JP2008260146A - Manufacturing method and recording method of thermal transfer object sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the adhesion of a laminate layer excellent and to give a high gloss thereto. <P>SOLUTION: A dye accepting layer forming composition containing at least a dyeing resin, a mold release agent and a crosslinking agent is applied on at least one side of a base 12 and water droplets are formed on the applied composition. The composition is dried to remove the water droplets so that indentations 14 are formed. The base whereon the dye accepting layer forming composition is formed is subjected to aging so as to form a dye accepting layer 13 having the indentations 14 formed on the side onto which the laminate layer 3 is to be transferred. Thus, a thermal transfer object sheet 1 which has the dye accepting layer 13 keeping the indentations 14 cut in the base 12 is manufactured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the present invention, when the ink ribbon on which the dye layer and the laminate layer are formed is heated by the thermal head, and the dye and the laminate layer are thermally transferred to the dye receiving layer, the adhesion of the laminate layer to the dye receiving layer is improved. The present invention relates to a method for manufacturing a thermal transfer sheet and a recording method using the thermal transfer sheet obtained by the method for manufacturing a thermal transfer sheet.

  As a method for recording images and characters, for example, a dye layer containing a sublimation dye provided on an ink ribbon is heated with a thermal head in accordance with an image signal, and the sublimated dye is applied to a heat-transfer sheet with a resin. There is a sublimation type thermal transfer system in which images and characters are printed by thermal transfer to a dye receiving layer formed by the above method. While this thermal transfer system has the features of high sensitivity, high dyeability, and the ability to form high-density and glossy clear images and characters at a high speed, it is necessary to improve the storage stability of images and characters. There is an increasing demand for improving the storage stability of images and characters.

  In a thermal transfer sheet on which a dye is thermally transferred, a dye receiving layer for receiving the dye is formed on a substrate, and the dye receiving layer receives the dye to form an image or a character. In thermal transfer sheets, a laminate layer formed of a transparent film is thermally transferred to the surface of the dye receiving layer on which images and characters are printed in order to protect the surface and discoloration of images and characters printed by the sublimation thermal transfer method. Thus, the printed images and characters are protected. The thermal transfer of the laminate layer to the heat-transferable sheet not only protects printed images and characters, but also has the purpose of giving the images and characters gloss.

  This laminate layer is provided, for example, along with the dye layer on the base material of the ink ribbon. Like the dye, the laminate layer is heated from the back side of the ink ribbon by a thermal head, a heat roller, etc., and peeled off at the interface with the substrate, so that it is thermally transferred onto the dye receiving layer on which images and characters are printed. (For example, refer to Patent Document 1).

  By the way, in the heat transfer sheet, when a plurality of sheets are stacked and stored, the dye receiving layer may stick to the back surface of another heat transfer sheet placed thereon, and blocking may occur in which the heat transfer sheets stick to each other. . In such a thermal transfer sheet, it is necessary to improve the releasability of the dye receiving layer so as to prevent blocking or to facilitate the peeling of the dye layer of the ink ribbon from the dye receiving layer when the dye is thermally transferred. is there. In the thermal transfer sheet, a release agent such as silicone oil is added to the dye receiving layer in order to improve the peelability of the dye receiving layer (see, for example, Patent Document 2).

  However, in a thermal transfer sheet, when a release agent is contained in the dye receiving layer, if it is stored for a long time, the release agent in the dye receiving layer bleeds out to the surface, and the dye receiving layer and the laminate layer The adhesiveness is lowered, and the laminate layer is easily peeled off from the dye receiving layer. This manifests itself as a phenomenon that the laminate layer is not on the heat-transfer sheet, or that the laminate layer is on the heat-transfer sheet but has insufficient adhesion. At the location where the chipping of the laminate or the floating of the laminate occurs, gas, water such as ozone, or water causes a discoloration of the printed image or characters and a decrease in glossiness, and the printed image or characters are damaged.

  In such a thermal transfer sheet, in order to improve the adhesion and surface smoothness of the laminate layer so that the laminate layer bonded to the dye receiving layer does not peel off, the laminate layer is superimposed on the dye receiving layer and heated. There is a method of heating and pressurizing with a cooling separation type belt fixing type smoothing processing machine provided with a pressure means and a cooling means (see, for example, Patent Document 3).

  However, even if the surface of the thermal transfer sheet is treated in this way, it is impossible to prevent the release agent from bleeding out, and to prevent deterioration of the adhesion of the laminate layer due to the release agent bleeding out. Can not do it. In addition, when such a method is employed, the provision of a belt fixing type smoothing processor leads to an increase in the size of the thermal transfer printer device and an increase in power consumption.

JP-A-4-241991 Japanese Patent Laid-Open No. 7-228064 JP 2004-284267 A

  The present invention has been proposed in view of such conventional circumstances, and improves the adhesion of the laminate layer to the dye-receiving layer, has a high gloss, and has a long shelf life. It is an object of the present invention to provide a method and a recording method using the thermal transfer sheet.

  The method for producing a thermal transfer sheet according to the present invention that achieves the above-described object has a dye receiving layer comprising a dye receiving layer forming composition on at least one surface of a substrate, and is laminated on the dye receiving layer. A method for producing a thermal transfer sheet in which a layer is thermally transferred, wherein a dye receiving layer forming composition containing at least a dyeing resin, a release agent and a crosslinking agent is applied on at least one surface of a substrate. Then, water droplets are formed on the coated dye-receiving layer forming composition, the coated dye-receiving layer forming composition is dried, the water droplets are removed to form irregularities, and the above dye-receiving layer forming composition is formed. An aging treatment is performed on the substrate, and the dye receiving layer having the irregularities formed on the surface to which the laminate layer is thermally transferred is formed.

  The recording method according to the present invention that achieves the above-described object uses the thermal transfer sheet obtained by the above-described method for manufacturing a thermal transfer sheet, and thermally transfers the dye and the laminate layer to the dye receiving layer with a thermal head. This is a recording method in which the surface of the dye receiving layer after recording the dye and the laminate layer by thermal transfer with a thermal head is recorded at a 20 ° gloss (post-recording gloss) and the unevenness of the dye receiving layer before recording. The ratio of the formed surface to the 20 ° glossiness (before-recording glossiness) is (after-recording glossiness) / (before-recording glossiness)> 1.6.

  In the present invention, when forming the dye-receiving layer on the substrate, after coating the dye-receiving layer forming composition on the substrate, water droplets are formed on the coated dye-receiving layer forming composition and dried. By removing the water droplets, the traces of the water droplets are formed as irregularities, and the irregularities are formed on the surface of the dye receiving layer. As a result, in the present invention, since the unevenness is formed on the surface of the dye receiving layer, the adhesion area with the laminate layer thermally transferred to the dye receiving layer is increased, and the adhesion of the laminate layer to the dye receiving layer is increased. improves. In the present invention, the unevenness is formed in the dye-receiving layer, so that images and characters after recording become highly glossy. Therefore, in the present invention, there is no chipping or flocculation of the laminate, the laminate layer adheres to the dye receiving layer, high gloss, and excellent long-term storage stability.

  Further, in the present invention, the 20 ° glossiness of the surface of the dye receiving layer after recording by thermal transfer of the dye and the laminate layer (the glossiness after recording) and the surface on which the unevenness of the dye receiving layer before recording is formed. It is further obtained by forming irregularities on the dye-receiving layer so that the ratio to the 20 ° glossiness (pre-recording glossiness) is (post-recording glossiness) / (pre-recording glossiness)> 1.6. The image and characters printed are highly glossy.

  Hereinafter, a manufacturing method of a thermal transfer sheet to which the present invention is applied and a recording method using the thermal transfer sheet will be described in detail with reference to the drawings. The thermal transfer sheet 1 shown in FIGS. 1 and 2 is composed of, for example, three colors such as yellow, magenta, and cyan, or four colors including black, a sublimable disperse dye, a heat-fusible dye, or a heat-diffusible dye. To a thermal transfer printer device 5 having a thermal transfer sheet, that is, an ink ribbon 4, in which a dye layer 2 for each color and a laminate layer 3 that is thermally transferred to the surface of the thermal transfer sheet 1 and protects the formed images and characters are arranged side by side. Used. The thermal transfer printer device 5 is provided with a thermal head 6 for heating the dye layer 2 and the laminate layer 3 from the back surface of the ink ribbon 4 and a position facing the thermal head 6, and presses the thermal transfer sheet 1 against the thermal head 6. A platen 7, a plurality of ribbon guides 8 that guide the travel of the mounted ink ribbon 4, and a pinch roller 9 a and a capstan roller that travel the thermal transfer sheet 1 between the thermal head 6 and the platen 7 together with the ink ribbon 4. 9b, a paper discharge roller 10 for discharging the thermal transfer sheet 1 after recording, that is, after printing, and a conveyance roller 11 for conveying the thermal transfer sheet 1 to the thermal head 6 side.

  In the thermal transfer printer device 5 having such a configuration, as shown in FIG. 2, the winding side spool 4 a of the ink ribbon 4 is placed between the thermal head 6 and the platen 7 while pressing the platen 7 against the thermal head 6. In FIG. 2, the ink ribbon 4 is moved from the supply spool 4b to the take-up spool 4a by rotating in the winding direction indicated by the arrow A, and the heat transfer sheet 1 is sandwiched between the pinch roller 9a and the capstan roller 9b. Then, the thermal transfer sheet 1 is caused to travel in the paper discharge direction by rotating the capstan roller 9b and the paper discharge roller 10 in the paper discharge direction indicated by the arrow B in FIG. When printing, first, thermal energy is applied from the thermal head 6 to the yellow dye layer 2 of the ink ribbon 4 to thermally transfer the yellow color material to the thermal transfer sheet 1 that is running overlapping the ink ribbon 4. To do. After the yellow dye is thermally transferred, in order to thermally transfer the magenta dye to the image forming portion where the yellow dye is thermally transferred and the characters are formed, the heat transfer sheet 1 is transferred to the thermal head 6 side (in FIG. 1) by the conveying roller 11. The head of the image forming unit is opposed to the thermal head 6, and the magenta dye layer 2 of the ink ribbon 4 is opposed to the thermal head 6. As in the case of thermal transfer of the yellow dye layer 2, thermal energy is also applied to the magenta dye layer 2 to thermally transfer the magenta color material to the image forming portion of the thermal transfer sheet 1. The cyan color material and the laminate layer 3 are also thermally transferred to the image forming unit in the same manner as when magenta is thermally transferred, and cyan and the laminate layer 3 are sequentially thermally transferred to the thermal transfer sheet 1 to print color images and characters.

  As shown in FIG. 1, the thermal transfer sheet 1 to which the dye and the laminate layer 3 are thermally transferred as described above has a two-layer structure in which a dye receiving layer 13 for receiving a dye is laminated on a substrate 12. The substrate 12 is, for example, in the form of a sheet and holds the dye receiving layer 13 laminated on one main surface. The dye receiving layer 13 is located on the outermost surface and receives the dye from the ink ribbon 4.

  Specifically, the base material 12 is preferably any paper or film such as plain paper, fine paper, coated paper, cast roll paper, cellulose fiber paper, etc., and may be a laminate of plastic sheets, for example. A paper substrate is more preferred.

  The dye receiving layer 13 formed on the substrate 12 is formed of a dye receiving layer forming composition in which at least a dyeing resin, a release agent, and a crosslinking agent are mixed in a solvent.

  The dyeing resin holds the dye thermally transferred from the ink ribbon 4, and for example, a polyester resin or an acrylic resin is used.

  The release agent is contained in the dye receiving layer 13 so that the ink ribbon 4 is easily peeled off from the thermal transfer sheet 1 when the dye or the laminate layer 3 is thermally transferred from the ink ribbon 4. As the mold release agent, silicone oil or the like, which is generally used as a mold release agent for a thermal transfer sheet, can be used.

  The crosslinking agent causes the substance in the dye receiving layer forming composition to undergo a crosslinking reaction to cure the dye receiving layer 13. As a crosslinking agent, what is generally used as a crosslinking agent of a to-be-heated transfer sheet, such as an isocyanate compound, can be used, for example.

  For example, an organic solvent such as toluene or methyl ethyl ketone is used as a solvent for mixing them.

  In addition, an inorganic pigment such as titanium oxide or a fluorescent brightening agent may be added to the dye receiving layer 13 in order to improve whiteness. In addition, an antistatic agent may be added to the dye receiving layer 13 or the surface may be coated with an antistatic agent in order to prevent the generation of static electricity when traveling inside the thermal transfer printer device 5.

  The thickness of the dye receiving layer 13 is preferably 1 to 10 μm, more preferably 2 to 7 μm. If the thickness of the dye receiving layer 13 is less than 1 μm, there may be a problem that the density and sensitivity of images and characters formed by thermal transfer of the dye are lowered. On the other hand, when the thickness of the dye receiving layer 13 exceeds 10 μm, the effect of the dye receiving layer 13 is saturated and not only is uneconomical, but also the strength of the dye receiving layer 13 may decrease.

  As shown in FIG. 1, the heat transfer sheet 1 having the above-described configuration has fine irregularities 14 formed on the surface of the dye receiving layer 13 on the side where the laminate layer 3 is bonded. In the thermal transfer sheet 1, by forming fine irregularities 14 on the surface of the dye receiving layer 13, the area to be bonded to the laminate layer 3 becomes larger than when formed on a flat surface, that is, the specific surface area is increased. The adhesion of the laminate layer 3 is improved. Moreover, in this thermal transfer sheet 1, the printed image and characters become highly glossy due to the fine irregularities 14 formed on the surface of the dye receiving layer 13.

  Further, in the thermal transfer sheet 1, when the fine irregularities 14 are formed on the surface of the dye receiving layer 13, it is preferable that the 20 ° glossiness of the surface of the dye receiving layer 13 is less than 40. In the thermal transfer sheet 1, the fine irregularities 14 are formed so that the 20 ° glossiness of the surface of the dye receiving layer 13 is less than 40. The gloss of characters can be improved.

  Further, in the thermal transfer sheet 1, 20 ° glossiness (hereinafter also referred to as post-recording glossiness) and printing (recording) of the surface of the dye receiving layer 13 after printing (recording) images and characters by the thermal transfer printer device 5. ) Fine irregularities 14 on the surface of the dye receiving layer 13 so that the ratio to the 20 ° glossiness (hereinafter also referred to as pre-recording glossiness) of the surface of the previous dye receiving layer 13 satisfies the following formula (1). Is preferably formed.

  Formula (1) is (Glossiness after recording) / (Glossiness before recording)> 1.6.

  In the thermal transfer sheet 1, by satisfying the formula (1), the adhesiveness of the laminate layer 3 is good, and the obtained images and characters become more glossy. When (Glossiness after recording) / (Glossiness before recording) ≦ 1.6, chipping of the laminate, floating of the laminate, and matting occur.

Such a thermal transfer sheet 1 is manufactured according to FIG. First, in the coating step S1 of the dye-receiving layer-forming composition, as shown in FIG. 4, a dye in which at least a dyeing resin, a release agent, and a crosslinking agent are mixed in a solvent on the base material 12. The receiving layer forming composition is applied by, for example, a wire bar to form the composition layer 15 composed of the dye receiving layer forming composition. The coating amount of the dye receiving layer forming composition is preferably about 3 to 10 g / m ² in terms of dry weight.

  Next, in the humidifying step S2, immediately after the composition layer 15 is formed on the substrate 12, the composition layer 15 is humidified in a state where the solvent in the composition layer 15 is not evaporated, and the composition layer 15 Water droplets are formed on the surface. Examples of the method for humidifying the composition layer 15 include steam humidification, water spray humidification, and vaporization humidification. When the composition layer 15 is humidified, any means is effective, but by forming water droplets from the composition layer 15 side rather than the base material 12 side, water droplets can be easily formed on the surface. . In this humidification step S2, for example, the humidity is preferably 60% or more. In the humidification step S2, the crosslinking reaction of the crosslinking agent in the dye-receiving layer forming composition is started by humidifying the composition layer 15. When the 20 ° glossiness of the surface of the dye receiving layer 13 is less than 40, the humidification is performed in the humidification step S2.

  Next, in the drying step S3, the composition layer 15 is dried. As a drying method, there is a method of drying with hot air. In drying process S3, in order to dry the water droplet formed on the surface of the composition layer 15 in humidification process S2, it is preferable to set it as 100 degreeC or more. In addition, you may perform drying process S3 in multiple times. In the drying step S3, by drying the composition layer 15 and evaporating the water droplets, traces of the water droplets remain on the surface of the composition layer 15 as shown in FIG. Is done.

  Next, in the aging treatment step S4, an aging treatment is performed on the substrate 12 on which the composition layer 15 is formed. As the aging treatment, for example, the base material 12 on which the composition layer 15 is formed is aged for 24 hours to 48 hours in a constant temperature layer of 45 ° C. to 50 ° C. By this aging treatment, the dye-receiving layer 13 having the fine irregularities 14 formed on the substrate 12 is fixed, and the thermal transfer sheet 1 is obtained.

  In the manufacturing process as described above, when an isocyanate compound is used as the crosslinking agent, in addition to the manufacturing process described above, the coating process S1 to the drying process S3 are performed, and then the composition layer 15 is subjected to an aging treatment. It is preferable to add a step of humidifying the composition layer 15 before the aging treatment step S4.

  The main purpose of adding a humidification step between the drying step S3 and the aging treatment step S4 is that moisture promotes a cross-linking reaction between isocyanate groups in the composition layer 15. When an isocyanate compound is used as a crosslinking agent, the presence of moisture in the composition layer 15 promotes a crosslinking reaction between isocyanate groups. Therefore, by adding a humidification step to the manufacturing method described above, the crosslinking reaction starts by the humidification in the humidification step S2, and the crosslinking reaction is accelerated by the additional humidification step.

  The cross-linking reaction of the isocyanate compound is susceptible to the influence of the surrounding atmosphere when the manufacturing atmosphere varies. As a result of variation in the crosslinking reaction depending on the ambient atmosphere, the composition of the dye receiving layer 13, that is, the ratio of the reaction product and the unreacted product of the crosslinking reaction, or the structure of the reaction product is different. The heat conduction characteristics of 13 will change. As a result, in such a thermal transfer sheet 1, the adhesiveness of the laminate layer 3, the bleed-out amount of the release agent, the print sensitivity of the dye receiving layer 13, and the hue / tone of images and characters formed by thermal transfer of the dye. Becomes unstable. Therefore, in the humidification step for promoting the crosslinking reaction of the isocyanate compound, the crosslinking reaction is stabilized by controlling the moisture in the composition layer 15 to be constant. This humidification step is performed using a dryer device or a humidifier. As a method of adjusting the humidification, the moisture content of the atmosphere in the dryer apparatus or humidifier is appropriately controlled. When humidifying, it humidifies from the surface of the composition layer 15 or the back surface side of the base material 12.

  Further, in the aging treatment step S4 when the isocyanate compound is used as a crosslinking agent, the substrate 12 on which the composition layer 15 is formed is wound up in a roll shape, packaged as necessary, and humidified for aging treatment. Preferably it is done. For example, the aging treatment is preferably performed at 30 to 80 ° C. because the crosslinking reaction is promoted by performing the aging treatment at 30 to 80 ° C. When performing the aging treatment, pay attention to temperature unevenness so that heat is uniformly applied. Moreover, when performing aging in a roll state, you may perform a rewinding process.

  In the method for manufacturing the thermal transfer sheet 1 as described above, the fine irregularities 14 are formed on the surface of the dye receiving layer 13, whereby the laminate layer 3 is thermally transferred onto the dye receiving layer 13 as shown in FIG. Then, the adhesion area between the dye receiving layer 13 and the laminate layer 3 is increased, and the adhesion of the laminate layer 3 is improved. Thereby, in this thermal transfer sheet 1, even when a release agent is added to the dye receiving layer 13 and the release agent bleeds out, the laminate layer 3 does not peel off from the dye receiving layer 13. Floating can be prevented. In this heat transfer sheet 1, since it is possible to prevent the chipping of the laminate and the floating of the laminate, it is possible to prevent the printed image and characters from being discolored and the glossiness from being reduced by light, gas such as ozone, and water. It can be stored for a long time in a highly glossy state without damaging the printed images and characters.

  Further, in the method for manufacturing the thermal transfer sheet 1, when the fine irregularities 14 are formed on the surface of the dye receiving layer 13, the 20 ° glossiness of the surface of the dye receiving layer 13 is set to be less than 40. In addition, there are many irregularities 14, the adhesiveness of the laminate layer 3 can be further improved, and high gloss can be achieved.

  Further, in the method for manufacturing the thermal transfer sheet 1, the ratio between the glossiness after recording after printing an image or characters by the thermal transfer printer device 5 and the glossiness before recording before printing is ((Glossiness after recording) / ( By forming fine irregularities 14 on the surface of the dye receiving layer 13 so that the glossiness before recording)> 1.6, the obtained images and characters become more glossy.

  Moreover, in this manufacturing method of the thermal transfer sheet 1, when an isocyanate compound is used as the crosslinking agent of the dye receiving layer 13, a humidifying step is further added between the drying step S3 and the aging treatment step S4, so that a dryer apparatus or a humidifying step is performed. By adjusting the moisture content in the vessel so that the moisture in the composition layer 15 becomes constant, the crosslinking reaction of the isocyanate compound can be controlled to be constant, and the crosslinking reaction of the isocyanate compound is promoted. At the same time, the crosslinking reaction becomes stable. In the method for producing the thermal transfer sheet 1, the crosslinking reaction of the isocyanate compound is stabilized, whereby the composition of the dye receiving layer 13, that is, the ratio of the reaction product of the crosslinking reaction to the unreacted material is biased. It is possible to suppress the difference in structure and to stabilize the heat conduction characteristics of the dye receiving layer 13. Thus, in the method for manufacturing the thermal transfer sheet 1, the adhesiveness of the laminate layer 3, the bleed-out amount of the release agent, the print sensitivity of the dye receiving layer 13, the hue of images and characters formed by transferring the dye, Color tone is stable.

  In the thermal transfer sheet 1, a low density layer that softens the impact when pressed by the thermal head 6 between the base material 12 and the dye receiving layer 13, or a dye thermally transferred to the dye receiving layer 13 is used as the base material. A barrier layer for preventing dye migration may be provided so as not to migrate to 12.

  Hereinafter, preferred embodiments of the present invention will be described based on experimental results.

<Example 1>
In Example 1, a low-density layer is formed on the base material as a layer that softens the impact when pressed by the thermal head, and the thermally transferred dye moves to the base material side on the low-density layer. A barrier layer to be prevented was formed, and a dye receiving layer for receiving the dye was formed on the barrier layer to prepare a thermal transfer sheet.

  The low-density coating solution for forming the low-density layer is 35 parts of styrene acrylic hollow particles (trade name: SX866 (B), manufactured by JSR Corporation) and 15 parts of polyvinyl alcohol (trade name: PVA205, manufactured by Kuraray Co., Ltd.). Part, 50 parts of styrene-butadiene latex (trade name: PT1004, manufactured by Asahi Kasei Co., Ltd.) and 200 parts of water were prepared.

  The barrier layer coating solution for forming the barrier layer was prepared by mixing 100 parts of polyvinyl alcohol (trade name: PVA420, manufactured by Kuraray Co., Ltd.) and 1000 parts of water.

  The dye-receiving layer-forming composition for forming the dye-receiving layer comprises 100 parts of polyester resin (trade name: Byron 200, manufactured by Toyobo), 5 parts of silicone oil (trade name: KF6002, manufactured by Shin-Etsu Chemical Co., Ltd.), poly It was prepared by mixing 5 parts of isocyanate (trade name: Takenate D-140N, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.) and 400 parts of a toluene / methyl ethyl ketone = 1/1 (mass ratio) mixed solution.

In Example 1, art paper (trade name: OK Kanto N, 174 g / m ² , manufactured by Oji Paper Co., Ltd.) having a thickness of 150 μm was used as a base material, and a low-density coating solution was formed on the base material by a wire bar device. Is applied so that the low-density layer after drying becomes 40 g / m ² and dried to form a low-density layer, and then the barrier layer after drying becomes 1.5 g / m ² on this low-density layer. Thus, the barrier layer coating solution was applied and dried to form a barrier layer. Thereafter, the dye receiving layer forming composition is applied with a wire bar device so that the dried dye receiving layer is 4 g / m ² on the barrier layer, and 80 ° C. before the solvent in the dye receiving layer forming composition is dried. Dye-receiving layer having fine irregularities formed on the surface after being left in a 60% constant temperature and humidity layer for 10 seconds, dried in an oven at 110 ° C. for 2 minutes, and subjected to an aging treatment in a constant temperature layer at 50 ° C. for 24 hours. A thermal transfer sheet having the following characteristics was prepared.

<Example 2>
In Example 2, after forming a low-density layer and a barrier layer on the substrate in the same manner as in Example 1, the dye-receiving layer was formed on the barrier layer so that the dried dye-receiving layer was 4 g / m ^2. The composition is applied and left in a 50 ° C. 90% constant temperature and humidity layer for 20 seconds before drying the solvent, then dried in an oven at 120 ° C. for 1 minute, and then left in a 40 ° C. and 95% constant temperature and humidity layer for 1 minute. A thermal transfer sheet having a dye-receiving layer having fine irregularities formed on the surface was produced by aging treatment at a constant temperature layer of 45 ° C. for 24 hours.

<Example 3>
In Example 3, after forming a low-density layer and a barrier layer on the substrate in the same manner as in Example 1, the dye-receiving layer-forming composition was formed on the barrier layer so that the dye-receiving layer was 4 g / m ^2. Apply and spray water on the surface of the dye-receiving layer-forming composition coated on the substrate using a spray bottle before the solvent is dried, dry in a 120 ° C. oven for 1 minute, and then in a constant temperature layer at 40 ° C. A thermal transfer sheet having a dye-receiving layer having fine irregularities formed on the surface was produced by aging treatment for 48 hours.

<Comparative example 1>
In Comparative Example 1, a low-density layer and a barrier layer were formed on the substrate in the same manner as in Example 1, and then the dye-receiving layer was formed on the barrier layer so that the dried dye-receiving layer was 4 g / m ^2. After coating the composition, it was dried in an oven at 110 ° C. for 2 minutes, and subjected to an aging treatment in a constant temperature layer at 50 ° C. for 24 hours as an aging treatment step, thereby producing a heat transfer sheet. In Comparative Example 1, since the humidification process is not performed after the dye-receiving layer forming composition is applied, the fine unevenness formed by the humidification process is not formed on the surface of the dye-receiving layer.

<Comparative example 2>
In Comparative Example 2, a low-density layer and a barrier layer were formed on the substrate in the same manner as in Example 1, and then the dye-receiving layer was formed on the barrier layer so that the dried dye-receiving layer was 4 g / m ^2. After the composition is applied and before the solvent is dried, it is allowed to stand in a 50 ° C. and 50% constant temperature and humidity layer for 20 seconds, and then dried in an oven at 120 ° C. for 1 minute. It was allowed to stand for a while and was subjected to an aging treatment for 48 hours in a 45 ° C. constant temperature layer to produce a heat-transfer transfer sheet. In Comparative Example 2, after the dye-receiving layer forming composition was applied, it was left in a 50 ° C. and 50% constant temperature and humidity layer for 20 seconds, but it was not an environment where water droplets were formed. The fine unevenness | corrugation formed by is not formed.

<Comparative Example 3>
In Comparative Example 3, a low-density layer and a barrier layer were formed on the substrate in the same manner as in Example 1, and then the dye-receiving layer was formed on the barrier layer so that the dried dye-receiving layer was 4 g / m ^2. After applying the composition, water is sprayed on the back surface of the substrate by spraying, dried in an oven at 120 ° C. for 1 minute, and then left in an 80 ° C. 60% constant temperature and humidity layer for 1 minute. A timed aging treatment was performed to prepare a heat-transferable sheet. In Comparative Example 3, since the dye receiving layer forming composition is applied and then water is sprayed from the back side of the substrate, the surface of the dye receiving layer of the obtained thermal transfer sheet is formed by water droplets. Fine irregularities are not formed.

  For the heat-transfer sheets of Examples 1 to 3 and Comparative Examples 1 to 3 produced as described above, evaluation of adhesion of the laminate layer and measurement of glossiness were performed. The evaluation results and the measurement results are shown in Table 1.

  Regarding the adhesiveness of the laminate layer, a thermal transfer printer device (UPC-C15, Sony) on which a laminate layer of a thermal transfer sheet (ink ribbon) (UP-CR10L, manufactured by Sony Corporation) was cut and pasted on the yellow color material layer portion was mounted. Co., Ltd.) printed 16 gradations with a yellow signal, measured the transfer start gradations of the laminate layers for the heat-transfer sheets of Examples and Comparative Examples, and evaluated the suitability of the laminates according to the following criteria. In Table 1, when transfer start gradation ≦ 8 gradations, that is, even when the thermal energy of the thermal head is small, when the laminate layer is thermally transferred to the thermal transfer sheet, it is indicated by ◎, and 8 gradations <transfer start In the case of gradation ≤ 12 gradations, that is, when larger thermal energy is applied than in the case of ◎, when the laminate layer is thermally transferred to the thermal transfer sheet, it is indicated by ○, 12 gradations <transfer start gradation ≤ 14th floor In the case of tone, that is, when larger thermal energy is applied than in the case of ◯, when the laminate layer is thermally transferred to the thermal transfer sheet, it is indicated by Δ, and in the case of 14 <transfer start gradation, that is, larger than in the case of Δ When the thermal energy is applied, it is indicated by x when the laminate layer is transferred to the thermal transfer sheet. In practice, if the evaluation results are ◎ and ○, there is no problem.

  Regarding glossiness, the gloss on the dye receiving layer side before printing and the gloss on the dye receiving layer side after printing gray using UP-CR10L (manufactured by Sony Corporation) as a thermal transfer sheet (Nippon Denki) The color was measured with a color industry company). The incident angle at the time of measurement is 20 °.

  From the results shown in Table 1, in Example 1 to Example 3 in which the thermal transfer sheet was produced by the thermal transfer sheet manufacturing method to which the present invention was applied, fine irregularities are formed on the surface of the dye receiving layer. Compared with Comparative Examples 1 to 3 in which the unevenness formed without applying the present invention is not formed, the laminate layer adheres to the dye-receiving layer even when the laminate layer is thermally transferred with small thermal energy, and the adhesiveness is good. It turns out that it becomes. In Examples 1 to 3, since the glossiness of the dye-receiving layer before printing is less than 40 and (Glossiness before recording) / (Glossiness after recording)> 1.6, the glossiness is high. It turns out that it is. Therefore, in Examples 1 to 3, it is understood that the adhesiveness of the laminate layer is good, and when the image or characters are printed, high gloss is obtained and the heat transfer sheet is excellent in long-term storage. .

  On the other hand, in Comparative Examples 1 to 3, since the fine irregularities are not formed in the dye receiving layer, the adhesion area with the laminate layer does not increase, and the laminate layer is a dye unless high thermal energy is applied. It can be seen that the laminate layer does not adhere to the receiving layer and the adhesion of the laminate layer is poor. In Comparative Examples 1 to 3, since the glossiness of the dye-receiving layer before printing is greater than 40 or (Glossiness before recording) / (Glossiness after recording)> 1.6 is not satisfied, It can be seen that high gloss cannot be obtained.

  From the above, in the method for producing a thermal transfer sheet, when forming the dye-receiving layer, humidification is performed, water droplets are formed on the surface, and fine irregularities are formed. It can be seen that high gloss can be obtained.

It is sectional drawing which shows the state by which the laminate layer was thermally transferred on the to-be-heated transfer sheet obtained by the manufacturing method of the to-be-heated transfer sheet to which this invention is applied. It is the schematic of the thermal transfer printer apparatus which prints using the said to-be-heated transfer sheet. It is a figure which shows the process of the manufacturing method of the thermal transfer sheet to which this invention is applied. It is sectional drawing which shows the state which applied the dye receiving layer forming composition on the base material. It is sectional drawing of the thermal transfer sheet obtained by the manufacturing method of the thermal transfer sheet to which this invention is applied.

Explanation of symbols

  1 thermal transfer sheet, 2 dye layer, 3 laminate layer, 4 ink ribbon, 5 thermal transfer printer device, 6 thermal head, 7 platen, 8 ribbon guide, 9a pinch roller, 9b capstan roller, 10 paper discharge roller, 11 transport roller , 12 Base material, 13 Dye-receiving layer, 14 Concavity and convexity, 15 Composition layer

Claims (4)

In a method for producing a thermal transfer sheet having a dye receiving layer comprising a dye receiving layer forming composition on at least one surface of a substrate, and a laminate layer being thermally transferred onto the dye receiving layer,
On at least one surface of the substrate, a dye receiving layer forming composition containing at least a dyeing resin, a release agent, and a crosslinking agent is applied,
Forming water droplets on the coated dye-receiving layer forming composition,
Drying the coated dye-receiving layer forming composition, removing the water droplets to form irregularities,
A thermal transfer sheet, wherein the substrate on which the dye-receiving layer-forming composition is formed is subjected to an aging treatment to form the dye-receiving layer having irregularities formed on the surface on which the laminate layer is thermally transferred. Manufacturing method. The crosslinking agent is an isocyanate compound,
2. The thermal transfer sheet according to claim 1, wherein the dye-receiving layer-forming composition is humidified after the dye-receiving layer-forming composition is dried and before the aging treatment is performed on the substrate. Production method.   2. The method for producing a thermal transfer sheet according to claim 1, wherein the surface of the dye receiving layer on which the unevenness is formed has a 20 ° glossiness of less than 40. 3. A dye and a laminate layer are thermally transferred by a thermal head and recorded on the dye receiving layer of the thermal transfer sheet having the dye receiving layer formed of the dye receiving layer forming composition formed on at least one surface of the substrate. In the recording method,
In the heat-transfer sheet, first, on at least one surface of the substrate, a dye-receiving layer-forming composition containing at least a dyeing resin, a release agent, and a crosslinking agent is applied, and then the coating is performed. Water droplets are formed on the processed dye-receiving layer forming composition, then the coated dye-receiving layer forming composition is dried, the water droplets are removed to form irregularities, and then the dye-receiving layer is formed. An aging treatment is performed on the base material on which the forming composition is formed, and the above-mentioned dye-receiving layer is obtained by forming irregularities on the surface on which the laminate layer is thermally transferred,
Glossiness of 20 ° (glossiness after recording) of the surface of the dye receiving layer after recording the dye and the laminate layer by thermal transfer with the thermal head, and a surface on which the unevenness of the dye receiving layer before recording is formed The recording method is characterized in that the ratio to the 20 ° glossiness (before-recording glossiness) is (after-recording glossiness) / (before-recording glossiness)> 1.6.

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