JP6350078B2 - Thermal transfer image receiving sheet - Google Patents

Description

  The present invention relates to a thermal transfer image-receiving sheet on which an image is formed by thermal transfer of a sublimation dye, and an output product in which a uniform image is formed on the entire surface without causing margins at the edges and without causing image unevenness such as kogation. It is related with the thermal transfer image receiving sheet which can obtain easily.

  It is widely performed to transfer characters from a thermal transfer recording medium to a thermal transfer image receiving sheet using a thermal transfer method to form characters and images. As a thermal transfer system, a sublimation type thermal transfer system and a melt type thermal transfer system are known. Of these, the sublimation type thermal transfer method uses a sublimation dye as a coloring material, and uses a heating element such as a thermal head to transfer the dye in the sublimation dye layer formed on the thermal transfer sheet onto the thermal transfer image receiving sheet. To form.

  Currently, among the thermal transfer systems, the sublimation thermal transfer system can easily form full-color images with various functions of the printer, so digital camera self-prints, cards such as identification cards, amusement output, etc. Widely used. With the diversification of applications, market demands for miniaturization, higher speed, and lower costs are increasing, and so-called eco-products that have reduced environmental impact during manufacturing have attracted particular attention in recent years. It is one of the attachments.

  The thermal transfer image receiving sheet applied to this sublimation type thermal transfer system is constituted by providing a dye receiving layer for receiving a sublimable dye on the surface of an image receiving sheet substrate. The sublimable dye moves from the thermal transfer recording medium to the dye receiving layer and is dyed, and the full color image is formed on the dye receiving layer. A thermal transfer image receiving sheet in which various layers are formed between a substrate and a dye receiving layer is also known. For example, a heat insulating layer or an undercoat layer.

  By the way, in response to a demand for downsizing of a printer, a system using a sheet-like thermal transfer image receiving sheet instead of a roll is known. In order to satisfy both the demand for downsizing and the requirement that there is no margin at the edge as in conventional photographic prints, a method of cutting the margin after image formation can be cited. Providing a cutting device in the printer leads to an increase in size, complexity, and cost of the printer. Therefore, as a method for cutting margins, there is a method in which perforations are provided in advance at the end of the sheet-type thermal transfer image receiving sheet. By forming an image so as to straddle the perforation and then separating the end portion from the perforation, it is possible to obtain a print having an image formed on the entire surface with no margin (see Patent Document 1).

Japanese Patent No. 4202570

  By the way, water or a hydrophilic solvent is used as a solvent or dispersion medium, and an aqueous coating agent in which a resin is dissolved or dispersed in the solvent or dispersion medium is used to form the dye-receiving layer and the undercoat layer. When an image is formed by forming a perforation on the thermal transfer image-receiving sheet, an image quality defect in which the color tone of the image in the vicinity of the perforation is matted, so-called koge may appear.

Kogyo refers to a phenomenon in which, when an image with a high print density is formed, a portion is matted and a uniform image quality cannot be obtained. Although the mechanism of kogation is not clear, it is considered that each of the water-based layers absorbs moisture through the perforation and the moisture is vaporized at random, so that the surface of the print product where the moisture is vaporized is partially matted.

  Accordingly, if each of the layers formed on the base material including the dye receiving layer and the undercoat layer is made of an organic solvent, it is expected to prevent kogation, but cannot meet the demand for reducing the environmental load. On the other hand, unless a perforation is provided on the thermal transfer image receiving sheet, a print having an image formed on the entire surface cannot be obtained when the sheet is used in a small printer using a sheet.

  Therefore, in order to solve the above-mentioned problems, the object of the present invention is to provide an image quality without causing a kogation defect by subjecting a thermal transfer image-receiving sheet having a water-based layer on a substrate to an appropriate shape perforation. The object is to provide an excellent thermal transfer image-receiving sheet.

  As a result of intensive studies, the present inventor has found that the above problems can be solved by appropriately defining the dimensions of the cut and uncut perforations provided on the thermal transfer image receiving sheet, and has completed the present invention.

That is, a first aspect of the present invention, which has a coating layer of a single layer or multiple layers on a substrate is a long body, a dye-receiving layer coating layer on the surface to receive a sublimable dye, these A thermal transfer image receiving sheet, wherein at least one of the layers is a thermal transfer image receiving sheet formed by coating an aqueous coating agent, and has a perforation that can be cut off at both front and rear ends in the conveying direction of the image forming area. In the sheet,
The perforation is composed of a cut portion of 200 to 500 μm and an uncut portion of 100 μm or more, and is calculated by (length of cut portion) / (length of cut portion + length of uncut portion). The thermal transfer image-receiving sheet is characterized in that moisture absorption of the layer formed by coating with an aqueous coating agent is suppressed by having a cut rate of 60% or more and 80% or less.

The invention described in claim 2 is a dye receiving layer having a multi-layered coating layer on a long substrate and the surface coating layer receiving a sublimation dye. A thermal transfer image-receiving sheet in which at least one of the layers positioned below is a layer formed by coating a water-based coating agent, and can be cut off at both front and rear ends in the conveying direction of the image forming region In the thermal transfer image receiving sheet having an eye,
The perforation is composed of a cut portion of 200 to 500 μm and an uncut portion of 100 μm or more, and is calculated by (length of cut portion) / (length of cut portion + length of uncut portion). The thermal transfer image-receiving sheet is characterized in that moisture absorption of the layer formed by coating with an aqueous coating agent is suppressed by having a cut rate of 60% or more and 80% or less.

  Next, the invention described in claim 3 is characterized in that the perforation extends in a direction intersecting with the conveyance direction of the printer.

  As can be seen from examples and comparative examples described later, when the length of the uncut portion is 100 μm or more, kogation near the perforation can be prevented. When the cut rate is 60% or less, it cannot be said that it is easy to cut from the perforation.

It is a perspective view which shows an example of the thermal transfer image receiving sheet which concerns on embodiment based on this invention. It is a perspective view which shows the other example of the thermal transfer image receiving sheet which concerns on embodiment based on this invention.

The thermal transfer image receiving sheet according to the present invention comprises a base material and a dye receiving layer as essential components. In addition to this, other layers may be included, but the dye-receiving layer must be located on the surface of the thermal transfer image-receiving sheet and be capable of receiving the sublimation dye transferred from the thermal transfer recording medium and dyeing the dye. . Examples of other layers positioned between the substrate and the dye receiving layer include a heat insulating layer, a buffer layer, and an undercoat layer.

  Of each of these layers provided on the substrate, at least one layer needs to be a layer formed by coating an aqueous coating agent. Of these layers, all of the layers formed by coating are preferably layers formed by coating an aqueous coating agent. This is because the environmental load can be reduced because the coating is performed without using an organic solvent.

  As described above, each layer under the dye receiving layer absorbs moisture through the perforation, and it is assumed that the moisture is randomly vaporized, thereby attracting kogation. Therefore, it is located under the dye receiving layer. The advantage of the present invention is utilized when at least one of the layers is a layer formed by coating an aqueous coating agent.

  The thermal transfer image-receiving sheet according to the present invention needs to be provided with perforated perforations. This is because after the sublimation dye is transferred to form an image, the blank portion is cut off from the perforation and removed to produce a print having the image on the entire surface. For this purpose, the perforation needs to be provided at a part that enters the image forming area from the boundary between the area where the image is formed (image forming area) and the area where the image is not formed (margin). A print having an image on the entire surface can be obtained by cutting and removing at the perforation.

  For these reasons, when the thermal transfer image receiving sheet according to the present invention is in a sheet form and the perforation extends in a direction that intersects the conveyance direction of the printer, the advantages of the present invention can be utilized. Desirably, the perforation extends in a direction orthogonal to the conveyance direction of the printer. That is, when a sheet-like thermal transfer image-receiving sheet is conveyed and transferred, it is difficult to transfer and print on the front and rear end portions in the conveying direction, and untransferred blank portions are likely to be generated at the front and rear end portions. Therefore, by removing the front and rear end portions in the transport direction by cutting from the perforation after transfer printing, a print having an image formed on the entire surface can be obtained. For the same reason, it is desirable that the perforation is disposed at the end of the thermal transfer image receiving sheet. Although it is desirable that they are arranged at both front and rear ends in the transport direction, any one of the ends may be used.

  The thermal transfer image receiving sheet according to the present invention may have a long outer shape. Also in this case, it is desirable that the perforation extends in a direction intersecting with the conveyance direction of the printer. In this case, after forming an image by transferring a sublimation dye, the image is formed on the entire surface by cutting off at the perforations to separate each sheet into a sheet-like print and removing the blank portion. Printed can be obtained. Of course, it is desirable to arrange the perforations at both front and rear ends in the conveyance direction of the image forming area.

  By the way, the perforation is one in which cut portions and uncut portions are alternately and repeatedly arranged so that the perforation can be bent and separated. By bending the thermal transfer image receiving sheet at this perforation and separating and removing the end portion, it is possible to obtain a print having no blank portion and an image formed on the entire surface. The cut portion is a portion obtained by cutting the thermal transfer image receiving sheet into a linear shape, and desirably penetrates the thermal transfer image receiving sheet from the dye receiving layer to the substrate. Further, the uncut portion is a portion where everything from the dye receiving layer to the base material remains.

By the way, as described above, when the perforation is formed on the thermal transfer image-receiving sheet, each layer of the water system absorbs moisture through the perforation, and the moisture is randomly vaporized to induce kogation. By adjusting, the manifestation can be suppressed. In order to suppress the occurrence of kogation, the blade does not enter the undercoat layer or the dye receiving layer, and the moisture absorption is not performed on the cut portion where moisture absorption or moisture vaporization may be promoted by the blade entering each layer. It is preferable to provide a sufficient uncut portion that does not induce vaporization of moisture. Moreover, visual manifestation can be suppressed by the length of the cut part which attracts a koge, and the ratio with an uncut part. More specifically, for a cut part having a length of 200 to 500 μm, the length of the uncut part is 100 μm or more, and (the length of the cut part) / (the length of the cut part + the length of the uncut part) The cut rate calculated in step S) may be 80% or less. When the length of the cut portion exceeds 500 μm, the cut portion that attracts the kogation is too long, and the kogation becomes visually apparent no matter how the uncut portion is formed. If the length of the uncut part is less than 100 μm, the uncut part that suppresses the kogation is too short and the kogation resulting from the cut part becomes obvious, and if the cut rate exceeds 80%, the kogation caused by the uncut part A koge will be revealed without catching up the inhibitory effect.

  Further, if the length of the cut portion is reduced, the ratio of the thickness of the thermal transfer image-receiving sheet is relatively increased, so that the perforation may not be formed well. However, if the length is 200 μm or more, the perforation is satisfactorily formed. be able to. This is because it is difficult to form a stable perforation because the sewing machine blade must be engraved or cut very finely. Further, when the cut rate calculated by (length of cut portion) / (length of cut portion + length of uncut portion) is 60% or less, it is easy to bend the thermal transfer image-receiving sheet at a perforation. No more. For this reason, by providing an uncut portion having a length of 100 μm or more and a cut rate exceeding 60% with respect to a cut portion having a length of 200 to 500 μm, the thermal transfer image-receiving sheet can be easily folded and cut. It becomes possible.

  For the above reasons, the perforation of the thermal transfer sheet is composed of a cut portion of 200 to 500 μm and an uncut portion of 100 μm or more, and (length of cut portion) / (length of cut portion + uncut portion) The cut rate calculated by the length of 60) is not less than 60% and not more than 80%, so that it can be easily folded and separated, an image-formed print can be obtained on the entire surface, and there is no kogation. Image quality can be obtained.

  Next, the present invention will be described in more detail with reference to preferred embodiments.

  FIG. 1 is a perspective view showing an example of a thermal transfer image receiving sheet 1. This thermal transfer image receiving sheet is a sheet-like thermal transfer image receiving sheet in which a heat insulating layer 2, an undercoat layer 3, and a dye receiving layer 4 are provided in this order on a substrate 1, and the dye receiving layer 4 is a surface of the thermal transfer image receiving sheet 1. Is located. The undercoat layer 3 and the dye receiving layer 4 are layers formed by coating an aqueous coating agent. The thermal transfer image-receiving sheet has a sheet-like outer shape, and perforations 5 and 6 that can be cut off are provided at both front and rear ends in the conveying direction in a direction crossing the conveying direction.

  FIG. 2 is a perspective view showing another example of the thermal transfer image receiving sheet of the present invention, and a back layer 5 is provided on the other surface of the substrate 1. Others are the same as the example shown in FIG.

  The thickness of the thermal transfer image-receiving sheet is 50 μm or more and 400 μm or less in consideration of the stiffness of the printed material, and more preferably 100 μm or more and 300 μm or less.

  As the substrate 1, conventionally known materials can be used, for example, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polyethylene, synthetic resins such as polyvinyl chloride, polycarbonate, polyvinyl alcohol, polystyrene and polyamide. Films and papers such as high-quality paper, medium-quality paper, coated paper, art paper, and resin-laminated paper can be used alone or in combination. The thickness of the substrate 1 can be in the range of 25 μm or more and 250 μm or less in consideration of the stiffness, strength, heat resistance, etc. of the printed material, but more preferably 50 μm or more and 200 μm or less.

  Next, as the heat insulating layer 2, any conventionally known film can be used as long as it is a polyolefin film containing voids. A heat insulation layer using a composite film with a skin layer provided on one or both sides of the foam film can be mentioned, but considering the smoothness and glossiness that affect the image quality, the skin layer on one or both sides of the foam film It is preferable to use a composite film provided with. Moreover, by using a polyolefin film, it is possible to prevent image quality defects (nonuniformity) peculiar to hollow particles. Although the thing of the range of 10 micrometers or more and 80 micrometers or less can be used for the thickness of the heat insulation layer 2, More preferably, the thing of about 20 micrometers or more and 60 micrometers or less is preferable.

  The heat insulating layer 2 can be bonded to the base material 1 with an adhesive layer. As the material used for the adhesive layer, conventionally known resins and adhesives can be used. For example, polyolefin resins such as polyethylene, urethane resins, acrylic resins, polyester resins, epoxy resins, phenol resins, vinyl acetate resins Resins can be used. Among these, polyethylene, urethane resin, and acrylic resin are preferable.

  The undercoat layer 3 is a layer provided for improving the adhesion of the dye-receiving layer 4 and adjusting the print density during image formation. The undercoat layer can be formed by coating an aqueous solvent with a water-soluble resin or water-soluble polymer dissolved or dispersed in an aqueous solvent. It can also be formed by coating an aqueous coating agent composed of an aqueous emulsion.

  Examples of water-soluble resins or water-soluble polymers include water-soluble acrylic resins such as polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylic acid ester, polyacrylic acid ester copolymer, polymethacrylic acid, gelatin, starch, and casein. And modified products thereof.

  Examples of aqueous emulsions include polyolefin emulsions, vinyl chloride resin emulsions, vinyl chloride-vinyl acetate resin emulsions, vinyl chloride resin emulsions such as vinyl chloride-acrylic resin emulsions, acrylic resin emulsions, urethane resin emulsions, and some of the solvents are water. Can be mentioned.

  The thickness of the undercoat layer 3 can be in the range of 0.1 μm or more and 3 μm or less, more preferably about 0.2 μm or more and 1.0 μm or less. If the thickness is less than 0.1 μm, it is difficult to adjust the thickness of the undercoat layer. If the thickness is less than 0.1 μm, the print density may vary, and the heat insulating layer 2 and the dye-receiving layer. There is a risk of lowering the adhesion between them. On the other hand, if it exceeds 1 μm, the print density may be lowered. Therefore, in view of material cost, it is preferably 1 μm or less. Moreover, the undercoat layer 3 may contain a crosslinking agent, an antioxidant, a fluorescent dye, and a known additive as necessary.

  Next, the dye receiving layer 4 has a function of receiving and dyeing a sublimable dye released from the thermal transfer recording medium. The dye-receiving layer 4 can be formed by coating a solvent-based coating agent using an organic solvent as a solvent or dispersion medium, but is formed by coating an aqueous coating agent using an aqueous solvent as a solvent or dispersion medium. It is desirable to do. As the aqueous coating agent, an aqueous resin emulsion can be preferably used. Among these, vinyl chloride resin emulsions such as vinyl chloride resin emulsions, vinyl chloride-vinyl acetate resin emulsions, vinyl chloride-acrylic resin emulsions can be particularly preferably used.

The dye receiving layer 4 preferably contains a release agent. As the release agent, for example, various oils and emulsions such as silicones, fluorines and phosphates, surfactants, various fillers such as metal oxides and silica, waxes, and the like can be used. These may be used alone or in combination of two or more. Among these, it is preferable to use a silicone emulsion. Moreover, the dye receiving layer 4 may contain a crosslinking agent, an antioxidant, a fluorescent dye, and a known additive as necessary.

  The thickness of the dye receiving layer 4 can be in the range of 0.1 μm or more and 10 μm or less, but preferably about 0.2 μm or more and 8 μm or less.

  Next, the back surface layer 7 is provided for improving printer transportability, preventing blocking with the dye receiving layer 4, and preventing curling of the thermal transfer image receiving sheet before and after printing. As the material used for the back layer 7, conventionally known materials can be used. For example, polyolefin resins such as polyethylene resins and polypropylene resins, acrylic resins, polycarbonate resins, polyvinyl alcohol resins, polyvinyl acetal resins, polyester resins, polystyrene resins. Resins such as resin and polyamide can be used. Moreover, you may contain well-known additives, such as a filler and an antistatic agent, as needed.

  Next, the processing method of the perforations 5 and 6 is not particularly limited, but a method of forming a perforation by placing a thermal transfer image receiving sheet on a pedestal and moving up and down a mold to which a perforation blade is attached, A method of forming a perforation by attaching a perforation blade in the width direction of the roll cylinder, attaching an impression cylinder so as to come into contact with each other, and conveying the thermal transfer image-receiving sheet between the cylinder and the impression cylinder (so-called horizontal perforation processing) Or a method of forming a perforation by transporting a thermal transfer image-receiving sheet between a disk-shaped sewing blade and an impression cylinder using a disk-shaped sewing blade (rotary blade) and an impression cylinder in contact with the disk (rotary blade) ( So-called vertical perforation) can be used.

  Below, the material used for each Example and each comparative example of this invention is shown. In the text, “part” is based on mass unless otherwise specified, and the present invention is not limited to the examples.

Example 1
A long fine paper having a thickness of 140 μm was used as a substrate, and a polyethylene resin layer having a thickness of 30 μm was formed as a back layer by a melt extrusion method.

  Next, between the surface opposite to the polyethylene resin layer side of the base material and the heat insulating layer, a polyethylene resin is melt extruded to form a polyethylene resin layer having a thickness of 15 μm. The heat insulating layer was bonded together. As the heat insulating layer, a 40 μm thick foamed polypropylene film provided with a skin layer on one side was used, and the polyethylene resin was melt-extruded and bonded to the side where the skin layer was not provided.

  Next, an undercoat layer was formed by applying and drying an undercoat layer coating solution composed of an aqueous emulsion on the heat insulating layer so that the thickness after drying was 0.5 μm. Further, on the undercoat layer, a dye-receiving layer coating solution comprising an aqueous emulsion was applied and dried so that the thickness after drying was 3 μm, thereby forming a dye-receiving layer. The composition of the undercoat layer coating solution and the composition of the dye-receiving layer coating solution are as follows.

<Undercoat layer coating solution>
Polyolefin emulsion 20 parts (Arrow Base SB-1010, manufactured by Unitika Ltd.)
20 parts of vinyl chloride copolymer emulsion (Viniblanc 603, manufactured by Nissin Chemical Industry Co., Ltd.)
Tripropylene glycol monomethyl ether 4 parts Pure water 56 parts.

<Dye-receiving layer coating solution>
35.5 parts of vinyl chloride copolymer emulsion (Vinibrand 900 manufactured by Nissin Chemical Industry Co., Ltd.)
Modified silicone oil 1.5 parts (X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.)
63 parts pure water.

  With respect to the thermal transfer image-receiving sheet which is the above long body, the length of the cut portion is 400 μm and the length of the uncut portion is at both ends of the image forming region in the front and rear direction in the conveyance direction and included in the image forming region. A perforation that can be cut off by a rotary blade was formed so that repeated perforations of 120 μm could be formed, and a thermal transfer image-receiving sheet of Example 1 of the present invention was produced. The perforations were formed so as to extend in a direction perpendicular to the transport direction.

(Example 2)
A thermal transfer image-receiving sheet of Example 2 was produced in the same manner as Example 1 except that the length of the cut part was 400 μm and the length of the uncut part was 180 μm.

(Example 3)
A thermal transfer image-receiving sheet of Example 3 was produced in the same manner as in Example 1 except that the length of the cut part was 350 μm and the length of the uncut part was 120 μm.

Example 4
A thermal transfer image receiving sheet of Example 4 was produced in the same manner as in Example 1 except that the length of the cut part was 350 μm and the length of the uncut part was 180 μm.

(Example 5)
A thermal transfer image receiving sheet of Example 5 was produced in the same manner as in Example 1 except that the length of the cut part was 300 μm and the length of the uncut part was 120 μm.

(Example 6)
A thermal transfer image receiving sheet of Example 6 was produced in the same manner as in Example 1 except that the length of the cut part was 250 μm and the length of the uncut part was 120 μm.

(Comparative Example 1)
A thermal transfer image-receiving sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the length of the cut part was 600 μm and the length of the uncut part was 120 μm.

(Comparative Example 2)
A thermal transfer image-receiving sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that the length of the cut part was 400 μm and the length of the uncut part was 60 μm.

(Comparative Example 3)
A thermal transfer image-receiving sheet of Comparative Example 3 was produced in the same manner as in Example 1 except that the length of the cut part was 300 μm and the length of the uncut part was 250 μm.

(Comparative Example 4)
Example 1 except that the length of the cut part was 300 μm and the length of the uncut part was 60 μm
In the same manner, a thermal transfer image receiving sheet of Comparative Example 4 was produced.

(Comparative Example 5)
A thermal transfer image-receiving sheet of Comparative Example 5 was produced in the same manner as in Example 1 except that the length of the cut part was 250 μm and the length of the uncut part was 250 μm.

(Comparative Example 6)
A thermal transfer image-receiving sheet of Comparative Example 6 was prepared in the same manner as in Example 1 except that the length of the cut part was 250 μm and the length of the uncut part was 400 μm.

<Preparation of thermal transfer recording medium>
As the base material of the thermal transfer recording medium, a polyethylene terephthalate film with a single-sided easy-adhesion treatment having a thickness of 4.5 μm is used. It apply | coated and dried so that it might become 1.0 g / m < ² >, and the base material with a heat resistant slipping layer was obtained. Next, a primer layer having the following composition is applied to the easy-adhesion treated surface of the substrate with a heat resistant slipping layer, and then the thermal transfer layer coating solution is applied so that the coating amount after drying is 1.0 g / m ^2. The thermal transfer layer was formed by coating and drying to obtain a thermal transfer recording medium.

<Heat resistant slipping layer coating solution>
Silicone acrylic graft polymer 50.0 parts (Toa Gosei Co., Ltd. US-350)
Methyl ethyl ketone 50.0 parts.

<Primer layer coating solution>
Polyvinyl alcohol 2.5 parts
Isopropyl alcohol 30.0 parts
67.5 parts of pure water.

<Thermal transfer layer coating solution>
C. I. Solvent Blue 36 2.5 parts
C. I. Solvent Blue 63 2.5 parts
Polyvinyl acetal resin 5.0 parts
45.0 parts of toluene
45.0 parts of methyl ethyl ketone.

<Print evaluation>
Using the thermal transfer image receiving sheets and thermal transfer recording media of Examples 1 to 6 and Comparative Examples 1 to 6, a solid image was printed on the thermal transfer image receiving sheet, and then stored in an environment of 35 ° C. and 80% RH for 2 hours. evaluated. The thermal printer for evaluation used for printing has a printing speed of 2.0 msec / line and a resolution of 300 × 300 DPI.

  Further, it was evaluated whether the perforations of the printed material could be easily cut out by folding them once so as to form a valley fold on the dye receiving layer or the back surface. The evaluation results are shown in Table 1.

<Criteria for koge evaluation>
Evaluation of koge was performed according to the following criteria. Δ or more is a level where there is no practical problem.

○: No matting is observed Δ: Only a slight matting is observed ×: Matting is recognized

<Criteria for cutting evaluation>
Cutting evaluation was performed according to the following criteria. Δ or more is a level where there is no practical problem.

○: Folded once and can be easily cut out Δ: Folded once and cut off, but fuzz is visible at the cut edge ×: Cannot be cut off unless bent multiple times.

<考察>
実施例１，実施例２，比較例２は、いずれも、カット部の長さが４００μｍのミシン目を設けたものである。

<Discussion>
In each of Example 1, Example 2, and Comparative Example 2, a perforation having a cut portion length of 400 μm is provided.

  Therefore, when Example 1, Example 2, and Comparative Example 2 are compared with each other, in Comparative Example 2 in which the length of the uncut portion is 60 μm, kogation occurs near the perforation, whereas Kogation does not occur in both Example 1 (the length of the uncut portion is 120 μm) and Example 2 (the length of the uncut portion is 180 μm) in which the length of the cut portion is 120 μm or more. From this result, it can be seen that the length of the uncut portion is related to whether or not kogation occurs. That is, when the length of the cut portion is 400 μm, it can be estimated that no kogation occurs near the perforation if the length of the uncut portion is 120 μm or more, and kogation occurs at 60 μm. In addition, between 60 micrometers and 120 micrometers, the presence or absence of a kogation is unknown.

  Therefore, referring to Examples 3 to 6 in which the length of the cut portion is changed between 250 to 400 μm, no kogation occurs in the vicinity of the perforation in these Examples 3 to 6. Among these Examples 3 to 6, the uncut part having the shortest length is Example 3, Example 5 and Example 6, and the length of the uncut part is 120 μm. If the length is 100 μm or more, it can be reasonably estimated that no kogation occurs. That is, in the case where the length of the cut portion is 250 to 400 μm, if an uncut portion having a length of 100 μm or more is provided, kogation does not occur.

  However, in Comparative Example 1, the length of the cut portion is 600 μm and the length of the uncut portion is 120 μm. Therefore, the length of the uncut portion is 100 μm or more, but kogation occurs near the perforation. . This is because the length of the cut portion is too long, and no matter how the uncut portion is provided, the cut portion cannot be completely suppressed, and the kogation becomes apparent. Therefore, the length of the cut portion may be 500 μm or less.

  By the way, it can be seen from the results of Example 3 and Example 4 and the results of Example 5 and Comparative Example 3 that the ease of cutting is lowered when the uncut portion is long.

  Moreover, it can be seen from the results of Comparative Example 3, Comparative Example 5 and Comparative Example 6 that the ease of cutting is reduced even when the cut rate is low. The cut rate of Comparative Example 3 is 55%, the cut rate of Comparative Example 5 is 50%, and the cut rate of Comparative Example 6 is 38%. That is, by setting the cut rate to exceed 60%, the perforation can be broken and easily separated.

  Therefore, by making the length of the cut part 200 to 500 μm, the length of the uncut part 100 μm or more and the cut rate 60% or more and 80% or less, it can be easily folded and separated. Thus, it is possible to obtain a print having an image formed on the entire surface, and to obtain an excellent image quality free from burnt.

The thermal transfer image-receiving sheet obtained by the present invention can be used in a sublimation thermal transfer type sheet-fed printer, and can easily obtain a high-quality full-color print in response to downsizing and higher functionality of the printer. Therefore, it can be widely used for digital camera self-printing and amusement output. It can also contribute to reducing the environmental impact of manufacturing.

1: Base material 2: Thermal insulation layer 3: Undercoat layer 4: Dye-receiving layer 5, 6: Perforation 7: Back layer

Claims (3)

It has a single-layer or multiple-layer coating layer on a long substrate, and the surface coating layer is a dye-receiving layer that receives a sublimation dye, and at least one of these layers is an aqueous coating. In the thermal transfer image receiving sheet that is a layer formed by coating the agent, and has a perforation that can be cut off at both front and rear ends in the conveying direction of the image forming region ,
The perforation is composed of a cut portion of 200 to 500 μm and an uncut portion of 100 μm or more, and is calculated by (length of cut portion) / (length of cut portion + length of uncut portion). The thermal transfer image-receiving sheet , wherein the cut rate is 60% or more and 80% or less, thereby suppressing moisture absorption of the layer formed by coating with an aqueous coating agent . A multi-layered coating layer is formed on a substrate that is a long body, and the coating layer on the surface is a dye-receiving layer that receives a sublimable dye, and at least one of the layers positioned under the dye-receiving layer. In the thermal transfer image receiving sheet which is a layer formed by coating a water-based coating agent, and has a perforation that can be cut off at both front and rear ends in the conveyance direction of the image forming region ,
The perforation is composed of a cut portion of 200 to 500 μm and an uncut portion of 100 μm or more, and is calculated by (length of cut portion) / (length of cut portion + length of uncut portion). The thermal transfer image-receiving sheet , wherein the cut rate is 60% or more and 80% or less, thereby suppressing moisture absorption of the layer formed by coating with an aqueous coating agent .   The thermal transfer image receiving sheet according to claim 1, wherein the perforation extends in a direction crossing a conveyance direction of the printer.

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