Decorative sheet for building material, decorative material, and method for producing decorative sheet

Abstract

To provide a decorative sheet for a building material capable of enhancing design effect by suppressing the generation of printing wrinkles and a whitening phenomenon even if water-based ink is used, a decorative material and a method for manufacturing the decorative sheet.SOLUTION: A decorative sheet for a building material includes a base material 11 and an ink layer 12 formed on a front surface of the base material 11, wherein the base material 11 is made of titanium paper, and the ink layer 12 is formed by printing using an ink-jet printing machine including at least four color inks including a black ink in addition to three color inks of a cyan ink, a magenta ink, and a yellow ink so that the inks permeate at least a part of the front surface of the base material 11. In the ink layer 12 printed on the surface of the base material 11, the ratio of the black ink to the total ink is 50% or more in the color range of L *> 20 in the Lab color space specified by CIE.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a decorative sheet used in building materials such as general fittings, a decorative material, and a method for manufacturing a decorative sheet. [Background technology]

[0002] Traditionally, titanium paper has been used as a substrate for printing an ink layer on building materials, and water-based inks have been used to print the image on the ink layer. Water-based inks are less toxic and odorous than solvent-based inks, and are highly non-flammable, making them environmentally friendly. Furthermore, because titanium paper is compatible with water-based inks, using it as a substrate for decorative sheets on which an ink layer is formed by inkjet printing using water-based inks can impart a high level of design to the sheets (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-206109 Summary of the Invention [Problem to be solved by the invention]

[0004] In the past, when reproducing dark colors (dark colors) using water-based inkjet printing, the three-color system of yellow ink, magenta ink, and cyan ink was used preferentially. This meant that the absolute amount of ink increased when printing a pattern, which in turn increased the amount of water that soaked into the substrate. As a result, on substrates made of titanium paper, printing wrinkles occurred, which reduced the design quality. Furthermore, if the amount of ink is increased, whitening of the resin layer is likely to occur during the resin impregnation process into the substrate after the pattern is printed, which may result in a reduction in the design quality.

[0005] The present disclosure focuses on the above points, and its purpose is to provide a decorative sheet for building materials, a decorative material, and a method for manufacturing a decorative sheet, which can suppress the occurrence of printing wrinkles and whitening and improve design even when using aqueous ink. [Means for solving the problem]

[0006] A decorative sheet for building materials according to one embodiment of the present disclosure is a decorative sheet for building materials having an ink layer with a pattern formed on the surface side of a substrate, the substrate being made of titanium paper, the ink layer being formed by printing using an inkjet printer equipped with at least four colors of ink, namely, cyan ink, magenta ink, and yellow ink, plus black ink, so that the ink soaks into at least a portion of the surface of the substrate, the ink layer being printed by substituting the black ink in preference to the three color inks, and the ink layer after printing on the surface of the substrate is characterized in that the proportion of the black ink to all inks is 50% or more in the color range of L*>20 in the Lab color space defined by CIE.

[0007] A decorative material for building decoration according to one embodiment of the present disclosure is characterized by comprising a substrate for decorative material and the decorative sheet according to any one of claims 1 to 6 attached to the substrate. A manufacturing method of a decorative sheet according to one embodiment of the present disclosure is a manufacturing method of a decorative sheet for building materials in which an ink layer having a pattern is formed on the surface side of a substrate, the substrate being made of titanium paper, and the ink layer is formed by printing using an inkjet printer equipped with at least four color inks, namely, three color inks of cyan ink, magenta ink, and yellow ink, plus a black ink, so that the ink soaks into at least a portion of the surface of the substrate, The method is characterized by including a black replacement step in which the ink layer is replaced with the black ink in preference to the three color inks, and a replacement result assessment step in which, after the black replacement step, the ink layer is printed using the black ink and the ink layer after printing on the surface of the substrate is assessed to determine whether the proportion of the black ink in all inks is 50% or more in the color range of L*>20 in the Lab color space defined by CIE. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a decorative sheet for building materials, a decorative material, and a method for manufacturing a decorative sheet, which can suppress the occurrence of printing wrinkles and whitening and improve design even when using aqueous ink. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a decorative sheet according to a first embodiment of the present disclosure. [Figure 2] FIG. 3 is a cross-sectional view of a decorative material according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, identical or similar parts are designated by identical or similar reference numerals, and redundant description will be omitted. Each drawing is a schematic diagram and may differ from the actual product. The embodiments described below exemplify devices and methods for embodying the technical ideas of the present disclosure, and the technical ideas of the present disclosure are not limited to the devices and methods exemplified in the following embodiments. The technical ideas of the present disclosure can be modified in various ways within the technical scope described in the claims. Furthermore, the directions of "left and right" and "up and down" in the following description are merely defined for the convenience of explanation and do not limit the technical ideas of the present disclosure. Therefore, for example, if the page is rotated 90 degrees, "left and right" and "up and down" are read interchangeably, and of course, if the page is rotated 180 degrees, "left" becomes "right" and "right" becomes "left."

[0011] (decorative sheet) In FIG. 1, 1 denotes a decorative sheet according to a first embodiment of the present disclosure (hereinafter referred to as this embodiment), which is used for building materials such as general fittings. The decorative sheet 1 has the following layers laminated in order: The following layers will be described later. (1) Base material 11 (2) Ink layer 12 (3) Ink-receiving layer 13 (4) Transparent resin layer 14 Although the layers of the decorative sheet 1 are configured from the above-mentioned (1) to (4), the present invention is not limited to this, and although not shown, the ink-receiving layer 13 may be omitted. The decorative sheet 1 according to this embodiment only needs to have an ink layer 12 having a design formed at least on the surface side (upper surface side) of the substrate 11.

[0012] (base material) The substrate 11 is preferably used as a substrate for printing using aqueous inks and is made of a material with high workability, specifically titanium paper, which is paper with titanium oxide incorporated. Titanium paper is preferred because it has high workability when printing dark color patterns. Titanium paper base paper is formed by incorporating titanium white into cellulose pulp. Titanium paper base paper is obtained, for example, by adding a paper stock containing titanium oxide (e.g., titanium dioxide) to calendered printing base paper and using a Fourdrinier paper machine. The substrate 11 has a basis weight of 80 g / m 2 Preferably, the basis weight is 70 g / m or less. 2 More than 80g / m 2 It is more preferable that the basis weight is within the following range: When the basis weight of the substrate 20 is within this range, the hiding power, processability, and color tone as a colored base paper can be improved.

[0013] (ink layer) The ink layer 12 is a layer that imparts design to the decorative sheet 1. The ink layer 12 is provided on one surface (upper surface) of the substrate 11, and is formed by inkjet printing using a water-based ink so that it soaks into at least a portion of the surface of the substrate 11. As such a water-based ink, a known water-based ink for inkjet printing is used. The water-based ink contains, for example, an aqueous solvent and a colorant dispersed in the aqueous solvent, and other additives may also be added.

[0014] The colorant may be, for example, a pigment or a dye. Pigments are preferably used from the viewpoints of water resistance, light resistance, and resistance to deterioration (discoloration, etc.) due to water resistance and light resistance. Dyes, on the other hand, have very small particle sizes and low viscosity, so that the viscosity does not increase easily even when the proportion of the dye component in the ink is increased. Furthermore, dyes are easily soluble in solvents, so there is no need to add a dispersant, which is one of the factors that increases viscosity. Therefore, dyes are preferred in that they can achieve both high colorability and smooth printing.

[0015] The ink layer 12 is printed using an inkjet printer equipped with at least four colors of ink (CMYK), including three colors of ink (CMY) - cyan ink (C), magenta ink (M), and yellow ink (Y) - plus black ink (K). Furthermore, although CMY has been exemplified as three color inks, the present invention is not limited to this, and may further include inks of colors other than black ink (such as light blue), and may have five or more colors.

[0016] Of the three color inks, for example, ultramarine, cobalt blue, phthalocyanine blue, etc. can be used as the colorant for the cyan ink. As the colorant for magenta ink, for example, cadmium red, quinacridone, azo, etc. can be used. As the colorant for the yellow ink, for example, yellow lead, titanium yellow, isoindolinone yellow, etc. can be used.

[0017] (black ink) The black in black ink (K) means achromatic black. For black ink, use ink with gradation in density. Here, "ink with gradations in density" refers to black ink diluted with a solvent, or "gray ink" in which the pigment concentration of black ink has been adjusted (hereinafter, "ink with gradations in density" will also be referred to as "gray ink"). The pigment in black ink contains at least carbon, such as carbon black. Although carbon black is used as an example of the pigment, the pigment is not limited thereto, and any known pigment can be used, such as titanium oxide, zinc oxide, iron-composite oxide, iron oxide, organic pigment, metallic pigment, pearl pigment, etc., of which iron-composite oxide is used as a heat-shielding pigment.

[0018] The ink layer 12 has a pattern, such as a wood grain pattern, although not shown. Although a wood grain pattern has been given as an example of the pattern, this is not limited to this and any pattern can be used. For example, in addition to a wood grain pattern, a stone grain pattern, a fabric pattern, an abstract pattern, a geometric pattern, or a combination of two or more of these may also be used.

[0019] (percentage of black ink in the ink layer) In this embodiment, the ink layer 12 is printed by substituting black ink (K) in preference to the three color inks (CMY). As a result, in the ink layer 12 printed on the surface of the substrate 11, the proportion of black ink to all inks is 50% or more in the color range of L*>20 in the Lab color space defined by the CIE. The proportion of black ink may be, for example, the proportion of black ink in the number of dots per inch (dpi) in the region of the ink layer 12 in the color range of L*>20. CIE also stands for "Commission Internationale de l'Eclairage" (International Commission on Illumination).

[0020] "L*" is the lightness of achromatic colors, where "L*=0" is black, "L*=100" is diffuse white, and white is even higher for specular colors. "L*>20" corresponds to "gray" (dark gray to light gray) between "white" and "black" to "white." Here, "prioritizing three-color ink (CMY)" means that, when dark colors such as black and gray among the color components of the ink layer 12 can be expressed using three-color ink (CMY) or can also be expressed using black ink (K) that includes gray ink, priority is given to expressing them using the latter, i.e., black ink (K). In the ink layer 12 of the decorative sheet 1 according to this embodiment, when expressing a color that falls within the color range of L*>20, ink substitution is performed so that black ink is used preferentially over the three color inks (CMY). As a result, as described above, in the ink layer 12, the proportion of black ink to all inks in the color range of L*>20 is 50% or more. In the decorative sheet 1, substitution can be performed by the black substitution process described below to give priority to black ink over the three color inks (CMY) when printing the ink layer 12.

[0021] Furthermore, the proportion of black ink in the ink layer 12 being "50% or more" is within the acceptable range, ranging from 50% to 100%, preferably 80% or more, and more preferably closer to 100%. If it is less than 50%, black (dark color) will be expressed using CMY colors in the color range of L*>20, which increases the amount of ink used to form the ink layer 12 and may result in printing wrinkles on the substrate 11. If it is less than 50%, there is also a risk of metamerism occurring.

[0022] As described above, by prioritizing black ink in the color range of L*>20 in the ink layer 12 and making the proportion of black ink equal to or greater than 50% of all inks, dark colors (black, gray) that would normally be expressed using three color inks (CMY) can be expressed using the density gradation of black ink. As a result, compared to when three color inks (CMY) are used preferentially to express dark colors, the amount of ink used is reduced, and the amount of ink that soaks into the substrate 11 is suppressed. Therefore, in the decorative sheet 1, the occurrence of printing wrinkles on the substrate 11 is suppressed, improving design properties. Furthermore, metamerism can be suppressed.

[0023] The substrate 11 has a basis weight of 100 g / m 2 By using the titanium paper described above, it is possible to suppress printing wrinkles, but the titanium paper that is suitable for decorative sheets has a basis weight of 80 g / m 2 The following are common: As basis weight changes, hiding power, processability, color tone, etc. also change, so it is necessary to suppress printing wrinkles without increasing basis weight. As described above, the decorative sheet 1 of this embodiment prioritizes black ink in the color range of L*>20 in the ink layer 12, thereby suppressing printing wrinkles without increasing the basis weight of the titanium paper that makes up the substrate 11.

[0024] (ink receiving layer) An ink-receiving layer 13 may be provided on the substrate 11 to improve the color development of the ink and increase the density gradation. By providing the ink-receiving layer 13, the water-based ink sprayed onto the decorative sheet 1 is retained in the ink-receiving layer 13, preventing excessive penetration into the fibers of the substrate 20, thereby improving the color development and density gradation of the ink. The ink-receiving layer 13 may be formed as needed, and may be omitted from the decorative sheet 1. The ink-receiving layer 13 may contain, for example, calcium carbonate.

[0025] (Transparent resin layer) A transparent resin layer 14 is formed on the surface of the ink layer 12 (the side opposite the substrate 11). When the ink-receiving layer 13 is not provided, the transparent resin layer 14 is provided on the side of the ink layer 12 opposite the substrate 11, and functions as a top coat layer for the decorative sheet 1. The transparent resin layer 14 may be formed from a resin material appropriately selected depending on the function required of the top coat layer depending on the usage environment and application of the decorative sheet 1. The transparent resin layer 14 is preferably formed from a transparent material so as to protect the ink layer 12 while allowing the design of the ink layer 12 to be visible from the top surface of the decorative sheet 1 (the top surface of the transparent resin layer 14). Furthermore, the transparent resin layer 14 is preferably formed from a high-strength resin material so as to protect the top surface of the decorative sheet 1. In other words, the transparent resin layer 14 is preferably formed from a transparent resin material.

[0026] When higher heat resistance, scratch resistance, and contamination resistance are required for the transparent resin layer 14, the transparent resin layer 14 is preferably formed of a melamine resin. The transparent resin layer 14 is formed by impregnating the substrate 11 with a transparent resin. Although melamine resin imparts high heat resistance, scratch resistance, and stain resistance to the decorative sheet 1, it can cause whitening, which can reduce the design of the decorative sheet 1. However, the decorative sheet 1 having the substrate 11 and ink layer 12 of this embodiment can suppress printing wrinkles and also suppress whitening of the transparent resin layer 14. Whitening of the transparent resin layer 14 using melamine resin often occurs due to insufficient impregnation of the melamine resin into the substrate 11. In the decorative sheet 1 of this embodiment, when expressing dark colors in the ink layer 12, black ink is used in preference to three-color ink (CMY), which reduces the amount of ink that soaks into the substrate 11. This makes it easier for the melamine resin to impregnate the substrate 11, making whitening of the transparent resin layer 14 formed from the melamine resin less likely to occur.

[0027] The transparent resin layer 14 is preferably formed to a thickness of 1 μm or more and 30 μm or less. When the thickness of the transparent resin layer is within this range, it can sufficiently function as a surface protection layer, and the transparent resin layer is not formed unnecessarily thick, which leads to reduced manufacturing costs.

[0028] (Decorative sheet manufacturing method) A method for producing the decorative sheet 1 having the above configuration will now be described. The decorative sheet 1 is manufactured by (1) providing a substrate 11 with (3) an ink-receiving layer 13, (2) printing an ink layer 12, and (4) impregnating the substrate 11 with the resin material of a transparent resin layer 14. Specifically, the substrate 11 is made of titanium paper, and the ink layer 12 is formed by printing using an inkjet printer equipped with at least four colors of ink: cyan ink, magenta ink, yellow ink, and black ink, so that the ink soaks into at least a portion of the surface of the substrate 11. The method for producing the ink layer 12 includes the following steps. The following (a) and (b) will be explained later. (a) Black replacement process (b) Replacement result determination step The steps of the manufacturing method are not limited to the above-described steps (a) and (b), and although not shown, steps (a) and (b) may be repeated multiple times.

[0029] (Black replacement process) The black substitution process is a process in which the ink used to print the ink layer 12 is replaced with black ink (K) in preference to the three color inks (CMY). As a result, the black ink (K) is used in preference to the three color inks (CMY). In other words, among the color components of the ink layer 12, dark colors such as black and gray are preferentially expressed using black ink (K). The black replacement process can be calculated using a program and the results can be used.

[0030] (Replacement result determination process) The substitution result determination process is a process in which, after the black substitution process, an ink layer 12 is printed using black ink (K), and it is determined whether the proportion of black ink (K) in the printed ink layer 12 is 50% or more of the proportion of all inks in the color range of L*>20 in the Lab color space defined by CIE. If the proportion of black ink in the above color range is less than 50% of all inks, black will be expressed using CMY colors, and the amount of ink used to form the ink layer 12 will increase, which may result in printing wrinkles on the substrate 11 and whitening of the transparent resin layer 14. There is also a risk of metamerism occurring. As with the black replacement process, the replacement result determination process may be calculated using a program, or may use experimentally measured values. For example, the proportion of black ink in the ink layer 12 may be measured by enlarging the dots that make up the pattern on the surface of the ink layer 12 with a scope.

[0031] (Effects of this embodiment) The decorative sheet 1 according to this embodiment and the above-described modified examples can achieve the effects described below. (1) The decorative sheet 1 of this embodiment is a decorative sheet for building materials, having an ink layer 12 with a pattern formed on the surface side of the substrate 11, the substrate 11 being made of titanium paper, and the ink layer 12 being formed by printing using an inkjet printer equipped with at least four colors of ink, namely cyan ink, magenta ink, and yellow ink, plus black ink, so that the ink penetrates at least a portion of the surface of the substrate 11, the ink layer 12 being printed by replacing the three color inks with the black ink in preference to the other three color inks, and in the ink layer 12 after printing on the surface of the substrate 11, the proportion of the black ink to all inks is 50% or more in the color range of L*>20 in the Lab color space defined by CIE. With this configuration, dark colors (black, gray) that were previously expressed using three color inks (CMY) can be expressed using density gradations of black ink, so compared to when three color inks (CMY) are used preferentially to express dark colors, the amount of ink used is reduced and the amount of ink that soaks into the substrate 11 is suppressed. Therefore, in the decorative sheet 1, the occurrence of printing wrinkles in the substrate 11 and whitening in the transparent resin layer is suppressed, improving the design properties. (2) The substrate 11 has a basis weight of 70 g / m 2 More than 80g / m 2 It may be made of titanium paper that is within the following ranges: This configuration makes it possible to improve the hiding power, processability, and color tone of the colored base paper. (3) The black ink used in the ink layer 12 may have gradations in density. According to this configuration, dark colors (black, gray) that have been expressed using three color inks (CMY) can be more reliably expressed using density gradations of black ink. (4) In the ink layer 12 printed on the surface of the substrate 11, the proportion of the black ink to all inks may be 80% or more in the color range of L*>20 in the Lab color space defined by the CIE. According to this configuration, it is possible to reliably prevent an increase in the amount of ink used to form the ink layer 12, and to more reliably prevent the occurrence of printing wrinkles. (5) A transparent resin layer 14 may be formed on the surface of the ink layer 12 opposite to the substrate 11 . With this configuration, the upper surface of the decorative sheet 1 can be protected. (6) The transparent resin layer 14 may be made of a melamine resin. This configuration allows the decorative sheet 1 to have improved heat resistance, scratch resistance, and stain resistance. (8) A method for manufacturing a decorative sheet for building materials in which an ink layer 12 having a pattern is formed on the surface side of a substrate 11, The substrate 11 is made of titanium paper. The ink layer 12 is formed by printing using an inkjet printer equipped with at least four color inks, namely, three color inks, i.e., cyan ink, magenta ink, and yellow ink, plus a black ink, so that the inks penetrate into at least a part of the surface of the base material; a black ink replacement step of replacing the ink layer 12 with the black ink in preference to the three color inks; After the black substitution step, the ink layer 12 is printed using the black ink, The method includes a substitution result determination process for determining whether the ink layer 12 after printing on the surface of the substrate 11 has a proportion of the black ink of 50% or more of all inks in the color range of L*>20 in the Lab color space defined by the CIE. According to this configuration, dark colors (black, gray) that have been expressed using three color inks (CMY) can be expressed using density gradations of black ink, so compared to when three color inks (CMY) are preferentially used to express dark colors, the amount of ink used can be reduced and the amount of ink that soaks into the substrate 11 can be suppressed. Therefore, the occurrence of printing wrinkles on the substrate 11 and whitening in the transparent resin layer can be suppressed, and the design can be improved.

[0032] (decorative materials) A decorative material 10 according to a second embodiment of the present disclosure (hereinafter referred to as this embodiment) will be described with reference to Figure 2. The decorative material 10 is used as a building material such as general fittings. This embodiment is characterized in that the decorative sheet 1 explained with reference to FIG. 1 is attached to the surface of a substrate 20 for a decorative material to form a decorative material 10 for building decoration. That is, the decorative material 10 comprises a substrate 20 and a decorative sheet 1 attached to the substrate 20. The decorative material 10 has the following layers laminated in order: The following (1) and (2) will be discussed later. (1) Substrate 20 (2) Adhesive layer 30 (3) Decorative sheet 1 Although the layers of the decorative material 10 are configured by the above-mentioned (1) to (3), the present invention is not limited to this, and although not shown, the adhesive layer 30 may be omitted.

[0033] (substrate) The substrate 20 may be made of a material suitable for the application of the decorative material 10. The substrate 20 may be made of any desired plate material, such as a wood-based plate, a metal plate, or a volcanic glass multi-layer plate. Examples of wood-based board materials that can be used include MDF (Medium Density Fiberboard), plywood, and particle board. The metal plate may be an aluminum substrate or the like. The volcanic glass multi-layer plate is preferably a plate made from, for example, volcanic glass deposit powder, mineral fiber, etc., but is not particularly limited as long as it has excellent non-combustibility.

[0034] A sealer layer (not shown in FIG. 2) may be provided on the surface of the substrate 20. The sealer layer provided on the surface of the substrate 20 facing the decorative sheet 1 contains a sealant and is provided to further enhance the adhesiveness between the substrate 20 and the decorative sheet 1. The sealer layer provided on the surface of the substrate 20 opposite the decorative sheet 1 contains a sealant and is provided to further enhance the adhesion between the decorative material 10 and the surface to which it is attached. It is preferable that the sealer layer provided on the surface of the substrate 20 opposite the decorative sheet 1 is thicker than the sealer layer provided on the surface of the substrate 20 facing the decorative sheet 1, i.e., that a larger amount of sealant is applied.

[0035] The type of sealer contained in the sealer layer is not particularly limited, but examples thereof include chloroprene rubber-based sealers, urethane-based sealers, isocyanate-based sealers, and epoxy-based sealers. The same type of sealer may be used for the sealer layer and the sealer layer, or different types of sealer may be used. The sealer layer is formed by applying a sealant to the substrate 20 using, for example, a roll coater using a sponge roll.

[0036] (adhesive layer) The adhesive layer 30 may be formed of an adhesive selected according to the material of the substrate 20. Furthermore, if a sealer layer is provided on the surface of the substrate 20, the adhesive layer 30 may be formed of an adhesive selected according to the sealer layer. The adhesive that constitutes the adhesive layer 30 is not particularly limited, but examples thereof include acrylic adhesives, vinyl acetate adhesives, ethylene vinyl acetate adhesives, urethane adhesives, isocyanate adhesives, and melamine resin adhesives.

[0037] A method for manufacturing the decorative material 10 having the above configuration will be described. The decorative material 10 is produced by attaching the substrate 20 to the back surface (the surface opposite to the ink layer 12) of the base material 11 of the produced decorative sheet 1 via the adhesive layer 30. (Operation of the second embodiment) According to the second embodiment, by inkjet printing, the ink layer is printed by substituting black ink (K) in preference to three-color ink (CMY), thereby providing a decorative material 10 to which a decorative sheet 1 is attached that can improve design by suppressing the occurrence of printing wrinkles on the substrate 11 and whitening in the transparent resin layer 14. Metamerism can also be suppressed.

[0038] <Example> Below, a description will be given of Example 1 of the decorative sheet according to the present disclosure, as well as Comparative Examples 1 and 2. Note that the present disclosure is not limited to Example 1 below.

[0039] Example 1 In Example 1, a decorative sheet was produced as follows. Base material: 80g / m 2 Titanium paper (KSH-801P: manufactured by Kohjin Co., Ltd.) was used. A wood grain pattern (50% gray (L*=53 in Lab color space)) was printed on one surface of the substrate by inkjet printing using a total of four types of water-based ink: three-color ink (CMY) and black ink (K) to form an ink layer. When printing the wood grain pattern, a black substitution process was used to print black as 80% of the total ink. Next, the substrate with the ink layer formed thereon was impregnated with melamine resin, and the melamine resin was cured to form a transparent resin layer. In this way, the decorative sheet of Example 1 was produced. Example 2 Base material: 70g / m 2 A decorative sheet of Example 2 was produced in the same manner as in Example 1, except that titanium paper was used. Example 3 When printing a wood grain pattern (50% gray) in the ink layer, the proportion of black ink was set to 50% of the total ink. A decorative sheet of Example 4 was produced in the same manner as Example 1. Example 4 When printing a wood grain pattern (50% gray) in the ink layer, the proportion of black ink was set to 50% of the total ink. A decorative sheet of Example 4 was produced in the same manner as Example 2.

[0040] (Comparative Example 1) When printing a wood grain pattern (50% gray) in the ink layer, the proportion of black ink was set to 40% of the total ink. A decorative sheet of Comparative Example 1 was produced in the same manner as in Example 1. (Comparative Example 2) When printing the wood grain pattern (50% gray) in the ink layer, only three-color ink (CMY) was used without using black ink. Otherwise, a decorative sheet of Comparative Example 2 was produced in the same manner as in Example 1. (Comparative Example 3) A decorative sheet of Comparative Example 3 was produced in the same manner as in Example 2, except that the proportion of black ink was 40% of the total ink when printing a wood grain pattern (50% gray) in the ink layer. Comparative Example 4 When printing the wood grain pattern (50% gray) in the ink layer, only three-color ink (CMY) was used, without using black ink. Otherwise, a decorative sheet of Comparative Example 2 was produced in the same manner as in Example 2.

[0041] (Evaluation method and criteria) The evaluation method and criteria are as follows.

[0042] (Design evaluation of substrate) When preparing the decorative sheets for each example and comparative example, after printing the ink layer on the substrate, the printing wrinkles were visually checked, and the results were evaluated as "○" if no printing wrinkles occurred, "△" if slight printing wrinkles occurred, and "×" if printing wrinkles occurred. (Design evaluation of transparent resin layer) The wood grain pattern was visually inspected from the top surface of each decorative sheet, and if the wood grain pattern was printed clearly and without any distortion, it was rated as "○", if the wood grain pattern was visually inspected and there were some distortions or chips or the decorative sheet had turned white and the wood grain pattern was difficult to see (visibility was reduced in some areas), it was rated as "△", and if the wood grain pattern was inspected and there were chips all over or the decorative sheet had turned white and the wood grain pattern was almost impossible to see (visibility was reduced overall), it was rated as "×".

[0043] (Evaluation results) The evaluation results of the decorative sheets are shown in Table 1. When the design of the substrate and the design of the transparent resin layer were both rated "△" or higher, the design was deemed to be acceptable for use as a product and was therefore rated as "pass."

[0044] [Table 1]

[0045] Of Examples 1-4 and Comparative Examples 1-4, only Example 1-4 passed the test. Specifically, as shown in Table 1, the decorative sheets of each Example, in which black ink (K) was used in an ink layer in a color range of L*>20 in the Lab color space, accounted for 50% or more of the total ink, suppressed printing wrinkles on the substrate and whitening of the transparent resin layer, and were found to have improved design properties, compared to the decorative sheets of Comparative Examples 1-4, in which black ink (K) accounted for less than 50% of the total ink. For example, it was found that by using a black ink ratio of 50% as in Examples 3 and 4, printing wrinkles and whitening were suppressed (evaluated as "△"), and a design suitable for use as a product was imparted. Furthermore, it was found that by using a black ink ratio of 80% as in Examples 1 and 2, printing wrinkles and whitening of the transparent resin layer did not occur (evaluated as "◯"), and decorative sheets with superior design properties could be provided. As a result, it can be inferred that the proportion of black ink (K) should be 50% or more, that is, the allowable range is 50% to 100%, and that it is preferable to be 80% or more, that is, closer to 100%.

[0046] Comparative Examples 1-4 also failed. Comparative Examples 1 and 3 used black ink (K) at 40% of the total ink, and it is presumed that the proportion of K was too low, especially in terms of suppressing printing wrinkles. Comparative Examples 2 and 4 were printed without using K, and it is presumed that the increased amount of ink used was the cause of the reduced design of both the substrate and the transparent resin layer.

[0047] The decorative sheet and decorative material of the present disclosure are not limited to the above-described embodiments and examples, and various modifications are possible within the scope that does not impair the features of the invention.

[0048] Furthermore, for example, the present disclosure can be configured as follows. (1) A decorative sheet for building materials, in which an ink layer having a pattern is formed on the surface side of a substrate, The substrate is made of titanium paper, the ink layer is formed by printing using an inkjet printer equipped with at least four color inks, namely, three color inks, i.e., cyan ink, magenta ink, and yellow ink, plus a black ink, so that the inks penetrate into at least a part of the surface of the base material; The ink layer is printed by substituting the black ink in preference to the three color inks; In the ink layer after printing on the surface of the substrate, the proportion of the black ink to all inks is 50% or more in the color range of L*>20 in the Lab color space defined by CIE. A decorative sheet for building materials characterized by: (2) The substrate has a basis weight of 70 g / m 2 More than 80g / m 2 It is made of titanium paper that is within the following range The decorative sheet for building materials according to (1) above, characterized in that (3) The black ink used should have a gradation of density. A decorative sheet for building materials according to (1) or (2) above. (4) In the ink layer after printing on the surface of the substrate, the proportion of the black ink to all inks is 80% or more in the color range of L*>20 in the Lab color space defined by CIE. The decorative sheet for building materials according to any one of (1) to (3) above, characterized in that: (5) A transparent resin layer is formed on the surface of the ink layer opposite to the substrate. The decorative sheet for building materials according to any one of (1) to (4) above, characterized in that: (6) The transparent resin layer is formed of a melamine resin. The decorative sheet for building materials according to (5) above. (7) a decorative substrate; The decorative sheet according to any one of (1) to (6) above is attached to the decorative material substrate. A decorative material for building decoration characterized by: (8) A method for manufacturing a decorative sheet for building materials, in which an ink layer having a pattern is formed on the surface side of a substrate, comprising: The substrate is made of titanium paper, the ink layer is formed by printing using an inkjet printer equipped with at least four color inks, namely, three color inks, i.e., cyan ink, magenta ink, and yellow ink, plus a black ink, so that the inks penetrate into at least a part of the surface of the base material; a black ink replacement step of replacing the ink layer with the black ink in preference to the three color inks; After the black replacement step, the ink layer is printed using the black ink; and a substitution result determination step of determining whether the ink layer after printing on the surface of the substrate has a ratio of the black ink to all inks of 50% or more in a color range of L*>20 in the Lab color space defined by CIE. A method for producing a decorative sheet for building materials, comprising: [Explanation of symbols]

[0049] 1 decorative sheet 11 Base material 12 Ink layer 13 Ink-receiving layer 14 Transparent resin layer 10 Cosmetic materials 20 PCB 30 Adhesive layer

Claims

1. A decorative sheet for building materials, in which an ink layer having a pattern is formed on the surface side of a substrate, The substrate is made of titanium paper, the ink layer is formed by printing using an inkjet printer equipped with at least four color inks, namely, three color inks of cyan ink, magenta ink, and yellow ink, plus a black ink, so that the inks penetrate into at least a part of the surface of the base material; The ink layer is printed by substituting the black ink in preference to the three color inks; In the ink layer after printing on the surface of the substrate, the proportion of the black ink to all inks is 50% or more in the color range of L*>20 in the Lab color space defined by CIE. A decorative sheet for building materials characterized by:

2. The substrate has a basis weight of 70 g / m ２ 80g / m or more ２ It is made of titanium paper that is within the following range 2. The decorative sheet for building materials according to claim 1.

3. The black ink used should have a gradation of density.

3. The decorative sheet for building materials according to claim 2.

4. In the ink layer after printing on the surface of the substrate, the proportion of the black ink to all inks is 80% or more in the color range of L*>20 in the Lab color space defined by CIE. The decorative sheet for building materials according to claim 3.

5. A transparent resin layer is formed on the surface of the ink layer opposite to the substrate.

5. The decorative sheet for building materials according to claim 4.

6. The transparent resin layer is formed of a melamine resin. The decorative sheet for building materials according to claim 5.

7. a decorative material substrate; The decorative sheet according to any one of claims 1 to 6 attached to the decorative material substrate. A decorative material for building decoration characterized by:

8. A method for manufacturing a decorative sheet for building materials, in which an ink layer having a pattern is formed on the surface side of a substrate, comprising: The substrate is made of titanium paper, the ink layer is formed by printing using an inkjet printer equipped with at least four color inks, namely, three color inks of cyan ink, magenta ink, and yellow ink, plus a black ink, so that the inks penetrate into at least a part of the surface of the base material; a black ink replacement step of replacing the ink layer with the black ink in preference to the three color inks; After the black replacement step, the ink layer is printed using the black ink; and a substitution result determination step of determining whether the ink layer after printing on the surface of the substrate has a ratio of the black ink to all inks of 50% or more in a color range of L*>20 in the Lab color space defined by CIE. A method for producing a decorative sheet for building materials, comprising:

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