Support for thermal transfer image receiving sheet, thermal transfer image receiving sheet, method for manufacturing a thermal transfer image receiving sheet, method for manufacturing a support for a thermal transfer image receiving sheet, and sheet lamination apparatus.

Abstract

To provide a thermal transfer image receiving sheet which can form a thermal transfer image with high quality while suppressing a manufacturing cost and also can form the thermal transfer image with a variety of expressions by selectively changing a state of an image surface.SOLUTION: A support for a thermal transfer image receiving sheet laminates a base material 11, a resin layer 12 and a film 20 in this order. At least either on a boundary between the base material 11 and the resin layer 12 or in the vicinity of the boundary, one or more cavities 30 are disposed, and the cavities 30 have a height of 0.5 μm or more and 15 μm or less in the laminating direction of the base material 11, the resin layer 12 and the film 20.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] This disclosure relates to a support for a thermal transfer image receiving sheet that constitutes a thermal transfer image receiving sheet by supporting a receiving layer, and a thermal transfer image receiving sheet equipped therewith. This disclosure also relates to a method for manufacturing a thermal transfer image receiving sheet, a method for manufacturing a support for a thermal transfer image receiving sheet, and a sheet laminating apparatus that can be used therein. [Background technology]

[0002] Image formation methods utilizing thermal transfer include sublimation thermal transfer methods and fusion thermal transfer methods. In the sublimation thermal transfer method, a thermal transfer sheet having a colorant layer containing a sublimable dye on a substrate and a thermal transfer image receiving sheet having a receiving layer on a support are placed on top of each other, and a thermal transfer image is formed by transferring the sublimable dye contained in the colorant layer of the thermal transfer sheet to the receiving layer of the thermal transfer image receiving sheet.

[0003] The support for a thermal transfer image receiving sheet generally comprises a paper substrate, an adhesive layer, and a film in that order, with the receiving layer supported on the film. The support can be manufactured, for example, by passing the paper substrate and film between a pair of rollers and pouring a resin that forms an adhesive layer between the paper substrate and the film, thereby bonding the paper substrate and the film via the adhesive layer (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-193252 [Overview of the project] [Problems that the invention aims to solve]

[0005] As mentioned above, when bonding a paper substrate and a film, if they are pressed together with excessive force, the adhesive layer may excessively conform to the unevenness of the paper substrate's surface, which can significantly impair the smoothness of the film's surface.

[0006] Furthermore, when forming a thermal transfer image using a thermal transfer image receiving sheet with a receiving layer on a film whose smoothness has been compromised as described above, the receiving layer may deform or become easily deformed in accordance with the irregularities on the surface of the film, which can result in poor surface texture of the thermal transfer image. For this reason, conventionally, when high-quality images were required, coated paper or the like with a smooth surface was used as the paper substrate.

[0007] However, coated paper is generally more expensive than uncoated paper, which has lower smoothness, so using coated paper to form a support structure results in higher manufacturing costs. Therefore, if it becomes possible to form high-quality thermal transfer images using thermal transfer receiving sheets made from uncoated paper, the benefits in terms of manufacturing and image provision would be significant.

[0008] Furthermore, while poor surface bonding of a thermal transfer image is generally considered to result in poor quality, there may be cases where it is desirable to intentionally create an image with uneven bonding or to partially alter the bonding. Realizing a thermal transfer image receiving sheet that allows for such selective bonding adjustments would provide new value.

[0009] This disclosure has been made in consideration of the above circumstances, and its purpose is to provide a thermal transfer image receiving sheet that can form high-quality thermal transfer images while suppressing manufacturing costs, and can form thermal transfer images with diverse expressions by selectively changing the state of the image surface. [Means for solving the problem]

[0010] The support for a thermal transfer image receiving sheet according to the present disclosure is a support for a thermal transfer image receiving sheet in which a base material, a resin layer, and a film are laminated in this order, and at least one of the boundary between the base material and the resin layer and the vicinity of the boundary has one or more voids, and the height of the voids in the lamination direction of the base material, the resin layer, and the film is 0.5 μm or more and 15 μm or less.

[0011] The voids may be formed so as to be recessed in the direction from the resin layer toward the base material.

[0012] The voids may have a height of 0.5 μm or more and 15 μm or less in a first cross-section when the base material, the resin layer, and the film are cut in a plane including the lamination direction.

[0013] The voids may have a width of 1 μm or more and 1000 μm or less.

[0014] One or more voids may exist in a range of 1 mm in a first direction orthogonal to the lamination direction on the first plane.

[0015] Two or more voids may exist in a range of 1 mm in the first direction.

[0016] The support for a thermal transfer image receiving sheet according to the present disclosure has one or more second cross-section voids with a height in the lamination direction of 0.5 μm or more and 15 μm or less at least one of the boundary between the base material and the resin layer and the vicinity of the boundary in a second cross-section when the base material, the resin layer, and the film are cut in a plane including the lamination direction and orthogonal to the first cross-section.

[0017] The second cross-section voids may be formed so as to be recessed in the direction from the resin layer toward the base material.

[0018] The second cross-section voids may have a width of 1 μm or more and 1000 μm or less.

[0019] One or more of the second cross-sectional voids may be present in a range of 1 mm in the second direction orthogonal to the stacking direction on the second cross-section.

[0020] Two or more of the second cross-sectional voids may be present in a range of 1 mm in the second direction.

[0021] The base material is a paper base material, and the first cross-section may extend in a direction substantially parallel to the fiber direction of the paper base material.

[0022] The surface roughness SRa of the surface of the base material on the resin layer side is 1 μm or more and 3 μm or less, and the surface roughness SRa of the surface of the film on the side opposite to the resin layer side of the film may be 0.01 μm or more and 0.1 μm or less.

[0023] Further, the thermal transfer image receiving sheet according to the present disclosure includes the above-described support for a thermal transfer image receiving sheet and a receiving layer provided on the film of the support for a thermal transfer image receiving sheet.

[0024] The surface roughness SRa of the surface of the receiving layer on the side opposite to the support for a thermal transfer image receiving sheet side may be 2.2 μm or less.

[0025] Further, a method for manufacturing a thermal transfer image receiving sheet according to the present disclosure is a method for manufacturing a thermal transfer image receiving sheet in which a base material, a resin layer, and a receiving material having a film and a receiving layer integrated with each other are laminated in this order, a supply step of supplying a resin for forming the resin layer onto the base material or onto the film in the receiving material by melt extrusion, a bonding step of bonding the base material and the film in the receiving material with the resin layer formed of the resin by overlapping the base material and the receiving material with the resin interposed therebetween and passing them between a first roller and a second roller, and laminating the base material and the receiving material, at least one of the outer peripheral surfaces of the first roller and the second roller is elastically deformable, Either one of the first roller and the second roller is biased toward the other and can be pushed back in a direction away from the other, or the first roller and the second roller are biased toward each other and can be pushed back in a direction away from each other. In the bonding step, when the substrate, the resin layer, and the receiving material are passed between the first roller and the second roller, the outer surface of at least one of the elastically deformable first roller and the second roller is elastically deformed, and / or the first roller and the second roller move apart relative to each other, thereby adjusting the amount of penetration of the resin layer into the surface of the substrate and bonding the substrate and the film in the receiving material with the resin layer.

[0026] The bonding process may be performed either when there is no clearance between the first roller and the second roller, or when there is clearance between the first roller and the second roller.

[0027] Let d1 be the clearance between the first roller and the second roller before the substrate, the resin layer, and the receiving material are passed through it, and let hs be the total thickness of the substrate, the resin layer, and the receiving material before they are passed between the first roller and the second roller. The bonding process may be carried out under conditions where d1-hs is between -250 μm and -50 μm.

[0028] In the bonding process, when passing the substrate, the resin layer, and the receiving material between the first roller and the second roller, a pressure of 0.05 MPa to 0.4 MPa may be applied to the substrate, the resin layer, and the receiving material.

[0029] The first roller, of the two rollers, is set to be able to be pushed back away from the second roller while biased toward the second roller, and the method for manufacturing a thermal transfer image receiving sheet further comprises the steps of preparing a clearance adjustment mechanism that increases the proportion of biasing force applied as the first roller moves away from an initial position where it does not bear a biasing force toward the second roller, thereby pulling the first roller, which is biased toward the second roller, away from the second roller, and adjusting the movement position of the clearance adjustment mechanism. In the step of adjusting the movement position of the clearance mechanism, By adjusting the movement position of the clearance adjustment mechanism, when there is no clearance between the first roller and the second roller, the amount of elastic deformation of at least one of the elastically deformable outer surfaces of the first roller and the second roller can be adjusted. Or, The process may further include an adjustment step of providing a clearance between the first roller and the second roller and adjusting the size of the clearance.

[0030] Furthermore, the method for manufacturing a thermal transfer image receiving sheet according to this disclosure is: A method for manufacturing a thermal transfer image receiving sheet, comprising laminating a base material, a resin layer, and a receiving material having a film and a receiving layer in this order, A supply step of supplying the resin that forms the resin layer onto the substrate or onto the film in the receiving material by melt extrusion, The process includes a bonding step in which the base material and the receiving material are overlapped with the resin in between and passed between a first roller and a second roller, thereby bonding the base material and the receiving material via the resin layer formed by the resin, In the bonding step, a pressure of 0.05 MPa to 0.4 MPa is applied to the laminate containing the substrate, the resin layer, and the receiving material when passing the substrate, the resin layer, and the receiving material between the first roller and the second roller, in a method for manufacturing a thermal transfer image receiving sheet.

[0031] Furthermore, the method for manufacturing a support for a thermal transfer image receiving sheet according to this disclosure is: A method for manufacturing a support for a thermal transfer image receiving sheet, comprising laminating a substrate, a resin layer, and a film in this order, A supply step of supplying the resin that forms the resin layer onto the substrate or the film by melt extrusion, The process includes a bonding step in which the substrate and the film are overlapped with the resin in between and passed between a first roller and a second roller, thereby bonding the substrate and the film via the resin layer formed by the resin, The outer circumferential surface of at least one of the first roller and the second roller is elastically deformable, This is a method for manufacturing a support for a thermal transfer image receiving sheet, wherein one of the first roller and the second roller is biased toward the other and can be pushed back toward the other, or the first roller and the second roller are biased toward each other and can be pushed back toward each other, and in the bonding step, when the substrate, the resin layer and the film are passed between the first roller and the second roller, the outer surface of at least one of the elastically deformable first roller and the second roller is elastically deformed, and / or the first roller and the second roller move apart relative to each other, thereby bonding the substrate and the film while adjusting the amount of penetration of the resin layer into the surface of the substrate.

[0032] Furthermore, the method for manufacturing a support for a thermal transfer image receiving sheet according to this disclosure is: A method for manufacturing a support for a thermal transfer image receiving sheet, comprising laminating a substrate, a resin layer, and a film in this order, A supply step of supplying the resin that forms the resin layer onto the substrate or the film by melt extrusion, The process includes a bonding step in which the substrate and the film are overlapped with the resin in between and passed between a first roller and a second roller, thereby bonding the substrate and the film via the resin layer formed by the resin, In the bonding step, a pressure of 0.05 MPa to 0.4 MPa is applied to the laminate containing the substrate, the resin layer, and the film when passing the substrate, the resin layer, and the film between the first roller and the second roller, in a method for manufacturing a support for a thermal transfer image receiving sheet.

[0033] Furthermore, the sheet bonding apparatus according to this disclosure comprises a first roller and a second roller arranged so that their rotation axes are parallel to each other, a biasing mechanism that applies a biasing force to the first roller toward the second roller, and a clearance adjustment mechanism capable of bearing at least a portion of the biasing force. The clearance adjustment mechanism has a movable member, and as the movable member moves from an initial position where it does not bear the biasing force to a position where it increases the proportion of the biasing force it bears, the first roller may be pulled further away from the second roller.

[0034] The first roller may be pivotably supported by an arm and may come into contact with or separate from the second roller in accordance with the swinging motion of the arm.

[0035] The moving member has an inclined surface and, by moving from the initial position, directly or indirectly contacts the first roller with the inclined surface, and the moving member may operate in a direction away from the initial position to pull the first roller away from the second roller via the inclined surface.

[0036] The biasing mechanism may also be an air cylinder. [Effects of the Invention]

[0037] According to this disclosure, it is possible to provide a thermal transfer image receiving sheet that can form high-quality thermal transfer images while suppressing manufacturing costs, and can also form thermal transfer images with diverse expressions by selectively changing the state of the image surface. [Brief explanation of the drawing]

[0038] [Figure 1] This is a cross-sectional view showing the layered structure of a thermal transfer image receiving sheet according to one embodiment of the present disclosure, obtained by cutting it in a plane that includes the direction in which the layered components are stacked. [Figure 2] Figure 1 is a cross-sectional view showing the layered structure of a thermal transfer image receiving sheet support, which constitutes a part of the thermal transfer image receiving sheet, when cut in a plane that includes the direction in which the layered components are stacked. [Figure 3] Figure 2 is a schematic enlarged view showing the boundary between the substrate and the resin layer of the support for the thermal transfer image receiving sheet. [Figure 4] Figure 2 shows an SEM image of the boundary between the substrate and the resin layer of the support for the thermal transfer image receiving sheet. [Figure 5] This figure shows an SEM image of the boundary between the substrate and the resin layer of a thermal transfer image receiving sheet support, which is different from the thermal transfer image receiving sheet support shown in Figure 2. [Figure 6A] This figure shows a thermal transfer image receiving sheet and a thermal transfer sheet for transferring a sublimation dye onto the thermal transfer image receiving sheet. [Figure 6B] This figure shows the thermal transfer process using the thermal transfer image receiving sheet and thermal transfer sheet shown in Figure 6A. [Figure 6C] Figure 6B shows the thermal transfer image receiving sheet after thermal transfer. [Figure 7A] This figure shows a thermal transfer image receiving sheet different from the thermal transfer image receiving sheet shown in Figure 6A, and a thermal transfer sheet for transferring a sublimation dye to the said thermal transfer image receiving sheet. [Figure 7B] This figure shows the process of thermal transfer using the thermal transfer image receiving sheet and thermal transfer sheet shown in Figure 7A. [Figure 7C] Figure 7B shows the thermal transfer image receiving sheet after thermal transfer. [Figure 8A] This figure shows an example of how to use the thermal transfer imaging sheet shown in Figure 1. [Figure 8B] This figure shows an example of a thermal transfer image formed by the method of use shown in Figure 8A. [Figure 9] This figure shows a manufacturing system for producing the thermal transfer image receiving sheet shown in Figure 1. [Figure 10]This figure shows a magnified view of a sheet lamination device, which is part of the manufacturing system shown in Figure 9. [Figure 11] Figure 10 shows an example of clearance adjustment using the clearance adjustment mechanism of the sheet bonding device. [Figure 12] Figure 10 shows an example of clearance adjustment using the clearance adjustment mechanism of the sheet bonding device. [Figure 13] This figure shows a table relating to the manufacturing conditions for the examples and comparative examples. [Figure 14] This figure shows a table of evaluation results for the examples and comparative examples. [Modes for carrying out the invention]

[0039] An embodiment of this disclosure will be described below. Note that, for the sake of illustration and ease of understanding, the scale and aspect ratios of the drawings attached to this specification may be altered and exaggerated from those of the actual object. Furthermore, in the following description, embodiments may be described using vertical directions, etc., based on the orientation of the drawings. However, this disclosure is not limited to the directions described in the embodiments.

[0040] <<Thermal Transfer Image Receiving Sheet>> First, a thermal transfer image receiving sheet 1 according to one embodiment of the present disclosure will be described. Figure 1 is a cross-sectional view showing the layer structure of the thermal transfer image receiving sheet 1. The thermal transfer image receiving sheet 1 shown in Figure 1 comprises a support 10 for the thermal transfer image receiving sheet and a receiving layer 22. The receiving layer 22 is the outermost layer of the thermal transfer image receiving sheet 1. In this embodiment, the receiving layer 22 is provided on the support 10 for the thermal transfer image receiving sheet via a primer layer 21.

[0041] <Support for thermal transfer imaging sheets> Figure 2 is a cross-sectional view showing the layer structure of a thermal transfer image receiving sheet support 10, which constitutes a part of the thermal transfer image receiving sheet 1. The thermal transfer image receiving sheet support 10 is constructed by laminating a base material 11, a resin layer 12, and a film 20 in that order, with the resin layer 12 bonding the base material 11 and the film 20. In this embodiment, a receiving layer 22 is provided on the film 20 via a primer layer 21. A back surface layer 13 is provided on the surface of the base material 11 opposite to the surface facing the resin layer 12. Note that the thermal transfer image receiving sheet support 10 only needs to include at least a base material 11, a resin layer 12, and a film 20, and be capable of supporting the receiving layer 22; its layer structure is not particularly limited.

[0042] (base material) As the base material 11, high-quality paper, coated paper, resin-coated paper, art paper, cast-coated paper, cardboard, synthetic paper (polyolefin-based, polystyrene-based), synthetic resin or emulsion-impregnated paper, synthetic rubber latex-impregnated paper, synthetic resin-added paper, cellulose fiber paper, etc. are available. There are no particular limitations on the thickness of the base material 11, for example, it is 10 μm to 300 μm. Particularly preferred is a thickness of 100 μm to 200 μm.

[0043] As will be described in detail later, in this embodiment, a void 30 (see Figure 3, etc.) is formed at or near the boundary between the substrate 11 and the resin layer 12. This void 30 is formed, for example, by laminating the resin layer 12 and the substrate 11 so that the resin layer 12 does not fill the inner space of the concave parts on the surface of the substrate 11, or by laminating the resin layer 12 and the substrate 11 so that the voids formed inside the substrate 11 are not crushed. Even if the surface roughness of the substrate 11 is relatively large, for example, if the resin layer 12 and the substrate 11 are laminated so that the resin layer 12 does not fill the inner space of the concave parts on the surface of the substrate 11, the surface of the resin layer 12 opposite to the substrate 11 becomes smooth, and the film 20 and the receiving layer 22 can be made smooth while suppressing manufacturing costs. In other words, the film 20 and the receiving layer 22 on the substrate 11 and resin layer 12 can be made smooth without using an expensive substrate with a smooth surface, and as a result, manufacturing costs for obtaining high-quality images can be suppressed. As will be explained in more detail later, if, for example, a void 30 is intentionally formed at the boundary between the substrate 11 and the resin layer 12, it becomes possible to form thermal transfer images with a variety of expressions.

[0044] The substrate 11 in this embodiment is selected from the viewpoint of being able to suppress manufacturing costs and from the viewpoint of being able to actively form voids 30 by utilizing the roughness of the substrate 11. Specifically, for example, the surface roughness SRa of the substrate 11 is preferably 1 μm or more and 5 μm or less, and more preferably 1 μm or more and 3 μm or less. This makes it possible to achieve both the formation of thermal transfer images with diverse expressions and improved image quality. In this disclosure, surface roughness SRa refers to the average roughness of the center surface, calculated by performing a three-dimensional cross-sectional measurement using a Surfcom 1400G manufactured by Tokyo Seimitsu Co., Ltd., in accordance with JIS B 0601:1982, under the following measurement conditions, and then applying "slope correction: curve correction" to the obtained cross-sectional curve data. Furthermore, the MD direction of the substrate is an abbreviation for Machine Direction and refers to the flow direction of the roll paper when manufacturing the support for the thermal transfer image receiving sheet, and the TD direction is an abbreviation for Transverse Direction and refers to the direction perpendicular to the MD direction. Furthermore, when viewing a print in isolation, or when the MD and TD directions of the substrate cannot be clearly determined, the direction in which the fibers (pulp) of the substrate are primarily oriented shall be considered the MD direction. This direction may differ from the MD and TD directions of the actual papermaking process, but it shall conform to the standard method of evaluating surface roughness, that is, evaluating to maximize roughness regardless of whether it is a random or non-random pattern. <Measurement conditions> • Measurement range: TD direction 40mm x MD direction 20mm • Measurement direction: Measure while sweeping the needle in the TD direction (the second direction D2 described later). • Measurement pitch (X): 19.541 μm • Measurement pitch (Y): 290.000 μm • Number of measurement points (X): 2018 points • Number of measurement lines (Y): 70 lines • λs filter: None • Tilt correction: None ·Measurement speed: 1.500mm / s • Movement return speed: 3,000 mm / s • Y-axis return position: Measurement start position • Pickup type: Standard pickup • Polarity reversal: forward rotation

[0045] Furthermore, the surface smoothness of the substrate 11 is preferably 10 seconds or more and 5000 seconds or less. More preferably, it is 20 seconds or more and 500 seconds or less. In this disclosure, the smoothness is measured in accordance with JIS P 8155:2010. As such a base material 11, commercially available base materials can be used. For example, as high-quality paper, suitable options include Kinbishi N, Kinbishi A, Dia Foam, Broad High-Quality H, Cream Elega, Cream Elega Bulky, Dia Bulky, Mitsubishi Bulky Book Paper 55A, Mitsubishi Bulky Book Paper 65A from Mitsubishi Paper Mills Ltd., NPI High-Quality, NPI High-Quality Bulky, NPI Foam, Shiraoi from Nippon Paper Industries Ltd., Utrillo High-Quality from Daio Paper Corporation, OK Prince High-Quality Paper, OK High-Quality Paper from Oji Paper Co., Ltd., Star Pack, Linden Comic, SS Comic Paper from Marusumi Paper Co., Ltd., and Raicho High-Quality from Chuetsu Pulp Co., Ltd. In addition, various grades of coated paper such as A1, A2, and A3 are available, with A2 and A3 coated paper being less expensive than A1. Suitable coated papers include Pearl Coat, Real White Gloss, and Casadia Gloss from Mitsubishi Paper Mills Ltd., Aurora Coat, Ultima Gloss, Silver Diamond S, Pegasus Bulky 8, and Aurora S from Nippon Paper Industries Ltd., and Utrillo Coat from Daio Paper Corporation and Oji Paper Co., Ltd.

[0046] (film) The film 20 may be a stretched or unstretched film of a highly heat-resistant polyester such as polyethylene terephthalate or polyethylene naphthalate, or a plastic such as polyolefin, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyamide, or polymethylpentene, or a white opaque film formed by adding a white pigment or filler to these synthetic resins, or a film having microvoids inside.

[0047] Among these, so-called void films, which have microvoids, are advantageous for forming clear images. Void films can be made by the following two methods to create voids (micro-pores). One method involves kneading inorganic fine particles into a polymer and creating microvoids with the inorganic fine particles as nuclei when the compound is stretched. The other method involves creating a compound by blending a polymer (one or more types) that is incompatible with the main resin. Microscopically, the polymers in this compound form a fine sea-island structure. When this compound is stretched, microvoids are generated by delamination of the sea-island interface or by large deformation of the polymers forming the islands. The thickness of the void film used as film 20 is usually 10 μm to 100 μm, preferably 20 μm to 50 μm.

[0048] The surface roughness SRa of the film 20 on the side opposite to the resin layer 12 (the side facing the receiving layer 22) is preferably 0.01 μm to 0.8 μm, and more preferably 0.01 μm to 0.5 μm. This makes it possible to improve productivity, reduce manufacturing costs, and maintain the smoothness of the receiving layer. The thermal transfer image receiving sheet 1 is formed by laminating the substrate 11, resin layer 12, film 20, primer layer 21, and receiving layer 22 in this order. When the surface roughness SRa of the film 20 is within the above range, the surface of the receiving layer 22 is also finished smoothly.

[0049] (Resin layer) The resin layer 12 for bonding the substrate 11 and the film 20 is formed by melt-extruded resin; that is, the resin layer 12 is formed when the melt-extruded resin solidifies as it cools. The resin used to form the resin layer 12 is preferably a thermoplastic resin. Specifically, as thermoplastic resins, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-α-olefin copolymer, ethylene-polypropylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-maleic acid copolymer, ionomer resin, graft polymerization of unsaturated carboxylic acids, unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, or ester monomers onto polyolefins, or copolymers, or resins obtained by graft-modifying polyolefins with maleic anhydride, etc., can be used. The resin used to form the resin layer 12 may be one of the above materials or a combination of two or more. Among these, polyolefins are preferred. In particular, LDPE (low-density polyethylene) with a density of 0.93 g / cm³ as measured according to JIS K 6760:1995 is preferred. 3 Preferably, it is 0.90 g / cm³. 3 More than 0.93g / cm 3 It is more preferable that the following is the case: 0.915 g / cm³ 3 More than 0.925g / cm 3 The following is particularly preferable: When LDPE within the above density range is used as the resin for forming the resin layer 12, it has adhesive properties and can be used alone. In addition, because of its low elastic modulus, the print quality is good and it is easier to achieve curl balance.

[0050] The melting point of the resin used to form the resin layer 12 is preferably 100°C or higher, and more preferably 120°C or higher. Furthermore, when using LDPE, the melting point is preferably between 105°C and 110°C. The melting point in this disclosure is the value measured according to JIS K 7121:2012.

[0051] The thickness of the resin layer 12 is not particularly limited, but is preferably 10 μm or more and 20 μm or less in the dry state. Thereby, both the printing quality and the curl balance of the image receiving paper can be achieved.

[0052] (Back surface layer) The back surface layer 13 can be appropriately selected and used according to the application of the thermal transfer image receiving sheet 1 or the like. Among these, it is preferable that the back surface layer 13 has a function of improving the conveyance property of the thermal transfer image receiving sheet 1 or a curl prevention function. The back surface layer 13 can be formed mainly of a resin material such as polyolefin, vinyl resin, (meth)acrylic resin, cellulose resin, polyester, polyamide, polycarbonate, styrene resin, and polyurethane.

[0053] The back surface layer 13 may be formed of a melt-extruded resin, that is, the back surface layer 13 may be formed by the solidification of the melt-extruded resin as it cools.

[0054] The resin used for forming the back surface layer 13 is preferably a polyolefin having a melting point of 100° C. or higher, and more preferably a polyolefin having a melting point of 120° C. or higher. In particular, the polyolefin is HDPE (high density polyethylene), and the density is preferably 0.93 g / cm 3 or higher, and more preferably 0.93 g / cm 3 or higher and 0.96 g / cm 3 or lower, and particularly preferably 0.94 g / cm 3 or higher and 0.95 g / cm 3 or lower. When HDPE within the above density range is used as the resin for forming the back surface layer 13, a function of improving the conveyance property and a curl prevention function can be ensured.

[0055] The thickness of the back surface layer 13 is not particularly limited, but is preferably 15 μm or more and 40 μm or less in the dry state, and more preferably 20 μm or more and 30 μm or less. Thereby, a tension balance similar to that of the laminated portion of the LDPE / void film on the front surface side can be achieved, and the curl of the support for the thermal transfer image receiving sheet or the thermal transfer image receiving sheet can be reduced.

[0056] <receptor layer> The receiving layer 22 receives the dye migrated from the heat transfer sheet and maintains the formed image. The surface roughness SRa of the receiving layer 22 is preferably 2.2 μm or less. Examples of resins for forming the receiving layer 22 include polycarbonate, polyester, polyamide, acrylic resin, cellulose resin, polysulfone, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal, polyurethane, polystyrene, polypropylene, polyethylene, polyester, ethylene-vinyl acetate copolymer, and epoxy resin.

[0057] The receiving layer 22 may contain a release agent to improve release properties from the heat transfer sheet. Examples of mold release agents include polyethylene wax, amide wax, solid waxes such as Teflon® powder, fluorine-based or phosphate ester-based surfactants, silicone oils, and silicone resins. Examples of silicone oils include various modified silicone oils such as reactive silicone oils and solidifying silicone oils. Modified silicone oils are particularly preferred. Preferred modified silicone oils include amino-modified silicone, epoxy-modified silicone, aralkyl-modified silicone, epoxy-aralkyl-modified silicone, alcohol-modified silicone, vinyl-modified silicone, and urethane-modified silicone, but epoxy-modified silicone, aralkyl-modified silicone, and epoxy-aralkyl-modified silicone are particularly preferred. It is also preferable to use two or more of these mold release agents in combination. The amount of these modified silicone oils added is preferably 0.5 parts by mass to 30 parts by mass per 100 parts by mass of the resin constituting the receiving layer.

[0058] Furthermore, pigments and fillers such as titanium dioxide, zinc oxide, kaolin, clay, calcium carbonate, and fine silica powder may be added to the receiving layer 22 for the purpose of improving whiteness and further enhancing image clarity. Plasticizers such as phthalate compounds, sebacate compounds, and phosphate compounds may also be added. The receiving layer 22 may also further contain crosslinking agents, solidifying agents, catalysts, ultraviolet absorbers, antioxidants, light stabilizers, etc.

[0059] The receiving layer 22 can be formed by applying and drying a coating solution in which a thermoplastic resin and other necessary additives, such as a mold release agent, are dissolved or dispersed in an organic solvent or water. Examples of coating methods include gravure printing, screen printing, and reverse roll coating using a gravure plate. The thickness of the receiving layer 22 formed in this way is preferably 0.5 μm to 50 μm in a dry state, and more preferably 2 μm to 10 μm.

[0060] <Primer layer> The primer layer 21 is provided to improve the adhesion between the film 20 and the receiving layer 22. Examples of resins that make up the primer layer 21 include polyurethane, polyester, polycarbonate, polyamide, acrylic resin, polystyrene, polysulfone, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal, polyvinyl alcohol, epoxy resin, cellulose resin, ethylene-vinyl acetate copolymer, polyethylene, and polypropylene.

[0061] White materials such as titanium dioxide, zinc oxide, magnesium carbonate, and calcium carbonate may be added to the primer layer 21 to provide whiteness and opacity. Furthermore, stilbene compounds, benzimidazole compounds, and benzoxazole compounds may be added as fluorescent whitening agents to enhance whiteness, hindered amine compounds, hindered phenol compounds, benzotriazole compounds, and benzophenone compounds may be added as UV absorbers or antioxidants to improve the lightfastness of the image, or cationic acrylic resins, polyaniline, and various conductive fillers may be added to provide antistatic properties. The thickness of the primer layer 21 is preferably 0.1 μm to 10 μm.

[0062] Alternatively, the receiving layer 22 and the primer layer 21 may be provided on the film 20 of the thermal transfer image receiving sheet support 10 in the order of primer layer 21 and receiving layer 22 after the support 10 for the thermal transfer image receiving sheet is manufactured by laminating the base material 11, the resin layer 12, and the film 20. Or, a receiving material may be manufactured by bonding the film 20 and the receiving layer 22 with the primer layer 21, and then this receiving material may be bonded to the base material 11 with the resin layer 12.

[0063] <Boundary between substrate and resin layer in support for thermal transfer image receiving sheet> Figure 3 is a schematic enlarged view showing the boundary between the substrate 11 and the resin layer 12. As mentioned above, in this embodiment, one or more voids 30 are formed at the boundary between the substrate 11 and the resin layer 12. In Figure 3, four voids 30 formed in part of the boundary between the substrate 11 and the resin layer 12 are shown. The following describes the configuration of the boundary between the substrate 11 and the resin layer 12 in the thermal transfer image receiving sheet support 10.

[0064] The void 30 is formed at or near the boundary between the resin layer 12 and the substrate 11. The void 30 shown in Figure 3 is formed at the boundary and is recessed in the direction from the resin layer 12 toward the substrate 11. More specifically, the void 30 is formed by a recessed portion on the surface of the substrate 11 facing the resin layer 12. The height H of the void 30 in the lamination direction of the substrate 11, resin layer 12, and film 20 (the thickness direction of the thermal transfer image receiving sheet support 10) is 0.5 μm or more and 15 μm or less. Figure 3 also shows a first cross-section when the substrate 11, resin layer 12, and film 20 are cut by a plane (first direction cross-section) that includes the lamination direction and extends in the first direction D1 in the figure, which is parallel to the plane perpendicular to the lamination direction. The width of the void 30 in the first direction D1, indicated by the symbol W in Figure 3, is 1 μm or more and 1000 μm or less. In other words, the void 30 has a height H of 0.5 μm to 15 μm and a width W of 1 μm to 1000 in the first cross-section when the substrate 11, resin layer 12, and film 20 are cut in a first direction D1 parallel to the plane perpendicular to the lamination direction. The term "boundary" refers to the boundary between the two opposing resin layers 12 and the base material 11, as described above. The term "near the boundary" refers to the area within the boundary from the point where the resin layer 12 and the base material 11 are in contact, extending towards the base material 11 to 10% of the thickness of the base material 11, and the area within the boundary from the point where the resin layer 12 and the base material 11 are in contact, extending towards the resin layer 12 to 10% of the thickness of the resin layer 12.

[0065] The first direction D1 is the so-called MD (Machine Direction), and if the thermal transfer image receiving sheet 1 is wound in a roll, it is its longitudinal direction, or in other words, the winding direction. Also, if the substrate 11 is a paper substrate and a fiber direction exists, the fiber direction usually coincides with the MD, so the first direction D1 is usually parallel to or approximately parallel to the fiber direction. The fiber direction of a paper substrate can be confirmed, for example, by microscopic observation of the surface. On the other hand, even if the substrate 11 is a paper substrate and a fiber direction exists, a void 30 having a height H of 0.5 μm or more and a width W of 1 μm or more and 1000 may exist at the boundary of the cross-section in a direction different from the fiber direction.

[0066] Preferably, there is one or more of the aforementioned voids 30 within a 1 mm range in the first direction D1, and more preferably, there are two or more. However, it is preferable that the number of voids 30 within a 1 mm range in the first direction D1 be 50 or less. This suppresses a decrease in adhesion between the resin layer 12 and the substrate 11 while fully achieving the effects of the present disclosure.

[0067] Furthermore, the thermal transfer image receiving sheet 1 also has one or more voids (hereinafter referred to as "second cross-sectional voids") at the boundary between the substrate 11 and the resin layer 12 on the second cross-section when the substrate 11, resin layer 12 and film 20 are cut on a plane (second-direction cross-section) that includes the lamination direction extending in the second direction D2 perpendicular to the first direction D1. Although not shown, these second cross-sectional voids have a height of 0.5 μm to 15 μm and a width of 1 μm to 1000 μm in the lamination direction. The second cross-sectional voids are formed to be recessed in the direction from the resin layer 12 toward the substrate 11, similar to the voids 30 described above. Preferably, there is one or more second cross-sectional voids in a 1 mm range in the second direction D2, and more preferably, there are two or more. However, as described above, it is preferable that the number of second cross-sectional voids in a 1 mm range in the second direction D2 be 50 or less. This allows the effects of the present disclosure to be fully realized while suppressing a decrease in adhesion between the resin layer 12 and the substrate 11.

[0068] Figure 4 shows an SEM image of the boundary between the substrate 11 and the resin layer 12, showing two voids 30. As described above, the voids 30 are formed by laminating the resin layer 12 and the substrate 11, for example, by not filling the inner space of the concave parts on the surface of the substrate 11 with the resin layer 12, as shown in Figure 4. The same applies to the second cross-sectional void. The thermal transfer image receiving sheet 1 is formed by laminating the substrate 11, resin layer 12, film 20, primer layer 21 and receiving layer 22 in this order. When the above layers are laminated such that voids 30 are formed at or near the boundary between the substrate 11 and the resin layer 12, it becomes less likely for irregularities to occur on the film 20 side of the resin layer 12 and on the receiving layer 22 side of the film 20, and these surfaces become smooth. As a result, the surface of the receiving layer 22 can also be formed smoothly. In this case, the surface roughness SRa of the surface of the receiving layer 22 is preferably 2.2 μm or less. This ensures good quality of thermal transfer images.

[0069] Furthermore, when a void 30 is formed at the boundary between the substrate 11 and the resin layer 12, by adjusting the heat pressure during heat transfer, in other words, by adjusting the amount of heat and / or the magnitude of the printing pressure during heat transfer, it is possible to perform heat transfer to the receiving layer 22 in a way that the void 30 is maintained in some areas, while performing heat transfer in a way that causes the receiving layer 22 to partially indent towards the void 30 in other areas. This makes it possible to partially change the texture of the heat-transferred image and to form a heat-transferred image with ingenious decorations.

[0070] On the other hand, Figure 5 shows an SEM image of the boundary between the substrate 111 and the resin layer 112 of the thermal transfer image receiving sheet support 110, which is used for a different comparison than the thermal transfer image receiving sheet support 10. The thermal transfer image receiving sheet support 110 shown in Figure 5 is formed by laminating a base material 111, a resin layer 112, and a film 120 in that order, and is formed by lamination that generates stronger pressure compared to the thermal transfer image receiving sheet support 10 of the present invention. As a result, as shown in Figure 5, the resin layer 112 penetrates into the concave parts of the surface of the base material 111. In this state, irregularities occur or become more likely to occur on the surface of the resin layer 112 facing the film 120 and on the surface of the film 120 facing the receiving layer, and their smoothness may be impaired. As a result, during thermal transfer image formation, the surface of the receiving layer may deform or become more prone to deformation in accordance with the irregularities on the surface of the film 120, which may reduce image quality. Furthermore, even if the thermal pressure during thermal transfer is adjusted, it is difficult to intentionally create areas with altered texture in the thermal transfer image. Therefore, the thermal transfer image receiving sheet 1 according to this embodiment is significant in that it can improve the quality of the thermal transfer image and obtain images with diverse expressions compared to thermal transfer image receiving sheets manufactured in a way that prevents the formation of voids.

[0071] The presence or absence of a void 30 at or near the boundary between the substrate 11 and the resin layer 12 can be confirmed, for example, by cutting the thermal transfer image receiving sheet 1 or the thermal transfer image receiving sheet support 10 along a plane including the lamination direction, exposing the cross-section, and obtaining and observing a 1000x magnified SEM image of the cross-section. Specifically, this can be confirmed by cutting the thermal transfer image receiving sheet 1 or the thermal transfer image receiving sheet support 10 along a plane including the first direction D1 and the lamination direction, exposing the cross-section, and obtaining and observing a 1000x magnified SEM image of the cross-section. Furthermore, the presence or absence of a second cross-sectional void at or near the boundary between the substrate 11 and the resin layer 12 can be confirmed, for example, by cutting the thermal transfer image receiving sheet 1 or the thermal transfer image receiving sheet support 10 along a plane including the second direction D2 and the lamination direction, exposing the cross-section, and obtaining and observing a 1000x magnified SEM image of the cross-section. When performing the cutting described above, it is preferable to cut the thermal transfer image receiving sheet 1 or the support for the thermal transfer image receiving sheet 10 from the side of the back layer 13 using a blade or ion beam, in which case the collapse of the void 30 caused by the cutting can be suppressed. In addition, the void can be confirmed using a non-destructive method. In this case, it is preferable to observe the internal structure three-dimensionally using X-ray CT imaging to confirm the existence and dimensions of the void. In some cases, the void 30 exposed from the side can also be confirmed by observing the side of the thermal transfer image receiving sheet 1 or the support for the thermal transfer image receiving sheet 10.

[0072] <Image formation by thermal transfer using a thermal transfer image receiving sheet> The following describes the formation of a thermal transfer image using a thermal transfer image receiving sheet 1 according to this embodiment, in which a void 30 is provided at or near the boundary between an inexpensive, rough-surfaced substrate 11 and a resin layer 12, and the formation of a thermal transfer image using a thermal transfer image receiving sheet 100 having a thermal transfer image receiving sheet support 110 in which no void 30 exists at the boundary between the substrate 111 and the resin layer 112, as shown in Figure 5.

[0073] Figure 6A shows a thermal transfer image receiving sheet 1 according to this embodiment and a thermal transfer sheet 200 for transferring a sublimation dye to the thermal transfer image receiving sheet 1. The thermal transfer sheet 200 may be a known type and comprises a sheet-shaped support substrate 201, a thermal transfer color material layer 202 provided sequentially on one surface of the support substrate 201, and an overcoat layer (protective layer). The thermal transfer color material layer 202 is a layer containing a sublimation dye and, for example, includes multiple dye-containing portions of different colors.

[0074] When forming a thermal transfer image by thermal transfer, as shown in Figure 6B, the receiving layer 22 of the thermal transfer image receiving sheet 1 and the thermal transfer colorant layer 202 of the thermal transfer sheet 200 are superimposed so that they are in contact. While applying printing pressure with the thermal head 220 so that the thermal transfer colorant layer 202 is pressed against the receiving layer 22, a voltage is applied to the thermal transfer colorant layer 202 at the position where the sublimation dye is to be transferred to perform heating.

[0075] In the thermal transfer image formed by the thermal transfer method described above, the dye 202i is held in the receiving layer 22, as shown in Figure 6C. In this embodiment, the surface of the receiving layer 22 of the thermal transfer image receiving sheet 1 is smooth, resulting in a good formation of the thermal transfer image and enabling the acquisition of good image quality.

[0076] On the other hand, Figure 7A shows a thermal transfer image receiving sheet 100 different from the one shown in Figure 6A, in which there is no void 30 at the boundary between the inexpensive, rough-surfaced paper substrate 111 and the resin layer 112, and the thermal transfer image receiving sheet 200 shown in Figure 6A. The thermal transfer image receiving sheet 100 is made by laminating the substrate 111, resin layer 112, film 120, primer layer 121, and receiving layer 122 in this order. In the thermal transfer image receiving sheet 100, as shown in Figure 5, the surface of the resin layer 112 on the film 120 side is rough due to the resin layer 112 being embedded in the inner space of the concave part of the surface of the substrate 111. As a result, there is a void 130 at the boundary between the film 120 and the primer layer 121, the surface of the film 120 on the receiving layer 122 side is rough, and the surface of the receiving layer 122 is rough.

[0077] In this case, as shown in Figure 7B, when printing pressure is applied by the thermal head 220 so that the heat-transferable colorant layer 202 is pressed against the receiving layer 122, and a voltage is applied to the heat-transferable colorant layer 202 to heat it at the position where the sublimation dye is transferred, the receiving layer 122 may deform or become easily deformed in accordance with the unevenness of the film surface, which may result in poor formation of the heat-transfer image. Specifically, as shown in Figure 7C, the surface of the receiving layer 122 after heat transfer may become rough, and the quality of the heat-transfer image may be significantly reduced. Therefore, according to the thermal transfer image receiving sheet 1 of this embodiment, high-quality thermal transfer images can be formed while suppressing manufacturing costs. In other words, even when using a substrate with a relatively rough surface, it is possible to obtain high-quality thermal transfer images, thus enabling the formation of high-quality thermal transfer images while suppressing manufacturing costs.

[0078] <Examples of thermal transfer imaging sheet usage> On the other hand, as described above, the thermal transfer image receiving sheet 1 according to this embodiment allows for partial changes in the texture of the thermal transfer image by adjusting the thermal pressure during thermal transfer. This is achieved by performing thermal transfer to the receiving layer 22 in a way that maintains the voids 30 in some areas, while performing thermal transfer in other areas that causes the receiving layer 22 to partially indent towards the voids 30. Figures 8A and 8B show how to use such a thermal transfer image receiving sheet 1. Of course, if a print is formed by applying relatively low thermal pressure to the entire surface of the image receiving paper, a print with good texture across the entire surface can be produced. Conversely, if a print is formed by applying relatively high thermal pressure to the entire surface of the image receiving paper, the print will reflect the rough texture of the original paper.

[0079] In other words, in the area indicated by the symbol A1 in Figure 8A, thermal transfer is performed so that the receiving layer 22 is partially concave toward the void 30, and in the area indicated by the symbol A2, thermal transfer is performed on the receiving layer 22 so that the void 30 is maintained. In this case, as shown in the thermal transfer image in Figure 8B, it is possible to create a decoration such that the surface of the area AC enclosed by the two circles on the image surface becomes silky, while the surface of the other parts remains smooth.

[0080] As described above, the thermal transfer image receiving sheet 1 according to this embodiment comprises a support 10 for the thermal transfer image receiving sheet, in which a base material 11, a resin layer 12, and a film 20 are laminated in this order, and the resin layer 12 adheres the base material 11 and the film 20. The support 10 for the thermal transfer image receiving sheet has one or more voids 30 at or near the boundary between the base material 11 and the resin layer 12, and the height of the voids 30 is 0.5 μm or more and 15 μm or less.

[0081] In the thermal transfer image receiving sheet support 10 or thermal transfer image receiving sheet 1 in which the gap 30 is formed in this manner, when formed by lamination, irregularities are less likely to occur on the surface of the resin layer 12 facing the film 20 and on the surface of the film 20 facing the receiving layer 22, and these surfaces become smooth. As a result, the surface of the receiving layer 22 can also be made smooth, so that a high-quality thermal transfer image with a smooth surface can be formed. Since the above-mentioned void 30 is caused by the unevenness of the base material 11, if a smooth base material is used as the base material 11, unevenness will be less likely to occur on the film 20 side of the resin layer 12 and on the receiving layer 22 side of the film 20, and the surface of the receiving layer 22 may also become smooth. However, in this case, the cost of the base material will be higher, which will increase the manufacturing cost. In contrast, in this embodiment, even if an inexpensive, relatively rough base material is used as the base material 11, the surface of the receiving layer 22 can be made smooth, which is advantageous in terms of cost.

[0082] Furthermore, in the thermal transfer image receiving sheet 1 according to this embodiment, by adjusting the thermal pressure during thermal transfer, it is possible to partially change the texture of the thermal transfer image by performing thermal transfer to the receiving layer 22 so that the voids 30 are maintained in some areas, while performing thermal transfer so that the receiving layer 22 partially indents toward the voids 30 in other areas. Of course, if the print is formed by applying relatively low thermal pressure to the entire surface of the image receiving paper, a print with good texture across the entire surface can be produced. Conversely, if the print is formed by applying relatively high thermal pressure to the entire surface of the image receiving paper, the print will reflect the rough texture of the original paper.

[0083] Therefore, according to the thermal transfer image receiving sheet support 10 or thermal transfer image receiving sheet 1 of this embodiment, it is possible to form high-quality thermal transfer images while suppressing manufacturing costs, and to form thermal transfer images with diverse expressions by selectively changing the state of the image surface.

[0084] <<Manufacturing system for thermal transfer image receiving sheets>> Next, an example of a manufacturing system 50 capable of producing a thermal transfer image receiving sheet 1 will be described using Figures 9 to 12. The manufacturing system 50 shown in Figure 9 comprises a resin laminating device 60 and a sheet laminating device 70. The resin laminating device 60 is a device for integrating the substrate 11 and the back layer 13, and the sheet laminating device 70 is a device for integrating the film 20 to the side of the substrate 11 opposite to the side of the back layer 13, or for integrating a receiving material 24 which is formed by laminating the film 20, primer layer 21 and receiving layer 22. The parts of the manufacturing system 50 will be described in detail below.

[0085] <Resin lamination equipment> The resin lamination apparatus 60 includes a first press roller 61 and a first chill roller 62, which are arranged so that their rotation axes are parallel to each other, and a first die 63 for melt-extruding the resin that forms the back layer 13. In Figure 9, as the base material 11 and the back layer forming resin 13R, which will be described later, pass between the outer circumferential surfaces of the first press roller 61 and the first chill roller 62, the outer circumferential surfaces of the first press roller 61 and the first chill roller 62 separate from each other, forming a "gap". On the other hand, the resin lamination apparatus 60 can be set to either have a clearance between the outer circumferential surfaces of the first press roller 61 and the first chill roller 62, or to have no clearance. It should be noted that the "clearance" provided between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62 has a different meaning from the "gap" mentioned above. "Clearance" refers to the space between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62 in the direction connecting the center of the first press roller 61 and the center of the first chill roller 62, when the base material 11 and the back layer forming resin 13R, which will be described later, are not passing through. If there is no clearance, it means that the outer surface of the first press roller 61 and the outer surface of the first chill roller 62 are in contact. On the other hand, "gap" refers to the gap that is created between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62 as the base material 11 and the back layer forming resin 13R, which will be described later, pass through. In the bonding process using the resin bonding apparatus 60 in this embodiment, whether a clearance is provided or not, when the base material 11 and the back layer forming resin 13R (described later) pass between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62, the outer surfaces of the first press roller 61 and the outer surface of the first chill roller 62 separate from each other, as shown in Figure 9, creating a "gap". Specifically, even though the first press roller 61 and the first chill roller 62 are set to be in contact, a "gap" can be created when the base material 11 and the back layer forming resin 13R are fed between them. Of course, a "clearance" may be provided between the first press roller 61 and the first chill roller 62. However, if a clearance is provided between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62, the size of the clearance is set to be smaller than the total thickness of the base material 11 and the back layer forming resin 13R. In Figure 9, a "gap" equivalent to the thickness of the base material 11 and the molten resin exists between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62.

[0086] The first press roller 61 is a rubber roller, and the first chill roller 62 is a metal roller, with the outer surface of the first press roller 61 being more elastically deformable than the outer surface of the first chill roller 62. The types of the first press roller 61 and the first chill roller 62 are not particularly limited; for example, both the first press roller 61 and the first chill roller 62 may be made of rubber rollers. In the illustrated example, the first press roller 61 is configured to convey the base material 11 by its rotation, but the first chill roller 62 may also be configured to convey the base material 11.

[0087] The first die 63 is the discharge port portion of the molten resin in the molten resin extruder, and is also called the die head. The first die 63 is positioned above the first press roller 61 and the first chill roller 62, and is configured to supply resin (hereinafter referred to as back-layer forming resin 13R) to the side of the substrate 11 opposite to the side facing the first press roller 61 before the substrate 11 is fed between the outer circumferential surfaces of the first press roller 61 and the first chill roller 62. The horizontal position of the first die 63 is adjustable, and in the illustrated example, the first die 63 is positioned on the first press roller 61 side, supplying the back-layer forming resin 13R to the substrate 11 on the first press roller 61 before it is fed between the outer circumferential surfaces of the first press roller 61 and the first chill roller 62. The first die 63 can also be positioned on the first chill roller 62 side to supply the back-layer forming resin 13R to the first chill roller 62 or to the substrate 11 on the first chill roller 62.

[0088] The first die 63 melts and extrudes a constant amount of the back layer forming resin 13R in a curtain-like manner, thereby forming a back layer 13 of a constant thickness on the substrate 11 being transported at a constant speed. The substrate 11 with the back layer 13 is then fed between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62 and sandwiched, thereby bonding the substrate 11 to the back layer 13 in a stable, integrated state. The back layer 13 is formed when the back layer forming resin 13R solidifies, and since the first chill roller 62 is made of metal, it promotes the cooling of the back layer forming resin 13R, thus accelerating the solidification of the back layer 13. The material of the first chill roller 62 is not particularly limited, but metal is preferred from the viewpoint of resin cooling.

[0089] When the first press roller 61 is made of rubber, the rubber hardness of its outer surface is preferably 40 to 95, and particularly preferably 50 to 85. If the rubber hardness is less than 40, the adhesion between the base material 11 and the back layer 13 tends to become unstable, and if the rubber hardness is greater than 95, the change in the amount of rubber deformation becomes smaller, the amount of roller relief tends to increase, and the roller fluctuations become larger, so the above numerical range is preferable. In this disclosure, rubber hardness refers to the rubber hardness measured using a durometer (Type A) in accordance with JIS K 6253:1997.

[0090] Furthermore, the first chill roller 62 preferably has a surface roughness Rmax of 5 μm or more and 35 μm or less, more preferably 8 μm or more and 30 μm or less, and particularly preferably 10 μm or more and 20 μm or less. This helps to suppress manufacturing defects in the back layer. It also reduces the surface roughness of the back layer 13, which helps to suppress uneven adhesion during bonding by the sheet bonding device 70. Furthermore, it improves handling properties. The first chill roller 62 preferably has a surface roughness Ra of 1 μm to 8 μm, and particularly preferably 2 μm to 5 μm. In this disclosure, the surface roughness Rmax of the first chill roller 62 refers to the "maximum height" calculated by performing a "cutoff" process on the obtained cross-sectional curve data, after performing a two-dimensional cross-sectional measurement using a SurfCorder SE-40 manufactured by Kosaka Research Institute Co., Ltd., in accordance with JIS B 0601:1982, under the following measurement conditions. Similarly, the surface roughness Ra of the first chill roller 62 refers to the "centerline average roughness" calculated in the same manner. These also apply to the second chill roller 72 described later. <Measurement conditions> Measurement conditions: Length: 2.5mm Ride Speed: 0.5 m / s Cutoff: R+W (where R represents "roughness" and W represents "undulation")

[0091] Furthermore, the first press roller 61 preferably has a surface roughness Ra of 0.6 μm or more and 5 μm or less, and more preferably 0.9 μm or more and 3 μm or less. In this disclosure, the surface roughness Ra of the first press roller 61 refers to the "arithmetic mean roughness" measured using a VK-150 laser microscope manufactured by Keyence Corporation, in accordance with JIS B 0601:2001. Specifically, a 10 mm x 10 mm measurement sample is cut from the first press roller, and the Ra is calculated by observing a 2 mm x 2 mm measurement target. The same procedure is followed for the second press roller 71, which will be described later. The base material 11 and resin layer 12 that have passed between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62 are sent to the sheet laminating device 70. In this embodiment, an inversion device 90 is provided between the resin laminating device 60 and the sheet laminating device 70. The inversion device 90 reverses the orientation of the base material 11 and the resin layer 12.

[0092] <Sheet laminating machine> Next, the sheet laminating apparatus 70 will be described. The sheet laminating apparatus 70 performs sheet lamination after the resin lamination process has been performed by the resin laminating apparatus 60. The sheet laminating apparatus 70 includes a second press roller 71 and a second chill roller 72 arranged so that their rotation axes are parallel to each other, a second die 73 for melting and extruding the resin that will form the resin layer 12, a biasing mechanism 74 for biasing the second press roller 71 toward the second chill roller 72, and a clearance adjustment mechanism 75 for adjusting the clearance between the second press roller 71 and the second chill roller 72. Here, the sheet laminating apparatus 70 corresponds to the sheet laminating apparatus of the present disclosure, the first roller in the present disclosure corresponds to the second press roller 71, and the second roller in the present disclosure corresponds to the second chill roller 72.

[0093] In the illustrated example, as the laminate of the base material 11 and the receiving material 24, which has a back surface layer 13 (described later) provided thereon, passes between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72, the outer surfaces of the second press roller 71 and the outer surface of the second chill roller 72 separate from each other, forming a "gap". In the sheet bonding apparatus 70, it is also possible to set whether there is a clearance between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72 or whether there is no clearance. In other words, in the illustrated example, the roller follower 77 and the moving member 81 (described later) are in contact, and a clearance is provided between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72, but it may be set to have no clearance. In other words, they may be in contact with each other. In the bonding process performed in this embodiment, whether or not a clearance is provided, when the laminate of the base material 11 and the receiving material 24, which is provided with the back layer 13 described later, passes between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72, the outer surfaces of the second press roller 71 and the outer surface of the second chill roller 72 separate from each other, as shown in Figure 9, and a "gap" is formed. However, when a clearance is provided, its size is set to be smaller than the thickness of the laminate of the base material 11 and the receiving material 24, which is provided with the back layer 13. As will be described in detail later, whether or not a clearance is provided between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72, and the size of the clearance when a clearance is provided, can be adjusted using the biasing mechanism 74 and the clearance adjustment mechanism 75 described above. In the sheet lamination apparatus 70, "clearance" refers to the space between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72 in the direction connecting the center of the second press roller 71 and the center of the second chill roller 72, when the base material 11, resin layer 12, and film 20 are not passing through. If there is no clearance, it means that the outer surface of the second press roller 71 and the outer surface of the second chill roller 72 are in contact. On the other hand, in the sheet lamination apparatus 70, "gap" refers to the gap that is created between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72 as the base material 11, resin layer 12, and film 20 pass through.

[0094] The second press roller 71 is a rubber roller, and the second chill roller 72 is a metal roller, with the outer surface of the second press roller 71 being more elastically deformable than the outer surface of the second press roller 71. The types of the second press roller 71 and the second chill roller 72 are not particularly limited; for example, both the second press roller 71 and the second chill roller 72 may be made of rubber rollers. However, it is preferable that at least one of the second press roller 71 and the second chill roller 72 be elastically deformable.

[0095] In the illustrated example, the second press roller 71, by its rotation, transports the substrate 11 with the back layer 13 and guides it between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72, and the second chill roller 72, by its rotation, transports the receiving material 24 with the film 20 positioned on the outer surface and guides it between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72. However, the second press roller 71 may guide the receiving material 24 to the space between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72, and the second chill roller 72 may guide the substrate 11 with the back layer 13 to the space between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72.

[0096] The second die 73 is the discharge port portion of the molten resin in the molten resin extruder and is also called the die head. The second die 73 is positioned above the second press roller 71 and the second chill roller 72, and supplies resin (hereinafter referred to as resin layer forming resin 12R) onto the side of the receiving material 24 opposite to the side facing the second chill roller 72, i.e., onto the film 20, before the receiving material 24 is fed between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72. The horizontal position of the second die 73 is adjustable. In the illustrated example, the second die 73 is positioned on the side facing the second chill roller 72, supplying the resin layer forming resin 12R to the receiving material 24 on the second chill roller 72 before it is fed between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72. However, the second die 73 can also be positioned on the side facing the second press roller 71 to supply the resin layer forming resin 12R to the substrate 11. As shown in Figure 9, the second die 73 is positioned above the second press roller 71 and the second chill roller 72, and before the receiving material 24 is fed between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72, the second die 73 supplies resin (hereinafter referred to as resin layer forming resin 12R) onto the side of the receiving material 24 opposite to the side facing the second chill roller 72, i.e., onto the film 20. This prevents the resin from penetrating into the interior of the substrate 11.

[0097] The second die 73 melts and extrudes a fixed amount of resin layer forming resin 12R in a curtain-like manner, thereby forming a resin layer 12 of a fixed thickness on the receiving material 24 being conveyed at a constant speed. The laminate of the receiving material 24 with the resin layer forming resin 12R and the base material 11 is then fed between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72 and sandwiched, thereby integrating the base material 11 and the receiving material 24 with the resin layer 12. At this time, the resin layer 12 is formed as the resin layer forming resin 12R solidifies, and as it solidifies, it adheres the base material 11 and the receiving material 24.

[0098] When the second press roller 71 is composed of a rubber roller, the rubber hardness of its outer surface is preferably 30 to 90, and particularly preferably 50 to 80. As described above, the thermal transfer image receiving sheet 1 according to this embodiment has voids 30, which are formed by laminating the resin layer 12 and the base material 11 so as not to fill the inner space of the concave portion of the surface of the base material 11 with the resin layer 12. When the rubber hardness is 30 or higher, the variation in the amount of rubber deformation due to the presence or absence of grip caused by the rotation of the rubber becomes uniform. As a result, the amount of molten resin that penetrates into the concave portion of the base material 11 also becomes constant, and a uniform surface can be formed when viewed from the surface. The depth to which this molten resin fills into the inner space of the concave portion of the base material 11 is such that the molten resin penetrates from a heat-melted, flexible state in contact with the outermost surface of the base material 11 to a depth where the hardness balance of the resin hardness is maintained as it penetrates into the internal space of the concave portion of the base material 11 and solidifies. When the rubber hardness is less than 90, this balance is optimized, and an ideal void can be formed on the surface of the base paper.

[0099] Furthermore, the surface roughness Ra of the second press roller 71 is preferably 0.6 μm or more and 5 μm or less, more preferably 0.9 μm or more and 3 μm or less, and particularly preferably 0.9 μm or more and 1 μm or less. If the surface of the second press roller 71 is rough, the smoothness of the resin layer 12 may be impaired, so the surface of the second press roller 71 should be as smooth as possible.

[0100] Furthermore, the second chill roller 72 has a surface roughness Rmax of 2 μm or less, preferably 1 μm or less, and more preferably 0.7 μm or less. Also, the second chill roller 72 has a surface roughness Ra of 3 μm or less, preferably 1 μm or less, and more preferably 0.1 μm or less. If the surface of the second chill roller 72 is rough, the smoothness of the side of the receiving layer 22 or the film 20 opposite to the substrate 11 side may be impaired, so the surface of the second chill roller 72 should be as smooth as possible.

[0101] The following describes the configuration related to clearance adjustment in the sheet bonding device 70. In the sheet bonding apparatus 70, the second press roller 71 is pivotably supported by an arm 76, and the second press roller 71 contacts or separates from the second chill roller 72 in accordance with the swinging of the arm 76. The arm 76 supports the second press roller 71 at one end and is connected to a biasing mechanism 74 at the other end. The pivot point P of the arm 76 is provided between the support portion of the second press roller 71 and the connection portion with the biasing mechanism 74.

[0102] When bonding is performed by the sheet bonding device 70, the biasing mechanism 74 applies a force from the other end of the arm 76 to cause the arm 76 to swing, thereby moving the second press roller 71 toward the second chill roller 72. In this embodiment, the biasing mechanism 74 is an air cylinder, and when the biasing mechanism 74 applies a force from the other end of the arm 76 to cause the arm 76 to swing, if no clearance is provided, the second press roller 71 remains stationary pressed against the second chill roller 72. On the other hand, if a clearance is provided, the second press roller 71 remains stationary with the arm 76 pressed against the clearance adjustment mechanism 75 via the roller follower 77 described later. At this time, the inside of the air cylinder is filled with compressed air, and the air cylinder functions like an air spring. In other words, the biasing force applied by the biasing mechanism 74 is adjusted to such an extent that, even when the second press roller 71 is biased toward the second chill roller 72, the second press roller 71 can move away from the second chill roller 72 (be pushed back). Note that the biasing mechanism 74 is not limited to an air cylinder, but may be a hydraulic cylinder, for example. The biasing mechanism 74 can adjust the force (pressure) that presses the second press roller 71 toward the second chill roller 72, or the force (pressure) that presses the arm 76 toward the clearance adjustment mechanism 75, and can be adjusted, for example, in the range of 0.14 MPa to 0.60 MPa. In the embodiments described later, this pressure will be referred to as "cylinder pressure". In addition, the above description described the case where there is a pivot point P between the biasing mechanism 74 and the arm 76, but the same applies when the pivot point P is located at the end in the positional relationship of the three points. Furthermore, even when the second press roller, which does not have a pivot point P, is operated by a servo system, clearance adjustment is possible by varying the pressing force of the servo itself or by making the servo mechanism variable.

[0103] As described above, when the biasing mechanism 74 applies force from the other end of the arm 76 to cause the arm 76 to swing, the clearance adjustment mechanism 75, more specifically, contacts the roller follower 77 (contact portion) provided on the arm 76 to restrict the movement of the second press roller 71, thereby making it possible to adjust the size of the clearance between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72. Alternatively, if there is no clearance, it is possible to adjust the degree of contact between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72. Such a clearance adjustment mechanism 75 is capable of bearing at least a portion of the biasing force that biases the second press roller 71 toward the second chill roller 72. Specifically, as the moving member 81, described later, moves from an initial position (shown in Figure 11) where it does not bear the biasing force of the biasing mechanism 74 that biases the second press roller 71 toward the second chill roller 72, to a direction that increases the proportion of the biasing force it bears (upward in Figure 9), the clearance adjustment mechanism 75 pulls the second press roller 71, which is biased toward the second chill roller 72, further away from the second chill roller 72. As a result, regardless of whether the clearance adjustment mechanism 75 bears or does not bear a portion of the biasing force that biases the second press roller 71 toward the second chill roller 72, the second press roller 71 can move toward the second chill roller 72 as the substrate, resin, or film passes through.

[0104] Figure 10 shows a sheet bonding apparatus 70, with a close-up view of the clearance adjustment mechanism 75 in particular. The clearance adjustment mechanism 75 in this embodiment includes a movable member 81 with an inclined surface 81S and a holding member 82. The moving member 81 moves from the initial position where it does not bear the biasing force of the biasing mechanism 74 in a direction that increases the proportion of the biasing force it bears (upward in Figure 9), thereby coming into contact with the roller follower 77 at the inclined surface 81S. Here, "the direction that increases the proportion of the biasing force it bears" means the direction that pulls the second press roller 71 away from the second chill roller 72 against the biasing force of the biasing mechanism 74. The holding member 82 holds the movable member 81 according to its position. In this clearance adjustment mechanism 75, the arm 76 is pulled away from the second chill roller 72 via the inclined surface 81S and roller follower 77 in response to the movement of the movable member 81 in a direction away from its initial position (in a direction that increases the biasing force burden ratio (upward in Figure 9)).

[0105] Figures 11 and 12 show an example of clearance adjustment by the clearance adjustment mechanism 75. In Figure 11, the movable member 81 is in an initial position where it does not bear the biasing force from the biasing mechanism 74, specifically, the movable member 81 does not contact the roller follower 77 or does not bear the biasing force even if it does contact it, and the second press roller 71 and the second chill roller 72 are in contact. In this case, the second press roller 71 is stationary in a state pressed against the second chill roller 72. When the movable member 81 does not bear any biasing force from the biasing mechanism 74, the outer surface of the second press roller 71 becomes greatly deformed. Here, the clearance adjustment mechanism 75 can reduce the amount of deformation (elastic deformation) of the outer surface of the second press roller 71 by moving the movable member 81 upward from the initial position.

[0106] On the other hand, Figure 12 shows the state in which the movable member 81 has moved upward from the initial position. In the state shown in Figure 12, the movable member 81 bears all of the biasing force from the biasing mechanism 74, and a clearance C is provided between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72. Here, the clearance adjustment mechanism 75 can further increase the clearance C by moving the movable member 81 upward, and decrease the clearance C by moving the movable member 81 downward. The clearance C is the distance x between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72 in the direction connecting the centers of the second press roller 71 and the second chill roller 72. The size of such clearance C may be determined, for example, from an enlarged image of the space between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72. Alternatively, it may be calculated based on the position of the movable member 81 of the clearance adjustment mechanism 75. The clearance C can be measured by inserting a gap gauge into the gap between the second press roller 71 and the second chill roller.

[0107] As described above, the sheet lamination device 70 can adjust the size of the clearance between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72, and adjust the amount of deformation of the outer surface of the second press roller 71 when the outer surface of the second press roller 71 and the outer surface of the second chill roller 72 come into contact, in accordance with the movement of the movable member 81 of the clearance adjustment mechanism 75. By making such adjustments, it is possible to adjust the pressure applied to the laminate when the base material 11, the resin layer 12, and the receiving material 24 are passed between the second press roller 71 and the second chill roller 72.

[0108] More specifically, in the sheet lamination apparatus 70 of this embodiment, by adjusting the clearance or contact state between the second press roller 71 and the second chill roller 72, when the base material 11, resin layer 12, and receiving material 24 are passed between the second press roller 71 and the second chill roller 72, the outer surface of the second press roller 71 is elastically deformed, or / or the second press roller 71 and the second chill roller 72 are relatively separated, thereby avoiding excessive pressure on the base material 11, resin layer 12, and receiving material 24. As described above, the thermal transfer image receiving sheet 1 of this embodiment has a void 30, which is formed by laminating the resin layer 12 and the base material 11 so as not to fill the inner space of the concave portion on the surface of the base material 11 with the resin layer 12. In other words, according to the sheet lamination apparatus 70 of this embodiment, the resin layer 12 adheres to the base material 11 and the film 20 in the receiving material 24 while adjusting the amount of penetration of the resin layer 12 into the surface of the base material 11, thereby avoiding excessive pressure on the base material 11, the resin layer 12 adheres to the surface of the base material 11, and the film 20 in the receiving material 24. This makes it possible to laminate the resin layer 12 and the base material 11 without filling the inner space of the concave parts on the surface of the base material 11 with the resin layer 12.

[0109] <Method for manufacturing a thermal transfer image receiving sheet> Hereinafter, an example of a method for manufacturing a thermal transfer image receiving sheet 1 using the manufacturing system 50 will be described with reference to Figure 9, etc. The manufacturing method described herein comprises an adjustment step of adjusting the clearance or contact state between the second press roller 71 and the second chill roller 72 using a clearance adjustment mechanism 75; a first supply step of supplying a back layer forming resin 13R using a resin laminating device 60; a first laminating step of laminating the base material 11 and the back layer 13 using the resin laminating device 60; a second supply step of supplying a resin layer forming resin 12R using a sheet laminating device 70; and a second laminating step of laminating the base material 11 and the receiving material 24 using the sheet laminating device 70.

[0110] <Adjustment process> In the adjustment process, the clearance between the second press roller 71 and the second chill roller 72, or the amount of deformation of the outer surface of the second press roller 71 in a contact state (the amount of elastic deformation of the second press roller 71), is adjusted by adjusting the position of the movable member 81 of the clearance adjustment mechanism 75.

[0111] The inventors of this invention have found that, in order to avoid excessive pressure on the substrate 11, resin layer 12, and receiving material 24 and to form a gap 30 at the interface between the substrate 11 and the resin layer 12, when d1 is the clearance between the second press roller 71 and the second chill roller 72 before the substrate 11, resin layer 12, and receiving material 24 are passed through, and hs is the total thickness of the substrate 11, resin layer 12, and receiving material 24 before they are passed between the second press roller 71 and the second chill roller 72, it is preferable that d1-hs be between -250 μm and -50 μm, and particularly preferable that it be between -230 μm and -50 μm. This preferred numerical range is based on the premise that the total thickness hs of the substrate 11, resin layer 12, and receiving material 24 is between 100 μm and 300 μm. Furthermore, the inventors have found it preferable to apply a pressure of 0.05 MPa to 0.4 MPa to the laminate containing the base material 11, resin layer 12, and receiving material 24 when passing them between the second press roller 71 and the second chill roller 72. In the embodiments described later, this pressure will be referred to as "nip pressure". In this embodiment, considering the total thickness hs of the base material 11, resin layer 12, and receiving material 24, d1-hs is set to -250 μm to -50 μm, and the clearance or contact state between the second press roller 71 and the second chill roller 72 is adjusted so that a pressure of 0.05 MPa to 0.4 MPa is applied to the laminate when passing the base material 11, resin layer 12, and receiving material 24 between the second press roller 71 and the second chill roller 72. By setting the pressure in the range of 0.05 MPa to 0.4 MPa, air entrapment is suppressed, the adhesion state is stabilized, and a laminate with a good surface quality can be obtained. During this adjustment, the biasing mechanism 74 is also driven. At this time, the pressure that the biasing mechanism 74 applies to the second press roller 71 via the arm 76 is set to a constant value. In this embodiment, the relationship between the pressure output by the biasing mechanism 74, the clearance or contact state between the second press roller 71 and the second chill roller 72, and the pressure applied to the laminate including the base material 11, resin layer 12, and receiving material 24, which passes between the second press roller 71 and the second chill roller 72, is predetermined. In the adjustment process, after determining the pressure output by the biasing mechanism 74 and the desired pressure to be applied to the laminate including the base material 11, resin layer 12, and receiving material 24, which passes between the second press roller 71 and the second chill roller 72, the clearance or contact state between the second press roller 71 and the second chill roller 72 can be adjusted to the desired state by referring to the above relationship.

[0112] The above pressure refers to the pressure applied to the base material 11, the resin layer 12, and the receiving material 24 in the lamination direction of the base material 11, the resin layer 12, and the receiving material 24. Furthermore, the pressure applied to the base material 11, the resin layer 12, and the receiving material 24 as they pass between the second press roller 71 and the second chill roller 72 can be determined by, for example, passing pressure-sensitive paper between the second press roller 71 and the second chill roller 72 and observing the state of the pressure-sensitive paper after it has passed. The inventor of this invention measured the pressure applied to the laminate of the base material 11, the resin layer 12, and the receiving material 24 under the conditions of each embodiment described later, using pressure-sensitive paper as a representation of the laminate, and the maximum pressure measured was approximately 0.4 MPa. The pressure applied to the laminate can also be measured by measuring the pressure as the laminate (base material 11, resin layer 12, receiving material 24) passes through load cells corresponding to the second press roller 71 and the second chill roller 72, respectively. Through these measurements, even when measuring the pressure applied to the laminate of the substrate 11, resin layer 12, and receiving material 24 under the conditions of each embodiment described later, the calculated pressure was approximately 0.4 MPa at its maximum. In each embodiment, a thermal transfer image receiving sheet 1 with a smooth surface of the receiving layer 22 was obtained. Therefore, the upper limit of the preferred range for the pressure applied to the laminate of the substrate 11, resin layer 12, and receiving material 24 was set to 0.4 MPa or less. On the other hand, if the pressure applied to the laminate of the substrate 11, resin layer 12, and receiving material 24 is less than 0.05 MPa, the adhesive state between the substrate 11, resin layer 12, and receiving material 24 may become unstable. Also, air entrapment is more likely to occur. Therefore, the upper and lower limits of the preferred range for the pressure applied to the laminate of the substrate 11, resin layer 12, and receiving material 24 were set to 0.05 MPa. By setting the pressure within this range, air entrapment is suppressed, the adhesive state is stabilized, and a laminate with a good surface quality can be obtained.

[0113] After the adjustment process described above, the rollers of the resin laminating device 60 and the rollers of the sheet laminating device 70 are driven.

[0114] <1st supply process> The first supply process is performed after the first press roller 61 and first chill roller 62 of the resin laminating apparatus 60, the second press roller 71 and second chill roller 72 of the sheet laminating apparatus 70, and the biasing mechanism 74 are driven. When the first press roller 61 and first chill roller 62 of the resin laminating apparatus 60 rotate, the base material 11 is conveyed by the first chill roller 62. In the first supply process, before the base material 11 is fed between the outer circumferential surface of the first press roller 61 and the outer circumferential surface of the first chill roller 62, the back layer forming resin 13R is supplied to the side of the base material 11 opposite to the side facing the first press roller 61. As described above, the back layer forming resin 13R is melt-extruded from the first die 63 in a curtain-like manner in a fixed amount. This forms a back layer 13 made of the back layer forming resin 13R of a fixed thickness on the base material 11 being conveyed at a constant speed.

[0115] <First lamination process> In the first bonding step, the base material 11, on which the back layer 13 is provided as described above, is fed between the outer surface of the first press roller 61 and the outer surface of the first chill roller 62 and sandwiched, thereby bonding the base material 11 so that the back layer 13 is stably integrated with it.

[0116] <Second supply process> The base material 11, with the integrated back layer 13, is guided between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72 by the rotation of the second press roller 71. Simultaneously, the second chill roller 72 conveys the receiving material 24 by its rotation, guiding it between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72. In the second supply step, before the receiving material 24 is fed between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72, the resin layer forming resin 12R is supplied to the side of the receiving material 24 opposite to the side facing the second chill roller 72, i.e., onto the film 20. As described above, the resin layer forming resin 12R is melt-extruded from the second die 73 in a curtain-like manner in a fixed amount. This forms a resin layer 12 of a fixed thickness on the receiving material 24 being conveyed at a constant speed, consisting of the resin layer forming resin 12R.

[0117] <Second lamination process> In the second bonding step, the laminate of the receiving material 24, on which the resin layer 12 is provided as described above, and the base material 11 is fed between the outer surface of the second press roller 71 and the outer surface of the second chill roller 72 and sandwiched, thereby bonding the base material 11 and the receiving material 24 together in a stable state where they are integrated by the resin layer 12. Here, the pressure applied to the base material 11, the resin layer 12, and the receiving material 24 as they pass between the second press roller 71 and the second chill roller 72 is prevented from becoming excessively large through adjustment in the adjustment step.

[0118] By the manufacturing method described above, a support 10 for a thermal transfer image receiving sheet or a thermal transfer image receiving sheet 1 having a void 30 at the boundary between the base material 11 and the resin layer 12 can be manufactured. In the manufacturing method described above, the base material 11 and the receiving material 24 are integrated by the resin layer 12, but the base material 11 and the film 20 may be integrated by the resin layer 12, and then the receiving layer 22 may be laminated on the film 20. In this case, only the film 20 is transported by the second chill roller 72 of the sheet laminating device 70. [Examples]

[0119] Next, examples of the present disclosure and comparative examples thereof will be described.

[0120] The thermal transfer image receiving sheets of Examples 1-7 and 9-17 described below have the same configuration as the thermal transfer image receiving sheet 1 described in the above embodiment, and comprise a base material 11, a resin layer 12, a back layer 13, a film 20, a primer layer 21, and a receiving layer 22. Example 8 is a support for a thermal transfer image receiving sheet, comprising a base material 11, a resin layer 12, a back layer 13, and a film 20. The smoothness, SRa, form, adhesion, and cost were evaluated by forming a primer and a receiving layer on the heat insulating layer surface of this support.

[0121] Examples 1 to 17 were manufactured using the manufacturing system 50 described above, and were manufactured after adjusting the clearance or contact state between the second press roller 71 and the second chill roller 72 by the clearance adjustment mechanism 75 so that the inner space of the concave portion on the surface of the base material 11 is not filled with the resin layer 12.

[0122] On the other hand, Comparative Examples 1 and 2 are thermal transfer image receiving sheets, but they are manufactured under different manufacturing conditions than Examples 1-7 and 9-17. Specifically, Comparative Examples 1 and 2 are manufactured using the manufacturing system 50 described above, but the clearance adjustment mechanism 75 is not used. As a result, in Comparative Examples 1 and 2, the resin layer 12 and the substrate 11 are subjected to high pressure between the second press roller 71 and the second chill roller 72.

[0123] The materials and manufacturing conditions of the components used in each example and comparative example are described below. Figure 13 shows the manufacturing conditions for each example and comparative example.

[0124] <Example 1> High-quality paper was used as the base material 11. The smoothness of the high-quality paper was 60 seconds, the surface roughness SRa was 3.5 μm, the thickness was 178 μm, and the density was 0.87 g / cm³. 3 That is the case. The back layer 13 was formed with a polyolefin mixture of HDPE (high-density polyethylene) and LDPE (low-density polyethylene) in an 8:2 ratio to a thickness of 24 μm. The thickness of the back layer 13, 24 μm, is the thickness when the back layer forming resin 13R that forms the back layer 13 is applied onto the substrate 11 by melt extrusion. The melting point of the above polyolefin is 127°C, and its density is 0.948 g / cm³. 3 That is the case. The resin layer 12 was formed using polyolefin, which is LDPE (low-density polyethylene), to a thickness of 15 μm. The thickness of the resin layer 12, 15 μm, is the thickness when the resin layer-forming resin 12R that forms the resin layer 12 is applied onto the film 20 by melt extrusion. The melting point of the above polyolefin is 107°C, and its density is 0.916 g / cm³. 3 That is the case. Film 20 is a void film with a thickness of 35 μm. The material of the void film is polypropylene.

[0125] A primer layer-forming coating solution with the following composition was applied to the film and dried to form a primer layer with a thickness of 0.8 μm.

[0126] <Coating liquid for primer layer> • Polyester 4.2 parts by mass (Polyester® WR-905, Nippon Synthetic Chemical Industry Co., Ltd.) Titanium dioxide 8.4 parts by mass (TCA-888 Sakai Chemical Industry Co., Ltd.) • Isopropyl alcohol (IPA) 10 parts by mass • Water 30 parts by mass

[0127] A coating solution for forming a receptor layer having the following composition was applied to the primer layer formed as described above, and dried to form a receptor layer with a thickness of 3 μm, thereby obtaining the thermal transfer image receiving sheet of this disclosure.

[0128] <Coating liquid for forming a receptive layer> • Vinyl chloride-vinyl acetate copolymer 60 parts by mass (Solvine® C, Nisshin Chemical Industry Co., Ltd.) • Epoxy-modified silicone resin 1.2 parts by mass (X-22-3000T Shin-Etsu Chemical Co., Ltd.) • Methylstil-modified silicone resin 0.6 parts by mass (X-24-510 Shin-Etsu Chemical Co., Ltd.) • Methyl ethyl ketone 2.5 parts by mass • Toluene 2.5 parts by mass

[0129] The thickness of the laminate, consisting of the above-mentioned components (11, 12, 13, 20, 21, 22), before it is inserted between the second press roller 71 and the second chill roller 72, is 251 μm. Note that simply adding the thickness of the base material 11 (178 μm), the back layer 13 (24 μm), the resin layer 12 (15 μm), the film 20 (35 μm), the primer layer 21 (0.8 μm), and the receiving layer 22 (3 μm) results in 255.8 μm, which is greater than the thickness of the laminate described above (251 μm). The reason the thickness of the laminate before it is inserted between the second press roller 71 and the second chill roller 72 is less than the simply added thickness is that when the back layer 13 is sandwiched between the first press roller 61 and the first chill roller 62 of the resin laminating device 60, some of the back resin penetrates into the uneven areas on the back surface of the paper base material. This reduction in thickness occurs similarly in the following other examples and comparative examples.

[0130] The clearance between the second press roller 71 and the second chill roller 72 before the above laminate is inserted (before sand lamination) is 50 μm. This clearance is formed by the clearance adjustment mechanism 75 bearing all of the biasing force from the biasing mechanism 74. Here, let d1 be the clearance between the second press roller 71 and the second chill roller 72 before the base material 11, resin layer 12, and receiving material 24 are passed through, and let hs be the total thickness of the base material 11, resin layer 12, and receiving material 24 before they are passed between the second press roller 71 and the second chill roller 72. Then d1-hs is -201 μm (see "Difference" in the table).

[0131] The second press roller 71 is a rubber roller with a rubber hardness of Hs70. The surface roughness Ra of the outer surface of the second press roller 71 is 0.99.

[0132] The surface roughness Ra of the second chill roller 72 is 0.08, and the surface roughness Rmax is 0.69.

[0133] The second die 73 drops the resin layer forming resin 12R from the endpoint of the second chill roller 72 on the second press roller 71 side in the direction connecting the center of the second press roller 71 and the center of the second chill roller 72, at a position 9 mm toward the center of the second press roller 71 in the same direction.

[0134] The biasing mechanism 74 is an air cylinder, and its press pressure (cylinder pressure) is 0.42 MPa. The press roller is pressed at 0.88 MPa due to the lever ratio of the two arms. Separately, using pressure-sensitive paper (Fujifilm ultra-low pressure LLLW) as a substitute for image receiving paper, the pressure (nip pressure) measured according to the difference (-201 μm) between the laminate thickness (251 μm) and the "roller clearance (50 μm)" was 0.20 MPa or less. Nip pressure measurements were also performed in Examples 2-17 and Comparative Examples 1 and 2. The nip pressure values ​​measured for each example and comparative example are shown in the table in Figure 13.

[0135] <Example 2> The substrate 11 has a smoothness of 50 seconds, a surface roughness SRa of 3.5 μm, a thickness of 147 μm, and a density of 0.87 g / cm³. 3 High-quality paper was used. Furthermore, the thickness of the laminate before it enters the space between the second press roller 71 and the second chill roller 72 is 220 μm. Therefore, d1-hs is -170 μm. Other conditions are the same as in Example 1.

[0136] <Example 3> The substrate 11 has a smoothness of 410 sec, a surface roughness SRa of 2.6 μm, a thickness of 155 μm, and a density of 1.02 g / cm³. 3 High-quality paper was used. Furthermore, the thickness of the laminate before it enters the space between the second press roller 71 and the second chill roller 72 is 228 μm. Therefore, d1-hs is -178 μm. Other conditions are the same as in Example 1.

[0137] <Example 4> The substrate 11 has a smoothness of 110 seconds, a surface roughness SRa of 2.2 μm, a thickness of 165 μm, and a density of 0.91 g / cm³. 3 High-quality paper was used. Furthermore, the thickness of the laminate before it enters the space between the second press roller 71 and the second chill roller 72 is 238 μm. Therefore, d1-hs is -188 μm. Other conditions are the same as in Example 1. <Example 5> The substrate 11 has a smoothness of 410 sec, a surface roughness SRa of 2.8 μm, a thickness of 160 μm, and a density of 1.01 g / cm³. 3 High-quality paper was used. Furthermore, the thickness of the laminate before it enters the space between the second press roller 71 and the second chill roller 72 is 233 μm. Therefore, d1-hs is -183 μm. Other conditions are the same as in Example 1. <Example 6> The substrate 11 has a smoothness of 140 seconds, a surface roughness SRa of 2.1 μm, a thickness of 155 μm, and a density of 0.93 g / cm³. 3 High-quality paper was used. Furthermore, the thickness of the laminate before it enters the space between the second press roller 71 and the second chill roller 72 is 228 μm. Therefore, d1-hs is -178 μm. Other conditions are the same as in Example 1. <Example 7> The press pressure of the air cylinder, which is the biasing mechanism 74, is 0.14 MPa. Other conditions are the same as in Example 2.

[0138] <Example 8> In Example 8, only the film 20 is laminated to the substrate 11 via the resin layer 12 in the sheet laminating apparatus 70. The thickness of the film 20 is 35 μm. d1-hs is -166 μm. Other bonding conditions are the same as in Example 2. Furthermore, after bonding the front and back surfaces together, a primer and a receiving layer were applied to create a thermal transfer image receiving sheet.

[0139] <Example 9> In Example 9, the second die 73 drops the resin layer forming resin 12R onto the end point of the second chill roller 72 on the second press roller 71 side in the direction connecting the center of the second press roller 71 and the center of the second chill roller 72. Other conditions are the same as in Example 2.

[0140] <Example 10> The clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 150 μm. Furthermore, the rubber hardness of the second press roller 71 is Hs60. Other conditions are the same as in Example 2.

[0141] <Example 11> The clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 100 μm. Other conditions are the same as in Example 10.

[0142] <Example 12> The clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 50 μm. Other conditions are the same as in Example 10.

[0143] <Example 13> The clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 0 μm. In Example 13, there is no gap between the second press roller 71 and the second chill roller 72, but they are not pressing against each other. Other conditions are the same as in Example 10.

[0144] <Example 14> The clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 0 μm. The second press roller 71 and the second chill roller 72 are pressing against each other such that the outer surface of the second press roller 71 is compressed by 50 μm. In the table, (-50) represents the amount of compression (elastic deformation) of the outer surface of the second press roller 71. Other conditions are the same as in Example 10. In addition, during the manufacturing of Example 14, the clearance adjustment mechanism 75 bears a portion of the biasing force provided by the biasing mechanism 74.

[0145] <Example 15> The clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 0 μm. The second press roller 71 and the second chill roller 72 are pressing against each other such that the outer surface of the second press roller 71 is compressed by 150 μm. Other conditions are the same as in Example 10. Furthermore, during the manufacturing of Example 15, the clearance adjustment mechanism 75 also bears a portion of the biasing force provided by the biasing mechanism 74.

[0146] <Example 16> The clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 0 μm. The second press roller 71 and the second chill roller 72 are pressing against each other such that the outer surface of the second press roller 71 is compressed by 250 μm. Other conditions are the same as in Example 10. Furthermore, during the manufacturing of Example 16, the clearance adjustment mechanism 75 also bears a portion of the biasing force provided by the biasing mechanism 74.

[0147] <Example 17> The clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 0 μm. In Example 17, there is no gap between the second press roller 71 and the second chill roller 72, but they are not pressing against each other. Other conditions are the same as in Example 2.

[0148] <Comparative Example 1> In Comparative Example 1, the clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 0 μm. The second press roller 71 and the second chill roller 72 are pressing against each other such that the outer surface of the second press roller 71 is compressed by approximately 2000 μm. Other conditions are the same as in Example 2. During the manufacturing of Comparative Example 1, the clearance adjustment mechanism 75 does not bear any biasing force from the biasing mechanism 74. That is, the laminate is subjected to large pressure by the second press roller 71 and the second chill roller 72. Separately, pressure-sensitive paper (manufactured by Fujifilm Corporation, LLLW for ultra-low pressure) was used as the image receiving paper, and the pressure measured according to the thickness of the laminate (220 μm) was 0.74 MPa.

[0149] <Comparative Example 2> In Comparative Example 2, the clearance between the second press roller 71 and the second chill roller 72 before the laminate is inserted (before sand lamination) is 0 μm. The second press roller 71 and the second chill roller 72 are pressing against each other such that the outer surface of the second press roller 71 is compressed by approximately 2000 μm. Other conditions are the same as in Example 7. Even during the manufacturing of Comparative Example 2, the clearance adjustment mechanism 75 does not bear any biasing force from the biasing mechanism 74. In other words, the laminate is subjected to large pressure between the second press roller 71 and the second chill roller 72. Separately, pressure-sensitive paper (manufactured by Fujifilm Corporation, LLLW for ultra-low pressure) was used as the image receiving paper, and the pressure measured according to the thickness of the laminate (220 μm) was 0.41 MPa.

[0150] <Rating> The above examples and comparative examples were evaluated from the viewpoints of (1) the smoothness of the surface of the receiving layer or film, (2) the surface roughness of the surface of the receiving layer or film, (3) the surface formation of the thermal transfer image, (4) the adhesion between the substrate and the film, and (5) the manufacturing cost. Details of (1) to (5) are as follows.

[0151] (1) Smoothness The smoothness (seconds) used for evaluation was measured in accordance with JIS P 8155:2010. When the surface smoothness of the receiving layer or film (Example 8) is high, the surface of the thermal transfer image becomes smooth, and it can be evaluated that a high-quality thermal transfer image can be obtained.

[0152] (2) Surface roughness The surface roughness SRa used for evaluation was measured in accordance with JIS B 0601:1982. When the surface roughness of the receiving layer or film (Example 8) is small, the surface of the thermal transfer image becomes smooth, and it can be evaluated that a high-quality thermal transfer image can be obtained.

[0153] (3) Ground conditions The image background was evaluated by visual inspection using a dye-sublimation thermal transfer printer (ALTECH ADS Co., Ltd., MEGAPIXELIII) to print grayscale images onto thermal transfer receiving sheets prepared using the thermal transfer receiving sheet materials according to the examples and comparative examples, or the thermal transfer receiving sheet support materials according to the examples. (Evaluation Criteria) A: The gray image was uniform, no surface irregularities were observed, and it had good smoothness, texture, and feel. B: The gray image was almost uniform, and although some surface irregularities were observed, the smoothness, texture, and feel were slightly inferior, but there were no practical problems. C: The gray image could not be formed uniformly, the surface irregularities were noticeable, and the texture was quite bothersome, lacking smoothness, texture, and feel.

[0154] (4) Adhesiveness After attaching mending tape (manufactured by Nichiban Co., Ltd.) to the thermal transfer image receiving sheet, the mending tape was peeled off the thermal transfer image receiving sheet so that the surface of the mending tape formed a 45-degree angle with the surface of the thermal transfer image receiving sheet, and the adhesion between the substrate 11 and the film 20 was evaluated. The evaluation criteria are as follows: (Evaluation Criteria) A: No delamination occurred at the interface between the substrate and the film. B: Delamination occurred at part of the interface between the substrate and the film, or heat damage was observed in the film. C: Delamination occurred at most of the interface between the substrate and the film.

[0155] (5) Manufacturing costs If the substrate used in Examples 1-17 and Comparative Examples 1 and 2 is less expensive than coated paper (for example) with a smoothness of 2000 seconds or more and a surface roughness of SRa 1.0 or less, which is commonly used in thermal transfer image receiving sheets to obtain high-quality thermal transfer images, it will be evaluated as A (Good).

[0156] The evaluation results described above are shown in Figure 14. Figure 14 also shows the results of confirming the presence or absence of voids in the SEM images of the cross-sections of the thermal transfer imaging sheets for each example and comparative example. The acceleration voltage during SEM image acquisition was 3.0kV. The cross-sections confirmed were the MD (first direction D1) cross-section and the TD (second direction D2) cross-section. To observe the voids in the cross-section of the MD, the thermal transfer image receiving sheet 1 or the support for the thermal transfer image receiving sheet 10 was cut along a plane including the first direction D1 and the stacking direction, the cross-section was exposed, and a 1000x magnification SEM image of the cross-section was acquired to observe a 1 mm area in the first direction D1. The void in the cross-section of TD (second cross-sectional void) was observed by cutting the thermal transfer image receiving sheet 1 or the support for the thermal transfer image receiving sheet 10 along a plane including the second direction D2 and the stacking direction, exposing the cross-section, and obtaining a 1000x magnification SEM image of the said cross-section to observe a 1 mm area in the second direction D2. When performing the above-described cutting, the thermal transfer image receiving sheet 1 or the support for the thermal transfer image receiving sheet 10 was cut from the side of the receiving layer 22 using a cutting tool.

[0157] As shown in Figure 14, the surface smoothness of the receiving layer 22 in Examples 1 to 17 was very smooth, with many examples having a lamination time of 35,000 seconds or more, and especially 50,000 seconds or more. Furthermore, the surface roughness (SRa) of Examples 1 to 17 was 2.2 μm or less, which further demonstrated their smoothness. Image observation after actual thermal transfer also showed good formation in all cases. Adhesion between the substrate 11 and the film 20 was also good, except for Example 10. Moreover, since Examples 1 to 17 all use high-quality paper, they are advantageous in terms of manufacturing costs. It is presumed that the impact on adhesion in Example 10 was due to the lower lamination pressure compared to the other examples.

[0158] On the other hand, the surface smoothness of the receiving layer in Comparative Examples 1 and 2 was less than 20000, and the surface roughness SRa was 2.4 or higher, indicating that the smoothness was inferior compared to the examples. Furthermore, image observation after the actual thermal transfer also showed that the formation was not good.

[0159] In the table in Figure 14, the top row, "Total number of voids with a height of 0.5 μm or more and a width of 1 μm or more," represents the sum of the number of voids in a 1 mm range in the first direction D1 and the number of voids in a 1 mm range in the second direction D2. In the table in the top row of Figure 14, below the table for "MD direction cross-section," the number and size of voids confirmed in the first direction D1 are shown. Similarly, in the table in the top row of Figure 14, below the table for "TD direction cross-section," the number and size of voids confirmed in the second direction D2 are shown.

[0160] In each embodiment, one to two voids 30 were observed in each direction. In Example 5, no voids were observed in the cross-section in the second direction D2, which is presumed to be due to a slightly increased pressure on the laminate. On the other hand, in Comparative Examples 1 and 2, almost no voids were observed.

[0161] The results, which show that voids 30 in each embodiment, confirm that when appropriate manufacturing conditions are set using the clearance adjustment mechanism 75, it is possible to manufacture a thermal transfer image receiving sheet 1 or a thermal transfer image receiving sheet support 10 in which voids 30 are formed. Furthermore, it was confirmed that in a thermal transfer image receiving sheet 1 or a thermal transfer image receiving sheet support 10 in which voids 30 are formed, the receiving layer 22 becomes smooth, and when thermal transfer is performed, a high-quality thermal transfer image with good formation and smoothness can be formed.

[0162] Although embodiments and examples of the present disclosure have been described above, the present disclosure is not limited to the embodiments or examples described above, and various modifications can be made to the embodiments described above. For example, although the embodiments described above are based on a sublimation thermal transfer method, the present disclosure can also be applied to a fusion thermal transfer method. [Explanation of Symbols]

[0163] 1…Thermal transfer image receiving sheet 10…Support for thermal transfer imaging sheet 11...Base material 12… Resin layer 12R…Resin layer forming resin 13…Back layer 13R…Resin for forming the back layer 20...film 21…Primer layer 22…Receptive layer 24…Receiving material 30...Void 50…Manufacturing System 60…Resin lamination device 61...First press roller 62...First Chillola 63...First Dive 70…Sheet laminating device 71... Second press roller 72...2nd Chillola 73... Second Dive 74...Biasing mechanism 75…Clearance adjustment mechanism 76... Arm 77...Laura Follower 81...Moving member 81S…Slope surface 82…Retaining member

Claims

1. A method for manufacturing a thermal transfer image receiving sheet, comprising laminating a base material, a resin layer, and a receiving material having a film and a receiving layer in this order, A supply step of supplying the resin that forms the resin layer onto the substrate or onto the film in the receiving material by melt extrusion, The process includes a bonding step in which the base material and the receiving material are overlapped with the resin in between and passed between a first roller and a second roller, thereby bonding the base material and the receiving material via the resin layer formed by the resin, In the bonding process, when passing the substrate, the resin layer, and the receiving material between the first roller and the second roller, a pressure of 0.05 MPa or more and 0.4 MPa or less is applied to the laminate including the substrate, the resin layer, and the receiving material. When the clearance between the first roller and the second roller is d1, and the total thickness of the base material, the resin layer, and the receiving material is hs, A method for manufacturing a thermal transfer image receiving sheet, wherein the lamination step is performed under conditions in which d1-hs is between -250 μm and -70 μm.

2. A method for manufacturing a support for a thermal transfer image receiving sheet, comprising laminating a substrate, a resin layer, and a film in this order, A supply step of supplying the resin that forms the resin layer onto the substrate or the film by melt extrusion, The process includes a bonding step in which the substrate and the film are overlapped with the resin in between and passed between a first roller and a second roller, thereby bonding the substrate and the film via the resin layer formed by the resin, In the lamination process, when passing the substrate, the resin layer, and the film between the first roller and the second roller, a pressure of 0.05 MPa or more and 0.4 MPa or less is applied to the laminate including the substrate, the resin layer, and the film. When the clearance between the first roller and the second roller is d1, and the total thickness of the substrate and the resin layer is hs, A method for manufacturing a support for a thermal transfer image receiving sheet, wherein the bonding step is performed under conditions in which d1-hs is between -250 μm and -70 μm.

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