Recording medium, and method for manufacturing recorded article having stereoscopic image

Abstract

To provide a recording medium which enables formation of a stereoscopic image where clear uneven feeling is expressed, and a method for manufacturing a recorded article having a stereoscopic image where clear uneven feeling is expressed using the recording medium.SOLUTION: A recording medium includes a base material, and a foam layer which is provided on the base material and contains a foam material foamed by heat and a binder resin. A water contact angle to the surface of the foam layer after 30 seconds after water is brought into contact with the surface of the foam layer is 30° or more and 80° or less, and a ratio of a diameter of water droplets after 30 seconds after water is brought into contact with the surface of the foam layer to a diameter of water droplets after 0.01 second after the water is brought into contact with the surface of the foam layer is 1.3 times or less. A method for manufacturing a recorded article having a stereoscopic image includes the steps of: applying a foam promotion liquid to the recording medium; foaming a foam material, and forming a stereoscopic image.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a recording medium and a method for manufacturing a recording product having a stereoscopic image.

Background Art

[0002] Conventionally, as one method for forming a stereoscopic image, a method using a recording medium provided with a thermally expandable sheet that expands by foaming according to the amount of heat absorbed on one surface of a base material is known. Specifically, after forming a light absorption pattern of a grayscale image on the thermally expandable sheet of this recording medium, light is irradiated to generate heat according to the grayscale of the image, causing the thermally expandable material to expand by foaming and forming a stereoscopic image (Patent Document 1).

[0003] Also, a method has been proposed in which a plasticizer for the shell wall resin of a foaming capsule is applied or printed on a stereoscopic image forming layer of a recording material for stereoscopic image formation provided with a stereoscopic image forming layer containing foaming capsules, and then the foaming capsules are heated and foamed to form a stereoscopic image (Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the method proposed in Patent Document 1, when printing black ink or the like on the heat-absorbing portion, the heat-absorbing portion is foamed and expanded to create a raised surface before the color image is printed. Therefore, it was necessary to print a solid white image over the entire surface of the recording medium before printing the color image. On the other hand, in the method proposed in Patent Document 2, a transparent plasticizer is applied, so the effort of printing a solid white image as in the method proposed in Patent Document 1 is unnecessary, and a three-dimensional image can be formed efficiently. However, there was room for further improvement in the sense of unevenness of the formed three-dimensional image.

[0006] Therefore, an object of the present invention is to provide a recording medium capable of forming a three-dimensional image with a clear sense of relief. Another object of the present invention is to provide a method for manufacturing a recording material having a three-dimensional image with a clear sense of relief. [Means for solving the problem]

[0007] In other words, the present invention provides a recording medium comprising a base material and a foamed layer provided on the base material, the foamed layer containing a heat-activated foaming material and a binder resin, wherein the contact angle of water with respect to the surface of the foamed layer 30 seconds after water is brought into contact with the surface of the foamed layer is 30° or more and 80° or less, and the ratio of the diameter of a water droplet 30 seconds after water is brought into contact with the surface of the foamed layer to the diameter of a water droplet 0.01 seconds after water is brought into contact with the surface of the foamed layer is 1.3 times or less.

[0008] Furthermore, the present invention provides a method for manufacturing a recording material having a three-dimensional image, comprising the steps of: applying a foaming accelerator containing a foaming accelerator component that lowers the foaming start temperature of the foaming material and water to a recording medium comprising a base material and a foamed layer provided on the base material, the foaming layer containing a foaming material that foams when heated and a binder resin; and heating the foamed layer of the recording medium to which the foaming accelerator has been applied to cause the foaming material to foam and form a three-dimensional image, wherein the contact angle of water with respect to the surface of the foamed layer 30 seconds after water is brought into contact with the surface of the foamed layer is 30° or more and 80° or less, and the ratio of the diameter of the water droplet 30 seconds after water is brought into contact with the surface of the foamed layer to the diameter of the water droplet 0.01 seconds after water is brought into contact with the surface of the foamed layer is 1.3 times or less. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a recording medium capable of forming a three-dimensional image with a clear sense of relief. Furthermore, according to the present invention, it is possible to provide a method for manufacturing a recording material having a three-dimensional image with a clear sense of relief. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view showing an example of the recording medium of the present invention. [Figure 2] This is a schematic diagram showing the general configuration of a manufacturing apparatus for recording materials containing three-dimensional images. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below with reference to preferred embodiments. Unless otherwise specified, the physical properties are those obtained at room temperature (25°C).

[0012] <Recording medium> When attempting to form a three-dimensional image by promoting the foaming of a foaming material using a foaming accelerator containing a foaming-promoting component, it is necessary to have the foaming accelerator near the foaming material. To have the foaming accelerator near the foaming material, it is important to allow the foaming accelerator to penetrate into the depth direction of the foaming layer. As a result of our research, we have found that by satisfying the following requirements (i) and (ii), it is possible to efficiently penetrate an aqueous foaming accelerator containing water into the depth direction of the foaming layer, leading to the present invention. (i) The contact angle of water with the surface of the foam layer 30 seconds after water is brought into contact with the surface of the foam layer is between 30° and 80°. (ii) The ratio of the diameter of a water droplet 30 seconds after contact with the foamed layer to the diameter of a water droplet 0.01 seconds after contact with the foamed layer is 1.3 times or less.

[0013] If the ratio of the diameter of a water droplet 30 seconds after contact with the foam layer to the diameter of a water droplet 0.01 seconds after contact with the foam layer surface is greater than 1.3, then the aqueous foaming accelerator will excessively wet the surface of the foam layer. This will cause the accelerator to spread more easily in the lateral direction of the foam layer than in the depth direction, affecting the clarity of the resulting three-dimensional image. In other words, it is important to suppress the lateral wetting of the foam layer while prioritizing the penetration of the foaming accelerator into the depth direction of the foam layer.

[0014] In addition, when the contact angle of water with respect to the surface of the foam layer exceeds 80° 30 seconds after bringing water into contact with the surface of the foam layer, the penetration rate of the foam promoting liquid into the foam layer is slow, and it becomes difficult for the foam promoting liquid to penetrate to the lower part of the foam layer. When it is necessary to form a stereoscopic image at a higher speed, the permeability of the foam promoting liquid into the foam layer is important. On the other hand, when the contact angle of water with respect to the surface of the foam layer is less than 30° 30 seconds after bringing water into contact with the surface of the foam layer, the penetration rate of the foam promoting liquid into the foam layer becomes too fast. For this reason, before the foam promoting component interacts with the foam material and sufficiently promotes the foaming property of the foam material, the foam promoting liquid passes through. As a result, the foaming property of the foam material existing near the surface of the foam layer is particularly likely to decrease, and it becomes difficult to express a distinct uneven feeling. Further, the contact angle of water with respect to the surface of the foam layer 30 seconds after bringing water into contact with the surface of the foam layer is preferably 30° or more and 75° or less.

[0015] FIG. 1 is a cross-sectional view schematically showing an example of a recording medium used in a method for manufacturing a recording article having a stereoscopic image of the present invention. As shown in FIG. 1, the recording medium 10 has a base material 11 and a foam layer 12 provided on the base material 11 and containing a foam material such as foam particles 13 that foam by heat. Hereinafter, details of the recording medium of the present invention will be described.

[0016] (Base material) The base material 11 functions as a support for supporting the foam layer 12 (FIG. 1). The type of the base material is not particularly limited. Examples of the base material include paper made of ordinary natural pulp; kenaf paper; plastic film sheets such as polypropylene, polyethylene, and polyester; so-called synthetic paper or non-woven fabric obtained by making synthetic fibers, synthetic pulp, or synthetic resin films look like paper; and the like.

[0017] (Foam layer) [Foam material] As shown in Figure 1, the foamed layer 12 is a layer provided on at least one surface of the substrate 11, containing a foaming material such as foamed particles 13 and a binder resin 14. As the foaming material, chemical foaming materials or microencapsulated foaming materials (foamed particles 13) can be used. Among these, microencapsulated foaming materials (foamed particles 13) are preferred. The foamed particles 13 have a shell layer 15 containing a thermoplastic resin and a volatile material 16 enclosed within the shell layer 15, and are also called a heat-expandable microencapsulated foaming material. When heat is applied to the foamed particles 13, the thermoplastic resin constituting the shell layer 15 softens, and the volatile material 16 enclosed within the shell layer 15 vaporizes and expands in volume. As a result, the foamed particles 13 expand like a balloon.

[0018] Examples of thermoplastic resins contained in the shell layer include polystyrene, styrene-acrylic acid ester copolymer, polyamide resin, polyacrylic acid ester, polyvinylidene chloride, polyacrylonitrile, polymethyl methacrylate, vinylidene chloride-acrylonitrile, methacrylic acid ester-acrylic acid copolymer, vinylidene chloride-acrylic acid copolymer, and vinylidene chloride-acrylic acid ester copolymer. Among these, polyacrylonitrile is preferred as the thermoplastic resin.

[0019] Examples of the volatile material include low molecular weight hydrocarbons such as ethane, ethylene, propane, propene, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, heptane, and petroleum ether; chlorofluorocarbons such as CCl3F, CCl2F2, CClF3, and CClF2-CClF2; tetraalkylsilanes such as tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, and trimethyl-n-propylsilane; and the like. Among them, the volatile material is preferably a hydrocarbon having a molecular weight of 120 or less. Also, there is no particular limitation on the lower limit of the molecular weight of the volatile material (hydrocarbon), but for example, it is preferably 50 or more. Among them, from the viewpoint of foamability, the volatile material is preferably isobutane. The content of the foam particles in the foam layer is preferably 5% by mass or more and 95% by mass or less based on the total mass of the foam layer.

[0020] The foam start temperature of the foaming material is preferably 80°C or higher and 100°C or lower. When manufacturing the recording medium, usually, after applying a coating liquid containing the foaming material onto a substrate, the coating liquid is dried to form a foam layer. If the foam start temperature of the foaming material is less than 80°C, it is necessary to set the temperature during drying of the coating liquid lower than the foam start temperature, so the productivity of the recording medium may be slightly reduced. On the other hand, if the foam start temperature of the foaming material exceeds 100°C, the heating temperature during forming the three-dimensional image becomes high, so excessive thermal energy may be required.

[0021] [Binder resin] The foamed layer 12 contains a binder resin 14 to enhance adhesion to the substrate 11 (Figure 1). The binder resin plays an important role in preventing the foamed layer from peeling off the substrate when the foaming material in the foamed layer foams due to heat. It is preferable to use a water-insoluble resin as the binder resin. By including a water-insoluble resin in the binder resin, the binder resin becomes less likely to dissolve even with water in the foaming accelerator, thus suppressing the decrease in adhesion between the foamed layer and the substrate caused by the foaming accelerator. Furthermore, even if an aqueous ink containing water is applied to the recording medium, the decrease in adhesion between the foamed layer and the substrate can be suppressed for the same reason. Here, a water-insoluble resin refers to a resin in which 95% or more by mass remains when the resin is immersed in 80°C hot water for 2 hours.

[0022] The binder resin is preferably at least one water-insoluble resin selected from the group consisting of acrylic resin, urethane resin, and polyacrylonitrile resin. Furthermore, the water-insoluble resin is preferably a non-absorbent resin. The foamed layer may contain a water-soluble resin together with the water-insoluble resin, as long as the effects of the present invention are obtained.

[0023] When manufacturing water-insoluble resins, a dispersible emulsion is typically prepared by polymerizing monomers in water while using water-soluble resins such as polyvinyl alcohol or surfactants. However, the water-soluble resins or surfactants used as dispersants during the manufacturing of the water-insoluble resin may affect the water permeability of the foamed layer containing the water-insoluble resin. Therefore, it is necessary to appropriately select the type of water-insoluble resin from the viewpoint of controlling properties such as the contact angle with water and the wetting properties of the formed foamed layer surface.

[0024] The glass transition temperature of the binder resin is preferably 70°C or more lower than the foaming start temperature of the foaming material, and more preferably 80°C or more lower. By using a binder resin whose glass transition temperature is 70°C or more lower than the foaming start temperature of the foaming material, it is possible to suppress the occurrence of problems such as the foaming material becoming difficult to foam. The glass transition temperature of the binder resin is preferably between -10°C and 10°C.

[0025] The binder resin is preferably a resin that can be softened by the foam-promoting component in the foam-promoting liquid. By using a resin that softens with the foam-promoting component as the binder resin, the binder resin in the area to which the foam-promoting liquid is applied softens, thereby improving foaming properties.

[0026] From the perspective of further improving the foaming properties of the foam layer, the Martens hardness of the foam layer, measured in accordance with ISO 14577, is 15 N / mm². 2 The following is preferable: The Martens hardness of the foamed layer varies depending on the properties of the binder resin contained in the foamed layer. Therefore, it is preferable to select the properties of the binder resin so that the Martens hardness of the foamed layer is within an appropriate range.

[0027] From the viewpoint of further improving the foaming properties of the foam layer, it is preferable that the creep CIT1 of the foam layer after increasing the load, measured under the conditions shown below, be between 25 and 70. The creep CIT1 of the foam layer, like the Martens hardness mentioned above, varies depending on the properties of the binder resin contained in the foam layer. Therefore, it is preferable to select the properties of the binder resin so that the creep CIT1 of the foam layer falls within an appropriate range. [conditions] • Indentation force F: 3.0 μm / 20s • Creep time C: 20.0s

[0028] The mass ratio of the foaming material to the binder resin is preferably 5:95 to 90:10. By keeping the mass ratio of the foaming material to the binder resin within the above range, both the foaming properties of the foaming material and the binding properties of the binder resin to the substrate can be improved. The foamed layer may also contain components such as pigments, antioxidants, dyes, and surfactants, as long as they do not impair the foaming properties.

[0029] The arithmetic mean roughness Ra of the foamed layer surface is preferably 1.0 μm or more, and more preferably 1.6 μm or more. By setting the arithmetic mean roughness Ra of the foamed layer surface to 1.0 μm or more, the surface area of ​​the foamed layer surface becomes sufficiently large, and the permeability of the foaming accelerator can be improved.

[0030] (Method of manufacturing recording medium) To manufacture a recording medium, first, a coating liquid for a foamed layer containing a foaming material and a binder resin is applied to the surface of a substrate to form a coating layer. Then, the formed coating layer is dried to form a foamed layer, thereby obtaining a recording medium. Conventional known air knife coaters, die coaters, blade coaters, gate roll coaters, bar coaters, rod coaters, roll coaters, gravure coaters, curtain coaters, etc., can be used to apply the coating liquid for the foamed layer to the surface of the substrate. Methods for drying the coating layer include, for example, blowing hot air onto it. Drying conditions (temperature, airflow, time, etc.) should be set appropriately depending on the type of substrate and the composition of the coating liquid. However, the drying temperature must be lower than the foaming start temperature of the foaming material used. The contact angle of water with respect to the surface of the foamed layer, and the ratio of the diameter of a water droplet 30 seconds after contact with the surface of the foamed layer to the diameter of a water droplet 0.01 seconds after contact with the surface of the foamed layer, can be appropriately adjusted by controlling the type and amount of binder resin used. Furthermore, the ratio of the water contact angle and water droplet diameter can be adjusted by controlling the type and amount of surfactant added to the foam layer as needed.

[0031] 2 g / m² per side of the base material2 It is preferable to provide the above foam layer, 20 g / m² 2 It is even more preferable to provide the above foamed layer. 2g / m 2 By providing the above foam layer, the foaming properties can be further improved.

[0032] A back coat layer may be provided on the surface of the substrate opposite to the surface on which the foam layer is provided. The back coat layer may be the same layer as the foam layer containing the foaming material, or it may be a layer other than the foam layer. In addition, an adhesive layer containing an adhesive resin such as acrylic resin or an ink-receiving layer for fixing colorants may be formed.

[0033] <Method of manufacturing a record> By using the aforementioned recording medium, it is possible to manufacture a recording material having a three-dimensional image with a clear sense of relief. Specifically, the method for manufacturing a recording material having a three-dimensional image according to the present invention comprises the steps of applying a foaming accelerator to the above-mentioned recording medium and heating the foamed layer of the recording medium to which the foaming accelerator has been applied to cause the foaming material to foam and form a three-dimensional image. The foaming accelerator contains a foaming accelerating component that lowers the foaming start temperature of the foaming material and water.

[0034] Examples of heating devices for heating the foamed layer of the recording medium to a desired temperature include dryers, ovens, heating elements, and irons.

[0035] (Foaming accelerator) The foaming accelerator is a liquid composition containing a foaming-promoting component that lowers the foaming initiation temperature of the foaming material, and water.

[0036] [Foam-promoting ingredients] The foaming accelerator contains foaming-promoting components that lower the foaming initiation temperature of foaming materials such as foaming particles. When the foaming accelerator containing foaming-promoting components is applied to the foaming layer of a recording medium by methods such as inkjet ejection or coating, the thermoplastic resin contained in the shell layer of the foaming particles can be softened. As a result, it is presumed that the foaming initiation temperature of the foaming particles can be shifted to a lower temperature.

[0037] The foam-promoting component can be any component capable of softening the thermoplastic resin contained in the shell layer of the foam particles, and can be appropriately selected and used depending on the type of thermoplastic resin. In particular, the foam-promoting component is preferably a compound that does not have hydroxyl groups. The boiling point of the compound that does not have hydroxyl groups used as a foam-promoting component is higher than the temperature at which the foam layer is heated. Therefore, even when the foam layer is heated, the compound that does not have hydroxyl groups does not easily vaporize and can contribute to the softening of the thermoplastic resin in the shell layer. The content of the compound that does not have hydroxyl groups used as a foam-promoting component is preferably 10% by mass or more and 70% by mass or less, based on the total mass of the foam-promoting liquid.

[0038] The absolute difference (|SP1-SP2|) between the solubility parameter (SP1) of the resin forming the shell layer of the foamed particles (microcapsules) and the solubility parameter (SP2) of the foaming-promoting component is preferably 3.5 or less. By having the absolute difference of the solubility parameters within the above numerical range, the foaming properties in the region of the foamed layer where the foaming-promoting liquid containing the foaming-promoting component is applied can be further improved. Examples of foaming-promoting components include 2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone.

[0039] The absolute difference (|HSP1-HSP2|) between the Hansen solubility parameter (HSP1) of the resin forming the shell layer of the foam particles (microcapsules) and the solubility parameter (HSP2) of the foam-promoting component is preferably 20 or less. Having the absolute difference of the Hansen solubility parameters within this range allows for further improvement of the foaming properties in the region of the foam layer where the foam-promoting solution containing the foam-promoting component is applied.

[0040] The solubility parameters (SP values) of the thermoplastic resin and foam-promoting component forming the shell layer are both calculated values. Furthermore, the Hansen solubility parameters (HSP values) of the thermoplastic resin and foam-promoting component forming the shell layer are both measured and calculated using dynamic light scattering.

[0041] [Other ingredients] If the foam-promoting component is a liquid at room temperature (25°C), the foam-promoting component itself may be used as the foam-promoting solution. Furthermore, the foam-promoting solution may contain other components besides the foam-promoting component. For example, it is preferable to include additional liquid components such as solvents to improve the discharge stability of the foam-promoting solution. Water and various water-soluble organic solvents can be used as solvents. In particular, the foam-promoting solution is preferably an aqueous solution containing water. Deionized water (ion-exchanged water) is preferred as the water. Examples of water-soluble organic solvents include alcohols, glycols, glycol ethers, and nitrogen-containing compounds.

[0042] Other components besides the liquid component include water-soluble organic compounds that are solid at 25°C, such as urea and its derivatives, trimethylolpropane, and trimethylolethane. Furthermore, various additives such as pH adjusters, defoamers, rust inhibitors, preservatives, fungicides, antioxidants, reduction inhibitors, and chelating agents may be included in the foaming accelerator as needed.

[0043] <Manufacturing apparatus for recording materials containing three-dimensional images> An apparatus for manufacturing a recording material having a three-dimensional image (hereinafter also simply referred to as "a recording material manufacturing apparatus") comprises a means for applying a foaming accelerator to a recording medium, and a heating means for heating the foamed layer of the recording medium to which the foaming accelerator has been applied. The recording medium comprises a base material and a foamed layer provided on the base material, which contains a foaming material that foams when heated and a binder resin. The foaming accelerator contains a foaming-promoting component that lowers the foaming initiation temperature of foamed particles and water. The heating means is a means for heating the foamed layer of the recording medium and causing the foamed particles to foam to form a three-dimensional image. This recording material manufacturing apparatus can be suitably used in the above-described method for manufacturing a recording material.

[0044] The recording device may also include an ink storage section for storing ink, and an ink application means for ejecting ink from an inkjet recording head to record an image on a recording medium. Furthermore, the recording device may also include a foaming accelerator storage section for storing foaming accelerator liquid. Additionally, the recording device may include a transport means for transporting the recording medium.

[0045] The arrangement of the foam-accelerating liquid dispensing means, the ink dispensing means, and the heating means can be adjusted as appropriate. The arrangement of the foam-accelerating liquid dispensing means, the ink dispensing means, and the heating means in a recording apparatus will be described below with reference to the drawings.

[0046] Figure 2 is a schematic diagram showing the general configuration of a manufacturing apparatus for recording materials having a three-dimensional image. In the manufacturing apparatus shown in Figure 2, the recording medium 21 is transported in the direction of arrow A by a transport means for transporting the recording medium. The ink application means 24 may be located either upstream or downstream of the foaming accelerator application means 22 with respect to the transport direction A of the recording medium 21, and may be located either upstream or downstream of the heating means 23. Figure 2(a) shows the configuration when the ink application means 24 is located downstream of the foaming accelerator application means 22 and downstream of the heating means 23 with respect to the transport direction A of the recording medium 21. Figure 2(b) shows the configuration when the ink application means 24 is located downstream of the foaming accelerator application means 22 and upstream of the heating means 23 with respect to the transport direction A of the recording medium 21. Figure 2(c) shows the configuration when the ink application means 24 is located upstream of the foaming accelerator application means 22 and upstream of the heating means 23 with respect to the transport direction A of the recording medium 21.

[0047] The foaming accelerator can be applied to the foam layer of the recording medium 21 by ejecting the foaming accelerator from an inkjet recording head equipped with a foaming accelerator application means 22 positioned at a predetermined location along the transport direction of the recording medium 21 (direction of arrow A in Figure 2). The heating means 23 is a means for heating the foam layer of the recording medium 21 to which the foaming accelerator has been applied. The heating means 23 can be any heating device capable of heating the foaming material in the foam layer to a desired temperature. Examples of such heating devices include a hair dryer, oven, heating element, and iron. [Examples]

[0048] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited in any way by the following examples unless it exceeds the gist of the invention. Regarding the amount of components, "parts" and "%" refer to mass unless otherwise specified.

[0049] <Preparing the foaming particles> The types of foamed particles H1, H2, and H3 shown in Table 1 were prepared. The foaming initiation temperature of each foamed particle was measured using a thermomechanical analyzer (TMA) (product name "TMA2940", manufactured by TA instruments) according to the following procedure. 25 μg of the sample was placed in an aluminum container with a diameter of 7 mm and a depth of 1 mm, and a load of 0.1 N was applied from above. In this state, the container was heated from 60°C to 200°C at a heating rate of 5°C / min, and the displacement in the vertical direction of the measurement terminal was measured. The temperature at which the displacement began was defined as the "foaming initiation temperature". The results are shown in Table 1.

[0050] TIFF2023138415000001.tif64170

[0051] <Preparing the binder resin> We prepared binder resins B1 to B8, as shown in Table 2.

[0052] TIFF2023138415000002.tif139170

[0053] <Manufacturing of recording media> (Recording medium 1) Polypropylene synthetic paper (product name "New Yupo FGS110", manufactured by Yupo Corporation) was prepared as the base material. 100 parts of binder resin B2 and 50 parts of foamed particles H2 were added to deionized water and thoroughly stirred to obtain coating solution 1 with a solid content concentration of 43%. The obtained coating solution 1 was applied at a coating rate of 40 g / m². 2 After coating the substrate in this manner, the foamed layer was formed by drying it in an 80°C oven for 5 minutes, thereby obtaining recording medium 1.

[0054] (Recording media 2, 3, 6-9, 11-14, 16) Recording media 2, 3, 6-9, 11-14, and 16 were obtained in the same manner as described above for recording media 1, except that the formulation and drying temperature of the coating solution were as shown in Table 3.

[0055] (Recording medium 4) 100 parts of binder resin B1 and 50 parts of foamed particles H2 were added to deionized water, and a surfactant was added to a concentration of 0.10%, and the mixture was thoroughly stirred to obtain coating solution 2 with a solid content of 43%. The surfactant used was "Surfinol 465" (manufactured by Nisshin Chemical Co., Ltd.). Then, recording medium 4 was obtained in the same manner as recording medium 1 described above, except that coating solution 2 was used instead of coating solution 1.

[0056] (Recording medium 5) 100 parts of binder resin B1 and 50 parts of foamed particles H2 were added to deionized water, and a surfactant was added to a concentration of 0.05%, and the mixture was thoroughly stirred to obtain coating solution 3 with a solid content of 43%. The surfactant used was "Surfinol 465" (manufactured by Nisshin Chemical Co., Ltd.). Then, recording medium 5 was obtained in the same manner as recording medium 1 described above, except that coating solution 2 was used instead of coating solution 1.

[0057] (Recording medium 10) A recording medium prepared in the same manner as recording medium 1 described above was subjected to calendar processing to obtain recording medium 10.

[0058] (Recording medium 15) As the recording medium 15, a paper whose surface bulges when heated (product name "Zytex2", manufactured by Zychem) was used.

[0059] TIFF2023138415000003.tif129170

[0060] <Measurement of physical properties of recording media> (contact angle) 4.0 μL of water was brought into contact with the surface of the foam layer of the recording medium. Then, using a contact angle meter (product name "1100DAT", manufactured by FIBRO), the contact angle between the surface of the foam layer and the water was measured 30 seconds after contact. The results are shown in Table 4.

[0061] (Water dot diameter) 4.0 μL of water was brought into contact with the surface of the foam layer of the recording medium. Then, using a contact angle meter (product name "1100DAT", manufactured by FIBRO), the diameter of the water droplet (D1 (μm)) 0.01 seconds after contact and the diameter of the water droplet (D2 (μm)) 30 seconds after contact were measured, and the value of D2 / D1 (times) was calculated. The results are shown in Table 4.

[0062] (Arithmetic mean roughness Ra) In accordance with ISO 4287:1997, the arithmetic mean roughness Ra of the foamed layer surface of the recording medium was measured under the conditions described below. The results are shown in Table 4. • Measuring device: Product name "Surfcorder SE3500", manufactured by Kosaka Laboratory. • Cutoff value: 0.8mm • Evaluation length: 5 times the cutoff value

[0063] (Martens hardness and creep CIT1) In accordance with ISO 14577, a microhardness tester (product name "Picodenter HM500", manufactured by Fischer Instruments) was used to measure the Martens hardness (N / mm²) of the foamed layer of the recording medium under the following conditions. 2 ) and creep CIT1 were measured. The results are shown in Table 4. Martens hardness is the load required to indent the object to be measured with an indenter to form a depression of a certain depth, and is a physical property value that serves as an indicator of the degree of hardness of the object to be measured. Creep CIT1 is a parameter that represents the change in indentation depth when creep is applied at a constant test load for a certain period of time. • Indentation force F: 3.0 μm / 20s • Creep time C: 20.0s

[0064] TIFF2023138415000004.tif129170

[0065] <Preparation of foaming accelerator> (Foaming accelerator 1) 30 parts of dimethyl sulfoxide, 0.5 parts of a nonionic surfactant (product name "Acetylenel E100", manufactured by Kawaken Fine Chemicals), and 69.5 parts of deionized water were mixed. After thorough stirring, the mixture was pressure filtered through a 1.2 μm pore size filter to obtain foaming accelerator solution 1.

[0066] (Foaming accelerator 2) 30 parts of propylene glycol monomethyl ether, 0.5 parts of a nonionic surfactant (product name "Acetylenel E100", manufactured by Kawaken Fine Chemicals), and 69.5 parts of deionized water were mixed. After thorough stirring, the mixture was pressure filtered through a 1.2 μm pore size filter to obtain foaming accelerator solution 2.

[0067] <Manufacturing of records> Foaming accelerators 1 and 2 were filled into cartridges, respectively, and installed in an inkjet recording device (product name "PIXUS MG3630", manufactured by Canon). In this embodiment, the recording duty cycle of an image recorded under the condition that two drops of ink of approximately 11.2 ng are applied to a unit area of ​​1 / 600 inch x 1 / 600 inch is defined as 100%.

[0068] (Example 1) Using the inkjet recording device described above, foaming accelerator 1 was applied to the foam layer of recording medium 1 so that the recording duty cycle was 100%. Fifteen seconds after applying foaming accelerator 1, a hot air gun (product name "HL2010E1", manufactured by Sakaguchi Electric Heating Co., Ltd.) was used to heat the foam layer to which foaming accelerator 1 had been applied for 30 seconds until the surface temperature reached 90°C. This caused the foam particles H2 in the foam layer to foam, forming a three-dimensional image and obtaining the recorded material 1.

[0069] (Examples 2-9, Comparative Examples 1-7) Recordings 2 to 16 were obtained in the same manner as in Example 1 described above, except that the types of recording media and foaming accelerators shown in Table 5 were used, and the heating conditions shown in Table 5 were also used.

[0070] <Rating> (Foam height) A digital micrometer (product name "M-30", manufactured by Sony) was used to measure the height of the foamed portion (foam height) relative to the height of the unfoamed portion on the surface of the obtained recording material. The results are shown in Table 5. A: The foaming height was 200 μm or more. B: The foam height was between 100 μm and 200 μm. C: The foam height was less than 100 μm.

[0071] (Peeling of the foam layer from the substrate) The surface of the obtained recordings was visually inspected, and the peeling of the foam layer from the substrate was evaluated according to the evaluation criteria shown below. The results are shown in Table 5. A: No peeling of the foam layer from the substrate was observed. C: Delamination of the foam layer from the substrate was observed.

[0072] TIFF2023138415000005.tif137170 [Explanation of Symbols]

[0073] 10: Recording media 11: Base material 12: Foam layer 13: Foaming particles 14: Binder resin 15: Shell layer 16: Volatile materials 21: Recording media 22: Means for providing foaming accelerator 23:Heating means 24: Ink application method

Claims

1. A recording medium comprising: a substrate; and a foam layer provided on the substrate, the foam layer containing a foam material that foams upon heating and a binder resin, a contact angle of water with respect to the surface of the foam layer 30 seconds after the surface of the foam layer is brought into contact with water is 30° or more and 80° or less; A recording medium characterized in that the ratio of the diameter of a water droplet 30 seconds after contacting the surface of the foamed layer with water to the diameter of a water droplet 0.01 seconds after contacting the surface of the foamed layer with water is 1.3 or less.

2. 2. The recording medium according to claim 1, wherein the foam material is foam particles having a shell layer containing a thermoplastic resin and a volatile material encapsulated within the shell layer.

3. the thermoplastic resin is polyacrylonitrile, 3. The recording medium according to claim 2, wherein the volatile material is isobutane.

4. 4. The recording medium according to claim 1, wherein the binder resin is at least one selected from the group consisting of an acrylic resin, a urethane resin, and a polyacrylonitrile resin.

5. 4. The recording medium according to claim 1, wherein the glass transition temperature of the binder resin is lower by 70[deg.] C. or more than the foaming initiation temperature of the foam material.

6. 4. The recording medium according to claim 1, wherein the foaming material has a foaming initiation temperature of 80° C. or higher and 100° C. or lower.

7. 4. The recording medium according to claim 1, wherein the binder resin has a glass transition temperature of -10°C or higher and 10°C or lower.

8. 4. The recording medium according to claim 1, wherein the arithmetic mean roughness Ra of the surface of the foam layer is 1.0 [mu]m or more.

9. The Martens hardness of the foam layer is 15 N / mm ２ 4. The recording medium according to claim 1, wherein the recording medium is:

10. 4. The recording medium according to claim 1, wherein the creep CIT1 of the foamed layer after an increase in load measured under the following conditions is 25 or more and 70 or less. [conditions] Push-in force F: 3.0 μm / 20 s Creep time C: 20.0 s

11. 4. The recording medium according to claim 1, wherein the contact angle of water with the surface of the foam layer 30 seconds after the surface of the foam layer is brought into contact with water is 30° or more and 75° or less.

12. A recording medium described in any one of claims 1 to 3, wherein the binder resin includes a water-insoluble resin.

13. The recording medium according to claim 12, wherein the binder resin further contains a water-soluble resin.

14. A recording medium according to any one of claims 1 to 3, wherein the foam layer further contains a surfactant.

15. a step of applying a foaming-promoting liquid containing a foaming-promoting component that lowers the foaming initiation temperature of the foaming material and water to a recording medium including a substrate and a foam layer provided on the substrate, the foam layer containing a foaming material that foams upon heating and a binder resin; a step of heating the foam layer of the recording medium to which the foaming-promoting liquid has been applied, thereby foaming the foaming material and forming a three-dimensional image, a contact angle of water with respect to the surface of the foam layer 30 seconds after the surface of the foam layer is brought into contact with water is 30° or more and 80° or less; A method for producing a recorded matter having a three-dimensional image, characterized in that the ratio of the diameter of a water droplet 30 seconds after bringing water into contact with the surface of the foam layer to the diameter of a water droplet 0.01 seconds after bringing water into contact with the surface of the foam layer is 1.3 or less.

16. 16. The method for producing a recorded matter having a three-dimensional image according to claim 15, wherein the foaming-promoting component is at least one selected from the group consisting of 2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone.

17. The method for producing a recorded matter having a three-dimensional image according to claim 15, wherein the foaming promoting liquid is an aqueous foaming promoting liquid containing the water.

18. 18. The method for producing a recorded material having a three-dimensional image according to claim 15, wherein the contact angle of water with the surface of the foam layer 30 seconds after contacting the surface of the foam layer with water is 30° or more and 75° or less.

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