Decorative sheets and decorative panels

Abstract

The present invention provides a decorative sheet having a surface protective layer with excellent adhesion to the underlying layer, excellent surface hardness, scratch resistance, and workability, and excellent design properties. 【Solution means】A decorative sheet having at least a base sheet, a pattern layer, a transparent resin layer, and a surface protective layer, (1) The surface protective layer contains a crosslinking and curing type resin, (2) In the infrared spectroscopic measurement of the surface protective layer, when the height of the peak appearing at 855 - 1325 cm , , -1 is A and the height of the peak appearing at 1650 - 1800 cm -1 is B, the peak height ratio ((A / B)×100(%)) of A and B is 105% or more and 400% or less, (3) In the infrared spectroscopic measurement of the surface protective layer, when the height of the peak appearing at 3200 - 3500 cm -1 is C, the peak height ratio ((B / C)×100(%)) of B and C is 1000% or more and 6000% or less, (4) The pattern layer is a wood grain pattern having a characteristic part and a non - characteristic part. The surface protective layer has a recess (D1) synchronized with the characteristic part of the pattern layer on the side opposite to the side having the pattern layer. The pattern layer has a recess (D2) located in the stacking direction of the recess (D1) on the side opposite to the side having the base sheet, and the depth H of the recess (D1) is larger than the depth h of the recess (D2). A decorative sheet characterized by the above.

Description

Technical Field

[0001] The present invention relates to a decorative sheet and a decorative board.

Background Art

[0002] Decorative sheets are used by being adhered to the surfaces of wooden boards, plastic boards, etc. for the purpose of protecting and decorating the surface. And the decorative boards obtained thereby are used for various purposes such as ornaments, building materials, furniture, etc.

[0003] For the decorative sheets used for the above-mentioned purposes, it is required that the surface protective layer exhibits adhesion to the lower layer. In particular, a film having a small number of polar groups may be used for the surface of the lower layer, and it is required that the surface protective layer of the decorative sheet also exhibits adhesion to such a film.

[0004] As a decorative sheet having a surface protective layer that exhibits adhesion to a film, a hard coat film in which a hard coat layer is provided on at least one side of a base film has been proposed (see Patent Document 1).

[0005] However, the hard coat film provided with the hard coat layer of Patent Document 1 does not have sufficient adhesion between the base film and the hard coat film when used for various purposes, and there is room for improvement.

[0006] In addition, since the decorative sheet is used by being adhered to the surface of a wooden board, a plastic board, etc., an object may collide with it. Therefore, surface hardness and scratch resistance are required for the surface of the decorative sheet.

[0007] In addition, since the decorative sheet is used by being adhered to the surface of an article for the purpose of decoration, it is necessary to follow the shape of the article. Therefore, the decorative sheet is required to have processability that allows it to be processed following the shape of the article. The hard coat film described in Patent Document 1 has not been studied for processability and has a problem of poor processability.

[0008] Furthermore, in order to give the decorative panel a visual design, the decorative sheet may be embossed or otherwise processed to create an uneven surface, thereby providing a three-dimensional visual effect. For example, Patent Document 2 discloses a decorative sheet in which a pattern is printed on one side of a base sheet, a transparent thermoplastic resin layer having an uneven pattern that matches the pattern, a surface protection layer that protects the surface of the transparent thermoplastic resin layer, and a gloss adjustment layer having a pattern with a gloss level that matches the pattern are laminated in this order, and the resin constituting the surface protection layer is embedded in the unevenness of the uneven pattern.

[0009] In the decorative sheet described in Patent Document 2, an uneven pattern is formed on the side of the transparent thermoplastic resin layer that has a surface protective layer. This synchronizes the pattern of the printed pattern layer with the uneven pattern of the transparent thermoplastic resin layer, improving the tactile feel and three-dimensionality, and enhancing the realism of the pattern.

[0010] In recent years, there has been a demand for extremely superior design qualities in which the pattern of the design layer and the uneven shape formed on the decorative sheet are in harmony, and the decorative sheet described in Patent Document 2 is insufficient in this regard.

[0011] Therefore, there is a need for the development of a decorative sheet that has excellent adhesion to the underlying layer, excellent surface hardness, scratch resistance, and processability, as well as excellent design. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2017-177667 [Patent Document 2] Japanese Patent Publication No. 2016-182748 [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] The present invention aims to provide a decorative sheet in which the surface protective layer has excellent adhesion to the underlying layer, excellent surface hardness, scratch resistance, and processability, and excellent design. [Means for solving the problem]

[0014] As a result of diligent research, the present inventors have found a decorative sheet having at least a base sheet, a pattern layer, a transparent resin layer, and a surface protective layer, wherein (1) the surface protective layer contains a cross-linked curable resin, and (2) the infrared spectroscopic spectrum of the surface protective layer is 855 to 1325 cm⁻¹. -1 The height of the peak that appears is A, 1650-1800cm. -1 (3) In the infrared spectral measurement of the surface protective layer, the peak height ratio of A to B is 105% or more and 400% or less. -1 The present invention was found to achieve the above objective by using a decorative sheet in which the peak height of B and C is 1000% or more and 6000% or less, (4) the pattern layer is a wood grain pattern having characteristic parts and non-characteristic parts, the surface protective layer has a recess (D1) on the side opposite to the side having the pattern layer that is in harmony with the characteristic parts of the pattern layer, the pattern layer has a recess (D2) on the side opposite to the side having the base sheet that is located in the lamination direction of the recess (D1), and the depth H of the recess (D1) is greater than the depth h of the recess (D2).

[0015] In other words, the present invention relates to the following decorative sheets and decorative panels. 1. A decorative sheet having at least a base sheet, a pattern layer, a transparent resin layer, and a surface protective layer, (1) The surface protective layer contains a cross-linked curing resin, (2) In the infrared spectroscopic measurement of the surface protective layer, 855-1325 cm⁻¹ -1 Let A be the height of the peak that appears, between 1650 and 1800 cm. -1When the peak height appearing is B, the peak height ratio of A to B ((A / B) × 100 (%)) is between 105% and 400%. (3) In the infrared spectral measurement of the surface protective layer, 3200 to 3500 cm -1 When the peak height appearing is C, the peak height ratio of B to C ((B / C) × 100 (%)) is between 1000% and 6000%. (4) The pattern layer is a wood grain pattern having characteristic portions and non-characteristic portions, the surface protective layer has a recess (D1) on the side opposite to the side having the pattern layer that is in harmony with the characteristic portion of the pattern layer, the pattern layer has a recess (D2) on the side opposite to the side having the base sheet that is located in the lamination direction of the recess (D1), and the depth H of the recess (D1) is greater than the depth h of the recess (D2). A decorative sheet characterized by the following features. 2. The decorative sheet according to item 1, wherein the peak height ratio between A and B is 110% or more and 300% or less, and the peak height ratio between B and C is 1300% or more and 5500% or less. 3. The decorative sheet according to item 1 or 2, wherein the cross-linked curable resin includes an ionizing radiation curable resin. 4. The decorative sheet according to item 3, wherein the ionizing radiation-curable resin includes an acrylic resin having a (meth)acryloyl group. 5. The decorative sheet according to any one of claims 1 to 4, wherein the surface protective layer comprises at least one selected from the group consisting of antibacterial agents, antiviral agents, and allergen reducing agents. 6. A decorative panel having a decorative sheet as described in any of items 1 to 5 on a base material. [Effects of the Invention]

[0016] The decorative sheet of the present invention has excellent adhesion of the surface protective layer to the underlying layer, excellent surface hardness, scratch resistance, and processability, as well as excellent design. Therefore, decorative panels made by laminating the decorative sheet of the present invention can be used in various building materials, furniture, and the like. [Brief explanation of the drawing]

[0017] [Figure 1] It is a figure showing an example of the result of infrared spectroscopic measurement of the surface protective layer of the cosmetic sheet of the present invention. [Figure 2] It is a figure explaining a method of determining the height of a peak in the infrared spectroscopic measurement of the surface protective layer of the cosmetic sheet of the present invention. [Figure 3] It is a figure explaining a method of determining the height of a peak in the infrared spectroscopic measurement of the surface protective layer of the cosmetic sheet of the present invention. [Figure 4] It is a figure showing an example of the layer structure of the cosmetic sheet of the present invention. [Figure 5] It is a figure explaining the synchronization between the characteristic part of the pattern layer of the cosmetic sheet of the present invention and the recess (D1). [Figure 6] It is a figure showing an example of the layer structure of the decorative board of the present invention. [Figure 7] It is a figure showing an example of hydrogen bonding between molecules of the crosslinking and curing type resin.

Embodiments for Carrying Out the Invention

[0018] 1. Decorative sheet The cosmetic sheet of the present invention is a cosmetic sheet having at least a base sheet, a pattern layer, a transparent resin layer, and a surface protective layer, wherein (1) the surface protective layer contains a crosslinking and curing type resin, and (2) in the infrared spectroscopic measurement of the surface protective layer, when the height of the peak appearing at 855 to 1325 cm -1 is taken as A and the height of the peak appearing at 1650 to 1800 cm -1 is taken as B, the peak height ratio ( (A / B)×100(%)) of A and B is 105% or more and 400% or less, and (3) in the infrared spectroscopic measurement of the surface protective layer, at 3200 to 3500 cm -1(4) The decorative sheet is characterized in that the peak height ratio of B to C ((B / C) × 100 (%)) when the peak height appearing is C is 1000% or more and 6000% or less, (5) the pattern layer is a wood grain pattern having characteristic parts and non-characteristic parts, the surface protective layer has a recess (D1) on the side opposite to the side having the pattern layer that is in harmony with the characteristic parts of the pattern layer, the pattern layer has a recess (D2) on the side opposite to the side having the base sheet that is located in the stacking direction of the recess (D1), and the depth H of the recess (D1) is greater than the depth h of the recess (D2).

[0019] As the decorative sheet of the present invention has the above-mentioned features, the surface protective layer of the decorative sheet has excellent adhesion to the underlying layer, excellent surface hardness, scratch resistance and processability, and excellent design. In particular, the decorative sheet of the present invention has a configuration in which (4) a recess (D1) on the side opposite to the side having the patterned layer is synchronized with the characteristic portion of the patterned layer, and the depth H of the recess (D1) is greater than the depth h of the recess (D2), thereby exhibiting extremely excellent design in which the pattern of the patterned layer and the uneven shape formed on the decorative sheet are synchronized.

[0020] As described above, the decorative sheet of the present invention exhibits an infrared spectral measurement of the surface protective layer, with a range of 855 to 1325 cm⁻¹. -1 Let A be the height of the peak that appears, between 1650 and 1800 cm. -1 When the peak height appearing at is denoted as B, the peak height ratio of A to B ((A / B) × 100 (%)) is between 105% and 400%, and in infrared spectroscopic spectral measurement of the surface protective layer, at 3200-3500 cm⁻¹, -1 When the peak height appearing in the graph is C, the peak height ratio of B to C ((B / C) × 100 (%)) is between 1000% and 6000%. This will be explained using a diagram below.

[0021] Figure 1 shows an example of the results of infrared spectral (hereinafter also referred to as "IR") measurement of the surface protective layer of the decorative sheet of the present invention. In Figure 1, A represents the peak due to ether bonding, B represents the peak due to ester bonding, and C represents the peak due to urethane bonding.

[0022] In this specification, the height of each peak is measured as follows: As shown in Figure 2, two base points b1 and b2 are taken for each peak, and a baseline bL is drawn by connecting the base points with a straight line. Next, a vertical line is drawn downward from the position p of the peak top, and the intersection point bp with the baseline bL is specified. The length h between p and bp is taken as the peak height.

[0023] Furthermore, as shown in Figure 3, if peak A has multiple peaks, the peak heights are measured as follows: That is, if there are two adjacent peaks as shown in Figure 3, and the heights h1-1 and h2-1 from the valley between the two peaks to the peak apex are 0.010 Abs or greater, the two peak heights h1 and h2 are added together to determine the peak height. Note that in Figure 3, the peak with peak top p2 has adjacent peaks p1 and p3 on both sides, and there are two heights, h2-1 and h2-2, from the valley between the two peaks to the peak apex. In this case, the shorter height, h2-1, is used to determine whether it is 0.010 Abs or greater.

[0024] In this specification, the infrared spectroscopic spectrum of the surface protective layer can be measured using commercially available infrared spectroscopic spectroscopy equipment.

[0025] The decorative sheet of the present invention exhibits an infrared spectral measurement of the surface protective layer, with a range of 855 to 1325 cm⁻¹. -1 Let A be the height of the peak that appears, between 1650 and 1800 cm. -1The peak height ratio ((A / B) × 100(%)) of A to B, where B is the peak height appearing in the sample, is between 105% and 400%. If the peak height ratio of A to B is less than 105%, there are too many ester bonds in the surface protective layer, making the surface protective layer too hard and reducing the processability of the decorative sheet. If the peak height ratio of A to B exceeds 400%, there are too many ether bonds, making the surface protective layer too soft and reducing the surface hardness and scratch resistance of the decorative sheet. The peak height ratio of A to B is preferably between 110% and 300%, and more preferably between 150% and 250%.

[0026] The decorative sheet of the present invention, in infrared spectral measurement of the surface protective layer, shows a range of 3200 to 3500 cm⁻¹. -1 The peak height ratio of B to C ((B / C) × 100(%)), where C is the peak height appearing in the sample, is between 1000% and 6000%. If the peak height ratio of B to C is less than 1000%, there are too many urethane bonds in the surface protective layer, and the hydrogen bonds between the -NH groups and -C=O groups in the urethane bonds increase excessively, as shown in Figure 7, making the surface protective layer too hard and reducing the processability of the decorative sheet. If the peak height ratio of B to C exceeds 6000%, there are too few urethane bonds in the surface protective layer, making the surface protective layer too soft and reducing the surface hardness and scratch resistance of the decorative sheet. The peak height ratio of B to C is preferably between 1300% and 5500%, and more preferably between 1500% and 5200%.

[0027] One adjustment method for adjusting the peak height ratio between A and B, and the peak height ratio between B and C, to within the above range is to change the formulation of the cross-linked curable resin used to form the surface protective layer. When the cross-linked curable resin formulation contains many ether bonds and few ester bonds, the peak height ratio between A and B increases. Conversely, when the cross-linked curable resin formulation contains few ether bonds and many ester bonds, the peak height ratio between A and B decreases. Also, when the cross-linked curable resin formulation contains many ester bonds and few urethane bonds, the peak height ratio between B and C increases. Conversely, when the cross-linked curable resin formulation contains few ester bonds and many urethane bonds, the peak height ratio between B and C decreases.

[0028] The following describes in detail each layer of the decorative sheet of the present invention. In the decorative sheet of the present invention, the surface is the so-called "front surface," which is the surface opposite to the surface that comes into contact with the substrate when the decorative sheet of the present invention is laminated onto a substrate, and is the surface that is visible after lamination. In this specification, the direction of the surface of the decorative sheet of the present invention may be referred to as "front" or "top," and the opposite side may be referred to as "back" or "bottom." In the following description, the lower and upper limits of a numerical range represented by "~" mean "greater than or equal to or less than or equal to" (for example, α~β means α or greater and β or less).

[0029] Furthermore, the layer thickness in this specification is the value measured in areas of the decorative sheet that do not have any uneven shapes such as embossing or protruding fine particles.

[0030] (Structure of the decorative sheet of the present invention) The decorative sheet of the present invention only needs to have at least a base sheet, a pattern layer, a transparent resin layer, and a surface protection layer, and it is preferable that the surface protection layer is on the outermost surface of the decorative sheet. The specific configuration can be appropriately set according to the application of the decorative sheet, etc. For example, as shown in Figure 4, a layer configuration can be given in which a base sheet 11, a pattern layer 12, an adhesive layer (not shown), a transparent resin layer 13, and a surface protection layer 14 are in that order. In Figure 4, the pattern layer 12 has a wood grain pattern having a characteristic portion 2a and a non-characteristic portion 2b. The surface protection layer 14 has a recess (D1) on the side opposite to the side having the pattern layer 12 that is in harmony with the characteristic portion of the pattern layer 12, and the pattern layer 12 has a recess (D2) on the side opposite to the side having the base sheet 11 that is located in the stacking direction of the recess (D1), and the depth H of the recess (D1) is greater than the depth h of the recess (D2).

[0031] The synchronization between the characteristic portion of the pattern layer of the decorative sheet of the present invention and the recess (D1), the recess (D2), etc., will be explained with reference to Figure 5.

[0032] (Recessed parts (D1) and (D2)) As shown in Figure 5, the decorative sheet of the present invention has a surface protective layer 14 on the side opposite to the side having the pattern layer 12, with a recess (D1) that is in harmony with the characteristic portion 12a of the pattern layer 12. Furthermore, the pattern layer 12 has a recess (D2) on the side opposite to the side having the base sheet 11, located in the lamination direction of the recess (D1).

[0033] In Figure 5, the recess (D1) of the decorative sheet 1 of the present invention has a shape that is consistent with the characteristic portion 12a of the pattern layer 12. The recess (D1) may be shaped to resemble the outer outline of the characteristic portion 12a of the pattern layer 12, or it may be a simplified shape of the outer outline of the characteristic portion 12a of the pattern layer 12, or a similar shape that is a reduced or enlarged version of the outer outline of the characteristic portion 12a.

[0034] Figures 5(a) to 5(c) illustrate the synchronization between the characteristic portion of the pattern layer and the recess (D1) of the decorative sheet of the present invention, and the recess (D2). In Figure 5(c), the recess (D1) of the surface protective layer of the decorative sheet 1 of the present invention is positioned to be in synchronization with the characteristic portion 12a of the pattern layer 12 in terms of positional relationship. The positional relationship between the recess (D1) and the characteristic portion 2a of the pattern layer 12 is preferably such that the characteristic portion 12a of the pattern layer 12 and the recess (D1) of the surface protective layer overlap in the lamination direction, as shown in Figure 5(c). Furthermore, in the decorative sheet of the present invention, it is sufficient that the surface protective layer has a recess (D1) that is synchronized with the characteristic portion of the pattern layer. Although not shown, the characteristic portion 12a of the pattern layer 12 and the recess (D1) of the surface protective layer may be positioned to partially overlap, or the characteristic portion 2a of the pattern layer 12 and the recess (D1) of the surface protective layer may be positioned so as not to overlap. However, even when positioned so as not to overlap, it is preferable that the recess (D1) be located near the characteristic portion 12a of the pattern layer 12 when the decorative sheet is viewed from above. "Nearby" means that, when viewed from above, the positional difference between the characteristic portion 12a and the recess (D1) corresponding to the characteristic portion 12a is 3 mm or less. These positional relationships can be appropriately set depending on the design of the pattern layer 12.

[0035] Furthermore, the synchronization relationship between the recess (D1) and the characteristic portion 12a does not necessarily have to be established across the entire surface protective layer; there may be areas where the synchronization does not occur, as long as it does not impair the aesthetic appearance of the decorative sheet.

[0036] As shown in Figure 5(c), the decorative sheet of the present invention has recesses (D2) located in the stacking direction of recesses (D1). That is, recesses (D2) are located in a position that overlaps with recesses (D1) in the stacking direction. Furthermore, recesses (D2) may be formed in the characteristic portion 12a of the pattern layer 12, or they may be formed extending from the characteristic portion 12a to the non-characteristic portion 2b of the pattern layer 12, or recesses (D2) may not be formed in the characteristic portion 12a of the pattern layer 12 (recesses (D2) may be formed in the non-characteristic portion 12b).

[0037] In the decorative sheet of the present invention, the depth H of the recess (D1) is greater than the depth h of the recess (D2). The decorative sheet of the present invention, having such recesses (D1) and recesses (D2), exhibits an extremely superior design with a visually three-dimensional effect, as the pattern of the patterned layer and the recesses are in harmony. The relationship between the depth H of recess (D1) and the depth h of recess (D2) is established between recesses (D1) and recess (D2) that are located in the stacking direction (overlapping when viewed from above).

[0038] In the decorative sheet of the present invention, from the viewpoint of more favorably imparting a three-dimensional feel, the ratio (h / H) of the depth h of recess (D2) to the depth H of recess (D1) is preferably 0.25 or more and 0.60 or less, more preferably 0.26 or more and 0.55 or less, even more preferably 0.28 or more and 0.50 or less, and particularly preferably 0.30 or more and 0.48 or less.

[0039] The depth H of the recess (D1) should be such that it can adequately provide a three-dimensional effect. For example, 50 μm to 200 μm is preferred, and 55 μm to 190 μm is more preferred. The depth h of the recess (D2) should be such that 13 μm to 100 μm is preferred, and 17 μm to 92 μm is more preferred.

[0040] Furthermore, the above numerical ranges for depth H and depth h do not necessarily have to be met in all recesses (D1) and recesses (D2). If the aesthetic appearance of the decorative sheet is not impaired, there may be recesses (D1) and recesses (D2) that do not satisfy the above numerical ranges. For example, if the aesthetic appearance of the decorative sheet is not impaired, there may be some synchronized recesses (D1) and recesses (D2) where the relationship between depth H and depth h is not satisfied.

[0041] However, from the viewpoint of appropriately imparting aesthetic appeal, it is preferable that when viewing the decorative sheet 1 in plan view and checking recesses (D1) and recesses (D2) located in the stacking direction within any 10cm x 10cm area, less than 30% of the total do not satisfy the relationship that depth H > depth h. Such confirmation can be performed by applying the electron microscope and its measurement conditions described later.

[0042] The width W of the recess (D1) shown in Figure 5(c) depends on the pattern formed on the pattern layer 12, but is preferably 400 μm to 2000 μm, and more preferably 500 μm to 1500 μm. The width w of the recess (D2) shown in Figure 5(c) is preferably 5 μm to 400 μm, and more preferably 10 μm to 100 μm.

[0043] The decorative sheet of the present invention preferably has a protrusion (D3) on the base sheet 11 side of the pattern layer 12 and a protrusion (D4) on the opposite side of the pattern layer 12, located in the lamination direction of the recesses (D1) and recesses (D2), as shown in Figure 5(c). In this case, the depths of the recesses and protrusions preferably decrease in the order of recess (D1), recess (D2), protrusion (D3), and protrusion (D4).

[0044] Furthermore, in the decorative sheet 1, if there is a protrusion (D5, not shown) on the transparent resin layer 13 side of the surface protective layer 14 located in the lamination direction of the recesses (D1) and recesses (D2), it is preferable that the depths of the recesses and protrusions decrease in the order of protrusion (D5), recess (D1), recess (D2), protrusion (D3), and protrusion (D4). By having such recesses or protrusions D1 to D5, it is possible to suitably show a design that is in harmony with the pattern of the patterned layer and the recesses and protrusions. The relationship between the depths of the recesses or protrusions D1 to D5 is established between recesses or protrusions D1 to D5 that are located in the lamination direction (overlapping when viewed from above).

[0045] The width W and depth H of recess (D1), and the width w and depth h of recess (D2) can be measured by the following method. Specifically, Figure 5(a) is a schematic perspective view showing an example of the decorative sheet of the present invention, Figure 5(b) is a schematic top view showing an example of the decorative sheet of the present invention, and Figure 5(c) is a schematic cross-sectional view showing the layer structure of the decorative sheet of the present invention. For measurement, as shown in Figure 5(a), a recess formed on the surface of the decorative sheet 1 is selected. As shown in Figure 5(b), the major axis and minor axis of the selected recess are determined. Next, as shown in Figure 5(c), the sheet is cut along the minor axis, and the cut surface is observed with an electron microscope to measure the width (W and w) and depth (H and h) of recesses (D1) and (D2).

[0046] As shown in Figure 5(c), the depth H of the recess (D1) refers to the vertical distance from the surface of the surface protection layer 14 to the deepest part of the recess (D1), and the depth h of the recess (D2) refers to the vertical distance from the surface of the pattern layer 12 to the deepest part of the recess (D2). The long axis of the recess refers to the axis passing through the point where the length of the straight line connecting two points on the outer circumference of the recess is maximum, and the short axis of the recess refers to the axis passing through the point where the length is maximum in the direction perpendicular to the long axis.

[0047] In the decorative sheet of the present invention, the width W and depth H of recess (D1), and the width w and depth h of recess (D2) refer to the average values ​​calculated by randomly selecting 10 recesses formed on the surface of the decorative sheet 1 and measuring them using the method described above. As for the measurement conditions with an electron microscope, for example, measurements can be taken by observing at a magnification of 300x using a shape analysis laser microscope (measurement unit "VK-X1050", base "VK-D1", controller "VK-X1000" (manufactured by KEYENCE)).

[0048] The following describes in detail each layer that constitutes the decorative sheet of the present invention.

[0049] (Surface protective layer) The decorative sheet of the present invention has a surface protective layer. In this specification, the surface protective layer contains a cross-linked curable resin.

[0050] Examples of cross-linked curing resins include thermosetting resins and ionizing radiation curing resins (e.g., electron beam curing resins). In particular, from the viewpoint of scratch resistance due to high surface hardness, convex shape retention, and productivity, it is preferable that the surface protective layer contains an ionizing radiation curing resin, and it is even more preferable that the resin constituting the surface protective layer is an ionizing radiation curing resin.

[0051] Examples of thermosetting resins include unsaturated polyester resins, polyurethane resins (including two-component curing polyurethanes), epoxy resins, aminoalkyd resins, phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, melamine-urea cocondensation resins, silicon resins, and polysiloxane resins.

[0052] The above resins may be given curing agents such as crosslinking agents and polymerization initiators, polymerization accelerators, etc. For example, isocyanates and organic sulfonates can be added to unsaturated polyester resins and polyurethane resins as curing agents, organic amines can be added to epoxy resins, and peroxides such as methyl ethyl ketone peroxide and radical initiators such as azoisobutylnitrile can be added to unsaturated polyester resins.

[0053] Methods for forming a surface protective layer with a thermosetting resin include, for example, applying a solution of the thermosetting resin using a coating method such as roll coating or gravure coating, and then drying and curing it.

[0054] Ionizing radiation-curable resins are not limited to resins that undergo a crosslinking polymerization reaction upon irradiation with ionizing radiation and transform into a three-dimensional polymer structure. For example, one or more prepolymers, oligomers, and monomers having polymerizable unsaturated bonds or epoxy groups in their molecules that can be crosslinked by irradiation with ionizing radiation can be used. Examples include acrylate resins such as urethane acrylate, polyester acrylate, and epoxy acrylate; silicon resins such as siloxane; polyester resins; and epoxy resins.

[0055] The ionizing radiation-curable resin preferably contains an acrylic resin having (meth)acryloyl groups. By including an acrylic resin having (meth)acryloyl groups as the ionizing radiation-curable resin, hydrogen bonds are formed between the molecules of the ionizing radiation-curable resin, further improving the surface hardness and scratch resistance of the surface protective layer.

[0056] Ionizing radiation includes visible light, ultraviolet light (near-ultraviolet, vacuum ultraviolet, etc.), X-rays, electron beams, and ion beams, but among these, ultraviolet light and / or electron beams are preferred.

[0057] Suitable ultraviolet light sources include ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, blacklight fluorescent lamps, and metal halide lamps. The wavelength of the ultraviolet light is approximately 190-380 nm.

[0058] Various electron beam accelerators can be used as electron sources, such as Cockcroftwald type, Van de Graft type, resonant transformer type, insulated core transformer type, linear type, Dynamitron type, and high-frequency type. The electron beam energy is preferably around 100 to 1000 keV, and more preferably around 100 to 300 keV. The electron beam irradiation dose is preferably around 2 to 15 Mrad.

[0059] Ionizing radiation-curable resins can be sufficiently cured by irradiation with electron beams, but when curing by irradiation with ultraviolet light, it is preferable to add a photopolymerization initiator (sensitizer).

[0060] For resin systems having radically polymerizable unsaturated groups, at least one of the following photopolymerization initiators can be used: acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, Michler benzoyl benzoate, Michler ketone, diphenyl sulfide, dibenzyl disulfide, diethyl oxide, triphenylbiimidazole, isopropyl-N,N-dimethylaminobenzoate, etc. For resin systems having cationic polymerizable functional groups, at least one of the following can be used: aromatic diazonium salts, aromatic sulfonium salts, metallocene compounds, benzoin sulfonic acid esters, fryloxysulfoxonium diallylodosyl salt, etc.

[0061] The amount of photopolymerization initiator added is not particularly limited, but is generally about 0.1 to 10 parts by mass per 100 parts by mass of ionizing radiation-curable resin.

[0062] Furthermore, in recent years, the use of biomass-derived resins, which have a low environmental impact, has been explored in various fields. The resin forming the surface protective layer of the decorative sheet of the present invention can also contain biomass-derived components, and specifically, biomass polyolefins and the like can be used.

[0063] The surface protection layer may be a single layer or a multi-layer structure of two or more layers. In this invention, if the surface protection layer consists of multiple layers, each layer contains a cross-linked curable resin. Furthermore, when the surface protection layer consists of multiple layers, the infrared spectral measurement of the surface protection layer is performed by measuring the infrared spectral spectrum of the stacked surface protection layers starting from the outermost surface protection layer.

[0064] The thickness of the surface protective layer is not particularly limited as long as it does not hinder the effects of the present invention, but is preferably 1 to 200 μm, more preferably 1 to 100 μm, even more preferably 3 to 50 μm, and particularly preferably 4 to 40 μm.

[0065] The surface protective layer may contain fine particles. Examples of fine particles include inorganic fillers such as silica, aluminum oxide, silicon carbide, silicon dioxide, calcium titanate, barium titanate, magnesium pyroborate, zinc oxide, silicon nitride, zirconium oxide, chromium oxide, iron oxide, boron nitride, diamond, corundum, and glass fibers; and organic material powders or beads such as acrylic, cross-linked alkyl, cross-linked styrene, benzoguanamine resin, urea-formaldehyde resin, phenolic resin, polyethylene, and nylon. One or more types of the fine particles can be used.

[0066] The average particle size of the fine particles is preferably greater than or equal to the thickness of the surface protective layer, and to exhibit scratch resistance, it is preferably less than "thickness of the surface protective layer + 40 μm", and more preferably "thickness of the surface protective layer + 30 μm" or less.

[0067] The average particle diameter of fine particles can be measured by known methods such as laser diffraction, Coulter counter, and sedimentation. Note that the average particle diameter refers to the mode diameter.

[0068] The content of fine particles in the surface protective layer is preferably 3 to 50 parts by mass, and more preferably 5 to 30 parts by mass, per 100 parts by mass of the resin component forming the surface protective layer.

[0069] Silica has siloxane bonds (-Si-O-Si-), which are similar to ether bonds (-COC-). Therefore, if the surface protective layer contains silica, it may affect the peak height A mentioned above. However, even if the surface protective layer contains silica, if the peak height ratio ((A / B) × 100 (%)) of the peak heights A and B mentioned above is between 105% and 400%, the surface protective layer of the decorative sheet of the present invention can exhibit the desired performance.

[0070] Silicone may be added to the surface protective layer. When silicone is added to the surface protective layer, the amount of silicone added is preferably 0.1 to 1 part by mass, and more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of the resin (resin component) constituting the surface protective layer, from the viewpoint of achieving both ease of wiping and slipperiness.

[0071] The surface protective layer may contain various additives as needed, such as solvents, dyes, pigments and other colorants, fillers such as inorganic fillers, defoamers, leveling agents, thixotropy-imparting agents, flame retardants, antibacterial agents, antiviral agents, and allergen-reducing agents.

[0072] As an inorganic filler, it can be used as a means of imparting a predetermined surface property to the surface protective layer by incorporating an inorganic filler larger than the thickness of the surface protective layer into the surface protective layer. Furthermore, the inorganic filler can also be used as a matting agent, and by including the inorganic filler in the surface protective layer, it is expected that the hardening shrinkage of the surface protective layer will be suppressed. Therefore, in this invention, it is preferable that the inorganic filler is surface-treated (hydrophobic treatment). In addition, among these additives, it is preferable to include at least one selected from the group consisting of antibacterial agents, antiviral agents, and allergen reducing agents in the surface protective layer, which is the outermost layer, in order to easily obtain the effect.

[0073] Examples of inorganic fillers include silica, aluminum oxide, silicon carbide, silicon dioxide, calcium titanate, barium titanate, magnesium pyroborate, zinc oxide, silicon nitride, zirconium oxide, chromium oxide, iron oxide, boron nitride, diamond, corundum, and glass fibers.

[0074] The method for surface treatment (hydrophobic treatment) of inorganic fillers is not particularly limited and can be carried out by known methods. Examples include: hydrophobic treatment of inorganic fillers with a silicone oil-based treatment agent; treatment of inorganic fillers with an alkylsilazane-based treatment agent, a trimethylsilylating agent, and / or an alkoxysilane, followed by hydrophobic treatment of the inorganic fillers with the aforementioned silicone oil-based treatment agent; hydrophobic treatment of inorganic fillers with a silicone oil-based treatment agent, followed by further treatment with a trimethylsilylating agent or an alkylsilazane-based treatment agent; hydrophobic treatment of inorganic fillers with an alkoxysilane; treatment of inorganic fillers with an alkoxysilane, followed by further treatment with a silicone oil-based treatment agent, or a silicone oil-based treatment agent and an alkoxysilane; and treatment of inorganic fillers with dimergol siloxane, and / or trimethylsilanol or a cyclic siloxane. In addition to the hydrophobic treatment methods described above, other methods of hydrophobic treatment include treatment with various coupling agents such as silane coupling agents, titanate coupling agents, and aluminate coupling agents; surfactants such as phosphoric acid-based and fatty acid-based surfactants; and treatment with oils, stearic acid, etc. Hereinafter, all of the above-mentioned products for hydrophobic treatment of untreated inorganic fillers (for example, all of the treatment agents such as silicone oil-based treatment agents, silane coupling agents, surfactants, etc.) will be collectively referred to as hydrophobic treatment agents.

[0075] The method for hydrophobizing inorganic fillers with a hydrophobic treatment agent is not particularly limited and can be carried out by known methods. For example, methods include adding (e.g., spraying) a stock solution of the hydrophobic treatment agent or a solution of the hydrophobic treatment agent diluted in water or an organic solvent to untreated inorganic fillers (dry treatment method); or treating (e.g., immersing) the untreated inorganic fillers in a stock solution of the hydrophobic treatment agent, an aqueous solution containing the hydrophobic treatment agent, or an organic solvent containing the hydrophobic treatment agent, and then drying them (wet treatment method). Such treatment results in (a) the inorganic filler surface being coated with the hydrophobic treatment agent, (b) the hydrophobic treatment agent being adsorbed, or (c) the inorganic filler being coated with and adsorbed by the hydrophobic treatment agent (a combination of (a) and (b)). As a result, hydrophobized inorganic fillers are obtained. Note that the hydrophobic treatment agent may be used alone or in combination of two or more types.

[0076] The above-mentioned antibacterial agents include inorganic antibacterial agents and organic antibacterial agents. In particular, inorganic antibacterial agents are generally safer than organic antibacterial agents and are preferable because they also have superior durability and heat resistance. Inorganic antibacterial agents are antibacterial metals such as silver, copper, and zinc supported on various inorganic carriers. When included in a surface protective layer, the amount of antibacterial agent added is preferably 0.1 to 10 parts by mass per 100 parts by mass of the resin component of the surface protective layer, but the details can be adjusted as appropriate depending on the type of antibacterial agent.

[0077] The above-mentioned antiviral agents can generally be broadly classified into organic and inorganic types. Organic antiviral agents include quaternary ammonium salts, quaternary phosphonium salts, pyridines, pyrithiones, benzimidazoles, organic iodines, isothiazolins, anions, and ethers. Inorganic antiviral agents include metal ions such as silver, copper, and zinc supported on carriers such as zeolites, apatite, zirconia, glass, and molybdenum oxide. When included in a surface protective layer, the amount of antiviral agent added is preferably 0.1 to 10 parts by mass per 100 parts by mass of the resin component of the surface protective layer, but the details can be appropriately adjusted depending on the type of antiviral agent.

[0078] Among the above organic antiviral agents, benzimidazole-based antiviral agents, anionic-based antiviral agents, or ether-based antiviral agents that maintain their particle shape are particularly preferred. Here, "maintaining particle shape" means that they exist in a granular state without dissolving in the composition (ink before curing) that becomes the curable resin of the surface protective layer. Therefore, in the process of forming the surface protective layer, the particles of imidazole-based compounds, anionic-based compounds, or ether-based compounds tend to float to the surface, making it easier to unevenly distribute the particles of imidazole-based compounds, anionic-based compounds, or ether-based compounds to the outermost surface of the surface protective layer. By unevenly distributing the particles of imidazole-based compounds, anionic-based compounds, or ether-based compounds to the outermost surface of the surface protective layer, the amount of antiviral agent required to obtain the desired antiviral effect can be suppressed, thus making it easier to suppress the decrease in the scratch resistance of the surface protective layer.

[0079] The above-mentioned anionic antiviral agents preferably include, for example, styrene resin, styrene polymer derivative compounds, and unsaturated carboxylic acid derivative compounds. Furthermore, the above-mentioned styrene polymer derivative compounds and unsaturated carboxylic acid derivative compounds preferably contain at least one structure from among styrene, sodium sulfonate, acrylic acid, maleic acid, and fumaric acid, and more preferably contain all of these structures. This is because viruses can be broadly classified into two types based on whether or not they have an envelope, and it is thought that the structure of the antiviral agent that can effectively inhibit the activity of each type is different. Therefore, for example, if the expectation is to be effective only against influenza viruses, which are non-enveloped viruses, it is sufficient to include only styrene polymer derivative compounds, and in some cases, sufficient effect can be obtained by including only styrene resin.

[0080] Among the inorganic antiviral agents mentioned above, silver-based antiviral agents are preferred from the viewpoint of having no biotoxicity and excellent safety, and among them, phosphate-based glass silver-supported compounds or silver zeolite compounds, and molybdenum silver oxide double salt compounds are even more preferred because they exhibit antiviral performance even in small amounts, thus allowing for a reduction in the amount added.

[0081] When the above-mentioned silver-based antiviral agent is included in the surface protective layer, discoloration may occur depending on the surface protective layer (discoloration may occur due to heat and light in the state of the paint in which it is added, or due to heat and light after the surface protective layer has been formed). In this case, it is possible to improve the situation by adding UV inhibitors, light stabilizers, etc., in a timely manner. For example, with respect to the above-mentioned silver molybdenum oxide double salt compound, a discoloration improvement effect can be expected by using a benzotriazole compound.

[0082] The above-mentioned allergen reducing agent contains either an inorganic compound or an organic compound, and each may be used individually or mixed with two or more different types. The inorganic compound is preferably a material supporting a metal. When included in a surface protective layer, the amount of allergen reducing agent added is preferably 0.1 to 10 parts by mass per 100 parts by mass of the resin component of the surface protective layer, but the details can be appropriately adjusted depending on the type of allergen reducing agent.

[0083] A method for forming a surface protective layer containing an ionizing radiation-curable resin includes, for example, a method in which a solution (resin composition for forming a surface protective layer) containing (1) a resin such as an ionizing radiation-curable resin, and (2) optionally other resins, fine particles, ultraviolet absorbers, antibacterial agents, and the above-mentioned various additives is applied by a coating method such as gravure coating or roll coating, and then the ionizing radiation-curable resin is cured to form the surface protective layer.

[0084] (Base sheet) A base sheet is a layer on which patterns and designs are sequentially laminated on its surface (front side).

[0085] As the base sheet, for example, a sheet (film) formed from a thermoplastic resin is preferred. Specifically, examples include olefin resins such as polyethylene, ethylene-α-olefin copolymer, polypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, propylene-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate copolymer saponified, ethylene-(meth)acrylic acid copolymer, and ethylene-(meth)acrylic acid ester copolymer; polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, ionomer, acrylic acid ester polymer, and methacrylic acid ester polymer. In recent years, the use of biomass-derived resins, which have a low environmental impact, has been explored in many fields, and the resin used to form the base sheet of the decorative sheet of the present invention can also contain biomass-derived components. Specifically, biomass polyolefins can be used. The base sheet is formed by using these resins individually or in combination of two or more types.

[0086] In this specification, "(meth)acrylic acid" means acrylic acid and / or methacrylic acid, and the same applies to other parts that are indicated with "(meth)".

[0087] The base sheet may be colored. In this case, the thermoplastic resin described above can be colored by adding a coloring agent (pigment or dye). As coloring agents, inorganic pigments such as titanium dioxide, carbon black, and iron oxide, organic pigments such as phthalocyanine blue, and various dyes can be used. One or more of these can be selected from publicly known or commercially available products. The amount of coloring agent added can also be set appropriately according to the desired color.

[0088] The base sheet may contain various additives as needed, such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, UV absorbers, and light stabilizers.

[0089] In the base sheet, the UV absorber, light stabilizer, and flame retardant can be the same as those used in the transparent resin layer described later, and in the same amounts.

[0090] The thickness of the base sheet can be set appropriately depending on the application and method of use of the final product, but generally 20 to 300 μm is preferred.

[0091] The base sheet may, if necessary, be subjected to corona discharge treatment on its surface (front side) to improve the adhesion of the ink forming the pattern layer. The method and conditions for corona discharge treatment should be carried out according to known methods. In addition, if necessary, corona discharge treatment may be applied to the back side of the base sheet, or a primer layer may be formed on the back side.

[0092] (Pattern layer) The decorative sheet of the present invention has a patterned layer.

[0093] The pattern layer provides a desired pattern (design) to the decorative sheet, and in the decorative sheet of the present invention, the pattern is a wood grain pattern comprising the characteristic portion and non-characteristic portion described above.

[0094] The method for forming the pattern layer is not particularly limited. For example, it may be formed on the surface of the substrate sheet by a printing method using an ink obtained by dissolving (or dispersing) a known coloring agent (dye or pigment) together with a binder resin in a solvent (or dispersion medium). From the viewpoint of reducing the VOCs of the decorative sheet, an aqueous composition may also be used as the ink.

[0095] Examples of colorants include inorganic pigments such as carbon black, titanium white, zinc oxide, 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; metallic powder pigments such as aluminum powder and bronze powder; pearlescent pigments such as titanium dioxide-coated mica and bismuth oxide; fluorescent pigments; and luminescent pigments. These colorants can be used individually or in combination of two or more. These colorants may also be used with fillers such as silica, extender pigments such as organic beads, neutralizing agents, surfactants, etc.

[0096] As binder resins, in addition to hydrophilic treated polyester-based urethane resins, polyester, polyacrylate, polyvinyl acetate, polybutadiene, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene-acrylate copolymer, rosin derivatives, alcohol adducts of styrene-maleic anhydride copolymer, and cellulose resins can also be used. More specifically, for example, polyacrylamide resins, poly(meth)acrylic acid resins, polyethylene oxide resins, poly-N-vinylpyrrolidone resins, water-soluble polyester resins, water-soluble polyamide resins, water-soluble amino resins, water-soluble phenolic resins, and other water-soluble synthetic resins; water-soluble natural polymers such as polynucleotides, polypeptides, and polysaccharides can also be used. Furthermore, for example, modified natural rubber, synthetic rubber, polyvinyl acetate resins, (meth)acrylic resins, polyvinyl chloride resins, polyurethane-polyacrylic resins, etc., or mixtures of the above natural rubber, etc., and other resins can also be used. The above binder resins can be used alone or in combination of two or more types.

[0097] Examples of solvents (or dispersion media) 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, n-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. These solvents (or dispersion media) can be used individually or in combination of two or more.

[0098] Furthermore, in recent years, the use of biomass-derived resins, which have a low environmental impact, has been explored in many fields, and the binder resin that forms the pattern layer of the decorative sheet of the present invention can also contain biomass-derived components. For example, biomass-derived urethane (meth)acrylate can be used, and specifically, a binder resin can be made that contains urethane (meth)acrylate containing at least a polyol, an isocyanate compound, and hydroxy(meth)acrylate, and at least one selected from the group consisting of the above polyol, isocyanate compound, and hydroxy(meth)acrylate is a biomass-derived component.

[0099] Printing methods used to form the pattern layer include, for example, gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and inkjet printing. Furthermore, when forming a solid-color pattern layer covering the entire surface, 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 can be used. Other methods such as hand-painting, suminagashi (marbling), photography, transfer, laser beam lithography, electron beam lithography, partial metal deposition, and etching may also be used, or combined with other formation methods.

[0100] The thickness of the pattern layer is not particularly limited and can be set appropriately according to the product characteristics, but the layer thickness is approximately 0.1 to 10 μm.

[0101] (Colored opacity layer) In the decorative sheet of the present invention, a colored opacifying layer may be further formed between the base sheet and the pattern layer.

[0102] The colored opacifying layer only needs to be able to conceal the base color of the adherend when the decorative sheet and the adherend are joined together, and is usually formed to cover the base sheet.

[0103] The above-mentioned known printing method can be used to form the colored opacity layer. Furthermore, the ink used to form the pattern layer can be used as is.

[0104] The application amount is 2-30g / m². 2 A range of this is desirable. The thickness of the colored opacity layer is usually about 0.1 to 20 μm, preferably about 1 to 10 μm.

[0105] (adhesive layer) To improve the adhesion between the transparent resin layer and the pattern layer, as described later, an adhesive layer may be formed on the pattern layer. The adhesive layer is preferably a transparent adhesive layer, and this transparent adhesive layer may include colorless transparent, colored transparent, or translucent.

[0106] The adhesive is not particularly limited, and any adhesive known in the field of decorative sheets can be used.

[0107] Adhesives known in the field of decorative sheets include, for example, thermoplastic resins such as polyamide resins, acrylic resins, and vinyl acetate resins, and thermosetting resins such as urethane resins. These adhesives can be used individually or in combination of two or more. Two-component curing polyurethane resins or polyester resins using isocyanate as a curing agent can also be used.

[0108] The above-mentioned known printing methods can be used to form the transparent adhesive layer.

[0109] The thickness of the transparent adhesive layer is not particularly limited, but the thickness after drying is approximately 0.1 to 30 μm, preferably 1 to 20 μm.

[0110] (Transparent resin layer) The decorative floor sheet of the present invention has a transparent resin layer.

[0111] The transparent resin layer is not particularly limited as long as it is transparent, and includes colorless transparent, colored transparent, translucent, etc. Examples of resins constituting the transparent resin layer include polypropylene such as polyethylene, ethylene-α-olefin copolymer, homopolypropylene, and random polypropylene; olefin resins such as polymethylpentene, polybutene, ethylene-propylene copolymer, propylene-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate copolymer saponified, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and olefin-based elastomers; polyethylene terephthalate, polybutylene terephthalate, polyamide, ionomer, acrylic acid ester polymer, methacrylic acid ester polymer, polycarbonate, and cellulose triacetate. In recent years, the use of biomass-derived resins, which have a low environmental impact, has been explored in many fields, and the resin forming the transparent resin layer of the decorative sheet of the present invention can also contain biomass-derived components, specifically biomass polyolefins, etc. The transparent resin layer can be made using these resins individually or in combination of two or more types.

[0112] The transparent resin layer is preferably a transparent thermoplastic resin layer, more preferably an olefin-based resin such as polypropylene resin or polyethylene resin, and even more preferably the resin constituting the transparent resin layer is the above-mentioned olefin-based resin or ionomer-based resin.

[0113] The transparent resin layer may be colored as long as it remains transparent, but it is preferable not to include any coloring agents.

[0114] The transparent resin layer may further contain various additives as needed. Examples include lubricants such as silicone resin, wax, and fluororesin; colorants such as dyes and pigments; antioxidants; ultraviolet absorbers; light stabilizers; and flame retardants. The content of the above additives is not particularly limited, and for example, it is 0.1% by mass or more and 10% by mass or less, with the transparent resin layer being 100% by mass.

[0115] The transparent resin layer preferably contains an ultraviolet absorber from the viewpoint of providing weather resistance.

[0116] Examples of UV absorbers include benzotriazole-based UV absorbers, benzophenone-based UV absorbers, and triazine-based UV absorbers. Among these, triazine-based UV absorbers are preferred. One or more types of UV absorbers can be used.

[0117] Among triazine-based UV absorbers, hydroxyphenyltriazine-based UV absorbers in which at least one organic group selected from hydroxyphenyl groups, alkoxyphenyl groups, and organic groups containing these groups is linked to a triazine ring are more preferred, and hydroxyphenyltriazine-based UV absorbers represented by the following general formula (A) are even more preferred. Because hydroxyphenyltriazine-based UV absorbers have a branched structure, they are expected to be less prone to bleeding out from the transparent resin layer, and thus provide superior weather resistance over a longer period.

[0118] [ka]

[0119] In general formula (A), R 11 R is a divalent organic group, 12 is -C(=O)OR 15 The ester group shown is R 13 , R 14 and R 15 Each of these is an independently monovalent organic group, n 11 and n 12 Each of these is an independent integer between 1 and 5.

[0120] R 11Examples of divalent organic groups include aliphatic hydrocarbon groups such as alkylene groups and alkenylene groups. From the viewpoint of weather resistance, alkylene groups are preferred, and the number of carbon atoms is preferably 1 to 20, more preferably 1 to 12, even more preferably 1 to 8, and particularly preferably 1 to 4. The alkylene group and alkenylene group may be linear, branched, or cyclic, but linear and branched are preferred.

[0121] Examples of alkylene groups having 1 to 20 carbon atoms include various propylene groups such as methylene, 1,1-ethylene, 1,2-ethylene, 1,3-propylene, 1,2-propylene, and 2,2-propylene (hereinafter, "various" refers to linear, branched, and their isomers), various butylene, various pentylene, various hexylene, various heptylene, various octylene, various nonylene, various desilene, various undecylen, various dodecylen, various tridecylen, various tetradecylen, various pentadecylen, various hexadecylen, various heptadecylen, various octadecylen, various nonadecylen, and various eicosilene groups.

[0122] R 13 and R 14 Examples of monovalent organic groups include alkyl groups, alkenyl groups, cycloalkyl groups, aryl groups, and arylalkyl groups, with aromatic hydrocarbon groups such as aryl groups and arylalkyl groups being preferred, and aryl groups being particularly preferred. Among these, R 13 and R 14 A phenyl group is preferred as the monovalent organic group.

[0123] The aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably 6 to 12 carbon atoms, and even more preferably 6 to 10 carbon atoms, such as phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, and various naphthyl groups. The arylalkyl group is preferably an arylalkyl group having 7 to 20 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 7 to 10 carbon atoms, such as benzyl group, phenethyl group, various phenylpropyl groups, various phenylbutyl groups, various methylbenzyl groups, various ethylbenzyl groups, various propylbenzyl groups, various butylbenzyl groups, and various hexylbenzyl groups.

[0124] R 15 Examples of monovalent organic groups include alkyl groups, alkenyl groups, cycloalkyl groups, aryl groups, and arylalkyl groups, with aliphatic hydrocarbon groups such as alkyl groups and alkenyl groups being preferred, and alkyl groups being more preferred. That is, R 12 Preferably, alkyl ester groups and alkenyl ester groups are used, with alkyl ester groups being more preferred.

[0125] Examples of alkyl groups include alkyl groups having 1 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and even more preferably 6 to 12 carbon atoms, such as methyl groups, ethyl groups, various propyl groups, various butyl groups, various pentyl groups, various hexyl groups, various octyl groups, various nonyl groups, various decyl groups, various undecyl groups, various dodecyl groups, various tridecyl groups, various tetradecyl groups, various pentadecyl groups, various hexadecyl groups, various heptadecyl groups, various octadecyl groups, various nonadecyl groups, and various eicosyl groups.

[0126] Examples of alkenyl groups include, preferably, alkenyl groups having 2 to 20 carbon atoms, more preferably 3 to 16 carbon atoms, and even more preferably 6 to 12 carbon atoms, such as vinyl groups, various propenyl groups, various butenyl groups, various pentenyl groups, various hexenyl groups, various octenyl groups, various nonenyl groups, various decenyl groups, various undecenyl groups, various dodecenyl groups, various tridecenyl groups, various tetradecenyl groups, various pentadecenyl groups, various hexadecenyl groups, various heptadecenyl groups, various octadecenyl groups, various nonadecenyl groups, and various icocenyl groups.

[0127] More specifically, hydroxyphenyltriazine compounds used as hydroxyphenyltriazine-based ultraviolet absorbers represented by general formula (A) include R 11 is an alkylene group having 1 to 20 carbon atoms, and R 12 However, R 15 R is an alkyl ester group having 1 to 20 C12, 13 and R 14 is an aryl group having 6 to 20 carbon atoms, n 11 and n 12 A hydroxyphenyltriazine compound with 1 is preferred, R 11 is an alkylene group having 1 to 12 carbon atoms, R 12 However, R 15 R is an alkyl ester group having 2 to 16 C16 C16, 13 and R 14 is an aryl group having 6 to 12 carbon atoms, n 11 and n 12 A hydroxyphenyltriazine compound with 1 is more preferred, R 11 is an alkylene group having 1 to 8 carbon atoms, and R 12 However, R 15 R is an alkyl ester group having 6 to 12 C 13 and R 14 is an aryl group having 6 to 10 carbon atoms, n 11 and n 12 A hydroxyphenyltriazine compound with 1 is even more preferred, R 11is an alkylene group having 1 to 4 carbon atoms, R 12 However, R 15 R is an ester group which is an alkyl group having 8 carbon atoms, 13 and R 14 is a phenyl group, n 11 and n 12 A hydroxyphenyltriazine compound with a ratio of 1 is particularly preferred.

[0128] Examples of the above hydroxyphenyltriazine compounds include 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]phenol, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[(hexyl)oxy]phenol, 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-ethyl-hexanoic acid-2-[4-(4,6-diphenyl-[1,3,5]triazine-2-yl)-3-hydroxy- Examples include phenoxy-ethyl ester, octanoic acid-2-[4-(4,6-diphenyl-[1,3,5]triazine-2-yl)-3-hydroxyphenoxy]ethyl ester, 2,4,6-tris{2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)}-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine, 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-s-triazine, 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1-3-5-triazine, and mixtures thereof, modified products, polymers, derivatives, etc.

[0129] The amount of ultraviolet absorber is preferably 0.2 to 10.0 parts by mass, more preferably 0.5 to 5.0 parts by mass, and even more preferably 1.0 to 4.0 parts by mass, per 100 parts by mass of the resin component constituting the transparent resin layer.

[0130] Examples of light stabilizers include aromatic compounds, amine compounds, organic acid compounds, catechin compounds, and hindered amine compounds, with hindered amine compounds being preferred. Hindered amine compounds are those having a structure that includes a 2,2,6,6-tetramethylpiperidine skeleton within the molecule.

[0131] The content of the light stabilizer is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 8.0 parts by mass, and even more preferably 1.0 to 5.0 parts by mass, per 100 parts by mass of the resin component constituting the transparent resin layer. It is preferable that the light stabilizer contains a hindered amine compound within the above range.

[0132] Examples of the above-mentioned flame retardants include halogen-based flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, aluminum-based flame retardants, antimony-based flame retardants, magnesium-based flame retardants, boron-based flame retardants, and zirconium-based flame retardants. From an environmental standpoint, non-halogen-based flame retardants are more preferably used. The above-mentioned flame retardants can be used individually or in combination of two or more types.

[0133] Examples of phosphorus-based flame retardants include phosphinate metal salt-based flame retardants and phosphazene-based flame retardants. Furthermore, regardless of the type, the content of the flame retardant is preferably 3 parts by mass or more, and preferably 30 parts by mass or less, per 100 parts by mass of the resin component constituting the transparent resin layer. By staying within this range, the flame retardancy of the decorative sheet is improved while suppressing the impairment of the required performance inherent in the decorative sheet.

[0134] The thickness of the transparent resin layer is usually around 20 to 200 μm, but it may exceed this range depending on the application of the decorative sheet.

[0135] (Primer layer) A primer layer may be provided on the transparent resin layer. The primer layer can be formed by applying a known primer to the surface of the transparent resin layer. Examples of primers include urethane resin primers made of acrylic-modified urethane resin (acrylic urethane resin), primers made of urethane-cellulose resin (for example, a resin made by adding hexamethylene diisocyanate to a mixture of urethane and nitrate), and resin primers made of a block copolymer of acrylic and urethane. Additives may be added to the primer as needed. Examples of additives include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, ultraviolet absorbers, and light stabilizers. The amount of additives can be appropriately set according to the product characteristics.

[0136] The amount of primer to be applied is not particularly limited, but is usually 0.1 to 100 g / m². 2 Preferably 0.1 to 50 g / m 2 It is to that extent.

[0137] The thickness of the primer layer is not particularly limited, but is usually 0.01 to 10 μm, preferably about 0.1 to 1 μm.

[0138] (Primer layer on the back) A primer layer may be provided on the back surface of the base sheet (the surface opposite to the surface on which the pattern layer is laminated), if necessary. This is particularly effective when laminating a decorative sheet with a base material (adherend) to produce a decorative panel.

[0139] The backside primer layer can be formed by applying a known primer to the substrate sheet. Examples of primers include urethane resin primers made of acrylic-modified urethane resin (acrylic urethane resin), primers made of urethane-cellulose resin (for example, a resin made by adding hexamethylene diisocyanate to a mixture of urethane and nitrate), and resin primers made of acrylic and urethane block copolymers. Additives may be added to the primer as needed. Examples of additives include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, UV absorbers, and light stabilizers. The amount of additives can be appropriately set according to the product characteristics.

[0140] The amount of primer to be applied is not particularly limited, but is usually 0.1 to 100 g / m². 2 Preferably 0.1 to 50 g / m 2 It is to that extent.

[0141] The thickness of the primer layer on the back surface is not particularly limited, but is usually 0.01 to 10 μm, preferably about 0.1 to 1 μm.

[0142] (Synthetic resin backing layer) A synthetic resin backer layer (hereinafter also simply referred to as the "backer layer") may be provided on the back surface of the base sheet. This synthetic resin layer enhances scratch resistance and mitigates the influence of the base material (adhered material). The scratch resistance mentioned above refers specifically to resistance to dents caused by localized loads. The decorative sheet of the present invention has sufficient scratch resistance even without a backer layer, but various performance characteristics, such as scratch resistance, can be further enhanced by providing a backer layer.

[0143] A suitable method for forming the backer layer is extrusion molding of molten resin, and for example, extrusion molding using a T-die is preferred.

[0144] Methods for bonding the back surface of the base sheet to the backer layer include bonding the base sheet and the backer layer obtained by extruding molten resin by heat fusion, and bonding by providing an adhesive layer (and a primer layer if necessary) between the base sheet and the backer layer.

[0145] The resins that make up the backer layer are not limited to these, but include thermoplastic resins such as polyethylene, polypropylene (PP), polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polymethylene, polymethylpentene, polyethylene terephthalate, amorphous polyethylene terephthalate (A-PET), highly heat-resistant polyalkylene terephthalate (for example, polyethylene terephthalate in which part of the ethylene glycol is replaced with 1,4-cyclohexanedimethanol or diethylene glycol, so-called trade name PET-G (manufactured by Eastman Chemical Company)), polybutylene terephthalate (PBT), polycarbonate, polyarylate, polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, polyimide, polystyrene, polyamide, and ABS (acrylonitrile-butadiene-styrene copolymer). In recent years, the use of biomass-derived resins with low environmental impact has been explored in many fields, and the resin forming the backer layer of the decorative sheet of the present invention can also contain biomass-derived components, specifically biomass polyolefins. These resins can be used individually or in combination of two or more.

[0146] The thickness of the backer layer can be set appropriately depending on the application and usage of the final product, and is generally preferred to be between 100 and 800 μm. Among these, 100 to 600 μm is more preferred.

[0147] The backer layer may be subjected to known easy-adhesion treatments on the bonding surface, such as corona discharge treatment, plasma treatment, degreasing treatment, or surface roughening treatment, as needed. Furthermore, a primer layer may be provided on the back surface to improve adhesion to the adherend.

[0148] (Vesiculation of various additives contained in each layer of the decorative sheet) The various additives added to each of the aforementioned layers of the decorative sheet of the present invention (such as inorganic fillers added to the primer layer and surface protective layer) are preferably vesicled. The method for vesicling the various additives is not particularly limited and can be done by known methods, with supercritical reverse-phase evaporation being preferred.

[0149] Vesicle formation methods include the supercritical reverse-phase evaporation method, as well as the Bangham method, extrusion method, hydration method, reverse-phase evaporation method, and freeze-thaw method. Briefly explaining these vesicle formation methods, the Bangham method involves placing chloroform or a chloroform / methanol mixed solvent in a container such as a flask, then adding phospholipids and dissolving them. After that, the solvent is removed using an evaporator to form a thin film of lipids, and after adding a dispersion of additives, vesicles are obtained by hydrating and dispersing with a vortex mixer. The extrusion method involves preparing a phospholipid solution of the thin film and obtaining vesicles by passing it through a filter instead of using a mixer as an external perturbation in the Bangham method. The hydration method is almost the same preparation method as the Bangham method, but instead of using a mixer, vesicles are obtained by gently stirring and dispersing. The reverse-phase evaporation method involves dissolving phospholipids in diethyl ether or chloroform, adding a solution containing additives to create a W / O emulsion, removing the organic solvent from the emulsion under reduced pressure, and then adding water to obtain vesicles. The freeze-thaw method uses cooling and heating as external perturbations, and vesicles are obtained by repeating this cooling and heating process.

[0150] The supercritical reverse-phase evaporation method is described in detail below. The supercritical reverse-phase evaporation method is a method for forming capsule-shaped vesicles containing the various additives as encapsulating materials in a single membrane by adding an aqueous phase containing various water-soluble or hydrophilic encapsulating materials to a mixture obtained by uniformly dissolving a substance that forms the outer membrane of a vesicle in carbon dioxide in a supercritical state or under temperature or pressure conditions above the supercritical point. Supercritical carbon dioxide refers to carbon dioxide in a supercritical state above the critical temperature (30.98°C) and critical pressure (7.3773±0.0030 MPa), while carbon dioxide under temperature or pressure conditions above the critical point refers to carbon dioxide under conditions where only the critical temperature or only the critical pressure exceeds the critical conditions. By this method, single-layer lamellar vesicles with a diameter of 50 to 800 nm can be obtained. Generally, a vesicle is a general term for a vesicle containing a liquid phase inside a vesicle with a closed spherical membrane structure, and in particular, those whose outer membrane is composed of biolipids such as phospholipids are called liposomes.

[0151] Examples of the phospholipids mentioned above include glycerophospholipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidic acid, phosphatidylglycerol, phosphatidylinositol, cardiolipin, egg yolk lecithin, hydrogenated egg yolk lecithin, soy lecithin, and hydrogenated soy lecithin, as well as sphingophospholipids such as sphingomyelin, ceramide phosphorylethanolamine, and ceramide phosphorylglycerol.

[0152] The outer film can also be composed of nonionic surfactants or dispersants such as mixtures of nonionic surfactants with cholesterol or triacylglycerols.

[0153] As the nonionic surfactants mentioned above, one or more of the following can be used: polyglycerin ether, dialkylglycerin, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, polyoxyethylene polyoxypropylene copolymer, polybutadiene-polyoxyethylene copolymer, polybutadiene-poly2-vinylpyridine, polystyrene-polyacrylic acid copolymer, polyethylene oxide-polyethylethylene copolymer, polyoxyethylene-polycaprolactam copolymer, etc.

[0154] The above-mentioned cholesterols may include one or more types such as cholesterol, α-cholestanol, β-cholestanol, cholestan, desmosterol (5,24-cholestadien-3β-ol), sodium cholate, and cholecalciferol.

[0155] The outer membrane of the liposome described above may be formed from a mixture of phospholipid and a dispersant. In the decorative sheet of the present invention, by using liposomes formed from phospholipid for the outer membrane, the compatibility between the resin composition, which is the main component of each layer, and various additives can be improved.

[0156] (Manufacturing method for decorative sheets) The decorative sheet of the present invention is obtained by forming at least a base sheet, a pattern layer, a transparent resin layer, and a surface protection layer on the outermost surface. For example, it can be obtained by laminating a pattern layer, a transparent adhesive layer, a transparent resin layer, and a primer layer on a base sheet, and then forming a surface protection layer on the outermost surface.

[0157] Furthermore, when embossing is applied to a decorative sheet, it may be done either before or after forming the surface protective layer. For example, in a specific embodiment, 1) a pattern layer, a transparent resin layer, and a primer layer may be formed sequentially on the base sheet, then a surface protective layer may be formed, and finally embossing may be applied. In another specific embodiment, 2) a pattern layer, a transparent resin layer, and a primer layer may be formed sequentially on the base sheet, then embossing may be applied, and finally a surface protective layer may be formed. In yet another specific embodiment, 3) a pattern layer and a transparent resin layer may be formed sequentially on the base sheet, then embossing may be applied, followed by a primer layer, and finally a surface protective layer may be formed.

[0158] Embossing is done, for example, at a sheet temperature of 120°C to 160°C and a density of 10 to 40 kg / cm². 2 The raised and recessed pattern can be transferred to the printed side of the decorative sheet using pressure.

[0159] 2. Decorative panels The decorative panel of the present invention is a decorative panel having the above-mentioned decorative sheet on a base material. It is sufficient that the decorative sheet is laminated on the base material such that the surface protective layer of the decorative sheet becomes the outermost layer.

[0160] The base material (adhered material) is not limited, and the same materials as known decorative panels can be used. Examples include wood, metal, ceramics, plastics, and glass. In particular, the decorative sheet of the present invention can be suitably used on wood. Specific examples of wood materials include veneers, wood single-ply, wood plywood, wood fiberboard, particleboard, and medium-density fiberboard (MDF) made from various materials such as cedar, cypress, zelkova, pine, lauan, teak, and meranti.

[0161] The lamination method is not limited; for example, a method of attaching the decorative sheet to the substrate using an adhesive can be employed. The adhesive can be appropriately selected from known adhesives depending on the type of substrate, etc. Examples include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ionomer, as well as butadiene / acrylonitrile rubber, neoprene rubber, and natural rubber. These adhesives can be used individually or in combination of two or more types.

[0162] The decorative panels manufactured in this manner can be used, for example, as interior materials for buildings such as walls, ceilings, and floors; as surface decorative panels for building fixtures such as window frames, doors, and handrails; and as surface decorative panels for furniture or cabinets for electrical equipment, office automation equipment, etc. In particular, the decorative panels of the present invention can be suitably used as flooring materials. [Examples]

[0163] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to these examples.

[0164] Example 1 (Production of decorative sheets) A primer layer (backside primer layer) was provided on the back surface of a base sheet made of a 60 μm thick colored polypropylene film. Next, a pattern layer was formed on the surface of the base sheet by printing, and then an adhesive layer was formed on the pattern layer. An 80 μm thick sheet of transparent polypropylene resin (transparent random polypropylene resin) was laminated on the adhesive layer using an extrusion lamination method to form a transparent resin layer. Next, a corona discharge treatment was applied to the surface of the transparent random polypropylene resin sheet, and then a primer layer was formed by coating it with a two-component curing urethane resin.

[0165] A surface protection layer-forming composition containing an ionizing radiation-curable resin including a urethane acrylate oligomer was applied to the entire surface of the primer layer using a gravure coating method to a thickness of 15 μm. Then, under conditions of an oxygen concentration of 200 ppm or less, the surface protection layer was formed by irradiating with an electron beam using an electron irradiation device at an acceleration voltage of 165 KeV and 5 Mrad. Furthermore, the surface protection layer side was heated with an infrared non-contact heater to soften the base sheet and the transparent resin layer, after which embossing was performed by hot pressure.

[0166] Furthermore, as the urethane acrylate oligomer contained in the ionizing radiation-curable resin that forms the surface protective layer, a mixed resin was used, which was prepared by mixing the following urethane acrylate oligomers in the following proportions. A composition for forming the surface protective layer was prepared by adding the following ultraviolet absorber, light stabilizer, and additives in the following amounts to 100 parts by mass of the mixed resin. • Bifunctional urethane acrylate oligomer A (polyol component is polyester diol, Tg: 25℃, molecular weight 1500) • Hexafunctional aliphatic urethane acrylate oligomer B (Tg: 200℃ or higher, molecular weight 1500, manufactured by Kyoeisha Chemical Co., Ltd., UA306H) Mixing ratio (mass ratio) A:B=80:20 • UV absorber: Tinuvin 400 (manufactured by BASF Ltd.) 5 parts by mass • Light stabilizer: Tinuvin 123 (manufactured by BASF Corporation) 2 parts by mass (Additives) • Diluting solvent: 50 parts by mass of ethyl acetate • Gloss adjuster: Inorganic filler L-121 (manufactured by AGC SI-TEC Co., Ltd.) 8 parts by mass

[0167] (Manufacturing of decorative panels) Apply 80g / m² of water-based emulsion adhesive (BA-10L (main component): BA-11B (hardener) = 100:2.5 (mass ratio) manufactured by Japan Coating Resin Co., Ltd.) to a 2.5mm thick medium-density fiberboard (MDF). 2 The material was uniformly coated, and then bonded to the primer layer side of the decorative sheet obtained above. The decorative panel was then cured at room temperature for three days to produce the decorative panel.

[0168] Example 2 (Nanomerization of nucleating agents using supercritical reverse-phase evaporation) The nano-processing of nucleating agents using supercritical reverse-phase evaporation was performed by the following method. First, 100 parts by mass of methanol, 82 parts by mass of a phosphate ester metal salt-based nucleating agent (ADEKA NA-11, manufactured by ADEKA Corporation), and 5 parts by mass of phosphatidylcholine were placed in a high-pressure stainless steel container maintained at 60°C and sealed. Carbon dioxide was injected to bring the pressure to 20 MPa, creating a supercritical state. Next, 100 parts by mass of ion-exchanged water was injected while vigorously stirring. After stirring for 15 minutes while maintaining the temperature and pressure inside the container, carbon dioxide was released and the pressure was returned to atmospheric pressure to obtain nucleating agent vesicles having an outer membrane made of phospholipids containing the nucleating agent.

[0169] (Formation of transparent resin layer, patterned layer, and base sheet) The polypropylene resin containing the nucleating agent vesicles obtained as described above (transparent random polypropylene resin) was extruded to a thickness of 80 μm to form a transparent resin layer.

[0170] Furthermore, a pattern layer was created on one side of an opaque 60 μm polypropylene sheet (base sheet) by gravure printing using a two-component urethane ink (V180; manufactured by Toyo Ink Co., Ltd.), and a primer coat was applied to the other side of the base sheet. Next, a transparent resin layer was applied to the surface of the pattern layer using a dry laminating adhesive (Takelac A540; manufactured by Mitsui Chemicals, Inc.; application amount 2 g / m²). 2 It was bonded via a dry lamination method.

[0171] (Formation of embossed patterns) Next, an embossed pattern was formed on the other side of the transparent resin layer by pressing it with an embossing die roll.

[0172] (Formation of surface protective layer) On the embossed surface described above, the following surface protection layer-forming composition 1 (amount applied after drying (described as film thickness after drying; the same applies hereinafter) 5 μm) and surface protection layer-forming composition 2 (amount applied after drying 10 μm) were sequentially layered, and by irradiating with ultraviolet light of a wavelength of 300 nm using an ultraviolet irradiation device, a surface protection layer consisting of surface protection layer 1 (lower layer) and surface protection layer 2 (upper layer) was formed.

[0173] [Composition 1 for forming surface protective layer] Composition 1 for forming a surface protective layer was prepared by adding the following ultraviolet absorber, light stabilizer, and additives in the following amounts to 100 parts by mass of the main component. • Main component: Acrylic polyol (acrylic polyol containing urethane bonds, curing agent (forms urethane bonds through bonding with isocyanate containing NH groups)) (glass transition temperature approximately 100°C, weight-average molecular weight Mw approximately 40,000, hydroxyl value 12) • UV absorber: Tinuvin 399 (manufactured by BASF Corporation) 5 parts by mass • Light stabilizer: Tinuvin 123 (manufactured by BASF Corporation) 3 parts by mass (Additives) • Diluting solvent: 50 parts by mass of ethyl acetate • Gloss adjuster: Inorganic filler L-121 (manufactured by AGC SI-TEC Co., Ltd.) 15 parts by mass • Hardener: Duranate TAP-100 (manufactured by Asahi Kasei Corporation) 5 parts by mass

[0174] [Composition 2 for forming surface protective layer] A mixed resin was prepared by blending the following resins in a mass ratio of A:B:C = 60:30:10. A surface protective layer-forming composition 2 was prepared by adding the following light stabilizer, photopolymerization initiator, and additives to 100 parts by mass of the mixed resin in the amounts specified below. • Resin A: Polyfunctional urethane acrylate oligomer having 3 to 15 functional groups • Resin B: Polyfunctional urethane acrylate oligomer having 2 to 9 functional groups • Resin C: 100 parts by mass of acrylic polyol with a glass transition temperature of approximately 100°C, a weight-average molecular weight Mw of approximately 50,000, and a hydroxyl value of 15, per 5 parts by mass of the curing agent Duranate TAP-100 (manufactured by Asahi Kasei Corporation). • Light stabilizer: Sanol LS765 (manufactured by BASF Ltd.) 3 parts by mass • Photopolymerization initiator: Irgacure 907 (manufactured by BASF Ltd.) 2.5 parts by mass • Photopolymerization initiator: Irgacure 184 (manufactured by BASF Ltd.) 2.5 parts by mass (Additives) • Diluting solvent: 50 parts by mass of ethyl acetate • Gloss adjuster: Inorganic filler L-121 (manufactured by AGC SI-TEC Co., Ltd.) 10 parts by mass

[0175] (Manufacturing of decorative panels) Apply 80g / m² of water-based emulsion adhesive (BA-10L (main component): BA-11B (hardener) = 100:2.5 (mass ratio) manufactured by Japan Coating Resin Co., Ltd.) to a 2.5mm thick medium-density fiberboard (MDF). 2 The material was uniformly coated, and then bonded to the primer layer side of the decorative sheet obtained above. The decorative panel was then cured at room temperature for three days to produce the decorative panel.

[0176] Example 3 As the urethane acrylate oligomer contained in the ionizing radiation-curable resin that forms the surface protective layer, a mixed resin was used, which was a mixture of the following urethane acrylate oligomers in the following proportions. To 100 parts by mass of this mixed resin, an ultraviolet absorber, a light stabilizer, and additives in the same proportions as in Example 1 were added to prepare a composition for forming the surface protective layer. Otherwise, decorative sheets and decorative panels were prepared in the same manner as in Example 1. • Bifunctional urethane acrylate oligomer A (polyol component is polyester diol, Tg: 25℃, molecular weight 1500) • Bifunctional urethane acrylate oligomer B (polyol component is polyester diol, Tg: -55℃, molecular weight 5000) • Hexafunctional urethane acrylate oligomer C (Tg: 200℃ or higher, molecular weight 1500, manufactured by Kyoeisha Chemical Co., Ltd., UA306H) Mixing ratio (mass ratio) A:B:C=60:10:30

[0177] Example 4 As the urethane acrylate oligomer contained in the ionizing radiation-curable resin that forms the surface protective layer, a mixed resin was used, which was a mixture of the following urethane acrylate oligomers in the following proportions. To 100 parts by mass of this mixed resin, an ultraviolet absorber, a light stabilizer, and additives in the same proportions as in Example 1 were added to prepare a composition for forming the surface protective layer. Otherwise, decorative sheets and decorative panels were prepared in the same manner as in Example 1. • Bifunctional urethane acrylate oligomer A (polyol component is polyester diol, Tg: 25℃, molecular weight 1500) • Hexafunctional urethane acrylate oligomer C (Tg: 200℃ or higher, molecular weight 1500, manufactured by Kyoeisha Chemical Co., Ltd., UA306H) Mixing ratio (mass ratio) A:B=65:35

[0178] Example 5 (Production of decorative sheets) A primer layer (backside primer layer) was provided on the back surface of a base sheet made of a 60 μm thick colored polypropylene film. Next, a pattern layer was formed on the surface of the base sheet by printing, and then an adhesive layer was formed on the pattern layer. A 140 μm thick sheet of transparent polypropylene resin (transparent random polypropylene resin) was laminated on the adhesive layer using an extrusion lamination method to form a transparent resin layer. Next, a corona discharge treatment was applied to the surface of the transparent random polypropylene resin sheet, and then a primer layer was formed by coating it with a two-component curing urethane resin.

[0179] After applying surface protective layer-forming composition 1 to the entire surface of the primer layer using a gravure coating method with a coating thickness of 14 μm, surface protective layer-forming composition 2 was applied to the entire surface with a thickness of 18 μm. In an environment with an oxygen concentration of 200 ppm or less, the surface protective layer was formed by irradiating with an electron beam using an electron irradiation device under the conditions of an acceleration voltage of 165 KeV and 5 Mrad. Furthermore, the surface protective layer side was heated with an infrared non-contact heater to soften the base sheet and transparent resin layer, and then embossing was performed by hot pressure (2 coats).

[0180] Furthermore, as the urethane acrylate oligomer contained in the ionizing radiation-curable resin that forms the surface protective layer, a mixed resin was used, which was prepared by mixing the following urethane acrylate oligomers in the following proportions. A composition for forming the surface protective layer was prepared by adding the following ultraviolet absorber, light stabilizer, and additives in the following amounts to 100 parts by mass of the mixed resin.

[0181] <Composition 1 for forming surface protective layer> • Bifunctional urethane acrylate oligomer A (polyol component is polyester diol, Tg: 25℃, molecular weight 1500) 100 parts by mass • UV absorber: Tinuvin 400 (manufactured by BASF Ltd.) 5 parts by mass • Light stabilizer: Tinuvin 123 (manufactured by BASF Corporation) 2 parts by mass (Additives) • Diluting solvent: 50 parts by mass of ethyl acetate

[0182] <Composition 2 for forming surface protective layer> • Bifunctional urethane acrylate oligomer A (polyol component is polyester diol, Tg: 25℃, molecular weight 1500) • Hexafunctional aliphatic urethane acrylate oligomer B (Tg: 200℃ or higher, molecular weight 1500, manufactured by Kyoeisha Chemical Co., Ltd., UA306H) Mixing ratio (mass ratio) A:B=80:20 • UV absorber: Tinuvin 400 (manufactured by BASF Ltd.) 5 parts by mass • Light stabilizer: Tinuvin 123 (manufactured by BASF Corporation) 2 parts by mass (Additives) • Diluting solvent: 50 parts by mass of ethyl acetate • Gloss adjuster: Inorganic filler L-121 (manufactured by AGC SI-TEC Co., Ltd.) 8 parts by mass

[0183] Comparative Example 1 As resins for forming a surface protective layer, the urethane acrylate-based UV-curable resin composition "TOMAX FA-3246" (solids content 40%, manufactured by Nippon Chemical Paint Co., Ltd.) and the urethane acrylate-based UV-curable resin "Art Resin UN-904" (solids content 100%, (meth)acryloyloxy group count: 10, manufactured by Negami Kogyo Co., Ltd.) were used as the main components, and were blended so that the solids content ratio (mass ratio) of TOMAX FA-3246 and UN-904 was 80 / 20. Irgacure 184 (photopolymerization initiator, manufactured by BASF) was added in an amount equivalent to 3 parts by mass relative to the solids content of the resin composition, and then diluted with butyl acetate until the solids content concentration in the coating for forming the surface protective layer was 30%, and the mixture was thoroughly stirred to prepare the coating for forming the surface protective layer. The prepared surface protective coating was applied to the surface of the primer layer using a bar coater, and then dried with hot air in an 80°C drying oven for 1 minute to form a coating layer with a thickness of 5.0 μm. Next, a UV irradiation device set at a height of 60 mm above the coated surface of the coating layer was used to irradiate it with a UV dose of 250 mJ / cm². 2 UV irradiation was performed under the specified conditions to cure and form a surface protective layer. Otherwise, the decorative sheet and decorative panel of Comparative Example 1 were prepared in the same manner as in Example 1.

[0184] The following measurements were performed using the decorative sheets prepared in the examples and comparative examples.

[0185] [IR peak height ratio] An infrared spectrophotometer (IRAffinity-1A, Shimadzu Corporation) was used to measure the infrared spectral spectrum of the surface protective layer of the decorative sheet. On a spectral chart with absorbance on the vertical axis, the range was 855–1325 cm⁻¹. -1 The height of the peak that appears is A, 1650-1800cm. -1 The peak that appears is B, 3200-3500cm. -1Let C be the height of the peak appearing in the graph, and the ratio (A / B) × 100 and (B / C) × 100 were defined as the peak height ratio.

[0186] To measure peak height, a baseline was drawn for each wavelength range, and the length of the line connecting the peak apex to the baseline so that it was horizontal to the vertical axis was measured. If there were multiple peaks within a wavelength range, two peaks were considered "two peaks" if the difference between the peak and trough of adjacent peaks was 0.010 Abs or more, and the sum of the heights of these peaks was defined as the "peak height."

[0187] [Adhesion] A grid peel test was conducted on the surface protective layer of the decorative sheet under JIS-K5600-5-6 conditions, specifically at 25°C and 50% RH. Specifically, a cutter knife was used to make 11 vertical and 11 horizontal cuts at 1mm intervals in a grid pattern on the surface protective layer of the decorative sheet, creating a total of 100 squares. Adhesive tape No. 252 manufactured by Sekisui Chemical Co., Ltd. was then applied to these squares, pressed evenly with a spatula, and peeled off at a 60-degree angle. After repeating the pressing and peeling process five times at the same location, the number of remaining layers of the surface protective layer was measured and evaluated according to the evaluation criteria below. For evaluation of adhesion after the environmental test, the decorative sheet was left in a humid heat environment of 60°C and 90% RH for three weeks, and then the adhesion was evaluated at 25°C. Note that the vertical direction of the decorative sheet refers to the winding direction of the decorative sheet roll (MD direction in the manufacturing equipment), and the horizontal direction of the decorative sheet refers to the width direction of the decorative sheet roll (TD direction in the manufacturing equipment). (Evaluation Criteria) ++:100 pieces + :95 or more and 99 or less - :80 or more and 94 or less --:79 or less

[0188] [Scratch resistance] 300g / m² of steel wool (Bonstar Co., Ltd. #0000) is applied to the surface protective layer of the decorative sheet. 2The materials were brought into contact with the surface under a load and a rubbing test was performed under the condition of 300 back-and-forth movements. In accordance with the test method of JIS-K5600-5-10, the surface protective layer side of the decorative sheet was rubbed 100 times back and forth with steel wool #0000 under a load of 1 kg, and the degree of scratching was evaluated according to the evaluation criteria below. (Evaluation Criteria) ++: No scratches + : A small scratch may occur. - : Numerous injuries occur

[0189] [Pencil hardness] The pencil hardness was measured according to the test method conforming to JIS K5600-5-4. The hardness at which no scratches appeared on the surface was defined as the pencil hardness.

[0190] [Whitening due to folding] Test specimens were prepared by cutting decorative sheets into 10cm x 10cm pieces. These test specimens were then sharply folded 180 degrees in both the vertical and horizontal directions (both vertical and horizontal) so that the surface protective layer side was the peak, and evaluated according to the evaluation criteria below. Note that the vertical direction of the decorative sheet refers to the winding direction of the decorative sheet roll (MD direction in the manufacturing equipment), and the horizontal direction refers to the width direction of the decorative sheet roll (TD direction in the manufacturing equipment). (Evaluation Criteria) ++: Not bleached at all + : Although there is some whitening, it is not noticeable. - : It is bleached and noticeable.

[0191] [Design] The decorative sheet was visually inspected from above, and the observer judged, based on their perception, whether the pattern of the patterned layer and the recessed areas were in harmony, and evaluated according to the judgment criteria shown below. ++: It feels like they are in harmony, and I also sense a more three-dimensional design. +: It feels like it's in harmony, and I sense a three-dimensional design. - : It feels like they are in harmony, but I don't sense any three-dimensional design.

[0192] The results are shown in Table 1.

[0193] [Table 1]

[0194] From the results in Table 1, in Examples 1 and 2, the peak height ratio of A to B was 221 or 116, indicating that they have an appropriate amount of ester bonds. This resulted in an appropriate hardness for the surface protective layer, excellent scratch resistance, pencil hardness, and bending whitening, demonstrating that they possess a combination of these properties. Furthermore, in Examples 1 and 2, the peak height ratio of B to C was 1723 or 5057, indicating an appropriate amount of urethane bonds. As shown in Figure 7, it is thought that hydrogen bonds are formed with the ester bonds in the surface protective layer, resulting in a ++ rating for adhesion. Additionally, hydrolysis is suppressed, leading to a ++ rating for adhesion after environmental testing.

[0195] Furthermore, the results in Table 1 show that in Example 3, the surface protective layer was relatively softer compared to the surface protective layers of Examples 1 and 2. Specifically, the peak height ratio of A to B was larger compared to Examples 1 and 2, indicating fewer ester bonds, resulting in a softer surface protective layer. Although scratch resistance and pencil hardness were slightly inferior compared to Examples 1 and 2, bending whitening was more suppressed. Additionally, in Example 3, the peak height ratio of B to C was larger compared to Examples 1 and 2, indicating fewer urethane bonds, resulting in slightly inferior adhesion compared to Examples 1 and 2. Moreover, it was more susceptible to hydrolysis, resulting in slightly inferior adhesion after environmental testing.

[0196] Furthermore, as shown in Table 1, it was found that in Example 4, the surface protective layer was relatively harder and more brittle compared to the surface protective layers of Examples 1 and 2. Specifically, the peak height ratio of A to B was smaller compared to Examples 1 and 2, indicating a greater number of ester bonds, resulting in a harder surface protective layer. Although the pencil hardness was rated H, the bending whitening was rated +. In addition, in Example 4, the peak height ratio of B to C was smaller compared to Examples 1 and 2, indicating a greater number of urethane bonds. As shown in Figure 7, it is thought that hydrogen bonds are formed between the ester bonds in the surface protective layer, resulting in a ++ adhesion rating. Furthermore, hydrolysis is more suppressed, leading to a ++ adhesion rating after environmental testing.

[0197] Furthermore, as shown in Table 1, in Example 5, the thickness of the transparent resin layer is increased, and the surface protective layer has a two-layer (two-coat) structure. However, it was found that all evaluation items, including adhesion, adhesion after environmental testing, scratch resistance, pencil hardness, bending whitening, and design aesthetics, were evaluated to be equivalent to those of Example 4.

[0198] Furthermore, as shown in Table 1, in Examples 1 to 4, the surface protective layer has recesses (D1) that are synchronized with the characteristic parts of the pattern layer, and the pattern layer has recesses (D2) located in the stacking direction of recesses (D1). The depth H of recesses (D1) is greater than the depth h of recesses (D2). As a result, it was found that the pattern of the pattern layer and the uneven shape formed on the decorative sheet are synchronized, resulting in extremely excellent design aesthetics. In contrast, in Comparative Example 1, the depth h of recesses (D2) is 0, and there are no recesses (D2), resulting in a design aesthetics evaluation of -, indicating inferior design aesthetics.

[0199] Example 6 Decorative sheets and decorative panels were prepared in the same manner as in Example 1, except that 3 parts by mass of a phosphate-based glass silver-supported compound (PG-711, manufactured by Koa Glass Co., Ltd.) was added as an antiviral agent to 100 parts by mass of an ionizing radiation-curable resin that forms the surface protective layer. The peak height ratios of surface protective layers A and B, and B and C were the same as in Example 1.

[0200] The decorative sheets prepared in Example 1 and Example 6 were used for the following evaluations.

[0201] [Antiviral] <Evaluation Method> The decorative sheets produced in Example 1 and Example 6 were subjected to antiviral performance tests using a method compliant with the antiviral test method (ISO21702), and the antiviral activity value against influenza virus was calculated and evaluated based on the evaluation criteria below. The results are shown in Table 2. A + rating indicates that there are no problems in actual use. In Table 2, the antiviral agent (parts by mass) refers to the amount of antiviral agent used (parts by mass) per 100 parts by mass of ionizing radiation-curable resin. <Evaluation Criteria> +: Antiviral activity value was 2.0 or higher. -: Antiviral activity value was less than 2.0.

[0202] The results are shown in Table 2.

[0203] [Table 2] [Explanation of Symbols]

[0204] 1: Decorative sheet 11: Base sheet 12: Pattern layer 12a: Characteristic parts of the pattern layer 12b: Non-feature areas of the pattern layer 13: Transparent resin layer 14: Surface protective layer D1: Recess (D1) D2: Recess (D2) D3: Protrusions on the base sheet side of the patterned layer D4: The raised portion on the opposite side of the patterned layer of the base sheet. W: Width of recess (D1) w: width of the recess (D2) 2: Base material

Claims

1. A decorative sheet having at least a base sheet, a pattern layer, a transparent resin layer, and a surface protective layer, (1) The surface protective layer contains a cross-linked curing resin, (2) In the infrared spectroscopic measurement of the surface protective layer, 855 to 1325 cm⁻¹ －１ Let A be the height of the peak that appears, between 1650 and 1800 cm. －１ When the peak height appearing is B, the peak height ratio of A to B ((A / B) × 100 (%)) is between 105% and 400%. (3) In the infrared spectroscopic measurement of the surface protective layer, 3200 to 3500 cm －１ When the peak height appearing is C, the peak height ratio of B to C ((B / C) × 100 (%)) is between 1000% and 6000%. (4) The pattern layer is a wood grain pattern having characteristic portions and non-characteristic portions, the surface protective layer has a recess (D1) on the side opposite to the side having the pattern layer that is in harmony with the characteristic portion of the pattern layer, the pattern layer has a recess (D2) on the side opposite to the side having the base sheet that is located in the stacking direction of the recess (D1), and the depth H of the recess (D1) is greater than the depth h of the recess (D2). A decorative sheet characterized by the following features.

2. The decorative sheet according to claim 1, wherein the peak height ratio between A and B is 110% or more and 300% or less, and the peak height ratio between B and C is 1300% or more and 5500% or less.

3. The decorative sheet according to claim 1, wherein the cross-linked curable resin includes an ionizing radiation curable resin.

4. The decorative sheet according to claim 3, wherein the ionizing radiation-curable resin includes an acrylic resin having a (meth)acryloyl group.

5. The decorative sheet according to claim 1, wherein the surface protective layer comprises at least one selected from the group consisting of antibacterial agents, antiviral agents, and allergen reducing agents.

6. A decorative panel having a decorative sheet according to any one of claims 1 to 5 on a base material.

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