JP6915265B2 - Decorative sheet and decorative board - Google Patents

Description

The present invention relates to a decorative sheet and a decorative board, and particularly relates to a decorative sheet and a decorative board which are excellent in making unevenness inconspicuous.

Conventionally, decorative sheets have been used for the surfaces of interior or exterior materials such as walls, floors and ceilings of buildings, interior or exterior materials such as vehicles, furniture and home appliances (for example, Patent Document 1). ). The surface of the decorative sheet is formed as an uneven surface, which can contribute to the improvement of design. In the field of interior materials, decorative sheets are attached to a base material made of gypsum board, resin panel, or the like to form a decorative board. Further, in the field of furniture and the like, the decorative sheet is attached to a base material made of a resin plate, a wooden plate or the like to form a decorative board.

JP 2010-150702

The covering surface of the base material on which the decorative sheet is laminated is usually a flat surface. The decorative sheet laminated on the covering surface as a flat surface can exhibit a design property according to the uneven shape of the surface. However, unevenness called "non-landing" may be formed on the covering surface of the base material. As a typical non-landing example, irregularities related to fasteners such as screws for fixing the base material are exemplified. When a fastener such as a screw for fixing the base material is used, a hole for accommodating the screw head is formed in the base material. When the screw head is completely accommodated in the hole of the base material, a non-landing as a recess is formed at a position on the screw head. Further, when the screw head protrudes from the covering surface of the base material, the screw head itself forms a non-landing portion as a convex portion. Further, when the base material has a joint groove, such a joint groove forms a non-landing as a recess. In addition, the surface of the base material may have various irregularities.

Then, the presence of such non-landing material may be visually recognized from the decorative sheet, and in this case, the design property is greatly deteriorated.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a decorative sheet and a decorative board capable of making unevenness inconspicuous.

The first decorative sheet according to the present invention is
A decorative sheet having a surface as an uneven surface,
When light is projected onto the surface from a direction inclined by 82 ° with respect to the normal direction of the decorative sheet, a shadow having a length d of 3 mm or more and a width w of 3 mm or more is formed when observed from the normal direction of the decorative sheet. Makeup sheet.

In the first decorative sheet according to the present invention
In the histogram showing the height of the surface, the average height of one of the section having the highest frequency and the section having the second highest frequency is the average of the other of the section having the highest frequency and the section having the second highest frequency. It may be 2/3 or less of the height.

The second decorative sheet according to the present invention is
A decorative sheet having a surface as an uneven surface,
In the histogram showing the height of the surface, the average height of one of the section having the highest frequency and the section having the second highest frequency is the average of the other of the section having the highest frequency and the section having the second highest frequency. It is less than 2/3 of the height.

The first decorative board according to the present invention is
With the first or second decorative sheet according to the present invention described above,
A decorative board including a base material on which the decorative sheets are laminated.
The covering surface to which the decorative sheet of the base material is attached has partial unevenness and has a partial unevenness.
Observed from the normal direction of the decorative board when light is projected onto the covering surface of the base material on which the decorative sheet is not laminated from a direction inclined by 82 ° with respect to the normal direction of the decorative board. With the length of the shadow caused by the unevenness as a reference length, the decorative sheet is a region not located on the unevenness of the covering surface from a direction inclined by 82 ° with respect to the normal direction of the decorative board. When light is projected onto the surface, a shadow having a length equal to or longer than the reference length is formed when observed from the normal direction of the decorative board.

The second decorative board according to the present invention is
A decorative sheet with a surface as an uneven surface,
A decorative board including a base material on which the decorative sheets are laminated.
The covering surface to which the decorative sheet of the base material is attached has partial unevenness and has a partial unevenness.
Observed from the normal direction of the decorative board when light is projected onto the covering surface of the base material on which the decorative sheet is not laminated from a direction inclined by 82 ° with respect to the normal direction of the decorative board. With the length of the shadow caused by the unevenness as a reference length, the decorative sheet is a region not located on the unevenness of the covering surface from a direction inclined by 82 ° with respect to the normal direction of the decorative board. When light is projected onto the surface, a shadow having a length equal to or longer than the reference length is formed when observed from the normal direction of the decorative board.

According to the present invention, the non-landing can be made inconspicuous.

FIG. 1 is a view for explaining one embodiment of the present invention, and is a vertical cross-sectional view showing a decorative boat and a decorative sheet. FIG. 2 is a diagram showing an example of the layer structure of the decorative sheet of FIG. FIG. 3 is a diagram for explaining a virtual convex landlessness. FIG. 4 is a photograph showing the surface of a decorative sheet attached to a virtual convex land. FIG. 5 is a graph showing the relationship between the spatial frequency and the non-land concealment property. FIG. 6 is a graph showing the relationship between the power spectrum of a certain wavelength component and the non-land concealment property. FIG. 7 is a histogram of the surface height measured for an example of a decorative sheet. FIG. 8 is a photograph showing the surface of the decorative sheet to be measured in FIG. 7. FIG. 9 is a graph showing the surface height variation in one cross section of the decorative sheet shown in FIG. FIG. 10 is a histogram of surface heights measured for other examples of decorative sheets. FIG. 11 is a photograph showing the surface of the decorative sheet measured in FIG. 10. FIG. 12 is a graph showing surface height variation in one cross section of the decorative sheet shown in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In the drawings attached to the present specification, the scale, aspect ratio, etc. are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

Further, in the present specification, the terms "board", "sheet", and "film" are not distinguished from each other based only on the difference in designation. For example, "sheet" is a concept that includes members that can be called boards and films, and therefore "decorative sheets" are distinguished only by the difference in name from members called "decorative boards" and "decorative films". I don't get it.

1 and 2 are diagrams for explaining one embodiment according to the present invention. As shown in FIG. 1, the decorative board 10 has a base material 30 and a decorative sheet 20. The decorative sheet 20 has a front surface 21 and a back surface 22 as a pair of main surfaces facing each other. As shown in FIG. 1, the decorative sheet 20 is used by being laminated on the covering surface 31 of the base material 30. At this time, the back surface 22 of the decorative sheet 20 faces the covering surface 31 of the base material 30. On the other hand, the surface 21 of the decorative sheet 20 is formed as an uneven surface. The decorative sheet 20 can exhibit excellent designability due to the uneven shape of the surface 21. In particular, in the decorative sheet 20 and the decorative board 10 described here, it is possible to effectively eliminate the influence of the unevenness 32 formed on the covering surface 31 of the base material 30 and effectively exhibit the expected design. It has been devised to make it.

First, the configurations of the decorative board 10 and the decorative sheet 20 will be schematically described, and then the structural features of the surface 21 of the decorative sheet 20 will be described.

The decorative sheet 20 is a member that forms the outermost surface of interior materials such as walls, floors and ceilings of buildings, interior materials such as vehicles, furniture and electrical equipment. Therefore, as long as the surface shape described later can be secured, a configuration suitable for the use of interior materials, furniture, electrical equipment, etc. can be adopted. In the example shown in FIG. 2, the decorative sheet 20 includes a surface layer 201 forming the front surface 21, a base material 202 supporting the surface layer 201, and an adhesive layer 203 laminated on the base material 202 to form the back surface 22. ,have.

Here, an example of a method for manufacturing the decorative sheet 20 that functions as wallpaper will be described. Further, in the following description, the material of the decorative sheet 20 will also be illustrated.

First, a resin layer A containing a foaming agent that forms the surface layer 201 is laminated on a base material 202 formed of a fibrous sheet or the like. At this time, the resin layer A is bonded to the base material 202 in a non-foamed state by a melt extrusion laminating method using a T die. It is also possible to provide non-foaming transparent resin layers B and C on the front and back surfaces of the resin layer A and extrude three layers. As the material composition of the resin layer A, an olefin resin such as an ethylene-methacrylic acid copolymer (EMAA) or an ethylene-vinyl acetate copolymer (EVA) can be used as the main raw material. As other materials, inorganic fillers, pigments, foaming agents, foaming aids, cross-linking aids, stabilizers, lubricants and the like can be blended in known formulations. It is preferable that the surface layer 201 before foaming has a thickness of about 0.04 to 0.1 mm and is foamed in a later step to form a foamed resin layer of about 0.3 to 1.0 mm.

Examples of the transparent resin layer B provided on the front surface side of the resin layer A (the surface opposite to the base material 202) include an ethylene-methacrylic acid copolymer (EMAA) and an ethylene-vinyl acetate copolymer (EVA). Is preferable. Further, from the viewpoints of improving surface strength, improving stain resistance, preventing rheumatism during extrusion, etc., the thickness is preferably 5 to 20 μm. On the other hand, as the transparent resin layer C provided on the back side surface (the surface in contact with the base material 202) of the resin layer A, an ethylene-vinyl acetate copolymer (EVA) is preferable. The thickness is preferably 5 to 10 μm from the viewpoint of adhesion to the base material 202 and prevention of rheumatism during extrusion.

Next, if necessary, a pattern layer is provided on the resin layer A (or the transparent resin layer B). Gravure printing, flexographic printing, etc. are used to form the pattern layer. As the printing ink, a printing ink containing a colorant, a binder resin, and a solvent can be used. These inks may be known or commercially available. Further, a surface protection layer may be laminated on the pattern layer. As the surface protective layer, known methods such as gravure printing, flexographic printing, film laminating, and extruding laminating can be used. The surface protective layer may contain a known filler such as silica if the purpose is to adjust the gloss. If the purpose is surface strength, those containing an ionizing radiation curable resin as a resin component are preferable. The thickness is preferably 0.1 to 15 μm.

Subsequently, the above-mentioned decorative sheet base material may be subsequently irradiated with ionizing radiation. The foamability and strength can be adjusted by irradiating the resin layer A with an electron beam. The conditions for electron beam irradiation are preferably an acceleration voltage of 150 to 250 kv and an irradiation amount of 10 to 70 kGy.

When the surface layer 201 is formed on the base material 202 as described above, the decorative sheet base material is subsequently passed through a heating foaming furnace to be foamed so that the thickness of the surface layer 201 is 5 to 10 times. The heating conditions are not particularly limited as long as the foamed resin layer is formed by the decomposition of the thermally decomposable foaming agent, but the temperature inside the furnace is preferably 200 to 400 ° C.

Next, an uneven shape (embossed pattern) is formed on the outermost surface layer (surface layer 201). The uneven shape can be shaped by embossing (concavo-convex shaping using an embossed plate). Examples of the uneven shape imparted to the surface 21 include a wood grain pattern, a stone plate surface pattern, a fabric texture (texture pattern) pattern, a satin finish pattern, a sand grain pattern, and a hairline pattern. There are various methods for producing the embossed plate, and for example, the methods described in JP-A-2010-287204 and JP-A-2011-148184 can be adopted.

After that, the decorative sheet 20 is obtained by forming the adhesive layer 203 on the back side surface of the base material 202, which is on the opposite side of the surface layer 201.

The base material 30 on which the decorative sheet 20 described above is laminated is determined according to the use of the decorative sheet 20. When the decorative sheet 20 forms an interior material for decorating the surfaces of walls, floors, ceilings, etc., the base material 30 is made of wood such as a single board, plywood, laminated wood, perchle board, or timber board made of wood of various trees, for example. It is a plate material, a cement-based material such as concrete or mortar, a gypsum board, an inorganic non-plywood board made of calcium silicate or the like, or a gold board made of iron, aluminum or the like. When the decorative sheet 20 forms an interior material for a vehicle or the like, the base material 30 is, for example, a resin plate material or a metal plate. When the decorative sheet 20 forms furniture or an electric product, the base material 30 is, for example, a wooden board material or a resin board material.

Next, the uneven shape (concave and convex pattern) formed on the surface 21 of the decorative sheet 20 will be described.

The decorative sheet 20 is laminated on the covering surface 31 of the base material 30 and fixed to the base material 30. The covering surface 31 of the base material 30 is preferably a flat surface. In this case, it is possible to prevent the surface 21 of the decorative sheet 20 from being deformed such as wrinkles, whereby the surface 21 of the decorative sheet 20 can exhibit the expected design. However, as already described, the covering surface 31 may include unevenness 32 as a part thereof. As an example, when the base material 30 is fixed to another member using a screw or the like, the head of the screw may protrude from the covering surface 31 of the base material 30 to form a convex portion. On the contrary, a hole (recess) for accommodating the head of the screw may be formed on the covering surface 31 of the base material 30, and a recess may be formed on the head of the screw accommodated in the hole. Further, when a plurality of plate materials are arranged side by side to form the base material 30, a groove-shaped recess is formed between the plurality of plate materials. The unevenness formed on the covering surface 31 of the base material 30 is called "non-landing", and its presence may be visually recognized through the decorative sheet 20. In this case, not only the design of the surface 21 of the decorative sheet 20 is lowered, but also the existence itself impairs the design of the decorative sheet 20 and the decorative board 10. Therefore, the inventors of the present invention have made extensive studies on the concealment of the non-land, and have found a structure of an uneven surface that can make the non-land inconspicuous.

First, the experiments conducted by the inventors will be described. In this experiment, the relationship between the ability to make the non-landing inconspicuous, that is, the non-landing concealment property, and the cross-sectional shape of the surface 21 of the decorative sheet 20 was investigated.

In this experiment, first, a total of 40 kinds of decorative sheets having a textured pattern and a non-textured pattern uneven shape were prepared on the surface. Next, as shown in FIG. 3, a sticker s having a diameter of 10 mm and a circular shape in a plan view was attached on a flat covering surface to form a virtual convex non-land. Convex non-land is the first virtual non-land c1 to which one sticker s with a thickness of 100 μm is pasted, and the second virtual non-land c2 to 5 which is pasted with 2 to 5 same seals each. A virtual non-land c5 and was formed. Forty kinds of patterned decorative sheets were attached to the area on the covering surface where the first virtual land c1 to the fifth virtual land c5 were formed. FIG. 4 shows the surface of an example of a decorative sheet attached on the first virtual land c1, the second virtual land c2, the fourth virtual land c4, and the fifth virtual land c5.

For each of the 40 types of decorative sheets, the surface of each decorative sheet was visually observed with the naked eye to confirm whether or not the presence of the first virtual land c1 to the fifth virtual land c5 was visually observed. For each pattern of the decorative sheet, the same number of points as the number in which the first virtual land c1 to the fifth virtual land c5 were not visually recognized were given. That is, the evaluation of the pattern in which none of the first virtual landing c1 to the fifth virtual landing c5 was visually recognized was given as 5 points, and the evaluation of the pattern in which only the fifth virtual landing c5 was observed was given as 4 points. The evaluation of the pattern in which only 5 virtual non-landing c5 and 4th virtual non-landing c4 were observed was given as 3 points, and the pattern in which only 5 virtual non-landing c5, 4th virtual non-landing c4 and 3rd virtual non-landing c3 were observed. 5 virtual landing c5, 4th virtual landing c4, 3rd virtual landing c3 and 2nd virtual landing c2 were all observed. The evaluation of the observed pattern in all of c5 to the first virtual non-landing c1 was set to 0 points. Then, such evaluation points were obtained for 2 to 10 points per the decorative sheet of the same pattern, and the average value of the plurality of evaluation points was used as the evaluation of the non-land concealment property of the decorative sheet of the pattern. A pattern with an evaluation score of 2.5 points or more was evaluated as a pattern with high non-land concealment.

Next, one or more decorative sheets with each pattern were prepared, and a total of 388 samples were prepared. Then, for each of the 388 samples, image data was collected for surface height variation. 9 and 12 show examples of surface height fluctuations. A 3D shape measuring instrument VR3000 manufactured by KEYENCE was used for collecting image data. Next, the line shape representing the height fluctuation of the surface was frequency-resolved, and the correlation with the evaluation points of the non-land concealment property given to the patterns forming each sample was investigated. The graph shown in FIG. 5 shows the relationship between each spatial frequency and the degree of correlation with the non-land concealment property. In the graph of FIG. 5, the vertical axis shows the degree of correlation with the non-land concealment property, and the horizontal axis shows the spatial frequency. From the graph of FIG. 5, it was found that the component of a specific spatial frequency included in the surface height fluctuation exhibits excellent non-land concealment property with respect to a predetermined virtual non-land. More specifically, the component having a wavelength of 3 mm to 12.8 mm included in the surface height fluctuation showed excellent non-land concealment property with respect to a virtual non-land shape having a circular shape in a plan view having a diameter of 10 mm. ..

Furthermore, the present inventors investigated the correlation between the power spectrum of the component having a wavelength of 5.12 mm and the evaluation point of the non-land concealment property. The graph shown in FIG. 6 shows the degree of correlation with the non-land concealment property in each power spectrum. In the graph of FIG. 6, the vertical axis shows the degree of correlation with the non-land concealment property, and the horizontal axis shows the value of the power spectrum. From the graph of FIG. 6, it was found that an excellent non-land concealment property is exhibited when the component having a wavelength of 5.12 mm included in the surface height fluctuation has ^{a power spectrum of about 4.6 μm 2.} Was done.

From the above experiments, the inventors of the present invention, in order to effectively make the non-landing inconspicuous, it is effective that the height fluctuation of the surface 21 of the decorative sheet 20 includes a specific wavelength component in a specific power spectrum or more. I confirmed that. Then, the inventors of the present invention have found that the fact confirmed in the experiment makes the height variation of the surface 21 of the decorative sheet 20 more than a predetermined amplitude and a predetermined wavelength in order to effectively make the non-landing inconspicuous. It was considered to mean that it is effective to include the unevenness of the components. From this point of view, when the experiment was repeated, the surface 21 of the decorative sheet 20 produced a shadow formed by the non-landing, in other words, a shadow (dark part) having the same length as the dark part formed by the presence of the non-landing. It was concluded that the inclusion of the convex portion to be formed and the concave portion (or flat portion) that does not hinder the formation of the shadow makes it possible to effectively make the non-landing inconspicuous.

Based on the above findings, we propose the three configurations described below as specific configurations to effectively make the non-landing inconspicuous.

(First condition (a))
First, the following condition (a) is proposed as the first feature that makes the uneven land inconspicuous.
Condition (a): When light is projected onto the surface 21 from a direction inclined by 82 ° with respect to the normal direction nd of the decorative sheet 20, the length d is 3 mm or more and the length d is 3 mm or more when observed from the normal direction of the decorative sheet 20. A shadow b having a width w of 3 mm or more is formed.

Here, the normal direction nd of the decorative sheet is the normal direction nd with respect to the sheet surface of the decorative sheet, and the sheet surface of the decorative sheet is the overall and global view of the decorative sheet. Refers to a surface that coincides with a plane. Normally, the decorative sheet 20 has a height difference of the surface 21, but has a substantially constant thickness as a whole and overall. Therefore, when the back surface 22 is joined to the flat surface, the normal direction of the decorative sheet coincides with the normal direction to the back surface. The shadow is a region on the surface 21 where light is blocked by the convex portion 21a of the surface 21. The shadow length d refers to the length of the shadow b along the direction parallel to the incident direction of the light when observed from the normal direction nd of the decorative sheet. FIG. 1 shows a surface parallel to the incident direction of light. Therefore, the length d of the shadow b defined by the condition (a) is the sheet surface of the decorative sheet 20 of the shadow b shown in FIG. It will be the length along.

The deterioration in design due to the detection of non-landing tends to be a problem when the decorative sheet 20 is observed from its normal direction nd. Then, when observing from the normal direction nd of the decorative sheet 20, the non-landing is easily detected in the direction greatly inclined with respect to the normal direction of the decorative sheet 20, typically, the decorative sheet 20. This is a case where light is incident from a direction inclined by 82 ° with respect to the normal direction nd to form a shadow due to non-landing.

On the other hand, as a typical non-landing that causes a deterioration in design, there is an unevenness related to a fastener such as a screw for fixing the base material 30. When a screw for fixing the base material 30 is used, a hole (recess) in which the screw head is housed is formed in the base material 30. When the screw head is completely accommodated in the hole of the base material 30, a non-landing as a recess is formed between the screw head and the covering surface 31. Further, when the screw head protrudes from the covering surface 31 of the base material, the screw head itself forms a non-landing portion as a convex portion. Naturally, it varies depending on the fasteners such as screws for fixing the base material 30, the use of the base material 30, and the like, but the size is substantially constant without any significant difference. Then, when light is incident from a direction inclined by 82 ° with respect to the normal direction nd of the decorative sheet 20, a typical non-landing caused by a fastener such as a screw shields the light and blocks the non-landing. The length of the shadow formed by the presence is about 3 mm. In particular, when the decorative sheet 20 and the decorative board 10 are interior materials, the size of the screw for fixing the base material 30 made of a wooden board or gypsum board does not fluctuate significantly, and the length is about 3 mm. Will form a shadow.

Therefore, when the condition (a) is satisfied, the surface 21 of the decorative sheet 20 can form a shadow similar to the shadow formed by the typical non-landing caused by the fastener such as a screw. As a result, according to the decorative sheet 20 satisfying the condition (a), it is possible to effectively prevent the presence of non-landing from being visually recognized, and thereby the surface 21 of the decorative sheet 20 has the expected design. Can be demonstrated without being harmed by non-landing. In particular, when the decorative sheet 20 and the decorative board 10 used for the interior material, for example, the wallpaper satisfy the condition (a), unevenness is visually recognized in the observation from the normal direction of the decorative sheet 20 unless the decorative sheet 20 is carefully observed. It is possible to avoid this.

(Second condition (b))
Next, by including a convex portion that creates a shadow (dark portion) having a length similar to that of the dark portion formed by the presence of the non-land, and a concave portion (or a flat portion) that does not hinder the formation of the shadow. The following condition (b) is proposed as the second feature for embodying the technical idea of effectively making the land inconspicuous.
Condition (b): When light is projected onto the covering surface 31 of the base material 30 on which the decorative sheet 20 is not laminated from a direction inclined by 82 ° with respect to the normal direction nd of the decorative board 10, the decorative board 10 The covering surface is inclined by 82 ° with respect to the normal direction nd of the decorative board 10 with the length d of the shadow b caused by the unevenness 32 of the covering surface 31 observed from the normal direction nd as the reference length sd. When light is projected onto the surface 21 of the decorative sheet 20, which is a region not located on the unevenness 32 of 31, a shadow b having a length d equal to or greater than the reference length sd appears in the observation from the normal direction nd of the decorative board 10. It is formed.

Here, the normal direction nd of the decorative board is a direction that coincides with the normal direction nd of the decorative sheet. Normally, the decorative sheet 20 has a height difference of the surface 21, but has a substantially constant thickness as a whole and overall. Therefore, when the covering surface 31 has a flat surface, the normal direction nd of the decorative board coincides with the normal direction to the covering surface 31. The shadow length b is treated in the same manner as in the condition (a).

A shadow formed on the covering surface 31 when light is projected onto the covering surface 31 of the base material 30 on which the decorative sheet 20 is not laminated is defined as a reference shadow sb. The reference length sd corresponds to the length of the reference shadow sb on the covering surface 31, in other words, the length of the shadow caused by the unevenness 32 forming the unevenness on the covering surface 31. Therefore, satisfying the condition (b) means that the height fluctuation of the decorative sheet 20 on the surface 21 forms a shadow similar to the shadow formed by the non-land. Therefore, according to the decorative board 10 satisfying the condition (b), it is possible to effectively prevent the presence of non-landing from being visually recognized, whereby the surface 21 of the decorative sheet 20 has the expected design. It can be demonstrated without being harmed by non-land. In particular, when the decorative board 10 used for the interior material, for example, wallpaper satisfies the condition (b), it is possible to avoid the appearance of unevenness in the observation from the normal direction of the decorative sheet 20 unless the decorative sheet 20 is carefully observed. It becomes possible to do.

In the example shown in FIG. 1, the unevenness 32 on the covering surface 31 is formed as a concave portion 32a. The reference length sd of the reference shadow sb on the covering surface 31 formed by the recess 32a is larger than the length of the shadow b2 on the surface 21 formed by the second convex portion 21b of the surface 21. Is also longer, but shorter than the length of the shadow b1 on the surface 21 formed by the first convex portion 21a. That is, in the illustrated example, a shadow b1 having a length equal to or greater than the reference length sd is formed on the surface 21 due to the height variation of the surface 21 of the decorative sheet 20. As a result, the landing can be effectively made inconspicuous regardless of the form of the landing.

By the way, when the decorative sheet 20 is laminated on the unevenness 32 of the covering surface 31, the decorative sheet 20 usually works to flatten the unevenness 32 of the covering surface 31. That is, the height variation of the sheet surface of the decorative sheet 20 laminated on the base material 30 is more relaxed than the height variation of the covering surface 31. Also in the example shown in FIG. 1, the reference shadow sb is formed along with the unevenness 32 in the region above the unevenness 32 of the covering surface 31 rather than the length (reference length) sd on the covering surface 31. The shadow length b3 on the surface 21 of the decorative sheet 20 is shorter. Therefore, in practice, the non-landing can be effectively made inconspicuous even under conditions looser than the feature (b). As confirmed by the inventor of the present invention, the following condition (b') was able to sufficiently effectively make the non-landing inconspicuous.
Condition (b'): The decorative board 10 when light is projected onto the covering surface 31 of the base material 30 on which the decorative sheet 20 is not laminated from a direction inclined by 82 ° with respect to the normal direction nd of the decorative board 10. The length d of the shadow b caused by the unevenness 32 of the covering surface 31 observed from the normal direction nd of the decorative board 10 is set as the reference length sd, and the covering is performed from a direction inclined by 82 ° with respect to the normal direction nd of the decorative board 10. When light is projected onto the surface 21 of the decorative sheet 20, which is a region not located on the unevenness 32 of the surface 31, the length d is 80% or more of the reference length sd when observed from the normal direction nd of the decorative board 10. Shadow b, more preferably a shadow b having a length d of 90% or more of the reference length sd, and even more preferably a shadow b having a length d equal to or more than the reference length sd.

(Third condition (c))
Next, by including a convex portion that creates a shadow (dark portion) having a length similar to that of the dark portion formed by the presence of the non-land, and a concave portion (or a flat portion) that does not hinder the formation of the shadow. The following condition (c) is proposed as the third feature for embodying the technical idea of effectively making the land inconspicuous.
-Condition (c): In the histogram showing the height at each position of the surface 21, the average height of one of the section with the highest frequency (class, bin) and the section with the second highest frequency is the highest frequency. It is less than 2/3 of the average height of the other section and the section with the second highest frequency.

In condition (c), in creating a histogram showing the height of the surface 21, it is first necessary to measure the height at each position of the surface 21. To measure the height of the surface 21, first, the decorative sheet 20 to be measured is attached to a flat surface. Next, a sample of 100 mm × 100 mm is prepared, and the height at each position in the sample is measured by a 3D shape measuring device VR3000 manufactured by KEYENCE. The height is measured at 250,000 or more measurement positions, preferably 1,000,000 or more measurement positions so that the height measurement position covers almost the entire area of the 100 mm × 100 mm sample. Next, in preparing the histogram, the interval between the minimum measured value and the maximum measured value is divided into 100 or more sections. Usually, it is divided into 256 sections for convenience of digital processing. This section is also called a "bin" or "class", and in the created histogram, the number (frequency) of the measured values included in each section is shown on the vertical axis.

7 and 10 show an example of a histogram created based on actual height measurements. The histogram shown in FIG. 7 is data on the surface height distribution of the decorative sheet having the pattern shown in FIG. 8, and FIG. 9 shows the surface height variation in one cross section of the decorative sheet shown in FIG. Is shown. Similarly, the histogram shown in FIG. 10 is data on the surface height distribution of the decorative sheet having the pattern shown in FIG. 11, and FIG. 12 shows the surface of the decorative sheet in one cross section shown in FIG. It shows height fluctuations.

In order to hide the non-land, it is not enough to provide a convex part that creates a shadow (dark part) of the same length as the dark part formed by the presence of the non-land, and a concave part (or a concave part) that does not hinder the formation of the shadow. It is also important to include the flat part). Therefore, in order to promote the formation of shadows to conceal the non-land, it is necessary to have a height distribution in which multiple peaks are formed in the histogram as compared with a height distribution that follows a uniform height distribution or a normal distribution. Is valid. Moreover, the area ratio is increased in order to realize that the shadow formed by the high-height portion where the area ratio is high is formed with a sufficient length on the low-height portion where the area ratio is high. It is preferable that a sufficient height difference is formed between the high height portion and the low height portion where the area ratio is high. That is, a height distribution in which two peaks are clearly formed in hiss and grams showing a height distribution is preferable for concealing non-land. As a result of diligent studies by the present inventors on this point, it was possible to effectively make the non-landing inconspicuous when the condition (c) is satisfied. In particular, when the decorative board 10 used for the interior material, for example, wallpaper satisfies the condition (c), it is possible to avoid the appearance of unevenness in the observation from the normal direction of the decorative sheet 20 unless the decorative sheet 20 is carefully observed. It becomes possible to do.

In the histogram shown in FIG. 7, the section having the highest frequency was a section having a surface height of 691 μm or more and less than 698 μm. The section with the second highest frequency was the section where the surface height was 285 μm or more and less than 292 μm. The average height of the section having the second highest frequency was 2/3 or less of the average height of the section having the highest frequency, and the histogram shown in FIG. 7 satisfied the condition (c). Actually, when the decorative sheet having the pattern shown in FIG. 8 was laminated on the covering surface 31 containing the non-landing, even if it was carefully observed, the above-mentioned typical non-landing was not detected. ..

On the other hand, in the histogram shown in FIG. 10, the section having the highest frequency was a section having a surface height of 657 μm or more and less than 661 μm. The section with the second highest frequency was the section where the surface height was 634 μm or more and less than 638 μm. The average height of the section with the highest frequency was 636 μm. That is, the section having the highest frequency and the section having the second highest frequency are adjacent sections along the horizontal axis indicating the height. As a result, there is no big difference between the average height of the section with the highest frequency of 659 μm and the average height of the section with the second highest frequency of 636 μm (that is, the average height of the section with the second highest frequency is the highest. (Exceeding 2/3 of the average height of the high frequency section), the histogram shown in FIG. 11 did not satisfy the condition (c). Actually, when the decorative sheet having the pattern shown in FIG. 11 was laminated on the covering surface 31 containing the non-landing, the above-mentioned typical non-landing could be detected by normal observation.

In one embodiment described above, the decorative sheet 20 has a surface 21 as an uneven surface, and projects light onto the surface 21 from a direction inclined by 82 ° with respect to the normal direction nd of the decorative sheet 20. In this case, a shadow b having a length d of 3 mm or more and a width w of 3 mm or more is formed when the decorative sheet 20 is observed from the normal direction nd. According to such a decorative sheet 20, a shadow b having a length d similar to that of a shadow b formed by a typical non-landing caused by a fastener such as a screw for fixing the base material 30 is a makeup. The uneven shape of the surface 21 of the sheet 20 causes it to be formed on the surface 21. Thereby, it is possible to effectively conceal a typical non-land and effectively prevent the presence of the non-land from being visually perceived. Therefore, the pattern (concave and convex shape) of the surface 21 of the decorative sheet 20 is not impaired by the presence of non-landing, and the decorative sheet 20 can effectively exhibit the expected design.

Further, in the above-described embodiment, in the histogram showing the height of the surface 21 of the decorative sheet 20, the average height of one of the section having the highest frequency (class, bin) and the section having the second highest frequency is set to It is less than 2/3 of the average height of the other of the section with the highest frequency and the section with the second highest frequency. Such a surface 21 has a high altitude portion (for example, a portion called a convex portion) that creates a shadow (dark portion) of a sufficient length and a low altitude portion that has a constant area ratio that does not hinder the formation of the shadow. And will be included. Therefore, a shadow b similar to the shadow (dark part) formed by the presence of the non-land is formed on the surface 21 due to the uneven shape of the surface 21 of the decorative sheet 20. Thereby, the non-land can be effectively concealed and the presence of the non-land can be effectively prevented from being visually detected. Therefore, the pattern (concave and convex shape) of the surface 21 of the decorative sheet 20 is not impaired by the presence of non-landing, and the decorative sheet 20 can effectively exhibit the expected design.

Further, in the above-described embodiment, when light is projected onto the covering surface 31 of the base material 30 on which the decorative board 10 is not laminated from a direction inclined by 82 ° with respect to the normal direction nd of the decorative board 10. The covering surface 31 is inclined by 82 ° with respect to the normal direction nd of the decorative board 10 with the length of the shadow b caused by the unevenness 32 observed from the normal direction nd of the decorative board 10 as the reference length sd. When light is projected onto the surface 21 of the decorative sheet 20 which is a region not located on the unevenness 32 of the above, a shadow b having a length d equal to or more than the reference length sd is formed when observed from the normal direction nd of the decorative board 10. NS. The decorative sheet 20 can form a shadow similar to the shadow formed by the non-land by the height variation on the surface 21. As a result, it is possible to effectively prevent the presence of non-landing from being visually recognized, and therefore, the surface 21 of the decorative sheet 20 can exhibit the expected design without being impaired by non-landing.

Although the present invention has been described above based on the illustrated embodiments, the present invention is not limited to these embodiments, and can be implemented in various other embodiments.

10 Decorative board 20 Decorative sheet 21 Surface 21a Convex part 22 Back surface 201 Surface layer 202 Base material 203 Adhesive layer 30 Base material 31 Covering surface 32 Concavo-convex 32a Concave b Shadow d Length

Claims (5)

A decorative sheet having a surface as an uneven surface,
When light is projected onto the surface from a direction inclined by 82 ° with respect to the normal direction of the decorative sheet, a shadow having a length d of 3 mm or more and a width w of 3 mm or more is formed when observed from the normal direction of the decorative sheet. Makeup sheet. In the histogram showing the height of the surface divided into 256 sections, the average height of one of the section having the highest frequency and the section having the second highest frequency is the section having the highest frequency and the section having the second highest frequency. The decorative sheet according to claim 1, which is 2/3 or less of the average height of the other of the many sections. A decorative sheet having a surface as an uneven surface,
In the histogram showing the height of the surface divided into 256 sections, the average height of one of the section having the highest frequency and the section having the second highest frequency is the section having the highest frequency and the section having the second highest frequency. A decorative sheet that is less than 2/3 of the average height of the other of the many sections. The decorative sheet according to any one of claims 1 to 3 and
A decorative board including a base material on which the decorative sheets are laminated.
The covering surface to which the decorative sheet of the base material is attached has partial unevenness and has a partial unevenness.
Observed from the normal direction of the decorative board when light is projected onto the covering surface of the base material on which the decorative sheet is not laminated from a direction inclined by 82 ° with respect to the normal direction of the decorative board. With the length of the shadow caused by the unevenness as a reference length, the decorative sheet is a region not located on the unevenness of the covering surface from a direction inclined by 82 ° with respect to the normal direction of the decorative board. A decorative board in which when light is projected onto the surface, a shadow having a length equal to or longer than a reference length is formed when the decorative board is observed from the normal direction. A decorative sheet with a surface as an uneven surface,
A decorative board including a base material on which the decorative sheets are laminated.
The covering surface to which the decorative sheet of the base material is attached has partial unevenness and has a partial unevenness.
Observed from the normal direction of the decorative board when light is projected onto the covering surface of the base material on which the decorative sheet is not laminated from a direction inclined by 82 ° with respect to the normal direction of the decorative board. With the length of the shadow caused by the unevenness as a reference length, the decorative sheet is a region not located on the unevenness of the covering surface from a direction inclined by 82 ° with respect to the normal direction of the decorative board. A decorative board in which when light is projected onto the surface, a shadow having a length equal to or longer than a reference length is formed when the decorative board is observed from the normal direction.

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