Decorative sheet

Abstract

Provided is a decorative sheet having high ink adhesiveness without using an oil-based ink that has a high burden on the environment. This decorative sheet is provided with: a base paper; a thermoplastic resin layer provided on one surface side of the base paper; an ink layer provided on the surface side of the thermoplastic resin layer opposite to the base paper, the ink layer containing an aqueous ink and, as a curing agent, at least one of a xylenediamine-based curing agent, a polycarbodiimide-based curing agent, and an aziridine-based curing agent; and a surface protection layer provided on the surface side of the ink layer opposite to the thermoplastic resin layer. The amount of the curing agent added in the ink layer is preferably 1-30 parts by mass per 100 parts by mass of the water-based ink.

Description

Technical Field

[0001] The present disclosure relates to decorative sheets. Background Art

[0002] In the past, for example, a decorative sheet has been proposed in which a thermoplastic resin layer, a pattern layer, and a surface protection layer are sequentially laminated on one side of a base paper. In such a decorative sheet, for reasons such as printing the pattern clearly and cleanly or having high quick-drying properties, the pattern is printed using an oil-based ink such as acrylic ink.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-075442 Summary of the invention

[0006] An object of the present disclosure is to obtain a decorative sheet having high ink adhesion without using an oil-based ink that has a high load on the environment.

[0007] In order to achieve the above-mentioned object, a decorative sheet according to one embodiment of the present disclosure comprises: base paper; a thermoplastic resin layer provided on one surface of the base paper; an ink layer provided on a surface of the thermoplastic resin layer opposite to the base paper, the ink layer containing an aqueous ink and at least one of a xylene diamine-based curing agent, a polycarbodiimide-based curing agent, and an aziridine-based curing agent as a curing agent; and a surface protection layer provided on the surface side of the ink layer opposite to the thermoplastic resin layer.

[0008] In addition, another embodiment of the present disclosure relates to a decorative sheet comprising: a base paper; a thermoplastic resin layer provided on one side of the base paper; an ink layer provided on the thermoplastic resin layer on the side opposite to the base paper, the ink layer comprising an aqueous ink and at least one of a xylene diamine-based curing agent, a polycarbodiimide-based curing agent, and an aziridine-based curing agent as a curing agent;

[0009] and a surface protection layer provided on the side of the ink layer opposite to the thermoplastic resin layer.

[0010] Effects of the Invention

[0011] According to one aspect of the present disclosure, a decorative sheet having high ink adhesion can be provided without using oil-based ink. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a cross-sectional view showing a configuration example of a decorative sheet according to an embodiment of the present disclosure.

[0013] Figure 2This is a cross-sectional view showing another configuration example of a decorative sheet according to one embodiment of the present disclosure.

[0014] Figure 3 This is a cross-sectional view showing another configuration example of a decorative sheet according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0015] One embodiment of the present disclosure will be described with reference to the drawings.

[0016] Here, the structure shown in the drawings is schematic, and the relationship between thickness and plane size, the ratio of thickness of each layer, etc. are different from the actual situation. In addition, the embodiment shown below illustrates the structure used to concretize the technical idea of ​​the present disclosure. The technical idea of ​​the present disclosure does not limit the material, shape, structure, etc. of the constituent parts to the following contents. The technical idea of ​​the present disclosure can be variously modified within the technical scope specified by the claim items recorded in the claims.

[0017] 1. First Implementation

[0018] (1.1) Basic composition of decorative sheets

[0019] Below, refer to Figure 1 A decorative sheet 1 according to an embodiment of the present disclosure will be described. Figure 1 As shown, the decorative sheet 1 includes at least a base paper 11, a thermoplastic resin layer 12, an ink layer 13, and a surface protection layer 14. In this embodiment, the ink layer 13 includes a solid ink layer 13A and a pattern layer 13B provided on the side of the thermoplastic resin layer 12. In the decorative sheet 1 according to one embodiment of the present disclosure, the ink layer 13 is formed of an aqueous ink containing at least one of a xylene diamine-based curing agent, a polycarbodiimide-based curing agent, and an aziridine-based curing agent as a curing agent.

[0020] Hereinafter, each layer of the decorative sheet 1 will be described in detail.

[0021] <Raw material layer>

[0022] In the decorative sheet 1 , a base paper 11 and a thermoplastic resin layer 12 form a base material layer.

[0023] (Original paper)

[0024] The base paper 11 is a layer that becomes the base of the decorative sheet 1. As the base paper 11, for example, a paper reinforcing paper containing resin between cellulose fibers can be used. As the paper reinforcing paper, a material containing 50% by mass or more of cellulose fibers relative to the total mass of the paper reinforcing paper is preferred. In addition, the thickness of the paper reinforcing paper is preferably 15 μm or more and less than 60 μm. In addition, the weight per square meter of the paper reinforcing paper is preferably 10 g / m 2Above 50g / m 2 As a result, the base paper 11 can have sufficient thickness and rigidity as the base of the decorative sheet 1 , so that the decorative sheet 1 is less likely to wrinkle, and the decorative sheet 1 can be prevented from warping or curling.

[0025] (Thermoplastic resin layer)

[0026] The thermoplastic resin layer 12 is a moisture-proof sheet-like layer provided on one surface side of the base paper 11. The "moisture-proof" refers to a property that water vapor is difficult to pass through.

[0027] The thermoplastic resin layer 12 is preferably a thermoplastic resin such as an olefin resin having a melting point of 140° C. or more, and more preferably a thermoplastic resin such as an olefin resin having a melting point of 150° C. or more. Examples of olefin resins include polypropylene (PP), polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl alcohol (PVA), polyvinylidene chloride (PVDF), and polyamide (PA). The resin material constituting the thermoplastic resin layer 12 is preferably selected according to the curing method of the resin material constituting the surface protection layer 14.

[0028] The ink layer 13 described later is formed using water-based ink. Therefore, when forming the ink layer 13, the raw material layer printed with the water-based ink is heated to dry the water-based ink. By setting the melting point of the resin material constituting the thermoplastic resin layer 12 to be 140° C. or higher, the softening of the thermoplastic resin layer 12 when forming the ink layer 13 can be suppressed, thereby preventing the occurrence of warping or curling of the decorative sheet 1.

[0029] The thickness of the thermoplastic resin layer 12 is 10 μm or more and preferably 20% or more relative to the thickness of the base paper 11. Thus, the thermoplastic resin layer 12 can obtain a sufficient moisture-proof effect as the thermoplastic resin layer 12. In addition, the thickness of the thermoplastic resin layer 12 is preferably 90% or less relative to the thickness of the base paper 11. Thus, the occurrence of warping or curling of the decorative sheet 1 can be prevented.

[0030] The interlayer strength between the base paper 11 and the thermoplastic resin layer 12 is preferably 1.1 N / cm or more. This makes it difficult for the thermoplastic resin layer 12 to be peeled off from the base paper 11.

[0031] An ink layer 13 made of aqueous ink for printing is formed directly above the thermoplastic resin layer 12. Therefore, a treatment for improving wettability may be performed on the surface of the thermoplastic resin layer 12 on which the ink layer 13 is to be provided. Examples of the treatment for improving wettability include corona treatment.

[0032] In order to prevent weather-resistant degradation, the thermoplastic resin layer 12 preferably contains at least one of an ultraviolet absorber and a light stabilizer. In addition, the thermoplastic resin layer 12 may contain an antioxidant and other various additives as appropriate.

[0033] <Ink layer>

[0034] As described above, the ink layer 13 includes the solid ink layer 13A and the pattern layer 13B provided on the thermoplastic resin layer 12 side.

[0035] (Solid ink layer)

[0036] The solid ink layer 13A is a layer for imparting color to the entire decorative sheet 1. The solid ink layer 13A is provided on the thermoplastic resin layer 12 on the side opposite to the base paper 11, that is, on the surface of the thermoplastic resin layer 12 opposite to the base paper 11. The solid ink layer 13A covers the entire thermoplastic resin layer 12 and imparts a desired base color to ensure concealment of the surface to which the decorative sheet 1 is attached.

[0037] In the present embodiment, the solid ink layer 13A is formed by water-based ink. The water-based ink, for example, contains a polyurethane resin and a water-based crosslinking agent. The water-based ink may contain a two-liquid curing urethane-based solvent-free adhesive as an adhesive forming each adhesive layer, and the adhesive contains a polyol component partially modified with terminal acids, and a polyisocyanate component. The polyisocyanate component is, for example, a mixture of an aliphatic polyisocyanate and an aromatic polyisocyanate. Since the water-based ink does not contain volatile organic compounds (VOC), it is possible to improve the environment of the production site and solve the problems caused by the residual organic solvent in the decorative sheet 1.

[0038] In addition, the solid ink layer 13A contains at least one of a xylene diamine curing agent, a polycarbodiimide curing agent, and an aziridine curing agent as a curing agent. When an isocyanate curing agent used in an oil-based ink is mixed with an aqueous ink, the isocyanate curing agent reacts with the solvent in the aqueous ink, i.e., water, and the ink gels, and the solid ink layer 13A cannot be formed. Therefore, in the solid ink layer 13A of the present embodiment using an aqueous ink, the above-mentioned curing agent needs to be used. In addition, as a printing method for the solid ink layer 13A, for example, a gravure printing method or a flexographic printing method can be used.

[0039] The amount of the curing agent added to the solid ink layer 13A is preferably 1 to 30 parts by mass, more preferably 3 to 10 parts by mass, relative to 100 parts by mass of the water-based ink. When the curing agent is added to the water-based ink within this range, the ink adhesion of the solid ink layer 13A to the thermoplastic resin layer 12 is improved.

[0040] (Pattern layer)

[0041] The pattern layer 13B is a layer for giving the decorative sheet 1 a design based on a pattern. The pattern layer 13B is formed on the solid ink layer 13A as a base, and is a layer printed to show a pattern. Like the solid ink layer 13A, the pattern layer 13B is formed of an aqueous ink containing at least one of a xylene diamine curing agent, a polycarbodiimide curing agent, and an aziridine curing agent as a curing agent.

[0042] As the pattern of the pattern layer 13B, any pattern may be used, for example, a wood grain pattern, a stone grain pattern, a cloth grain pattern, a cork pattern, an abstract pattern, or a combination of two or more of these.

[0043] <Surface protection layer>

[0044] The surface protection layer 14 is a layer for protecting the surface of the decorative sheet 1 , and is provided on the surface side of the ink layer 13 opposite to the thermoplastic resin layer 12 .

[0045] There is no particular limitation on the material of the surface protection layer 14, and the same material as that used for the surface protection layer in the conventional decorative sheet can be used. For example, as the material of the surface protection layer 14, a thermosetting resin or an ionizing radiation curing resin can be used, preferably an aqueous resin. As thermosetting resins, urethane resins, acrylic resins, unsaturated polyester resins, diallyl phthalate resins, phenolic resins, epoxy resins, melamine resins, urea resins, silicone resins, etc. can be cited. In addition, as an ionizing radiation curing resin, for example, a composition having at least one of the following as a main component can be used: a prepolymer, oligomer, and monomer having a polymerizable unsaturated bond such as a (meth)acryloyl group, which has the property of undergoing a cross-linking reaction by irradiation with ionizing radiation such as an electron beam or ultraviolet rays.

[0046] When the surface protection layer 14 is a thermosetting resin, the surface protection layer 14 preferably contains at least one of a xylene diamine curing agent, a polycarbodiimide curing agent, and an aziridine curing agent together with the water-based resin. By making the surface protection layer 14 contain these curing agents, the hardness of the resin can be increased, and the solvent resistance and scratch resistance of the surface protection layer 14 can be improved. The combination of the curing agent added to the surface protection layer 14 and the curing agent added to the ink layer 13 can be any combination.

[0047] The surface protection layer 14 may be a single layer or a multilayer of 2 to 3 layers. In the case of a multilayer, a matte resin and a glossy resin may be applied separately to give a glossy matte expression.

[0048] (1.2) Other components of decorative sheets

[0049] (1.2.1) Other Configuration Example 1

[0050] In the above embodiment, an example is shown in which the ink layer 13 includes a solid ink layer 13A and a pattern layer 13B, but other structures are also possible. Figure 2 As shown, the solid ink layer 13A may be omitted from the ink layer 13 .

[0051] (1.2.2) Other configuration examples 2

[0052] In the above embodiment, an example is shown in which the surface of the surface protection layer 14 is not treated, but the decorative sheet 1 may also include a surface protection layer 14A that has been subjected to surface modification instead of the surface protection layer 14. For example, when forming the surface protection layer 14A, after applying the resin material, ionizing radiation of a predetermined wavelength may be irradiated to the resin material, and then the resin material may be cured. Figure 3 As shown, it is possible to form a surface protection layer 14A having a surface-modified surface with an uneven shape.

[0053] The ionizing radiation irradiated to the resin material has a lower wavelength and a higher energy, because it is easier to cut the molecular bonds of organic matter and cause surface shrinkage, so it is preferred. As the ionizing radiation, it is preferred to use vacuum ultraviolet light (VUV: Vacuum Ultra Violet) with a wavelength of 200nm or less, and specifically, it is preferred to use ionizing radiation with a central wavelength of 172nm.

[0054] (1.3) Effects of this embodiment

[0055] The decorative sheet 1 according to the present embodiment has the following effects.

[0056] (1) The decorative sheet involved in this embodiment comprises: base paper; a thermoplastic resin layer provided on one surface of the base paper; an ink layer provided on the surface of the thermoplastic resin layer opposite to the base paper, the ink layer containing an aqueous ink and at least one of a xylene diamine-based curing agent, a polycarbodiimide-based curing agent, and an aziridine-based curing agent as a curing agent; and a surface protection layer provided on the surface side of the ink layer opposite to the thermoplastic resin layer.

[0057] Thereby, it is possible to obtain a decorative sheet having high ink adhesion and capable of suppressing warping or curling of the decorative sheet without using an oil-based ink that has a high load on the environment.

[0058] (2) In the decorative sheet according to the present embodiment, it is preferable to include at least one of a picture layer and a solid ink layer as the ink layer.

[0059] The pattern layer and the solid ink layer are both formed of an aqueous ink containing at least one of a xylene diamine curing agent, a polycarbodiimide curing agent, and an aziridine curing agent as a curing agent. Thus, the pattern layer and the solid ink layer are appropriately formed without gelling.

[0060] (3) In the decorative sheet according to the present embodiment, the amount of the curing agent added to the ink layer is preferably 1 part by mass or more and 30 parts by mass or less relative to 100 parts by mass of the aqueous ink.

[0061] This improves the ink adhesion of the ink layer to the thermoplastic resin layer.

[0062] (4) In the decorative sheet according to the present embodiment, the surface protection layer preferably contains a thermosetting resin as an aqueous resin and at least one of a xylenediamine-based curing agent, a polycarbodiimide-based curing agent, and an aziridine-based curing agent.

[0063] This can increase the hardness of the resin and improve the solvent resistance and scratch resistance of the surface protection layer.

[0064] (5) In the decorative sheet according to the present embodiment, the surface protection layer preferably contains an ionizing radiation curable resin as an aqueous resin.

[0065] This can increase the hardness of the resin and improve the solvent resistance and scratch resistance of the surface protection layer.

[0066] (6) In the decorative sheet according to the present embodiment, the thermoplastic resin layer is preferably formed of a thermoplastic resin having a melting point of 140° C. or higher.

[0067] Thus, the thermoplastic resin layer does not soften with respect to the heat applied when the ink layer is formed using the aqueous ink, and warping or curling of the decorative sheet can be suppressed.

[0068] (7) In the decorative sheet according to the present embodiment, the thermoplastic resin layer preferably contains at least one of an ultraviolet absorber and a light stabilizer.

[0069] Thereby, the weather resistance of the raw material layer can be improved, and peeling of the ink layer due to deterioration of the raw material layer can be suppressed.

[0070] Example

[0071] Hereinafter, the present disclosure will be described in more detail by way of examples, but the present disclosure is not limited to the examples.

[0072] <Example 1>

[0073] On one side of the base paper (HPN29 manufactured by Tenma Tokushu Co., Ltd.), polypropylene (PP) with a melting point of 165°C containing an ultraviolet absorber (UVA) and a light stabilizer (HALS) is laminated by melt extrusion molding, and cured to form a thermoplastic resin layer. The thickness of the cured thermoplastic resin layer is 20 μm. Thus, a raw material layer is formed by laminating the base paper and the thermoplastic resin layer. The interlaminar strength between the base paper and the thermoplastic resin layer was measured, and the result was 1.2 N / cm. Regarding the interlaminar strength, after fixing the base paper side of the raw material layer to the MDF (medium density fiberboard) with double-sided tape, it was reinforced with a 25 mm wide transparent tape to prevent the thermoplastic resin layer from tearing, and then measured using a load cell type tensile testing machine. The measurement conditions of the interlaminar strength at this time are set to a tensile speed of 200 mm / min, and the measurement width (width of the test piece) is set to 25 mm.

[0074] Next, a solid ink layer was formed on the surface of the thermoplastic resin layer side of the raw material layer by water-based gravure printing using water-based ink (LTW205 manufactured by Liochem). In the water-based ink, 6 parts by mass of a xylene diamine curing agent as a curing agent was added to 100 parts by mass of the water-based ink, and after diluting with water and gravure printing, it was dried to form a solid ink layer. Next, a pattern was printed using a water-based ink containing the same xylene diamine curing agent as the solid ink layer, and it was dried to form a pattern layer. Thus, an ink layer including a solid ink layer and a pattern layer was formed.

[0075] Next, a water-based resin, that is, a thermosetting resin (LW163 manufactured by Liochem Co., Ltd.) to which a xylene diamine curing agent was added was applied to the entire surface of the pattern layer. Then, the curing agent added to the thermosetting resin was reacted to cure the thermosetting resin, thereby forming a surface protective layer. Thus, the decorative sheet of Example 1 was formed.

[0076] <Example 2>

[0077] The decorative sheet of Example 2 was prepared in the same manner as in Example 1 except that polyethylene terephthalate (PET) having a melting point of 255° C. was used instead of polypropylene in the thermoplastic resin layer of the raw material layer. The interlaminar strength between the base paper and the thermoplastic resin layer was 0.6 N / cm.

[0078] <Example 3>

[0079] The decorative sheet of Example 3 was prepared in the same manner as in Example 1 except that the curing agent added to the ink layer and the surface protective layer was a polycarbodiimide-based curing agent instead of the xylenediamine curing agent.

[0080] <Example 4>

[0081] The decorative sheet of Example 4 was prepared in the same manner as in Example 1 except that the curing agent added to the ink layer and the surface protection layer was an aziridine-based curing agent instead of the xylenediamine curing agent.

[0082] <Example 5>

[0083] The decorative sheet of Example 5 was formed in the same manner as in Example 1 except that the ink layer was made into only the pattern layer.

[0084] <Example 6>

[0085] A decorative sheet of Example 6 was formed in the same manner as in Example 1 except that the ink layer was made to be only the pattern layer and the curing agent added to the pattern layer and the surface protection layer was made a polycarbodiimide-based curing agent instead of the xylenediamine curing agent.

[0086] <Example 7>

[0087] A decorative sheet of Example 7 was formed in the same manner as in Example 1 except that the ink layer was made to be only the pattern layer and the curing agent added to the pattern layer and the surface protection layer was made an aziridine-based curing agent instead of the xylenediamine curing agent.

[0088] <Example 8>

[0089] A decorative sheet of Example 8 was prepared in the same manner as in Example 1, except that no ultraviolet absorber (UVA) and no light stabilizer (HALS) were added to the thermoplastic resin of the raw material layer.

[0090] <Example 9>

[0091] A decorative sheet of Example 9 was produced by the same method as in Example 1 except that no curing agent was added to the surface protection layer.

[0092] <Example 10>

[0093] A decorative sheet of Example 10 was prepared in the same manner as in Example 1, except that the amount of the xylenediamine curing agent added to the aqueous ink of the solid ink layer and the pattern layer was 1 part by mass.

[0094] <Example 11>

[0095] A decorative sheet of Example 11 was prepared in the same manner as in Example 1, except that the amount of the xylenediamine curing agent added to the aqueous ink of the solid ink layer and the pattern layer was 10 parts by mass.

[0096] <Example 12>

[0097] A decorative sheet of Example 12 was prepared in the same manner as in Example 1, except that the amount of the xylenediamine curing agent added to the aqueous ink of the solid ink layer and the pattern layer was changed to 30 parts by mass.

[0098] <Example 13>

[0099] A decorative sheet of Example 13 was prepared in the same manner as in Example 1 except that a medium-density polyethylene (PE) having a melting point of 135° C. was used instead of polypropylene to form the thermoplastic resin layer of the raw material layer.

[0100] <Example 14>

[0101] As the surface protection layer, an electron beam curing resin without adding a curing agent is used instead of a thermosetting resin, and after the electron beam curing resin is applied to the entire surface of the pattern layer, an electron beam is irradiated to cure the electron beam curing resin to form a surface protection layer. Except for this, the decorative sheet of Example 14 is formed in the same manner as Example 1.

[0102] <Comparative Example 1>

[0103] A decorative sheet of Comparative Example 1 was prepared in the same manner as in Example 1 except that no curing agent was added to the aqueous ink of the solid ink layer and the pattern layer and the aqueous resin of the surface protection layer.

[0104] <Comparative Example 2>

[0105] A decorative sheet of Comparative Example 2 was prepared in the same manner as in Example 1 except that the curing agent added to the aqueous ink of the solid ink layer and the pattern layer and the aqueous resin of the surface protection layer was an isocyanate curing agent instead of the xylene diamine curing agent.

[0106] [evaluate]

[0107] The decorative sheets obtained in Examples 1 to 14 and Comparative Examples 1 and 2 were subjected to the following evaluations.

[0108] [Ink Adhesion Evaluation]

[0109] The ink adhesion of the decorative sheets was evaluated. For the decorative sheets obtained in Examples 1 to 14 and Comparative Examples 1 to 2, the surface protective layer was removed with an eraser, and then a transparent tape was attached and abruptly peeled off at an angle of 90°. The evaluation criteria were set to the following three levels.

[0110] A: No ink layer is peeled off by the transparent tape

[0111] B: The ink layer is not peeled off by the transparent tape but the base paper is torn

[0112] C: The ink layer-raw material layer interface is peeled off by the transparent tape

[0113] [Evaluation of curling properties]

[0114] The curling property of the decorative sheet caused by the formation of the ink layer was evaluated.

[0115] The decorative sheets obtained in Examples 1 to 14 and Comparative Examples 1 to 2 were cut into a size of 10 cm × 10 cm to form a sample. Next, the sample was placed on a plane and left to stand for 48 hours at 25°C and 50% RH. Then, the distances between the four corners of the sample and the plane were measured and the average was calculated. The evaluation criteria were set to the following three levels.

[0116] A: The average distance between the four corners of the sample and the plane is less than 3 cm

[0117] B: The average distance between the four corners of the sample and the plane is more than 3 cm and less than 5 cm

[0118] C: The average distance between the four corners of the sample and the plane exceeds 5 cm

[0119] [Evaluation of scratch resistance]

[0120] The decorative sheets obtained in Examples 1 to 14 and Comparative Examples 1 to 2 were subjected to a scratch resistance test according to Class 32 of European Standard "EN 16094". The two test methods, MSR-A3 and MSR-B3, were evaluated using the test results 1 to 5, respectively, according to the following three levels.

[0121] A: If the rating is 4 or above

[0122] B: Rating 3

[0123] C: Rating 2 or less

[0124] The above evaluation results are shown in Table 1 below.

[0125]

[0126] As shown in Table 1, the decorative sheets of each embodiment containing a xylene diamine curing agent, a polycarbodiimide curing agent, or an aziridine curing agent in the aqueous ink of the ink layer, or the aqueous ink of the ink layer and the thermosetting resin (thermosetting aqueous resin) of the aqueous resin as the surface protective layer, have higher ink adhesion than the decorative sheets of each comparative example in which the ink layer and the surface protective layer do not contain the above curing agent. In comparative example 1 in which no curing agent is added to the ink layer and the surface protective layer, the ink adhesion is reduced and the scratch resistance is reduced. In addition, in comparative example 2 in which an aqueous ink and an isocyanate curing agent are mixed, the isocyanate curing agent reacts with water in the aqueous ink, the ink gels, and an ink layer cannot be formed.

[0127] In addition, the decorative sheets of Examples 1 to 12 and 14 in which the thermoplastic resin layer is formed of a thermoplastic resin having a melting point of 140° C. or higher have better curling properties than the decorative sheet of Example 13 in which the thermoplastic resin layer is formed of a thermoplastic resin having a melting point of less than 140° C. When the ink layer uses an aqueous ink, heat is applied to the sheet body in order to dry the ink. Therefore, when the melting point of the thermoplastic resin is set to a temperature above a predetermined temperature, the thermoplastic resin layer does not soften even when heat is applied, and a decorative sheet without warping is obtained.

[0128] In addition, when the amount of xylene diamine-based curing agent, polycarbodiimide-based curing agent or aziridine-based curing agent added to the ink layer is not less than 1 part by mass and not more than 30 parts by mass, the ink adhesion is improved, and when the added amount is not less than 3 parts by mass and not more than 10 parts by mass, there is no surface where the ink layer peels off, and the ink adhesion is further improved.

[0129] It should be noted that the decorative sheet of the present disclosure is not limited to the above-mentioned embodiments and examples, and various modifications can be made within the scope not impairing the characteristics of the invention.

[0130] Explanation of symbols

[0131] 1 decorative sheet

[0132] 11 base paper

[0133] 12 Thermoplastic resin layer

[0134] 13 Ink layer

[0135] 13A solid ink layer

[0136] 13B pattern layer

[0137] 14 Surface protection layer

[0138] 14A surface protection layer

Claims

1. A decorative sheet comprising: Original paper; A thermoplastic resin layer provided on one side of the base paper; an ink layer provided on the surface of the thermoplastic resin layer opposite to the base paper, the ink layer comprising an aqueous ink and at least one of a xylene diamine curing agent, a polycarbodiimide curing agent and an aziridine curing agent as a curing agent; and A surface protection layer is provided on a surface of the ink layer opposite to the thermoplastic resin layer.

2. The decorative sheet according to claim 1, wherein: The ink layer includes at least one of a pattern layer and a solid ink layer.

3. The decorative sheet according to claim 1, wherein: The amount of the curing agent added to the ink layer is 1 part by mass or more and 30 parts by mass or less relative to 100 parts by mass of the aqueous ink.

4. The decorative sheet according to claim 3, wherein: The amount of the curing agent added to the ink layer is 3 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the aqueous ink.

5. The decorative sheet according to claim 1, wherein: The surface protection layer includes a thermosetting resin as an aqueous resin and at least one of the xylenediamine-based curing agent, the polycarbodiimide-based curing agent, and the aziridine-based curing agent.

6. The decorative sheet according to claim 1, wherein: The surface protection layer contains an ionizing radiation curable resin as an aqueous resin.

7. The decorative sheet according to claim 1, wherein: The thermoplastic resin layer is formed of a thermoplastic resin having a melting point of 140° C. or higher.

8. The decorative sheet according to claim 7, wherein: The thermoplastic resin layer is an olefin resin.

9. The decorative sheet according to claim 8, wherein: The olefin resin is selected from the group consisting of polypropylene (PP), polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl alcohol (PVA), polyvinylidene chloride (PVDF) and polyamide (PA).

10. The decorative sheet according to any one of claims 7 to 9, wherein: The thermoplastic resin layer contains at least one of an ultraviolet absorber and a light stabilizer.

11. A decorative sheet comprising: Original paper; A thermoplastic resin layer provided on one side of the base paper; an ink layer provided on the thermoplastic resin layer on the side opposite to the base paper side, the ink layer comprising an aqueous ink and at least one of a xylene diamine curing agent, a polycarbodiimide curing agent and an aziridine curing agent as a curing agent; and A surface protection layer is provided on the side of the ink layer opposite to the thermoplastic resin layer.

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