Thermal transfer type ink ribbon

Abstract

To provide a thermofusible transfer type ink ribbon which is excellent in environmental preservation performance under high temperature environment, is less likely to cause planar peeling on a printed image even when printing is performed under high temperature environment, and has good printing sensitivity.SOLUTION: There is provided a thermofusible transfer type ink ribbon 1 in which a heat-resistant lubricant layer 3 is provided on one surface of a base material film 2, and a transfer control layer 4 and an ink layer 5 are sequentially stacked on the other surface, wherein the ink layer 5 contains a coloring component and a binder component, the binder component of the ink layer 5 contains an ethylenic copolymer resin having a melting peak temperature of 60°C or higher, aliphatic hydrocarbon synthesis wax fine particles having a melting peak temperature of 100°C or higher, and a tackifier resin, and the transfer control layer 4 contains 50 mass% or more and 95 mass% or less of the aliphatic hydrocarbon synthesis wax fine particles having a melting peak temperature of 100°C or higher of the whole transfer control layer, and 5 mass% or more and 50 mass% or less of carboxylic acid-modified polyolefin having a melting peak temperature of 100°C or higher of the whole transfer control layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a thermal transfer type ink ribbon that is excellent in environmental storage performance and printing quality under high-temperature environments, and further has good printing sensitivity.

Background Art

[0002] A thermal transfer type ink ribbon provided with an ink layer containing at least a coloring component such as a pigment and a binder component such as various waxes and resins on a base film is loaded into a thermal transfer printer and used, and is widely used for printing character information, barcodes, etc. on display labels, management labels, etc. in offices, factories, logistics warehouses, etc.

[0003] Compared with office printers, thermal transfer printers are made with a simple structure, so they are excellent in maintainability, less likely to break down, and it is possible to make the printer compact. For these reasons, they are widely used in various places and environments.

[0004] However, for example, in places where air conditioning is not very effective in summer, or in environments where the temperature is particularly high, such as in a food production line, even just by installing a thermal transfer printer, a blocking phenomenon may occur in the thermal transfer type ink ribbon loaded inside the thermal transfer printer, or the ink layer or transfer control layer of the thermal transfer type ink ribbon may soften and deform, resulting in problems such as deterioration of printing quality due to environmental storage performance problems of the thermal transfer type ink ribbon.

[0005] Furthermore, in a high-temperature environment as described above, when continuous printing is performed using a thermal transfer printer, the heat generated during printing is not dissipated and accumulates in the thermal head, and this heat tends to easily cause a printing quality problem called planar peeling in the printed image.

[0006] Regarding the surface peeling, as shown in Fig. 2, the surface peeling refers to the printed image 7b that is unevenly formed in a scaly or wavy shape on the side opposite to the conveyance direction of the printing medium 6 of the printed image 7a that was originally planned to be formed. While the printed image 7a is firmly transferred and adhered to the printing medium 6, the peeled part 7b is usually not firmly adhered to the printing medium 6 even if it is transferred, or is not adhered at all. When this surface peeling occurs, in printing such as character information, not only does it look bad in appearance, but in severe cases, the characters cannot be recognized. In printing such as barcodes, not only do problems in print quality such as poor barcode reading occur, but also problems such as the peeled part coming off and scattering, contaminating the printing medium and the surrounding environment occur.

[0007] To explain an example of the general printing mechanism performed by a thermal transfer printer, as shown in Fig. 3, the printing medium 6 and the thermal melting transfer type ink ribbon 1 are set in the thermal transfer printer in a state where they are sandwiched between the thermal head 8 and the platen roll 9 of the thermal transfer printer and are pressure-bonded. At the time of printing, the transfer control layer 4 and the ink layer 5 of the part where the printed image is formed are heated by the thermal head 8 to be softened and melted. After they are wetted or infiltrated into the surface layer part of the printing medium 6 and then cooled and solidified to a certain extent, the thermal melting transfer type ink ribbon 1 and the printing medium 6 are peeled off, whereby the printed image composed of the transfer control layer 4 and the ink layer 5 is formed on the printing medium 6.

[0008] During normal printing, the transfer control layer 4 and the ink layer 5 between A and B in Fig. 3 are overheated by the thermal head 8 to be firmly softened and melted, and delamination occurs near the interface between the transfer control layer 4 and the base film 2 where the adhesive force is the weakest, and only the transfer control layer 4 and the ink layer 5 between A and B in Fig. 3 are transferred to the printing medium 6. That is, only the printed image that was originally planned to be formed in the part 7a of Fig. 3 is formed.

[0009] However, during printing when planar peeling occurs, although the thermal head 8 only heats between A and B in Fig. 3, for some reason, due to the heat accumulated in the thermal head 8 during printing, at least only the transfer control layer 4 on the side closer to the base material film 2 between B and C in Fig. 3 softens and melts, but the ink layer 5 does not soften and melt, or a state occurs where the transfer control layer 4 and the ink layer 5 between B and C soften and melt incompletely. This causes, when peeling the thermal transfer type ink ribbon 1 and the medium to be printed 6, a part of the transfer control layer 4 and the ink layer 5 between B and C in Fig. 3 to be transferred as a printed image 7b which is a planar peeling part in a form pulled by the originally planned printed image 7a. The part of this printed image 7b is transferred in a form forcibly pulled by the part of the printed image 7a. Since the transfer control layer 4 and the ink layer 5 are mechanically and forcibly broken at the position C in Fig. 3, the fracture surface is formed unevenly like on scales or wavy. Also, since the ink layer 5 between B and C in Fig. 3 is not softened and melted at all, or is only softened and melted incompletely, although it is transferred to the medium to be transferred 6, it does not adhere at all, or does not adhere firmly. When such planar peeling occurs, it causes problems such as the above-mentioned printing quality problems and contamination problems, and thus improvement has been conventionally demanded.

[0010] To improve such problems, Patent Document 1 proposes a thermal transfer type ink ribbon in which a heat-resistant lubricity layer is provided on one surface of a base material film, and a transfer control layer and an ink layer are sequentially laminated on the other surface. The ink layer contains a thermoplastic resin with a glass transition temperature of 50°C or higher and 110°C or lower, and further, the transfer control layer contains 50% by mass or more of fine particles composed of high-density polyethylene wax with a melting peak temperature of 110°C or higher and 135°C or lower and a temperature difference between the melting peak temperature and the supplementary melting start temperature within 10.0°C.

[0011] If the hot-melt transfer type ink ribbon proposed in Patent Document 1 is used, it has excellent environmental storage performance in a high-temperature environment, and further, when printing is performed in a high-temperature environment, planar peeling is less likely to occur in the printed image. On the other hand, when the addition amount of the thermoplastic resin having a relatively high glass transition point added to the ink layer increases, or the addition amount of the high-melting-point high-density polyethylene wax showing specific melting characteristics added as the main component of the transfer control layer increases, the printing sensitivity deteriorates, and the range of printing energy capable of maintaining good printing quality tends to be relatively narrow. As a result, depending on the type of thermal transfer printer and the printing environment, problems such as streaky printing may occur.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0013] The present invention has been made in view of such a situation, and the main problem is to provide a hot-melt transfer type ink ribbon that has excellent environmental storage performance in a high-temperature environment, is less likely to cause planar peeling in the printed image when printing in a high-temperature environment, and has good printing sensitivity.

Means for Solving the Problems

[0014] In order to solve the above problems, as a result of the inventor's study, a hot-melt transfer type ink ribbon is provided with a heat-resistant lubricity layer on one surface of a base film, and a transfer control layer and an ink layer are sequentially laminated on the other surface. The ink layer contains a coloring component and a binder component. The binder component of the ink layer contains an ethylene-based copolymer resin having a melting peak temperature of 60°C or higher, aliphatic hydrocarbon synthetic wax fine particles having a melting peak temperature of 100°C or higher, and a tackifier resin. The transfer control layer contains aliphatic hydrocarbon synthetic wax fine particles having a melting peak temperature of 100°C or higher in the range of 50% by mass or more and 95% by mass or less of the entire transfer control layer and carboxylic acid-modified polyolefin having a melting peak temperature of 100°C or higher in the range of 5% by mass or more and 50% by mass or less of the entire transfer control layer. By using such a hot-melt transfer type ink ribbon, it has excellent environmental storage performance in a high-temperature environment of 50°C, and it is difficult for planar peeling to occur in the printed image when printing is performed in a high-temperature environment of 40°C. Furthermore, it has been found that the printing sensitivity is also good.

Effects of the Invention

[0015] When the hot-melt transfer type ink ribbon of the present invention is used, problems such as blocking phenomenon and deterioration of printing quality are less likely to occur even when stored in a high-temperature environment. Problems such as planar peeling in the printed image when printing is performed in a high-temperature environment are also less likely to occur. Furthermore, since the printing sensitivity is good, malfunctions due to printing sensitivity are less likely to occur even when used in various printers and various environments.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

[0017] As shown in FIG. 1, the thermal transfer type ink ribbon 1 of the present invention has a structure in which a heat-resistant lubricating layer 3 is provided on one surface of a base film 2, and a transfer control layer 4 and an ink layer 5 are sequentially laminated on the other surface.

[0018] <<Each component of the thermal transfer type ink ribbon>> Next, details of each component of the thermal transfer type ink ribbon in the present invention are shown below.

[0019] <Base film> The base film used in the present invention is not particularly limited as long as it has a certain degree of heat resistance and strength, and conventionally known materials can be appropriately selected and used. Examples of such heat-resistant base films include polyethylene terephthalate film (PET film), polypropylene film, polystyrene film, polyimide film, polyamide film, polycarbonate film, polyvinyl chloride film, etc. Among them, it is most preferable to use a polyethylene terephthalate film. The thickness of the base film is not particularly limited, but it may be appropriately considered according to the material so that the strength, heat resistance, and thermal conductivity are appropriate, and it may be in the range of 2 μm or more and 12 μm or less. However, due to good thermal conductivity, a range of 3 μm or more and 6 μm or less is more preferable.

[0020] <Heat-resistant lubricating layer> In the thermal transfer type ink ribbon of the present invention, in order to prevent the base film from breaking, the base film from fusing to the thermal head, wrinkles from occurring on the base film, foreign substances from accumulating on the thermal head, or a sticking phenomenon in which the slipperiness between the base film and the thermal head deteriorates due to the heat of the thermal head during printing, a heat-resistant lubricating layer is provided on one surface of the base film (the surface on the side where the thermal head contacts during printing). The heat-resistant lubricating layer may be provided by applying a paint for the heat-resistant lubricating layer to the base film using various known coating machines and then drying it with a hot air dryer or the like, or a method of providing it simultaneously during the film formation of the base film may be adopted.

[0021] The raw materials used for the heat-resistant and lubricious layer of the present invention are not particularly limited. For example, various known heat-resistant resins such as various silicone-modified resins, fluorine-based resins, polyolefin-based resins, cellulose-based resins, and polyimide-based resins are used as the main raw materials. Furthermore, various known adhesive resins (such as polyester-based resins, polyurethane-based resins, epoxy-based resins, etc.), various known cross-linking agents, various known lubricants (such as derivatives of higher fatty acids and their metal salts, various waxes, silicone oil, silicone resin powder, silicone rubber powder, liquid polyolefin, etc.), and various organic and inorganic fillers, etc. can be appropriately and properly selected as other raw materials according to the required quality and used.

[0022] The coating amount of the heat-resistant and lubricious layer after drying is not particularly limited, and it can be appropriately selected and determined from the range of 0.01 g / m 2 or more and 0.50 g / m 2 or less according to the usage situation and the type of printer, etc. However, for reasons of cost and performance stability, a range of 0.05 g / m 2 or more and 0.40 g / m 2 or less is more preferable. If the coating amount of the heat-resistant and lubricious layer after drying is less than 0.01 g / m 2 , the expected heat-resistant effect cannot be obtained. On the contrary, if the coating amount of the heat-resistant and lubricious layer after drying is 0.5 g / m 2 or more, the sensitivity during printing deteriorates, or there is a tendency for problems such as peeling of the heat-resistant and lubricious layer from the base film, i.e., the problem of foil peeling, to occur.

[0023] <Transfer control layer> In the present invention, a transfer control layer for controlling the peeling force between the base film and the ink layer and the sharpness of printing, etc. is provided between the base film and the ink layer. In addition to the role of a normal transfer control layer, the transfer control layer of the present invention needs to be a transfer control layer that does not adversely affect the environmental storage performance in a high-temperature environment and further satisfies the performance of suppressing the occurrence of planar peeling in the printed image when printing is performed in a high-temperature environment.

[0024] As a result of examining a thermally fusible substance for imparting peelability to be added to the transfer control layer in order to satisfy the performance described above by the present inventor, it was found that it is preferable to add a thermally fusible substance that has a relatively high melting point, has sharp melting characteristics near the melting point, has a low impurity content, and has very good releasability from other layers during melting. As a result of further examining such a thermally fusible substance, it was found that it is most preferable to add an aliphatic hydrocarbon synthetic wax as a main component to the transfer control layer. Examples of the aliphatic hydrocarbon synthetic wax include polyethylene wax, polypropylene wax, olefin copolymers having a number average molecular weight of 10,000 or less (for example, ethylene-propylene copolymers, ethylene-α-olefin copolymers, propylene-α-olefin copolymers), and Fischer-Tropsch wax. However, from the viewpoint of good printing sensitivity and releasability and excellent effect of suppressing the occurrence of planar peeling in the printed image when printing is performed in a high-temperature environment, it is more preferable to add at least one of Fischer-Tropsch wax and polyethylene wax, and it is most preferable to add Fischer-Tropsch wax.

[0025] The above-mentioned aliphatic hydrocarbon synthetic wax added to the transfer control layer can more effectively suppress the occurrence of planar peeling in the printed image by improving the foil-cutting property of the transfer control layer itself. Therefore, it is preferably dispersed and present in the transfer control layer. The above-mentioned aliphatic hydrocarbon synthetic wax added to the transfer control layer of the present invention is used in a state of being processed into fine particles. As such fine particles of aliphatic hydrocarbon synthetic wax, it is preferable to use an emulsion or dispersion in which water is used as a main dispersion medium and the aliphatic hydrocarbon synthetic wax is dispersed in a state of being micronized in the dispersion medium. By adding the aliphatic hydrocarbon synthetic wax in a state of being dispersed in fine particles in the transfer control layer, by providing a structural difference, an adhesive force difference, and a melting peak temperature difference between the fine particle portion and the other portion, it becomes possible to easily control the releasability from other layers during printing and to further improve the foil-cutting property of the transfer control layer. As a result, it becomes possible to more effectively suppress the occurrence of planar peeling in the printed image.

[0026] Regarding the average particle diameter of the aliphatic hydrocarbon synthetic wax fine particles, a range of 0.1 μm or more and 10.0 μm or less is preferable, and a range of 0.1 μm or more and 5.0 μm or less is more preferable. If the average particle diameter of the aliphatic hydrocarbon synthetic wax fine particles is within the above range, it is possible not only to effectively suppress the occurrence of planar peeling in the printed image when printing in a high-temperature environment, but also because the interface between the ink layer and the transfer control layer becomes moderately smooth, the peeling force between the ink layer and the transfer control layer becomes appropriate, and the transferability of the ink layer is good and problems such as foil peeling of the ink layer are less likely to occur. Regarding the average particle diameter of the aliphatic hydrocarbon synthetic wax fine particles in the present invention, the transfer control layer is photographed by magnifying it 10,000 times with an electron microscope, and 20 arbitrary aliphatic hydrocarbon synthetic wax fine particles are randomly selected from the photographed image, and the maximum diameter of each fine particle is measured, and the average is calculated by obtaining the average.

[0027] Furthermore, as a result of examining the thermal properties of the aliphatic hydrocarbon synthetic wax fine particles added to the transfer control layer by the present inventor, it was found that the melting peak temperature (JIS K7121) measured by differential scanning calorimetry of the aliphatic hydrocarbon synthetic wax fine particles is preferably 100 °C or higher. As a result of the examination by the present inventor, if the melting peak temperature of the aliphatic hydrocarbon synthetic wax fine particles is 100 °C or higher, the aliphatic hydrocarbon synthetic wax fine particles do not easily soften in a high temperature environment of 50 °C, so that the softening and deformation of the transfer control layer itself can be suppressed. Therefore, there is an effect of improving the environmental storage performance in a high temperature environment, and at the same time, it has been found that there is an effect of suppressing the occurrence of planar peeling in the printed image when printing is performed in a high temperature environment of 40 °C. On the other hand, when the melting peak temperature of the aliphatic hydrocarbon synthetic wax fine particles is lower than 100 °C, the reverse transfer phenomenon tends to occur easily during printing, and the transferability of printing tends to deteriorate. In addition, as a result of the aliphatic hydrocarbon synthetic wax fine particles gradually starting to soften in a high temperature environment of 50 °C, the transfer control layer tends to soften and deform, and the environmental storage performance tends to deteriorate. Furthermore, planar peeling tends to particularly easily occur in the printed image when printing is performed in a high temperature environment.

[0028] The upper limit of the melting peak temperature of the aliphatic hydrocarbon synthetic wax fine particles is not particularly limited, but from the viewpoints of printing sensitivity and transferability, it is preferably 140 °C or lower, and more preferably 130 °C or lower. Conversely, when the melting peak temperature of the aliphatic hydrocarbon synthetic wax fine particles exceeds the above upper limit, the amount of heat required for printing increases, or the melt viscosity of the aliphatic hydrocarbon synthetic wax fine particles increases, which gradually causes the printing sensitivity and the transferability of printing to deteriorate. As a result, the range of printing energy at which appropriate printing can be performed with a thermal transfer printer becomes narrow, and problems such as printing streaks tend to easily occur in a low temperature environment.

[0029] The addition amount of the aliphatic hydrocarbon synthetic wax fine particles added to the transfer control layer is preferably at least 50% by mass or more of the entire transfer control layer, more preferably 65% by mass or more. Conversely, as the upper limit of the addition amount, it is preferably 95% by mass or less of the entire transfer control layer, more preferably 85% by mass or less. If the addition amount of the aliphatic hydrocarbon synthetic wax fine particles is within the above range, the environmental storage performance in a high-temperature environment is good, and it is possible to effectively suppress the occurrence of planar peeling in the printed image when printing is performed in a high-temperature environment. When the addition amount of the aliphatic hydrocarbon synthetic wax fine particles is below the lower limit of the above range, the environmental storage performance in a high-temperature environment and the planar peeling of the printed image when printing is performed in a high-temperature environment tend to deteriorate. Conversely, when exceeding the upper limit of the above range, since the adhesion to the base film rapidly decreases, etc., the planar peeling of the printed image when printing is performed in a high-temperature environment tends to rapidly deteriorate, or foil peeling of the ink layer or the transfer control layer tends to easily occur.

[0030] The transfer control layer of the present invention contains aliphatic hydrocarbon synthetic wax fine particles, which are a heat-melting substance, as a main component. However, with only aliphatic hydrocarbon synthetic wax fine particles, problems such as foil peeling of the ink layer or the transfer control layer are likely to occur due to insufficient adhesion between the base film and the transfer control layer and between the ink layer and the transfer control layer, or the planar peeling of the printed image when printing is performed in a high-temperature environment tends to deteriorate significantly. Therefore, in addition to the aliphatic hydrocarbon synthetic wax fine particles, it is preferable to add a thermoplastic resin having adhesiveness to the transfer control layer of the present invention.

[0031] As the thermoplastic resin having adhesiveness added to the transfer control layer of the present invention, it is preferable to use a thermoplastic resin having appropriate adhesiveness, not adversely affecting the transferability of printing, not adversely affecting the environmental storage performance in a high-temperature environment, and not causing planar peeling in the printed image when printing is performed in a high-temperature environment. As a result of the inventor's study on such a thermoplastic resin, it has been found that it is preferable to use a carboxylic acid-modified polyolefin.

[0032] The carboxylic acid-modified polyolefin added to the transcription control layer of the present invention refers to a polyolefin modified with at least one or more various unsaturated carboxylic acids or their anhydrides. The polymerization method of the carboxylic acid-modified polyolefin is not particularly limited, and it may be a block copolymer or a random copolymer obtained by copolymerizing an unsaturated carboxylic acid or its anhydride as a copolymerization component with a polyolefin (olefin polymer or olefin copolymer), or it may be a graft copolymer obtained by grafting an unsaturated carboxylic acid or its anhydride onto a polyolefin.

[0033] The polyolefin that is the main component of the carboxylic acid-modified polyolefin refers to various olefin polymers and various olefin copolymers. Examples of polyolefins that can be used as raw materials for the carboxylic acid-modified polyolefin added to the transcription control layer of the present invention include polyethylene, polypropylene, ethylene-propylene copolymer, and copolymers of ethylene or propylene with various α-olefins (e.g., 1-butene, isobutene, 4-methyl-1-pentene, 1-hexene, 1-octene). These can be suitably selected and used according to the required quality.

[0034] Examples of the unsaturated carboxylic acids and their anhydrides that constitute the carboxylic acid-modified polyolefin added to the transcription control layer of the present invention include fumaric acid, maleic acid, itaconic acid, citraconic acid, anicotinic acid, acrylic acid, methacrylic acid, and anhydrides of the above unsaturated carboxylic acids. These can be suitably used according to the required quality, but it is more preferable to use fumaric acid, maleic acid, maleic anhydride, itaconic acid, and itaconic anhydride. By modifying the polyolefin with a carboxylic acid, it becomes possible to impart adhesiveness to the polyolefin.

[0035] Regarding the carboxylic acid-modified polyolefin added to the transcription control layer of the present invention, the ratio of the unsaturated carboxylic acid and its anhydride constituting the carboxylic acid-modified polyolefin is not particularly limited, but it is preferably 0.1% by mass or more and 20.0% by mass or less of the entire carboxylic acid-modified polyolefin, more preferably in the range of 0.1% by mass or more and 10.0% by mass or less, and most preferably in the range of 0.1% by mass or more and 5.0% by mass or less.

[0036] The carboxylic acid-modified polyolefin may be further modified with a derivative of an unsaturated carboxylic acid, if necessary. Examples of the unsaturated carboxylic acid derivative include various unsaturated carboxylic acid esters and various unsaturated carboxylic acid amides. However, it is more preferable to use an unsaturated carboxylic acid ester. Examples of the unsaturated carboxylic acid ester include various fumaric acid esters, various maleic acid esters, various itaconic acid esters, various citraconic acid esters, various angelic acid esters, various acrylic acid esters, and various methacrylic acid esters. These can be suitably used according to the required quality, but it is more preferable to use various acrylic acid esters and various methacrylic acid esters. By further modifying the carboxylic acid-modified polyolefin with an unsaturated carboxylic acid derivative, it is expected to obtain effects such as improving the compatibility with other resins and further imparting adhesiveness.

[0037] Regarding the carboxylic acid-modified polyolefin added to the transcription control layer of the present invention, the ratio of the unsaturated carboxylic acid derivative constituting the carboxylic acid-modified polyolefin is not particularly limited, but it is preferably 0.1% by mass or more and 30.0% by mass or less of the entire carboxylic acid-modified polyolefin, more preferably in the range of 0.1% by mass or more and 10.0% by mass or less.

[0038] When the inventor studied the carboxylic acid-modified polyolefin to be added to the transfer control layer of the present invention, it was found that it is more preferable to use carboxylic acid-modified polyethylene or carboxylic acid-modified polypropylene, and it is most preferable to use carboxylic acid-modified polypropylene. In particular, when carboxylic acid-modified polypropylene is added to the transfer control layer, the inventor found that it is possible to more effectively suppress the occurrence of planar peeling in the printed image when printing is performed in a high-temperature environment. The polyolefin component in the carboxylic acid-modified polyethylene in the present invention includes polyethylene or an ethylene-α-olefin copolymer containing 10 mol% or less of the α-olefin monomer. Similarly, the polyolefin component in the carboxylic acid-modified polypropylene in the present invention includes polypropylene or a propylene-α-olefin copolymer containing 10 mol% or less of the α-olefin monomer.

[0039] As a result of the inventor's study on the thermal properties of the carboxylic acid-modified polyolefin to be added to the transfer control layer, it was found that the melting peak temperature measured by differential scanning calorimetry of the carboxylic acid-modified polyolefin is preferably 100 °C or higher, and more preferably 110 °C or higher. If the melting peak temperature of the carboxylic acid-modified polyolefin is 100 °C or higher, the carboxylic acid-modified polyolefin hardly softens in a high-temperature environment of 50 °C, so that the transfer control layer itself does not soften or deform, and as a result, the environmental storage performance in a high-temperature environment of 50 °C is improved, and at the same time, the effect of suppressing the occurrence of planar peeling in the printed image when printing is performed in a high-temperature environment of 40 °C can be greatly improved. Conversely, when the peak temperature of the carboxylic acid-modified polyolefin is lower than 100 °C, the environmental storage performance in a high-temperature environment of 50 °C gradually deteriorates, and in particular, the planar peeling of the printed image when printing is performed in a high-temperature environment tends to deteriorate rapidly.

[0040] The upper limit of the melting peak temperature of the carboxylic acid-modified polyolefin is not particularly limited, but from the viewpoint of printing sensitivity, it is preferably 165°C or lower, and more preferably 150°C or lower. If the upper limit of the melting peak temperature of the carboxylic acid-modified polyolefin is within the above range, the printing sensitivity and the environmental storage performance under high-temperature environments are good, and it is possible to effectively suppress the occurrence of planar peeling in the printed image when printing is performed under high-temperature environments.

[0041] As a result of further examination by the present inventors on the thermal properties of the aliphatic hydrocarbon synthetic wax fine particles and the carboxylic acid-modified polyolefin added to the transfer control layer, it was found that when the melting peak temperature of the carboxylic acid-modified polyolefin is higher than that of the aliphatic hydrocarbon synthetic wax fine particles, it is possible to more effectively suppress the occurrence of planar peeling in the printed image when printing is performed under high-temperature environments.

[0042] The addition amount of the carboxylic acid-modified polyolefin to the transfer control layer is preferably at least 5% by mass or more of the entire transfer control layer, and more preferably 15% by mass or more. Conversely, as the upper limit of the addition amount, it is preferably 50% by mass or less of the entire transfer control layer, and more preferably 35% by mass or less. If the addition amount of the carboxylic acid-modified polyolefin is within the above range, not only will a sufficient effect be exhibited in suppressing the occurrence of planar peeling in the printed image when printing is performed under high-temperature environments, but also the transferability of the printing will be good and the suppression of foil peeling of the ink layer and the transfer control layer will also be good. If the addition amount of the carboxylic acid-modified polyolefin is below the lower limit of the above range, planar peeling is likely to occur in the printed image when printing is performed under high-temperature environments, or foil peeling of the ink layer and the transfer control layer is likely to occur. Conversely, if the addition amount of the carboxylic acid-modified polyolefin exceeds the upper limit of the above range, the environmental storage performance and the transferability of the printing under high-temperature environments tend to deteriorate gradually.

[0043] In addition to the aliphatic hydrocarbon synthetic wax fine particles and carboxylic acid-modified polyolefin described above, various known organic and inorganic fillers, surfactants, viscosity modifiers, antistatic agents, and other various additives may be appropriately added in a small amount as necessary to the extent that the required quality of the transfer control layer is not impaired.

[0044] The coating amount of the transfer control layer of the present invention after drying is not particularly limited, and it may be appropriately selected from the range of 0.1 g / m 2 or more and 1.0 g / m 2 or less. However, considering the printing sensitivity and transferability, it is more preferable to select from the range of 0.2 g / m 2 or more and 0.8 g / m 2 or less. If the coating amount of the transfer control layer after drying is less than 0.1 g / m 2 , peeling at the interface between the transfer control layer and the base film may not be appropriately performed, and transfer defects tend to occur. Conversely, if the coating amount of the transfer control layer after drying exceeds 1.0 g / m 2 , foil peeling of the ink layer or the transfer control layer tends to occur, and the printing sensitivity tends to deteriorate.

[0045] <Ink layer> In the hot melt transfer type ink ribbon of the present invention, as the outermost layer on the transfer control layer provided on the base film, an ink layer containing at least a coloring component such as various known organic and inorganic pigments such as carbon black and a binder component such as a thermoplastic resin and various known waxes is provided. The addition amount of the colorant is not particularly limited, but it is preferably appropriately used from the range of 10% by mass or more and 50% by mass or less, more preferably 15% by mass or more and 30% by mass or less of the entire ink layer according to the usage situation. If the addition amount is less than 10% by mass, the printing density of the printed matter is not sufficient, and if it exceeds 50% by mass, it tends to have an adverse effect on the transferability of the printing.

[0046] As a result of the inventor's examination of the binder component added to the ink layer of the present invention, from the viewpoint of improving printing sensitivity, transferability of printing, and adhesiveness of the printed image to the transfer medium such as a label, it is preferable to add an adhesive resin with a relatively low melting point. In addition, as a result of considering the compatibility with the above-described transfer control layer, it has been found that it is preferable to use an ethylene-based copolymer resin.

[0047] The ethylene-based copolymer resin added to the ink layer of the present invention is a copolymer having an ethylene component as a main constituent component. As those particularly preferably used as the ethylene-based copolymer resin, ethylene-methyl (meth) acrylate copolymer, ethylene-ethyl (meth) acrylate copolymer, ethylene-propyl (meth) acrylate copolymer, ethylene-butyl (meth) acrylate copolymer and other ethylene-(meth) acrylate copolymer resins, ethylene-(meth) acrylamide copolymer resins, and ethylene-vinyl acetate copolymer resins are preferably used. Further, it is also possible to use those obtained by modifying the various copolymer resins with various carboxylic acids, maleic anhydride, etc. Furthermore, as a result of the inventor's examination, it has been found that it is most preferable to use an ethylene-vinyl acetate copolymer resin as the ethylene-based copolymer added to the ink layer. Note that the "(meth) acrylate" is a technical term including "acrylate" and "methacrylate".

[0048] The ethylene-based copolymer resin added to the ink layer of the present invention is composed of ethylene as the main constituent component and other constituent components copolymerized with ethylene such as vinyl acetate and various (meth) acrylates. In the ethylene-based copolymer resin used in the present invention, it is preferable that the proportion of the other constituent components is at least 5% by mass or more of the entire ethylene-based copolymer resin, more preferably 10% by mass or more, and most preferably 20% by mass or more. Conversely, the proportion of the other constituent components copolymerized with ethylene in the entire ethylene-based copolymer resin is preferably at most 40% by mass of the entire ethylene-based copolymer resin, and more preferably at most 30% by mass. If the proportion of the other constituent components copolymerized with ethylene is within the above range, the printing sensitivity, the transferability of printing, and the adhesion of the printed image to the medium to be transferred are good, and furthermore, planar peeling of the printed image when printing is performed in a high-temperature environment tends to be less likely to occur.

[0049] As a result of the study by the present inventor on the thermal properties of the ethylene-based copolymer resin added to the ink layer of the present invention, the lower limit of the melting peak temperature measured by the differential scanning calorimetry of the ethylene-based copolymer resin is preferably 60°C or higher, and more preferably 70°C or higher. Conversely, the upper limit of the melting peak temperature of the ethylene-based copolymer resin is preferably 110°C or lower, and more preferably 90°C or lower. If the melting peak temperature of the ethylene-based copolymer resin is within the above range, not only are the printing sensitivity and the transferability of printing good, and the adhesiveness of the printed image to the medium to be printed is also good, but also the environmental storage performance under a high-temperature environment of 50°C does not deteriorate significantly, and planar peeling of the printed image when printing is performed in a high-temperature environment of 40°C does not deteriorate significantly. On the other hand, when the melting peak temperature of the ethylene-based copolymer resin falls below the lower limit of the above range, the environmental storage performance under a high-temperature environment and planar peeling of the printed image when printing is performed in a high-temperature environment deteriorate rapidly. Also, when the melting peak temperature of the ethylene-based copolymer resin exceeds the upper limit of the above range, the printing sensitivity and the transferability of printing deteriorate rapidly, and as a result, the adhesiveness of the printed image to the medium to be printed also deteriorates.

[0050] The lower limit of the addition amount of the ethylene-based copolymer resin to the ink layer is preferably 20% by mass or more, more preferably 25% by mass or more, of the entire ink layer. Conversely, the upper limit of the addition amount of the ethylene-based copolymer resin to the ink layer is preferably 50% by mass or less, more preferably 40% by mass or less, of the entire ink layer. If the addition amount of the ethylene-based copolymer resin to the ink layer is within the above range, not only the printing sensitivity and transferability of the printing are good, and the adhesiveness of the printed image to the medium to be printed is also good, but also the environmental storage performance under a high temperature environment of 50 °C does not deteriorate significantly, and the surface peeling of the printed image when printing is performed under a high temperature environment of 40 °C does not deteriorate significantly. On the other hand, when the addition amount of the ethylene-based copolymer resin to the ink layer is below the lower limit of the above range, the printing sensitivity and transferability of the printing deteriorate, and as a result, the adhesiveness of the printed image to the medium to be printed also tends to deteriorate. Also, when the addition amount of the ethylene-based copolymer resin to the ink layer exceeds the upper limit of the above range, the environmental storage performance under a high temperature environment and the surface peeling of the printed image when printing is performed under a high temperature environment tend to deteriorate.

[0051] By adding the above-described ethylene-based copolymer resin as a binder component of the ink layer, it becomes possible to improve printing sensitivity and transferability of printing. On the other hand, when adding the ethylene-based copolymer resin, regarding the environmental storage performance in a high-temperature environment and the planar peeling of the printed image when printing is performed in a high-temperature environment, it does not show a good tendency. Therefore, if only the ethylene-based copolymer resin is used as the binder component of the ink layer, the environmental storage performance in a high-temperature environment of 50 °C will not be satisfactory, and when printing is performed in a high-temperature environment of 40 °C, severe planar peeling will occur in the printed image. From such a situation, as a result of the inventor's examination of other raw materials as the binder component, in addition to the ethylene-based copolymer resin as the binder component of the ink layer, to improve the printing sensitivity and suppress the occurrence of planar peeling in the printed image when printing is performed in a high-temperature environment and to improve the environmental storage performance in a high-temperature environment, it is preferable to add a heat-fusible substance such as wax, and in particular, it has been found that it is more preferable to add an aliphatic hydrocarbon synthetic wax having a melting peak temperature of 100 °C or higher. Furthermore, as a result of the inventor's examination, by adding fine particles of an aliphatic hydrocarbon synthetic wax having a melting peak temperature of 100 °C or higher as the binder component of the ink layer, it has been found that it becomes possible to effectively improve the environmental storage performance in a high-temperature environment and suppress the occurrence of planar peeling in the printed image when printing is performed in a high-temperature environment.

[0052] As the raw material of the aliphatic hydrocarbon synthetic wax fine particles added as a binder component of the ink layer of the present invention, the aliphatic hydrocarbon synthetic wax can preferably be the same as the aliphatic hydrocarbon synthetic wax added to the transfer control layer described above. Examples of such aliphatic hydrocarbon synthetic waxes include polyethylene wax, polypropylene wax, olefin copolymers with a number average molecular weight of 10,000 or less (e.g., ethylene-propylene copolymer, ethylene-α olefin copolymer, propylene-α olefin copolymer), and Fischer-Tropsch wax. However, from the viewpoints of excellent transferability of printing, environmental storage performance under high-temperature environments, and excellent effect of suppressing the occurrence of planar peeling in the printed image when printing is performed under high-temperature environments, it is more preferable to add at least one of Fischer-Tropsch wax and polyethylene wax, and it is most preferable to add polyethylene wax.

[0053] The aliphatic hydrocarbon synthetic wax added as a binder component of the ink layer of the present invention can more effectively suppress the occurrence of planar peeling in the printed image by improving the foil cutting property of the ink layer itself. Therefore, it is preferably dispersed and present in the ink layer. The aliphatic hydrocarbon synthetic wax added to the ink layer of the present invention is used in a state of being processed into fine particles. By dispersing and adding the aliphatic hydrocarbon synthetic wax in the ink layer in the form of fine particles, by providing structural differences, adhesion differences, and melting peak temperature differences between the fine particle portion and other portions, it becomes possible to easily control the releasability from other layers during printing and to further improve the foil cutting property of the ink layer. As a result, it becomes possible to more effectively suppress the occurrence of planar peeling in the printed image.

[0054] Although there is no particular limitation on the average particle diameter of the aliphatic hydrocarbon synthetic wax fine particles added as a binder component of the ink layer of the present invention, a range of 1.0 μm or more and 40.0 μm or less is preferable, and a range of 2.0 μm or more and 30.0 μm or less is more preferable. If the average particle diameter of the aliphatic hydrocarbon synthetic wax fine particles is within the above range, the environmental storage performance in a high-temperature environment, the suppression of the surface peeling of the printed image when printing in a high-temperature environment, the foil cuttability of the ink layer, the printing sensitivity, the transferability of printing, etc. will not be adversely affected. In particular, when the average particle diameter of the aliphatic hydrocarbon synthetic wax fine particles is larger than the film thickness of the ink calculated from the adhesion amount after drying of the ink layer and the density of each raw material, the aliphatic hydrocarbon synthetic wax fine particles protrude from the surface of the ink layer, and the environmental storage performance (especially the anti-blocking performance) in a high-temperature environment is greatly improved. Regarding the average particle diameter of the aliphatic hydrocarbon synthetic wax fine particles, the ink layer is photographed with an electron microscope magnified 10,000 times, and 20 arbitrary aliphatic hydrocarbon synthetic wax fine particles are randomly selected from the photographed image, and the maximum diameter of each fine particle is measured and the average is calculated.

[0055] As a result of the inventors' examination of the thermal properties of the aliphatic hydrocarbon synthetic wax fine particles added as a binder component of the ink layer of the present invention, the lower limit of the melting peak temperature measured by differential scanning calorimetry of the aliphatic hydrocarbon synthetic wax fine particles is preferably 100°C or higher. Conversely, the upper limit of the melting peak temperature of the aliphatic hydrocarbon synthetic wax fine particles is preferably 140°C or lower, and more preferably 130°C or lower. If the melting peak temperature of the aliphatic hydrocarbon synthetic wax fine particles is within the above range, it is possible to improve the environmental storage performance in a high-temperature environment and the suppression effect of planar peeling of the printed image when printing is performed in a high-temperature environment. On the other hand, when the melting peak temperature of the aliphatic hydrocarbon synthetic wax fine particles is below the lower limit of the above range, the environmental storage performance in a high-temperature environment deteriorates, and the planar peeling of the printed image when printing is performed in a high-temperature environment tends to deteriorate. Conversely, when the melting peak temperature of the aliphatic hydrocarbon synthetic wax fine particles exceeds the upper limit of the above range, the printing sensitivity, the transferability of printing, and the adhesion of the printed image to the printing medium tend to deteriorate.

[0056] The addition amount of the aliphatic hydrocarbon synthetic wax fine particles added as a binder component of the ink layer of the present invention is preferably at least 5% by mass or more of the entire ink layer, and more preferably 10% by mass or more. Conversely, as the upper limit of the addition amount, it is preferably 30% by mass or less of the entire ink layer, and more preferably 25% by mass or less. If the addition amount of the aliphatic hydrocarbon synthetic wax fine particles is within the above range, it is possible to improve the environmental storage performance in a high-temperature environment and effectively suppress the planar peeling of the printed image when printing is performed in a high-temperature environment. On the other hand, when the addition amount of the aliphatic hydrocarbon synthetic wax fine particles is below the lower limit of the above range, the environmental storage performance in a high-temperature environment and the planar peeling of the printed image when printing is performed in a high-temperature environment tend to deteriorate easily. Conversely, when exceeding the upper limit of the above range, the printing sensitivity, the transferability of printing, and the adhesion of the printed image to the printing medium tend to deteriorate.

[0057] As the binder component of the ink layer of the present invention, in addition to the above-described ethylene-based copolymer resin and aliphatic hydrocarbon synthetic wax fine particles, a resin having an effect of further improving the transferability of printing and the adhesiveness of the printed image to the medium to be printed, and further improving the foil cutting property of the ink layer is preferably added. Examples of the resin having such an effect include various known tackifying resins, such as wood rosin, rosin ester, hydrogenated rosin, disproportionated rosin, polymerized rosin, modified rosin, pinene resin, dipentene resin, hydrogenated terpene resin, aromatic-modified terpene resin, aromatic-modified hydrogenated terpene resin, terpene phenol resin, hydrogenated terpene phenol resin, C5 hydrocarbon resin, C9 hydrocarbon resin, C5 / C9 hydrocarbon copolymer resin, hydrogenated C5 hydrocarbon resin, hydrogenated C9 hydrocarbon resin, hydrogenated C5 / C9 hydrocarbon copolymer resin, chroman resin, chroman-indene resin, various phenolic tackifying resins, various styrenic tackifying resins, ketone resin, etc. These tackifying resins can be appropriately selected and used alone or in combination of plural.

[0058] Among the above tackifying resins, styrenic tackifying resins are particularly preferably used as the tackifying resin of the binder component of the ink layer of the present invention. Examples of the styrenic tackifying resin include styrenic monomer polymers, α-methylstyrene polymers, α-methylstyrene / styrene copolymers, copolymers of styrenic monomers and aliphatic hydrocarbons, copolymers of styrenic monomers and (meth)acrylic acid derivatives, copolymers of styrenic monomers and aromatic hydrocarbons, and ternary copolymers of styrenic monomers, α-methylstyrene, and aliphatic hydrocarbons. It has been found that by using a styrenic tackifying resin as the tackifying resin of the binder component of the ink layer, it is possible to effectively suppress the planar peeling of the printed image when printing is performed in a high-temperature environment.

[0059] As the tackifying resin added as a binder component of the ink layer of the present invention, it is preferable to use a resin having a relatively low molecular weight with a number average molecular weight of several hundreds to several thousands or less, having a large number of functional groups in its structure, having compatibility with other resins, and having a function of improving the tack and adhesiveness of the added layer. By adding the tackifying resin to the ink layer, it is expected to improve pigment dispersibility, printing sensitivity, transferability and adhesiveness of printing to the transfer medium, and foil cutting property of the ink layer. As the tackifying resin used in the present invention, from the viewpoint of improving environmental storage performance in a high-temperature environment and suppressing planar peeling of a printed image when printing is performed in a high-temperature environment, it is preferable to use a tackifying resin having a relatively high softening point or high glass transition point.

[0060] As a result of the inventor's examination of the thermal properties of the tackifying resin added as a binder component of the ink layer of the present invention, the glass transition point measured by differential scanning calorimetry of the tackifying resin is preferably in the range of 50°C or higher and 110°C or lower, and more preferably in the range of 60°C or higher and 90°C or lower. Further, the softening point of the tackifying resin (softening point by the ring and ball method JIS K5601-2-2 (1999)) is preferably in the range of 110°C or higher and 170°C or lower, and more preferably in the range of 120°C or higher and 160°C or lower. If the glass transition point or softening point of the tackifying resin is within the above range, it will not adversely affect printing sensitivity and environmental storage performance in a high-temperature environment, and further it will be possible to suppress the occurrence of planar peeling during printing in a high-temperature environment.

[0061] The addition amount of the tackifying resin added as a binder component of the ink layer of the present invention is preferably in the range of 5% by mass or more and 30% by mass or less, and more preferably in the range of 5% by mass or more and 25% by mass or less. If the addition amount of the tackifying resin is within the above range, the transferability and adhesiveness to the medium to be printed will be good, the adverse effect on the environmental storage performance in a high-temperature environment will be small, and further it will be possible to effectively suppress the planar peeling of the printed matter when printing is performed in a high-temperature environment.

[0062] In the ink layer of the present invention, in addition to the coloring components described above, the ethylene-based copolymer resin, aliphatic hydrocarbon synthetic wax fine particles, and tackifier resin that are binder components, various known organic and inorganic fillers, surfactants, viscosity modifiers, antistatic agents, and other various additives may be appropriately added in small amounts as required, as long as the required quality of the ink layer is not impaired.

[0063] The coating amount after drying of the ink layer of the present invention is not particularly limited, and it may be appropriately selected according to the required quality from the range of 0.5 g / m 2 or more and 2.0 g / m 2 or less. However, from the viewpoints of cost and performance stability, it is more preferable to appropriately select from the range of 0.7 g / m 2 or more and 1.5 g / m 2 or less. If the coating amount after drying of the ink layer is less than 0.5 g / m 2 , sufficient printing density and rub resistance tend not to be obtained. On the contrary, if the coating amount exceeds 2.0 g / m 2 , the printing sensitivity tends to deteriorate, and the planar peeling of the printed image tends to deteriorate due to the deterioration of the foil cutting property of the ink layer.

Examples

[0064] Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[0065] <Regarding the formation method of the base film and the heat-resistant lubricity layer> Using a gravure coater, the following heat-resistant lubricity layer coating material was applied to one side of a polyethylene terephthalate film (PET film) with a thickness of 4.5 μm by the gravure coater, and the solvent component was volatilized and dried by a hot air dryer to form a heat-resistant lubricity layer with an adhesion amount after drying of 0.2 g / m 2 to be achieved. (Composition of the coating material for the heat-resistant lubricity layer) Raw material component Mass % · Silicone-modified polyester polyurethane resin Methyl ethyl ketone / toluene = 1 / 1 solvent solution (solid content 15 mass %) 25.0 · Methyl ethyl ketone 60.0 · Toluene 15.0 The coating material for the heat-resistant and lubricious layer is prepared by respectively weighing a mixed solvent of methyl ethyl ketone and toluene and a solution obtained by dissolving a silicone-modified polyester polyurethane resin in a solvent with a mass ratio of methyl ethyl ketone to toluene of 1:1 so that the solid content is 15% by mass according to the above formulation, putting them into a container, and stirring and mixing them with a dissolver or the like. The above-described method for preparing the coating material for the heat-resistant and lubricious layer and the method for forming the heat-resistant and lubricious layer are merely examples and are not limited thereto, and various known methods can be used. In addition, the heat-resistant base film and the heat-resistant and lubricious layer were used in all of the examples and comparative examples of the present invention.

[0066] <Regarding the method for forming the transfer control layer> Details and formation methods of the transfer control layers of the examples and comparative examples of the present invention are shown below.

[0067] Details of each heat-meltable substance used in the transfer control layers of the examples and comparative examples of the present invention are shown in Table 1, and details of each thermoplastic resin are shown in Table 2.

[0068]

Table 1

[0069]

Table 2

[0070] (Method for producing the coating material for the transfer control layer) Using the emulsion raw materials obtained by emulsifying each of the thermally fusible substances described in Table 1 in water, the dispersion raw materials obtained by dispersing each of the thermoplastic resins described in Table 2 in water, and isopropanol, paints 1 to 13 for the transfer control layer shown in Tables 3 and 4 were prepared. Note that as the emulsion raw materials and dispersion raw materials, commercially available raw materials containing the compositions shown in Table 1 and Table 2 as solid components may be appropriately used, or substances prepared by emulsifying or dispersing the compositions shown in Table 1 and Table 2 in water may be used. As a specific method for preparing the paint for the transfer control layer, each raw material is weighed and put into a container so as to have the blending amounts shown in Tables 3 and 4, and then prepared by sufficiently stirring and mixing with a stirrer.

[0071]

Table 3

[0072]

Table 4

[0073] (Method for forming the transfer control layer) Next, the method for forming the transfer control layer used in the examples and comparative examples will be specifically described. After applying each of the paints for the transfer control layer shown in Tables 3 and 4 to the other surface of the surface provided with the heat-resistant lubricity layer of the above-described PET film by a gravure coater, the dispersion medium components such as water and isopropanol contained in the paint are volatilized and dried by a hot air dryer, and each transfer control layer is formed so that the adhesion amount after drying becomes 0.5 g / m 2 Note that the method for preparing the paint for the transfer control layer and the method for forming the transfer control layer described above are merely examples and are not limited thereto, and various known methods can be used. In addition, details of the solid content mass ratio (mass ratio of the components of the transfer control layer) of each raw material in the transfer control layers of each of the formed examples and comparative examples are separately described in Tables 9 to 11 below.

[0074] <Regarding the method for forming the ink layer> Details of the ink layers and formation methods of the examples and comparative examples of the present invention are shown below.

[0075] Details of each adhesive resin used in the ink layers of the examples and comparative examples of the present invention are shown in Table 5, details of each heat-fusible substance are shown in Table 6, and details of each tackifier resin are shown in Table 7.

[0076]

Table 5

[0077]

Table 6

[0078]

Table 7

[0079] (Method for preparing the paint for the ink layer) First, toluene and the heat-melting substance described in Table 6 are weighed and put into a sealable container capable of stirring and heating so that the mass ratio is "toluene: heat-melting substance = 9:1". After sealing the container, heat it while stirring to completely dissolve the heat-melting substance in toluene. Then, gradually cool the solution while stirring to precipitate fine particles of the heat-melting substance in toluene, thereby creating a toluene dispersion of the heat-melting substance with a solid content of 10% by mass. Further, in another sealable container capable of stirring and heating, toluene, the adhesive resin shown in Table 5, and the tackifier resin shown in Table 7 are weighed and put in according to the mass ratios shown in Table 8. After sealing the container, heat it while stirring to create a solution in which the adhesive resin and the tackifier resin are completely dissolved in toluene. After cooling the toluene solution of the adhesive resin and the tackifier resin to room temperature, weigh and put in the prepared toluene dispersion of the heat-melting substance according to the mass ratios shown in Table 8, then stir and mix. Further, after weighing and putting in the other raw materials described in Table 8 according to the mass ratios shown in Table 8, stir and mix to create an adjustment liquid before dispersion by a disperser. Finally, disperse the adjustment liquid by a bead mill to an appropriate paint state as required, thereby completing the preparation of the paints for each ink layer shown in Table 8.

[0080]

Table 8

[0081] (Method for forming the ink layer) Next, the method for forming the ink layer used in the examples and comparative examples will be specifically described. After applying each paint for the ink layer shown in Table 8 onto the upper layer of the transfer control layer provided on the above-described PET film by a gravure coater, the dispersion medium and solvent components such as toluene, methyl ethyl ketone, and isopropanol contained in the paint are volatilized and dried by a hot air dryer, and the adhesion amount after drying is 1.0 g / m 2Each ink layer was formed so as to achieve the above. Note that the method for producing the paint for the ink layer and the method for forming the ink layer described above are merely examples and are not limited thereto, and various known methods can be used. In addition, the details of the solid content mass ratio of each raw material (mass ratio of the components of the ink layer) in the ink layers of each of the formed Examples and Comparative Examples are separately described in Tables 9 to 11 below.

[0082] <<Regarding the evaluation method>> The printing test conditions and various evaluation methods using the thermally fusible transfer type ink ribbons of the Examples and Comparative Examples having the configurations shown in Tables 9 to 11 below prepared are shown below.

[0083] <Printing test conditions> Using the thermally fusible transfer type ink ribbons of the Examples and Comparative Examples, various printing tests were conducted under the following conditions. Printer: CL4NX-J (manufactured by Sato Co., Ltd.) Printing resolution: 305 dpi Printing speed: 5 inch / sec Printing density: 5 / 10, 9 / 10 Substrate to be printed: PET label

[0084] <(Evaluation 1) Evaluation of the printing sensitivity of non-environment-preserved test samples> Using the thermally fusible transfer type ink ribbons of the Examples and Comparative Examples that have not undergone the environmental preservation test, the state of each printed image when printing was performed under the above printing test conditions in an environment with a temperature of 25°C was visually observed, and the printing sensitivity was evaluated under the following conditions. A... No printing smear occurs at all. B... Printing smear occurs slightly in part. C... Printing smear occurs clearly almost over the entire surface. D... The printing smear is severe and almost no printing is transferred.

[0085] <(Evaluation 2) Evaluation of the printing quality of non-environment-preserved test samples> Using the thermal transfer type ink ribbons of the examples and comparative examples that had not undergone the environmental storage test, the state of each printed image when printing was performed under the above printing test conditions in an environment with a temperature of 25°C was visually inspected, and the print quality was evaluated under the conditions shown below. A ··· There is no printing smear or sheet-like peeling occurring in the printed image at all. B ··· Slight printing smear and / or sheet-like peeling occur in a part of the printed image. C ··· Printing smear and / or sheet-like peeling clearly occur in a part of the printed image. D ··· Severe printing smear and / or sheet-like peeling occur in almost the entire printed image.

[0086] <(Evaluation 3) Evaluation of the printing sensitivity of the environmental storage test samples> After conducting an environmental storage test in which the thermal transfer type ink ribbons of the examples and comparative examples were left standing and stored for 96 hours in the atmosphere inside a thermostatic chamber set at a temperature of 50°C and a humidity of 80% RH, using the thermal transfer type ink ribbons left standing for 24 hours in a room temperature environment with a temperature of 25°C, the state of each printed image when printing was performed under the above printing test conditions in an environment with a temperature of 25°C was visually inspected, and the printing sensitivity was evaluated under the conditions shown below. A ··· No printing streaks occur at all. B ··· Printing streaks occur slightly in a part. C ··· Printing streaks clearly occur in almost the entire area. D ··· The printing streaks are severe and almost no printing is transferred.

[0087] <(Evaluation 4) Evaluation of the print quality of the environmental storage test samples> After conducting an environmental storage test in which the thermal transfer type ink ribbons of the examples and comparative examples were left standing and stored for 96 hours in the atmosphere inside a thermostatic chamber set at a temperature of 50°C and a humidity of 80% RH, using the thermal transfer type ink ribbons left standing for 24 hours in a room temperature environment with a temperature of 25°C, the state of each printed image when printing was performed under the above printing test conditions in an environment with a temperature of 25°C was visually inspected, and the print quality was evaluated under the conditions shown below. A ··· There is no printing smear or sheet-like peeling occurring in the printed image at all. B ··· Slight printing smudging and / or planar peeling has occurred in part of the printed image. C ··· Printing smudging and / or planar peeling has clearly occurred in part of the printed image. D ··· Severe printing smudging and / or planar peeling has occurred in almost the entire printed image.

[0088] <(Evaluation 5) Evaluation of changes in printing sensitivity and printing quality by environmental storage test (Environmental storage performance)> The states of the respective printed images in the evaluations of (Evaluation 1) to (Evaluation 4) above were visually compared and evaluated under the conditions shown below. A ··· There is no change in printing sensitivity and printing quality after the environmental storage test. B ··· After the environmental storage test, at least one of printing sensitivity, printing smudging, and planar peeling has deteriorated slightly compared to before the environmental storage test. C ··· After the environmental storage test, at least one of printing sensitivity, printing smudging, and planar peeling has clearly deteriorated compared to before the environmental storage test. D ··· After the environmental storage test, at least one of printing sensitivity, printing smudging, and planar peeling has deteriorated significantly compared to before the environmental storage test.

[0089] <(Evaluation 6) Evaluation of blocking resistance (Environmental storage performance)> For the evaluation of blocking resistance, a ribbon sample (width 50 mm, length 100 m, ink side wound inside) was prepared by winding a slit piece of the original roll of a thermal transfer type ink ribbon with a predetermined size around a plastic core and processing it into a roll shape. The ribbon sample was statically stored in the atmosphere in a thermostatic chamber set at a temperature of 50°C and a humidity of 80% RH for 96 hours, and then cooled in a room temperature environment at a temperature of 25°C for 24 hours. The state of blocking when the winding of the ribbon sample was unwound was visually observed and evaluated under the conditions shown below. A ··· No blocking is observed at all. B ··· Slight blocking is observed near the plastic core of the ribbon sample. Blocking is partially observed between the middle of the winding of the C···ribbon sample and the vicinity of the plastic core. Blocking is observed over the entire surface of the D···ribbon sample.

[0090] <(Evaluation 7) Evaluation of the planar peeling of the printed image in printing under a high-temperature environment> After leaving the printer used for the printing test, the PET label of the medium to be printed, and the thermal transfer type ink ribbon used for printing in the atmosphere in a thermostatic chamber with the temperature set at 40°C for 1 hour, printing was continued in the same thermostatic chamber at a printing density of 5 / 10 under the above printing conditions, and each printed image was visually confirmed and evaluated under the conditions shown below. A···No planar peeling has occurred in the printed image. B···Slight planar peeling has occurred in a part of the printed image. C···Planar peeling has clearly occurred in a part of the printed image. D···Severe planar peeling has occurred over almost the entire surface of the printed image.

[0091] The thermal transfer type ink ribbons of each example and comparative example were created by the method described above, and the mass ratios of the components of the ink layer and transfer control layer of each example and comparative example and the results of the various evaluations described above are shown in Tables 9 to 11 below.

[0092]

Table 9

[0093]

Table 10

[0094]

Table 11

[0095] From the results of Tables 9 to 11, like the hot melt transfer type ink ribbons of Examples 1 to 9, the ink layer contains a coloring component and a binder component, and the binder component of the ink layer contains an ethylene-based copolymer resin having a melting peak temperature of 60°C or higher, aliphatic hydrocarbon synthetic wax fine particles having a melting peak temperature of 100°C or higher, and a tackifier resin. The transfer control layer contains aliphatic hydrocarbon synthetic wax fine particles having a melting peak temperature of 100°C or higher in the range of 50% by mass or more and 95% by mass or less of the entire transfer control layer and carboxylic acid-modified polyolefin having a melting peak temperature of 100°C or higher in the range of 5% by mass or more and 50% by mass or less of the entire transfer control layer. When using such a hot melt transfer type ink ribbon, even when an environmental storage test is conducted in a high-temperature environment, almost no blocking phenomenon occurs, and there is almost no deterioration in printing sensitivity or print quality. Also, almost no planar peeling occurs in the printed image when printing is performed in a high-temperature environment, and furthermore, the printing sensitivity is good.

[0096] On the other hand, regarding the transfer control layer, as in Comparative Examples 1 to 3 in Table 9, when a carboxylic acid-modified polyolefin having a melting peak temperature of less than 100°C is used in the transfer control layer instead of a carboxylic acid-modified polyolefin having a melting peak temperature of 100°C or higher, the planar peeling of the printed image when printing in a high-temperature environment becomes extremely poor, and the printing density becomes high (printing density 9 / 10) regardless of whether there is an environmental storage test in a high-temperature environment, and planar peeling of the printed image occurs significantly. Furthermore, the print quality (planar peeling) deteriorates before and after the environmental storage test in a high-temperature environment. Also, as in Comparative Examples 4 to 6 in Table 9, when fine particles of a heat-fusible substance having a melting peak temperature of less than 100°C are used in the transfer control layer instead of fine particles of an aliphatic hydrocarbon synthetic wax having a melting peak temperature of 100°C or higher, various problems occur, such as the planar peeling of the printed image deteriorating when printing in a high-temperature environment as in Comparative Example 4, the printing sensitivity deteriorating before and after the environmental storage test in a high-temperature environment as in Comparative Example 5, and reverse transfer occurring during printing and the print not being transferred to the label at all as in Comparative Example 6. Also, as in Comparative Example 7 in Table 10, when there is no carboxylic acid-modified polyolefin in the transfer control layer, planar peeling is likely to occur in the printed image, and planar peeling clearly occurs in the printed image particularly when printing in a high-temperature environment. Also, as in Comparative Example 8, when the carboxylic acid-modified polyolefin in the transfer control layer contains more than 50% by mass of the entire transfer control layer, the transferability of the print deteriorates, and as a result, the printing sensitivity becomes extremely poor.

[0097] Next, looking at the ink layer, as in Comparative Example 9 of Table 11, when a substance with a melting peak temperature of less than 60°C is used as the ethylene-based copolymer resin, which is the binder component of the ink layer, the printing quality (surface peeling) after the environmental storage test in a high-temperature environment deteriorates, and surface peeling of the printed image also clearly occurs when printing is performed in a high-temperature environment. Also, as in Comparative Example 10 of Table 11, when the type of ink layer used in the thermal melting transfer type ink ribbon of Patent Document 1 is used as the ink layer, although surface peeling does not occur in the printed image, the printing sensitivity is not good, and the printing is blurred at a printing density of 5 / 10. Further, as in Comparative Example 11 and Comparative Example 12 of Table 11, when fine particles of a heat-melting substance with a melting peak temperature of less than 100°C are used in the ink layer instead of the aliphatic hydrocarbon synthetic wax fine particles with a melting peak temperature of 100°C or more, surface peeling clearly occurs in the printed image when printing is performed in a high-temperature environment, and furthermore, in Comparative Example 11, the printing quality (surface peeling) after the environmental storage test in a high-temperature environment deteriorates. Also, as in Comparative Example 13 of Table 11, when no aliphatic hydrocarbon synthetic wax fine particles with a melting peak temperature of 100°C or more are added to the binder component of the ink layer, the printing sensitivity and printing quality (surface peeling) after the environmental storage test in a high-temperature environment deteriorate, and the blocking phenomenon also clearly occurs. Also, as in Comparative Example 14 of Table 11, when no tackifying resin is added to the binder component of the ink layer, significant surface peeling occurs in the printed image regardless of the printing test conditions.

Industrial Applicability

[0098] The thermal melting transfer type ink ribbon of the present invention can be used not only in thermal transfer printers used for general applications such as printing character information, barcodes, etc. on various forms, product tags, and logistics management labels, but also as a thermal melting transfer type ink ribbon for thermal transfer printers that are particularly likely to be used in high-temperature environments.

Explanation of Symbols

[0099] 1; Thermal melting transfer type ink ribbon 2; Base film 3; Heat-resistant lubricity layer 4; Transfer control layer 5; Ink layer 6; Substrate to be printed (such as label) 7a; Printed image (the printed image originally planned to be formed) 7b; Printed image (the peeled-off part) 8; Thermal head 9; Platen roll

Claims

1. A hot-melt transfer type ink ribbon in which a heat-resistant lubricious layer is provided on one surface of a base film, and a transfer control layer and an ink layer are sequentially laminated on the other surface, wherein the ink layer contains a coloring component and a binder component, the binder component of the ink layer contains an ethylene-based copolymer resin having a melting peak temperature of 60°C or higher, aliphatic hydrocarbon synthetic wax fine particles having a melting peak temperature of 100°C or higher, and a tackifying resin, the transfer control layer contains aliphatic hydrocarbon synthetic wax fine particles having a melting peak temperature of 100°C or higher in the range of 50% by mass or more and 95% by mass or less of the entire transfer control layer and carboxylic acid-modified polyolefin having a melting peak temperature of 100°C or higher in the range of 5% by mass or more and 50% by mass or less of the entire transfer control layer.

2. The hot-melt transfer type ink ribbon according to claim 1, wherein the ink layer contains aliphatic hydrocarbon synthetic wax fine particles, which are the binder component of the ink layer, in the range of 5% by mass or more and 30% by mass or less of the entire ink layer.

3. The hot-melt transfer type ink ribbon according to claim 1 or claim 2, wherein the ink layer contains an ethylene-based copolymer resin, which is the binder component of the ink layer, in the range of 20% by mass or more and 50% by mass or less of the entire ink layer.

4. The hot-melt transfer type ink ribbon according to any one of claims 1 to 3, wherein the average particle diameter of the aliphatic hydrocarbon synthetic wax fine particles contained in the transfer control layer is in the range of 0.1 μm or more and 5.0 μm or less.

5. The hot-melt transfer type ink ribbon according to any one of claims 1 to 4, wherein the ethylene-based copolymer resin, which is the binder component of the ink layer, is an ethylene-vinyl acetate copolymer resin.

6. The hot-melt transfer type ink ribbon according to any one of claims 1 to 5, wherein the aliphatic hydrocarbon synthetic wax fine particles, which are the binder component of the ink layer, are composed of at least one of Fischer-Tropsch wax fine particles and polyethylene wax fine particles.

7. The hot-melt transfer type ink ribbon according to any one of claims 1 to 6, wherein the aliphatic hydrocarbon synthetic wax fine particles contained in the transfer control layer are composed of at least one of Fischer-Tropsch wax fine particles and polyethylene wax fine particles.

8. The hot-melt transfer type ink ribbon according to any one of claims 1 to 7, wherein the aliphatic hydrocarbon synthetic wax fine particles contained in the transfer control layer are composed of Fischer-Tropsch wax fine particles.

9. The hot-melt transfer type ink ribbon according to any one of claims 1 to 8, wherein the carboxylic acid-modified polyolefin contained in the transcription control layer is carboxylic acid-modified polypropylene.

10. The hot-melt transfer type ink ribbon according to any one of claims 1 to 9, wherein the tackifier resin of the binder component of the ink layer is a styrene-based tackifier resin.

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