JP7104461B2 - Thermal transfer recording medium - Google Patents

Description

The present invention relates to a melt-type thermal transfer recording medium in which a colored layer is provided in a streak pattern on a substrate.

Conventionally, in Patent Document 1 and Patent Document 2, in order to print a plurality of colors at the same time with one ribbon, a heat transferable ink layer (colored layer) colored on a substrate is formed in a striped shape (streak shape). Intermittently provided thermal transfer recording media (hereinafter referred to as “stripe-coated thermal transfer recording medium”) have been proposed.

Such a streak-coated thermal transfer recording medium is used, for example, for printing on a split packaging machine for drug packaging, and the method of taking the drug and precautions are displayed in red, and the name of the patient to be taken, the name of the drug, etc. are displayed. In order to print in black, a thermal transfer recording medium in which a plurality of colored layers such as red and black are provided intermittently in a streak pattern is used. At present, the speed of the split packaging machine for medicine packaging is increasing in order to perform more packaging work, and the speed of the printer for printing on the medicine packaging is also required. In order to speed up printing with a thermal transfer recording medium, it is necessary to reduce printing energy, that is, to increase sensitivity. Conventionally, a release layer having a low melting point has been provided between a colored layer and a base material in order to increase the sensitivity of a molten thermal transfer recording medium.

However, in the streak-coated thermal transfer recording medium, when a release layer having a low melting point is provided between the colored layer and the base material for the purpose of increasing sensitivity, the thermal transfer recording medium is wound intermittently in a pancake state. A so-called set-off occurred in which the components of the release layer were transferred to the back surface side from the uncoated portion (the portion where the release layer was exposed) of the colored layer provided in the above. The thermal transfer recording medium of Patent Document 2 has been proposed as a method of achieving high-speed printing while taking measures against such set-off. That is, in Patent Document 2, in a thermal transfer recording medium in which a release layer, an intermediate layer, and a streak-coated colored layer are laminated in this order on a base material, the thermoplastic component contained in the release layer and its constituent ratio, and the composition ratio thereof, and By specifying the thermoplastic component contained in the intermediate layer and its constituent ratio, a thermal transfer recording medium has been proposed in which the thermal transfer recording medium is made highly sensitive and the printing speed is increased while taking measures against set-off.

The thermal transfer recording medium of Patent Document 2 has a form in which the colored layer is transferred with an intermediate layer, which is a lower layer, at the time of thermal transfer. The thermal transfer recording medium of Patent Document 2 has lower sensitivity than the thermal transfer recording medium in which only the colored layer is transferred, and there is a limit to further high sensitivity, and it is an extra intermediate compared to the conventional thermal transfer recording medium. Since a layer is required, a streak-coated thermal transfer recording medium having a simple layer structure in which only the colored layer is transferred without a lower layer has been desired.

The streak-coated thermal transfer recording medium is used, for example, for printing in a split packaging machine for drug packaging as described above, and it is premised that both paper and plastic are used as the object to be printed. .. Then, when paper is used as the object to be printed, in order for the heat-transferred colored layer to be fixed to the paper, the melted colored layer enters the gap inside the paper from the surface of the paper and firmly adheres to the paper. It needs to be fixed. Therefore, the colored layer of the streak-coated thermal transfer recording medium is preferably a layer containing wax as a main component.

However, inks containing wax as a main component generally have poor wettability with respect to a lower layer such as a base material. When ink containing wax as the main component is applied in a streak pattern due to poor wettability, the ink tends to collect on both ends of the streak (hereinafter referred to as the ear), and the coating thickness of the ear is the central part. The so-called ear-standing phenomenon occurs, which is thicker than that of the ink. The locally thick ears have poor adhesion to the lower layer, and the thick ears are less flexible than the other parts. For this reason, when the thermal transfer recording medium is conveyed in the printer and the traveling direction is changed so that the thermal transfer recording medium is bent by a roller in the printer or the like, the selvage portion that is inflexible and has poor adhesion to the lower layer becomes , It becomes impossible to follow the shape change of the lower layer such as the base material, and the colored layer falls off from the lower layer starting from the ear part, and the inside of the printer and the packaging sheet which is the printed matter become dirty (so-called). There was a problem of powder falling).

Jinkai Sho 57-196568 JP-A-2018-161774

The present invention has been made in view of the above circumstances, and even if a simple layer structure in which a streaky colored layer is transferred without a lower layer during thermal transfer, when paper is used as an object to be printed. In addition, the heat-transferred colored layer is well fixed to the printed matter, and the streaky colored layer does not come off from the thermal transfer recording medium due to the ears of the streaky colored layer (so-called powder removal). It is a provision of a thermal transfer recording medium having a layer.

The first invention is a thermal transfer recording medium having a transfer control layer laminated on a base film and having a colored layer provided on the transfer control layer with ink containing a plurality of streaky waxes as a main component. The transfer control layer contains urethane-modified copolymerized polyester resin in the solid content of the transfer control layer in an amount of 29 to 39% by weight, and particles having an average particle diameter of 0.15 μm to 2.00 μm in the solid content of the transfer control layer. The thermal transfer recording medium is characterized by containing 10 to 30% by weight of the above, and 4 to 20% by weight of the silicone-modified urethane resin in the solid content of the transfer control layer.

The second invention is the thermal transfer recording medium according to the first invention, wherein the streaky colored layer is a streak in which the traveling direction of the thermal transfer recording medium is the longitudinal direction.

The third invention is the thermal transfer recording medium according to either the first invention or the second invention, wherein the particles are aluminum silicate particles.

The fourth invention is the thermal transfer recording medium according to any one of the first to third inventions, wherein an adhesive layer is further laminated on the colored layer.

In the thermal transfer recording medium of the present invention, since the main component of the streaky colored layer is wax, even when paper is used as the object to be printed, the colored layer melted during thermal transfer is transferred from the surface of the paper to the inside of the paper. The colored layer, which has entered the gap and is firmly fixed to the paper and has been thermally transferred, is well fixed to the printed matter. Further, in the thermal transfer recording medium of the present invention, the transfer control layer to be the lower layer of the colored layer is made of urethane-modified copolymerized polyester resin in an amount of 29 to 39% by weight based on the solid content, and the average particle size is 0.15 μm to 2.00 μm. By forming a layer containing 10 to 30% by weight of certain particles in the solid content, the retention of the transfer control layer with respect to the streaky colored layer becomes stronger except during thermal transfer, and the streaky colored layer becomes ears. However, the streaky colored layer does not fall off from the thermal transfer recording medium (so-called powder drop). In the thermal transfer recording medium of the present invention, thermal transfer is performed by laminating a colored layer containing wax as a main component on a transfer control layer containing 4 to 20% by weight of a silicone-modified urethane resin in addition to the above components. The holding power of the transfer control layer to the colored layer was easily lost during thermal transfer without lowering the holding power of the transfer control layer to the streaky colored layer except for the occasion. Therefore, according to the present invention, even if the colored layer has a simple layer structure in which the colored layer is transferred without a lower layer during thermal transfer, or when paper is used as the printed material, the printed material of the heat-transferred colored layer is printed. It is possible to provide a thermal transfer recording medium which has good fixation to the surface and does not cause the colored layer to fall off from the thermal transfer recording medium (so-called powder removal) due to the ears of the streaky colored layer.

The method of evaluating the dropout of the colored layer from the base material is shown.

The thermal transfer recording medium of the present invention will be described in more detail below.

The thermal transfer recording medium of the present invention is a thermal transfer recording medium in which a transfer control layer that is not transferred by itself is provided on one surface of a base material, and a streaky colored layer is provided on the transfer control layer.

(Base material)
As the base material of the thermal transfer recording medium of the present invention, it is generally used as a base film for a polyester film such as a polyethylene terephthalate film and a polyethylene naphthalate film, a polycarbonate film, a polyamide film, an aramid film and other types of thermal transfer recording medium. Various plastic films can be used. Also, high-density thin paper such as condenser paper can be used. The thickness of the base material is usually about 1 to 10 μm, and is preferably in the range of 1 to 6 μm in order to improve heat transfer.

(Transfer control layer)
The thermal transfer recording medium of the present invention is provided with a transfer control layer between the base material and the colored layer. The transfer control layer itself is a layer that is not transferred by thermal transfer, and the upper streaky colored layer can be easily released during thermal transfer, and the upper streaky colored layer does not fall off until thermal transfer. It is required to keep it.

The transfer control layer of the present invention preferably contains a urethane-modified copolymerized polyester resin in an amount of 29 to 39% by weight, more preferably 32 to 39% by weight, based on the solid content. Further, the transfer control layer of the present invention preferably contains 10 to 30% by weight of particles having an average particle diameter of 0.15 μm to 2.00 μm in the solid content. By containing particles having an average particle diameter of 0.15 μm to 2.00 μm, the transfer control layer can be provided with irregularities on the surface. The average thickness (after drying) of the transfer control layer is preferably 0.1 μm or more and 0.3 μm. As described above, the transfer control layer of the present invention contains particles having an average particle diameter larger than the average thickness of the layer, and the particles are fixed in a state of protruding from the surface of the transfer control layer. That is, the particles are in a state of protruding from the layer made of a thin binder. The transfer control layer of the present invention contains a urethane-modified copolymerized polyester resin, and the adhesiveness of the urethane-modified copolymerized polyester resin fixes particles protruding from the layer to a layer made of a thin binder. Further, in the transfer control layer of the present invention, a layer made of a thin binder is formed on the surface of particles protruding from the layer made of a thin binder due to the film-forming property of forming a tough film of urethane-modified copolymerized polyester resin. can do.

As described above, in the transfer control layer of the present invention, the surface of the particles protruding from the layer made of the thin binder is also covered with the layer made of the thin binder. Since the layer made of the thin binder has adhesiveness due to the urethane-modified copolymerized polyester resin, the surface of the particles on the transfer control layer also has adhesiveness. When the colored layer is laminated on the transfer control layer, the colored layer is laminated so as to mesh with the unevenness of the surface of the transfer control layer, and is in contact with the surface of the transfer control layer having adhesiveness over a wide contact area. .. Therefore, the colored layer is firmly held by the transfer control layer.

If the content of the transfer control layer of the urethane-modified copolymerized polyester resin in the solid content is less than 29% by weight, the transfer control layer does not have sufficient adhesiveness, and the streaky colored layer may come off. .. On the other hand, if the content of the urethane-modified copolymerized polyester resin in the solid content exceeds 39% by weight, the adhesiveness of the transfer control layer becomes too strong, and transfer defects may occur during thermal transfer.

When the average particle size of the particles contained in the transfer control layer is less than 0.15 μm, the unevenness on the surface of the transfer control layer is too small, and the effect of preventing the streaky colored layer from falling off from the transfer control layer is sufficiently obtained. I can't. On the other hand, if the average particle size exceeds 2.00 μm, particles that cannot be fixed to the transfer control layer may be generated, and the number of irregularities on the surface of the transfer control layer per unit area decreases, resulting in streaks from the transfer control layer. The effect of preventing the colored layer from falling off is not sufficiently obtained. Further, when the content of the particles in the solid content of the transfer control layer is less than 10% by weight, the number of irregularities on the surface of the transfer control layer per unit area is reduced, and the streaky colored layer is removed from the transfer control layer. The effect of prevention is not sufficiently obtained. On the other hand, when the content of the particles exceeds 30% by weight, the ratio of the binder component of the transfer control layer decreases, the transfer control layer itself becomes brittle, the ability to hold the colored layer decreases, and the colored layer falls off.

If the average thickness of the transfer control layer is less than 0.1 μm, sufficient holding power for the streaky colored layer cannot be obtained, and the streaky colored layer falls off. On the other hand, if it exceeds 0.3 μm, the holding force on the streaky colored layer increases too much, and the streaky colored layer may become poorly transferred during thermal transfer. The thickness of the transfer control layer in the present invention is not the actual measurement value of the layer thickness but the transfer applied per unit area because the transfer control layer may contain particles having a particle size exceeding 0.3 μm. It shall mean a solution obtained by dividing the volume of solid content of the control layer by the unit area.

As described above, in the present invention, by incorporating the urethane-modified copolymerized polyester resin and the particles in the transfer control layer, the retention force of the transfer control layer against the streaky colored layer is obtained, and the transfer control is performed by this retention force. It is possible to prevent the streaky colored layer from falling off from the layer. Further, in the present invention, by further incorporating the silicone-modified urethane resin into the transfer control layer, the transfer control layer can be transferred with high sensitivity during thermal transfer without lowering the holding power of the transfer control layer against the streaky colored layer. It will be possible.

The content of the silicone-modified urethane resin in the solid content of the transfer control layer is preferably 4 to 20% by weight. If the content of the silicone-modified urethane resin in the solid content of the transfer control layer is less than 4% by weight, the effect of enabling highly sensitive transfer of the colored layer during thermal transfer cannot be obtained. On the other hand, if it exceeds 20% by weight, the effect of preventing the streaky colored layer from falling off is reduced.

By containing the silicone-modified urethane resin in the transfer control layer in the above-mentioned preferable ratio in addition to the urethane-modified copolymerized polyester resin and the particles having the above average particle size, the colored layer is not melted except during thermal transfer. The state in which the transfer control layer firmly holds the streaky colored layer is maintained. On the other hand, when the colored layer at the time of thermal transfer is in a melted state, the transfer control layer contains the silicone-modified urethane resin in the above-mentioned preferable ratio, so that the transfer control layer has a reduced ability to hold the streaky colored layer. Highly sensitive transfer of the colored layer is possible.

As the particles used for the transfer control layer, any particles can be used regardless of whether they are organic or inorganic as long as the average particle diameter is 0.15 μm or more and 2.0 μm or less, but aluminum silicate particles and the like are preferably used. be able to.

The transfer control layer preferably contains a thermoplastic resin as another component. The thermoplastic resin is not particularly limited, but the polyester resin is preferable among the thermoplastic resins because it has good compatibility with the urethane-modified copolymerized polyester resin.

(Colored layer)
The colored layer of the thermal transfer recording medium of the present invention is a layer provided in a streak pattern on the transfer control layer, and is a heat-transferred layer composed of a heat-meltable or heat-softening vehicle and a colorant. The colored layer may have a plurality of streaks whose longitudinal direction is the traveling direction of the thermal transfer recording medium, or may be a plurality of streaks whose longitudinal direction is orthogonal to the traveling direction of the thermal transfer recording medium. In the present invention, the vehicle contains wax as a main component, and one type of wax may be used alone, or two or more types may be used in combination. Further, by incorporating an adhesive resin in the colored layer, the peeling force of the colored layer from the transfer control layer at the time of thermal transfer may be adjusted, and additives may be appropriately used for various purposes. May be good. By using wax as the main component of the vehicle in the streaky colored layer, the layer is made mainly of wax. Therefore, the colored layer is surely melted during thermal transfer, and the adhesiveness to the lower layer is easily lost. Highly sensitive transfer is possible. The fact that the colored layer contains wax as a main component indicates that the material having the highest content ratio among the colored layer materials is wax.

Examples of the wax that is the main component of the vehicle of the colored layer include natural waxes such as lanolin, carnauba wax, candelilla wax, montan wax, selecin wax, and rice wax, petroleum waxes such as paraffin wax and microcrystallin wax, and oxide waxes. , Synthetic ester wax, polyethylene wax, α-olefin-maleic anhydride copolymer wax, urethanized wax, Fishertroph wax, synthetic petroleum wax and other synthetic waxes. These may be used alone or in combination of two or more. The content of the wax in the solid content of the colored layer is preferably 55 to 85% by weight. When the content of the wax in the solid content of the colored layer is less than 55% by weight, the transfer sensitivity during thermal transfer is lowered. On the other hand, if it exceeds 85% by weight, a sufficient amount of the colorant cannot be contained in the colored layer, and a sufficient print density cannot be secured.

Examples of the adhesive resin include polyolefins such as polyethylene, polypropylene, polyisobutylene, polystyrene, and ethylene-propylene rubber, celluloses such as ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethyl cellulose, and cellulose triacetate. Derivatives, copolymers of poly (meth) acrylic acid and its esters, polyvinyl acetals such as polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyacetals, polyamides, polyimides, nylons, polyester resins, urethane resins, epoxy resins, etc. be able to. Ethylene-vinyl acetate copolymer resin is preferable in that the peeling force of the colored layer from the transfer control layer during thermal transfer can be easily adjusted.

As described above, in the thermal transfer recording medium of the present invention, the vehicle of the colored layer contains wax as the main component. Therefore, even when paper such as glassin paper is used as the object to be printed, the molten colored layer ink is produced. It penetrates into the fine irregularities on the paper surface and is firmly fixed to the printed matter. The adhesive resin content of the colored layer is preferably 3% by weight or more and 15% by weight or less in the solid content of the colored layer. When the adhesive resin content of the colored layer is less than 3% by weight, blocking (in the so-called pancake state in which the thermal transfer recording medium is wound around the shaft, to the back side of the heat-resistant slippery layer on which the colored layers are overlapped, etc.) The problem of migration) is likely to occur. When the adhesive resin content of the colored layer exceeds 15% by weight, the peeling force of the colored layer from the base material during thermal transfer becomes large, wrinkles of the printed matter are likely to occur due to printing, and the printing sensitivity is increased. descend.

Examples of the additive include plasticizers, antifoaming agents, surfactants, antioxidants, dispersants, tackifiers and the like.

As the colorant, colorants of all colors including cyan, magenta, yellow, red, blue, and black can be used, and organic and inorganic colors generally used in this type of heat-transferred color layer. Color pigments, dyes, etc. can be used. The content of the colorant in the solid content of the colored layer is preferably 10 to 30% by weight. If the content of the colorant in the solid content of the color layer is less than 10% by weight, the color becomes too light and a sufficient concentration cannot be obtained in the transferred color layer. When the content of the colorant in the solid content of the color layer exceeds 30% by weight, the color layer becomes brittle and the color layer easily peels off from the transfer control layer, causing blocking.

The thickness of the colored layer (thickness after drying, the same applies hereinafter) is preferably 1.6 μm or more and 2.4 μm or less. Although it depends on the color of the colored layer, if the thickness of the colored layer is less than 1.6 μm, a sufficient print density cannot be obtained, which is not preferable. In addition, the colored layer may melt too much during transfer and the print may be crushed. Further, if the thickness of the colored layer exceeds 2.4 μm, blocking is likely to occur, the sharpness of the colored layer at the time of thermal transfer is deteriorated, and the transferability is lowered, which is not preferable. The width of the colored layer is not particularly limited, but as the width of the colored layer becomes narrower, the contact area between the transfer control layer and the colored layer decreases, so that the colored layer is more likely to fall off from the transfer control layer. In the thermal transfer recording medium of the present invention, if the width of the colored layer is 1 mm or more, the colored layer does not fall off from the transfer control layer. The upper limit of the width of the colored layer is not particularly limited as long as it is 1 mm or more, but a colored layer having a width of 1 mm to 30 mm is generally used depending on the intended use.

(Adhesive layer)
In the thermal transfer recording medium of the present invention, an adhesive layer containing wax as a main component may be laminated as a heat-meltable or heat-softening vehicle as the outermost layer on the colored layer. One type of wax as a vehicle of the adhesive layer may be used alone, or two or more types may be used in combination. Further, a thermoplastic resin or an additive may be appropriately used for various purposes. By laminating the adhesive layer on the colored layer, the peeling from the transfer control layer and the functional differentiation of the adhesiveness to the printed matter can be achieved, and the performance of each can be optimized individually, so that the streaks are streaky. The effect of preventing the colored layer from falling off is further enhanced, and the performance of the thermal transfer recording medium can be easily improved.

Since the adhesive layer does not need to contain a colorant, it can be made thinner than the colored layer. Since the adhesive layer does not need to contain a colorant and can be a colorless and transparent layer, and is a thin layer, the adhesive layer can cover the colored layer and be provided with a width wider than that of the colored layer. Even if the adhesive layer is provided with a width wider than that of the colored layer in this way, since the adhesive layer is a thin layer, it does not adversely affect the transfer performance of the colored layer during thermal transfer, and the adhesive layer is colorless and transparent. , The color of the transferred colored layer does not differ from the expected color. Since the adhesive layer can be provided with a width wider than that of the colored layer, the adhesive layer does not fall off by itself (so-called powder falling). Further, by providing the adhesive layer with a width wider than that of the streaky colored layer, the adhesive layer is in a state of covering the colored layer, so that the effect of preventing the streaky colored layer from falling off from the transfer control layer is also obtained. Can be enhanced. The adhesive layer may be provided on the entire surface of the thermal transfer recording medium.

The effect of facilitating the performance improvement of the thermal transfer recording medium by providing the adhesive layer is that when the printed matter is paper, the effect of preventing the colored layer from falling off from the transfer control layer is not reduced. For example, to improve the fixability to the printed matter. For example, if the melting point of the vehicle of the colored layer is lowered, the colored layer is easily melted during thermal transfer and easily penetrates into the gaps on the surface of the paper to be printed, thereby further improving the fixability to the printed material. Can be done. However, if the melting point of the vehicle of the colored layer is lowered, the colored layer becomes soft and the colored layer becomes soft if the thermal transfer recording medium is used immediately after being stored at a high temperature or if it is used at a high temperature. The possibility of falling off from the transfer control layer (so-called powder dropping occurs) increases. On the other hand, if an adhesive layer having a lower melting point of the vehicle than the colored layer is laminated on the colored layer without changing the melting point of the vehicle of the colored layer, the effect of preventing the colored layer from falling off from the transfer control layer is reduced. It is possible to improve the fixability to the printed matter without causing the printing. Since the melting point of the vehicle of the colored layer is not changed, the effect of preventing the colored layer from falling off from the transfer control layer is not reduced. On the other hand, since an adhesive layer having a lower melting point of the vehicle than the colored layer is provided on the colored layer, the adhesive layer in contact with the printed matter during thermal transfer is easily melted, and only the colored layer is formed. In comparison, the molten vehicle permeates through the gaps on the surface of the paper to be printed, and the fixability to the printed material is enhanced. As described above, since the adhesive layer can be provided with a width wider than that of the colored layer, the melting point of the vehicle of the adhesive layer can be lowered as long as the so-called blocking that the adhesive layer moves to the back surface side does not occur. However, there is no risk of problems such as the adhesive layer falling off (so-called powder falling off).

Examples of waxes used for the adhesive layer include natural waxes such as lanolin, carnauba wax, candelilla wax, montan wax, selecin wax and rice wax, petroleum waxes such as paraffin wax and microcrystallin wax, oxide waxes and synthetic ester waxes. , Polyethylene wax, α-olefin-maleic anhydride copolymer wax, urethanized wax, Fishertropch wax, synthetic wax such as synthetic petroleum wax and the like. These may be used alone or in combination of two or more. The content of the wax in the solid content in the adhesive layer is preferably 55 to 100% by weight, and when the content of the wax in the solid content in the adhesive layer is less than 55% by weight, the printing sensitivity during thermal transfer becomes high. descend.

The thickness of the adhesive layer is preferably 0.3 μm or more and 0.7 μm or less. If the thickness of the adhesive layer is less than 0.3 μm, the effect of providing the adhesive layer cannot be obtained. Further, if the thickness of the adhesive layer exceeds 0.7 μm, the heat transfer property in the adhesive layer deteriorates at the time of thermal transfer, the adhesive layer is not sufficiently melted, and transfer failure to the printed matter is likely to occur. As long as the thickness of the adhesive layer is within the above range, even if the adhesive layer is provided on the entire surface of the thermal transfer recording medium, the transfer sensitivity of printing does not decrease.

The adhesive layer may contain a thermoplastic resin (including an elastomer). As the thermoplastic resin (including the elastomer) to be added to the adhesive layer, in addition to the thermoplastic resin exemplified as the adhesive resin in the colored layer, known ones can be used, and even if one kind of resin is used alone. Often, two or more types may be used in combination. However, due to the increased heat of fusion of the adhesive layer, the adhesive layer is less likely to melt than the colored layer during thermal transfer, and the thermoplastic resin is contained to such an extent that the fixability when the printed matter is paper is reduced. It is not preferable to do so. In addition, the adhesive layer may contain particles to prevent blocking. Examples of the particles contained for preventing blocking include silica particles. When particles are contained, a dispersant may be contained in order to improve the dispersion of the particles.

Examples of the additive added to the adhesive layer include a plasticizer, a defoaming agent, a surfactant, an antioxidant, a dispersant, and a tackifier. The adhesive layer provided on the colored layer does not need to contain a colorant, and the range of adjustment of the content of the main component wax, the thermoplastic resin, the additive, and the like is widened. Therefore, by providing the adhesive layer, it becomes easy to adjust the content of the thermoplastic resin, additives, and the like in addition to the wax to make the thermal transfer recording medium highly sensitive and prevent blocking.

(Heat-resistant slippery layer)
In the thermal transfer recording medium of the present invention, a heat-resistant slippery layer is provided on the opposite surface of the surface on which the colored layer of the base material is provided. By providing the heat-resistant slippery layer, it is possible to reduce damage to the base material by the transfer head of the printer during printing. By providing the heat-resistant slippery layer, damage to the base material is reduced, so that it is possible to prevent a so-called stick in which the transfer head sticks to the base material during printing and cannot move smoothly.

As the material of the heat-resistant slippery layer of the present invention, a heat transfer recording medium conventionally used can be used without particular limitation. Among these, silicone-modified urethane resin, silicone-modified acrylic resin, or a mixture thereof is particularly preferable as a material for the heat-resistant slippery layer, considering the heat resistance to the thermal head, the point of reducing the dynamic friction coefficient at high temperature, and the cost. ..

In addition to particles, the heat-resistant slipping layer of the present invention may contain other additives such as lubricants and antistatic agents.

The thickness of the heat-resistant slipping layer of the present invention (thickness after drying, the same applies hereinafter) is preferably 0.05 to 0.8 μm from the viewpoint of achieving a good stick-preventing effect and preventing deterioration of thermal conductivity. If the thickness of the heat-resistant slipping layer is less than 0.05 μm, the heat resistance may be insufficient and sticks may be generated during printing, or the base material may melt and printing may not be possible. If it exceeds 0.8 μm, the thermal conductivity may deteriorate and printing may be hindered.

The thermal transfer recording medium of the present invention can be used as a printed matter on semi-transparent sheet-shaped paper and / or transparent or translucent sheet-shaped plastic. Examples of translucent sheet-like paper and / or transparent or translucent sheet-like plastic include paper such as glassin paper and polyethylene-laminated glassin paper, polyethylene terephthalate film, nylon film, low-density polyethylene film, and biaxially stretched polypropylene. Examples thereof include paper and / or plastic used as a conventionally known packaging material which is a film such as a film and a polyethylene laminated cellophane.

The thermal transfer recording medium of the present invention can also be used for a drug packaging machine or the like that prints translucent sheet-shaped paper and / or transparent or translucent sheet-shaped plastic in a folded state. In such a drug packaging machine or the like, a sheet is made into a cylinder by sealing both ends of the sheets that are stacked in a folded state in half, and an object to be packaged such as a drug is stored inside the cylinder.

The tensile elastic modulus of the translucent sheet-like paper and / or the transparent or translucent sheet-like plastic printed using the thermal transfer recording medium of the present invention is preferably 400 MPa or more and 2000 MPa or less. If the tensile elastic modulus is less than 400 MPa, the sheet may be stretched due to the tension generated by the printer, so that it cannot be used. On the other hand, a sheet having a tensile elastic modulus exceeding 2000 MPa is not suitable for packaging because the sheet is too thick or too hard.

The present invention will be described in more detail with reference to Examples 1 to 11 and Comparative Examples 1 to 8 below. The present invention is not limited to these examples. Hereinafter, with respect to the blending amount of each material, those labeled as parts shall indicate parts by weight unless otherwise specified. Unless otherwise specified, the layers other than the colored layer shall be applied to the entire surface of the thermal transfer recording medium (base material).

(Example 1)
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 34.00 parts Polyester resin (100% solid content) 34.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles (average particle size 1) .00 μm solid content 100%) 20.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Red colored layer)
The materials of the following formulation are kneaded to prepare a red colored layer ink, which is coated on the transfer control layer so as to form a stripe in the longitudinal direction of a substrate having a thickness of 2.0 μm and a coating width of 7.0 mm. A red colored layer was prepared.
Polyethylene wax (melting point 99 ° C, solid content 100%) 72.00 parts Dispersant (solid content 100%) 5.00 parts Ethylene-vinyl acetate copolymer resin (melting point 90 ° C, solid content 100%)
8.00 parts Red pigment (100% solid content) 15.00 parts

(Black colored layer)
The materials of the following formulation are kneaded to prepare a black colored layer ink, which is coated on the transfer control layer so as to form a stripe in the longitudinal direction of a substrate having a thickness of 2.0 μm and a coating width of 7.0 mm. A black colored layer was prepared.
Polyethylene wax (melting point 99 ° C, solid content 100%) 72.00 parts Dispersant (solid content 100%) 5.00 parts Ethylene-vinyl acetate copolymer resin (melting point 89 ° C, solid content 100%)
8.00 parts Carbon black pigment (100% solid content) 15.00 parts

(Heat-resistant slippery layer)
The materials of the following formulation are kneaded to prepare a heat-resistant slippery layer ink, and the thickness after drying is adjusted to 0.2 μm, and the base material surface opposite to the surface on which the colored layer and the transfer control layer are laminated. A heat-resistant slippery layer was prepared by coating and drying the ink, and a thermal transfer recording medium was prepared.
Silicone modified urethane resin 25.00 parts (Dialomer manufactured by Dainichiseika Kogyo Co., Ltd., solid content 20%)
Isocyanate 3.00 parts Solvent (MEK) 140.00 parts Solvent (toluene) 25.00 parts

(Example 2)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 38.00 parts Polyester resin (100% solid content) 30.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles (average particle size 1) .00 μm solid content 100%) 20.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Example 3)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 30.00 parts Polyester resin (100% solid content) 38.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles (average particle size 1) .00 μm solid content 100%) 20.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Example 4)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 38.00 parts Polyester resin (100% solid content) 38.00 parts Silicone-modified urethane resin (100% solid content) 4.00 parts Aluminum silicate particles (average particle size 1) .00 μm solid content 100%) 20.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Example 5)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 30.00 parts Polyester resin (100% solid content) 30.00 parts Silicone-modified urethane resin (100% solid content) 20.00 parts Aluminum silicate particles (average particle size 1) .00 μm solid content 100%) 20.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Example 6)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 39.00 parts Polyester resin (100% solid content) 39.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles (average particle size 1) .00 μm Solid content 100%) 10.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Example 7)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 29.00 parts Polyester resin (100% solid content) 29.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles (average particle size 1) .00 μm solid content 100%) 30.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Example 8)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 34.00 parts Polyester resin (100% solid content) 34.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles (average particle size 0) .15 μm solid content 100%) 20.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Example 9)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 34.00 parts Polyester resin (100% solid content) 34.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles (average particle size 2) .00 μm solid content 100%) 20.00 parts Solvent (MEK) 112.50 parts Solvent (toluene) 112.50 parts

(Example 10)
(Adhesive layer)
Other than kneading the materials of the following formulation to prepare an adhesive layer ink, adjusting the thickness after drying to 0.5 μm, coating on the colored layer, drying and laminating the adhesive layer on the colored layer. Made a thermal transfer recording medium in the same manner as in Example 1.
Carnauba wax (melting point 83 ° C, solid content 30% aqueous solution) 32.75 parts Silica particles (average particle diameter 0.5 μm, solid content 100%) 6.05 parts Particle dispersant (branched polymer, solid content 100%) 0 .80 parts Solvent (IPA) 11.90 parts Solvent (methanol) 64.70 parts

(Example 11)
A thermal transfer recording medium was prepared by the same method as in Example 1 except that the black-colored layer and the red-colored layer were coated so that the coating width was 1.0 mm.

(Comparative Example 1)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 25.00 parts Polyester resin (100% solid content) 43.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles
(Average particle size 1.00 μm solid content 100%) 20.00 parts
Solvent (MEK) 112.50 parts
Solvent (toluene) 112.50 parts

(Comparative Example 2)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 45.00 parts Polyester resin (100% solid content) 23.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles (average particle size 1) .00 μm solid content 100%) 20.00 parts
Solvent (MEK) 112.50 parts
Solvent (toluene) 112.50 parts

(Comparative Example 3)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin 39.00 parts Polyester resin (100% solid content) 39.00 parts Silicone-modified urethane resin (100% solid content) 2.00 parts Aluminum silicate particles (average particle size 1.00 μm solid content 100%) ) 20.00 copies
Solvent (MEK) 112.50 parts
Solvent (toluene) 112.50 parts

(Comparative Example 4)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 29.00 parts Polyester resin (100% solid content) 29.00 parts Silicone-modified urethane resin (100% solid content) 22.00 parts Aluminum silicate particles
(Average particle size 1.00 μm solid content 100%) 20.00 parts
Solvent (MEK) 112.50 parts
Solvent (toluene) 112.50 parts

(Comparative Example 5)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 40.00 parts Polyester resin (100% solid content) 40.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles
(Average particle size 1.00 μm, solid content 100%) 8.00 parts
Solvent (MEK) 112.50 parts
Solvent (toluene) 112.50 parts

(Comparative Example 6)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 28.00 parts Polyester resin (100% solid content) 28.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles
(Average particle size 1.00 μm solid content 100%) 32.00 parts
Solvent (MEK) 112.50 parts
Solvent (toluene) 112.50 parts

(Comparative Example 7)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 34.00 parts Polyester resin (100% solid content) 34.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles
(Average particle size 0.10 μm solid content 100%) 20.00 parts
Solvent (MEK) 112.50 parts
Solvent (toluene) 112.50 parts

(Comparative Example 8)
From Example 1, a thermal transfer recording medium was prepared by the same method as in Example 1 except that the transfer control layer was changed to the following formulation.
(Transfer control layer)
A transfer control layer ink is prepared by kneading the materials of the following formulation, adjusted to a thickness of 0.15 μm after drying on a 4.5 μm PET film used as a base material, and coated on the base material. The transfer control layer was prepared by processing and drying.
Urethane-modified copolymerized polyester resin (100% solid content) 34.00 parts Polyester resin (100% solid content) 34.00 parts Silicone-modified urethane resin (100% solid content) 12.00 parts Aluminum silicate particles
(Average particle size 2.20 μm solid content 100%) 20.00 parts
Solvent (MEK) 112.50 parts
Solvent (toluene) 112.50 parts

(Evaluation of dropout of colored layer from substrate)
The thermal transfer recording media prepared in Examples 1 to 11 and Comparative Examples 1 to 8 were left at room temperature and humidity for 1 week, and then cut into strips having a width of 50 mm to prepare evaluation samples. The positions of the red and black streaky colored layers in each sample were set to be approximately the same in all samples. After each sample has a length required for evaluation, it is set in a measuring instrument as shown in FIG. As a method of setting the thermal transfer recording medium, first, a surface of a slide glass cut into a thickness of 1.3 mm, a width of 26 mm, and a length of 100 mm and a surface having a thickness of 1.3 mm and a length of 100 mm is perpendicular to the direction of gravity (horizontal plane). Set so that Next, set the thermal transfer recording medium so that the set slide glass and the colored layer side of the thermal transfer recording medium are in contact with each other. In this state, the surface of the transfer recording medium on the colored layer side is brought into contact with the surface of the slide glass having a thickness of 1.3 mm and a length of 100 mm and the surface of the slide glass having a width of 26 mm and a length of 100 mm without any gap. Next, as shown in FIG. 1, by attaching a weight of 784 mN to the thermal transfer recording medium, a tension is applied to the thermal transfer recording medium, and in the state where the tension is applied, the thermal transfer recording medium is horizontally moved at 20 mm / sec. A dropout test was performed with a movement of 200 mm. The presence or absence of the streaky colored layer of each thermal transfer recording medium after the dropout test was visually confirmed according to the following evaluation criteria. The evaluation results are shown in Tables 1 and 2.
◯: The streaky colored layer did not float or fall off at all.
Δ: A part of the streaky colored layer was floating, but it was at a level where there was no problem in use.
X: The streaky colored layer fell off and was at a level that could not be used for printing.

(Print sensitivity evaluation)
The thermal transfer recording media produced in Examples 1 to 10 and Comparative Examples 1 to 8 are set in a state where they can be printed using a thermal transfer printer of a drug packaging device manufactured by Takazono Co., Ltd., and then printing is performed using the same printer. did. As the object to be printed, polyethylene laminated glassine paper having a tensile elastic modulus of 500 MPa (printing is on the glassine paper side) was used. As the printing pattern, 10-point uppercase letters A to Z were printed for both the red colored layer and the black colored layer. The printing speed was 180 mm / sec. The printing condition was visually confirmed according to the following evaluation criteria. The evaluation results are shown in Tables 1 and 2.
◯: There was no printing chipping or density decrease.
X: There was chipping of printing or a decrease in density.

(Table 1)

(Table 2)

Claims (4)

A thermal transfer recording medium having a transfer control layer laminated on a base film and a colored layer provided on the transfer control layer with ink containing a plurality of streaky waxes as a main component, wherein the transfer control layer is The urethane-modified copolymerized polyester resin is 29 to 39% by weight in the solid content of the transfer control layer, and the particles having an average particle diameter of 0.15 μm to 2.00 μm are 10 to 30% by weight in the solid content of the transfer control layer. %, A thermal transfer recording medium containing 4 to 20% by weight of a silicone-modified urethane resin in the solid content of the transfer control layer. The thermal transfer recording medium according to claim 1, wherein the streak-shaped colored layer has a streak shape in which the traveling direction of the thermal transfer recording medium is the longitudinal direction. The thermal transfer recording medium according to claim 1 or 2, wherein the particles are aluminum silicate particles. The thermal transfer recording medium according to any one of claims 1 to 3, wherein an adhesive layer is further laminated on the colored layer.

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