Method for manufacturing decorative sheet and method for manufacturing resin-impregnated decorative plate

Abstract

To provide a method for manufacturing a decorative sheet using an inkjet printing method which can obtain a resin-impregnated decorative plate that can express a good gloss-matte design.SOLUTION: A method for manufacturing a decorative sheet includes a supporting body manufacturing step of manufacturing a supporting body 10 having a porous base material 1 and a design layer 3, and a release layer formation step of forming a release layer 4 having a pattern shape on a surface on the design layer side of the supporting body, wherein the supporting body has a polar group-containing resin layer containing a resin having one or more polar groups of a hydroxy group, an amino group and a carboxy group, between the porous base material and the design layer, or on a surface opposite to the porous base material of the design layer, the release layer formation step has coating treatment of coating a composition for forming a release layer by an inkjet printing method, and forming a coating layer, first curing treatment of irradiating the coating layer with ultraviolet light, and second curing treatment of performing electron beam irradiation treatment after the first curing treatment, and thereby obtaining a release layer from the coating layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a decorative sheet and a method for producing a resin-impregnated decorative board using an inkjet printing method. [Background technology]

[0002] Conventionally, resin-impregnated decorative boards are known that are obtained by impregnating a porous substrate with a precursor (uncured resin) such as a melamine resin, and then curing the resin precursor. Resin-impregnated decorative boards are used for walls, furniture, floors, etc. in homes, stores, public facilities, etc.

[0003] A melamine decorative board expressing a design feeling of a gloss matte tone is known. For example, Patent Document 1 discloses a decorative sheet for manufacturing a melamine decorative board, which comprises a support layer having a first surface and a second surface located opposite to the first surface, and a release layer provided on a part of the first surface of the support layer, the support layer comprises a paper base material and a coating layer forming the first surface of the support layer, the release layer contains a cured product of an ionizing radiation curable resin, and the coating layer contains a predetermined amount of casein. A decorative board manufactured using such a decorative sheet can express a design feeling of a gloss matte tone by showing different design feelings between a first region overlapping with the release layer in the thickness direction and a second region in which a cured resin layer is arranged that does not overlap with the release layer in the thickness direction.

[0004] In the field of decorative sheets for melamine decorative boards, the decorative sheets need to be suitable for further post-processing, and it is common to use a special paper called titanium paper with opacity as the base material, so gravure printing is more often used than inkjet printing for the production of decorative sheets. On the other hand, inkjet printing is attracting attention in the production of decorative sheets because, compared to gravure printing, it is easier to produce small lots and a wide variety of products, there is no problem with the repeat length of the pattern depending on the cylinder diameter, and it allows for printing at a higher resolution than printing with a general gravure engraved cylinder.

[0005] Patent Documents 2 to 4 describe inkjet printing base paper used in decorative sheets for melamine decorative boards. In Patent Documents 2 to 4, the main purpose is to improve color development during pattern printing without impairing processability during melamine resin impregnation by forming an inkjet receiving layer on the printing base paper. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6915489 [Patent Document 2] Patent No. 6405992 [Patent Document 3] Patent No. 6933717 [Patent Document 4] Patent No. 6427242 Summary of the Invention [Problem to be solved by the invention]

[0007] In the manufacture of decorative sheets for resin-impregnated decorative boards that express a glossy matte design, by forming a release layer using an inkjet printing method, as described above, there is no limit to the repeat length of the pattern and high-resolution printing is possible. Therefore, the design freedom of the resin-impregnated decorative board can be increased by the synergistic effect with the design effect of the glossy matte design.

[0008] On the other hand, when the release layer is printed by the inkjet printing method, there is a particular problem that the composition for forming the release layer is particularly likely to penetrate into the porous substrate compared to when the release layer is printed by the gravure printing method. Therefore, the release layer becomes thin and sufficient release performance cannot be obtained, and a good design may not be obtained.

[0009] The present disclosure has been made in consideration of the above circumstances, and has as its main object to provide a method for manufacturing a decorative sheet for a resin-impregnated decorative board using an inkjet printing method, which is capable of obtaining a resin-impregnated decorative board that can express a good gloss matte design. [Means for solving the problem]

[0010] The present disclosure provides a method for producing a decorative sheet used in the production of resin-impregnated decorative boards, the method comprising: a support manufacturing step of manufacturing a support having a porous substrate and a design layer; and a release layer forming step of forming a release layer having a pattern shape on the surface of the support facing the design layer, the support having a polar group-containing resin layer between the porous substrate and the design layer, or on the surface of the design layer opposite the porous substrate, the support containing a resin having one or more polar groups, such as a hydroxyl group, an amino group, or a carboxyl group, the release layer forming step comprising a coating process of applying a release layer-forming composition by inkjet printing to form a coating layer, a first curing process of irradiating the coating layer with ultraviolet light, and a second curing process of obtaining the release layer from the coating layer by irradiating it with electron beams after the first curing process.

[0011] The present disclosure also provides a method for producing a resin-impregnated decorative board, the method comprising: a preparation step of preparing a decorative sheet by the above-mentioned method for producing a decorative sheet; a laminate formation step of forming a laminate having, in this order in the thickness direction, a core substrate, the decorative sheet, a curable resin layer containing a curable resin, and a release film, (ii) the surface of the decorative sheet facing the porous substrate is arranged to face the core substrate, and (iii) the decorative sheet is impregnated with the curable resin; a heating and pressurizing step of heating and pressurizing the laminate to cure the curable resin while forming a cured resin layer from the curable resin layer to obtain a cured laminate; and a peeling step of peeling the release film from the cured laminate to remove the cured resin layer arranged in a first region that overlaps with the release layer in the thickness direction, while leaving the cured resin layer arranged in a second region that does not overlap with the release layer in the thickness direction. Effect of the Invention

[0012] The present disclosure provides a method for manufacturing a decorative sheet for a resin-impregnated decorative board using an inkjet printing method, and has the effect of providing a method for manufacturing a decorative sheet that can obtain a resin-impregnated decorative board that can express a good gloss matte design. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view illustrating a method for producing a decorative sheet in the present disclosure. [Diagram 2] 1 is a schematic cross-sectional view illustrating a support according to the present disclosure. [Diagram 3] 1 is a schematic cross-sectional view illustrating a decorative sheet according to the present disclosure. [Figure 4] 1 is a schematic cross-sectional view illustrating a method for producing a resin-impregnated decorative board according to the present disclosure. [Diagram 5] 1 is a schematic cross-sectional view illustrating a resin-impregnated decorative board according to the present disclosure. [Figure 6] FIG. 2 is a schematic plan view illustrating a polar group-containing resin layer according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The following describes the embodiments with reference to the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the description of the embodiments exemplified below. In addition, in order to clarify the description, the drawings may show the width, thickness, and shape of each part in a schematic manner compared to the actual form, but this is merely an example and should not be interpreted as being limiting.

[0015] In this specification, when describing a mode in which another component is disposed on a certain component, the term "above" or "below" includes both cases in which another component is disposed directly above or below the certain component so as to be in contact with the component, and cases in which another component is disposed above or below the certain component with another component interposed therebetween, unless otherwise specified. In addition, in this specification, when describing a mode in which another component is disposed on the surface of a certain component, the term "on the surface" includes both cases in which another component is disposed directly above or below the certain component so as to be in contact with the component, and cases in which another component is disposed above or below the certain component with another component interposed therebetween, unless otherwise specified.

[0016] A. Manufacturing method of decorative sheet The manufacturing method of the decorative sheet in the present disclosure will be described in detail below. Figures 1(a) to (d) are schematic cross-sectional views illustrating the manufacturing method of the decorative sheet in the present disclosure. The manufacturing method of the decorative sheet 20 in the present disclosure is a manufacturing method of a decorative sheet used in manufacturing a resin-impregnated decorative board, and includes a support manufacturing step (Figure 1(a)) of manufacturing a support 10 having a porous substrate 1 and a design layer 3, and a release layer forming step (Figures 1(b) to 1(d)) of forming a release layer 4 having a pattern shape on the surface of the support 10 on the design layer 3 side. In Figures 1(a) to 1(d), the support 10 has a predetermined polar group-containing resin layer 2 between the porous substrate 1 and the design layer 3. In Figures 1(a) to 1(d), the design layer 3 has a pattern layer y1 and a design layer y2. In the present disclosure, the release layer forming process includes a coating process (FIG. 1(b)) in which a release layer forming composition is applied by inkjet printing to form a coating layer 4', a first curing process (FIG. 1(c)) in which the coating layer 4' is irradiated with ultraviolet light, and a second curing process (FIG. 1(d)) in which a release layer 4 is obtained from the coating layer 4' by performing an electron beam irradiation process after the first curing process.

[0017] In the manufacture of decorative sheets for resin-impregnated decorative panels that express a glossy matte design, when the release layer is printed by inkjet printing, the composition (ink) for forming the release layer must have inkjet dischargeability in order to obtain stable printability. Specifically, it is preferable to reduce the viscosity of the composition for forming the release layer in order to prevent clogging in the head. In addition, it is preferable to reduce the average particle size of the filler used in order to prevent poor dispersion (sedimentation) of the filler.

[0018] When the viscosity of the release layer forming composition is reduced, the fluidity of the release layer forming composition increases, so that the penetration into the porous substrate becomes excessive. Therefore, the thickness of the release layer present on the surface of the decorative sheet becomes thin. If the release layer becomes thin, when the cured resin layer on the release layer is peeled off in the post-processing for producing a resin-impregnated decorative board, the cured resin layer cannot be peeled off sufficiently and remains, so that the gloss mat design may not be easily expressed. In addition, the release layer forming composition soaked into the porous substrate becomes uncured, so that the problem of odor due to the remaining monomer occurs. On the other hand, if the impregnation into the porous substrate is reduced too much, the release layer tends to remain thick, but the uncured resin such as hydrophilic melamine resin is also difficult to impregnate, which causes an obstruction when processing into a decorative substrate.

[0019] In addition, curing by electron beam irradiation is preferable for curing the release layer forming composition soaked into the porous substrate. Since the wavelength of electron beams is very short compared to ultraviolet light, they have permeability to the porous substrate, and can efficiently cure the soaked release layer forming composition. Here, in order to suppress the penetration of the release layer forming composition into the porous substrate as much as possible, it is preferable that the lead time from inkjet ink ejection to curing is short. However, the electron beam irradiation device is generally large, and it is technically difficult to make it into a mechanism integrated with the print head like a UV-LED device. Therefore, the time from inkjet ink ejection to electron beam irradiation tends to be long.

[0020] According to the present disclosure, after the release layer forming composition is applied by inkjet printing to form a coating layer, the first curing treatment can be performed quickly by ultraviolet irradiation, so that the penetration of the release layer forming composition into the porous substrate can be suppressed. Therefore, the release layer can be prevented from becoming thin, and a good gloss matte design can be obtained. In addition, a low gloss (matte) design is often required for the release layer. In the present disclosure, the first curing treatment can be performed quickly after the coating treatment, so that the leveling of the coating layer can be limited and the gloss value can be reduced. In addition, according to the present disclosure, the first curing treatment is performed after the first curing treatment, so that the curing of the release layer forming composition partially soaked into the porous substrate and the degree of crosslinking of the release layer can be improved by performing the second curing treatment by electron beam irradiation. By improving the degree of crosslinking of the release layer, the releasability to the cured resin layer (for example, a melamine resin layer) becomes good.

[0021] Furthermore, by using a support having a polar group-containing resin layer containing a resin having a specific polar group, the penetration of the release layer-forming composition into the porous substrate can be further suppressed, and a decorative sheet having good impregnation with uncured resin such as melamine resin having hydrophilicity to the porous substrate can be obtained. Therefore, according to the present disclosure, a decorative sheet capable of obtaining a resin-impregnated decorative board capable of expressing a good gloss matte design can be manufactured.

[0022] In addition, according to the present disclosure, since the release layer can be formed by the inkjet printing method, it is possible to express a release layer with a larger pattern with higher resolution than when the release layer is formed by the gravure printing method. For example, in the case of a decorative sheet in which a design layer and a release layer are formed by the inkjet printing method, a large-sized resin-impregnated decorative board that imitates marble, exceeding 3 m in size, can be manufactured.

[0023] 1. Support manufacturing process This step is a step of producing a support. Figures 2(a) to 2(d) are schematic cross-sectional views illustrating the support in the present disclosure. The support 10 produced in this step has a porous substrate 1 and a design layer 3, and further has a polar group-containing resin layer 2 containing a resin having at least one polar group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group. As shown in Figures 2(a) and 2(c), the polar group-containing resin layer 2 may be disposed between the porous substrate 1 and the design layer 3. On the other hand, as shown in Figures 2(b) and 2(d), the polar group-containing resin layer 2 may be disposed on the surface of the design layer 3 opposite to the porous substrate 1.

[0024] As shown in Figures 2(a) and 2(b), the design layer 3 may have a pattern layer y formed partially (particularly in a pattern) so as to cover a part of the porous substrate 1 when viewed from the thickness direction. As shown in Figures 2(c) and 2(d), the design layer 3 may have a plurality of pattern layers y1 and y2. Although not shown in particular, the design layer may have a solid layer formed so as to cover the entire surface of the porous substrate.

[0025] (1) Polar group-containing resin layer The polar group-containing resin layer contains a resin containing at least one polar group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group. By containing the resin having the polar group, the polar group-containing resin layer does not inhibit the impregnation of the uncured resin such as a hydrophilic melamine resin into the porous substrate, and can reduce the permeability of the release layer-forming composition into the porous substrate.

[0026] The polar group-containing resin layer is formed between the porous substrate and the design layer, or on the surface of the design layer opposite to the porous substrate. In the present disclosure, as shown in Fig. 2(a) and Fig. 2(c), the polar group-containing resin layer 2 is preferably formed between the porous substrate 1 and the design layer 3. This is because the color and gloss of the polar group-containing resin layer 2 are unlikely to affect the design of the design layer. In addition, as described later, when the polar group-containing resin layer 2 contains inorganic particles, the polar group-containing resin layer 2 can also function as an ink receiving layer, improving the color development of the design layer.

[0027] A resin having a polar group contains at least one of the following polar groups: a hydroxy group (-OH), an amino group (-NH2), and a carboxy group (-COOH). The polar group may be ionized and stabilized, for example, by the influence of a solvent or other functional groups. Therefore, the "hydroxy group (-OH)" is in the ionized state, "-O - " and the above "amino group (-NH2)" is in the ionized state "-NH3 + " is a concept that includes "carboxyl group (-COOH)" in its ionized state, "-COO - " is a concept that includes

[0028] The resin having a polar group is preferably a resin that dissolves or disperses in water, methanol, or ethanol. This is because the impregnation of uncured resins such as hydrophilic melamine resins is improved. Here, "dissolves or disperses in water, methanol, or ethanol" means that the following test is performed and certain standards are met. That is, the following operations are performed with reference to JIS K8001:2017, Section 3.2. 1) Prepare 100 ml each of water, methanol or ethanol as a solvent. 2) At 20°C ± 5°C, add 0.1 g of each resin (0.1 ml if liquid) to each of the above solvents. 3) Shake vigorously for 30 seconds every 5 minutes. 4) After 30 minutes, shake vigorously for 30 seconds and then leave to stand for 1 minute. If the following phenomena are not visually confirmed, it is determined that the solution has "dissolved or dispersed." -Solids are present at the bottom of the container. Phase separation of the solvent and resin (oil droplets) occurs on the top surface of the solvent, in the solvent, or at the bottom of the container.

[0029] Examples of resins having one or more polar groups, such as a hydroxy group (-OH), an amino group (-NH2), or a carboxy group (-COOH), include aqueous proteins such as casein, cellulose derivatives such as cellulose, acetyl cellulose, cellulose nitrate, hydroxypropyl cellulose, and carboxymethyl cellulose, polyvinyl alcohol derivatives such as polyvinyl butyral resin, amino resins such as melamine resin, (meth)acrylic acid resins, phenolic resins, acrylic polyols, and natural polymers (for example, polynucleotides, polypeptides, and polysaccharides). The polar group-containing resin layer in the present disclosure preferably contains one or more of casein, melamine resin, polyvinyl alcohol, polyvinyl alcohol derivative, cellulose and cellulose derivative as a resin having a polar group, and more preferably contains casein. As the casein, α-casein, β-casein, γ-casein or a mixture thereof can be used. As the casein, derivatives such as sodium caseinate and ammonium caseinate can be used alone or in combination.

[0030] The polar group-containing resin layer is preferably arranged so as to cover the entire surface of the porous substrate when viewed from the thickness direction. The polar group-containing resin layer does not inhibit the impregnation of uncured resin such as hydrophilic melamine resin, and by arranging such a polar group-containing resin layer so as to cover the entire surface of the porous substrate, the degree of freedom of the pattern of the release layer can be improved, and as a result, the design can be improved. The entire surface of the porous substrate refers to an area of ​​90% or more of the surface of the porous substrate that functions as a decorative sheet. The polar group-containing resin layer may be arranged so as to cover 95% or more of the surface of the porous substrate that functions as a decorative sheet, or may be arranged so as to cover 100% of the surface of the porous substrate.

[0031] The statement that "the polar group-containing resin layer is disposed so as to cover the entire surface of the porous substrate" will be described in more detail with the use of several examples. FIG. 6 is a schematic plan view illustrating the polar group-containing resin layer in the present disclosure. In FIG. 6, the design layer 3 is omitted. As shown in FIG. 6(a), when the polar group-containing resin layer 2 completely covers the porous substrate 1 as viewed in the thickness direction, the polar group-containing resin layer 2 is disposed so as to cover the entire surface of the porous substrate 1 (100% of the portion functioning as a decorative sheet). Also, as shown in FIG. 6(b), when both ends of the porous substrate 1 are exposed from the polar group-containing resin layer 2 as viewed in the thickness direction, the both ends do not function as decorative sheets. Therefore, the entire surface of the porous substrate 1 is defined except for the region not functioning as a decorative sheet. In FIG. 6(b), the polar group-containing resin layer 2 is disposed so as to cover the entire surface of the porous substrate 1 (100% of the portion functioning as a decorative sheet). Similarly, as shown in Fig. 6(c), when the outer edge of the porous substrate 1 is located outside the outer edge of the polar group-containing resin layer 2 over the entire circumference when viewed in the thickness direction, the region of the porous substrate 1 exposed from the polar group-containing resin layer 2 does not function as a decorative sheet. Therefore, the entire surface of the porous substrate 1 is defined except for the region that does not function as a decorative sheet. In Fig. 6(c), the polar group-containing resin layer 2 is arranged so as to cover the entire surface of the porous substrate 1 (100% of the portion functioning as a decorative sheet).

[0032] On the other hand, in FIG. 6(d), the entire surface of the porous substrate 1 functions as a decorative sheet when viewed from the thickness direction. On the other hand, inside the outer edge of the polar group-containing resin layer 2, there is a region α (for example, an uncoated portion prepared for the purpose of design expression) where the polar group-containing resin layer 21 is not formed. In this case, if the total area of ​​the region α is less than 10% of the surface of the porous substrate 1 (the portion functioning as a decorative sheet), it can be said that "the polar group-containing resin layer is arranged so as to cover the entire surface of the porous substrate". Also, in FIG. 6(e), the entire surface of the porous substrate 1 functions as a decorative sheet when viewed from the thickness direction. On the other hand, there is a region α (for example, an uncoated portion prepared for the purpose of design expression) where the polar group-containing resin layer 2 is not formed so as to divide the polar group-containing resin layer 2. In this case, if the total area of ​​the region α is less than 10% of the surface of the porous substrate 1 (the portion functioning as a decorative sheet), it can be said that "the polar group-containing resin layer is arranged so as to cover the entire surface of the porous substrate". Similarly, in Fig. 6(f), when viewed in the thickness direction, the entire surface of the porous substrate 1 functions as a decorative sheet. On the other hand, there is a region α where the polar group-containing resin layer 2 is not formed. In this case, if the total area of ​​the region α is less than 10% of the surface of the porous substrate 1 (the portion functioning as a decorative sheet), it can be said that "the polar group-containing resin layer is arranged so as to cover the entire surface of the porous substrate."

[0033] Also, as shown in FIG. 6(g), when both ends of the porous substrate 1 are exposed from the polar group-containing resin layer 2 as viewed in the thickness direction, the both ends do not function as decorative sheets. Therefore, the entire surface of the porous substrate 1 is defined, except for the area not functioning as a decorative sheet. In FIG. 6(g), an area α where the polar group-containing resin layer 2 is not formed (for example, an uncoated part prepared for the purpose of design expression) exists inside the outer edge of the polar group-containing resin layer 2. In this case, if the total area of ​​the area α is less than 10% of the part of the surface of the porous substrate 1 that functions as a decorative sheet, it can be said that "the polar group-containing resin layer is arranged so as to cover the entire surface of the porous substrate". Also, as shown in FIG. 6(h), when the outer edge of the porous substrate 1 is located outside the outer edge O1 of the polar group-containing resin 2 over the entire circumference as viewed in the thickness direction, the area of ​​the porous substrate 1 exposed from the polar group-containing resin 2 outside the outer edge O1 does not function as a decorative sheet. Therefore, the entire surface of the porous substrate 1 is defined, except for the area not functioning as a decorative sheet. As shown in Fig. 6(h), when the outer edge O2 of the polar group-containing resin layer 2 has a complex shape, the rectangular outer edge O1 is set so that the area of ​​the polar group-containing resin layer 2 is maximized. Also, in Fig. 6(h), there is a region α where the polar group-containing resin layer 2 is not formed. In this case, when the total area of ​​the region α is less than 10% of the portion of the surface of the porous substrate 1 that functions as a decorative sheet, it can be said that "the polar group-containing resin layer is arranged so as to cover the entire surface of the porous substrate."

[0034] The ratio of the resin having the polar group to the resin components contained in the polar group-containing resin layer is, for example, 20% by mass or more, may be 30% by mass or more, may be 40% by mass or more, or may be 50% by mass or more. On the other hand, the ratio of the resin having the polar group is, for example, 100% by mass or less, may be 90% by mass or less. If the content of the resin having the polar group is within the above range, the penetration of the release layer forming composition into the porous substrate can be further suppressed without inhibiting the penetration of the uncured resin into the porous substrate.

[0035] In addition, the polar group-containing resin layer may contain other resins as resin components in addition to the above-mentioned resins having polar groups. Examples of other resins include (meth)acrylic resins, ester urethane resins, acrylamide resins, ethylene oxide resins, N-vinylpyrrolidone resins, ester resins, amide resins, vinyl acetate resins, vinyl chloride resins, urethane (meth)acrylic resins, natural rubber, and synthetic rubber. Among these, (meth)acrylic resins and urethane (meth)acrylic resins are preferred.

[0036] The polar group-containing resin layer preferably contains inorganic particles. By containing inorganic particles, the layer can function as an inkjet receiving layer, and the color development of the design layer is improved. Examples of inorganic particles include silica particles, alumina particles, and calcium carbonate particles. Among them, silica particles are preferred. In the present disclosure, only one type of inorganic particles may be used, or two or more types may be used. The inorganic particles may function as a white pigment, which will be described later.

[0037] The average particle size of the inorganic particles is, for example, 0.3 μm or more and 10 μm or less, and may be 0.5 μm or more and 7 μm or less, or 1 μm or more and 5 μm or less. The average particle size is D50 according to the volume-based particle size distribution measured by a laser diffraction scattering method. The content of the inorganic particles is, for example, 5 parts by mass or more and 40 parts by mass or less, and may be 10 parts by mass or more and 35 parts by mass or less, relative to 100 parts by mass of the resin component of the polar group-containing resin layer.

[0038] The polar group-containing resin layer may or may not contain a colorant. The colorant may be the same as the colorant used in the design layer described later, but among them, white pigments such as titanium oxide, calcium carbonate, zinc oxide, barium sulfate, and silica are preferred.

[0039] The polar group-containing resin layer may contain additives such as extender pigments (eg, organic beads), neutralizing agents, and surfactants, if necessary.

[0040] The polar group-containing resin layer may have a single-layer structure, or may have a multi-layer structure in which a plurality of layers are laminated.

[0041] The method for forming the polar group-containing resin layer includes, for example, a coating method using an ink for forming a polar group-containing resin layer, which contains a resin component containing at least a resin having a polar group, an additive, and a solvent (or a dispersion medium). For example, the ink for forming a polar group-containing resin layer is applied to one side of a porous substrate and dried to obtain a polar group-containing resin layer.

[0042] Examples of the solvent (or dispersion medium) include petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ester-based organic solvents such as ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, and propylene glycol; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based organic solvents such as diethyl ether, dioxane, and tetrahydrofuran; chlorine-based organic solvents such as dichloromethane, carbon tetrachloride, trichloroethylene, and tetrachloroethylene; and inorganic solvents such as water.

[0043] Examples of the coating method for forming the polar group-containing resin layer include various coating methods such as roll coating, knife coating, air knife coating, die coating, lip coating, comma coating, kiss coating, flow coating, and dip coating, and various printing methods such as gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and inkjet printing.

[0044] The thickness of the polar group-containing resin layer is not particularly limited, but is, for example, 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1 μm or more. On the other hand, the thickness of the polar group-containing resin layer is, for example, 6 μm or less, preferably 4 μm or less. If the thickness of the polar group-containing resin layer is the above value or more, the penetration of the release layer forming composition (release layer ink) into the porous substrate can be further suppressed. If the thickness of the polar group-containing resin layer is the above value or less, the impregnation of the uncured resin becomes better. The thickness of the polar group-containing resin layer is the average value of the thicknesses measured at 10 points by observing the cross section obtained by cutting the decorative sheet in the thickness direction with an optical microscope.

[0045] The coating amount (basis weight) of the polar group-containing resin layer is not particularly limited, but is, for example, 0.1 g / m 2 More than 0.5 g / m 2 If the coating amount of the polar group-containing resin layer is equal to or more than the above value, the permeation of the release layer-forming composition into the porous substrate can be further suppressed. On the other hand, the coating amount (basis weight) of the polar group-containing resin layer is, for example, 10 g / m 2 Less than 5 g / m 2 When the coating amount of the polar group-containing resin layer is the above-mentioned value or less, the impregnation property of the uncured resin becomes better.

[0046] (2) Design layer The design layer in the present disclosure is disposed on one side of the porous substrate. The design layer preferably has a pattern. Examples of the design layer pattern include organic patterns, inorganic patterns, and abstract patterns. An organic pattern is a pattern derived from the life activities of living organisms such as animals and plants. An inorganic pattern is a pattern that does not fall under the organic pattern. An abstract pattern is a pattern that interprets an object (for example, an image that exists in nature) abstractly and does not express a clear shape. Examples of organic patterns include wood grain patterns, leather patterns, floral patterns, and botanical patterns. Examples of inorganic patterns include stone patterns, concrete patterns, sand patterns, cloth patterns, metal patterns, tile patterns, and brick masonry patterns. Examples of abstract patterns include flickering patterns (for example, ink flickering patterns), smoke patterns, and marble patterns.

[0047] The design layer has, for example, a pattern layer. The design layer may have a solid layer on the porous substrate side of the pattern layer. In the present disclosure, the pattern layer means a layer formed partially (particularly in a pattern) on one side of the porous substrate. The solid layer means a layer formed on the entire surface of one side of the porous substrate.

[0048] The design layer contains, for example, a colorant and a resin component. Examples of the colorant include inorganic pigments such as carbon black, titanium white, zinc oxide, red iron oxide, Prussian blue, and cadmium red; organic pigments such as azo pigments, lake pigments, anthraquinone pigments, quinacridone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazine pigments; metal powder pigments such as aluminum powder and bronze powder; pearlescent pigments such as titanium oxide-coated mica and bismuth oxide chloride; fluorescent pigments; and luminous pigments. Dyes may also be used as the colorant.

[0049] Examples of the resin component include (meth)acrylic resin, ester urethane resin, acrylamide resin, ethylene oxide resin, N-vinylpyrrolidone resin, ester resin, amide resin, vinyl acetate resin, vinyl chloride resin, urethane (meth)acrylic resin, natural rubber, and synthetic rubber. In the present invention, it is preferable to contain an aqueous resin as the resin component. When an aqueous resin is used, it is difficult to inhibit the impregnation of uncured resin such as melamine resin having hydrophilicity. In this case, the design layer can be formed by inkjet printing using an aqueous ink containing water as the main solvent. Examples of the aqueous resin used in the design layer include resins obtained by emulsion polymerization of ethylenically unsaturated monomers. Examples of the resins obtained by emulsion polymerization of ethylenically unsaturated monomers include the resin particles described in JP-A-2013-28658, and among them, (meth)acrylic resins. As the ink for forming the design layer in the present disclosure, a (meth)acrylic resin emulsion in which the above-mentioned colorant is dispersed is preferably used.

[0050] The design layer may contain any additive other than the above-mentioned colorant and resin component as necessary. The thickness of the design layer is not particularly limited, but is, for example, 0.1 μm or more and 20 μm or less.

[0051] The method for forming the design layer includes, for example, a coating method using an ink for forming a design layer containing a colorant, a resin component, and a solvent (or a dispersion medium). For example, the ink for forming the design layer is applied to one side of the porous substrate and dried to obtain a design layer.

[0052] Examples of the solvent (or dispersion medium) include petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ester-based organic solvents such as ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, and propylene glycol; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based organic solvents such as diethyl ether, dioxane, and tetrahydrofuran; chlorine-based organic solvents such as dichloromethane, carbon tetrachloride, trichloroethylene, and tetrachloroethylene; and inorganic solvents such as water.

[0053] Examples of the coating method include printing methods. Examples of the printing method include inkjet printing, gravure printing, offset printing, screen printing, flexographic printing, and electrostatic printing. Examples of the coating method for forming a solid layer include various coating methods such as roll coating, knife coating, air knife coating, die coating, lip coating, comma coating, kiss coating, flow coating, and dip coating. In the present disclosure, it is preferable to use inkjet printing. As described above, inkjet printing has advantages over gravure printing, such as easy production of small lots and a wide variety of products, no problem of repeat length of pattern pitch depending on cylinder diameter, and higher resolution printing compared to printing with a general gravure engraved cylinder.

[0054] (3) Porous base material The porous substrate in the present disclosure is a substrate impregnated with a curable resin (uncured resin) during the manufacture of the resin-impregnated decorative board. Examples of the porous substrate include permeable fibrous substrates. Examples of the permeable fibrous substrate include paper, synthetic paper, nonwoven fabric, and woven fabric. Examples of the paper include titanium paper, tissue paper, craft paper, linter paper, paperboard, gypsum board paper, fine paper, coated paper, parchment paper, and Japanese paper. In addition, vinyl wallpaper rolls (paper dry-laminated with polyvinyl chloride resin) can also be used as the fibrous substrate. Other examples of the fibrous substrate include nonwoven fabrics or woven fabrics containing inorganic fibers such as glass fiber, asbestos, potassium titanate fiber, alumina fiber, silica fiber, and carbon fiber. Other examples of the fibrous substrate include nonwoven fabrics or woven fabrics containing synthetic resin fibers such as polyester, vinylon, polyethylene, and polypropylene. Among these porous substrates, titanium paper, thin paper, kraft paper, coated paper, art paper, parchment paper, paraffin paper and Japanese paper are preferred in terms of impregnation with the curable resin. Titanium paper is particularly preferred as a porous substrate because it has excellent impregnation with the curable resin and excellent hiding power.

[0055] The porous substrate may be colored. For example, a colorant is added at the manufacturing stage of the porous substrate to obtain a colored porous substrate. For example, when the porous substrate is paper, a colorant is added at the papermaking stage to obtain colored paper. Examples of the colorant include inorganic pigments such as titanium dioxide, carbon black, and iron oxide, organic pigments such as phthalocyanine blue, and various dyes. The amount of the colorant is appropriately set according to the desired color tone. The porous substrate may also contain various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, ultraviolet absorbers, and light stabilizers, as necessary.

[0056] The basis weight of the porous substrate is not particularly limited, but is, for example, 40 g / m 2 More than 150g / m 2 The thickness of the porous substrate is not particularly limited, but is, for example, 50 μm or more and 170 μm or less. For example, in order to improve the adhesion of the ink that forms the design layer, the surface of the porous substrate on the design layer side may be subjected to a corona discharge treatment.

[0057] In this step, the support 10 shown in Figures 2(a) and 2(c) can be manufactured by forming a polar group-containing resin layer 2 on one side of the porous substrate 1, and forming a design layer 3 on the side of the polar group-containing resin layer 2 opposite the porous substrate 1. The support 10 shown in Figures 2(b) and 2(d) can be manufactured by forming a design layer 3 on one side of the porous substrate 1, and forming a polar group-containing resin layer 2 on the side of the design layer 3 opposite the porous substrate 1. The method of forming the polar group-containing resin layer and the design layer is as described above.

[0058] 2. Release layer formation process The method for producing a decorative sheet according to the present disclosure includes a release layer forming step of forming a patterned release layer on the design layer side of the support after the support manufacturing step. The release layer forming step includes a coating step of forming a coating layer by applying a release layer forming composition by inkjet printing, a first curing step of irradiating the coating layer with ultraviolet light, and a second curing step of obtaining a release layer from the coating layer by irradiating the coating layer with electron beams after the first curing step.

[0059] (1) Coating process First, the release layer forming composition is applied to the design layer side of the support by inkjet printing to form a coating layer. As shown in FIG. 1(b), the "design layer 3 side of the support 10" refers to the surface of the support 10 located on the design layer 3 side when the porous substrate 1 is used as a reference. The release layer forming composition preferably contains, for example, a curable compound. In this case, the release layer has a cured product of the curable compound. The release layer contains a cured product of the curable compound, which improves abrasion resistance. In addition, the release layer contains a cured product of the curable compound, which improves releasability from the cured resin layer.

[0060] The ratio of the curable compound in the release layer forming composition is, for example, 50% by mass or more, and may be 60% by mass or more, while the ratio of the curable compound is, for example, 80% by mass or less, and may be 70% by mass or less.

[0061] As the curable compound, for example, an ionizing radiation curable compound is used. In this case, the release layer forming composition usually contains an ultraviolet ray curable polymerization initiator in addition to the ionizing radiation curable compound.

[0062] The ionizing radiation curable compound is not limited as long as it undergoes a crosslinking polymerization reaction by irradiation with ionizing radiation and changes into a three-dimensional polymer structure. Examples of the ionizing radiation curable compound include monomers, prepolymers, and oligomers having polymerizable unsaturated bonds or epoxy groups in the molecule that can be crosslinked by irradiation with ionizing radiation. In the present disclosure, only one type of ionizing radiation curable compound may be used, or two or more types may be used. Among them, it is preferable to use a polymerizable monomer as the ionizing radiation curable compound. This is because a viscosity suitable for the inkjet printing method can be obtained. In the present disclosure, the ratio of the polymerizable monomer to the ionizing radiation curable compound contained in the release layer forming composition is, for example, 50% by mass or more, may be 70% by mass or more, or may be 80% by mass or more. On the other hand, the above ratio of the polymerizable monomer is, for example, 100% by mass or less, and may be 90% by mass or less. Preferably, the above ratio of the polymerizable monomer is 100% by mass.

[0063] The weight average molecular weight of the polymerizable monomer is preferably 1500 or less, more preferably 1000 or less. When the weight average molecular weight is within the above range, the release layer forming composition tends to have a low viscosity. On the other hand, the weight average molecular weight of the polymerizable monomer is, for example, 140 or more, and may be 180 or more. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0064] Examples of the polymerizable monomer include (meth)acrylate monomers having a radically polymerizable unsaturated group in the molecule. In particular, polyfunctional (meth)acrylates are preferred. The term "(meth)acrylate" means acrylate or methacrylate. The polyfunctional (meth)acrylate monomer is not particularly limited as long as it is a (meth)acrylate monomer having two or more ethylenically unsaturated bonds in the molecule. The polyfunctional (meth)acrylate monomer may be used alone or in combination of two or more. The number of functional groups of the polyfunctional (meth)acrylate monomer is preferably 2 to 8, more preferably 2 to 6.

[0065] Examples of polyfunctional (meth)acrylate monomers include (meth)acrylates such as hexanediol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and modified products thereof.

[0066] In addition, the release layer forming composition of the present disclosure preferably uses a monofunctional (meth)acrylate monomer in combination with a polyfunctional (meth)acrylate monomer as a polymerizable monomer for the purpose of reducing the viscosity. In this case, the mass ratio of the polyfunctional (meth)acrylate monomer to the total mass of the polyfunctional (meth)acrylate monomer and the monofunctional (meth)acrylate monomer is, for example, 30 mass% or more, and may be 40 mass% or more. On the other hand, the above-mentioned ratio of the polyfunctional (meth)acrylate monomer is, for example, 80 mass% or less, and may be 70 mass% or less.

[0067] In the present disclosure, in order to carry out the first treatment of irradiating ultraviolet rays, the composition for forming the release layer preferably has a photopolymerization initiator together with the ionizing radiation curable compound. As the photopolymerization initiator, for example, at least one of acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, Michler's benzoyl benzoate, Michler's ketone, diphenyl sulfide, dibenzyl disulfide, diethyl oxide, triphenyl biimidazole, isopropyl-N,N-dimethylaminobenzoate, monoacylphosphine oxide, etc. can be used. The amount of the photopolymerization initiator contained in the composition for forming the release layer is not particularly limited, but is, for example, 5 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the ionizing radiation curable compound. The composition for forming the release layer may contain a crosslinking agent and a polymerization accelerator.

[0068] The release layer forming composition may contain particles. The particles are used, for example, as pigments. Examples of the particles include inorganic particles and synthetic resin particles. Examples of the inorganic particles include silica, alumina, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, and kaolin. Examples of the synthetic resin particles include acrylic beads, urethane beads, nylon beads, silicone beads, silicone rubber beads, polycarbonate beads, and polyolefin wax (for example, polypropylene wax, polyethylene wax).

[0069] The average particle size of the particles used in the composition for forming the release layer is, for example, 5.0 μm or less, preferably 1.5 μm or less, and more preferably 1.0 μm or less. By having the average particle size of the particles in the above range, poor dispersion (sedimentation) of the particles can be suppressed, and stable printability can be obtained. On the other hand, the average particle size of the particles is, for example, 0.3 μm or more, and may be 0.5 μm or more. The average particle size is D50 according to the volume-based particle size distribution measured by a laser diffraction scattering method. The content of the particles is, for example, 5 parts by mass or more and 40 parts by mass or less, and may be 10 parts by mass or more and 30 parts by mass or less, or may be 10 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the resin component of the composition for forming the release layer.

[0070] The composition for forming the release layer may contain a release agent. The addition of the release agent improves the releasability of the release layer. Examples of the release agent include silicone-based release agents such as silicone oil, wax-based release agents such as polyolefin wax, and fluorine-based release agents. The silicone oil may be reactive silicone oil or non-reactive silicone oil.

[0071] Reactive silicone oil refers to modified silicone oils that have an organic group introduced into the side chain or end, and have reactivity due to the nature of the organic group introduced.Specific examples of reactive silicone oils include modified silicone oil side chain type, modified silicone oil both ends type, modified silicone oil one end type, modified silicone oil side chain both ends type, etc., in which the organic group introduced is amino-modified, epoxy-modified, mercapto-modified, carboxyl-modified, carbinol-modified, phenol-modified, methacryl-modified, heterogeneous functional group-modified, etc.These reactive silicone oils can be used alone or in combination of two or more.

[0072] The non-reactive silicone oil is not particularly limited as long as it is a silicone oil that does not have a reactive functional group such as an amino group, an epoxy group, a mercapto group, a carboxy group, a hydroxy group, a (meth)acryloyl group, or an allyl group. Examples of the non-reactive silicone oil include silicone oils made of polysiloxane, polyether-modified silicone oils, aralkyl-modified silicone oils, fluoroalkyl-modified silicone oils, long-chain alkyl-modified silicone oils, higher fatty acid ester-modified silicone oils, higher fatty acid amide-modified silicone oils, and phenyl-modified silicone oils. These non-reactive silicone oils can be used alone or in combination of two or more kinds.

[0073] The content of the release agent is, for example, 0.1 parts by mass or more and 50 parts by mass or less, optionally 0.5 parts by mass or more and 20 parts by mass or less, optionally 3 parts by mass or more and 20 parts by mass or less, or optionally 3 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the resin component of the composition for forming the release layer. The release layer may be colorless or colored. In the latter case, the release layer forming composition preferably contains a colorant. The colorant may be the same as the colorant used in the design layer described above.

[0074] The composition for forming the release layer may contain additives such as ultraviolet absorbers, infrared absorbers, light stabilizers, polymerization inhibitors, crosslinking agents, antistatic agents, antioxidants, leveling agents, coupling agents, plasticizers, defoamers, fillers, thermal radical generators, and aluminum chelating agents, as necessary.

[0075] The release layer forming composition is preferably an ink suitable for inkjet printing. For example, from the viewpoint of suppressing clogging in the print head, the viscosity of the release layer forming composition is preferably 15 mPa·s or less, more preferably 10 mPa·s or less. On the other hand, the viscosity of the release layer forming composition is, for example, 1 mPa·s or more.

[0076] In the coating process, the coating layer is formed by ejecting the release layer forming composition from an inkjet head and depositing the coating droplets on the substrate. The coating layer is preferably formed to match the pattern of the design layer. "Synchronization" means that the shapes and positions of the two target patterns are roughly the same. Specifically, it means that the shapes and positions of the pattern of the coating layer (release layer) and at least a part of the pattern constituting the design layer's design match to an extent that does not impair the realism and luxury. In FIG. 1(b), the design layer 3 has pattern layers y1 and y2, and the coating layer 4' is formed to match the pattern layer y1. By arranging the pattern of the coating layer (release layer) to match the pattern of the design layer, a high texture can be obtained. On the other hand, the coating layer (release layer) does not have to be arranged to match the pattern of the design layer.

[0077] Examples of patterns formed by the release layer include, for example, in the case where the design layer has a wood grain pattern, recesses such as the duct parts of a wood grain board, the spring wood areas, or low gloss areas; in the case of a stone grain pattern, recesses in a travertine marble board, recesses in the cleavage surface of a granite board, and other unevenness on the surface of a stone slab; in the case of a cloth grain pattern, the texture of a cloth surface; in the case of a leather pattern, the wrinkled shape of leather grain; in the case of a tiled pattern or brickwork pattern, recesses in the joints; and other patterns such as pear-finished, sand-grained, hairline, striped grooves, letters, symbols, and geometric patterns.

[0078] (2) First hardening treatment In the first curing treatment, the coating layer is irradiated with ultraviolet light. By irradiating with ultraviolet light as the first curing treatment, the coating layer can be quickly cured after the coating treatment. Therefore, it is possible to suppress the penetration of the release layer forming composition into the porous substrate. The ultraviolet light irradiation is preferably performed by a UV-LED device integrated with an inkjet device. This is because the first curing treatment can be performed immediately after the coating treatment.

[0079] In many cases, a low gloss design is required for the area of ​​the release layer that is finally formed. In the present disclosure, the time from the discharge (coating process) of the release layer forming composition to the first curing process can be shortened, so that the leveling of the coating layer is limited and the gloss value can be kept lower.

[0080] Examples of ultraviolet light sources include UV-LED lamps, ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, black light fluorescent lamps, and metal halide lamps. The wavelength of the ultraviolet light is, for example, 250 nm or more and 400 nm or less. The illuminance of the ultraviolet light is, for example, 1 mW / cm. 2 More than 5mW / cm 2 or more, 10 mW / cm 2 On the other hand, the illuminance of the ultraviolet light may be, for example, 100 mW / cm 2 Less than 50mW / cm 2 The integrated amount of ultraviolet light may be, for example, 4000 mJ / m 2 More than 5000mJ / m 2 On the other hand, for example, 8000 mJ / m 2 Less than 7000mJ / m 2 It may be the following.

[0081] In the present disclosure, the time from ink landing, in which the release layer forming composition is discharged from an inkjet head and deposited on a substrate in the coating process, to the start of light irradiation in the first curing process is preferably 20 seconds or less, and more preferably 10 seconds or less. On the other hand, the above time may be, for example, 0.1 seconds or more, or 1 second or more.

[0082] (3) Second hardening treatment In the present disclosure, after the first curing process, a second curing process is performed to obtain a release layer from the coating layer by performing an electron beam irradiation process. By performing the electron beam irradiation process, the release layer forming composition that has partially permeated into the porous substrate can be completely cured, so that odor due to the remaining monomer can be suppressed. In addition, the degree of crosslinking of the coating layer can be improved, so that a release layer with good releasability can be obtained.

[0083] Examples of electron beam sources include various electron beam accelerators such as Cockcroft-Walt type, Van de Graff type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type. The energy of the electron beam is, for example, 100 kV or more and 1000 kV or less, and may be 100 kV or more and 300 kV or less. The dose of the electron beam is, for example, 20 kGy or more and 150 kGy or less (2 Mrad or more and 15 Mrad or less), and is preferably selected in the range of 30 kGy or more and 100 kGy or less (3 Mrad or more and 10 Mrad or less).

[0084] The curing rate of the release layer after the second curing treatment (i.e., the curing rate of the ionizing radiation curable compound) is, for example, 90% or more, and may be 95% or more. The curing rate of the release layer after the second curing treatment is a value calculated by measuring the peak intensity of the peak derived from the ionizing radiation curable functional group by IR measurement (infrared spectroscopy measurement) and using the following formula. Curing rate (%)=(1-(peak strength of release layer after second curing treatment / peak strength of composition for forming release layer))×100(%)

[0085] (4) Release layer The release layer in the present disclosure is disposed on the surface of the support on the design layer side and has a pattern shape. When the design layer has a pattern layer, it is preferable that at least a part of the release layer is disposed on the surface of the pattern layer opposite to the porous substrate side. The release layer has releasability with respect to the cured resin layer located between the release layer and the release film in the manufacturing process of the resin-impregnated decorative board described later. By having such releasability, for example, in the resin-impregnated decorative board 100 shown in Figures 5(a) and 5(b) manufactured using the decorative sheet in the present disclosure, the cured resin layer 31 gives a glossy design feel, and the release layer 4 gives a matte design feel, thereby expressing a clear glossy matte design feel.

[0086] The thickness of the release layer is not particularly limited, but is, for example, 0.1 μm or more and 20 μm or less, preferably 0.3 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 8 μm or less. In addition, when the area of ​​the release layer is S1 and the area of ​​the porous substrate is S2 when viewing the decorative sheet from the thickness direction, the ratio of S1 to S2 (S1 / S2) is, for example, 5% or more, and may be 10% or more. Meanwhile, S1 / S2 is, for example, 80% or less, and may be 70% or less, or may be 60% or less.

[0087] 3. Decorative sheets Figures 3(a) to 3(d) are schematic cross-sectional views illustrating decorative sheets according to the present disclosure. As shown in Figures 3(a) and 3(c), decorative sheet 20 according to the present disclosure may have porous substrate 1, polar group-containing resin layer 2, design layer 3, and release layer 4, in this order. On the other hand, as shown in Figures 3(b) and 3(d), decorative sheet 20 according to the present disclosure may have porous substrate 1, design layer 3, polar group-containing resin layer 2, and release layer 4, in this order.

[0088] When the decorative sheet in the present disclosure has a porous substrate 1, a polar group-containing resin layer 2, a design layer 3, and a release layer 4 in this order as shown in FIG. 3(a), it is preferable that the pure water contact angle is low in the release layer 4 and the polar group-containing resin layer 2 exposed from the design layer 3 as viewed in the thickness direction. Also, as shown in FIG. 3(b) and FIG. 3(d), when the decorative sheet has a porous substrate 1, a design layer 3, a polar group-containing resin layer 2, and a release layer 4 in this order, it is preferable that the pure water contact angle is low in the polar group-containing resin layer 2 exposed from the release layer 4 as viewed in the thickness direction. This is because the impregnation of uncured resins such as hydrophilic melamine resins is improved. The pure water contact angle is obtained by the following method. That is, the decorative sheet is placed on a horizontal surface with the release layer facing up. Next, a water droplet (pure water, 2.0 μL) is dropped vertically onto the horizontal surface. At this time, the water droplets are not dropped on the boundary between the polar group-containing resin layer and the release layer, but are dropped so that the entire water droplets come into contact with the polar group-containing resin layer. After dropping the water droplets, wait for 1 second, and measure the contact angle between the polar group-containing resin layer and pure water using a contact angle meter (fully automatic contact angle meter DMo-702, manufactured by Kyowa Interface Science Co., Ltd.). The above measurement is performed at any 10 points, and the average value is taken as the pure water contact angle. The pure water contact angle may be 80° or less, 60° or less, or 40° or less. On the other hand, the pure water contact angle may be 0°. In other words, the pure water may completely penetrate the decorative sheet.

[0089] When viewed from the thickness direction, the polar group-containing resin layer 2 exposed from the release layer 4 (the release layer 4 and the design layer 3 in FIG. 3(a)) preferably has high wettability. This is because the impregnation of uncured resins such as hydrophilic melamine resins is improved. The wettability is determined by the following method. 1) Prepare tension checkers (manufactured by Pacific Chemical Co., Ltd.) with dyne numbers of 40 mN / m, 46 mN / m, 50 mN / m, 54 mN / m, 60 mN / m, 67 mN / m, and 70 mN / m. 2) Draw a line of 30 cm or more on the surface of the decorative sheet using a tension checker. Do not draw the line only on the release layer, but make sure that the drawn line includes the polar group-containing resin layer that does not have a release layer laminated thereon. 3) After drawing the line, leave it for 2 seconds and wipe the surface with a dry cloth. Then, visually check whether there are any ink marks or discoloration caused by the tension checker on the polar group-containing resin layer. Repeat this operation three times at one dyne number. 4) Perform steps 2) and 3) above for each of the prepared dyne numbers. 5) As a result of 4) above, the highest dyne number at which ink marks or discoloration were observed (including cases where ink marks or discoloration were observed even once out of three times) will be used to determine the wettability of the decorative sheet. The wettability is, for example, 50 mN / m or more, may be 54 mN / m or more, or may be 60 mN / m or more, while the wettability is, for example, 70 mN / m or less.

[0090] The decorative sheet in the present disclosure is used for producing a resin-impregnated decorative board, which will be described later and therefore will not be described here.

[0091] B. Manufacturing method of resin-impregnated decorative panels 4 is a schematic cross-sectional view illustrating a method for manufacturing a resin-impregnated decorative board according to the present disclosure. First, as shown in FIG. 4(a) and FIG. 4(b), the porous substrate 1 of the decorative sheet 20 described above is impregnated with a curable resin via the polar group-containing resin layer 2 and the design layer 3, and a curable resin layer 30 containing the curable resin and covering the design layer 3 and the release layer 4 is formed.

[0092] Next, as shown in Figure 4 (c), a release film 40 is placed on the side of the curable resin layer 30 opposite the design layer 3, and a core substrate 50 is placed on the side of the decorative sheet 20 facing the porous substrate 1 (the side of the decorative sheet 20 that is located on the porous substrate 1 side with respect to the design layer 3) to produce the laminate 11.

[0093] 4(d), the laminate 11 is heated and pressurized to cure the curable resin, forming a cured resin layer 31 from the curable resin layer 30, and producing a cured laminate 12. In addition, by applying pressure, the surface properties of the release film 40 are reflected on the surface of the cured resin layer 31.

[0094] Next, as shown in FIG. 4(e), the release film 40 is peeled off from the cured laminate 12, and at the same time, the cured resin layer 31 located between the release layer 4 and the release film 40 is also peeled off toward the release film 40. As a result, the cured resin layer 31 arranged in the first region R1 that overlaps with the release layer 4 in the thickness direction is removed, while the cured resin layer 31 arranged in the second region R2 that does not overlap with the release layer 4 in the thickness direction is left. At this time, the cured resin layer 31 that is not peeled off toward the release film 40 becomes, for example, a gloss layer. In addition, the release layer 4 becomes, for example, a matte layer. As a result, the core substrate 50, the porous substrate 1, the polar group-containing resin layer 2, the design layer 3, and the release layer 4 are separated in the thickness direction D. T In this order, a resin-impregnated decorative board 100 is obtained which further has a cured resin layer 31 disposed between the patterns of the release layer 4 and which contains a cured product of the curable resin.

[0095] According to the present disclosure, by using the decorative sheet described above, a resin-impregnated decorative board can be obtained that has good impregnation properties with uncured resin, which is a precursor of melamine resin, etc., and can stably express a gloss matte design.

[0096] 1. Preparation process This step is a step of manufacturing and preparing a decorative sheet by the method for manufacturing a decorative sheet described above. The method for manufacturing a decorative sheet and the decorative sheet are as described above.

[0097] 2.Laminate formation process In this step, as shown in FIG. 4(c), (i) the core substrate 50, the decorative sheet 20, the curable resin layer 30 containing the curable resin, and the release film 40 are laminated in a thickness direction D T This is a process for forming a laminate 11 having the above components in this order, (ii) the surface of the decorative sheet 20 facing the porous substrate 1 faces the core substrate 50, and (iii) the decorative sheet 20 is impregnated with a curable resin.

[0098] The method of forming such a laminate is not particularly limited. For example, as shown in Fig. 4(b), the decorative sheet 20 is impregnated with a curable resin, and a curable resin layer 30 is formed that covers the design layer 3 and the release layer 4 and contains a curable resin, and then, as shown in Fig. 4(c), a release film 40 is disposed so as to face the curable resin layer 30, and a core substrate 50 is disposed so as to face the porous substrate 1. This allows the laminate 11 to be obtained.

[0099] As the curable resin, a wide variety of thermosetting resins can be used, including, for example, melamine-based resins (melamine-based resin precursors), melamine-urea co-condensation resins, unsaturated polyester-based resins, polyurethane-based resins (including two-component curing polyurethanes), epoxy-based resins, aminoalkyd-based resins, phenol-based resins, urea-based resins, diallyl phthalate-based resins, guanamine-based resins, silicon-based resins, and polysiloxane-based resins.

[0100] In this step, for example, the decorative sheet is immersed in a curable resin composition containing a curable resin. After immersion, it is preferable to dry the sheet. At this time, a part of the curable resin may be cured to a semi-cured state. Methods for impregnating the curable resin include, for example, a method of immersing the decorative sheet 20 in a bath containing the curable resin; a method of applying the curable resin to the decorative sheet 20 using a coater such as a kiss coater or a comma coater; and a method of spraying the curable resin onto the decorative sheet 20 using a spray device or a shower device.

[0101] The ratio of the curable resin in the curable resin composition is, for example, 50% by mass or more, or may be 70% by mass or more, or may be 90% by mass or more. The curable resin composition may contain, for example, water, alcohol, or an organic solvent as a solvent.

[0102] An example of the core substrate 50 is phenol resin-impregnated paper. The phenol resin-impregnated paper is obtained by impregnating kraft paper, which is a core paper, with phenol resin and drying it.

[0103] Examples of resins constituting the release film include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyolefin resins such as polyethylene and polypropylene, and acrylic resins. The release film may have a release layer containing a cured product of the ionizing radiation curable resin composition on the surface facing the curable resin layer.

[0104] 3. Heat and pressure process In this step, as shown in Fig. 4(d), the laminate 11 is heated and pressurized to cure the curable resin, forming a cured resin layer 31 from the curable resin layer 30, and obtaining a cured laminate 12. The heating temperature is, for example, 90°C or higher and 160°C or lower. The pressure applied is, for example, 50 kg / cm. 2 More than 150kg / cm 2 The heating and pressurizing time is, for example, 30 seconds or more and 30 minutes or less.

[0105] 4. Peeling process In this step, as shown in FIG. 4( e ), the release film 40 is peeled off from the cured laminate 12 to form a laminate in the thickness direction D T In this step, the cured resin layer 31 arranged in the first region R1 overlapping with the release layer 3 is removed, while the cured resin layer 31 arranged in the second region R2 not overlapping with the release layer 4 in the thickness direction is left. This results in a resin-impregnated decorative board 100 having a porous substrate 1, a polar group-containing resin layer 2, a design layer 3, a release layer 4 arranged on the surface of the design layer 3 opposite the porous substrate 1 and having a pattern shape, and a cured resin layer 31 arranged between the patterns of the release layer 4 of the decorative sheet. The polar group-containing resin layer 2 may be formed between the porous substrate 1 and the design layer 3, or may be arranged on the surface of the design layer 3 opposite the porous substrate 1.

[0106] 5. Resin-impregnated decorative panels 5(a) and 5(b) are schematic cross-sectional views illustrating examples of resin-impregnated decorative boards obtained by the above-mentioned steps. The resin-impregnated decorative board 100 shown in FIG. 5 has the above-mentioned decorative sheet 20 and a core substrate 50 arranged so as to face the porous substrate 1 of the decorative sheet, and is oriented in the thickness direction D. T Viewed from the top, the resin-impregnated decorative board 100 has a first region R1 that overlaps with the release layer 4 and a second region R2 that does not overlap with the release layer 4, and in the second region R2, a cured resin layer 31 containing a cured product of a curable resin is arranged on the side of the design layer 3 opposite the porous substrate 1, and the porous substrate 1 contains a cured product of a curable resin.

[0107] The resin-impregnated decorative board of the present disclosure has a porous core substrate 50 on the surface of the decorative sheet 20 facing the porous substrate 1 (the surface of the decorative sheet 20 located on the porous substrate 1 side with respect to the design layer 2).

[0108] The porous substrate in the resin-impregnated decorative board contains a cured product of a curable resin. The resin-impregnated decorative board has a cured resin layer disposed between patterns of a release layer. The cured product of the curable resin filled in the porous substrate and the cured product of the curable resin contained in the cured resin layer are formed from the same curable resin.

[0109] The thickness of the cured resin layer is not particularly limited, but may be, for example, 1 μm or more, or 10 μm or more. On the other hand, the thickness of the cured resin layer may be, for example, 500 μm or less, or 300 μm or less. The thickness of the cured resin layer is preferably greater than the thickness of the release layer. That is, the cured resin layer preferably protrudes from the release layer in the thickness direction.

[0110] The resin-impregnated decorative board in the present disclosure is used, for example, by being disposed on the surface of a substrate. Examples of substrates include wood members, resin members, metal members, and ceramic members. Examples of wood members include wood veneer, wood plywood, particle board, and wood fiberboard. Examples of wood used for wood members include cedar, cypress, pine, and lauan. Examples of resins used for resin members include vinyl chloride resins, (meth)acrylic resins, ester resins, styrene resins, olefin resins, acrylonitrile-butadiene-styrene copolymers (ABS resins), phenolic resins, cellulose resins, carbonate resins, melamine resins, and rubber. Examples of metals used for metal members include iron and aluminum. The material of the ceramic members may be ceramics such as glass and porcelain, non-cement ceramic materials such as gypsum, and non-ceramic ceramic materials such as ALC (lightweight aerated concrete).

[0111] The resin-impregnated decorative board of the present disclosure can be used, for example, as a building material or furniture. The building material can be an interior material or an exterior material. The building material can be, for example, a wall, a floor, a ceiling, a door, or a shelf. The furniture can be, for example, a table, a desk, or a cabinet.

[0112] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits similar effects is included in the technical scope of the present disclosure. EXAMPLES

[0113] [Example 1] (Manufacturing decorative sheets) As a porous substrate, the basis weight is 80g / m 2Titanium paper (PM-67P, manufactured by KJ Specialty Paper Co., Ltd.) was prepared. The inorganic component (ash content) of the titanium paper was 23% by mass. A composition for polar group-containing resin layer, containing water-soluble casein, acrylic resin ("Ode SPTI" manufactured by DIC Graphics), and silica as an inorganic component, was applied to the porous substrate at a rate of 1 g / m2 using a gravure coater so as to cover the entire surface of the substrate when viewed from the thickness direction. 2 The composition for the polar group-containing resin layer was composed of 34% by mass of water-soluble casein, 39% by mass of acrylic resin emulsion, and 27% by mass of silica, based on the solid content.

[0114] Furthermore, on the side of the polar group-containing resin layer opposite the porous substrate, an ink for forming a design layer prepared by the method described below was used to inkjet print the wood grain pattern data using an inkjet printer (SOLJET EJ-640 manufactured by Roland) with a resolution set to drawing conditions of vertical x horizontal = 600 x 600 dpi, thereby obtaining a wood grain pattern design layer.

[0115] <Adjustment of ink for forming design layer> The following color pigments were dispersed and mixed into an aqueous acrylic resin emulsion, and the mixture was diluted with a solvent (water) to obtain a printing ink for forming a design layer. Water-based acrylic resin emulsion Color pigments (quinacridone, isoindolinone, phthalocyanine blue, carbon black)

[0116] Next, a release layer forming composition having the following composition was used, using a Tritec inkjet device "Stage JET" (customized machine) and a Konica Minolta KM512 as the inkjet head, to coat a pattern that corresponds to the ducts (winter grain) of the wood grain data in sync with the pattern layer, thereby obtaining a coating layer 15 μm thick (coating process).

[0117] <Release layer forming composition> 1) Polymerizable compound Isobornyl acrylate 12% by mass Acryloylmorphine 14% by mass Tetrahydrofurfuryl acrylate 14% by mass 1,6-Hexanediol diacrylate 12% by mass Dimethylol-tricyclodecane diacrylate 12% by mass Caprolactone-modified dipentaerythritol hexaacrylate 5% by mass 2) Polymerization initiator Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide 7% by mass 3) Silicone Additives "Product name: BYK-UV3500 manufactured by BYK Chemie" 6% by mass 4) Pigment dispersants "Product name: BYKJET9151 manufactured by BYK Chemie" 6% by mass 5) Pigments ·Silica particle size 0.5μm 12% by mass

[0118] Immediately after the above coating process, a UV-LED (wavelength = 395 nm / cumulative light amount = 5000 mJ / m 2 ) was used for ultraviolet irradiation (first curing treatment). Next, an electron beam was irradiated under conditions of an acceleration voltage of 165 kV and an exposure dose of 30 kGy to form a release layer (second curing treatment). In this way, a decorative sheet having, in this order, a porous substrate, a polar group-containing resin layer, a design layer, and a release layer having a pattern shape was produced.

[0119] [Comparative Example 1] As a porous substrate, the basis weight is 80g / m 2 Titanium paper (PM-67P, manufactured by KJ Specialty Paper Co., Ltd.) was prepared. The inorganic component (ash content) of the titanium paper was 23 mass %. The composition for polar group-containing resin layer having the above composition was applied to the porous substrate at a rate of 1 g / m2 using a gravure coater so as to cover the entire surface of the substrate when viewed in the thickness direction. 2The ink was then applied to the surface of the polar group-containing resin layer opposite to the porous substrate, and the ink for forming the design layer having the above composition was used to inkjet print the wood grain pattern data on the surface of the polar group-containing resin layer opposite to the porous substrate, using an inkjet printer (SOLJET EJ-640 manufactured by Roland Corporation) with a resolution set to a drawing condition of vertical x horizontal = 600 x 600 dpi, to thereby obtain a wood grain pattern design layer.

[0120] Next, using the composition for forming the release layer having the above composition, an inkjet device "Stage JET" (customized machine) manufactured by Tritec Corporation and an inkjet head "KM512 manufactured by Konica Minolta Inc." were used to coat a pattern that was linked to the ducts (winter grain) of the wood grain data in sync with the pattern layer, thereby obtaining a coating layer with a thickness of 15 μm (coating process).

[0121] Immediately after the above coating process, a UV-LED (wavelength = 395 nm / cumulative light amount = 5000 mJ / m 2 ) was used for ultraviolet irradiation. This produced a decorative sheet having, in this order, a porous substrate, a polar group-containing resin layer, a design layer, and a release layer having a pattern shape.

[0122] [Comparative Example 2] As a porous substrate, the basis weight is 80g / m 2 Titanium paper (PM-67P, manufactured by KJ Specialty Paper Co., Ltd.) was prepared. The inorganic component (ash content) of the titanium paper was 23% by mass. On one side of the porous substrate, the ink for forming the design layer having the above composition was used, and an inkjet printer (SOLJET EJ-640 manufactured by Roland Corporation) was used to inkjet print the wood grain pattern data, setting the resolution to drawing conditions of vertical x horizontal = 600x600dpi, to obtain a wood grain pattern design layer.

[0123] Next, using the composition for forming the release layer having the above composition, an inkjet device "Stage JET" (customized machine) manufactured by Tritec Corporation and an inkjet head "KM512 manufactured by Konica Minolta Inc." were used to coat a pattern that was linked to the ducts (winter grain) of the wood grain data in sync with the pattern layer, thereby obtaining a coating layer with a thickness of 15 μm (coating process).

[0124] Immediately after the above coating process, a UV-LED (wavelength = 395 nm / cumulative light amount = 5000 mJ / m 2 ) was used for ultraviolet irradiation (first curing treatment). Next, an electron beam was irradiated under conditions of an acceleration voltage of 165 kV and an exposure dose of 30 kGy to form a release layer (second curing treatment). This produced a decorative sheet having, in this order, a porous substrate, a polar group-containing resin layer, a design layer, and a release layer having a pattern shape.

[0125] [Comparative Example 3] As a porous substrate, the basis weight is 80g / m 2 Titanium paper (PM-67P, manufactured by KJ Specialty Paper Co., Ltd.) was prepared. The inorganic component (ash content) of the titanium paper was 23% by mass. On one side of the porous substrate, the ink for forming the design layer having the above composition was used, and an inkjet printer (SOLJET EJ-640 manufactured by Roland Corporation) was used to inkjet print the wood grain pattern data, setting the resolution to drawing conditions of vertical x horizontal = 600x600dpi, to obtain a wood grain pattern design layer.

[0126] Next, using the composition for forming the release layer having the above composition, an inkjet device "Stage JET" (customized machine) manufactured by Tritec Corporation and an inkjet head "KM512 manufactured by Konica Minolta Inc." were used to coat a pattern that was linked to the ducts (winter grain) of the wood grain data in sync with the pattern layer, thereby obtaining a coating layer with a thickness of 15 μm (coating process).

[0127] Immediately after the above coating process, a UV-LED (wavelength = 395 nm / cumulative light amount = 5000 mJ / m 2) was used for ultraviolet irradiation. This produced a decorative sheet having, in this order, a porous substrate, a polar group-containing resin layer, a design layer, and a release layer having a pattern shape.

[0128] [Production of melamine laminate] (Preparation of release film) A release layer-forming composition was prepared by mixing 60 parts by mass of an ionizing radiation curable monomer (Aronix M400 manufactured by Toagosei Co., Ltd.), 0.6 parts by mass of a reactive silicone (X-22-164B manufactured by Shin-Etsu Chemical Co., Ltd.), and 40 parts by mass of methyl ethyl ketone (manufactured by Maruzen Petrochemical Co., Ltd.) with a process homogenizer PH91 (manufactured by SMT Corporation) by stirring at a rotation speed of 2000 rpm for 1 hour. A coating liquid containing 100 parts by mass of an ionizing radiation curable monomer (ARONIX (registered trademark) M350 manufactured by Toagosei Co., Ltd.), 2 parts by mass of a reactive silicone (X-22-164B manufactured by Shin-Etsu Chemical Co., Ltd.), 8 parts by mass of silica (Salisia 450 manufactured by Fuji Silysia Chemical Ltd.), and 50 parts by mass of ethyl acetate was applied at a rate of 5 g / m to the adhesive surface of a 50 μm-thick PET film (Cosmoshine (registered trademark) A4160 manufactured by Toyobo Co., Ltd.). 2 The coating was applied in an amount of (when dry) and cured by irradiating with an electron beam of 5 Mrad at an acceleration voltage of 165 kV, thereby producing a release film having a peeling layer.

[0129] (Production of melamine laminate) A liquid uncured melamine resin composition containing 60 parts by mass of uncured melamine resin (water-soluble methylol melamine resin, Nika Resin S-260 manufactured by Nippon Carbide Industries Co., Ltd.), 35 parts by mass of water, and 5 parts by mass of isopropyl alcohol was applied to the decorative sheet produced above using an impregnation device until the uncured melamine resin composition was 80 g / m 2 The composition was impregnated so as to obtain the ratio (when dried) and then dried to produce an impregnated decorative sheet.

[0130] The impregnated decorative sheet is made by impregnating craft paper with phenolic resin liquid, with a basis weight of 245g / m 2The resulting laminate was then laminated on top of three sheets of phenol resin-impregnated core paper (obtained by impregnating a core craft paper with a liquid uncured resin composition made of phenol resin). Furthermore, the above release film was laminated on the release layer side of the impregnated decorative sheet so that the peeling layer of the release film was in contact with the printed surface of the impregnated decorative sheet, obtaining a laminate. The resulting laminate was sandwiched between two mirror plates and pressed with a pressure of 100 kg / cm using a heat press. 2 The molded product was heated and molded at a molding temperature of 150°C for 10 minutes to produce a molded product (cured laminate). In the molded product, a melamine resin layer containing a cured melamine resin was formed between the release layer and the release film. The release film was peeled off from the cured resin layer containing the cured product of the melamine resin to obtain a melamine decorative board.

[0131] [Appearance evaluation] The gloss / matt design of the resulting melamine decorative boards was visually evaluated according to the following criteria. The results are shown in Table 1. Evaluation criteria A: There is no remaining hardened resin layer in the duct section, and the gloss matte effect is fully confirmed. B: Remaining hardened resin layer is present in the duct section, and the gloss matte effect in the duct section is slight. C: The cured resin layer in the duct section does not peel off, and the gloss matte effect is not confirmed.

[0132] [Table 1]

[0133] As shown in Table 1, the decorative sheet of Example 1 enabled the production of a melamine decorative board having a better gloss and matte design than Comparative Examples 1 to 3.

[0134] Thus, in the present disclosure, for example, the following inventions are provided:

[0135] [1] A method for producing a decorative sheet used in the production of a resin-impregnated decorative board, comprising: A support manufacturing process for manufacturing a support having a porous substrate and a design layer; A release layer forming step of forming a release layer having a pattern shape on the surface of the support on the side of the design layer, The support has a polar group-containing resin layer containing a resin having one or more polar groups, either a hydroxy group, an amino group, or a carboxy group, between the porous substrate and the design layer, or on the surface of the design layer opposite the porous substrate; The release layer forming step includes: The method for producing a decorative sheet includes a coating process in which a release layer-forming composition is applied by inkjet printing to form a coating layer, a first curing process in which the coating layer is irradiated with ultraviolet rays, and a second curing process in which the release layer is obtained from the coating layer by performing an electron beam irradiation process after the first curing process.

[0136] [2] The method for producing a decorative sheet according to [1], wherein the resin having a polar group comprises at least one of casein, a melamine-based resin, polyvinyl alcohol, a polyvinyl alcohol derivative, cellulose, and a cellulose derivative.

[0137] [3] The method for producing a decorative sheet according to [1] or [2], wherein the resin having a polar group contains casein.

[0138] [4] The method for producing a decorative sheet according to any one of [1] to [3], wherein the polar group-containing resin layer contains inorganic particles.

[0139] [5] The method for producing a decorative sheet according to any one of [1] to [4], wherein the support has the polar group-containing resin layer between the porous substrate and the design layer.

[0140] [6] The method for producing a decorative sheet according to any one of [1] to [5], wherein the design layer is formed by an inkjet printing method.

[0141] [7] The method for producing a decorative sheet according to any one of [1] to [6], wherein the composition for forming a release layer contains particles having an average particle size of 1.5 μm or less.

[0142] [8] The method for producing a decorative sheet according to any one of [1] to [7], wherein the porous substrate comprises titanium paper.

[0143] [9] The method for producing a decorative sheet according to any one of [1] to [8], wherein the resin-impregnated decorative board is a melamine decorative board.

[0144]

[10] The method for producing a decorative sheet according to any one of [1] to [9], wherein the composition for forming a release layer contains a curable compound.

[0145]

[11] The method for producing a decorative sheet according to

[10] , wherein the curable compound is an ionizing radiation curable compound.

[0146]

[12] The method for producing a decorative sheet according to

[11] , wherein the ionizing radiation curable compound has a polymerizable monomer.

[0147]

[13] A method for producing a resin-impregnated decorative board, comprising: A preparation step of preparing a decorative sheet by the method for producing a decorative sheet according to any one of [1] to

[12] ; (i) a laminate formation step of forming a laminate having a core substrate, the decorative sheet, a curable resin layer containing a curable resin, and a release film in this order in the thickness direction, (ii) a surface of the decorative sheet on the porous substrate side is arranged to face the core substrate, and (iii) the decorative sheet is impregnated with the curable resin; a heating and pressurizing step of heating and pressurizing the laminate to cure the curable resin and form a cured resin layer from the curable resin layer to obtain a cured laminate; a peeling step of peeling the release film from the cured laminate to remove the cured resin layer arranged in a first region that overlaps with the release layer in the thickness direction, while leaving the cured resin layer arranged in a second region that does not overlap with the release layer in the thickness direction; A method for producing a resin-impregnated decorative board comprising the steps of: [Explanation of symbols]

[0148] 1...Porous base material 2...Polar group-containing resin layer 3…Design layer 4…Release layer 10...Support 20...Decorative sheet 30…Curable resin layer 31...cured resin layer 40...Release film 50…Core base material 100...Resin-impregnated decorative board

Claims

1. A method for producing a decorative sheet used in the production of a resin-impregnated decorative board, comprising: A support manufacturing process for manufacturing a support having a porous substrate and a design layer; A release layer forming step of forming a release layer having a pattern shape on the surface of the support on the side of the design layer, The support has a polar group-containing resin layer containing a resin having one or more polar groups, either a hydroxy group, an amino group, or a carboxy group, between the porous substrate and the design layer, or on the surface of the design layer opposite the porous substrate; The release layer forming step includes: A method for producing a decorative sheet, comprising: a coating process in which a release layer-forming composition is applied by inkjet printing to form a coating layer; a first curing process in which the coating layer is irradiated with ultraviolet rays; and a second curing process in which the release layer is obtained from the coating layer by performing an electron beam irradiation process after the first curing process.

2. The method for producing a decorative sheet according to claim 1, wherein the resin having a polar group comprises at least one of casein, a melamine-based resin, polyvinyl alcohol, a polyvinyl alcohol derivative, cellulose, and a cellulose derivative.

3. The method for producing a decorative sheet according to claim 1 , wherein the resin having a polar group includes casein.

4. The method for producing a decorative sheet according to claim 1 , wherein the polar group-containing resin layer contains inorganic particles.

5. The method for producing a decorative sheet according to claim 1 , wherein the support has the polar group-containing resin layer between the porous substrate and the design layer.

6. The method for producing a decorative sheet according to claim 1 , wherein the design layer is formed by an inkjet printing method.

7. The method for producing a decorative sheet according to claim 1 , wherein the composition for forming a release layer contains particles having an average particle size of 1.5 μm or less.

8. The method for producing a decorative sheet according to claim 1 , wherein the porous substrate comprises titanium paper.

9. The method for producing a decorative sheet according to claim 1 , wherein the resin-impregnated decorative board is a melamine decorative board.

10. The method for producing a decorative sheet according to claim 1 , wherein the composition for forming a release layer contains a curable compound.

11. The method for producing a decorative sheet according to claim 10, wherein the curable compound is an ionizing radiation curable compound.

12. The method for producing a decorative sheet according to claim 11 , wherein the ionizing radiation curable compound has a polymerizable monomer.

13. A method for producing a resin-impregnated decorative board, comprising: A preparation step of preparing a decorative sheet by the method for producing a decorative sheet according to any one of claims 1 to 12; (i) a laminate forming step of forming a laminate having a core substrate, the decorative sheet, a curable resin layer containing a curable resin, and a release film in this order in the thickness direction, (ii) a surface of the decorative sheet on the porous substrate side is arranged to face the core substrate, and (iii) the decorative sheet is impregnated with the curable resin; a heating and pressurizing step of heating and pressurizing the laminate to cure the curable resin and form a cured resin layer from the curable resin layer to obtain a cured laminate; a peeling process in which the release film is peeled off from the cured laminate, thereby removing the cured resin layer arranged in a first region that overlaps with the release layer in the thickness direction, while leaving the cured resin layer arranged in a second region that does not overlap with the release layer in the thickness direction; A method for producing a resin-impregnated decorative board comprising the steps of:

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