Support for thermal transfer image receiving sheet, thermal transfer image receiving sheet, method for manufacturing thermal transfer image receiving sheet, method for manufacturing support for thermal transfer image receiving sheet, and sheet laminating device

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] The present disclosure relates to a support for a thermal transfer image receiving sheet that supports a receiving layer to form a thermal transfer image receiving sheet, and a thermal transfer image receiving sheet including the support. The present 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 device that can be used for the methods. [Background technology]

[0002] Image forming methods using thermal transfer include a dye-sublimation type thermal transfer method and a melting type thermal transfer method. In the dye-sublimation type thermal transfer method, a thermal transfer sheet having a color material layer containing a sublimation dye on a substrate and a thermal transfer image receiving sheet having a receiving layer on a support are superimposed on each other, and the sublimation dye contained in the color material layer of the thermal transfer sheet is transferred to the receiving layer of the thermal transfer image receiving sheet to form a thermal transfer image.

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

[0004] [Patent Document 1] JP 2015-193252 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, when the paper base material and the film are bonded together, if they are clamped with a strong force, the adhesive layer may excessively conform to the irregularities on the surface of the paper base material, which may cause the smoothness of the film surface to be significantly impaired.

[0006] When a thermal transfer image is formed using a thermal transfer image receiving sheet having a receiving layer on a film with impaired smoothness as described above, the receiving layer may be deformed or easily deformed in response to the unevenness of the film surface, resulting in poor surface texture of the thermal transfer image. For this reason, in the past, when a high-quality image was required, coated paper or the like with a smooth surface was used as the paper substrate.

[0007] However, since coated paper is more expensive than fine paper, which generally has a lower smoothness than coated paper, there is a problem that manufacturing costs are high when forming a support using coated paper, etc. Therefore, if it becomes possible to form a high-quality thermal transfer image using a thermal transfer image-receiving sheet made using fine paper, etc., there is a great merit in terms of manufacturing and image provision.

[0008] In addition, when the surface texture of a thermal transfer image becomes poor, it is generally judged to be of poor quality, but there may be cases where it is desired to form an image with uneven texture or to change the texture partially. If a thermal transfer image receiving sheet that allows selective adjustment of such texture is realized, it will be possible to provide new value.

[0009] The present disclosure has been made in consideration of the above-mentioned situation, and its purpose is to provide a thermal transfer image receiving sheet that can form high-quality thermal transfer images while reducing manufacturing costs, and can form thermal transfer images with a wide variety of expressions by selectively changing the condition 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 substrate, a resin layer, and a film are laminated in this order, and which has one or more voids at or near the boundary between the substrate and the resin layer, and the height of the void in the stacking direction of the substrate, the resin layer, and the film is 0.5 μm or more and 15 μm or less.

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

[0012] The void may have a height of 0.5 μm or more and 15 μm or less in a first cross section obtained by cutting the substrate, the resin layer, and the film along a plane including the stacking direction.

[0013] The gap may have a width of at least 1 μm and at most 1000 μm.

[0014] One or more of the voids may be present on the first surface within a range of 1 mm in a first direction perpendicular to the stacking direction.

[0015] There may be two or more voids within a range of 1 mm in the first direction.

[0016] The support for a thermal transfer image receiving sheet according to the present disclosure may have one or more second cross-sectional gaps having a height in the stacking direction of 0.5 μm or more and 15 μm or less at or near the boundary between the substrate and the resin layer in a second cross-section obtained when the substrate, the resin layer, and the film are cut in a plane that includes the stacking direction and is perpendicular to the first cross-section.

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

[0018] The second cross-sectional gap may have a width of not less than 1 μm and not more than 1000 μm.

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

[0020] Two or more second cross-sectional gaps may exist within a range of 1 mm in the second direction.

[0021] The substrate may be a paper substrate, and the first cross section may extend in a direction substantially parallel to a fiber direction of the paper substrate.

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

[0023] Moreover, a thermal transfer image receiving sheet according to the present disclosure includes the above-mentioned 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 receiving layer on the side opposite to the support for the thermal transfer image receiving sheet may be 2.2 μm or less.

[0025] In addition, a method for producing a thermal transfer image receiving sheet according to the present disclosure is a method for producing a thermal transfer image receiving sheet by laminating a substrate, a resin layer, and a receiving material having a film and a receiving layer integrated with each other in this order, comprising the steps of: A supplying step of supplying a resin that forms the resin layer onto the substrate or onto the film of the receiving material by melt extrusion; a lamination step of overlapping the substrate and the receiving material with the resin sandwiched therebetween and passing the overlapping substrate and the receiving material between a first roller and a second roller, thereby bonding the substrate and the receiving material together with the resin layer formed by the resin; an outer circumferential surface of at least one of the first roller and the second roller is elastically deformable; one of the first roller and the second roller is biased toward the other roller and can be pushed back in a direction away from the other roller, or the first roller and the second roller are biased toward each other and can be pushed back in directions away from each other, This is a method for manufacturing a thermal transfer image receiving sheet, in which, when the substrate, the resin layer, and the receiving material are passed between the first roller and the second roller in the bonding process, the outer peripheral surface of at least one of the first roller and the second roller, which are elastically deformable, elastically deforms and / or the first roller and the second roller move away from each other, thereby adhering the substrate and the film on the receiving material with the resin layer while adjusting the amount of penetration of the resin layer into the surface of the substrate.

[0026] The laminating step may be performed in a state where there is no clearance between the first roller and the second roller, or in a state where there is a clearance between the first roller and the second roller.

[0027] The clearance between the first roller and the second roller before the substrate, the resin layer, and the receiving material are passed is d1, and the total thickness of the substrate, the resin layer, and the receiving material before the substrate, the resin layer, and the receiving material are passed between the first roller and the second roller is hs, The laminating step may be performed in a state where d1-hs is −250 μm or more and −50 μm or less.

[0028] In the lamination process, when the substrate, the resin layer, and the receiving material are passed between the first roller and the second roller, a pressure of 0.05 MPa or more and 0.4 MPa or less may be applied to the substrate, the resin layer, and the receiving material.

[0029] The first roller of the first roller and the second roller is set so as to be able to be pushed back in a direction away from the second roller while being biased toward the second roller, and the manufacturing method for a thermal transfer image receiving sheet further includes a step of preparing a clearance adjustment mechanism that operates to increase the burden ratio of the biasing force as the first roller moves farther away from an initial position in which it does not bear the biasing force biasing the first roller toward the second roller, thereby moving the first roller biased toward the second roller farther away from the second roller, and a step of adjusting the movement position of the clearance adjustment mechanism. In the step of adjusting the movement position of the clearance mechanism, By adjusting a moving position of the clearance adjustment mechanism, an amount of elastic deformation of an outer circumferential surface of at least one of the first roller and the second roller, which is elastically deformable, is adjusted in a state in which there is no clearance between the first roller and the second roller; or Or, The method 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] In addition, a method for producing a thermal transfer image receiving sheet according to the present disclosure includes the steps of: A method for producing a thermal transfer image receiving sheet, comprising laminating a substrate, a resin layer, and a receiving material having a film and a receiving layer in this order, comprising: A supplying step of supplying a resin that forms the resin layer onto the substrate or onto the film of the receiving material by melt extrusion; a lamination step of overlapping the base material and the receiving material with the resin sandwiched therebetween and passing the overlapping parts between a first roller and a second roller to laminate the base material and the receiving material via the resin layer formed by the resin, In the lamination process, when the substrate, the resin layer, and the receiving material are passed 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, in this method for manufacturing a thermal transfer image receiving sheet.

[0031] In addition, a method for producing a support for a thermal transfer image receiving sheet according to the present disclosure includes the steps of: A method for producing a support for a thermal transfer image receiving sheet, comprising laminating a substrate, a resin layer, and a film in this order, the method comprising the steps of: a supplying step of supplying a resin that forms the resin layer onto the substrate or the film by melt extrusion; a lamination process of laminating the base material and the film with the resin sandwiched therebetween and passing the laminate between a first roller and a second roller, thereby laminating the base material and the film via the resin layer formed of the resin, an outer circumferential surface of at least one of the first roller and the second roller is elastically deformable; One of the first roller and the second roller is biased toward the other roller and can be pushed back in a direction away from the other roller, 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, and when the substrate, the resin layer, and the film are passed between the first roller and the second roller in the bonding process, the outer peripheral surface of at least one of the first roller and the second roller, which is elastically deformable, elastically deforms and / or the first roller and the second roller move away from 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. This is a method for manufacturing a support for a thermal transfer image receiving sheet.

[0032] In addition, a method for producing a support for a thermal transfer image receiving sheet according to the present disclosure includes the steps of: A method for producing a support for a thermal transfer image receiving sheet, comprising laminating a substrate, a resin layer, and a film in this order, the method comprising the steps of: a supplying step of supplying a resin that forms the resin layer onto the substrate or the film by melt extrusion; a lamination process of laminating the base material and the film with the resin sandwiched therebetween and passing the laminate between a first roller and a second roller, thereby laminating the base material and the film via the resin layer formed of the resin, In the lamination process, when the substrate, the resin layer, and the film are passed 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, in this method for manufacturing a support for a thermal transfer image receiving sheet.

[0033] In addition, the sheet bonding apparatus according to the present disclosure is a sheet bonding apparatus comprising 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 bias the first roller toward the second roller, and a clearance adjustment mechanism that can bear at least a portion of the biasing force. The clearance adjustment mechanism may have a movable member, and as the movable member moves from an initial position in which it does not bear the biasing force in a direction in which it increases the proportion of the biasing force it bears, the first roller may be pulled farther away from the second roller.

[0034] The first roller may be supported by an arm so as to be capable of swinging, and may come into contact with or move away from the second roller in response to the swinging of the arm.

[0035] The movable member may have an inclined surface, and as it moves from the initial position, it directly or indirectly contacts the first roller at the inclined surface, and the movable member may operate to pull the first roller away from the second roller via the inclined surface in response to movement away from the initial position.

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

[0037] According to the present 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 form thermal transfer images with a wide variety of expressions by selectively changing the condition of the image surface. [Brief description of the drawings]

[0038] [Figure 1] 1 is a cross-sectional view showing a layer structure of a thermal transfer image receiving sheet according to an embodiment of the present disclosure, cut along a plane including a direction in which the constituent members of the layer structure are stacked. [Diagram 2] 2 is a cross-sectional view showing a layer structure of a support for a thermal transfer image receiving sheet constituting a part of the thermal transfer image receiving sheet shown in FIG. 1, cut along a plane including the direction in which the constituent members of the layer structure are stacked. [Diagram 3] 3 is an enlarged view showing a schematic diagram of a boundary between a substrate and a resin layer of the support for the thermal transfer image-receiving sheet shown in FIG. 2. FIG. [Figure 4] FIG. 3 is a diagram showing an SEM image of the boundary between the substrate and the resin layer of the support for the thermal transfer image-receiving sheet shown in FIG. [Diagram 5] 3 is a diagram showing an SEM image of the boundary between the substrate and the resin layer of a support for a thermal transfer image-receiving sheet different from the support for a thermal transfer image-receiving sheet shown in FIG. 2. FIG. [Figure 6A] FIG. 2 is a diagram showing the thermal transfer image-receiving sheet shown in FIG. 1 and a thermal transfer sheet for transferring a sublimation dye to the thermal transfer image-receiving sheet. [Figure 6B] FIG. 6B is a diagram showing a state of thermal transfer using the thermal transfer image receiving sheet and the thermal transfer sheet shown in FIG. 6A. [Figure 6C] FIG. 6C is a diagram showing the thermal transfer image-receiving sheet after the thermal transfer shown in FIG. 6B. [Figure 7A] 6B is a diagram showing a thermal transfer image-receiving sheet different from the thermal transfer image-receiving sheet shown in FIG. 6A and a thermal transfer sheet for transferring a sublimation dye to the thermal transfer image-receiving sheet. FIG. [Figure 7B] FIG. 7B is a diagram showing a state of thermal transfer using the thermal transfer image receiving sheet and thermal transfer sheet shown in FIG. 7A. [Figure 7C] FIG. 7C is a diagram showing the thermal transfer image receiving sheet after the thermal transfer shown in FIG. 7B. [Figure 8A] 2 is a diagram showing an example of a method of using the thermal transfer image receiving sheet shown in FIG. 1. FIG. [Figure 8B] FIG. 8B is a diagram showing an example of a thermal transfer image formed by the method of use shown in FIG. 8A. [Figure 9] FIG. 2 is a diagram showing a production system for producing the thermal transfer image receiving sheet shown in FIG. [Figure 10]10 is an enlarged view of a sheet bonding device that constitutes a part of the manufacturing system shown in FIG. 9. [Figure 11] 11 is a diagram showing an example of clearance adjustment by a clearance adjusting mechanism of the sheet bonding apparatus shown in FIG. 10. FIG. [Figure 12] 11 is a diagram showing an example of clearance adjustment by a clearance adjusting mechanism of the sheet bonding apparatus shown in FIG. 10. FIG. [Figure 13] FIG. 2 is a table showing the manufacturing conditions of the examples and comparative examples. [Figure 14] FIG. 1 is a table showing the evaluation results of examples and comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] An embodiment of the present disclosure will be described below. In the drawings attached to this specification, the scale and aspect ratio may be appropriately changed and exaggerated from those of the actual objects for the convenience of illustration and ease of understanding. In addition, in the following description, the embodiment may be described using the up-down direction based on the direction of the drawings. However, the present disclosure is not limited to the directions described in the embodiment.

[0040] <<Thermal transfer image receiving sheet>> First, a thermal transfer image receiving sheet 1 according to an embodiment of the present disclosure will be described. Fig. 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 Fig. 1 includes a support 10 for the thermal transfer image receiving sheet and a receiving layer 22. The receiving layer 22 is a layer located on the outermost surface 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 image receiving sheet> 2 is a cross-sectional view showing the layer structure of the thermal transfer image receiving sheet support 10 constituting a part of the thermal transfer image receiving sheet 1. The thermal transfer image receiving sheet support 10 is formed by laminating a substrate 11, a resin layer 12, and a film 20 in this order, and the substrate 11 and the film 20 are bonded by the resin layer 12. In this embodiment, a receiving layer 22 is provided on the film 20 via a primer layer 21. In addition, a back layer 13 is provided on the surface of the substrate 11 opposite to the surface on the resin layer 12 side. The thermal transfer image receiving sheet support 10 is provided with at least the substrate 11, the resin layer 12, and the film 20, and may be capable of supporting the receiving layer 22, and the layer structure is not particularly limited.

[0042] (base material) The substrate 11 may be made of fine paper, coated paper, resin-coated paper, art paper, cast-coated paper, paperboard, 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. There is no particular limitation on the thickness of the substrate 11, and it is, for example, 10 μm or more and 300 μm or less. It is particularly preferably 100 μm or more and 200 μm or less.

[0043] Although details will be described later, in this embodiment, a void 30 (see FIG. 3, etc.) is formed at least in the boundary between the substrate 11 and the resin layer 12 and in the vicinity of the boundary. The void 30 is formed, for example, by laminating the resin layer 12 and the substrate 11 so that the inner space of the recessed portion on the surface of the substrate 11 is not filled with the resin layer 12, or by laminating the resin layer 12 and the substrate 11 so that the void formed inside the substrate 11 is not crushed. Even if the surface roughness of the substrate 11 is relatively large, for example, when the resin layer 12 and the substrate 11 are laminated so that the inner space of the recessed portion on the surface of the substrate 11 is not filled with the resin layer 12, the surface of the resin layer 12 opposite to the substrate 11 side becomes smooth, and the film 20 and the receiving layer 22 can be made smooth while suppressing the manufacturing cost. In other words, the film 20 and the receiving layer 22 on the substrate 11 and the resin layer 12 can be made smooth without using an expensive substrate with a smooth surface, and as a result, the manufacturing cost for obtaining a high-quality image can be suppressed. Although the details will be described later, for example, if a gap 30 is intentionally formed at the boundary between the substrate 11 and the resin layer 12, it becomes possible to form a thermal transfer image with a variety of expressions.

[0044] The base material 11 in this embodiment is selected from the viewpoints of suppressing the manufacturing cost and of enabling the gaps 30 to be actively formed by utilizing the roughness of the base material 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, which allows for both formation of a thermal transfer image with a wide variety of expressions and improvement in image quality. In this disclosure, the surface roughness SRa refers to the center surface average roughness calculated by performing three-dimensional cross-sectional measurement under the following measurement conditions using a Surfcom 1400G manufactured by Tokyo Seimitsu Co., Ltd. in accordance with JIS B 0601:1982, and applying "tilt correction: curve correction" to the obtained cross-sectional curve data. The MD direction of the substrate is an abbreviation for Machine Direction, and refers to the flow direction of the roll paper when preparing a support for a 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. In addition, when the MD and TD directions of the substrate cannot be clearly determined, such as when viewing a print alone, the direction in which the substrate fibers (pulp) are primarily oriented is taken as MD. This direction may differ from the MD and TD in the actual papermaking process, but it follows the standard method of evaluating surface roughness, that is, evaluating the direction where the roughness is maximized, regardless of whether the pattern is random or non-random. <Measurement conditions> Measurement range: TD 40mm x MD 20mm Measurement direction: Measurement is taken while sweeping the needle in the TD direction (the second direction D2 described below). Measurement pitch (X): 19.541 μm Measurement pitch (Y): 290.000μm Number of measurements (X): 2018 Number of measurement lines (Y): 70 lines λs filter: None Tilt correction: None ·Measurement speed: 1.500mm / s Travel return speed: 3.000mm / s Y-axis return position: Measurement start position Pickup type: Standard pickup Polarity Reversal: Normal

[0045] The surface smoothness of the substrate 11 is preferably from 10 seconds to 5000 seconds, and more preferably from 20 seconds to 500 seconds. In this disclosure, smoothness is measured in accordance with JIS P 8155:2010. Commercially available substrates can be used as the substrate 11. For example, fine paper such as Kinbishi N, Kinbishi A, Diamond Form, Broad Fine H, Cream Elegance, Cream Elegance Bulky, Diamond Bulky, Mitsubishi Bulky Book Paper 55A, and Mitsubishi Bulky Book Paper 65A manufactured by Mitsubishi Paper Mills, NPI Fine, NPI Fine Bulky, NPI Form, and Shiraoi manufactured by Nippon Paper Industries Co., Ltd., Utrillo Fine Paper manufactured by Daio Paper Corporation, OK Prince Fine Paper and OK Fine Paper manufactured by Oji Paper Co., Ltd., Star Pack, Linden Comic, and SS Comic Paper manufactured by Marusumi Paper Co., Ltd., and Raicho Fine Paper manufactured by Chuetsu Pulp Co., Ltd. can be suitably used. In addition, there are various grades of coated paper, A1, A2, and A3, and A2 and A3 coated papers are cheaper than A1. Suitable coated papers include Pearl Coat, Real White Gloss, and Casadia Gloss, all manufactured by Mitsubishi Paper Mills Co., Ltd.; Aurora Coat, Ultima Gloss, Silver Diamond S, Pegasus Bulky 8, and Aurora S, all manufactured by Nippon Paper Industries Co., Ltd.; and Utrillo Coat, all manufactured by Daio Paper Co., Ltd. and Oji Paper Co., Ltd.

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

[0047] Among them, a so-called void film having microvoids is advantageous in forming a clear image. Voids (micropores) can be generated in a void film by the following two methods. One is a method in which inorganic fine particles are kneaded in a polymer, and when the compound is stretched, microvoids are generated using the inorganic fine particles as nuclei. The other is a method in which a compound is prepared by blending a polymer (one type or multiple types may be used) that is incompatible with the main resin. When viewed microscopically, the polymers in this compound form a fine sea-island structure. When this compound is stretched, microvoids are generated due to peeling at the sea-island interface or large deformation of the polymers that form the islands. The thickness of the void film used as the film 20 is usually 10 μm or more and 100 μm or less, and preferably 20 μm or more and 50 μm or less.

[0048] The surface roughness SRa of the surface of the film 20 opposite to the resin layer 12 side (the surface on the receiving layer 22 side) is preferably 0.01 μm or more and 0.8 μm or less, more preferably 0.01 μm or more and 0.5 μm or less. 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, the resin layer 12, the film 20, the primer layer 21, and the receiving layer 22 in this order, and 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 together is formed by melt-extruded resin, that is, the resin layer 12 is formed by solidifying the melt-extruded resin as it cools. The resin used to form the resin layer 12 is preferably a thermoplastic resin. Specifically, as the thermoplastic resin, 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, resin obtained by graft-polymerizing unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, or ester monomer to polyolefin, or copolymer, or resin obtained by graft-modifying maleic anhydride to polyolefin, 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 of them. Among these, polyolefins are preferred. In particular, LDPE (low density polyethylene) having a density of 0.93 g / cm3 as measured according to JIS K 6760:1995 is preferred. 3 It is preferable that the density is 0.90 g / cm or less. 3 More than 0.93g / cm 3 More preferably, it is 0.915 g / cm or less. 3 More than 0.925g / cm 3 It is particularly preferable that the density is within the above range. When LDPE having the above range is used as the resin for forming the resin layer 12, it has adhesiveness and can be used alone. In addition, since the elastic modulus is low, the print quality is good and it is easy to balance the curl.

[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. When LDPE is used, the melting point is preferably 105°C or higher and 110°C or lower. In addition, the melting point in this disclosure is a 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 to 20 μm in a dry state, which allows both print quality and curl balance of the image receiving paper to be achieved.

[0052] (Back layer) The back surface layer 13 can be appropriately selected from those having the desired functions depending on the application of the thermal transfer image receiving sheet 1. In particular, it is preferable for the back surface layer 13 to have a function of improving the transportability and curl prevention functions of the thermal transfer image receiving sheet 1. The back surface layer 13 can be formed mainly from 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 by melt-extrusion of a resin, that is, the back surface layer 13 may be formed by solidifying the melt-extrusion of a resin as it cools.

[0054] The resin used to form the back surface layer 13 is preferably a polyolefin having a melting point of 100° C. or more, more preferably a polyolefin having a melting point of 120° C. or more. In particular, the polyolefin is HDPE (high density polyethylene) having a density of 0.93 g / cm 3 It is preferable that the content is 0.93 g / cm or more. 3 More than 0.96g / cm 3 More preferably, it is 0.94 g / cm or less. 3 More than 0.95g / cm 3 It is particularly preferable that the density is within the above range. When HDPE having the above density range is used as the resin used for forming the back surface layer 13, the function of improving transportability and the function of preventing curling can be ensured.

[0055] The thickness of the back layer 13 is not particularly limited, but is preferably 15 μm to 40 μm, more preferably 20 μm to 30 μm in a dry state, which allows a tension balance to be achieved similar to that of the LDPE / void film laminate on the front side, and reduces curling of the support for the thermal transfer image receiving sheet or the thermal transfer image receiving sheet.

[0056] <Receptive layer> The receiving layer 22 is for receiving the dye transferred from the thermal transfer sheet and maintaining the formed image. The surface roughness SRa of the surface 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 the releasability from the thermal transfer sheet. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder, fluorine-based or phosphate-based surfactants, silicone oil, and silicone resin. Examples of the silicone oil include various modified silicone oils such as reactive silicone oil and solidified silicone oil. Among them, modified silicone oil is preferable. As the modified silicone oil, amino-modified silicone, epoxy-modified silicone, aralkyl-modified silicone, epoxy-aralkyl-modified silicone, alcohol-modified silicone, vinyl-modified silicone, and urethane-modified silicone can be preferably used, and epoxy-modified silicone, aralkyl-modified silicone, and epoxy-aralkyl-modified silicone are particularly preferable. It is also preferable to use two or more of these release agents in combination. The amount of these modified silicone oils to be added is preferably 0.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the resin constituting the receiving layer.

[0058] In order to improve the whiteness and further increase the clarity of the image, pigments and fillers such as titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, and finely powdered silica may be added to the receiving layer 22. Plasticizers such as phthalate compounds, sebacic acid ester compounds, and phosphate compounds may also be added. In addition, the receiving layer 22 may further contain crosslinkers, solidifiers, catalysts, ultraviolet absorbers, antioxidants, light stabilizers, and the like.

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

[0060] <Primer layer> Primer layer 21 is provided to improve adhesion between film 20 and receiving layer 22. Examples of resins constituting 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] The primer layer 21 may contain whitening materials such as titanium oxide, zinc oxide, magnesium carbonate, and calcium carbonate to impart whiteness and hiding power. Furthermore, stilbene compounds, benzimidazole compounds, and benzoxazole compounds may be added as fluorescent brighteners to enhance whiteness, hindered amine compounds, hindered phenol compounds, benzotriazole compounds, and benzophenone compounds may be added as ultraviolet absorbers or antioxidants to enhance the light resistance of the image, or cationic acrylic resins, polyaniline, and various conductive fillers may be added to impart antistatic properties. The thickness of the primer layer 21 is preferably 0.1 μm or more and 10 μm or less.

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

[0063] <Boundary between substrate and resin layer in support for thermal transfer image-receiving sheet> Fig. 3 is an enlarged view showing a schematic diagram of the boundary between the substrate 11 and the resin layer 12. As described above, in this embodiment, one or more voids 30 are formed at the boundary between the substrate 11 and the resin layer 12. Fig. 3 shows four voids 30 formed at a part of the boundary between the substrate 11 and the resin layer 12. The structure of the boundary between the substrate 11 and the resin layer 12 in the support 10 for a thermal transfer image receiving sheet will be described below.

[0064] The void 30 is formed at least in the boundary between the resin layer 12 and the substrate 11 and in the vicinity of the boundary. The void 30 shown in FIG. 3 is formed at the boundary and is formed to be recessed in the direction from the resin layer 12 toward the substrate 11. More specifically, the void 30 is formed by a recessed portion present 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, the resin layer 12, and the film 20 (thickness direction of the thermal transfer image receiving sheet support 10) is 0.5 μm or more and 15 μm or less. FIG. 3 also shows a first cross section when the substrate 11, the resin layer 12, and the film 20 are cut at a plane (first direction cut surface) including the lamination direction extending in the first direction D1 in the figure 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 FIG. 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 or more and 15 μm or less on a first cross section obtained by cutting the substrate 11, resin layer 12, and film 20 in a first direction D1 parallel to a plane perpendicular to the stacking direction, and has a width W of 1 μm or more and 1000 μm or less. In addition, the boundary refers to the portion that is the boundary between the resin layer 12 and the substrate 11 that face each other as described above, and the vicinity of the boundary refers to the range from the portion of the boundary where the resin layer 12 and the substrate 11 contact each other to 10% of the thickness of the substrate 11 toward the substrate 11 side, and the range from the portion of the boundary where the resin layer 12 and the substrate 11 contact each other to 10% of the thickness of the resin layer 12 toward the resin layer 12 side.

[0065] The first direction D1 is the so-called MD (Machine Direction), and when the thermal transfer image receiving sheet 1 is wound in a roll, it is its longitudinal direction, in other words, the winding direction. When the substrate 11 is a paper substrate and has a fiber direction, the fiber direction usually coincides with the MD, so that the first direction D1 is usually parallel or approximately parallel to the fiber direction. The fiber direction of the paper substrate can be confirmed, for example, by observing the surface with a microscope. On the other hand, even when the substrate 11 is a paper substrate and has a fiber direction, there may be cases where a void 30 having a height H of 0.5 μm or more and 15 μm or less and a width W of 1 μm or more and 1000 μm or less exists at the boundary of the cross section in a direction different from the fiber direction.

[0066] It is preferable that one or more voids 30 exist within a range of 1 mm in the first direction D1, and more preferably two or more voids 30 exist within a range of 1 mm in the first direction D1. However, the number of voids 30 within a range of 1 mm in the first direction D1 is preferably 50 or less. This makes it possible to sufficiently achieve the effects of the present disclosure while suppressing a decrease in adhesion between the resin layer 12 and the substrate 11.

[0067] 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, the resin layer 12, and the film 20 are cut along a plane (second direction cut surface) including the lamination direction extending in the second direction D2 perpendicular to the first direction D1. Although not shown, the second cross-sectional void has 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 void is also formed to be recessed in the direction from the resin layer 12 toward the substrate 11, similar to the void 30. It is preferable that one or more second cross-sectional voids exist within a range of 1 mm in the second direction D2, and more preferably two or more second cross-sectional voids exist within a range of 1 mm in the second direction D2. However, as described above, the number of second cross-sectional voids within a range of 1 mm in the second direction D2 is preferably 50 or less. This makes it possible to suppress a decrease in adhesion between the resin layer 12 and the substrate 11 while still achieving the effects of the present disclosure.

[0068] FIG. 4 is a diagram showing an SEM image of the boundary between the substrate 11 and the resin layer 12, and two voids 30 are shown. As described above, the voids 30 are formed by laminating the resin layer 12 and the substrate 11 so that the inner space of the recessed portion on the surface of the substrate 11 is not filled with the resin layer 12, as shown in FIG. 4. This is the same for the second cross-sectional void. The thermal transfer image receiving sheet 1 is formed by laminating the substrate 11, the resin layer 12, the film 20, the primer layer 21, and the receiving layer 22 in this order, and when the above layers are laminated so that a void 30 is formed at least at the boundary between the substrate 11 and the resin layer 12 and in the vicinity of the boundary, unevenness is unlikely to occur on the surface of the resin layer 12 on the film 20 side and the surface of the film 20 on the receiving layer 22 side, 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 the thermal transfer image.

[0069] Furthermore, when voids 30 are formed at the boundary between the substrate 11 and the resin layer 12, by adjusting the heat pressure during thermal transfer, in other words, by adjusting the amount of heat and / or the magnitude of printing pressure during thermal transfer, thermal transfer can be performed on the receiving layer 22 so that voids 30 are maintained in some areas, and in other areas so that the receiving layer 22 is partially recessed toward voids 30, making it possible to partially change the texture of the thermal transfer image and also forming a thermal transfer image with ingenious decoration.

[0070] On the other hand, FIG. 5 is a diagram showing an SEM image of the boundary between the substrate 111 and the resin layer 112 of the substrate 110 for thermal transfer image receiving sheet, which is different from the substrate 10 for thermal transfer image receiving sheet. The substrate 110 for thermal transfer image receiving sheet shown in FIG. 5 is formed by laminating the substrate 111, the resin layer 112, and the film 120 in this order, and is formed by lamination that generates a stronger pressure than the substrate 10 for thermal transfer image receiving sheet of the present invention. As a result, as shown in FIG. 5, the resin layer 112 is embedded in the concave portion of the surface of the substrate 111. In such a state, unevenness occurs or is easily generated on the surface of the resin layer 112 on the film 120 side and the surface of the film 120 on the receiving layer side, and the smoothness of these surfaces may be impaired. As a result, during the formation of a thermal transfer image, the surface of the receiving layer may be deformed or may be easily deformed according to the unevenness of the surface of the film 120, and the image quality may be reduced. Even if the heat pressure during thermal transfer is adjusted, it is difficult to intentionally form a portion in the thermal transfer image where the texture is changed. Therefore, the thermal transfer image receiving sheet 1 of this embodiment is useful in that it can improve the quality of the thermal transfer image and can produce images with a wider variety of expressions than thermal transfer image receiving sheets manufactured so that no voids are formed.

[0071] The presence or absence of the 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 support 10 for the thermal transfer image receiving sheet in a plane including the lamination direction, exposing the cross section, and obtaining and observing a 1000x SEM image of the cross section. Specifically, the presence or absence of the 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 support 10 for the thermal transfer image receiving sheet in a plane including the second direction D2 and the lamination direction, exposing the cross section, and obtaining and observing a 1000x SEM image of the cross section. When performing the cutting as described above, it is preferable to cut the thermal transfer image receiving sheet 1 or the support 10 for the thermal transfer image receiving sheet from the side of the back layer 13 with a blade, an ion beam, or the like, and in this case, it is possible to suppress the collapse of the voids 30 caused by cutting. The voids can also be confirmed in a non-destructive manner. In this case, it is preferable to observe the internal structure three-dimensionally by X-ray CT imaging to confirm the presence and size of the voids. Even when observing the side of the thermal transfer image receiving sheet 1 or the support 10 for the thermal transfer image receiving sheet, the voids 30 exposed from the side may be confirmed.

[0072] <Image formation by thermal transfer using a thermal transfer image receiving sheet> Below, we will explain the formation of a thermal transfer image using a thermal transfer image receiving sheet 1 of this embodiment, in which a void 30 is provided at or near the boundary between an inexpensive substrate 11 having a rough surface 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] 6A shows a thermal transfer image receiving sheet 1 according to the present 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 one, and includes a sheet-like supporting substrate 201, a thermally transferable color material layer 202 provided in surface order on one surface of the supporting substrate 201, and an overcoat layer (protective layer). The thermally transferable color material layer 202 is a layer containing a sublimation dye, and includes, for example, a plurality of dye-containing portions having 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 color material layer 202 of the thermal transfer sheet 200 are superimposed so that they are in contact with each other, and printing pressure is applied by the thermal head 220 so that the thermal transfer color material layer 202 is pressed against the receiving layer 22, while a voltage is applied to the thermal transfer color material layer 202 at a position where the sublimation dye is to be transferred, thereby heating it.

[0075] In the thermal transfer image formed by the above-mentioned thermal transfer, as shown in Fig. 6C, the dye 202i is held in the receiving layer 22. Here, in the thermal transfer image receiving sheet 1 according to the present embodiment, the surface of the receiving layer 22 is smooth, so that the formed thermal transfer image has good texture, and good image quality can be obtained.

[0076] On the other hand, FIG. 7A shows a thermal transfer image receiving sheet 100 different from that shown in FIG. 6A, in which there is no void 30 at the boundary between the substrate 111 made of inexpensive paper with a rough surface and the resin layer 112, and the thermal transfer sheet 200 shown in FIG. 6A. The thermal transfer image receiving sheet 100 is formed by laminating the substrate 111, the resin layer 112, the film 120, the primer layer 121, and the receiving layer 122 in this order. In the thermal transfer image receiving sheet 100, as shown in FIG. 5, the resin layer 112 is inserted into the inner space of the concave portion on the surface of the substrate 111, and therefore the surface of the resin layer 112 on the film 120 side is rough. 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 Fig. 7B, when a voltage is applied to the thermally transferable color material layer 202 at a position where the sublimation dye is transferred while applying printing pressure with the thermal head 220 so that the thermally transferable color material layer 202 is pressed against the receiving layer 122, the receiving layer 122 may deform or become easily deformed according to the unevenness of the film surface, resulting in poor texture of the thermally transferred image. Specifically, as shown in Fig. 7C, the surface of the receiving layer 122 after thermal transfer may become rough, resulting in a situation in which the quality of the thermally transferred image may be significantly reduced. Therefore, according to the thermal transfer image receiving sheet 1 of the present embodiment, a high-quality thermal transfer image can be formed while suppressing the manufacturing cost. In other words, even if a substrate having a relatively rough surface is used, a high-quality thermal transfer image can be obtained, so that a high-quality thermal transfer image can be formed while suppressing the manufacturing cost.

[0078] <Examples of using thermal transfer image receiving sheets> On the other hand, as described above, the thermal transfer image receiving sheet 1 according to this embodiment can adjust the heat pressure during thermal transfer to perform thermal transfer on the receiving layer 22 so that the voids 30 are maintained in some parts, and perform thermal transfer on the receiving layer 22 so that the voids 30 are partially recessed in other parts, thereby making it possible to partially change the texture of the thermal transfer image. Figures 8A and 8B show a method of using such a thermal transfer image receiving sheet 1. Of course, if a print is formed by applying a relatively low heat pressure to the entire surface of the image receiving paper, a print with good texture can be produced all over. Conversely, if a print is formed by applying a relatively high heat pressure to the entire surface of the image receiving paper, the print will reflect the rough texture of the base paper.

[0079] That is, in the portion indicated by reference symbol A1 in Fig. 8A, thermal transfer is performed so that the receiving layer 22 is partially recessed toward the voids 30, and in the portion indicated by reference symbol A2, thermal transfer is performed on the receiving layer 22 so as to maintain the voids 30. In this case, as in the thermal transfer image shown in Fig. 8B, it is possible to perform decoration such that the surface in the area AC surrounded by two circles on the image surface becomes silk-like and the surface of the other portions becomes smooth.

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

[0081] When the thermal transfer image receiving sheet support 10 or the thermal transfer image receiving sheet 1 in which the voids 30 are formed in this way is formed through lamination, the surface of the resin layer 12 on the film 20 side and the surface of the film 20 on the receiving layer 22 side are less likely to be uneven, and these surfaces are 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 voids 30 are caused by the unevenness of the substrate 11, if a smooth substrate is used as the substrate 11, the surface of the resin layer 12 on the film 20 side and the surface of the film 20 on the receiving layer 22 side are less likely to be uneven, and the surface of the receiving layer 22 can also be smooth. However, in this case, the cost of the substrate is high, which increases the manufacturing cost. In contrast, in this embodiment, even if an inexpensive and relatively rough substrate is used as the substrate 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 heat pressure during thermal transfer, thermal transfer is performed on the receiving layer 22 so that the voids 30 are maintained in some areas, and thermal transfer is performed so that the receiving layer 22 is partially recessed toward the voids 30 in other areas, thereby making it possible to partially change the texture of the thermally transferred image. Of course, if a print is formed by applying a relatively low heat pressure to the entire surface of the receiving paper, a print with good texture can be produced all over. Conversely, if a print is formed by applying a relatively high heat pressure to the entire surface of the receiving paper, the print will reflect the coarse texture of the base 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 by selectively changing the condition of the image surface, it is possible to form thermal transfer images with a wide variety of expressions.

[0084] <<Thermal transfer image receiving sheet manufacturing system>> Next, an example of a manufacturing system 50 capable of manufacturing the thermal transfer image receiving sheet 1 will be described with reference to Figs. 9 to 12. The manufacturing system 50 shown in Fig. 9 includes 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 surface layer 13, and the sheet laminating device 70 is a device for integrating the film 20 with the surface of the substrate 11 opposite to the surface on the back surface layer 13 side, or for integrating a receiving material 24 in which the film 20, the primer layer 21 and the receiving layer 22 are laminated. Each part of the manufacturing system 50 will be described in detail below.

[0085] <Resin lamination equipment> The resin laminating device 60 has a first press roller 61 and a first chill roller 62 arranged so that their rotation axes are parallel to each other, and a first die 63 that melt-extrudes a resin that forms the back surface layer 13. In FIG. 9, as the substrate 11 and the back surface layer forming resin 13R described later pass between the outer circumferential surface of the first press roller 61 and the outer circumferential surface of the first chill roller 62, the outer circumferential surface of the first press roller 61 and the outer circumferential surface of the first chill roller 62 are separated from each other to form a "gap". On the other hand, in the resin laminating device 60, it is possible to set whether a clearance is provided between the outer circumferential surface of the first press roller 61 and the outer circumferential surface of the first chill roller 62 or whether there is no clearance. The "clearance" provided between the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62 and the above-mentioned "gap" have different meanings. The "clearance" refers to the interval between the outer peripheral surface of the first press roller 61 and the outer peripheral 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 substrate 11 and the back layer forming resin 13R described later do not pass through. When there is no clearance, it means that the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62 are in contact with each other. On the other hand, the "gap" refers to the gap that occurs between the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62 as the substrate 11 and the back layer forming resin 13R described later pass through. In lamination by the resin laminating device 60 in this embodiment, whether a clearance is provided or not, when the substrate 11 and the back surface layer forming resin 13R described later pass between the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62, the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62 are separated from each other as shown in FIG. 9, and a "gap" is generated. Specifically, even though the first press roller 61 and the first chill roller 62 are set in a contact state, the substrate 11 and the back surface layer forming resin 13R are carried in between these two rollers, and thus a "gap" may be generated. Of course, a "clearance" may be provided between the first press roller 61 and the first chill roller 62. However, when a clearance is provided between the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62, the size of the clearance is set to be smaller than the total thickness of the substrate 11 and the back surface layer forming resin 13R. In FIG. 9, between the outer circumferential surface of the first press roller 61 and the outer circumferential surface of the first chill roller 62, there is a “gap” that corresponds to the thickness of the substrate 11 and the molten resin.

[0086] The first press roller 61 is a rubber roller, and the first chill roller 62 is a metal roller, and the outer circumferential surface of the first press roller 61 is more elastically deformable than the outer circumferential 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, and for example, both the first press roller 61 and the first chill roller 62 may be rubber rollers. In the illustrated example, the first press roller 61 transports the substrate 11 by its rotation, but the first chill roller 62 may transport the substrate 11.

[0087] The first die 63 is an outlet portion of the molten resin in the molten resin extruder, and is also called a die head. The first die 63 is disposed above the first press roller 61 and the first chill roller 62, and is configured to supply a resin (hereinafter, the back layer forming resin 13R) to the surface of the substrate 11 opposite to the surface on the first press roller 61 side before the substrate 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 position of the first die 63 in the horizontal direction can be adjusted, and in the illustrated example, the first die 63 is positioned on the first press roller 61 side, and supplies the back layer forming resin 13R to the substrate 11 on the first press roller 61 before being fed between the outer circumferential surface of the first press roller 61 and the outer circumferential surface of the first chill roller 62. Note that the first die 63 can also supply the back layer forming resin 13R to the substrate 11 on the first chill roller 62 or the first chill roller 62 by being disposed on the first chill roller 62 side.

[0088] The first die 63 melts and extrudes a constant amount of the back layer forming resin 13R in a curtain shape, thereby forming a back layer 13 of a constant thickness made of the back layer forming resin 13R on the substrate 11 being transported at a constant speed. The substrate 11 provided with the back layer 13 is then fed between the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62 and sandwiched therebetween, so that the substrate 11 and the back layer 13 are bonded together in a stable integrated state. The back layer 13 is formed by solidifying the back layer forming resin 13R, and the first chill roller 62 is made of metal and promotes the cooling of the back layer forming resin 13R, so that the solidification of the back layer 13 is promoted. The material of the first chill roller 62 is not particularly limited, but is preferably made of metal from the viewpoint of cooling the resin.

[0089] When the first press roller 61 is formed of a rubber roller, the rubber hardness of its outer circumferential surface is preferably 40 or more and 95 or less, particularly 50 or more and 85 or less. If the rubber hardness is less than 40, the adhesive state between the base material 11 and the back surface layer 13 tends to become unstable, while if the rubber hardness is more than 95, the change in the amount of rubber crushing becomes small, the amount of escape of the roller tends to increase, and the fluctuation of the roller increases, so the above numerical range is preferable. In addition, the rubber hardness in this disclosure means the rubber hardness measured by a durometer (type A) conforming to JIS K 6253:1997.

[0090] 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 can suppress manufacturing defects of the back surface layer. This also leads to a reduction in the surface roughness of the back surface layer 13, and can suppress the occurrence of uneven adhesion during lamination by the sheet laminating device 70. Furthermore, the handling properties are improved. The first chill roller 62 preferably has a surface roughness Ra of 1 μm or more and 8 μm or less, and particularly preferably 2 μm or more and 5 μm or less. In this disclosure, the surface roughness Rmax of the first chill roller 62 means the "maximum height" calculated by performing a "cut-off" process on the cross-sectional curve data obtained by performing two-dimensional cross-sectional measurement under the following measurement conditions using a Surfcorder SE-40 manufactured by Kosaka Laboratory Co., Ltd. in accordance with JIS B 0601:1982. The surface roughness Ra of the first chill roller 62 means the "center line average roughness" calculated in a similar manner. The same applies to the second chill roller 72 described below. <Measurement conditions> Measurement conditions: Length: 2.5mm Return Speed: 0.5m / s Cutoff: R+W (R stands for "roughness" and W stands for "waviness")

[0091] Moreover, the surface roughness Ra of the first press roller 61 is preferably 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 means the "arithmetic mean roughness" measured using a laser microscope VK-150 manufactured by Keyence Corporation in accordance with JIS B 0601:2001. Specifically, a measurement sample of 10 mm x 10 mm is cut out from the first press roller, and a measurement target of 2 mm x 2 mm is observed and calculated. This is the same for the second press roller 71 described below. The substrate 11 and the resin layer 12 that have passed between the outer circumferential surface of the first press roller 61 and the outer circumferential surface of the first chill roller 62 are sent to the sheet laminating device 70. Here, 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 inverts the orientations of the substrate 11 and the resin layer 12 from front to back.

[0092] <Sheet bonding device> Next, the sheet laminating device 70 will be described. The sheet laminating device 70 performs the sheet laminating process after the resin laminating process is performed by the resin laminating device 60. The sheet laminating device 70 has 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 that melts and extrudes the resin that forms the resin layer 12, a biasing mechanism 74 that biases the second press roller 71 toward the second chill roller 72, and a clearance adjustment mechanism 75 that adjusts the clearance between the second press roller 71 and the second chill roller 72. Here, the sheet laminating device 70 corresponds to the sheet laminating device of the present disclosure, and 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 substrate 11 provided with the backing layer 13 described later and the receiving material 24 passes between the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72, the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72 are separated from each other to form a "gap". In the sheet laminating device 70, it is also possible to set whether a clearance is provided between the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72 or whether there is no clearance. In other words, in the illustrated example, the roller follower 77 described later and the moving member 81 are in contact with each other, and a clearance is provided between the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72, but it may be set to a state where there is no clearance. In other words, they may be in contact with each other. In the lamination performed in this embodiment, whether a clearance is provided or not, when the laminate of the substrate 11 provided with the backing layer 13 described later and the receiving material 24 passes between the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72, the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72 are separated from each other as shown in FIG. 9, forming a "gap". However, when a clearance is provided, the size of the clearance is set to be smaller than the thickness of the laminate of the substrate 11 provided with the backing layer 13 and the receiving material 24. Although details will be described later, the above-mentioned biasing mechanism 74 and clearance adjustment mechanism 75 can be used to adjust whether or not a clearance is provided between the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72 and the size of the clearance when a clearance is provided. In the sheet bonding apparatus 70, the term "clearance" refers to the gap between the outer peripheral surface of the second press roller 71 and the outer peripheral 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 substrate 11, the resin layer 12, and the film 20 are not passing through. When there is no clearance, it means that the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72 are in contact with each other. On the other hand, in the sheet bonding apparatus 70, the term "gap" refers to the gap that occurs between the outer peripheral surface of the second press roller 71 and the outer peripheral surface of the second chill roller 72 as the substrate 11, the resin layer 12, and the film 20 pass through.

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

[0095] In the illustrated example, the second press roller 71 conveys the substrate 11 provided with the backing layer 13 by its rotation and guides it between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72, and the second chill roller 72 conveys the receiving material 24 by its rotation with the film 20 located on the outer circumferential side and guides it between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72. However, it is also possible that the second press roller 71 guides the receiving material 24 to between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72, and the second chill roller 72 guides the substrate 11 provided with the backing layer 13 to between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72.

[0096] The second die 73 is an outlet of the molten resin in the molten resin extruder, and is also called a die head. The second die 73 is disposed above the second press roller 71 and the second chill roller 72, and supplies resin (hereinafter, resin layer-forming resin 12R) to the surface of the receiver 24 opposite to the surface on the second chill roller 72 side, i.e., onto the film 20, before the receiver 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 position of the second die 73 can be adjusted in the horizontal direction, and in the illustrated example, the second die 73 is disposed on the second chill roller 72 side and supplies the resin layer-forming resin 12R to the receiver 24 on the second chill roller 72 before being fed between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72, but the second die 73 can also supply the resin layer-forming resin 12R to the substrate 11 by disposing it on the second press roller 71 side. 9, the second die 73 is disposed above the second press roller 71 and the second chill roller 72, and supplies a resin (hereinafter, resin layer-forming resin 12R) to the surface of the receiving material 24 opposite to the surface on the second chill roller 72 side, i.e., onto the film 20, 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. This makes it possible to suppress the resin from permeating into the substrate 11.

[0097] The second die 73 melt-extrudes a constant amount of the resin layer-forming resin 12R into a curtain shape, thereby forming a resin layer 12 of a constant thickness made of the resin layer-forming resin 12R on the receiving material 24 being transported at a constant speed. The laminate of the receiving material 24 provided with the resin layer-forming resin 12R and the substrate 11 is then fed between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72 and sandwiched therebetween, thereby integrating the substrate 11 and the receiving material 24 with the resin layer 12. At this time, the resin layer 12 is formed by the solidification of the resin layer-forming resin 12R, and as it solidifies, it bonds the substrate 11 and the receiving material 24 together.

[0098] When the second press roller 71 is a rubber roller, the rubber hardness of the outer peripheral surface is preferably 30 or more and 90 or less, particularly 50 or more and 80 or less. As described above, the thermal transfer image receiving sheet 1 according to this embodiment has the void 30, and the void 30 is formed by laminating the resin layer 12 and the substrate 11 so that the inner space of the concave portion on the surface of the substrate 11 is not filled with the resin layer 12. When the rubber hardness is 30 or more, the variation in the amount of rubber deformation caused by the rotation of the rubber due to the presence or absence of a grip is uniformed. This makes the amount of molten resin penetrating into the concave portion of the substrate 11 constant, and a uniform surface can be formed when viewed from the surface. The depth to which the molten resin fills the inner space of the concave portion of the substrate 11 is a depth at which the molten resin penetrates from a soft state in which the molten resin is in contact with the outermost surface of the substrate 11 and is soft, and penetrates into the inner space of the concave portion of the substrate 11 and hardens to a depth at which the hardness balance of the resin hardness is achieved. 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] The second press roller 71 preferably has a surface roughness Ra of 0.6 μm to 5 μm, more preferably 0.9 μm to 3 μm, and particularly preferably 0.9 μm to 1 μm. If the surface of the second press roller 71 is rough, the smoothness of the resin layer 12 may be impaired, so it is preferable that the surface of the second press roller 71 is as smooth as possible.

[0100] 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. 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 surface of the receiving layer 22 or the film 20 opposite the substrate 11 side may be impaired, so it is preferable that the surface of the second chill roller 72 is as smooth as possible.

[0101] The following describes the configuration related to clearance adjustment in the sheet bonding device 70. In the sheet bonding device 70, the second press roller 71 is supported by an arm 76 so as to be able to swing, and the second press roller 71 comes into contact with or separates from the second chill roller 72 in response to 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. In addition, a swing fulcrum 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 lamination is performed by the sheet laminating device 70, the urging mechanism 74 applies a force for swinging the arm 76 from the other end side of the arm 76, and as a result, the second press roller 71 moves toward the second chill roller 72. In this embodiment, the urging mechanism 74 is an air cylinder, and when the urging mechanism 74 applies a force for swinging the arm 76 from the other end side of the arm 76, if no clearance is provided, the second press roller 71 stops in a state where it is pressed against the second chill roller 72. On the other hand, if a clearance is provided, the second press roller 71 stops in a state where the arm 76 is 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. That is, the biasing force applied by the biasing mechanism 74 is adjusted to such an extent that the second press roller 71 can move (push back) in a direction away from the second chill roller 72 even when the second press roller 71 is biased toward the second chill roller 72. The biasing mechanism 74 is not limited to an air cylinder, and may be, for example, a hydraulic cylinder. The biasing mechanism 74 can adjust the force (pressure) pressing the second press roller 71 against the second chill roller 72 or the force (pressure) pressing the arm 76 against the clearance adjustment mechanism 75, and can adjust the force (pressure) within a range of, for example, 0.14 MPa to 0.60 MPa. In the embodiment described below, the pressure is referred to as "cylinder pressure." In the above description, the case where the swing fulcrum P is between the biasing mechanism 74 and the arm 76 is described, but the same applies when the swing fulcrum P is located at the end in the positional relationship of the three points. Also, when the second press roller, which does not have a swing fulcrum P, is operated by a servo system, the clearance can be adjusted by varying the pressing force of the servo itself or the servo mechanism.

[0103] As described above, when the biasing mechanism 74 applies a force for swinging the arm 76 from the other end side of the arm 76, the clearance adjustment mechanism 75, specifically, contacts a 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 circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72. Alternatively, when there is no clearance, it becomes possible to adjust the degree of contact between the outer circumferential surface of the second press roller 71 and the outer circumferential 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. In detail, the clearance adjustment mechanism 75 moves the second press roller 71, which is biased toward the second chill roller 72, farther away from the second chill roller 72 as the movable member 81 described below moves from an initial position (state shown in Figure 11) in which 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 in which the proportion of the biasing force it bears (upward in Figure 9). This allows the second press roller 71 to move in a direction away from the second chill roller 72 when the substrate, resin, or film passes through, regardless of whether or not the clearance adjustment mechanism 75 bears part of the force that presses the second press roller 71 toward the second chill roller 72.

[0104] 10 shows the sheet bonding apparatus 70, and in particular shows an enlarged view of the clearance adjustment mechanism 75. The clearance adjustment mechanism 75 in this embodiment has a moving member 81 having an inclined surface 81S, and a holding member . 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 FIG. 9 ), thereby contacting the roller follower 77 at the inclined surface 81S. Here, the "direction that increases the proportion of the biasing force it bears" refers to 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 moving member 81 according to the moving position. In this type of clearance adjustment mechanism 75, the arm 76 is configured to be pulled away from the second chill roller 72 via the inclined surface 81S and the roller follower 77 in response to movement of the movable member 81 in a direction away from the initial position (in a direction that increases the proportion of the biasing force (upward in Figure 9)).

[0105] 11 and 12 are diagrams showing an example of clearance adjustment by the clearance adjustment mechanism 75. FIG. 11 shows a state in which the moving member 81 is disposed at an initial position where it does not bear the biasing force of the biasing mechanism 74, specifically, where the moving member 81 does not contact the roller follower 77 or does not bear the biasing force even if it does contact the roller follower 77, and the second press roller 71 and the second chill roller 72 are in contact with each other. In this case, the second press roller 71 is stationary in a state where it is pressed against the second chill roller 72. Then, when the moving member 81 does not bear the biasing force of the biasing mechanism 74 at all, the outer circumferential surface of the second press roller 71 is greatly crushed. Here, the clearance adjustment mechanism 75 can reduce the amount of crushing (elastic deformation) of the outer circumferential surface of the second press roller 71 by moving the moving member 81 upward from the initial position.

[0106] On the other hand, Fig. 12 shows a state in which the movable member 81 has moved upward from the initial position. In the state shown in Fig. 12, the movable member 81 bears all of the urging force of the urging mechanism 74, and a clearance C is provided between the outer circumferential surface of the second press roller 71 and the outer circumferential 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 can decrease the clearance C by moving the movable member 81 downward. The dimension of clearance C is the distance x between the outer circumferential surface of second press roller 71 and the outer circumferential surface of second chill roller 72 in a direction connecting the center of second press roller 71 and the center of second chill roller 72. The size of such clearance C may be found, for example, from an enlarged image of the space between the outer circumferential surface of second press roller 71 and the outer circumferential surface of second chill roller 72. It may also be calculated based on the position of moving member 81 of clearance adjustment mechanism 75. The dimension of clearance C can be actually 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 bonding device 70 can adjust the size of the clearance between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72, and can adjust the amount of crushing of the outer circumferential surface of the second press roller 71 when the outer circumferential surface of the second press roller 71 comes into contact with the outer circumferential surface of the second chill roller 72, in accordance with the movement of the movable member 81 of the clearance adjustment mechanism 75. By such adjustment, it becomes possible to adjust the pressure applied to the laminate of the substrate 11, the resin layer 12, and the receiving material 24 when these are passed between the second press roller 71 and the second chill roller 72.

[0108] More specifically, in the sheet laminating device 70 of the present embodiment, by adjusting the clearance or contact state between the second press roller 71 and the second chill roller 72, when the substrate 11, the resin layer 12, and the receiving material 24 are passed between the second press roller 71 and the second chill roller 72, the outer peripheral surface of the second press roller 71 is elastically deformed and / or the second press roller 71 and the second chill roller 72 are relatively separated from each other, thereby preventing the pressure applied to the substrate 11, the resin layer 12, and the receiving material 24 from becoming excessively large. As described above, the thermal transfer image receiving sheet 1 of the present embodiment has a void 30, and this void 30 is formed by laminating the resin layer 12 and the substrate 11 so that the resin layer 12 does not fill the inner space of the recessed portion on the surface of the substrate 11. That is, according to the sheet bonding apparatus 70 of this embodiment, by preventing the pressure applied to the substrate 11, the resin layer 12, and the receiving material 24 from becoming excessively large, the substrate 11 and the film 20 in the receiving material 24 are bonded together by the resin layer 12 while adjusting the amount of penetration of the resin layer 12 into the surface of the substrate 11. This allows the resin layer 12 and the substrate 11 to be laminated together so that the resin layer 12 does not fill the inner spaces of the recesses in the surface of the substrate 11.

[0109] <Method of manufacturing the thermal transfer image receiving sheet> An example of a method for manufacturing the thermal transfer image receiving sheet 1 using the manufacturing system 50 will be described below with reference to Fig. 9 etc. The manufacturing method described here includes 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 the back surface layer forming resin 13R using a resin laminating device 60, a first laminating step of laminating the base material 11 and the back surface layer 13 using the resin laminating device 60, a second supply step of supplying the 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 position of the movable member 81 of the clearance adjustment mechanism 75 is adjusted to adjust the amount of crushing of the outer surface of the second press roller 71 (the amount of elastic deformation of the second press roller 71) in the clearance or contact state between the second press roller 71 and the second chill roller 72.

[0111] The inventors of the present invention have found that, in order to form a gap 30 at the interface between the substrate 11 and the resin layer 12 while avoiding excessive pressure being applied to the substrate 11, the resin layer 12, and the receiving material 24, when the clearance between the second press roller 71 and the second chill roller 72 before the substrate 11, the resin layer 12, and the receiving material 24 are passed is d1, and the total thickness of the substrate 11, the resin layer 12, and the receiving material 24 before the substrate 11, the resin layer 12, and the receiving material 24 before the substrate 11, the resin layer 12, and the receiving material 24 are passed between the second press roller 71 and the second chill roller 72 is hs, it is preferable that d1-hs is -250 μm or more and -50 μm or less, and particularly preferable that it is -230 μm or more and -50 μm or less. This preferable numerical range is based on the premise that the total thickness hs of the substrate 11, the resin layer 12, and the receiving material 24 is 100 μm or more and 300 μm or less. The inventors of the present invention have further found that it is preferable to apply a pressure of 0.05 MPa or more and 0.4 MPa or less to the laminate including the substrate 11, the resin layer 12, and the receiving material 24 when passing them between the second press roller 71 and the second chill roller 72. In the examples described later, this pressure is called "nip pressure". In this embodiment, taking into consideration the total thickness hs of the substrate 11, the resin layer 12, and the receiving material 24, the clearance or contact state between the second press roller 71 and the second chill roller 72 is adjusted so that d1-hs is -250 μm or more and -50 μm or less, and a pressure of 0.05 MPa or more and 0.4 MPa or less is applied to the laminate when passing the substrate 11, the resin layer 12, and the 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 or more and 0.4 MPa or less, it is possible to suppress air entrapment, stabilize the adhesion state, and obtain a laminate with good surface quality. During this adjustment, the urging mechanism 74 is also driven. At this time, the pressure applied by the urging mechanism 74 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 urging 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 substrate 11 including the back layer 13, the resin layer 12, and the receiving material 24 passing between the second press roller 71 and the second chill roller 72 is specified in advance. In the adjustment process, the pressure output by the urging mechanism 74 and the pressure desired to be applied to the laminate including the substrate 11, the resin layer 12, and the receiving material 24 passing between the second press roller 71 and the second chill roller 72 are determined, and then the clearance or contact state between the second press roller 71 and the second chill roller 72 can be adjusted to a desired state by referring to the above relationship.

[0112] The pressure is the pressure applied to the substrate 11, the resin layer 12, and the receiving material 24 in the stacking direction of the substrate 11, the resin layer 12, and the receiving material 24. The pressure applied to the substrate 11, the resin layer 12, and the receiving material 24 passing between the second press roller 71 and the second chill roller 72 can be determined from the state of the pressure-sensitive paper after passing between the second press roller 71 and the second chill roller 72. The inventors of the present invention measured the pressure applied to the laminate of the substrate 11, the resin layer 12, and the receiving material 24 under the conditions of each example described below, assuming the pressure-sensitive paper as the laminate, and the measured pressure was a maximum of about 0.4 MPa. The pressure applied to the laminate can also be measured by measuring the pressure when the laminate (substrate 11, resin layer 12, receiving material 24) passes by using load cells corresponding to the second press roller 71 and the second chill roller 72. By such measurements, even when the pressure applied to the laminate of the substrate 11, the resin layer 12, and the receiving material 24 was measured under the conditions of each example described later, the calculated pressure was a maximum of about 0.4 MPa. In each example, 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 of the pressure applied to the laminate of the substrate 11, the resin layer 12, and the 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, the resin layer 12, and the receiving material 24 is less than 0.05 MPa, the adhesive state between the substrate 11, the resin layer 12, and the receiving material 24 may become unstable. In addition, air entrapment is likely to occur. Therefore, the upper and lower limits of the preferred range of the pressure applied to the laminate of the substrate 11, the resin layer 12, and the receiving material 24 were set to 0.05 MPa. By setting the pressure in this range, air entrapment can be suppressed, the adhesive state can be stabilized, and a laminate with good surface quality can be obtained.

[0113] After the above-mentioned adjustment process, 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 step is performed after the first press roller 61 and the first chill roller 62 of the resin laminating device 60, the second press roller 71 and the second chill roller 72 of the sheet laminating device 70, and the urging mechanism 74 are driven. When the first press roller 61 and the first chill roller 62 of the resin laminating device 60 rotate, the substrate 11 is transported by the first chill roller 62. In the first supply step, before the substrate 11 is fed between the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62, the back surface layer forming resin 13R is supplied to the surface of the substrate 11 opposite to the surface on the first press roller 61 side. As described above, the back surface layer forming resin 13R is melt-extruded in a constant amount in a curtain shape from the first die 63. As a result, the back surface layer 13 made of the back surface layer forming resin 13R of a constant thickness is formed on the substrate 11 being transported at a constant speed.

[0115] <First lamination process> In the first bonding process, the substrate 11 having the back surface layer 13 provided thereon as described above is fed between the outer peripheral surface of the first press roller 61 and the outer peripheral surface of the first chill roller 62 and sandwiched therebetween, thereby bonding the substrate 11 and the back surface layer 13 in a stable integrated state.

[0116] <Second supply process> The substrate 11 with the integrated back surface layer 13 is guided between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72 by the rotation of the second press roller 71, and at the same time, the second chill roller 72 conveys the receiving material 24 by its rotation and guides it between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72. In the second supplying step, 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 resin layer forming resin 12R is supplied to the surface of the receiving material 24 opposite to the surface on the second chill roller 72 side, i.e., onto the film 20. As described above, the resin layer forming resin 12R is melt-extruded in a constant amount in a curtain shape from the second die 73. As a result, a resin layer 12 of a constant thickness made of the resin layer forming resin 12R is formed on the receiving material 24 being conveyed at a constant speed.

[0117] <Second lamination process> In the second lamination step, the laminate of the receiving material 24 provided with the resin layer 12 as described above and the substrate 11 is fed between the outer circumferential surface of the second press roller 71 and the outer circumferential surface of the second chill roller 72 and sandwiched therebetween, so that the substrate 11 and the receiving material 24 are laminated together in a stable state integrated by the resin layer 12. Here, the pressure applied to the substrate 11, resin layer 12, and receiving material 24 passing between the second press roller 71 and the second chill roller 72 is prevented from becoming excessively large by adjustment in the adjustment step.

[0118] By the above-described manufacturing method, it is possible to manufacture a support 10 for a thermal transfer image receiving sheet or a thermal transfer image receiving sheet 1 having a gap 30 at the boundary between the substrate 11 and the resin layer 12. In the manufacturing method described above, the substrate 11 and the receiving material 24 are integrated with the resin layer 12, but the receiving layer 22 may be laminated on the film 20 after the substrate 11 and the film 20 are integrated with the resin layer 12. 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 will be described.

[0120] The thermal transfer image receiving sheets of Examples 1 to 7 and 9 to 17 described below have the same configuration as the thermal transfer image receiving sheet 1 described in the above embodiment, and include a substrate 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, and includes a substrate 11, a resin layer 12, a back layer 13, and a film 20. The smoothness, SRa, texture, 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 above-mentioned manufacturing system 50, and were manufactured after adjusting the clearance or contact condition between the second press roller 71 and the second chill roller 72 using the clearance adjustment mechanism 75 so that the inner space of the recessed portion on the surface of the substrate 11 was not filled with the resin layer 12.

[0122] On the other hand, Comparative Examples 1 and 2 are thermal transfer image receiving sheets, but are manufactured under different manufacturing conditions than those of Examples 1 to 7 and 9 to 17. More specifically, Comparative Examples 1 and 2 are manufactured by the above-mentioned manufacturing system 50, but without using the clearance adjustment mechanism 75. Therefore, in Comparative Examples 1 and 2, the resin layer 12 and the substrate 11 are subjected to a large pressure between the second press roller 71 and the second chill roller 72.

[0123] The materials and manufacturing conditions of the members used in each example and comparative example are described below. The manufacturing conditions of each example and comparative example are shown in FIG.

[0124] <Example 1> Fine paper was used as the substrate 11. The smoothness of the fine paper was 60 seconds, the surface roughness SRa was 3.5 μm, the thickness was 178 μm, and the density was 0.87 g / cm 3 It is. The back surface layer 13 was formed to a thickness of 24 μm from polyolefin obtained by mixing HDPE (high density polyethylene) and LDPE (low density polyethylene) in a ratio of 8:2. The thickness of the back surface layer 13, 24 μm, is the thickness when the back surface layer forming resin 13R forming the back surface layer 13 is applied onto the substrate 11 by melt extrusion. The melting point of the polyolefin is 127° C., and the density is 0.948 g / cm 3 It is. The resin layer 12 was formed to a thickness of 15 μm from polyolefin, which is LDPE (low density polyethylene). The thickness of the resin layer 12, 15 μm, is the thickness when the resin layer-forming resin 12R forming the resin layer 12 is applied onto the film 20 by melt extrusion. The melting point of the polyolefin is 107° C., and the density is 0.916 g / cm 3 It is. The film 20 is a void film having a thickness of 35 μm, and is made of polypropylene.

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

[0126] <Coating fluid for primer layer> Polyester 4.2 parts by weight (Polyester (registered trademark) WR-905, Nippon Synthetic Chemical Industry Co., Ltd.) Titanium oxide 8.4 parts by weight (TCA-888 Sakai Chemical Industry Co., Ltd.) Isopropyl alcohol (IPA) 10 parts by weight ·Water 30 parts by mass

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

[0128] <Coating solution for forming receiving layer> Vinyl chloride-vinyl acetate copolymer 60 parts by weight (Solvine (registered trademark) C, Nissin Chemical Industry Co., Ltd.) Epoxy modified silicone resin 1.2 parts by weight (X-22-3000T Shin-Etsu Chemical Co., Ltd.) Methylstyrene-modified silicone resin 0.6 parts by weight (X-24-510 Shin-Etsu Chemical Co., Ltd.) Methyl ethyl ketone 2.5 parts by weight Toluene 2.5 parts by weight

[0129] The thickness of the laminate made of the above-mentioned members (11, 12, 13, 20, 21, 22) before entering between the second press roller 71 and the second chill roller 72 is 251 μm. If the thickness of the base material 11 (178 μm), the thickness of the back layer 13 (24 μm), the thickness of the resin layer 12 (15 μm), the thickness of the film 20 (35 μm), the thickness of the primer layer 21 (0.8 μm), and the thickness of the receiving layer 22 (3 μm) are simply added together to obtain a thickness of 255.8 μm, which is larger than the thickness of the laminate described above (251 μm). The reason why the thickness of the laminate before entering between the second press roller 71 and the second chill roller 72 is smaller than the thickness obtained by simply adding the thicknesses 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, a part of the back resin penetrates into the uneven portion on the back surface of the paper base material. Such a reduction in thickness also occurs in the other examples and comparative examples described below.

[0130] The size of 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. Such a clearance is formed by the clearance adjustment mechanism 75 bearing all of the biasing force of the biasing mechanism 74. Here, when 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 pass through is d1, and the total thickness of the substrate 11, resin layer 12, and receiving material 24 before they pass between the second press roller 71 and the second chill roller 72 is hs, d1-hs is -201 μm (see "Difference" in the table).

[0131] The second press roller 71 is a rubber roller, and has a rubber hardness of Hs 70. The surface roughness Ra of the outer circumferential 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 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 to a position 9 mm toward the center of the second press roller 71 in the direction connecting the centers of the second press roller 71 and the second chill roller 72.

[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, pressure-sensitive paper (Fujifilm LLLW for ultra-low pressure) was used as the receiving paper, and the pressure (nip pressure) measured according to the difference (-201 μm) between the laminate thickness (251 μm) and the "clearance between the rollers (50 μm)" was 0.20 MPa or less. The nip pressure was also measured in Examples 2 to 17 and Comparative Examples 1 and 2. The nip pressure values ​​measured for each of the Examples and Comparative Examples are shown in the table shown in FIG.

[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 / cm 3 The paper used was high-quality paper. Furthermore, the thickness of the laminate before entering between second press roller 71 and second chill roller 72 is 220 μm. d1-hs is −170 μm. The other conditions were the same as in the first embodiment.

[0136] <Example 3> The substrate 11 has a smoothness of 410 seconds, a surface roughness SRa of 2.6 μm, a thickness of 155 μm, and a density of 1.02 g / cm 3 The paper used was high-quality paper. Furthermore, the thickness of the laminate before entering between second press roller 71 and second chill roller 72 is 228 μm. d1-hs is −178 μm. The other conditions were the same as in the first embodiment.

[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 / cm 3 The paper used was high-quality paper. Furthermore, the thickness of the laminate before entering between second press roller 71 and second chill roller 72 is 238 μm. d1-hs is −188 μm. The other conditions were the same as in the first embodiment. <Example 5> The substrate 11 has a smoothness of 410 seconds, a surface roughness SRa of 2.8 μm, a thickness of 160 μm, and a density of 1.01 g / cm 3 The paper used was high-quality paper. Furthermore, the thickness of the laminate before entering between second press roller 71 and second chill roller 72 is 233 μm. d1-hs is −183 μm. The other conditions were the same as in the first embodiment. <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 / cm 3 The paper used was high-quality paper. Furthermore, the thickness of the laminate before entering between second press roller 71 and second chill roller 72 is 228 μm. d1-hs is −178 μm. The other conditions were the same as in the first embodiment. <Example 7> The pressing pressure of the air cylinder which is the biasing mechanism 74 is 0.14 MPa. The other conditions were the same as in Example 2.

[0138] <Example 8> In Example 8, in the sheet bonding apparatus 70, only the film 20 is bonded to the substrate 11 via the resin layer 12. The thickness of the film 20 is 35 μm. d1-hs is −166 μm. The other lamination conditions were the same as in Example 2. After laminating the front and back surfaces, a primer and a receptor layer were applied to prepare 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. The other conditions were the same as in Example 2.

[0140] <Example 10> The size of 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. The rubber hardness of the second press roller 71 is Hs60. The other conditions were the same as in Example 2.

[0141] <Example 11> The size of 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. The other conditions were the same as in Example 10.

[0142] <Example 12> The size of 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. The other conditions were the same as in Example 10.

[0143] <Example 13> The size of 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. The other conditions were the same as in Example 10.

[0144] <Example 14> The size of 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 press against each other so that the outer circumferential surface of the second press roller 71 is crushed by 50 μm. Note that (-50) in the table is the amount of crushing (amount of elastic deformation) of the outer circumferential surface of the second press roller 71. The other conditions were the same as in Example 10. During the manufacturing of the fourteenth embodiment, the clearance adjustment mechanism 75 bears part of the biasing force of the biasing mechanism 74.

[0145] <Example 15> The size of 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 press against each other so that the outer circumferential surface of the second press roller 71 is compressed by 150 μm. The other conditions were the same as in Example 10. During the manufacturing of the fifteenth embodiment, the clearance adjustment mechanism 75 also bears part of the biasing force of the biasing mechanism 74.

[0146] <Example 16> The size of 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 press against each other so that the outer circumferential surface of the second press roller 71 is compressed by 250 μm. The other conditions were the same as in Example 10. During the manufacture of the sixteenth embodiment, the clearance adjustment mechanism 75 also bears part of the biasing force of the biasing mechanism 74.

[0147] <Example 17> The size of 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. The other conditions were the same as in Example 2.

[0148] <Comparative Example 1> In Comparative Example 1, the size of 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 press against each other so that the outer circumferential surface of the second press roller 71 is compressed by about 2000 μm. The other conditions were the same as in Example 2. During the production of Comparative Example 1, clearance adjustment mechanism 75 does not bear any of the urging force from urging mechanism 74. That is, the laminate receives a large pressure between second press roller 71 and second chill roller 72. Separately, pressure-sensitive paper (manufactured by Fuji Film Corporation, LLLW for ultra-low pressure) was used as the image-receiving paper, and the pressure measured in accordance with the thickness of the laminate (220 μm) was 0.74 MPa.

[0149] <Comparative Example 2> In Comparative Example 2, the size of 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 press against each other so that the outer circumferential surface of the second press roller 71 is compressed by about 2000 μm. The other conditions were the same as in Example 7. During the production of Comparative Example 2, clearance adjustment mechanism 75 also does not bear any of the urging force from urging mechanism 74. That is, the laminate is subjected to a large pressure between second press roller 71 and second chill roller 72. Separately, pressure-sensitive paper (manufactured by Fuji Film Corporation, LLLW for ultra-low pressure) was used as the image-receiving paper, and the pressure measured in accordance with the thickness of the laminate (220 μm) was 0.41 MPa.

[0150] <Evaluation> 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 receiving layer or film, (3) the surface texture of the thermally transferred image, (4) the adhesion between the substrate and the film, and (5) the manufacturing cost. The details of (1) to (5) are as follows.

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

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

[0153] (3) Geography The texture of the image was evaluated by visual observation using a dye-sublimation thermal transfer printer (MEGAPIXELIII, manufactured by ALTECH ADS Co., Ltd.) to print a gray image on the thermal transfer image-receiving sheet of the Examples and Comparative Examples, or on a thermal transfer image-receiving sheet prepared using the support for the thermal transfer image-receiving sheet of the Examples, and the texture was evaluated according to the following evaluation criteria. (Evaluation Criteria) A: The gray image was uniform, no irregularities were observed on the surface, and the image had good smoothness, texture, and feel. B: The gray image is almost uniform, and although some surface irregularities are observed, the smoothness, texture, and feel are somewhat poor, but there is no problem in practical use. C: The gray image was not uniformly formed, the surface was uneven and the texture was quite noticeable, and the smoothness, texture and feel were lacking.

[0154] (4) Adhesiveness After sticking mending tape (manufactured by Nichiban Co., Ltd.) to the thermal transfer image receiving sheet, the mending tape was peeled off from the thermal transfer image receiving sheet so that the surface of the mending tape was at 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 were as follows. (Evaluation Criteria) A: No peeling occurred at the interface between the substrate and the film. B: Part of the interface between the substrate and the film was peeled off, or heat damage was observed in the film. C: Peeling occurred over most of the interface between the substrate and the film.

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

[0156] The above evaluation results are shown in Figure 14. Figure 14 also shows the results of checking the presence or absence of voids in SEM images of the cross sections of the thermal transfer image receiving sheets of each Example and Comparative Example. The acceleration voltage when acquiring the SEM images was 3.0 kV. The cross sections checked were the cross section in MD (first direction D1) and the cross section in TD (second direction D2). The voids in the MD cross section were observed over a range of 1 mm in the first direction D1 by cutting the thermal transfer image receiving sheet 1 or the support 10 for the thermal transfer image receiving sheet in a plane including the first direction D1 and the stacking direction, exposing the cross section, and obtaining a 1000x SEM image of the cross section. The voids in the cross section of TD (second cross-sectional voids) were observed by cutting the thermal transfer image receiving sheet 1 or the support 10 for the thermal transfer image receiving sheet in a plane including the second direction D2 and the stacking direction, exposing the cross section, and obtaining a 1000x SEM image of the cross section to observe a range of 1 mm in the second direction D2. When carrying out the above-mentioned cutting, the thermal transfer image-receiving sheet 1 or the support 10 for the thermal transfer image-receiving sheet was cut from the side of the receiving layer 22 with a blade.

[0157] As shown in FIG. 14, the surface smoothness of the receiving layer 22 in Examples 1 to 17 was 35,000 seconds or more, and many of them were very smooth, especially 50,000 seconds or more. The surface roughness SRa of Examples 1 to 17 was 2.2 μm or less, and the smoothness could be evaluated from this point of view. Furthermore, the texture was good in all images observed after the actual thermal transfer. The adhesion between the substrate 11 and the film 20 was also good except for Example 10. Furthermore, since all Examples 1 to 17 use high-quality paper, they are advantageous in terms of manufacturing costs. It is presumed that the influence on the adhesion of Example 10 was caused by the pressure during lamination being smaller than that of the other Examples.

[0158] On the other hand, the surface smoothness of the receiving layer in Comparative Examples 1 and 2 was less than 20,000, and the surface roughness SRa was 2.4 or more, which means that the smoothness was impaired compared to the Examples. Furthermore, even when the image was observed after the actual thermal transfer, the texture was not good.

[0159] The "total number of voids with a height of 0.5 μm or more and a width of 1 μm or more" in the top row of the table in Fig. 14 is an item indicating the total number of voids within a range of 1 mm in the first direction D1 and the number of voids within a range of 1 mm in the second direction D2. The number and size of voids confirmed in the first direction D1 are shown below the "MD cross section" in the top row of the table in Fig. 14. The number and size of voids confirmed in the second direction D2 are shown below the "TD cross section" in the top row of the table in Fig. 14.

[0160] In each example, one or two voids 30 were found in each direction. In example 5, no voids were found in the cross section in the second direction D2, which is presumed to be due to a somewhat increased pressure applied to the laminate. On the other hand, in comparative examples 1 and 2, almost no voids were found.

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

[0162] Although the embodiment and examples of the present disclosure have been described above, the present disclosure is not limited to the above-mentioned embodiment or examples, and various modifications can be made to the above-mentioned embodiment. For example, the above-mentioned embodiment is based on the premise of a dye-sublimation type thermal transfer method, but the present disclosure can also be applied to a melting type thermal transfer method. [Explanation of symbols]

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

Claims

1. A method for producing a thermal transfer image receiving sheet, comprising laminating a substrate, a resin layer, and a receiving material having a film and a receiving layer in this order, comprising: A supplying step of supplying a resin that forms the resin layer onto the substrate or onto the film of the receiving material by melt extrusion; a lamination step of overlapping the base material and the receiving material with the resin sandwiched therebetween and passing the overlapping parts between a first roller and a second roller to laminate the base material and the receiving material via the resin layer formed of the resin, an outer circumferential surface of at least one of the first roller and the second roller is elastically deformable; one of the first roller and the second roller is biased toward the other roller and can be pushed back in a direction away from the other roller, or the first roller and the second roller are biased toward each other and can be pushed back in directions away from each other, A method for manufacturing a thermal transfer image receiving sheet, in which, when the substrate, the resin layer, and the receiving material are passed between the first roller and the second roller in the bonding process, the outer peripheral surface of at least one of the first roller and the second roller, which are elastically deformable, elastically deforms and / or the first roller and the second roller move away from each other, thereby bonding the substrate and the receiving material while adjusting the amount of penetration of the resin layer into the surface of the substrate.

2. 2. The method for manufacturing a thermal transfer image receiving sheet according to claim 1, wherein in the lamination process, when the substrate, the resin layer, and the receiving material are passed 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 substrate, the resin layer, and the receiving material.

3. The first roller is configured to be able to be pushed back in a direction away from the second roller while being biased toward the second roller, preparing a clearance adjustment mechanism that operates to increase a burden ratio of the biasing force as the first roller moves farther away from an initial position where the first roller does not bear the biasing force toward the second roller, thereby greatly separating the first roller biased toward the second roller from the second roller; and adjusting a movement position of the clearance adjustment mechanism, In the step of adjusting the movement position of the clearance adjustment mechanism, By adjusting a moving position of the clearance adjustment mechanism, an amount of elastic deformation of an outer circumferential surface of at least one of the first roller and the second roller, which is elastically deformable, is adjusted in a state in which there is no clearance between the first roller and the second roller; or Or, The method for producing a thermal transfer image receiving sheet according to claim 1 or 2, further comprising the step of adjusting a size of the clearance by providing a clearance between the first roller and the second roller.

4. A method for producing a support for a thermal transfer image receiving sheet, comprising laminating a substrate, a resin layer, and a film in this order, the method comprising the steps of: a supplying step of supplying a resin that forms the resin layer onto the substrate or the film by melt extrusion; a lamination process of laminating the base material and the film with the resin sandwiched therebetween and passing the laminate between a first roller and a second roller, thereby laminating the base material and the film via the resin layer formed of the resin, an outer circumferential surface of at least one of the first roller and the second roller is elastically deformable; one of the first roller and the second roller is biased toward the other roller and can be pushed back in a direction away from the other roller, or the first roller and the second roller are biased toward each other and can be pushed back in directions away from each other, A method for manufacturing a support for a thermal transfer image receiving sheet, in which, when the substrate, the resin layer, and the film are passed between the first roller and the second roller in the bonding process, the outer peripheral surface of at least one of the first roller and the second roller, which are elastically deformable, elastically deforms and / or the first roller and the second roller move away from 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.

Images