Thermal transfer recording medium and printing apparatus

Abstract

Provided is a thermal transfer recording medium capable of recording two-color characters, the thermal transfer recording medium being capable of suppressing the occurrence of edge lines of one color, which are generated during transfer of the other color, in a thermal transfer recording medium capable of recording two-color characters. A thermal transfer recording medium (47) includes: a base layer (48) having a front surface (53) and a back surface (54); and a fusion layer (70), a first thermal transfer layer (50), an intermediate layer (51), and a second thermal transfer layer (52) that are sequentially laminated on the front surface (53) of the base layer (48) so as to be in direct contact with each other. In a first state in which the thermal transfer recording medium (47) is heated to a first temperature or higher and a second temperature or lower and then cooled to a third temperature or lower (for example, during low-temperature heating), the sum of the thicknesses of all layers before thermal transfer is smaller than that of the first thermal transfer layer (50), said layers being fractured and separated from the base material layer (48) side.

Description

Technical Field

[0001] The present invention relates to a thermal transfer recording medium capable of recording characters in different colors and a printing device for transferring the thermal transfer recording medium to a printed medium. Background Art

[0002] For example, Patent Documents 1 and 2 disclose thermal transfer recording media capable of recording text in different colors (for example, two colors, black and red). Such thermal transfer recording media are provided in a dedicated printing device. By adjusting the energy applied to the thermal head of the printing device, text in different colors can be transferred to the printed medium.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-094843

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 62-227788

[0007] Patent Document 3: Japanese Patent Application Laid-Open No. 63-214481 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] One embodiment of the present invention provides a thermal transfer recording medium capable of recording two-color characters, in which the occurrence of fringing of one color generated when transferring the other color can be suppressed.

[0010] Technical means for solving technical problems

[0011] A thermal transfer recording medium involved in one embodiment of the present invention is composed of a substrate layer, a first ink layer containing a first ink, and a second ink layer containing a second ink stacked in sequence, at least a portion of the first ink layer and the second ink layer are thermally transferred to a printed medium, and in a first state in which the thermal transfer recording medium is heated to a temperature above a first temperature and below a second temperature and then cooled to a temperature below a third temperature, when an external force is applied to the substrate layer and the second ink layer in a direction away from each other, the first ink layer and the second ink layer or within the second ink layer are broken, and in a second state in which the thermal transfer recording medium is heated to a temperature exceeding the second temperature and then cooled to a temperature below the third temperature, when the external force is applied, the first ink layer and the substrate layer or within the first ink layer are broken, and in the first state, the total thickness of all layers that are broken and leave the substrate layer side before thermal transfer is thinner than the first ink layer.

[0012] Effects of the Invention

[0013] According to the thermal transfer recording medium according to one embodiment of the present invention, it is possible to suppress the occurrence of fringing of one color of two-color text that is generated when transferring the other color. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0018] Figure 5A and Figure 5B This is a diagram showing an example of a printing pattern by the printing device.

[0019] Figure 6 The diagram shows a pattern of fringes generated during thermal transfer.

[0020] Figure 7 Yes means Figure 3 Diagram of the circuit pattern of the heating element of the thermal head.

[0021] Figure 8 It is used to illustrate Figure 7 A diagram of the temperature distribution of the heating element.

[0022] Fig. 9 This is a diagram for explaining the manner in which heat is transferred from a thermal head to a thermal transfer recording medium.

[0023] Fig.10 This is a diagram showing the relationship between the heating reaching temperature and the adhesive force at the boundaries of a plurality of layers of the thermal transfer recording medium.

[0024] Fig.11 This is a diagram for explaining the principle of generation of the fringes.

[0025] Fig.12 It is a diagram for explaining the solution to the above-mentioned fringing.

[0026] Fig.13 This is a schematic cross-sectional view showing a layer structure of a thermal transfer recording medium according to an embodiment of the present invention.

[0027] Fig.14 This is a diagram showing the relationship between the elapsed time in the heating step and the cooling step and the reaching temperature of the thermal transfer recording medium.

[0028] Fig.15 It is a diagram showing a state in which the thermal transfer recording medium is peeled off.

[0029] Fig.16 It is a diagram showing a state in which the thermal transfer recording medium is peeled off.

[0030] Fig.17 It is a diagram showing a state in which the thermal transfer recording medium is peeled off.

[0031] Fig.18 It is a diagram showing a state where the thermal transfer recording medium is peeled off.

[0032] Fig.19 It is a diagram showing a state where the thermal transfer recording medium is peeled off. DETAILED DESCRIPTION

[0033] Next, embodiments of the present invention will be described in detail with reference to the drawings.

[0034] [Overall Structure of Printing Device 1]

[0035] Figure 1 It is a diagram schematically showing the structure of a printing device 1 according to an embodiment of the present invention.

[0036] Reference Figure 1 The printing device 1 is a thermal transfer printer that transfers ink from an ink ribbon 3 as text to a printing tape 2 as an example of a printed medium. The printing tape 2 may include, for example, a strip-shaped film tape including a substrate to which the ink is directly transferred, a paper label tape having a plurality of paper labels arranged on a strip-shaped substrate, or the like.

[0037] The characters recorded on the printing tape 2 may include, for example, typical characters, symbols such as barcodes and QR codes (registered trademarks), numbers, figures, patterns, etc. The printing device 1 according to this embodiment can record characters in different colors (for example, two colors, black and red) on the printing tape 2 .

[0038] The printing device 1 mainly includes a housing 4 , a tape cassette 5 accommodated in the housing 4 , a thermal head 6 , a platen cylinder 7 , and a control substrate 8 .

[0039] The housing 4 may be, for example, a box-shaped member made of a plastic shell. 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. The printing tape 2 can be separated into labels of a size per unit of use by cutting with the cutter and taken out.

[0040] The tape cassette 5 may be a detachable cassette relative to the housing 4. The tape cassette 5 may be moved in the tape conveying direction D1 (in Figure 1 The printing tape roll 10 (in other words, it may be a label tape roll), the supply roller 11, the ink ribbon roll 12, the ink ribbon peeling member 13, and the ink ribbon winding roll 14 are sequentially accommodated from the upstream side to the downstream side (in a direction from the right side to the left side). In this embodiment, the printing tape roll 10 and the ink ribbon roll 12 are of the type used in a state of being accommodated in the tape cassette 5, but, for example, they may also be of the type used by being directly mounted on the printing device 1.

[0041] The printing tape roll 1 is made by winding the printing tape 2 into a cylindrical shape, and is rotatably held in the tape cassette 5, for example. A tape drive shaft 16 provided in the housing 4 is inserted into the supply roller 11. The rotational force R1 generated by the drive of the tape drive shaft 16 is transmitted to the supply roller 11, so that the supply roller 11 rotates.

[0042] 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 R2 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.

[0043] The ink ribbon peeling member 13 may be a guide member for changing the conveying direction D2 of the ink ribbon 3. The ink ribbon peeling member 13 may have a shape capable of abutting against the ink ribbon 3 being conveyed, such as 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 peeling member 13 abuts against the ink ribbon 3 being conveyed, and changes the conveying direction D2 of the ink ribbon 3 at a large angle relative to the conveying direction D1 of the printing ribbon 2. As a result, the printing ribbon 2 and the ink ribbon 3 are pulled apart, and the ink ribbon 3 is peeled off from the printing ribbon 2.

[0044] The thermal head 6 is disposed between the printing tape roller 10, 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 (for example, a heating resistor, etc.) 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.

[0045] The platen drive shaft 21 provided in the housing 4 is inserted into the platen cylinder 7. The rotational force R3 generated by driving the platen drive shaft 21 is transmitted to the platen cylinder 7, so that the platen cylinder 7 rotates. The control board 8 is an electronic device that performs electrical control of the printing device 1, and is provided inside the housing 4.

[0046] [Electrical Structure of Printing Device 1]

[0047] Figure 2 It is a block diagram showing the electrical structure of the printing device 1 .

[0048] 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.

[0049] The ROM 24 stores various programs for driving the printing device 1 (for example, executing Figure 3 and 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.

[0050] 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 supply 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 supply roller 11, the ribbon winding roller 14, and the impression roller 7 to rotate.

[0051] [Flow of Printing Process by Printing Device 1]

[0052] Figure 3 4 and 4 are schematic diagrams for explaining the heating process and the cooling process of the printing device 1. Figure 4B It is a schematic diagram for explaining the cooling process and the transfer process of the printing device 1 . Figure 4B is from Figure 4A This is an enlarged view of the main part when the transfer pattern is viewed in the direction of arrow 4B. Figure 5A and Figure 5B 1 is a diagram showing an example of a printed pattern 44 by the printing device 1. Figure 1 and Figure 3 to Figure 5A and Figure 5B , the printing process based on the printing device 1 is specifically described.

[0053] When printing characters on the printing tape 2 , the printing tape 2 is fed out from the printing tape roll 10 by the rotational drive of the supply drum 11 , and the ink ribbon 3 is fed out from the ink ribbon roll 12 by the rotational drive of the ink ribbon take-up roller 14 .

[0054] Therefore, if Figure 1 and Figure 3As shown, the printing tape 2 and the ink ribbon 3 are conveyed toward the downstream side in a state where they overlap each other. In the printing tape 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 tape 2 side is an adhesive surface 33 (front surface), and the surface on the opposite side is a back surface 34.

[0055] Reference Figure 3 The ink ribbon 3 includes: a base layer 35, a first ink layer 36 as an example of a first thermal transfer layer, and a second ink layer 37 as an example of a second thermal transfer layer. The first ink layer 36 and the second ink layer 37 are sequentially stacked on a surface 38 as an example of a first surface of the base layer 35. The surface on the opposite side of 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 from each other. 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.

[0056] The ink ribbon 3 is conveyed toward the thermal head 6 in a state of contact with the second ink layer 37 and the printing ribbon 2. In the thermal head 6, as shown in FIG. Figure 3 Specifically, the heating element 20 that generates heat by energizing 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 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, so that it is transported to the downstream side while being heated by the thermal head 6.

[0057] The heating element 20 may be controlled to have the same temperature throughout, or may be controlled to have different temperatures in parts. Figure 3 As shown, the first portion 40 of the heating element 20 may be controlled to be a first heating temperature, and the second portion 41 of the heating element 20 may be controlled to be a second heating temperature different from the first heating temperature. Thus, the ink ribbon 3 may include a first portion 42 heated by the first heating temperature and a second portion 43 heated by the 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 ribbon 2.

[0058] Reference Figure 3 and 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 has been 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.

[0059] Afterwards, if Figure 4AAs shown in FIG. 2 and FIG. 3 , the ink ribbon peeling member 13 selectively changes only the conveying direction D2 of the ink ribbon 3, thereby applying an external force F1 to the base material 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 pulled apart, and the ink ribbon 3 is wound around the ink ribbon winding roller 14. At this time, in the ink ribbon 3, the first portion 42 and the second portion 43 heated by the thermal head 6 are selectively left on the printing ribbon 2, thereby performing the transfer process. For example, in the first portion 42, the base material layer 35 and the laminated body including the first ink layer 36 and the second ink layer 37 can be peeled off and the laminated body can be transferred. On the other hand, in the second portion 43, the first ink layer 36 and the second ink layer 37 can be peeled off and the second ink layer 37 can be selectively transferred.

[0060] Thus, a printed pattern 44 of different colors (for example, two colors, black and red) is formed on the printing tape 2. Figure 5A As shown, the printed pattern 44 can have different colors for each individual character. Figure 5A In the example, when viewed from the printing surface 31 of the printing tape 2, the red pattern 45 based on the second ink layer 37 can be seen on the outermost surface of the letters "A" and "C", and the black pattern 46 based on the first ink layer 36 can be seen on the outermost surface of "B". Figure 5B As shown, the printed pattern 44 can also be seen in both a red pattern 45 and a black pattern 46 for each character portion.

[0061] After the transfer of the ink ribbon 3, the printing tape 2 on which the characters are recorded is taken out from the take-out port 9 of the printing device 1. Through the above steps, the printing tape 2 on which the characters are printed can be obtained.

[0062] [An example of a problem in two-color printing]

[0063] In the thermal transfer type thermal printer (printing device 1), after the ink ribbon 3 is heated by the thermal head 6 according to the pattern of recording information, the ink ribbon 3 is peeled off from the printing tape 2. As a result, the ink layers 36 and 37 are selectively melted or softened according to the heating pattern, and are peeled off from the base material layer 35 and transferred to the printing surface 31 of the printing tape 2, and text is recorded on the printing surface 31. The above-mentioned patent documents 1 and 2 also disclose the above-mentioned two-color thermal transfer printing, which has the following problems.

[0064] For example, Figure 6 The printed pattern 44 of the ink ribbon is shown in which red is transferred when heated at a low temperature and black is transferred when heated at a high temperature. When only one color pattern of a two-color pattern is selectively transferred, fringing may occur. For example, referring to Figure 6In the black patterns 46 arranged in a water ball shape with intervals between each other, the red pattern 45 may be selectively transferred to the peripheral portion of each pattern as a fringing 80. The main cause of such fringing 80 can be considered to be the temperature distribution in the surface of the ink ribbon 3. For example, the peripheral portion of each pattern does not reach the required temperature for transferring the black pattern 46. The temperature distribution of the ink ribbon 3 is caused by the temperature distribution of the heating element 20 of the thermal head 6. Figure 7 to Figure 11 , the generation principle of the edge pattern 80 is described in detail.

[0065] Figure 7 Yes means Figure 3 FIG. 2 is a diagram showing a circuit pattern of the heating element 20 of the thermal head 6. Figure 8 It is used to illustrate Figure 7 The temperature distribution of the heating element 20 is shown in FIG. Figure 7 and Figure 8 In the figure, the heating element 20 is shaded for clarity.

[0066] Reference Figure 7 and Figure 8 , the more detailed structure of the thermal head 6 and the temperature distribution of the heating element 20 are described. Figure 7 In the thermal head 6, a plurality of heating elements 20 are regularly arranged at a predetermined pitch P1. For example, the plurality of heating elements 20 are arranged in a row vertically at right angles to the conveying direction D1 of the belt. Alternatively, the plurality of heating elements 20 may be arranged in rows in the vertical and horizontal directions.

[0067] In this embodiment, each heating element 20 is rectangular. The length L2 of each heating element 20 in the main scanning direction D3 can be, for example, greater than 15 μm and less than 300 μm. The length L3 of each heating element 20 in the sub-scanning direction D4 can be longer than the length L2 in the main scanning direction D3. The sub-scanning direction D4 is a direction orthogonal to the main scanning direction D3, and can be the conveying direction D1 of the printing tape 2. The prescribed spacing P1 is, for example, the distance from the center to the center of two adjacent heating elements 20. The prescribed spacing P1 can be, for example, 84.7 μm (300 dpi).

[0068] The plurality of heating elements 20 may have one terminal connected to a common electrode 81 (e.g., GND potential) shared by all the heating elements 20, and another terminal connected to electrically independent individual electrodes 82. The first drive circuit 28 controls the heating temperature of each heating element 20 by adjusting the power supplied to each individual electrode 82 and the power-on time.

[0069] Reference Figure 8The temperature distribution diagram on the lower side of the heating element 20 shows the temperature distribution along the sub-scanning direction D4 of the heating element 20, and the temperature distribution diagram on the right side of the heating element 20 shows the temperature distribution along the main scanning direction D3 of the heating element 20. When electric power (energy) is supplied to each heating element 20, the electric energy is converted into thermal energy, so that each heating element 20 generates heat. The temperature rise value of the heating element 20 due to the heat generation can be obtained, for example, by the following formula (1).

[0070] T1=Q / C+T0···(1)

[0071] In the formula (1), T1 = temperature rise value, T0 = ambient temperature, Q = applied energy, and C = heat capacity of the heating element 20 (depending on the shapes and materials of the thermal head 6 and the heating element 20).

[0072] When the applied energy Q is applied to the entire shaded portion of the heating element 20, the heating temperature T1 value of the heating element will be macroscopically in the shape of the temperature distribution shown by the dotted line 83 according to formula (1). However, the movement of heat has the property of flowing from the high temperature side to the low temperature side, so the heat will escape to the periphery of the heating element 20 to which the applied energy Q is not applied, that is, the low temperature surrounding temperature T0 side. Therefore, as a microscopic temperature distribution, as shown by the solid line 84, it becomes a mountain-shaped temperature distribution shape that is higher as it approaches the center and becomes lower as it moves from the center to the periphery. Simply put, this is because it is difficult for heat to escape from the center of the heating element 20, while it is easy for heat to escape from the periphery.

[0073] Fig. 9 This is a diagram for explaining the manner in which heat is transferred from the thermal head 6 to the ink ribbon 3 .

[0074] Reference Fig. 9 , from Figure 8 The heat of each heating element 20 is sequentially transferred from the base material layer 35 to the first ink layer 36 and the second ink layer 37 to the inside of the ink ribbon 3. Fig. 9 , the heat transfer method from the heating element 20 to the inside of the ink ribbon 3 is represented by the semi-elliptical temperature curves 85A to 85F. The temperature curves 85A to 85F are respectively the first temperature curve 85A, the second temperature curve 85B, the third temperature curve 85C, the fourth temperature curve 85D, the fifth temperature curve 85E and the sixth temperature curve 85F in the order of proximity to the heating element 20. The area surrounded by each of the temperature curves 85A to 85F is the first temperature area 86A, the second temperature area 86B, the third temperature area 86C, the fourth temperature area 86D, the fifth temperature area 86E and the sixth temperature area 86F. When heating based on the heating element 20, the reaching temperatures of the temperature areas 86A to 86F have the relationship of 86A>86B>86C>86D>86E>86F.

[0075] Therefore, when heated, a magnitude relationship of the reaching temperatures is generated in the thickness direction of the ink ribbon 3. For example, if the reaching temperature Tb (T base ), the reaching temperature Th (T high ) and the reaching temperature T1 (T low ), then there is a relationship of Tb>Th>Tl. Fig. 9 In the figure, for the sake of clarity, the portions directly below the heating element 20 at the boundaries of the layers of the ink ribbon 3 are conceptually shown as a rectangular first boundary 87 , a second boundary 88 , and a third boundary 89 .

[0076] Moreover, in the in-plane direction (direction perpendicular to the thickness direction) of the ink ribbon 3, the reaching temperatures Tb, Th, and Tl are also different and produce a magnitude relationship (temperature distribution). For example, in the second boundary 88 (first ink layer 36-second ink layer 37), the center is the second temperature region 86B, but the peripheral portion is the third temperature region 86C, which is lower than the center. Such temperature distribution in the in-plane direction of each boundary 87-89 is related to the generation of the fringes 80.

[0077] Fig.10 This is a diagram showing the relationship between the heating reaching temperature and the peeling force (adhesive force) at the multiple layer boundaries of the ink ribbon 3 .

[0078] Before describing the relationship between the temperature distribution in the in-plane direction of each boundary portion 87 to 89 and the generation of the fringes 80, refer to Fig.10 , the relationship between the reaching temperatures Tb, Th, Tl of the boundaries 87 to 89 of the layers of the ink ribbon 3 and the peeling force (adhesive force) of the boundaries 87 to 89 will be described.

[0079] Reference Fig.10 , Fig.10 The horizontal axis represents the reaching temperature of the boundary portions 87 to 89 of each layer of the ink ribbon 3. Fig.10 The vertical axis represents the force (peeling force) required for peeling off the boundary portions 87 to 89 of each layer of the ink ribbon 3 . Fig.10 The solid line 90 shows the relationship between the reaching temperature Th and the peeling force in the second boundary 88 (first ink layer 36 - second ink layer 37). Fig.10 The single-dot chain line 91 represents the relationship between the reaching temperature T1 and the peeling force in the third boundary 89 (the second ink layer 37-printing tape 2). Fig.10 The two-dot chain line 92 shows the relationship between the reaching temperature Tb and the peeling force in the first boundary portion 87 (base material layer 35 - first ink layer 36).

[0080] like Fig.10 As shown, the magnitude relationship of the peeling force at each boundary 87 to 89 is not constant, but changes according to the change of the reaching temperature Tb, Th, Tl of the boundary 87 to 89. For example, Fig.10 The horizontal axis of can be mainly divided into three sections according to the magnitudes of the reaching temperatures Tb, Th, and Tl of the boundaries 87 to 89. The three sections include a first section 93, a second section 94, and a third section 95.

[0081] The first section 93 is the section where the range of the reaching temperatures Tb, Th, and Tl of the boundaries 87 to 89 is the lowest. The magnitude relationship of the peeling forces at the boundaries 87 to 89 in the first section 93 is the third boundary 89 < the second boundary 88 < the first boundary 87. The peeling force at the third boundary 89 is almost 0 (zero), so the ink ribbon 3 is not adhered to the printing ribbon 2.

[0082] That is, the first section 93 may be an initial state before energy is applied by the thermal head 6 (a state before thermal transfer).

[0083] The range of reaching temperature Tb, Th, Tl of the boundary portions 87 to 89 of the second interval 94 is between the first interval 93 and the third interval 95. The magnitude relationship of the peeling force at each boundary portion 87 to 89 in the second interval 94 is second boundary portion 88 < first boundary portion 87 < third boundary portion 89, or second boundary portion 88 < third boundary portion 89 < first boundary portion 87. Therefore, the second ink layer 37 is adhered to the printing tape 2 via the third boundary portion 89, and the bonding state between the base material layer 35 and the first ink layer 36 is fully maintained via the first boundary portion 87. On the other hand, the bonding force between the first ink layer 36 and the second ink layer 37 via the second boundary portion 88 is the lowest. Therefore, in the second interval 94, if the external force F1 (refer to Figure 4A , B) is applied to the ink ribbon 3, peeling occurs at the second boundary portion 88 where the adhesive force is weakest. As a result, so-called reverse printing occurs in which the first ink layer 36 remains on the substrate layer 35 side, while only the second ink layer 37 is selectively thermally transferred to the printing tape 2. Therefore, the text recorded on the printing tape 2 becomes the color tone of the second ink layer 37, for example, red.

[0084] The third section 95 is the section where the range of the reaching temperatures Tb, Th, and Tl of the boundaries 87 to 89 is the highest. The magnitude relationship of the peeling forces at the boundaries 87 to 89 in the third section 95 is that the first boundary 87 < the third boundary 89 < the second boundary 88, or the first boundary 87 < the second boundary 88 < the third boundary 89. Therefore, the second ink layer 37 is adhered to the printing tape 2 via the third boundary 89, and the adhesion between the first ink layer 36 and the second ink layer 37 is fully maintained via the second boundary 88. On the other hand, the adhesion between the substrate layer 35 and the first ink layer 36 via the first boundary 87 is the lowest. Therefore, in the third section 95, if the external force F1 (refer to Figure 4A , B) is applied to the ink ribbon 3, peeling occurs at the first boundary portion 87 where the adhesive force is weakest. As a result, the entirety of the ink ribbon 3, that is, the first ink layer 36 and the second ink layer 37, are thermally transferred integrally to the printing tape 2. Therefore, the text recorded on the printing tape 2, for example, becomes the color tone of the first ink layer 36 located on the outermost layer after transfer, for example, black.

[0085] Thus, it can be seen that when the external force F1 is applied to the ink ribbon 3, the boundary portion of the three boundary portions 87 to 89 that becomes the peeling position is related to the reaching temperature of the boundary portions 87 to 89. For example, during low-temperature heating (second interval 94) when low energy is applied to the heating element 20, the first ink layer 36 and the second ink layer 37 become the peeling position, and the thermal transfer color becomes red.

[0086] On the other hand, during high-temperature heating (third section 95 ) when high energy is applied to the heating element 20 , a separation position is formed between the base material layer 35 and the first ink layer 36 , and the thermal transfer color becomes black.

[0087] Therefore, in order to correctly transfer the two-color text without generating the fringes 80, the reaching temperatures Th and Tl of the second boundary 88 and the third boundary 89 are limited to the case where the reaching temperatures Th and Tl are consistent in the in-plane direction of the boundary and the temperature conditions required for transfer are satisfied. Fig. 9 As shown, temperature distribution usually occurs in the in-plane direction of the ink ribbon 3 , which is a factor causing the fringes 80 .

[0088] Fig.11 This is a diagram for explaining the principle of generation of the fringe 80 . Fig.12 80 is a diagram for explaining a solution to the fringing 80. Fig.11 In the description, the thickness direction of the ink ribbon 3 is referred to as direction D5, and the in-plane direction of the ink ribbon 3 orthogonal to the thickness direction D5 is referred to as D6.

[0089] Reference Fig.11The solid line drawn in the shape of a mountain represents the first temperature distribution curve 96 of the temperature Th reached on the outermost surface of the ink ribbon 3 that was not transferred during the transfer of the second ink layer 37 and remained on the side of the substrate layer 35. The top is the highest temperature, and the temperature decreases as it approaches the hem. The single-point dashed line drawn in the shape of a mountain represents the second temperature distribution curve 97 of the temperature Tl reached on the outermost surface of the ink ribbon 3 (i.e., the third boundary 89). The top is the highest temperature, and the temperature decreases as it approaches the hem. The two straight lines crossing the first temperature distribution curve 96 and the second temperature distribution curve 97 are, from the top, the high-temperature side boundary conditions 98 (corresponding to Fig.10 Th-tar) and the low temperature side boundary condition required for red transfer 99 (corresponding to Fig.10 Tl-tar).

[0090] Reference Fig.11 On the left side (during low temperature heating), the first temperature distribution curve 96 is located between the low temperature side boundary condition 99 and the high temperature side boundary condition 98 (second interval 94) throughout the in-plane direction D6 of the printed pattern 44. On the other hand, the second temperature distribution curve 97 does not reach the high temperature side boundary condition 98 throughout the in-plane direction D6 of the printed pattern 44. Fig.10 Under this condition, the peeling force of the second boundary portion 88 is minimum at any position in the in-plane direction D6 of the printed pattern 44, so peeling occurs at the second boundary portion 88 throughout the entire in-plane direction D6 of the printed pattern 44. Therefore, no fringing 80 is generated, and red transfer can be performed.

[0091] Reference Fig.11 On the right side, throughout the entire in-plane direction D6 of the printed pattern 44, the first temperature distribution curve 96 exceeds the low-temperature side boundary condition 99. On the other hand, the second temperature distribution curve 97 exceeds the high-temperature side boundary condition 98 (third interval 95) at the central portion 100 which is more likely to become high temperature, but exists between the low-temperature side boundary condition 99 and the high-temperature side boundary condition 98 (second interval 94) at the peripheral portion 101 which is more likely to become low temperature than the central portion 100. Under such circumstances, the peeling force at the first boundary portion 87 (between the substrate layer 35 and the first ink layer 36) is not sufficiently reduced, and the magnitude relationship of the peeling force at the peripheral portion 101 becomes Fig.10 That is, the peeling force at the second boundary portion 88 becomes minimum, so peeling occurs at the second boundary portion 88. Thus, the edge 80 is selectively generated at the peripheral edge portion 101 of the printed pattern 44.

[0092] Therefore, if Fig.12As shown, in order to suppress such fringes 80, the inventors of the present application have discovered that the fringes 80 can be suppressed by making the temperature difference between the reaching temperature Th of the second boundary portion 88 and the reaching temperature Tl of the third boundary portion 89 and the temperature difference between the high-temperature side boundary condition (Th_tar) and the low-temperature side boundary condition (Tl_tar) close to each other. In other words, it has been discovered that the fringes 80 can be suppressed by making |Th-Tl| close to |(Tl_tar)-(Th_tar)|. More specifically, by adjusting the thickness of the second ink layer 37 to be small, the heat transfer amount to the third boundary portion 89 can be increased by shortening the heat transfer distance between the second boundary portion 88 and the third boundary portion 89. Thus, as Fig.12 As shown, the top of the second temperature distribution curve 97 is relatively higher than the second boundary portion 88, so that |Th-Tl|=|(Tl_tar)-(Th_tar)| can be approached.

[0093] [Specific structure of thermal transfer recording medium]

[0094] Next, an example of the structure of the thermal transfer recording medium 47 (ink ribbon) that can suppress the occurrence of the fringes 80 will be described.

[0095] Fig.13 FIG. 4 is a schematic cross-sectional view showing a layer structure of a thermal transfer recording medium 47 according to an embodiment of the present invention. Fig.13 , a thermal transfer recording medium 47 is shown in a state of being adhered to a printing tape 2 as an example of a medium to be printed.

[0096] The thermal transfer recording medium 47 can be used as the ink ribbon 3 for Figure 1 to Figure 4A , and the printing device 1 and the printing process shown in B. The thermal transfer recording medium 47 includes: a base layer 48, a back layer 49, a fusion layer 70, a first thermal transfer layer 50, an intermediate layer 51, and a second thermal transfer layer 52. The fusion layer 70, the first thermal transfer layer 50, the intermediate layer 51, and the second thermal transfer layer 52 are sequentially stacked on a surface 53, which is an example of a first surface of the base layer 48. The surface of the base layer 48 on the opposite side to the surface 53 may be a back surface 54. The back layer 49 is stacked on the back surface 54 of the base layer 48. The first thermal transfer layer 50 and the second thermal transfer layer 52 may be referred to as a first ink layer and a second ink layer, respectively.

[0097] The thermal transfer recording medium 47 of the present invention is characterized by comprising a base layer 48 and a fusion layer 70, a first thermal transfer layer 50, an intermediate layer 51, and a second thermal transfer layer 52 which are sequentially stacked in direct contact with each other on a surface 53 of the base layer 48. The intermediate layer 51 contains a thermoplastic elastomer as an adhesive. The intermediate layer 51 may also be omitted.

[0098] Hereinafter, specific components and physical properties of the base layer 48 , the back layer 49 , the fusion layer 70 , the first thermal transfer layer 50 , the intermediate layer 51 , and the second thermal transfer layer 52 included in the thermal transfer recording medium 47 will be described in detail.

[0099] (1) Base material layer 48

[0100] As the substrate layer 48, for example, films of resins such as polysulfone, polystyrene, polyamide, polyimide, polycarbonate, polypropylene, polyester, and cellulose triacetate, thin paper such as capacitor paper and glassine paper, and cellophane can be cited. Among these, 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 48 can be arbitrarily set according to the specifications of the thermal transfer printer, etc. For example, the thickness of the substrate layer 48 is 1 μm or more, preferably 2 μm or more.

[0101] For example, the thickness of the base material layer 48 is 10 μm or less, preferably 8 μm or less. For example, the thickness of the base material layer 48 is 1 μm or more and 10 μm or less, preferably 2 μm or more and 8 μm or less.

[0102] (2) Back layer 49

[0103] The back layer 49 improves the heat resistance, sliding property, and scratch resistance of the back surface 54 of the base material layer 48 in contact with the thermal head 6. Examples of the back layer 49 include silicone resin, fluororesin, silicone-fluorine copolymer resin, nitrocellulose resin, silicone-modified polyurethane resin, and silicone-modified acrylic resin. The back layer 49 may contain a lubricant as needed.

[0104] The back layer 49 can be formed, for example, by applying a coating obtained by dissolving or dispersing the above-mentioned resin or the like in an arbitrary solvent to the back surface 54 of the base material layer 48 and then drying the coating. The thickness of the back layer 49 can be arbitrarily set according to the specifications of a thermal transfer printer, for example. The thickness of the back layer 49 can be adjusted by the amount of the back layer 49 applied.

[0105] For example, the coating amount of the back surface layer 49 is 0.05 g / m 2 Above, preferably 0.1 g / m 2 For example, the coating amount of the back layer 49 is 0.5 g / m 2 Below, preferably 0.4g / m 2 For example, the coating amount of the back surface layer 49 is expressed as 0.05 g / m 2 Above and 0.5g / m 2Below, preferably 0.1g / m 2 Above and 0.4g / m 2 The specific thickness of the back surface layer 49 is, for example, 0.05 μm or more and 0.5 μm or less, and preferably 0.1 μm or more and 0.4 μm nm or less.

[0106] (3) Welding layer 70

[0107] The welding layer 70 includes, for example, at least one selected from the group consisting of polyamide resin, polyester resin, epoxy resin, phenolic resin, and polyvinyl alcohol resin. In view of improving affinity and adhesion with respect to the base layer 48 and the first thermal transfer layer 50 during low-temperature heating, the welding layer 70 is preferably formed using a polyamide resin.

[0108] Examples of the polyamide resin include polyamides obtained by polycondensation of three-membered or more lactams, polymerizable aminocarboxylic acids, dibasic acids and diamines or salts thereof, or mixtures thereof. These polyamide resins can be used alone or in combination of two or more.

[0109] Specific commercial products of polyamide resins include, for example, 1310 (softening point: 120±5°C, melt viscosity: 1500 to 4500 mPa·s / 200°C), 1315 (softening point: 130±5°C, melt viscosity: 7000 to 18000 mPa·s / 200°C), 1320 (softening point: 100±5°C, melt viscosity: 11000 to 20000 mPa·s / 200°C) of the Tohmide (registered trademark) series manufactured by T&K TOKA Co., Ltd. ·s / 200℃), 1340 (softening point: 140±5℃, melt viscosity: 8000~16000mPa·s / 200℃), TXC-243A (softening point: 105±5℃, melt viscosity: 5000~10000mPa·s / 200℃), TXC-245A (softening point: 90±5℃, melt viscosity: 1000~2000mPa·s / 200℃), etc.

[0110] In addition, in the present application, when comparing the temperatures related to the thermal deformation of a plurality of substances, in the case of a substance having a softening point such as a polyamide resin, the softening point is used as the comparison temperature. In the case of a substance having a melting point (for example, wax described later), the melting point is used as the comparison temperature. In the case of a substance having a glass transition temperature without having both a melting point and a softening point (for example, a polyester resin described later), the glass transition temperature is used as the comparison temperature.

[0111] Specific commercially available products of polyester resins include, for example, UE-3320, UE-9820, UE-3350, UE-3380, etc. in the UNILATE (registered trademark) series produced by Unitika Co., Ltd., and 200 (glass transition temperature: 67°C), 600 (glass transition temperature: 47°C), GK-360 (glass transition temperature: 56°C), GK-810 (glass transition temperature: 46°C), GK-680 (glass transition temperature: 10°C), etc. in the VYLON (registered trademark) series produced by Toyobo Co., Ltd.

[0112] Specific commercial products of epoxy resins include, for example, 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): 98°C, number average molecular weight Mn: about 1600), and 1005 (softening point (ring and ball method): 106°C, number average molecular weight Mn: about 1800). ), 1005F, 1009F (softening point (Ring and Ball method): 144°C, number average molecular weight Mn: about 144°C), 1004FS (softening point (Ring and Ball method): 100°C), 1006FS (softening point (Ring and Ball method): 112°C), 1007FS (softening point (Ring and Ball method): 124°C).

[0113] Specific commercial products of phenolic resins include, for example, TD-2131 (softening point: 78 to 82° C.), TD-2106 (softening point: 88 to 95° C.), TD-2093 (softening point: 98 to 102° C.), TD-2090 (softening point: 117 to 123° C.) in the PHENOLITE (registered trademark) series manufactured by DIC Corporation, and BRG-555 (softening point: 66 to 72° C., melt viscosity: 0.3 to 0.5 Pa·s / 125° C.) in the SHOWNOL (registered trademark) series manufactured by AICA Industries, Ltd. ), BRG-556 (softening point: 77~83℃, melt viscosity: 0.1~0.3Pa·s / 150℃), BRG-557 (softening point: 82~88℃, melt viscosity: 0.2~0.4Pa·s / 150℃), BRG-558 (softening point: 93~98℃, melt viscosity: 0.8~1.2Pa·s / 150℃), CRG-951 (softening point: 93~99℃, melt viscosity: 0.2~0.8Pa·s / 150℃), TAM-005 (softening point: 80~88℃, melt viscosity: 0.3~0.5Pa·s / 150℃), etc.

[0114] As the polyvinyl alcohol-based resin, for example, a partially saponified polyvinyl alcohol-based resin having a saponification degree of 90 or less is preferred. In addition, the degree of polymerization of the polyvinyl alcohol-based resin is, for example, 2000 or less, preferably about 500. Specific commercially available products of the polyvinyl alcohol-based resin include, for example, B-05 (saponification degree: 86.5 to 89.5 mol %, polymerization degree: about 500, viscosity (4%, 20°C): 5.0 to 6.0 mPa·s), B-17 (saponification degree: 87.0 to 89.0 mol %, polymerization degree: about 1600, viscosity (4%, 20°C): 21 to 25 mPa·s), B-20 (saponification degree: 87.0 to 89.0 mol %, polymerization degree: about 2000, viscosity (4%, 20°C): 27 to 33 mPa·s) in the DENKA POVAL (registered trademark) series manufactured by DENKA (Co., Ltd.), and Kuraray Poval (registered trademark) series: 48-80 (saponification degree: 78.5 to 80.5 mol%, viscosity (4%, 20°C): 45.0 to 51.0 mPa·s), 3-88 (saponification degree: 87.0 to 89.0 mol%, viscosity (4%, 20°C): 3.2 to 3.6 mPa·s), 5-88 (saponification degree: 86.5 to 89.0 mol%, viscosity (4%, 20°C): 4.6 to 5.4 mPa·s), etc.

[0115] The softening point of the polyamide resin used for the welding layer 70 is, for example, 90° C. or higher, preferably 110° C. or higher, and more preferably 125° C. or higher. When the softening point is within this range, the high adhesive force between the base layer 48 and the first thermal transfer layer 50 can be maintained without softening at a relatively low temperature during low-temperature transfer.

[0116] The welding layer 70 can be formed, for example, by applying a coating obtained by dissolving or dispersing a material for forming the welding layer 70 in an arbitrary solvent onto the surface 53 of the base layer 48 and then drying the coating.

[0117] (4) First thermal transfer layer 50

[0118] The first thermal transfer layer 50 can be formed, for example, by any thermoplastic resin. In order to improve the affinity and adhesion to the welding layer 70 and the intermediate layer 51, the first thermal transfer layer 50 is preferably formed by using epoxy resin as the thermoplastic resin. Epoxy resin has excellent affinity and adhesion to the base layer 48 composed of a polyester film such as PET and the thermoplastic elastomer forming the intermediate layer 51. The first thermal transfer layer 50 can be formed by using epoxy resin as the thermoplastic resin in a state where the hardener is not added (removed).

[0119] As epoxy resin, for example, bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, resol novolac epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol AD ​​epoxy resin, propylene glycol ether, aliphatic epoxy resins such as pentaerythritol polyglycidyl ether, 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. can be listed. As specific examples of epoxy resin, there is no particular limitation, but for example, the following various epoxy resins can be listed. These epoxy resins can be used alone or in combination of two or more.

[0120] The basic solid types of JER (registered trademark) series epoxy resins manufactured by Mitsubishi Chemical Corporation include 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 1650), 1007 (softening point (ring and ball method): 128°C, number average molecular weight Mn: about 2900), 1009 (softening point (ring and ball method): 144°C, number average molecular weight Mn: about 3800), 1010 (number average molecular weight Mn: about 5500), 1003F (softening point (ring and ball method): 96°C), 1004F (softening point (ring and ball method): 103°C), 1005F, 1009F (softening point (ring and ball method): 144°C), 1004FS (softening point (ring and ball method): 100°C), 1006FS (softening point (ring and ball method): 112°C), 1007FS (softening point (ring and ball method): 124°C).

[0121] The softening point of the epoxy resin used for the first thermal transfer layer 50 is, for example, 95° C. or higher, preferably 110° C. or higher, and more preferably 125° C. or higher.

[0122] The first thermal transfer layer 50 may contain an adhesive in addition to the epoxy resin. By containing an adhesive, the affinity and adhesion to the welding layer 70 and 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.

[0123] In order to improve the affinity and compatibility with epoxy resin and the affinity and adhesion with the welding layer 70 and the intermediate layer 51, an acrylic adhesive is preferably used as the adhesive. Specific examples of the acrylic adhesive are not particularly limited, but the following various acrylic adhesives can be cited. These acrylic adhesives can be used alone or in combination of two or more.

[0124] 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: 40% by mass), BPS5160 (non-volatile content: 33% by mass), BPS5213K (non-volatile content: 40% by mass), BPS5156D (non-volatile content: 34 ... 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%), BPS 5565K (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%), BPS6130TF (non-volatile content: 5 volatile 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 %).

[0125] Solvent-based adhesives (re-peelable) manufactured by Lion Specialty Chemicals include 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%).

[0126] The acrylic adhesive used for the first thermal transfer layer 50 may be used together with a tackifier.

[0127] For example, this is because the chelation of the first thermal transfer layer 50 can be improved, unnecessary peeling can be suppressed, and the clarity of the recorded text can be improved. Examples of the tackifier include rosin glycerol ester, terpene phenolic resin, rosin ester, etc. Specific examples of the tackifier are not particularly limited, but examples include the following various tackifiers. These tackifiers can be used alone or in combination of two or more.

[0128] YS produced by YASUHARA CHEMICAL (Co., Ltd.) POLYSTER series of terpene phenolic resins include U130 (softening point: 130±5℃), U115 (softening point: 115±5℃), T160 (softening point: 160±5℃), T145 (softening point: 145±5℃), T130 (softening point: 130±5℃), T115 (softening point: 115±5℃), T100 (softening point: 100±5℃), T80 (softening point: 80±5℃), S145 (softening point: 145±5℃), G150 (softening point: 150±5℃), G125 (softening point: 125±5℃), N125 (softening point: 125±5℃), K125 (softening point: 125±5℃), and TH130 (softening point: 130±5℃).

[0129] ESTER GUM produced by Arakawa Chemical Industries, Ltd. includes AA-G (softening point (ring and ball method): 82-88°C), AA-L (softening point (ring and ball method): 82-88°C), AA-V (softening point (ring and ball method): 82-95°C), 105 (softening point (ring and ball method): 100-110°C), AT (viscosity: 20000-40000 mPa·s), H (softening point (ring and ball method): 68-75°C), and HP (softening point (ring and ball method): above 80°C).

[0130] GA-100 (softening point (ring and ball method): 100-110°C), AZ (softening point (ring and ball method): 950-105°C), C (softening point (ring and ball method): 117-127°C), D-125 (softening point (ring and ball method): 120-130°C), D-135 (softening point (ring and ball method): 130-140°C), D-160 (softening point (ring and ball method): 150-165°C), and KK (softening point (ring and ball method): above 165°C) of the PENSEL (registered trademark) series of rosin esters produced by Arakawa Chemical Industries, Ltd.

[0131] The softening point of the tackifier used for the first thermal transfer layer 50 is, for example, 60° C. or higher, and preferably 120° C. or lower.

[0132] The first thermal transfer layer 50 may contain any colorant. As the colorant, one or more various colorants corresponding to the color tone of the first thermal transfer layer 50 may be used. As the colorant, for example, a pigment may be used. In consideration of improving the weather resistance of the text, etc., the colorant used for the first thermal transfer layer 50 is preferably a pigment. For example, as a pigment for coloring the first thermal transfer layer 50 in black, carbon black is preferably used. There is no particular limitation as a specific example of carbon black, but the following various carbon blacks can be cited as examples. These carbon blacks can be used alone or in combination of two or more.

[0133] MA77 powder produced by Mitsubishi Chemical Co., Ltd. (LFF, DBP absorption: 68cm 3 / 100g), MA7 powder (LFF, DBP absorption: 66cm 3 / 100g), MA7 granules (LFF, DBP absorption: 65cm 3 / 100g), MA8 powder (LFF, DBP absorption: 57cm 3 / 100g), MA8 granules (LFF, DBP absorption: 51cm 3 / 100g), MA11 powder (LFF, DBP absorption: 64cm 3 / 100g), MA100 powder (LFF, DBP absorption: 100cm 3 / 100g), MA100 granules (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).

[0134] Mitsubishi Chemical Co., Ltd. produced #3030B (furnace method, DBP absorption: 130cm 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).

[0135] #5500 (furnace method, DBP absorption: 155cm 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).

[0136] L (furnace method, DBP absorption: 120cm 3 / 100g), L6 (furnace method, DBP absorption: 126cm 3 / 100g).

[0137] Birla Carbon's CONDUCTEX (registered trademark) series of 975 (furnace method, 170cm 3 / 100g)、SC(furnace method, 115cm 3 / 100g).

[0138] 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).

[0139] 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).

[0140] EC300J (vaporization method, DBP absorption: 360cm) in the KETJENBLACK (registered trademark) series produced by Lion Specialty Chemicals (Co., Ltd.) 3 / 100g), EC600DJ (vaporization method, DBP absorption: 495cm 3 / 100g).

[0141] The ratio of each component in the first thermal transfer layer 50 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.

[0142] 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.

[0143] 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.

[0144] Among the components contained in the first thermal transfer layer 50 , 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 falls within the above-mentioned range (the same applies hereinafter).

[0145] The first thermal transfer layer 50 can be formed, for example, by directly applying a coating obtained by dissolving or dispersing the above-mentioned components in an arbitrary solvent onto the fusion layer 70 and then drying the coating. Figure 5A and Figure 5BAs shown, the characters recorded on the printing tape 2 are color-coded. The first thermal transfer layer 50 is preferably formed directly on the fusion layer 70 in consideration of adjusting the adhesion between the first thermal transfer layer 50 and the fusion layer 70 and other layers for color coding.

[0146] (5) Middle layer 51

[0147] As described above, 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.

[0148] 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).

[0149] The content of styrene in the thermoplastic elastomer of 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 thermal transfer layer 50 and the second thermal transfer layer 52 cannot be maintained during low-temperature transfer, and the color of the text becomes turbid. If the styrene content is too low, the rubber elasticity of the intermediate layer 51 becomes too high, and there is a case where the second thermal transfer layer 52 cannot be peeled off during high-temperature transfer, resulting in turbidity in the color of the text.

[0150] The melt flow rate (hereinafter, may be simply described 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. MFR can be obtained, for example, by the measurement method specified in ISO 1133-1:2011, and may be MFR at a temperature of 190°C and a load of 2.16 kg. Hereinafter, unless there is a specific description of the measurement conditions of MFR, the conditions are a temperature of 190°C and a load of 2.16 kg.

[0151] Thermoplastic elastomers with an MFR exceeding 400 g / 10 min tend to have an excessively strong affinity with the second thermal transfer layer 52. Therefore, there is a case where the second thermal transfer layer 52 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 thermal transfer recording medium 47, that is, the base material layer 48, the first thermal transfer layer 50, the intermediate layer 51, and the second thermal transfer layer 52 are attached to the printing surface 31 of the printing tape 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 thermal transfer layer 50 and the second thermal transfer layer 52 cannot be maintained during low-temperature transfer, and the color of the text becomes turbid.

[0152] In contrast, if the thermoplastic elastomer has an MFR of 400 g / 10 min or less, the problems that may occur when using a thermoplastic elastomer having an MFR exceeding 400 g / 10 min can be suppressed. Furthermore, even if thermal transfer recording is performed continuously, the color tone on the printing surface 31 of the printing tape 2 is less likely to be turbid and is clearly separated into two colors, and no unnecessary peeling occurs, and text with excellent clarity can be recorded. In order to further improve 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, even within the above range.

[0153] The lower limit of MFR is not particularly limited, and even the thermoplastic elastomer with a measurement result of "No Flow" at the aforementioned temperature of 190°C and a load of 2.16 kg can be used. Specific examples of the thermoplastic elastomer are not particularly limited, but the following various thermoplastic elastomers can be listed, for example. These thermoplastic elastomers can be used alone or in combination of two or more.

[0154] 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: NoFlow), 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) in the Tuftec (registered trademark) series of SEBS produced by Asahi Kasei Co., Ltd.

[0155] Tufprene (registered trademark) series SBS produced 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).

[0156] Asaprene (registered trademark) T series SBS produced 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).

[0157] The SEPS of SEPTON (registered trademark) series produced by Kuraray (Co., Ltd.) are 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 is measured under the conditions of temperature 230°C and load 2.16 kg.

[0158] Among the SEEPS of the SEPTON (registered trademark) series produced by Kuraray (Co., Ltd.), there are 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 is measured under the conditions of a temperature of 230°C and a load of 2.16 kg.

[0159] 5125 (MFR: 4 g / 10 min) and 5127 (MFR: 5 / 10 min) of the HYBRAR (registered trademark) series of vinyl SIS produced by Kuraray (Co., Ltd.).

[0160] Ultrasen (registered trademark) series EVA produced by Tosoh Co., Ltd. includes 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). 0min), 537 (MFR: 8.5g / 10min), 537L (MFR: 8.5g / 10min), 537S-2 (MFR: 8.5g / 10min), 541 (MFR: 9.0g / 10mi n), 541L (MFR: 9.0g / 10min), 530 (MFR: 75g / 10min), 526 (MFR: 25g / 10min), 630 (MFR: 1.5g / 10min), 631 (M FR: 1.5g / 10min), 636 (MFR: 2.5g / 10min), 625 (MFR: 14g / 10min), 626 (MFR: 3.0g / 10min), 627 (MFR: 0.8g / 10min), 633 (MFR: 20g / 10min), 635 (MFR: 2.4g / 10min), 640 (MFR: 2.8g / 10min), 634 (MFR: 4.3g / 10min), 6 80 (MFR: 160g / 10min), 681 (MFR: 350g / 10min), 751 (MFR: 5.7g / 10min), 710 (MFR: 18g / 10min), 720 (MFR: 1 50g / 10min), 722 (MFR: 400g / 10min), 750 (MFR: 30g / 10min), 752 (MFR: 60g / 10min), 760 (MFR: 70g / 10min).

[0161] The intermediate layer 51 may be made of a polyolefin resin, a long-chain alkyl resin, or the like in addition to the thermoplastic elastomer.

[0162] Examples of polyolefin resins include SURFLEN (registered trademark) P-1000 manufactured by Mitsubishi Chemical Co., Ltd. Examples of long-chain alkyl resins include 1010, 1010S, 1050, 1070, and 406 of the Piloil (registered trademark) series manufactured by Lion Specialty Chemicals Co., Ltd.

[0163] 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 in an arbitrary solvent onto the first thermal transfer layer 50 and then drying the coating.

[0164] (6) Second thermal transfer layer 52

[0165] The second thermal transfer layer 52 can be formed of any thermoplastic resin, for example. Examples of the thermoplastic resin used for the second thermal transfer layer 52 include epoxy resin, polyester resin, polyolefin resin, etc. The thermoplastic resin can be appropriately selected according to the material of the printing ribbon 2, etc. When the first thermal transfer layer 50 is formed of epoxy resin, the second thermal transfer layer 52 is preferably also formed of epoxy resin.

[0166] By forming the second thermal transfer layer 52 from an epoxy resin, the adhesion force of the first thermal transfer layer 50 to the fusion layer 70 and the intermediate layer 51 and the adhesion force of the second thermal transfer layer 52 to the printing tape 2 can be counteracted. As a result, during low-temperature transfer, the first thermal transfer layer 50 and the intermediate layer 51 can be well separated to the substrate layer 48 side, and the second thermal transfer layer 52 can be well separated to the printing tape 2 side. Examples of the epoxy resin include various epoxy resins exemplified as the epoxy resin of the first thermal transfer layer 50. These epoxy resins can be used alone or in combination of two or more.

[0167] The second thermal transfer layer 52 may contain wax in addition to the thermoplastic resin. By containing wax, the first thermal transfer layer 50 and the intermediate layer 51 can be separated well to the substrate layer 48 side, and the second thermal transfer layer 52 can be separated well to the printing tape 2 side during low-temperature transfer.

[0168] 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 the wax include, but are not particularly limited to, carnauba wax No. 1 flake, No. 2 flake, No. 3 flake, No. 1 powder, and No. 2 powder (all of which have a melting point of 80 to 86° C.) produced 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.) produced by Nippon Seiwa Co., Ltd., microcrystalline waxes such as EMUSTAR-0001 (melting point: 84° C.) and EMUSTAR-042X (melting point: 84° C.) produced by Nippon Seiwa Co., Ltd., and Fischer-Tropsch waxes such as FNP-0090 (condensation point: 90° C.), SX80 (condensation point: 83° C.), FT-0165 (melting point: 73° C.), and FT-0070 (melting point: 72° C.) produced by Nippon Seiwa Co., Ltd. These waxes may be used alone or in combination of two or more.

[0169] The second thermal transfer layer 52 may contain any colorant. As the colorant, one or more kinds of colorants corresponding to the color tone of the second thermal transfer layer 52 may be used. As the colorant, for example, a pigment may be used. Considering the improvement of the weather resistance of the text, etc., the colorant used for the second thermal transfer layer 52 is preferably a pigment. For example, as a pigment for coloring the second thermal transfer layer 52 in red, the following various red pigments may be listed. These red pigments may be used alone or in combination of two or more.

[0170] 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.

[0171] The ratio of each component in the second thermal transfer layer 52 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.

[0172] The ratio of the colorant such as red pigment to 100 parts by mass of the epoxy resin is, for example, 70 parts by mass or more, preferably 80 parts by mass or more, and the ratio of the colorant such as red pigment 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.

[0173] The ratio of the coloring agent such as red pigment 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, and preferably 80 parts by mass or more and 120 parts by mass or less.

[0174] The second thermal transfer layer 52 is formed, for example, by applying a coating obtained by dissolving or dispersing the above-mentioned components in an arbitrary solvent onto the intermediate layer 51 and then drying the coating.

[0175] In the thermal transfer recording medium 47, for example, there is a Figure 1 and Figure 3 ) is set to a lower energy and thermal transfer is performed at a relatively low temperature. In this case, in this embodiment, the second thermal transfer layer 52 softens and the adhesion relative to the substrate layer 48 is reduced. On the other hand, the adhesion between the first thermal transfer layer 50 and the second thermal transfer layer 52 is reduced. At this time, the welding layer 70 hardly softens due to its high softening point, thereby maintaining a high adhesion between the substrate layer 48 and the first thermal transfer layer 50. As a result, during thermal transfer, reverse transfer occurs in which the first thermal transfer layer 50 and the intermediate layer 51 remain on the substrate layer 48 side, and only the second thermal transfer layer 52 is thermally transferred to the printing surface 31 of the printing tape 2. Therefore, the text recorded on the printing surface 31 of the printing tape 2 becomes the color tone of the second thermal transfer layer 52, for example, red.

[0176] On the other hand, the thermal transfer recording medium 47 may be thermally transferred at a higher temperature by setting the energy applied to the thermal head 6 higher. In this case, the fusion layer 70 further softens, and the adhesion between the fusion layer 70 and the base layer 48 is greatly reduced. As a result, the entire thermal transfer layer, that is, the fusion layer 70, the first thermal transfer layer 50, the intermediate layer 51, and the second thermal transfer layer 52 are thermally transferred to the printing surface 31 of the printing tape 2 as a whole. The text recorded on the printing surface 31 of the printing tape 2 becomes the color tone of the first thermal transfer layer 50 located on the outermost layer after transfer, for example, black.

[0177] As a result, it is possible to record a pattern of two colors, for example, black and red, using a general-purpose thermal transfer printer that supports two-color recording.

[0178] Therefore, according to the present invention, a general-purpose thermal transfer printer that supports two-color recording can be used. Even if thermal transfer recording is performed continuously, the color tone is unlikely to be turbid and is clearly separated into two colors. There is no unnecessary peeling, and text with excellent clarity can be recorded.

[0179] [Thickness of Each Layer of Thermal Transfer Recording Medium 47]

[0180] One of the characteristics of the thermal transfer recording medium 47 according to one embodiment of the present invention is that the total thickness of the transferred material separated from the base layer 48 by thermal transfer during low temperature heating is thinner than the first thermal transfer layer 50. Figure 1 to Figure 4A , and the heating process and cooling process shown in B are described in detail, and the characteristics of the thickness of the thermal transfer recording medium 47 are mentioned.

[0181] Fig.14 Yes means Figure 1 to Figure 4A , B is a diagram showing the relationship between the elapsed time in the heating step and the cooling step and the reaching temperature of the thermal transfer recording medium 47.

[0182] Fig.14 The horizontal axis of represents the elapsed time of the printing process of the printing device 1. t0 represents the start time of printing, t1 represents the end time of heating by the thermal head 6, and t2 represents the time when the ink ribbon peeling member 13 is reached. Fig.14 The vertical axis represents the arrival temperature of the thermal transfer recording medium 47. The arrival temperature of the thermal transfer recording medium 47 can be defined as the temperature of the thermal transfer recording medium 47 that changes due to external factors. The external factors may include, for example, heating by the thermal head 6, natural cooling of the thermal transfer recording medium 47 during transportation, and the like.

[0183] Reference Fig.14 In the printing device 1, the temperature output (temperature energy) of the thermal head 6 is controlled by the control circuit 22, so that the reaching temperature of the thermal transfer recording medium 47 can be controlled. For example, a relatively low first energy is applied to the thermal head 6 in the heating process. In this case, the temperature of the thermal transfer recording medium 47 is as shown by the first temperature curve 55 of the single-point dashed line, from the ambient temperature (for example, room temperature) T of the thermal transfer recording medium 47 to the temperature T of the thermal transfer recording medium 47. E It increases exponentially and reaches T R1 .

[0184] Reach temperature T R1 It can be defined as a temperature above the first temperature T1 and below the second temperature T2.

[0185] For example, the first temperature T1 is 60° C. to 120° C., preferably 70° C. to 90° C. For example, the second temperature T2 is 80° C. to 180° C., preferably 130° C. to 150° C. The reaching temperature TR1 The temperature can be set appropriately according to the output setting method of the thermal head 6 of the printing device 1 used. For example, the reaching temperature can be set in association with quantitative parameters such as the voltage, current, and power-on time supplied to the heating element 20 of the thermal head 6. In addition, the reaching temperature can be set in association with a relative value relative to a predetermined reference value (for example, the value before power-on is set to 0 (zero)).

[0186] On the other hand, in the heating process, a second energy relatively higher than the first energy is applied to the thermal head 6. In this case, the temperature of the thermal transfer recording medium 47 increases from the ambient temperature T to the ambient temperature T as shown by the second temperature curve 56 of the solid line. E And it increases exponentially to reach T R2 . Reach temperature T R2 It can also be defined as a temperature exceeding the second temperature T2.

[0187] After the heating process, the thermal transfer recording medium 47 is naturally cooled in the section until it reaches the ink ribbon peeling member 13 (see also Figure 3 and Figure 4A , B) In the cooling process, the temperature of the thermal transfer recording medium 47 is reduced from the reaching temperature T R1 and T R2 It decreases exponentially and reaches T P The reaching temperature at this time is T P It is the temperature at which a portion of the thermal transfer recording medium 47 is peeled off by the ribbon peeling member 13, and thus can be defined as the peeling temperature T P . Peeling temperature T P Preferably, the third temperature T3 is lower than the first temperature T1 (i.e., the first temperature T1 is higher than the third temperature T3), for example, 40°C to 90°C, preferably 60°C to 80°C. The first temperature T1, the second temperature T2, and the third temperature T3 can be appropriately set within the temperature range required for transferring the printing tape 2 in consideration of the chemical composition and physical properties of the ink of the thermal transfer recording medium 47.

[0188] The temperature curve (cooling curve) of the thermal transfer recording medium 47 in the cooling process eventually converges to a fixed temperature regardless of which heating control is performed in the heating process, as shown in the first temperature curve 55 or the second temperature curve 56. Therefore, in order to ensure a longer cooling process time (t1→t2), the peeling temperature T of the first temperature curve 55 or the second temperature curve 56 can be set to P In order to extend the cooling process time, for example, the distance between the thermal head 6 and the ink ribbon stripping component 13 can be extended ( Figure 1 For example, the peeling distance L1 can be Fig.14The state of the thermal transfer recording medium 47 after the heating process and the cooling process are performed according to the temperature change shown by the first temperature curve 55 is defined as the first state C1. Fig.14 The state of the thermal transfer recording medium 47 after the heating process and the cooling process are performed according to the temperature change shown by the second temperature curve 56 is defined as a second state C2.

[0189] In this way, in the printing device 1, by controlling the temperature output (temperature energy) of the thermal head 6, the starting temperature (ambient temperature T E ) and final temperature (peeling temperature T P ) is fixed, and the reaching temperature of the thermal transfer recording medium 47 is changed in various ways. Considering this temperature control, for example, by Fig.13 The temperature output of the thermal head 6 is controlled by adjusting the physical properties of the base layer 48, the back layer 49, the welding layer 70, the first thermal transfer layer 50, the intermediate layer 51 and the second thermal transfer layer 52 of the thermal transfer recording medium 47, thereby controlling the adhesion between the layers of the thermal transfer recording medium 47.

[0190] Furthermore, the thermal transfer recording medium 47 has the following condition: the total thickness of all layers that are broken and separated from the base material layer 48 side in the first state C1 (the total thickness of the transfer material) is thinner than the first thermal transfer layer 50. In this embodiment, the above condition can be satisfied by adjusting the thickness of each layer of the fusion layer 70, the first thermal transfer layer 50, the intermediate layer 51, and the second thermal transfer layer 52.

[0191] The thicknesses of the fusion layer 70 , the first thermal transfer layer 50 , the intermediate layer 51 , and the second thermal transfer layer 52 can be confirmed based on, for example, a SEM (Scanning Electron Microscope) image or a TEM (Transmission Electron Microscope) image of the thermal transfer recording medium 47 .

[0192] The thickness of the welding layer 70 can be adjusted by, for example, the coating amount of the welding layer 70. For example, the coating amount of the welding layer 70 is 0.1 g / m 2 Above, preferably 0.2 g / m 2 For example, the coating amount of the welding layer 70 is expressed as 1.5 g / m 2 Below, preferably 1.0g / m 2 the following.

[0193] For example, the coating amount of the welding layer 70 is 0.1 g / m 2 Above and 1.5g / m 2 Below, preferably 0.2g / m 2 Above and 1.0g / m 2 the following.

[0194] The specific thickness (before printing) of the welding layer 70 may be, for example, 0.05 μm or more and 1.5 μm or less, and preferably 0.2 μm or more and 1.0 μm or less.

[0195] The thickness of the first thermal transfer layer 50 can be adjusted, for example, by the coating amount of the first thermal transfer layer 50. For example, the coating amount of the first thermal transfer layer 50 is 0.1 g / m 2 Above, preferably 0.5g / m 2 For example, the coating amount of the first thermal transfer layer 50 is 3.0 g / m 2 Below, preferably 2.5g / m 2 For example, the coating amount of the first thermal transfer layer 50 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 specific thickness (before printing) of the first thermal transfer layer 50 may be, for example, 0.05 μm or more and 3.0 μm or less, and preferably 0.5 μm or more and 2.5 μm or less.

[0196] The thickness of the intermediate layer 51 can be adjusted, for example, by the coating amount of the intermediate layer 51. For example, the coating amount of the intermediate layer 51 is 0.1 g / m 2 Above, preferably 0.2 g / m 2 For example, the coating amount of the intermediate layer 51 is expressed as 2.0 g / m 2 Below, preferably 1.5g / m 2 the following.

[0197] For example, the coating amount of the intermediate layer 51 is 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.

[0198] The specific thickness (before printing) of the intermediate layer 51 is, for example, 0.05 μm or more and 2.0 μm or less, and may also be preferably 0.2 μm or more and 1.5 μm or less. The intermediate layer 51 is preferably thinner than the first thermal transfer layer 50 and the second thermal transfer layer 52. This is because if the intermediate layer 51 containing no coloring agent such as a pigment is too thick, the film breaking property may be deteriorated, and the clarity of the recorded pattern may be reduced.

[0199] The thickness of the second thermal transfer layer 52 can be adjusted, for example, by the coating amount of the second thermal transfer layer 52. For example, the coating amount of the second thermal transfer layer 52 is 0.2 g / m 2 Above, preferably 1.0 g / m 2 For example, the coating amount of the second thermal transfer layer 52 is 7.0 g / m 2 Below, preferably 5.0g / m 2 For example, the coating amount of the second thermal transfer layer 52 is expressed as 0.2 g / m 2 Above and 7.0g / m 2 Below, preferably 1.0g / m 2 Above and 5.0g / m 2 The specific thickness (before printing) of the second thermal transfer layer 52 is, for example, 0.05 μm or more and 7.0 μm or less, and may preferably be 1.0 μm or more and 5.0 μm or less.

[0200] In addition, the total thickness of the transfer is preferably less than 13.5 μm. This is because, if the total thickness of the transfer exceeds 10 μm, the heating temperature of the thermal head 6 needs to be set high, which may damage the life of the thermal head 6. In addition, when the thickness of the first thermal transfer layer 50 (in this embodiment, black) is extremely different from the thickness of the second thermal transfer layer 52 (in this embodiment, red) (for example, a thickness difference of more than four times), even if black printing is performed, the influence of red is also great, and there is a possibility that black will deteriorate. Therefore, it is necessary to adjust the thickness of the first thermal transfer layer 50 and the second thermal transfer layer 52 and the selection of the colorant within the range of an appropriate coating amount.

[0201] [Peeling Mode of Thermal Transfer Recording Medium 47]

[0202] Figure 15 to Figure 19 2 is a diagram showing a peeled state of the thermal transfer recording medium 47. Figure 15 to Figure 19 , a plurality of peeling modes are listed for the thermal transfer recording medium 47. Figure 15 to Figure 19 The peeling modes are referred to as the first peeling mode to the fifth peeling mode. From the viewpoint of the energy supplied to the thermal head 6, the following can be distinguished: Figure 15 to Figure 18The low energy peeling mode and Fig.19 High energy peeling mode shown.

[0203] Figure 15 to Figure 18 is through Fig.14 The peeling mode is when peeling (thermal transfer) is performed in the first state C1 by heating control (applying low energy) of the first temperature curve 55. Fig.15 In the first peeling mode, the breaking strength between the intermediate layer 51 and the second thermal transfer layer 52 in the first state C1 is the smallest in the thermal transfer recording medium 47, and peeling occurs at these interfaces. Fig.16 In the second peeling mode, the breaking strength in the second thermal transfer layer 52 in the first state C1 becomes the minimum in the thermal transfer recording medium 47, and peeling occurs inside the second thermal transfer layer 52. Fig.17 In the third peeling mode, the breaking strength in the intermediate layer 51 in the first state C1 becomes the minimum in the thermal transfer recording medium 47, and peeling occurs inside the intermediate layer 51. Fig.18 In the fourth peeling mode, in the first state C1, the layer in contact with the second thermal transfer layer 52 is a mixed layer 61 formed by melting and mixing the components of the first thermal transfer layer 50 and the intermediate layer 51. In addition, the breaking strength between the mixed layer 61 and the second thermal transfer layer 52 is the smallest in the thermal transfer recording medium 47, and peeling occurs at their interface.

[0204] Fig.15 The first peeling mode and Fig.18 The fourth peeling mode is interface failure, Fig.16 The second peeling mode and Fig.17 The third peeling mode is cohesion failure. Figure 15 to Figure 18 In any of the peeling modes, the second thermal transfer layer 52 is transferred to the printing tape 2 .

[0205] Fig.19 is through Fig.14 The peeling mode is when peeling (thermal transfer) is performed in the second state C2 by heating control (application of high energy) according to the second temperature curve 56.

[0206] exist Fig.19 In the fifth peeling mode, in the second state C2, the breaking strength between the base material layer 48 and the fusion layer 70 is the smallest in the thermal transfer recording medium 47, and peeling (interfacial failure) occurs at their interface.

[0207] according to Fig.19 In the peeling mode, the first thermal transfer layer 50 and the second thermal transfer layer 52 in a bonded state are selectively transferred to the printing tape 2 .

[0208] The thermal transfer recording medium 47 is Figure 15 to Figure 19Which peeling mode is broken can be confirmed, for example, by observing the cross section of the thermal transfer recording medium 47 after breaking. For example, it can be confirmed based on a SEM (Scanning Electron Microscope) image or a TEM (Transmission Electron Microscope) image of the thermal transfer recording medium 47 after breaking.

[0209] As described above, in the first to fourth peeling modes, the text recorded on the printing surface 31 of the printing tape 2 becomes the color tone of the second thermal transfer layer 52, such as red. In the fifth peeling mode, the text recorded on the printing surface 31 of the printing tape 2 becomes the color tone of the first thermal transfer layer 50, such as black.

[0210] Example

[0211] Hereinafter, the present invention will be further described based on experimental examples, but the structure of the present invention is not limited to these examples.

[0212] [Coating material for the first thermal transfer layer]

[0213] 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 first thermal transfer layer coating having a solid content concentration of 22.5 mass %.

[0214] The ratio of the active ingredient in the acrylic adhesive was 80 parts by mass per 100 parts by mass of the epoxy resin.

[0215] [Table 1]

[0216] Element Mass Epoxy resin 100 Acrylic adhesive 200 Tackifier 28.3 Carbon Black 166.7

[0217] The components in the table are as follows.

[0218] Epoxy resin: JER1007 manufactured by Mitsubishi Chemical Corporation (basic solid type, softening point (ring and ball method): 128°C, number average molecular weight Mn: about 2900)

[0219] Acrylic adhesive: AS-665 manufactured by Lion Specialty Chemicals (Inc.) (solid content concentration: 40% by mass)

[0220] Tackifier: terpene phenolic resin, YS POLYSTER T80 produced by YASUHARA CHEMICAL (Co., Ltd.) (softening point: 80±5℃)

[0221] Carbon black: MA100 powder produced by Mitsubishi Chemical Co., Ltd. (LFF, DBP absorption: 100cm 3 / 100g)

[0222] [Paint for welding layer]

[0223] A polyamide resin (Tohmide 1315 manufactured by T&K TOKA Co., Ltd., softening point: 130±5° C.) was dissolved in a mixed solvent of toluene and methyl ethyl ketone (MEK) in a mass ratio of 1 / 1 to prepare a welding layer coating having a solid content concentration of 10% by mass.

[0224] [Coating for intermediate layer (1)]

[0225] A thermoplastic elastomer (Tuftec H1521, SEBS, MFR: 12.3 g / 10 min, styrene content 18% by mass, manufactured by Asahi Kasei Corporation) 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.

[0226] [Coating for intermediate layer (2)]

[0227] The intermediate layer coating (2) was prepared in the same manner as the intermediate layer coating (1) except that the same amount of modified polyolefin resin (SURFLEN (registered trademark) P-1000 manufactured by Mitsubishi Chemical Corporation) was added instead of the thermoplastic elastomer. The solid content concentration was 10% by mass.

[0228] [Coating for the second thermal transfer layer]

[0229] The components shown in Table 2 below were dissolved in a mixed solvent of toluene and MEK in a mass ratio of 1 / 4 to prepare a coating material for a second thermal transfer layer having a solid content concentration of 28% by mass.

[0230] [Table 2]

[0231] Element Mass Epoxy resin 100 wax 7.1 Red Pigment 92.9

[0232] The components in the table are as follows.

[0233] Epoxy resin: JER1004 manufactured by Mitsubishi Chemical Corporation (basic solid type, softening point (ring and ball method): 97°C, number average molecular weight Mn: about 1650)

[0234] Wax: Carnauba wax No. 2 powder produced by Toyo Komei Co., Ltd. (melting point: 80-86°C)

[0235] Red pigment: CI Pigment Red 53:1 (SYMULER (registered trademark) LakeRed C-102 produced by DIC Corporation)

[0236] [Experimental Examples 1 to 6]

[0237] (1) Production of thermal transfer recording media

[0238] First, a PET film with a thickness of 4.5 μm was prepared as a substrate layer. Next, a film with a solid content of 0.1 g / m2 per unit area made of a silicone resin was formed on the side (back side) opposite to the surface on which the thermal transfer layer was formed. 2 The back layer of the substrate layer. Next, the solid content per unit area of ​​the previously prepared coating for the fusion layer was adjusted so that it had a thickness shown in Table 3 below, and after being applied to the surface of the substrate layer, it was dried to form a fusion layer. Next, the solid content per unit area of ​​the previously prepared coating for the first thermal transfer layer was adjusted so that it had a thickness shown in Table 3 below, and after being applied to the fusion layer, it was dried to form a first thermal transfer layer. Next, the solid content per unit area of ​​any of the previously prepared coatings for the intermediate layer was adjusted so that it had a thickness shown in Table 3 below, and after being applied to the first thermal transfer layer, it was dried to form an intermediate layer. Next, the solid content per unit area of ​​the previously prepared coating for the second thermal transfer layer was adjusted so that it had a thickness shown in Table 3 below, and after being applied to the intermediate layer, it was dried to form a second thermal transfer layer, and a thermal transfer recording medium was manufactured. The composition of each layer of the thermal transfer recording medium obtained in Experimental Examples 1 to 6 is shown in Table 3 below.

[0239] (2) Evaluation

[0240] (2-1) Evaluation of edge printing properties

[0241] The thermal transfer recording medium produced in each experimental example was cut into a ribbon of a predetermined width, wound into a roll, and set in a thermal transfer printer (a prototype printer manufactured by Brother Industries, Ltd.). The main specifications of the thermal transfer printer are as follows.

[0242]

[0243] Next, in an environment with an outdoor temperature of 25°C, the energy value pre-set in the thermal transfer printer and applied to the thermal head was set to a low energy (0.25mJ / dot: 25V (0.34W / dot) / 750μsec, red), and a prescribed printing pattern was recorded on the surface of a variable information printing label material (polyester film (white·glossy), FR1415-50 produced by LINTEC Co., Ltd.). The printed pattern is a pattern in which a plurality of 5dot×5dot squares are arranged in a water ball shape with intervals. Then, one of the water balls of the printed pattern is magnified and observed under a microscope. The area ratio (black / (red+black)) of the image printed in red and the image printed in black (periphery) in the water ball is calculated, and the printability of the edge pattern is evaluated based on the following criteria.

[0244] ○: Area ratio is less than 10%.

[0245] △: The area ratio is 10% or more and less than 20%.

[0246] ×: The area ratio is 20% or more.

[0247] (2-2) Evaluation of recording clarity

[0248] The thermal transfer recording medium manufactured in each experimental example was cut into an ink ribbon of a specified width, wound into a roll, and set in a thermal transfer printer (a prototype printer produced by Brother Industries, Ltd.) of the same specification as (2-1). After bonding, the energy value pre-set in the thermal transfer printer and applied to the thermal head was set to low energy (0.25mJ / dot: 25V (0.34W / dot) / 750μsec, red) or high energy (0.34mJ / dot: 25V (0.34W / dot) / 1000μsec, black) in an environment with an outside temperature of 25°C, and a bar code was recorded on the surface of a variable information printing label material (polyester film (white glossy), FR1415-50 produced by LINTEC Co., Ltd.). The recorded barcodes were read using a barcode verifier (Laser Sampling Elite IS manufactured by MUNAZO Co., Ltd.) to determine the decodability level specified in the American National Standards Institute standard (ANSI X3.182-1990), and the clarity of the recording was evaluated using the following criteria.

[0249] 0: The decodability level of both black and red is A [excellent] or B [good].

[0250] △: The decodability level of either black or red is C [good], and the other is C [good] or higher.

[0251] ×: The decodability level of at least one of black and red is D [pass] or F [fail].

[0252] The results are shown in Tables 3 to 4. In Experimental Examples 1 to 6, Experimental Examples 1 to 4 may be Examples, and Experimental Examples 5 to 6 may be Comparative Examples.

[0253] (2-3) Observation of fracture position

[0254] The thermal transfer recording medium manufactured in each experimental example was cut into a ribbon of a specified width, wound into a roll, and set in a thermal transfer printer (a prototype printer produced by Brother Industries, Ltd.) of the same specification as (2-1). The energy value pre-set in the thermal transfer printer to be applied to the thermal head was set to low energy (0.25mJ / dot: 25V (0.34W / dot) / 750μsec, red) or high energy (0.34mJ / dot: 25V (0.34W / dot) / 1000μsec, black) in an environment with an outside temperature of 25°C, and a solid image of 70 mm square was recorded on the surface of a variable information printing label material (polyester film (white glossy), FR1415-50 produced by LINTEC Co., Ltd.). In any case, the peeling distance of the thermal transfer printer was ensured to be 110 mm, so the peeling process was performed after sufficient cooling (below 60°C). The cross section of the obtained solid image was observed using a transmission electron microscope (TEM: HT7820 manufactured by Hitachi High-Tech Co., Ltd., accelerating voltage 100 kV). In each of the black transfer and the red transfer, it was confirmed where the thermal transfer recording medium broke. The break position was distinguished by the peeling mode as described below.

[0255] First peeling mode: between the middle layer and the second thermal transfer layer (interface damage reference Fig.15 )

[0256] Second peeling mode: Inside the second thermal transfer layer (cohesion failure reference Fig.16 )

[0257] The third peeling mode: inside the middle layer (cohesion failure reference Fig.17 )

[0258] Fourth peeling mode: between the mixed layer and the second thermal transfer layer (interface damage reference Fig.18 )

[0259] Fifth peeling mode: between the substrate layer and the weld layer (interface damage reference Fig.19 )

[0260] The results are shown in Tables 3 and 4. In Tables 3 and 4, only the circled numbers represent the first to fifth peeling modes, respectively. In addition, in Tables 3 and 4, when multiple peeling modes are shown, it means that different peeling modes are generated in the in-plane direction of the thermal transfer recording medium. In addition, since Experimental Example 2 has a layer structure without an intermediate layer, the peeling mode of Experimental Example 2 strictly speaking generates Fig.16 , Fig.18 and Fig.19 A peeling mode in which the intermediate layer 51 is omitted.

[0261] [Table 3]

[0262]

[0263] [Table 4]

[0264]

[0265]

[0266] Comparison between Experimental Example 1 and Experimental Examples 5 and 6 shows that fringing printability can be improved by making the second thermal transfer layer thinner than the first thermal transfer layer. In Experimental Examples 5 and 6, the thickness of the second thermal transfer layer is greater than that of the first thermal transfer layer, and as a result, it is believed that fringing is more likely to occur.

[0267] In Experimental Example 2, without the intermediate layer, the first thermal transfer layer and the second thermal transfer layer were in contact and adjacent to each other, so fringing was more likely to occur than in Experimental Example 1. In addition, the first thermal transfer layer was difficult to separate from the second thermal transfer layer, resulting in poor clarity.

[0268] Regarding Experimental Example 3, when the intermediate layer was formed relatively thick, the edge printing property was good. On the other hand, the chelating property of the intermediate layer was poor, resulting in poor clarity due to excess peeling and the like.

[0269] Regarding Experimental Example 4, if the intermediate layer is a cohesion-destructible material such as polyolefin, the peeling position under low-temperature printing is inside the intermediate layer, and the transferred material becomes part of the second thermal transfer layer and the intermediate layer.

[0270] Even in this case, it is known that the edge printability can be improved as long as the total thickness of the transfer is thinner than the first thermal transfer layer before transfer. However, since the intermediate layer causes cohesive failure, the clarity is inferior to the case of using a thermoplastic elastomer (SEBS) for the intermediate layer.

[0271] Explanation of symbols

[0272] 1: Printing device

[0273] 2: Printing tape

[0274] 3: Ink ribbon

[0275] 20: Heating element

[0276] 31: Printing surface

[0277] 32: Back

[0278] 33: Bonding surface

[0279] 34: Back

[0280] 35: Base material layer

[0281] 36: First ink layer

[0282] 37: Second ink layer

[0283] 38: Surface

[0284] 39: Back

[0285] 40: Part I

[0286] 41: Part 2

[0287] 42: Part 1

[0288] 43: Part 2

[0289] 44: Printing pattern

[0290] 45: Red pattern

[0291] 46: Black pattern

[0292] 47: Thermal transfer recording medium

[0293] 48: Base material layer

[0294] 49: Back layer

[0295] 50: First thermal transfer layer

[0296] 51: Middle layer

[0297] 52: Second thermal transfer layer

[0298] 53: Surface

[0299] 54: Back

[0300] 80: Edge pattern

[0301] 87: First Boundary

[0302] 88: Second Boundary

[0303] 89: The third boundary

[0304] 96: First temperature distribution curve

[0305] 97: Second temperature distribution curve

[0306] 98: High temperature side boundary condition

[0307] 99: Low temperature side boundary condition

[0308] 100: Center

[0309] 101: Peripheral

[0310] C1: First state

[0311] C2: Second state

[0312] F1: External force

[0313] T1: First temperature

[0314] T2: Second temperature

[0315] T3: Third temperature

[0316] T R1 : Arrival temperature

[0317] T R2 : Arrival temperature

[0318] T b : Arrival temperature

[0319] T0: Ambient temperature

[0320] Th: reaching temperature

[0321] T1: Temperature rise value

[0322] Tl: arrival temperature.

Claims

1. A thermal transfer recording medium, comprising a substrate layer, a first ink layer containing a first ink, and a second ink layer containing a second ink stacked in sequence, wherein at least a portion of the first ink layer and the second ink layer is thermally transferred to a printed medium, characterized in that: In a first state where the thermal transfer recording medium is heated to a temperature not less than a first temperature and not more than a second temperature and then cooled to a temperature not more than a third temperature, when an external force is applied to the substrate layer and the second ink layer in a direction away from each other, the first ink layer and the second ink layer are broken or in the second ink layer, In a second state where the thermal transfer recording medium is heated to a temperature exceeding the second temperature and then cooled to a temperature below the third temperature, when the external force is applied, the first ink layer is broken between the first ink layer and the base material layer or within the first ink layer, In the first state, the total thickness before thermal transfer of all the layers that are broken and separated from the base material layer side is thinner than the first ink layer.

2. The thermal transfer recording medium according to claim 1, characterized in that: When the external force is applied in the first state, the breaking strength between the first ink layer and the second ink layer or within the second ink layer is the smallest in the thermal transfer recording medium. When the external force is applied in the second state, the breaking strength between the first ink layer and the base layer or within the first ink layer is the smallest in the thermal transfer recording medium.

3. The thermal transfer recording medium according to claim 1 or 2, characterized in that: The thermal transfer recording medium includes an intermediate layer between the first ink layer and the second ink layer.

4. The thermal transfer recording medium according to claim 3, characterized in that: When the external force is applied in the first state, the intermediate layer and the second ink layer are broken.

5. The thermal transfer recording medium according to claim 4, characterized in that: When the external force is applied in the first state, the breaking strength between the intermediate layer and the second ink layer is minimum in the thermal transfer recording medium.

6. The thermal transfer recording medium according to claim 3, characterized in that: When the external force is applied in the first state, the intermediate layer is internally broken.

7. The thermal transfer recording medium according to claim 6, characterized in that: When the external force is applied in the first state, the breaking strength of the intermediate layer is the smallest in the thermal transfer recording medium.

8. The thermal transfer recording medium according to claim 1 or 2, characterized in that: The thermal transfer recording medium has a fusion layer between the base material layer and the first ink layer. When the external force is applied in the second state, the welding layer and the base material layer are broken.

9. The thermal transfer recording medium according to claim 8, characterized in that: When the external force is applied in the second state, the breaking strength between the fusion layer and the base layer is the smallest in the thermal transfer recording medium.

10. The thermal transfer recording medium according to claim 1 or 2, characterized in that: The first temperature is equal to or higher than the third temperature.

11. The thermal transfer recording medium according to claim 1 or 2, characterized in that: The first state is a state in which the base material layer of the thermal transfer recording medium is heated to a temperature not lower than the first temperature and not higher than the second temperature and then cooled to a temperature not higher than the third temperature. The second state is a state in which the base material layer of the thermal transfer recording medium is heated to a temperature exceeding the second temperature and then cooled to a temperature not higher than the third temperature.

12. A printing device, performing: A heating step of heating the thermal transfer recording medium while the thermal transfer recording medium is in contact with a medium to be printed, the thermal transfer recording medium being formed by sequentially stacking a substrate layer, a first ink layer containing a first ink, and a second ink layer containing a second ink; a cooling step of cooling the thermal transfer recording medium heated by the heating step; and The transfer step applies an external force to the base material layer and the second ink layer of the thermal transfer recording medium cooled by the cooling step in a direction away from each other, thereby transferring at least a part of the first ink and the second ink to the printed medium, characterized in that: In the heating step and the cooling step, The first portion of the thermal transfer recording medium is heated to a temperature that is higher than a first temperature and lower than a second temperature and then cooled to a third temperature or lower as a first state, and the second portion of the thermal transfer recording medium is heated to a temperature that is higher than the second temperature and then cooled to a temperature or lower than the third temperature as a second state, In the transfer process, By applying the external force, the thermal transfer recording medium is broken between the first ink layer and the second ink layer or in the second ink layer at the first portion of the thermal transfer recording medium, and the second ink is transferred to the printed medium, and the total thickness of all the transferred layers before thermal transfer is thinner than the first ink layer. By applying the external force, the thermal transfer recording medium is broken between the first ink layer and the base material layer or in the first ink layer at the second portion of the thermal transfer recording medium, and the first ink and the second ink are transferred to the printed medium.

13. A box, characterized in that Built-in: The thermal transfer recording medium according to claim 1 or 2; and A printed medium to which a portion of the thermal transfer recording medium is thermally transferred.

Images