Thermal transfer recording medium and printing apparatus

Abstract

Provided is a thermal transfer recording medium, in which the generation of a fringe of one color at the time of transfer of the other color can be suppressed in a thermal transfer recording medium capable of recording text in two colors. A thermal transfer recording medium (47) includes a base material layer (48) having a 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) which are stacked in this order in direct contact with each other on the surface (53) of the base material layer (48). The sum of the thicknesses of all the layers that are broken and depart from the base material layer (48) side before thermal transfer when 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 in a first state (for example, at the time of low-temperature heating) is thinner than the first thermal transfer layer (50).

Description

Technical Field

[0001] This invention relates to a heat transfer recording medium capable of recording text of different colors and a printing apparatus for transferring the heat transfer recording medium to a text medium. Background Technology

[0002] For example, Patent Documents 1 and 2 disclose thermal transfer recording media capable of recording text of different colors (e.g., black and red). This thermal transfer recording medium is installed in a dedicated printing apparatus. By adjusting the energy applied to the thermal head of the printing apparatus, text of different colors can be transferred to the printing medium.

[0003] Existing technical documents

[0004] Patent documents

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

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

[0007] Patent Document 3: Japanese Patent Application Publication No. 63-214481 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] One embodiment of the present invention provides a thermal transfer recording medium that, in a thermal transfer recording medium capable of recording two-color text, can suppress the generation of edge patterns of the other color during the transfer of one color.

[0010] Technical means for solving technical problems

[0011] An embodiment of the present invention relates to 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, which are sequentially stacked. At least a portion of the first ink layer and the second ink layer are thermally transferred to the printing medium. In a first state, after 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 breaks between the two ink layers or within the second ink layer. In a second state, after 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 breaks between the two ink layers or within the first ink layer. The total thickness of all layers that break and leave the substrate layer side in the first state before thermal transfer is thinner than the first ink layer.

[0012] The effects of the invention

[0013] According to one embodiment of the present invention, a thermal transfer recording medium is capable of suppressing the generation of freckles of the other color when transferring one color of a two-color text. Attached Figure Description

[0014] Figure 1 This is a schematic diagram illustrating the structure of a printing apparatus according to one embodiment of the present invention.

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

[0016] Figure 3 This is a schematic diagram illustrating the heating and cooling processes of the printing apparatus.

[0017] Figure 4A and Figure 4B This is a schematic diagram illustrating the cooling process and the transfer process of the printing apparatus.

[0018] Figure 5A and Figure 5B This is a diagram illustrating an example of a printed pattern based on the printing apparatus.

[0019] Figure 6 It is a diagram representing the pattern of the edge texture produced during heat transfer.

[0020] Figure 7 It means Figure 3 A diagram of the circuit pattern of the heating element of the thermistor.

[0021] Figure 8 It is used for explanation Figure 7 A diagram showing the temperature distribution of the heating element.

[0022] Figure 9 This diagram illustrates how heat is transferred from the thermal head to the thermal transfer recording medium.

[0023] Figure 10 This is a graph showing the relationship between the heating temperature reached and the adhesive force at the multiple layer boundaries of the thermal transfer recording medium.

[0024] Figure 11 This is a diagram used to illustrate the principle behind the generation of the edge pattern.

[0025] Figure 12 This is a diagram used to illustrate the solution to the aforementioned edge pattern.

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

[0027] Figure 14 It is a graph showing the relationship between the elapsed time in the heating and cooling processes and the temperature reached by the heat transfer recording medium.

[0028] Figure 15 This is a diagram showing the peeling state of the thermal transfer recording medium.

[0029] Figure 16 This is a diagram showing the peeling state of the thermal transfer recording medium.

[0030] Figure 17 This is a diagram showing the peeling state of the thermal transfer recording medium.

[0031] Figure 18 This is a diagram showing the peeling state of the thermal transfer recording medium.

[0032] Figure 19 This is a diagram showing the peeling state of the thermal transfer recording medium. Detailed Implementation

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

[0034] [Overall structure of printing apparatus 1]

[0035] Figure 1 This is a schematic diagram illustrating the structure of a printing apparatus 1 according to one embodiment of the present invention.

[0036] Reference Figure 1 The printing apparatus 1 is a thermal transfer printer that uses ink from ink tape 3 to transfer text onto a printing tape 2, which is an example of a printing medium. The printing tape 2 may include, for example, a strip-shaped film tape containing a substrate to which ink is directly transferred, or a paper label tape with multiple paper labels arranged on a strip-shaped substrate.

[0037] The text recorded on the printing tape 2 may include, for example, typical text, barcodes, QR codes (registered trademarks), numbers, images, patterns, etc. The printing apparatus 1 according to this embodiment is capable of recording text of different colors (e.g., black and red) onto the printing tape 2.

[0038] The printing apparatus 1 mainly includes: a housing 4, a cartridge 5 housed inside the housing 4, a thermal head 6, an impression cylinder 7, and a control board 8.

[0039] The housing 4 can be, for example, a box-shaped component made of a plastic shell. An outlet 9 for removing the printed tape 2 after printing is formed on the outer wall of the housing 4. A cutter (not shown) can be provided near the outlet 9. The printed tape 2 can be separated into labels of the size for each use unit by cutting with the cutter.

[0040] The cassette 5 can be a detachable cassette relative to the housing 4. The cassette 5 can be mounted from the conveying direction D1 of the printing tape 2 (in... Figure 1 In the printing apparatus 1, the upstream side (from right to left) and the downstream side are sequentially housed a printing tape roller 10 (or label tape roller), a supply roller 11, an ink ribbon roller 12, an ink ribbon peeling member 13, and an ink ribbon winding roller 14. In this embodiment, the printing tape roller 10 and the ink ribbon roller 12 are used in a state where they are housed in a tape cassette 5, but they may also be used in a state where they are directly mounted on the printing apparatus 1.

[0041] The printing roller 1 is made by winding the printing belt 2 into a cylindrical shape, and is held rotatably by a shaft 15 in the tape cassette 5. A belt drive shaft 16 provided in the housing 4 is inserted into the supply roller 11. The rotational force R1 generated by driving the belt drive shaft 16 is transmitted to the supply roller 11, thereby causing the supply roller 11 to rotate.

[0042] The ribbon roller 12 is made by winding the ribbon 3 into a cylindrical shape, and is held rotatably by a shaft 17 in the tape cartridge 5. A ribbon drive shaft 18 provided in the housing 4 is inserted into the ribbon winding roller 14. The rotational force R2 generated by driving the ribbon drive shaft 18 is transmitted to the ribbon winding roller 14, thereby rotating the ribbon winding roller 14.

[0043] The ribbon peeling component 13 can be a guide component that changes the transport direction D2 of the ribbon 3. The ribbon peeling component 13 can have a shape capable of contacting the transported ribbon 3, such as a roller or blade shape. The ribbon 3 is partially heat-pressed against the printing belt 2 by the thermal head 6 and is transported together with the printing belt 2 toward the outlet 9. The ribbon peeling component 13 contacts the ribbon 3 during transport, causing the transport direction D2 of the ribbon 3 to change at a large angle relative to the transport direction D1 of the printing belt 2. As a result, the printing belt 2 and the ribbon 3 are pulled apart, thus peeling the ribbon 3 from the printing belt 2.

[0044] The thermal head 6 is positioned between the printing belt roller 10, the ink belt roller 12, and the ink belt peeling member 13 in the transport direction D1 of the printing belt 2. The thermal head 6 includes a substrate 19 and a heating element 20 (e.g., a heating resistor) formed on the substrate 19. Joule heat generated by energizing the heating element 20 is used for thermal transfer of ink from the ink belt 3.

[0045] An impression drive shaft 21, for example, provided in the housing 4, is inserted into the impression cylinder 7. The rotational force R3 generated by driving the impression drive shaft 21 is transmitted to the impression cylinder 7, thereby causing the impression cylinder 7 to rotate. The control board 8 is an electronic device that performs electrical control of the printing apparatus 1 and is provided inside the housing 4.

[0046] [Electrical structure of printing device 1]

[0047] Figure 2 This is a block diagram representing the electrical structure of the printing apparatus 1.

[0048] Reference Figure 2 A control circuit 22 is provided on the control board 8 of the printing apparatus 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, for example, via a data bus (not shown).

[0049] ROM 24 stores various programs for driving the printing apparatus 1 (e.g., executing...). Figure 3 and Figure 4A (The control programs for each process shown in B, etc.). CPU 23 utilizes the temporary storage function of RAM 26 and performs signal processing according to the program stored in ROM 24, thereby controlling the printing apparatus 1 as a whole. Memory 25 may be constituted, for example, a part of the storage area of ​​ROM 24. A table for displaying the remaining amount (consumption) of ink tape 3 on the display unit (not shown) of housing 4 can be pre-stored in memory 25.

[0050] The input / output I / F27 is electrically connected to a first drive circuit 28 and a second drive circuit 29. The first drive circuit 28 controls the energization of the heating element 20 of the thermal head 6. The second drive circuit 29 controls the output of drive pulses to the drive motor 30 that drives the rotation of the drive supply roller 11, the ink ribbon winding roller 14, and the impression roller 7.

[0051] [Flowchart of the printing process based on printing apparatus 1]

[0052] Figure 3 This is a schematic diagram illustrating the heating and cooling processes of printing apparatus 1. Figure 4A and Figure 4B This is a schematic diagram illustrating the cooling process and the transfer process of printing apparatus 1. Figure 4B From Figure 4A The main part of the transfer pattern is enlarged when viewed in the direction of arrow 4B. Figure 5A and Figure 5B This is a diagram showing an example of a printed pattern 44 based on printing apparatus 1. (Refer to...) Figure 1 and Figures 3 to 5A and Figure 5B The printing process based on printing apparatus 1 will be described in detail.

[0053] When printing text onto the printing tape 2, the printing tape 2 is fed out from the printing tape roller 10 by the rotation drive of the supply roller 11, and the ink tape 3 is fed out from the ink tape roller 12 by the rotation drive of the ink tape winding roller 14.

[0054] Therefore, as Figure 1and Figure 3 As shown, the printing belt 2 and the ink belt 3 are conveyed downstream with their surfaces overlapping each other. In the printing belt 2, the side facing the ink belt 3 is the printing surface 31 (surface), and the opposite side is the back surface 32. In the ink belt 3, the side facing the printing belt 2 is the adhesive surface 33 (surface), and the opposite side is the back surface 34.

[0055] Reference Figure 3 The ink ribbon 3 includes: a substrate layer 35, a first ink layer 36 as an example of a first heat transfer layer, and a second ink layer 37 as an example of a second heat transfer layer. The first ink layer 36 and the second ink layer 37 are sequentially stacked on a surface 38, which is an example of a first side of the substrate layer 35. The side opposite to the surface 38 of the substrate layer 35 is the back surface 39 (the back surface 34 of the ink ribbon 3). The first ink layer 36 and the second ink layer 37 contain colorants of different colors. For example, the first ink layer 36 may contain a black colorant as an example of a first ink, and the second ink layer 37 may contain a red colorant as an example of a second ink.

[0056] The ink ribbon 3 is conveyed toward the thermal head 6 while in contact with the second ink layer 37 and the printing ribbon 2. In the thermal head 6, as... Figure 3 The heating process is performed as shown. Specifically, a heating element 20, which is heated by electricity, is pressed against the ink belt 3, so that the heat is transferred through the substrate layer 35 to the first ink layer 36 and the second ink layer 37. The stack of the ink belt 3 and the printing belt 2 is sandwiched between the thermal head 6 and the impression cylinder 7, so that it is heated by the thermal head 6 while being transported downstream.

[0057] The heating element 20 can be controlled to a uniform temperature throughout, or it can be controlled to have different temperatures in some parts. For example... Figure 3 As shown, the first heating element 40 of the heating element 20 may be controlled at a first heating temperature, and the second heating element 41 of the heating element 20 may be controlled at 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 melts or softens, thereby making close contact with the printing belt 2.

[0058] Reference Figure 3 and Figure 4A B. A cooling process is performed in the interval between the thermal head 6 and the ribbon stripping component 13. Specifically, the ribbon 3, which is hot-pressed onto the printing ribbon 2 during the heating process, is naturally cooled in the interval from the thermal head 6 to the ribbon stripping component 13, and the temperature decreases toward the operating environment temperature of the printing apparatus 1.

[0059] After that, as Figure 4AAs shown in Figure B, the tape peeling member 13 selectively changes only the transport direction D2 of the tape 3, thereby applying an external force F1 to the substrate layer 35 and the second ink layer 37 in a direction away from each other. As a result, the printing tape 2 and the tape 3 are pulled apart, and the tape 3 is wound onto the tape winding roller 14. At this time, the first portion 42 and the second portion 43, heated by the thermal head 6, are selectively retained on the printing tape 2, thereby performing a transfer process. For example, in the first portion 42, a peel can occur between the substrate layer 35 and the laminate containing the first ink layer 36 and the second ink layer 37, thus transferring the laminate. On the other hand, in the second portion 43, a peel can occur between the first ink layer 36 and the second ink layer 37, thus selectively transferring the second ink layer 37.

[0060] Thus, different colored patterns 44 (e.g., black and red) are formed on the printing belt 2. For example... Figure 5A As shown, the printed pattern 44 can have different colors for each individual character. Figure 5A In the image, when viewed from the printing surface 31 side of the printing belt 2, the outermost surfaces of the letters "A" and "C" may show a red pattern 45 based on the second ink layer 37, while the outermost surface of the letter "B" may show a black pattern 46 based on the first ink layer 36. On the other hand, as... Figure 5B As shown, the printed pattern 44 can also be seen with both red pattern 45 and black pattern 46 on each part of each text.

[0061] After the ink tape 3 is transferred, the printed tape 2 with the text recorded on it is taken out from the outlet 9 of the printing device 1. Through the above process, the printed tape 2 with the text printed on it can be obtained.

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

[0063] In a thermal transfer printer (printing apparatus 1), after the ink ribbon 3 is heated by the thermal head 6 according to the pattern for recording information, the ink ribbon 3 is peeled off from the printing belt 2. As a result, the ink layers 36 and 37 selectively melt or soften according to the heating pattern, thereby peeling off from the substrate layer 35 and transferring to the printing surface 31 of the printing belt 2, where text is recorded. The aforementioned patent documents 1 and 2 also disclose such two-color thermal transfer printing, which has the following problems.

[0064] For example, Figure 6 A printed pattern 44 is shown, in which red is transferred when heated at a low temperature and black is transferred when heated at a high temperature. Edge patterns (Japanese: フリンジ) may occur when selectively transferring only one color of a two-color pattern. For example, see [reference]. Figure 6In the black patterns 46 arranged in a spherical pattern with intervals between each other, red patterns 45 may be selectively transferred as borders 80 to the periphery of each pattern. The main reason for this border 80 can be considered to be the temperature distribution within the surface of the ink ribbon 3, where, for example, the periphery of each pattern does not reach the temperature required for the transfer of the black patterns 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. Referring hereafter... Figures 7-11 The principle of edge pattern 80 is explained in detail.

[0065] Figure 7 It means Figure 3 The diagram shows the circuit pattern of the heating element 20 of the thermistor head 6. Figure 8 It is used for explanation Figure 7 A diagram showing the temperature distribution of the heating element 20. Figure 7 and Figure 8 In the image, the heating element 20 is shaded for clarity.

[0066] Reference Figure 7 and Figure 8 A more detailed explanation of the structure of the thermal head 6 and the temperature distribution of the heating element 20 will follow. First, refer to... Figure 7 In the thermal head 6, multiple heating elements 20 are regularly arranged at a predetermined spacing P1. For example, the multiple heating elements 20 may be arranged longitudinally in a column perpendicular to the transport direction D1 of the printing belt 2. Alternatively, the multiple heating elements 20 may be arranged in rows and columns in both the longitudinal and transverse 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, 15 μm or more and 300 μm or less. 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 transport direction D1 of the printing tape 2. The specified spacing P1 is, for example, the distance from center to center between two adjacent heating elements 20. The specified spacing P1 can be, for example, 84.7 μm (300 dpi).

[0068] Multiple heating elements 20 may have one terminal connected to a common electrode 81 (e.g., GND potential) shared by all heating elements 20, and another terminal connected to an individually independent electrode 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 energizing 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 electricity (energy) is supplied to each heating element 20, the electrical energy is converted into heat energy, thereby causing each heating element 20 to heat up. The temperature rise of the heating element 20 based on the heating can be calculated, for example, using the following equation (1).

[0070] T1=Q / C+T0···(1)

[0071] In equation (1), T1 = temperature rise, T0 = ambient temperature, Q = applied energy, and C = heat capacity of heating element 20 (depending on the shape and material of the thermistor head 6 and heating element 20).

[0072] When energy Q is applied to the entire shaded portion of the heating element 20, the heating temperature of the heating element 20, i.e., the temperature rise T1, will macroscopically become the temperature distribution shape shown by the dashed line 83 according to equation (1). However, heat has the property of flowing from the high temperature side to the low temperature side. Therefore, heat will escape towards the periphery of the heating element 20 where no applied energy Q is applied, i.e., towards the low temperature side T0. Thus, as shown by the solid line 84, the microscopic temperature distribution becomes a mountain-shaped temperature distribution shape, which is higher closer to the center and lower towards the periphery. Simply put, this is because heat is difficult to escape from the center of the heating element 20, while heat is easy to escape from the periphery.

[0073] Figure 9 This diagram illustrates how heat is transferred from the thermal head 6 to the ink tape 3.

[0074] Reference Figure 9 , from Figure 8 The heat from each heating element 20 is transferred sequentially from the substrate layer 35 toward the first ink layer 36 and the second ink layer 37 to the interior of the ink tape 3. Figure 9 In the diagram, the heat transfer from the heating element 20 to the interior of the ink ribbon 3 is represented by semi-elliptical temperature curves 85A to 85F. Temperature curves 85A to 85F, in order of proximity to the heating element 20, 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. The region enclosed by each of temperature curves 85A to 85F is the first temperature region 86A, the second temperature region 86B, the third temperature region 86C, the fourth temperature region 86D, the fifth temperature region 86E, and the sixth temperature region 86F. During heating based on the heating element 20, the reached temperatures of temperature regions 86A to 86F exhibit a relationship of 86A > 86B > 86C > 86D > 86E > 86F.

[0075] Therefore, during heating, a temperature relationship is established along the thickness direction of the ink ribbon 3. For example, comparing the temperature Tb(T) at the first boundary 87 between the substrate layer 35 and the first ink layer 36... base The arrival temperature Th(T) of the second boundary 88 between the first ink layer 36 and the second ink layer 37 high The arrival temperature Tl(T) of the third boundary 89 between the second ink layer 37 and the printing belt 2. low If Tb > Th > Tl, then there exists a size relationship between them. Figure 9 In order to make it clear, the portion directly below the heating element 20 at the boundary of each layer of the ink tape 3 is conceptually shown as a rectangular first boundary 87, a second boundary 88, and a third boundary 89.

[0076] Furthermore, the temperatures Tb, Th, and Tl vary in the in-plane direction (orthogonal to the thickness direction) of the ink band 3, resulting in a temperature distribution. For example, in the second boundary section 88 (first ink layer 36-second ink layer 37), the central part is the second temperature region 86B, but the peripheral part is the third temperature region 86C, which is lower than the central part. Such in-plane temperature distributions of the boundary sections 87-89 are related to the generation of the edge texture 80.

[0077] Figure 10 This is a graph showing the relationship between the heating temperature reached at the boundaries of multiple layers of the ink tape 3 and the peel force (adhesion).

[0078] Before explaining the relationship between the temperature distribution in the in-plane direction of each boundary section 87-89 and the generation of edge texture 80, refer to Figure 10 The relationship between the arrival temperatures Tb, Th, and Tl of the boundary portions 87-89 of each layer of the ink tape 3 and the peel force (adhesion force) of the boundary portions 87-89 is explained.

[0079] Reference Figure 10 , Figure 10 The horizontal axis represents the arrival temperature of the boundary between the layers of ink ribbon 3, 87-89. Figure 10 The vertical axis represents the force (peeling force) required to peel off the layers of the ink tape 3 at the boundaries 87-89. Figure 10 The solid line 90 represents the relationship between the arrival temperature Th and the peeling force in the second dividing section 88 (first ink layer 36 - second ink layer 37). Figure 10 The single-dotted line 91 indicates the relationship between the arrival temperature Tl and the peel force in the third dividing section 89 (second ink layer 37 - printing belt 2). Figure 10 The double-dotted line 92 indicates the relationship between the arrival temperature Tb and the peeling force in the first dividing part 87 (substrate layer 35 - first ink layer 36).

[0080] like Figure 10 As shown, the magnitude of the peeling force at each boundary 87-89 is not constant, but varies according to the arrival temperatures Tb, Th, and Tl at the boundary 87-89. For example, Figure 10 The horizontal axis can be divided into three main intervals based on the magnitudes of the arrival temperatures Tb, Th, and Tl at the boundary 87–89. These three intervals include the first interval 93, the second interval 94, and the third interval 95.

[0081] The first interval 93 is the interval with the lowest reaching temperatures Tb, Th, and Tl at the boundaries 87-89. The relationship between the peel forces at the boundaries 87-89 within the first interval 93 is: third boundary 89 < second boundary 88 < first boundary 87. The peel force at the third boundary 89 is almost zero, therefore the ink tape 3 is not adhered to the printing tape 2.

[0082] That is, the first interval 93 can be based on the initial state before the energy of the thermal head 6 is applied (the state before thermal transfer).

[0083] The temperature ranges Tb, Th, and Tl at the boundary portions 87-89 of the second interval 94 are between the first interval 93 and the third interval 95. The magnitudes of the peel forces at each boundary portion 87-89 in the second interval 94 are in the order of 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 bonded to the printing tape 2 via the third boundary portion 89, and the adhesion between the substrate layer 35 and the first ink layer 36 is sufficiently maintained via the first boundary portion 87. On the other hand, the adhesion between the first ink layer 36 and the second ink layer 37 is lowest via the second boundary portion 88. Therefore, in the second interval 94, if an external force F1 (refer to...) Figure 4A When the ink is applied to the ink belt 3, peeling occurs at the second boundary 88 where the adhesion is weakest. This results in a so-called reverse printing where the first ink layer 36 remains on the side of the substrate layer 35, while only the second ink layer 37 is selectively heat-transferred to the printing belt 2. Therefore, the text recorded on the printing belt 2 becomes the hue of the second ink layer 37, for example, red.

[0084] The third interval 95 is the interval with the highest range of temperatures Tb, Th, and Tl at the boundary portions 87-89. The relationship between the peel forces at each boundary portion 87-89 within the third interval 95 is: first boundary portion 87 < third boundary portion 89 < second boundary portion 88, or first boundary portion 87 < second boundary portion 88 < third boundary portion 89. Therefore, the second ink layer 37 is bonded to the printing tape 2 via the third boundary portion 89, and the adhesion between the first ink layer 36 and the second ink layer 37 is sufficiently maintained via the second boundary portion 88. On the other hand, the adhesion force between the substrate layer 35 and the first ink layer 36 via the first boundary portion 87 is at its lowest. Therefore, in the third interval 95, if an external force F1 (refer to...) Figure 4A When the ink is applied to the ink belt 3, peeling occurs at the first dividing point 87 where the adhesion is weakest. As a result, the entire ink belt 3, namely the first ink layer 36 and the second ink layer 37, is integrally thermally transferred to the printing belt 2. Therefore, the text recorded on the printing belt 2 becomes, for example, the tone of the outermost first ink layer 36 after the transfer, such as black.

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

[0086] On the other hand, when the high-energy heating of the heating element 20 is applied at a high temperature (third interval 95), the substrate layer 35 and the first ink layer 36 become a peeling position, and the heat transfer color becomes black.

[0087] Therefore, in order to correctly transfer two-color text without producing edge patterns 80, the conditions for transfer are limited to situations where the arrival temperatures Th and Tl of the second dividing section 88 and the third dividing section 89 are uniformly consistent throughout the in-plane direction of the dividing section, and the temperature conditions required for transfer are met. For example... Figure 9 As shown, temperature distribution is typically generated in the in-plane direction of ink ribbon 3, which is the cause of edge pattern 80.

[0088] Figure 11 This diagram illustrates the principle behind the generation of the edge pattern 80. Figure 12 This diagram illustrates the solution to edge pattern 80. Figure 11 In this paper, the thickness direction of ink ribbon 3 is referred to as direction D5, and the in-plane direction of ink ribbon 3, which is orthogonal to the thickness direction D5, is referred to as D6.

[0089] Reference Figure 11The solid line drawn in the shape of a mountain represents the first temperature distribution curve 96, which shows the temperature Th reaching the outermost surface of the ink band 3 that was not transferred during the transfer of the second ink layer 37 and remains on the side of the substrate layer 35. The top is the highest temperature, and the temperature decreases towards the bottom. The dashed line drawn in the shape of a mountain represents the second temperature distribution curve 97, which shows the temperature Tl reaching the outermost surface of the ink band 3 (i.e., the third boundary 89). The top is the highest temperature, and the temperature decreases towards the bottom. The two straight lines that cross the first temperature distribution curve 96 and the second temperature distribution curve 97, from top to bottom, represent the high-temperature side boundary conditions 98 required for black transfer (corresponding to...). Figure 10 The low-temperature side boundary condition required for the Th_tar) and red transfer (corresponding to 99) Figure 10 (Tl_tar).

[0090] Reference Figure 11 On the left side (during low-temperature heating), the first temperature distribution curve 96, covering the entire in-plane direction D6 of the printed pattern 44, exists between the low-temperature boundary condition 99 and the high-temperature boundary condition 98 (second interval 94). On the other hand, the second temperature distribution curve 97, covering the entire in-plane direction D6 of the printed pattern 44, does not reach the high-temperature boundary condition 98. (Refer to...) Figure 10 Under these conditions, the peeling force at the second dividing portion 88 is minimal at any position in the in-plane direction D6 of the printed pattern 44. Therefore, peeling occurs uniformly at the second dividing portion 88 throughout the in-plane direction D6 of the printed pattern 44. Consequently, no edge lines 80 are generated, and red transfer can be performed.

[0091] Reference Figure 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 center 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 compared to the center portion 100. Under such circumstances, the peel 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 of the peel force at the peripheral portion 101 becomes... Figure 10 The size relationship is shown in the second interval 94. That is, the peeling force at the second dividing point 88 becomes minimal, so peeling occurs at the second dividing point 88. As a result, edge lines 80 are selectively generated at the periphery 101 of the printed pattern 44.

[0092] Therefore, as Figure 12As shown, the inventors of this application discovered that, in order to suppress edge patterns 80, edge patterns 80 can be suppressed by making the temperature difference between the arrival temperature Th of the second boundary 88 and the arrival temperature Tl of the third boundary 89, and the temperature difference between the high-temperature side boundary condition (Th_tar) and the low-temperature side boundary condition (Tl_tar), close. That is, it was discovered that edge patterns 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 amount of heat transferred to the third boundary 89 can be increased by reducing the heat transfer distance between the second boundary 88 and the third boundary 89. Thus, as... Figure 12 As shown, the top of the second temperature distribution curve 97 is relatively higher than the second boundary 88, so it can approach |Th-Tl|=|(Tl_tar)-(Th_tar)|.

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

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

[0095] Figure 13 This is a schematic cross-sectional view illustrating the layer structure of a thermal transfer recording medium 47 according to one embodiment of the present invention. Figure 13 The image shows a thermal transfer recording medium 47 in a state where it is adhered to a printing tape 2, which is an example of a printing medium.

[0096] Thermal transfer recording medium 47 can be used as ink ribbon 3 for Figures 1 to 4A The printing apparatus 1 and printing process are shown in Figures B and C. The heat transfer recording medium 47 includes: a substrate layer 48, a back layer 49, a weld layer 70, a first heat transfer layer 50, an intermediate layer 51, and a second heat transfer layer 52. The weld layer 70, the first heat transfer layer 50, the intermediate layer 51, and the second heat transfer layer 52 are sequentially stacked on a surface 53, which is an example of a first surface of the substrate layer 48. The side of the substrate layer 48 opposite to the surface 53 can be a back surface 54. The back layer 49 is stacked on the back surface 54 of the substrate layer 48. The first heat transfer layer 50 and the second heat transfer layer 52 can 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 substrate layer 48 and a weld layer 70, a first thermal transfer layer 50, an intermediate layer 51, and a second thermal transfer layer 52, which are sequentially and directly in contact with each other on the surface 53 of the substrate layer 48. The intermediate layer 51 comprises a thermoplastic elastomer as an adhesive. The intermediate layer 51 may also be omitted.

[0098] The following provides a detailed description of the specific composition and properties of the substrate layer 48, back layer 49, weld layer 70, first heat transfer layer 50, intermediate layer 51, and second heat transfer layer 52 included in the heat transfer recording medium 47.

[0099] (1) Substrate layer 48

[0100] Examples of substrate layer 48 include films made of resins such as polysulfone, polystyrene, polyamide, polyimide, polycarbonate, polypropylene, polyester, and cellulose triacetate; thin sheets such as capacitor paper and glassine paper; and celluloid. Among these, films made of polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate are preferred from the viewpoints of mechanical strength, dimensional stability, heat treatment resistance, and price. The thickness of substrate layer 48 can be arbitrarily set, for example, according to the specifications of the thermal transfer printer. For example, the thickness of substrate layer 48 is 1 μm or more, preferably 2 μm or more.

[0101] For example, the thickness of the substrate layer 48 is 10 μm or less, preferably 8 μm or less. For example, the thickness of the substrate 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, slip resistance, and abrasion resistance of the back side 54 of the substrate layer 48 that contacts the thermal head 6. Examples of materials that can be used for the back layer 49 include silicone resin, fluoropolymer, silicone-fluoropolymer, nitrocellulose resin, silicone-modified polyurethane resin, and silicone-modified acrylic resin. The back layer 49 may also contain a lubricant if needed.

[0104] The back layer 49 can be formed, for example, by applying a coating obtained by dissolving or dispersing the aforementioned resin in any solvent onto the back side 54 of the substrate layer 48 and then drying it. The thickness of the back layer 49 can be arbitrarily set, for example, according to the specifications of the thermal transfer printer. The thickness of the back layer 49 can be adjusted by the amount of coating applied to the back layer 49.

[0105] For example, the coating weight of the back layer 49 is expressed as 0.05 g / m², which is the amount of solids per unit area. 2 The above is preferably 0.1 g / m 2 That's all. For example, the coating weight of the back layer 49, expressed as solids content per unit area, is 0.5 g / m². 2 The preferred value is 0.4 g / m 2 For example, the coating weight of the back layer 49 is expressed as 0.05 g / m², which is the amount of solids per unit area. 2 Above and 0.5g / m 2The preferred value is 0.1 g / m 2 Above and 0.4g / m 2 The specific thickness of the back 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 or less.

[0106] (3) Welded layer 70

[0107] The weld layer 70 comprises at least one selected from the group consisting of polyamide resins, polyester resins, epoxy resins, phenolic resins, and polyvinyl alcohol resins. To improve the affinity and adhesion between the weld layer 70 and the substrate layer 48 and the first heat transfer layer 50 during low-temperature heating, the weld layer 70 is preferably formed using a polyamide resin.

[0108] Examples of polyamide resins include those obtained by condensation polymerization of lactams with three or more membered rings, polymerizable aminocarboxylic acids, diacids and diamines or their salts, or mixtures thereof. These polyamide resins can be used alone or in combination of two or more.

[0109] As specific commercially available polyamide resins, examples include the Tohmide (registered trademark) series produced by T&K TOKA Inc., specifically: 1310 (softening point: 120±5℃, melting viscosity: 1500~4500mPa·s / 200℃), 1315 (softening point: 130±5℃, melting viscosity: 7000~18000mPa·s / 200℃), and 1320 (softening point: 100±5℃, melting viscosity: 11000~20000mPa). (·s / 200℃), 1340 (softening point: 140±5℃, melting viscosity: 8000~16000mPa·s / 200℃), TXC-243A (softening point: 105±5℃, melting viscosity: 5000~10000mPa·s / 200℃), TXC-245A (softening point: 90±5℃, melting viscosity: 1000~2000mPa·s / 200℃), etc.

[0110] Furthermore, in this application, when comparing temperatures related to the heat distortion of multiple substances, the softening point is used as the comparison temperature for substances having a softening point, such as polyamide resins. For substances having a melting point (e.g., waxes described later), the melting point is used as the comparison temperature. For substances that do not have both a melting point and a softening point but have a glass transition temperature (e.g., polyester resins described later), the glass transition temperature is used as the comparison temperature.

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

[0112] Commercially available epoxy resins include, for example, those from the JER (registered trademark) series of epoxy resins manufactured by Mitsubishi Chemical Corporation, such as 1001 (softening point (ring and ball method): 64°C, number average molecular weight Mn: approx. 900), 1002 (softening point (ring and ball method): 78°C, number average molecular weight Mn: approx. 1200), 1003 (softening point (ring and ball method): 89°C, number average molecular weight Mn: approx. 1300), 1055 (softening point (ring and ball method): 93°C, number average molecular weight Mn: approx. 1600), 1004 (softening point (ring and ball method): 97°C, number average molecular weight Mn: approx. 1650), and 1004AF (softening point (ring and ball method): 1001 (softening point (ring and ball method): 64°C, number average molecular weight Mn: approx. 900), which are basic solid types. ): 97℃, number-average molecular weight Mn: approx. 1650), 1007 (softening point (ring and ball method): 128℃, number-average molecular weight Mn: approx. 2900), 1009 (softening point (ring and ball method): 144℃, number-average molecular weight Mn: approx. 3800), 1010 (number-average molecular weight Mn: approx. 5500), 1003F (softening point (ring and ball method): 96℃), 1004F (softening point (ring and ball method): 103℃), 1005F, 1009F (softening point (ring and ball method): 144℃), 1004FS (softening point (ring and ball method): 100℃), 1006FS (softening point (ring and ball method): 112℃), 1007FS (softening point (ring and ball method): 124℃).

[0113] Commercially available phenolic resins include, for example, those from the PHENOLITE (registered trademark) series produced by DIC (Industrial and Commercial Corporation): TD-2131 (softening point: 78-82℃), TD-2106 (softening point: 88-95℃), TD-2093 (softening point: 98-102℃), and TD-2090 (softening point: 117-123℃); and BRG-555 (softening point: 66-72℃, melting viscosity: 0.3-0.5 Pa·s / 125℃) from the SHONOLU (registered trademark) series produced by AICA Industries (Industrial and Commercial Corporation). Products include: BRG-556 (softening point: 77~83℃, melting viscosity: 0.1~0.3Pa·s / 150℃), BRG-557 (softening point: 82~88℃, melting viscosity: 0.2~0.4Pa·s / 150℃), BRG-558 (softening point: 93~98℃, melting viscosity: 0.8~1.2Pa·s / 150℃), CRG-951 (softening point: 93~99℃, melting viscosity: 0.2~0.8Pa·s / 150℃), and TAM-005 (softening point: 80~88℃, melting viscosity: 0.3~0.5Pa·s / 150℃).

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

[0115] The softening point of the polyamide resin used for the weld layer 70 is, for example, 90°C or higher, preferably 110°C or higher, and more preferably 125°C or higher. As long as the softening point is within this range, it can maintain high adhesion between the substrate layer 48 and the first heat transfer layer 50 at relatively low temperatures during low-temperature transfer with almost no softening.

[0116] The weld layer 70 can be formed, for example, by applying a coating obtained by dissolving or dispersing the forming material used for the weld layer 70 in any solvent onto the surface 53 of the substrate layer 48 and then drying it.

[0117] (4) First heat transfer layer 50

[0118] The first heat transfer layer 50 can be formed, for example, with any thermoplastic resin. Considering improving affinity and adhesion with respect to the weld layer 70 and the intermediate layer 51, epoxy resin is preferably used as the thermoplastic resin for forming the first heat transfer layer 50. Epoxy resin has excellent affinity and adhesion with the substrate layer 48 made of a polyester film such as PET and the thermoplastic elastomer forming the intermediate layer 51. The first heat transfer layer 50 can be formed using epoxy resin without (without) a hardener.

[0119] Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic varnish type epoxy resin, methyl phenolic varnish type epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol AD ​​type epoxy resin, propylene glycol glycoxy ether, pentaerythritol polyglycidyl ether and other aliphatic epoxy resins, epoxy resins obtained from aliphatic or aromatic amines and epichlorohydrin, epoxy resins obtained from aliphatic or aromatic carboxylic acids and epichlorohydrin, heterocyclic epoxy resins, spirocyclic epoxy resins, epoxy-modified resins, brominated epoxy resins, etc. There are no particular limitations on specific examples of epoxy resins, but various epoxy resins such as those listed below can be included. These epoxy resins can be used alone or in combination of two or more.

[0120] Mitsubishi Chemical Corporation's JER (registered trademark) series of epoxy resins, including the following as basic solid types: 1001 (softening point (ring and ball method): 64°C, number average molecular weight Mn: approx. 900), 1002 (softening point (ring and ball method): 78°C, number average molecular weight Mn: approx. 1200), 1003 (softening point (ring and ball method): 89°C, number average molecular weight Mn: approx. 1300), 1055 (softening point (ring and ball method): 93°C, number average molecular weight Mn: approx. 1600), 1004 (softening point (ring and ball method): 97°C, number average molecular weight Mn: approx. 1650), and 1004AF (softening point (ring and ball method): 97°C, number average molecular weight Mn: approx. 1650). Mn: approx. 1650), 1007 (softening point (ring and ball method): 128℃, number average molecular weight Mn: approx. 2900), 1009 (softening point (ring and ball method): 144℃, number average molecular weight Mn: approx. 3800), 1010 (number average molecular weight Mn: approx. 5500), 1003F (softening point (ring and ball method): 96℃), 1004F (softening point (ring and ball method): 103℃), 1005F, 1009F (softening point (ring and ball method): 144℃), 1004FS (softening point (ring and ball method): 100℃), 1006FS (softening point (ring and ball method): 112℃), 1007FS (softening point (ring and ball method): 124℃).

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

[0122] In addition to epoxy resin, the first heat transfer layer 50 may also contain an adhesive. By containing an adhesive, the affinity and adhesion between the weld layer 70 and the intermediate layer 51 can be further improved. Examples of adhesives include rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, vinyl alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinylpyrrolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives.

[0123] Considering the need to improve affinity and compatibility with epoxy resin, as well as affinity and adhesion to the weld layer 70 and intermediate layer 51, acrylic adhesives are preferred as the adhesive. Specific examples of acrylic adhesives are not particularly limited, but various acrylic adhesives such as those listed below can be cited. These acrylic adhesives can be used alone or in combination of two or more.

[0124] Toyo Komei (Co., Ltd.) manufactures the ORIBAIN (registered trademark) BPS (solvent-based) series of solvent-based solvents, including BPS1109 (non-volatile component: 39.5% by mass), BPS3156D (non-volatile component: 34% by mass), BPS4429-4 (non-volatile component: 45% by mass), BPS4849-40 (non-volatile component: 40% by mass), BPS5160 (non-volatile component: 33% by mass), and BPS5213K (non-volatile component: 33% by mass). BPS5215K (non-volatile component: 39% by mass), BPS5227-1 (non-volatile component: 41.5% by mass), BPS5296 (non-volatile component: 37% by mass), BPS5330 (non-volatile component: 40% by mass), BPS5375 (non-volatile component: 45% by mass), BPS5448 (non-volatile component: 40% by mass), BPS5513 (non-volatile component: 44.5% by mass), BPS 5565K (non-volatile component: 45% by mass), BPS5669K (non-volatile component: 46% by mass), BPS5762K (non-volatile component: 45.5% by mass), BPS5896 (non-volatile component: 37% by mass), BPS5978 (non-volatile component: 35% by mass), BPS6074HTF (non-volatile component: 52% by mass), BPS6080TFK (non-volatile component: 45% by mass), BPS6130TF (non-volatile component: 45% by mass), BPS6130TF (non-volatile component: 45% by mass), BPS6074HTF (non-volatile component: 52% by mass), BPS6080TFK (non-volatile component: 45% by mass), BPS6130TF (non-volatile component: 45% by mass), BPS6074HTF (non-volatile component: 45 ...074HTF (non-volatile component: 45% by mass), BPS6080TFK (non-volatile component: 45% by mass), BPS6080TFK (non-volatile component: 45% by mass), BPS6080TFK (non-volatile component: 45% by mass), BPS6080TFK (non-volatile component: 45% Volatile components: 45.5% by mass), BPS6153K (non-volatile components: 25% by mass), BPS6163 (non-volatile components: 37% by mass), BPS6231 (non-volatile components: 56% by mass), BPS6421 (non-volatile components: 47% by mass), BPS6430 (non-volatile components: 33% by mass), BPS6574 (non-volatile components: 57% by mass), BPS8170 (non-volatile components: 36.5% by mass), BPS HS-1 (non-volatile components: 40% by mass).

[0125] LION SPECIALTY CHEMICALS (Industrial and Commercial Corporation) manufactures the following solvent-based adhesives (re-peel type): AS-325 (solids concentration: 45% by mass), AS-375 (solids concentration: 45% by mass), AS-409 (solids concentration: 45% by mass), AS-417 (solids concentration: 45% by mass), AS-425 (solids concentration: 45% by mass), AS-455 (solids concentration: 45% by mass), AS-665 (solids concentration: 40% by mass), AS-1107 (solids concentration: 43% by mass), and AS-4005 (solids concentration: 45% by mass).

[0126] The acrylic adhesive used for the first heat transfer layer 50 can be used in conjunction with a tackifier.

[0127] For example, this is because it can improve the chelation of the first heat transfer layer 50, suppress excessive peeling, and improve the clarity of the recorded text. Examples of tackifiers include rosin glycerol esters, terpene phenolic resins, and rosin esters. Specific examples of tackifiers are not particularly limited, but various tackifiers such as those listed below can be included. These tackifiers can be used alone or in combination of two or more.

[0128] YS manufactured by YASUHARA CHEMICAL (Co., Ltd.) The POLYSTER series of terpene phenolic resins includes 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] Arakawa Chemical Industry Co., Ltd. produces ESTER GUM with the following components: AA-G (softening point (ring and ball method): 82-88℃), AA-L (softening point (ring and ball method): 82-88℃), AA-V (softening point (ring and ball method): 82-95℃), 105 (softening point (ring and ball method): 100-110℃), AT (viscosity: 20000-40000 mPa·s), H (softening point (ring and ball method): 68-75℃), and HP (softening point (ring and ball method): 80℃ or higher).

[0130] Arakawa Chemical Industry Co., Ltd. produces the following rosin esters under the PENSEL (registered trademark) series: GA-100 (softening point (ring and ball method): 100-110℃), AZ (softening point (ring and ball method): 95-105℃), C (softening point (ring and ball method): 117-127℃), D-125 (softening point (ring and ball method): 120-130℃), D-135 (softening point (ring and ball method): 130-140℃), D-160 (softening point (ring and ball method): 150-165℃), and KK (softening point (ring and ball method): above 165℃).

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

[0132] The first heat transfer layer 50 may contain any colorant. As the colorant, one or more colorants corresponding to the hue of the first heat transfer layer 50 can be used. For example, pigments can be used as the colorant. Considering improving the weather resistance of the text, pigments are preferred as the colorant used for the first heat transfer layer 50. For example, carbon black is preferred as the pigment used to color the first heat transfer layer 50 black. There are no particular limitations on specific examples of carbon black, but various types of carbon black, such as the following, can be cited. These carbon blacks can be used alone or in combination of two or more.

[0133] MA77 powder (LFF, DBP absorption: 68cm³) manufactured by Mitsubishi Chemical Corporation 3 / 100g), MA7 powder (LFF, DBP absorption: 66cm) 3 / 100g), MA7 granules (LFF, DBP absorption: 65cm³) 3 / 100g), MA8 powder (LFF, DBP absorption: 57cm) 3 / 100g), MA8 granules (LFF, DBP absorption: 51cm³) 3 / 100g), MA11 powder (LFF, DBP absorption: 64cm) 3 / 100g), MA100 powder (LFF, DBP absorption: 100cm³) 3 / 100g), MA100 granules (LFF, DBP absorption: 95cm³) 3 / 100g), MA100R powder (LFF, DBP absorption: 100cm) 3 / 100g), MA100R granules (LFF, DBP absorption: 95cm³) 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 Corporation's #3030B (furnace process, DBP absorption: 130 cm³) 3 / 100g), #3040B (furnace method, DBP absorption: 114cm³) 3 / 100g), #3050B (furnace method, DBP absorption: 175cm³) 3 / 100g), #3230B (furnace method, DBP absorption: 140cm³) 3 / 100g), #3350B (furnace method, DBP absorption: 164cm³) 3 / 100g), #3400B (furnace method, DBP absorption: 175cm³) 3 / 100g).

[0135] The TOKABLACK (registered trademark) series #5500 (furnace furnace, DBP absorption: 155cm³) produced by CARBON (Co., Ltd.) 3 / 100g), #4500 (furnace method, DBP absorption: 168cm³) 3 / 100g), #4400 (furnace method, DBP absorption: 135cm³) 3 / 100g), #4300 (furnace method, DBP absorption: 142cm³) 3 / 100g).

[0136] ORION ENGINEERED CARBONS' PRINTEX (registered trademark) series L (furnace process, DBP absorption: 120cm³) 3 / 100g), L6 (furnace method, DBP absorption: 126cm³) 3 / 100g).

[0137] Birla Carbon's CONDUCTEX (registered trademark) series includes the 975 (furnace process, DBP absorption: 170 cm³) 3 / 100g), SC (furnace method, DBP absorption: 115cm) 3 / 100g).

[0138] CABOT's VULCAN (registered trademark) series includes the XC72 (furnace furnace, DBP absorption: 174 cm³). 3 / 100g), 9A32 (furnace method, DBP absorption: 114cm³) 3 / 100g), the 3700 from the BLACK PEARLS series produced by the same company (furnace method, DBP absorption: 111cm³). 3 / 100g).

[0139] DENKA (Co., Ltd.) manufactures DENKABLACK (registered trademark) series of DENKABLACK granules (acetylene method, DBP absorption: 160 cm³). 3 / 100g), FX-35 (acetylene method, DBP absorption: 220cm³), 3 / 100g), HS-100 (acetylene method, DBP absorption: 140cm³) 3 / 100g).

[0140] LION SPECIALTY CHEMICALS (Co., Ltd.) manufactures the KETJENBLACK (registered trademark) series EC300J (gasification method, DBP absorption capacity: 360cm³). 3 / 100g), EC600JD (gasification method, DBP absorption: 495cm³) 3 / 100g).

[0141] There are no particular limitations on the proportions of the components in the first heat transfer layer 50. The proportion of the acrylic adhesive to 100 parts by weight of epoxy resin is, for example, 30 parts by weight or more, preferably 40 parts by weight or more. The proportion of the acrylic adhesive to 100 parts by weight of epoxy resin is, for example, 150 parts by weight or less, preferably 100 parts by weight or less. The proportion of the acrylic adhesive to 100 parts by weight of epoxy resin is, for example, 30 parts by weight or more and 150 parts by weight or less, preferably 40 parts by weight or more and 100 parts by weight or less.

[0142] The proportion of the tackifier to 100 parts by weight of epoxy resin is, for example, 3 parts by weight or more, preferably 5 parts by weight or more. The proportion of the tackifier to 100 parts by weight of epoxy resin is, for example, 150 parts by weight or less, preferably 100 parts by weight or less. The proportion of the tackifier to 100 parts by weight of epoxy resin is, for example, 3 parts by weight or more and 150 parts by weight or less, preferably 5 parts by weight or more and 100 parts by weight or less.

[0143] The proportion of the colorant, such as carbon black, to 100 parts by weight of epoxy resin is, for example, 100 parts by weight or more, preferably 130 parts by weight or more. The proportion of the colorant to 100 parts by weight of epoxy resin is, for example, 230 parts by weight or less, preferably 200 parts by weight or less. The proportion of the colorant to 100 parts by weight of epoxy resin is, for example, 100 parts by weight or more and 230 parts by weight or less, preferably 130 parts by weight or more and 200 parts by weight or less.

[0144] Furthermore, regarding the components of the first heat transfer layer 50 that are supplied in liquid form dissolved or dispersed in any solvent, the amount of each component can be adjusted in such a way that the proportion of the effective component is within the range described above (the same applies below).

[0145] The first heat transfer layer 50 can be formed, for example, by directly applying a coating obtained by dissolving or dispersing the above-mentioned components in any solvent onto the weld layer 70 and then drying it. In this invention, as... Figure 5A and Figure 5BAs shown, the text recorded on the printing tape 2 is distinguished by color. Considering that the adhesion between the first heat transfer layer 50 and the weld layer 70, as well as other layers, needs to be adjusted for this color distinction, the first heat transfer layer 50 is preferably formed directly on the weld layer 70.

[0146] (5) Intermediate layer 51

[0147] As described above, the intermediate layer 51 comprises a thermoplastic elastomer. In particular, the intermediate layer 51 is preferably formed solely of a thermoplastic elastomer. The thermoplastic elastomer forming the intermediate layer 51 preferably comprises 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-butene-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 styrene content in the thermoplastic elastomer contained in the intermediate layer 51 is, for example, 10% by mass or more and 70% by mass or less, preferably 15% by mass or more and 50% by mass or less. If the styrene content is too high, the rubbery elasticity of the intermediate layer 51 decreases, resulting in a failure to maintain adhesion to the first heat transfer layer 50 and the second heat transfer layer 52 during high-temperature transfer, and causing the text to appear cloudy. If the styrene content is too low, the rubbery elasticity of the intermediate layer 51 becomes too high, resulting in a failure to peel off the second heat transfer layer 52 during low-temperature transfer, leading to a cloudy text color.

[0150] The melt flow rate (hereinafter, may only be referred to as "MFR") of the thermoplastic elastomer contained in the intermediate layer 51 is, for example, 1000 g / 10 min or less, preferably 400 g / 10 min or less. The MFR can be determined, for example, by the test method specified in ISO 1133-1:2011, and can be the MFR at a temperature of 190°C and a load of 2.16 kg. Hereinafter, unless specifically stated otherwise, the conditions for measuring the MFR are a temperature of 190°C and a load of 2.16 kg.

[0151] Thermoplastic elastomers with a melt viscosity (MFR) exceeding 400 g / 10 min tend to have an excessively strong affinity for the second heat transfer layer 52. Therefore, there is a possibility that the second heat transfer layer 52 cannot be peeled off during low-temperature transfer, resulting in cloudy text. Furthermore, there is a possibility that the entire heat transfer recording medium 47—i.e., the substrate layer 48, the first heat transfer layer 50, the weld layer 70, the intermediate layer 51, and the second heat transfer layer 52—is adhered to the printing surface 31 of the printing belt 2. Thermoplastic elastomers with a MFR exceeding 400 g / 10 min have low melt viscosity and high fluidity, therefore, during low-temperature transfer, the adhesion between the first heat transfer layer 50 and the second heat transfer layer 52 cannot be maintained, resulting in cloudy text.

[0152] In contrast, if the MFR of the thermoplastic elastomer is 400 g / 10 min or less, the problems that arise when using thermoplastic elastomers with an MFR exceeding 400 g / 10 min can be suppressed. Furthermore, even with continuous heat transfer recording, the tones on the printing surface 31 of the printing belt 2 are less likely to become muddy and are clearly separated into two colors, and no excessive peeling occurs, resulting in text with excellent clarity. To further improve these effects, the MFR of the thermoplastic elastomer is preferably 2.5 g / 10 min or less, even within the aforementioned range, and particularly preferably 2.3 g / 10 min or less.

[0153] There is no particular limitation on the lower limit of MFR (Medium Flow Rate), and even thermoplastic elastomers that show "No Flow" at a temperature of 190°C and a load of 2.16 kg as described above can be used. Specific examples of thermoplastic elastomers are not particularly limited, but various thermoplastic elastomers such as those listed below can be cited. These thermoplastic elastomers can be used alone or in combination of two or more.

[0154] The following are SEBS products from the Tuftec (registered trademark) series manufactured by Asahi Kasei Corporation: H1521 (MFR: 2.3g / 10min), H1051 (MFR: less than 0.8g / 10min), H1052 (MFR: less than 13.0g / 10min), H1272 (MFR: NoFlow), P1083 (MFR: 3.0g / 10min), P1500 (MFR: 4.0g / 10min), P5051 (MFR: 3.0g / 10min), and P2000 (MFR: 3.0g / 10min).

[0155] Asahi Kasei Corporation manufactures the Tufprene (registered trademark) series of SBS products, including A (MFR: 2.6g / 10min), 125 (MFR: 4.5g / 10min), and 126S (MFR: 4.5g / 10min).

[0156] Asahi Kasei Corporation manufactures the following SBS series of Asaprene (registered trademark): 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] Kuraray, a joint-stock company, manufactures the SEPTON (registered trademark) series of SEPS products, including 2002 (MFR: 70g / 10min), 2004F (MFR: 5g / 10min), 2005 (MFR: No Flow), 2006 (MFR: No Flow), 2063 (MFR: 7g / 10min), and 2104 (MFR: 0.4g / 10min). The MFR of these SEPS products was measured at 230°C with a loading of 2.16kg.

[0158] Kuraray, a joint-stock company, manufactures SEPTON (registered trademark) series SEEPS, including 4033 (MFR: <0.1g / 10min), 4044 (MFR: No Flow), 4055 (MFR: No Flow), 4077 (MFR: No Flow), and 4099 (MFR: No Flow). The MFR of these SEEPS were measured at 230°C with a loading of 2.16kg.

[0159] Kuraray, Inc. manufactures HYBRAR (registered trademark) series vinyl SIS products 5125 (MFR: 4g / 10min) and 5127 (MFR: 5g / 10min).

[0160] Tosoh Corporation manufactures the Ultrasen (registered trademark) series of EVA, including 514R (MFR: 0.41g / 10min), 515 (MFR: 2.5g / 10min), 510 (MFR: 2.5g / 10min), 510F (MFR: 2.5g / 10min), 520F (MFR: 2.0g / 10min), 540 (MFR: 3.0g / 10min), and 540F (MFR: 3.0g / 10min). 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 can be a polyolefin resin or a long-chain alkyl resin, in addition to a 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 from the Piroyl (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 the forming material used for the intermediate layer 51 in any solvent onto the first heat transfer layer 50 and then drying it.

[0164] (6) Second heat transfer layer 52

[0165] The second heat transfer layer 52 can be formed from any thermoplastic resin. Examples of thermoplastic resins used for the second heat transfer layer 52 include epoxy resin, polyester resin, and polyolefin resin. The thermoplastic resin can be appropriately selected based on the forming material of the printing belt 2. If the first heat transfer layer 50 is formed from epoxy resin, the second heat transfer layer 52 is preferably also formed from epoxy resin.

[0166] By forming the second heat transfer layer 52 from epoxy resin, the adhesion force of the first heat transfer layer 50 to the weld layer 70 and the intermediate layer 51, and the adhesion force of the second heat transfer layer 52 to the printing belt 2, can be counteracted. Therefore, during low-temperature transfer, the first heat transfer layer 50 and the intermediate layer 51 can be well separated to the substrate layer 48 side, and the second heat transfer layer 52 can be well separated to the printing belt 2 side. Various epoxy resins, such as those used for the first heat transfer layer 50, can be cited as examples. These epoxy resins can be used alone or in combination of two or more.

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

[0168] As a wax, any wax that has affinity and compatibility with thermoplastic resins such as epoxy resins can be used. Natural waxes such as carnauba wax, paraffin wax, and microcrystalline wax, as well as synthetic waxes such as Fischer-Tropsch wax, can be used. There are no specific limitations on the specific examples of waxes, but examples that can be listed include: carnauba wax flakes No. 1, No. 2, No. 3, No. 1 powder, and No. 2 powder produced by Toyo Komi (Co., Ltd.) (all with melting points of 80-86℃); paraffin waxes such as EMUSTAR-1155 (melting point: 69℃), EMUSTAR-0135 (melting point: 60℃), and EMUSTAR-0136 (melting point: 60℃) produced by Nippon Seika (Co., Ltd.); microcrystalline waxes such as EMUSTAR-0001 (melting point: 84℃) and EMUSTAR-042X (melting point: 84℃) produced by Nippon Seika (Co., Ltd.); and Fischer-Tropsch waxes such as FNP-0090 (freezing point: 90℃), SX80 (freezing point: 83℃), FT-0165 (melting point: 73℃), and FT-0070 (melting point: 72℃) produced by Nippon Seika (Co., Ltd.). These waxes can be used alone or in combination of two or more.

[0169] The second heat transfer layer 52 may contain any colorant. One or more colorants corresponding to the hue of the second heat transfer layer 52 can be used as the colorant. For example, pigments can be used as the colorant. Considering improving the weather resistance of the text, pigments are preferred as the colorant used for the second heat transfer layer 52. For example, various red pigments can be listed below as pigments used to color the second heat transfer layer 52 red. These red pigments can 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] There are no particular limitations on the proportions of the components in the second heat transfer layer 52. For example, the proportion of wax to epoxy resin is 3 parts by mass or more, preferably 5 parts by mass or more. For example, the proportion of wax to epoxy resin is 11 parts by mass or less, preferably 9 parts by mass or less. For example, the proportion of wax to epoxy resin is 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 proportion of the colorant, such as the red pigment, to 100 parts by weight of epoxy resin is, for example, 70 parts by weight or more, preferably 80 parts by weight or more. The proportion of the colorant, such as the red pigment, to 100 parts by weight of epoxy resin is, for example, 140 parts by weight or less, preferably 120 parts by weight or less.

[0173] The ratio of the colorant, such as the red pigment, to 100 parts by weight of epoxy resin is, for example, 70 parts by weight or more and 140 parts by weight or less, preferably 80 parts by weight or more and 120 parts by weight or less.

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

[0175] In the thermal transfer recording medium 47, for example, there exists material to be applied to the thermal head 6 (see reference). Figure 1 and Figure 3 In this embodiment, the energy setting is lower, resulting in a lower temperature for heat transfer. In this case, the second heat transfer layer 52 softens, and the adhesion force relative to the substrate layer 48 decreases. On the other hand, the adhesion force between the first heat transfer layer 50 and the second heat transfer layer 52 decreases. At this time, the weld layer 70, having a high softening point, hardly softens, thus maintaining a high adhesion force between the substrate layer 48 and the first heat transfer layer 50. As a result, during heat transfer, a reverse print is generated where the first heat transfer layer 50 and the intermediate layer 51 remain on the substrate layer 48 side, and only the second heat transfer layer 52 is heat-transferred to the printing surface 31 of the printing belt 2. Therefore, the text recorded on the printing surface 31 of the printing belt 2 becomes the hue of the second heat transfer layer 52, for example, red.

[0176] On the other hand, the thermal transfer recording medium 47 may have a situation where the energy applied to the thermal head 6 is set higher, resulting in thermal transfer at a higher temperature. In this case, the weld layer 70 softens further, for example, the adhesion between it and the substrate layer 48 is significantly reduced. As a result, the entire thermal transfer layer, namely the weld layer 70, the first thermal transfer layer 50, the intermediate layer 51, and the second thermal transfer layer 52, is integrally thermally transferred to the printing surface 31 of the printing belt 2. The text recorded on the printing surface 31 of the printing belt 2 becomes the color of the outermost first thermal transfer layer 50 after transfer, such as black.

[0177] As a result, it is possible to use a general-purpose thermal transfer printer that corresponds to two-color recording to record patterns in, for example, black and red.

[0178] Therefore, according to the present invention, a general thermal transfer printer corresponding to two-color recording can be used to clearly separate the two colors even when thermal transfer recording is performed continuously, and no excessive peeling is produced, so that text with excellent clarity can be recorded.

[0179] [Thickness of each layer of the thermal transfer recording medium 47]

[0180] One characteristic of the thermal transfer recording medium 47 according to one embodiment of the present invention is that the total thickness of the transfer material leaving the substrate layer 48 by thermal transfer during low-temperature heating is thinner than that of the first thermal transfer layer 50. Hereinafter, [further details will be provided]. Figures 1 to 4A The heating and cooling processes shown in B are described in detail, and the characteristics of the thickness of the thermal transfer recording medium 47 are mentioned.

[0181] Figure 14 It means Figures 1 to 4A The graph shown in Figures B illustrates the relationship between the elapsed time of the heating and cooling processes and the arrival temperature of the heat transfer recording medium 47.

[0182] Figure 14 The horizontal axis represents the elapsed time of the printing process in printing device 1. t0 indicates the start of printing, t1 indicates the end of heating based on thermal head 6, and t2 indicates the time when the ink ribbon peeling part 13 is reached. Figure 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. These external factors may include, for example, heating based on the thermal head 6, natural cooling during the transport of the thermal transfer recording medium 47, etc.

[0183] Reference Figure 14 In the printing apparatus 1, the temperature output (temperature energy) of the thermal head 6 is controlled by the control circuit 22, thereby controlling the arrival temperature of the thermal transfer recording medium 47. For example, a relatively low first energy is applied to the thermal head 6 during the heating process. In this case, the temperature of the thermal transfer recording medium 47 is as shown by the first temperature curve 55 with a single-dotted line, which is determined from the ambient temperature (e.g., room temperature) T around the thermal transfer recording medium 47. E It increases exponentially to reach T R1 .

[0184] Reaching 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 or higher and 120°C or lower, preferably 70°C or higher and 90°C or lower. For example, the second temperature T2 is 80°C or higher and 180°C or lower, preferably 130°C or higher and 150°C or lower. The temperature reached is T...R1 The output setting method of the thermal head 6 of the printing apparatus 1 can be appropriately set according to the printing apparatus 1 used. For example, the temperature reached can be set in relation to quantitative parameters such as the voltage, current, and energizing time supplied to the heating element 20 of the thermal head 6. Alternatively, the temperature reached can be set in relation to a relative value relative to a predetermined reference value (e.g., setting the value before energizing to 0 (zero)).

[0186] On the other hand, during the heating process, a second energy, which is 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, as shown by the solid line in the second temperature curve 56, increases from the ambient temperature T. E And it increases exponentially to reach T. R2 Reaching temperature T R2 It can also be defined as the temperature exceeding the second temperature T2.

[0187] After the heating process, the thermal transfer recording medium 47 cools naturally in the interval up to the ink ribbon peeling member 13 (see also...). Figure 3 and Figure 4A (B). During the cooling process, the temperature of the thermal transfer recording medium 47 decreases from the temperature reached T. R1 and T R2 It decreases exponentially to reach T P The temperature T at this point P It is the temperature at which part of the thermal transfer recording medium 47 is peeled off by the ink ribbon peeling component 13, and therefore can be defined as the peeling temperature T. P Peeling temperature T P Preferably, the third temperature T3 is below. 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, above 40°C and below 90°C, preferably above 60°C and below 80°C. The values ​​of the first temperature T1, the second temperature T2, and the third temperature T3 can be appropriately set within the temperature range required for the transfer of ink by the printing belt 2, taking into account the chemical composition and physical properties of the ink of the thermal transfer recording medium 47.

[0188] The temperature profile (cooling profile) of the heat transfer recording medium 47 in the cooling process converges to a fixed temperature regardless of which heating control is applied during the heating process as shown by the first temperature profile 55 and the second temperature profile 56. Therefore, in order to ensure a longer cooling process time (t1→t2), the peeling temperature T of the first temperature profile 55 and the second temperature profile 56 can be increased. P The process is largely the same. To extend the cooling process time, for example, simply increase the distance between the thermal head 6 and the ribbon stripping component 13. Figure 1 The peeling distance L1 is sufficient. For example, it can be achieved by... Figure 14The state of the heat transfer recording medium 47 after the heating and cooling processes are performed by the temperature changes shown in the first temperature curve 55 is defined as the first state C1. In contrast, the state of the heat transfer recording medium 47 after the heating and cooling processes are performed by the temperature changes shown in the first temperature curve 55 can be defined as the first state C1. Figure 14 The state of the heat transfer recording medium 47 after the heating and cooling processes are performed by the temperature changes shown in the second temperature curve 56 is defined as the second state C2.

[0189] Thus, in the printing apparatus 1, by controlling the temperature output (temperature energy) of the thermal head 6, the starting temperature (ambient temperature T) can be maintained throughout the process from the start of the heating process to the end of the cooling process. E ) and final temperature (peeling temperature T) P The temperature is fixed, while the arrival temperature of the thermal transfer recording medium 47 varies. This temperature control can be achieved, for example, by adjusting the temperature according to... Figure 13 The temperature output of the thermal head 6 is controlled by the physical properties of the substrate layer 48, back layer 49, welding layer 70, first thermal transfer layer 50, intermediate layer 51 and 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 break away from the substrate layer 48 side during 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 weld layer 70, the first thermal transfer layer 50, the intermediate layer 51, and the second thermal transfer layer 52.

[0191] Furthermore, 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, for example, based on SEM (Scanning Electron Microscope) images, TEM (Transmission Electron Microscope) images, etc., of the thermal transfer recording medium 47.

[0192] The thickness of the weld layer 70 can be adjusted, for example, by the coating amount of the weld layer 70. For example, the coating amount of the weld layer 70 is expressed as 0.1 g / m² of solid content per unit area. 2 The above is preferably 0.2 g / m 2 The above. For example, the coating weight of the weld layer 70, expressed as solid content per unit area, is 1.5 g / m². 2 The preferred value is 1.0 g / m 2 the following.

[0193] For example, the coating weight of the weld layer 70 is expressed as 0.1 g / m², which is the amount of solids per unit area. 2 Above and 1.5g / m 2 The preferred value is 0.2 g / m 2 Above and 1.0g / m 2 the following.

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

[0195] The thickness of the first heat transfer layer 50 can be adjusted, for example, by the coating amount of the first heat transfer layer 50. For example, the coating amount of the first heat transfer layer 50, expressed as the amount of solids per unit area, is 0.1 g / m². 2 The above is preferably 0.5g / m 2 The above. For example, the coating weight of the first heat transfer layer 50, expressed as solid content per unit area, is 3.0 g / m². 2 The preferred value is 2.5 g / m³. 2 For example, the coating weight of the first thermal transfer layer 50 is expressed as 0.1 g / m², which is the amount of solids per unit area. 2 Above and 3.0g / m 2 The preferred value is 0.5 g / m 2 Above and 2.5g / m 2 The specific thickness (before printing) of the first heat transfer layer 50 can be, for example, 0.05 μm or more and 3.0 μm or less, preferably 0.5 μm or more and 2.5 μm or less.

[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 expressed as 0.1 g / m² of solid content per unit area. 2 The above is preferably 0.2 g / m 2 That's all. For example, the coating weight of intermediate layer 51, expressed as solid content per unit area, is 2.0 g / m². 2 The preferred value is 1.5 g / m³. 2 the following.

[0197] For example, the coating weight of intermediate layer 51 is expressed as 0.1 g / m², which is the amount of solids per unit area. 2 Above and 2.0g / m 2 The preferred value is 0.2 g / m 2 Above and 1.5g / m 2 the following.

[0198] The specific thickness of the intermediate layer 51 (before printing) is, for example, 0.05 μm or more and 2.0 μm or less, and preferably 0.2 μm or more and 1.5 μm or less. The intermediate layer 51 is preferably thinner than the first heat transfer layer 50 and the second heat transfer layer 52. This is because if the intermediate layer 51, which does not contain pigments or other colorants, is too thick, the film's cross-sectional properties will deteriorate, potentially reducing the clarity of the recorded pattern.

[0199] The thickness of the second heat transfer layer 52 can be adjusted, for example, by the coating amount of the second heat transfer layer 52. For example, the coating amount of the second heat transfer layer 52, expressed as the amount of solids per unit area, is 0.2 g / m². 2 The above, preferably 1.0 g / m 2 The above. For example, the coating weight of the second heat transfer layer 52, expressed as solid content per unit area, is 7.0 g / m². 2 The preferred value is 5.0 g / m³. 2 For example, the coating amount of the second heat transfer layer 52 is expressed as 0.2 g / m², which is the amount of solids per unit area. 2 Above and 7.0g / m 2 The preferred value is 1.0 g / m 2 Above and 5.0g / m 2 The specific thickness (before printing) of the second heat transfer layer 52 is, for example, 0.05 μm or more and 7.0 μm or less, and preferably 1.0 μm or more and 5.0 μm or less.

[0200] Furthermore, the total thickness of the transfer material is preferably 13.5 μm or less. This is because if the total thickness of the transfer material exceeds 10 μm, the heating temperature of the thermal head 6 needs to be set higher, which may damage the lifespan of the thermal head 6. Additionally, when the thickness of the first thermal transfer layer 50 (black in this embodiment) differs drastically from the thickness of the second thermal transfer layer 52 (red in this embodiment) (e.g., a difference of more than four times), even when printing black, the influence of red is significant, and there is a possibility of black color degradation. Therefore, it is necessary to adjust the thickness of the first thermal transfer layer 50 and the second thermal transfer layer 52, as well as the selection of the colorant, within an appropriate coating amount range.

[0201] [Peeling mode of thermal transfer recording medium 47]

[0202] Figures 15-19 This is a diagram showing the peeling state of the thermal transfer recording medium 47. (Refer to...) Figures 15-19 Several peeling modes are listed for thermal transfer recording medium 47. These modes can be... Figures 15-19 The stripping modes are sequentially referred to as the first stripping mode to the fifth stripping mode. From the perspective of the energy supplied to the thermal head 6, they can be distinguished as follows: Figures 15-18The low-energy stripping mode shown and Figure 19 The high-energy stripping mode is shown.

[0203] Figures 15-18 It is through Figure 14 The first temperature curve 55 is used for heating control (applying low energy) and the peeling mode is performed during peeling (thermal transfer) in the first state C1. Figure 15 In the first peeling mode, the fracture strength between the intermediate layer 51 and the second thermal transfer layer 52 is minimum in the thermal transfer recording medium 47 under the first state C1, and peeling occurs at these interfaces. Figure 16 In the second peeling mode, the fracture strength within the second thermal transfer layer 52 under the first state C1 is minimized in the thermal transfer recording medium 47, resulting in peeling within the second thermal transfer layer 52. Figure 17 In the third peeling mode, the fracture strength within the intermediate layer 51 in the first state C1 is minimized in the thermal transfer recording medium 47, resulting in peeling within the intermediate layer 51. Figure 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. Furthermore, the fracture strength between the mixed layer 61 and the second thermal transfer layer 52 is the lowest in the thermal transfer recording medium 47, and peeling occurs at their interface.

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

[0205] Figure 19 It is through Figure 14 The second temperature curve 56 is used for heating control (applying high energy) and the peeling mode is performed when peeling (thermal transfer) is carried out in the second state C2.

[0206] exist Figure 19 In the fifth peeling mode, the fracture strength between the substrate layer 48 and the weld layer 70 in the second state C2 is the lowest in the thermal transfer recording medium 47, and peeling (interface failure) occurs at their interface.

[0207] according to Figure 19 In the peeling mode, the first heat transfer layer 50 and the second heat transfer layer 52, which are in an adhesive state, are selectively transferred to the printing belt 2.

[0208] Thermal transfer recording media 47 Figures 15-19Which detachment mode of fracture can be identified, for example, by observing the cross-section of the fractured thermal transfer recording medium 47. For example, it can be identified based on SEM (Scanning Electron Microscope) images, TEM (Transmission Electron Microscope) images, etc., of the fractured thermal transfer recording medium 47.

[0209] As described above, in the first to fourth peel modes, the text recorded on the printing surface 31 of the printing belt 2 becomes the color of the second heat transfer layer 52, for example, red. In the fifth peel mode, the text recorded on the printing surface 31 of the printing belt 2 becomes the color of the first heat transfer layer 50, for example, black.

[0210] Example

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

[0212] [Coating for the first heat transfer layer]

[0213] The components shown in Table 1 below are dissolved in a mixed solvent of toluene and methyl ethyl ketone (MEK) in a mass ratio of 1 / 4 to prepare a coating for a first heat transfer layer with a solid component concentration of 22.5% by mass.

[0214] The proportion of the active ingredient in acrylic adhesives is 80 parts by weight of epoxy resin per 100 parts by weight.

[0215] [Table 1]

[0216] Epoxy resin 100 acrylic adhesives 200 Tackifier 28.3 carbon black 166.7

[0217] The components in the table are described below.

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

[0219] Acrylic adhesive: AS-665 (solids concentration: 40% by mass) manufactured by LION SPECIALTY CHEMICALS (Industrial and Commercial Corporation)

[0220] Tackifier: Terpene phenolic resin, YS POLYSTERT80 (softening point: 80±5℃) manufactured by YASUHARA CHEMICAL (Co., Ltd.)

[0221] Carbon black: MA100 powder (LFF, DBP absorbance: 100 cm⁻¹) manufactured by Mitsubishi Chemical Corporation. 3 / 100g)

[0222] Coating for weld lines

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

[0224] [Intermediate layer coating (1)]

[0225] A thermoplastic elastomer (Tuftec H1521, SEBS, MFR: 2.3 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 with a solid content concentration of 10% by mass (1).

[0226] [Intermediate layer coating (2)]

[0227] Instead of thermoplastic elastomer, the intermediate layer coating (2) is prepared by mixing the modified polyolefin resin (SURFLEN P-1000 manufactured by Mitsubishi Chemical Corporation) in the same amount as the intermediate layer coating (1), thereby forming the intermediate layer coating. The solid component concentration is 10% by mass.

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

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

[0230] [Table 2]

[0231] Epoxy resin 100 wax 7.1 Red pigment 92.9

[0232] The components in the table are described below.

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

[0234] Wax: Carnauba wax No. 2 powder (melting point: 80-86℃) manufactured by Toyo Komi (Co., Ltd.)

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

[0236] [Experimental Examples 1-6]

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

[0238] First, a 4.5 μm thick PET film is prepared as the substrate layer. Next, a silicone-based resin with a solid content of 0.1 g / m² per unit area is formed on the side of this substrate layer opposite to the surface where the heat transfer layer will be formed (the back side). 2 The back layer is then formed. Next, the solid content per unit area of ​​the previously prepared weld layer is adjusted using a coating to achieve the thickness shown in Tables 3-4 below, and then dried after being applied to the surface of the substrate layer, thereby forming the weld layer. Next, the solid content per unit area of ​​the previously prepared first heat transfer layer coating is adjusted to achieve the thickness shown in Tables 3-4 below, and then dried after being applied to the weld layer, thereby forming the first heat transfer layer. Next, the solid content per unit area of ​​any one of the previously prepared intermediate layers is adjusted using a coating to achieve the thickness shown in Tables 3-4 below, and then dried after being applied to the first heat transfer layer, thereby forming the intermediate layer. Next, the solid content per unit area of ​​the previously prepared second heat transfer layer coating is adjusted to achieve the thickness shown in Tables 3-4 below, and then dried after being applied to the intermediate layer, thereby forming the second heat transfer layer, thus manufacturing the heat transfer recording medium. The composition of each layer of the heat transfer recording medium obtained in Experimental Examples 1-6 is shown in Tables 3-4 below.

[0239] (2) Evaluation

[0240] (2-1) Evaluation of printability of edge pattern

[0241] The thermal transfer recording media manufactured in each experimental example were cut into ink ribbons of a specified width, wound into rollers, and placed in a thermal transfer printer (a prototype printer manufactured by Brother Industries, Inc.). The main specifications of this thermal transfer printer are shown below.

[0242]

[0243] Next, under an ambient temperature of 25°C, the energy value applied to the thermal head in the thermal transfer printer was set to a low value (0.25 mJ / dot: 25V (0.34 W / dot) / 750 μsec, red). A specified printing pattern was recorded on the surface of a variable information label material (polyester film (white gloss), FR1415-50 manufactured by LINTEC Inc.). The printing pattern was a pattern composed of multiple squares of 5 dots × 5 dots arranged in a sphere-like pattern with intervals. Then, one of the spheres of the printed pattern was observed under a microscope under magnification. The area ratio (black / (red + black)) of the image printed in red and the image printed in black (periphery) in the sphere was calculated, and the printability of the edge was evaluated based on the following criteria.

[0244] 〇: Area ratio less than 10%.

[0245] △: Area ratio is 10% or more but less than 20%.

[0246] ×: Area ratio is 20% or more.

[0247] (2-2) Evaluation of Record Clarity

[0248] The thermal transfer recording media manufactured in each experimental example were cut into ink ribbons of a specified width and wound into rollers. These rollers were then placed in a thermal transfer printer of the same specifications as (2-1) (a prototype printer manufactured by Brother Industries, Inc.). The ink ribbons were bonded to the thermal printhead at an ambient temperature of 25°C. The energy value applied to the thermal printhead was set to low energy (0.25 mJ / dot: 25V (0.34 W / dot) / 750 μsec, red) or high energy (0.34 mJ / dot: 25V (0.34 W / dot) / 1000 μsec, black) in the thermal transfer printer. Barcodes were then recorded on the surface of a variable information label material (polyester film (white, glossy), FR1415-50 manufactured by LINTEC Inc.). Furthermore, the decodability level specified in the American National Standards Institute (ANSI X3.182-1990) is determined based on the results of reading the recorded barcode using a barcode verifier (MUNAZO (Incorporated) Laser Sampling Elite IS), and the clarity of the record is evaluated using the following criteria.

[0249] 〇: Both black and red have a decodeability rating of A [Excellent] or B [Superior].

[0250] △: Either black or red has a decodeability level of C [Good], and the other has a decodeability level of C [Good] or higher.

[0251] ×: At least one of black and red has a decodeability rating of D [pass] or F [fail].

[0252] The results are shown in Tables 3 and 4. Alternatively, in Experiments 1 to 4, Experiments 5 to 6 may be exemplary cases and Experiments 5 to 6 may be comparative cases.

[0253] (2-3) Observation of the fracture location

[0254] The thermal transfer recording media manufactured in each experimental example were cut into ink ribbons of a specified width and wound into rollers. These rollers were then placed in a thermal transfer printer of the same specifications as (2-1) (a prototype printer manufactured by Brother Industries, Inc.). Bonding was performed at an ambient temperature of 25°C. The energy values ​​applied to the thermal head in the thermal transfer printer were set to low energy (0.25 mJ / dot: 25V (0.34 W / dot) / 750 μsec, red) or high energy (0.34 mJ / dot: 25V (0.34 W / dot) / 1000 μsec, black), respectively. A solid image of 70 mm square was recorded on the surface of variable information label material (polyester film (white, glossy), FR1415-50 manufactured by LINTEC, Inc.). In all cases, the peel distance of the thermal transfer printer was ensured to be 110 mm, therefore peeling was performed after sufficient cooling (below 60°C). The cross-sections of the obtained solid images were observed using a transmission electron microscope (TEM: Hitachi High Technology Co., Ltd. HT7820, accelerating voltage 100kV). In each of the black and red transfers, the location of the fracture in the thermal transfer recording medium was identified. The fracture locations are distinguished by the peeling pattern, as described below.

[0255] First peeling mode: Between the intermediate layer and the second heat transfer layer (interface damage reference) Figure 15 )

[0256] Second peeling mode: The interior of the second heat transfer layer (coagulation destruction reference) Figure 16 )

[0257] Third stripping mode: the interior of the intermediate layer (cohesion failure reference) Figure 17 )

[0258] Fourth peeling mode: Between the hybrid layer and the second thermal transfer layer (interface damage reference) Figure 18 )

[0259] Fifth peeling mode: Between the substrate layer and the weld layer (interface failure reference) Figure 19 )

[0260] The results are shown in Tables 3 and 4. In Tables 3 and 4, only circled numbers are used to represent the first to fifth peeling modes, respectively. Furthermore, in Tables 3 and 4, when multiple peeling modes are shown, it indicates that different peeling modes were generated in the in-plane direction of the thermal transfer recording medium. Additionally, since Experimental Example 2 lacks an intermediate layer structure, the peeling mode of Experimental Example 2, strictly speaking, generated from... Figure 16 , Figure 18 and Figure 19 The stripping mode omits the state of intermediate layer 51.

[0261] [Table 3]

[0262]

[0263] [Table 4]

[0264]

[0265]

[0266] A comparison of Experiment 1 and Experiments 5-6 shows that making the second heat transfer layer thinner than the first heat transfer layer improves the printability of edge patterns. In Experiments 5-6, the thickness of the second heat transfer layer was greater than or equal to the thickness of the first heat transfer layer, resulting in easier edge pattern generation.

[0267] Regarding Experimental Example 2, without an intermediate layer, the first and second heat transfer layers are in contact and adjacent, thus making it easier to produce edge patterns compared to Experimental Example 1. Furthermore, the first and second heat transfer layers are difficult to separate, resulting in poor image sharpness.

[0268] Regarding Experiment 3, when the intermediate layer was relatively thick, the edge printability was good. On the other hand, the poor chelation of the intermediate layer resulted in poor clarity due to excessive peeling, etc.

[0269] Regarding Experiment 4, if the intermediate layer is a coagulation-destructive material such as polyolefin, the peeling location under low-temperature printing is inside the intermediate layer, and the transfer material becomes part of the second heat transfer layer and the intermediate layer.

[0270] Even in this case, it is known that as long as the total thickness of the transfer material is thinner than the first heat transfer layer before transfer, the printability of the edge texture can be improved. However, due to the cohesion failure caused by the intermediate layer, the result is a result with poorer clarity compared to the case where thermoplastic elastomer (SEBS) is used for the intermediate layer.

[0271] Symbol Explanation

[0272] 1: Printing apparatus

[0273] 2: Printing tape

[0274] 3: Ink ribbon

[0275] 20: Fever Element

[0276] 31: Printed surface

[0277] 32: Back

[0278] 33: Adhesive surface

[0279] 34: Back

[0280] 35: Substrate layer

[0281] 36: First ink layer

[0282] 37: Second ink layer

[0283] 38: Surface

[0284] 39: Back

[0285] 40: Part One

[0286] 41: Part Two

[0287] 42: Part One

[0288] 43: Part Two

[0289] 44: Printed Pattern

[0290] 45: Red pattern

[0291] 46: Black pattern

[0292] 47: Thermal transfer recording media

[0293] 48: Substrate layer

[0294] 49: Back layer

[0295] 50: First heat transfer layer

[0296] 51: Intermediate Layer

[0297] 52: Second heat transfer layer

[0298] 53: Surface

[0299] 54: Back

[0300] 80: Border

[0301] 87: First dividing section

[0302] 88: Second dividing section

[0303] 89: Third Boundary

[0304] 96: First temperature distribution curve

[0305] 97: Second temperature distribution curve

[0306] 98: High-temperature side boundary conditions

[0307] 99: Low-temperature side boundary conditions

[0308] 100: Central Department

[0309] 101: Peripheral Section

[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: Arrival Temperature

[0321] T1: Temperature rise

[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, sequentially stacked, wherein at least a portion of the first ink layer and the second ink layer is thermally transferred to a printing medium, characterized in that, In a first state where the thermal transfer recording medium is heated to above a first temperature and below a second temperature, and then cooled to 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 break apart, or break within the second ink layer. In a second state, after the thermal transfer recording medium has been heated to a temperature exceeding the second temperature and then cooled to a temperature below the third temperature, the first ink layer breaks between itself and the substrate layer or within the first ink layer when the external force is applied. The total thickness of all layers that break off from the substrate layer side in the first state before heat transfer is thinner than the first ink layer. The first temperature is higher than the third temperature.

2. The thermal transfer recording medium according to claim 1, characterized in that, When the external force is applied in the first state, the fracture strength between the first ink layer and the second ink layer, or within the second ink layer, is the minimum in the thermal transfer recording medium. When the external force is applied in the second state, the fracture strength between the first ink layer and the substrate layer or within the first ink layer is the minimum 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 break.

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

7. The thermal transfer recording medium according to claim 6, characterized in that, When the external force is applied in the first state, the fracture strength of the intermediate layer is the minimum 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 weld layer between the substrate layer and the first ink layer. When the external force is applied in the second state, the welded layer breaks off from the substrate layer.

9. The thermal transfer recording medium according to claim 8, characterized in that, When the external force is applied in the second state, the fracture strength between the welded layer and the substrate layer is the minimum in the thermal transfer recording medium.

10. The thermal transfer recording medium according to claim 1 or 2, characterized in that, The first state is the state in which the substrate layer of the thermal transfer recording medium is heated to above the first temperature and below the second temperature, and then cooled to below the third temperature. The second state is the state in which the substrate layer of the thermal transfer recording medium is heated to a temperature exceeding the second temperature and then cooled to a temperature below the third temperature.

11. A printing apparatus, performing: The heating process involves heating the heat transfer recording medium while it is in contact with the medium being printed. The heat transfer recording medium is composed of a substrate layer, a first ink layer containing a first ink, and a second ink layer containing a second ink, which are stacked sequentially. A cooling process to cool the thermal transfer recording medium after it has been heated by the heating process; and The transfer process involves applying an external force to the substrate layer and the second ink layer of the heat transfer recording medium, which have been cooled by the cooling process, in a direction moving away from each other, thereby transferring at least a portion of the first ink and the second ink to the printing medium, characterized in that... In the heating process and the cooling process, A first state is defined as heating a first portion of the thermal transfer recording medium to a temperature above a first temperature and below a second temperature, and then cooling it to a temperature below a third temperature. A second state is defined as heating a second portion of the thermal transfer recording medium to a temperature exceeding the second temperature and then cooling it to a temperature below the third temperature. In the transfer process, By applying the external force, the heat transfer recording medium is broken between or within the first ink layer and the second ink layer in the first portion of the heat transfer recording medium, transferring the second ink to the printing medium. The total thickness of all the transferred layers before heat transfer is thinner than the first ink layer. By applying the external force, the thermal transfer recording medium is broken at the second portion of the thermal transfer recording medium between the first ink layer and the substrate layer or within the first ink layer, thereby transferring the first ink and the second ink to the printed medium. The first temperature is higher than the third temperature.

12. A box, characterized in that, Built-in features: The thermal transfer recording medium as described in claim 1 or 2; and A printed medium for thermal transfer of a portion of the thermal transfer recording medium.

Images