JP5540549B2 - Thermal transfer recording medium - Google Patents

Description

  The present invention relates to a thermal transfer recording medium having at least a protective layer for protecting an image such as a character or a picture thermally transferred and recorded on a thermal transfer member.

  2. Description of the Related Art Conventionally, a sublimation type thermal transfer system or a melt type thermal transfer system has been widely employed as a system for recording an image such as a character or a picture on a thermal transfer body. The sublimation thermal transfer system is a thermal transfer recording layer surface of a thermal transfer recording medium provided with a thermal transfer recording layer containing a dye or a binder on a support, and a thermal transfer having a receiving layer for receiving the dye on another support. The surface of the receptor layer of the body is superposed on each other, and the dye in the thermal transfer recording layer is sublimated by selectively applying heat from a thermal head or the like from the surface of the thermal transfer recording medium where the thermal transfer recording layer is not provided. In this method, a desired image is recorded. This sublimation thermal transfer system is widely used for monochrome printing such as letters and diagrams, and color printing such as digital camera images or computer graphics images.

On the other hand, the melt-type thermal transfer system has a thermal transfer recording layer surface of a thermal transfer recording medium provided with a heat-fusible thermal transfer recording layer containing a pigment, wax or the like on a support, and a coating provided with a receiving layer on another support. By superimposing the surface of the receiving layer of the thermal transfer body on each other and heating with a thermal head or the like, a part of the thermal transfer recording layer is selectively transferred to the receiving layer side, so that an image such as a desired character or picture can be obtained. This is a recording method.
After an image such as a character or a picture is recorded on the thermal transfer medium by these thermal transfer methods, the durability and weather resistance of the printed matter can be improved by covering the surface with a protective layer as necessary.

  By the way, in a recent thermal transfer recording printer with a compact design, the winding diameter after use of the wound thermal transfer recording medium set in the printer becomes too larger than the winding diameter before use. There is a problem that the printer stops automatically before it is used up.

  In order to solve this problem, several methods have been proposed. As an example, in a thermal transfer recording medium having a thermal transfer recording layer on one side of a support and a heat resistant slipping layer on the other side of the support, an aziridine compound and an aziridine compound are added to the heat resistant slipping layer. On the other hand, there is a method (Patent Document 1) that includes a group having reactivity and imparts high heat resistance. A method of providing a sticking prevention layer containing a compound containing polyparabanic acid on the same surface as the heat resistant slipping layer of the thermal transfer recording medium described in Patent Document 1 (Patent Document 2) has also been proposed.

JP-A-1-31686 JP-A-3-53990

However, since the plastic deformability of the thermal transfer recording medium is greatly affected by physical properties such as the thermal contraction rate and tensile elastic modulus of the support constituting the thermal transfer recording medium, the heat resistance of the heat resistant slipping layer is improved as in Patent Document 1. It is not possible to suppress an increase in the winding diameter of the thermal transfer recording medium after use. Further, even if the sticking prevention layer is provided as in Patent Document 2 to prevent the support from sticking to the thermal head, the winding diameter of the thermal transfer recording medium wound up after the thermal transfer recording is not greatly increased. It cannot be suppressed, and the problem of the automatic stop of the printer accompanying an increase in the winding diameter has not been completely avoided.

  The present invention solves the above-mentioned problems in the thermal transfer recording medium, and includes a release layer at the time of thermal transfer recording by containing fine particles in the release layer which is a constituent layer of the protective layer. When the release layer is peeled off at the interface, fine particles are positioned on the release surface of the release layer, and when the thermal transfer recording medium is wound up after thermal transfer recording, the sliding property between the heat-resistant slipping layer facing the release layer and this release layer It is an object of the present invention to provide a thermal transfer recording medium capable of improving the above-described characteristics and thereby suppressing an increase in the winding diameter of the thermal transfer recording medium.

A thermal transfer recording medium is provided with a protective layer having at least a multilayer structure of a release layer and a release layer on one side of a support and at least a heat-resistant slipping layer on the other side. The release layer and the release layer are peeled at the interface, and the release layer contains at least a binder and fine particles composed of cellulose or cellulose acetate propionate, and is protected after being used for thermal transfer recording. The thermal transfer recording medium is characterized in that a static friction coefficient between the layer and the heat resistant slipping layer is 0.3 or less, and Tg of the binder resin constituting the heat resistant slipping layer is 40 or more.

  The invention according to claim 2 is the value of r / h in the thermal transfer recording medium according to claim 1, wherein the average particle diameter of the fine particles is r and the film thickness of the release layer is h. Is in the range of 1.0 to 8.0.

Furthermore, the invention according to claim 3 is the thermal transfer recording medium according to claim 1 or 2 , wherein the release layer further contains oil, and the amount of oil added is 0 in terms of the resin solid content ratio. 0.1 to 10 parts, and the static friction coefficient between the protective layer and the heat-resistant slip layer after being used for thermal transfer recording is 0.1 or more.

  The thermal transfer recording medium according to the present invention is provided with at least a protective layer having a multilayer structure of a release layer and a release layer on one side of a support, and at least a heat-resistant slipping layer on the other side. In the thermal transfer recording medium, the release layer contains at least a binder and fine particles, and after being subjected to the thermal transfer recording, the static friction coefficient between the protective layer and the heat-resistant slipping layer is 0.3 or less, so that the winding deviation is reduced. In addition, it is possible to suppress an increase in the winding diameter during winding after thermal transfer recording, and the printer does not automatically stop when the winding diameter increases. Can be used for thermal transfer recording.

Furthermore, when the average particle diameter of the fine particles in the release layer is r and the film thickness of the release layer is h, the value of r / h is about 1.0 to 8.0, Occurrence of print omission can be prevented more reliably.
Further, by including fine particles in the release layer at a ratio of about 0.1 to 5.0 parts by resin solids ratio, the gloss of an image recorded by a thermal transfer recording medium of a type to which no fine particles are added can be improved. Almost the same glossiness can be imparted to the transfer recorded image.
Furthermore, by adding oil to the release layer and setting the amount of addition to a resin solid content ratio of about 0.1 to 10.0 parts, it is possible to wind up without causing winding misalignment. In addition, transfer defects are less likely to occur. In addition, since the coefficient of static friction between the protective layer and the heat-resistant slipping layer can be lowered after the thermal transfer recording, the increase in the winding diameter when wound after use can be suppressed to a very low level.

It is explanatory drawing which shows the general | schematic cross-section structure of the thermal transfer recording medium which concerns on one Embodiment of this invention. It is explanatory drawing which shows the schematic cross-sectional structure of the thermal transfer recording medium which concerns on other embodiment of this invention.

  Hereinafter, the thermal transfer recording medium of the present invention will be described in more detail. FIG. 1 shows a schematic sectional configuration of a thermal transfer recording medium 1 according to an embodiment of the present invention, and FIG. 2 shows a schematic sectional configuration of a thermal transfer recording medium 10 according to another embodiment of the present invention. It is.

  These thermal transfer recording media 1, 10 basically have a protective layer 7 having a multilayer structure of at least a release layer 3, 13 and a release layer 4, 14 on one surface of the support 2, 12. 17 and at least the heat-resistant slip layers 8 and 18 are provided on the other surface. Reference numerals 6 and 16 denote transfer protective layers that are transferred to the thermal transfer medium side during thermal transfer recording, and 15 denotes an adhesive layer provided on the release layer 14.

As the supports 2 and 12, those equivalent to those used as the supports of conventionally known thermal transfer recording media can be used, but those having excellent mechanical strength, heat resistance and the like are preferable. Specifically, a synthetic resin film made of polyethylene terephthalate, polyethylene naphthalate, polystyrene, polypropylene, polycarbonate, polyvinyl chloride, polyvinyl alcohol, polysulfone, aliphatic polyamide, aromatic polyamide, polyimide, polyamideimide, and condenser paper And papers such as paraffin paper. Among these, a polyethylene terephthalate film is preferably used in consideration of physical properties and workability.
These may be used singly or may be used in combination as an appropriate combination. In addition, the thickness of the supports 2 and 12 can be in the range of about 2 to 50 μm in consideration of operability, workability and the like. However, in consideration of handling properties such as transfer suitability and workability, 2 The thing of about 10 micrometers is preferable.

  Further, in order to prevent thermal contraction due to heat of the thermal head or breakage due to friction with the thermal head, the heat-resistant slipping layer 8, 18 is provided. Examples of the constituent material of the heat-resistant slip layers 8 and 18 include a cellulose resin, a polyester resin, an acrylic resin, a vinyl resin, and a polyurethane resin. In addition, a crosslinking agent may be included for the purpose of improving heat resistance, or a lubricant such as silicone oil may be included for the purpose of improving lubricity. Moreover, you may use what modified | denatured the said resin with silicone.

  The thickness of the heat resistant slip layers 8 and 18 may be about 0.1 to 2.5 μm, and more preferably about 0.5 to 1.5 μm. When the thickness of the heat resistant slipping layer is smaller than 0.1 μm, the heat resistance from the thermal head becomes inferior, and the thermal contraction of the support tends to occur during thermal transfer recording. On the other hand, if the thickness is larger than 2.5 μm, the heat from the thermal head is not easily transmitted to the thermal transfer recording layer, and a printed matter having a desired density may not be obtained.

On the other hand, the Tg (glass transition point) of the binder resin constituting the heat-resistant slip layers 8 and 18 is preferably 40 ° C. or higher. When the Tg is 40 ° C. or higher, the so-called ribbon strength at the time of thermal transfer recording is further increased, and the ears are cut (a phenomenon in which the non-printed parts on both sides of the thermal transfer recording medium are broken by thermal contraction), tears, tears (printed part end point) Printing failure due to the phenomenon that the image is cut off).

  In order to improve the adhesion between the supports 2 and 12 and the heat-resistant slip layers 8 and 18 or the thermal transfer recording layer, an easy adhesion layer may be provided on one or both surfaces of the support. . As the constituent material of the easy-adhesion layer, those having compatibility with both the support and the heat-resistant slipping layer or the thermal transfer recording layer are suitable, and specifically, unsaturated such as acrylic acid, methacrylic acid and maleic acid. Examples thereof include carboxylic acid resins, polyurethane resins, polyester resins and the like.

  The thickness of such an easy-adhesion layer is preferably set in a range that does not hinder the conduction of heat applied from the thermal head or the like to the thermal transfer recording layer. Specifically, it is about 0.01 to 1 μm, more preferably about 0.05 to 0.5 μm.

  The easy-adhesion layer can be formed by applying a thin film of an easy-adhesive on the support by a known application method. Moreover, you may make it form simultaneously in the process in which the plastic film used as a support body is formed into a film. Moreover, you may make it improve adhesiveness by adjusting the surface roughness of one or both surfaces of a support body, without providing an easily bonding layer.

  On the other hand, the transfer protection layers 6 and 16 are applied to the thermal transfer medium on which images such as characters and pictures are recorded by a thermal head or the like from the side opposite to the formation surface of the transfer protection layer 6 of the thermal transfer recording media 1 and 10. It is a layer for protecting images such as characters and pictures transferred by heat. The transfer protective layers 6 and 16 are composed of a single release layer 4 as shown in FIG. 1 or a laminate structure of the release layer 14 and the adhesive layer 15 as shown in FIG. It is. Here, the adhesive layer 15 is a layer provided in order to ensure more reliably the adhesion between the surface of the heat-transferred body on which images such as characters and pictures are recorded and the release layer 14.

During thermal transfer recording, peeling occurs between the transfer protective layers 6 and 16 and the release layers 3 and 13, and only the transfer protective layers 6 and 16 are transferred to the surface of the thermal transfer body. In the present invention, the layers provided on the supports 2 and 12 are collectively referred to as protective layers 7 and 17 as shown in FIGS.

  On the other hand, the constituent material of the release layers 3 and 13 is not particularly limited. For example, water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, chlorinated rubber, Natural rubber derivatives such as cyclized rubber, waxes such as natural wax and synthetic wax, cellulose derivatives such as nitrocellulose, cellulose and cellulose acetate propionate, acrylic, polyurethane, polyamide, polyimide, polyacetal, chlorine And thermoplastic resins such as fluorinated polyolefins and vinyl chloride-vinyl acetate copolymers, and thermosetting resins such as melamine, epoxy, polyurethane, and silicone.

  As the fine particles contained in the release layers 3 and 13, various fillers such as metal oxide, silica, and silicone can be used. The shape is preferably spherical, and among them, silicone-based spherical fine particles are preferably used. The fine particles may be used alone or in combination of two or more.

  It is preferable that the value of r / h is about 1.0 to 8.0, where r is the average particle diameter of the fine particles and h is the thickness of the release layer. A degree of 2.0 to 5.0 is more preferable. When the value of r / h is less than 1.0, since the fine particles are covered with the release layer after thermal transfer recording, the coefficient of static friction between the protective layer and the heat-resistant slipping layer in the thermal transfer recording medium after thermal transfer recording is It is difficult to suppress an increase in the winding diameter of the thermal transfer recording medium in the printer as in the case of the thermal transfer recording medium to which fine particles are not added, and the printer is likely to be automatically stopped. On the other hand, if the value of r / h exceeds 8.0, the fine particles may fall off during the thermal transfer recording or easily migrate to the surface of the image that has been thermally transferred and recorded. It becomes easy to do.

  The fine particles may be added to the release layer at a resin solid content ratio of about 0.1 to 5.0 parts, preferably about 1.0 to 1.5 parts. Addition of more than 5.0 parts of fine particles causes a significant decrease in the glossiness in the transfer recording part on the surface of the transfer target.

  Further, the release layers 3 and 13 may contain oil. As the oil, silicone-based, fluorine-based, and phosphate ester-based oils can be used. Among these, it is preferable to use silicone oil.

  The oil may be added at a ratio of about 0.1 to 10 parts, preferably about 1.0 to 5.0 parts, as a resin solid content ratio in the release layer. If it is less than 0.1 part, the coefficient of static friction between the protective layer and the heat-resistant slip layer of the thermal transfer recording medium after thermal transfer recording is difficult to decrease, and the effect of addition hardly appears. On the other hand, if it exceeds 10 parts, the thermal transfer recording medium tends to meander in the printer, and winding misalignment tends to occur. In addition, it may cause a transfer failure related to peeling at the interface between the release layer and the support (or the easy adhesion layer).

  On the other hand, the release layers 4 and 14 are made of, for example, a binder, an ultraviolet absorber, a functional additive that imparts releasability, slipperiness, and the like, and have a thickness of about 0.3 to 3 μm. .

  Examples of the binder constituting the release layers 4 and 14 include styrene resins such as polystyrene and poly α-methylstyrene, acrylic resins such as polymethyl methacrylate and polyethyl acrylate, polyvinyl chloride, and polyvinyl acetate. , Vinyl chloride-vinyl acetate copolymer, polyvinyl resins such as polyvinyl butyral, polyvinyl acetal, polyester resin, polyamide resin, epoxy resin, polyurethane resin, petroleum resin, ionomer, ethylene-acrylic acid copolymer, ethylene-acrylic acid Synthetic resins such as ester copolymers, cellulose derivatives such as nitrocellulose, ethyl cellulose, cellulose acetate propionate, rosin, rosin-modified maleic resin, ester gum, polyisobutylene rubber, butyl rubber, styrene-butadiene rubber , Butadiene - acrylonitrile rubbers, natural resins and synthetic rubber derivatives such as polychlorinated olefins, carnauba wax, waxes such as paraffin wax. In particular, acrylic resins, polyester resins, cellulose derivatives, and epoxy resins are exemplified.

  In addition, as a constituent material of the adhesive layer 15 formed on the release layer 14 having such a configuration, styrene resins such as polystyrene and poly α-methylstyrene, acrylic resins such as polymethyl methacrylate and polyethyl acrylate, Polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl resins such as polyvinyl butyral, polyvinyl acetal, polyester resin, polyamide resin, epoxy resin, polyurethane resin, petroleum resin, ionomer, ethylene-acrylic acid copolymer Polymers, synthetic resins such as ethylene-acrylic acid ester copolymers, cellulose derivatives such as nitrocellulose, ethyl cellulose, cellulose acetate propionate, rosin, rosin-modified maleic resin, ester gum, polyisobutylene rubber, butyl rubber, styrene - butadiene rubber, butadiene - acrylonitrile rubbers, natural resins and synthetic rubber derivatives such as polychlorinated olefins, carnauba wax, waxes such as paraffin wax. In particular, acrylic resins and cellulose derivatives are preferably used.

  If necessary, silicone oils, surfactants, mold release agents, waxes, slip agents represented by organic or inorganic fillers, UV absorbers, light stabilizers, heat stabilizers, flame retardants, antioxidants An antiblocking agent, a catalyst accelerator, a colorant, a light scattering agent, a gloss adjusting agent, a fluorescent whitening agent, an antistatic agent, and the like can be added.

  The transfer protective layers 6 and 16 having a single layer or multiple layers as described above may contain an ultraviolet absorber. By transferring the transfer protective layer containing the ultraviolet absorber to the thermal transfer member, the weather resistance of the printed matter can be improved. Further, if necessary, a surfactant, an antiblocking agent, an antioxidant, an antistatic agent, etc. may be added. Further, layers having these functions may be stacked.

  Each layer constituting the transfer protection layers 6 and 16 is formed by applying a thin film of those constituent materials on the release layers 3 and 13 by a wet coating method such as bar coating, blade coating, air knife coating, gravure coating, roll coating, Thereafter, the coated thin film may be provided by drying.

  Further, the transfer protection layers 6 and 16 may be formed by transferring using a thermal transfer cover sheet in which only the transfer protection layer having the above-described configuration is provided on the sheet base material. Transfer and formation is performed using a thermal transfer recording medium in which a thermal transfer recording layer of each color of a yellow thermal transfer recording layer, a magenta thermal transfer recording layer, and a cyan thermal transfer recording layer and a transfer protective layer having the above-described configuration are provided on a material. Also good.

The thermal transfer recording layer exhibiting the above yellow, magenta, and cyan hues is a layer made of a constituent material including a color material, a binder, and the like.
As the coloring material, for example, a heat sublimable dye is used, and among them, a sublimable disperse dye is preferably used. Specifically, diarylmethane, triarylmethane, thiazole, methine, azomethane, xanthene, axazine, thiazine, azine, acridine, azo, spirodipyran, isorinospiropyran, fluorane And sublimable disperse dyes such as rhodamine lactams and anthraquinones.

  More specifically, examples of the yellow component include C.I. I. Solvent Yellow 14, 16, 29, 30, 33, 56, 93 etc., C.I. I. Disperse Yellow 7, 33, 60, 141, 201, 231 and the like are magenta components such as C.I. I. Solvent Red 18, 19, 27, 143, 182, C.I. I. Disperse thread 60, 73, 135, 167, C.I. I. Disperse violet 13, 26, 31, 56, etc. are used as C.I. I. Solvent Blue 11, 36, 63, 105, C.I. I. Disperse blue 24, 72, 154, 354 and the like can be mentioned, but are not necessarily limited thereto. These dyes may be used alone or in combination.

  As the binder constituting the thermal transfer recording layer, polyvinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl acetal, polyvinyl butyral, ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, A cellulose resin such as cellulose acetate propionate, a polyester resin, a phenoxy resin, a styrene-acrylonitrile copolymer resin, a polycarbonate resin, a polyacrylamide resin, or the like can be used.

The Tg of these binder resins is preferably 60 ° C. or higher. If it is 110 degreeC or more, it is more preferable. When Tg is low, there is a high possibility of causing a printing failure.
Moreover, the weight ratio (dye / binder) of the dye and the binder as described above is 0.1 to 0.1.
About 3.0 is preferable. More preferably, it is about 0.5 to 1.5. If it is less than 0.1, the dye density becomes small, so that the color development sensitivity becomes insufficient and a good thermal transfer image may not be obtained. On the other hand, when it is larger than 3.0, the solubility of the dye in the binder is extremely lowered, so that the storage stability of the thermal transfer recording layer is lowered and the dye is likely to precipitate.

  The thermal transfer recording layer may contain fine particles. By incorporating fine particles, irregularities are formed on the surface of the thermal transfer recording layer, and the contact area of the thermal transfer body with the receiving layer is reduced, so that sticking during storage can be prevented and separation during thermal transfer recording can be prevented. The moldability can be improved.

  The fine particles may be organic fine particles or inorganic fine particles, but those that do not shrink due to heat from the thermal head are preferable. Specific examples include silica particles, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, talc, kaolin, clay, silicone particles, polyethylene particles, polypropylene particles, polystyrene particles, polymethyl methacrylate resin particles, polyurethane resin particles, and the like. be able to. Further, the fine particles may be used alone or in combination of two or more.

  The fine particles are preferably contained in the thermal transfer recording layer in a resin solid content ratio of about 0.01 to 5 parts. When the resin solid content ratio is smaller than 0.01 part, a difference in thermal shrinkage between the support and the thermal transfer recording layer occurs, and thermal wrinkles are likely to occur in the thermal transfer recording medium. On the other hand, if the resin solid content ratio is larger than 5 parts, sublimation of the dye in the thermal transfer recording layer may be inhibited, and transfer unevenness may occur or a printed matter having a desired density may not be obtained.

  On the other hand, a thermal transfer body that performs thermal transfer recording using the thermal transfer recording medium having such a configuration includes a support and a receiving layer. As the support, those equivalent to those used as the support for the thermal transfer recording medium can be used, and those excellent in mechanical strength, flexibility, heat resistance and the like are preferably used. Specifically, polyester films such as polyethylene terephthalate and polyethylene naphthalate, plastic films made of polyethylene, polyvinyl chloride, polycarbonate, polyester, polysulfane, polyimide, polyvinyl alcohol, aromatic polyamide, aramid film, etc. Examples thereof include paper base materials such as paper, coated paper, and synthetic paper. The thickness of the support is not particularly limited, but is generally about 25 to 250 μm, more preferably about 75 to 200 μm.

  In addition, as the receiving layer, when the thermal transfer recording medium is of a type containing a sublimation dye in the thermal transfer recording layer, for example, a butyral resin having a dyeing property to the sublimation dye, polyethylene, polyurethane, polypropylene , Polyvinyl chloride, polybutadiene, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, polyamide, polyester, polycaprolactone, polyvinyl acetal, epoxy, ketone, or modified resins and blends thereof Or the like, or a crosslinked product thereof can be used. These can be used alone or in admixture of two or more.

  If the film thickness of the image receiving layer is too thin, the reflection density of the thermal transfer recording image is lowered and it becomes difficult to form a good image. On the other hand, if it is too thick, color bleeding or the like is liable to occur, and the image quality may be lowered. Therefore, it is generally about 1 to 30 μm, preferably about 3 to 10 μm.

  The image receiving layer preferably contains various release agents for the purpose of preventing thermal fusion to the thermal transfer recording medium during thermal transfer recording. As such a release agent, a known release agent can be appropriately selected and used. Specifically, various types of silicone-based, fluorine-based and phosphate ester-based oils, various fillers such as surfactants, metal oxides, silica, and the like can be used. Among these, silicone oil is preferably used. . The amount of addition varies depending on the constituent conditions of the image receiving layer, but generally it is preferably about 1 to 30% by weight.

Examples of the present invention will be described below.
First, a thin film of a release layer constituting material having the following composition is applied to the surface of a 4.5 μm thick polyethylene terephthalate film having a heat-resistant slip treatment on the back surface, and dried to form a release layer (with a layer thickness of 1. 0 μm) was formed.

[Composition of release layer forming material]
-30.0 parts by weight of cellulose derivative-35.0 parts by weight of toluene-35.0 parts by weight of methyl ethyl ketone-1.0 part by weight of silicone fine particles (average particle size: 2.0 µm)

  Next, an ink composition for a thermal transfer recording layer having the following composition was prepared.

[Composition of thermal transfer recording layer forming ink]
[Yellow layer ink]
Yellow dye 5.0 parts by weight Butyral resin 5.0 parts by weight Methyl ethyl ketone 45.0 parts by weight Toluene 45.0 parts by weight [magenta layer forming ink]
-Magenta dye 5.0 parts by weight-Butyral resin 5.0 parts by weight-Methyl ethyl ketone 45.0 parts by weight-Toluene 45.0 parts by weight [ink for forming a cyan layer]
-Cyan dye 5.0 parts by weight-Butyral resin 5.0 parts by weight-Methyl ethyl ketone 45.0 parts by weight-Toluene 45.0 parts by weight

  Then, after providing the yellow layer, the magenta layer, and the cyan layer in the surface order with each thermal transfer recording layer forming ink having the above composition on the release layer formed in the above step, the above release layer forming material and Using a release layer forming material having the following composition, a protective layer having a two-layer structure in the order of a release layer and a release layer was further provided to obtain a thermal transfer recording medium according to Example 1 of the present invention. The layer thicknesses of the release layer and the release layer were 0.5 μm and 3.0 μm, respectively.

[Composition of release layer forming material]
-Modified acrylic resin 30.0 parts by weight-Toluene 35.0 parts by weight-Methyl ethyl ketone 35.0 parts by weight

Next, a base material sheet having a multilayer structure of foamed polypropylene film (thickness: 50 μm) / adhesive resin layer / coated paper (coating amount: 108 g / m ² ) / adhesive resin layer / foamed polypropylene film (thickness: 50 μm) was used. Then, after applying a thin film on one surface using a receiving layer forming ink having the following composition and drying, the film was aged at 45 ° C. for 1 week to obtain a thermal transfer member with a receiving layer (film thickness 4 μm). Obtained.

[Composition of receiving layer forming ink]
-Vinyl chloride-vinyl acetate copolymer 50.0 parts by weight-Silicone oil 2.0 parts by weight-Methyl ethyl ketone 25.0 parts by weight-Toluene 25.0 parts by weight

  Using the adhesive layer forming ink having the following composition, the adhesive layer is further laminated on the release layer, and the film thicknesses of the release layer, the release layer, and the adhesive layer are 0.5 μm, 1.0 μm, and 3.0 μm, respectively. A thermal transfer recording medium according to Example 2 of the present invention was obtained in the same manner as Example 1 except that a protective layer was provided.

[Composition of ink for forming adhesive layer]
-Modified acrylic resin 30.0 parts by weight-Toluene 35.0 parts by weight-Methyl ethyl ketone 35.0 parts by weight

  A thermal transfer recording medium according to Example 3 of the present invention was obtained in the same manner as Example 2 except that the coating amount was adjusted so that the film thickness of the release layer was 0.2 μm.

  A thermal transfer recording medium according to Example 4 of the present invention was obtained in the same manner as Example 2 except that the coating amount was adjusted so that the film thickness of the release layer was 0.25 μm.

  A thermal transfer recording medium according to Example 5 of the present invention was obtained in the same manner as in Example 2 except that the coating amount was adjusted so that the film thickness of the release layer was 2.0 μm.

  A thermal transfer recording medium according to Example 6 of the present invention was obtained in the same manner as in Example 2 except that the fine particles in the release layer were contained so that the resin solid content ratio was 0.1 parts.

  A thermal transfer recording medium according to Example 7 of the present invention was obtained in the same manner as in Example 2 except that the fine particles in the release layer were contained so that the resin solid content ratio was 5.0 parts.

  A thermal transfer recording medium according to Example 8 of the present invention was obtained in the same manner as in Example 2 except that the fine particles in the release layer were contained so that the resin solid content ratio was 6.0 parts.

  A thermal transfer recording medium according to Example 9 of the present invention was obtained in the same manner as in Example 2 except that the release layer contained silicone oil in a resin solid content ratio of 3.0 parts.

  A thermal transfer recording medium according to Example 10 of the present invention was obtained in the same manner as in Example 9 except that the release layer contained oil at a resin solid content ratio of 0.1 part.

  A thermal transfer recording medium according to Example 11 of the present invention was obtained in the same manner as Example 9 except that the release layer contained oil so that the resin solid content ratio was 10 parts.

A thermal transfer recording medium according to Example 12 of the present invention was obtained in the same manner as in Example 9 except that the release layer contained oil at a resin solid content ratio of 12 parts.
[Comparative Example 1]

A thermal transfer recording medium for comparison was obtained in the same manner as in Example 2 except that the fine particles in the release layer were changed to 0 part.
[Comparative Example 2]

A thermal transfer recording medium for comparison was obtained in the same manner as in Example 2 except that the fine particles in the release layer were 0 parts and the oil was contained in a resin solid content ratio of 3.0 parts. .
[Comparative Example 3]

Comparison was made in the same manner as in Example 2 except that the coating amount was adjusted so that the film thickness of the release layer was 2.2 μm, and the oil was contained so that the resin solid content ratio was 3.0 parts. A thermal transfer recording medium for was obtained.
[Comparative Example 4]

  The comparison was made in the same manner as in Example 2 except that the fine particles in the release layer were 0.05 parts in resin solids ratio and the oil was contained in 3.0 parts in resin solids ratio. A thermal transfer recording medium was obtained.

  Then, after the thermal transfer layer surface of the obtained thermal transfer recording medium and the receiving layer surface of the transfer target are overlapped, the thermal transfer recording is performed by transferring the dye using a thermal head, and then the transfer protective layer is transferred to form the thermal transfer image formed product Got.

  Then, the static friction coefficient between the protective layer and the heat-resistant slipping layer of the thermal transfer recording medium after use was measured by a tilt method.

  Next, after performing continuous printing using all of the thermal transfer recording medium set in the printer in the winding state, the winding diameter after use of the used thermal transfer recording medium wound in the printer is measured. When the increase rate of the winding diameter after use with respect to the initial winding diameter is 5.0% or less, the evaluation is ○, and when it exceeds that, the evaluation is ×.

  Next, it was confirmed whether or not the thermal transfer recording medium after use had caused winding deviation. When the winding was not shifted, the evaluation was ○, and when it was, the evaluation was ×.

  Moreover, the following evaluation was performed with respect to the obtained image. The results are shown in Table 1.

〔Evaluation item〕
Glossiness: The glossiness of the obtained thermal transfer recorded image was measured with a glossmeter, and when it was 85.0 or more, it was evaluated as “good”, and when it was less than that, it was evaluated as “poor”.
-Missing print: The image after printing was visually confirmed. If no missing print occurred, the evaluation was ○, and if it occurred, the evaluation was x.
Transfer defect: The image after printing was visually confirmed, and the evaluation was evaluated as “B” when no transfer defect of the transfer protective layer occurred, and “C” when it occurred.

  As described above, in the thermal transfer recording medium of the present invention, fine particles are added to the release layer constituting the protective layer, and after use in thermal transfer recording, the static friction coefficient between the protective layer and the heat-resistant slipping layer is 3. Since it was 0 or less, the increase rate of the winding diameter of the thermal transfer recording medium after thermal transfer recording could be suppressed to 5.0% or less. Then, when the average particle diameter of the fine particles is r and the thickness of the release layer is h, the value of r / h is 1.0 to 8.0. Occurrence of print omission due to omission or transfer to the image surface could be prevented. Moreover, the glossiness of the surface of the printed material could be maintained at a high value of 85.0 or more by setting the addition amount of the fine particles to 0.1 to 5.0 parts in terms of the resin solid content ratio. By adding oil to the release layer at a resin solid content ratio of 0.1 to 10 parts in the release layer, no winding deviation occurs and no transfer failure of the protective layer occurs. Stable printing was possible.

DESCRIPTION OF SYMBOLS 1, 10 ... Thermal transfer recording medium 2, 12 ... Support body 3, 13 ... Release layer 4, 14 ... Release layer 6, 16 ... Transfer protection layer 7, 17 ... Protection layer 8, 18 ... Heat-resistant slip layer 15 ... Adhesion layer

Claims (3)

A thermal transfer recording medium is provided with a protective layer having at least a multilayer structure of a release layer and a release layer on one side of a support and at least a heat-resistant slipping layer on the other side. The release layer and the release layer are peeled at the interface, and the release layer contains at least a binder and fine particles composed of cellulose or cellulose acetate propionate, and is protected after being used for thermal transfer recording. A thermal transfer recording medium, wherein a static friction coefficient between the layer and the heat resistant slipping layer is 0.3 or less, and Tg of a binder resin constituting the heat resistant slipping layer is 40 or more.   The r / h value is 1.0 to 8.0, where r is the average particle diameter of the fine particles and h is the thickness of the release layer. Thermal transfer recording medium. The release layer further contains oil, and the amount of oil added is 0.1 to 10 parts in terms of resin solid content, and the static friction between the protective layer and the heat-resistant slipping layer after being used for thermal transfer recording. The thermal transfer recording medium according to claim 1 , wherein the coefficient is 0.1 or more.

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