled off from the recording body, two-color printing is performed by changing the time from the end of the application of the heat energy to the peeling of the support body, and at least one of the first heat-melt ink layer and the second heat-melt ink layer contains silicone oil or a fluorine-based surfactant.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Publication No. 2-5596 Summary of the invention

[0008] Problems to be solved by the invention

[0009] One embodiment of the present disclosure provides a thermal transfer recording medium, a transferred film, and a method for manufacturing the transferred film, wherein, in a transferred film in which a transfer pattern including a stack of a first ink layer and a second ink layer is visually recognized through a transparent film, even when the second ink layer is a surface side ink layer (observation side ink layer), the color of the first ink layer visually recognized through the second ink layer can be made close to an ideal color.

[0010] Solutions to Solve Problems

[0011] The thermal transfer recording medium involved in one embodiment of the present disclosure is transferred to a transparent film, which includes a substrate layer and a first ink layer and a second ink layer stacked on the substrate layer in sequence, the second ink layer has light transmittance that allows the first ink layer to be visually identified, and the L value of the color difference of the reflected light from the second ink layer is less than 20.

[0012] Effects of the Invention

[0013] According to the thermal transfer recording medium involved in one embodiment of the present disclosure, the second ink layer has a light transmittance that allows the first ink layer to be visually identified. As a result, a film in which a stack of the first ink layer and the second ink layer is transferred to a transparent film in such a way that the second ink layer becomes the surface side ink layer (the observation side ink layer) can be formed. Since the second ink layer has a light transmittance that allows the first ink layer to be visually identified, in the transferred film, the color of the first ink layer can be identified through the second ink layer. In addition, the L value of the color difference of the reflected light from the second ink layer is less than 20. Therefore, even when the first ink layer is covered by the second ink layer, the color of the first ink layer visually identified through the second ink layer can be made close to an ideal color (e.g., black). BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram schematically showing the structure of a printing device according to an embodiment of the present invention.

[0015] Figure 2 is a block diagram showing the electrical structure of the printing device.

[0016] Figure 3 This is a schematic diagram for explaining a heating process and a cooling process of the printing apparatus.

[0017] Figure 4A as well as Figure 4B This is a schematic diagram for explaining a cooling process and a transfer process of the printing device.

[0018] Figure 5A This is a schematic cross-sectional view showing a layer structure of a transferred belt according to an embodiment of the present disclosure.

[0019] Figure 5B This is a schematic cross-sectional view showing a layer structure of a transferred belt according to an embodiment of the present disclosure.

[0020] Figure 5C This is a schematic cross-sectional view showing a layer structure of a transferred belt according to an embodiment of the present disclosure.

[0021] Figure 5D This is a schematic cross-sectional view showing a layer structure of a transferred belt according to an embodiment of the present disclosure.

[0022] Fig. 6A as well as Figure 6B This is a diagram showing an example of a printing pattern by the printing device. DETAILED DESCRIPTION

[0023] Next, embodiments of the present invention will be described in detail with reference to the drawings.

[0024] [Overall Structure of Printing Device 1]

[0025] Figure 1 It is a diagram schematically showing the structure of a printing device 1 according to an embodiment of the present invention.

[0026] Reference Figure 1 The printing device 1 is a thermal transfer type thermal printer that transfers ink from an ink ribbon 3 as an example of a thermal transfer recording medium to a printing tape 2 as an example of a printed medium as text. In the present embodiment, the printing tape 2 is, for example, a transparent base film to which the ink is directly transferred. Here, the so-called "transparent" of the printing tape 2 can be defined as the printing tape 2 having a degree of transparency that allows the shape and color of the text transferred to the printing tape 2 to be recognized from the opposite side of the transfer surface (printing surface).

[0027] The characters recorded on the printing tape 2 may include typical characters, symbols such as barcodes and QR codes (registered trademarks), numbers, patterns, designs, etc. The printing device 1 according to this embodiment can record characters of different colors (for example, black and red) on the printing tape 2 .

[0028] The printing device 1 mainly includes a housing 4 , a tape cassette 5 accommodated in the housing 4 , a thermal head 6 , a platen roller 7 , a nip roller 71 , and a control substrate 8 .

[0029] The housing 4 may be a box-shaped member made of a plastic shell, for example. An outlet 9 for taking out the printed printing tape 2 is formed on the outer wall of the housing 4. A cutter (not shown) may be provided near the outlet 9. By cutting with the cutter, the printing tape 2 can be separated into labels of the size of each unit for use and taken out.

[0030] The tape cassette 5 may be a detachable cassette relative to the housing 4. The tape cassette 5 may be inserted in the tape conveying direction D1 (in the direction of Figure 1 The printing tape roll 10 (in other words, it may also be a label tape roll), the ink ribbon roll 12, the ink ribbon peeling member 13, the ink ribbon winding roll 14, the laminating roll 72, and the laminating film roll 73 are sequentially accommodated from the upstream side to the downstream side (in the direction from the right side to the left side). In the present embodiment, the printing tape roll 10, the ink ribbon roll 12, the laminating roll 72, and the laminating film roll 73 are of the type used in the state of being accommodated in the tape box 5, but they may also be of the type directly assembled to the printing device 1 for use, for example.

[0031] The printing tape roll 10 is produced by winding the printing tape 2 into a cylindrical shape, and is rotatably held in the tape cassette 5 , for example.

[0032] The ink ribbon roller 12 is made by winding the ink ribbon 3 into a cylindrical shape, and is rotatably held in the ribbon cassette 5, for example. The ink ribbon drive shaft 18 provided in the housing 4 is inserted into the ink ribbon winding roller 14. The rotational force R1 generated by the driving of the ink ribbon drive shaft 18 is transmitted to the ink ribbon winding roller 14, so that the ink ribbon winding roller 14 rotates.

[0033] The ink ribbon stripping member 13 may be a guide member for changing the conveying direction D2 of the ink ribbon 3. The ink ribbon stripping member 13 may have a shape capable of abutting against the ink ribbon 3 being conveyed, for example, may have a roller shape or a blade shape. The ink ribbon 3 is partially thermally pressed against the printing ribbon 2 by the thermal head 6, and is conveyed toward the removal port 9 together with the printing ribbon 2. The ink ribbon stripping member 13 abuts against the ink ribbon 3 in the middle of conveying, and causes the conveying direction D2 of the ink ribbon 3 to be suddenly changed relative to the conveying direction D1 of the printing ribbon 2. As a result, the printing ribbon 2 and the ink ribbon 3 are separated, and the ink ribbon 3 is stripped from the printing ribbon 2.

[0034] The laminating roller 72 can be inserted with, for example, a laminating roller drive shaft 75 provided in the housing 4. The rotational force R4 generated by the driving of the laminating roller drive shaft 75 is transmitted to the laminating roller 72, so that the laminating roller 72 rotates. Figure 1 As shown, it is provided inside the tape cassette 5 and partially exposed on the conveying path of the printing tape 2. Thus, in a state where the tape cassette 5 is provided, the printing tape 2 can be conveyed while being sandwiched between the laminating roller 72 and the pinch roller 71.

[0035] The laminating film roll 73 is produced by winding a laminating tape 76 into a cylindrical shape, and the laminating film roll 73 is rotatably held in the tape cassette 5 , for example.

[0036] The thermal head 6 is disposed between the printing tape roller 10 and the ink ribbon roller 12 and the ink ribbon peeling member 13 in the conveying direction D1 of the printing tape 2. The thermal head 6 includes a substrate 19 and a heating element 20 (such as a heating resistor) formed on the substrate 19. The Joule heat generated by the conduction of electricity to the heating element 20 is used for thermal transfer of the ink of the ink ribbon 3.

[0037] For example, a platen drive shaft 21 provided in the housing 4 is inserted into the platen roller 7. A rotational force R generated by driving the platen drive shaft 21 is transmitted to the platen roller 7, and the platen roller 7 rotates.

[0038] A pinch roller drive shaft 74 provided in the housing 4, for example, is inserted into the pinch roller 71. A rotational force R3 generated by driving the pinch roller drive shaft 74 is transmitted to the pinch roller 71, and the pinch roller 71 rotates.

[0039] The control board 8 is an electronic device that performs electrical control of the printing device 1 , and is provided inside the housing 4 .

[0040] [Electrical Structure of Printing Device 1]

[0041] Figure 2 It is a block diagram showing the electrical structure of the printing device 1 .

[0042] Reference Figure 2 The control circuit 22 is provided on the control substrate 8 of the printing device 1. The control circuit 22 may include a CPU 23, a ROM 24, a memory 25, a RAM 26, and an input / output I / F 27 (interface). These are electrically connected via a data bus (not shown), for example.

[0043] The ROM 24 stores various programs for driving the printing device 1 (for example, Figure 3 as well as Figure 4A , B, etc.). The CPU 23 uses the temporary storage function of the RAM 26 and performs signal processing according to the program stored in the ROM 24, thereby controlling the printing device 1 as a whole. The memory 25 can be composed of, for example, a part of the storage area of ​​the ROM 24. The memory 25 can store in advance a table for displaying the remaining amount (consumption) of the ink ribbon 3 on the display unit (not shown) of the housing 4.

[0044] The first drive circuit 28 and the second drive circuit 29 are electrically connected to the input / output I / F 27. The first drive circuit 28 performs power-on control of the heating element 20 of the thermal head 6. The second drive circuit 29 performs drive control of outputting drive pulses to the drive motor 30 that drives the ribbon winding roller 14, the platen roller 7, the clamping roller 71, and the laminating roller 72 to rotate.

[0045] [Flow of Printing Process by Printing Device 1]

[0046] Figure 3 This is a schematic diagram for explaining a heating process and a cooling process of the printing apparatus 1 . Figure 4A as well as Figure 4B This is a schematic diagram for explaining a cooling process and a transfer process of the printing device 1 . Figure 4B is from Figure 4A An enlarged view of the main part when observing the transfer pattern in the direction of arrow 4B. Figure 1 , Figure 3 as well as Figure 4A , B describes in detail the printing process performed by the printing device 1.

[0047] In order to print characters on the printing tape 2, the printing tape 2 is pulled out from the printing tape roller 10 by the rotation drive of the platen roller 7, and the ink ribbon 3 is pulled out from the ink ribbon roller 12 by the rotation drive of the ink ribbon winding roller 14. Figure 1 as well as Figure 3As shown, the printing ribbon 2 and the ink ribbon 3 are conveyed toward the downstream side in a state of overlapping each other. In the printing ribbon 2, the surface on the ink ribbon 3 side is a printing surface 31 (front surface), and the surface on the opposite side is a back surface 32. In the ink ribbon 3, the surface on the printing ribbon 2 side is an adhesive surface 33 (front surface), and the surface on the opposite side is a back surface 34.

[0048] Reference Figure 3 The ink ribbon 3 includes a base layer 35, a first ink layer 36, and a second ink layer 37. The first ink layer 36 and the second ink layer 37 are stacked in this order on a surface 38 of the base layer 35 as an example of a first surface. The surface opposite to the surface 38 of the base layer 35 is a back surface 39 (back surface 34 of the ink ribbon 3). The first ink layer 36 and the second ink layer 37 contain colorants of different colors. For example, the first ink layer 36 may contain a black colorant as an example of a first ink, and the second ink layer 37 may contain a red colorant as an example of a second ink.

[0049] The ink ribbon 3 is conveyed toward the thermal head 6 in a state where the second ink layer 37 is in contact with the printing ribbon 2. In the thermal head 6, as shown in FIG. Figure 3 Specifically, the heating element 20, which generates heat due to power supply, is pressed against the ink ribbon 3, so that the heat is transferred to the first ink layer 36 and the second ink layer 37 via the base material layer 35. The stack of the ink ribbon 3 and the printing ribbon 2 is sandwiched between the thermal head 6 and the platen roller 7, and is transported to the downstream side while being heated by the thermal head 6.

[0050] The heating element 20 can be controlled to have the same temperature as a whole, or to have different temperatures in some parts. Figure 3 As shown, the first portion 40 of the heating element 20 may be controlled to a relatively low first heating temperature, and the second portion 41 of the heating element 20 may be controlled to a second heating temperature higher than the first heating temperature. The first heating temperature may be controlled by applying a relatively low first energy to the thermal head 6, and the second heating temperature may be controlled by applying a relatively high second energy to the thermal head 6 compared to the first energy.

[0051] The first heating temperature may be, for example, 60°C or more and 120°C or less, preferably 70°C or more and 90°C or less. For example, the second heating temperature may be 80°C or more and 180°C or less, preferably 130°C or more and 150°C or less. The first energy and the second energy may be set to match the specification of the printing device 1 in such a manner that the thermal head 6 is heated to the first heating temperature and the second heating temperature, respectively. For example, in a printing device 1 having a specification in which the applied energy can be set directly by a voltage value, the voltage value may be set, and in a printing device 1 having a specification in which the applied energy is increased or decreased by adjusting the energy divided into a plurality of levels, an appropriate level of energy may be set.

[0052] Thus, the ink ribbon 3 may include a first portion 42 heated at a first heating temperature and a second portion 43 heated at a second heating temperature. In the first portion 42 and the second portion 43 of the ink ribbon 3, at least a portion or all of the first ink layer 36 and the second ink layer 37 are melted or softened, thereby being in close contact with the printing tape 2.

[0053] Reference Figure 3 as well as Figure 4A , B, a cooling process is performed in the area between the thermal head 6 and the ink ribbon stripping member 13. Specifically, the ink ribbon 3 that is thermally pressed to the printing ribbon 2 in the heating process is naturally cooled in the area from the thermal head 6 to the ink ribbon stripping member 13, and the temperature is reduced toward the use environment temperature of the printing device 1.

[0054] Next, if Figure 4A As shown in FIG. 2 and FIG. 3 , only the conveying direction D2 of the ink ribbon 3 is selectively changed by the ink ribbon peeling member 13, so that an external force F1 is applied to the base layer 35 and the second ink layer 37 in a direction away from each other. As a result, the printing ribbon 2 and the ink ribbon 3 are separated, and the ink ribbon 3 is wound around the ink ribbon winding roller 14. At this time, the first portion 42 and the second portion 43 of the ink ribbon 3 that have been heated by the thermal head 6 selectively remain on the printing ribbon 2, thereby performing the transfer process. For example, in the first portion 42, peeling may occur between the base layer 35 and the laminated body including the first ink layer 36 and the second ink layer 37, thereby transferring the laminated body. On the other hand, in the second portion 43, peeling may occur between the first ink layer 36 and the second ink layer 37, thereby selectively transferring the second ink layer 37.

[0055] Then, if Figure 1 As shown, the laminating tape 76 is attached to the printing tape 2 to which the first ink layer 36 and the second ink layer 37 are transferred. The transferred tape 55 on which characters are recorded and formed by laminating the laminating tape 76 to the printing tape 2 is taken out from the take-out port 9 of the printing device 1.

[0056] [Layer Structure of Transferred Belt 55]

[0057] Figure 5A as well as Figure 5B It is a schematic cross-sectional view showing the layer structure of the transferred belt 55 according to one embodiment of the present disclosure. Fig. 6A as well as Figure 6B This is a diagram showing an example of a printed pattern 44 by the printing device 1 .

[0058] Reference Figure 5A as well as Figure 5B The transferred tape 55 includes: a printed matter 56 including the printing tape 2 to which a part of the ink ribbon 3 is transferred; and a laminating tape 76 laminating to the printed matter 56. The laminating tape 76 may also be called a laminating film. Figure 5A The cross section of the portion of the transferred belt 55 where the stacked body of the first ink layer 36 and the second ink layer 37 is transferred as the first transfer layer 57 is shown. Figure 5B The cross section of the portion of the transferred belt 55 to which the second ink layer 37 is selectively transferred as the second transfer layer 58 is shown.

[0059] In the transferred tape 55 of the present embodiment, the laminating tape 76 is formed as a backing film that supports the first transfer layer 57 and the second transfer layer 58. The printing tape 2 is formed as a transparent covering film that physically protects the first transfer layer 57 and the second transfer layer 58 from external influences. Therefore, in the first transfer layer 57 and the second transfer layer 58, the second ink layer 37 on the side close to the printing tape 2 is the surface side ink layer (the observation side ink layer). People can Figure 5A as well as Figure 5B As indicated by hollow arrows 59 and 60 , the colors of the first ink layer 36 and the second ink layer 37 are recognized by light that passes through the printing tape 2 and is reflected by the first ink layer 36 or the second ink layer 37 .

[0060] The first transfer layer 57 and the second transfer layer 58 form a printed pattern 44 of different colors (for example, two colors recognized as black and red) on the transferred belt 55. Fig. 6A As shown, the printed pattern 44 can have different colors for individual characters. Fig. 6A In the example, when the printed pattern 44 is observed from the back side 32 of the printing tape 2, a red pattern 45 based on the second ink layer 37 can be recognized on the outermost surface of the letters "A" and "C", and a black pattern 46 based on the first ink layer 36 can be recognized on the outermost surface of "B". Figure 6B As shown, the printed pattern 44 can recognize both a red pattern 45 and a black pattern 46 for each character portion.

[0061] Next, the layer structure of the transferred belt 55 will be described in more detail.

[0062] As described above, the transferred tape 55 is formed by laminating the printed matter 56 and the laminating tape 76 .

[0063] The printed material 56 includes a printing tape 2, and a first transfer layer 57 and a second transfer layer 58 selectively formed on the printing surface 31 of the printing tape 2. The first transfer layer 57 includes the second ink layer 37, the intermediate layer 51, and the first ink layer 36 sequentially stacked on the printing surface 31, and the second transfer layer 58 is the second ink layer 37 formed on the printing surface 31.

[0064] (1) Printing tape 2

[0065] The printing tape 2 is not particularly limited as long as it is a transparent base film to which ink is directly transferred, and examples thereof include resin films such as polyester, polyethylene, polypropylene, polyamide, polyimide, polycarbonate, polystyrene, and fluororesin. Among them, a film of polyethylene terephthalate (PET) as a polyester is preferred from the viewpoints of mechanical strength, dimensional stability, heat treatment resistance, price, etc. The printing tape 2 may be a single layer of any of the above resin films, or a laminated film formed by laminating a plurality of the above resin films.

[0066] The thickness of the printing tape 2 can be arbitrarily set according to the specifications of the thermal transfer printer, the characteristics required by the printing tape 2, etc. For example, the thickness of the printing tape 2 is 1 μm or more, preferably 10 μm or more. For example, the thickness of the printing tape 2 is 100 μm or less, preferably 50 μm or less. For example, the thickness of the printing tape 2 is 1 μm or more and 100 μm or less, preferably 10 μm or more and 50 μm or less. As long as the thickness of the printing tape 2 is within this range, the transfer tape 55 can be given appropriate softness and exhibit sufficient mechanical strength and elasticity. If the softness of the transfer tape 55 is emphasized, the printing tape 2 can be made thinner than the above range. Thus, the transfer tape 55 can be well pasted even on complex curved surfaces. On the other hand, if the mechanical strength and elasticity of the transfer tape 55 are emphasized, the printing tape 2 can be made thicker than the above range. Thus, it is possible to suppress the situation where the printing tape 2 is wrinkled during the transportation of the printing device 1 and the laminating of the laminating tape 76.

[0067] The printing tape 2 may be a non-stretched film that is not stretched during the manufacturing process, or a stretched film that is stretched by uniaxial stretching, biaxial stretching, or the like. In addition, the surface of the printing tape 2 (printing surface 31 and back surface 32) may be subjected to surface finishing such as gloss processing and matte processing. In addition, a primer layer for improving the printability of the printing tape 2, an outer coating for adjusting the friction force, a release layer using silicone for protecting the surface of the printing tape 2 before use, etc. may also be formed separately. These layers may be part of the printing tape 2 in concept.

[0068] As a numerical value indicating the transparency of the printing tape 2, for example, the total light transmittance measured in accordance with JIS K 7361 can be used. The total light transmittance of the printing tape 2 can be, for example, 80% or more, preferably 85% or more. The total light transmittance of the printing tape 2 can be measured, for example, using a haze meter.

[0069] (2) First ink layer 36

[0070] The first ink layer 36 can be formed of any thermoplastic resin, for example. The first ink layer 36 is preferably formed of epoxy resin as the thermoplastic resin in order to improve the affinity and adhesion to the intermediate layer 51. The first ink layer 36 can be formed of epoxy resin without (without) the curing agent as the thermoplastic resin.

[0071] Examples of epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, alicyclic epoxy resins, hydrogenated bisphenol A epoxy resins, hydrogenated bisphenol AD ​​epoxy resins, propylene glycol glycoxyether, pentaerythritol polyglycidyl ether and other aliphatic epoxy resins, epoxy resins obtained from aliphatic or aromatic amines and epichlorohydrin, epoxy resins obtained from aliphatic or aromatic carboxylic acids and epichlorohydrin, heterocyclic epoxy resins, spiro-ring-containing epoxy resins, epoxy-modified resins, brominated epoxy resins, etc. Specific examples of epoxy resins are not particularly limited, and examples thereof include the following various epoxy resins. These epoxy resins can be used alone or in combination of two or more.

[0072] Among the substantially solid epoxy resins of the JER (registered trademark) series manufactured by Mitsubishi Chemical Corporation, 1001 [softening point (ring and ball method): 64°C, number average molecular weight Mn: about 900], 1002 [softening point (ring and ball method): 78°C, number average molecular weight Mn: about 1200], 1003 [softening point (ring and ball method): 89°C, number average molecular weight Mn: about 1300], 1055 [softening point (ring and ball method): 93°C, number average molecular weight Mn: about 1600], 1004 [softening point (ring and ball method): 97°C, number average molecular weight Mn: about 1650], 1004AF [softening point (ring and ball method): 97°C, number average molecular weight Mn: about 2900〕、1009〔softening point (ring and ball method): 144℃、number average molecular weight Mn: about 3800〕、1010〔number average molecular weight Mn: about 5500〕、1003F〔softening point (ring and ball method): 96℃〕、1004F〔softening point (ring and ball method): 103℃〕、1005F、1009F〔softening point (ring and ball method): 144℃〕、1004FS〔softening point (ring and ball method): 100℃〕、1006FS〔softening point (ring and ball method): 112℃〕、1007FS〔softening point (ring and ball method): 124℃〕。

[0073] The softening point of the epoxy resin used in the first ink layer 360 is, for example, 95° C. or higher, preferably 110° C. or higher, and more preferably 125° C. or higher. If the softening point is within this range, the first ink layer 36 and the base layer 35 (see FIG. 3 ) can be prevented from fusing at a relatively low temperature during low-temperature transfer. Figure 3 as well as Figure 4A Since the low-temperature transfer range of the first ink layer 36 can be sufficiently extended to the high-temperature side, even if thermal transfer recording is performed continuously, turbidity of color tone can be suppressed.

[0074] The first ink layer 36 may contain an adhesive in addition to the epoxy resin. By containing an adhesive, the affinity and adhesion to the intermediate layer 51 can be further improved. Examples of the adhesive include rubber adhesives, acrylic adhesives, silicone adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinyl pyrrolidone adhesives, polyacrylamide adhesives, and cellulose adhesives.

[0075] In consideration of improving affinity and compatibility with epoxy resin and affinity and adhesion to the intermediate layer 51, an acrylic adhesive is preferably used as the adhesive. Specific examples of the acrylic adhesive are not particularly limited, and for example, the following various acrylic adhesives can be cited. These acrylic adhesives can be used alone or in combination of two or more.

[0076] BPS1109 (non-volatile content: 39.5% by mass), BPS3156D (non-volatile content: 34% by mass), BPS4429-4 (non-volatile content: 45% by mass), BPS4849-40 (non-volatile content: 40% by mass), BPS5160 (non-volatile content: 33% by mass), BPS5213K (non-volatile content: 35% by mass), BPS5160 (non-volatile content: 33% by mass), BPS5213K (non-volatile content: 35% by mass), BPS5156D (non-volatile content: 34 ...56D (non-volatile content: 34% by mass), BPS5156D (non-volatile content: 34% by mass), BPS5156D (non-volatile content: 34% by mass), %), BPS5215K (non-volatile content: 39 mass %), BPS5227-1 (non-volatile content: 41.5 mass %), BPS5296 (non-volatile content: 37 mass %), BPS5330 (non-volatile content: 40 mass %), BPS5375 (non-volatile content: 45 mass %), BPS5448 (non-volatile content: 40 mass %), BPS5513 (non-volatile content: 44.5 mass %), BPS5565 K (non-volatile content: 45 mass%), BPS5669K (non-volatile content: 46 mass%), BPS5762K (non-volatile content: 45.5 mass%), BPS5896 (non-volatile content: 37 mass%), BPS5978 (non-volatile content: 35 mass%), BPS6074HTF (non-volatile content: 52 mass%), BPS6080TFK (non-volatile content: 45 mass%), BPS6130 ... Component: 45.5 mass %), BPS6153K (non-volatile component: 25 mass %), BPS6163 (non-volatile component: 37 mass %), BPS6231 (non-volatile component: 56 mass %), BPS6421 (non-volatile component: 47 mass %), BPS6430 (non-volatile component: 33 mass %), BPS6574 (non-volatile component: 57 mass %), BPS8170 (non-volatile component: 36.5 mass %), BPS HS-1 (non-volatile component: 40 mass %).

[0077] Among the solvent-based adhesives (re-peelable type) manufactured by Lion Chemical Co., Ltd., AS-325 (solid content concentration: 45 mass %), AS-375 (solid content concentration: 45 mass %), AS-409 (solid content concentration: 45 mass %), AS-417 (solid content concentration: 45 mass %), AS-425 (solid content concentration: 45 mass %), AS-455 (solid content concentration: 45 mass %), AS-665 (solid content concentration: 40 mass %), AS-1107 (solid content concentration: 43 mass %), and AS-4005 (solid content concentration: 45 mass %).

[0078] The acrylic adhesive used in the first ink layer 36 may be used in combination with a tackifier. This is because, for example, the breakability of the first ink layer 36 can be improved, unnecessary peeling can be suppressed, and the clarity of the recorded text can be improved. Examples of the tackifier include ester gum, terpene phenol resin, rosin ester, etc. Specific examples of the tackifier are not particularly limited, and examples include the following various tackifiers. These tackifiers can be used alone or in combination of two or more.

[0079] Terpene-phenol resins of the YS Polyster series manufactured by Yasuhara Chemical Co., Ltd. include U130 (softening point: 130±5°C), U115 (softening point: 115±5°C), T160 (softening point: 160±5°C), T145 (softening point: 145±5°C), T130 (softening point: 130±5°C), T115 (softening point: 115±5°C), T100 (softening point: 100±5°C), T80 (softening point: 80±5°C), S145 (softening point: 145±5°C), G150 (softening point: 150±5°C), G125 (softening point: 125±5°C), N125 (softening point: 125±5°C), K125 (softening point: 125±5°C), and TH130 (softening point: 130±5°C).

[0080] Among Ester Gum manufactured by Arakawa Chemical Industries, Ltd., AA-G [softening point (ring and ball method): 82 to 88°C], AA-L [softening point (ring and ball method): 82 to 88°C], AA-V [softening point (ring and ball method): 82 to 95°C], 105 [softening point (ring and ball method): 100 to 110°C], AT [viscosity: 20,000 to 40,000 mPa·s], H [softening point (ring and ball method): 68 to 75°C], HP [softening point (ring and ball method): 80°C or more].

[0081] Among the Pensel (registered trademark) series of rosin esters manufactured by Arakawa Chemical Industries, Ltd., GA-100 [softening point (ring and ball method): 100 to 110°C], AZ [softening point (ring and ball method): 950 to 105°C], C [softening point (ring and ball method): 117 to 127°C], D-125 [softening point (ring and ball method): 120 to 130°C], D-135 [softening point (ring and ball method): 130 to 140°C], D-160 [softening point (ring and ball method): 150 to 165°C], and KK [softening point (ring and ball method): 165°C or more].

[0082] The softening point of the thickener used in the first ink layer 36 is, for example, 60° C. or higher, preferably 120° C. or lower. If the softening point is within this range, the first ink layer 36 and the intermediate layer 51 can be well reversely transferred to the substrate layer 48 during high-temperature transfer. Since the high-temperature transfer range of the first ink layer 36 can be sufficiently extended to the low-temperature side, turbidity of the color tone can be suppressed.

[0083] The first ink layer 36 may contain any colorant. As the colorant, one or more various colorants corresponding to the color tone of the first ink layer 36 may be used. As the colorant, for example, a pigment and a dye may be used. Considering the concealment of the substrate, it is preferred to use a pigment as the colorant used in the first ink layer 36. That is, by suppressing the transmission of light through the first ink layer 36, the black color of the first ink layer 36 can be well identified through the printing tape 2 and the second ink layer 37. For example, carbon black is preferably used as a pigment for coloring the first ink layer 36 in black. There is no particular limitation as a specific example of carbon black, and for example, the following various carbon blacks may be listed. These carbon blacks may be used alone or in combination of two or more.

[0084] MA77 powder made by Mitsubishi Chemical Corporation〔LFF, DBP absorption: 68cm 3 / 100g〕、MA7 powder〔LFF、DBP absorption: 66cm 3 / 100g〕、MA7 granular〔LFF、DBP absorption: 65cm 3 / 100g〕、MA8 powder〔LFF、DBP absorption: 57cm 3 / 100g〕、MA8 granular〔LFF、DBP absorption: 51cm 3 / 100g〕、MA11 powder〔LFF、DBP absorption: 64cm 3 / 100g〕、MA100 powder〔LFF、DBP absorption: 100cm 3 / 100g〕、MA100 granular〔LFF、DBP absorption: 95cm 3 / 100g〕、MA100R powder〔LFF、DBP absorption: 100cm 3 / 100g〕、MA100R granular〔LFF、DBP absorption: 95cm 3 / 100g〕、MA100S powder〔LFF、DBP absorption: 100cm 3 / 100g〕、MA230 powder〔LFF、DBP absorption: 113cm 3 / 100g〕、MA220 powder〔LFF、DBP absorption: 93cm 3 / 100g〕、MA14 powder〔LFF、DBP absorption: 73cm 3 / 100g〕.

[0085] Mitsubishi Chemical Corporation #3030B (furnace method, DBP absorption: 130 cm 3 / 100g)、#3040B(Furnace method, DBP absorption: 114cm 3 / 100g)、#3050B(Furnace method, DBP absorption: 175cm 3 / 100g), #3230B (furnace method, DBP absorption: 140cm 3 / 100g)、#3350B(Furnace method, DBP absorption: 164cm 3 / 100g), #3400B (furnace method, DBP absorption: 175cm 3 / 100g).

[0086] Tokablack (registered trademark) series manufactured by Tokai Carbon Co., Ltd., #5500 (furnace method, DBP absorption: 155 cm 3 / 100g)、#4500(Furnace method, DBP absorption: 168cm 3 / 100g)、#4400(Furnace method, DBP absorption: 135cm 3 / 100g)、#4300(Furnace method, DBP absorption: 142cm 3 / 100g).

[0087] ORION ENGINEERED CARBONS PRINTEX (Japanese: プリンテックス; registered trademark) series L (furnace method, DBP absorption: 120cm 3 / 100g), L6 (furnace method, DBP absorption: 126cm 3 / 100g).

[0088] Birla Carbon's CONDUCTEX (Japanese: コンダクテックス; registered trademark) series, 975 (furnace method, 170cm 3 / 100g), SC (furnace method, 115cm 3 / 100g).

[0089] CABOT's VULCAN series, XC72 (furnace method, DBP absorption: 174 cm 3 / 100g), 9A32 (furnace method, DBP absorption: 114cm 3 / 100g), 3700 (furnace method, DBP absorption: 111cm 3 / 100g).

[0090] DenkaBlack (registered trademark) series manufactured by Denka Co., Ltd., DenkaBlack granular products (acetylene method, DBP absorption: 160cm 3 / 100g), FX-35 (acetylene method, DBP absorption: 220cm 3 / 100g), HS-100 (acetylene method, DBP absorption: 140cm 3 / 100g).

[0091] Lion Chemical Co., Ltd.'s Ketjenblack (registered trademark) series, EC300J (vaporization method, DBP absorption: 360 cm 3 / 100g), EC600DJ (vaporization method, DBP absorption: 495cm 3 / 100g).

[0092] The ratio of each component in the first ink layer 36 is not particularly limited. The ratio of the acrylic adhesive to 100 parts by mass of the epoxy resin is, for example, 30 parts by mass or more, preferably 40 parts by mass or more. The ratio of the acrylic adhesive to 100 parts by mass of the epoxy resin is, for example, 150 parts by mass or less, preferably 100 parts by mass or less. The ratio of the acrylic adhesive to 100 parts by mass of the epoxy resin is, for example, 30 parts by mass or more and 150 parts by mass or less, preferably 40 parts by mass or more and 100 parts by mass or less.

[0093] The ratio of the tackifier to 100 parts by mass of the epoxy resin is, for example, 3 parts by mass or more, preferably 5 parts by mass or more. The ratio of the tackifier to 100 parts by mass of the epoxy resin is, for example, 150 parts by mass or less, preferably 100 parts by mass or less. The ratio of the tackifier to 100 parts by mass of the epoxy resin is, for example, 3 parts by mass or more and 150 parts by mass or less, preferably 5 parts by mass or more and 100 parts by mass or less.

[0094] The ratio of the colorant such as carbon black to 100 parts by mass of the epoxy resin is, for example, 100 parts by mass or more, preferably 130 parts by mass or more. The ratio of the colorant to 100 parts by mass of the epoxy resin is, for example, 230 parts by mass or less, preferably 200 parts by mass or less. The ratio of the colorant to 100 parts by mass of the epoxy resin is, for example, 100 parts by mass or more and 230 parts by mass or less, preferably 130 parts by mass or more and 200 parts by mass or less.

[0095] It should be noted that, among the components contained in the first ink layer 36 , the components supplied in a liquid state dissolved or dispersed in an arbitrary solvent may be blended in an amount adjusted so that the ratio of the effective component therein is within the above range (the same applies hereinafter).

[0096] The first ink layer 36 can be formed, for example, by applying a coating prepared by dissolving or dispersing the above-mentioned components in an arbitrary solvent directly or via an arbitrary release layer on the surface 38 of the substrate layer 35 and then drying the coating. Fig. 6A as well as Figure 6B As shown, the text recorded on the printing tape 2 is color-separated. In order to perform this color separation, if the adjustment of the adhesion between the first ink layer 36 and the base layer 35 and other layers is taken into consideration, the first ink layer 36 is preferably formed directly on the surface 38 of the base layer 35 without the release layer.

[0097] The thickness of the first ink layer 36 can be arbitrarily set according to, for example, the specifications of the thermal transfer printer, etc. The thickness of the first ink layer 36 can be adjusted by the amount of the first ink layer 36 applied.

[0098] For example, the coating amount of the first ink layer 36 is 0.1 g / m 2 Above, preferably 0.5g / m 2 For example, the coating amount of the first ink layer 36 is 3.0 g / m 2 Below, preferably 2.5g / m 2 For example, the coating amount of the first ink layer 36 is expressed as 0.1 g / m 2 Above and 3.0g / m 2 Below, preferably 0.5g / m 2 Above and 2.5g / m 2 the following.

[0099] The specific thickness of the first ink layer 36 (before printing) is, for example, 0.05 μm or more, preferably 0.5 μm or more. The thickness of the first ink layer 36 is, for example, 3.0 μm or less, preferably 2.5 μm or less. The thickness of the first ink layer 36 can be, for example, 0.05 μm or more and 3.0 μm or less, preferably 0.5 μm or more and 2.5 μm or less. The thickness of the first ink layer 36 can be confirmed based on, for example, a SEM (Scanning Electron Microscope) image or a TEM (Transmission Electron Microscope) image of the ink ribbon 3.

[0100] (3) Middle layer 51

[0101] The intermediate layer 51 contains a thermoplastic elastomer. In particular, the intermediate layer 51 is preferably formed only of a thermoplastic elastomer. The thermoplastic elastomer forming the intermediate layer 51 preferably contains at least one of a styrene-based thermoplastic elastomer and an acetate-based thermoplastic elastomer.

[0102] Examples of styrene-based thermoplastic elastomers include styrene-butadiene-styrene block copolymers (SBS), styrene-ethylene·butylene-styrene block copolymers (SEBS), styrene-ethylene·propylene-styrene block copolymers (SEPS), styrene-ethylene / ethylene·propylene-styrene block copolymers (SEEPS), and styrene-isoprene-styrene block copolymers (SIS). Examples of acetate-based thermoplastic elastomers include ethylene-vinyl acetate copolymers (EVA).

[0103] The content of styrene in the thermoplastic elastomer included in the intermediate layer 51 is, for example, 10% by mass or more and 70% by mass or less, preferably 15% by mass or more and 50% by mass or less. If the styrene content is too high, the rubber elasticity of the intermediate layer 51 is reduced, and there is a case where the adhesion to the first ink layer 36 and the second ink layer 37 cannot be maintained during low-temperature transfer, or the color of the text becomes turbid. If the styrene content is too low, the rubber elasticity of the intermediate layer 51 becomes too large, so there is a case where the second ink layer 37 cannot be peeled off during high-temperature transfer and the color of the text becomes turbid.

[0104] The melt flow rate (hereinafter, sometimes abbreviated as "MFR") of the thermoplastic elastomer contained in the intermediate layer 51 is, for example, 1000 g / 10 min or less, preferably 400 g / 10 min or less. The MFR may be, for example, the MFR at a temperature of 190° C. and a load of 2.16 kg obtained by the measurement method specified in ISO 1133-1:2011. Hereinafter, the measurement conditions of the MFR are 190° C. and a load of 2.16 kg unless otherwise specified.

[0105] Thermoplastic elastomers with an MFR exceeding 400 g / 10 min tend to have an excessively strong affinity with the second ink layer 37. Therefore, there is a case where the second ink layer 37 cannot be peeled off during high-temperature transfer, and the color of the text becomes turbid. In addition, there is a case where the entire ink ribbon 3, that is, the base material layer 35, the first ink layer 36, the intermediate layer 51, and the second ink layer 37 are attached to the printing surface 31 of the printing ribbon 2. Thermoplastic elastomers with an MFR exceeding 400 g / 10 min have a low melt viscosity and high fluidity, so there is a case where the adhesion to the first ink layer 36 and the second ink layer 37 cannot be maintained during low-temperature transfer, or the color tone of the text becomes turbid.

[0106] On the other hand, if a thermoplastic elastomer having an MFR of 400 g / 10 min or less is used, the problems that may occur when a thermoplastic elastomer having an MFR exceeding 400 g / 10 min is used can be suppressed. Furthermore, even if thermal transfer recording is performed continuously, the color tone is not easily turbid on the printing surface 31 of the printing tape 2 and is clearly separated into two colors, and no unnecessary peeling occurs, and text with excellent clarity can be stably recorded. In order to further enhance these effects, the MFR of the thermoplastic elastomer is preferably 2.5 g / 10 min or less, and particularly preferably 2.3 g / 10 min or less in the above range.

[0107] There is no particular restriction on the lower limit of MFR, and the thermoplastic elastomer with a measurement result of "No Flow" at the temperature of 190°C and a load of 2.16 kg described above can also be used. There is no particular restriction on specific examples of the thermoplastic elastomer, and for example, the following various thermoplastic elastomers can be listed. These thermoplastic elastomers can be used alone or in combination of two or more.

[0108] Among the SEBS of the Tuftec (registered trademark) series manufactured by Asahi Kasei Corporation, H1521 [MFR: 2.3 g / 10 min], H1051 [MFR: less than 0.8 g / 10 min], H1052 [MFR: less than 13.0 g / 10 min], H1272 [MFR: no flow], P1083 [MFR: 3.0 g / 10 min], P1500 [MFR: 4.0 g / 10 min], P5051 [MFR: 3.0 g / 10 min], and P2000 [MFR: 3.0 g / 10 min].

[0109] Among the Tufprene (registered trademark) series of SBS manufactured by Asahi Kasei Corporation, A [MFR: 2.6 g / 10 min], 125 [MFR: 4.5 g / 10 min], and 126S [MFR: 4.5 g / 10 min].

[0110] Among Asaprene (registered trademark) T series SBS manufactured by Asahi Kasei Corporation, T-411 [MFR: no flow], T-432 [MFR: no flow], T-437 [MFR: no flow], T-438 [MFR: no flow], and T-439 [MFR: no flow].

[0111] Among the SEPS of the SEPTON (registered trademark) series manufactured by Kuraray Co., Ltd., 2002〔MFR: 70 g / 10 min〕, 2004F〔MFR: 5 g / 10 min〕, 2005〔MFR: no flow〕, 2006〔MFR: no flow〕, 2063〔MFR: 7 g / 10 min〕, and 2104〔MFR: 0.4 g / 10 min〕, the MFR of these SEPS was measured under the conditions of a temperature of 230°C and a load of 2.16 kg.

[0112] Among the SEEPS of the SEPTON (registered trademark) series manufactured by Kuraray Co., Ltd., 4033〔MFR: <0.1 g / 10 min〕, 4044〔MFR: no flow〕, 4055〔MFR: no flow〕, 4077〔MFR: no flow〕, and 4099〔MFR: no flow〕. The MFR of these SEEPS was measured under the conditions of a temperature of 230°C and a load of 2.16 kg.

[0113] Among the HYBRAR (registered trademark) series of vinyl SIS manufactured by Kuraray Co., Ltd., 5125 [MFR: 4 g / 10 min] and 5127 [MFR: 5 / 10 min].

[0114] Ultrathene (registered trademark) series EVA manufactured by Tosoh Corporation: 514R [MFR: 0.41 g / 10 min], 515 [MFR: 2.5 g / 10 min], 510 [MFR: 2.5 g / 10 min], 510F [MFR: 2.5 g / 10 min], 520F [MFR: 2.0 g / 10 min], 540 [MFR: 3.0 g / 10 min], 540F [MFR: 3.0 g / 10 min] in], 537 [MFR: 8.5g / 10min], 537L [MFR: 8.5g / 10min], 537S-2 [MFR: 8.5g / 10min], 541 [MFR: 9.0g / 10min] , 541L [MFR: 9.0g / 10min], 530 [MFR: 75g / 10min], 526 [MFR: 25g / 10min], 630 [MFR: 1.5g / 10min], 631 [MFR :1.5g / 10min], 636 [MFR: 2.5g / 10min], 625 [MFR: 14g / 10min], 626 [MFR: 3.0g / 10min], 627 [MFR: 0.8g / 1 0min], 633 [MFR: 20g / 10min], 635 [MFR: 2.4g / 10min], 640 [MFR: 2.8g / 10min], 634 [MFR: 4.3g / 10min], 68 0 [MFR: 160g / 10min], 681 [MFR: 350g / 10min], 751 [MFR: 5.7g / 10min], 710 [MFR: 18g / 10min], 720 [MFR: 15 0g / 10min], 722 [MFR: 400g / 10min], 750 [MFR: 30g / 10min], 752 [MFR: 60g / 10min], 760 [MFR: 70g / 10min].

[0115] The intermediate layer 51 can be formed, for example, by applying a coating obtained by dissolving or dispersing a material for forming the intermediate layer 51 including at least a thermoplastic elastomer in an arbitrary solvent onto the first ink layer 36 and then drying the coating.

[0116] The thickness of the intermediate layer 51 can be arbitrarily set according to the specifications of the thermal transfer printer, for example. The thickness of the intermediate layer 51 can be adjusted by the coating amount of the intermediate layer 51. For example, the coating amount of the intermediate layer 51 is expressed as 0.1 g / m 2 Above, preferably 0.2 g / m 2 For example, the coating amount of the intermediate layer 51 is 2.0 g / m 2Below, preferably 1.5g / m 2 For example, the coating amount of the intermediate layer 51 is expressed as 0.1 g / m 2 Above and 2.0g / m 2 Below, preferably 0.2g / m 2 Above and 1.5g / m 2 the following.

[0117] The specific thickness of the intermediate layer 51 (before printing) is, for example, 0.05 μm or more, preferably 0.2 μm or more. The thickness of the intermediate layer 51 is, for example, 2.0 μm or less, preferably 1.5 μm or less. The thickness of the intermediate layer 51 can be, for example, 0.05 μm or more and 2.0 μm or less, preferably 0.2 μm or more and 1.5 μm or less. The thickness of the intermediate layer 51 can be confirmed based on, for example, a SEM (Scanning Electron Microscope) image or a TEM (Transmission Electron Microscope) image of the ink ribbon 3.

[0118] It should be noted that due to the limitation of coating accuracy, the thickness of the intermediate layer 51 may sometimes have errors depending on the measurement position. The coating amount and thickness of the intermediate layer 51 may also include such errors. For example, 0.2 g / m 2 The intermediate layer 51 formed by the coating amount may include a coating amount of 0.1 g / m 2 The coating amount forms an area of ​​thickness of the case.

[0119] (4) Second ink layer 37

[0120] The second ink layer 37 can be formed of any thermoplastic resin, for example. Examples of the thermoplastic resin used in the second ink layer 37 include epoxy resin, polyester resin, polyolefin resin, etc. The thermoplastic resin can be appropriately selected according to the material of the printing ribbon 2. When the first ink layer 36 is formed of epoxy resin, it is preferred that the second ink layer 37 is also formed of epoxy resin.

[0121] By forming the second ink layer 37 with epoxy resin, the adhesion of the first ink layer 36 to the substrate layer 35 and the intermediate layer 51 can be balanced with the adhesion of the second ink layer 37 to the printing tape 2. As a result, the first ink layer 36 and the intermediate layer 51 can be well separated to the substrate layer 35 side, and the second ink layer 37 can be separated to the printing tape 2 side during high-temperature transfer. Since the high-temperature transfer range can be extended to the low-temperature side, the effect of suppressing color turbidity can be further improved. As the epoxy resin, various epoxy resins exemplified as the epoxy resin of the first ink layer 36 can be cited. These epoxy resins can be used alone or in combination of two or more.

[0122] The second ink layer 37 may contain wax in addition to the thermoplastic resin. By containing wax, the first ink layer 36 and the intermediate layer 51 can be separated to the substrate layer 35 side, and the second ink layer 37 can be separated to the printing tape 2 side during high-temperature transfer. Therefore, the high-temperature transfer range can be extended to the low-temperature side, and the effect of suppressing color turbidity can be further improved.

[0123] As the wax, any wax having affinity and compatibility with thermoplastic resins such as epoxy resins can be used. For example, natural waxes such as carnauba wax, paraffin wax, and microcrystalline wax, and synthetic waxes such as Fischer-Tropsch wax can be used. Specific examples of waxes are not particularly limited, and examples thereof include carnauba wax No. 1 flakes, No. 2 flakes, No. 3 flakes, No. 1 powder, and No. 2 powder (all of which have a melting point of 80 to 86°C) manufactured by Toyo Chemical Co., Ltd., paraffin waxes such as EMUSTAR-1155 (melting point: 69°C), EMUSTAR-0135 (melting point: 60°C), and EMUSTAR-0136 (melting point: 60°C) manufactured by Nippon Seiwa Co., Ltd., microcrystalline waxes such as EMUSTAR-0001 (melting point: 84°C) and EMUSTAR-042X (melting point: 84°C) manufactured by Nippon Seiwa Co., Ltd., and Fischer-Tropsch waxes such as FNP-0090 (freezing point: 90°C), SX80 (freezing point: 83°C), FT-0165 (melting point: 73°C), and FT-0070 (melting point: 72°C) manufactured by Nippon Seiwa Co., Ltd. These waxes can be used alone or in combination of two or more.

[0124] The second ink layer 37 may contain any colorant. As the colorant, one or more kinds of colorants corresponding to the color tone of the first ink layer 37 may be used. The colorant may be, for example, a pigment and a dye. From the viewpoint of ensuring transparency relative to the first ink layer 36, the second ink layer 37 preferably contains a colorant including at least a dye. The second ink layer 37 preferably contains only a dye as a colorant, but may contain a dye and a pigment whose proportion is less than that of the dye.

[0125] Here, the second ink layer 37 that ensures transparency relative to the first ink layer 36 can be defined as having light transmittance such that, when the printed pattern 44 of the first transfer layer 57 is observed from the second ink layer 37 side, the printed pattern 44 can be visually recognized as the color of the first ink layer 36. Figure 5A When the transferred belt 55 is observed in the direction indicated by the hollow arrow 59, the printed pattern 44 is recognized as the color of the first ink layer 36. As a numerical value indicating the transparency of the second ink layer 37, for example, the total light transmittance measured in accordance with JIS K7361 can be used. The total light transmittance of the second ink layer 37 can be, for example, 16% or more, preferably 16.5% or more. The total light transmittance of the second ink layer 37 can be measured, for example, using a haze meter.

[0126] When dyes and pigments are used together, the mixing ratio (mass ratio) of the dyes is, for example, more than 70 mass %, preferably 80 mass % or more, and more preferably 90 mass %. As the mass ratio of the dyes increases, the transparency of the second ink layer 37 relative to the first ink layer 36 can be improved.

[0127] For example, as dyes for coloring the second ink layer 37 in red, oil-soluble dyes, acid dyes, basic dyes, gold-containing dyes, or various salt-forming dyes thereof, the following various red dyes can be cited. These red pigments can be used alone or in combination of two or more.

[0128] CI Basic Red 1, 12, 13; CI Acid Red 13, 14, 18, 27, 50, 52; CI Solvent Red 25, 27, 30, 35, 49, 83, 89, 100, 122, 138, 149, 150, 160, 179, 218, 230; CI Direct Red 20, 37, 39, 44; CI Disperse Red 5, 7, 13, 17.

[0129] For example, the following various red pigments are listed as pigments for coloring the second ink layer 37 in red. These red pigments can be used alone or in combination of two or more.

[0130] CI Pigment Red 5, 7, 9, 12, 48 (Ca), 48 (Mn), 49, 52, 53, 53:1, 57 (Ca), 57:1, 97, 112, 122, 123, 149, 168, 177, 178, 179, 184, 202, 206, 207, 209, 242, 254, 255.

[0131] In addition, the L value of the color difference of the reflected light from the second ink layer 37 having the composition exemplified is 20 or less, preferably 15 or less, more preferably 10 or less, and particularly preferably 5 or less. The L value may be, for example, a reflection concentration (L value) measured when a light beam is incident from the second ink layer 37 side of the ink ribbon 3 using a reflection colorimeter. If the L value of the reflected light from the second ink layer 37 is within the above range, the transparency relative to the first ink layer 36 can be sufficiently ensured.

[0132] The ratio of each component in the second ink layer 37 is not particularly limited. The ratio of the wax to 100 parts by mass of the epoxy resin is, for example, 3 parts by mass or more, preferably 5 parts by mass or more. The ratio of the wax to 100 parts by mass of the epoxy resin is, for example, 11 parts by mass or less, preferably 9 parts by mass or less. The ratio of the wax to 100 parts by mass of the epoxy resin is, for example, 3 parts by mass or more and 11 parts by mass or less, preferably 5 parts by mass or more and 9 parts by mass or less.

[0133] The ratio of the colorant such as the red dye to 100 parts by mass of the epoxy resin (the total amount of the colorant) is, for example, 70 parts by mass or more, preferably 80 parts by mass or more. The ratio of the colorant such as the red dye to 100 parts by mass of the epoxy resin is, for example, 140 parts by mass or less, preferably 120 parts by mass or less. The ratio of the colorant such as the red dye to 100 parts by mass of the epoxy resin is, for example, 70 parts by mass or more and 140 parts by mass or less, preferably 80 parts by mass or more and 120 parts by mass or less.

[0134] The second ink layer 37 can be formed, for example, by applying a coating agent obtained by dissolving or dispersing the above-mentioned components in an arbitrary solvent on the intermediate layer 51 and then drying the coating agent.

[0135] The thickness of the second ink layer 37 can be arbitrarily set according to the specifications of the thermal transfer printer, for example. The thickness of the second ink layer 37 can be adjusted by the coating amount of the second ink layer 37. For example, the coating amount of the second ink layer 37 is expressed as 0.2 g / m 2 Above, preferably 1.0 g / m 2 For example, the coating amount of the second ink layer 37 is 7.0 g / m 2 Below, preferably 5.0g / m 2 For example, the coating amount of the second ink layer 37 is 0.2 g / m 2 Above and 7.0g / m 2 Below, preferably 1.0g / m 2 Above and 5.0g / m 2 the following.

[0136] The specific thickness of the second ink layer 37 (before printing) is, for example, 0.05 μm or more, preferably 1.0 μm or more. The thickness of the second ink layer 37 is, for example, 7.0 μm or less, preferably 5.0 μm or less. The thickness of the second ink layer 37 can be, for example, 0.05 μm or more and 7.0 μm or less, preferably 1.0 μm or more and 5.0 μm or less. The thickness of the second ink layer 37 can be confirmed based on, for example, a SEM (Scanning Electron Microscope) image, a TEM (Transmission Electron Microscope) image, or the like of the ink ribbon 3.

[0137] The laminating tape 76 includes a base layer 61, a first adhesive layer 62, a second adhesive layer 63, and a release layer 64. The first adhesive layer 62 is formed on the adhesive surface 65 of the base layer 61, and the second adhesive layer 63 is formed on the release surface 66 on the opposite side of the adhesive surface 65. The laminating tape 76 is attached to the printed matter 56 via the first adhesive layer 62.

[0138] (5) Base material layer 61

[0139] As the substrate layer 61, for example, films of resins such as polysulfone, polystyrene, polyamide, polyimide, polycarbonate, polypropylene, polyester, triacetate, thin papers such as capacitor paper and glassine, and cellophane can be listed. Among them, films of polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate are preferred from the viewpoints of mechanical strength, dimensional stability, heat treatment resistance, price, etc. The thickness of the substrate layer 61 can be arbitrarily set according to the specifications of the thermal transfer printer, for example. For example, the thickness of the substrate layer 61 is 1 μm or more, preferably 10 μm or more. For example, the thickness of the substrate layer 61 is 100 μm or less, preferably 50 μm or less. For example, the thickness of the substrate layer 61 is 1 μm or more and 100 μm or less, preferably 10 μm or more and 50 μm or less.

[0140] (6) First adhesive layer 62

[0141] The first adhesive layer 62 is not particularly limited as long as it is an adhesive layer used for bonding the films to each other, and examples thereof include acrylic adhesives, rubber adhesives, and the like. The thickness of the first adhesive layer 62 is, for example, 1 μm or more, preferably 10 μm or more. For example, the thickness of the first adhesive layer 62 is 100 μm or less, preferably 50 μm or less. For example, the thickness of the first adhesive layer 62 is 1 μm or more and 100 μm or less, preferably 10 μm or more and 50 μm or less.

[0142] (7) Second adhesive layer 63

[0143] As the second adhesive layer 63, there is no particular limitation as long as it is an adhesive layer used for bonding the films to each other, and for example, an adhesive material used in the first adhesive layer 62 can be used. The thickness of the second adhesive layer 63 is, for example, 2 μm or more, preferably 10 μm or more. For example, the thickness of the second adhesive layer 63 is 100 μm or less, preferably 50 μm or less. For example, the thickness of the second adhesive layer 63 is 2 μm or more and 100 μm or less, preferably 10 μm or more and 50 μm or less.

[0144] (8) Peeling layer 64

[0145] When the transferred tape 55 is attached to an object, the release layer 64 is peeled off from the laminating tape 76 to expose the second adhesive layer 63. The transferred tape 55 can be attached to the object via the exposed second adhesive layer 63. As the release layer 64, for example, release paper coated with a release agent such as silicone can be cited.

[0146] It should be noted that if Figure 5C as well as Figure 5D As shown, the bonding tape 76 may not include the base material layer 61 .

[0147] According to the transferred tape 55 having the above-described layer structure, the second ink layer 37 has a light transmittance that allows the first ink layer 36 to be visually recognized. Thus, a film in which the laminated body of the first ink layer 36 and the second ink layer 37 is transferred to the transparent printing tape 2 in such a manner that the second ink layer 37 becomes the surface-side ink layer (the observation-side ink layer) can be formed. Since the second ink layer 37 has a light transmittance that allows the first ink layer 36 to be visually recognized, the color of the first ink layer 36 can be recognized through the second ink layer 37 in the transferred tape 55. In addition, the L value of the color difference of the reflected light from the second ink layer 37 is 20 or less. Therefore, even when the first ink layer 36 is covered by the second ink layer 37, the color of the first ink layer 36 visually recognized through the second ink layer 37 can be made close to the ideal color (black in this embodiment).

[0148] The embodiments of the present disclosure described above are illustrative in all aspects and should not be interpreted restrictively, and are intended to include modifications in all aspects.

[0149] Based on the description of this specification and the accompanying drawings, the following additional features can be extracted.

[0150] [Appendix 1-1]

[0151] A thermal transfer recording medium, which is transferred to a transparent film, wherein:

[0152] The thermal transfer recording medium comprises:

[0153] a substrate layer; and

[0154] A first ink layer and a second ink layer are sequentially stacked on the substrate layer,

[0155] The second ink layer has light transmittance that allows the first ink layer to be visually recognized, and an L value of color difference of reflected light from the second ink layer is 20 or less.

[0156] [Appendix 1-2]

[0157] In addition to the thermal transfer recording medium described in Supplement 1-1,

[0158] In a state where the second ink layer is in contact with the transparent film, the thermal transfer recording medium is heated by the application of a relatively low first energy and then cooled, and when an external force is applied to the substrate layer and the second ink layer in a direction away from each other, the stack of the first ink layer and the second ink layer is transferred to the transparent film.

[0159] When the second ink layer is in contact with the transparent film, the thermal transfer recording medium is heated and then cooled due to the application of a second energy relatively higher than the first energy, and when an external force is applied to the substrate layer and the second ink layer in directions away from each other, the second ink layer is selectively transferred to the transparent film.

[0160] [Appendix 1-3]

[0161] The thermal transfer recording medium according to Supplementary Note 1-1 or Supplementary Note 1-2, wherein the second ink layer contains 80% by mass or more of a dye as a color material.

[0162] [Appendix 1-4]

[0163] The thermal transfer recording medium according to any one of Supplementary Notes 1-1 to 1-3, wherein the first ink layer contains a thermoplastic resin and a binder.

[0164] [Appendix 1-5]

[0165] The thermal transfer recording medium according to any one of Supplementary Notes 1-1 to 1-4, wherein the second ink layer contains a thermoplastic resin and wax.

[0166] [Appendix 1-6]

[0167] The thermal transfer recording medium according to any one of Supplementary Notes 1-1 to 1-5, further comprising an intermediate layer formed between the first ink layer and the second ink layer.

[0168] [Appendix 1-7]

[0169] The thermal transfer recording medium according to Appendix 1-6, wherein the intermediate layer contains a styrene-based thermoplastic elastomer.

[0170] [Appendix 1-8]

[0171] A transferred film is formed by sequentially laminating a first ink layer, a second ink layer having light transmittance that allows the first ink layer to be visually recognized, and a transparent film, wherein:

[0172] The total light transmittance of the second ink layer is greater than 16%.

[0173] The total light transmittance of the transparent film is greater than 80%.

[0174] [Appendix 1-9]

[0175] On the basis of the transferred film described in Appendix 1-8,

[0176] The transfer-finished film comprises:

[0177] a printed article including a laminate of the transparent film, the first ink layer, and the second ink layer; and

[0178] The laminating layer includes a first adhesive layer laminated on the printed material on the first ink layer side, and the base material layer adhered to the printed material via the first adhesive layer.

[0179] [Notes 1-10]

[0180] The transferred film according to Appendix 1-9, wherein the laminating layer further includes a second adhesive layer laminated on the base layer on the opposite side of the first adhesive layer, and a release layer laminated on the base layer via the second adhesive layer.

[0181] [Appendix 1-11]

[0182] A method for manufacturing a transferred film, wherein:

[0183] The method for manufacturing the transferred film comprises:

[0184] A heating step of heating a thermal transfer recording medium in a state where the second ink layer is in contact with a transparent film, wherein the thermal transfer recording medium comprises a substrate layer and a laminate of a first ink layer and a second ink layer sequentially laminated on the substrate layer, the second ink layer has light transmittance that allows the first ink layer to be visually recognized, and an L value of a color difference of reflected light from the second ink layer is 20 or less;

[0185] a cooling step of cooling the thermal transfer recording medium heated in the heating step; and

[0186] The transfer process applies external force to the base layer and the first ink layer of the thermal transfer recording medium cooled by the cooling process in directions away from each other, thereby transferring the transfer layer of the stack including at least the first ink layer and the second ink layer to the transparent film.

[0187] [Appendix 1-12]

[0188] Based on the method for producing a transferred film described in Supplement 1-11,

[0189] In the heating process, a first portion of the thermal transfer recording medium is heated by applying a relatively low first energy, and a second portion of the thermal transfer recording medium is heated by applying a relatively high second energy compared to the first energy,

[0190] In the transfer step, the stack of the first ink layer and the second ink layer is transferred to the transparent film at the first portion of the thermal transfer recording medium, and the second ink layer is selectively transferred to the transparent film at the second portion of the thermal transfer recording medium.

[0191] Example

[0192] Hereinafter, the present invention will be further described based on a plurality of samples, but the structure of the present invention is not limited to these examples.

[0193] [Black coloring layer coating agent (1)]

[0194] The components shown in Table 1 below were dissolved in a mixed solvent of toluene and methyl ethyl ketone (MEK) at a mass ratio of 1 / 4 to prepare a black coloring layer coating (1) having a solid content concentration of 22.5 mass %. The ratio of the active ingredient in the acrylic adhesive was 80 mass parts per 100 mass parts of the epoxy resin.

[0195]

Table 1

[0196]

[0197] The components in the table are as follows.

[0198] Epoxy resin: JER1007 manufactured by Mitsubishi Chemical Corporation [basically solid type, softening point (ring and ball method): 128°C, number average molecular weight Mn: about 2900]

[0199] Acrylic adhesive: AS-665 manufactured by Lion Chemical Co., Ltd. [solid content concentration: 40% by mass]

[0200] Tackifier: terpene phenol resin, YS Polyster T80 manufactured by Yasuhara Chemical Co., Ltd. (softening point: 80 ± 5°C)

[0201] Carbon black: MA100 powder manufactured by Mitsubishi Chemical Corporation〔LFF, DBP absorption: 100 cm 3 / 100g〕

[0202] [Black coloring layer coating agent (2)]

[0203] A black coloring layer coating agent (2) was prepared in the same manner as the black coloring layer coating agent (1) except that the acrylic adhesive and the tackifier were not added.

[0204] [Intermediate layer coating (1)]

[0205] A thermoplastic elastomer [Tuftec H1521 manufactured by Asahi Kasei Corporation, SEBS, MFR: 12.3 g / 10 min, styrene content 18% by mass] was dissolved in a mixed solvent of toluene and hexane in a mass ratio of 1:1 to prepare an intermediate layer coating (1) having a solid content concentration of 10% by mass.

[0206] [Intermediate layer coating (2)]

[0207] An intermediate layer coating (2) was prepared in the same manner as the intermediate layer coating (1) except that an equal amount of Tuftec H1517 (SEBS, MFR: less than 3.0 g / 10 min, styrene content 43% by mass) manufactured by Asahi Kasei Corporation was added as the thermoplastic elastomer. The solid content concentration was 10% by mass.

[0208] [Intermediate layer coating (3)]

[0209] An intermediate layer coating (3) was prepared in the same manner as the intermediate layer coating (1) except that an equal amount of Tuftec H1272 (SEBS, MFR: non-flowing, styrene content 35% by mass) manufactured by Asahi Kasei Corporation was added as the thermoplastic elastomer. The solid content concentration was 10% by mass.

[0210] [Intermediate layer coating (4)]

[0211] An intermediate layer coating (4) was prepared in the same manner as the intermediate layer coating (1) except that an equal amount of Tufprene A (SBS, MFR: 2.6 g / 10 min, styrene content 40% by mass) manufactured by Asahi Kasei Corporation was added as a thermoplastic elastomer. The solid content concentration was 10% by mass.

[0212] [Intermediate layer coating (5)]

[0213] An intermediate layer coating (5) was prepared in the same manner as the intermediate layer coating (1) except that an equal amount of Ultrathene 634 (EVA, MFR: 4.3 g / 10 min) manufactured by Tosoh Corporation was added as the thermoplastic elastomer. The solid content concentration was 10% by mass.

[0214] [Intermediate layer coating (6)]

[0215] An intermediate layer coating (6) was prepared in the same manner as the intermediate layer coating (1) except that an equal amount of Ultrathene 722 (EVA, MFR: 400 g / 10 min) manufactured by Tosoh Corporation was added as the thermoplastic elastomer. The solid content concentration was 10% by mass.

[0216] [Intermediate layer coating (7)]

[0217] An intermediate layer coating (7) was prepared in the same manner as the intermediate layer coating (1) except that an equal amount of Ultrathene 725 (EVA, MFR: 1000 g / 10 min) manufactured by Tosoh Corporation was added as the thermoplastic elastomer. The solid content concentration was 10% by mass.

[0218] [Intermediate layer coating (8)]

[0219] An intermediate layer coating (8) was prepared in the same manner as the intermediate layer coating (1) except that an equal amount of amorphous polyester resin (VYLON (registered trademark) 200 manufactured by Toyobo Co., Ltd.) was added as a thermoplastic resin instead of the thermoplastic elastomer. The solid content concentration was 10% by mass.

[0220] The material names, MFRs, and styrene contents of the intermediate layer coatings (1) to (8) are summarized in Table 2. The proportions of the constituent components are omitted because the solid content / toluene / hexane ratios of the intermediate layer coatings (1) to (8) are 10 / 45 / 45.

[0221]

Table 2

[0222]

[0223] [Red coloring layer coating agent (1)]

[0224] 100 parts by mass of epoxy resin [JER1004 manufactured by Mitsubishi Chemical Corporation [basically solid type, softening point (ring and ball method): 97°C, number average molecular weight Mn: about 1650]], 7.1 parts by mass of low melting point wax [carnauba wax No. 2 powder manufactured by Toyo Chemical Co., Ltd. (melting point: 80-86°C)], and 92.9 parts by mass of red colorant [red dye VALIFASTRED 1320 manufactured by Oriental Chemical Industry Co., Ltd. (CI base red 1 and onium salt of azo dye)] were dissolved in a mixed solvent of toluene and MEK in a mass ratio of 1 / 4 to prepare a coating material (1) for a red coloring layer having a solid content concentration of 28% by mass.

[0225] [Red coloring layer coating (2)]

[0226] A red coloring layer coating (2) was prepared in the same manner as the red coloring layer coating (1), except that a mixture of a red dye [VALIFASTRED1320 (CI base red 1 and an onium salt of an azo dye) manufactured by Oriental Chemical Industry Co., Ltd.] and a red pigment [SYMULER (registered trademark) LAKE RED C CONC210 (CI pigment red 53:1) manufactured by DIC Corporation] was added as a red coloring agent (mixing ratio = red dye 9:red pigment 1). The solid content concentration was 28% by mass.

[0227] [Red coloring layer coating (3)]

[0228] A red coloring layer coating (3) was prepared in the same manner as the red coloring layer coating (1), except that a mixture of a red dye [VALIFASTRED1320 (CI base red 1 and an onium salt of an azo dye) manufactured by Oriental Chemical Industry Co., Ltd.] and a red pigment [SYMULER (registered trademark) LAKE RED C CONC210 (CI pigment red 53:1) manufactured by DIC Corporation] was added as a red coloring agent (mixing ratio = red dye 8: red pigment 2). The solid content concentration was 28% by mass.

[0229] [Red coloring layer coating agent (4)]

[0230] A red coloring layer coating (4) was prepared in the same manner as the red coloring layer coating (1), except that a mixture of a red dye [VALIFASTRED1320 (CI base red 1 and an onium salt of an azo dye) manufactured by Oriental Chemical Industry Co., Ltd.] and a red pigment [SYMULER (registered trademark) LAKE RED C CONC210 (CI pigment red 53:1) manufactured by DIC Corporation] was added as a red coloring agent (mixing ratio = red dye 7: red pigment 3). The solid content concentration was 28% by mass.

[0231] The material names and compounding ratios of the red coloring layer coating agents (1) to (4) are summarized as shown in Table 3 below.

[0232]

Table 3

[0233]

[0234] [Sample 1~15]

[0235] (1) Manufacturing of ink ribbons (thermal transfer recording media)

[0236] First, a PET film with a thickness of 4.5 μm was prepared as a base layer. Next, a silicone resin having a solid content of 0.1 g / m2 per unit area was formed on the opposite side (back side) of the base layer on which the transfer layer was formed. 2 Next, any of the previously prepared black coloring layer coating agents is applied to the surface of the substrate layer and then dried to form a solid content per unit area of ​​1.5 g / m 2 Next, any intermediate layer coating agent prepared previously is applied on the black coloring layer and then dried to form a black coloring layer having a solid content per unit area of ​​1 g / m 2 Next, any of the previously prepared red coloring layer coating agents was applied onto the intermediate layer and then dried to form a solid content per unit area of ​​2.5 g / m 2 The compositions of the respective layers of the ink ribbons obtained from Samples 1 to 15 are shown in Tables 4 to 6 below.

[0237] (2) Evaluation

[0238] (2-1) Transmittance of substrate film

[0239] First, the total light transmittance of the transparent substrate film used in the preparation of the transferred film was measured. There were two types of substrate films used. One was a glossy transparent PET film [Lumirror (registered trademark) #50-S10 manufactured by Toray Industries, Ltd.], and the other was a matte transparent PET film [a film obtained by sandblasting Lumirror (registered trademark) #50-S10 manufactured by Toray Industries, Ltd.]. In Tables 4 to 6, the former is indicated as "PET" and the latter is indicated as "matte PET".

[0240] The transmittance of each substrate film was measured by cutting the film into 30 mm squares to prepare evaluation samples using a haze meter (NDH7000 manufactured by Nippon Denshoku Industries, Ltd.). The results are shown in Tables 4 to 6.

[0241] (2-2) Reflection concentration

[0242] A white PET sheet with a thickness of 330 μm was laid, and the ink ribbon produced by each sample was placed on the white PET sheet with the substrate layer at the bottom. Next, a light beam was incident from the red coloring layer side, and the reflection density (L value) was measured. The reflection density was measured using a reflection colorimeter (Spectro Photometer NF777 manufactured by Nippon Denshoku Industries Co., Ltd.). The results are shown in Tables 4 to 6.

[0243] (2-3) Printing transmittance

[0244] The ink ribbon produced from each sample was cut into strips of a predetermined width, wound into a roll, and installed in a thermal transfer printer (a prototype printer manufactured by Brother Industries, Ltd.). The main specifications of the thermal transfer printer are as follows.

[0245] <Resolution> 300dpi line thermal head

[0246] <Resistance of heating element>1830Ω

[0247] <Transfer load> 30N / 2inch

[0248] <Transport speed> 20mm / sec

[0249] <Peeling distance> 110mm

[0250] Next, in an environment with an outside temperature of 25°C, the energy value pre-set in the thermal transfer printer to be applied to the thermal head was set to 100 (low temperature, black). Then, a 70 mm square solid image was thermally transferred to the surface of the transparent base film shown in Tables 4 to 6 at a printing speed of 5 inches / sec. Thus, a transferred film was obtained in which a laminated body of a red coloring layer and a black coloring layer was formed as a transfer layer so that the red coloring layer was on the base film side.

[0251] Next, the print transmittance of the transferred film is evaluated. Print transmittance is an index for comparing the light transmittance of the red coloring layer covering the black coloring layer. The better the evaluation of the print transmittance, the more it can be identified as black when the black coloring layer is observed through the transparent substrate film and the red coloring layer. Specifically, a white PET sheet with a thickness of 330 μm is laid, and the transferred film is placed on the white PET sheet with the transparent substrate film on top. Next, a light beam is incident from the transparent substrate film side to measure the reflection concentration (L value, a value and b value). The reflection concentration is measured using a reflection colorimeter (Spectro Photometer NF777 manufactured by Nippon Denshoku Industries (Co., Ltd.). The print transmittance is evaluated according to the following criteria. Regarding the target values ​​of each numerical value of the reflection concentration that can be identified as black, L value ≤ 25, a value ≤ 17, and b value ≤ 7. The results are shown in Tables 4 to 6.

[0252] ○: Black (L value, a value, and b value are all within the target range).

[0253] △: The color has a red tint and can be recognized as black. (One or less of the L value, a value, and b value are outside the target range.)

[0254] ×: Brown (two or more items among the L value, a value, and b value are outside the target range).

[0255] (2-4) Printing stability

[0256] The ink ribbon produced from each sample was cut into strips of a specified width and wound into a roll, and installed in a thermal transfer printer with the same specifications as (2-3). Next, the energy value pre-set in the thermal transfer printer to be applied to the thermal head was set to three levels of energy for the low temperature side and the high temperature side under an external temperature of 25°C. Then, a 70 mm square solid image was thermally transferred to the surface of the transparent substrate film shown in Tables 4 to 6 at a printing speed of 5 inches / sec.

[0257] Regarding the energy value applied to the thermal head, for the low temperature side, there are three levels of 100 as a reference value and 90 and 110 around it. Thus, a transferred film is obtained in which a laminate of a red coloring layer and a black coloring layer is formed as a transfer layer in such a way that the red coloring layer becomes the substrate film side. On the other hand, for the high temperature side, there are three levels of 170 as a reference value and 160 and 180 around it. Thus, a transferred film is obtained in which the red coloring layer is selectively peeled off from the substrate layer and formed on the transparent substrate film as a transfer layer.

[0258] Next, the printing stability of each transferred film was evaluated. Printing stability is an indicator for comparing the size of the energy range required to form the desired transfer layer. The larger the energy range, the more stable the desired transfer layer can be achieved, so the printing stability is higher. Specifically, solid images transferred with three levels of energy on the low temperature side and the high temperature side were compared, and the printing stability was evaluated using the following benchmarks. The results are shown in Tables 4 to 6.

[0259] 4: There is no change in the three levels, and the energy range that can be printed is larger.

[0260] 3: Turbidity or failure to print exists at any energy level around the reference value.

[0261] 2: Turbidity or failure to print any two energy levels around the reference value.

[0262] 1: Turbidity or failure to print Any three energy levels around the reference value.

[0263] 0: Both the reference energy 100 and 170 are turbid or cannot be printed.

[0264] (2-5) Transmittance of red coloring layer

[0265] The ink ribbon produced from each sample was cut into strips of a specified width and wound into a roll, and installed in a thermal transfer printer with the same specifications as (2-3). Next, under an external temperature of 25°C, the energy value pre-set in the thermal transfer printer and applied to the thermal head was set to 170 (high temperature, red). Then, a 70 mm square solid image was thermally transferred to the surface of the transparent substrate film shown in Tables 4 to 6 at a printing speed of 5 inches / sec. Thus, a transferred film was obtained in which the red coloring layer was selectively peeled off from the substrate layer and formed as a transfer layer on the transparent substrate film.

[0266] Next, each solid image was cut into 30 mm squares to prepare an evaluation sample, and the transmittance of the red coloring layer was measured. The transmittance was measured using a haze meter (NDH7000 manufactured by Nippon Denshoku Industries). Specifically, first, the total light transmittance (%) of the evaluation sample was measured. Similarly, the total light transmittance (%) of the blank (non-printed portion of the transferred film) was measured. Then, the total light transmittance (%) of the red coloring layer alone was calculated by the formula: total light transmittance (%) of the evaluation sample / total light transmittance (%) of the blank × 100. The results are shown in Tables 4 to 6.

[0267]

Table 4

[0268]

[0269]

Table 5

[0270]

[0271]

Table 6

[0272]

[0273] According to the comparison of the L value of the ink ribbon used in samples 1 to 6 and samples 8 to 15 with the L value of the ink ribbon used in sample 7, if the L value of the color difference of the reflected light from the red coloring layer side of the ink ribbon (ink ribbon) is 20 or less, good printing transmittance can be exhibited in the transferred film. That is, in the transferred films of samples 1 to 6 and samples 8 to 15, when the black coloring layer is observed through the transparent base film and the red coloring layer, it can be recognized as black. In addition, according to the comparison of samples 1 and 3 with sample 4, especially if the L value is 15 or less, it can be closer to black. On the other hand, according to the comparison of sample 4 with sample 6, even if the L value is the same, if a matte-processed transparent PET film is used as the base film, the printing transmittance can be improved.

[0274] In addition, it can be seen that the print transmittance can be improved by increasing the ratio of the red dye in the red coloring layer. If the transmittance of the red coloring layer of sample 1 (red dye: red pigment = 10:0), sample 3 (red dye: red pigment = 9:1), sample 4 (red dye: red pigment = 8:2) and sample 7 (red dye: red pigment = 7:3) is compared, it can be seen that the transmittance can be improved as the ratio of the red dye increases. In particular, the transmittance of the red coloring layer of samples 1 and 3 is excellent.

[0275] Next, from the comparison between Sample 1 and Sample 2, it can be seen that when an intermediate layer is provided between the black coloring layer and the red coloring layer, the printing stability is excellent. That is, by providing an intermediate layer, it is not easy to produce excess peeling, and text with excellent clarity can be recorded. In addition, from the perspective of printing stability, from the comparison between Samples 1 and 9 to 11 and Samples 12 to 15, it can be seen that as the intermediate layer, a styrene-based thermoplastic elastomer (SEBS, SBS) is preferred, and SEBS is particularly preferred. In addition, from the comparison between Sample 1 and Sample 8, it can be seen that in order to improve the printing stability, it is preferred to make the black coloring layer contain an acrylic adhesive and a tackifier.

[0276] Description of Reference Numerals

[0277] 2 printing tape; 3 ink ribbon; 35 base material layer; 36 first ink layer; 37 second ink layer; 42 first part; 43 second part; 44 printed pattern; 45 red pattern; 46 black pattern; 51 intermediate layer; 55 transfer-finished tape; 56 printed matter; 57 first transfer layer; 58 second transfer layer; 61 base material layer; 62 first adhesive layer; 63 second adhesive layer; 64 peeling layer; 76 laminating tape.

Claims

1. A thermal transfer recording medium, which is transferred to a transparent film, wherein: The thermal transfer recording medium comprises: a substrate layer; and A first ink layer and a second ink layer are sequentially stacked on the substrate layer, The second ink layer has light transmittance that allows the first ink layer to be visually recognized, and an L value of color difference of reflected light from the second ink layer is 20 or less.

2. The thermal transfer recording medium according to claim 1, wherein In a state where the second ink layer is in contact with the transparent film, the thermal transfer recording medium is heated by the application of a relatively low first energy and then cooled, and when an external force is applied to the substrate layer and the second ink layer in a direction away from each other, the stack of the first ink layer and the second ink layer is transferred to the transparent film. When the second ink layer is in contact with the transparent film, the thermal transfer recording medium is heated and then cooled due to the application of a second energy relatively higher than the first energy, and when an external force is applied to the substrate layer and the second ink layer in directions away from each other, the second ink layer is selectively transferred to the transparent film.

3. The thermal transfer recording medium according to claim 1, wherein The second ink layer contains 80% by mass or more of a dye as a color material.

4. The thermal transfer recording medium according to claim 1, wherein The first ink layer includes a thermoplastic resin and a binder.

5. The thermal transfer recording medium according to claim 1, wherein The second ink layer includes a thermoplastic resin and wax.

6. The thermal transfer recording medium according to any one of claims 1 to 5, wherein The thermal transfer recording medium further includes an intermediate layer formed between the first ink layer and the second ink layer.

7. The thermal transfer recording medium according to claim 6, wherein The intermediate layer includes a styrene-based thermoplastic elastomer.

8. A transferred film, which is formed by sequentially laminating a first ink layer, a second ink layer having light transmittance that allows the first ink layer to be visually recognized, and a transparent film, wherein: The total light transmittance of the second ink layer is greater than 16%. The total light transmittance of the transparent film is greater than 80%.

9. The transferred film according to claim 8, wherein The transfer-printed film comprises: a printed article including a laminate of the transparent film, the first ink layer, and the second ink layer; and The laminating layer includes a first adhesive layer laminated on the printed material on the first ink layer side, and the base material layer adhered to the printed material via the first adhesive layer.

10. The transferred film according to claim 9, wherein The lamination layer further includes a second adhesive layer laminated on the base layer on the opposite side of the first adhesive layer, and a release layer laminated on the base layer via the second adhesive layer.

11. A method for producing a transferred film, wherein: The method for manufacturing the transferred film comprises: A heating step of heating a thermal transfer recording medium in a state where the second ink layer is in contact with a transparent film, wherein the thermal transfer recording medium comprises a substrate layer and a laminate of a first ink layer and a second ink layer sequentially laminated on the substrate layer, the second ink layer has light transmittance that allows the first ink layer to be visually recognized, and an L value of a color difference of reflected light from the second ink layer is 20 or less; a cooling step of cooling the thermal transfer recording medium heated in the heating step; and The transfer process applies external force to the base layer and the first ink layer of the thermal transfer recording medium cooled by the cooling process in directions away from each other, thereby transferring the transfer layer of the stack including at least the first ink layer and the second ink layer to the transparent film.

12. The method for producing a transferred film according to claim 11, wherein: In the heating process, a first portion of the thermal transfer recording medium is heated by applying a relatively low first energy, and a second portion of the thermal transfer recording medium is heated by applying a relatively high second energy compared to the first energy, In the transfer step, the stack of the first ink layer and the second ink layer is transferred to the transparent film at the first portion of the thermal transfer recording medium, and the second ink layer is selectively transferred to the transparent film at the second portion of the thermal transfer recording medium.

Images